Abstract:
Polycarbonates are provided with hydrolytic stability by combining the polycarbonate polymer with a carboxylic acid salt of cadmium. The cadmium salt provides improved hydrolytic stability to both polycarbonates based on diphenols and halogenated diphenols over conventional stabilizers, and does not detrimentally affect other properties such as color stability, haze, initial tensile strength and elongation.

Description:
This application is a continuation in part of our copending application Ser. No. 866,881 filed Jan. 4, 1978 now abandoned which itself is a continuation of application Ser. No. 777,205 filed Mar. 14, 1977, now abandoned, which in turn is a continuation of our application Ser. No. 659,316, filed Feb. 19, 1976, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to polycarbonates and more particularly to polycarbonates having improved hydrolytic stability. 
     2. Description of the Prior Art 
     Polycarbonates derived from reactions involving organic dihydroxy compounds and carbonic acid derivatives have found extensive commercial application because of their excellent mechanical and physical properties. These thermoplastic polymers are particularly suited for the manufacture of molded products where impact strength, rigidity, toughness, thermal and dimensional stability as well as excellent electrical properties are required. 
     Further in many applications, especially those requiring extensive service in the presence of heat and light, polycarbonates are used because of their resistance to these constant conditions. The polycarbonates resistance to extensive light and heat is in many instances attributable to stabilizers which prevent deterioration of optical and molecular properties. Among the most extensively used stabilizers are the neutral esters of phosphorous acid including the alkyl and aryl phosphites and the oxetane phosphites. More extensive discussions involving some phosphite stabilizers can be found in U.S. Pat. No. 3,794,629. Although these stabilizers are effective in protecting the polycarbonate from heat and light they cause the polycarbonate to deteriorate, due to hydrolysis, when exposed to water under elevated temperatures. 
     In some applications polycarbonates are provided with enhanced flame retardant characteristics by using aromatic diols with bromine or chlorine atoms which have a tendency to free radically dissociate and degrade the polycarbonate. To prevent this degradation phosphites have also been added. However, the phosphites, just as in the case of the non-halogenated polycarbonates have a tendency to make the polycarbonate more susceptible to hydrolytic attack. 
     Thus in accordance with the present invention polycarbonates are provided having improved hydrolytic stability over conventional stabilizers yet with the other desirable properties of the polycarbonate left substantially unmodified. 
     SUMMARY OF THE INVENTION 
     A polycarbonate is provided with enhanced hydrolytic stability which is comprised of an effective amount of a carboxylic acid salt of cadmium and a polycarbonate resin. 
     DETAILED DESCRIPTION OF THE INVENTION 
     When used herein &#34;polycarbonate resin&#34; means the neat resin without additives; &#34;Polycarbonate&#34; means both the formulated polycarbonate resin with additives therein and also the final molded plastic product. 
     The polycarbonate resins useful in practice of the invention are those having a weight average molecular weight between 10,00 and 200,000 and more preferably a melt flow rate range of 1 to 24 g/10 min at 300° C. (ASTM 1238) and are produced by reacting di-(monohydroxyaryl)alkanes or dihydroxybenzenes and substituted dihydroxybenzenes with derivatives of the carbonic acids such as carbonic acid diester, phosgene, bis-chloro-carbonic acid esters of di-(monohydroxyaryl)-alkanes and the bis-chloro-carbonic acid esters of the dihydroxybenzenes and the substituted dihydroxybenzenes. 
     The two aryl residues of the di-(monohydroxyaryl)alkanes applied according to the invention can be alike or different. The aryl residues can also carry substituents which are not capable of reacting in the conversion into polycarbonates, such as halogen atoms or alkyl groups, for example, the methyl, ethyl, propyl or tert-butyl groups. The alkyl residue of the di-(monohydroxyaryl)alkanes linking the two benzene rings can be an open chain or a cycloaliphatic ring and may be substituted if desired, for example by an aryl residue. 
     Suitable di-(monohydroxyaryl)-alkanes are for example (4,4&#39;-dihydroxy-diphenyl)-methane, 2,2&#39;-(4,4&#39;-dihydroxy-diphenyl)-propane, 1,1-(4,4&#39;-dihydroxy-diphenyl)cyclohexane, 1,1-(4,4&#39;-dihydroxy-3,3&#39;-dimethyl-diphenyl)cyclohexane, 1,1-(2,2&#39;-dihydroxy-4,4&#39;-dimethyl-diphenyl)butane, 2,2-(2,2&#39;-dihydroxy-4,4&#39;-di-tert.-butyl-diphenyl)propane or 1,1&#39;-(4,4&#39;-dihydroxy-diphenyl)-1-phenyl-ethane, furthermore methane derivatives which carry besides two hydroxyaryl groups an alkyl residue with at least two carbon atoms and a second alkyl residue with one or more carbon atoms, such as 2,2-(4,4&#39;-dihydroxy-diphenyl)-butane, 2,2-(4,4&#39;-dihydroxy-diphenyl)-pentane (melting point 149°-150° C.), 3,3-(4,4&#39;-dihydroxy-diphenyl)-pentane, 2,2-(4,4&#39;-dihydroxy-diphenyl)-hexane, 3,3-(4,4&#39;-dihydroxydiphenyl)-hexane, 2,2-(4,4&#39;-dihydroxy-diphenyl)-4-methylpentane, 2,2-(4,4&#39;-dihydroxy-diphenyl)-heptane, 4,4-(4,4&#39;-dihydroxy-diphenyl)-heptane (melting point 148°-149° C.) or 2,2-(4,4&#39;-dihydroxy-diphenyl)-tri-decane. Suitable di-(monohydroxyaryl)-alkanes, the two aryl residues of which are different are, for example, 2,2-(4,4&#39;-dihydroxy-3&#39;-methyl-diphenyl)-propane and 2,2-(4,4&#39;-dihydroxy-3-methyl-3&#39;-isopropyl-diphenyl)-butane. Suitable di-(monohydroxyaryl)-alkanes, the aryl residues of which carry halogen atoms are for instance 2,2-(3,5,3&#39;5&#39;-tetrachloro-4,4&#39;-dihydroxy-diphenyl)-propane, 2,2-(3,5,3&#39;5&#39;-tetrabromo-4,4&#39;-dihydroxy-diphenyl)-propane, (3,3&#39;-dichloro-4,4&#39;-dihydroxy-diphenyl)-methane and 2,2&#39;-dihydroxy-5,5&#39;-difluoro-diphenyl-methane. Suitable di-(monohydroxyaryl)-alkanes, the alkyl residue of which, linking the two benzene rings, is substituted by an aryl residue are for instance (4,4&#39;-dihydroxydiphenyl)-phenyl-methane and 1,1-(4,4&#39;-dihydroxy-diphenyl)-1-phenyl-ethane. 
     Suitable dihydroxybenzenes and substituted dihydroxybenzenes are hydroquinone, resorcinol, pyrocatecol, methyl hydroquinone and the like. Other suitable dihydroxyaromatic compounds are 4,4&#39;-dihydroxydiphenyl, 2,2&#39;-dihydroxy-diphenyl, dihydroxynaphthalene, dihydroxyanthracene and compounds represented by the structural formula: ##STR1## wherein X is ##STR2## 
     In order to obtain special properties, mixtures of various di-(monohydroxyaryl)-alkanes can also be used, thus mixed polycarbonate resins are obtained. By far the most useful polycarbonate resins are those based on 4,4&#39;-dihydroxy-diaryl methanes and more particularly bisphenol A [2,2-(4,4&#39;dihydroxy-diphenyl)-propane]. Thus when flame retardant characteristics are to be imparted to the basic polycarbonate resin, a mixture of bisphenol A and tetrabromobisphenol A [2,2-(3,5,3&#39;5&#39;-tetrabromo-4,4&#39;dihydroxy-diphenyl)-propane] is utilized when reacting with phosgene or a like carbonic acid derivative. 
     The polycarbonates resins are prepared by methods known to those skilled in the art and more particularly by methods disclosed in U.S. Pat. Nos. 3,028,365, 2,999,846, 3,248,414, 3,153,008, 3,215,668, 3,187,065, 2,970,137, 2,991,273 and 2,999,835 all incorporated herein by reference. 
     In some uses, pigments may be added to the polycarbonate to form opaque colored molded products. The pigments used to opacify and color the polycarbonate are those conventionally known to skilled artisans for use in high molecular weight thermoplastic pigmentation. By far titanium dioxide is the most preferred pigment to opacify and whiten molded articles because of its high index of refraction, extreme whiteness and brightness. However, other white pigments such as lithopone, zinc sulfide, zinc oxide, antimony trioxide, and the like may be used. To impart color (other than white) to the polycarbonate pigments such as red lead, cuprous oxide, cadmium reds, cinnabar, antimony vermilion (red and brown pigments); zinc yellow, chrome yellows and oranges, cadmium yellow, antimony yellow, (orange and yellow pigments); chrome greens, chrome oxide greens (green pigments); cobalt blue, lampblacks, vegetable blacks, animal blacks (black pigments) and the like may be used. 
     In addition to the inorganic pigments, recited above, organic pigments may be used such as pigment chlorine, lithol fast yellow, touidine red, permanent orange and the like. Dyes may be added to impart color to the polycarbonate such as the phthalocyanies, the anthraquinones and the like. 
     The cadmium salts homogeneously incorporated in the polycarbonate which are useful in the practice of the invention are those which are soluble in the polycarbonate resin and readily incorporated therein and based on carboxylic acids and cadmium. In particular, cadmium 2-ethylhexanoate, cadmium laurate, cadmium octoate and cadmium acetate have found the most extensive utility for providing increased hydrolytic stability to the polycarbonate in the practice of the invention. 
     When cadmium 2-ethylhexanoate is used in the practice of the invention preferably a 66 weight percent solid solution of cadmium 2-ethylhexanoate is incorporated into the polycarbonate at a level of 0.01 to 0.1 percent by weight based on the weight of the polycarbonate resin cadmium laurate is also added to the polycarbonate in an amount between 0.01 and 0.1% by weight based on the weight of the polycarbonate resin. 
    
    
     The invention will be further illustrated by way of the following examples. 
     EXAMPLE I 
     A polycarbonate resin which was the reaction product of bisphenol A and phosgene having a melt flow at 300° C. of 3 to 6 grams/10 min. (ASTM D1238) was tinted with 0.00093 g of an anthraquinone blue dye per pound of polycarbonate resin and 0.00064 g of an anthraquinone violet blue dye per pound of polycarbonate resin; 0.05 percent by weight, based on the polycarbonate resin of a 66 weight percent solution of cadmium 2-ethylhexanoate was incorporated into the polycarbonate. The polycarbonate resin, the cadmium 2-ethylhexanoate and the tint were tumble blended and then extruded into pellets; 1/8&#34; sample bars were prepared for impact, tensile and elongation testing. Further the impact and tensile bars were tested for hydrolytic stability. The test results for hydrolytic stability are reported on table I. The samples were tested after oven aging at 130° C. for tensile strength and elongation; the results of the oven aging tests are reported on table II. Tests for optical and melt stability were conducted by molding specimens at 520° F. and 700° F. and by aging the polycarbonate at 375° C. The results of the optical and melt stability tests are reported on table III. The effect of hydrolysis on aging the molded samples at 82° C. in water were conducted; the results of these tests are reported on table IV. Oven aging tests at 130° C. were conducted to determine the effect of such aging on optical properties; the results of such tests are reported on table V. In all of the examples the percentage of cadmium 2-ethylhexanoate shown is that of a 66 percent solids solution thereof. 
     EXAMPLE II-IX 
     Example I was repeated except that the stabilizer and pigmentation were varied. The following formulations keyed to the specific examples show the constituents of the particular polycarbonate. 
     
         ______________________________________Example  Formulation______________________________________Example  Polycarbonate resin of Example III     0.00093g/lb polycarbonate resin of  anthraquinone blue dye  0.00064g/lb polycarbonate resin of  anthraquinone violet dye  0.05% phenylneopentyl phosphiteExample  Polycarbonate resin of Example IIII    0.00093g/lb polycarbonate resin of  anthraquinone blue dye  0.00064g/lb polycarbonate resin of  anthraquinone violet dye  0.08% tris(3-ethyl-3-methylol oxetane) phosphiteExample  Polycarbonate resin of Example IIV     0.00093g/lb polycarbonate resin of  anthraquinone blue dye  0.00064g/lb polycarbonate resin of  anthraquinone violet dye  1.36g/lb of polycarbonate resin of hydroxy-  benzotriazole  0.05% cadmium 2-ethylhexanoate solutionExample  Polycarbonate resin of Example IV      0.00093g/lb polycarbonate resin of  anthraquinone blue dye  0.00064g/lb polycarbonate resin of  anthraquinone violet dye  1.36g/lb of polycarbonate resin of hydroxy-  benzotriazole  0.05% phenylneopentyl phosphiteExample  Polycarbonate resin of Example IVI     0.00093g/lb polycarbonate resin of  anthraquinone blue dye  0.00064g/lb polycarbonate resin of  anthraquinone violet dye  1.36g/lb polycarbonate resin of hydroxybenzotriazole  0.08% tris(3-ethyl-3-methylol oxetane)-phosphiteExample  Polycarbonate resin of Example IVII    0.00093g/lb polycarbonate resin of  anthraquinone blue dye  0.00064g/lb polycarbonate resin of  anthraquinone violet dye  0.5% the cerotic acid ester of ceryl alcohol  1.36g/lb polycarbonate resin of hydroxybenzotriazole  0.05% cadmium 2-ethylhexanoate solutionExample  Polycarbonate resin of Example IVIII   0.00093g/lb polycarbonate resin of  anthraquinone blue dye  0.00064g/lb polycarbonate resin of  anthraquinone violet dye  0.5% the cerotic acid ester of ceryl alcohol  1.36g/lb polycarbonate resin of hydroxybenzotriazole  0.05% phenylneopentyl phosphiteExample  Polycarbonate resin of Example IIX     0.00093g/lb polycarbonate resin of  anthraquinone blue dye  0.00064g/lb polycarbonate resin of  anthraquinone violet dye  0.5% of the cerotic acid ester of ceryl alcohol  1.36g/lb of hydroxybenzotriazole  0.08% tris(3-ethyl-3-methylol-oxetane) phosphite______________________________________ 
    
     The cerotic acid ester of ceryl alcohol is incorporated into the polycarbonate as a mold release in accordance with the teachings of U.S. Pat. No. 3,836,499 incorporated herein by reference. 
     The hydroxybenzotriazole is a stabilizer for resistance to ultraviolet light. The polycarbonates of Examples II through IX were prepared and tested in accordance with Example I. The results of the tests are reported in the following tables. 
     
                                           TABLE I__________________________________________________________________________EFFECT ON TENSILE, ELONGATION AND IMPACT PROPERTIESOF POLYCARBONATES HAVING VARIOUS STABILIZERSTHEREIN DURING AGING IN WATER AT 82° C.__________________________________________________________________________          Stabilizer                Tensile Yield                       Tensile Ult.                              Elong.                                   Elong.                                        ImpactExampleStabilizer          Concn. %                Str. psi                       Str. psi                              Yield %                                   Ult. %                                        Ft.-Lbs.__________________________________________________________________________                Control (Unaged)I    cadmium 2-ethyl-          0.05  9000   9200   8    100  20.68hexanoateII   phenylneopentyl          0.05  9133   9400   8    102  18.91phosphiteIII  oxetane phosphite.sup.1          0.08  9400   9400   8    100  19.06IV   cadium 2-ethyl-          0.05  8933   9000   8    100  18.34hexanoateV    phenylneopentyl          0.05  9300   9000             17.28phosphiteVI   oxetane phosphite          0.08  9867   9867    3-10                                   103  17.10VII  cadmium 2-ethyl-          0.05  9300   9617   10   106  19.06hexanoateVIII phenylneopentyl          0.05  9600   9600   11   102  18.25phosphiteIX   oxetane phosphite          0.08  9867   9867   11   102  17.51                3 DaysI    cadmium 2-ethyl-          0.05  9200   9200   6    20-80                                        16.95hexanoateII   phenylneopentyl          0.05  9800   9800   6     6- 95                                        11.46phosphiteIII  oxetane phosphite.sup.1          0.08  10100  10100  6     7-45                                        15.74IV   cadmium 2-ethyl-          0.05  9800   9800   6    45-90                                        12.3hexanoateV    phenylneopentyl          0.05  10000  10000  7    90    2.58phosphiteVI   oxetane phosphite          0.08  10500  10500  6      7.45                                         2.92VII  cadmium 2-ethyl-          0.05  9600   9600   7     20-105                                         2.22hexanoateVIII phenylneopentyl          0.05  10000  10000  7    65    1.97phosphiteIX   oxetane phosphite          0.08  10300  10300  5    5     2.09                6 DaysI    cadmium 2-ethyl-          0.05  9600   9600   6     5-70                                        15.61hexanoateII   phenylneopentyl          0.05  9900   9900   5    20-90                                         2.54phosphiteIII  oxetane phosphite.sup.1          0.08  10200  10200  6    8    15.52IV   cadmium 2-ethyl-          0.05  10000  10000  6     35-100                                         2.68hexanoateV    phenylneopentyl          0.05  10200  10200  7    40    1.95phosphiteVI   oxetane phosphite          0.08  8300   8300   6    7     2.27VII  cadmium 2-ethyl-          0.05  9700   9700   6     6-60                                         2.06hexanoateVIII phenylneopentyl          0.05  10200  10200  7    80    1.52phosphiteIX   oxetane phosphite          0.08  10600  10600  5    15-60                                         1.68                12 DaysI    cadmium 2-ethyl-          0.05  9500   9500   8    20-95                                        15.74hexanoateII   phenylneopentyl          0.05  9900   9900   8    20    1.75phosphiteIII  oxetane phosphite.sup.1          0.08  10100  10100  8    8    2.1IV   cadmium 2-ethyl-          0.05  4300   4300   4    4    FailhexanoateV    phenylneopentyl          0.05  4500   4500   4    4    FailphosphiteVI   oxetane phosphite          0.08  1200   1200   &lt;2   &lt;2   FailVII  cadmium 2-ethyl-          0.05  9600   9600   8     8-35                                        FailhexanoateVIII phenylneopentyl          0.05  5800   5800   4    4    Failphosphite -IX          oxetane phosphite                0.08   3000   3000 2    2 Fail__________________________________________________________________________          Stabilizer                Tensile Yield                       Tensile Ult.                              Elong.                                   Elong.                                        ImpactExampleStabilizer          Concn. %                Str. psi                       Elong. psi                              Yield psi                                   Ult. %                                        Ft.-lbs.__________________________________________________________________________                24 DaysI    cadmium 2-ethyl-          0.05  9800   7300-9800                              5     5-40                                         11.3hexanoate                          66% highII   phenylneopentyl          0.05  10150   7300-10200                              5     5-20                                        0.6phosphite              67% low     66% highIII  oxetane phosphite.sup.1          0.08  --     10567  2         1.6IV   cadmium 2-ethyl-          0.05  --     1900   --   1    FailhexanoateV    phenylneopentyl          0.05  --     2000   --   1    FailphosphiteVI   oxetane phosphite          0.08  --      800   --   1    FailVII  cadmium 2-ethyl-          0.05  4400   4400   &lt;1   1    FailhexanoateVIII phenylneopentyl          0.05  --     1867   --   1    FailphosphiteIX   oxetane phosphite          0.08  --     1200   --   1    Fail__________________________________________________________________________ .sup.1 oxetane phosphite is tris(3ethyl-3-methylol oxetane)phosphite. 
    
     
                                           TABLE II__________________________________________________________________________EFFECT ON TENSILE AND ELONGATION PROPERTIESOF POLYCARBONATES HAVING VARIOUS STABILIZERSTHEREIN DURING OVEN AGING AT 130° C.          Stabilizer                Tensile Yield                       Tensile Ult.                             Elong.                                  Elong.ExampleStabilizer          Concn. %                Str. psi                       Str. psi                             Yield %                                  Ult. %__________________________________________________________________________                       ControlI    cadmium 2-ethyl-          0.05   9000   9200 8    100hexanoateII   phenylneopentyl          0.05   8933   9000 8    100phosphiteIII  oxetane phosphite.sup.1          0.08   9300   9617 10   106IV   cadmium 2-ethyl-          0.05   9133   9400 8    102hexanoateV    phenylneopentyl          0.05   9300   9000 8    100phosphiteVI   oxetane phosphite          0.08   9600   9600 11   102VII  cadmium 2-ethyl-          0.05   9400   9400 8    100hexanoateVIII phenylneopentyl          0.05   9867   9867 8    103phosphiteIX   oxetane phosphite          0.08   9867   9867 11   102                       3 DaysI    cadmium 2-ethyl-          0.05  10600  10600 8    75hexanoateII   phenylneopentyl          0.05  10600  10600 8    90phosphiteIII  oxetane phosphite.sup.1          0.08  --     --    --   --IV   cadmium 2-ethyl-          0.05  11000  11000 8     30-105hexanoateV    phenylneopentyl          0.05  11000  11000 8    10-70phosphiteVI   oxetane phosphite          0.08  11000  11000 8     40-105VII  cadmium 2-ethyl-          0.05  11400  11400 8    20hexanoateVIII phenylneopentyl          0.05  11300  11300 8    25phosphiteIX   oxetane phosphite          0.08  11200  11200 8    10-55                       6 DaysI    cadmium 2-ethyl-          0.05  11000  11000 9     30-100hexanoateII   phenylneopentyl          0.05   7666  11033 9    42phosphiteIII  oxetane phosphite.sup.1          0.08   8000  11000 9    90IV   cadmium 2-ethyl-          0.05   8000  11433 10   20-50hexanoateV    phenylneopentyl          0.05   8033  11466 9    45phosphiteVI   oxetane phosphite          0.08   7966  11200 9     35-105VII  cadmium 2-ethyl-          0.05  11933  11933 11   14hexanoateVIII phenylneopentyl          0.05  10400  11266 10   20phosphiteIX   oxetane phosphite          0.08   8233  11233 8    25-70                       12 DaysI    cadmium 2-ethyl-          0.05  11300   11300                             7    30-75hexanoateII   phenylneopentyl          0.05  11400  11400 8    20phosphiteIII  oxetane phosphite.sup.1          0.08  11400  11400 8    10-85IV   cadmium 2-ethyl-          0.05  11500  11500 7    10-75hexanoateV    phenylneopentyl          0.05  11500  11500 8    10-50phosphiteVI   oxetane phosphite          0.08  12000  12000 8    10-50VII  cadmium 2-ethyl-          0.05  11800  11800 7    38hexanoateVIII phenylneopentyl          0.05  11500  11500 7    22phosphiteIX   oxetane phosphite          0.08  11800  11800 8    10-25                       24 DaysI    cadmium 2-ethyl-          0.05  10800  10800 8    88hexanoateII   phenylneopentyl          0.05  10800  10800 8    15phosphiteIII  oxetane phosphite.sup.1          0.08  10400  10400 8    45IV   cadmium 2-ethyl-          0.05  10900  10900 8     50-105hexanoateV    phenylneopentyl          0.05  10900  10900 7    40-85phosphiteVI   oxetane phosphite          0.08  11100  11100 8    11-75VII  cadmium 2-ethyl-          0.05  11200  11200 7     7-75hexanoateVIII phenylneopentyl          0.05  11600  11600 8    11phosphiteIX   oxetane phosphite          0.08  11400  11400 8    12__________________________________________________________________________ .sup.1 oxetane phosphite is tris(3ethyl-3-methylol oxetane)phosphite. 
    
     
                                           TABLE III__________________________________________________________________________OPTICAL AND MELT STABILITY PROPERTIES OF POLYCARBONATE USING VARIOUSSTABILIZERS                          700° F.        Stabilizer              520° F. Molding                          Molding                                 Irradiation                                        Melt StabilityExampleStabilizer        Concn. %              Y %                 YI  % Haze                          Y %                             YI  Y %                                    YI  at 375° C. APHA__________________________________________________________________________                                        colorI    cadmium 2-        0.05  84.31                 0.68                     1.06 84.79                             2.38                                 83.89                                    10.43                                        900ethylhexanoateII   phenyl- 0.05  84.85                 1.49                     1.18 83.70                             2.88                                 84.35                                    12.09                                        800-900neopentylphosphiteIII  oxetane 0.08  85.26                 -0.86    85.61                             -0.41                                 84.20                                    9.49                                        &gt;1000phosphite.sup.1IV   cadmium 2-        0.05  84.32                 1.10                     1.2  84.36                             3.17                                 83.15                                    4.65                                        &gt;1000ethylhexanoateV    phenyl- 0.05  85.32                 1.51                     1.2  85.28                             3.41                                 84.33                                    6.06                                        &gt;1000neopentylphosphiteVI   oxetane 0.08  85.23                 -0.45                     1.0  84.01                             3.49                                 84.42                                    3.50                                        &gt;1000phosphiteVII  cadmium 2-        0.05  80.19                 2.53                     1.08 79.82                             5.22                                 80.99                                    6.09                                        &gt;&gt;1000ethylhexanoateVIII phenyl- 0.05  84.59                 0.22                     1.20 83.98                             2.18                                 84.09                                    4.35                                        &gt;&gt;1000neopentylphosphiteIX   oxetane 0.08  84.83                 -0.96                     1.20 82.84                             5.06                                 83.78                                    3.13                                        &gt;&gt;1000phosphite__________________________________________________________________________ .sup.1 oxetane phosphite is tris(3ethyl-3-methylol oxetane) phosphite. 
    
     
                       TABLE IV______________________________________EFFECT ON OPTICAL PROPERTIES OFPOLYCARBONATE HAVING VARIOUS STABILIZERSON AGING IN WATER AT 82° C.Ex-ample Stabilizer    Concn.   Y %  YI    Haze %______________________________________              UnagedI     cadmium 2-ethyl-               (0.05%)  84.31                             0.68  1.06 hexanoateII    phenylneopentyl               (0.05%)  84.85                             1.49  1.18 phosphiteIII   oxetane phosphite.sup.1               (0.08%)  85.26                             -0.86IV    cadmium 2-ethyl-               (0.05%)  84.32                             1.10  1.2 hexanoateV     phenylneopentyl               (0.05%)  85.32                             1.51  1.2 phosphiteVI    oxetane phosphite               (0.08%)  85.23                             -0.45 1.0              3 DaysI     cadmium 2-ethyl-               (0.05%)  83.91                             1.20  1.70 hexanoateII    phenylneopentyl               (0.05%)  84.82                             1.78  1.0 phosphiteIII   oxetane phosphite.sup.1               (0.08%)  85.09                             -0.81 2.0IV    cadmium 2-ethyl-               (0.05%)  83.97                             1.19  3.0 hexanoateV     phenylneopentyl               (0.05%)  84.66                             1.87  1.6 phosphiteVI    oxetane phosphite               (0.08%)  85.22                             -0.59 1.4              6 DaysI     cadmium 2-ethyl-               (0.05%)  84.86                             1.29  1.60 hexanoateII    phenylneopentyl               (0.05%)  85.72                             2.08  1.7 phosphiteIII   oxetane phosphite.sup.1               (0.08%)  85.99                             - 0.37                                   1.6IV    cadmium 2-ethyl-               (0.05%)  84.85                             1.47  1.5 hexanoateV     phenylneopentyl               (0.05%)  84.80                             1.97  1.9 phosphiteVI    oxetane phosphite               (0.08%)  85.72                             -0.27 1.7              12 DaysI     cadmium 2-ethyl-               (0.05%)  84.35                             1.23  1.16 hexanoateII    phenylneopentyl               (0.05%)  85.15                             2.12  1.62 phosphiteIII   oxetane phosphite.sup.1               (0.08%)  85.32                             -0.54 1.77IV    cadmium 2-ethyl-               (0.05%)  --   --    -- hexanoateV     phenylneopentyl               (0.05%)  84.96                             2.06  1.52 phosphiteVI    oxetane phosphite               (0.08%)  85.22                             -0.38 0.84              24 DaysI     cadmium 2-ethyl-               (0.05%)  83.98                             1.56  3.1 hexanoateII    phenylneopentyl               (0.05%)  83.95                             3.45  4.7 phosphiteIII   oxetane phosphite.sup.1               (0.08%)  84.66                             0.62  5.1IV    cadmium 2-ethyl-               (0.05%)  83.39                             1.60  2.4 hexanoateV     phenylneopentyl               (0.05%)  83.64                             4.21  4.9 phosphiteVI    oxetane phosphite               (0.08%)  84.53                             0.80  3.3______________________________________ .sup.1 oxetane phosphite is tris(3ethyl-3-methylol oxetane) phosphite. 
    
     
                       TABLE V______________________________________EFFECT ON OPTICAL PROPERTIES OFPOLYCARBONATE WITH VARIOUS STABILIZERSDURING OVEN AGING AT 130° C.Ex-ample Stabilizer    Concn.   Y %  YI    Haze %______________________________________              UnagedI     cadmium 2-ethyl-               (0.05%)  84.31                             0.68  1.06 hexanoateII    phenylneopentyl               (0.05%)  84.85                             1.49  1.18 phosphiteIII   oxetane phosphite.sup.1               (0.08%)  85.26                             -0.86 1.42IV    cadmium 2-ethyl-               (0.05%)  84.32                             1.10  1.2 hexanoateV     phenylneopentyl               (0.05%)  85.32                             1.51  1.2 phosphiteVI    oxetane phosphite               (0.08%)  85.23                             -0.45 1.0              3 DaysI     cadmium 2-ethyl-               (0.05%)  84.17                             1.35  1.13 hexanoateII    phenylneopentyl               (0.05%)  84.62                             2.00  1.48 phosphiteIII   oxetane phosphite.sup.1               (0.08%)  85.49                             -0.73 1.01IV    cadmium 2-ethyl-               (0.05%)  83.63                             1.48  1.70 hexanoateV     phenylneopentyl               (0.05%)  84.92                             2.01  1.21 phosphiteVI    oxetane phosphite               (0.08%)  85.07                             -0.64 1.32              6 DaysI     cadmium 2-ethyl-               (0.05%)  84.17                             1.51  1.2 hexanoateII    phenylneopentyl               (0.05%)  83.05                             2.27  1.6 phosphiteIII   oxetane phosphite.sup.1               (0.08%)  85.48                             -0.69 1.4IV    cadmium 2-ethyl-               (0.05%)  84.05                             1.61  1.9 hexanoateV     phenylneopentyl               (0.05%)  84.74                             2.28  1.8 phosphiteVI    oxetane phosphite               (0.08%)  85.16                             -0.54 1.3              12 DaysI     cadmium 2-ethyl-               (0.05%)  82.88                             2.02  -- hexanoateII    phenylneopentyl               (0.05%)  83.64                             3.09  -- phosphiteIII   oxetane phosphite.sup.1               (0.08%)  84.37                             -0.76 --IV    cadmium 2-ethyl-               (0.05%)  82.89                             2.17  -- hexanoateV     phenylneopentyl               (0.05%)  82.69                             4.03  -- phosphiteVI    oxetane phosphite               (0.08%)  83.78                             -0.33 --              24 DaysI     cadmium 2-ethyl-               (0.05%)  82.86                             2.56  2.7 hexanoateII    phenylneopentyl               (0.05%)  80.97                             5.87  3.5 phosphiteIII   oxetane phosphite.sup.1               (0.08%)  84.20                             3.89  2.8IV    cadmium 2-ethyl-               (0.05%)  82.01                             3.21  3.4 hexanoateV     phenylneopentyl               (0.05%)  79.66                             8.49  3.4 phosphiteVI    oxetane phosphite               (0.08%)  83.71                             0.50  3.9______________________________________ .sup.1 oxetane phosphite is tris(3ethyl-3-methylol oxetane) phosphite. 
    
     In table I the data show the cadmium 2-ethylhexanoate stabilized polycarbonate to have improved elongation and impact properties over polycarbonate formulated with conventional stabilizers after aging under hydrolyzing conditions. 
     In table II the data shows no reduction in oven heat aging properties using cadmium 2-ethylhexanoate. 
     In table III the data demonstrate that cadmium 2-ethylhexanoate imparts substantially similar optical and melt stabilities to those obtained using other commercial stabilizers. The samples prepared for table III were molded at two different temperatures 520° F. and 700° F. The variable Y is a measure of brightness and is better with the higher value. YI is the yellowness index, the closer the number is to zero the better the color of the polycarbonate article. Irradiation designates the brightness and yellowness after 310 hrs. after exposure of the polycarbonate article to sunlamp light. The samples for irradiation testing were molded between 540° and 570° F. 
     As is demonstrated by the above examples, cadmium organic salts provide enhanced hydrolytic stability to polycarbonates over conventional stabilizer without detrimentally effecting the other desirable physical properties for which polycarbonates are used. 
     EXAMPLE X 
     A polycarbonate resin which was the reaction product of bisphenol A and phosgene having a melt flow rate at 300° C. of 6 to 12 g/10 min (ASTM 1238) was tumble blended with a copolycarbonate resin based on bisphenol A and tetrabromobisphenol A having 10 percent by weight bromine therein. The blended resin had a melt flow rate at 300° C. of 6 to 12 g/10 min. (ASTM 1238). Sufficient copolymer was used to impart 5% bromine to the total polycarbonate mixture. 0.1 percent by weight based on the weight of total polycarbonate and copolycarbonate resin of a 66% cadmium 2-ethylhexanoate solution was also tumble blended with the resins. The tumble blend was extruded and cut into pellets. The pellets were molded and tested for impact half-life testing. The impact half-life durability is the time taken during aging at 70° F. and 100% relative humidity for the sample to reach one-half of its original impact strength. The test results are reported on Table VI. 
     EXAMPLES XI and XII 
     Example X was repeated substituting the conventional stabilizers distearyl pentaerythritol diphosphite (Example XI) and tri (mixed mono and dinonyl phenyl) phosphites (Example XII). Test results are reported on Table VI. 
     EXAMPLE XIII 
     Example X was repeated except no stabilizer was added to the polycarbonate. Test results are reported on Table VI. 
     
                       TABLE VI______________________________________IMPACT STRENGTH HALF-LIFE ON AGING AT 70° C.WITH 100% RELATIVE HUMIDITY                    Stabilizer                             Half LifeExample   Stabilizer     Concn.   (Days)______________________________________X         cadmium 2-ethyl-                    0.1      65     hexanoateXI        distearyl pentaery-                    0.1      48.3     thritol diphosphiteXII       tri (mixed mono and                    0.1      56.8     dinonyl phenyl)     phosphitesXIII                              87.1______________________________________ 
    
     As is demonstrated by Table VI cadmium 2-ethylhexanoate provides improved hydrolytic stability over conventional polycarbonate stabilizers. However, the cadmium 2-ethylhexanoate stabilized polycarbonate is worse in hydrolytic stability than the neat resin. It is necessary to add a stabilizer to the polycarbonate to provide protection from heat and light. The cadmium salts of the invention provide this protection to halogenated polycarbonate resins while imparting improved hydrolytic stability over conventional stabilizers. 
     
                       TABLE VII______________________________________CONCENTRATION OF ADDITIVES IN PC FORCOMPARATIVE TESTING OF RETENTION OFOVERALL PROPERTIES DURING AGING______________________________________                       Molecular                                Molecular             Wt % PC   Formula  Wt______________________________________1.  Cadmium       0.05      C.sub.16 H.sub.30 O.sub.4 Cd                                398.74    2-ethylhexanoate2.  Cadmium Octoate             0.033     C.sub.16 H.sub.30 O.sub.4 Cd                                398.743.  Cadmium Laurate             0.042     C.sub.24 H.sub.46 O.sub.4 Cd                                510.954.  Cadmium Valerate             0.026     C.sub.10 H.sub.18 O.sub.4 Cd                                314.585.  Cadmium Myristate             0.047     C.sub.28 H.sub.54 O.sub.4 Cd                                567.056.  Cadmium Palmitate             0.052     C.sub.32 H.sub.62 O.sub.4 Cd                                623.167.  Cadmium Stearate             0.056     C.sub.36 H.sub.70 O.sub.4 Cd                                679.328.  Cadmium Acetate             0.015     C.sub.4 H.sub.6 O.sub.4 Cd                                230.499.  Zinc Octoate  0.035     C.sub.16 H.sub.30 O.sub.4 Zn                                351.775.9 g of cadmium octoate was mixed with 4.1 g of phenyl diphenylphosphinite* and the combined mixture was heated to 100° C. for 1hour. This mixture was used in compounding with polycarbonate.10. 0.10% of a mixture of cadmium octoate and phenyl diphenylphosphinite (in 5.9/4.1 ratio)11. 0.30% of a mixture of cadmium octoate and phenyl diphenylphosphinite (in 5.9/4.1 ratio)12. The polycarbonate resin (MERLON M-50) which was utilizedfor comparative testing was the reaction product of bisphenol Aand phosgene having a melt flow at 300° C. of 3 to 6 grams/10min.(ASTM D-1238) and having a natural color of 7.5. The additives(1-11 above) were incorporated into the polycarbonate using adry blend/extrusion compounding technique.The properties studied for comparison of effectiveness were:(a) Impact retention at 105° C. (dry air aging) and at 82°C. (180° F.)aging in water;(b) Critical thickness property loss during dry air aging at 105°C.and water aging at 82° C. (180° F.);(c) Retention of tensile properties at 130° C. (dry air aging) andat82° C. (aging in water);(d) Color retention between moldings at 520° F. and 700°F.;(e) Discoloration (measured by yellowness index changes) during dryair aging at 130° C.13. All of the additives were compounded with polycarbonate at thesame mol percent level.______________________________________ *Phenyl diphenyl phosphinite was prepared from the reaction of phenyl dichloro phosphine and phenol in presence of TEA. The crude product obtained was redistilled. 
    
     
                                           TABLE VIII__________________________________________________________________________EFFECT ON IMPACT PROPERTIES (NOTCHED) OF M-50 COMPOUNDEDWITH VARIOUS ADDITIVES DURING OVEN AGING AT 130° C. AND WATERAGING AT 82° C.   Cadmium                                    Cadmium Octoate/   2-ethyl-         Cadmium               Cadmium                     Cadmium                          Cadmium                               Cadmium                                    Cadmium                                         Cadmium                                              Phenyl diphenyl   hexanoate         Laurate               Octoate                     Valerate                          Stearate                               Palmitate                                    Acetate                                         Myristate                                              phosphinite__________________________________________________________________________Additive Wt %   0.05  0.042 0.033 0.026                          0.056                               0.052                                    0.015                                         0.047                                              0.059/                                                    0.177/                                              0.041 0.122ImpactPropertiesAged in Ovenat 105° C.1/8&#34; NotchedIzod ft lbs/in(0 hr)  17.32      17.45         17.61            17.99               17.98                  17.33                     17.58                          17.58                               17.13                                    17.40                                         16.87                                              14.51                                                 17.50                                                    13.30                                                       16.17(8 hrs) 17.76      -- 17.74            -- 17.42                  -- 12.44                          --   2.67 --   2.10 2.41                                                 -- 1.67                                                       --(16 hrs)   17.69      -- 17.37            -- 13.25                  -- 7.37 --   2.09 --   1.99 1.92                                                 -- 1.51                                                       --(24 hrs)   -- 16.86         -- 17.52               -- 16.99                     --   7.76 --   17.12                                         --   -- 1.89                                                    -- 1.17(32 hrs)   17.24      -- 17.27            -- 12.36                  -- 2.18 --   2.09 --   1.63 1.73                                                 -- -- --(64 hrs)   11.94      -- 7.77            -- 2.20                  -- 1.84 --   1.84 --   1.42 1.63                                                 -- -- --(72 hrs)   -- 16.82         -- 12.30               -- 2.86                     --   2.00 --   7.38 --   -- 1.66                                                    -- 1.22(128 hrs)   12.46      -- 2.57            -- 1.83                  -- 1.60 --   1.70 --   --   -- -- -- --(144 hrs)   -- 3.48         -- 3.38               -- 2.43                     --   1.84 --   2.20 --   -- 1.50                                                    -- 1.14(288 hrs)   -- 1.99         -- 2.07               -- 1.84                     --   1.66 --   1.97 --   -- 1.60                                                    -- 1.11(670 hrs)   -- -- -- -- -- -- --   --   --   --   --   -- -- -- --Water agedat 82° C.1/8&#34; NotchedIzod ft lbs/in(0 day) 17.32      17.45         17.61            17.99               17.98                  17.33                     17.58                          17.58                               17.13                                    17.40                                         16.87                                              14.51                                                 17.50                                                    13.30                                                       16.17(1 day) 17.71      17.84         13.18            18.06               3.39                  1.76                     7.95 1.30 1.36 17.80                                         1.07 1.34                                                 16.40                                                    0.21                                                       1.50(3 days)   17.84      12.43         17.11            17.32               0.60                  1.15                     1.02 0.94 1.36 19.27                                         0.60 0.58                                                 2.86                                                    0.24                                                       0.99(6 days)   18.08      12.66         17.42            17.69               1.02                  0.94                     --   0.58 --   2.20 --   -- 2.61                                                    -- 0.79(12 days)   17.53      12.25         17.24            12.48               0.55                  0.81                     --   0.53 --   1.86 --   -- -- -- 0.51(24 days)   -- 12.76         -- 8.02               -- 0.53                     --   --   --   1.55 --   -- -- -- --__________________________________________________________________________ 
    
     
                                           TABLE IX__________________________________________________________________________EFFECT ON CRITICAL THICKNESS PROPERTIES OF M-50 COMPOUNDEDWITH VARIOUS ADDITIVES DURING OVEN AGING AT 130° C. AND WATERAGING AT 82° C.       Cadmium                             Cadmium Octoate/       2-ethyl-             Cadmium                   Cadmium                         Cadmium                               Cadmium                                     Cadmium                                           Phenyl diphenyl       hexanoate             Laurate                   Octoate                         Valerate                               Palmitate                                     Myristate                                           phosphinite__________________________________________________________________________Additive Wt %        0.05 0.042 0.033 0.026 0.052 0.047 0.059/                                                0.177/                                           0.041                                                0.122Oven Aging at 105° C. 0 hr       212   207   202   187   182   182   167  152 4 hrs      202   202   145   135   135   120   110  110 8 hrs      150   160   137   132   122   112   112  &lt;100 16 hrs     145   142   122   122   122   112   112  &lt;100 32 hrs     142   137   135   122   122   102   102 64 hrs     132   125   115   112   105   100   &lt;100128 hrs     132   122   102   102   102   100   &lt;100Aged at 82° C. in H.sub.2 O 0 day      212   207   202   187   182   182   167  152 1 day      192   192   &lt;120  &lt;120  &lt;100  &lt;100  &lt;100 &lt;100 3 days     177   165   &lt;100  105   &lt;100  &lt;100  &lt;100 &lt;100 6 days     177   17212 days     172   167__________________________________________________________________________ 
    
     
                                           TABLE X__________________________________________________________________________Water Aged (82° C.) Tensile Properties of PolycarbonatesCompounded with Various Cadmium Salts and Zinc Salts of Organic Acids                 Cadmi-                 um 2-                     Cadmi-             Cadmium Octoate/                 ethyl-                     um                 Phenyl                 hexa-                     Octo-                         Zinc Cadmium                                   Cadmium                                        Diphenyl    CadmiumAged  Additive        noate                     ate Octoate                              Laurate                                   Acetate                                        Phosphinite Stearate__________________________________________________________________________ Additive Wt. %  0.05                     0.033                         0.035                              0.041                                   0.015                                        0.059/0.041                                              0.177/0.123                                                    0.059/.0410 Days Initial Tensile PropertiesUS    Tensile Strength at Yield, psi                 9300                     9,300                         9,000                              9300 9,100                                        9,200 9,200 9,300SI    Tensile Strength at Yield, MPa                 64.1                     64.1                         62   64.1 62.7 63.4  63.4  64.1US    Ultimate Tensile Strength, psi                 9300                     8,600                         9,200                              8000 9,100                                        9,800 9,500 9,200SI    Ultimate Tensile Strength, MPa                 64.1                     59.3                         63.4 55.2 62.7 67.6  65.5  63.4US    Tensile Strength, Failure, psi                 9100                     9,200                         9,200                              9300 9,000                                        9,800 8,900 9,100SI    Tensile Strength, Failure, MPa                 62.7                     63.4                         63.4 64.1 62   67.6  61.4  62.7 Elongation, Yield %                 8   9   5    8    9    8     8     8 Ultimate Elongation %                 105 40-105                         110  100  100  114   25-118                                                    1003 Days(72 hours)US    Tensile Strength at Yield, psi                 9400                     11,700                         10,300                              9500 9,800                                        9,000 --    --SI    Tensile Strength at Yield, MPa                 64.81                     80.7                         71   65.5 67.6 62US    Ultimate Tensile Strength, psi                 9400                     11,700                         10,700                              9500 9,800                                        9,000 11,400                                                    11,400SI    Ultimate Tensile Strength, MPa                 64.81                     80.7                         71   65.5 67.6 62    78.6  78.6US    Tensile Strength, Failure, psi                 8000                     10,500                         7,000                              8000 7,300                                        6,800 --    11,400SI    Tensile Strength, Failure, MPa                 55.2                     72.4                         53.8 55.2 50.3 46.9        78.6 Elongation, Yield %                 8   6   6    7    6    5     --    -- Ultimate Elongation %                 9-30                     8   40-100                              8-40 15-35                                        10-50 10    46 Days(144 hours)US    Tensile Strength at Yield, psi                 --  --  --   9600 10,200                                        9,200 --    --SI    Tensile Strength at Yield, MPa                              66.2 70.3 63.4US    Ultimate Tensile Strength, psi                 9400                     12,300                         9,500                              9600 10,200                                        9,200 12,000                                                    9,600SI    Ultimate Tensile Strength, MPa                 64.81                     84.8                         65.5 66.2 70.3 63.4  82.7  66.2US    Tensile Strength, Failure, psi                 9400                     12,300                         9,500                              7100 8,400                                        6,600 --    9,600SI    Tensile Strength, Failure, MPa                 64.81                     84.8                         65.5 49   58   45.5        66.2 Elongation, Yield %                 --  --  --   7    8    5     --    -- Ultimate Elongation %                 7   6   2    8-90 8-60 6     5     412 Days(288 hours)US    Tensile Strength at Yield, psi                 9300                     --       --   10,200                                        10,000                                              --    --SI    Tensile Strength at Yield, MPa                 64.1US    Ultimate Tensile Strength, psi                 9100                     10,600   9700 10,200                                        10,000                                              10,500                                                    4,600SI    Ultimate Tensile Strength, MPa                 62.7                     73  Samples                              66.9 70.3 69    72.4  3US    Tensile Strength, Failure, psi                 9000                     10,600                         Cracked                              9700 8,400                                        9,100 10,500                                                    4,600SI    Tensile Strength, Failure, MPa                 62  73       66.9 58   62.7  72.4  31.7 Elongation, Yield %                 8            --   5    8     --    -- Ultimate Elongation %                 7            6    5-80 6-12  3     324 Days(576 hours)US    Tensile Strength at Yield, psi                 --  --  --   9800 10,800                                        10,000                                              --    --SI    Tensile Strength at Yield, MPa                              67.5 74.5 69US    Ultimate Tensile Strength, psi                 9400                     5,500                         3,100                              9800 10,800                                        10,000                                              4,700 1,200SI    Ultimate Tensile Strength, MPa                 64.81                     38  21   67.5 74.5       32    8.3US    Tensile Strength, Failure, psi                 9400                     5,500                         3,100                              9000 9,700                                        9,100 --    1,200SI    Tensile Strength, Failure, MPa                 64.81                     38  21   62   67   62.7        8.3 Elongation, Yield %                 5   2   --   6    5    5     --    -- Ultimate Elongation %                 --  --  1    1    8    6     1     1__________________________________________________________________________ 
    
     
                                           TABLE XI__________________________________________________________________________Dry Air Aged (130° C.) Tensile Properties of PolycarbonatesCompounded with Various Cadmium Saltsand Zinc Salts of Organic Acids                Cadmium-                  Cadmium                2-Ethyl-                      Cadmium                           Zinc Cadmium                                     Cadmium                                          Octoate/Phenyl                                                     CadmiumAged Additive        Hexanoate                      Octoate                           Octoate                                Laurate                                     Acetate                                          Diphenyl                                                     Stearateite__________________________________________________________________________Additive Wt. %  0.05  0.033                           0.035                                0.041                                     0.015                                          0.059/                                               0.177/                                                     0.056                                          0.041                                               0.1520 DaysInitial Tensile PropertiesUS   Tensile Strength at Yield, psi                9,300 9,300                           9,000                                9,300                                     9,100                                          9,200                                               9,200 9,300SI   Tensile Strength at Yield, MPa                64.1  64.1 62   62   62.7 63.4 63.4  64.1US   Ultimate Tensile Strength, psi                9,300 8,600                           9,200                                9,300                                     9,100                                          9,800                                               9,500 9,200SI   Ultimate Tensile Strength, MPa                63.4  59.3 63.4 64.1 62.7 67.6 65.5  63.4US   Tensile Strength, Failure, psi                9,100 9,700                           9,200                                9,000                                     9,000                                          9,800                                               8,900 9,100SI   Tensile Strength, Failure, MPa                62.7  66.9 63.4 62   62   67.6 61.4  62.7Elongation, Yield %                8     9    5    8    9    8    8     8Ultimate Elongation %                105   40-105                           110  100  100  114  25-118                                                     1053 DaysUS   Tensile Strength at Yield, psi                10,800                      11,400                           11,400                                10,900                                     11,000                                          10,400                                               10,900                                                     11,600SI   Tensile Strength at Yield, MPa                74.5  78.6 78.6 75.1 75.8 71.7 75.1  80US   Ultimate Tensile Strength, psi                10,900                      11,400                           11,400                                10,900                                     11,000                                          10,400                                               10,900                                                     11,600SI   Ultimate Tensile Strength, MPa                75.1  78.6 78.6 75.1 75.8 71.7 75.1  80US   Tensile Strength, Failure, psi                9,800 9,100                           8,800                                9,900                                     11,000                                          10,400                                               10,900                                                     11,600SI   Tensile Strength, Failure, MPa                67.6  62.7 60.7 68.3 75.8 71.7 75.1  80Elongation, Yield %                5     5    6    5    5    8    5     5Ultimate Elongation % 40-60     7-60 75-105                                          80-105                                               50-110                                                     5-356 DaysUS   Tensile Strength at Yield, psi                10,300                      10,800                           10,600                                10,300                                     10,600                                          10,600                                               11,200                                                     10,600SI   Tensile Strength at Yield, MPa                71.1  74.5 73.1 71.1 73.1 73.1 77.2  73.1US   Ultimate Tensile Strength, psi                10,300                      10,800                           10,700                                10,300                                     10,300                                          10,600                                               11,200                                                     9,700SI   Ultimate Tensile Strength, MPa                73.1  74.5 73.8 71.1 71.1 73.1 77.2  66.9US   Tensile Strength, Failure, psi                8,600 7,800                           9,700                                7,600                                     8,300                                          8,000                                               7,600 8,600SI   Tensile Strength, Failure, MPa                59.3  53.8 66.9 52.4 57.2 55.2 52.4  59.3Elongation, Yield %                8     7    4    6    4    10   5     4Ultimate Elongation %                100             7-25 7-20 60-115                                               5-70  2-712 DaysTensile Strength at Yield, psi                11,000                      11,000                           --   11,000                                     12,200                                          11,400                                               --    --Tensile Strength at Yield, MPa                75.8  75.8 --   75.8 84.1 78.6 --    --Ultimate Tensile Strength, psi                11,000                      11,800                           6,000                                11,000                                     11,200                                          11,400                                               10,600                                                     --Ultimate Tensile Strength, MPa                75.8  81.4 41.4 75.8 77.2 78.6 73.1  --Tensile Strength, Failure, psi                10,000                      11,800                           6,000                                9,900                                     10,000                                          9,100                                               10,600                                                     --Tensile Strength, Failure, MPa                70    81.4 41.4 68.3 70   62.7 73.1  --Elongation, Yield %                10    10   --   10   5    8    --    --Ultimate Elongation %                10-100                      10   2    10-55                                     5-15 10-75                                               6     --24 DaysTensile Strength at Yield, psi                --    --   --   --   10,700                                          11,300                                               --    --Ultimate Tensile Strength, psi                9,700 3,900                           1,050                                9,800                                     10,700                                          11,300                                               Samples                                                     2,700Tensile Strength, Failure, psi                9,800 3,900                           1,050                                9,800                                     8,500                                          10,100                                               degraded                                                     2,700Elongation, Yield %                  6    5    totallyUltimate Elongation %                6                    12   10__________________________________________________________________________ 
    
     
                                           TABLE XII__________________________________________________________________________COLOR RETENTION AT 550°  F. AND 700° F. MOLDINGS AS WELL ASAGING PROPERTIES                                      OVEN AGED AT 130° C.                      550° F.                            700° F.                                      6 days 12 days                                                   24 days                  Wt %                      Y %                         YI Y % YI    Y % YI Y %                                                YI Y__________________________________________________________________________                                                       % YI                                                       .Cadmiun 2-ethylhexanoate                  0.05                      88.23                         3.3                            88.26                                3.3   88.39                                          4.9                                             87.17                                                10.4                                                   88.06                                                       6.0                      88.47                         3.6                            88.52                                4.0   88.02                                          4.1                                             88.37                                                4.1                                                   88.26                                                       4.5Cadmium Laurate        0.042                      88.01                         3.7                            87.77                                6.4   88.11                                          5.2                                             -- -- 87.91                                                       6.3Cadmium                    88.16                         4.4                            88.17                                5.9   87.64                                          5.0                                             87.86                                                5.0                                                   87.45                                                       5.6Cadmium Octoate        0.033                      87.72                         6.3                            59.11                                15.1  87.35                                          9.0                                             86.05                                                11.2                                                   85.93                                                       12.3                      88.55                         7.4                            55.26*                                61.6  87.81                                          9.1                                             86.81                                                11.2                                                   85.82                                                       14.9Cadmium Stearate       0.056                      88.46                         9.4                            42.91                                13.4   Not aged since specimens show                                      a high                                      discoloration at 550°                                      F. and 700° F.                                      molding.Cadmium Acetate        0.015                      88.03                         4.6                            69.70                                15.2  --  -- -- -- 87.73                                                       7.4Zinc Octoate           0.035                      88.74                         5.2                            70.23                                46.9  87.33                                          5.8                                             87.93                                                6.5                                                   86.06                                                       14.0Cadmium Valerate       0.026                      87.60                         5.2                            63.89                                33.8  Since these compositions did                                      not exhibitCadmium Palmitate      0.052                      87.83                         8.3                            63.76                                41.4  retention of impact properties                                      during ovenCadmium Myristate      0.047                      87.86                         7.5                            65.38                                33.2  and water aging, the optical                                      property agingCadmium Octoate/phenyl diphenyl phosphinite                  0.059/                      88.77                         4.98                            61.63*                                48.96*                                      studies were not evaluated.                  0.041                      --  --                             -- --    87.80                                          4.62                                             88.07                                                4.5                                                   87.24                                                       5.7Cadmium Octoate/phenyl diphenyl phosphinite                  0.177/                      82.47                          68                            (degraded)                  0.123                      --  --                             -- --    76.93                                          9.10                                             76.70                                                8.2                                                   74.27                                                       13.7__________________________________________________________________________ *Exhibited splaying 700° F. molding with 1 min 550° F. molding with 35 secs cycle 
    
     From a review of the data of Tables VIII-XII, it can be noted that while several of the additives do, in fact, impart equivalent and at times superior properties to the polycarbonate composition in some tests than do the instantly claimed cadmium salts, only the instantly claimed polycarbonates containing cadmium 2-ethylhexanoate, cadmium octoate, cadmium laurate and cadmium acetate exhibit the best overall combination of tensile, impact and optical properties. 
     Although the invention has been described with reference to specific materials, the scope of the invention is only to be limited as is set forth in the accompanying claims.