ORGANIC COMPOUNDS THAT CONTAIN SULPHUR, AND THEIR USE AS ADDITIVES IN POLYMERS

Abstract: The invention relates to a compound of the formula (I) A-NH-- (CH₂) n , -N-(CH₂) n , - -NH-A wherein n′ is 1, 2, 3 or 4 and X is S or S-S- where each A is where Y is H, Cl or Br, and preferably when used as a flame retardant at least one Y is Cl or Br or where n² is 0, 1 and n³ is 0, 1 R′, R² and R³ are H, or straight or branched alkyl of 1 to 8 carbons, or where Y is the same as defined above. The new compounds are suitable for use in polymers as synergists for antioxidants or as antioxidants per se. The invention furthermore concerns articles of manufacture made of polymers which comprise compounds of formula (I).

Description: Polymer Parts and Compound Useful Therein Brief Statement of the invention This invention is directed to a compound of the formula (I) EMI1.1 where n' is 1, 2, 3 or 4 and X is S or S-S where each A is EMI1.2 where Y is H, Cl or Br, and preferably when used as a flame retardant at least one Y is Cl or Br EMI1.3 where n2 is 0, 1 and n3 is 0, 1 R', R2 and R3 are H, or straight or branched alkyl of 1 to 8 carbons, or EMI1.4 where Y is the same as defined above, and its use in polymers as a synergist for antioxidants used in such polymers or as antioxidant in its own right, and articles of manufacture made comprising polymers with the compound of formula (I). While it would be expected that the compound (I) would have nil antioxidant properties at elevated temperatures in a polymer, unexpectedly the compound of formula (I) appears to have antioxidant properties comparable to compounds which would be considered to be primary antioxidants. The compound will also, when used in combination with one or more primary antioxidants substantially and unexpectedly increase the useful life of the polymer at elevated temperatures without requiring the high loading of the primary antioxidants (also referred to as chain-breaking antioxidants). While it may be possible to use additional antioxidants, to achieve the increased polymer life at elevated temperatures, primary antioxidants commonly used tend to diffuse out of the polymer at high concentrations and form undesirable coating (termed blooming) on the surface thereof. In addition, the loss of primary antioxidant will over a piod of time permit oxidation to take place at an accelerated rate and thereby significantly decrease the mechanical and electrical properties of the polymer thus shortening its lifetime. The commonly used antioxidant synergist (synergists are sometimes referred to as secondary antioxidants, and also referred to as peroxide-decomposing antioxidants) DLTDP (dilauryl thiodipropionate) also is known to bloom. The present invention is useful in polymers used for electrical insulation, in heat-shrinkable tubing and other parts, e.g. end caps made of polyethylene and used for electrical purposes, as well as in other plastic (polymer) parts used as utensils or as parts of the tubs of washing machines to prevent them from becoming brittle due to loss of antioxidant (because of soapy water causing the antioxidants commonly used to leach out of the plastic). The compound of formula(I) is particularly useful in heatrecoverable (heat-shrinkable) articles of manufacture such as tubing, end caps and other hollow articles to which heat is applied to cause shrinkage because the lack of blooming permits coating with adhesives which may contain metal particles. Polymers-in which the compound of formula (I) are useful in this invention include all thermoplastics and thermohardening (thermosetting) plastics in which antioxidants are employed. Suitable plastics may include polyolefins such polyethylene (high and low density), polypropylene, polybutylene, substituted polyolefins such as halogenated oleo in polymers and copolymers of same and silane-grafted polyethylenes, e.g. grafted using a silane such as vinyl trimethoxy silane as the grafting agent (see U.S. Patent No. 3,086,242). The compound of formula (I) would also be useful with any polymer whose useful properties are adversely affected by oxidative degradation such as esters, amides (e.g. nylon), phenolics, acrylics, rubber, urethanes, vinyls, styrenes (e.g. ABS), and others used in the plastics industry. See the Text PLASTICS IN THE MODERN WORLD by E.G. Couzens and V.E. Yarsly (C) 1968, published by Pelican Books, Inc., Maryland U.S.A., for other polymers used in industry and useful in this invention. Prior art patents showing heat-recoverable plastics and articles include U.S. Patents 4,048,129, 4,016,356, 3,982,546 and 3,959,052. It should be understood that heatrecoverable articles are meant to include those that are treated by irridation or chemically treated to produce such articles. Exemples of primary antioxidants useful in a polymer with the compound of formular (I) include: ANTIOXIDANTS Commercial Name Chemical Name Irganox 1010 tetrakisrmethylene-3(3', 5'-di-tert- butyl-4' -hydroxyphenyl) propionate3 methane Santonox R 4,4' -thiobis (3 -methyl-6-tert-butyl phenol) Irganox 1024 N ,N' -bis (3, 5-di-tert-butyl-4-hydroxy- hydrocinnamoyl) hydrazine Cyanox 1729 Bis (4-tert-butyl-3 hydroxy-2 ,6-dimethyl benyzl)dithiolterephthalate Ethyl 330 1 ,3,5,Trimethyl-2 ,4,6-tris[3,5 di-tert Butyl- 4 hydroxy benzyl-benzene Agerite White di-P-naphthyl-p-phenylene-diamine Irganox 1035 thiodiethylene bis (3,5-di-tert-butyl 4 -hydroxy) hydrocinnamate Other suitable commercial antioxidants include Good-Rite 3114, Plastanox 2246, Naugard 445, Naugard XL-1, Irganox 1093, Irganox 1076, Topanol CA, and Irganox 565. Other antioxidants (normally termed primary antioxidants) in the art may be found in the text ANTIOXIDANTS, RECENT DEVELOPMENTS, CHEMICAL TECHNOLOGY REVIEW NO. 127, by M. William Ranney, Noyes Data Corporation (C) 1979, Library of Congress, Catalog No. 79-84425. In using this invention to form polymeric articles, while the compound of formula (I) acts as a synergist, it is preferred that an amount of the compound of formula (I) to the amount of antioxidant is in the ratio of 1 : 10 to 10 : 1 with the total weight of antioxidant and the compound of formula (I) being within the range of .05 to 10 % based on the weight of the polymer (resin). The compound of formula (I) provides the sulfur for synergism with primary (strong) antioxidants (see list of antioxidants on previous page) and also includes the hydrazone group EMI5.1 which is normally considered only as a mild antioxidant but a powerful copper (metal) deactivator. Accordingly, the compound of formula (I) could be very useful in polymers which contact copper, e.g. insulation for copperwire used in the telephone and power industry. The compound of formula (I) is substantially insoluble in polymers (does not migrate) and is not volatile (substantially no weight loss after 13 hours at 200 OC with a stream of oxygen flowing over it). In using the compound of formula (I) by itself in a polymer, the concentration used should preferably be between .05 to 10 % of the weight of the polymer depending upon environmental conditions to be met when used solely as an antioxidant. When used also as a flame retardant the total weight of the compound of formula (I) should be within the range of 0,05 to 150 % of the weight of the polymer and is generally 50 to 100 %. In Figs. 1 to 7 there are shown various forms of the invention. Figs. 1 to 5 illustrate hollow articles as does Fig. 7. Figs. 1, 2 and 3 illustrate a tube 20 formed of material such as polyethylene and containing an antioxidant and the compound of formula (I) or the compound of formula (I) alone. The tube is formed by conventional technology to be heat-shrinkable, e.g. see U.S. Patents 3,086,242 and 3,303,243. See U.K. Patent Application No. 1601063 published October 21, 1981 for an illustration of chemically-produced heat-shrinkable material. Conventional crosslinked silanegrafted polyethylene is shown in U.S. Patent 3,086,242. The material of U.S. Patent 3,086,242 will be modified by the incorporation of antioxidant and the compound of formula (I) as disclosed herein. The tube 20 is shrunk as shown in Fig. 3 over electrical cable 21 to provide an insulative protective cover which will protect against moisture and other deleterious substances. Figs. 4 and 5 illustrate a heat-recoverable end cap 25 (a closed at one end hollow article) with Fig. 5 showing the end cap 25 shrunk over a pair of wires 26 and 27. The end cap 25 is made by using the polymer material of the invention in a manner well known in the art. Figs. 6 and 7 show a sheet 30 of material of the invention rolled over upon itself as in Fig. 7 to form a tube. The sheet may be heat-recoverable or not depending upon the desires of the end use. A heat-recoverable sheet may be made by methods known in the art. In this invention, the preferred primary antioxidants are those characterized in the art as hindered phenolics or aromatic amines. The compound of formula I where Y is Cl or Br and in addition to the antioxidant properties, also have particularly useful flame retardant properties and may be used primarily as flame retardants in polymer compositions. Preferred compounds of the formula (I) include the compounds of formula (IA) EMI7.1 where X is S or S-S; The compounds of the formula IB EMI7.2 where X is S or S-S R2 is straight or branched alkyl of 1 to 8 carbons R1 is H or straight or branched alkyl of 1 to 8 carbon atoms n = 0 or 1; The compounds of the formula (IC) EMI8.1 where Y is H, Cl or Br and X is S or S-S; The compounds of the formula (ID) EMI8.2 where R1 is an alkyl group of one to eight carbon atoms, n = 0 or 1, R2 = H or straight or branched alkyl of 1 to 8 carbon atoms, X is S or S - S; and the compound of the formula (IE) EMI8.3 where Y is defined as above. Brief Description of the Drawings Fig. 1 is a side view of a tube; Fig. 2 is an end view of a tube; Fig. 3 is a sectional view of the tube of Figs. 1 and 2 shrunk over wire or cable; Fig. 4 is a sectional view of an end cap; Fig. 5 is a sectional view of the end cap of Fig. 4 shrunk over a pair of wires; Fig. 6 is a top view of a sheet of polymer material of the invention; and Fig. 7 is a perspective view of the sheet of Fig. 6 rolled up upon itself to form a tube. The following examples are illustrative of the practice of the invention and are not intended for purposes of limitation. All parts are by weight and all temperatures are in centigrade. Example 1 Preparation of the compound of formula (IA) where X equals The dibenzal derivative of the dihydrazide of thiodipropionic acid compound of formula (IA) may be prepared in two steps as follows: Sixty ml. of water is heated to about 60 OC and 10 grams of dimethyl thiodipropionate EMI9.1 are added with stirring. To this two-phase composition is added 7,3 grams of hydrazine hydrate CNH2NHJH2O (a 50 % excess) while stirring is continued. In about 5 minutes the suspension clarifies and reaction appears to be complete. Stirring is continued for an additional 25 minutes and the solution is cooled to about 5 OC (crystals form at about 35 to 40 C), filtered and dried. The yield is about 7.5 grams of thiodipropionic acid dihydrazide, m.p. 154 OC (Perkin-Elmer DSC -2 calorimeter at a heating rate of 100/minute). The yield may be increased by re-using the mother liquor in place of the water, by concentrating the mother liquor, or by diluting with a poor solvent for the dihydrazide such as methanol. The thiodipropionic acid hydrazide EMI10.1 is used without further purification. To 300 ml. of methanol at about 60 OC is added 20.6 grams of the thiopropionic dihydrazide, with stirring. Then a solution of 21.5 grams (slight excess) of benzaldehyde and one drop of glacial acetic in 200 ml. of methanol is added to the stirred suspension of the dihydrazide. Reaction is complete within about 20 minutes and the mixture is cooled, filtered, washed with methanol, and dried. A nearly quantitative yield (36 grams) of the dibenzal derivative of the dihydrazide of thiodipropionic acid is obtained (compound of formula (LA) where X is S). This material melts at about 243 OC (Perkin-Elmer DSC-2 calorimeter at a heating rate of 10 OC/minute). It is substantially white and is insoluble in boiling water and other hot common solvents except that it is soluble in hot N,N-dimethylformamide. It is insoluble in hydrocarbon polymers such as low-density polyethylene, high-density polyethylene, and ethylene-vinyl acetate copolymers at ordinary temperatures but can dissolve in these polymers at temperatures above about 200 OC. The conditions used above result in agglomerated particles which are easy to filter and yet which are easily broken down to a talc-like powder when dry. Because of its polar nature this compound (material) is not soluble in the above mentioned polymers at their use temperatures and therefore does not diffuse through the polymer and then bloom (form an undesirable surface coating). Further, inspite of its low molecular weight, the material is not easily volatilized because of its polar nature. For example, there was no weight loss, or gain, after 13 hours when a sample of this material was exposed to flowing oxygen at 200 OC. Example 2 Using the compound of example 1 a number of compositions were prepared by mixing the proportions of ingredients (percent by weight shown) into a polymer comprising 9 % vinyl acetate - 91 % ethylene copolymer (commercially known as U.S. Industrial Chemicals UE 637) on a heated, two-roll mill, molding into a sheet approximately 75 mils thick as shown below: i) 2 parts by weight of Irganox 101Q and 5 parts by weight hydrazone ef example 1 and 93 parts by weight of the polymer ii) 2 parts by weight of Irganox 1010 + 3 parts by weight of the compound of example 1 and 95 parts by weight of the polymer; and iii) 0.3 part by weight of the compound of example 1 and 99.7 parts by weight of the polymer. Example 3 Preparation of the compount of formula (IA) where X equals S-S The dibenzal derivative of the dihydrazide of dithiodipropionic acid compound of formula (I) may be prepared in two steps as follows: Sixty ml. of water is heated to about 60 OC and 11.6 grams of dimethyl dithiodipropionate EMI12.1 are added with stirring. To this two-phase composition is added 7.4 grams of hydrazine hydrate LNH2NH2]H2o (a 50 % excess) while stirring is continued. In about 5 minutes the suspension clarifies and reaction appears to be complete. Stirring is continued for an additional 25 minutes and the solution is cooled to about 5 OC (crystals form at about 35 to 40 OC), filtered and dried. The yield is about 8.5 grams of dithiodipropionic acid dihydrazide (NP 131 OC). The yield may be increased by re-using the mother liquor in place of the water, by concentrating the mother liquor, or by diluting with a poor solvent for the dihydrazide such as methanol. The dithiodipropionic acid hydrazide EMI12.2 is used without further purification. To 300 ml. of methanol at about 60 OC is added 23.8 grams of the dithiopropionic dihydrazide, with stirring. Then a solution of 21.5 grams (slight excess) of benzaldehyde and one drop of glacial acetic in 200 ml. of methanol is added to the stirred suspension of the dihydrazide. Reaction is complete within about 20 minutes and the mixture is cooled, filtered, washed with methanol, and dried. A nearly quantitative yield (41 grams) of the dibenzal derivative of the dihydrazide of dithiodipropionic acid is obtained (compound of formula (I) where X is .9-S). This material melts at about 194 C (Perkin-Elmer DSC-2 calorimeter at a heating rate of 10 C/minute). It is substantially white and is insoluble in boiling water. The conditions used above also result in agglomerated particles which are easy to filter and yet which are easily broken down to a talc-like powder when dry. Because of its polar nature this compound (material) is not soluble in the above mentioned polymers at their use temperatures and therefore does not diffuse through the polymer and then bloom (form an undesirable surface coating). Example 4 Using the compound of example 3 a number of compositions are prepared by mixing the proportions of ingredients (percent by weight shown) into a polymer comprising 9 % vinyl acetate - 91 % ethylene copolymer (commercially known as U.S. Industrial Chemicals UE 637) on a heated, two-roll mill, molding into a sheet approximately 75 mils thick as shown below: i) 2 parts by weight of Irganox 1010 and 5 parts by weight hydrazone of example 3 and 93 parts by weight of the polymer; ii) 2 parts by weight of Irganox 1010 + 3 parts by weight of the compound of example 3 and 95 parts by weight of the polymer; and iii) 0.3 part by weight of the compound of example 3 and 99.7 parts by weight of the polymer. Example 5 Preparation of the compound EMI14.1 prepared in two steps as follows: Sixty ml. of water is heated to about 60 OC and 10 grams of dimethyl thiodipropionate EMI14.2 are added with stirring. To this two-phase composition is added 7.3 grams of hydrazine hydrate tNH2NH H2O (a 50 % excess) while stirring is continued. In about 5 minutes the suspension clarifies and reaction appears to be complete. Stirring is continued for an additional 25 minutes and the solution is cooled to about 5 "C (crystals form at about 35 to 40 OC), filtered and dried. The yield is about 7.5 grams of thiodipropionic acid dihydrazide, m.p. 154 "C (Perkin-Elmer DSC -2 calorimeter at a heating rate of 100/minute). The yield may be increased be re-using the mother liquor in place of the water, by concentrating the mother liquor, or by diluting with a poor solvent for the dihydrazide such as methanol. The thiodipropionic acid hydrazide EMI15.1 is used without further purification. To 300 ml. of methanol at about 60 OC is added 20.6 grams of the thiopropionic dihydrazide, with stirring. Then a solution of 30.9 grams (slight excess) of 4-hydroxy-3-methoxybenzaldehyde and one drop of glacial acetic in 200 ml. of methanol is added to the stirred suspension of the dihydrazide. Reaction is complete within about 20 minutes and the mixture is cooled, filtered, washed with methanol, and dried. A nearly quantitative yield (50 grams) of the desired derivative of the dihydrazide of thiodipropionic acid is obtained (Compound of formula (IB)). This material is substantially white. The conditions used above result in an agglomerated particle which is easy to filter and yet which is easily broken down to a talc-like powder when dry. Because of their polar nature, these compounds of formula (IB) do not diffuse including the preferred compound through the polymer and then bloom (form an undesirable surface coating). Further, in spite of their low molecular weight, the compounds of formula (IB) are not easily volatilized because of their polar nature. Example 6 Using the compound of example 5 a number of compositions are prepared by mixing the proportions of ingredients (percent by weight shown) into a polymer comprising 9 8 vinyl acetate - 91 % ethylene copolymer (commercially known as U.S. Industrial Chemicals UE 637) on a heated, two-roll mill, molding into a sheet approximately 75 mils thick as shown below: i) 2 parts by weight of Irganox 1010 and 5 parts by weight hydrazone of example 5 and 93 parts by weight of the polymer; ii) 2 parts by weight of Irganox 1010 + 3 parts by weight of the compounds of example 5 and 95 parts by weight of the polymer; iii) 0.3 part by weight of the compounds of example 5 and 99.7 parts by weight of the polymer. Unexpectedly, the compositions prepared above were essentially transparent despite the polar nature of the compounds of formula (IB) in contrast to the opacity observed when an unsubstituted phenyl compound of formula (IA) is used. Thus the compounds of formula (IB) have particular advantage in the preparation of clear plastic materials. Other compounds of formula (IB) are made by i) using the appropriately substituted benzaldehydes in an amount corresponding to their molecular weight for the sulfide compounds where X equals S. Examples of commercially available aldehydes include a Nisaldehyde, 2-hexyloxybenzaldehyde, 4-octyloxybenzaldehyde; ii) using in place of dimethyl thiodipropionate an equivalent amount of commercially available dimethyl dithiodiproprionate corresponding to its molecular weight to prepare a dihydrazide from which compounds of formula (IB) in which X equals S - S may be prepared as disclosed herein. Example 7 Preparation of the preferred compound of formula (ID) EMI17.1 The derivative of the dihydrazide of thiodipropionic acid (compound of formula above) may be prepared in two steps as follows: Sixty ml. of water is heated to about 60 OC and 10 grams of dimethyl thiodipropionate EMI17.2 are added with stirring. To this two-phase composition is added 7.3 grams of hydrazine hydrate fNH2NH2JH2O (a 50 % excess) while stirring is continued. In about 5 minutes the suspension clarifies and reaction appears to be complete. Stirring is continued for an additional 25 minutes and the solution is cooled to about 5 OC (crystals form at about 35 to 40 OC), filtered and dried. The yield is about 7.5 grams of thiodipropionic acid dihydrazide, m.p. 154 OC (Perkin-Elmer DSC -2 calorimeter at a heating rate of 100/minute). The yield may be increased by re-using the mother liquor in place of the water, by concentrating the mother liquor, or by diluting with a poor solvent for the dihydrazide such as methanol. The thiodipropionic acid hydrazide EMI18.1 is used without further purification. To 300 ml. of methanol at about 60 OC is added 20.6 grams of the thiopropionic dihydrazide, with stirring. Then a solution of 27.6 grams (slight excess) of O-hydroxyacetophenone and one drop of glacial acetic in 200 ml of methanol is added to the stirred suspension of the dihydrazide. Reaction is complete within about 20 minutes and the mixture is cooled, filtered, washed with methanol, and dried. A nearly quantitative yield (45 grams) of the desired derivative of the dihydrazide of thiodipropionic acid is obtained (preferred compound). This preferred compound melts at about 203 OC (Perkin Elmer DSC 2 calorimeter at a heating rate of 10 C/minute). The compound is substantially white. The conditions used above result in an agglomerated particle which is easy to filter and yet which is easily broken down to a talc-like powder when dry. Because of their polar nature, these compounds of formula (ID) do not diffuse through the polymer and then bloom (form an undesirable surface coating) Further, in spite of their low molecular weight, the compounds of formula (ID) are not easily volatilized because of their polar nature. Example 8 Using the preferred compound of example 7 a number of compositions were prepared by mixing the proportions of ingredients (percent by weight shown) into a polymer comprising 9 % vinyl acetate - 91 % ethylene copolymer (commercially known as U.S. Industrial Chemicals UE 637) on a heated, two-roll mill, molding into a sheet approximately 75 mils thick as shown below: i) 2 parts by weight of Irganox 1010 and 5 parts by weight hydrazone of example 7 and 95 parts by weight of the polymer; ii) 2 parts by weight of Irganox 1010 and 3 parts by weight of the compound of example 7 and 95 parts by weight of the polymer; and iii) 0.3 part by weight of the compound of example 7 and 99.7 parts by weight of the polymer. Unexpectedly, the compositions prepared above were essentially transparent despite the polar nature of the compound of formula (ID) in contrast to the opacity observed when an unsubstituted phenyl compound of formula (IA) is used. Thus the compounds of formula (ID) have particular advantages in the preparation of clear plastic materials. Examples of other commercially available ketones useful for the preparation of compounds of formula (ID) include 4=hydroxyacetophenone, 3-hydroxybutyrophenone, 4-methoxybutyrophenone and 2, 5-dimethoxyacetophenone. An example of a commercially available material which is useful for preparing compounds of formula (ID) where X equals S - S is dimethyl dithiodipropionate. This material (on an equivalent molecular basis) thus replaces the dimethyl thiodipropionate used in example 7. Example 9 Preparation of the compound of formula (IC) Where X is S and each Y is Br. The compound of this example may be prepared in two steps as follows: Sixty ml. of water is heated to about 60 OC and 10 grams of dimethyl thiodipropionate EMI20.1 are added with stirring. To this two-phase composition is added 7.3 grams of hydrazine hydrate lNH2NH2 H2O (50 % excess) while stirring is continued. In about 5 minutes the suspension clarifies and reaction appears to be complete. Stirring is continued for an additional 25 minutes and the solution is cooled to about 5 OC (crystals form at about 35 to 40 OC), filtered and dried. The yield is about 7.5 grams of thiodipropionic acid dihydrazide, m.p. 154 OC (Perkin-Elmer DSC -2 calorimeter at a heating rate of 100/minute). The yield may be increased by re-using the mother liquor in place of the water, by concentrating the mother liquor, or by diluting with a poor solvent for the dihydrazide such as methanol. The thiodipropionic acid hydrazide EMI21.1 is used without further purification. To 300 ml. of water at room temperature is added 10 grams of powered tetrabromophthalic anhydride and 10 grams of the thiopropionic dihydrozide. The mixture is stirred at room temperature for 1 hour and then the temperature is raised to approximately 100 OC over a two-hour period. The solid is filtered, washed with water and dried. A nearly quantitative yield (19 grams) compound of formula (IC) is obtained. This ditetrabromo compound (where each Y is Br and X is S) has a small endotherm at about 165 cc (Perkin-Elmer DSC -2 calorimeter at a heating rate of 10 OC/minute). It is substantially white and is insoluble in boiling water. Example 10 Using the compound of example 9 a number of compositions are prepared by mixing the proportions of ingredients (percent by weight shown) into a polymer comprising 9 % vinyl acetate - 91 % ethylene copolymer (commercially known as U.S. Industrial Chemicals UE 635) on a heated, two-roll mill, molding into a sheet approximately 75 mils thick as shown below: i) 0,5 part by weight of Naugard Xl.-l t2,2'-oxamidobis ethyl 3 (3, 5-ditert-butyl-4-hydroxyphenyl) propionateg and 3 parts by weight compound of example 9 and 100 parts by weight of the polymer; ii) 3 parts by weight of the compound of example 9 and 100 parts by weight of the polymer; and iii) 1 part by weight of the compound of example 9 and 100 parts by weight of the polymer. Example 11 Preparation of the compound of formula (IC) where X equals S - S and each Y is Br. The dibenzyl derivative of the dihydrazide of thiodipropionic acid (compound of formula (ICd may be prepared in two steps as follows: Sixty ml. of water is heated to about 60 OC and 11.6 grams of dimethyl dithiodipropionate EMI22.1 are added with stirring. To this two-phase composition is added 7.4 grams of hydrazine hydrate LNH2NHJHO (a 5p % excess) while stirring is continued, In about 5 minutes the suspension clarifies and reaction appears to be complete. 8tiring is continued for an additional 25 minutes and the solution is cooled to about 5 OC (crystals form at about 35 to 40 OC), filtered and dried. The yield is about 8.5 grams of dithiodipropionic acid dihydrazide (M.P. 131 OC), The yield may be increased by re-using the mother liquor in place of the water, by concentrating the mother liquor, or by diluting with a poor solvent for the dihydrazide such as methanol. The dithiodipropionic acid hydrazide EMI23.1 is used without further purification. To 300 ml. of water at room temperature is added 10 grams of tetrabromophthalic anhydride and 11.6 grams of thedithiddipropionic dihydrazide, with stirring. After one hour the temperature is raised to approximately 100 OC over a two-hour period. The solid is filtered, washed with water, and dried. A nearly quantitative yield (19.5 grams) of the compound of formula (IC) is obtained. It is substantially white and is insoluble in boiling water. Example 12 Using the compound of example 11 a number of compositions are prepared by mixing the proportions of ingredients (percent by weight shown) into a polymer comprising 9 % vinyl acetate - 91 % ethylene copolymer (commercially known as U.S. Industrial Chemicals UE 635) on a heated, two-roll mill, molding into a sheet approximately 75 mils thick as shown below: i) 0.5 part by weight of Naugard XL-1 E2,2'-oxamidobis ethyl, 3 (3,5-di-tert-butyl-4-hydroxyphenyl) pro pionatei and 3 parts by weight compound of example 11 and 100 parts by weight of the polymer; ii) 3 parts by weight of the compound of example 11 and 100 parts by weight of the polymer; and iii) 1 part by weight of the compound of example 11 and 100 parts by weight of the polymer. Examples of commercially available materials from which compounds of formula (IC) are preparable include 4-chlorophthalic acid, 4,5-dichlorophthalic acid, phthalic anhydride, and pyromellitic dianhydride. Example 13 Preparation of a compound of formula (IE) where each Y is Cl and X is S. The compound of formula (IE) is prepared in two steps as follows: Sixty ml. of water is heated to about 60 OC and 10 grams of dimethyl thiodipropionate EMI24.1 are added with stirring. To this two-phase composition is added 7.3 grams of hydrazine hydrate fNH2NHJH2O (a 50 % excess) while stirring is continued. In about 5 minutes the suspension clarifies and reaction appears to be complete. Stirring is continued for an additional 25 minutes and the solution is cooled to about 5 OC (crystals form at about 35 to 40 OC), filtered and dried. The yield is about 7.5 grams of thiodipropionic acid dihydrazide, m.p. 154 OC (Perkin-Elmer DSC -2 calorimeter at a heating rate of 100/minute). The yield may be increased by re-using the mother liquor in place of the water, by concentrating the mother liquor, or by diluting with a poor solvent for the dihydrazide such as methanol. The thiodipropionic acid hydrazide EMI25.1 is used without further purification. To 300 mL of water at room temperature is added 8 grams of powdered 1,4,5,6,7, 7-hexachloro-norbornene-2 , 3,-dicarboxylic anhydride (chlorendic anhydride)and 10 grams of the thiopropionic dihydrazide, with stirring. After approximately one hour the temperature is raised to 100 OC over a two-hour period. The material is washed with water, filtered and dried. A nearly quantitative yield (17 grams) of the compound of formula (IE) where each Y is Cl and X is S is obtained. This material melts at about 280 OC (Perkin-Elmer DSC-2 calorimeter at a heating rate of 10 C per minute). It is substantially white and is insoluble in boiling water. Example 14 Using the compound of formula (IE) prepared in example 13 a number of compositions were prepared by mixing the proportions of ingredients (percent by weight shown) into a polymer comprising 9 % vinyl acetate - 91 % ethylene copolymer (commercially known as U.S. Industrial Chemicals UE 635) on a heated, two-roll mill, molding into a sheet approximately 75 mils thick as shown below: i) 0.5 part by weight of Naugard LX-1 r2,2-oxamido bis ethyl, 3 (3,5-di-tert-butyl-hydroxyphenyl) propionate and 3 parts by weight compound of formula (IE) and 100 parts by weight of the polymer; ii) 3 parts by weight of the compound of formula (IE) and 100 parts by weight of the polymer; and iii) 1 part by weight of the compound of formula (IE) and 100 parts by weight of the polymer; and iv) 0,47 part by weight of the compound of formula (IE) and 100 parts by weight of an ethylene homopolymer (commercially known as U.S. Industrial Chemicals NA 254). Example 15 Preparation of the compound of formula (IE) where each Y is Cl and X is S - S, the compound of formula (IE) is prepared in two steps as follows: Sixty ml. of water is heated to about 60 OC and 11.6 grams of dimethyl dithiodipropionate EMI26.1 are added with stirring. To this two-phase composition is added 7.3 grams of hydrazine hydrate ENH2NH23H2O (a 50 % excess) while stirring is continued. In about 5 minutes the suspension clarifies and reaction appears to be complete. Stirring is continued for an additional 25 minutes and the solution is cooled to about 5 OC (crystals form at about 35 to 40 OC), filtered and dried. The yield is about 7.5 grams of dithiodipropionic acid dihydrazide, m.p. 131 OC (Perkin-Elmer DSC -2 calorimeter at a heating rate of 100 per minute). The yield may be increased by re-using the mother liquor in place of the water, by concentrating the mother liquor, or by diluting with a poor solvent for the dihydrazide such as methanol. 11.6 gms of the dithiodipropionic acid hydrazide EMI27.1 and 8 grams of powdered 1,4,5,6,7,7-hexychloro-norbornene2,3-dicarboxylic anhydride are used without further purification. To 300 ml. of water at room temperature is added the 11.6 grams and 8.0 grams of the above compounds, with stirring. After approximately one hour, the temperature is raised to 100 OC over a two-hour period. The material is washed with water, filtered and dried. A nearly quantitative vield (17 grams) of the compound of formula (IE) is obtained. This material is sdinnr.tially white and is insoluble in boiling water and has a m.p. greater than 200 CC. Example 16 Using the compound of formula (IE) prepared in example 15 a number of compositions were prepared by mixing the proportions of ingredients (percent by weight shown) into a polymer comprising 9 % vinyl acetate - 91 % ethylene co polymer (commercially known as U.S. Industrial Chemicals UE 635) on a heated, two-roll mill, molding into a sheet approximately 75 mils thick as shown below: i) 0.5 part by weight of Naugard XL-1 L2,2-oxamidabis ethyl, 3(3,5-di-tert-butyl-hydroxyphenyl)propionatel and 3 parts by weight of the compouna (IE) of example 15 and 100 parts by weight of the polymer; ii) 3 parts by weight of the compound of formula (IE) and 100 parts by weight of the polymer; iii) 1 part by weight of the compound of formula (IE) and 100 parts by weight of the polymer; and iv) 0.49 part by weight of the compound of formula (IE) and 100 parts by weight of an ethylene homopolymer (commercially known as U.S. Industrial Chemicals NA 254). An example of a non-hologenated aliphatic carboxylic anhydride which can be used to prepare a non-flame retardant antioxidant of type (IE) is cyclohexane dicarboxylic anhydride.

Claims: Claims 1. A compound of the formula (I) EMI29.1 where n' is 1, 2, 3 and X is S or S-S where each A is EMI29.2 where Y is H, Cl or Br, and preferably when used as a flame retardant at least one Y is Cl or Br or EMI29.3 where n2 is 0, 1 and n3 is O 1 R', R2 and R3 are H, or straight or branched alkyl of 1 to 8 carbons, or EMI29.4 where Y is the same as defined above. 2. A composition comprising a polymer and the compound of formula I. 3. A compound of claim 1 which is EMI30.1 where X is S or S - S. 4. The compound of claim 3 where X is S. 5. The compound of claim 3 where X is S - S. 6. A compound of claim 1 which is EMI30.2 where X is S or S - S R2 is straight or branched alkyl of 1 to 8 carbons R1 is H or straight or branched alkyl of t to 8 carbon atoms n = 0 or 1 7. The compound of claim 6 which is EMI30.3 8. The compound of claim 6 in which X is S - S. 9. A compound of the formula (I) EMI31.1 where R1 is an alkyl group of one to eight carbon atans, n = 0 or 1, R2 = H or straight or branched alkyl of 1 to 8 carbon atoms, X is S or S - S. 10. The compound of claim 9 in which the compound is of the formula EMI31.2 11. A compound of the formula (I) EMI31.3 where Xis S or S - S and Y is H, Cl or Br. 12. The compound of claim 11 in which X is S and each Y is Br. 13. The compound of claim 11 in which X is S and each Y is Cl. 14. A compound of claim 1 EMI32.1 where X is S or S - S and Y is Cl or Br or H. 15. The compound of claim 14 in which each Y is Cl. 16. The compound of claim 14 in which each Y is Br. The compound of any of claims 3 to 16 in a polymer.

Inventors: HANSEN, RALPH HOLM
Applicants: CANUSA COATING SYSTEMS LIMITED
Application year: 1983
Main classification: C07C149
IPC codes: C07D209, C08K5