Abstract:
A dispersing agent for use in a thermosetting composition, a thermosetting composition containing said dispersing agent, and application thereof to thermosetting composition having no yield point. The dispersing agent acting on mineral fillers and used in filled acrylic or polyester resin-based thermosetting compositions belongs to the family of organophosphates corresponding to the general formula: ##STR1## where: A is a branched or unbranched polyaryl group, 
     x and y are whole numbers between 0 and 100 such that x+y is a whole number greater than 40 but not greater than 100, ##STR2## B and E are independently a branched or unbranched polyaryl group, or an alkyl, aryl, arylalkyl, alkylaryl, alkanoyl, or amine radical, and in B and E, and R 1  and R 2  may be identical or different, x1, y1, x2 and y2 are whole numbers, and the sums x1+y1 and x2+y2 are not greater than 100.

Description:
This is a division of application Ser. No. 07/820,257, filed on Jan. 14, 1992 U.S. Pat. No. 5,412,139. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a new organophosphate dispersing agent and a thermosetting composition, comprising a thermosetting unsaturated polyester resin containing a monomer which may subsequently be copolymerized with the polyester resin, or an alkyd-, acrylic- or phenolic-type molding resin, a pulverulent mineral filler, and a dispersing agent. The dispersing agent makes it possible to obtain highly-filled thermosetting molding compositions having no yield point and low viscosities under very low shear ratios. 
     Discussion of the Background 
     During the fabrication of molded articles from a composition based on thermosetting resins of unsaturated polyester, alkyd, acrylic, or phenolic-type molding resins, in accordance with one of the conventional sheet-molding (sheet molding composition--SMC) and bulk molding (bulk molding composition--BMC) techniques, it becomes increasingly necessary to increase the quantity of mineral filler in order to reduce the cost of the molded articles. It is also necessary to preserve mechanical, thermal, dielectric, and aesthetic properties of the resins, as well as to obtain a viscosity of the mixture which is as low as possible at high and low shear ratios. In fact, the lack of a yield point allows the resin to be easily worked at all stages of the molding operation. In order to add fillers to these resins, the use of conventional organophosphate dispersing agents is well known. 
     Patent Applications JP 61-101527, JP 62-207337, JP 62-235353 disclose the addition of organophosphates to mixtures containing a maximum of 100 parts filler for 100 parts resin. For greater concentrations of mineral filler ranging up to 65%, U.S. Pat. No. 4,183,843 claims the use of polar esters of phosphoric acid. When used in small proportions, these products reduce the viscosity of the mixture of calcium carbonate and/or aluminum hydroxide and/or titanium dioxide and/or silicon dioxide and/or clay with unsaturated polyester-type resins under high shear ratios. However, the viscosity under very low shear ratios remains very great and there exists a yield point which makes the formulations difficult to handle. Furthermore, it has been observed that the viscosity of the thermosetting composition increases in a directly proportional manner to the quantity of these polar phosphated esters used, resulting in a thickening effect. 
     SUMMARY OF THE INVENTION 
     Accordingly, one object of this invention is to provide a thermosetting molding composition having no yield point and low Brookfield viscosities under high shear ratios and containing a dispersing agent and up to 75% by weight of a pulverulent mineral filler. 
     A further object of this invention is to provide a new dispersing agent that can be added to a thermosetting composition filled up to 75% by weight without producing a thickening effect. 
     A further object of this invention is to provide a new dispersing agent that can be added to a highly-filled thermosetting composition without producing a yield point, and without affecting the mechanical, thermal, dielectric, and aesthetic properties of the thermosetting composition. 
     A further object of the invention is to provide a new dispersing agent that can be added to a highly-filled thermosetting composition without producing a yield point and can be used in sheet-molding composition (SMC) and bulk molding composition (BMC) techniques. 
     A further object of the invention is to improve the surface state (Low Profile) of articles fabricated using a thermosetting composition containing the dispersing agent according to the invention. 
     These objects are achieved by preparing a thermosetting composition, comprising: 
     (a) a thermosetting resin, 
     (b) a pulverulent mineral filler in a quantity ranging up to 75% by weight of the total weight of the resin and the filler, 
     (c) an organophosphate dispersing agent, in an amount of 0.3 to 5% by weight of the weight of the filler, having the general formula: ##STR3## where: A is a branched or unbranched polyaryl group, 
     x and y are whole numbers between 0 and 100 such that x+y is a whole number greater than 40 but not greater than 100, ##STR4## x1 and y1 are whole numbers between 0 and 100 such that x1+y1 is a whole number not greater than 100, 
     B is a branched or unbranched polyaryl group, or an alkyl, aryl, arylalkyl, alkylaryl, alkanoyl, or amine radical, ##STR5## x2 and y2 are whole numbers between 0 and 100 such that x2 +y2 is a whole number not greater than 100, 
     E is a branched or unbranched polyaryl group, or an alkyl, aryl, arylalkyl, alkylaryl, alkanoyl, or amine radical, and R 1  and R 2  may be identical or different. 
     These objects are further achieved by using an organophosphate dispersing agent for acting on mineral fillers in thermosetting resins, wherein said agent has the following general formula (I): ##STR6## where: A is a branched or unbranched polyaryl group, 
     x and y are whole numbers between 0 and 100 such that x+y is a whole number greater than 40 but not exceeding 100, ##STR7## x1 and y1 are whole numbers between 0 and 100 such that x1+y1 is a whole number not greater than 100, 
     B is a branched or unbranched polyaryl group, or an alkyl, aryl, arylalkyl, alkylaryl, alkanoyl, or amine radical, ##STR8## x2 and y2 are whole numbers between 0 and 100 such that x2+y2 is a whole number not greater than 100, 
     E is a branched or unbranched polyaryl group, or an alkyl, aryl, arylalkyl, alkylaryl, alkanoyl, or amine radical, and R 1  and R 2  may be identical or different. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
     FIGS. 1-3 show the infrared spectrum of various dispersing agents disclosed herein; and 
     FIGS. 4 and 5 show the curves for the variation of the Brookfield viscosity in mPa.s at 0.5 R/mn and 100 R/mn as a function of the number of moles of alkylene oxide contained in the general formula (I) of the dispersing agent. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The dispersing agent corresponding to general formula (I) preferably contains a branched or unbranched polyaryl group A having molecular weight range between 127 and 2000. B and E, may be branched or unbranched polyaryl groups, or alkyl, aryl, arylalkyl, alkylaryl, alkanoyl, or amine radicals, preferably containing up to 18 carbon atoms. The polyaryl group A may be di(phenyl-1-ethyl) phenols, commonly called distyrylphenols, tri(phenyl-1-ethyl) phenols, commonly called tristyrylphenols, and oligomers of polystyrene or styrene copolymer oligomers with another monomer. B and E may be the same as the above-mentioned radicals A and may be lauryl, stearyl, nonyl-phenol, etc. The sum x+y is preferably 50 to 60. 
     While the prior art discloses polar phosphate ester-type dispersants which are added in quantities of from 0.05% to 1% by weight in relation to the weight of the filler in filled thermosetting composition having a filler content ranging up to 65% of the total weight of the filler and the thermosetting resin, the dispersing agent having the general formula (I) according to the invention is added in a quantity of from 0.3% to 5%, and preferably from 0.5% to 3%, by weight in relation to the weight of the filler. The dispersing agent having the general formula (I) is added while stirring the thermosetting resin just before, just after, or simultaneously with the addition of the pulverulent mineral filler in a quantity ranging up to 75% by weight in relation to the total weight of the resin and of the pulverulent mineral filler. 
     The thermosetting composition according to the invention comprises a thermosetting resin, a quantity of pulverulent mineral fillers ranging up to 75% by weight of the weight of the resin and the filler, the dispersing agent according to the invention, and optionally, other additives. The composition has no yield point, i.e., it has low viscosity under a very low shear ratio, and has a viscosity less than or equal to that of compositions according to prior art under higher shear ratios. 
     The thermosetting filled composition may comprise: 
     (a) a thermosetting resin chosen from among acrylics, phenolic molding compositions, alkyds, unsaturated polyesters produced by the condensation reaction of maleic anhydride, optionally in the presence of phthalic anhydride, and an alkylene glycol or polyalkylene glycol having a low molecular weight, and styrene can be copolymerized with the polyester resins and/or unsaturated polyester resins; 
     (b) a quantity of up to 75% by weight in relation to the total weight of the resin and the pulverulent mineral filler, of a pulverulent mineral filler chosen from among the mineral salts and/or oxides, such as natural or precipitated calcium carbonate, magnesium carbonate, zinc carbonate, dolomite, calcium sulfate, aluminum hydroxide, metallic oxides such as zinc oxide, iron oxides, titanium oxide, wollastonite, and more particularly chosen from among calcium carbonate, aluminum hydroxide, calcium sulfate, and titanium oxide; 
     (c) a quantity of between 0.3% and 5% by weight, and preferably from 0.5% to 3% by weight, of the weight of the filler of the organophosphate dispersing agent having the general formula (I); and 
     (d) optionally, other conventional additives chosen, in particular, from among thermal or photochemical stabilizers, oxidation inhibitors, shrinkage inhibitors, static inhibitors, plasticizers, lubricants, unmolding agents, flame retardants, glass fibers and balls, and mineral thickeners such as magnesium hydroxide. 
     The thermosetting composition containing the dispersing agent according to the invention is characterized by its Brookfield viscosities under high and low shear ratios, measured using an RVT-type Brookfield viscometer at different rotating speeds of the module. The dispersing agent having the general formula (I) is characterized by its acid value, measured using a titrimetric method in accordance with standard NF T30-402 and by its infrared spectrum produced using the IR 398 infrared spectrophotometer equipped with a 3 600 DATA terminal station marketed by the PERKIN ELMER Corporation. 
     Other features of the invention will become apparent in the course of the following description of exemplary embodiments which are given for illustration of the invention and are not intended to be limiting thereof. 
     EXAMPLE 1 
     Preparation of the Thermosetting Composition 
     In a glass crucible of approximately 500 ml equipped with a GRENIER-CHARVET laboratory stirring apparatus, 200 g of an unsaturated polyester resin marketed by WALTER MADER AG under the name CRISTIC 192 LV and having a Brookfield viscosity of 350 mPa.s at 1OR/mn, 20° C. module 3, and 370 mPa.s at 10OR/mn, 20° C. module 3, was added to 2 g of a dispersing agent. The mixture was then homogenized for 30 seconds using the stirring apparatus at a rate of 1,000 R/mn. Next, 200 g of an aluminum hydroxide pulverulent mineral filler, of which 50% of the particles were less than 2.3 μm and all of the particles were less than 50 μm, marketed by the MARTINSWERK company under the name MARTINAL OL 104-C, was added to the mixture of over 10 minutes under agitation while increasing the speed gradually to 2,000 R/mn. 
     Measurement of the Rheology of the Composition 
     The composition was kept at 23° C. for 48 hours. After temperature verification, the same module 6 of the RVT-type Brookfield viscometer was used to measure the Brookfield viscosities of the composition obtained under different shear ratios at a temperature of 23° C. 
     This operating method was carried out for each of the following dispersants: 
     Test 1 
     Dispersant according to prior art marketed by ROHM &amp; HAAS under the name TRITON QS-44, having an acid value of I A  =294 mg/g according to Standard NF T30-402. The infrared spectrum is shown in FIG. 1. 
     Test 2 
     Dispersant according to prior art marketed by PHILIP A. HUNT Company under the name WAYFOS M100, having an acid value of I A  =148 mg/g according to Standard NF T30-402. The infrared spectrum is shown in FIG. 1. 
     Test 3 
     Dispersant according to prior art marketed by the BYK Company under the name BYK W990, having an acid value of I A  =88 mg/g according to Standard NF T30-402. The infrared spectrum is shown in FIG. 1. 
     Test 4 
     Dispersant according to the invention, named product 4, composed of a mixture containing 41% of a phosphoric monoester and 59% of a phosphoric diester having general formula (I) , where: 
     For the monoester: ##STR9## x=48 y=2 R 1  =R 2  =H 
     For the diester: ##STR10## x=48 y=2 ##STR11## x1=48 y1=2 B=A R 2  =H 
     An acid value of I A  =56 mg/g was determined in accordance with Standard NF T30-402. The infrared spectrum is shown in FIG. 2. 
     Test 5 
     Dispersing agent according to the invention, named product 5, composed of a phosphoric monoester having general formula (I), where: ##STR12## x=100 y=0 R 1  =R 2  =H 
     An acid value of I A  =25 mg/g was determined in accordance with Standard NF T30-402. The infrared spectrum is shown in FIG. 2. 
     Table I presents the Brookfield viscosities measured for each of the above-mentioned compositions, all of which have the same base resin (CRISTIC 192 LV), the same MARTINAL OL-104-C content (50% by weight of the total of the resin and the filler), the same dispersant content (1% by weight of the filler), but as the single variable, the chemical formula of the dispersing agent. 
     
                                           TABLE I__________________________________________________________________________           PRIOR ART         INVENTIONTEST   NO.      1     2     3     4     5__________________________________________________________________________Resin  Type     Cristic                 Cristic                       Cristic                             Cristic                                   Cristic           192 LV                 192 LV                       192 LV                             192 LV                                   192 LV__________________________________________________________________________Filler Type     Martinal                 Martinal                       Martinal                             Martinal                                   Martinal           OL 104 C                 OL 104 C                       OL 104 C                             OL 104 C                                   OL 104 C  Quantity in % by           50%   50%   50%   50%   50%  weight of the  filler and resin__________________________________________________________________________Dispersant  Type     Triston                 Wayfos                       BYK   Product                                   Product           QS-44 M100  W990  4     5  Quantity in % by           1%    1%    1%    1%    1%  weight of the  filler__________________________________________________________________________Brookfield  0.5 R/mn 180,000                 182,000                       162,000                             10,000                                   14,000viscosity  1 R/mn   106,000                 110,000                       102,000                             10,000                                   13,000module 6 in  2.5 R/mn 54,800                 56,000                       54,000                             8,800 10,000mPa · s (cP)  5 R/mn   34,000                 34,000                       34,000                             7,200 8,200  10 R/mn  21,600                 21,600                       21,800                             6,200 7,500  20 R/mn  14,200                 14,200                       14,500                             5,250 6,650  50 R/mn  8,540 8,400 8,800 4,300 5,940  100 R/mn 6,700 5,900 6,400 3,900 5,550__________________________________________________________________________ 
    
     Table I shows that the thermosetting compositions containing the dispersing agent according to the invention have low Brookfield viscosities under low shear ratios (0.5 R/mn to 20 R/mn) and high shear ratios (beginning at 50 R/mn) and have no yield point. The compositions obtained using prior art dispersing agents possess a yield point. Moreover, the compositions containing the dispersing agent according to the invention possess Brookfield viscosities that are lower than those obtained using a prior art dispersing agent at all tested shear ratios. 
     EXAMPLE 2 
     Under the same conditions as in Example 1, 400 g of natural calcium carbonate, having particle sizes smaller than 50 μm, 50% of which are smaller than 3.2 μm, and marketed by OMYA, S.A. under the name MILLICARB were added to a mixture of 200 g of an unsaturated polyester resin marketed by WALTER MADER AG under the name CRISTIC 192 LV and 2 g of dispersing agent. 
     Using the same operating procedure as in Example 1, the Brookfield viscosities of the thermosetting compositions containing the following dispersing agents were measured: 
     Test 6 
     Dispersant according to prior art marketed by PHILIP A. HUNT under the name WAYFOS M100, previously used in Test 2. 
     Test 7 
     Dispersant according to the invention, called product 4, previously used in test 4. 
     Test 8 
     Disperant according to the invention, called product 8, composed of a phosphoric monoester corresponding to general formula (I), where: ##STR13## x=60 y=0 R 1  =R 2  =H 
     An acid value of I A  - 39 mg/g was determined in accordance with Standard NF T30-402. The infrared spectrum is shown in FIG. 2. 
     Test 9 
     &#34;Invention limit&#34; dispersant, called product 9, composed of a phosphoric monoester corresponding to general formula (I), where: ##STR14## x=40 y=0 R 1  =R 2  =H 
     An acid value of I A  =55 mg/g was determined in accordance with Standard NF T30-402. The infrared spectrum is shown in FIG. 3. 
     Test 10 
     Dispersant according to prior art, called product 10, corresponding to the general formula: 
     
         (CH.sub.3 --(CH.sub.2).sub.8).sub.2 --C.sub.6 H.sub.3 --(O--CH.sub.2 --CH.sub.2).sub.50 --OPO.sub.3 H.sub.2 
    
     having no polyaryl A radical and having an acid value of I A  =55 mg/g. The infrared spectrum is shown in FIG. 1. 
     Table II presents the Brookfield viscosities for each of the above-mentioned composition, all of which have the same base resin (CRISTIC 192 LV), the same MILLICARB content (66% by weight of the total weight of the resin and filler, the same dispersant content (0.5% by weight of the filler), but as the single variable, the chemical formula of the dispersing agent. 
     
                                           TABLE II__________________________________________________________________________                               INVENTION                                       PRIOR           PRIOR ART                  INVENTION    LIMIT   ART__________________________________________________________________________TEST   NO.      6      7       8    9       10__________________________________________________________________________Resin  Type     Cristic                  Cristic Cristic                               Cristic Cristic           192 LV 192 LV  192 LV                               192 LV  192 LV__________________________________________________________________________Filler Type     Millicarb                  Millicarb                          Millicarb                               Millicarb                                       Millicarb  Quantity in % by           66%    66%     66%  66%     66%  weight of the  filler and resin__________________________________________________________________________Dispersant  Type     Wayfos Product Product                               Product Product           M100   4       8    9       10  Quantity in % by           0.5%   0.5%    0.5% 0.5%    0.5%  weight of the  filler__________________________________________________________________________Brookfield  0.5 R/mn 88,000 4,000   4,000                               3,600   4,000viscosity  1 R/mn   55,000 4,000   4,000                               3,600   4,000module 6 in  2.5 R/mn 31,200 4,480   4,400                               4,080   4,480mPa · s (cP)  5 R/mn   22,000 4,800   4,700                               4,560   4,960  10 R/mn  16,700 5,240   5,100                               5,4440  5,920  20 R/mn  13,750 6,220   6,100                               7,250   7,800  50 R/mn  12,100 8,670   8,600                               11,300  11,720  100 R/mn 11,300 10,600  10,600                               14,500  15,320__________________________________________________________________________ 
    
     Table II shows that the thermosetting compositions obtained using the dispersing agent according to the invention (Tests 7 and 8) are the only ones which lack a yield point and have minimal viscosities for all tested shear ratios. Although Tests 9 and 10 have no yield point, they have increased viscosities at higher shear ratios. The composition containing the dispersing agent according to the prior art (Test 6) has high viscosities for low shear ratios. 
     Tests 7, 8, 9, and 10 are different based upon the dispersant used. In Tests 7 and 8, the dispersant contains a polyaryl radical and 50 or 60 units of alkylene oxide. In Test 9, the dispersant contains a polyaryl radical but only has 40 units of ethylene oxide. Similarly, the difference among the dispersants used in Tests 7 and 10 arise from the radical, which is not polyaryl in Test 10, while the number of alkylene oxide groups is identical. 
     Thus, the dispersants used must have more than 40 units of alkylene polyoxide groups and a polyaryl radical in order to obtain a thermosetting composition without a yield point and with minimal Brookfield viscosities at high shear ratios. 
     EXAMPLE 3 
     Thermosetting compositions are prepared under the same conditions and having the same quantities as the compositions in Example 1 except that the dispersants are as follows: 
     Test 11 
     Dispersant according to the prior art, marketed by the PHILIP A. HUNT Company under the name WAYFOS M100, previously used in Test 2. 
     Test 12 
     Dispersant according to the invention, named product 4, previously used in Tests 4 and 7. 
     Test 13 
     Dispersant according to the invention, named product 8, previously used in Test 8. 
     Test 14 
     Dispersant according to the invention, named product 5, previously used in Test 5. 
     Test 15: 
     &#34;Invention limit&#34; dispersant, named product 15, composed of a mixture or phosphoric mono- and diester corresponding to general formula (I), where: 
     For the monoester: ##STR15## x=16 y=0 R 1  =R 2  =H 
     For the diester: ##STR16## x=16 y=0 ##STR17## x1=16 y1=0 B=A R 2  =H 
     An acid value of I A  =60 mg/g was determined in accordance with Standard NF T30-402. The infrared spectrum is shown in FIG. 3. 
     Test 16 
     &#34;Invention limit&#34; dispersant, called product 9, previously used in Test 9. 
     Using the same operating procedures used in Example 1, the viscosities of the thermosetting compositions were measured and are presented in Table III. 
     
                                           TABLE III__________________________________________________________________________                                     INVENTION          PRIOR ART    INVENTION     LIMIT__________________________________________________________________________TEST  NO.      11     12    13      14    15      16__________________________________________________________________________Resin Type     Cristic                 Cristic                       Cristic Cristic                                     Cristic Cristic          192 LV 192 LV                       192 LV  192 LV                                     192 LV  192 LV__________________________________________________________________________Filler Type     Martinal                 Martinal                       Martinal                               Martinal                                     Martinal                                             Martinal          OL 104 C                 OL 104 C                       OL 104 C                               OL 104 C                                     OL 104 C                                             OL 104 C Quantity in %          50%    50%   50%     50%   50%     50% by weight of the filler and resin__________________________________________________________________________Disper- Type     Wayfos Product                       Product Product                                     Product Productsant           M100   4     8       5     15      9 Quantity in %          1%     1%    1%      1%    1%      1% by weight of the filler__________________________________________________________________________Brookfield 0.5 R/mn 182,000                 10,000                       4,000*  14,000                                     20,000  10,000viscosity 1 R/mn   110,000                 10,000                       4,000*  13,000                                     20,000  10,000module 6 2.5 R/mn 56,000 8,800 4,000*  10,000                                     20,000  10,000in    5 R/mn   34,000 7,200 4,250*  8,200 15,000  8,400mPa · s 10 R/mn  21,600 6,200 4,000*  7,500 12,500  7,200(cP)  20 R/mn  14,200 5,250 3,860*  6,650 11,000  6,500 50 R/mn  8,400  4,300 3,640*  5,940 11,000  6,300 100 R/mn 5,900  3,900 3,540*  5,550 9,700   5,900__________________________________________________________________________ *Indicates that the viscosity was measured using module 5, since viscosit was too low to use module 6? 
    
     Based on the results in Table III, curves 1 and 2 (illustrated in FIGS. 4 and 5, respectively) were plotted. Curve 1 (FIG. 4) shows the variation of the Brookfield viscosity in mPa.s at 0.5 R/mn as a function of the number of moles of alkylene oxide contained in the general formula (I) of the dispersant. Curve 2 (FIG. 5) shows the variation of the Brookfield viscosity in mPa.s at 100 R/mn as a function of the number of moles of alkylene oxide contained in the general formula (I) of the dispersant. These lines confirm the observation that, when there are more than 40 alkylene oxide groups in the dispersant used, the Brookfield viscosity of the thermosetting composition is very low for low shear ratios and minimal for higher shear ratios, and that the preferred range of the number of alkylene oxide groups contained in the dispersing agent having the general formula (I) is between 50 and 60 groups. 
     EXAMPLE 4 
     Under the conditions of Example 1, the proportion of filler added to the mixture composed of resin and dispersant was increased while the proportion of dispersant in relation to the filler was maintained as a constant. 
     Tests 17 to 22 were prepared using 200 g of unsaturated polyester resin marketed by WALTER MADER AG under the name CRISTIC 192 LV as follows: 
     Test 17 
     400 g of calcium carbonate having an average granulometry of 3.2 μm, marketed by OMYA S.A. under the name MILLICARB, and 4 g of the dispersant marketed by the PHILIP A. HUNT Company under the name WAYFOS M100. 
     Test 18 
     500 g of the calcium carbonate used in Test 17, and 5 g of the dispersant used in Test 17. 
     Test 19 
     600 g of the calcium carbonate used in Test 17, and 6 g of the dispersant used in Test 17. 
     Test 20 
     400 g of the calcium carbonate used in Test 17, and 4 g of the dispersant according to the invention, termed product 8, previously used in Test 8. 
     Test 21 
     500 g of the calcium carbonate used in Test 17, and 5 g of the dispersant, product 8. 
     Test 22 
     600 g of the calcium carbonate used in Test 17, and 6 g of the dispersant, product 8. 
     Under the operating conditions used in Example 1, the Brookfield viscosities of the thermosetting compositions were measured using modules 6 and 7. The results are presented in Table IV. 
     
                                           TABLE IV__________________________________________________________________________                PRIOR ART           INVENTION__________________________________________________________________________TEST  NO.      17    18     19     20    21      22__________________________________________________________________________Resin Type     Cristic                Cristic                       Cristic                              Cristic                                    Cristic Cristic          192 LV                192 LV 192 LV 192 LV                                    192 LV  192 LV__________________________________________________________________________Filler Type     Millicarb                Millicarb                       Millicarb                              Millicarb                                    Millicarb                                            Millicarb Quantity in %          66.6% 71.4%  75.0%  66.6% 71.4%   75.0% by weight of the filler and resin__________________________________________________________________________Disper- Type     Wayfos                Wayfos Wayfos Product                                    Product Productsant           M100  M100   M100   8     8       8 Quantity in %          1%    1%     1%     1%    1%      1% by weight of the filler__________________________________________________________________________Brookfield 0.5 R/mn 200,000                512,000                       1,176,000                              4,000*                                    10,000* 40,000viscosity 1 R/mn   124,000                296,000                       704,000                              5,000*                                    10,000* 40,000module 7 2.5 R/mn 64,000                153,000                       392,000                              5,600*                                    11,200* 41,600in    5 R/mn   41,600                101,600                       273,600                              6,000*                                    12,000* 44,000mPa · s 10 R/mn  28,400                70,400 204,000                              6,300*                                    13,000* 53,200(cP)  20 R/mn  21,000                52,000 167,600                              6,800*                                    15,300* 78,400 50 R/mn  15,520                38,000 Measurement                              8,600*                                    23,840  Measurement                       impossible           impossible,                       material             material                       unsuitable           unsuitable 100 R/mn 13,240                32,000 idem   11,280                                    32,000  idem__________________________________________________________________________ *Indicates that the viscosity was measured using module 6, since viscosit was too low to be measured using module 7 
    
     Table IV shows that the thermosetting composition according to the invention preserves the absence of a yield point despite the increase in filler content. 
     EXAMPLE 5 
     Under the conditions of Example 1, thermosetting compositions were prepared using increasing quantities of the dispersing agent. For 200 g of unsaturated polyester resin marketed by WALTER MADER AG under the name CRISTIC 192LV, and for 400 g of natural calcium carbonate marketed by OMYA, S.A. under the name MILLICARB, 2 g of dispersant were used for Tests 23 and 24, 4 g for Tests 25 and 26, 8 g for Tests 27 and 28, and 20 g for Tests 29 and 30. 
     Under the operating conditions of Example 1, modules 5, 6, or 7 were used to measure the Brookfield viscosities of the thermosetting compositions thus obtained. Table V, below, shows that the addition of increasing quantities of dispersing agent according to the invention, added in a proportion ranging up to 5% by weight, and preferably 3% by weight, of the filler, allows a lowering of the Brookfield viscosity of the thermosetting composition, while the dispersants according to prior art produce a thickening effect under a low shear ratio (up to 20 R/mn). 
     This capacity to lower the Brookfield viscosity-makes it possible to chose the desired viscosity for the composition by adjusting the quantity of dispersant to be added. 
     
                                           TABLE V__________________________________________________________________________TEST  NO.   23   24   25   26   27   28   29   30__________________________________________________________________________Resin Type  Cristic            Cristic                 Cristic                      Cristic                           Cristic                                Cristic                                     Cristic                                          Cristic       192 LV            192 LV                 192 LV                      192 LV                           192 LV                                192 LV                                     192 LV                                          192 LV__________________________________________________________________________Filler Type  Millicarb            Millicarb                 Millicarb                      Millicarb                           Millicarb                                Millicarb                                     Millicarb                                          Millicarb Quantity       66%  66%  66%  66%  66%  66%  66%  66% in % by weight filler + resin__________________________________________________________________________Disper- Type  Wayfos            Product                 Wayfos                      Product                           Wayfos                                Product                                     Wayfos                                          Productsant        M100 8    M100 8    M100 8    M100 8 Quantity       0.5% 0.5% 1%   1%   2%   2%   5%   5% in % by weight filler__________________________________________________________________________Brookfield 0.5 R/mn       120,000            5,600*                 218,000                      5,600*                           314,000                                5,600*                                     524,000                                          8,000*viscosity 1 R/mn       72,000            6,000*                 130,000                      6,400*                           178,000                                5,600*                                     294,000                                          8,000*module 6 2.5 R/mn       40,400            6,400*                 69,600                      6,400*                           90,000                                5,800*                                     144,000                                          8,500*in    5 R/mn       27,600            7,000*                 46,400                      7,000*                           56,200                                6,000*                                     86,800                                          8,600*mPa · s 10 R/mn       23,500            8,200*                 32,600                      7,640*                           37,400                                6,100*                                     58,400                                          8,600*(cP)  20 R/mn       18,700            10,600*                 24,800                      8,500*                           26,500                                6,400*                                     54,600**                                          9,500 50 R/mn       17,500**            14,600**                 21,200**                      12,100**                           20,200**                                7,100*                                     32,800**                                          9,700 100 R/mn       16,800**            16,800**                 17,600**                      13,200**                           15,800**                                8,200                                     24,000**                                          10,600**__________________________________________________________________________ *Indicates that the measurements were made using module 5, since viscosities were too low for module 6 **Indicates that the measurements were made using module 7, since viscosities were too high for module 6 
    
     EXAMPLE 6 
     Under the conditions of Example 1, thermosetting compositions were prepared using several types of resins. Tests 31 to 33 were conducted using 200 g of acrylic resin, marketed by the I.C.I. company under the name MODAR 826 HT and having a Brookfield viscosity of 220 mPa.s at 10 R/mn (module 4) and of 250 mPa.s at 100 R/mn (module 4) at ambient temperature; 400 g of natural calcium carbonate marketed by OMYA, S.A. under the name of MILLICARB; and 4 g of dispersant. Tests 34 to 36 were conducted with 200 g of an unsaturated polyester resin having a higher molecular weight and a Brookfield viscosity of 2,880 mPa.s at 10 R/mn (module 5) and 2,940 mPa.s at 100 R/mn (module 5) at ambient temperature; 300 g of the same calcium carbonate as previously used; and 4 g of dispersant. Tests 37 and 38 were performed using 200 g of an unsaturated polyester resin distributed by the STRAND GLASS Company under the name CRISTIC 191 LV, whose Brookfield viscosity is 700 mPa.s at 10 R/mn (module 3) and 250 mPa.s at 100 R/mn, (module 3) at ambient temperature; 400 g of the same calcium carbonate as previously used; and 8 g of dispersant. 
     Once these thermosetting compositions were prepared, the same operating procedure as in Example 1 was implemented in order to measure their Brookfield viscosities, which appear in Table VI, below. 
     
                                           TABLE VI__________________________________________________________________________TEST  NO.   31   32   33   34   35   36   37   38__________________________________________________________________________Resin Type  Modar            Modar                 Modar                      Polyester                           Polyester                                Polyester                                     Cristic                                          Cristic       826 HT            826 HT                 826 HT                      high mol.                           high mol.                                high mol.                                     191 LV                                          191 LV                      weight                           weight                                weight__________________________________________________________________________Filler Type  Millicarb            Millicarb                 Millicarb                      Millicarb                           Millicarb                                Millicarb                                     Millicarb                                          Millicarb Quantity       66%  66%  66%  60   60   60   66%  66% in % by weight filler + resin__________________________________________________________________________Disper- Type  Wayfos            Product                 Product                      Wayfos                           Triton                                Product                                     Wayfos                                          Productsant        M100 4    8    M100 QS44 8    M100 8 Quantity       1%   1%   1%   1.3% 1.3% 1.3% 2%   2% in % by weight filler__________________________________________________________________________Brookfield 0.5 R/mn       110,000            10,000                 20,000                      432,000*                           424,000*                                32,000*                                     400,000*                                          10,000viscosity 1 R/mn       65,000            8,000                 16,000                      260,000*                           260,000*                                32,000*                                     228,000*                                          13,000module 6 2.5 R/mn       34,000            6,000                 10,800                      144,000*                           134,400*                                32,000*                                     122,000*                                          13,200in    5 R/mn       22,000            5,400                 8,800                      96,000*                           92,000*                                28,800*                                     81,600*                                          13,600mPa · s 10 R/mn       14,800            4,900                 7,500                      68,000*                           66,400*                                28,800*                                     56,800*                                          14,200(cP)  20 R/mn       10,500            4,550                 6,550                      51,000*                           52,000*                                29,200*                                     41,400*                                          15,400 50 R/mn       7,320            4,280                 6,000                      36,560*                           40,960*                                30,240*                                     30,100*                                          18,500 100 R/mn       6,020            4,250                 5,870                      30,000*                           34,220*                                30,000*                                     25,100*                                          23,600*__________________________________________________________________________ *Indicates that the measurements were made using module 7 since viscosities were too high for module 6 
    
     Table VI shows that the dispersants according to the invention are effective for various types of resins. 
     EXAMPLE 7 
     Under the operating conditions of Example 1, thermosetting compositions were fabricated using two types of fillers. Test 39 was conducted using 300 g of an unsaturated polyester resin marketed by WALTER MADERAG under the name CRISTIC 192 LV; 300 g of titanium dioxide marketed by the THANN &amp; MULHOUSE Company under the name AT1; and 3 g of dispersing agent according to the invention, called product 8. Test 40 was conducted using the same quantities and types of resin and filler as in Test 39, but without the dispersing agent. Test 41 was conducted using 300 g of the same unsaturated polyester resin used in Tests 39 and 40; 400 g of hydrous calcium sulfate having an average granulometry of approximately 15 micrometers; and 2 g of the dispersing agent according to the invention used in Test 39, named product 8. Test 42 was conducted using the types and amounts of resin and filler used in test 41, but without the dispersing agent. 
     Once these thermosetting compositions were prepared, the operating procedure used in Example 1 was used to measure their Brookfield viscosities, which are provided in Table VII, below. 
     
                                           TABLE VII__________________________________________________________________________TEST  NO.     39    40   41   42__________________________________________________________________________Resin Type    Cristic               Cristic                    Cristic                         Cristic         192 LV               192 LV                    192 LV                         192 LV__________________________________________________________________________Filler Type    TiO.sub.2               TiO.sub.2                    Calcium                         Calcium         ATT   ATT  sulfate                         sulfate Quantity in %         50%   50%  66%  66% by weight of resin + filler__________________________________________________________________________Disper- Type    Product    Productsant          8          8 Quantity in %         1%    0%   0.5% 0% by weight of filler__________________________________________________________________________Brookfield 0.5 R/mn         10,000               32,000                    30,000                         200,000viscosity 1 R/mn  8,000 25,000                    40,000                         130,000module 6 2.5 R/mn         6,800 22,800                    53,000                         90,000in    5 R/mn  6,000 20,800                    57,000                         74,000mPa · s 10 R/mn 5,200 18,700                    54,600                         64,000(cP)  20 R/mn 4,750 16,800                    46,600                         52,000* 50 R/mn 4,200 13,200                    40,400                         52,000* 100 R/mn         3,900 9,800*                    29,200                         Measurement                         impossible,                         material                         unsuitable__________________________________________________________________________ *Indicates that measurements were made using module 7, since viscosities were too high for module 6 
    
     Table VII shows that the dispersing agent according to the invention is also effective for pulverulent mineral fillers other than calcium carbonate and aluminum hydroxide, such as titanium oxide and calcium sulfate. 
     Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.