JPS6216222B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermosetting unsaturated polyester resin composition having excellent impact resistance, surface properties, and rigidity, and a method for producing the same. Typically, unsaturated polyester resins include unsaturated polyester, vinyl monomer, curing agent, glass fiber,
It is obtained by curing a composition consisting of a filler and the like. In this case, low shrinkage agents such as methacrylic polymers are used for applications where surface properties are important, and thickeners such as magnesium oxide are used for applications that require intermediate products such as bulk or sheet molding compounds (BMC or SMC). It is further blended. Generally, unsaturated polyester resins are used in a wide range of fields as thermosetting resins with excellent rigidity, heat resistance, and electrical properties. In recent years, as the movement to reduce the weight of automobiles has become more active, attempts have been made to use unsaturated polyester resins for automobile exterior panel parts and structural parts. In these applications, easily moldable
It is usually used in the form of BMC and SMC, but there is a tendency for impact resistance and surface performance to be more important than ever, especially for their cured products, and improving them has become an important issue. . Many attempts have been made to improve the impact resistance or surface properties of unsaturated polyester resins, and a typical example is the addition of diene rubber. For example, JP-A-48-34289, JP-A-Sho.
No. 49-30480 discloses a method of adding a styrene-butadiene block copolymer. However, in these methods, layer separation occurs between the rubber and the unsaturated polyester during the compounding or molding stage, resulting in a cured product with poor impact resistance and surface properties. Also, JP-A-49-
No. 18167 describes a method for obtaining a highly flexible unsaturated polyester elastomer composition by using a styrene-butadiene-block copolymer or its carboxylated product in combination with a plasticizer. This method is not preferred because a cured product with hardness or rigidity cannot be obtained. Furthermore, JP-A-52-148588, JP-A-54-130653
No. 1 proposes a method of adding a styrene-butadiene block copolymer containing a terminal carboxyl group or a salt thereof. However, even with this method, the problem of layer separation between rubber and unsaturated polyester cannot be essentially solved, and impact resistance and surface properties have not been successfully improved. Another problem with using the styrene-butadiene block copolymer as an additive is that it is difficult to dissolve it in the vinyl monomer. Generally, block copolymers are used after being dissolved in vinyl monomer, but in this case, the viscosity of the solution becomes too high, which not only makes dissolution work extremely difficult, but also requires the amount of rubber added to be limited. I am in an emergency situation. The purpose of the present invention is to improve the unsaturated polyester resin containing the above-mentioned styrene-butadiene block copolymer as an additive, and to produce a thermosetting unsaturated polyester resin with excellent impact resistance, surface properties, and rigidity, as well as solubility and An object of the present invention is to provide a method for producing a thermosetting unsaturated polyester resin composition having excellent molding workability. That is, the present invention provides (a) an unsaturated polyester, (b) a modified block copolymer in which a dicarboxylic acid group or its derivative group is bonded to a branched block copolymer consisting of a vinyl aromatic compound and a conjugated diene compound (c) Vinyl monomer A composition comprising the above (a) to (c), a curing agent and other additives as necessary,
The modified block copolymer of component (b) contains 0.05 to 5% by weight of unreacted unsaturated dicarboxylic acid or its derivative.
This is a thermosetting unsaturated polyester resin composition characterized by containing: Further, the present invention provides a first mixture containing (a) an unsaturated polyester and (c) a vinyl monomer, and (b) a branched block copolymer consisting of a vinyl aromatic compound and a conjugated diene compound having dicarboxylic acid groups and / or a modified block copolymer having a derivative group thereof bound thereto, and (c) a second mixture containing a vinyl monomer, and at that time, either or both of the first mixture and the second mixture contains a curing agent. A thermosetting method characterized in that the modified block copolymer of component (b) contains 0.05 to 5% by weight of unreacted unsaturated dicarboxylic acid or its derivatives, in a method of mixing other additives as necessary. This is a method for producing a polyester resin composition. In a preferred embodiment of the present invention, in addition to the curing agent, the composition contains fillers, fiber reinforcing agents,
At least one selected from thickeners and low shrinkage agents
A further preferred embodiment is the inclusion of seeds, in particular fillers and fiber reinforcing agents, or additionally thickeners and/or low-shrinkage agents. The modified block copolymer of the present invention has extremely good affinity with fillers such as calcium carbonate or glass fibers, and layer separation from unsaturated polyesters occurs significantly in the presence of these fillers or glass fibers. I'm getting tired. The modified block copolymer of the present invention has a branched polymer structure and is characterized by low viscosity when dissolved in vinyl monomer and easy solubility. The composition using the modified block copolymer of the present invention is partially or entirely ionically crosslinked by a thickener such as magnesium oxide, and therefore has a characteristic that the thickening effect thereof is remarkable. There is. This feature indicates that the composition of the present invention is suitable for applications such as BMC and SMC. The composition of the present invention is characterized by its excellent compression and injection molding properties. In particular, it has advantages such as excellent filling properties into a mold during injection molding and less mold deposits. In summary, the composition of the present invention is excellent in terms of uniformity, molding workability, thickening properties, etc., and the cured composition thereof is excellent in terms of impact resistance, rigidity, surface properties, quality stability, etc. be able to. In addition, the manufacturing method of the present invention has excellent features in terms of melting work, molding work, etc. The present invention will be explained in detail below. The unsaturated polyester, which is component (a) of the composition of the present invention, contains a dibasic acid at least partially containing an unsaturated dicarboxylic acid or anhydride thereof, or a mixture thereof, and a dihydric alcohol or a mixture thereof. This was obtained by adapting. In this case, it is also possible to add various amounts of saturated dicarboxylic acids or their anhydrides in order to modify the polyester. Preferred unsaturated dicarboxylic acids or anhydrides are maleic acid and fumaric acid or anhydrides thereof. Other examples of such acids or anhydrides include itaconic acid, citraconic acid,
Chloromaleic acid, mesaconic acid, glutaconic acid or anhydrides thereof. Preferred saturated dicarboxylic acids or anhydrides thereof include phthalic acid, succinic acid, adipic acid, azelaic acid, isophthalic acid,
selected from chlorendic acid, tetrafluorophthalic acid or anhydrides thereof. Typical dihydric alcohols used here include various linear glycols such as ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, 1,3-butanediol, neopentyl glycol, and 1,4-cyclohexanediol. There are methanol and mixtures of such glycols and cyclohexanedimethanol with hydroxylated alkyl ethers of bisphenol A. The modified block copolymer which is the component (b) of the composition of the present invention is a branched block copolymer consisting of a vinyl aromatic compound and a conjugated diene compound as a base, and a dicarboxylic acid group and/or a derivative group thereof. It is a combination of contained molecular units, specifically a graft of unsaturated dicarboxylic acid and/or its derivatives. A branched block copolymer (hereinafter simply referred to as "branched block copolymer") comprising the vinyl aromatic compound and a conjugated diene compound as a base.
contains one or more, preferably two or more, polymer blocks mainly composed of a vinyl aromatic compound, and one or more polymer blocks mainly composed of a conjugated diene compound. In this branched block copolymer, the weight ratio of the vinyl aromatic compound to the conjugated diene compound is generally 5/95 to 95/5,
Preferably 10/90 to 85/15, more preferably
The composition ranges from 20/80 to 60/40. The microstructure of the conjugated diene compound units of the branched block copolymer has a 1,2-vinyl content of 70% or less, preferably 40% or less. In the branched block copolymer, the weight ratio of the polymer block mainly composed of a vinyl aromatic compound to the polymer block mainly composed of a conjugated diene compound is 5/95 to 95/5, preferably 10/90. ~
It's in the 90/10 range. The polymer block of the branched block copolymer mainly consisting of a vinyl aromatic compound is the hard segment of the branched block copolymer, and the weight ratio of the vinyl aromatic compound to the conjugated diene compound in this block is 60/ 40-100/0, preferably
Composition range from 80/20 to 100/0, more preferably
100/0, and the distribution of the minor component of the conjugated diene compound in this block can be random, tapered (increasing or decreasing monomer component along the molecular chain), partially block-like, or any combination thereof. It may be. When there are two or more polymer blocks mainly composed of vinyl aromatic compounds, each block may have the same structure or different structures. On the other hand, a polymer block mainly composed of a conjugated diene compound is a soft segment in a block copolymer, and in this block, the weight ratio of the vinyl aromatic compound and the conjugated diene compound is 0/100 to 40/
60, preferably in the composition range from 0/100 to 30/70, and the distribution of the minor vinyl aromatic compound in this block is random, tapered,
It may be partially block-shaped or a combination thereof. Further, when two or more polymer blocks mainly composed of a conjugated diene compound are contained, each block may have the same structure or different structures. As the vinyl aromatic compound constituting the branched block copolymer, one or more types are selected from styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, etc.
Styrene is particularly preferred. On the other hand, examples of conjugated diene compounds include butadiene, isoprene, 1,3-
One or more types are selected from pentadiene, etc., and among them, butadiene or a combination of conjugated diene compounds mainly composed of butadiene is preferred,
Particularly preferred is butadiene. In the block copolymer, the number average molecular weight of each polymer block is 1000 to 300000, preferably 3000.
~200,000, more preferably 5,000~100,000, and the number average molecular weight of the whole branched block copolymer is 5,000~1,000,000, preferably 10,000~
The molecular weight distribution (ratio of weight average molecular weight to number average molecular weight) is 1.01 to 10, preferably 1.01 to 5. Furthermore, the molecular structure of the branched block copolymer may be any branched structure, but is preferably selected from one or more types having a radial or general formula represented by the following formula. (S-B)- _o X, (B-S)- _o X, (S-B-S)-
_o
X, (B-S-B) - _o , n represents an integer of 3 or more. ] The most preferable branched structure is one in which n is 3 in the above formula.
or 4, that is, 3-branched or 4-branched radial. Further, the above-mentioned branched block copolymer may be slightly modified with an organic compound or an inorganic compound as long as its properties are not lost. The various polymer structure conditions for the branched block copolymer described above are preferable conditions for maintaining the properties of the thermosetting unsaturated polyester resin composition of the present invention and its cured composition. The branched block copolymer used in the present invention is usually prepared by polymerizing a vinyl aromatic compound and a conjugated diene compound in an inert hydrocarbon solvent such as benzene, hexane, or cyclohexane using an organolithium compound such as butyllithium as a polymerization catalyst. Obtained by anionic polymerization. A preferred embodiment is a method in which the block copolymer having a lithium active end obtained by the above method is bonded with a trifunctional or more functional coupling agent such as silicon tetrachloride, tin tetrachloride, carbon tetrachloride, etc. The above-mentioned branched block copolymer is not limited to one kind, but it is also possible to combine two or more kinds of block copolymers having different polymer structures, such as styrene content, molecular weight, number of blocks, etc. Next, the unsaturated dicarboxylic acid or its derivative grafted onto the block copolymer will be further explained. These unsaturated dicarboxylic acids or derivatives thereof are added to the conjugated diene portion of the branched block copolymer at the position of its active unsaturated bond.
These are branched block copolymer polymer 1
more than 1 per molecule, preferably more than 1
A number of up to 200, more preferably between 2 and 20, must be added. If the amount added is other than this, the properties of the resin composition of the present invention or its cured resin composition will be lost. The above limitations are particularly important in maintaining the thickening properties and uniformity of the resin composition. The bonding amount of the dicarboxylic acid groups or its derivative groups in the modified block copolymer can be determined by measuring the dicarboxylic acid groups or its derivative groups in the modified block copolymer obtained by the method described below using an infrared spectrophotometer, titration, etc. It can be easily measured by the following method. Examples of the unsaturated dicarboxylic acids or derivatives thereof include maleic acid, fumaric acid, chloromaleic acid, itaconic acid, cis-4-cyclohexene-
1,2-dicarboxylic acid, endo-cis-bicyclo[2,2,1]-5-heptene-2,3-dicarboxylic acid, acid anhydrides of these dicarboxylic acids,
There are esters, amides, imides, etc. Inside,
Maleic acid, fumaric acid, maleic anhydride, especially maleic anhydride are preferred. The modified block copolymer of the present invention can be obtained by grafting an unsaturated dicarboxylic acid or a derivative thereof to the block copolymer in a molten state or a solution state, with or without the use of a radical initiator. can get. The method for producing these modified block copolymers is not particularly limited in the present invention, but the modified block copolymers obtained may contain undesirable parts such as gels, or their fluidity may be reduced, resulting in poor processability. It is not preferable to use a production method that results in a poor reaction quality, and it is preferable, for example, to carry out the graft reaction under melt-mixing conditions such as an extruder that substantially does not generate radicals. At this time, unreacted unsaturated dicarboxylic acids or derivatives thereof generally remain in the modified block copolymer, but in the present invention, it is necessary to leave a specific amount of this unreacted material as is. . In the most preferred embodiment, these unreacted substances are reduced to 0.05
It is to be left in the modified block copolymer at a proportion of ~5% by weight, preferably 0.1~2% by weight. The remaining unreacted substances have an advantageous effect in improving the workability of dissolving the modified block copolymer in the vinyl monomer. The vinyl monomer, component (c) of the composition of the present invention, acts as a crosslinking component. Examples of vinyl monomers include β-alkyl substituted derivatives of various acrylic acids in which the alkyl group contains 1 to 8 carbons, such as ethyl acrylic acid, propyl acrylic acid, butyl acrylic acid, amyl acrylic acid, hexyl acrylic acid. acids, heptyl acrylic acid, octyl acrylic acid, phenyl acrylic acid, phenyl acrylic acid, vinyl acrylic acid, etc., as well as acrylate monomers such as methyl acrylate, methyl methacrylate, ethyl acrylate, butyl methacrylate, butyl acrylate, acrylamide, methacrylic anhydride, alkylaminoacrylate , dialkylamino acrylate, etc. Other diallyl phthalates may also be used. Also styrene monomer and its various substituted derivatives, such as styrene, α-methylstyrene, aminostyrene, methylethylaminostyrene, methoxystyrene, chlorostyrene, dichlorostyrene, dimethylstyrene, trimethylstyrene, tert-butylstyrene, sodium styrene sulfonate. , p-benzystyrene or p-phenoxystyrene and similar aryl-substituted styrenes. Further useful vinyl monomers include carboxylic esters or anhydrides such as maleic anhydride and fumaric, crotonic, itaconic and their anhydrides, maleimide,
Fumarates such as diethyl- and dioctyl fumarate, dialkyl phthalates, diallyl cyanurates and conjugated dienes such as 1,3-butadiene, isoprene, piperylene, methylpentadiene and chloroprene and 2-methoxybutadiene and 1-cyanobutadiene. Monomers containing methoxy, ethoxy and cyano derivatives of conjugated dienes. Acrylonitrile and its derivatives, such as methacrylonitrile, are also suitable. Vinyl monomers of the present invention include various vinyl monomers and vinylidene monomers, such as vinyl acetate, vinyl acetylene, vinyl chloride, vinylene carbonate, vinyl-2-chloroethyl ether, vinylidene chloride, C ₈ -C ₁₈ alkyl vinyl ethers. , vinyl esters of _C8 to _C18 fatty acids,
2-vinylfuran, vinylphenol, vinyltoluene, vinylphenyldisiloxane, 2-vinylpyridine, 4-vinylpyridine, vinylpyrrole, vinylpyrrolidone, vinylsulfonic acid, vinylurethane, methylvinylketone, 2-vinylquinoline, vinyl Carbazoles are included as well as divinyl monomers such as divinylbenzene, 2,3-divinylpyridine, divinylsulfone and 2,5-divinyl-6-methylpyridine. Preferred vinyl monomers include styrene, vinyltoluene, diallyl phthalate, triallyl cyanurate, chlorostyrene, divinylbenzene, α-methylstyrene, methyl methacrylate, methyl acrylate, diallyl phthalate, and the like. Styrene is particularly preferred. The composition ratio of each component constituting the composition of the present invention is within the following range with respect to 100 parts by weight of each component (a), (b), and (c). That is, component (a) is
The amount ranges from 10 to 90 parts by weight, preferably from 20 to 80 parts by weight, and more preferably from 20 to 60 parts by weight. Component (b) is in the range of 2 to 70 parts by weight, preferably 5 to 50 parts by weight, and more preferably 5 to 40 parts by weight. (c) The ingredients are
It ranges from 10 to 80 parts by weight, preferably from 20 to 70 parts by weight. As the curing agent of the present invention, organic peroxides, organic hydroperoxides and azo compounds can be used. Some peroxides useful in the present invention include dialkyl peroxides and diacyl peroxides. Dialkyl peroxide has the general structure R-OO
-R', in which R and R' are the same or different primary, secondary or tertiary alkyl groups,
It is a cycloalkyl group, an aralkyl group or a heterocyclic group. Groups of peroxides suitable for use in the present invention include dicumyl peroxide, dicumyl peroxide,
tert-butyl peroxide, tert-butyl cumyl peroxide and 2,5-dimethyl-2,
Contains 5-bis(tert-butylperoxy)hexane. Diacyl peroxide has the general structure RC(O)
OOC(O)R', where R and R' are the same or different alkyl, cycloalkyl, aralkyl, aryl or heterocyclic groups. Examples of some diacyl peroxides suitable for use in the present invention include dilauroyl peroxide, dibenzoyl peroxide,
These include dicetyl peroxide, didecanoyl peroxide, di-(2,4-dichlorobenzoyl) peroxide, diisononanoyl peroxide and 2-methylpentanoyl peroxide. Additionally, other peroxides useful in the present invention include methyl ethyl ketone peroxide, cyclohexanone peroxide, and the like, as well as particularly preferred peresters such as tert-butyl peroctoate and tert-butyl perbenzoate. Examples of hydroperoxides suitable for use in the present invention include tert-butyl hydroperoxide, cumyl hydroperoxide, 2,5
-dimethyl-2,5-dihydroperoxyhexane, p-methane hydroperoxide and diisopropylbenzene hydroperoxide. Examples of azo compounds that can be used in the present invention include diazoaminobenzene, N,N'-dichloroazodicarboxylic acid amide, azodicarboxylic acid diethyl ester, 1-cyano-1-(tert-butylazo)cyclohexanone, and azobis(iso butyronitrile). The amount of the curing agent used in the present invention is 0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, based on the total of 100 parts by weight of components (a), (b), and (c) of the composition of the present invention. Parts by weight, more preferably 1 to 2 parts by weight. The thickeners used in the invention are selected from the oxides and/or hydroxides of metals from group of the periodic table, such as the oxides and hydroxides of magnesium, calcium, strontium, barium and zinc. Preferably it is magnesium and/or calcium. The above-mentioned thickener is used in an amount of 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, based on a total of 100 parts by weight of components (a), (b), and (c) of the composition of the present invention. used. The fiber reinforcing agent used in the present invention includes glass, metal,
Silicate, asbestos, cellulose, carbon, graphite, polyester, polyacrylic, polyamide,
Selected from fibers such as polyolefin. Preferred are chopped glass fibers. The above fiber reinforcing agent is component a of the composition of the present invention,
5 to 300 parts per 100 parts by weight of component (b) and component (c)
The amount used is preferably 20 to 200 parts by weight, more preferably 20 to 100 parts by weight. The filler of the present invention is preferably an inorganic particulate filler, such as calcium carbonate, calcium silicate, silica, calcined clay, chalk, talc, limestone,
Selected from anhydrous calcium sulfate, barium sulfate, asbestos, powdered glass, quartz, aluminum hydrate, aluminum oxide, antimony oxide, etc. The above filler is component (a) of the composition of the present invention, and (b)
It is used in an amount of 50 to 800 parts by weight, preferably 100 to 400 parts by weight, and more preferably 100 to 300 parts by weight, based on a total of 100 parts by weight of component (c). Low shrinkage agents that can be used in the present invention include homogeneous polymers such as polystyrene, poly(meth)acrylate, polyvinyl acetate, polyvinyl chloride, polyethylene, polypropylene, polyamide, polycarbonate, and cellulose polymers. selected from polymers or copolymers. Principal copolymers include homopolymers of methyl methacrylate, ethyl methacrylate, butyl methacrylate and ethyl acrylate, and copolymers of methyl methacrylate with acrylic acid and methacrylic acid and/or their lower alkyl esters. Examples include copolymers of methyl methacrylate containing a small amount of one or more of lauroyl methacrylate, isobornyl methacrylate, acrylamide, hydroxyethyl methacrylate, styrene, 2-ethylhexyl acrylate, acrylonitrile, methacrylic acid, methacrylamide, methyloylacrylamide, and cetylstearyl methacrylate. be able to. Other useful copolymers include styrene-acrylonitrile, vinyl chloride-vinyl acetate, and the like. These low shrinkage agents are used in an amount of 0 to 40 parts by weight, preferably 0 to 20 parts by weight, based on a total of 100 parts by weight of components (a), (b), and (c) of the composition of the present invention. used in amounts of In addition to the above, the composition of the present invention may also contain, for example, pigments, colorants, lubricants or mold release agents, stabilizers, silane coupling agents, flame retardants, and the like.
Specific examples of pigments include titanium oxide, carbon black, and phthalocyanine. Examples of lubricants or mold release agents include aluminum, calcium, magnesium, and zinc salts of stearic acid. Stabilizers include barium, tin octoate, tris (nonylphenyl) phosphite, alkyl phenols such as BHT, quinones,
There are amines, etc. A preferred method for producing the thermosetting unsaturated polyester resin composition of the present invention is as follows. That is, a mixture containing an unsaturated polyester as the component (a) of the present invention and a vinyl monomer as the component (c), a modified block copolymer as the component (b), and a vinyl monomer as the component (c). This manufacturing method involves mixing a mixture obtained by preferably adding a filler to a solution of a filler and a filler. This method is a preferred method for suppressing layer separation between the modified block copolymer and the unsaturated polyester. The thermosetting unsaturated polyester resin composition of the present invention described above is preferably molded by a method such as compression molding or injection molding through an intermediate form such as BMC or SMC, and is molded into automobile parts, transportation equipment such as boats, bathtubs, etc. , construction equipment such as septic tanks, and other industrial products. Example 1 A mixed solution consisting of 1.05 mol of maleic anhydride and 1.1 mol of propylene glycol was reacted to synthesize an unsaturated polyester with an oxidation level of 40. This unsaturated polyester was dissolved in styrene to obtain a solution with a solid content of 65% by weight (Sample A). Sequential polymerization of styrene and butadiene in cyclohexane solvent using n-butyllithium catalyst,
Next, this solution was sequentially treated with carbon dioxide gas and hydrochloric acid to obtain a styrene-butadiene block copolymer containing terminal carboxyl groups and having a styrene content of 40% by weight (Sample B-1). Styrene and butadiene were sequentially polymerized in the same manner as the above method, and 0.25 mol of silicon tetrachloride was added per 1 mol of lithium active end to this solution to produce a radial branched styrene-butadiene block copolymer with a styrene content of 40% by weight. was obtained (sample B-2). The branched block copolymer of Sample B-2 was reacted with maleic anhydride in the absence of a radical initiator in an extruder. In this way, a modified block copolymer containing unreacted maleic anhydride was obtained (Sample B-3). Furthermore, this modified block copolymer of Sample B-3 was placed in a vacuum dryer and degassed to obtain a modified block copolymer from which unreacted maleic anhydride was completely removed (Sample B-4). The (modified) block copolymers thus obtained (sample B-1, B-2, B-3, B-4) were dissolved in styrene to obtain a styrene solution with a solid content of 30% by weight (each Samples C-1, C-2, C-3, C
-4). Table 1 shows the physical properties of the above modified or unmodified block copolymers. From Table 1, the modified block copolymer within the scope of the present invention (Sample B-3) has a styrene solution viscosity compared to the block copolymer containing a terminal carboxyl group outside the scope of the present invention (Sample B-1). It can be seen that it has the advantage of low dissolution and easy dissolution, and that the thickening phenomenon after addition of magnesium oxide is extremely remarkable.

【table】

[Table] Example 2 A formulation before curing was obtained according to the formulation () shown in Table 2. The formulation was prepared as follows. Styrene solution of unsaturated polyester (sample A)
were stirred, and polymethyl methacrylate, t-butyl perbenzoate, zinc stearate, and calcium carbonate were added and mixed. In this solution, (denatured)
Styrene solution of block copolymer (sample C-1,
A mixture of C-2, C-3 or C-4) and calcium carbonate (1:1) was added and mixed with stirring. Further, magnesium hydroxide and glass fiber were mixed to obtain a pre-cured formulation. The above mixture was compression molded at a temperature of 150° C., a pressure of 100 Kg/cm ² and a time of 3 minutes. Table 3 shows the physical properties of the cured product.
Shown below.

【table】

【table】

【table】

[Table] From Table 3, the unsaturated polyester resin composition containing the modified block copolymer (Sample B-3) within the scope of the present invention has physical properties representing impact resistance such as tensile strength, elongation, and dart impact. It can be seen that the surface properties are also excellent. Example 3 Radial branched styrene with a styrene content of 70% and 15 maleic anhydride grafted per polymer molecule according to the method of Samples B-2 and B-4.
A butadiene block copolymer was obtained (Sample B-
5). In addition, when preparing Sample B-5, the remaining amount of maleic anhydride before removing unreacted maleic anhydride was 0.2% by weight (this modified block copolymer containing residual maleic anhydride was used as Sample B-5). 6). Using this sample B-5 and sample B-6, Table 2
A compound was obtained according to the recipe and molded under the same conditions as in Example 2. Table 3 shows the physical properties of the cured formulations. Example 4 A commercially available unsaturated polyester resin, Ligorac M-411-1 (manufactured by Showa Kobunshi Co., Ltd., styrene solution of isophthalic acid-based unsaturated polyester), and the modified or unmodified block copolymer (Sample B-
1, B-2, and B-3), a formulation according to the formulation of Example 2 was obtained. Table 4 shows the properties of this formulation before and after thickening. Furthermore, the above compound was made into BMC and injection molded using an injection molding machine for BMC (IR-80A manufactured by Toshiba Machine). Continuous molding was performed at an injection pressure of 800 Kg/cm ² , an injection time of 15 seconds, a cylinder temperature of 80°C, a mold temperature of 145°C, and a curing time of 50 seconds. Table 5 shows the performance of the obtained molded product.

【table】

[Table] Table 4 shows that the formulation using the modified block copolymer (Sample B-3) within the range of the present invention is excellent in thickening properties and dispersion stability. In particular, when a block copolymer outside the scope of the present invention was used, surface stickiness and stringiness were observed, and it is thought that layer separation occurred. Also, from Table 5, modified block copolymers within the scope of the present invention (sample B-
It can be seen that the composition using 3) has excellent impact resistance and moldability even in injection molding.

Claims (1)

[Claims] 1. (a) Unsaturated polyester (b) A modified block copolymer in which a dicarboxylic acid group and/or its derivative group is bonded to a branched block copolymer consisting of a vinyl aromatic compound and a conjugated diene compound. (c) Vinyl monomer In a composition comprising the above (a) to (c), a curing agent and other additives as necessary,
The modified block copolymer of component (b) contains 0.05 to 5% by weight of unreacted unsaturated dicarboxylic acid or its derivative.
A thermosetting unsaturated polyester resin composition characterized by containing: 2. The composition according to claim 1, wherein the dicarboxylic acid group derivative group of component (b) is a dicarboxylic acid anhydride group. 3. The composition according to claim 1, wherein component (b) is a modified block copolymer having dicarboxylic acid anhydride groups bonded thereto. 4. The composition according to claim 1, wherein component (b) is a modified block copolymer having more than one dicarboxylic acid group or its derivative group bonded per molecule of the copolymer. 5. The composition according to claim 1, wherein component (b) is a modified block copolymer in which 2 to 20 dicarboxylic acid groups or derivative groups thereof are bonded per molecule of the copolymer. 6. The composition according to claim 1, wherein the branched block copolymer as component (b) has three or more branches. 7. The composition according to claim 1, wherein the branched block copolymer as component (b) has four radial branches. 8. The composition according to claim 1, wherein the branched block copolymer of component (b) is coupled by a halogen group-containing polyfunctional treatment. 9. The composition according to claim 1 or 8, wherein the branched block copolymer as component (b) is coupled with a silicon compound. 10. The composition according to claim 8 or 9, wherein the branched block copolymer as component (b) is a four-branched copolymer coupled with a silicon halide. 11. The composition according to claim 1, wherein the modified block copolymer as component (b) has succinic anhydride groups bonded thereto. 12. The composition according to claim 1, wherein the branched block copolymer as component (b) contains 60% by weight or less of a vinyl aromatic compound. 13. The composition of claim 1, wherein component (b), the branched block copolymer, contains more than 60% by weight of a vinyl aromatic compound. 14 Other additives include fillers, fiber reinforcing agents,
The composition according to claim 1, which is at least one selected from thickeners and low-shrinkage agents. 15. The composition according to claim 1, wherein the other additives are fillers and fiber reinforcing agents. 16. The composition according to claim 1, wherein the other additives are fillers, fiber reinforcing agents and thickeners. 17. The composition according to claim 1, wherein the other additives are fillers, fiber reinforcing agents and low shrinkage agents. 18 Other additives include fillers, fiber reinforcing agents,
Claim 1, which is a thickening agent and a low shrinkage agent
Compositions as described in Section. 19 A dicarboxylic acid group and/or its derivative is added to the first mixture containing (a) an unsaturated polyester and (c) a vinyl monomer, and (b) a branched block copolymer consisting of a vinyl aromatic compound and a conjugated diene compound. A modified block copolymer having a group bonded thereto and a second mixture containing the (c) vinyl monomer are mixed, and at that time, either or both of the first mixture and the second mixture is added with a curing agent and, if necessary, a curing agent. In the method of mixing other additives, the modified block copolymer of component (b) contains 0.05 to
A method for producing a thermosetting unsaturated polyester resin composition characterized by containing 5% by weight. 20. The method for producing a thermosetting unsaturated polyester resin composition according to claim 19, wherein a filler is mixed in the second mixture.