JPH07206986A - Unsaturated polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain an unsaturated polyester resin composition composed of an unsaturated polyester resin, a specific polymer, a vinyl monomer and a curing agent and useful for the production of an automobile part, etc., excellent in shock resistance surface properties, weatherability, heat resistance and dimensional stability. CONSTITUTION:This unsaturated polyester resin composition is composed of (A) an unsaturated polyester resin in an amount of, preferably, 20-60 pts.wt., (B) an epoxy-modified block polymer obtained by the epoxidation of the double bonds of a conjugate diene-containing unsaturated-hydrocarbon moieties of a block copolymer comprising polymer blocks mainly containing vinyl aromatic compounds and polymer blocks mainly containing conjugate diene compounds in a molecule (an epoxy equivalent is preferably 140--10000), in an amount of, preferably, 5-40 pts.wt., (C) a vinyl monomer, e.g. styrene in an amount of, preferably, 20-70 pts.wt. and (D) a curing agent, e.g. dicumyl peroxide in an amount of, preferably, 0.5-3 pts.wt. (based on the total of the components A to C of 100 pts.wt.).

Description

Detailed Description of the Invention

[0001]

The present invention relates to impact resistance, surface characteristics,
The present invention relates to a thermosetting unsaturated polyester resin composition having excellent weather resistance and heat resistance.

[0002]

2. Description of the Related Art Unsaturated polyester is a thermosetting resin having excellent mechanical strength, chemical resistance, heat resistance, electrical characteristics, etc., and is used as automobile parts, electric equipment parts, industrial parts, furniture, bathtubs, toilet bowls, etc. Used in a wide range of fields.

Since these unsaturated polyesters have a molding shrinkage of 4 to 12% upon curing, thermoplastic resins such as polystyrene, polymethylmethacrylate, and polyvinyl acetate are blended as "low-shrinking agents". Is common. However, even in these cases, even if the unsaturated polyester resin and the low-shrinking agent cause phase separation after compounding, or even a molded product, unfavorable manifestation characteristics such as warpage and waviness are still attracted.

On the other hand, as the weight reduction of automobiles has become more active, attempts have been made to adopt unsaturated polyester for outer panel parts and structural parts of automobiles. It is usually used in the form of easy bulk molding compound (BMC) or sheet molding compound (SMC).
Further, the cured product is required to have impact resistance and surface characteristics more than ever before. Therefore, in the unsaturated polyester composition, these surface characteristics and thickening characteristics after compounding are important subjects for improvement together with impact resistance.

To solve these problems, a method of adding a styrene-butadiene block copolymer (see, for example, Japanese Unexamined Patent Publication No.
JP-A-48-34289, JP-A-49-30480) or a method of adding a hydrogenated and / or carboxylic acid-modified styrene-butadiene block copolymer (for example, JP-A-52-148588, JP-A-52-148588). JP-A-54-130653, JP-A-56-115309, JP-A-56-115310, JP-A-58-8718, etc.) have been proposed, but for the complete solution of the problem. Has not been reached, the surface properties of the cured product are still insufficient,
Further, from the viewpoint of production, the handling viscosity is too high, and problems remain in terms of thickening properties.

[0006]

In view of the above situation, the present invention provides a cured product of unsaturated polyester which is excellent not only in impact resistance but also in surface smoothness, surface glossiness and dimensional stability. It is an object.

[0007]

That is, the present invention provides an unsaturated polyester composition modified with an epoxy-modified block copolymer.

The present invention will be described in detail below.

The unsaturated polyester used as the component (a) in the present invention is obtained by a condensation reaction of an α, β-unsaturated dibasic acid or a mixture thereof with a saturated dibasic acid and a polyhydric alcohol. Is.

Examples of the dibasic acid component include maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, chlorinated maleic acid, glutaconic acid and acid anhydrides thereof. Examples of the saturated dibasic acid include phthalic acid, halogenated phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, het acid, endomethylenetetrahydrophthalic acid, succinic acid, adipic acid, glutaric acid, sebacic acid, pimeline. An acid or an acid anhydride thereof can be mentioned. Also, if necessary,
A monobasic acid such as acrylic acid or methacrylic acid or a polybasic acid such as trimellitic acid, hemimellitic acid or trimesic acid can be used as a modifier together with the above dibasic acid.

As the polyhydric alcohol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol,
Dipropylene glycol, tripropylene glycol,
Polypropylene glycol, 1,3-butanediol,
Examples thereof include tetramethylene glycol, 1,6-hexane glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, and ethylene oxide and / or propylene oxide adduct of hydrogenated bisphenol A. In addition, if necessary, higher aliphatic alcohols such as amyl alcohol, octyl alcohol, pentyl alcohol, and hexyl alcohol, and polyhydric alcohols such as tetrahydrofurfuryl alcohol can be used in combination.

The method for producing the unsaturated polyester obtained from these components may be any known method.

Next, the epoxidized block copolymer used as the component (b) of the present invention is mainly composed of a polymer block A mainly containing a vinyl aromatic compound and a conjugated diene compound in the same molecule. Is obtained by epoxidizing a block copolymer consisting of the polymer block B described above. For example, A-B, A-B-A, B-A-B-
It is an epoxidized vinyl aromatic compound-conjugated diene compound block copolymer having a structure of A, (AB) ₄ Si, (B-A-B) ₄ Si and the like. Further, the unsaturated bond of the conjugated diene compound of the block polymer may be partially hydrogenated.

The block copolymer referred to herein is a block copolymer composed of a polymer block A containing a vinyl aromatic compound as a main component and a polymer block B containing a conjugated diene compound as a main component. The copolymerization ratio of the group compound and the conjugated diene compound is 5:95 to 70:30, especially 10:90.
A polymerization ratio of ~ 60: 40 is preferred. The number average molecular weight of the block copolymer used in the present invention is in the range of 5,000 to 600,000, preferably 10,000 to 500,000, and the molecular weight distribution is a ratio Mw of the weight average molecular weight Mw and the number average molecular weight Mn.
It is 10 or less when expressed by / Mn.

The vinyl aromatic compound constituting the block polymer used in the present invention is, for example, styrene,
One or more of α-methylstyrene, vinyltoluene, p-tertiary butylstyrene, divinylbenzene, p-methylstyrene, 1,1-diphenylstyrene and the like can be selected, and styrene is preferable.
Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, phenyl-1,3-. One kind or two or more kinds are selected from butadiene and the like, and among them, butadiene, isoprene and a combination thereof are preferable.

As the method for producing the block polymer used in the present invention, any method can be used as long as it has the above-mentioned structure. For example, Japanese Examined Japanese Patent Sho 40-23798
Issue, Japanese Examined Sho 43-17979, Examined Sho 46-32415, Examined Sho 56-2
According to the method described in Japanese Patent No. 8925, a vinyl aromatic compound--8704, Japanese Patent Publication No. 43-6636, or Japanese Patent Publication No. 59-133203 is used in an inert solvent using a lithium catalyst or the like.
According to the method described in the publication, hydrogenation can be carried out in the presence of a hydrogenation catalyst in an inert solvent to synthesize the partially hydrogenated block copolymer used in the present invention.
The method of epoxy-modifying these block copolymers is not particularly limited in the present invention. It can be obtained by reacting with an epoxidizing agent.

As the inert solvent, for example, hexane, cyclohexane, toluene, benzene, ethyl acetate, carbon tetrachloride, chloroform and the like can be used.

Hydroperoxides include hydrogen peroxide, tertiary butyl hydroperoxide, cumene peroxide and the like. Examples of peracids include performic acid, peracetic acid, perbenzoic acid, and trifluoroperacetic acid. Of these, peracetic acid is industrially produced in large quantities, is available at low cost, and has high stability.
It is a poxidizing agent. Further, a catalyst can be used as necessary during the epoxidation. For example, in the case of peracids, an alkali such as sodium carbonate or an acid such as sulfuric acid can be used as a catalyst. There is no strict regulation on the amount of epoxidizing agent, the optimum amount in each case is
It will depend on such variables as the particular epoxidizing agent used, the desired degree of epoxidation, and the particular block copolymer used.

There are no strict restrictions on the epoxidation reaction conditions. The reaction temperature range that can be used depends on the reactivity of the epoxidizing agent used. For example, peracetic acid is 0
70 ° C. is preferable, and decomposition of peracetic acid occurs above 70 ° C. No special manipulation of the reaction mixture is necessary, for example the mixture may be stirred for 2-10 hours. Isolation of the obtained epoxy-modified copolymer can be carried out by a suitable method, for example, a method of precipitating with a poor solvent, a method of charging the polymer in hot water with stirring, and removing the solvent by distillation. The degree of epoxidation of the epoxy-modified block polymer in the present invention is calculated by the following formula after titration with hydrobromic acid.

[0020] The epoxy equivalent of the epoxy-modified block polymer in the present invention is 140 to 10,000 g / mol, particularly preferably 200
~ 6000 g / mol.

Next, the vinyl monomer used as the component (c) in the present invention acts as a crosslinking component of the compound (unsaturated polyester composition). Examples of the vinyl monomer include styrene and various substitution products of styrene, for example, α-methylstyrene, vinyltoluene, dimethylstyrene, trimethylstyrene, halogenated styrene, tertiary butyl styrene, styrene sulfonate, amino. Vinyl aromatic compounds such as styrene, p-benzylstyrene, p-phenoxystyrene, acrylic acid or methacrylic acid and methyl alcohol, ethyl alcohol, propyl alcohol, octyl alcohol, hexyl alcohol, tetrahydrofurfuryl alcohol, ethylene glycol, propylene glycol Esters with aliphatic alcohols such as 2-aminoethyl-methacrylate, N, N-diethylamino-acrylate,
Acrylic acid or methacrylic acid derivatives such as N, N-diethylamino-methacrylate, maleic acid, fumaric acid,
Α, β-Unsaturated dicarboxylic acids such as crotonic acid and itaconic acid, or their anhydrides, esters, amides, imides, etc., and fumaric acid esters such as diethyl fumarate and dioctyl fumarate, as well as various vinyls. Monomers and vinylidene monomers such as acrylonitrile, methacrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride, vinylene carbonate, vinyl-2-
Chloroethyl ether, alkyl vinyl ethers of C ₈ ~ C _18, fatty acid ethers of C ₈ -C _18, 2-bi
Examples thereof include nylfuran, vinylphenol, vinylphenyldisiloxane, 2-vinylpyridine, 4-vinylpyridine, vinylpyrrole, vinylpyrrolidone, vinylsulfonic acid, vinylurethane, methylvinylketone-2-vinylquinoline and vinylcarbazole.
Also use conjugated diene compounds such as 1,3-butadiene, isoprene, piperine, methylpentadiene and chloroprene, and alkoxy and cyano derivatives of conjugated dienes such as 2-methoxybutadiene and 1-cyanobutadiene. You can

Further, a polyfunctional crosslinkable vinyl monomer,
For example, diallyl maleate, diallyl phthalate, divinylbenzene, divinyl ether, neopentyl glycol diacrylate, diallyl cyanurate, triallyl cyanurate, diallyl phenyl phosphate, 2,
3-divinylpyridine, divinylsulfone, 2,5-divinyl-6-methylpyridine and the like can also be used. Preferred examples of these vinyl monomers include styrene, α-methylstyrene, vinyltoluene, chlorostyrene, divinylbenzene, methylmethacrylate, methylacrylate, diallylphthalate and triallyl cyanurate.

As the curing agent as the component (d) used in the present invention, organic peroxide, organic hydroperoxide and azo compound can be used. Peroxides useful in the present invention include dialkyl peroxides and diacyl peroxides.

Alkyl peroxide has the general structure R--
OO-R ', where R and R'are the same or different primary, secondary or tertiary alkyl groups, cycloalkyl groups, aralkyl groups or heterocyclic groups. The group of peroxides suitable for use in the compositions of the present invention includes dicumyl peroxide, di-tertiary-butyl peroxide, tertiary-butyl cumyl peroxide and 2,5-dimethyl-2,5-bis ( Tert-butylperoxy) hexane is also included. Diacyl peroxide has the general structure RC (O) -OO-C (O) R ', where R and R'are the same or different alkyl groups, cycloalkyl groups, aralkyl groups, allyl groups or heterocyclic groups. Is. Some examples of diacyl peroxides suitable for use in the present invention include dilauroyl peroxide, dibenzoyl peroxide, dicetyl peroxide, didecanyl peroxide, di-
There are (2,4-dichlorobenzoyl) peroxide, diisononanoyl peroxide and 2-methylpentanoyl peroxide.

Further, other peroxides useful in the present invention include particularly preferred peresters, such as tertiary-butyl peroxide and tertiary-butyl perbenzoate, as well as methyl ethyl ketone peroxide, cyclohexanone peroxide and the like.
Examples of hydroperoxides suitable for use in the present invention include, for example, tertiary-butyl hydroperoxide, cumyl hydroperoxide, 2,5-
Dimethyl-2,5-dihydroperoxyhexane, p
-Menta hydroperoxide and diisopropylbenzene hydroperoxide.

Examples of azo compounds usable in the present invention include diazoaminobenzene, N, N'-dichloroazodicarboxylic acid amide, azodicarboxylic acid diethyl ester, 1-cyano-1- (tertiary- Butylazo) cyclohexanone and azobis (isobutyronitrile).

The mixing ratio of each component constituting the unsaturated polyester composition of the present invention is 10 to 90 parts by weight, preferably 20 to 80 parts by weight, and more preferably 2 parts by weight of the component (a).
0-60 parts by weight, (b) component 2-70 parts by weight, preferably 5-50 parts by weight, more preferably 5-40 parts by weight, component (c) component 10-80 parts by weight, preferably 20-.
70 parts by weight of the curing agent (d)
The component is 0.1 to 10 parts by weight, preferably 0.1% by weight, based on 100 parts by weight in total of the components (a) to (c). It is 3 to 5 parts by weight, more preferably 0.5 to 3 parts by weight. If desired, various organometallic compounds can be added in desired amounts as curing accelerators.

In addition to the above, the composition of the present invention may contain the above-mentioned unmodified hydrogenated block copolymer and the block copolymer before hydrogenation in arbitrary ratios. In addition to the above, other additives such as thickeners, fiber reinforcing materials, inorganic fillers, low-shrinking agents, pigments, colorants, lubricants, release agents, etc. may be added as required. be able to.

The above-mentioned thickening agents are the compositions (a) to (a) of the present invention.
0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, can be suitably selected and used per 100 parts by weight of the component (c) in total.

The fiber reinforcing material is selected from fibers such as glass, metal, silicate, asbestos, cellulose, carbon, graphite, polyester, polyacryl, polyamide and polyolefin, and preferably glass fiber. These fiber reinforcing materials are used in an amount of 0 to 300 parts by weight, preferably 5 parts by weight, per 100 parts by weight of the components (a) to (c) of the present invention.
To 200 parts by weight, and more preferably 20 to 100 parts by weight.

The inorganic filler that can be used in the composition of the present invention is an inorganic particulate filler, such as calcium carbonate, calcium silicate, silica, calcined clay, chalk, talc, limestone, anhydrous calcium sulfate, It can be selected from barium sulfate, asbestos, powdered glass, briquette, aluminum hydrate, aluminum oxide, antimony oxide and the like, and the addition amount thereof is per 100 parts by weight of the compositions (a) to (c) of the present invention. 50-800 parts by weight, preferably 100-400 parts by weight, more preferably 100-400 parts by weight.
It can be used in the range of 300 parts by weight.

The low-shrinking agent which can be used in the present invention includes polystyrene type, poly (meth) acrylate type, polyvinyl acetate type, polyvinyl chloride type, polyethylene type,
Any one can be selected from homopolymers or copolymers such as polypropylene-based, polyamide-based, polycarbonate-based and cellulose-based polymers, and the addition amount thereof is 100 parts by weight in total of the compositions (a) to (c) of the present invention. 0
It can be used in the range of ˜40 parts by weight, preferably 2 to 20 parts by weight.

The preferred method for producing the unsaturated polyester composition of the present invention is as follows. That is, the unsaturated polyester resin which is the component (a) of the present invention and (c)
A first mixture containing a vinyl monomer as a component, and (b)
The modified hydrogenated block copolymer, which is the component, and the second mixture containing the vinyl monomer, which is the component (c), are mixed.
At this time, the curing agent of the component (d) is added to one or both of the first mixture and the second mixture in advance, and if necessary, a filler, a fiber reinforcement, a thickener, a low shrinkage agent, a release agent, etc. This is a method of mixing additives.

The unsaturated polyester resin composition of the present invention obtained by these methods can be molded by a method such as compression molding or injection molding through an intermediate compound such as SMC or BMC to obtain a cured product. .

The present invention will be further described below with reference to examples.

Reference Example 1: Preparation of unsaturated polyester resin (a-1) Maleic anhydride 0.7 mol, phthalic anhydride 1.4 mol, propylene glycol 2.0 mol, and diethylene glycol 0.2 mol. The mixture was heated to about 100 ° C. under a nitrogen stream, stirred, and gradually heated to about 210 ° C. while removing condensed water to the outside of the system, and the esterification reaction was performed at this temperature to give an acid value of 40. An unsaturated polyester resin was synthesized. This unsaturated polyester resin was dissolved in styrene to obtain a solution having a solid content concentration of 65% by weight.

(A-2) Further, 0.6 mol of isophthalic acid,
0.6 mol of phthalic anhydride, 1.4 mol of maleic anhydride,
A mixture of 2.6 mol of propylene glycol was subjected to an esterification reaction in the same manner as above to synthesize an unsaturated polyester resin having an acid value of 30. This unsaturated polyester resin was dissolved in styrene to obtain a solution having a solid content concentration of 65% by weight.

Reference Example B: Synthesis of Epoxidized Block Copolymer and Epoxidized Hydrogenated Block Copolymer> (b-1) Polystyrene in a reactor equipped with a stirrer, a reflux condenser and a thermometer Polybutadiene-
Block copolymer of polystyrene [Nippon Synthetic Rubber Co., Ltd.
Product name: TR2000] 300 g, ethyl acetate 15
00 g was charged and dissolved. Then, 169 g of a 30 wt% ethyl acetate solution of peracetic acid was continuously added dropwise, and an epoxidation reaction was carried out at 40 ° C. for 3 hours while stirring. The reaction solution is returned to room temperature and taken out from the reactor, a large amount of methanol is added to precipitate the polymer, which is filtered off, washed with water and dried to obtain an epoxy-modified polymer having an epoxy equivalent of 470 [oxirane oxygen 6.19%]. It was This was dissolved in styrene to obtain a solution having a solid content concentration of 30% by weight.

(B-2) Polystyrene-polybutadiene-polystyrene block copolymer [manufactured by Japan Synthetic Rubber Co., Ltd., trade name: TR2000] 300 g in a jacketed reactor equipped with a stirrer, a reflux condenser and a thermometer , Ethyl acetate 15
00g was charged and dissolved. Then, 43 g of a 30 wt% ethyl acetate solution of peracetic acid was continuously added dropwise, and an epoxidation reaction was carried out at 40 ° C. for 3 hours while stirring. The reaction solution is returned to room temperature and taken out from the reactor. A large amount of methanol is added to precipitate a polymer, which is separated by filtration, washed with water and dried to obtain an epoxy equivalent of 1
An epoxy-modified polymer of 820 [oxirane oxygen 6.08%] was obtained. This was dissolved in styrene to obtain a solution having a solid content concentration of 30% by weight.

(B-3) Polystyrene-polybutadiene-polystyrene block copolymer [manufactured by Japan Synthetic Rubber Co., Ltd., trade name: TR2400] 300 g in a jacketed reactor equipped with a stirrer, a reflux condenser and a thermometer , Ethyl acetate 15
00g was charged and dissolved. Then, 113 g of a 30 wt% ethyl acetate solution of peracetic acid was continuously added dropwise, and an epoxidation reaction was carried out at 40 ° C. for 3 hours while stirring. The reaction solution is returned to room temperature and taken out from the reactor, a large amount of methanol is added to precipitate the polymer, which is separated by filtration, washed with water and dried to obtain an epoxy-modified polymer having an epoxy equivalent of 695 [oxirane oxygen 6.15%]. It was This was dissolved in styrene to obtain a solution having a solid content concentration of 30% by weight.

(B-4) A block copolymer of polystyrene-polybutadiene-polystyrene in a jacketed reactor equipped with a stirrer, a reflux condenser, and a thermometer [Shell Chemical Co., Ltd., trade name: Califlex D1122]. 300g,
Cyclohexane 1500 g was charged and dissolved. Then, 177 g of a 30 wt% ethyl acetate solution of peracetic acid was continuously added dropwise, and an epoxidation reaction was carried out at 40 ° C. for 3 hours while stirring. Return the reaction solution to room temperature and take it out of the reactor.
Was added to precipitate a polymer, which was separated by filtration, washed with water and dried to obtain an epoxy-modified polymer having an epoxy equivalent of 448. This was dissolved in styrene to obtain a solution having a solid content concentration of 30% by weight.

(B-5) Block copolymer of polystyrene-polybutadiene-polystyrene in a jacketed reactor equipped with a stirrer, a reflux condenser and a thermometer [Shell Chemical Co., Ltd., trade name: Califlex TR1111] 300g,
Cyclohexane 1500 g was charged and dissolved. Then, 222 g of a 30 wt% ethyl acetate solution of peracetic acid was continuously added dropwise, and an epoxidation reaction was carried out at 40 ° C. for 3 hours with stirring. Return the reaction solution to room temperature and take it out of the reactor.
Was added to precipitate a polymer, which was separated by filtration, washed with water, and dried to obtain an epoxy-modified polymer having an epoxy equivalent of 362.

This was dissolved in styrene to give a solid content of 30
The solution was a weight% solution.

(B-6) A block copolymer of polystyrene-polyisoprene-polystyrene was added to a reactor equipped with a jacket equipped with a stirrer, a reflux condenser and a thermometer.
300 g of trade name: VS-1] having a vinyl-structured polyisoprene block manufactured by Kuraray and 1500 g of cyclohexane were charged and dissolved. Then, 222 g of a 30 wt% ethyl acetate solution of peracetic acid was continuously added dropwise, and an epoxidation reaction was carried out at 40 ° C. for 3 hours while stirring. The reaction solution is returned to room temperature and taken out of the reactor. A large amount of methanol is added to precipitate a polymer, which is filtered, washed with water and dried to obtain an epoxy equivalent of 375.
An epoxy-modified polymer of was obtained. This was dissolved in styrene to obtain a solution having a solid content concentration of 30% by weight.

(B-7) A reactor equipped with a stirrer and a thermometer equipped with a polystyrene-polybutadiene-
Block copolymer of polystyrene [Nippon Synthetic Rubber Co., Ltd.
Made, trade name: TR2000] 300 g, cyclohexane 3000 g are charged and dissolved, temperature is 60 ° C., and di-P-is used as a hydrogenation catalyst.
Triylbis (1-cyclopentadienyl) titanium
/ Cyclohexane solution (concentration 1 mmol / l) 40
0 ml of n-butyllithium solution (concentration 5 mmol / liter) 8 ml of 2.0 ml
Adding a mixture under hydrogen pressure of kg / cm ^2, it was allowed to react at hydrogen partial pressure of 2.5Kg / c m ² 30 min. The partially hydrogenated polymer solution thus obtained was dried under reduced pressure to remove the solvent (hydrogenation rate of the entire butadiene part was 30%). 300 g of this partially hydrogenated polymer and 1500 g of cyclohexane were charged and dissolved. Then 300g of 30% by weight ethyl acetate solution of peracetic acid
Was continuously added dropwise, and the epoxidation reaction was carried out at 40 ° C. for 3 hours with stirring. The reaction solution was returned to room temperature and taken out from the reactor, a large amount of methanol was added to precipitate the polymer, which was filtered, washed with water and dried to obtain an epoxy-modified polymer having an epoxy equivalent of 275. This was dissolved in styrene to obtain a solution having a solid content concentration of 30% by weight.

Examples 1 to 8 and Comparative Examples 1 to 7 In the styrene solution of the unsaturated polyester resin of the component (a) and the epoxidized block copolymer of the component (b) synthesized in the reference example, (d) The components tert-butyl peroxybenzoate, zinc stearate, calcium carbonate and magnesium oxide were blended in the composition shown in Table 1 to obtain a compound before curing.

This compound was aged in an oven at 40 ° C. for 48 hours, and the compound viscosity at 23 ° C. after aging and the viscosity of this compound at 70 ° C. were measured with a Brookfield viscometer HBT type. The results are shown in Table 1 and Table 2. In the comparative example, a styrene solution of the corresponding unreacted block copolymer was used instead of the styrene solution of the epoxidized block copolymer of the component (b). From these results, it is understood that the unsaturated polyester resin composition of the present invention has a higher compound viscosity at 70 ° C. as compared with the comparative example, and has a feature that the viscosity is not lowered at the time of heating.

[Examples 9 to 16 and Comparative Examples 8 to 14] 100 parts of glass fiber (PPG-3198, manufactured by PPG) was added to each of the basic compounding recipes of Examples 1 to 4 and Comparative Examples 1 to 3. S
MC was prepared and aged at 40 ° C. for 48 hours. Then 1
Pressure molding was performed under the conditions of 40 ° C. and 85 kg / cm ² to obtain a cured unsaturated polyester resin composition. The physical property measurement results of each molded product are shown in Tables 3 and 4.

From these results, the unsaturated polyester resin composition of the present invention has good surface smoothness with no "large waviness" and "small waviness". or,
Surface gloss was 60% or more, and excellent surface characteristics were exhibited. Further, it was found that the shrinkage rate at the time of molding is a negative value (expansion), and the effect as a low shrinkage agent is also excellent.
On the other hand, it was revealed that the unsaturated polyester resin composition using the unreacted block copolymer shown in Comparative Example is inferior in the balance of surface smoothness, surface gloss and low shrinkage.

[0050]

INDUSTRIAL APPLICABILITY According to the present invention, the component (b) is made of a specific epoxidized block copolymer to improve the initial viscosity of the compound and to reduce the viscosity decrease upon heating, thereby improving surface characteristics and dimensional stability. It is possible to provide an unsaturated polyester resin composition having excellent properties and impact resistance. The unsaturated polyester resin composition of the present invention can be particularly suitably used as a structural material for automobile parts including automobile skins, transportation equipment such as boats, bathtubs, septic tanks, dressing tables and chairs.

Table 1 1 Example 1 Example 2 Example 3 Example 4 Combination of unsaturated polyester resins (a-1) (a-1) (a-1) (a-1) (solid content 65% , Styrene solution) 50 50 50 50 Block copolymer (b-1) (b-2) (b-3) (b-4) (solid content 30%, styrene solution) 50 50 50 50 Tertiary butyl Peroxybenzoate 1 1 1 1 Zinc monostearate 4 4 4 4 Amount Calcium carbonate 150 150 150 150 parts Magnesium oxide 3 3 3 3 Viscosity compound viscosity at 23 ℃ after aging 175000 124000 158000 165000 Degree (poise) After special aging 70 ℃ Compound viscosity of 8800 7000 8900 7900 (poise) Table 1-2 Example 5 Example 6 Example 7 Example 8 Example unsaturated polyester resin (a-1) (a-1) (a-1) (a- 2) if (solid content of 65% styrene solution) 50 50 50 50 processing block copolymer (b-5) (b- 6) (b-7) (b-1) side (solid 30% styrene solution) 50 50 50 50 t-butylperoxy benzoate 1 1 1 1 double zinc stearate 4 4 4 4 weight calcium 150 150 150 150 parts of magnesium oxide carbonate 3 3 3 3 compound viscosity tacky aging after 23 ° C. 174000 138000 152000 160000 degree (poise) Special compound viscosity at 70 ° C after aging 8500 7400 9100 7700 property (poise) Table 2-1 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Unsaturated polyester resin (a-1) (a-1) (a-1) (a-1) (solid content 65%, styrene solution) 50 50 50 50 Block copolymer TR2000 TR2400 Califlex Califlex D1122 TR1111 (solid content 30%, styrene) Solution) 50 50 50 50 Tertiary butyl peroxybenzoate 1 1 1 1 Zinc monostearate 4 4 4 4 Amount Calcium carbonate 150 150 150 150 parts Magnesium oxide 3 3 3 3 Compound viscosity at 23 ° C after aging 17800 135000 150000 156000 Every time ( Poise) Compound viscosity at 70 ° C. after special aging 2200 1200 1400 1300 Properties (poise) Table 2-2 Comparative Example 5 Comparative Example 6 Comparative Example 7 Unsaturated polyester resin (a-1) (a-1) (a-2 ) (Solid content 65%, styrene solution) 50 50 50 Block copolymer VS-1 30% Hydrogenated TR2000 TR2000 method (solid content 30%, styrene solution) 50 50 50 Tertiary butyl peroxybenzoate 1 1 1 Zinc Bistearate 444 Calcium carbonate 150 150 150 parts Magnesium oxide 3 3 3 Compound viscosity at 23 ℃ after aging 17500 134000 156000 degrees (poise) Compound viscosity at 70 ℃ after aging 2500 1400 1300 Properties (poise) table 3-1 Example 9 Example 10 Example 11 Example 12 Formulation Basic formulation Same as Example 1, Example 2, Example 3, and Example 4 Same Same Same Same glass fiber 100 parts by weight 100 parts by weight 100 parts by weight 100 parts by weight Shrinkage rate (%) -0.05 -0.05 -0.04- 0.02 Large wave Nothing at all None at all None at all Small wave at all None None at all None At all Surface gloss (%) 75 72 70 69 Table 3-2 Example 13 Example 14 Example 15 Example 16 Formulation Basic composition Same as Example 5 and Example 6 and Example 7 and Example 8 Same Same Same same glass fiber 100 parts by weight 100 parts by weight 100 parts by weight 100 parts by weight Shrinkage (%) -0.04 -0.05 -0.03 -0.04 Large No wavy at all No nothing at all No at all Small wavy at all No at all No at all Surface gloss (%) 65 77 70 69 Table 4-1 Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Formulation Basic formulation Comparative Example 1 and Comparative Example 2 and Comparative Example 3 and Comparative Example 4 Same Same Same Same glass fiber 100 parts by weight 100 parts by weight 100 parts by weight 100 parts by weight Shrinkage (%) 0.01 0.02 0.01 0.01 Large wavy Large Large Large Large Large Large small Waving often more often greater surface gloss (%) 45 51 53 47 Table 4-2 Comparative Example 12 Comparative Example 13 Comparative Example 14 Formulation basic formulation Comparative Example 5 and Comparative Example 6 Same Same same glass fibers as in Comparative Example 7 and 100 Parts by weight 100 parts by weight 100 parts by weight Shrinkage (%) 0.02 0.02 0.01 Large wavy lots Many lots Small wavy lots Many lots Surface gloss (%) 55 40 52

Claims (3)

[Claims] 1. (a) Unsaturated polyester resin (b) A block copolymer composed of a polymer block A mainly containing a vinyl aromatic compound and a polymer block B mainly containing a conjugated diene compound in the same molecule. An epoxy-modified block polymer obtained by epoxidizing a double bond of an unsaturated carbon of a conjugated diene compound of the polymer. An unsaturated polyester resin composition comprising (c) a vinyl monomer (d) a curing agent. 2. A block weight composed of (a) an unsaturated polyester resin (b) a polymer block A mainly containing a vinyl aromatic compound and a polymer block B mainly containing a conjugated diene compound in the same molecule. An epoxy-modified block polymer obtained by epoxidizing a double bond of an unsaturated carbon of a conjugated diene compound of a partially hydrogenated block polymer obtained by partially hydrogenating a polymer. An unsaturated polyester resin composition comprising (c) a vinyl monomer (d) a curing agent. 3. The unsaturated polyester resin composition according to claim 1 or 2, wherein the epoxy modified block polymer as the component (b) has an epoxy equivalent of 140 to 10,000.