JPH0333747B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention exhibits excellent performance in compound viscosity characteristics before curing, surface characteristics (surface smoothness, surface gloss) of molded products after curing, and impact resistance, and is suitable for sheet molding compounds. The present invention relates to unsaturated polyester resin compositions that can be used as bulk molding compounds (SMC) or bulk molding compounds (BMC). (Prior Art) 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 outer panel parts and structural parts of automobiles. In general, molded products using unsaturated polyester resins have a mold shrinkage rate of 4 to 12% during curing, so thermoplastic resins such as polystyrene, polymethyl methacrylate, and polyvinyl acetate are usually It is formulated as a shrinking agent. However, even in these cases, phase separation may occur between the unsaturated polyester resin and the low shrinkage agent after compounding, and undesirable surface characteristics such as warpage and waviness may still be induced even after the molded product is formed. This is the current situation. Therefore, in unsaturated polyester resin compositions, there is a tendency to emphasize not only the improvement of impact resistance but also the surface properties and thickening properties after compounding, and improvement of these properties has become an important issue. . For this reason, many attempts to improve these properties have been proposed. For example, in JP-A-48-34289 and JP-A-49-30480, unsaturated polyester containing a styrene-butadiene block copolymer has been proposed. Resin compositions have been proposed. but,
In these methods, the added styrene-butadiene block copolymer component and unsaturated polyester resin component undergo phase separation after compounding, resulting in a cured product with poor surface properties and impact resistance. be. In an attempt to improve this drawback, JP-A-52-
148588 and JP-A-54-130653 propose unsaturated polyester resin compositions containing a styrene-butadiene block copolymer containing a carboxyl group or a salt thereof at the end of the molecular chain. However, even with these methods, the problem of phase separation between the rubber component and the unsaturated polyester resin component cannot be essentially solved, and the reality is that the surface properties and impact resistance have not been improved. Under these circumstances, attempts to further improve these problems were made in Japanese Patent Application Laid-open No. 115309/1983,
−115310, the contents of which are as follows:
This is an unsaturated polyester resin composition characterized by adding a modified block copolymer in which a dicarboxylic acid group and/or its derivative group is bonded to a styrene-butadiene block copolymer. Also,
For the same purpose, JP-A-58-8718 discloses that a molecular unit containing a carboxylic acid group or its derivative group is added to a hydrogenated block copolymer obtained by hydrogenating a styrene-butadiene block copolymer. A method of adding a bonded modified hydrogenated block copolymer has been proposed. However, although the above-mentioned problem of phase separation after compounding with the unsaturated polyester component has been improved by using these modified block copolymers, the surface properties of the resulting cured product are still insufficient, and further manufacturing From the above viewpoint, the handling viscosity is too high and the thickening properties are insufficient. [Means for Solving the Problems] The present invention has been made to solve the problems that could not be solved with the conventional techniques described above, and by using a specific modified hydrogenated block copolymer, impact resistance can be improved. This invention was made based on the discovery that a cured product of an unsaturated polyester resin composition having excellent surface smoothness, surface gloss, and dimensional stability as well as surface smoothness can be obtained. That is, the present invention comprises (a) an unsaturated polyester resin, (b) a polymer block A mainly composed of at least one vinyl aromatic compound, and a polymer block B mainly composed of at least one conjugated diene compound. Hydrogenating a block copolymer consisting of
0.01 to 20 parts by weight of an epoxy group-containing unsaturated compound is added to 100 parts by weight of a hydrogenated block copolymer obtained by hydrogenating at least 80% of the aliphatic double bonds based on the conjugated diene compound in the copolymer. The present invention provides an unsaturated polyester resin composition comprising a grafted modified hydrogenated block copolymer, (c) a vinyl monomer, and (d) a curing agent. The present invention will be described in detail below. The unsaturated polyester resin used as component (a) in the present invention is obtained by a condensation reaction between an α,β-unsaturated dibasic acid or a mixture of this and a saturated dibasic acid, and a polyhydric alcohol. It 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. In addition, saturated dibasic acids include phthalic acid, halogenated phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hettic acid, endomethylenetetrahydrophthalic acid, succinic acid, adipic acid, glutaric acid, sebacic acid, pimelic acid, or These acid anhydrides can be mentioned. Furthermore, if necessary, monobasic acids such as acrylic acid and methacrylic acid, and polybasic acids such as trimellitic acid, hemimelittic acid and trimesic acid can be used in combination with the above-mentioned dibasic acids as modifiers. Ethylene glycol is a polyhydric alcohol,
Diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3
-butanediol, tetramethylene glycol,
Examples include 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, and ethylene oxide and/or propylene oxide adducts of hydrogenated bisphenol A. Further, if necessary, higher aliphatic alcohols such as amyl alcohol, hexyl alcohol, pentyl alcohol, and octyl alcohol, and polyhydric alcohols such as tetrahydrofurfuryl alcohol can be used in combination. The unsaturated polyester resin obtained using these components may be produced by any known method. Next, the modified hydrogenated block copolymer used as component (b) of the present invention is a hydrogenated block copolymer to which an epoxy group-containing unsaturated compound is grafted, and the hydrogenated block copolymer used as the base teeth,
It is obtained by hydrogenating a block copolymer consisting of a polymer block A mainly composed of at least one vinyl aromatic compound and a polymer block B mainly composed of at least one conjugated diene compound. , for example, A-B, A-B-A, B-A-
B-A, (A-B-) ₄ -Si, A-B-A-B-A
This is a hydrogenated vinyl aromatic compound-conjugated diene compound block copolymer having the following structure. This hydrogenated block copolymer contains a vinyl aromatic compound in an amount of 5 to 95% by weight, preferably 10 to 80% by weight. , a homopolymer block of a vinyl aromatic compound, or a copolymer block of a vinyl aromatic compound and a hydrogenated conjugated diene compound containing more than 50% by weight and preferably 70% by weight or more of a vinyl aromatic compound. and furthermore, the polymer block mainly composed of a hydrogenated conjugated diene compound is a homopolymer block of a hydrogenated conjugated diene compound or a hydrogenated conjugated diene compound containing 50% by weight. It has a structure of a copolymer block of a hydrogenated conjugated diene compound and a vinyl aromatic compound containing more than 70% by weight, preferably 70% by weight or more. In addition, polymer block A mainly composed of these vinyl aromatic compounds and polymer block B mainly composed of hydrogenated conjugated diene compounds are composed of hydrogenated conjugated diene in the molecular chain of each polymer block. The distribution of the compound or vinyl aromatic compound may be random, tapered (monomer component increases or decreases along the molecular chain), partially block-like, or any combination thereof, and the vinyl aromatic When there are two or more polymer blocks each consisting mainly of a group compound and the hydrogenated conjugated diene compound, each polymer block may have the same structure or may have different structures. It may be a structure. As the vinyl aromatic compound constituting the hydrogenated block copolymer, one or more types can be selected from, for example, styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, etc.
Among them, styrene is preferred. Further, examples of the conjugated diene compound before hydrogenation constituting the hydrogenated conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-
One or more types are selected from 1,3-butadiene and the like, and among them, butadiene, isoprene, and a combination thereof are preferred. The microstructure of a polymer block mainly composed of a conjugated diene compound before hydrogenation can be arbitrarily selected. For example, in a polybutadiene block, the 1,2-vinyl bond structure is 20
~65%, preferably 25-45%. Further, the number average molecular weight of the hydrogenated block copolymer used in the present invention having the above structure is 5000 to 5000.
1,000,000, preferably 10,000 to 800,000, more preferably 30,000 to 500,000, and the molecular weight distribution [ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw/Mn)] is 10 or less. Further, the molecular structure of the hydrogenated block copolymer may be linear, branched, radial, or any combination thereof. These block copolymers may be produced by any method as long as they have the above structure. For example, by the method described in Japanese Patent Publication No. 40-23798, a vinyl aromatic compound-conjugated diene compound block copolymer is synthesized in an inert solvent using a lithium catalyst, and then such vinyl aromatic compound, As a method for producing a hydrogenated product of a conjugated diene compound block copolymer, for example,
Although it can also be obtained by the method described in Publication No. 8704 and Japanese Patent Publication No. 43-6636, titanium-based hydrogenated block copolymers exhibit particularly excellent weather resistance and heat deterioration resistance. Hydrogenated block copolymers synthesized using catalysts are most preferred; for example, JP-A-59-133203, JP-A-60-79005
A hydrogenated block copolymer, which will become the base of the modified hydrogenated block copolymer of the present invention, is synthesized by hydrogenation in an inert solvent in the presence of a titanium-based hydrogenation catalyst according to the method described in the publication. can do. At this time, at least 80% of the aliphatic double bonds based on the conjugated diene compound of the vinyl aromatic compound-conjugated diene compound block copolymer are hydrogenated, and the polymer block mainly composed of the conjugated diene compound is transformed into an olefin. It is necessary to convert the compound into a polymer block. In addition, hydrogen of an aromatic double bond based on a vinyl aromatic compound copolymerized into a polymer block A mainly composed of a vinyl aromatic compound and, if necessary, a polymer block B mainly composed of a conjugated diene compound. Although there is no particular restriction on the addition rate, it is preferable that the hydrogenation rate is 20% or less. The amount of non-hydrogenated aliphatic double bonds contained in the hydrogenated block copolymer can be easily determined using an infrared spectrophotometer, nuclear magnetic resonance apparatus, or the like. Next, the epoxy group-containing unsaturated compound used in the synthesis of the modified hydrogenated block copolymer of the present invention is as follows:
All compounds having an unsaturated group and an epoxy group in the molecule can be used, but preferred epoxy group-containing unsaturated compounds include compounds represented by the following general formulas () and (). (In the formula, R represents hydrogen, a lower alkyl group, or a lower alkyl group substituted with a glycidyl ester group.) (In the formula, R represents hydrogen, a lower alkyl group, or a lower alkyl group substituted with a glycidyl ester group.) Preferred specific examples include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, and allylglycidyl. Among them, preferred epoxy group-containing unsaturated compounds include glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether. In addition to these epoxy group-containing unsaturated compounds,
diglycidyl maleate, methylglycidyl maleate, ethylglycidyl maleate, isopropylglycidyl maleate, t-butylglycidyl maleate, diglycidyl fumarate, methylglycidyl fumarate, isopropylglycidyl fumarate, Epoxy group-containing unsaturated compounds such as diglycidyl itaconate, methylglycidyl itaconate, isopropylglycidyl itaconate, diglycidyl 2-methyleneglutarate, and methylglycidyl 2-methyleneglutarate can also be suitably used. These epoxy group-containing unsaturated compounds can be used alone or in combination of two or more. In order to obtain the modified hydrogenated block copolymer of the present invention, the epoxy group-containing unsaturated compound used during graft modification is preferably used in the range of usually 0.02 to 30 parts by weight per 100 parts by weight of the hydrogenated block copolymer. Can be done. The modified hydrogenated block copolymer of the present invention is obtained by grafting the above-mentioned epoxy group-containing unsaturated compound onto the hydrogenated block copolymer having the above structure in the presence or absence of an organic peroxide. The reaction can be carried out in either a molten state or a solution state. Furthermore, the modified hydrogenated block copolymer obtained by this modification reaction is 0.01 to 20 parts by weight, preferably 0.05 to 10 parts by weight, and more preferably 0.1 to 5 parts by weight per 100 parts by weight of the hydrogenated block copolymer. The epoxy group-containing unsaturated compound grafted thereon may contain 0 to 29.99 parts by weight of the unreacted epoxy group-containing unsaturated compound. Grafting amounts other than this will not give favorable results regarding the thickening properties and phase separation of the resulting unsaturated polyester resin composition after compounding. In particular, if the grafting amount exceeds 20 parts by weight, the desired This gives a compound with a much higher viscosity than the viscosity at the time of molding, making it difficult to mold, which is undesirable. Therefore, grafting amounts outside of these ranges are not preferable because the resulting cured product will have non-uniformity in surface characteristics and physical properties. Next, examples of organic peroxides that can be provided as needed in the graft reaction of this modified hydrogenated block copolymer include dicumyl peroxide, di-tert-butyl peroxide,
tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)
Hexane, 2,5-dimethyl-2,5-di(tert
-Butylperoxyhexine-3, n-butyl-
4,4-bis(tert-butylperoxy)valerate, 1,1-bis(tert-butylperoxy)
Examples include 3,3,5-trimethylcyclohexane, and one or more types can be suitably selected from these. In addition to these organic peroxides, radical initiators such as 2,3-dimethyl-2,3,diphenylbutane, 2,3-diethyl-2,3-diphenylbutane, and 2,3-dimethyl-2,6-diphenylbutane are also used. (p-
methylphenyl)butane, 2,3-dimethyl-
The graft reaction may be carried out using a compound such as 2,3-di(bromophenyl)butane. The above-mentioned organic peroxides and radical initiators that can be used in this graft reaction can be suitably used in the range of usually 0.01 to 5 parts by weight per 100 parts by weight of the hydrogenated block copolymer. Further, in the modified hydrogenated block copolymer of the present invention, unreacted epoxy group-containing unsaturated compounds may be completely removed or may be left as is. The production method can be carried out by any known method. For example, when the modified hydrogenated block copolymer is obtained using a kneader such as an extruder, the modified hydrogenated block copolymer is produced using a vent extruder. While carrying out the reaction, the amount of unreacted epoxy group-containing unsaturated compound remaining in the hydrogenated block copolymer may be controlled by forced venting. Furthermore, for example, an epoxy group-containing unsaturated compound can be grafted to the hydrogenated block copolymer in a state in which it is dissolved in a solvent or in a state in which it is suspended. When performing these graft reactions, it is also possible to coexist a vinyl monomer copolymerizable with the epoxy group-containing unsaturated compound, and naturally the modified hydrogenated block copolymer obtained here can be used in accordance with the present invention. (b)
It can be suitably used as a component. As the copolymerizable vinyl monomer, for example, vinyl monomers such as styrene, acrylonitrile, acrylic ester, and methacrylic ester can be suitably used. Furthermore, the amount of the grafted epoxy group-containing unsaturated compound in the modified hydrogenated block copolymer is
It can be easily determined by known methods, and specifically, it can be determined by instrumental analysis such as an infrared spectrophotometer or NMR, or by titration analysis of epoxy value. Furthermore, the remaining amount of unreacted epoxy group-containing unsaturated compounds contained in the modified hydrogenated block copolymer of the present invention can be easily measured by, for example, gas chromatography. As mentioned above, the method for producing the modified hydrogenated block copolymer of the present invention is not particularly limited in the present invention. Production methods that include undesirable components or that significantly increase the melt viscosity and solution viscosity and deteriorate processability are not preferred. An example of a preferred manufacturing method is, for example, in a vented extruder.
At a temperature of 150 to 350°C, the hydrogenated block copolymer, epoxy group-containing unsaturated compound, vinyl monomer that can be copolymerized with the epoxy group-containing unsaturated compound, organic peroxide, etc. are added as necessary. There is a method of melt-kneading and radical modification. At this time, a stabilizer may be added as necessary to prevent the formation of gel or the like. Examples of the stabilizer include known antioxidants, and phenolic antioxidants, phosphorus antioxidants, and sulfur antioxidants can be used alone or in combination. Next, the vinyl monomer used as component (c) in the present invention acts as a crosslinking component of the compound (unsaturated polyester resin composition). Examples of the vinyl monomer include styrene, various substituted products of styrene, such as α-methylstyrene, vinyltoluene, dimethylstyrene, trimethylstyrene, halogenated styrene, tert-butylstyrene, styrene sulfonate, amino styrene,
Vinyl aromatic compounds such as p-benzystyrene and p-phenoxystyrene, acrylic acid or methacrylic acid and methyl alcohol, ethyl alcohol, propyl alcohol, octyl alcohol,
Esters with aliphatic alcohols such as hexanol, tetrahydrofurfuryl alcohol, ethylene glycol, propylene glycol, etc.; acrylic acids or methacrylates such as 2-aminoethyl-methacrylate, N,N-diethylamino-acrylate, N,N-diethylamino-methacrylate; Acid derivatives, α, β-unsaturated dicarboxylic acids such as maleic acid, fumaric acid, crotonic acid, itaconic acid, etc. or their acid anhydrides, esters, amides, imides, etc., fumaric acids such as diethyl fumarate, dioctyl fumarate, etc. In addition to acid esters,
Various vinyl and vinylidene monomers, such as acrylonitrile, methacrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride, vinylene carbonate, vinyl-2-chloroethyl ether, _C8 - _C18 alkyl vinyl ethers, _C8 - _C18 vinyl ester of fatty acid, 2-
Examples include vinylfuran, vinylphenol, vinylphenyldisiloxane, 2-vinylpyridine, 4-vinylpyridine, vinylpyrrole, vinylpyrrolidone, vinylsulfonic acid, vinylurethane, methylvinylketone-2-vinylquinoline, vinylcarbazole, etc. . Also, conjugated diene compounds such as 1,3-butane diene, isoprene, piperylene, methylpentadiene, chloroprene, and 2-methoxybutane diene and 1-
Alkoxy and cyano derivatives of conjugated dienes such as cyanobutane diene can also be used. Furthermore, polyfunctional crosslinkable vinyl monomers such as diallyl maleate, diallyl phthalate, divinylbenzene, divinyl ether, neopentyl glycol diacrylate, diallyl cyanurate, triallyl cyanurate, diallylphenyl 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, vinyltoluene, α-methylstyrene, chlorostyrene, divinylbenzene, methyl methacrylate,
Examples include methyl acrylate, diallyl phthalate, triallyl cyanurate, and the like. The curing agent as component (d) used in the present invention is:
Organic peroxides, organic hydroperoxides and azo compounds can be used. Some peroxides useful in this invention include dialkyl peroxides and diacyl peroxides. Alkyl peroxides have the general structure R-OO-R', where R and R' are the same or different primary, secondary or tertiary alkyl, cycloalkyl, aralkyl or heterocyclic groups. . Groups of peroxides suitable for use in the compositions of the invention include dicumyl peroxide, di-tert-butyl peroxide,
tert-butylcumyl peroxide and 2,5
-dimethyl-2,5-bis(tert-butylperoxy)hexane. Diacyl peroxide has the general structure RC(O)-
OO-C(O)R', where R and
R' is the same or different alkyl group, cycloalkyl group, aralkyl group, aryl group or heterocyclic group. Some examples of diacyl peroxides suitable for use in the present invention include dilauroyl peroxide, dibenzoyl peroxide, dicetyl peroxide, didecanoyl peroxide, di-(2,4-dichlorobenzoyl)
There are peroxides, diisononanoyl peroxide and 2-methylpentanoyl peroxide. Additionally, other peroxides useful in the present invention include particularly preferred peresters, such as tert-
Along with butyl peroxide and tert-butyl perbenzoate, methyl ethyl ketone peroxide, cyclohexanone peroxide, and the like are included. Examples of hydroperoxides suitable for use in the present invention include, for example, tert-butyl hydroperoxide, cumyl hydroperoxide, 2,5-dimethyl-2,5-dihydroperoxyhexane, p- Mentha hydroperoxide and diisopropylbenzene hydroperoxide. Examples of azo compounds that can be used in the present invention include diazoaminobenzene, N,N'-dichloroazodicarboxylic acid amide,
Examples include azodicarboxylic acid diethyl ester, 1-cyano-1-(tert-butylazo)cyclohexanone and azobis(isobutyronitrile). The blending ratio of each component constituting the unsaturated polyester resin composition of the present invention is 10 to 90 parts by weight of component (a), preferably 20 to 80 parts by weight, more preferably 20 parts by weight.
~60 parts by weight, 2 to 70 parts by weight of component (b), preferably 5 to 50 parts by weight, more preferably 5 to 40 parts by weight, (c)
Component (d) of the curing agent is comprised of 10 to 80 parts by weight, preferably 20 to 70 parts by weight, and component (d) of the curing agent is
0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, more preferably
It is 0.5 to 3 parts by weight. In addition, desired amounts of various organometallic compounds and the like can be added as curing accelerators, if necessary. In addition to the above, it is also a practical aspect of the present invention that the composition of the present invention may contain the unmodified hydrogenated block copolymer described above and the hydrogenated block copolymer described above in any ratio. The embodiment may further include other additives as necessary, such as
Thickeners, fiber reinforcing materials, inorganic fillers, low shrinkage agents, pigments, coloring agents, lubricants, mold release agents, etc. can be added. The above-mentioned thickener is 0.5 to 10 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight of the components (a) to (c) of the composition of the present invention.
A suitable amount can be selected from 5 parts by weight. In addition, fiber reinforcement materials include glass, metal, silicate,
The fiber is selected from fibers such as asbestos, cellulose, carbon, graphite, polyester, polyacrylic, 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 to 200 parts by weight, and more preferably 20 to 100 parts by weight, per 100 parts by weight of the components (a) to (c) of the composition of the present invention. It can be suitably used. Inorganic fillers that can be used in the composition of the present invention are inorganic particulate fillers, such as calcium carbonate, calcium silicate, silica, calcined clay, chalk, talc, limestone, anhydrous calcium sulfate, barium sulfate, and asbestos. , powdered glass, quartz, aluminum hydrate, aluminum oxide, antimony oxide, etc., and the amount added is 50 to 100 parts by weight of the total of components (a) to (c) of the present invention.
It can be used in an amount of 800 parts by weight, preferably 100 to 400 parts by weight, and more preferably 100 to 300 parts by weight. Further, the low shrinkage agents that can be used in the composition of the present invention include polystyrene-based, poly(meth)acrylate-based, polyvinyl acetate-based, polyvinyl chloride-based, polyethylene-based, polypropylene-based, polyamide-based, polycarbonate-based, and cellulose-based. Any homopolymer or copolymer such as a polymer can be selected, and the amount added is 0 per 100 parts by weight of components (a) to (c) of the composition of the present invention.
It can be used in a range of 40 parts by weight, preferably 2 to 20 parts by weight. A preferred method for producing the unsaturated polyester resin composition of the present invention is as follows. That is, a first mixture containing an unsaturated polyester resin which is the component (a) of the present invention and a vinyl monomer which is the component (c), a modified hydrogenated block copolymer which is the component (b), and (c) A second mixture containing a vinyl monomer as a component is mixed, and at this time, a curing agent as component (d) and, if necessary, a filler, are added to either or both of the first mixture and the second mixture. This manufacturing method involves mixing additives such as a fiber reinforcing material, a thickener, a low shrinkage agent, and a mold release agent. The unsaturated polyester resin composition of the present invention obtained by these methods can be molded into a cured product by a method such as compression molding or injection molding, preferably through an intermediate compound such as SMC or BMC. [Effects of the Invention] By using a specific modified hydrogenated block copolymer as component (b), the present invention improves the initial viscosity of the compound, reduces the decrease in viscosity during heating, and improves surface properties and dimensional stability. It is possible to provide an unsaturated polyester resin composition with excellent properties and impact resistance. The unsaturated polyester resin composition of the present invention can be particularly suitably used as structural materials for automobile parts including automobile outer panels, transportation equipment such as boats, bathtubs, septic tanks, dressing tables, chairs, and the like. [Example] In order to explain the present invention in more detail, the present invention will be explained using Examples, but the present invention is not limited thereto. . Reference Example 1 Preparation of unsaturated polyester resin A mixture consisting of 0.7 mol of maleic anhydride, 1.4 mol of phthalic anhydride, 2.0 mol of propylene glycol, and 0.2 mol of diethylene glycol was heated to about 100°C under a nitrogen stream and stirred. , while gradually increasing the temperature to approximately 210℃ while removing condensed water from the system.
An esterification reaction was carried out at this temperature to synthesize an unsaturated polyester resin with an oxidation rate of 40. This unsaturated polyester resin was dissolved in styrene, and a solution having a solid content concentration of 65% by weight was used as component (a-1). Also, 0.6 mol of isophthalic acid, 0.6 mol of phthalic anhydride
A mixture consisting of 1.4 moles of maleic anhydride and 2.6 moles of propylene glycol was subjected to an esterification reaction in the same manner as above to synthesize an unsaturated polyester resin with an oxidation level of 30. This unsaturated polyester resin is dissolved in styrene, and the solid content concentration is 65% by weight.
The solution was used as component (a-2). Reference Example 2 Preparation of modified hydrogenated block copolymer It has a structure of hydrogenated polybutadiene-polystyrene-hydrogenated polybutadiene-polystyrene, the amount of bound styrene is 18% by weight, and 1 and 2% of the polybutadiene portion before hydrogenation. - Vinyl bond amount is 43%, number average molecular weight is 57000, molecular weight distribution is 1.03,
A hydrogenated block copolymer with a hydrogenation rate of 99% was published in 1983-
Synthesized using a Ti-based hydrogenation catalyst described in Publication No. 133203. Per 100 parts by weight of this hydrogenated block copolymer, 5.0 parts by weight of glycidyl methacrylate and 0.6 parts by weight of di-tert-butyl peroxide were mixed to give 190 parts by weight.
Forced venting using a vacuum pump in a 45mmφ vented twin-screw extruder set at ℃ (degree of vacuum: 750mmHg)
The denaturation reaction was carried out under pressure (gauge pressure). The obtained modified hydrogenated block copolymer was refluxed with acetone in a Soxhlet extractor for 20 hours, and the epoxy value was titrated and analyzed, and it was found that 2.9 parts by weight of glycidyl methacrylate had been grafted. Further, unreacted glycidyl methacrylate contained in this modified hydrogenated block copolymer was 0.8 parts by weight. This product was dissolved in styrene as component (c), and a solution with a solid content concentration of 30% by weight was used as component (b-1). Next, it has the structure of (polystyrene - hydrogenated polybutadiene) ₄ -Si, and the amount of bound styrene
30% by weight, 1 of the polybutadiene part before hydrogenation
2-vinyl bond amount is 60%, number average molecular weight is 93000,
A hydrogenated block copolymer with a molecular weight distribution of 1.48 and a hydrogenation rate of 99% was synthesized using a Ti-based hydrogenation catalyst described in JP-A-59-133203. This hydrogenated block copolymer
1.0 parts by weight of glycidyl methacrylate and 0.5 parts by weight of di-tert-butyl peroxide were mixed per 100 parts by weight, and forced venting (depressurization The denaturation reaction was carried out at a temperature of 750 mmHg (gauge pressure). The obtained modified hydrogenated block copolymer was refluxed with acetone in a Soxhlet extractor for 20 hours, and the epoxy value was titrated and analyzed, and it was found that 0.6 parts by weight of glycidyl methacrylate had been grafted. Further, this modified hydrogenated block copolymer contained 0.05 part by weight of unreacted glycidyl methacrylate. Dissolve this material in component (c) styrene to determine the solid content concentration.
A 30% by weight solution was used as component (b-2). Furthermore, it has a polystyrene-hydrogenated polybutadiene-polystyrene structure, with a bound styrene content of 30% by weight, a 1,2-vinyl bond content of the polybutadiene portion before hydrogenation of 32%, and a number average molecular weight.
44000, a molecular weight distribution of 1.05, and a hydrogenated block copolymer with a hydrogenation rate of 99% as described in JP-A-59-133203.
Synthesized using Ti-based hydrogenation catalyst. 2.0 parts by weight of glycidyl methacrylate and 0.5 parts by weight of di-tert-butyl peroxide were mixed per 100 parts by weight of this hydrogenated block copolymer, and a 45 mm film was prepared at 190°C.
The modification reaction was carried out using a φ vented twin-screw extruder while performing forced venting (degree of vacuum: 750 mmHg gauge pressure) using a vacuum pump. The obtained modified hydrogenated block copolymer was subjected to a reflex treatment using acetone in a Soxhlet extractor for 20 hours, and titration analysis of the epoxy value revealed that 1.4 parts by weight of glycidyl methacrylate had been grafted.
Further, the modified hydrogenated block copolymer after extraction with acetone did not contain any unreacted glycidyl methacrylate. This modified hydrogenated block copolymer containing no unreacted glycidyl methacrylate was dissolved in the styrene component (c), and a solution with a solid content concentration of 30% by weight was prepared (b-
3) As a component. Examples 1 to 4, Comparative Examples 1 to 3 A styrene solution of the unsaturated polyester resin as the component (a) synthesized in the reference example, a styrene solution of the modified hydrogenated block copolymer as the component (b), and a styrene solution of the modified hydrogenated block copolymer as the component (d). 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 viscosity of the aged compound at 23°C and the viscosity of this aged compound at 70°C were measured using a Bruckfield viscometer HBT type. The results are listed in Table 1. In the comparative example, instead of the styrene solution of the modified hydrogenated block copolymer as component (b), a styrene solution of the corresponding unreacted hydrogenated block copolymer was used. These results revealed that the unsaturated polyester resin composition of the present invention had a higher compound viscosity at 70° C. than the comparative example, and had the characteristics of less decrease in viscosity upon heating. Examples 5 to 8, Comparisons 4 to 6 Glass fiber (PPG-3198; manufactured by PPG) was added to each of the basic formulations of Examples 1 to 4 and Comparative Examples 1 to 3.
SMC was prepared by blending 100 parts and aged at 40°C for 48 hours. Thereafter, it was pressure molded under conditions of 140°C and 85 kg/cm ² to obtain a cured unsaturated polyester resin composition. Table 2 lists the physical property measurement results for each molded product. From this result, the unsaturated polyester resin composition of the present invention has a surface smoothness with "large undulations".
Also, no "small waviness" was observed, and the surface gloss was 60% or more, indicating excellent surface properties. Furthermore, the shrinkage rate during molding was negative (expansion), and it was found that it is highly effective as a low-shrinkage agent. On the other hand, it was revealed that the unsaturated polyester resin composition using the unmodified hydrogenated block copolymer shown in the comparative example was poor in the balance of surface smoothness, surface gloss, and low shrinkage.

【table】

【table】

Claims (1)

[Scope of Claims] 1 (a) an unsaturated polyester resin; (b) a polymer block A mainly composed of at least one vinyl aromatic compound; and a polymer block mainly composed of at least one conjugated diene compound. Hydrogenating a block copolymer consisting of B,
0.01 to 20 parts by weight of an epoxy group-containing unsaturated compound is added to 100 parts by weight of a hydrogenated block copolymer obtained by hydrogenating at least 80% of the aliphatic double bonds based on the conjugated diene compound in the copolymer. An unsaturated polyester resin composition comprising a grafted modified hydrogenated block copolymer, (c) a vinyl monomer, and (d) a curing agent.