JPH0217568B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is directed to fiber-reinforced plastics (hereinafter referred to as
This invention relates to a fiber-reinforced resin composition that has excellent water resistance, heat resistance, chemical resistance, and mechanical strength and is suitable for manufacturing (abbreviated as FRP). [Prior art] Due to the excellent physical properties of composite materials, FRP has been widely used in Japan in recent years, including construction materials such as bathtubs, septic tanks, and aquariums, as well as fishing boats, boats, and even corrosion-resistant equipment. , has been established in various fields, but as its applications become more diverse,
The performance required of FRP is also becoming increasingly sophisticated. For example, hot water storage tanks are now required to have water resistance and chemical resistance that exceed the water resistance and chemical resistance of existing radical curable resins. The water resistance and chemical resistance of FRP naturally depend on the structure of the polymer as a matrix. It is known that the constituent molecules of the polymer or main chain oligomer have ester bonds, and the concentration of these ester bonds is a factor that influences performance. Therefore, even if we try to further improve the physical properties of these existing radical-curing resins, there are factors such as ester bonds in the main chain that impair the physical properties, so it is difficult to improve the physical properties beyond a certain level. is virtually impossible. [Problems to be Solved by the Invention] The present inventors removed the drawbacks of existing radical curable resins and, as a result of various studies on curable resins as matrices, discovered that physical properties such as ester bonds in the main chain The main chain polymer is a polymer obtained by polymerization of vinyl monomers that does not contain any factors that impair the properties, and the side chain has an acryloyl group or methacryloyl group as a crosslinking point by radical curing via an epoxy residue structure. We have already proposed that a saturated bond type resin is effective. However, when this side chain unsaturated bond type resin is used alone as a matrix resin, it has the disadvantage that curing is slow and requires a relatively long time for complete curing. From this point of view, the present inventors further investigated and found that a curable resin composition comprising a side chain unsaturated bond type resin, an unsaturated alkyd, and, if necessary, a polymerizable monomer as a matrix resin, overcomes the above-mentioned drawbacks. The present invention was completed by discovering that the problem can be solved. [Means for solving the problem] That is, the present invention provides (A) general formula [However, A is a main chain consisting of a copolymer resin of at least one vinyl monomer selected from the group consisting of styrene, (meth)acrylic acid ester, vinyl chloride, vinyl acetate, and acrylonitrile and an acryloyl group or a methacryloyl group. , R is hydrogen or a methyl group,
Y is the residue of an epoxy resin in which the ester bond is removed from the epoxy group in the molecule formed by the ring-opening addition reaction with the carboxyl group. 95% by weight and (B) unsaturated polybasic acid obtained by esterifying an α/β-unsaturated polybasic acid or its acid anhydride, or a mixture of this and a saturated polybasic acid or its acid anhydride, and a polyhydric alcohol. 95 to 5% by weight of alkyd, and (C) a fibrous material, the polymerization content of the fibrous material being in the composition.
A fiber-reinforced resin composition characterized in that the content is in the range of 10 to 70%, and (D) if necessary, a polymerizable monomer is further added to 100 parts by weight of the mixture of side chain unsaturated bond type resin and unsaturated alkyd. It relates to a fiber-reinforced resin composition containing 10 to 60 parts by weight. [Function] In the present invention, the effect of blending the side chain unsaturated bond type resin and the unsaturated alkyd is extremely remarkable.
In other words, side chain unsaturated bond type resins have the disadvantage of slow curing and require a relatively long time for complete curing, while unsaturated alkyds have poor water resistance,
Although it has the disadvantage of insufficient chemical resistance and adhesion, these defects in both components can be resolved by mixing a high molecular weight (molecular weight of approximately 10,000 or more) side chain unsaturated bond type resin and unsaturated alkyd. When this resin is blended into a fibrous material as a matrix resin, a fiber-reinforced resin composition with excellent curability, water resistance, chemical resistance, and mechanical strength can be obtained. . As a first method, the side chain unsaturated bond type resin used in the present invention is prepared by: (1) per equivalent of epoxy group of the epoxy resin;
Acryloyl group or methacryloyl group [hereinafter abbreviated as (meth)acryloyl group] and epoxy group in the molecule obtained by reacting about 0.1 to 0.5 equivalents of acrylic acid or methacrylic acid [hereinafter abbreviated as (meth)acrylic acid]. and (2) a vinyl monomer, to produce a polymer-containing reaction mixture having epoxy resin groups in the side chains of the resulting polymer; It is produced by adding (meth)acrylic acid in an amount substantially equivalent to the epoxy groups remaining in the resulting reaction mixture to react the epoxy groups with the carboxyl groups. In addition, as a second method, (1) a vinyl copolymer having a carboxyl group in the side chain obtained by copolymerizing (meth)acrylic acid and a vinyl monomer, and (2) an epoxy group 1 of an epoxy resin. for equivalent weight
A vinyl copolymer with at least one component of an unsaturated epoxy resin having a (meth)acryloyl group and an epoxy group in the molecule obtained by reacting 0.5 to 0.9 equivalents of (meth)acrylic acid. It can also be produced by reacting the carboxyl groups in the unsaturated epoxy resin with the epoxy groups in the unsaturated epoxy resin in substantially equivalent amounts. A typical example of the unsaturated epoxy resin produced in (1) of the first method of the present invention is shown in the following formula (A): However, in the reaction of epoxy resin and (meth)acrylic acid at an equal equivalent ratio, (A) is not produced 100%, but the following di(meth)acrylate is produced even in small amounts, and at the same time, unreacted epoxy resin remains. ,next
A mixture of (B), (C) and (A) is obtained. If even a small amount of the vinyl ester (B) is formed among these components, it will appear as gelation due to crosslinking during polymerization, making it impossible to produce a side chain unsaturated bond type resin. Therefore, in order to prevent the formation of vinyl ester resin (B), the proportion of epoxy resin used should be
It is necessary to make the amount more than equimolar with acrylic acid, and the unsaturated epoxy resin used in the present invention inevitably becomes a mixture of the above-mentioned structure (A) and structure (C). The presence of the residual epoxy resin (C), which does not initially participate in the reaction with (meth)acrylic acid, becomes useful for improving properties by later attaching a (meth)acryloyl group depending on the application. The first method of the present invention is schematically shown as follows. (i) First, a desired amount of (meth)acrylic acid and an epoxy resin in an excess equivalent ratio to (meth)acryloyl groups are combined with a necessary reaction catalyst, such as a tertiary amine, an amine salt, a quaternary ammonium salt, Unsaturated epoxy resin (A) is produced by reaction using a metal salt. (ii) Then, after adding the required type and amount of vinyl monomer, the acryloyl group of the unsaturated epoxy resin (A) and the vinyl monomer are radically polymerized in the presence of an initiator such as azobisisobutyronitrile. This gives a polymer-containing reaction mixture with epoxy groups in the side chains. (iii) Furthermore, add the required amount of (meth)acrylic acid,
By reacting the epoxy groups remaining in the reaction mixture (ii) with the carboxyl groups, the desired polymer having vinyl ester groups in the side chains can be obtained. There are no particular limitations on the epoxy resin used in the present invention. For example, as a diglycidyl ether type of bisphenol A, Epicote 827 of Yuka Shell Co., Ltd.
828, 834, 1001, Dow Company DER-330, 331,
332, Ciba's GY-257, Dainippon Ink Chemical Co., Ltd.'s Epicron #840, 850, 810, Toto Kasei Co., Ltd. Epotote VD-115, -127, Asahi Kasei Co., Ltd. AE
Examples include R330 and 331. Dow's DEN-431 and 438 are typical examples of Novolac's glycidyl ether type epoxy resin. Although there are many types of cycloaliphatic epoxy resins in the literature, in practice only ERL-4221 from Union Carbide is commercially available, and this can also be used in the present invention. In addition, as a special epoxy resin, a biphenyl type resin called YX-4000 manufactured by Yuka Shell Co., Ltd. can also be used. A diglycidyl ether type epoxy resin using bisphenol F and bisphenol S instead of bisphenol A, such as Epicote 807 type manufactured by Yuka Shell Co., Ltd., can also be used. There is also a type in which alkylene oxide is added to bisphenol A and the terminal hydroxyl group is epoxidized with epichlorohydrin. Among these, preferred epoxy resins are phenyl glycidyl ether type polyaddition homologs synthesized from bisphenol and epichlorohydrin. Its general formula is shown, for example, as follows: (However, n=0 to 5, and R ₁ and R ₂ are hydrogen or methyl groups.) The most suitable type for the present invention is one in the above formula in which n is about 0 to 3. (Meta) when synthesizing unsaturated epoxy resin (A)
The ratio of acrylic acid to epoxy resin is 1 mole of (meth)acrylic acid (i.e. 1 mole of carboxyl group).
If the epoxy resin has 2 or 3 or more glycidyl ether type epoxy groups in one molecule, 1 mole or more if there are 2 epoxy groups, or 1 mole or more if there are more than 2 epoxy groups. It is necessary to use 1 mole or more, and the epoxy group needs to be in an amount of more than 2 equivalents. Preferably epoxy group 1
0.1 to 0.5 equivalents of (meth)acrylic acid are used per equivalent. Vinyl monomers for use with unsaturated epoxy resins to form polymeric cores include (meth)
Any type can be used as long as it is copolymerizable with an acryloyl group. Typical examples of these include styrene, α-methylstyrene, vinyltoluene, chlorostyrene, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tertiary butyl acrylate, 2-ethylhexyl acrylate, and methacrylate. Methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tertiary butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, tetrahydrofurfuryl methacrylate, acrylonitrile, acetic acid Examples include vinyl and vinyl chloride. Copolymerization can be carried out by bulk polymerization, solution polymerization, pearl polymerization, etc. In the case of bulk polymerization or solution polymerization, the copolymerization is used as it is in the next reaction with (meth)acrylic acid. In the case of pearl polymerization, the resulting copolymer is dissolved in a monomer or solvent and then reacted with (meth)acrylic acid with the epoxy groups in the polymer. When radical copolymerizing a mixture of an unsaturated epoxy resin and a vinyl monomer, known radical polymerization catalysts such as organic peroxides and azo compounds are used in combination. Furthermore, the ratio of the (meth)acryloyl group of the unsaturated epoxy resin to the vinyl monomer can be varied widely such that the ratio of the vinyl monomer is 99 mol% to 1 mol%, and varies depending on the application. However, generally between 95 mol% and 50 mol% is suitable. In order to react the epoxy groups remaining in the polymer which has an epoxy resin group in the side chain obtained from the copolymerization reaction with the carboxyl group, the amount of (meth)acrylic acid added to the polymer depends on the epoxy component used in the previous step. Although the amount varies depending on the amount, it is preferable to use an amount that will cause substantially all of the remaining epoxy groups to react. That is, it is preferable to use 0.9 to 1.1 equivalents, preferably 0.95 to 1.05 equivalents, of (meth)acrylic acid per equivalent of the remaining epoxy group. The second method for producing the curable resin of the present invention is to use an unsaturated epoxy resin obtained by reacting an epoxy resin with (meth)acrylic acid and a copolymer of (meth)acrylic acid and a vinyl monomer. This is a method of causing a reaction. What should be noted in the second method is that when producing the unsaturated epoxy resin, it is preferable to minimize the remaining amount of unreacted epoxy resin. If a large amount remains, it will cause gelation during the esterification reaction with the vinyl copolymer. Therefore, the ratio of (meth)acrylic acid used needs to be as close to the epoxy equivalent as possible, but since unsaturated epoxy resins are used for esterification reactions rather than copolymerization reactions, it is necessary to keep one epoxy group in the molecule. Therefore, it is preferable to react 0.5 to 0.9 equivalents of (meth)acrylic acid per equivalent of epoxy groups in the epoxy resin. In the second method, di(meth)acrylate resin is inevitably included, but since this resin originally has excellent basic performance, it does not impair the performance of the resin of the present invention. The second method of the present invention is schematically illustrated as follows. (b) A desired amount of epoxy resin and 0.5 to 0.9 equivalents of (meth)acrylic acid to the epoxy resin are reacted using the reaction catalyst described in (i) above to produce an unsaturated epoxy resin. let The epoxy resin used here is the same as that described in the first method. (b) A copolymer of vinyl monomer and (meth)acrylic acid is produced according to a conventional radical polymerization recipe. Examples of vinyl monomers include those exemplified in the first method. The ratio of vinyl monomer to (meth)acrylic acid is 99
Although it can vary widely in the range of ~1 mol%, 99-50 mol% is suitable. (c) The unsaturated epoxy resin produced in (a) and the copolymer in (b) are reacted so that the epoxy groups and carboxyl groups are substantially equivalent. Reaction is the first
This is similar to the method. The unsaturated alkyd used in the present invention is obtained by esterifying an α/β-unsaturated polybasic acid or its acid anhydride, or a mixture of this and a saturated polybasic acid or its acid anhydride with a polyhydric alcohol. That's what you get. Examples of the α/β-unsaturated polybasic acid or its acid anhydride include maleic anhydride, maleic acid, fumaric acid, and itaconic acid. As a saturated polybasic acid or its acid anhydride,
Examples include phthalic anhydride, isophthalic acid, terephthalic anhydride, hexahydrophthalic anhydride, succinic acid, adipic acid, sebacic acid, and tetrachlorophthalic anhydride. Although it has unsaturated bonds, it is not an unsaturated acid in the sense of α/β-unsaturated polybasic acids, but is a polybasic acid that is conventionally treated like a saturated acid. Examples include phthalic anhydride, methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, and Hett's acid. As the polyhydric alcohol, divalent to trivalent alcohols are used, and divalent glycol is usually preferably used. Typical examples include propylene glycol, dipropylene glycol, ethylene glycol, diethylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, hydrogenated bisphenol A, bisphenol A-ethylene oxide adduct, and bisphenol A-ethylene oxide adduct. Phenol A-propylene oxide adduct, 1,4-
Examples include cyclohexanedimethanol, trimethylolpropane, and glycerin. Esterification is carried out according to conventional methods. The type of unsaturated alkyd cannot be determined simply because it depends on the physical properties required for the product.
Copolymerizable monomers can be used in combination with unsaturated alkyds if necessary, and for most applications it is preferable to use monomers in combination, but for applications such as molding materials and decorative laminates, Monomers may not be used together. Examples of copolymerizable monomers include styrene, vinyltoluene, methyl methacrylate, diallyl phthalate, and the like. The mixing ratio of the side chain unsaturated bond type resin and the unsaturated alkyd cannot be determined unconditionally as it varies depending on the performance required of the product, but generally it is 5 to 95% by weight of the side chain unsaturated bond type resin, It preferably consists of 20-80% by weight and 95-5% by weight of unsaturated alkyds, preferably 80-20% by weight. Outside this range, the remarkable effects of the present invention cannot be obtained. When using a side chain unsaturated bond type resin and an unsaturated alkyd as a matrix resin, the balance between the viscosity and curability of the resin and the From the viewpoint of ensuring physical properties, it is preferable to use a polymerizable monomer in combination. Polymerizable monomers include styrene, methyl methacrylate, ethyl methacrylate, and acrylic acid 2.
Ethylhexyl, ethylene glycol diacrylate, polyethylene glycol diacrylate,
Ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, propylene glycol diacrylate, polypropylene glycol diacrylate, propylene glycol dimethacrylate, polypropylene glycol dimethacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate,
Examples include trimethylolpropane dimethacrylate, trimethylolpropane trimethacrylate, pentaerythrit triacrylate, pentaerythritute tetraacrylate, pentaerythritute trimethacrylate, pentaerythritate tetramethacrylate, etc., and these may be used in combination. . The amount of polymerizable monomer is a mixture of side chain unsaturated bond type resin and unsaturated alkyd.
The amount is preferably 10 to 60 parts by weight per 100 parts by weight. The fibrous material used in the present invention may be either organic fiber or inorganic fiber, and specific examples include glass fiber, carbon fiber, aromatic polyamide fiber, vinylon fiber, hemp, polyester fiber, etc. . In the fiber-reinforced resin composition of the present invention, the weight content of the fibrous material is preferably within the range of 10 to 70% of the total weight of the fibrous material and the matrix (resin) component, and is practically within the range of 20 to 50%. The inside is most preferable. The fiber-reinforced resin composition of the present invention needs to contain a curing catalyst in the processing stage, and the curing catalyst is mixed with the matrix resin and mixed with the fibrous material during the production of the fiber-reinforced resin composition. Alternatively, it may be added to the fiber-reinforced resin composition at the stage of processing the composition. The method for curing the fiber-reinforced resin composition of the present invention employs a heat-curing method when the fiber-reinforced resin composition contains an organic peroxide such as benzoyl peroxide, methyl ethyl ketone peroxide, kyumene hydroperoxide, etc. Alternatively, when the fiber-reinforced resin composition contains a photosensitizer such as benzoin, benzyl, benzophenone, 2-hydroxy-3-benzoylpropane, benzoin methyl ether, etc., an ultraviolet curing method may be employed. In addition, when the fiber-reinforced resin composition contains the organic peroxide and an accelerator such as an organic acid salt of cobalt (e.g. cobalt naphthenate), an aromatic tertiary amine (e.g. dimethylaniline), etc., it may be cured at room temperature. Good too. Fillers, colorants, mold release agents, and the like can be added to the fiber-reinforced resin composition as necessary. The fiber-reinforced resin composition of the present invention is shaped into a prepreg, or is molded by a commonly used method without going through the prepreg state, to form various final molded products. [Example] Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, "parts" and "%" in the examples mean "parts by weight" and "% by weight", respectively, unless otherwise specified. Example 1 (1) Synthesis of side chain unsaturated bond type resin (A) Production of unsaturated epoxy resin (a) In a separable flask equipped with a stirrer, a thermometer with a gas introduction tube, a reflux condenser, and a dropping funnel. As epoxy resin, 360g (1 mol) of Mitsubishi Yuka-Ciel's Epicote 827, 43g of methacrylic acid.
(0.5 mol), benzyldimethylamine 1.2 g, and parabenzoquinone 0.08 g are reacted for 3 hours at 120 to 130°C under air blowing conditions. The acid value becomes almost zero and the unsaturated epoxy resin (a) turns into a pale reddish brown syrup. Obtained as follows. For resin (a), the following formula [] is calculated as 223g, It is a mixture with 180 g of free epoxy resin. Synthesis of side chain epoxy resin (b) 250g of methyl ethyl ketone,
173 g (0.2 mol) of unsaturated epoxy resin (a), 100 g of styrene, and 3.5 g of azobisisobutyronitrile were charged, and 87 g of styrene (total amount of styrene: 1.8 mol) was added dropwise at 75° C. in a nitrogen stream. After 6 hours, add 2 more azobisisobutyronitrile
g was added, and the polymerization was further continued for 10 hours. When the polymerization rate reaches 96%, hydroquinone
Polymerization was stopped by adding 0.2 g. A solution of side chain epoxy resin (b) in methyl ethyl ketone (solid content 40%) was obtained in the form of a pale yellow liquid. As a result of GPC analysis, it was confirmed that it was a mixture of a polymer with a peak at a molecular weight of about 50,000 and unreacted epoxy resin. Synthesis of side chain unsaturated bond type resin (A) Add 52 g (0.60 mol) of methacrylic acid to the entire methyl ethyl ketone solution of the side chain epoxy resin (b) described above.
When 0.8 g of triphenylphosphine is charged and reacted for 16 hours at the boiling point of methyl ethyl ketone, the acid value is
10.4, 420 g of styrene monomer was added and heated under reduced pressure of 400 to 450 mmHg to remove methyl ethyl ketone. After about 6 hours, gas chromatographic analysis showed that the methyl ethyl ketone content was 0.3%, so heating was discontinued, and side chain unsaturated bond type resin [A] was obtained with a yellowish brown color and a viscosity of 1.9 poise. (2) Synthesis of unsaturated polyester resin (B) Into a four-necked flask equipped with a stirrer, a fractional condenser, a thermometer, and a gas inlet tube, add a bisphenol A-propylene oxide adduct (with propylene oxide at both ends). Add 350g of fumaric acid (1 mole each) and 116g of fumaric acid, and add 210~220 g
Esterification was carried out at °C. When the acid value reached 35.4, 0.05 g of hydroquinone was added, poured into a metal vat, and cooled to obtain an unsaturated alkyd with a yellowish brown color and a melting point of about 80°C. 300 parts of ground unsaturated alkyd and 300 parts of styrene
1 part in a three-necked flask while stirring.
The mixture was heated to 60°C and dissolved to obtain a yellowish brown unsaturated polyester resin (B) with a viscosity of 4.7 poise. A matrix resin solution was prepared by adding 2 parts of methyl ethyl ketone peroxide, 1 part of cobalt naphthenate, and 0.1 part of dimethylaniline to 100 parts of the side chain unsaturated bond type resin (A), unsaturated polyester resin, or a mixture thereof. . Next, #450 mats 3 with Surf Ace mats placed on top and bottom
The layer is impregnated with the matrix solution and cured.
A test piece of FRP was made (glass fiber content 27-29% by weight). The bending strength, boiling resistance and 10
% caustic soda solution immersion test results are shown in Table 1, and the type using the mixed resin performed well.

[Table] Example 2 (1) Synthesis of side chain unsaturated bond type resin (C) Synthesis of unsaturated epoxy resin (c) Two separators equipped with a stirrer, a thermometer with a gas introduction tube, a dropping funnel, and a reflux condenser 72g (1 mole) of acrylic acid, bisphenol in a blue flask
A228g (1 mol), 850g (2.5 mol) of Asahi Dow #332 as an epoxy resin, 4g of triphenylphosphine, and 0.4g of t-butylhydroquinone were reacted at 120 to 130°C for 4 hours. value
In step 8.1, a resin-like unsaturated epoxy resin (c) was obtained which was pale yellowish brown and had a softening point of about 40°C. Synthesis of side chain epoxy resin (d) 600 g of unsaturated epoxy resin (c), 200 g of ethyl acrylate, 260 g of styrene, 10 g of azobisisobutyronitrile, 800 g of methyl ethyl ketone, stirrer, reflux condenser, thermometer, gas introduction tube When the polymerization was continued for 16 hours under refluxing methyl ethyl ketone in a nitrogen stream, the polymerization rate reached 94%. Add 0.5g of hydroquinone to stop polymerization.
A side chain epoxy resin (d) was obtained in the form of a dark yellowish brown liquid. Synthesis of side chain unsaturated bond type resin (B) Add 72 g (1 mol) of acrylic acid to the total amount of the side chain epoxy resin (d) mentioned above, add 2 g of triphenylphosphine, and add After reacting for a period of time, the acid value became 1.4, and infrared analysis confirmed that the epoxy group had disappeared. The obtained methyl ethyl ketone solution of the side chain unsaturated bond type resin (B) was yellowish brown and had a viscosity of about 30 poise. (2) Synthesis of unsaturated polyester resin (D) 230 g of neopentyl glycol and 232 g of isophthalic acid were charged into a four-necked flask (1) equipped with a stirrer, a fractionating condenser, a thermometer, and a gas inlet tube, and the mixture was heated with a stream of nitrogen gas. Esterification was carried out at 200-210°C. When the acid value reached 21.7, 78 g of itaconic acid was added, and esterification was continued until the acid value reached 39.7. After lowering the temperature to 150°C, 0.08 g of hydroquinone and 200 g of trimethylolpropane triacrylate were added. Next, 132 g of methyl methacrylate was added and dissolved uniformly to form an unsaturated polyester resin with a Gardner color number of 2 and a viscosity of 24.9 poise.
(D) was synthesized. To 100 parts of side chain unsaturated bond type resin (C), unsaturated polyester resin (D), or a mixture thereof, 0.1 part of Tinuvin P manufactured by Ciba Corporation as an ultraviolet absorber and 1 part of benzoyl peroxide as a curing agent. A matrix resin solution was prepared by addition and dissolution. Then,
Two plies of #300 glass mat were impregnated with the above matrix resin solution, and both sides were covered with polyethylene terephthalate film to adhere and defoam.
The mixture was gelatinized in a constant temperature bath at 100°C, and then cured at 100°C for 15 minutes. The test results, focusing on the weather resistance of the obtained FRP, are shown in Table 2. Unsaturated polyester resin (D) was used as the matrix resin.
Side chain unsaturated bond type resin (C) with a small amount of FRP weather resistance
It was found that the addition of .

[Table] Example 3 (1) Synthesis of side chain unsaturated bond type resin (E) Synthesis of side chain carboxylic acid polymer (e) 48 g of methacrylic acid in a 3 ^L glass autoclave
(0.55 mol), styrene monomer 600 g, methyl ethyl ketone 400 g, t-dodecyl mercaptan 2
g, prepare 4 g of azobisisobutyronitrile,
Polymerization was carried out at 75°C for 15 hours. Hydroquinone 0.2g
was added to inhibit polymerization. The polymerization rate of styrene monomer was 88%, and the polymerization rate of methacrylic acid was 98%. An evaporation operation was performed while adding styrene monomer to remove methyl ethyl ketone at 60° C. under reduced pressure. Methyl ethyl ketone was removed until it became less than 0.1% by weight in the evaporation distillate. Non-volatile fraction
It became a 60% by weight liquid. Synthesis of ^unsaturated epoxy resin (f) 356 g (2
Epoxy equivalent), 130 g (1.5 mol) of methacrylic acid, 1.2 g of benzyldimethylamine, and 0.16 g of parabenzoquinone were charged and reacted at 110°C for 90 minutes.
The acid value was approximately 2. The approximate composition of the obtained unsaturated epoxy resin (f) was as follows. Unsaturated epoxy resin 218g Divinyl ester resin 266g Methacrylic acid 2g Others 1g 300g of styrene monomer was added to the above solution to prepare it for the next reaction. Synthesis of side chain unsaturated bond type resin (E) Add unsaturated epoxy resin solution (f) diluted with styrene monomer to 3 ^L containing side chain carboxylic acid polymer (e).
The entire amount was poured into a glass autoclave after washing with styrene. 5 g of triphenylphosphine and 0.54 g of parabenzoquinone were added and reacted at 120°C for 90 minutes. Styrene monomer 880g Side chain unsaturated bond type resin 870g Vinyl ester resin 266g The resin liquid having the above composition was a yellowish brown transparent liquid with a weight of 15.9 poise (25°C). (2) Synthesis of unsaturated polyester resin (F) In a four-necked flask equipped with a stirrer, a fractionating condenser, a gas inlet tube, and a thermometer, add 250 g of propylene glycol and 291 g of dimethyl terephthalate.
g and 2.5 g of zinc acetate were charged, and the transesterification reaction was carried out at 180 to 200° C. while distilling methanol. At the stage when about 90 c.c. of methanol has been distilled off,
147 g of maleic anhydride was added, and esterification was continued at 190 to 200°C in a nitrogen gas stream, and the reaction was stopped when the acid value reached 34.4. After lowering the temperature to 150°C, 0.06 g of hydroquinone was added, poured into a stainless steel vat, and cooled. The obtained unsaturated alkyd was light yellowish brown in color and had a softening point of about 75°C. 100 parts of unsaturated alkyd and 100 parts of ethyl acetate were mixed at room temperature to obtain an unsaturated polyester resin solution (F). A matrix resin was prepared using the same formulation as in Example 1 using a side chain unsaturated bond type resin (E), an unsaturated polyester resin solution (F), or a mixture thereof, and a test was conducted. The results are shown in Table 3.

〔Effect of the invention〕

The fiber-reinforced resin composition of the present invention has chemical resistance and water resistance because it uses a side chain unsaturated bond type resin having a (meth)acryloyl group at the end of the side chain via an epoxy structure and an unsaturated alkyd. It has excellent adhesion and mechanical strength, as well as good curability, and is extremely useful for various molded products.

Claims (1)

[Claims] 1 (A) General formula [However, A is a main chain consisting of a copolymer resin of at least one vinyl monomer selected from the group consisting of styrene, (meth)acrylic acid ester, vinyl chloride, vinyl acetate, and acrylonitrile and an acryloyl group or a methacryloyl group. , R is hydrogen or a methyl group,
Y is the residue of an epoxy resin in which the ester bond is removed from the epoxy group in the molecule formed by the ring-opening addition reaction with the carboxyl group. 95% by weight and (B) unsaturated polybasic acid obtained by esterifying an α/β-unsaturated polybasic acid or its acid anhydride, or a mixture of this and a saturated polybasic acid or its acid anhydride, and a polyhydric alcohol. 95 to 5% by weight of alkyd, and (C) a fibrous material, the polymerization content of the fibrous material being in the composition.
A fiber-reinforced resin composition characterized in that the fiber-reinforced resin composition is in the range of 10 to 70%. 2 Add a polymerizable monomer to 100 parts by weight of the mixture of side chain unsaturated bond type resin and unsaturated alkyd.
The fiber-reinforced resin composition according to claim 1, characterized in that 10 to 60 parts by weight is blended.