JPH0153894B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a high-strength and impact-resistant FRP (fiber-reinforced plastic) molding resin composition, which is useful for hand lay-up methods, preform matched metal die molding methods, sheet molding compound methods, etc. This invention relates to a new resin composition for FRP molding. A resin made by reacting an epoxy resin with an unsaturated monobasic acid such as methacrylic acid and dissolving an unsaturated ester in a polymerizable monomer such as styrene is generally called vinyl ester resin and is widely used as a material for casting, FRP, etc. used in However, although this vinyl ester resin has relatively high strength, it has the disadvantage of poor impact resistance. For this reason, in FRP helmets, FRP for automobile parts, etc., the thickness of the molded product must be increased, making it extremely difficult to reduce weight. The present inventors conducted intensive studies to develop a resin composition with high strength and high impact resistance, and found that a low-reactivity unsaturated polyester with a molecular weight per double bond of 400 to 21,000 is blended with a vinyl ester resin. The inventors have discovered that a resin composition with extremely high strength and high impact resistance can be obtained by this method, leading to the present invention. That is, the present invention provides (A) an unsaturated ester obtained by reacting a novolac epoxy resin or a bisphenol epoxy resin with acrylic acid or methacrylic acid and, if necessary, a polybasic acid; (B) a molecular weight per double bond; This invention relates to a resin composition for FRP molding (hereinafter referred to as a resin composition) comprising an unsaturated polyester having a polyester of 400 to 21,000 and optionally a polymerizable monomer (C).The present invention will be described in detail below. Explain. As the epoxy resin used for the unsaturated ester of the present invention, novolak epoxy resins or bisphenol epoxy resins may be used alone or in combination of two or more. Commercially available novolac epoxy resins include DEN431 manufactured by Dow Chemical Company,
Examples include DEN438, Epicote 152 and Epicote 154 manufactured by Ciel Chemical Co., Ltd., and EPN1138 manufactured by Ciba Corporation. In addition, as bisphenol epoxy resin,
It is a commercially available low-molecular-weight epoxy resin obtained using bisphenol as a reaction material, and commercially available products include Epicote 828, Epicote 1001, and Epicote 1004 manufactured by Ciel Chemical Co., Ltd., and Araldite 6094 and Araldite 6097 manufactured by Ciba Corporation. The above epoxy resin is reacted with acrylic acid or methacrylic acid. Polybasic acids that are reacted with epoxy resins as necessary include unsaturated dibasic acids such as maleic acid, fumaric acid, and itaconic acid, and saturated polybasic acids such as phthalic acid, isophthalic acid, adipic acid, and pyromellitic acid. . These can be used alone or in a mixture of two or more. When an epoxy resin is reacted with a polybasic acid, it becomes possible to attach an acid group to the side chain of an unsaturated ester, and this acid group reacts with a thickener such as magnesium oxide, so it is possible to use the sheet molding compound (SMC) method. It is particularly useful in Epoxy resin and acrylic acid or methacrylic acid and polybasic acid to be reacted as necessary are 60~
The mixture is heated to 150°C, preferably 70 to 130°C, and reacted to form an unsaturated ester. Approximately 1 equivalent of acrylic acid or methacrylic acid is used per 1 equivalent of epoxy resin. When reacting a polybasic acid, first react 1.0 equivalent of the epoxy resin with 1.0 equivalent or less of acrylic acid or methacrylic acid, usually 0.95 to 0.70 equivalent, and add the polybasic acid to 1.0 equivalent of unreacted epoxy group. It is preferable to react with 1.0 mol of. The acid value of the unsaturated ester produced is 50 or less, preferably 20 or less. In order to prevent gelation due to polymerization during the reaction, hydroquinone, ditertiary
It is preferable to use a polymerization inhibitor such as butylcatechol or hydroquinone monomethyl ether. In addition, during this esterification reaction, ammonium salts such as trimethylbenzylammonium chloride and pyridinium chloride, tertiary amines such as triethylamine and dimethylaniline, ferric chloride, lithium hydroxide, lithium chloride, and tin chloride are used. Esterification catalysts can also be used to shorten the reaction time. Next, an unsaturated polyester having a molecular weight per double bond of 400 to 21,000 will be explained. The materials used for unsaturated polyester include acids and alcohols that are normally used for unsaturated polyester.
As the acid, unsaturated dibasic acids such as maleic anhydride and fumaric acid, saturated dibasic acids such as isophthalic acid, terephthalic acid, orthophthalic acid, adipic acid, and tetrachlorophthalic anhydride are used. Alcohols include ethylene glycol, propylene glycol, neopentyl glycol,
Dibromoneopentyl glycol, dipropylene glycol, diethylene glycol, 2,2bis[para(hydroxy-n-proboxy)phenyl]
Polyhydric alcohols such as propane, trimethylolpropane and polybutadiene glycol are used. Linseed oil, soybean oil, transesterified oils thereof, fatty acids, etc. are used as necessary. Unsaturated polyesters may be modified with dicyclopentadiene, and the methods for modification include (1) a one-step synthesis method in which acid, alcohol, and dicyclopentadiene are simultaneously charged, condensed, and modified simultaneously, and (2) acid and alcohol. There is a two-step synthesis method in which the compound is added and condensed, and dicyclopentadiene is added and modified in the middle, and either method is possible. The amount of dicyclopentadiene used is not particularly limited, but it is preferably used in a range of 0.05 to 0.40 mol per 1.0 mol of the acid component. If the amount of dicyclopentadiene added is less than 0.05 mol, the compatibility with the vinyl ester resin tends to decrease, and if it exceeds 0.40 mol, the impact resistance tends to decrease. The reaction temperature when modifying unsaturated polyester with dicyclopentadiene is preferably in the range of 150 to 230°C. The molecular weight per double bond is calculated, for example, as follows. In the case of an unsaturated polyester obtained from maleic anhydride and propylene glycol, the molecular weight of maleic anhydride is 98, the molecular weight of propylene glycol is 76, and the total molecular weight is 174. Subtracting the molecular weight of water lost through condensation, 18, from this gives 156, which is the molecular weight per double bond. Maleic anhydride 0.3
Similarly, for an unsaturated polyester obtained from 0.7 moles of phthalic anhydride and 1.0 moles of propylene glycol, (98 x 0.3 + 148 x 0.7 +
76×1.0−18)÷0.3=636.7, that is, 636.7 is calculated as the molecular weight per double bond. The molecular weight per double bond is a calculated molecular weight and differs from the actual molecular weight. In addition, the calculation is performed assuming equimolar amounts of acid and glycol, without taking into account the glycol excess rate. When modifying unsaturated polyester with dicyclopentadiene, dicyclopentadiene is blended so that a portion of the dicyclopentadiene is added to the double bonds of the unsaturated polyester. The proportion of dicyclopentadiene added to the double bonds of the unsaturated polyester varies depending on the modification method, but it is determined by analyzing the NMR (nuclear magnetic resonance) spectrum of the unsaturated polyester after modification. The molecular weight per double bond of unsaturated polyester is
Must be in the range 400-21000 and 400
If it is less than 21,000, the impact resistance decreases, and if it exceeds 21,000, the strength decreases. The preferred molecular weight per double bond is 550 to 4400, which provides a good balance between strength and impact resistance. Further, in order to improve the impact resistance of the resin composition of the present invention, it is particularly effective when the unsaturated polyester is a soft type. Therefore, the softening point of unsaturated polyester (softening point JIS K by ring and ball method)
According to 2531. ) is preferably 70°C or less. Polymerizable monomers used as necessary include styrene, divinylbenzene, methylstyrene, vinyl acetate, methyl methacrylate, ethyl acrylate, and ethylene glycol dimethacrylate, but styrene is mainly used. Ru. Further, it is preferable to use p-methylstyrene because it improves heat resistance. In the present invention, it is not always necessary to use a polymerizable monomer. The proportion of unsaturated esters, unsaturated polyesters, and polymerizable monomers used is not particularly limited, but from the viewpoint of balance of strength and impact resistance, unsaturated esters should be 10 to 10%.
90 parts by weight, 0.1 to 50 parts by weight of unsaturated polyester,
The range of the polymerizable monomer is preferably 1 to 150 parts by weight,
More preferred ranges are 50 to 90 parts by weight of unsaturated ester, 0.5 to 40 parts by weight of unsaturated polyester, and 5 to 100 parts by weight of polymerizable monomer. Unsaturated esters have the best balance of strength and impact resistance.
60 to 90 parts by weight, 0.5 to 20 parts by weight of unsaturated polyester, and 10 to 50 parts by weight of polymerizable monomer. The resin composition of the present invention may contain a curing organic peroxide, a curing accelerator, a polymerization inhibitor, a filler, a reinforcing material, a mold release agent, a coloring agent, a thickener, etc., as necessary. Examples of the curing organic peroxide include t-butyl peroxybenzoate, benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide, and methyl ethyl ketone peroxide. As a curing accelerator, cobalt octenoate,
Examples include metal compounds such as cobalt naphthenate, potassium octenoate, and manganese naphthenate, and tertiary amines such as dimethylaniline and diethylaniline. Examples of polymerization inhibitors include hydroquinone, parabenzoquinone, catechol, and 2,5-diphenylparabenzoquinone. As a filler, calcium carbonate, clay,
Examples include barium sulfate and aluminum hydroxide. As reinforcing materials, glass fiber, vinylon fiber,
A roving-like material made of bundled fibers such as carbon fiber, short fibers, woven fabrics, knitted fabrics, yarns, braided fabrics, etc. may be used. Examples of mold release agents include zinc stearate and calcium stearate. As the colorant, all of the inorganic and organic colorants currently used for coloring unsaturated polyester resins can be used. As the thickener, metal oxides such as magnesium oxide and calcium oxide, metal hydroxides such as magnesium hydroxide, organic thickeners using diisocyanates such as diphenylmethane diisocyanate, and combinations thereof can be used. In addition, if necessary, thermoplastic polymers such as polystyrene, polyvinyl acetate, polymethyl methacrylate, and saturated polyester, and thermosetting polymers such as phenol, epoxy, and melamine may be used in combination with antimony trioxide. Flame retardants such as hexabromobenzene, chlorinated paraffin, etc. may also be used. The resin composition of the present invention can be applied not only to normal temperature and normal pressure molding methods such as hand lay-up and spray-up, but also to resin injection molding methods, preform mated metal die molding methods, sheet molding compound methods, and bulk molding methods. It can also be applied to molding compound methods, etc., and its range of applications is extremely wide. Examples of the present invention are shown below. Parts and percentages by weight are percentages by weight. Example 1 172.0 g (2.0 mol) of methacrylic acid, 151.2 g (0.40 mol) of bisphenol epoxy resin Epicoat 828 (manufactured by Ciel Chemical, epoxy equivalent 189), Epicoat 1001 (manufactured by Ciel Chemical, epoxy equivalent 475)
570.0g (0.60mol), 0.40g hydroquinone and 0.50g trimethylbenzylammonium chloride
A resin (VE-1) was obtained by mixing 70 parts of an unsaturated ester with an acid value of 9 obtained by heating at 120°C for 7 hours and 30 parts of styrene. Propylene glycol 418g (5.5mol), diethylene glycol 530g (5.0mol), adipic acid
146 g (1.0 mol), fumaric acid 348 g (3.0 mol), and phthalic anhydride 888 g (6.0 mol) were mixed at 150 g (1.0 mol) under a nitrogen stream.
The temperature was raised from °C to 210 °C in 5 hours, and then at 210 °C.
Unsaturated polyester with an acid value of 30 synthesized for 10 hours
Styrene 30 containing 70 parts and 0.005 parts of hydroquinone
A resin (UP-1) was obtained by mixing and dissolving the resin.
The molecular weight per double bond of this unsaturated polyester was 680, and the softening point measured by the ring and ball method was 50°C or less. FRP with a glass content of 60% was produced using VE-1 and UP-1 according to the formulation shown in Table 1. The strength is shown in Table 1, and it shows excellent strength properties, especially when heated (60°C). Also, due to its low modulus of elasticity, it had excellent impact resistance. Figure 1 shows the load-deformation curve when measuring the bending strength of the obtained FRP, where 1 is 23
Curve 3 is the curve at 60°C.
This shows that the obtained FRP has extremely good elongation at break. Example 2 Propylene glycol 418g (5.5mol), diethylene glycol 530g (5.0mol), adipic acid
146 g (1.0 mol), fumaric acid 116 g (1.0 mol), and phthalic anhydride 1184 g (8.0 mol) were added to 150 g (1.0 mol) under a nitrogen stream.
The temperature was raised from °C to 210 °C in 5 hours, and then at 210 °C.
Unsaturated polyester with an acid value of 32 synthesized for 10 hours
Styrene 30 containing 70 parts and 0.005 parts of hydroquinone
A resin (UP-2) was obtained by mixing and dissolving the resin.
The molecular weight per double bond of this unsaturated polyester was 2140, and the softening point measured by the ring and ball method was 50°C or less. When FRP with a glass content of 60% was produced using VE-1 and UP-2 with the formulation shown in Table 1, it showed excellent strength and high elongation. It also had excellent strength when heated (60°C) and elongation at break. Comparative Example 1 When VE-1 obtained in Example 1 was used to produce FRP with a glass content of 60% according to the formulation shown in Table 1, it had low elongation, low strength at heat, and poor impact resistance. It was inferior. Figure 1 shows the load-deformation curve when measuring the bending strength of the obtained FRP. 2
is the curve at 23°C, 4 is the curve at 60°C, and Example 1
It is shown that the elongation at break is inferior to that of FRP. Comparative Example 2 Propylene glycol 790g (10.5 mol), maleic anhydride 490g (5.0 mol), phthalic anhydride 740g
(5.0 mol) from 150℃ to 210℃ under nitrogen flow for 5 minutes.
70 parts of unsaturated polyester with an acid value of 35 obtained by raising the temperature for 7 hours and then synthesizing at 210℃ for 7 hours was mixed with 30 parts of styrene containing 0.005 part of hydroquinone and dissolved to obtain a resin (UP-3). Ta. The molecular weight per double bond of this unsaturated polyester was 362, and the softening point determined by the ring and ball method was 72°C. Using VE-1 and UP-3 obtained in Example 1, FRP with a glass content of 60% was made with the formulation shown in Table 1.
When produced, it was found to have low strength, significantly poor elongation, and poor impact resistance.

[Table] Example 3 86 g (1.0 mol) of methacrylic acid, 179 g (1 epoxy equivalent) of novolac epoxy resin DEN438 (manufactured by Dow Chemical Company, epoxy equivalent: 179), 0.054 g of hydroquinone, and 2.7 g of trimethylbenzylammonium chloride at 90°C. A resin (VE-2) was obtained by mixing 70 parts of an unsaturated ester having an acid value of 14 obtained by heating for 7 hours with 30 parts of styrene. Using VE-2 and UP-1 obtained in Example 1, resin cast products were obtained with the formulations shown in Table 2. The properties are shown in Table 2, and it showed excellent strength and high elongation. The heat distortion temperature also showed a high value. Comparative Example 3 Using VE-2 obtained in Example 3, resin cast products were obtained with the formulations shown in Table 2. The properties are shown in Table 2, and the elongation was low and the heat distortion temperature was also low.

【table】

[Table] Example 4 155.0 g (1.8 mol) of methacrylic acid, 113.4 g (0.30 mol) of bisphenol epoxy resin Epicoat 828 (manufactured by Ciel Chemical, epoxy equivalent 189), Epicoat 1001 (manufactured by Ciel Chemical, epoxy equivalent 475)
570.0g (0.60mol), 0.40g hydroquinone and 0.50g trimethylbenzylammonium chloride
When heated at 120°C for 5 hours, the acid value decreased to 8. 23.2 g (0.20 mol) of maleic acid was added to this, and 70 parts of an unsaturated ester with an acid value of 20 obtained by heating at 120°C for 2 hours was mixed with 30 parts of styrene to obtain a resin (VE-4). . 90 parts of VE-4, 10 parts of UP-2 obtained in Example 2
part, parabenzoquinone 0.01 part, tertiary butyl perbenzoate 1.0 part, calcium carbonate 120 parts,
4.0 parts of zinc stearate was mixed well to prepare a compound. Add 1.0 part of magnesium oxide (#20) to this compound, mix quickly,
It was coated on 64 parts of glass chopped strand mat (FEM-450 manufactured by Fuji Fiber Glass Co., Ltd.) placed on a polyethylene film and thoroughly impregnated to prepare SMC with a glass content of 28%. SMC
The adhesive to the film disappeared after 48 hours at 40°C. This SMC was molded at a molding temperature of 140° C., a molding time of 3 minutes, and a molding pressure of 50 kg/cm ² . Molded products have bending strength
22.0Kg/mm ² , flexural modulus 980Kg/mm ² , tensile strength
9.2Kg/mm ² , Shyalpee impact strength 51.9Kg・cm/cm ²
It showed excellent strength.

[Brief explanation of drawings]

Figure 1 shows the results obtained in Example 1 and Comparative Example 1.
It is a figure which shows the load-deformation curve at the time of the bending strength measurement of 23 degreeC and 60 degreeC of FRP. Explanation of symbols, 1... FRP of Example 1 (23°C),
2... FRP of Comparative Example 1 (23°C), 3... Example 1
FRP of Comparative Example 1 (60°C), 4... FRP of Comparative Example 1 (60°C).

Claims (1)

[Claims] 1 (A) Unsaturated ester obtained by reacting a novolac epoxy resin or bisphenol epoxy resin with acrylic acid or methacrylic acid and, if necessary, a polybasic acid (B) per double bond A resin composition for FRP molding, comprising an unsaturated polyester having a molecular weight of 400 to 21,000, and optionally (C) a polymerizable monomer. 2 10 to 90 parts by weight of unsaturated ester, 0.1 to 50 parts by weight of unsaturated polyester, 1 to 10 parts by weight of polymerizable monomer
150 parts by weight of the resin composition for FRP molding according to claim 1. 3 50 to 90 parts by weight of unsaturated ester, 0.5 to 40 parts by weight of unsaturated polyester, 5 to 5 parts of polymerizable monomer
100 parts by weight of the resin composition for FRP molding according to claim 1. 4 60 to 90 parts by weight of unsaturated ester, 0.5 to 20 parts by weight of unsaturated polyester, 10 to 10 parts of polymerizable monomer
50 parts by weight according to claim 1
Resin composition for FRP molding. 5. The resin composition for FRP molding according to claim 1, wherein the unsaturated polyester has a molecular weight per double bond of 550 to 4,400. 6. The resin composition for FRP molding according to claim 1, wherein the unsaturated polyester is an unsaturated polyester obtained by modification with dicyclopentadiene. 7. The resin composition for FRP molding according to claim 1, wherein the unsaturated polyester is an unsaturated polyester having a softening point of 70°C or less. 8. The resin composition for FRP molding according to claim 1, wherein the polymerizable monomer is p-methylstyrene.