JPH0347654B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a fiber-reinforced plastic intermediate material with excellent storage stability, hardenability, mechanical properties and growth. [Prior art] Fiber-reinforced plastics (hereinafter abbreviated as FRP) have the strength to be used as structural materials, are lightweight, and can be molded in many ways, so they have a very wide range of applications, from rockets for space exploration to miscellaneous goods. is being attempted. Conventionally, resins used in intermediate materials for fiber-reinforced plastics such as sheet molding compounds (SMC), bulk molding compounds (BMC), and prepregs reduce stickiness and improve fiber cohesiveness without significant polymerization and curing. For example, US Pat. No. 2,628,209 describes a method for increasing viscosity by adding magnesium oxide to an unsaturated polyester resin containing styrene and other polymerizable monomers. It describes what can be improved. However, this material is unsatisfactory in mechanical properties, particularly in interlaminar shear properties. In addition, Dale's combination of α, β-olefinic unsaturated dicarboxylic acid and anthracene used in the synthesis of unsaturated polyester
British Patent No. 949869 describes that mechanical properties are further improved by synthesizing alder adducts. However, although the above-mentioned method achieved certain results in terms of thickening properties, it was unsatisfactory in terms of mechanical properties, especially interlaminar shear strength properties and fatigue strength properties. Further, in JP-A-59-219364, unsaturated polyester resins and vinyl ester resins containing no carboxylic acid groups are used. Although this intermediate material has excellent mechanical properties, particularly interlaminar shear strength properties, it has poor thickening properties, is sticky, and has extremely low handleability. The present invention is characterized by the introduction of carboxylic acid groups into these resins, which can be expected to improve viscosity and reduce stickiness. [Solving the Problems and Structure of the Present Invention] The present inventors have arrived at the present invention as a result of conducting research on an FRP intermediate material that has excellent mechanical properties, storage stability, hardening properties, and thickening properties. The present invention provides vinyl ester resins and/or unsaturated polyester resins () having carboxylic acid groups,
Ethylenically, allylicly or maleimide unsaturated monomer () copolymerizable with (), catalyst for the polymerization of () and (), compound having at least one oxirane ring (), Curing agents for (excluding acid anhydrides, acids and amine compounds)
This is a fiber-reinforced plastic intermediate material characterized by comprising a reaction catalyst ( ), an alkaline earth metal oxide or hydroxide ( ), and an organic or inorganic fiber ( ). The vinyl ester resin having a carboxylic acid group used in the present invention is, for example, a compound obtained by adding an ethylenically unsaturated dicarboxylic acid to polyepoxide, or a compound obtained by adding an ethylenically unsaturated monocarboxylic acid to the polyepoxide, and then treating the resin with an acid anhydride. Examples include compounds in which the secondary alcoholic hydroxyl group of polyepoxide is made into a pendant carboxylic acid group.
Examples of polyepoxides include compounds having an epoxy group, such as diphenylol alcohol or novolak, polyglycidyl ethers of polyhydric phenols such as resols, polyglycidyl amines of amines such as p-aminophenol, 4,4'-diaminodiphenylmethane, etc. Examples include epoxy resins produced by epoxidation of cyclic compounds, poly(epoxyalkyl) ethers of aliphatic polyepoxy compounds, and glycidyl esters of aromatic or aliphatic carboxylic acids. Further, unsaturated polyester resins having carboxylic acid groups have many ester bonds within the molecule and are obtained by reacting glycol with dicarboxylic acid. As the dicarboxylic acid it is necessary to use an unsaturated dicarboxylic acid or a mixture of an unsaturated dicarboxylic acid and a saturated dicarboxylic acid. Glycols include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, 2,2,4-trimethyl-1,
3-pentanediol, 2,2-bis[para(2
-hydroxy-n-propoxy)phenylpropane], hydrogenated bisphenol A, and 4,4'-bis(2-hydroxyamino)octachlorbiphenyl. Saturated dicarboxylic acids include phthalic anhydride, isophthalic acid, adipic acid,
Examples include sebacic acid, tetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, hectic anhydride, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride. Examples of unsaturated dicarboxylic acids include maleic anhydride, fumaric acid, and itaconic acid. Glycol, unsaturated dicarboxylic acid, and saturated dicarboxylic acid may each be used alone, or a mixture of two or more thereof may be used. Ethylenic, allylic or maleimide unsaturated monomers () which can be copolymerized with () include styrene derivatives such as styrene, vinyltoluene and chlorostyrene, methyl methacrylate, methyl acrylate, glycidyl acrylate, glycidyl methacrylate, etc. Examples include (meth)acrylate derivatives, allyl esters such as diallyl phthalate, triallyl cyanurate, and triallyl isocyanurate, bismaleimide, phenylmaleimide, and the like. Examples of the catalyst () for the polymerization of () and () include peroxides active at medium to high temperatures such as benzoyl peroxide and t-butyl perbezoate, peroxides active at medium to high temperatures such as methyl ethyl ketone peroxide, and cyclohexane peroxide. . The compound () having at least one oxirane ring may be the same as the epoxy resin forming the skeleton of the vinyl ester resin, such as diphenylolpropane, diphenylolethane,
Polyglycidyl ethers of diphenylol alkanes such as diphenylolmethane, polyglycidyl ethers of polyhydric phenols such as novolak and resol, amines such as p-aminophenol, m-aminophenol, and 4,4'-diaminodiphenylmethane. Epoxy resins produced by epoxidation of alicyclic compounds such as polyglycidylamine, cyclohexane, dicyclopentadiene, methyl ester of 3,4-epoxy-6-methyl-cyclohexanecarboxylic acid, aliphatic resins such as ethylene glycol, glycerin, etc. Examples include poly(epoxyalkyl)ethers of polyepoxy compounds, glycidyl esters of aromatic or aliphatic carboxylic acids, and the like. Further, preliminary reaction products of these polyepoxides and amine compounds or acid anhydrides may be used. In addition to polyepoxide, monoepoxy compounds such as styrene oxide, butyl glycidyl ether, allyl glycidyl ether, and phenyl glycidyl ether can also be used. Curing agents (excluding acid anhydrides, acids, and amine compounds) for () include dicyandiamide,
Examples include guanidine derivatives such as 2,6-xylenyl-biguanide, o-tolylbiguanide, diphenylguanidine, and di-o-tolylguanidine, and dihydrazides such as adipyl dihydrazide and azelyl dihydrazide. As the reaction catalyst () for () and (), the general formula (In the formula, X and Y are a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group, an ethoxy group, a nitro group, or a group

[Formula] R ₁ and R ₂ represent an alkyl group, an allyl group, an alkoxy group, an alkenyl group, or an aralkyl group, and R ₁ and R ₂ may be taken together to form a heterocycle. preferable. Examples of the compound of formula 1 include the following compounds. N-(3-chloro-4-methoxyphenyl)-N,N'-dimethylurea, N-(4-chlorophenyl)-N',N'-dimethylurea, N-(3
-chloro-4-ethylphenyl)-N', N'-dimethylurea, N-(4-chlorophenyl)-N',
N'-dipropylurea, N-(3-chloro-4-methylphenyl)-N',N'-dimethylurea, N-
(3,4-dichlorophenyl)-N',N'-dimethylurea, N-(4-methyl-3-nitrophenyl)
-N',N'-dimethylurea, N-(4-ethoxyphenyl)-N',N'-dimethylurea, N-(4-chlorophenyl-carbamoyl)piperidine, N-
(4-chlorophenyl-carbamoyl)morpholine, etc. Other reaction catalysts include boron trifluoride, amine complexes, boron trichloride amine complexes, and amines such as monoethylamine and benzylamine. Any catalyst that does not contain free amine acid anhydride or carboxylic acid can be used as the reaction catalyst (). The above-mentioned compound having an oxirane ring (), curing agent () and reaction catalyst ()
By including FRP, the mechanical properties of the FRP intermediate material are improved. Examples of alkaline earth metal oxides or hydroxides include magnesium oxide, magnesium hydroxide, calcium oxide, and potassium hydroxide. Any material may be used as long as the prepolymers in the vinyl ester resin and unsaturated polyester resin are ionically crosslinked to each other to increase viscosity and improve handling properties. Examples of organic or inorganic fibers include inorganic fibers such as glass fibers, alumina fibers, silicon carbide fibers, boron fibers, carbon fibers, and organic fibers such as polyester fibers and polyaramid fibers. Two or more of these fibers may be used in combination. The reinforcing fibers are in the form of long fibers,
It may be any type of short fiber, and may be in any form such as a unidirectionally arranged tape, sheet-like material, cloth-like material, paper-like material, or string-like material. The blending ratio of (), () and () in the present invention is sufficient as long as it satisfies general radical polymerization systems, but generally ()/()/
The ratio in parentheses is preferably 1 to 99:99 to 1:0.1 to 5 by weight. If the catalyst () is less than 0.1, a sufficient curing rate cannot be obtained, and if it exceeds 5, the curing will be too rapid and is not suitable. The compounding ratio of (), () and () is not particularly limited as long as it satisfies the conditions necessary for curing general epoxy resins, but ()/
The ratio of ()/() is 100:0.05 to 50:0.01 by weight
A range of ~10 is preferred. In addition, the blending ratio of (), () and () blends to (), () and () blends is 97 to 3:3 to 97, especially 97 to 3 by weight.
40:3-60 is preferable. (),()as well as()
If the amount of the compound is less than 3, the adhesion is insufficient,
Moreover, if it exceeds 97, the actual rapid curing property becomes poor.
The amount of () to be added is preferably 0.05 to 20 parts relative to (); if it exceeds 20 parts, the viscosity will increase sharply and the handling properties will deteriorate. The method of mixing the components () to () is as follows:
After preparing the formulations of (), () and (),
It is preferable to prepare and add a mixture of (), (), (), and () to this from the viewpoint of efficiency and flowability, but () to () may also be blended together. If necessary, powdered fillers such as glass, silica, alumina, quartz, mica, calcium carbonate, barium sulfate, and clay may be added to the resin composition obtained in this manner in an amount of 5 to 70% by weight of the total amount. .
Furthermore, various coloring agents and mold release agents such as zinc stearate and phosphate esters may be added as necessary. Furthermore, other additives such as styrene, ethylene, methacrylic acid ester, etc. alone or in copolymers may be added in an amount of 0 to 30% by weight based on the total amount. The FRP intermediate material of the present invention can be produced by impregnating reinforcing fibers () with a resin composition using a lacquer method using a solvent or a hot melt method using no solvent. When using a solvent to impregnate reinforcing fibers with the resin composition, inert solvents such as acetone, methyl ethyl ketone, methylene chloride, chloroform, trichloroethylene, dioxane,
It is preferable to use tetrahydrofuran, benzene, toluene, etc. After impregnating the reinforcing fiber () with the resin composition, it is preferable to leave it at room temperature to 60°C, particularly at room temperature to 40°C, to increase the viscosity. Parts in the following examples mean parts by weight. Example 1 50 moles of maleic anhydride and 110 moles of diethylene glycol were esterified at 140 to 230°C for 3.5 hours,
Then 50 moles of phthalic anhydride and hydroquinone
7 parts of diallyl phthalate, 3 parts of t-butyl perbenzoate and 110 parts of an unsaturated polyester resin with an acid value of 45.5 and an unsaturated acid content of 20.2% were added and esterified for 3.1 hours at 140 to 230°C. Add 5 parts of magnesium oxide and mix on three rolls for 30 minutes.
The mixture was mixed and mixed to obtain a composition (a). Separately, 100 times the diglycidyl ether type epoxy resin of bisphenol A (epoxy equivalent: 200), 5 parts of dicyandiamide, and 3 parts of 1-(3,4-dichlorophenyl)-3,3-dimethylurea were mixed using a homomixer for 30 minutes. The mixture was mixed and mixed to obtain a composition (b). Compositions (a) and (b) were mixed in the proportions shown in Table 1 to obtain composition (A). 3 parts of zinc stearate was added to 100 parts of this composition (A), and then 120 parts of chopped strand glass fiber mat was impregnated.
SMC with low stickiness was obtained when kept under closed conditions at 40 °C for 120 h. This SMC at 135℃ and pressure 200
The flexural strength, flexural modulus, and interlaminar shear strength of the molded product cured at Kg/ ^cm2 for 5 minutes were determined according to ASTM D 2344-
Measured in accordance with 76. In addition, for comparison, a composition (a) was prepared without adding magnesium oxide, and a molded product was produced in the same manner as above, and the mechanical properties were measured. The results are shown in Table 1. Mixing ratio in the table =
0/100 is a comparative example.

[Table] *: Example without addition of magnesium oxide 2 Maleic acid added to 100 parts of bisphenol A diglycidyl ether type epoxy resin (epoxy equivalent: 177)
50 parts of lithium chloride, 0.8 parts of lithium chloride, and 0.06 times of hydroquinone were added and reacted at 100°C. 40 parts of styrene and 5 parts of t-butyl perbenzoate were mixed with 100 parts of the obtained vinyl ester having an acid value of 47.2, and then hydroxylated. 10 parts of calcium was added and thoroughly stirred to obtain composition (c). On the other hand, 100 parts of novolac type epoxy resin (epoxy equivalent: 160), dicyandiamide 5
and 1-(3,4-dichlorophnyl)-3,3-
Composition (d) was obtained by kneading 3 parts of dimethylurea in a homomixer for 30 minutes. After leaving composition (c) at room temperature for 20 hours, compositions (c) and (d) were mixed in the proportions shown in Table 2 to obtain composition (B). 3 parts of zinc stearate was added to 100 parts of this composition (B) to prepare chopped strand glass fiber SMC in the same manner as in Example 1, and the molded product had flexural strength, flexural modulus, and interlaminar shear strength. was measured. For comparison, a composition (c) was prepared without adding calcium hydroxide, and a molded product was produced in the same manner as above, and the mechanical properties were measured.
The results are shown in Table 2. Mixing ratio in the table = 0/
100 is a comparative example.

[Table] *: Calcium hydroxide-free Example 3 42 parts of acrylic acid, 0.7 parts of lithium chloride, and 0.06 parts of hydroquinone were added to 95 parts of novolac type epoxy resin (Epicote 152 manufactured by Yuka Ciel Epoxy Co., Ltd., epoxy equivalent weight 175). React at 100℃,
50 parts of succinic anhydride was added to 100 parts of the obtained reaction product, and the mixture was reacted at 130 to 240°C for 7 hours. 40 parts of styrene and 2.5 parts of t-butyl perbenzoate were mixed with 100 parts of the obtained vinyl ester resin,
Furthermore, 7.8 parts of magnesium oxide was added and stirred to obtain a composition (e). On the other hand, bisphenol A diglycidyl ether type epoxy resin (epoxy equivalent: 177)
90 parts, glycidyl methacrylate 10 parts and) 1-
Composition (f) was prepared by kneading 3 parts of (3,4-dichlorophenyl)-3,3-dimethylurea in a homomixer for 30 minutes.
I got it. After leaving (e) at room temperature for 20 hours, the composition
Composition (C) is obtained by mixing (e) and (f) in the proportions shown in Table 3.
I got it. 3 parts of zinc stearate was added to 100 parts of this composition (C), a chopped strand glass fiber SMC was prepared in the same manner as in Example 1, and the flexural strength, flexural modulus, and interlaminar shear The strength was measured. For comparison, a composition (e) was prepared without adding magnesium oxide, and a molded product was produced in the same manner as above, and the mechanical properties were measured. The results are shown in Table 3. The mixing ratio=0/100 in the table is a comparative example.

【table】

[Table] *: Example without addition of magnesium oxide 4 Unsaturated polyester resin synthesized in Example 1
40 parts of methyl methacrylate, 3 parts of benzoyl peroxide and 5 parts of magnesium oxide were added to a mixture of 100 parts of the vinyl ester resin synthesized in Example 2 and kneaded for 30 minutes on a triple roll to obtain composition (g). Obtained. On the other hand, 100 parts of 1,1,1-tris(p-glycidyloxyphenyl)-metal, 50 parts of bisphenol A diglycidyl ether type epoxy type (epoxy equivalent: 177), 5 parts of dicyandiamide, and 1-
Composition (h) was obtained by kneading 3 parts of (3,4-dichlorophenyl)-3,3-dimethylurea for 30 minutes using a homomixer. Compositions (g) and (h) in a weight ratio of 75/25
Composition (D) was obtained by mixing at a ratio of . This composition (D)
Add 3 parts of zinc cytearate to 100 parts,
After storing under closed conditions at ℃ for 20 hours, SMC was created using carbon fiber pyrofil (manufactured by Mitsubishi Rayon Co., Ltd.). This SMC (carbon fiber length: 1 inch, fiber content: 50% by weight) was molded under the same conditions as in Example 1, and the flexural strength, flexural modulus, and interlaminar shear strength of the molded product were measured. The results are shown in Table 4.

[Table] Example 5 100 parts of the vinyl ester resin synthesized in Example 2, 40 parts of methylene methacrylate, 2 parts of dicumyl peroxide, 3 parts of novolac type epoxy resin (epoxy equivalent: 160), bisphenol A diglycidyl ether type epoxy Resin (epoxy equivalent weight 177)
6 parts, 5 parts of dicyandiamide, 3 parts of 1-(3,4-dichlorophenyl)-3,3-dimethylurea,
3 parts of zinc stearate, 5 parts of magnesium oxide, 10 parts of phenylmaleimide, and chopped strand short glass fibers (fiber length: 1 inch) in an amount equal to the total weight of these were kneaded in a kneader at room temperature for 30 minutes. This composition was placed in a sealed container and heated to 100°C at 30°C.
I left it for a while. This was molded under the same conditions as in Example 1, and the bending strength, flexural modulus, and interlaminar shear strength of the molded product were measured. The results are shown in Table 5.

【table】

Claims (1)

[Claims] 1. Polymerization of vinyl ester resin having a carboxylic acid group and/or unsaturated polyester resin (), an ethylenic, allyl or maleimide unsaturated monomer () copolymerizable with (), () and () Catalysts for (), Compounds with at least one oxirane ring (), Curing agents for (excluding acid anhydrides, acids and amine compounds) (), ()
A fiber-reinforced plastic intermediate material comprising a reaction catalyst (), an alkaline earth metal oxide or hydroxide (), and an organic or inorganic fiber ().