JPS6330535A - Intermediate material for fiber-reinforced plastic - Google Patents

Abstract

PURPOSE:To obtain the title intermediate material excellent in storage stability, curability, adhesiveness, mechanical properties and heat resistance and decreased in heat buildup during curing, by mixing a specified resin composition with an organic or inorganic fiber. CONSTITUTION:An organic or inorganic fiber (i) is added to a resin composition obtained by adding a compound (f) having at least one oxirane ring, a curing agent (g) for component (f), except an acid (anhydride) and an amine compound, and a reaction catalyst (h) for components (f) and (g) to a mixture of a vinyl ester compound (a) obtained from a polyepoxide (I) having at least three epoxy groups of formula I (wherein A is a group of formula II or III, B is 0, alkylene, phenylene or a group of formula IV, R is a group of formula V, H, methyl or a halogen and at least two R groups are groups of formula V) and an ethylenically unsaturated carboxylic acid (II) in an amount less than the total amount of the epoxy groups of component (I) is mixed with an ethylenic, allylic or maleimide unsaturated monomer (b) copolymerizable with component (a), a polymerization catalyst (c) for components (a) and (b), a polyisocyanate compound (d) and a reaction accelerator (e) comprising an isocyanate and a hydroxyl group-containing compound.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides fibers made of a resin composition and reinforcing fibers that have excellent storage stability, curability, adhesiveness, mechanical properties, and heat resistance, and suppress heat generation during curing. Concerning reinforced plastic intermediate materials.

[Conventional technology]

Fiber-reinforced plastics (hereinafter abbreviated as FRP) have the strength to be used as structural materials, are lightweight, and can be molded in many different ways, so a very wide range of applications are being attempted.

Sheet molding compound (SMC) as part of FRP -? Bulk molding compound (BMC) can be molded into complex shaped moldings.
Since the molding time is very short, it is used for various purposes.

In recent years, with the trend toward FRP as a material used in high-temperature areas, we are developing resin compositions and reinforcing fibers that maintain storage stability, curability, and adhesiveness while suppressing curing heat generation, and also have heat resistance and mechanical properties. A fiber-reinforced plastic intermediate material is desired.

Generally, when a polyfunctional vinyl ester resin containing a novolak type is cured alone, it has heat resistance due to its polyfunctionality, but has poor mechanical properties. On the other hand, it is known that a system in which an epoxy resin is added to a vinyl ester resin has improved mechanical properties, but if the vinyl ester resin itself does not have heat resistance, the heat resistance after curing is poor. Also, JP-A-59-2193
In the invention of No. 24, a reaction product of a hydroxyl group-containing unsaturated polyester or epoxide and an ethylenically unsaturated carboxylic acid is used, but the present invention is characterized by having at least 6 or more functional groups in the molecule. This can be expected to improve heat resistance.

[Solution of problems and structure of the present invention]

The present inventors have improved heat resistance while maintaining mechanical properties,
As a result of conducting research on an FRP intermediate material having a matrix resin composition that has excellent storage stability, curability, and adhesion and suppresses curing heat generation, the present invention was achieved.

The present invention is based on the general formula %formula% (In the formula, A is R1 group -C-R or -C-C-R.

RRR B represents an oxygen atom, an alkylene group, a phenylene group, or a halogen atom, provided that the polyepoxide having two or more epoxy groups is ethylenically unsaturated with an amount equal to or less than the total amount of epoxy groups. Vinyl ester compound (1) obtained by reacting with carboxylic acid
), ethylenic, allylic or maleimide unsaturated monomers (n), (I) and (I[) that can be copolymerized with this
Catalyst for the polymerization of ) and (V)
reaction catalyst (6), polyisocyanate compound (4)
, a reaction accelerator between isocyanate and a compound having a hydroxyl group (■), and organic or inorganic fiber (■).

The vinyl ester compounds CI) used in the invention are obtained by reacting polyepoxides of the formula 1 with ethylenically unsaturated carboxylic acids equal to or less than m f [ of the epoxy groups.

Examples of the polyepoxide No. 2 include the following compounds. 1.1.1-(p-glycidyloxyphenyl)-methane, 1,1.1-(p-glycidyloxyphenyl)-ethane, 1,1,2.2-(p-glycidyloxyphenyl)-ethane, 1.1,2,2-
(p-glycidyloxyphenyl)-propane, 1t1
t3j (p-glycidyloxyphenyl)-propane, 1,1.3 = (p-glycidyloxyphenyl)-propane, etc.

Examples of ethylenically unsaturated carboxylic acids include methacrylic acid, acrylic acid, crotonic acid, and maleic acid.

Examples of the ethylenic, allylic or maleimide unsaturated monomer (II) include styrene, vinyltoluene, styrene derivatives such as chlorostyrene, methyl methacrylate, methyl acrylate, tallate, triallyl cyanurate, triallyl isocyanurate, etc. Examples include allyl ester, bismaleimide, phenylmaleimide, and the like.

Examples of the polymerization catalyst for (1) and (I[)@) include peroxides active at medium to high temperatures such as benzoyl peroxide and t-butyl perbenzoate, and peroxides active at medium to high temperatures such as methyl ethyl ketone and cyclohexanone peroxide.

Compounds containing at least one oxirane ring (2) include, for example, polyglycidyl ethers of diphenylolalkanes such as diphenylolpropane, diphenylolethane, and diphenylolmethane, and polyglycidyl ethers of polyhydric phenols such as novolak and resol. Epoxy produced by epoxidation of amines such as ether, p-amine phenol, m-amine phenol, and 4,4'-diaminodiphenylmethane, and alicyclic compounds such as polyglycidylamine, cyclohexane, cyclopentadiene, and dicyclopentadiene. resins, methyl esters of 3,4-epoxy-6-methyl-cyclohexanecarboxylic acid, poly(epoxyalkyl)ethers of aliphatic polyepoxy compounds such as ethylene glycol and glycerin, glycidyl esters of aromatic or aliphatic carboxylic acids, etc. Can be mentioned.

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.

Examples of curing agents (excluding acid anhydrides, acids, and amine compounds) for ■) include dicyandiamide, 2,6-xylenyl biguanide, 0-tolyl biguanide, diphenylguanidine, di-o-tolyl guanidine, etc. Miss Guanidine,
Examples include dihydrazides such as adipyl dihydrazide and azelyl dihydrazide.

(Incorporated) and ■) The reaction catalyst (2) has the general formula (in the formula,
Represents a methoxy group, ethoxy group, nidokyl group, allyl group, alkoxy group, alkenyl group or aralkyl group, R1
and R2 may be taken together to form a heterocycle) is preferred. Examples of the compound of formula 2 include the following compounds.

N-(3-rioo-4-methoxyphenyl)-N', N
'-Dimethylurea, N-(4-chlorophenyl) -N', N'-dimethylurea, N-(3-chloro-4-ethylphenyl)-', y-dimethylurea, N-(4-chlorophenyl) - N', N'-dipropylurea, N-(3-chloro-4-methylphenyl)-zo, N'-
dimethylurea, N-(3,4-dichlorophenyl)-dimethylurea, N-(4-methyl-3-nitrophenyl)-', gordimethylurea, 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, amines such as monoethylamine, benzylamine, and the like. Any catalyst that does not contain free amines, acid anhydrides, or carboxylic acids can be used as a reaction catalyst.

Examples of the polyisocyanate (4) include aromatic compounds such as 4,4'-diphenylmethane isocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hexamethylene diisocyanate, and metaxylylene diisocyanate. Mention may be made of group and aliphatic polyisocyanates and their crude products.

The reaction promoter (2) may be one that promotes the reaction between isocyanate and a compound having an alcoholic hydroxyl group, such as organotin compounds such as diptyltin dilaurate and tin octoate, lead naphthenate, and cobalt naphthenate. Examples include naphthenic acid metal salts such as .

Organic or inorganic fibers (examples include organic fibers, T-type polyester fibers, polyaramid fibers, etc., and inorganic fibers such as glass fibers, alumina fibers, silicone carbide fibers, boron fibers, carbon fibers, etc. Two or more of these fibers) The reinforcing fibers may be either long fibers or short rutted fibers, and may be in any form such as tapes, sheets, cloth, paper, strings, etc. arranged in one direction. It can be anything.

The blending ratio of (1), (II) and (I[[) in the present invention is sufficient as long as it satisfies the general radical polymerization system, but generally (1) / (I[) / ( II
The ratio of I) 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 is too rapid and is not suitable.

The compounding ratio of ■), ■), and (2) is not particularly limited as long as it satisfies the conditions necessary for curing general epoxy resins; The ratio of weight is 100: 0.05 ~ 50: 0.01 ~
A range of 10 is preferred. Also (1), (I[) and al
The blending ratio of the formulation l) to the formulations of (I), ■) and cJI) is 97-6:3-97 Special VC97-40:
3 to 6 o is preferable. If the amount of the compound (V), (V) and (2) is less than 6, the adhesion will not be sufficient, and if it exceeds 97, the substantial rapid curing property will be poor. The amount of (to) added is (1
) to CVI), the OH/NCO functional group ratio can be arbitrarily selected in the molar ratio range of 1:0.1 to 1. Depending on the amount added, the hardness, handleability, etc. of the resin composition can be adjusted. The amount of (2) added is preferably 0.01 to 5 parts per 100 parts of the blends of (1) to (4). The purpose of adding the cap is to adjust the reaction rate between the OH group and the NCO group, and from a physical standpoint, it is preferable that the amount added is small.

(As for the mixing method of components 11 to (to), (I), (
After preparing the formulations II), ■), ■ and (4),
The method of adding Gl/), ■) and (2) is preferred from the viewpoint of improving tack and flowability. The resin composition thus obtained may contain glass, silica, alumina, quartz, etc. as required.
Powdered fillers such as mica, calcium carbonate, barium sulfate, and clay may be added 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 copolymers are added in an amount of 0 to 30% by weight of the total amount.
It can also be added.

The FRP intermediate material of the present invention can be produced by impregnating reinforcing fibers (1) with the resin composition using a lacquer method using a solvent or a hot melt method using no solvent. When a solvent is used to impregnate reinforcing fibers with the resin composition, it is preferable to use an inert solvent such as acetone, methyl ethyl ketone, methylene chloride, chloroform, trichloroethylene, dioxane, tetrahydrofuran, benzene, toluene, or the like. After impregnating the reinforcing fibers with the resin composition, it is preferable to leave the resin composition at room temperature to 60°C, particularly at room temperature to 40°C, to thicken the resin composition.

Example 1 Tetrafunctional polyepoxide of the following formula (epoxy equivalent: 160
) 95 parts, 40 parts of methacrylic acid, and 0.0 parts of lithium chloride.
7 parts of vinyl ester and 0.05 part of hydroquinone were added and reacted at 100°C, and 4 parts of styrene was added to 60 parts of the obtained vinyl ester.
0 parts and 2.5 parts of t-butyl perbenzoate are added and mixed, then 10 parts of polymethylene polyphenylisocyanate (viscosity, 150 cps at 25°C, NCO content 40%) and 0.6 parts of diptyltin dilaurate. was added and stirred well to obtain a composition (ψ).Meanwhile, 100 parts of the polyepoxide, 5 parts of dicyandiamide, and 1-
Composition (b) was obtained by kneading 6 parts of (3,4-dichlorophenyl)=3,3-dimethylurea in a homomixer for 30 minutes. After leaving (α) at room temperature for 20 minutes, the composition (α)
) and (b) in the proportions shown in Table 1 to prepare composition (A).
) was obtained.

To 100 parts of this composition (A), 6 parts of zinc stearate was added, and then 120 parts of chopped strand glass fiber mat was impregnated with the mixture, and the mixture was left sealed at 40°C for 48 hours to achieve tackiness. A low SMC was obtained. This SMC was heated at 150°C for 5 minutes at a pressure of 3 Q k.
The bending strength and elastic modulus of the molded product cured by low pressure molding of g/cm2 were measured in accordance with ASTM D 790-71, and the interlaminar shear strength was measured in accordance with ASTM D2344-76. In addition, dynamic viscoelastic tests (Rheometrics)
inc, RDS 7700 type, part icMechani
tan δ (=G'/G', G'
: storage rigidity, all : loss rigidity) peak temperature was measured. For comparison, a bisphenol A diglycidyl ether type epoxy resin (epoxy equivalent: 177) was used in place of the tetrafunctional polyepoxide, and an SMC was prepared in the same manner as above, and its mechanical properties were examined. The results are shown in Table 1.

Example 2 Trifunctional polyepoxide of the following formula (epoxy equivalent: 160)
100 parts, 50 parts of acrylic acid, lithium chloride C1,
7 parts of vinyl ester and 0.06 part of hydroquinone were added and reacted at 100°C, and 4 parts of styrene was added to 60 parts of the obtained vinyl ester.
0 parts and 3 parts of t-butyl perbenzoate, then polymethylene polyphenylisocyanate (viscosity,
At 25° C., 10 parts of 150 cps1 (NCO content 31%) and 0.3 parts of dibutyltin dilaure were added and stirred thoroughly to obtain a composition (γ). On the other hand, 100 parts of cresol novolac type epoxy resin (epoxy equivalent: 175), 25 parts of bisphenol A diglycidyl ether type epoxy resin (epoxy equivalent: 190), 5 parts of dicyandiamide, and 1-(3,4-dichlorophenyl)-3,5- A composition (δ
) was obtained. After the composition (γ) was left at room temperature for 20 hours, the composition (δ) was mixed with a (δ)/(γ) ratio of 25/7 by weight.
5 to obtain a composition (B). To 100 parts of this composition (B), 3 parts of zinc stearate was added, a chopped strand glass fiber SMC was prepared in the same manner as in Example 1, and the bending strength of the molded product at 20°C and 150°C, Flexural modulus and glabellar shear strength were measured. For comparison, an SMC was prepared in the same manner except that a bisphenol A diglycidyl ether type epoxy resin was used instead of the trifunctional polyepoxide, and the mechanical properties were measured. The results are shown in Table 2.

Claims (1)

[Claims] General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, A is R, group ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, B is Oxygen atom, alkylene group, phenylene group, or group ▲There are mathematical formulas, chemical formulas, tables, etc.▼, R may be the same or different, and groups ▲There are mathematical formulas, chemical formulas, tables, etc.▼, hydrogen atom, methyl group, or Indicates a halogen atom, provided that two or more R are groups -
A vinyl ester compound obtained by reacting a polyepoxide having three or more epoxy groups represented by B-CH-CH_2 with an ethylenically unsaturated carboxylic acid having an amount equal to or less than the total amount of epoxy groups. I), an ethylenic, allylic or maleimide unsaturated monomer copolymerizable with it (II), (I)
and (II), a compound (IV) having at least one oxirane ring, a curing agent for (IV) (excluding acid anhydrides, acids and amine compounds) (V), ( I
V) and (V) reaction catalyst (IV), polyisocyanate compound (VII), reaction accelerator between isocyanate and a compound having a hydroxyl group (VIII), and organic or inorganic fiber (
IX) A fiber-reinforced plastic intermediate material.