JPS6018518A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To provide the titled composition containing specific amounts of specific brominated bisphenol epoxy resin, bisphenol epoxy resin, and hardener for epoxy resin, having a specific glass transition temperature, and capable of giving a portable semicured product by heating. CONSTITUTION:The objective composition having a glass transition temperature of 50-150 deg.C is obtained by mixing (A) 100pts.wt. of a brominated bisphenol epoxy resin having an epoxy equivalent of 700-5,000 and a bromine content of 30-52wt%, (B) 0-300pts.wt. of a bisphenol epoxy resin having an average molecular weight of 2,000-5,000, (C) a proper amount of an epoxy resin hardener (e.g. diethylenetriamine) and if necessary (D) a cure accelerator, an inorganic filler, a pigment, a reinforcing fiber, zinc stearate, etc. The composition is preheated, filled in a heated mold, taken out of the mold in a semicured state, and subjected to the post-curing in an unrestricted state to obtain a completely cured product.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition suitable for molding a cured epoxy resin product using a mold such as transfer molding, injection molding, or compression molding. The curable resin composition of the present invention can provide a semi-cured product with a portable strength by heating for a short period of time. Usage efficiency can be increased.

The activation energy of epoxy resins is lower than that of other thermosetting resins, such as phenolic resins and unsaturated polyester resins, and the temperature dependence of its curing rate is also small. Therefore, in order to cure in a short time, a polymercaptan compound is used as a curing agent, Na5CN,
A method of using a curing accelerator such as NaI together with an amine-based cured product has been carried out.

In the case of rapid curing, the storage stability (pot life) of the composition is short, so it is stored as a two-part solution, a resin solution and a curing agent solution.
In practice, both liquids are mixed and used immediately before curing. In this case, the epoxy resin has an epoxy equivalent of 160 to 2
Relatively low molecular weight liquid epoxy resins such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, and novolak epoxy resin are used. In so-called RIM, the two liquids are mixed in a nozzle, injected into the cavity of a mold, and cured in the mold. RIM uses epoxy as it does not cause clogging of the nozzle due to curing of both liquids, and it is difficult to design the nozzle and mold in order to fill every corner of the cavity of the injection mold with resin solution. Its share in the resin molding field is still small.

When molding epoxy resin, the resin composition (epoxy resin , curing agent, type of accelerator) and molding method are selected.

Epoxy resins with a long pot life have the advantage of being easy to mix with fillers, glass fibers, pigments, curing agents, etc., and are generally high molecular weight epoxy resins. Since this material is generally solid at room temperature, the molding material must be preheated and plasticized in advance, as is done in compression molding, transfer molding, and injection molding, and then the plasticized material is placed in the mold cavity. Fill under pressure, then heat under pressure (140-200℃)
It is then hardened and molded.

In these molding methods, it has been proposed to set the heating temperature to 220-250°C in order to speed up the curing time. This is undesirable because it causes deformation.

The present inventors believe that if a semi-cured product can be obtained with a hardened surface that does not deform even when taken out of the mold, post-curing of this semi-finished product should be set at an appropriate temperature. It can be carried out in a heated furnace while being removed from the mold.
Focusing on the fact that the mold from which the semi-finished product is taken out can be immediately used for the production of the next semi-cured product and the productivity of the product per mold is improved, an epoxy resin composition for producing such a semi-cured product has been developed. After conducting various studies, it was discovered that an epoxy resin composition with a specific blending ratio satisfies these conditions, and the present invention was achieved.

That is, the present invention provides the following: Component: epoxy equivalent is 700 to 5,000, bromine content is 30 to 52%, and brominated bisphenol epoxy resin 100 parts by weight Component (B): average molecular weight A composition containing 0 to 300 parts by weight of a bisphenol-based epoxy resin of 2,000 to 5,000 (0 liquid content: appropriate amount of epoxy resin curing agent, Φ) and (Q component). The present invention provides an epoxy resin composition having a glass transition temperature of 50 to 150°C.

In the present invention, the brominated bisphenol-based epoxy resin as the component (4) has, for example, the following general formula: A brominated bisphenol-based epoxy resin or a mixture thereof.

This brominated bisphenol-based epoxy resin is, for example,
Brominated bisphenols or a mixture of brominated bisphenols and bisphenols are reacted with epichlorohydrin in the presence of an alkaline catalyst, such as caustic soda (-
It is manufactured by casting (casting method). In addition, brominated bisphenols or a mixture of brominated bisphenols and bisphenols and epichlorohydrin can be combined with tetramethylammonium bromide, tetraethylammonium chloride, cetyltriethylammonium bromide, ethyltrinoenylphosphonimiodine, methyltrioctylphosphonium dimethylphosphate, etc. It can also be produced (two-step process) by carrying out an addition reaction in the presence of a catalyst, then adding caustic soda to complete the dehydrochlorination reaction. Furthermore, by reacting glycidyl ether of bisphenol with brominated bisphenols to obtain a polyphenol, and then reacting this with epichlorohydrin in the presence of caustic soda,
Alternatively, it can also be produced by reacting the brominated bisphenol-based epoxy resin obtained by method (2) with bisphenols to obtain a polyphenol, and then reacting the polyphenol with epichlorohydrin in the presence of caustic soda.

Examples of bisphenols include bisphenol S1, bisphenol A, and bisphenol F, and examples of AX-formed bisphenols include brominated products of these bisphenols.

It is necessary that the epoxy equivalent of the brominated bisphenol-based epoxy resin as component (4) is 700 to 5,000. When the epoxy equivalent is less than 700, the semi-cured product obtained is brittle and cannot be taken out from the mold in a semi-cured state. On the other hand, if the epoxy equivalent exceeds s, o o o, the crosslinking density of the epoxy resin is low, so the heat resistance of the cured product obtained will be low. The preferred epoxy equivalent is 1.500 to 3,50
It is 0.

In addition, the bromine content of this component (4) is 30 to 52% by weight.
It is. If the bromine content is less than 30% by weight, the glass transition temperature will be low and it will be difficult to adjust the glass transition temperature of the composition to 50° C. or higher, making it difficult to take out the semi-cured product. The bromine content of 52% by weight is the upper limit depending on the raw materials and production method, and it is not possible to produce a brominated bisphenol-based epoxy resin with a bromine content higher than this.

The epoxy resin of component (4) is Epikote YL903, Epikote YL906, Epikote YL from Yuka Shell Epoxy ■.
914 and YL915.

In addition, as a prisoner component, the epoxy equivalent is 700 to 1.500.
When using brominated bisphenol-based epoxy resin,
The resulting cured product is brittle and may crack due to impact, so a bisphenol-based epoxy resin [component Q3] with a number average molecular weight of 2.000 to 5.000 is used as (4)
It is preferable to use it in a proportion of 300 parts by weight or less, preferably 20 to 150 parts by weight, based on 100 parts by weight of the components. Such component noepoxy resins can be obtained from Yuka Shell Epoxy 2 under the trade names Epicote 1007 and Epicote 1009.

If the blended amount of the epoxy resin (6) exceeds 300 parts by weight, the flame retardant effect and quick curing function of the brominated bisphenol epoxy resin (2) component will decrease, and the resulting The heat resistance of the cured product also decreases.

Examples of curing agents with zero component include amino compounds having at least one hydrogen atom directly bonded to a nitrogen atom, such as diethylene amine, triethylenetetramine, methylhexamethylene diamine, inphorone diamine, xylene diamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, aniline formaldehyde resin; adducts of these amine compounds with other compounds such as epoxy group-containing compounds, acrylonitrile, acrylic esters, e.g. dimer acids of aliphatic polyamines and unsaturated fatty acids and polyamidoamines derived from; polycarboxylic acids or their anhydrides, such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, methylendomethylenetetrahydrophthalic anhydride,
Maleic anhydride, trimellitic anhydride, dodecenylsuccinic anhydride, chlorendic anhydride, etc.; polythiols, such as bis-(2-hydrothionityloxy)methane; secondary to tertiary amines, such as benzyldimethylamine, Tris-(dimethylaminomethyl)phenol, imidazole, pyridine, biridine, triethanolamine, etc.; polyenol such as novolak resin, phenol novolak resin, etc.; other dicyandiamide, BF3・amine salt, amine with the following structure having a spiro ring 3.9 -bis(3-aminopropyl) -2,4,8,
Examples include amines having a spiro ring obtained by reacting 2 moles of 10-tetraoxaspiro(S,S) undecane with 1 mole of butyl glycidyl ether.

Among these curing agents, those that are solid at room temperature are preferred for mixing with component (6), and from the viewpoint of curability and heat resistance of the resulting cured product, diaminodiphenylmethane, diaminodiphenylsulfone, metaphenylenediamine, etc. Aromatic amines are preferred.

The amount of curing agent for these zero components is theoretically determined by adding an amount of curing agent that contains chemically equivalent functional groups (>NHl-OH1-COOH) to the epoxy groups in the epoxy resin (2) and (2) to be cured. It may be used, but the optimum required amount will be determined experimentally. The specific amount is 2 to 30 parts by weight based on 100 parts by weight of the sum of (6) and (daily component).

The resin composition consisting of these components (4), (Bl and C) should be prepared so that its glass transition temperature (Tg) is 50 to 150°C. If the Tg of the composition is less than 50°C, when post-curing the semi-cured product taken out of the mold outside the mold, the post-curing temperature needs to be around 50°C, making it difficult to perform post-curing in a short time. Can not. Furthermore, the pot life of the composition is short, making it difficult to handle. Conversely, when Tg exceeds 150°C, the melting temperature of the composition is often 250°C or higher, and therefore the mold temperature of the molding container is also around 250°C. In that case, the thermal stability of the brominated epoxy resin becomes unstable.

In addition to these (4), (6) and the Ω component, a curing accelerator, inorganic filler, pigment, reinforcing fiber, zinc stearate, etc. can be blended. Such curing accelerators include:
Benzyldimethylamine, α-methylbenzyldimethylamine, 2-(dimethylaminomethyl)phenol, 2
, 4.6-tris(dimethylaminomethyl)phenol, 2,4.6-)tris(dimethylaminomethyl)phenol tri-2-ethylhexylate, pyridine,
piperazine, quinoline, hexamethylenetetramine, N
-Methylmorpholine, N,N'-dimethylpiperazine,
Triethanolamine, N-methylpiperazine, piperidine, morpholine, BF, piperidine, BFa imidazole, BFa 2-methylimidazole, piperidine acetate, imidazole acetate, 2-methylimidazole acetate, 2-methylimidazole, 2
-Ethyl-4-methylimidazole, 2-undecylimidazole, 2-hegetadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 2
-Methylimidazolium incyanurate, 1-cyanethyl-2-ethyl-4-methylimidazole, 2-
Examples include amine compounds having active hydrogen such as phenylimidazolium incyanurate and 1-cyanoethyl-2-cundecyl trimellitate imidazolium.

Inorganic fillers include mica, glass flakes, glass powder, silica powder, talc, calcium carbonate, etc. Pigments include titanium oxide, red iron, carbon black, etc., and reinforcing fibers include homone-treated glass fiber and epoxy silane-treated glass fiber. , aminosilane-treated glass fiber, carbon fiber, aramid fiber, etc.

The epoxy resin composition of the present invention is generally used in powder or tablet form. This molding material is heated to a temperature of 50 to 200°C, preferably 10
After preheating to 0~150℃, it is filled into a mold heated to 50~150℃, preferably 100~150℃, and then the plasticized material is placed in the corner of the mold by applying a pressure of 50~300Kr/cIl. After the mold is filled and shaped, it is removed from the mold before it is completely cured. It takes 1 to 3 minutes for this semi-cured product to exhibit sufficient strength to not deform even after being removed from the mold. The semi-cured product taken out is further post-cured at a temperature of 60 to 180° C. for 6 to 13 hours in an unrestrained state, resulting in a completely cured product.

Also in the field of epoxy resin casting, a cured product is obtained by pre-curing at 90-150°C for 1-4 hours and then post-curing at a temperature higher than the pre-curing temperature, for example 150-200°C for 3-10 hours. things are being done. In this case, pre-curing and post-curing are performed in the same mold.

In contrast to this casting method, when compression molding, transformer molding, or injection molding is performed using the resin composition of the present invention, only pre-curing is performed inside the mold, and post-curing can be performed outside the mold. Productivity per mold can be greatly improved.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 (a), 1-bisphenol A-based epoxy resin 1 Epicor) YL906″ D [1]-based shell epoxy ■ Product name, epoxy J11050, bromine content 50% by weight, T
g88℃] 100 parts by weight (b), 3 m + length chopped strand force ゛i, z-
11>n 30 parts by weight (C), 5.1 parts by weight of diaminodiphenylmethane The above (a> and (b) components were kneaded in a kneader at 140°C for 20 minutes, then (c) was added and kneaded for 2 minutes at the same temperature. After that, it was rapidly cooled to 20℃ and coarsely pulverized (Tg of the pulverized product was 67℃).
).

This pulverized material is transferred to the pot of the transfer molding machine (set temperature 1
80℃) for 120 seconds to plasticize, then 65℃
After filling the mold cavity of the transfer mold set to
The mold was opened and a plate-shaped semi-cured product was extracted.

This semi-cured product was post-cured by increasing the temperature stepwise at 60°C for 2 hours, 80°C for 1.5 hours, 95°C for 1 hour and 130°C for 30 minutes.
A cured product with no rigid deformation was obtained.

The heat distortion temperature of this cured product was 150°C or higher. Example 2 (a), Bisphenol A monochloride epoxy resin 1 Epicoat YL914" (epoxy equivalent 1465, bromine content 50% by weight, 'I'g101 °C] 100 parts by weight <b>, bisphenol A-based epoxy mJIW basket Epicoat 1009" [epoxy equivalent weight 2°850, molecular weight 3,750) 50 parts by weight (C), 150 parts by weight silica powder (d), diaminodiphenylsulfone 5 .3 parts by weight The above (a), Φ) and (C) were mixed in a kneader to 140
After mixing at ℃ for 20 minutes, (Y) was added, and the mixture was further kneaded for 2 minutes at the same temperature, then rapidly cooled to room temperature and pulverized (Tg of the pulverized product was 70°C).

This pulverized material was melted using an injection molding machine set at 40°C in the hopper, 120°C in the cylinder barrel, and 60°C in the mold, and then injected into the mold cavity. After 2 minutes, the mold was opened. , bosses, semi-hardened structural material with many lips (heavy Ji3
50F) was obtained.

This semi-cured structural material is post-cured at 60°C for 3 hours, 80°C for 3 hours, 95°C for 3 hours, 110°C for 2 hours, and 130°C for 2 hours to increase the temperature in stages to prevent deformation. A cured product was obtained.

The heat distortion temperature of this cured product was 150°C or higher. Example 3 (a), brominated bisphenol A-based epoxy resin "Epicote YL915" [epoxy equivalent: 2.569, bromine content: 50% by weight, Tgl: 14°C] 100 parts by weight (t)), 30 parts by weight of chopped strands of 3tWM length (C), 50 parts by weight of silica powder (d), Phenol novolac "'PN-80" (part name made of oil-based shell epoxy ■, melting point 80 °C] 4.5 parts by weight (e), 2-ethyl-4-methylimidazole 0.5
15 parts by weight of the above (a), to) and (e) in a kneader
The mixture was kneaded at 5°C for 20 minutes, then (d) and (e) were added, and the mixture was further kneaded at the same temperature for 2 minutes, then rapidly cooled and coarsely pulverized (Tg of the pulverized product was 92°C).

This pulverized product was transfer-molded for 3 minutes using a transfer molding machine with a pot temperature of 195°C and a mold temperature of 85°C, and was molded into a piece having a length of 12 m and a width of 125 +++ m.

A semi-cured product with a thickness of 10M was obtained.

This semi-cured product was heated at 90℃ for 3 hours and at 110℃ for 3 hours.
Post-curing was performed stepwise at 130°C for 3 hours, at 150°C for 2 hours, and at 170°C for 2 hours to obtain a specimen for bending tests without deformation.

The bending strength of this test piece was 1,230 Kg/lri, and the heat distortion temperature was 177°C.

Comparative Example 1 (a) 100 parts by weight of brominated bisphenol A-based epoxy resin "Epiny"YL906" (bromine content 50%) (b) 100 parts by weight of bisphenol A-based epoxy resin Takuebiko) 1004" (molecular weight 1600) (C), Silica powder 50 (d), Diaminodiphenylmethane 11 (a)
), (b) and (C) were kneaded in a kneader at 120°C for 20 minutes, and after adding (d), they were kneaded for 2 minutes at the same temperature, rapidly cooled, and then coarsely ground (Tg of the ground product was 42
℃).

Using a transfer molding machine set at a pot temperature of 150°C and a mold temperature of 40°C, this pulverized material was molded into a mold of 10 m long in 3 minutes.
A flat plate-like semi-cured product with a width of 7011111% and a thickness of +5- was obtained.

This semi-cured product is brittle and difficult to demold, and deforms even more at post-curing temperatures of 50°C or higher.
time, 3 hours at 95°C, 2 hours at 110°C and 130
Post-cure by heating at ℃ for 2 hours, heat distortion temperature is 155℃
A cured product with no deformation was obtained.

Comparative Example 2 (a) Brominated bisphenol A-based epoxy resin 'Epicor)'l': [,903'' [epoxy equivalent weight 468, bromine content 50% by weight, Tg 56°C] 100 parts by weight (b), calcium carbonate 100 (C) Diaminodiphenylsulfone 13.1
〃The above (a) and (b) were kneaded in a kneader at 100°C for 20 minutes, then (c) was added, and after kneading for 2 minutes at the same temperature, 2
It was rapidly cooled to 0°C and pulverized (Tg of the pulverized product was 40°C).

When this pulverized material was molded using a transfer molding machine set at a pot temperature of 150°C and a mold temperature of 25°C to form a specimen for a bending test, the semi-cured material could not be shaped even after 30 minutes after being pressurized. It was difficult to take it out without breaking it.

Examples 4 to 14, Comparative Examples 3 to 5 In Example 1, the composition shown in Table 1 was used as the epoxy resin composition, and the conditions for post-curing the semi-cured product were changed as shown in the table. was similarly transfer molded to obtain a cured epoxy resin.

The glass transition point of this cured product is shown in the same table.

Nao and epoxy resin are both oil-based shell epoxy■
Epicoat (trade name) manufactured by Co., Ltd. was used, and its grade number is listed in the table. The molecular weight of the epoxy resin is as follows.

Grade name Molecular weight Epicote 1001 (900) 1004 (1,600) 1007 (2,000) 1009 (3,750) 1100 (4,000) Further, the abbreviations of the accelerators in the table are as follows.

PN 80: 7x: 7-Luno, Hon./72E4M
Z: 2ethyl-4-methylimidazole (blank below)

Claims (1)

[Scope of Claims] 1), Component (A): 100 parts by weight of a brominated bisphenol epoxy resin having an epoxy equivalent of 700 to 5,000 and a bromine content of 30 to 52% by weight (B) Component: A composition containing 0 to 300 parts by weight of a bisphenol-based epoxy resin having an average molecular weight of 2,000 to s, o o o (component O: an appropriate amount of an epoxy resin curing agent as described above), (6), and component 0. , an epoxy resin composition characterized in that the composition has a glass transition temperature of 50 to 150°C. 2), (The epoxy resin composition according to claim 1, wherein the epoxy resin curing agent as the carbon component is an aromatic amine. 3), The epoxy equivalent of the epoxy resin as the component (A) but,
700 to 1.500, the epoxy resin composition according to claim 1 is
The epoxy resin composition according to claim 3, characterized in that the amount is 0 to 150 parts by weight.