JPH0446922A - Curable resin composition - Google Patents

Abstract

PURPOSE:To obtain a curable resin composition which can give a flexible cured product by mixing a specified alicyclic epoxy resin with an epoxy resin curing agent. CONSTITUTION:This curable resin composition essentially consists of an alicyclic epoxy resin of formula I and an epoxy resin curing agent. In formula I, X is a structure of formula II, Y<1> is a structure of formula III, Y<2> is a structure of formula IV, Y<3> is a structure of formula V. In formulas I-V, R is 1-30 C alkyl, or residue of an m-valent organic compound; R<a>, R<b> and R<11> to R<m9> are each hydrogen or generally 1-9C alkyl, and are simultaneously interconvertible; (c) is an integer of 4-8; nm is an integer of 0 or greater; and (m) is an integer of 1 or greater.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a curable resin composition containing an aliphatic cyclic epoxy resin and an epoxy resin curing agent.

While the cured products of conventional aliphatic cyclic epoxy resins are hard and brittle, this method is suitable for obtaining flexible cured products.

(Prior Art and Problems to be Solved by the Invention) Epoxy resins have good workability and excellent mechanical properties of cured products, and are used in many fields.

However, conventional epoxy resins have the disadvantage of being hard and brittle, which limits their applications.

In order to improve these drawbacks, flexible epoxy resins or flexibility imparters have traditionally been used, but these often have high viscosity, so products containing them have low viscosity. It is unsuitable for fields that require

In addition, the following formula (11) % formula% , it may be necessary to add a large amount of the flexible epoxy resin (11).

(Object of the Invention) The present invention was made in view of the above circumstances, and an object of the present invention is to provide a curable resin composition containing an aliphatic cyclic epoxy resin with excellent flexibility.

(Structure of the Invention) That is, the present invention [(a) The following general formula (1) [However, in formula (1), X is the following structure Ra (C) O- Yl is the following structure Y2 is the following structure Y3 has the following structure R is an alkyl having 1 to 30 carbon atoms, a monovalent organic compound residue, R and R and R11 to R19 are hydrogen, and - for boat fishing, contains 1 to 9 carbon atoms. An alkyl group can be converted into each group at the same time. C is an integer from 4 to 8,
nI represents an integer greater than or equal to 0, and nI represents an integer greater than or equal to 1.] (b) A curable resin composition characterized in that an epoxy resin curing agent capable of reacting with the epoxy resin of (a) is an essential component. be.

According to the present invention, there is provided a curable resin composition comprising an aliphatic cyclic epoxy resin (a) represented by the general formula (+) and an epoxy resin curing agent (b) that can react with the aliphatic cyclic epoxy resin. Ru.

The present invention will be explained in detail below.

In the general formula (1), R is an alkyl group having 1 to 30 carbon atoms, and is an m-valent organic compound residue.

It may be alicyclic or linear, and may have a double bond.

Alternatively, it may be an aromatic compound.

Ra5Rb is a hydrogen atom or an alkyl group, generally containing 1 to 9 carbon atoms, due to the lactone starting material.

For example, when ε-caprolactone is used as a raw material, RaR
All b are hydrogen.

Furthermore, when β-methyl-6 valerolactone is used, Ra
5Rb becomes an ethyl group and hydrogen, and when 3-ethylcaprolactone is used, Ra5Rb becomes an ethyl group and hydrogen.

Moreover, C is also determined by the raw material lactone.

For example, c-5 for ε-caprolactone, c-4 for valerolactone, and c-7 for cyclooctanonelactone.

nm is the number of moles of added lactone.

For example, when no lactone is added, nm-
When adding 0.5 moles, n, +n2+...+nm-5.

m is the number of polyfunctional alicyclic esters and corresponds to the number of functional groups of the raw material carboxylic acid and acid anhydride used.

As the aliphatic cyclic epoxy resin represented by the general formula (+), for example, when m is 1, caprolactone modified product (Ill) of 34-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3.4
-Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate modified with trimethylcaprolactone (1v), (Vl)l, 3.1-1 poxy-
6-methylcyclohexylmethyl-34-epoxy-6
-valerolactone modified product m(V)- of methylcyclohexanecarboxylate, and the like.

(Left below) Ye-C-+O(CH) C+-0CH2-Ye2
5 □ (Il+) CH3 Ye-C-←OCHCCH2CH- CHCH -CHC+0-CH2-Y n I (1v) CH3 -C-+OCH2 HCH2 CH- H3 CH2 C-→-OCH2 (m' CH3 -C-+OCH2 HCH2 CH H2 CH3 C+ O-CH2 CH3 Ye (IV)- MY -C-+OCH2 HCH2 Hs CH2 C-+-0-CH2 Ye (V) MY -C-+OCHCH2CH- CH3 CH2 C-Kanichi CH2-MY (■) In addition, in the (+) formula, when m is 2, the following formula [where Xl is the following structure 〇 - (CH2) C〇 - and R1 is the following structure, 0 + represents an integer of 1 or more] (■1) [However, xl represents the following structure -〇(CH2) O- (below the margin), R2 represents the following structure nl, n2 represents n, +n2 represents an integer greater than or equal to 1] ・・・・ml ) Also, in equation (1), if m is 4, the following equation l
e CH-Co ±

CH2 CH-CO-E-X'→-0 2n4 H2 ・ (■Il+) [However, in formula (■11+), Xl has the following structure 0- (CH2) 5-Co- is nl, n2 is nl+n
2+n3+n4-1] Also, in the formula, when m is 6, the following formula [However, in formula (1x), Xl is the following structure 〇 - (CH2) O, R2 is the following structure (the following Margin) [However, in formulas (Ill) to (IX), Ye may be as follows.

Furthermore, a method for synthesizing the aliphatic cyclic epoxy resin of general formula (1) is shown below.

First, it is produced by the following series of reactions.

(White space below) <Reaction> [A] Reaction> R-←-COOH) ■ Or [ ] [However, in the formula [ ], or the following structure (white space below) -0-←C product←--CO- C Yl has the following structure Y2 has the following structure (blank below) Y3 has the following structure or <reaction> R-←C00H) or (blank below) <Reaction-5> The curable resin of the present invention is produced by the following oxidation reaction. An aliphatic cyclic epoxy resin represented by formula (1), which is the main substance in the composition, is produced.

[B] -(+) In the dehydration esterification reactions of oxidation reaction-2> and <reaction-3>, carboxylic acid and alcohol can be charged and reacted all at once.

The reaction temperature can be 150-250°C. At the beginning of the temperature rise, a lot of water is distilled out, and even if the temperature is heated more than necessary, the temperature will not rise above the specified level.

As the reaction progresses and the amount of dehydrated water increases, the temperature of the reaction system also rises.

As the reaction progresses, the acid value in the system decreases, so this can be used as a guideline.

The molar ratio of carboxylic acid and alcohol to be charged is carboxylic acid 1
The amount of alcohol is 1.0 mole or more per mole. This is because the acid value in the system decreases more quickly when alcohol is in excess.

However, if the amount exceeds the required amount, it will take a long time to remove it after the reaction is completed, which is not desirable.

Alternatively, when an acid anhydride is used in <Reaction-2> and Reaction-3>, these reactions are an addition reaction between an acid anhydride and an alcohol, and a dehydration esterification reaction between a carposis acid and an alcohol.

The reaction proceeds even at relatively low temperatures.

However, in order to carry out the reaction industrially, the temperature is 100-250°C. The reaction between acid anhydride and alcohol proceeds at relatively low temperatures.

However, in the reaction of carboxylic acid and alcohol, it is advantageous to continuously remove water from the reaction system through a dehydration reaction, and therefore the reaction temperature is preferably 100° C. or higher under normal pressure. Further, at temperatures above 250°C, decomposition of lactone oligomers and coloring of the product are extremely undesirable.

Next, Reaction-1> and Reaction-4> are lactone modification reactions.

These reactions are carried out by adding a specified lactone to an ester or alcohol and adding a titanium catalyst or a tin catalyst to a temperature of 0°1 to 1100°C.
00pp can be added and the reaction can be carried out at 150-250°C.

Catalyst is 0. If it is less than lppm, the reaction will be slow, and 1100
Even if it is added in an amount of 00 pp or more, no great effect can be obtained.

Further, when the temperature is below 150°C, the speed is slow, and when it is above 250°C, the decomposition and coloring of the lactone are significant.

Furthermore, by epoxidizing the thus obtained compound of general formula [B], an aliphatic cyclic epoxy resin of general formula (1) can be obtained (reaction 5).

This epoxidation is performed using peracid or hydroperoxide.

In the case of epoxidation, peracids or various hydroperoxides can be used as the epoxidizing agent.

For example, peracids include performic acid, peracid, perpropionic acid, perbenzoic acid, trifluoroperacetic acid, and the like.

Examples of hydroperoxides include hydrogen peroxide, tert-butyl hydroperoxide, cumene peroxide, and metachloroperbenzoic acid. A catalyst can be used during epoxidation if necessary.

For example, in the case of a peracid, an alkali such as soda carbonate or an acid such as sulfuric acid may be used as a catalyst.

In the case of hydroperoxides, a catalytic effect can be obtained by using a mixture of tungstic acid and caustic soda together with hydrogen peroxide, an organic acid with hydrogen peroxide, or molybdenum hexacarbonyl with tajaripur hydroperoxide. I can do it.

[Reaction Conditions] The epoxidation reaction is carried out by adjusting whether or not a solvent is used and the reaction temperature depending on the equipment and physical properties of the raw materials.

The usable reaction temperature range is determined by the reactivity of the epoxidizing agent used.

Regarding peracetic acid, which is a preferred epoxidizing agent, 0 to
A range of 70°C is preferred.

At temperatures below 0°C, the reaction is slow, and at temperatures above 70°C, peracetic acid decomposes.

In addition, for the same reason, tertiary butyl hydroperoxide/molybdenum dioxide diacetylacetonate, which is an example of hydroperoxide,
°C is preferred.

The solvent can be used for purposes such as lowering the viscosity of the raw material and stabilizing the epoxidizing agent by diluting it.

In the case of peracetic acid, aromatic compounds, ether compounds, ester compounds, etc. can be used.

In particular, ethyl acetate or xylene are preferred solvents.

For example, in the case of peracids, alkalis such as soda carbonate and acids such as sulfuric acid may also be used as catalysts.

The molar ratio of the epoxidizing agent to the unsaturated bonds can be changed depending on the purpose, such as how much unsaturated bonds are desired to remain.

When the objective is to obtain a compound with a large number of epoxy groups, it is preferable to add the epoxidizing agent in an amount equivalent to or more than the amount of the unsaturated group.

However, due to economic efficiency and the problem of side reactions described below,
It is usually disadvantageous to exceed 0 times the molar amount, and in the case of peracetic acid, 1 to 5 times the molar amount is preferable.

Depending on the conditions of the epoxidation reaction, the substituents in the raw materials undergo a side reaction with the epoxidizing agent at the same time as the double bond is epoxidized, resulting in modified substituents that are included in the target compound.

However, trace amounts of by-products may be mixed into the resulting product, which may adversely affect the hue or acid value.

To prevent this, at least one of the following additives can be added.

Phosphoric acid, potassium phosphate, sodium phosphate, sodium ammonium hydrogen phosphate, pyrophosphoric acid, potassium birophosphate, sodium pyrophosphate, sodium 2-ethylhexyl pyrophosphate, potassium 2-ethylhexyl pyrophosphate, 2- Sodium ethylhexyl tripolyphosphate, potassium 2-ethylhexyl tripolyphosphate, sodium 2-ethylhexyltetrapolyphosphate, potassium 2-ethylhexyltetrapolyphosphate.

The amount added is 10 ppm to 1,010,000 pp, preferably 50 ppm to 11,000 pp in the reaction crude liquid.

The effect of these additions is generally thought to be the effect of chelating and inactivating metals mixed in from the reactor or raw materials.

[purification] The products can be separated in various ways.

The obtained reaction crude liquid can be used as a product by distilling off the solvent and the like as it is.

Low boiling conditions are 50°C to 200°C, preferably 80 to 16°C.
It is 0°C.

Further, the reaction can be carried out by adjusting the degree of reduced pressure depending on the boiling point of each solvent.

Since trace amounts of impurities are also produced in this reaction, it is preferable to wash with water to remove them.

When washing with water, benzene, toluene,
Aromatic compounds such as xylene, hydrocarbons such as hexane, heptane, and octane, and esters such as ethyl acetate and butyl acetate can be used.

The amount of water washing is 0.1 to 10 times, preferably 1 to 5 times, the volume of the reaction crude liquid.

Furthermore, in order to remove trace amounts of acid, it is also an effective method to wash with an alkaline aqueous solution and further wash with water. Examples of the alkaline aqueous solution used include NaOH, KOH, K
CoSNaCOSNaHCo,K
Aqueous solutions of alkaline substances such as HCO, NH3, etc. can be used.

The concentration used can be freely selected from a wide range.

Alkaline water washing and water washing at 10 to 90°C, preferably 1
It is preferable to carry out at a temperature range of 0 to 50°C.

After the water-washed liquid is separated into two layers, the organic layer is taken out, the boiling point is removed, and the product can be taken out.

The low boiling temperature is 50 to 200°C, preferably 80 to 160°C, and can be carried out by adjusting the degree of reduced pressure depending on the boiling point of each solvent.

The reaction can be carried out in any continuous or batch manner.

In the case of a batch method, it is preferable to charge the raw materials and additives into a reactor and then drop the epoxidizing agent.

When this is washed with water, the water is separated into two layers after washing with water, and the organic layer is evaporated in an evaporator to produce a product.

In the case of continuous operation, raw materials, epoxidizing agents, and additives can be continuously charged into a reactor and taken out continuously. The reactor may be of any type, such as a complete mixing tank or a piston flow type.

Furthermore, examples of epoxy resin curing agents that can react with the epoxy resin (b) component [i.e., component (a)] in the curable resin composition of the present invention include phthalic anhydride, trimellitic anhydride, Aromatic acid anhydrides such as pyromellitic acid, benzophenone tetracarboxylic anhydride, ethylene glycol bis(anhydrotrimellitate), glycerol tris(anhydrotrimellitate), maleic anhydride, succinic anhydride, tetrahydrophthalic anhydride , methyltetrahydrophthalic anhydride, methylnadic anhydride,
Cyclic aliphatic acid anhydrides such as hexahydrophthalic anhydride and methylhexahydrophthalic anhydride, other acid anhydrides, ethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, xylenediamine, metaphenylenediamine, diaminodiphenylsulfonediaminodiphenylmethane , amines such as polymethylenediamine, imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, dicyandiamide and its derivatives, polyamide Examples include resins, organic acid hydrazides, diaminomaleonitrile and its derivatives, melamine and its derivatives, boron trifluoride compounds such as boron trifluoride-amine complexes, and compounds containing silanol hydroxyl groups.

In addition, tertiary amines, borate esters,
Curing accelerators such as Lewis acids, organometallic compounds, organic acid metal salts, and imidazole may also be used.

Furthermore, modifiers and fillers commonly used for epoxy resins may be used in combination.

The amount of curing agent to be used with respect to the epoxy resin (a) component is 0.1 to 0.1 to
It is good to use it in the range of 5, preferably in the range of 5 to 1.5.

However, for boron trifluoride compounds such as boron trifluoride-amine complexes and compounds containing silanol hydroxyl groups, the amount used is o, oo.

It is good to use it in the range of 1 to 1.0, preferably in the range of 0.001 to 1.0.

Furthermore, the curing temperature of the curable resin composition of the present invention is 30
-200°C, preferably 80-180°C.

Furthermore, the aliphatic cyclic epoxy resin represented by the general formula (1) can be used in combination with other epoxy resins to impart flexibility to the other epoxy resins.

<Examples> The following examples specifically illustrate embodiments of the present invention, and are not intended to limit the scope of the present invention in any way.

Example 1 252 parts by weight of 3.4-epoxycyclohexylmethyl-3°4-epoxycyclohexanecarboxylate was added to ε
- General formula (1) modified with 114 parts by weight of caprolactone
100 parts by weight of the epoxy resin shown by (hereinafter referred to as epoxy resin A), 82 parts by weight of methylhexahydrophthalic anhydride
Parts by weight and 0.91 parts by weight of N,N-dimethylbenzylamine as a catalyst were placed in a beaker and mixed at room temperature, then poured into a mold and cured at 100°C for 5 hours.

Thereafter, it was further cured at 160° C. for 10 hours to obtain a cured product.

Example 2 252 parts by weight of 3.4-epoxycyclohexylmethyl-3°4-epoxycyclohexanecarboxylate was added to ε
- General formula (1) modified with 342 parts by weight of caprolactone
100 parts by weight of the epoxy resin shown by (hereinafter referred to as epoxy resin B), 42 parts by weight of hexahydrophthalic anhydride,
N as a catalyst.

7520.74 parts by weight of N-dimethylbenzyl was placed in a beaker, and the same procedure as in Example 1 was carried out to obtain a cured product.

Example 3 252 parts by weight of 3.4-epoxycyclohexylmethyl-3°4-epoxycyclohexanecarboxylate was added to ε
- General formula (1) modified with 570 parts by weight of caprolactone
100 parts by weight of the epoxy resin shown by (hereinafter referred to as epoxy resin C), 34 parts by weight of methylhexahydrophthalic anhydride
A cured product was obtained in the same manner as in Example 1 using 0.67 parts by weight of N,N-dimethylbenzylamine as the catalyst.

Example 4 45 parts by weight of epoxy resin C, 55 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 66 parts by weight of phthalic anhydride, 0.83 parts by weight of N,N-dimethylbenzylamine as a catalyst A cured product was obtained in the same manner as in Example 1.

Example 5 3.4-epoxy-6-methylcyclohexylmethyl-
280 parts by weight of 3,4-epoxy-6-methylcyclohexanecarboxylate was added to 4 parts by weight of trimethylcaprolactone.
100 parts by weight of an epoxy resin represented by the general formula (+) (hereinafter referred to as epoxy resin) modified with 68 parts by weight;
A cured product was obtained in the same manner as in Example 1 using 30 parts by weight of methylhexahydrophthalic anhydride and 0.65 parts by weight of N,N-dimethylbenzylamine as the catalyst.

Comparative Example 1 Using 100 parts by weight of 3.4-epoxycyclohexylmethyl-3°4-epoxycyclohexanecarboxylate, 114 parts by weight of methylhexahydrophthalic anhydride, and 1.07 parts by weight of N,N-dimethylbenzylamine as a catalyst. A cured product was obtained in the same manner as in Example 1.

Comparative Example 2 31 parts by weight of 3.4-epoxycyclohexylmethyl-3°4-epoxycyclohexanecarboxylate, 69 parts by weight of polyε-caprolactone polymer (average molecular weight 500), 38 parts by weight of methylhexahydrophthalic anhydride, as a catalyst The same procedure as in Example 1 was carried out using 0.69 parts by weight of N,N-dimethylbenzylamine, but no cured product was obtained.

Comparative Example 3 100 parts by weight of bis(3,4-epoxycyclohexylmethyl)adipate (flexible epoxy resin (I+)), 81 parts by weight of methylhexahydrophthalic anhydride, N,N-dimethylbenzylamine-0 as a catalyst , 91 parts by weight was used in the same manner as in Example 1 to obtain a cured product.

Table 1 shows the properties of the cured products obtained in Examples 1 to 5 and Comparative Examples 1 to 3.

The cured physical properties were measured under conditions of 20° C. and 65% RH.

Measurements of tensile strength, tensile elongation, elastic modulus, bending strength, bending elongation, Izot impact strength, and water pumping rate were performed according to JIS K6911.

In addition, the gelation time of the formulation was measured using a gel time tester manufactured by Kajime Seiki Seisakusho. The heat distortion temperature is J l5K
Measured according to 7207.

Furthermore, Tg was measured using a high-performance differential scanning calorimeter (DSC8230B manufactured by Rigaku Denki Co., Ltd.). 1I11 was established.

As is clear from Table 1, Examples 1 to 5 have excellent flexibility.

Furthermore, the greater the proportion of modified substances such as ε-caprolactone, the greater the flexibility effect.

In the case of bis(3,4-epoxycyclohexylmethyl) adipate in Comparative Example 3, flexibility is also observed, but the epoxy resin of the present invention has better flexibility by changing the proportion of modified substances. The range of grants will be expanded.

Furthermore, by using the epoxy resin of the present invention, the amount used can be reduced to provide the same degree of flexibility.

<Effects of the Invention> As detailed above, according to the present invention, a cured epoxy resin having excellent flexibility can be obtained, and it is used in the field of paint resins, electrodeposition paints, powder paint coating agents, etc. It is intended to be used as a hybrid baking paint and provide excellent characteristics such as imparting flexibility.

In addition, as raw materials for electrical materials, insulating varnish, LED encapsulant,
It can also be used to provide useful curing properties in applications such as semiconductor encapsulants, and also as sizing agents for glass fibers.

In addition, in Table 1, *l) hepoxide 2021
is 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate manufactured by Daicel Chemical Co., Ltd. *2) ERL4299 is bis(3°4-epoxycyclohexylmethyl) adipate manufactured by Union Carbide, *3) PCL-305 is polycaprolactone (molecular weight 500) manufactured by Daicel Chemical Co., Ltd.

(Margin below)

Claims (1)

[Claims] (1) (a) The following general formula (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼... (I) [However, in formula (I), X is the following structure ▲ Numerical formulas, chemical formulas, tables, etc. ▼ Y^1 has the following structure ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Y^2 has the following structure ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Y^3 has the following structure ▲ Numerical formulas, chemical formulas, tables, etc. etc. Represents ▼. R is alkyl having 1 to 30 carbon atoms, m-valent organic compound residue, R^a and R^b and R^1^1 to R^m
^9 is hydrogen, generally an alkyl group containing 1 to 9 carbon atoms, which can be replaced by each group at the same time. c.
is an integer of 4 to 8, nm is an integer of 0 or more, m is an integer of 1 or more] Aliphatic cyclic epoxy resin (b) Requires an epoxy resin curing agent that can react with the epoxy resin of (a) A curable resin composition comprising: