JPH0668005B2 - Method for producing flexible epoxy resin adduct - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a repair coating material, various jig / tool materials, mold materials,
Regarding a resin composition suitable for an adhesive or the like, more specifically,
The present invention relates to a fast-curing resin composition which has little toxicity such as odor and skin irritation, is easily cured at room temperature and has excellent heat resistance, and a flexible epoxy resin adduct that can be used for the composition.

[Background of the Invention]

Conventionally, room temperature curing type epoxy resin is used for paints, adhesives, castings, as a laminated material, and for mixing metal powder and other fillers into it to repair metal machinery, parts, etc. Or as a mold for plastic molding such as inspection jigs or vacuum molding, injection molding, urethane foam molding, RIM molding.

However, most of the conventionally used room temperature curing type epoxy resin compositions mainly have a strong odor of the curing agent used therein and a large skin irritation, and the obtained cured product has sufficient heat resistance. There was a big limitation when actually using it.

By the way, in the case of using an alicyclic epoxy resin having a high crosslink density, if an acid anhydride is used as a general curing agent, heat resistance is very high and a curing rate at high temperature is fast. However, in this case, heating at 150 ° C. or higher is usually required, and the reaction does not proceed sufficiently at room temperature.

Also known is a method of curing an alicyclic epoxy resin by using an organosilicon compound having a silanol group and an organoaluminum compound (for example, JP-A-51-118).
No. 728). However, in this case, the cross-linking density of the cured product is too high, and the impact resistance, adhesive strength, and strength are so small that they are not substantially satisfactory for the above-mentioned applications. Furthermore, in order to improve these properties, a method of modifying an epoxy resin with a polybutadiene having a carboxyl group at the terminal or a butadiene-acrylonitrile copolymer is also known (JP-A-59-109517). However, even in this case, the impact resistance, strength and adhesive strength are not always satisfactory, and the curing rate is room temperature (30 ° C).
In the following), there is a problem that it is considerably slow and cannot be effectively used as a fast-curing material.

Specific examples of repairing machines, devices, parts, etc. include leak prevention of pipes, valves, flanges, etc. for steam or heat medium,
There are leak prevention and corrosion prevention of the heating tank connection, repair of cracks in automobile engine blocks, crankcases, etc.However, conventional epoxy resin compositions have poor heat resistance and take a long time to completely cure. If it is hardened directly, it will cause foaming and poor curing, and even if it has relatively good room temperature curability and heat resistance, the flexibility of the cured product is poor and there are various problems such as brittleness, so its application is limited. It was In order to solve such a drawback, means such as increasing the molecular weight of the curing agent, or using an aromatic amine compound as the curing agent, using an alicyclic epoxy resin having a high crosslink density as the epoxy resin, etc. have been proposed. Some have been put to practical use.

However, if they are used, the viscosity of the resin composition becomes high, a new problem occurs in terms of workability, the heat resistance of the cured product is reduced, or the curing speed is greatly reduced,
It causes defects such that the cured product becomes extremely hard and brittle. For example, HDT of an epoxy resin cured with an aliphatic amine which is the most common curing agent or a modified product thereof (a large amount of an adduct of ethylene oxide or propylene oxide).
The (heat distortion temperature) is about 100 ° C. even after post-curing. Therefore, if an aromatic polyamine or a modified product thereof is used as a curing agent, the heat resistance can be expected to be improved, but the curability at room temperature is poor, and heat curing at 130 ° C. or higher is usually required. Epoxy resin, which does not exhibit sufficient physical properties when cured at room temperature, is used for repair materials such as those mentioned above, casting materials and overburden repair of corroded parts and repair of corroded parts of heat exchanger plates. There is a big limit to doing. Further, in such repair, it is usually necessary to suspend the operation of the mechanical device during the repair and cool the temperature of the repaired portion to near room temperature before performing the repair. This is because when the temperature of the repaired part is high, the viscosity of the repairing agent decreases, the coating fluidizes and sags before curing, and especially at a high temperature of 150 ° C or higher, ordinary epoxy resin does not cure properly or foams. It cannot be used by causing However, it is usually not possible to stop the operation of the machine each time. Therefore, if it can be used as an instant repairing agent while keeping the machine running and without lowering the temperature, the loss and maintenance cost due to the working time can be greatly reduced.

In addition, when used in the field, it is generally easy to adhere to hands and skin, and therefore, conventional repair agents often cause skin disorders such as "fogging", and also have a strong odor. Has also been needed. In addition, in the conventional repairing agent, the compounding ratio is often strictly regulated stoichiometrically (by weight ratio of about 100: 5 to 50), and even if it is easy to use, the volume ratio is 1: 1. . Therefore,
You can easily mix your own amount on site, and you can measure accurately and quickly 1: 1 by weight and volume ratio
There was a request for repair material.

In other applications, such as casting materials, adhesives, paints, and laminated materials, it is necessary to post-cure about 150 ° C in order to have an HDT of 150 ° C or higher. However, there has been a problem that deformation, warping, peeling, etc. occur unless it is pre-cured at 80 to 100 ° C., so that it cannot be actually used. Further, a composition having relatively good room temperature curability and heat resistance (for example, JP-A-59-10951).
In the case of the composition described in No. 7), when the temperature is below room temperature or when a thin layer such as an adhesive layer is formed, it is difficult to expect a curing acceleration effect due to self-heating and flexibility is insufficient. Actually, there was a usage limit.

[Outline of Invention]

The present invention has been made in view of the above points, and aims at the following points.

(I) To provide a fast-curing resin composition that is rapidly cured at room temperature (or from room temperature to high temperature) and has excellent heat resistance, flexibility, toughness, and adhesiveness.

(ii) To provide a fast-curing resin composition capable of instantaneous curing by controlling the curing temperature to a desired value so that the curing rate can be freely controlled.

(iii) To provide a fast-curing resin composition which has little odor and skin irritation and is excellent in safety.

(iv) To provide a fast-curing resin composition having excellent workability in terms of the blending ratio of each component when used.

(V) To provide a flexible epoxy resin adduct suitable for the composition as described above.

In order to achieve such an object, the flexible epoxy resin adduct of the present invention according to the first aspect is (a) a bisphenol-based epoxy resin and a polybutadiene having a carboxyl group at the terminal or a butadiene-acrylonitrile copolymer. It is characterized by being obtained by reacting a reaction product with an excess amount and an excess amount of the (b) alicyclic epoxy compound.

Furthermore, the present invention according to the second aspect is characterized in that the fast-curing resin composition comprises the following components as main components.

(A) alicyclic epoxy compound, (b) organosilicon compound having two or more silanol groups in one molecule, (c) (a) bisphenol epoxy resin and polybutadiene or butadiene-acrylonitrile having a carboxyl group at the end An epoxy resin adduct obtained by reacting a reaction product with an excess amount of a copolymer and (b) an excess amount of an alicyclic epoxy resin, (d) an aluminum chelate compound.

[Specific Description of the Invention]

Hereinafter, the present invention will be described in more detail. Details of each component are as follows.

Flexible epoxy resin adduct The flexible epoxy resin adduct according to the present invention is a reaction product of (i) a bisphenol epoxy resin and an excess amount of a polybutadiene or a butadiene-acrylonitrile copolymer having a carboxyl group at the terminal. And (b) is obtained by reacting with an excess amount of an alicyclic epoxy resin, and the adduct itself has excellent flexibility, but can be mixed with other resin compositions. Therefore, it is extremely excellent in improving the room temperature curability, heat resistance, flexibility, adhesiveness and toughness of the composition.

First, as the bisphenol-based epoxy resin used for the production of this adduct, a bisphenol A type or F type epoxy resin is preferably used, and specifically, bisphenol A diglycidyl ether and bisphenol A diβ are used.
Epoxy compounds such as methyl glycidyl ether, halogenated bisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, and bisphenol F diglycidyl ether are preferably used. Other types of epoxy resins, such as novolac type epoxy resins and glycidyl ester type epoxy resins, are particularly tough as compared with bisphenol type epoxy resins,
It is unsuitable in the present invention because it is inferior in adhesive strength.

As the polybutadiene having a carboxyl group at both ends of the polymer or the butadiene-acrylonitrile copolymer, the following commercially available products can be used, for example.

(A) Butadiene-acrylonitrile copolymer HYCAR CTBN 1300 × 8, 1300 × 13, 1300 ×
15 (Commercial product name, manufactured by Ube Industries, Ltd.) (b) Polybutadiene HYCAR CTB 2000 × 162, 2000 × 156, 2
000 × 165 (commercial product name, manufactured by Ube Industries, Ltd.) A rubber component is added to both ends of the epoxy resin by reacting the bisphenol epoxy with the polybutadiene (or the butadiene-acrylonitrile copolymer) in an excessive amount. The reaction product is obtained, and the alicyclic epoxy compound is reacted in excess with the reaction product to obtain the flexible epoxy resin adduct of the present invention. In the epoxy resin adduct according to the present invention thus obtained, the rubber component is located at both ends of the epoxy resin, so that the flexibility of the rubber component gives the epoxy resin high rigidity and high adhesive strength. In addition, by increasing the length of the molecular chain, it is considered to be excellent in improving the brittleness of the alicyclic epoxy resin, and improving the toughness, high adhesive strength and fast curing property.

In addition, when the flexible epoxy resin adduct is mixed in a mixed system of an alicyclic epoxy resin, a silanol compound and a metal powder, it has a remarkable effect in enhancing the storage stability of this system.

Fast-Curing Resin Composition As the alicyclic epoxy compound which is the component (a) of the fast-curing resin composition according to the present invention, a compound having an average of 2 or more epoxy groups per molecule is used. For these, the following compounds are preferably used.

For example, ERL-4221 (commercial product name, manufactured by Union Carbide), Celoxide # 2021 (commercial product name, manufactured by Daicel Chemical Industries, Ltd.) For example, ERL-4299 (commercial product name, manufactured by Union Carbide Co.) These can be used alone or in combination. The epoxy resins used in the present invention are limited to cycloaliphatic epoxies. Other epoxies, such as glycidyl ether type epoxy, glycidyl tester type epoxy, and glycidyl amine type epoxy, have a slower curing speed than ordinary cycloaliphatic epoxies at room temperature to a high temperature, and are used as a fast-curing material alone. It is unsuitable because it cannot be used in. However, even in alicyclic epoxies having one or less epoxy groups in one molecule, and other epoxies, adding a small amount as a reactive diluent or the like affects the curing rate, strength, adhesive strength and other physical properties. It can be used in a range not given.

The organosilicon compound of the component (b) used in the present invention has an average composition formula (In the above formula, R ₁ and R ₂ are hydrogen atoms, the same or different groups selected from substituted or unsubstituted monovalent organic groups, O <a <4, O ≦ b <4, O <c < 4, O <a + b + c
≦ 4), in which 10 mol% or more of the organic groups are phenyl groups and the amount of silanol groups is 2 or more in one molecule is particularly preferably used. When the amount of phenyl is less than 10 mol%, the compatibility with the alicyclic epoxy compound becomes poor, which is not preferable.

The mixing ratio of the alicyclic epoxy compound of the component (a) and the organosilicon compound in the present invention is such that the alicyclic epoxy compound 8
The range of 6 to 50% by weight and the organic silicon compound 14 to 50% by weight are preferable. When the alicyclic epoxy compound exceeds 86% by weight, self-heating is small at a temperature of room temperature or lower (about 30 ° C. or lower), which is not preferable as a fast-curing material. On the other hand, when it is less than 50%, heat resistance, It becomes a cured product with low strength and is not suitable for the above-mentioned applications.

As the flexible epoxy resin adduct of the component (c), the above-mentioned one is used, and the content thereof is the component (a) 1
5 to 30 parts by weight is preferable with respect to 00 parts by weight. If the content is less than 5 parts by weight, the cured product becomes brittle and the strength and adhesive strength are reduced, which is unsuitable for the above-mentioned uses. on the other hand,
If the content exceeds 30 parts by weight, the curing speed will slow down,
It is unsuitable because it cannot be used as a fast-curing material and its heat resistance tends to be significantly lowered.

Examples of the aluminum chelate compound used as the curing catalyst for the component (d) in the fast-curing resin composition of the present invention include aluminum monoacetylacetonate bis (ethylacetoacetate) (for example, aluminum chelate D (trade name) 76%). Isopropanol solution-Kawaken Fine Chemicals Co., Ltd., aluminum tris (acetylacetonate) (for example, Aluminum chelate A (trade name) -Kawaken Fine Chemicals Co., Ltd.), aluminum tris (ethylacetoacetate) (for example ALCH-). TR (trade name) -produced by Kawaken Fine Chemicals Co., Ltd. and the like can be preferably used.

The blending amount of the aluminum chelate compound is preferably 0.5 to 10 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the total amount of the alicyclic epoxy compound (a) and the organosilicon compound. If it is less than 0.5 part by weight, the reaction rate becomes slow, and it is not preferable as a fast-curing material particularly at room temperature (30 ° C. or less). On the other hand, if it exceeds 10 parts by weight, the pot life becomes extremely short even at room temperature,
It is not preferable because the heat resistance is lowered and the use becomes substantially difficult.

However, the catalyst component (d) that can be used in the present invention is limited to aluminum chelate compounds, and other conventionally known organoaluminum compounds, such as aluminum triisopropoxide, aluminum sec-butyrate, and mono sec.
-Aluminum alcoholates such as butoxyaluminum diisopropylate and aluminum isopropylate have poor storage stability, and when used at room temperature (30 ° C or less), they are in a thin layer form (2 mm or less) or a small amount (10 g or less). However, it is unsuitable since it cannot be used alone as a fast-curing material because of its poor self-heating and poor reactivity. (However, it is possible to mix a small amount within the range that does not affect the fast curing property). The reason for this is not clear, but it can be considered as follows. That is, it is considered that the organosilicon compound having a silanol group and the organoaluminum compound act as a two-way catalyst, and the rapid curing becomes remarkable by the cationic polymerization of the alicyclic epoxy resin, but in that case,
It is presumed that this is because an appropriate reaction induction period and high reactivity are realized only when an aluminum chelate compound is used.

Further, the fast-curing resin composition in the present invention is a fast-curing resin composition when three components of an alicyclic epoxy, an organosilicon compound having two or more silanol groups in one molecule, and an aluminum chelate compound are uniformly mixed. Since a curable resin composition can be formed and a cured product can be formed, by appropriately blending these three components, a rapid curable resin composition having a weight ratio and a volume ratio of 1: 1 can be easily obtained.

For example, solution A containing an alicyclic epoxy compound, an organosilicon compound and a flexible epoxy resin adduct, and solution B containing an alicyclic epoxy compound, a flexible epoxy resin adduct and an aluminum chelate compound. Can be prepared in advance and both solutions can be mixed at the time of use to form a cured product according to the purpose.

Further, in the composition of the present invention, other components can be additionally added according to various purposes and uses. For example, as the filler, iron powder, titanium powder, copper powder, metal powder such as aluminum powder calcium carbonate, barium sulfate, talc, glass beads, glass chopped strands, alumina, zinc oxide, titanium oxide, carbon black, etc. are used. Can be done. By adding such a filler, effects such as imparting thixotropy to the composition, reducing the coefficient of linear thermal expansion, reducing the cost, and suppressing the heat of curing to prolong the pot life can be obtained.

Furthermore, since the composition of the present invention is made of a material having low toxicity and odor, it is excellent in improving safety and workability.

Example of Invention

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Production Example 1 10 parts by weight of bisphenol A type epoxy compound (trade name: Epicoat 828-Yukaka Shell Epoxy Co., Ltd.) having an epoxy equivalent of 185 to 195 and HYCAR-CTBN1.
300 × 8 (manufactured by Ube Industries, Ltd.) 680 parts by weight and 15
After reacting at 0 ° C. for 6 hours, the mixture was cooled to 100 ° C., and then Celoxide # 2021 (manufactured by Daicel Chemical Industries, Ltd.)
100 parts by weight) was added thereto and reacted at 100 ° C. for 3 hours to obtain a flexible epoxy resin adduct (I) having an epoxy equivalent of 128 and a viscosity (25 ° C.) of 120,000 cps.

Example 1 R is composed of 65 mol% of methyl group and 35 mol% of phenyl group, a = 1.58 and silanol group OH.
Silicone resin having a base concentration of 5% (36 parts by weight), Celoxide # 2021 (56 parts by weight) and the flexible epoxy resin adduct (I) (8 parts by weight) obtained in Production Example 1 were uniformly mixed. Prepare (liquid A) and separately sell celoxide # 202
1 (89 parts by weight), 2 parts by weight of the flexible epoxy resin adduct (I) (9 parts by weight) obtained in Production Example 1 and 2 parts by weight of aluminum chelate D (Kawaken Fine Chemical Co., Ltd.) were uniformly mixed. (Solution B) was prepared. Since there is no strict stoichiometric regulation for the mixing ratio of A liquid and B liquid, there is no significant change in the physical properties of the cured product within the range of A / B = 4/1 to 1/2, but the curing speed In terms of workability, 1/1 is the best.

Table 1 below shows data comparing the gel time, curing time, heat generation of curing, physical properties of the cured product and the like with the conventional room temperature curing type fast curing resin composition.

Examples 2 to 3 and Comparative Examples 4 to 7 Table 2 shows the curing characteristics when the B liquid in which the aluminum compound (aluminum chelate compound) used in Example 1 was replaced with another aluminum compound was used. It was The compounding ratio is the same as in Example 1.

Example 4 and Comparative Examples 6 to 7 To 30 parts by weight of the liquid A shown in Example 1, 68 parts by weight of iron powder having an average particle size of 300 mesh and 2 parts by weight of VISCATOL A (MOONeY CHENICALS) as an anti-settling agent were uniformly added. The mixed product was the liquid (A-1), which was prepared by adding 68 parts by weight of the same iron powder to 30 parts by weight of the liquid B shown in Example 1 and further adding 2 parts by weight of biscatrol A as an anti-settling agent (B-1). Use as liquid.

Next, the flexible epoxy resin adduct (I) in the liquid B was used as a conventional epoxy resin adduct (II) shown in the following comparative production example.
The liquid having the composition replaced by is referred to as the liquid (B-2). In addition, the composition of the flexible epoxy resin adduct (I) in the solution A was set to 0 and the composition of the flexible epoxy resin adduct (II) in the solution B was set to 0. Is used as the solution (B-3).

Comparative Production Example Celoxide # 2021 and HYCARCTBN 130
0 × 8 was heated at a weight ratio of 700 to 200 at 100 ° C. for 3 hours to give an epoxy equivalent of 124 and a viscosity (25 ° C.) of 60,000 c.
An epoxy resin adduct (II) of ps was obtained.

Table 3 below shows effects such as impact resistance, strength, and adhesive force given to the cured product of the flexible epoxy resin adduct (I) according to the present invention. For comparison, the case where the conventionally known epoxy resin adduct (II) is used (Comparative Example 6) and the case where it is not used (Comparative Example 7) are also shown as Comparative Examples.

Change in curing time and HDT with compounding ratio Alicyclic epoxy compound (a) (Celoxide # 202
The change in curing time (time required to obtain a cured product of 2 mm thickness and 10 g at 25 ° C.) and the HDT (heat distortion temperature) when the compounding amount of 1) and the organosilicon compound (b) was changed Shown in Figure 1. However, the aluminum chelate compound was added in an amount of 3% by weight based on the amount of the alicyclic epoxy compound (a), and the amount of the flexible epoxy resin adduct added was 100 parts by weight of (a) + (b). 10 parts by weight.

As shown in this graph, when the compounding amount of the component (a) is in the range of about 50 to 86% by weight with respect to the total amount of (a) + (b), both fast curing property and heat resistance are obtained. Excellent characteristics can be obtained in.

Toxicity The composition of the present invention is advantageous in that it has less toxicity and skin irritation than conventional ones, and has excellent safety.
For reference, Table 4 below shows the chemical components (No. 1 to 3) used in the present invention and the chemical components (N
o.4-10) shows acute oral toxicity and SPI classification value.

[Brief description of drawings]

FIG. 1 is a graph showing changes in curing time and HDT (heat distortion temperature) with respect to the blending ratio of components.

Claims (1)

[Claims] 1. A reaction product of (a) a bisphenol epoxy resin and an excess amount of a polybutadiene or a butadiene-acrylonitrile copolymer having a carboxyl group at a terminal, and (b) an excess amount of an alicyclic epoxy compound. A method for producing a flexible epoxy resin adduct, which comprises reacting.