JPH05112632A - Method for curing epoxy resin - Google Patents

Abstract

PURPOSE:To properly control a pot life and a curing time and to cure the subject resin by using a mixture of an amine-based compound with an amine activity adjusting agent as a reaction initiator and curing an epoxy resin monomer with a polymercaptan-based curing agent. CONSTITUTION:In curing an epoxy resin monomer with a polymercaptan-based curing agent (preferably ether type polymercaptan), a mixture of 100 pts.wt. amine-based compound [e.g. tris(dimethylaminomethyl)phenol or N- methylpyrrolidine] and 1100 pts.wt. amine activity adjusting agent (e.g. carboxylic acid including acid anhydride as a curing retarder or organic acid comprising phenol as curing promoter) as a reaction initiator is added to the curing system to carry out the objective curing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used, for example, for materials such as adhesives, paints, and paving materials, and is applied when performing several steps per day or when it has to be cured in a short time. The present invention relates to an epoxy resin curing method.

[0002]

2. Description of the Related Art Conventionally, in curing an epoxy resin of this kind, an epoxy resin monomer is generally mixed with a polymercaptan type curing agent and an amine compound as a reaction initiator of the polymercaptan type curing agent. The curing reaction rate, that is, the curing time and the usable time (hereinafter referred to as the pot life) have been adjusted by selectively using the type of the system compound according to the ambient temperature at the time of curing.

[0003]

The amine compound as a reaction initiator has its own activity depending on its type. Utilizing such a property, it can be adjusted depending on the ambient temperature at the time of curing. By the conventional method of selecting the type of amine compound to be used, the curability of the epoxy resin is excellent, but it is difficult to make fine adjustments, and the physical properties of the cured product, such as tensile strength and There was a problem that the growth rate was not constant and caused a large variation.
Further, in the past, since ester-type polymercaptan as a curing agent was used in two liquids, the curing agent consisting of mercaptan and an amine compound undergoes a drastic change over time, and the mercaptan is hydrolyzed by the amine compound to react. The amine compound that is an initiator is neutralized, and as a result, it loses its function as a reaction initiator and the curing time and pot life cannot be adjusted. In addition, mercaptan hydrolysis causes a severe malodor. It was a thing.

The present invention has been earnestly studied in view of the above circumstances, and provides an epoxy resin curing method capable of appropriately adjusting the curing time and pot life without adversely affecting the physical properties of the cured product. The purpose is to do.

[0005]

In order to achieve the above object, an epoxy resin curing method according to the present invention comprises a step of curing an epoxy resin monomer with a polymercaptan type curing agent.
The usable time and the curing time are adjusted by blending an amine compound as a reaction initiator with an amine activity modifier added.

As the amine activity modifier, an organic acid consisting of a carboxylic acid as a curing retarder containing an acid anhydride or a phenol as a curing accelerator is used.

When the polymercaptan type curing agent is an ether type polymercaptan, it is used in a two-pack type in which it is pre-added to an amine type compound, and the polymercaptan type curing agent is an ester type polymercaptan. In this case, it is preferable to use 3 liquids.

When the amount of the amine compound is 100 parts by weight, it is desirable to add the amine activity modifier in a ratio of 1 to 100 parts by weight.

Hereinafter, each material used in the present invention will be described in detail. (1) Epoxy resin 1) Bisphenol A type epoxy resin a) Liquid resin (epoxy equivalent (EEW): 180 to 270) b) Solid resin (epoxy equivalent (EEW): 450 to 5000) 2) Bisphenol F type epoxy resin a ) Liquid resin (epoxy equivalent (EEW): 160 to 270) b) Solid resin (epoxy equivalent (EEW): 400 to 5000) 3) Novolac type epoxy resin a) Liquid resin (epoxy equivalent (EEW): 170 to 200) b) Solid resin (epoxy equivalent (EEW): 190 to 300) 4) Glycidylamine type epoxy resin a) Liquid resin (epoxy equivalent (EEW): 100 to 200) b) Solid resin (epoxy equivalent (EEW): 100 to 300) 5) Glycidyl ester type epoxy resin a) Liquid resin (epoxy equivalent (EEW) 150-500) 6) Glycidyl ether type epoxy resin a) Liquid resin (epoxy equivalent (EEW): 120-1200) 7) Other epoxy resins Various epoxy resins such as bisphenol AD type are mentioned, and solid, liquid and epoxy They can be used alone or in combination regardless of the equivalent weight. (2) Polymercaptan (SH equivalent is shown as an average value) 1) Ether-type polymercaptan a) Polymercaptans having an aromatic ring-Bisphenol A-type dihydrooxythiol SH equivalent: 230-Bisphenol F-type dihydrooxythiol SH Equivalent: 210 ・ Limonene dihydroxythiol SH equivalent: 175 b) Linear / side chain type polymercaptan ・ Polyoxypropylene poly 2-hydroxythiol SH equivalent: 280 ・ Ethylene glycol type di (poly) hydroxythiol SH equivalent : 90 2) Ester-type polymercaptans a) Aromatic ring-containing polymercaptans-Phthalate ester-type dimercaptans SH equivalent: 130 b) Linear / side-chain-type polymercaptans-Trimethylolpropane polymercaptopropionate H equivalent: 135 Venta pentaerythritol poly mercaptopropionate SH equivalent: 130 3) can be used in combination mono mercaptan Notwithstanding any other polymercaptan ether ester type. (3) Reaction initiator 1) Tertiary amine a) Amine having aromatic ring-Tris (dimethylaminomethyl) phenol-Benzyldimethylamine-m-Xylylenedi (dimethylamine) b) Heterocyclic amine-N, N'-dimethyl Piperazine, N-methylpyrrolidine, diaza-bicyclononane (including undecane), N-methylhydroxypiperidine c) straight chain / side chain amine, N, N, N ', N'-tetramethyldiaminoethane (propane to decane -N, N, N ', N', N'-pentamethyldiethylenetriamine 2) Polyamine a) Amine having aromatic ring-m-xylylenediamine and its modified products (epoxy resin adduct, etc.) b) Cyclic fat Group (including heterocycle) amines ・ Isophorone diamine and its modified products (epoxy resin adduct ) N-aminoethylpiperazine and its modified products (epoxy resin adducts, etc.) c) Aliphatic amines-Diaminoethane (including propane to decane) and its modified products (epoxy resin adducts, etc.)-Diethylenetriamine (tri-tetra, tetota) -Including penta) and its modified products (epoxy resin adduct, etc.)-Polyoxypropylene polyamine and its modified products (epoxy resin adduct, etc.) 3) Polyaminoamine (polyaminoimidazoline) and its modified products (4) Amine activity adjustment Agent 1) Aromatic carboxylic acid, benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, salicylic acid 2) Aliphatic carboxylic acid, formic acid, acetic acid, lactic acid, acrylic acid, propionic acid, octylic acid, oleic acid, linoleic acid・ Stearic acid ・ Butaric acid ・ Shi Oxalic acid, malonic acid, succinic acid, adipic acid, tartaric acid, sebacic acid, citric acid 3) cycloaliphatic carboxylic acid, dimer acid 4) acid anhydride, and among the compounds 1) to 3) above, it is converted to an acid anhydride. Possible compounds 5) Phenols (promoters) -Phenol-catechol-Hydruquinone-Bisphenol A and F-Naphthol-Cresol (including other alkylphenols) -Guayacol (including ethoxy) -Halogenated phenol-Resorcin-Xylenol ( 5) Other additives 1) Solvents, diluents, pigments, fillers, modifiers, etc.

Here, the EE of the compounded product when adjusting each chemical material used for curing the epoxy resin of the present invention
The W and SH equivalents and the addition amount of each material will be described. (1) Preparation of Epoxy Resin The EEW of the compounded product is expressed by the following (formula-1). However, (Formula-1) shows the case where two kinds of epoxy resins are mixed, when only one kind of epoxy resin is mixed, only a is added, and when three kinds of epoxy resins are mixed, c is added.

[0011]

[Equation 1]

(2) Preparation of polymercaptan The SH equivalent of the compounded product is expressed by the following (formula-2). However, (Formula-2) shows the case where two types of polymercaptans are blended, and when one type of polymercaptan is blended, a
In addition, when 3 types of polymercaptans are mixed, c is added.

[0013]

[Equation 2]

(3) Amount of Polymercaptan Added to Epoxy Resin The amount of polymercaptan added to 100 parts by weight of the epoxy resin is expressed by the following (formula-3). This (expression −
In 3), α = 120 to 40, preferably 100
The water resistance is remarkably reduced when α is 120 or more, and the strength is reduced when α is 40 or less. Incidentally, FIG. 1 is a graph showing changes in the tensile strength under water due to normal curing and underwater curing in the case of the experimental example in which the added weight part (phr) of polymercaptan was changed with respect to 100 parts by weight of the epoxy resin. The materials used in this experimental example are
The quantity and curing conditions are as follows. Epoxy resin used: (1) -1) EEW = 180 Mercaptan used: (2) -4) SH equivalent = 132.
5 Reaction initiator: (3-1) -1) was added to mercaptan at 10% Reaction modifier: (3-2) -3) was added to reaction initiator 10
10 parts by weight to 0 parts by weight Normal curing: 25 ° C x 1 day Underwater curing: 25 ° C x 1 day + 60 ° C Hot water x 1 day

[0015]

[Equation 3]

(4) Amount of reaction initiator added to polymercaptan (based on experimental results) (4-1) In the case of tertiary amine 3 to 3 parts of the reaction initiator relative to 100 parts by weight of polymercaptan.
It is 40 parts by weight, preferably 5 to 30 parts by weight. When it is 3 parts by weight or less, the strength is remarkably reduced, and when it is 30 parts by weight or more, the cured product becomes remarkably brittle. (4-2) In the case of amine having active hydrogen There are cases where mercaptan is used as a curing accelerator for amine and cases where amine is used as a reaction initiator for mercaptan. In the former case, 100 parts by weight of amine is used. 5 to 200 parts by weight of mercaptan, and in the latter case, 3 to 100 parts by weight of amine are suitable for 100 parts by weight of mercaptan.

Incidentally, FIG. 2 shows the polymer captan 100.
It is a graph which shows the change of the water-proof tensile strength by normal state curing and underwater curing in the case of the experiment example which changed the addition weight part (phr) of the tertiary amine with respect to weight part, and the elongation rate by normal state curing and underwater curing. The materials, amounts and curing conditions used in this experimental example are as follows. Epoxy resin used: (1) -1) EEW = 180 Mercaptan used: (2) -4) SH equivalent = 132.
5, α = 60 addition Reaction initiator: (3-1) -1) was added 10% to mercaptan Reaction modifier: (3-2) -3) was added to reaction initiator 10
10 parts by weight to 0 parts by weight Normal curing: 25 ° C x 1 day Underwater curing: 25 ° C x 1 day + 60 ° C Hot water x 1 day

(5) Amount of amine activity modifier added to amine (based on experimental results) 1 to 10 amine activity modifiers based on 100 parts by weight of amine
0 parts by weight is suitable.

The method of preparing and preparing the reaction initiator and the amine activity modifier is as follows. A 500 ml four-necked flask is equipped with a stirrer, a thermometer, a nitrogen charging port, and a sample charging port. The flask is sealed with nitrogen, and then an amine compound as a reaction initiator is charged. Then, the flask is heated to adjust the internal sample temperature to 30 to 80 ° C. Here, when the amine activity modifier is an organic acid, it may be added at the same time as the amine compound, or may be gradually added dropwise to react. After the heat generated by the reaction has subsided, the temperature is maintained at 80 ° C. for 1 hour to complete the reaction.
Further, in the case of a solid organic acid, it is heated to a temperature at which the organic acid is completely dissolved, and if completely dissolved, the reaction is completed by holding it at 80 ° C. for 1 hour as above.

[0020]

The above-described epoxy resin curing method is applied to materials such as adhesives, paints, and paving materials, and is applied when several steps are performed a day or when it is necessary to cure in a short time. To be done.

Here, the curing reaction rate is adjusted by selecting the kind of the amine compound added as a reaction initiator to polymercaptan, which is a curing agent for the epoxy resin monomer, according to the ambient temperature at the time of curing and the like. Instead, by adding an amine activity modifier such as an organic acid to the amine-based compound, the activity of the amine-based compound is delicately controlled, and the physical properties of the epoxy resin cured product are hardly adversely affected and the curing time And the pot life can be finely adjusted.

[0022]

[Examples] Examples of the present invention will be described below. 1-No. Two
9 and Comparative Example No. 1-No. 10 will be described. Basic composition of materials used: (1) Preparation of epoxy resin 1) Bisphenol A diglycidyl ether (EEW = 190) 80 parts 1.6-hexanediol diglycidyl ether (EEW = 150) 20 parts 2) Bisphenol A diglycidyl ether (EEW) = 190) 60 parts Phenol novolac diglycidyl ether (EEW = 178) 20 parts 1.6-Hexanediol diglycidyl ether (EEW = 150) 20 parts 3) Bisphenol A diglycidyl ether (EEW = 475) 30 parts Toluene 10 parts Xylene 10 Parts Methyl ethyl ketone 10 parts Rouge 8 parts Talc 32 parts Flow control agent 0.03 parts The EEW of the compounded product is as shown in (Formula-1). (2) Preparation of polymercaptan 1) Bisphenol A type dihydroxy thiol 90 parts Ethylene glycol type di (poly) hydroxy thiol 10 parts 2) Polyoxypropylene poly 2-hydroxy thiol 85 parts Ethylene glycol type di (poly) Hydroxythiol 15 parts 3) Polyoxypropylene poly 2-hydroxythiol 40 parts Limonene dihydroxythiol 60 parts 4) Trimethylolpropane polymercaptopropionate 50 parts Pentaerythritol polymercaptopropionate 50 parts Blended product The SH equivalent of is as shown in (Formula-2). (3-1) Reaction initiator 1) Tris (dimethylaminomethyl) phenol 2) N, N′-dimethylpiperazine 3) Diaza-bicycloundecane 4) N, N, N ′, N′-tetramethyldiaminohexane 5) m-Xylylenediamine (3-2) Amine activity modifier 1) Acetic acid 2) Lactic acid 3) Octylic acid 4) Benzoic acid 5) Salicylic acid 6) Isophthalic acid 7) Phenol

Including the test results for each item of curability, physical properties and water resistance of the coating film (cured product of epoxy resin) in each Comparative Example and each Example cured by the above-mentioned materials to be used, Comparative Examples and Examples are shown in Tables 1-5 below. The methods and conditions for each of the above test items are as follows. (1) Coating film curing test; C. I type coating film drying time measuring instrument-Measuring temperature 5 to 35 ° C-Film thickness 2 mil (2) Physical property test; -Testing machine Shimadzu Autograph DSS-5
000 and AGS-500 ・ Curing temperature 25 ° C ・ Curing and curing condition 25 ° C ・ Water resistance deterioration 60 ° C warm water ・ Measuring temperature 25 ° C (3) Visual judgment; ・ Coating state of coating film / cast material ・ Water resistant whitening in water resistance test Gender / Other

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

[0027]

[Table 4]

[0028]

[Table 5]

The example Nos. In Table 2 are as follows. As shown in 1-8, when using ether type polymercaptan,
Although it is possible to add the reaction initiator in advance, it is possible to use the example Nos. As shown in 9 to 29, when an ester-type polymercaptan is used, when a reaction initiator is added in advance, perhydrolysis occurs, the reaction initiator is neutralized, and finally the function as a reaction initiator is obtained. In the case of the ester type, it is desirable to use the three-liquid type because it loses the In addition, the example Nos. As shown in Nos. 25 to 27, when phenol is used as the amine activity modifier, the phenolic OH group acts to enhance the amine activity even though it is a weak acid, and therefore the addition of these causes a curing acceleration effect. Further, the example Nos. 20 ~
As shown in No. 22, when salicylic acid is used as an amine activity modifier, this salicylic acid is a phenolic OH.
It has both a group and a COOH group, and such a compound becomes an accelerator when added in a small amount, and acts as a retarder when the added amount is increased.

[0030]

As described above, according to the present invention, by adding an amine activity adjusting agent to an amine compound which is a reaction initiator, the amine activity which is liable to greatly vary depending on environmental conditions such as temperature is delicately adjusted. Control
The pot life and curing time can be adjusted appropriately without adversely affecting the physical properties of the cured epoxy resin such as tensile strength and elongation.

[Brief description of drawings]

FIG. 1 shows an epoxy resin curing method according to the present invention,
It is a graph which shows the change of the water-proof tensile strength by normal state curing and underwater curing in the case of the experiment example which changed the addition weight part of polymercaptan with respect to 100 weight part of epoxy resins.

FIG. 2 shows changes in water-resistant tensile strength due to normal curing and underwater curing in the case of an experimental example in which the addition weight part of the tertiary amine is changed with respect to 100 weight parts of polymercaptan, and
It is a graph which shows the growth rate by normal state curing and underwater curing.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Toshiyuki Fukumoto 2-10-3 Nagao Furniture Town, Hirakata City, Osaka Prefecture Daito Sangyo Co., Ltd. Hirakata Factory

Claims (5)

[Claims] 1. When curing an epoxy resin monomer with a polymercaptan curing agent, an amine compound as a reaction initiator to which an amine activity modifier is added is blended,
A method for curing an epoxy resin, which comprises adjusting a usable time and a curing time. 2. The method for curing an epoxy resin according to claim 1, wherein the amine activity modifier is an organic acid composed of a carboxylic acid as a curing retarder containing an acid anhydride or a phenol as a curing accelerator. 3. The method for curing an epoxy resin according to claim 1, wherein the polymercaptan-based curing agent is an ether-type polymercaptan, which is pre-added to the amine compound. 4. The polymercaptan-based curing agent is an ester-type polymercaptan and is used as a three-part liquid.
Epoxy resin curing method. 5. The method for curing an epoxy resin according to claim 1, wherein the amine activity adjusting agent is blended in a ratio of 1 to 100 parts by weight when the amine compound is 100 parts by weight.