JPH04202523A - Thermosetting composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in chemical and physical properties and weather resistance and useful as a coating material, etc., by mixing a compound containing epoxy groups, etc., a compound containing carboxyl groups, etc., and a specified latent heat-containing acid catalyst. CONSTITUTION:An objective composition containing, as the essential components, (A) a compound containing two or more epoxy groups in the molecule, e.g. a bisphenol-type epoxy resin and/or a compound containing two or more thiirane groups in the molecule, e.g. an alicyclic episulfide resin, (B) a compound having two or more groups selected from one or more kinds of groups among carboxyl group, e.g. contained in oxalic acid, carboxylic acid anhydride group, e.g. contained in pyromellitic acid and hetero-acid anhydride group obtained from a carboxylic acid and another acid and (C) a latent heat-containing acid catalyst composed of one or more compounds selected from sulfonic acid esters and phosphoric acid esters and showing an activity at >=50 deg.C. In addition, the ratio of the component (B) used is preferably 0.1-1.5 equivalent on functional group base based on the component (A).

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a novel thermosetting composition, more specifically, it provides a cured product with excellent chemical performance, physical performance, weather resistance, etc., and also has a short pot life. (e.g. paints, inks, adhesives,
The present invention relates to a thermosetting composition suitable for use in molded articles and the like.

[Prior Art] Conventionally, a compound containing an epoxy group or a thiirane group, and a reactive functional group that forms a chemical bond with the epoxy group or the thiirane group, such as a carboxyl group, a carboxylic acid anhydride group, or a carboxylic acid, have been used. Thermosetting compositions consisting of a compound containing a heteroanhydride group obtained from other acids have attracted attention because of the excellent physical properties of the resulting thermoset, and are used in paints, inks, adhesives, etc. It is widely used in fields such as molded products. An acid catalyst has been used in the thermosetting composition for the purpose of inducing or accelerating the curing reaction.

However, since the carboxyl group and the reactive functional group have high reactivity, when an acid catalyst is added to a composition in which a compound containing an epoxy group or a thiirane group and a compound containing a functional group such as a carboxyl group coexist, Problems such as a shortened pot life arise.

Therefore, in order to solve these problems, for example, in curing systems such as polyol/melamine systems that require an acid catalyst, it is necessary to use a thermally latent acid catalyst to improve storage stability. It is being done. Specific examples include (1) one using an ester compound of sulfonic acid and primary alcohol (Japanese Patent Publication No. 52-770);
(2) Using a mixture of phosphoric acid monoester and diester (U.S. Patent No. 4.237.241)
, (3) A method using an ester compound produced by an addition reaction between a sulfonic acid and an epoxy compound [Industrial and Engineering Chemistry. Product Research and Development (Ind.
ngChem, Proci, Res, Dev, ) J 2nd
2, pp. 440-444 (1983)], and (4) sulfonic acid or phosphoric acid neutralized with an amine are also known. Among these, the amine-neutralized type (4) neutralizes a strong acid with a weak base, so it cannot completely block the acid, and it does not completely block the acid. It cannot be said that it shows good storage stability compared to .

On the other hand, such a thermally latent acid catalyst can be used with a compound containing two or more epoxy groups or thiirane groups in one molecule, or with a carboxyl group, one carboxylic acid, an anhydride group, or a carboxylic acid in one molecule. Until now, no example has been known of its use for the purpose of accelerating the curing of a thermosetting composition comprising another acid and a compound containing two or more heteroacid anhydride groups.

[Problems to be Solved by the Invention] Under these circumstances, the present invention provides a cured product with excellent chemical performance, physical performance, weather resistance, etc. in a short curing time, and also has a long pot life. This was made for the purpose of providing a thermosetting composition.

[Means for Solving the Problems] As a result of intensive research to develop a thermosetting composition having the above-mentioned preferable properties, the present inventors found that two or more epoxy groups or thiirane groups are present in one molecule. Compounds containing two or more carboxyl groups, carboxylic anhydride groups, or heteroanhydride groups obtained from carboxylic acid and other acids in one molecule, and heat exhibiting activity at temperatures of 50°C or higher. The inventors have discovered that the object can be achieved with a composition containing a latent acid catalyst as an essential component, and have completed the present invention based on this knowledge.

That is, the present invention provides (A) a compound containing two or more epoxy groups and/or thiirane groups in one molecule, (B) 1
A compound containing at least two or more of one type selected from a carboxyl group, a carboxylic anhydride group, and a heteroanhydride group obtained from carboxylic acid and other acids in the molecule, and (C) 50°C or more The object of the present invention is to provide a thermosetting composition containing as an essential component a thermally latent acid catalyst that is active at a temperature of .

The present invention will be explained in detail below.

In the composition of the present invention, the compound used as component (A) may be any compound containing two or more epoxy groups and/or thiirane groups in one molecule (there is no particular restriction, There are no particular restrictions on the type of group.

Examples of the compound containing the epoxy group include glycidyl ether, glycidyl ester, alicyclic epoxy compound, aliphatic epoxy compound, etc. Specifically, bisphenol type resin, ring type epoxy resin, and glycidyl ( α such as meth)acrylate and 3,4-epoxy compound hexylmethyl(meth)acrylate
, homopolymers of β-unsaturated epoxy compounds, and α- and β-unsaturated compounds with no other reactive functional groups.
, copolymers with β-unsaturated compounds, and the like. Examples of the α,β-unsaturated compound having no reactive functional group include methyl (meth)acrylate, ethyl (meth)acrylate,
Acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate
Acrylate, isobutyl (meth)acrylate, 5e
C-butyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, styrene,
Examples include α-methylstyrene, p-vinyltoluene, and acrylonitrile.

On the other hand, examples of compounds containing a thiirane group include alicyclic episulfide compounds, aliphatic episulfide compounds, and specifically bisphenol type resins,
Alicyclic episulfide resins, as well as homopolymers of α,β-unsaturated episulfide compounds such as 3-(meth)acryloyloxypropylene episulfide and 3,4-episulfide cyclohexylmethyl (meth)acrylate, and unsaturated compounds thereof and a copolymer of α, β-unsaturated compound having no reactive functional group.

Examples of the α,β-unsaturated compound having no reactive functional group include those exemplified in the description of the compound containing an epoxy group.

This (A) component compound may have one or more epoxy groups and one or more thiirane groups, and if necessary,
It may contain functional groups other than epoxy groups and thiirane groups, such as hydroquine groups, acetal groups, vinyl ether groups, carbonyl groups, ester groups, and amide groups.

In the composition of the present invention, the compound (A) is 1
A species may be used, or two or more species may be used in combination.

In the composition of the present invention, the compound used as component (B) is selected from carboxyl groups, carboxylic anhydride groups, and heteroanhydride groups obtained from carboxylic acids and other acids in one molecule. at least one species
There is no particular restriction as long as it contains at least 1.

Specifically, examples of such compounds having two or more carboxyl groups in one molecule include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and decanic acid. Aliphatic polycarboxylic acids having 2 to 22 carbon atoms such as methylene dicarboxylic acid, maleic acid, and fumaric acid; aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid; and tetrahydrophthalic acid. , hexahydrophthalic acid, alicyclic polycarboxylic acids such as methylated hexahydrophthalic acid, polyester resins having two or more carboxyl groups in one molecule, acrylic resins, maleated polybutadiene resins, and the like. Examples of compounds having two or more carboxylic acid anhydride groups in one molecule include homopolymers such as itaconic anhydride and maleic anhydride, and α-, β- Examples include copolymers with unsaturated compounds. Furthermore, the (B
) In addition to the carboxyl group, carboxylic anhydride group, and heteroanhydride group, the compound of component ) may optionally contain a functional group that does not react with the above-mentioned functional groups and does not inhibit curing, such as a carbonyl group or an ester group. , amide group, etc.

In the composition of the present invention, the compound (B) component is 1
A species may be used, or two or more species may be used in combination.

The thermally latent acid catalyst used as component (C) in the composition of the present invention accelerates the curing reaction when the thermosetting composition of the present invention is cured, and provides the cured product with good chemical and physical performance. It is an essential component for achieving long-term stability during storage of the composition, and is not particularly limited as long as it exhibits activity as an acid catalyst at a temperature of 50° C. or higher. Specifically, ester compounds of sulfonic acid and primary alcohol (Japanese Patent Publication No. 52-770),
Phosphoric acid monoesters and diesters, mixtures of phosphoric acid monoesters and diesters (U.S. Pat. No. 4,237,
241 specification), ester compounds obtained by addition reaction between sulfonic acid and epoxy compounds [Industrial and Engineering Chemistry, Product Research (Ind, Eng, Chem, Prod, Res.

Dev, ) J Vol. 22, pp. 440-444 (19
1983)].

More specific examples of the sulfonic acid esters include R'-3-0-R' 0 ... (I) (
In the formula, R1 is a phenyl group, a substituted phenyl group, a naphthyl group, a substituted naphthyl group, or an alkyl group; R2 is an alkyl group having 3 to 18 carbon atoms bonded to a sulfonyloxy group via a primary carbon or a secondary carbon; aryl group, alkaryl group, alkanol group, saturated or unsaturated cycloalkyl or hydroxycycloalkyl group), such as methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid , sulfonic acids such as naphthalenesulfonic acid and nonylnaphthalenesulfonic acid, primary alcohols such as n-propanol, n-butanol, n-hexanol, n-octatool, or impropanol, 2-
Examples include esters with secondary alcohols such as butanol, 2-hexanol, 2-octatool, and cyclohexanol, as well as β-hydroxyalkyl sulfonic acid esters obtained by reacting the above-mentioned sulfonic acids with epoxy group-containing compounds. .

On the other hand, more specific examples of phosphoric acid esters include - formula % formula %) (R3 in the formula is an alkyl group, cycloalkyl group, or aryl group having 3 to 10 carbon atoms, and n is 1 or 2). The compounds represented, e.g. primary alcohols such as n-propanol, n-butanol, n-hexanol, n-octatool, 2-ethylhexanol or isopropanol, 2-butanol, 2-hexanol, 2-octatool Tools, phosphoric acid monoesters and phosphoric diesters of secondary alcohols such as cyclohexanol, and mono(β-hydroxyalkyl) phosphoric esters and di( Examples include β-hydroxyalkyl) phosphate esters.

The thermally latent acid catalyst of component (C) needs to show activity at a temperature of 50°C or higher, and if it shows activity as an acid catalyst at a temperature of less than 50°C, the thermosetting composition of the present invention The pot life of the product is short.

In the composition of the present invention, one type of thermally latent acid catalyst as component (C) may be used, or two or more types may be used in combination.

Regarding the usage ratio of component (A) and component (B) in the composition of the present invention, the functional group of component (B) is 0.1 to 1 equivalent of epoxy group and/or thiirane group of component (A).
It is desirable to use both components in a proportion that provides 1.5 equivalents.

In addition, the blending amount of the thermally latent acid catalyst as the component (C) is (
It is usually selected in the range of 0.01 to 10 parts by weight per 100 parts by weight of the total amount of components A) and (B).

The temperature and time required for curing the thermosetting composition of the present invention vary depending on the type of heat-latent acid catalyst used as component (A), component (B), or component (C), but usually 50 to Curing is completed by heating at a temperature in the range of 200° C. for about 2 minutes to 2 hours.

The thermosetting composition of the present invention can be used as it is or, if necessary, mixed with coloring pigments, fillers, solvents, ultraviolet absorbers, antioxidants, etc., for paints, inks, adhesives, molded products, etc. I can do it.

[Examples] Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

Production example 1 2 equipped with a cooling tube, thermometer, stirring device and dropping funnel
Methyl isobutyl ketone 488 in a 4-bottle flask
After heating to 100°C, add 64 parts by weight of acrylic acid and 232 parts by weight of methyl methacrylate.
Parts by weight, n-butyl acrylate 196 parts by weight, 2.2
A mixture of 20 parts by weight of '-azobisisobutyronitrile was added dropwise over 2 hours. 2.5 at 100℃ after completion of dropping
As a result of continuing the reaction for hours, a resin solution having an acid value of 100 mqKOH/y, a solid content of 50.5% by weight, and a number average molecular weight of 2,570 was obtained.

Production example 2 2 equipped with a cooling tube, thermometer, stirring device and dropping funnel
Methyl isobutyl ketone 488 in a 4-bottle flask
After heating to 100°C, 77 parts by weight of methacrylic acid, 194 parts by weight of methyl methacrylate, 221 parts by weight of n-butyl acrylate, and 2.2'-
A mixture of 20 parts by weight of azobisisobutyronitrile was added dropwise over 2 hours. After the dropwise addition was completed, the reaction was continued at 100° C. for 2.5 hours to obtain a resin solution having an acid value of 100 mqKOH/g, a solid content of 516% by weight, and a number average molecular weight of 3,000.

Production Example 3 2 equipped with a cooling tube, thermometer, stirring device and dropping funnel
After putting 315 parts by weight of 2-propatool into a four-bottle flask and cooling with water, 44.9 parts by weight of potassium t-butoxide was added and dissolved therein, and then p-chloride dissolved in 300 parts by weight of diethyl ether was added. 53.4 parts by weight of +-luenesulfonyl was added dropwise over 30 minutes. After dripping 1
After that time, the water bath was removed, and the reaction was continued for an additional hour. After the reaction was completed, the reaction mixture was washed three times with 300 parts by weight of water, and then Molecular Lube 4A I/16 [manufactured by Wako Tsumugi Co., Ltd., trade name] was added, followed by dehydration and drying, and the solvent was removed using an evaporator. By distilling off, 40 parts by weight of p-1-luenesulfonic acid (1-methylethyl) (yield 67%)
) was obtained.

The obtained thermal latent acid catalyst was dissolved in 238 parts by weight of xylene and diluted to 10% by weight in terms of p-toluenesulfonic acid.

Production Example 4.5 Perform the same operation as Production Example 3, except that 2-hexanol was used instead of 2-propanol in Production Example 3 for Production Example 4, and cyclohexanol was used for Production Example 5. In Production Example 4, p-toluenesulfonic acid (1-methylpentyl) was obtained in a yield of 67%, and in Production Example 5, p-toluenesulfonic acid (cyclohexyl) was obtained in a yield of 82%. The obtained thermally latent acid catalyst is
As in Production Example 3, each was diluted with xylene to a concentration of 10% by weight in terms of p-h luenesulfonic acid.

Examples 1 to 3 A mixture of 100 parts by weight of the polycarboxylic acid resin obtained in Production Example 1, 119 parts by weight of an epoxy curing agent ERL-4221 (manufactured by Union Carbide, trade name) and 45 parts by weight of xylene, In Example 1, a xylene solution of the sulfonic acid ester obtained in Production Example 3 was used, in Example 2, a xylene solution of the sulfonic acid ester obtained in Production Example 4, and in Example 3, a xylene solution of the sulfonic acid ester obtained in Production Example 5 was used. A thermosetting composition was prepared by adding 6.3 parts by weight of a xylene solution of each acid ester.

Next, after pouring this composition onto a tin plate,
Baked at 0°C for 30 minutes. The knoop hardness (according to ASTM D-1474) of the thus obtained coating film was measured at a portion having a dry film thickness of 30 μm. Also,
The pot life of each composition was evaluated by the change in viscosity after storage at 50° C. for 7 days. The results are shown in Table 1.

Examples 4 to 6 A mixture of 100 parts by weight of the polycarboxylic acid resin obtained in Production Example 2, 12.1 parts by weight of an epoxy curing agent ERL-4221 (manufactured by Union Carbide, trade name), and 45 parts by weight of xylene. In Example 4, a xylene solution of the sulfonic acid ester obtained in Production Example 3 was used, and in Example 5, a xylene solution of the sulfonic acid ester obtained in Production Example 4 was used.
In Example 6, 6.5 parts by weight of the xylene solution of the sulfonic acid ester obtained in Production Example 5 was added to prepare a thermosetting composition.

Next, after pouring this composition onto a tin plate,
Baked at 0°C for 30 minutes. The knoop hardness (according to ASTM D-1474) of the thus obtained coating film was measured at a portion having a dry film thickness of 30 μm. Also,
The pot life of each composition was evaluated by the change in viscosity after storage at 50° C. for 7 days. The results are shown in Table 1.

Comparative Examples 1 to 3 A mixture of 100 parts by weight of the polycarboxylic acid resin obtained in Production Example 1, 11.9 parts by weight of an epoxy curing agent ERL-4221 (manufactured by Union Carbide, trade name), and 45 parts by weight of xylene. In Comparative Example 1, xylene 6.3
In Comparative Example 2, 63 parts by weight of a 10% by weight isopropanol solution of p-toluenesulfonic acid was added, and in Comparative Example 3, a 10% by weight xylene solution of triethylamine was added to form a thermosetting composition. Prepared.

Next, after pouring this composition onto a tin plate,
Baked at 0°C for 30 minutes. The knoop hardness (according to ASTM D-1474) of the thus obtained coating film was measured at a portion having a dry film thickness of 30 μm. Also,
The pot life of each composition was evaluated by the change in viscosity after storage at 50° C. for 7 days. The results are shown in Table 1.

Comparative Examples 4 to 6 A mixture of 100 parts by weight of the polycarboxylic acid resin obtained in Production Example 2, 121 parts by weight of an epoxy curing agent ERL-4221 (manufactured by Union Carbide, trade name) and 45 parts by weight of xylene, In Comparative Example 4, 6.3 parts by weight of kiln was used, and in Comparative Example 5, 1 part by weight of p-toluenesulfonic acid was added to the kiln.
A thermosetting composition was prepared by adding 6.5 parts by weight of a 0% by weight isopropanol solution and, in Comparative Example 6, a 10% by weight solution of triethylamine in xylene.

Next, after pouring this composition onto a tin plate,
Baked at 0°C for 30 minutes. The knoop hardness (according to ASTM D-1474) of the thus obtained coating film was measured by laying it on a portion where the dry film thickness was 30 μm. Also,
The pot life of each composition was evaluated by the change in viscosity after storage at 50° C. for 7 days. The results are shown in Table 1.

(Margin below) Comparing Examples 1 to 6 and Comparative Examples 1 to 6 in Table 1, Comparative Examples 1 and 4 have knoop hardness values of 7.
8, which is smaller than the hardness values of 11 to 12 of the corresponding Examples 1 to 6, and it is recognized that Comparative Example 1.4 is inferior to Examples 1 to 6 in terms of hardness.

In addition, Comparative Example 2.3.5.6 is listed as a comparative example regarding pot life, but regarding viscosity change, Example 1
-6, the viscosity of Comparative Example 2.3.5.6 clearly increases within the same time period. This indicates that the pot life of the thermosetting composition of the present invention is longer than that of Comparative Example 2.3.5.6. Further, in Comparative Example 3.6, coloring was observed in the paint, but no coloring was observed in the thermosetting composition of the present invention.

That is, it can be seen that the thermosetting composition of the present invention is superior to the comparative example in all aspects.

[Effects of the Invention] The thermosetting composition of the present invention contains a compound containing two or more epoxy groups or thiirane groups in one molecule, a carboxyl group, a carboxylic acid anhydride group, a carboxylic acid, and other compounds in one molecule. A compound containing two or more heteroanhydride groups obtained from an acid and a thermally latent acid catalyst that is active at a temperature of 50°C or higher, and has excellent chemical performance, physical performance, and weather resistance. In addition to providing a cured product quickly, the composition has the advantage that the pot life is the same as that of the composition of the present invention without the catalyst.

The thermosetting composition of the present invention is suitably used, for example, in paints, inks, adhesives, and molded articles.

Claims (1)

[Scope of Claims] 1 (A) A compound containing two or more epoxy groups and/or thiirane groups in one molecule, (B) A compound containing a carboxyl group, a carboxylic acid anhydride group, and a carboxylic acid and other compounds in one molecule. A compound containing two or more of at least one type selected from hetero acid anhydride groups obtained from acids, and (C)5
A thermosetting composition comprising as an essential component a thermally latent acid catalyst that is active at temperatures of 0°C or higher. 2. The thermosetting composition according to claim 1, wherein the thermally latent acid catalyst is at least one selected from sulfonic acid esters and phosphoric acid esters.