JP2009079189A - Thermosetting composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new thermosetting composition which is free from factors causing instability in reaction such as curing inhibition, not generating released vaporizing matter, excellent in dimensional stability because of low shrinkage on curing, and excellent in stability of the cured coating film. <P>SOLUTION: This thermosetting composition as a curable composition utilizing Diels-Alder reaction uses a substance having specified structure as a diene and a dienophile, namely, it comprises a compound (A) carrying a plurality of conjugated carbon-carbon double bonds as sorbic esters in the molecule, and a compound (B) having two or more carbon-carbon double bonds in the molecule. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a novel thermosetting composition characterized in that it is cured by an addition reaction so that no elimination volatilization is generated, and since there is little curing shrinkage, it has excellent dimensional stability.

  The Diels-Alder reaction is one of the most well-known organic chemical reactions and was discovered in 1928 as a reaction between diene and dienophile. The characteristic is that the reaction proceeds by heat but does not proceed by light. It is also well known that reverse reactions occur.

Patent Document 1 describes a curable composition using this Diels-Alder adduct. This curable composition is used as a coating material for electrical or electronic components.
Patent Documents 2 and 3 describe resins having a cross-linked structure by Diels-Alder addition. Patent Document 2 uses a reversible reaction when a Diels-Alder addition site is heated, that is, a desorption reaction and an addition reaction occur, and Patent Document 3 uses the same property for recyclability. It is described that it can be used as a hot melt adhesive, a resin, a rubber flow preventive, an adhesive modifier, and the like. Japanese National Patent Publication No. 10-508655 Non-Patent Documents 1 and 2 describe the Diels-Alder reaction when furfuryl is used as the diene and maleimide is used as the dienophile. This system undergoes an addition reaction at room temperature, and at around 40 ° C. The reverse reaction has been shown to occur. : C. Goisse; Macromolecules 31,314-321 (1998) : R.Geneim; Macromolecules 35,7246-7253 (2002) As described above, the Diels-Alder reaction is characterized by reversible forward reaction (addition) and reverse reaction (desorption). When used as a curing reaction, the presence of a reverse reaction can cause a decrease in the durability and heat resistance of the coating film. Therefore, as a Diels-Alder reaction that can be suitably used for paints, the addition reaction, which is a normal reaction from the viewpoint of energy saving and coating workability, proceeds at a low temperature, and the elimination reaction, which is a reverse reaction from the viewpoint of durability of the cured coating film, is A combination of diene and dienophile that does not occur only at a high temperature is preferable, but a combination of diene and dienophile that has been highly practical as a coating material has not been found.

  There is no element that makes the reaction unstable such as curing inhibition, no release volatilization occurs, and there is little curing shrinkage, so it has excellent dimensional stability, and a novel thermosetting composition with excellent cured coating stability Get things.

  As a result of intensive studies, the inventor has found that the problem can be solved by using a substance having a specific structure as a diene and a dienophile in a curable composition utilizing Diels-Alder reaction, and has completed the present invention.

Thus, the present invention provides 1. Including a compound (A) in which a plurality of carbon-carbon double bonds conjugated in the molecule are supported as sorbic acid esters and a compound (B) having two or more carbon-carbon double bonds in the molecule. A thermosetting composition characterized.
2. The term in which the carbon-carbon double bond of the compound (B) is due to a maleimide group bonded to a hydrocarbon group which may contain at least one element selected from an oxygen atom, a nitrogen atom, a sulfur atom and a phosphorus atom The thermosetting composition according to 1.
3. Item 3. The thermosetting composition according to item 1, wherein two or more carbon-carbon double bonds in the compound (B) are supported on a side chain of the polymer by a (meth) acrylate group. Item 4. The thermosetting composition according to any one of Items 1 to 3, wherein the compound (A) and / or the compound (B) is a polymer having a number average molecular weight of 1000 or more.
5). Item that is bonded to any one of Items 1 to 4 using a curable composition.
6). Item 5. A coating composition comprising the curable composition according to any one of items 1 to 4.
7). Item 7. A coated article having a cured film of the coating composition according to item 6 on its surface.
Is disclosed.

There was obtained a novel thermosetting composition having no reaction unstable elements such as curing inhibition, no elimination volatilization, excellent dimensional stability before and after curing, and excellent stability of the cured coating film.

  The present invention is a curable composition for forming a cured coating film by Diels-Alder reaction of a compound having a specific structure. The diene and dienophile involved in the Diels-Alder reaction will be described below.

Many substances are known as conjugated dienes that undergo Diels-Alder reactions with conjugated carbon-carbon double bonds . Among them, cyclic dienes such as furan are the most prominent, and it is well known that the Diels-Alder reaction described in many textbooks is a ring-closing reaction between the cyclic diene and the cyclic ene. However, since cyclic dienes themselves are stable compounds, the Diels-Alder reverse reaction is likely to occur, so that the resulting ring-closing structure is not stable, and when used in adhesives and paints, the durability of the cured product is insufficient. Therefore, it is preferable to use a non-cyclic diene for the use of adhesives and paints. Typical examples of these acyclic conjugated dienes are sorbic acid (and its esters) in which the conjugated diene is adjacent to the carbonyl group, and linoleic acid in which the conjugated diene is isolated in the alkyl chain. (And its esters), and low molecular weight dienes such as butadiene and 1,3-pentadiene. Among these, low molecular weight diene has a low boiling point and is put to practical use as a curable composition.

  Both sorbic acid structure and linoleic acid structure become stable cured products by Diels-Alder reaction, but in the case of linoleic acid structure, it is widely known that the carbon adjacent to the conjugated diene undergoes oxygen attack and causes oxidative polymerization. Yes. This polymerization reaction has been widely used as a curing reaction for conventional dry paints. However, when used in a Diels-Alder curing system using a combination of diene and dienophile, the Diels-Alder reaction and this oxidative polymerization reaction become a competitive reaction during curing, and 1) the stability of the curing reaction is lacking. 2) The cured product is easily colored. 3) The outdoor weather resistance of the cured product is inferior. (It was considered that unreacted dienophile and isolated double bonds generated during oxidative polymerization remain in the cured product, which is considered to be the starting point of oxidative degradation.). On the other hand, it was found that the curing system using the sorbic acid structure does not cause these problems, and the inventors have used heat resistance (degradation reaction is unlikely) and outdoor weather resistance (photodegradation) as a diene used in the Diels-Alder curing system. It is found that the sorbic acid structure is particularly suitable for use in paints and adhesives from the viewpoint of durability that oxidation deterioration hardly occurs), and the present invention can be completed by a compound that supports it as an ester (sorbate). done.

Compound (A) carrying a plurality of sorbic acid esters
A compound in which a plurality of sorbic acid esters (hereinafter sometimes referred to as “sorbates”) are supported has an acrylic resin compound (hereinafter, a compound in which a plurality of sorbates are supported) may be referred to as “acrylic resins” because of its skeleton structure. ), A polyester resin compound (hereinafter, a compound in which a plurality of sorbates are supported may be referred to as “polyester resin”), an epoxy resin compound (hereinafter, a compound in which a plurality of sorbates are supported may be referred to as “epoxy resins”). And those obtained by further urethane modification (sometimes referred to as “acrylic urethane resin”, “polyester urethane resin”, “epoxy urethane resin” depending on the structure of the starting resin). it can. A known method can be used to synthesize these compounds.

  When the compound is an acrylic resin, it can be introduced into the starting acrylic resin copolymerized with an unsaturated monomer having an oxirane group by post-adding sorbic acid to the side chain oxirane group. As such an unsaturated monomer having an oxirane group, for example, glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate (Daicel Chemical Industries, Ltd. product: CYCLOMER A-200 or M-100) may be preferably used. I can do it. In producing the starting acrylic resin, an unsaturated monomer generally used as another unsaturated monomer to be copolymerized with an unsaturated monomer having an oxirane group can be used without any problem.

  At this time, the amount of the monomer having an oxirane group is preferably 5% by weight or more and 50% by weight or less with respect to the total monomer amount. If the amount is less than this, the amount of diene derived from sorbic acid per resin may be insufficient and sufficient curability may not be obtained. If the amount is too large, the resin is soluble in a solvent, and the carbon-carbon double bond in the molecule. In some cases, a uniform cured product cannot be obtained due to lack of compatibility with a compound having 2 or more. Also, instead of the method of adding sorbic acid to the oxirane group of the starting acrylic resin later, an unsaturated monomer having an oxirane group and a sorbate side chain monomer by esterification of sorbic acid are synthesized in advance and used as a comonomer for the acrylic resin. However, in this case, since the unsaturated group of sorbic acid also contributes to the polymerization reaction during the acrylic polymerization, the sorbate side chain monomer acts as a polyvalent monomer and the system gels during the polymerization.

  The amount of sorbic acid to be post-added with respect to the oxirane group of the starting acrylic resin may be equal, or less sorbic acid than the equivalent amount may leave unreacted oxirane groups.

  When there is an unreacted oxirane group, the oxirane group can cause a crosslinking reaction with other functional groups such as acid groups and amino groups, so that auxiliary crosslinking can be introduced into the curable composition of the present invention. Moreover, the effect which improves the adhesiveness to the base | substrate and raw material of the curable composition of this invention and the coating film to be overcoated can also be anticipated.

  Moreover, a well-known organic solvent and water can be used as a solvent of the acrylic resin which added sorbic acid. In particular, in the present invention, one or more acid monomers are used as a component of the copolymerization monomer, or an acid group is added by adding a polyvalent acid such as phthalic anhydride, maleic acid or trimellitic acid to a part of the oxirane group. Can be dissolved in water or self-emulsified by neutralizing a part or all of them with a basic substance. As another emulsification method, there is a method in which an appropriate amount of a surfactant is added to a resin to form an emulsion by forced emulsification. By making it aqueous by these methods, the curable composition of the present invention is more preferable because not only the elimination volatilization product is generated but also the VOC derived from the solvent can be greatly reduced.

  When the compound is an acrylic resin, sorbic acid is added to the starting acrylic resin obtained by copolymerizing an unsaturated monomer having an oxirane group and a small amount of a hydroxyl group-containing monomer, and then polyisocyanate is added to react with the hydroxyl group to obtain an acrylic urethane resin. You can also. In this case as well, it can be made aqueous by the same method as described above, or it can be made aqueous as a self-emulsifiable acrylic urethane resin by reacting an isocyanate compound and an acid having an OH group and then neutralizing the acid group part.

  When the compound is a polyester resin, a polyester resin is synthesized by a known method using a known polyhydric alcohol (and a monohydric alcohol if necessary) and a polyvalent carboxylic acid (and a monovalent carboxylic acid if necessary). By using sorbic acid as part of the carboxylic acid, a resin containing a sorbic acid ester can be synthesized. At this time, sorbic acid may be introduced by a method of synthesizing polyester by simultaneously charging with other polyester raw materials, or by synthesizing a starting polyester polyol with other raw materials in advance and then adding sorbic acid for esterification. In any case, a known organic solvent or water can be used as the solvent. In particular, in the present invention, the polyester resin can be made into a highly oxidized type, and a part or all of them can be neutralized with a basic substance to be dissolved in water or dispersed in water. At this time, the acid value of the polyester resin after introduction of sorbic acid is preferably 20 or more, more preferably 30 or more by using a primary or secondary amine such as triethylamine or diethanolamine and a neutralization equivalent of 0.8 or more. By neutralizing, a stable aqueous dispersion can be obtained. Needless to say, urethanization can be carried out by the same method as described in the description of the acrylic resin, and it can be made water-based as a self-emulsifying polyester urethane resin.

  When the compound is an epoxy resin, a desired resin can be synthesized by adding sorbic acid to the oxirane group. A commercially available epoxy resin can be suitably used as the starting resin, but when a linear bisphenol type epoxy resin is used as the starting resin, it has sorbate groups at both ends by adding an equivalent amount of sorbic acid to the oxirane group. Resin can be synthesized. In this case, an epoxy urethane resin can be obtained by connecting with diisocyanate using secondary hydroxyl groups present at both ends. On the other hand, when a novolac type epoxy resin is used as a starting resin, an epoxy resin having a sorbate group in the side chain can be synthesized. In order to obtain a resin having a high concentration of sorbic acid ester, it is preferable to use a novolac type epoxy resin as a starting resin.

  In the case of using a bisphenol type epoxy resin as a starting resin and in the case of using a novolac epoxy resin as a starting resin, an acid having an isocyanate compound and an OH group with respect to the OH group in the epoxy resin as described in the explanation of the acrylic resin. Can then be made aqueous as a self-emulsifying epoxy urethane resin by neutralizing the acid portion.

  Further, when the isocyanate is reacted (generally referred to as urethane modification), a mixed modified resin using two or more of acrylic resin, polyester resin, and epoxy resin as a starting resin may be used. This also has the effect of improving the compatibility between the starting resins, and is also effective as a method for adjusting the physical properties of the target curable composition.

  In the description so far, the compounds having an sorbate group as the starting resin are exemplified as an acrylic resin, a polyester resin and an epoxy resin. In the present invention, the molecular weight of the compound having a sorbate group is not particularly defined, but the molecular weight is preferably 1000 or more from the viewpoint of coating workability and durability of the cured product when used as an adhesive or a paint, and is 2000 or more. It is more preferable that When the molecular weight is less than 1000, when the cured composition is applied to the substrate, the viscosity is low, and there may be a problem in terms of coating workability such as sagging or shifting. However, in this case as well, if a compound having two or more carbon-carbon double bonds in the molecule used in combination has a molecular weight of 1000 or more, the mixture of both exhibits a sufficient viscosity, and in terms of coating workability such as sagging and slipping. We can suppress trouble.

Compound (B) having two or more carbon-carbon double bonds in the molecule
In the present invention, as the compound having a plurality of carbon-carbon double bonds in the molecule, known compounds can be appropriately used, or newly synthesized compounds may be used.

  Known compounds include polyacrylates: 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, polyethylene glycol diacrylate A-200, A-400, A-1000 and the like (Shin Nakamura Chemical Industries products) NK ester series), triacrylates such as trimethylolpropane triacrylate and pentaerythritol triacrylate, polyacrylates such as pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, and dipentaerythritol hexaacrylate. , Bismaleimides: 4,4′-diphenylmethane bismaleimide, metaphenylene bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3 -Dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, MIA-200 (Dainippon Ink Products, bismaleimide linked by polyalkylene glycol dicarboxylic acid structure), polymaleimides: polyphenylmethane maleimide ( Daiwa Kasei Kogyo Co., Ltd., BMI-2000) can be preferably used. Among these, maleimides such as bismaleimide and polymaleimide are preferable from the viewpoint of curability.

  These known compounds can be used as they are or dissolved in a solvent, but many of them have poor solubility in water. In order to make the curable composition of the present invention water-based rather than solvent-based, a solvent solution of a self-emulsifying sorbate-containing resin described above with a known compound having two or more carbon-carbon double bonds in these molecules A method of emulsifying after mixing and dissolving in the emulsion particles and incorporating them in the emulsion particles is used, but other forced emulsification methods and the like may be used.

  When a compound having two or more carbon-carbon double bonds in the molecule is newly synthesized, a compound in which two or more carbon-carbon double bonds are supported on the polymer side chain by (meth) acrylate groups. It is easy to synthesize.

  As a synthesis method of such a compound, 1) a method of post-adding (meth) acrylic acid to a side chain oxirane group to an acrylic resin copolymerized with an unsaturated monomer having an oxirane group, and 2) having a carboxylic acid group Examples thereof include a method of post-adding an unsaturated monomer having an oxirane group to the side chain carboxylic acid group to an acrylic resin copolymerized with an unsaturated monomer.

  As an unsaturated monomer having an oxirane group used in the method 1), for example, glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate (Daicel Chemical Industries, Ltd. product: CYCLOMER A-200 or M-100) Can be suitably used. In producing an acrylic resin, an unsaturated monomer generally used as another unsaturated monomer copolymerized with an unsaturated monomer having an oxirane group can be used without any problem.

  At this time, the amount of the monomer having an oxirane group is preferably 5% by weight or more and 50% by weight or less with respect to the total monomer amount. If the amount is less than this, the amount of carbon-carbon double bonds introduced by addition of (meth) acrylic acid per resin may be insufficient, and sufficient curability may not be obtained. In some cases, a uniform cured product cannot be obtained due to insufficient solubility and compatibility with a compound in which a plurality of conjugated carbon-carbon double bonds are supported as sorbic acid esters.

  The amount of (meth) acrylic acid to be post-added to the oxirane group of the acrylic resin may be equal, or less (meth) acrylic acid than the equivalent to leave an unreacted oxirane group. Also good.

  When there is an unreacted oxirane group, the oxirane group can cause a crosslinking reaction with other functional groups such as acid groups and amino groups, so that auxiliary crosslinking can be introduced into the curable composition of the present invention. Moreover, the effect which improves the adhesiveness to the base | substrate and raw material of the curable composition of this invention and the coating film to be overcoated can also be anticipated.

  Moreover, a well-known organic solvent and water can be used as a solvent of the acrylic resin which added (meth) acrylic acid. In particular, in the present invention, one or more acid monomers are used as a component of the copolymerization monomer, or an acid group is added by adding a polyvalent acid such as phthalic anhydride, maleic acid or trimellitic acid to a part of the oxirane group. Can be dissolved in water or self-emulsified by neutralizing a part or all of them with a basic substance. As another emulsification method, there is a method in which an appropriate amount of a surfactant is added to a resin to form an emulsion by forced emulsification. By making it aqueous by these methods, the curable composition of the present invention is more preferable because not only the elimination volatilization product is generated but also the VOC derived from the solvent can be greatly reduced.

  The unsaturated monomer having a carboxylic acid group used in the method 2) is not particularly limited, and examples thereof include carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, and maleic acid. In producing the acrylic resin, an unsaturated monomer generally used as another unsaturated monomer copolymerized with an unsaturated monomer having a carboxylic acid group can be used without any problem.

  At this time, the amount of the unsaturated monomer having a carboxylic acid group is preferably 5% by weight or more and 50% by weight or less based on the total amount of monomers. If the amount is less than this, the amount of carbon-carbon double bonds introduced by addition of an unsaturated monomer having an oxirane group (for example, glycidyl (meth) acrylate) per resin is insufficient and sufficient curability cannot be obtained. In many cases, the solubility of the resin in a solvent and the compatibility with a compound in which a plurality of conjugated carbon-carbon double bonds are supported as sorbic acid esters are insufficient, and a uniform cured product is obtained. It may not be possible.

  The amount of the unsaturated monomer having an oxirane group to be post-added with respect to the carboxylic acid group of the acrylic resin may be equal, or the amount of the unsaturated monomer having an oxirane group is less than the equivalent and the unreacted carboxylic acid group is added. An acid group may be left.

  Moreover, a well-known organic solvent and water can be used as a solvent of the acrylic resin which added the unsaturated monomer which has an oxirane group. In particular, in the present invention, an unreacted carboxylic acid group is left without adding an unsaturated monomer having an oxirane group to the total amount of carboxylic acid, and a part or all of them are neutralized with a basic substance. Water-soluble or self-emulsifying emulsion can be formed. As another emulsification method, there is a method in which an appropriate amount of a surfactant is added to a resin to form an emulsion by forced emulsification. By making it aqueous by these methods, the curable composition of the present invention is more preferable because not only the elimination volatilization product is generated but also the VOC derived from the solvent can be greatly reduced.

  Further, an unsaturated monomer having an oxirane group in advance instead of the method of adding (meth) acrylic acid to the oxirane group of the acrylic resin or the method of adding glycidyl (meth) acrylate to the carboxyl group of the acrylic resin later ( A (meth) acrylate side chain monomer obtained by esterification of (meth) acrylic acid may be synthesized, and an acrylic resin may be synthesized using it as a comonomer. In this case, the unsaturated group of the (meth) acrylate side chain may also be Since it is subjected to the polymerization reaction, the (meth) acrylate side chain monomer acts as a polyvalent monomer, and the system gels during the polymerization, which is not preferable.

  When the compound is an acrylic resin After adding (meth) acrylic acid to an acrylic resin obtained by copolymerizing an unsaturated monomer having an oxirane group and a small amount of a hydroxyl group-containing monomer, or containing an unsaturated monomer having a carboxylic acid group and a small amount of a hydroxyl group After adding an unsaturated monomer having an oxirane group to the side chain carboxylic acid group to the acrylic resin copolymerized with the monomer, the acrylic having a carbon-carbon double bond and a hydroxyl group in the side chain was synthesized in this manner. An acrylic urethane resin can also be obtained by adding polyisocyanate to the resin and reacting with a hydroxyl group. Also in this case, it can be made aqueous by the same method as described above, or it can be made aqueous as a self-emulsifiable acrylic urethane resin by reacting an acid having diisocyanate and OH group and then neutralizing the acid part.

  In the present invention, the molecular weight of the compound (B) having two or more carbon-carbon double bonds in the molecule is not particularly defined, but from the viewpoint of coating workability and durability of the cured product when used as an adhesive or paint. The molecular weight is preferably 1000 or more, and when the molecular weight is less than 1000, when the cured composition is applied to the substrate, the viscosity is low, and there may be problems in terms of coating workability such as sagging and shifting. . However, in this case as well, if the compound having a conjugated carbon-carbon double bond used in combination has a molecular weight of 1000 or more, the mixture of both exhibits a sufficient viscosity, which causes problems in terms of coating workability such as sagging and shifting. It can be suppressed.

  The curable composition of the present invention can further contain additives such as pigments, rheology modifiers, and coating surface smoothing agents that are generally used in paints and adhesives. Further, if necessary, a resin or a curing agent usually used for paints and adhesives may be used in combination as a base resin.

  When the curable composition of the present invention is used as a paint, a curable composition and, if necessary, a paint containing a pigment and an additive are prepared by a known method, and then water and / or other solvents are used as necessary. After being diluted to a desired viscosity using a coating method, a known coating method such as air spray method, airless spray method, brush coating, roll coating, spin coating, electrophoresis method, etc. A cured coating film can be obtained by coating and heating and baking to a temperature at which Diels-Alder addition proceeds. Since the article coated with the curable composition of the present invention is excellent in light resistance, it is suitable for applications such as trains, automobiles and other car bodies and body parts, poles, guardrails, warehouses and other outdoor structures, and electrical product housings. Yes.

  When the curable composition of the present invention is used as an adhesive, it is important to reduce volatile components such as water and solvent as much as possible before the adhesive is cured. Therefore, it is preferable to use a relatively low molecular weight compound having a molecular weight of about 1000 as the curable composition so that the solvent content is the minimum necessary for flow. Among them, a low Tg acrylic resin is used as a compound carrying a plurality of sorbates, and 1,6-hexanediol diacrylate and polyethylene glycol diacrylate A-200 are compounds having a plurality of carbon-carbon double bonds in the molecule. By using such a liquid substance as a reactive diluent, an adhesive having a solid content of 100% can be obtained. The adhesive is applied to one or both surfaces of the article to be bonded by a known method similar to that described for the paint. If a solvent such as water is included, the solvent is stripped off by air blow or the like, and then the adhesive surface is bonded, hot press, etc. It is bonded by the heating and pressing method. The article bonded with the curable composition of the present invention is excellent in dimensional stability at the time of curing, and is therefore suitable for bonding various components that require dimensional stability. Further, since it has excellent heat resistance, it is particularly suitable for the production of a laminated electric circuit board.

Hereinafter, the present invention will be described in more detail with reference to synthesis examples, examples and comparative examples. However, the present invention is not limited by these. “Part” and “%” are both based on mass.

Synthesis example 1
100 parts of propylene glycol methyl ether acetate was charged into a 1 L reaction vessel equipped with a thermometer, a thermostat, a stirrer, a condenser, and a dropping device, and the mixture was stirred and mixed in a nitrogen atmosphere and heated to 115 ° C. Next, for 30 parts of styrene, 14 parts of methyl methacrylate, 42 parts of n-butyl acrylate, and 14 parts of glycidyl methacrylate, tert-butyl peroxy-2-ethylhexanoate (trade name “Perbutyl O”, A mixture composed of 5 parts (manufactured by Nippon Oil & Fats Co., Ltd.) was uniformly added dropwise over 4 hours and then aged at the same temperature for 8 hours to obtain an acrylic resin solution 1.
According to JIS K0124-83, the number average molecular weight of this resin measured by GPC method was 7600 and the weight average molecular weight was 26600 at a flow rate of 1.0 ml / min at 40 ° C. using GPC tetrahydrofuran as an eluent. . The glass transition point measured by differential thermal analysis from −50 ° C. at a rate of temperature increase of 5 ° C./min was 10 ° C.
Synthesis example 2
To 200 parts of the acrylic resin solution obtained in Synthesis Example 1, 11 parts of sorbic acid (equivalent glycidyl group), 2 parts of tetrabutylammonium bromide and 0.5 parts of methoxyphenol were added, and an addition reaction was performed at 105 ° C. for 8 hours. It was. The reaction rate of sorbic acid by the acid value measurement after 8 hours was 95% or more. Thereafter, 11 parts of propylene glycol methyl ether acetate was added to adjust the concentration to obtain an acrylic resin solution A having a solid concentration of 50%.
Synthesis example 3
An acrylic resin with a solid content concentration of 50% was used in the same manner as in Synthesis Example 2 except that 7 parts of acrylic acid (equivalent glycidyl group) was used in place of sorbic acid and 7 parts of propylene glycol methyl ether acetate was added to adjust the concentration. Resin solution B was obtained.
Synthesis example 4
Instead of sorbic acid, 27.9 parts of “Hydien” (unsaturated fatty acid containing 60% conjugated linoleic acid manufactured by KF Trading) (equivalent to glycidyl group) and 27.9 parts of propylene glycol methyl ether acetate for concentration adjustment were used. An acrylic resin solution C having a solid content concentration of 50% was obtained in the same manner as in Synthesis Example 2 except that addition was performed.
Synthesis example 5
100 parts of propylene glycol methyl ether acetate was charged into a 1 L reaction vessel equipped with a thermometer, a thermostat, a stirrer, a condenser, and a dropping device, and the mixture was stirred and mixed in a nitrogen atmosphere and heated to 115 ° C. Next, for 30 parts of methyl methacrylate, 46 parts of n-butyl acrylate and 24 parts of glycidyl methacrylate, tert-butyl peroxy-2-ethylhexanoate (trade name “Perbutyl O”, Nippon Oil & Fats Co., Ltd. ) Produced) A mixture of 5 parts was uniformly dropped over 4 hours and then aged at the same temperature for 8 hours to obtain an acrylic resin solution 2.
The number average molecular weight of the obtained resin was 7600, and the weight average molecular weight was 27000. The glass transition point was 10 ° C.
Synthesis Example 6
To 200 parts of the acrylic resin solution obtained in Synthesis Example 5, 18 parts of sorbic acid, 2 parts of tetrabutylammonium bromide, and 0.5 parts of methoxyphenol were added, and an addition reaction was performed at 105 ° C. for 8 hours. The reaction rate of sorbic acid by the acid value measurement after 8 hours was 95% or more. Thereafter, 7 parts of succinic anhydride was further reacted at 105 ° C. for 3 hours to synthesize an acrylic resin having an acid value of 40 mg KOH / g, and 7.9 parts of dimethylethanolamine (equal molar amount with carboxylic acid in the system) was added. It was summed up. While strongly stirring the contents, propylene glycol methyl ether acetate was distilled off under reduced pressure, and water was added to obtain an aqueous dispersion D having a solid content concentration of 20%. At this time, the amount of propylene glycol methyl ether acetate distilled out of the system was about 75 g, and the amount of clean water added to the system was 417 g.
Synthesis example 7
To 200 parts of the acrylic resin solution obtained in Synthesis Example 5, 12 parts of acrylic acid, 2 parts of tetrabutylammonium bromide and 0.5 parts of methoxyphenol were added, and an addition reaction was performed at 105 ° C. for 8 hours. The reaction rate of acrylic acid by the acid value measurement after 8 hours was 95% or more. Thereafter, 7 parts of succinic anhydride was further reacted at 105 ° C. for 3 hours to synthesize an acrylic resin having an acid value of 40 mg KOH / g, and 7.6 parts of dimethylethanolamine (equal molar amount with carboxylic acid in the system) was added. It was summed up. While strongly stirring the contents, propylene glycol methyl ether acetate was distilled off under reduced pressure and water was added to obtain an aqueous dispersion E having a solid content concentration of 20%. At this time, the amount of propylene glycol methyl ether acetate distilled out of the system was about 70 g, and the amount of clean water added to the system was 400 g.
Synthesis example 8
100 parts of propylene glycol methyl ether acetate was charged into a 1 L reaction vessel equipped with a thermometer, a thermostat, a stirrer, a condenser, and a dropping device, and the mixture was stirred and mixed in a nitrogen atmosphere and heated to 115 ° C. Next, tert-butyl peroxy-2-ethylhexanoate (trade name “Perbutyl O”, Nippon Oil & Fats Co., Ltd.) was used as a polymerization initiator for 12 parts of methyl methacrylate, 40 parts of n-butyl acrylate and 48 parts of glycidyl methacrylate. ) Produced) A mixture of 5 parts was uniformly added dropwise over 4 hours and then aged at the same temperature for 8 hours to obtain an acrylic resin solution 3.
The number average molecular weight of the obtained resin was 7500, and the weight average molecular weight was 26300. The glass transition point was 10 ° C.
Synthesis Example 9
To 200 parts of the acrylic resin solution obtained in Synthesis Example 8, 38 parts of sorbic acid, 2 parts of tetrabutylammonium bromide and 0.5 parts of methoxyphenol were added, and an addition reaction was performed at 105 ° C. for 8 hours. The reaction rate of sorbic acid by the acid value measurement after 8 hours was 95% or more. Thereafter, 26 parts of hexahydrophthalic anhydride was further reacted at 105 ° C. for 3 hours to synthesize an acrylic resin having an acid value of 55 mg KOH / g, and 14.3 parts of dimethylethanolamine (equal molar amount with the carboxylic acid in the system) was added. Neutralized. While strongly stirring the contents, propylene glycol methyl ether acetate was distilled off under reduced pressure and water was added to obtain an aqueous dispersion F having a solid content concentration of 20%. At this time, the amount of propylene glycol methyl ether acetate distilled out of the system was about 75 g, and the amount of clean water added to the system was 565 g.
Synthesis Example 10
To 200 parts of the acrylic resin solution obtained in Synthesis Example 8, 24 parts of acrylic acid, 2 parts of tetrabutylammonium bromide, and 0.5 parts of methoxyphenol were added, and an addition reaction was performed at 105 ° C. for 8 hours. The reaction rate of acrylic acid by the acid value measurement after 8 hours was 95% or more. Thereafter, 24 parts of hexahydrophthalic anhydride was further reacted at 105 ° C. for 3 hours to synthesize an acrylic resin having an acid value of 55 mg KOH / g, and 12.9 parts of dimethylethanolamine (equal molar amount with carboxylic acid in the system) was added Neutralized. While strongly stirring the contents, propylene glycol methyl ether acetate was distilled off under reduced pressure, and water was added to obtain an aqueous dispersion G having a solid content concentration of 20%. At this time, the amount of propylene glycol methyl ether acetate distilled out of the system was about 70 g, and the amount of clean water added to the system was 510 g.
Synthesis Example 11
100 parts of propylene glycol methyl ether acetate was charged into a 1 L reaction vessel equipped with a thermometer, a thermostat, a stirrer, a condenser, and a dropping device, and the mixture was stirred and mixed in a nitrogen atmosphere and heated to 115 ° C. Next, from 36 parts of n-butyl acrylate and 64 parts of glycidyl methacrylate, 5 parts of tert-butyl peroxy-2-ethylhexanoate (trade name “Perbutyl O”, manufactured by NOF Corporation) as a polymerization initiator The resulting mixture was uniformly dropped over 7 hours and then aged at the same temperature for 8 hours to obtain an acrylic resin solution 4.
The number average molecular weight of the obtained resin was 7200, and the weight average molecular weight was 25000. The glass transition point was 10 ° C.
Synthesis Example 12
50 parts of sorbic acid, 2 parts of tetrabutylammonium bromide and 0.5 part of methoxyphenol were added to 200 parts of the acrylic resin solution 4: 200 obtained in Synthesis Example 11, and an addition reaction was performed at 105 ° C. for 8 hours. The reaction rate of sorbic acid by the acid value measurement after 8 hours was 95% or more. Thereafter, 29 parts of hexahydrophthalic anhydride was reacted at 105 ° C. for 3 hours to synthesize an acrylic resin having an acid value of 55 mg KOH / g, and 15.6 parts of dimethylethanolamine (equal molar amount with carboxylic acid in the system) was added. Neutralized. While strongly stirring the contents, propylene glycol methyl ether acetate was distilled off under reduced pressure, and water was added to obtain an aqueous dispersion G having a solid content concentration of 20%. At this time, the amount of propylene glycol methyl ether acetate distilled out of the system was about 75 g, and the amount of clean water added to the system was 625 g.
Synthesis Example 13
To 200 parts of the acrylic resin solution obtained in Synthesis Example 11, 32 parts of acrylic acid, 2 parts of tetrabutylammonium bromide and 0.5 parts of methoxyphenol were added, and an addition reaction was performed at 105 ° C. for 8 hours. The reaction rate of acrylic acid by the acid value measurement after 8 hours was 95% or more. Thereafter, 26 parts of hexahydrophthalic anhydride was further reacted at 105 ° C. for 3 hours to synthesize an acrylic resin having an acid value of 55 mg KOH / g, and 13.8 parts of dimethylethanolamine (equal molar amount with carboxylic acid in the system) was added. Neutralized. While strongly stirring the contents, propylene glycol methyl ether acetate was distilled off under reduced pressure and water was added to obtain an aqueous dispersion H having a solid content concentration of 20%. At this time, the amount of propylene glycol methyl ether acetate distilled out of the system was about 80 g, and the amount of clean water added to the system was 538 g.
Synthesis Example 14
In a 0.5 L reaction vessel equipped with a thermometer, thermostat, stirrer, condenser and dropping device, 100 parts of bisphenol A-4,4′-di-glycidyl ether, 62.6 parts of sorbic acid, tetrabutylammonium 2.4 parts of bromide, 0.1 part of t-butylhydroxytoluene and 110 parts of methyl isobutyl ketone were charged and stirred and mixed at 105 ° C. for 10 hours to obtain Compound J (molecular weight 562) in which both ends of the molecule were sorbates.
Table 1 shows a list of the synthesized ones.

Example 1
A glass beaker having a capacity of 200 ml was charged with 50 parts of an acrylic resin solution A and 48 parts of an acrylic resin solution B, and mixed sufficiently using a glass rod until the contents became uniform, thereby obtaining a curable composition a1.
Examples 2-9 and Comparative Examples 1-5
According to the composition shown in Table 2, the curable compositions of Examples 2 to 9 (curable compositions a2 to a9) and Comparative Examples 1 to 5 (curable compositions b1 to b5) were prepared in the same manner as in Example 1. Obtained. At this time, when using a material having a solid concentration of 100%, it was dissolved in acetone in advance to obtain a solution having a desired solid concentration, and then mixed with other materials.

Example 10 (Creation of cured coating film)
The curable composition a1 obtained in Example 1 was coated on a 100 mm × 150 mm × 0.4 mm untreated aluminum plate using a film applicator so that the dry film thickness was 20 μm. The coated plate after coating was allowed to stand at room temperature for 5 minutes, and then heated at a predetermined heating temperature (filled in Table 3: 120, 140, 160 ° C.) for 30 minutes using a hot air dryer to cure the coating film. The cured coating film was subjected to a rubbing test (Note 1), pencil hardness (Note 2), heat resistance test (Note 3), UV resistance test (Note 4), and water resistance test (Note 5).
Examples 11-13 and Comparative Examples 6-9
With the breakdown shown in Table 3, a test coated plate was prepared in the same procedure as in Example 10.
Example 14
The curable composition a4 obtained in Example 1 was applied to an untreated aluminum plate of 100 mm × 150 mm × 0.4 mm using an air spray so that the dry film thickness was 20 μm. The coated plate after coating was pre-dried at 80 ° C. for 5 minutes to volatilize water and solvent, and then heated at a predetermined heating temperature for 30 minutes using a hot air dryer to cure the coating film. The cured coating film was subjected to a rubbing test, pencil hardness, heat resistance test, ultraviolet resistance test, and water resistance test.
Examples 15 to 17 and Comparative Example 10
With the breakdown shown in Table 3, a test coated plate was prepared in the same procedure as in Example 14.
(Note 1): Approximately 2 ml of methylethylketone is placed on the surface of the coated plate, and two sheets of gauze (FC gauze manufactured by White Cross Co., Ltd.) are folded in four. It was. The state of the subsequent coated plate was evaluated.
○: No changes such as scratches or gloss on the painted surface.
Δ: Fine scratches occurred after rubbing, and gloss was clearly reduced.
X: The coating film was destroyed and peeled off and was not left on the coated plate.
(Note 2): According to JIS K 5600-5-4 (1999), a pencil lead is applied at an angle of about 45 degrees with respect to the test coating plate surface, and the front is pressed firmly against the test coating plate surface to the extent that the core does not break. Was moved about 10 mm at a uniform speed. The hardness symbol of the hardest pencil when this operation was repeated 5 times while changing the test location and the coating film was not torn was defined as pencil hardness.
(Note 3): The coated plate was left standing in a horizontal state for 60 minutes in a hot air dryer maintained at 200 ° C., taken out, allowed to cool to room temperature, and then the state of the coated surface was visually evaluated.
○: There is no change in the paint surface.
X: The coating surface has obvious changes such as yellowing, gloss, cracks, etc.
(Note 4)
The test plate is left at a right angle to the optical axis at a position of 50 cm from the 15 W sterilization lamp (with shade), and the sterilization line irradiance on the test plate surface is 1.5 W / m ² . And sterilization rays (ultraviolet light having a maximum intensity at 254 nm) were irradiated at room temperature for 8 hours. The state of the coated surface after irradiation was visually evaluated.
○: There is no change in the paint surface.
X: The coating surface has obvious changes such as yellowing, gloss, cracks, etc.
(Note 5)
After the test plate was immersed in warm water at 50 ° C. for 24 hours, water droplets on the pulled surface were wiped off, and the state of the coated surface was visually evaluated.
○: There is no change in the paint surface.
(Triangle | delta): Although whitening was seen on the coating surface, it returned to the original transparent coating surface when it was left for 24 hours.
X: The coating film was markedly whitened and peeled off simply by rubbing lightly.
Table 3 shows the breakdown of the test plates and the test results.

Example 18 (Preparation of adhesive strength evaluation material)
The curable composition a9 obtained in Example 9 was applied to one side of a clean aluminum plate (25 mm × 300 mm × 3 mm) using a film applicator so that the dry film thickness was 10 μm, and dried at 50 ° C. for 3 minutes. Residual solvent (acetone) was stripped. Thereafter, a PEEK plate (25 mm × 400 mm × 1.5 mm) was bonded and press bonded under predetermined heat treatment conditions. In accordance with JIS K 6854-2 (1999), a 180 ° peeling test (Note 6) was conducted to evaluate the adhesive strength. The number of repetitions was 5 times.
Example 19 and Comparative Example 11
Samples of Example 19 and Comparative Example 11 were prepared in the same manner as in Example 18 except that a3 and b3 were used as the curable compositions, respectively.
(Note 6): The test was performed in a constant temperature and humidity chamber at 23 ° C. and 50% relative humidity using a tensile tester “Autograph AG-50kN (manufactured by Shimadzu Corporation)” at a head speed of 2 mm / min.

  Table 4 shows the heat treatment conditions and the adhesive strength measurement results.

Claims (7)

Including a compound (A) in which a plurality of carbon-carbon double bonds conjugated in the molecule are supported as sorbic acid esters and a compound (B) having two or more carbon-carbon double bonds in the molecule. A thermosetting composition characterized. The carbon-carbon double bond of the compound (B) is due to a maleimide group bonded to a hydrocarbon group which may contain at least one element selected from an oxygen atom, a nitrogen atom, a sulfur atom and a phosphorus atom. Item 2. The thermosetting composition according to item 1. The thermosetting composition according to claim 1, wherein two or more carbon-carbon double bonds in the compound (B) are supported on a side chain of the polymer by a (meth) acrylate group. The thermosetting composition according to any one of claims 1 to 3, wherein the compound (A) and / or the compound (B) is a polymer having a number average molecular weight of 1000 or more. The article | item adhere | attached using the curable composition in any one of Claims 1 thru | or 4. The coating composition formed by containing the curable composition of any one of Claims 1 thru | or 4. The coated article which has the cured film of the coating composition of Claim 6 on the surface.