JPH11140279A - Active energy ray-curing type composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition having a low viscosity, providing a cured material more flexible than ever by including a specific oxetane com pound, a specific epoxy group-containing compound and a cationic polymeriza tion photoinitiator. SOLUTION: The objective compound includes (A) an oxetane compound of the formula (R<1> is methyl or ethyl), (B) a compound having two or more epoxy groups in a molecule and selected from an aromatic epoxide, an alicyclic epoxy compound or an aliphatic epoxy compound, (C) a cationic polymerization photoinitiator, preferably a diaryliodonium salt, a triarylsulfonium salt or the like and (D) optionally a monofunctional epoxy compound, an oxetane compound other than the component A, a cation-reactive compound, an inorganic filler, a dyestuff, a pigment, a viscosity modifier, a photosensitizer or the like. As the containing proportion, the content of the component A is 5-99 pts.wt. based on 100 pts.wt. total amount of components A and B and the content of the component C is preferably 0.1-20 wt.% based on the total amount of the components A and B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active energy ray-curable composition which has a low viscosity, is rapidly cured by irradiation with active energy rays such as ultraviolet rays or electron beams, and has excellent strength and elongation of a cured product. is there.

[0002]

2. Description of the Related Art Active energy ray-curable compositions are known for their properties such as paper, wood, plastic and metal because of their high curing speed, good workability due to the absence of solvents, and extremely low energy requirements. Has been widely used in various industries such as coatings for printing and the like and printing inks. As a typical compound conventionally used in this field, a (meth) acrylate oligomer is used.

However, compositions using conventional (meth) acrylate oligomers often have two or more (/) molecules per molecule for the purpose of improving curability upon irradiation with active energy rays. Since a polyfunctional (meth) acrylate containing a (meth) acryloyl group is used, the cured coating film obtained is often hard and has a low elongation. For this reason, when a cured coating film is formed, the impact resistance may be insufficient, or the coating film may not be able to follow a process such as bending, and peeling or cracking of the coating film may occur. Conventionally, in order to improve the flexibility of the cured coating film, urethane (meth) acrylate, which has excellent elongation of the cured coating film, is often used in combination, but urethane (meth) acrylate has a very high viscosity and is therefore easy to coat. However, even when used as a compounding system, the coatability was insufficient. In addition, in order to improve the flexibility of the cured coating film, a low molecular weight monofunctional (meth)
In some cases, an acrylate is blended, but in this case, the strength of the obtained cured coating film is reduced, and there is a disadvantage that the coating film becomes brittle.

[0004] In recent years, as an active energy ray-curable composition other than (meth) acrylate, a cationic photopolymerizable composition which is cured by cationic photopolymerization has been studied. However, most of the compounds used there are compounds having two or more reactive groups in one molecule, so many cured products have hard and non-elongated properties. Not obtained until. Further, a monofunctional epoxy compound such as phenylglycidyl ether may be used, but the curing property is very poor.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an active energy ray-curable composition which has a low viscosity and gives an unprecedented flexible cured product.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the present situation, and as a result, have found that it is effective to use a specific oxetane compound and an epoxy compound in combination, and to complete the present invention. Reached. Hereinafter, the present invention will be described in detail.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. Oxetane compound The oxetane compound used in the present invention is a compound represented by the following general formula (1) (hereinafter simply referred to as an oxetane compound).

[0008]

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However, in the formula (1), R ¹ is a methyl group or an ethyl group.

A compound having two or more epoxy groups in a molecule As a compound having two or more epoxy groups in a molecule (hereinafter, simply referred to as an epoxy compound), both monomers and oligomers thereof can be used. Specific examples of the compound include conventionally known aromatic epoxy compounds, alicyclic epoxy compounds, and aliphatic epoxy compounds.
Hereinafter, the epoxy compound means a monomer or an oligomer thereof.

Preferred as the aromatic epoxy compound are di- or polyglycidyl ethers obtained by reacting a polyhydric phenol having at least one aromatic nucleus or an alkylene oxide adduct thereof with epichlorohydrin, for example, bisphenol A Or a di- or polyglycidyl ether of an alkylene oxide adduct thereof, hydrogenated bisphenol A or a di- or polyglycidyl ether of an alkylene oxide adduct thereof, bisphenol F or a di- or polyglycidyl ether of an alkylene oxide adduct thereof, hydrogenated bisphenol F
Or di- or polyglycidyl ethers of the alkylene oxide adduct thereof, phenol novolak or polyglycidyl ether of the alkylene oxide adduct thereof, and cresol novolac or polyglycidyl ether of the alkylene oxide adduct thereof. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

The alicyclic epoxy compound is obtained by epoxidizing a compound having at least one cycloalkane ring such as a cyclohexene ring or a cyclopentene ring with a suitable oxidizing agent such as hydrogen peroxide or peracid. Cyclohexene oxide or cyclopentene oxide-containing compounds thus obtained are preferable, and specific examples thereof include compounds represented by the following formulas (2) and (3).

[0013]

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[0014]

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Preferred examples of the aliphatic epoxy compound include di- or polyglycidyl ethers of an aliphatic polyhydric alcohol or an alkylene oxide adduct thereof, and the like.
Representative examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, butanediol, pentanediol, hexanediol, glycerin, trimethylolpropane, pentaerythritol, Examples include aliphatic polyhydric alcohols such as solobitol and sorbitan, and polyglycidyl ethers of their alkylene oxide adducts. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

From the viewpoint of the strength of the cured product, the epoxy compound is preferably an aromatic epoxy compound.

In the present invention, two or more epoxy compounds can be used in combination.

Photo cationic polymerization initiator A photo cationic polymerization initiator is a compound that initiates cationic polymerization by irradiation with active energy rays. Various compounds can be used as the cationic photopolymerization initiator used in the composition of the present invention. Among these initiators, preferred are diaryliodonium salts and triarylsulfonium salts. Typical photocationic polymerization initiators are shown below.

[0019]

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[0020]

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[0021]

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[0022]

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In the above formulas, R ² is hydrogen, an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms, and R ³ is a hydrogen, a hydroxyalkyl group or a hydroxyalkoxy group. , Preferably a hydroxyethoxy group. M is a metal, preferably antimony, X is a halogen atom, preferably fluorine, and n is the valence of the metal, for example, 6 for antimony.

O Content In the composition of the present invention, the content of the oxetane compound and the epoxy compound may be determined in consideration of the required viscosity of the composition, hardness of the cured product, and the like. The preferred content of the oxetane compound is 5 to 99 parts by weight, more preferably 30 to 95 parts by weight, based on 100 parts by weight of the total amount of the oxetane compound and the epoxy compound in the composition. When the compounding ratio of the oxetane compound is less than 5 parts by weight, the flexibility of the cured coating film is insufficient, and when it exceeds 99 parts by weight, the curability may be reduced.

The preferred content of the cationic photopolymerization initiator is from 0.1 to 20% by weight, more preferably from 0.1 to 10% by weight, based on the total amount of the oxetane compound and the epoxy compound. . When the amount is less than 0.1% by weight, the curability is insufficient. On the other hand, when the amount is more than 20% by weight, the light transmittance becomes poor and uniform curing cannot be performed or the smoothness of the surface of the cured coating film. May be lost.

Other components In addition to the above essential components, a monofunctional epoxy compound, an oxetane compound other than the above, if necessary,
A cation-reactive compound such as a vinyl ether compound and the like, and an inert component such as an inorganic filler, a dye, a pigment, a viscosity modifier, a treating agent, and an ultraviolet ray blocking agent can be blended.

When the composition of the present invention is cured with visible light or ultraviolet light, a photosensitizer may be added in addition to the cationic photopolymerization initiator for the purpose of further improving the curability. Typical sensitizers that can be used in the present invention are those described by Crivello in Advanced in Polymer Science (Adv. In Plymer Sci., 62, 1 (1984)).
Can be used. Specific examples include pyrene, perylene, acridine orange, thioxanthone, 2-chlorothioxanthone, and benzoflavin.

Production Method As a method for producing the active energy ray-curable composition of the present invention, an oxetane compound, an epoxy compound and a cationic photopolymerization initiator may be mixed according to a conventional method.

Method of Use The quick-curing composition of the present invention is easily cured by irradiating it with active energy rays such as visible light, ultraviolet light and electron beams. When irradiating ultraviolet rays, various light sources can be used, such as a mercury lamp, a metal halide lamp, a xenon arc lamp, a fluorescent lamp, a carbon arc lamp, a tungsten-halogen copying lamp, and curing by irradiation light from the sun. Can be done. When irradiating with ultraviolet light, the intensity of irradiation on the substrate is at least 0.01 watt square centimeter, the composition is cured within 1 to 20 seconds, and the curing is continuously performed, for example, with a paper or metal coating line. It is preferable to perform it. In the case of curing with an electron beam, it is usually cured with an electron beam having an energy of 300 eV or less.
It is also possible to cure instantaneously with the dose of ad. The composition of the present invention can be applied to substrates such as metal, rubber, plastic, molded parts, film, paper, wood, glass cloth, concrete and ceramic. Uses of the composition of the present invention include, for example, woodwork paints, plastic paints, metal paints, paper paints, gloss varnishes, protective, decorative and insulating coatings, optical fiber paints, potting compounds, printing inks, Examples include sealants, adhesives, photoresists, wire insulation materials, textile coatings, laminates, impregnated tapes and printing plates.

[0030]

The present invention will now be described more specifically with reference to examples and comparative examples. Parts in Examples and Comparative Examples are parts by weight unless otherwise specified.

Example 1 A mixture of 75 parts of the following compound (A) as an oxetane compound and 25 parts of diglycidyl ether of bisphenol A as an epoxy compound was mixed with CYRACUREUVI-6990 manufactured by Union Carbide as a photocationic polymerization initiator.
An active energy ray-curable composition was prepared by adding and mixing parts. About the obtained composition, the viscosity, the tensile strength of the hardened | cured material, and the elongation were evaluated according to the following method. Table 2 shows the results.

[0032]

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Evaluation method-Measurement of viscosity The viscosity was measured at 25 ° C using an E-type rotary viscometer.

Measurement of Tensile Strength and Elongation A test piece for a tensile test was prepared by pouring the obtained composition into a mold having a thickness of 1 mm and matching a dumbbell No. 2 and sandwiching it with a PET film. / Cm with a high-pressure mercury lamp and cured by UV irradiation (3500 mJ / cm ² ). The tensile test was performed according to JIS K7113. The tensile speed was 10 mm / min.

[0035]

[Table 1]

The abbreviations in Table 1 have the following meanings. YD-128: bisphenol A type epoxy compound (Toto Kasei, molecular weight about 380, bifunctional epoxy compound) YDCN-704P: cresol novolak type epoxy compound (Toto Kasei, molecular weight about 2000, polyfunctional epoxy compound) M -5700: 2-hydroxy-3-phenoxypropyl acrylate (manufactured by Toagosei) SP-1509: bisphenol A type epoxy acrylate (manufactured by Showa Polymer) M-1310: urethane acrylate (manufactured by Toagosei) ・ EX-141: Phenyl glycidyl ether (manufactured by Nagase Kasei) ・ UVI-6990: mixture of hexafluorophosphate of triallylsulfonium and propylene carbonate (manufactured by Union Carbide) ・ Irg651: benzyl dimethyl ketal (manufactured by Ciba Geigy)

[0037]

[Table 2]

Examples 2 and 3 A composition was prepared in the same manner as in Example 1 except that the compositions of the oxetane compound and the epoxy compound were changed as shown in Table 1. The obtained composition was evaluated in the same manner as in Example 1. Table 2 shows the results.

Comparative Examples 1 to 3 Compositions were produced in the same manner as in Example 1 except that each component was changed as shown in Table 1. The obtained composition was prepared in Example 1.
Was evaluated in the same way as Table 2 shows the results.

[0040]

The active energy ray-curable composition of the present invention has low viscosity and excellent cured product flexibility.
Woodwork paints, plastic paints, metal paints, paper paints, gloss varnishes, coatings for protection, decoration and insulation, optical fiber paints, potting compounds, printing inks, sealants, adhesives, photoresists, wire insulation materials, It can be used for various applications such as textile coating, laminating, impregnating tape and printing plate, and has a great influence on the industry.

Claims (2)

[Claims] An active energy ray-curable composition comprising an oxetane compound represented by the following general formula (1), a compound having two or more epoxy groups in a molecule, and a cationic photopolymerization initiator. Embedded image However, in the formula (1), R ¹ is a methyl group or an ethyl group. 2. The active energy ray-curable composition according to claim 1, wherein the compound having two or more epoxy groups in the molecule is an aromatic epoxy compound.