JPH07247342A - Ultraviolet-curing resin composition and coating agent containing the same - Google Patents

Abstract

PURPOSE:To obtain a UV-curing resin composition excellent in adhesion to metal or plastic film. CONSTITUTION:The composition comprises an adduct of a bisphenol A epoxy resin with a phosphoric acid having at least one active hydrogen atom, a compound having at least two alicyclic epoxy groups and a cationic photopolymerization initiator. A coating film obtained from this composition has good processability and surface hardness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition which is cured by irradiation with ultraviolet rays, and more particularly to an ultraviolet curable resin composition which is useful as a coating agent for metals and plastic films.

[0002]

2. Description of the Related Art Conventionally, as an ultraviolet curable resin,
Unsaturated resins are widely used, but when they are crosslinked and cured in a short time, the volume shrinkage is large, and metals such as iron and aluminum, polyethylene terephthalate film (hereinafter abbreviated as PET film), polyvinyl chloride film. (Hereinafter, it is abbreviated as PVC film.) It has a drawback that it is difficult to adhere to plastic films. Also,
In addition to unsaturated resins, epoxy resins have also been investigated as ultraviolet curable resins, and among them, alicyclic epoxy resins have been drawing attention because of their fast curing speed. Although it has a feature that the volume shrinkage at the time of curing is smaller than that of an unsaturated resin, it is the current situation that the adhesiveness to metal and plastic films is not yet sufficiently obtained.

On the other hand, it has been attempted in the past to apply a compound obtained by adding phosphoric acid to a non-alicyclic epoxy resin to a thermosetting paint to improve the adhesion to a metal. There is no example of using it as a UV curable resin composition in combination with a cyclic epoxy resin.

[0004]

An object of the present invention is to provide an ultraviolet curable resin composition having excellent adhesion to metal and plastic films.

[0005]

That is, the present invention provides an adduct (A) of a bisphenol A type epoxy resin with at least one phosphoric acid having active hydrogen, and a compound having two or more alicyclic epoxy groups. There is provided an ultraviolet-curable resin composition comprising (B) and a cationic photopolymerization initiator (C).

As the bisphenol A type epoxy resin, Epicoat 828 (produced by Yuka Shell Epoxy Co., Ltd.), Epiclon 850S (produced by Dainippon Ink and Chemicals, Inc.) and the like are commercially available, and any of them can be used. Examples of phosphoric acids having at least one active hydrogen include orthophosphoric acid, pyrophosphoric acid, metaphosphoric acid, and phosphorous acid. In the present invention, the adduct (A) of the bisphenol A type epoxy resin and the phosphoric acid having at least one active hydrogen can be obtained by a conventional method. For example, a mixture of the two may be mixed with a solvent if necessary. Dilute to room temperature to 100 ° C
The reaction may be performed while stirring for 30 minutes to 5 hours. The bisphenol A type epoxy resin and the phosphoric acid having at least one active hydrogen are preferably added in an equivalent ratio such that the epoxy groups in the bisphenol A type epoxy resin remain. When all the epoxy groups are consumed, the curability of the obtained resin composition tends to decrease.

Examples of the compound (B) having two or more alicyclic epoxy groups include 3,4-epoxycyclohexylmethyl-
Examples include 3,4-epoxycyclohexylcarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, and the like. Addition product (A) of bisphenol A type epoxy resin and phosphoric acid having at least one active hydrogen
The ratio of the compound (B) having two or more alicyclic epoxy groups to each other is preferably in the range of 10/90 to 80/20 in weight ratio. If (A) is less than 10% by weight, the adhesion to metal and plastic films is not sufficient, and if it exceeds 80% by weight, the curability tends to decrease.

The cationic photopolymerization initiator (C) is an adduct (A) of a bisphenol A type epoxy resin with at least one phosphoric acid having active hydrogen and a compound (2) having two or more alicyclic epoxy groups. For the total weight of B)
It is used in the range of 0.1 to 10% by weight. As the cationic photopolymerization initiator (C), commercially available diazonium salt, halonium salt, sulfonium salt and the like can be used.

The ultraviolet-curable resin composition of the present invention can be used as a coating agent by adding organic and inorganic pigments, extender pigments, plasticizers, defoaming agents, leveling agents and the like, if necessary. The light source for curing the ultraviolet curable resin composition and the coating agent of the present invention is usually 350 to 50
A light source containing light with a wavelength in the range of 0 nm, for example a high pressure mercury lamp,
An ultra-high pressure mercury lamp, a xenon lamp, a carbon arc lamp, etc. can be used.

[0010]

EXAMPLES The present invention is described below with reference to examples, but the present invention is not limited to the following examples. In the examples, parts and% mean parts by weight and% by weight, respectively. [Production Example 1] 366 parts of bisphenol A type epoxy resin "Epicoat 828" (epoxy equivalent 183) and 366 parts of 1,2-dimethoxyethane were placed in a reaction vessel equipped with a stirrer, a cooler, a thermometer and a dropping funnel. Preparation, stirring 85
% A mixture of 23.1 parts of orthophosphoric acid and 92.4 parts of 1,2-dimethoxyethane was added dropwise over 4 hours, and then the contents were mixed at 80 ° C. for 3 hours.
The mixture was heated for a time to advance the addition reaction, and the reaction was terminated after confirming that the acid value was 0. By removing the solvent, the adduct (I) was obtained.

[Example 1] 30 parts of adduct (I), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate ("UVR-611" manufactured by Union Carbide Co., Ltd.
0 ") 65.5 parts, 4 parts of a cationic photopolymerization initiator (" UVI-6990 "manufactured by Union Carbide Co., Ltd.) and 0.5 part of a surfactant (" L-7604 "manufactured by Nippon Unicar Co., Ltd.) are mixed and stirred to prepare paint 1 Was produced. Apply this to a thickness of 7 μm on a 300 μm thick aluminum plate and tin-free steel plate, and on a 50 μm thick PET film and PVC film, and place each under a high pressure mercury lamp of 80 W / cm. It was passed at a speed of 5 m / min to cure the coating film.

Example 2 20 parts of adduct (I), bis (3,4-
Epoxycyclohexylmethyl) adipate (Union Carbide "UVR-6199") 75.5 parts, cationic photopolymerization initiator "UVI-6990" 4 parts and surfactant "L-7604"
0.5 part was mixed and stirred to prepare coating material 2. This was applied to a base material and cured in the same manner as in Example 1.

[Comparative Example 1] 95.5 parts of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate "UVR-6110", cationic photopolymerization initiator "UVI-69"
90 parts (4 parts) and surfactant (L-7604) 0.5 parts were mixed and stirred to prepare coating material 3. This was applied to a base material and cured in the same manner as in Example 1.

Comparative Example 2 Bis (3,4-epoxycyclohexylmethyl) adipate "UV" instead of "UVR-6110"
A coating material 4 was prepared in the same manner as in Comparative Example 1 except that "R-6199" was used, and the coating material 4 was applied to the substrate and the coating film was cured.

Table 1 shows the results of evaluation of the adhesion, workability and pencil hardness of the coating films obtained in the examples and comparative examples. The evaluation was performed as follows. (1) Adhesiveness Based on JIS K5400, the number of 100 stitches and the number of stitches in which the coating film was not peeled by the cellophane tape peeling test were displayed. (2) Workability Using a 1/2 inch rod with a DuPont impact tester, drop a 500 g weight from the height of 50 cm on the back side (metal surface) of the coating film and visually check for cracks in the coating film. It was evaluated by. ⊚: No abnormality. ○: Some cracks occurred. Δ: Many cracks occurred. X: Cracks were generated on the entire surface. (3) Pencil hardness Based on JIS K5400, the pencil hardness was measured using a Mitsubishi pencil "Uni".

[0016]

[Table 1]

[0017]

The coating film obtained from the ultraviolet-curable resin composition of the present invention has excellent adhesiveness to metal and plastic films, and also has good processability and surface hardness. It is suitable for ink vehicles and coatings.

Claims (4)

[Claims] 1. An adduct (A) of a bisphenol A type epoxy resin and a phosphoric acid having at least one active hydrogen.
And a compound (B) having two or more alicyclic epoxy groups
And a cationic photopolymerization initiator (C). 2. The ultraviolet curable resin composition according to claim 1, wherein the phosphoric acid having at least one active hydrogen is orthophosphoric acid. 3. A compound (B) having two or more alicyclic epoxy groups is 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate and bis (3,
The ultraviolet curable resin composition according to claim 1, which is one kind selected from 4-epoxycyclohexylmethyl) adipate or a mixture of both. 4. A coating agent containing the ultraviolet curable resin composition according to claim 1.