JPH07247341A - Ultraviolet-curing resin and coating agent containing the same - Google Patents

Abstract

PURPOSE:To obtain a UV-curing resin excellent in adhesion to metal or plastic film. CONSTITUTION:The resin is prepared by effecting the addition reaction of a compound (A) having at least two alicyclic epoxy groups with a phosphoric acid (B) having at least one active hydrogen in such a ratio that 0.005-0.2mol of the active hydrogen atoms of component B is present per mol of the epoxy groups of component A. A coating film obtained from this resin 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 curable by irradiation with ultraviolet rays, and more particularly to an ultraviolet curable resin 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, although attempts have been made to improve the adhesion to metal by applying a compound obtained by adding phosphoric acid to a non-alicyclic epoxy resin to a thermosetting coating, an ultraviolet curing type has been made. As an example, there is no example using a compound obtained by adding phosphoric acid to an alicyclic epoxy resin.

[0004]

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

[0005]

That is, the present invention provides a compound (A) having two or more alicyclic epoxy groups and a phosphoric acid (B) having at least one active hydrogen,
The active hydrogen of (B) is equivalent to 1 mol of the epoxy group of (A).
Provided is an ultraviolet-curable resin, which is added at a ratio of 0.005 to 0.2 mol.

The compound (A) having two or more alicyclic epoxy groups is 3,4-epoxycyclohexylmethyl-
Examples include 3,4-epoxycyclohexylcarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, and the like. The phosphoric acids (B) having at least one active hydrogen include orthophosphoric acid, pyrophosphoric acid,
Examples include metaphosphoric acid and phosphorous acid.

In the present invention, an adduct of an alicyclic epoxy compound and a phosphoric acid can be obtained by a conventional method. For example, a mixture of the two is diluted with a solvent, if necessary, at room temperature to 10 ° C.
The reaction may be carried out while stirring at 0 ° C for 30 minutes to 5 hours.
If the amount of active hydrogen of (B) is less than 0.005 mol relative to 1 mol of the epoxy group of (A), the adhesion to metal and plastic films is insufficient, and if it exceeds 0.2 mol, the curability tends to be poor.

The ultraviolet curable resin of the present invention is combined with a photopolymerization initiator and, if necessary, other epoxy resin, resin other than epoxy, organic and inorganic pigments, extender pigment, plasticizer, defoaming agent, leveling agent and the like. A coating agent is obtained by mixing. As the photopolymerization initiator, a commercially available cationic photoinitiator such as diazonium salt, halonium salt, or sulfonium salt can be used.

Other epoxy resins include bisphenol A, bisphenol F and halogenated bisphenol A.
Polyglycidyl ethers of divalent or higher polyhydric phenols such as bisphenol type epoxy resins such as diglycidyl ethers and novolac type epoxy resins such as phenol novolacs and cresol novolacs, ethylene glycol, propylene glycol And polyglycidyl ethers of polyhydric alcohols such as neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, and trimethylolpropane.

Examples of resins other than epoxy include vinyl resins, acrylic resins, polyester resins, polyurethane resins and polyether resins. An alicyclic monoepoxide may be added to the coating agent as a reactive diluent, and examples thereof include 4-vinylcyclohexene monoxide. The light source for curing the ultraviolet curable resin and coating material 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.

[0011]

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] 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate ("UVR-6110" manufactured by Union Carbide Co., Ltd.) was placed in a reaction vessel equipped with a stirrer, a cooler, a thermometer and a dropping funnel. ) 504 parts and 1,
Charge 504 parts of 2-dimethoxyethane, and add a mixture of 5.8 parts of 85% orthophosphoric acid (0.038 mol of active hydrogen to 1 mol of epoxy group) and 52.2 parts of 1,2-dimethoxyethane over 4 hours while stirring. Then, the contents were heated at 80 ° C. for 2 hours to proceed the addition reaction, and the reaction was terminated after confirming that the acid value became 0. By removing this solvent, an ultraviolet curable resin (I) was obtained.

[Production Example 2] 732 parts of bis (3,4-epoxycyclohexylmethyl) adipate ("UVR-6199" manufactured by Union Carbide Co.) and 1,2-dimethoxyethane 732 were placed in the same reaction vessel as in Production Example 1. 85 parts while stirring
% A mixture of orthophosphoric acid 11.5 parts (active hydrogen 0.075 mol per 1 mol of epoxy group) and 1,2-dimethoxyethane 103.5 parts was added dropwise over 4 hours, and then the contents were heated at 80 ° C. for 2 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. The solvent was removed to obtain an ultraviolet curable resin (II).

[Production Example 3] 504 parts of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate "UVR-6110" and 504 parts of 1,2-dimethoxyethane were placed in the same reaction vessel as in Production Example 1. Charge and stir
85% orthophosphoric acid 92.2 parts (based on 1 mol of epoxy group,
A mixture of active hydrogen (0.6 mol) and 1,2-dimethoxyethane (829.8 parts) was added dropwise over 4 hours, and then the contents were heated at 80 ° C for 2 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, an ultraviolet curable resin (III) was obtained.

[Example 1] To 95.5 parts of the ultraviolet curable resin (I), 4 parts of a cationic photopolymerization initiator ("UVI-6990" manufactured by Union Carbide) and a surfactant ("L- manufactured by Nippon Unicar Co., Ltd." 7604 ") 0.5 part was added and stirred to prepare paint 1.
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 Example 1 was repeated except that the ultraviolet curable resin (II) was used instead of the ultraviolet curable resin (I).
A coating material 2 was prepared and applied in the same manner as above, and the coating film was cured.

[Comparative Example 1] The same as Example 1 except that 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate "UVR-6110" was used in place of the ultraviolet curable resin (I). A coating material 3 was prepared and applied in the same manner, and the coating film was cured.

[Comparative Example 2] A coating material 4 was prepared and applied in the same manner as in Example 1 except that the ultraviolet curable resin (III) was used in place of the ultraviolet curable resin (I). It was irradiated, but the curing was insufficient and the coating film was sticky and could not be used for evaluation.

Table 1 shows the results of evaluating the adhesion, workability and pencil hardness of the coating films obtained in Examples 1 and 2 and Comparative Example 1. 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".

[0019]

[Table 1]

[0020]

The coating film obtained with the ultraviolet-curable resin of the present invention has excellent adhesion to metal and plastic films, and has good processability and surface hardness. It is suitable for vehicles, coating agents, etc.

Claims (4)

[Claims] 1. A compound (A) having two or more alicyclic epoxy groups and a phosphoric acid (B) having at least one active hydrogen, and (B) with respect to 1 mol of the epoxy group of (A). A UV-curable resin characterized in that 0.005 to 0.2 mol of active hydrogen is added. 2. The compound (A) having two or more alicyclic epoxy groups is 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate and bis (3,
The ultraviolet curable resin according to claim 1, which is one kind selected from 4-epoxycyclohexylmethyl) adipate or a mixture of both. 3. The ultraviolet curable resin according to claim 1, wherein the phosphoric acid (B) having at least one active hydrogen is orthophosphoric acid. 4. A coating agent containing the ultraviolet curable resin according to claim 1.