JPS58104914A - Photo-setting unsaturated polyester resin composition - Google Patents

Abstract

PURPOSE:The titled composition, prepared by incorporating an unsaturated polyester resin as a principal component with radically cleavable photopolymerization initiator and a hydrogen pulling photopolymerization initiator, and having improved surface hardening and adhesivity in the hardening. CONSTITUTION:A composition prepared by incorporating an unsaturated polyester resin (a polyester resin obtained by incorporating a vinyl monomer as a crosslinking agent with an unsaturated polyester prepared by dehydrogenating and condensing an unsaturated dibasic acid replaced by a saturated dibasic acid with a dihydric alcohol) as a principal component with 0.5-10wt% radically cleavable photopolymerization initiator, e.g. benzoin, and a hydrogen pulling photopolymerization initiator, e.g. dimethylamino-p-benzaldehyde, at 0.1-10 ratio between the radically cleavable and hydrogen pulling photopolymerization initiators. A crosslinking agent, e.g. diallyl phthalate, and if necessary another additive are added thereto, and the resultant mixture is irradiated with light to give the aimed photoset material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photocurable unsaturated polyester resin composition that has excellent curability, particularly surface curability, with ultraviolet light and excellent pickling properties during curing. be.

Unsaturated polyester resins include unsaturated dibasic acids such as maleic acid and 7-malic acid, or those in which a portion thereof has been replaced with saturated dibasic acids such as adipic acid and 7-taric anhydride, and ethylene glycol and propylene glycol. It is made by blending a vinyl monomer such as styrene or diallyl phthalate as a crosslinking agent into an unsaturated polyester obtained by dehydration condensation with a dihydric alcohol such as styrene or diallyl phthalate. Not only thermal polymerization type resin compositions in which a thermal polymerization initiator is blended into this composition, but also photopolymerization type unsaturated polyester resin compositions in which a photopolymerization initiator is blended with this composition are well known. In particular, if it is possible to improve the photocurability and adhesion during curing of the photopolymerizable unsaturated polyester resin set a'4fl:J, excellent products can be produced by applying this.

Therefore, the inventors conducted a series of studies to improve the photocurability and adhesion during curing of photopolymerizable unsaturated polyester resin compositions, and found that a radical cleavage type photoinitiator The present invention was achieved based on the finding that the desired objective could be achieved by using both a photopolymerization initiator and a hydrogen abstraction type photopolymerization initiator.

That is, the gist of the present invention is a photocurable unsaturated polyester resin composition that contains an unsaturated polyester resin as a main component and contains both a radical cleavage type photopolymerization initiator and a hydrogen abstraction type photopolymerization initiator. It is something to do.

The radical cleavage type photopolymerization initiator (photosensitizer) is a photopolymerization initiator that is decomposed by light such as ultraviolet rays to generate radicals. Benzoin is used as such a radical cleavage type photopolymerization initiator.

Benzoin alkyl ethers (benzoin ethyl ether, benzoin butyl ether, etc.), Hensyl, benzyl dimethyl ketal, etc. are used alone or in combination.

The hydrogen abstraction type photopolymerization initiator is a photopolymerization initiator that generates radicals when molecules excited by light such as ultraviolet rays abstract hydrogen. As such a hydrogen abstraction type photopolymerization initiator, dimethylamino-P-
benzaldehyde.

::1 Anthraquinones (2-ethylanthraquinone).

2-butylanthraquinone I), thioxanthone (2
-chlorothioxanthone, diisopropylthioxanthone, etc.) are used alone or in combination.

The blending ratio of photopolymerization initiators of the same type is not particularly limited, but the mutual blending ratio of radical cleavage type and hydrogen abstraction type is 0.
It is preferable to set it within the range of 1 to 1.0 from the viewpoint of sensitizing effect. Table 1 below shows preferred blending ratios depending on the film thickness (resin film thickness) of the photocurable unsaturated polyester resin composition.

The total amount of the radical cleavage type photopolymerization initiator and the hydrogen abstraction type photopolymerization initiator is 0.5% from the viewpoint of photocuring speed. :m
It is preferable to set it to Jlichi (hereinafter abbreviated as "chi") or more. However, it is advantageous in terms of cost and performance to use as little photopolymerization initiator as possible as long as the purpose can be achieved. From this point of view, it is preferable to set the limit to 10%. Therefore, the total amount of photopolymerization initiator is
Usually, it is set within the range of 0.5 to 10%.

The photocurable unsaturated polyester resin composition of the present invention contains (meth)acrylic esters such as hydroxyethyl methacrylate and vinyl monomers such as DAP in place of styrene, which has been generally used as a crosslinking agent. is preferably used as a crosslinking agent. In other words, the styrene that has been awarded so far is highly volatile and has a strong odor, which poses problems from an occupational health perspective.
It is preferable to use the above-mentioned compound as a crosslinking agent instead of styrene, which does not cause such problems. Also,
The photocurable unsaturated polyester resin composition of the present invention may contain additives, if necessary.

As described below, by using both a radical cleavage type photopolymerization initiator and a hydrogen abstraction type photopolymerization initiator, the photosensitization effect is synergistically achieved by δcIa, and the photopolymerization type photopolymerization initiator is used in combination. This improves the photocurability and adhesion during curing of the saturated polyester resin composition. The unsaturated polyester resin composition improved in this way has good adhesion upon curing and is highly photocurable, and is therefore particularly useful as electrical insulation paints and antirust paints. The reason why such an effect occurs is considered to be due to the following reasons.

That is, the characteristics of the radical cleavage type photopolymerization initiator and the hydrogen abstraction type photopolymerization initiator are as shown in Table 2 below.

In a sensitized system that uses two types of photoinitiators in combination, the hydrogen abstraction type photoinitiator transfers the absorbed light energy to the radical cleavage type photoinitiator. It is thought that the sensitizing effect is increased due to the sensitization effect of benzoin among radical cleavable photoinitiators.

This is remarkable when benzoin alkyl ethers, benzyl, benzyl methyl ketal, etc. are used in combination with dimethylamine-P-benzaldehyde, anthraquinones, thioxanthone, etc. among hydrogen abstraction type photo-initiators. This is considered to be because, in such a combination, energy transfer between the photo-I-synthesis initiators is particularly likely to occur. Next, the reason why adhesion during curing is improved is that in the case of hydrogen abstraction type photopolymerization initiators, there are many polymerization initiation sites, so the molecular weight of the polymer molecules is low, and this is caused by plasticizers or tackifiers. It is thought that the adhesion is improved because it acts as -.

Next, examples will be explained together with comparative examples. l 1-7. Comparative Examples 1 to 6] 06 mol of anhydride → ray/acid, 0.4 mol of 7-talic anhydride, 1.1 mol;
A liquid unsaturated polyester resin face was prepared by mixing 50 parts of unsaturated polyester (1! (It, the same hereinafter) made of propylene glycol with an acid value of 28, 20 parts of diallyl phthalate, 30 parts of hydroxyethyl methacrylate, and 70,005 parts of hydroquino. .A photopolymerization initiator having the composition shown in Table 5 below was mixed with 100 parts of this Fes in the ratio shown in Table 5 below and dissolved uniformly to obtain the desired product, which was then degreased and cleaned with acetone. It was coated on a copper plate to a thickness of 50μ using a film applicator.
351 type, high pressure water steel lamp (water cooling type) 80%'V/QI
Light was irradiated through an XB lamp).

In this case, curability was determined by the amount of exposure required for the surface hardness of the coating film to become H or higher. The exposure amount was actually measured using an Oak ■ integrated light meter UV, model -331PC2. In addition, the adhesion test is based on the coating film test method standard JIS K5400.
It was conducted using the Gobanmoku test method described in . The results of this series of tests are shown in Table 3. From Table 3, it can be seen that the Example products are superior in photocurability and adhesion during curing compared to the Comparative Example products.

(Hereafter, the rest is white) Table 3

Claims (5)

[Claims] (1) A photocurable unsaturated polyester resin composition comprising an unsaturated polyester resin as a main component and containing both a radical cleavage type photoinitiator and a hydrogen abstraction type photoinitiator. (2) The light according to claim 1, wherein the mutual compounding ratio of the radical cleavage type photoinitiator and the hydrogen abstraction type photoinitiator is set within the range of 0.1 to 1.0. Curable unsaturated polyester resin composition. (3) The radical cleavage type photoinitiator is at least one radical cleavage type photoinitiator selected from the group consisting of benzoin, benzoin alkyl ethers, benzyl dimethyl ketal, and benzyl, and the radical cleavage type photoinitiator is a hydrogen abstraction type photoinitiator. Claim 1 or 2, wherein the polymerization initiator is at least one hydrogen abstraction type photopolymerization initiator selected from the group consisting of dimethylamino-P-benzaldehyde, anthraquinones, and thioxanthones. A photocurable unsaturated polyester resin composition. (4) The light according to any one of claims 1 to 3, wherein the radical cleavage type photopolymerization initiator and the hydrogen abstraction type photopolymerization initiator are blended in a total of 0.5 to 10 ply. Curable unsaturated polyester resin composition. (5) The photocurable unsaturated polyester resin composition according to any one of claims 1 to 4, wherein a monomer such as diallyl phthalate or (meth)acrylic acid ester is used as the crosslinking agent.