JPS62190201A - Ultraviolet curing resin composition - Google Patents

Abstract

PURPOSE:An ultraviolet curing resin composition, containing a specific amount of a compound having an aryl group or specific thiol group, having a high curing rate and capable of giving required physical properties in a very short time. CONSTITUTION:A composition obtained by adding 0.01-5wt% of (A) a compound having an aryl group, e.g. dimethylthiophenol, etc., or (B) a compound having thiol group directly linked to a heterocyclic ring group having aromaticity, e.g. 2-mercaptobenzimidazole, etc., to an ultraviolet curing resin composition consisting of a photopolymerizable compound and photoinitiator.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an ultraviolet curable resin composition that has a rapid curing speed and can obtain required physical properties in an extremely short period of time.

[Prior art]

Ultraviolet curable resin compositions have the property of curing in a short time, so they are used in coating materials, potting materials, etc., but in order to further increase productivity, it is possible to get closer to the required properties as quickly as possible. Improvements have been made to increase the curing speed of resin compositions. Conventional methods include changing the type and amount of photoinitiators, and using photosensitizers.
It was expected that this would further increase the curing speed.

[Purpose of the invention]

The present invention was developed in view of these circumstances, and has made it possible to improve the curing speed and obtain the required physical properties in an extremely short period of time by incorporating a small amount of a specific compound. The purpose of the present invention is to provide an ultraviolet curable resin composition.

[Structure of the invention]

Therefore, in the present invention, 0.01% of a compound having a thiol group directly bonded to an aryl group or an aromatic heterocyclic group is added to an ultraviolet curable resin composition comprising a photopolymerizable compound and a photoinitiator. The gist of the present invention is an ultraviolet curable resin composition characterized by containing ~5% by weight.

Hereinafter, the configuration of the present invention will be explained in detail.

Compound (A) directly bonded to the aryl group used in the present invention
For example, thiophenol and the following general formula (1
), such as l-thiocresol, dimethylthiophenol, t-butylcuocresol, t-butylthiophenol, 4-chlorothiocatechol, 2.5-dichlorothiophenol, pentachlorothiophenol, These include 2-aminothiophenol and 2-nitrothiophenol.

R, = alkyl group, alkoxyl group, aryol group, nitrile group, nitro group, carboxyl group, amino group, halogen group, hydroxyl group, acetyl group, (Rt can be at any position of ortho, meta, or rose), and , thionaphthol, 1-
Also included are compounds with fused benzene rings such as mercapto-2-naphthol. In addition, the compound (B) having a thiol group directly bonded to a heterocyclic group having aromaticity refers to a compound (B) having a thiol group directly bonded to a carbon atom in a heterocyclic group such as pyridyl, quinolyl, furyl, coumaryl group, etc. Compounds such as furfuryl mercaptan, 2-mercaptopyridine, 2-mercaptoquinoline, 2-mercapto-4,6-dimethylpyridine, 7-mercaptocoumarin, 2-mercaptobenzimidazole, 1-methyl-2
-mercaptoimidazole, 2-mercaptobenzothiazole, 5-mercapto-2-methyl-1,3,4,-
Such as thiazole. A compound (A) directly bonded to these aryl groups or aromatic heterocyclic groups.

The content ratio of (B) is 0.0 as the amount that clearly increases the curing speed compared to when only the photopolymerization initiator is used.
It is 1% by weight or more. In addition, these thiol compounds are
In general, it has a strong odor and, furthermore, it is required to maintain the storage stability of the resin, so the maximum content is 5% by weight. That is, it is 0.01 to 5% by weight.

Here, the photopolymerizable compound refers to a compound having a (meth)acryloyl group, an oligomer having a (meth)acryloyl group, and a compound having an ethylenically unsaturated bond other than the (meth)acryloyl group.

Examples of compounds having a (meth)acryloyl group include phenoxyethyl (meth)acrylate, ethyl (
Monofunctional (meth)acrylates such as meth)acrylate, methyl (meth)acrylate, benzyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, lauryl (meth)acrylate, the following general Monofunctional (meth)acrylate as shown by formula (2), CIl□=C-C-(-QC)l2Cl(-hR4
... (2) 11I Rz 0 1h (n = 1 to 4) Rz = 11, CH,, R3 = H, C1h, 0C4H9, +1H 1,6-hexanethiol di(meth)acrylate, neobentyl glycol di (meth)acrylate, polyethylene glycol di(meth)acrylate, bifunctional (meth)acrylate such as di(meth)acrylate containing an ethylene oxide adduct of bisphenol A in its skeleton;
trimethylolpropane tri(meth)acrylate,
These include trifunctional (meth)acrylates such as tris(hydroxy-ethyl acryloyl) isocyanurate. Oligomers having (meth)acryloyl groups include urethane acrylates, epoxy acrylates, and polyester acrylates obtained from glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polyester glycol.

Compounds having ethylenically unsaturated bonds other than (meth)acryloyl groups include N-vinylpyridine, N-vinylpyrrolidone, styrene, α-methylstyrene, and the like. It is preferable to use two or more of these photopolymerizable compounds in combination in order to obtain properties as a coating material and a botting material.

As the photopolymerization initiator, either a radical cleavage type or a hydrogen abstraction type may be used. For example, benzyl dimethyl ketal, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methylpropiophenone, Toxyacetophenone, benzoin ethyl ether,
Benzylbenzophenone, 2-methylanthraquinone,
2,4-diethylthioxanthone and the like are effectively used.

These are blended to obtain an ultraviolet curable resin composition,
In the present invention, it has been discovered that the curing speed of ultraviolet curable resin compositions can be significantly increased by adding a small amount of the compounds (A) and (B), which are not generally used, to these ultraviolet curable resin compositions. It is.

Examples and comparative examples are shown below.

Examples, Comparative Examples +1) Ultraviolet curable resin compositions were obtained using the formulations (parts by weight) shown in Table 1 below. In Table 1, 0.5 parts by weight of thiophenol was added to the formulation of N12 and the formulation of Level 1, and the formulation of Case 4 to the formulation of Level 3, respectively. These blended ultraviolet curable resin compositions are prepared using an ultraviolet lamp (80W/cm, IKW, metal halide lamp).
50mJ/cd, 100mJ/cA, 200mJ
/CIA, 400mJ/cj light, 200μ thick
A sheet of 1.5 m was prepared, punched out using a plastic JIS No. 2 dumbbell, and its elastic modulus was measured. In comparative examples, the curing speeds of resins were compared in terms of saturation of elastic modulus.

Table-1 □□□□I Note) Urethane acrylate A knee CHzCHtOCCH=C11□(-(CHtCHI
CIl□CI (t-0 juice part 0 is PTM
G-average molecular weight of 850).

Urethane acrylate B: Monoacrylate A: Diacrylate A: Triacrylate A Nidris (hydroxyethyl acryloyl) isocyanurate.

Figure 1 shows 400mJ/ca! The elastic modulus when irradiated with light is 100, 50IIIJ/ci, 100mJ/
cIa, the elastic modulus when irradiated with light of 200 mJ/Ca is expressed as a percentage when irradiated with 400 ffiJ/-.

As can be seen by comparing No. 1 and Arashi 2, and No. 3 and No. 4 in Figure 1, the addition of thiophenol resulted in a reduction of 50 mJ/cj despite the same resin composition.
The elastic modulus increases when irradiated with light, and the curing speed improves in terms of saturation of the elastic modulus.

(2) An ultraviolet curable resin composition was obtained using the formulations (parts by weight) shown in Table 2 below. In Table 2, on floor 6, 2-mercaptobenzimidazole was added to floor 5, and on floor 7, 2-mercaptobenzimidazole was added to floor 5.
- 0.5 parts by weight of mercaptopyridine. A sheet was prepared using the ultraviolet curable resin composition blended above in the same manner as in (1) above, and its elastic modulus was measured. Furthermore, in a comparative example, the curing speeds of the resin compositions were compared in terms of the degree of saturation of the elastic modulus.

Table 2 Figure 2 shows the elastic modulus of 100 when irradiated with 400 mJ/cj light, 50 mJ/cd, 100+eJ/ca
The elastic modulus of the film when irradiated with light of t and 200a+J/cd is expressed as a percentage when irradiated with 400mJ/aJ.

In Fig. 2, as can be seen by comparing No. 5 and No. 6, and No. 5 and No. 7, they have aromatic properties similar to the thiophenol used in (1) above, despite having the same resin composition. Even when 2-methylcabutoviridine, a compound having a thiol group directly bonded to a heterocyclic group, is added,
The elastic modulus increases when irradiated with 50 mJ/cd light,
The curing speed in terms of percent saturation is improved.

〔Effect of the invention〕

As explained above, the ultraviolet curable resin composition of the present invention containing a compound having a thiol group directly bonded to an aryl group (or aromatic heterocyclic group) has a Since it can improve the curing speed without sacrificing properties, it has the advantage of achieving desired physical properties in a short time and improving productivity, making it suitable for optical fiber coating materials, botting materials, etc. Available.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are relationship diagrams between the elastic modulus ratio of the ultraviolet curable resin composition and the irradiated ultraviolet energy.

Claims (1)

[Claims] 0.01 to 5% of a compound having a thiol group directly bonded to an aryl group or an aromatic heterocyclic group is added to an ultraviolet curable resin composition consisting of a photopolymerizable compound and a photoinitiator.
% by weight of an ultraviolet curable resin composition.