JP2000007993A - Active energy ray-curable composition and formation of its film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a cured coating film excellent in film properties by the irradiation of active energy rays. SOLUTION: The objective active energy ray-curable composition comprises components below: (A) 19-95 wt.% of an epoxycyclohexylalkyltrialkoxysilane compound; (B) 1-40 wt.% of a compound containing at least two oxetane rings in the molecule; (C) 0-80 wt.% of a glycidoxyalkyltrialkoxysilane; and (D) 0.05-20 pts.wt., based on 100 pts.wt. of the total of (A)+(B)+(C), of a cationic photopolymerization initiator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel active energy ray-curable composition and a method for forming a film thereof.

[0002]

2. Description of the Related Art Conventionally, an active energy ray-curable composition which is cured by an active energy ray such as an ultraviolet ray or an electron beam,
For example, it is widely used for applications such as paints, inks and adhesives. In general, paints such as thermosetting paints and lacquers are not sufficiently cured immediately after finishing, so after a certain period of time (cooling, drying, etc.), winding, stacking,
In addition, there is a disadvantage that productivity is inferior due to transportation and the like. On the other hand, active energy ray-curable compositions can be cured in seconds and do not require heating, enabling high-speed curing and drying that could not be achieved with thermosetting paints and lacquer types. Widely used for various applications.

However, since the conventional active energy ray-curable composition is inhibited from curing by oxygen, it is usually cured by an active energy ray in the presence of an inert gas such as nitrogen. For this reason, there are problems that the cost is increased due to the necessity of special equipment and that the inert gas is not good for the human body.

[0004] As an active energy ray-curable composition, a composition containing an unsaturated group which is cured by irradiation with active energy rays is known. However, the composition has poor adhesion to a material or is susceptible to oxygen inhibition in air. There were problems that the irradiation energy required for curing was increased, the production cost was increased, and the safety was deteriorated.

[0005] Further, as an example which is hardly affected by curing inhibition by oxygen, for example, an active energy ray-curable composition comprising an oxetane compound and a cationic polymerization initiator described in JP-A-7-53711 is known. I have. However, it is difficult to obtain a film having high hardness because the film formed from this composition has insufficient curability,
There is a problem that it is not practical. In this publication, an oxetane compound having an alkoxysilyl group introduced therein is described as an oxetane compound, but there is no specific description about this.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to develop an active energy ray-curable composition which forms a film having excellent curability in the presence of oxygen, surface hardness and adhesion of the film. It was done.

[0007]

The present inventors have made intensive studies to solve the above problems, and as a result, have found that an epoxycyclohexylalkyl trialkoxysilane compound has two or more oxetane rings in one molecule. Combination of a compound and, if necessary, glycidoxyalkyl trialkoxysilane, and the addition of a cationic photopolymerization initiator provide an active energy ray-cured coating with high coating hardness and excellent performance such as adhesion and processability. It has been found that the present invention has been completed.

That is, the present invention relates to the following:
Epoxycyclohexylalkyl trialkoxysilane compound 19 to 95% by weight (B) Compound having two or more oxetane rings in one molecule 1 to 40% by weight (C) Glycidoxyalkyl trialkoxysilane 0 to 95% by weight
80% by weight (D) The cationic photopolymerization initiator was added to the above (A) + (B) +
(C) an active energy ray-curable composition comprising 0.05 to 20 parts by weight per 100 parts by weight of the active energy ray-curable resin composition; And applying an active energy ray to cure the coating to a thickness of 1 to 50 microns.

In the composition of the present invention, the cationic photopolymerization initiator is radically decomposed by an active energy ray, and the generated cation radical transfers energy or electron transfer to a hydroxysilyl group (hydrolyzate of an alkoxysilyl group). It is presumed that the hydroxysilyl group is excited to accelerate the cationic polymerization reaction of the alicyclic epoxy group, and that a high-hardness coating is formed by dehydration condensation between the hydroxysilyl groups to form a polymer. You. In addition, since a silane epoxy compound containing three hydroxysilyl groups in a molecule and a compound containing two or more oxetane rings in one molecule are used in combination, the crosslink density is large, the hardness is high, and mechanical properties are high. Excellent coating is formed.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The epoxycycloalkyl trialkoxysilane (A) used in the composition of the present invention includes:
The following general formula (1)

[0011]

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Wherein n is an integer of 1 to 4, and R ¹ is a methyl group, an ethyl group or a propyl group.

As this, for example, β- (3,4
-Epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltripropoxysilane, α- (3,4-epoxycyclohexyl) methyl Trimethoxysilane, α
-(3,4-epoxycyclohexyl) methyltriethoxysilane, γ- (3,4-epoxycyclohexyl)
Propyltrimethoxysilane, γ- (3,4-epoxycyclohexyl) propyltriethoxysilane, δ-
(3,4-epoxycyclohexyl) butyltrimethoxysilane, δ- (3,4-epoxycyclohexyl) butyltriethoxysilane, and the like.

The compound (B) having two or more oxetane rings in the molecule used in the present invention is not particularly limited, but for example, a compound represented by the following general formula (2) may be used. can do.

[0015]

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(Wherein m is an integer of 2, 3 or 4;
Z is oxygen or sulfur. R ² is hydrogen, fluorine, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group or a furyl group. R
³ is, for example, a group having 1 to 12 carbon atoms represented by the following formula (3)
A linear or branched alkylene group, or a linear or branched (poly) alkyleneoxy group. )

[0017]

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(In the above formula (3), R ⁴ is a methyl group, an ethyl group or a propyl group.) In the above formula (3), R ⁴ is the following (4), (5) and (6) )
Or a polyvalent group selected from the group consisting of

[0019]

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(In the formula (4), p is 0 or 1 to 20)
It is an integer of 00. R ⁵ is a radical selected from the group consisting of the same or different alkyl group and the following 1-10 carbon atoms (5). )

[0021]

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(In the formula (5), q is 0 or 1 to 10
It is an integer of 0. R ⁷ is the same or different and has 1 carbon atom
10 to 10 alkyl groups. R ⁶ is the same or different and is an alkyl group having 1 to 10 carbon atoms. )

[0023]

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(In the formula (6), R ⁸ is hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, a halogen atom, a nitro group, a cyano group, a mercapto group, a lower alkyl carboxy group. A rate group or a carboxyl group.)

[0025]

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(In the formula (7), R ⁹ represents oxygen, sulfur,
NH, SO, SO ₂ , CH ₂ , C (CH ₃ ) ₂ or C (CF
₃ ) It is ₂ . In the present invention, in the formula (2), R ² is preferably a lower alkyl group. As R ² , R ⁸ in Formula (6) is preferably a hydrogen atom or a hexamethylene group, and R ⁴ in Formula (3) is preferably an ethyl group. R ⁶ and R ⁷ are preferably a methyl group. Z is preferably oxygen. Another preferred specific example of the compound B is a compound represented by the formula (8)
And the compound of (9).

[0027]

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[0028]

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(In the formula (8), s is an integer of 25 to 200, and R ¹⁰ is the same or different and has 1 to 4 carbon atoms.
Is an alkyl group or a trialkylsilyl group. Also, a homopolymer of an oxetane ring-containing radically polymerizable monomer such as 3-methacryloxymethyl 3-ethyloxetane and 3-acryloxymethyl-3-ethyloxetane, and this monomer and other radically polymerizable unsaturated monomers (for example, , (Meth) acrylic acid having 1 to 24 carbon atoms
With alkyl or cycloalkyl esters, aromatic unsaturated compounds, vinyl monomers, etc.).

Glycidoxyalkylalkoxysilanes (C) that can be used as needed in the composition of the present invention include:
The following general formula (10)

[0031]

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Wherein t is an integer of 1 to 4, and R ¹¹ is a methyl group, an ethyl group or a propyl group.

Examples of this include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxyethyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane
Glycidoxymethyltriethoxysilane, γ-glycidoxyethyltripropoxysilane, γ-glycidoxymethyltripropoxysilane, γ-glycidoxymethyltrimethoxysilane, γ-glycidoxypropyltripropoxysilane, and the like. Can be

In the composition of the present invention, the above components (A), (B) and (C) are mixed in proportions of (A) to (A).
Component (A) is 19 to 95 based on the total amount of component (C)
% By weight, preferably from 25 to 70% by weight and component (B) being from 1 to 40% by weight, preferably from 5 to 30% by weight,
Component (C) is in the range of 0 to 80% by weight, preferably 5 to 50% by weight. When the amount of the component (A) is less than 19% by weight, the curability of the film is reduced, and the film hardness, workability, adhesion to the material, etc. are deteriorated. On the other hand, when the amount exceeds 95% by weight, the curing time is prolonged, resulting in poor productivity. Is not preferred. If the content of the component (B) is less than 1% by weight, the hardness of the coating film is deteriorated.

As the cationic photopolymerization initiator (D) used in the composition of the present invention, conventionally known ones can be used. Preferred examples of the initiator (D) include aryldiazonium salts, aryliodonium salts, and arylsulfonium salts. Specifically, as a product name, for example, Cyracure UVI-6
970, Cyracure UVI-6974, Cyracure UVI-6990, Cyracure UVI-6950 (all manufactured by Union Carbide of the United States, trade name), Irgacure 261 (Ciba Specialty Chemicals,
(Trade name), SP-150, SP-170 (above, manufactured by Asahi Denka Kogyo Co., Ltd., trade name), CG-24-61 (Chiba
Specialty Chemicals, product name), DAIC
AT-II (trade name, manufactured by Daicel Chemical Industries, Ltd.), CI-2
734, CI-2758, CI-2855 (all manufactured by Nippon Soda Co., Ltd., trade name), PI-2074 (Rhone Poulin, pentafluorophenylborate toluylcumyl iodonium salt), FFC509 (3M), BBI
102 (manufactured by Midori Kagaku) and the like.

The compounding ratio of the cationic photopolymerization initiator (D) is determined based on the total weight of the components (A) + (B) + (C) 100
It is 0.01 to 20 parts by weight, preferably 0.5 to 5 parts by weight based on parts by weight.

In the composition of the present invention, if necessary,
Other resins, reactive diluents, photopolymerization accelerators, fillers, colorants, pigments, pigment dispersants, fluidity regulators, leveling agents, defoamers, light stabilizers, antioxidants, thermal polymerization prohibited Even if it mixes an agent etc., it does not interfere at all.

The composition of the present invention can be used for paints, inks, adhesives and the like.

The composition of the present invention can be applied to substrates such as paper, plastic, metal, wood, and combinations thereof.

In the method of forming a coating film of the present invention, the active energy ray-curable composition is applied to the above-mentioned base material surface in a cured film thickness of 1 to 50 μm, preferably 3 to 20 μm. And then curing by irradiating with an active energy ray.

The coating can be performed by a conventionally known method, for example, a spray, roll coater, gravure coater, screen, spin coater, flow coater, electrostatic coating, or the like.

The active energy rays include, for example, ultraviolet rays, β rays, electron rays, etc. from a mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a xenon lamp, a carbon arc, a metal halide, a gallium lamp, an excimer and the like. Although the irradiation amount of the ultraviolet ray is not particularly limited, it is usually preferable to be in the range of about 10 to 2,000 mJ / cm ² . In the case of an electron beam, it is preferable to irradiate an electron beam of 50 to 300 Kev usually for 1 to 20 Mrad.

[0043]

The present invention will be described in more detail. In Examples and Comparative Examples, “parts” and “%” indicate weight.

Example 1 90 parts of β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 10 parts of xylylenedioxetane,
Eriether UE3320 (product name of Unitika, product name,
10 parts of a polyester resin) and 5 parts of CI-2855 (trade name, photocationic polymerization initiator, manufactured by Nippon Soda Co., Ltd.) were added and mixed to obtain an active energy ray-curable composition of Example 1.

The obtained composition was applied to a polycarbonate plate so as to have a thickness of 10 μm, and irradiated with 400 mJ / cm ² ultraviolet light in the air by a metal halide lamp. The appearance and adhesion of the obtained coating film were good. The pencil hardness was 6H, which was good. Further, the composition was applied on a glass plate, the coating film cured under the same conditions as above was peeled off from the glass plate, and the residue after extraction for 8 hours in acetone reflux (gel fraction) ) [(The weight of the sample after the test / the weight of the sample before the test) × 100 having the same meaning] was 95%.

Example 2 β- (3,4-Poxycyclohexyl) ethyltrimethoxysilane 60 parts, γ-glycidoxypropyltrimethoxysilane 20 parts, xylylenedioxetane 20 parts, paraloid B-66 (Rohm and Haas Co.) Made, product name,
5 parts of acrylic resin were mixed and dissolved, and Cyracure UVI-6990 (manufactured by Union Carbide, trade name,
4 parts of a cationic photopolymerization initiator (hereinafter the same meaning) were added to obtain an active energy ray-curable composition of Example 2.

The obtained composition was applied on an aluminum plate coated with an epoxy primer so as to have a thickness of 15 μm, and was cured by irradiating 300 mJ / cm ² with a high-pressure mercury lamp.

The appearance and adhesion of the obtained coating film were good. The pencil hardness was 7H, which was good.

Example 3 70 parts of β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 10 parts of γ-glycidoxypropyltrimethoxysilane, an oxetane group-containing acrylic copolymer (styrene / methyl methacrylate / hydroxyethyl Methacrylate / 3-methacryloxymethyl 3-ethyloxetane = 15/10/25/50 parts by weight was copolymerized by solution polymerization to remove the solvent, number average molecular weight 4,000, oxetane ring 2.7 / molecular weight 1,00
20 parts by weight). This dissolved composition 1
Four parts by weight of DAICAT-I (a product of Daicel Chemical Industries, trade name, photocationic polymerization initiator) was added to 00 parts by weight to obtain an active energy ray-curable composition of Example 3.

The resulting composition was coated on a sanded urethane-coated polymethyl methacrylate plate to a thickness of 8
It was coated to a thickness of μm, and irradiated with 300 mJ / cm ² ultraviolet light in the air from a metal halide lamp to cure the coating.

The appearance and adhesion of the obtained coating film were good. The pencil hardness was 6H, which was good. The gel fraction of this coating film was 96.5%.

Example 4 β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane 60 parts, γ-glycidoxypropyltrimethoxysilane 10 parts, xylylene dioxetane 5 parts, acrylic copolymer (styrene / methyl methacrylate) / N
-Butyl methacrylate / 2-ethylhexyl methacrylate / 3-methacryloxymethyl 3-ethyloxetane = 20/10/15/15/40, number average molecular weight 4,
The composition was obtained by mixing and dissolving 25 parts (200, containing 2.3 oxetane rings per 1,000 molecular weight). This composition 1
Sixty parts of Cyracure UVI-6990 was added to 00 parts and mixed to obtain an active energy ray-curable composition of Example 4.

The obtained composition was coated on a corona-treated polyester film so as to have a thickness of 5 μm, and was cured by irradiating 300 mJ / cm ² of ultraviolet light with a high-pressure mercury lamp in the air.

The appearance and adhesion of the obtained coating film were good. The pencil hardness was 5H, which was good.

Method for Testing and Evaluating Coating Film Performance Coating appearance: The degree of coating abnormality such as cracking, shrinkage, and gloss reduction on the coating surface was observed.

Adhesion: A 1 mm wide cut is made on the coating with a sharp blade so as to reach the material from the coating, and an adhesive cellophane tape is adhered to the coating. Evaluation was based on criteria. Good for each cut, thin and smooth on both sides, with no peeling at the intersection of the cut and at a glance at the intersection of the cut; slightly poor at slight intersection at the intersection of the cut, at a glance at the intersection of the cut and the square at the square There was no peeling at a glance, and the area of the defect was 5 times the area of the entire square.
%, Inferior or at the intersection of cuts,
The area of the defective part is 5 to 15% of the area of the entire square. The area of the defective part is extremely poor, and the width of the peeling due to the cut is large, and the area of the defective part exceeds 15% of the area of the entire square.

Coating film hardness: This was performed according to JIS K-5400. The evaluation was performed by the breaking method.

Solvent resistance: The coating film surface was rubbed and reciprocated with a finger with gauze impregnated with toluene, and the appearance of the coating film surface was observed. Good indicates no gloss reduction, slightly poor or slightly reduced gloss, poor or slightly reduced gloss, and extremely poor or significantly reduced gloss.

[0059]

Since the composition of the present invention has the above-mentioned constitution, it exerts a remarkable effect of forming a cured film having excellent film properties by irradiation with active energy rays in the presence of air. Things.

[0060]

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J038 DF022 DL051 DL052 JA13 JA69 JB16 JC17 KA03 KA04 NA12 NA23 PA17

Claims (2)

[Claims] 1. An epoxycyclohexylalkyl trialkoxysilane compound of the following component (A): 19 to 95% by weight; (B) a compound having two or more oxetane rings in one molecule: 1 to 40% by weight; (C) glycidoxy Alkyl trialkoxy silane 0
80% by weight (D) The cationic photopolymerization initiator was added to the above (A) + (B) +
(C) An active energy ray-curable composition comprising 0.05 to 20 parts by weight per 100 parts by weight. 2. The method according to claim 1, wherein the active energy ray-curable composition is applied to the surface of a substrate so that the applied amount is 1 to 50 μm in a cured film thickness, and then the composition is cured by irradiation with an active energy ray. A method for forming a film.