JP2916818B2 - Photosensitive composition for sandblasting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive composition which can be screen-printed when a pattern is formed on the surface of a substrate by sandblasting and has excellent blast resistance.

[0002]

2. Description of the Related Art Conventionally, when a pattern is formed by sandblasting on the surface of glass, ceramics, or the like, a method in which a paper, a rubber plate, or the like is attached to a base material, cut out with a cutter knife or the like, and sandblasted as a sandblast protective film. Are known.

However, in this method, the protection film is usually prepared by hand, and when the design is complicated and fine, it takes a lot of time and labor to form the protection film.

[0004] Therefore, a method has been proposed in which a protective film is formed on a substrate by photographic means using a liquid or plate-shaped photosensitive resin and sandblasted, or a method in which the protective film is formed by screen printing and sandblasted. .

[0005]

However, in the former method, a liquid or plate-shaped photosensitive resin is applied directly on a substrate,
Alternatively, it is necessary to paste and expose through a film having a desired pattern, dissolve and remove the unexposed portion, which is troublesome, and the work is very difficult, especially when creating a pattern on a large base material. . In the latter case, the ink may be a solvent-dry type or a two-component reaction-curable ink such as urethane, which may cause clogging during screen printing or a film thickness sufficient for screen printing. However, since the viscosity of the ink changes due to evaporation of the solvent, uniform printing cannot be performed.

[0006]

Means for Solving the Problems The inventors of the present invention have studied to solve the above-mentioned problems. As a result, (a) a compound having a repeating structure of a pentamethylenecarbonyloxy group represented by the following general formula;

[0007]

Embedded image n = 25-100

(B) a urethane acrylate having at least two ethylenically unsaturated groups, and (c) at least one urethane acrylate having a carboxyl group in the molecule.
A photosensitive composition for sandblasting comprising a compound having two ethylenically unsaturated groups and (d) a photopolymerization initiator is excellent in photocurability, adhesion to a substrate, sandblast resistance, and blasting. It has been found that it can be easily peeled off from the substrate later.

The substrate in the present invention means glass, metal, plastic, stone, wood and the like. In addition, those in which a paint, a metal film, or the like is formed on the surface of these substrates are also included.

The photosensitive composition of the present invention is screen-printed, pattern-printed, cured by irradiation with ultraviolet rays, and adheres to a substrate to form a sandblast-resistant protective film. Since screen printing is possible, it is suitable for mass production and contains no solvent, so there is no need to worry about energy loss and environmental pollution caused by the solvent. Ultraviolet light sources, ultraviolet fluorescent lamps, carbon arc lamps, and the like are examples of the ultraviolet light source.

The photosensitive composition of the present invention has excellent adhesion and impact resistance due to a compound having a repeating structure of a pentamethylenecarbonyloxy group, and a urethane acrylate having at least two ethylenically unsaturated groups. Accordingly, the cured protective film has characteristics such as excellent flexibility, adhesion, curability, and sandblast resistance.

The compound having a repeating structure of a pentamethylenecarbonyloxy group of the present invention is a crystalline or non-crystalline thermoplastic resin obtained by ring-opening ε-caprolactone, and is a liquid or a solid. Since this compound is very crystalline, it is amorphous and has a low molecular weight (about 10,000).
0 or less).

The urethane acrylate having at least two ethylenically unsaturated groups can be produced by a conventionally known method. For example, a compound having two carboxyl groups and a compound having two hydroxyl groups are reacted to produce a polyester having a terminal hydroxyl group, which is condensed with an aliphatic diisocyanate, for example, hexamethylene diisocyanate, and having a terminal isocyanate group. A compound is obtained by reacting the compound with an ethylenically unsaturated compound having a hydroxyl group in the molecule.

Examples of the compound having a carboxyl group in the molecule and having at least one ethylenically unsaturated group include a reaction product of phthalic acid and 2-hydroxyethyl acrylate, bisacrylamide acetic acid, and the like. These are useful when stripping with water after sandblasting or a thin alkaline aqueous solution.

In the present invention, a compound having a repeating structure of a pentamethylenecarbonyloxy group, a urethane acrylate having at least two ethylenically unsaturated groups, and at least one ethylenically unsaturated group having a carboxyl group in a molecule. When the compound having a repeating structure of pentamethylenecarbonyloxy group is 1 (the same applies to the parts by weight ratio or less), the compound having at least two ethylenically unsaturated groups and composed of an aliphatic hydrocarbon The urethane acrylate is in the range of 0.5 to 3, and the compound having a carboxyl group in the molecule and having at least one ethylenically unsaturated group is in the range of 0.5 to 1. If the urethane acrylate having at least two ethylenically unsaturated groups is less than 0.5, the curability upon irradiation with ultraviolet light is reduced,
Sandblast resistance is reduced. If it exceeds 3, the viscosity becomes high and screen printing becomes difficult. When the number of compounds having a carboxyl group in the molecule and having at least one ethylenically unsaturated group is less than 0.5, the releasability after sandblasting is reduced. The film tends to be brittle.

The photopolymerization initiator used in the present invention includes anthraquinones such as 1-chloroanthraquinone and 2-ethylanthraquinone, benzoins such as benzoin, benzoin methyl ether and benzoin ethyl ether, benzophenone and N, N-diethylamino. Conventionally known compounds such as benzophenones such as benzophenone and thioxanthones such as 1-chlorothioxanthone and 2-methylthioxanthone are used alone or in combination of two or more. This amount is 0.1 to 10% based on the sum of a urethane acrylate having at least two ethylenically unsaturated groups and a compound having at least one ethylenically unsaturated group having a carboxyl group in the molecule. Used in the range. If it is less than 0.1%, the curability decreases and the sandblast resistance decreases. If it exceeds 10%, no particularly remarkable effect is observed, and the performance may be deteriorated, which is not economical.

In the present invention, a compound having at least one ethylenically unsaturated group, a filler, a leveling agent,
An antifoaming agent or the like can be added. In addition, the protective film can be easily seen by adding a pigment, a dye or the like.

The method for forming a pattern on a substrate using the photosensitive composition of the present invention is a method of directly printing on a substrate by screen printing and curing by irradiating ultraviolet rays, or a method of printing on a transfer paper or a transfer film. UV curing and transfer. Since the photosensitive composition of the present invention has flexibility and tackiness even after being irradiated with ultraviolet rays, there is no limitation on the adhesive or composition even in the transfer method.

After the sandblasting, the protective film formed on the substrate is peeled off from the substrate. The method for peeling off the protective film is simply immersion in water or a thin alkaline aqueous solution. Although the immersion time varies depending on the thickness of the protective film and the type of the base material, the immersion time is usually about 10 minutes. Naturally, peeling can be performed in a shorter time if physical force is used.

[0020]

The photosensitive composition of the present invention is excellent in adhesion to a substrate even though it can be easily peeled off with water or a thin alkaline aqueous solution, and has sufficient curability and resistance even when the protective film is thin. There is an advantage of having blast properties.

Now, the present invention will be described in further detail with reference to Examples, but it should not be construed that the invention is limited thereto.

[0022]

EXAMPLES Example 1 Polyester, hexamethylene diisocyanate and ε-
The repeating structure of urethane acrylate having at least two ethylenically unsaturated groups synthesized from caprolactone-modified 2-hydroxyethyl acrylate (trade name: SR-6138, manufactured by Daicel UCB) and a pentamethylenecarboniloxy group was 50 parts by weight. 25 parts by weight of compound (trade name: Praxel L220AL manufactured by Daicel Chemical Co., Ltd.)
Phthalic acid mono (2-hydroxyethyl acrylate) 2
5 parts by weight were mixed. 3 parts by weight of dimethylbenzyl ketal, 3 parts by weight of 2,4-dimethylthioxanthone, 3 parts by weight of isoamyl p-dimethylaminobenzoate and 0.01 part by weight of methylhydroquinone were added to the obtained product and dissolved.

The above-prepared composition was applied to a glass plate by a screen printing plate (70 mesh) made of polyester for 300 minutes.
Print a μ pattern and use an ultra-high pressure mercury lamp for 100mJ / c
m ² and ultraviolet irradiation. The film thickness after irradiation was 40 μ.
When this pattern was sandblasted with an abrasive containing 80% or more of aluminum oxide powder having a particle size range of 70 to 85 μm at a blast pressure of 4 kg / cm ² and a distance of 15 cm for 45 seconds, the glass plate was carved about 0.3 mm, and There was no peeling of the pattern.

When this glass plate was immersed in water,
The print pattern was peeled off in minutes.

Example 2 Polyester, hexamethylene diisocyanate and ε-
The repeating structure of 75 parts by weight of a urethane acrylate having at least two ethylenically unsaturated groups (trade name: SR-6138, manufactured by Daicel UCB) and a pentamethylenecarboniloxy group synthesized from caprolactone-modified 2-hydroxyethyl acrylate was used. 25 parts by weight of a compound (trade name: Praxel L220AL manufactured by Daicel Chemical Co., Ltd.)
Phthalic acid mono (2-hydroxyethyl acrylate) 2
5 parts by weight were mixed. The obtained product was heated to 50 ° C., and 4 parts by weight of dimethylbenzyl ketal, 3 parts by weight of 2,4-dimethylthioxanthone, 3 parts by weight of isoamyl p-dimethylaminobenzoate, aluminum salt of N-nitrosophenylhydroxylamine 0 0.01 part by weight was added and dissolved.

The above-prepared composition was printed on a glass plate with a screen pattern made of polyester using a screen printing plate (355 mesh) having 65 halftone dots, and 125 m with an ultrahigh pressure mercury lamp.
J / cm ² UV irradiation was performed. The film thickness after irradiation was 10 μm. When this pattern was sandblasted with an abrasive containing 80% or more of aluminum oxide powder having a particle size range of 53 μm or less at a blast pressure of 3 kg / cm ² and a distance of 30 cm for 15 seconds, the glass plate was matted and the pattern was peeled. There was no.

When this glass plate was immersed in a 0.1% aqueous sodium carbonate solution, the printed pattern was peeled off in about 5 minutes.

Example 3 Polyester, hexamethylene diisocyanate and ε-
Urethane acrylate having at least two ethylenically unsaturated groups (trade name: SR-6178, synthesized from caprolactone-modified 2-hydroxyethyl acrylate)
75 parts by weight of a compound having a repeating structure of a pentamethylenecarbonyloxy group (trade name: Praxel A1220AL, manufactured by Daicel Chemical Co., Ltd.), 75 parts by weight, 25 parts by weight of mono (2-hydroxyethyl acrylate) phthalate, 25 parts by weight of nonylphenoxy polyethylene glycol monoacrylate were mixed. To this solution, 5 parts by weight of dimethylbenzyl ketal, 5 parts by weight of 2,4-dimethylthioxanthone, 5 parts by weight of ethyl p-dimethylaminobenzoate, 0.0 part of methylhydroquinone
2 parts by weight were dissolved.

When the composition prepared above was subjected to sand blasting in the same manner as in Example 1 except that the blast pressure was changed to 4 kg / cm ² , the glass plate was carved about 0.1 mm and the pattern did not peel off. When this glass plate was immersed in a 10% aqueous solution of triethanolamine, the pattern was peeled off in about 4 minutes.

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI G03F 7/12 G03F 7/12 (56) References JP-A-60-10242 (JP, A) JP-A-55-36812 (JP) JP-A-60-104939 (JP, A) JP-A-60-140938 (JP, A) JP-A-61-21118 (JP, A) JP-A-58-32662 (JP, A) 63-162715 (JP, A) JP-A-4-145111 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03F 7/032 G03F 7/004 G03F 7/027 G03F 7 / 028

Claims (1)

(57) [Claims] (A) a compound having a repeating structure of a pentamethylenecarboniloxy group represented by the following general formula: n = 25 to 100 (b) urethane acrylate having at least two ethylenically unsaturated groups, (c) at least one having a carboxyl group in the molecule
COMPOSITION HAVING EACH ETHYLENE UNSATURATED GROUP AND (d) A SENSITIVE COMPOSITION FOR SAND BLAST CONTAINING A PHOTOPOLYMERIZATION INITIATOR