JPH0515709B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel etherified product of N-methylolacrylamide and a photocurable resin composition containing this etherified product as a monomer component.
The resin composition of the present invention has particularly excellent suitability as a photosensitive resin plate-making material capable of water phenomenon or as an ink for printed wiring boards.

[Prior Art] In general, photocurable and water-soluble neutral liquid monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxy-3-propyl (meth)acrylate, and triethylene glycol. Known examples include methyl ether (meth)acrylate, methoxymethyl acrylamide, ethoxyethylacrylamide, dimethyl acrylamide, acryloylmorpholine, and vinylpyrrolidone.

[Problems to be solved by the invention] Conventional photocurable, water-soluble neutral liquid monomers have (a) high vapor pressure and are easily volatilized during photocuring;
(b) The photocuring speed is slow; (c) The photocured polymer becomes sticky or instantly dissolves, foams, or collapses when it comes into contact with water.
Monomers that do not have these drawbacks are hitherto unknown.

The present invention provides a novel photocurable monomer that does not have the above-mentioned drawbacks, and a photocurable resin composition containing this monomer as a main component.

[Means for solving the problems] The photocurable monomer according to the present invention has the following []
The photocurable resin composition according to the present invention is formed by disposing a photopolymerization initiator in a monomer represented by the following formula [ ].

The monomer [ ] of the present invention is acrylamide N
- It can be easily prepared by ether-type condensation of a methylol compound and tetrahydrofurfuryl alcohol.

For example, N-methylolated acrylamide and tetrahydrofurfuryl alcohol are reacted in the presence of an acid catalyst in an azeotropic solvent such as benzene or toluene at a temperature of 80 to 120°C to perform dehydration and etherification, resulting in a reaction product. After neutralizing the product, the catalyst and the like are removed by washing with water, and then the target monomer [] can be obtained by removing the solvent by means such as vacuum distillation or azeotropic distillation.

The monomer of the present invention [] is colorless, odorless, low viscosity,
Low volatility liquid, water, acetone, ethyl acetate,
Soluble in toluene etc. In addition, when a photopolymerization initiator is mixed with this and applied to the surface of glass, copper-clad laminates, iron plates, etc. and photocured, it cures quickly, has good adhesion to the surface to be coated, and has a high hardness. Forms a highly tough coating film. This coating film remains unchanged even after being immersed in running water for about 3 minutes, and does not become sticky due to moisture absorption.

By the way, photocurable coatings made of triethylene glycol methyl ether (meth)acrylate, acryloylmorpholine, vinyl pyrrolidone, etc., which are low volatility and water soluble, are easily sensitive to moisture, and when immersed in running water, they immediately dissolve and become sticky. This leads to the following.

In addition, since the monomer [] is compatible with known water-soluble monomers such as 2-hydroxyethyl (meth)acrylate and triethylene glycol methyl ether (meth)acrylate, it can be photopolymerized after being appropriately mixed with these monomers. Dissolve the initiator and photo-cure it, or add a radical initiator such as benzoyl peroxide or azobisisobutyronitrile, and add water, acetone, methyl ethyl ketone, or
By dissolving it in a solvent such as vinyl acetate or toluene and thermally polymerizing it, it is possible to obtain moisture-sensitive polymers, water-soluble polymers, and polymers with varying hardness.

The photocurable resin composition according to the present invention contains a photopolymerization initiator in addition to the above monomer [I]. Examples of photopolymerization initiators include benzoin, benzoin ethyl ether, benzyl, benzophenone, benzyl dimethyl ketal, hydroxycyclohexyl phenyl ketone, diethoxyacetophenone,
2-hydroxy-2-methylpropiophenone,
Michler's ketone, chlorothioxanthone, benzoylbenzyltrimethylammonium chloride, etc. can be used. These photopolymerization initiators are used in combination with a sensitizer such as dibutylamine, triethylamine, diethylaminoethyl methacrylate, etc., if necessary, and are blended into the composition in a range of 0.01 to 10% by weight.

The photocurable resin composition of the present invention is basically composed of the above monomer [] and a photopolymerization initiator, but a prepolymer of the monomer [] is blended into this composition. be able to. Furthermore, other types of monomers can be added as a third component to the resin composition of the present invention, preferably in an amount not exceeding 50% by weight. In this case, the monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxy-3-propyl (meth)acrylate, (meth)
Acrylic acid, (meth)acrylamide, triethylene glycol monomethyl ether (meth)acrylate, diethylene glycol monoethyl ether (meth)acrylate, dimethylaminoethyl (meth)acrylate, methoxymethylacrylamide, ethoxyethylacrylamide, (meth)acrylamidopropyltrimethylammonium Included are chloride, tert-butylacrylamide sulfonic acid, sodium styrene sulfonate, dimethylacrylamide, acryloylmorpholine, vinylpyrrolidone, vinyl acetate, and the like.

Furthermore, in the photocurable resin composition of the present invention, polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl Various synthetic resins such as cellulose, methylcellulose, sodium polyacrylate, polyethylene oxide, and polyacrylamide, as well as starch, etc. can be mixed, and like normal photocurable resin compositions, pigments, stabilizers, and antioxidants can be mixed. Agents, surfactants, wetting agents, viscosity modifiers, etc. can be mixed as necessary.

When applying the photocurable resin composition of the present invention to an object, any coating method such as a roll coater, brush coating, screen printing, etc. can be adopted, and water, methyl ethyl ketone, ethyl acetate, toluene, etc. If diluted with water, spray painting can also be used. However, because the resin composition of the present invention has a low viscosity even without a solvent due to its composition,
It can be applied directly without the aid of solvents, and in this case there is of course no need for preliminary drying before photocuring. The resin composition of the present invention adheres well to glass, copper-clad laminates, steel plates, etc., and has high hardness when cured, so it can be used as a photosensitive resin plate-making material or resist ink for printed wiring boards, etc. It is suitable as a photocurable resin in the field.

[Example] Example 1 (Monomer synthesis) A solution containing 204 g of tetrahydrofurfuryl alcohol, 284 g of toluene, 100 mg of hydroquinone monomethyl ether, and 2.4 g of maleic anhydride was heated and stirred, and 242 g of N-methylolacrylamide was added while blowing air. A 60% aqueous solution containing the solution was dropwise azeotropically dehydrated over a period of 2 hours, and reflux heating was continued until the dehydration was completed. The final reaction temperature at a reaction time of 6 hours is
It was 102℃. The amount of dehydrated water was 203g, which contained 3% formaldehyde. This corresponds to the theoretical amount of ether dehydration.

Next, when a caustic soda aqueous solution containing 20% of Glauber's salt was added and neutralized at 60°C, the mixture was separated into an upper layer mainly consisting of toluene, a middle layer containing the product, and a lower layer consisting of an alkali aqueous solution, and the middle layer was separated. 150 g of methyl ethyl ketone was added to this middle layer, washed with 20% sodium sulfate water, unreacted tetrahydrofurfuryl alcohol and N-methylolacrylamide were removed, toluene, methyl ethyl ketone, and water contained in the oil were distilled off under reduced pressure, and the remaining oil was removed. By filtering, 352 g of tetrahydrofurfuroxymethyl acrylamide was obtained. This product had a viscosity of 280 cps and was soluble in toluene, ethyl acetate, and water. Further, the results of elemental analysis and IR analysis of this product were as follows.

(a) Elemental analysis C H O N Measured value 57.6% 7.9% 26.5% 8.0% Theoretical value 58.4% 8.1% 25.9% 7.6% (b) IR analysis (liquid film on KBr) 3420cm ^-1 N-H stretching of acid amide Vibration 1670cm ^-1 C=0 stretching vibration of acid amide 1640cm ^-1 vinyl group CH ₂ =CH- stretching vibration 1540cm ^-1 N-H bending vibration of -1 acid amide 1400cm ^-1 vinyl group CH ₂ =CH- in-plane bending Vibration 1085 cm ^-1 Ether C-0-C stretching vibration Example 2 (monomer synthesis) A solution containing 153 g of tetrahydrofurfuryl alcohol, 213 g of toluene, 80 mg of hydroquinone monomethyl ether, and 2 g of oxalic acid contains 167 g of N-methylolacrylamide 75 Add % aqueous solution,
Azeotropically dehydrated by heating and stirring while blowing air,
Reflux heating was carried out until the dehydration was completed. reaction time
The final reaction temperature was 98°C for 5.5 hours. The amount of dehydrated water was 83.5g and contained 2.5% formaldehyde. This corresponds to 97.5% of the theoretical amount of ether dehydration.

Next, a post-treatment according to Example 1 was carried out to obtain tetrahydrofurfuroxymethylacrylamide.
Obtained 255g. The viscosity of this stuff is 230cps,
The results of elemental analysis and IR analysis were as follows.

(b) Elemental analysis C H O N Measured value 57.2% 7.8% 26.9% 8.1% (b) IR analysis (liquid film on KBr) The absorption pattern was the same as in Example 1.

Example 3 Dissolve 2% of the photopolymerization initiator benzophenone in the tetrahydrofurfuroxymethylacrylamide obtained in Example 1, apply this to a thickness of 30μ on a glass plate, and place it 15cm under an 80W/cm UV lamp. Place it on a belt conveyor that runs at a speed of 4 meters per minute.
After one exposure, the coated surface immediately lost its fluidity and tackiness, and after a total of four exposures, a smooth coating film with a pencil hardness of 3H was obtained. This coating did not peel off in a cross-cut adhesive tape peel test, did not change when immersed in toluene, and did not change even when immersed in running water for 3 minutes. However, the unexposed areas of the coating instantly dissolved in water and flowed out.

Example 4 2% of the photopolymerization initiator diethoxyacetophenone was dissolved in tetrahydrofurfuroxymethylacrylamide, and this was applied to a thickness of 30μ on an iron plate.
When exposed in the same manner as in Example 1, the coated surface lost its tackiness after two exposures, and the pencil hardness decreased after a total of five exposures.
A smooth coating film of 3H was obtained. This coating did not peel off in a cross-cut adhesive tape peel test, did not change when immersed in toluene, and did not change even when immersed in running water for 3 minutes.

Comparative Example 1 2% bensophenone was dissolved in water-soluble triethylene glycol methyl ether acrylate, and this was applied to a glass plate to a thickness of 30μ, Example 4
Similarly, this was exposed five times. The resulting coating film has a pencil hardness of B or less, remains sticky, and has a hardness of 30% when exposed to running water.
When it was soaked for a second, it softened and some of it dissolved.

Comparative Example 2 Dissolve 2% bensophenone in water-soluble acryloylmorpholine and spread it on a glass plate to a thickness of 30 μm.
As in Example 4, this was exposed five times. The resulting paint film had a pencil hardness of 3H and adhered well to the glass plate, but when immersed in running water for 30 seconds, the paint film partially dissolved and foamed.

Claims (1)

[Claims] 1. Tetrahydrofurfuroxymethylacrylamide represented by the following formula []. 2 Tetrahydrofurfuroxymethylacrylamide represented by the following formula [] and a photocurable resin composition containing a photopolymerization initiator.