JPS5850613B2 - Photocurable resin composition - Google Patents

Description

Detailed Description of the Invention The present invention relates to a photocurable resin composition, and more specifically to a photocurable resin composition that is self-photopolymerizable and that uses a so-called built-in photopolymerizable sensitizing compound that has a photosensitizing function. The present invention relates to a resin composition.

Many studies have been conducted on photocurable resin compositions due to their rapid curing properties and solvent-free properties.
This rapid curing property is largely influenced by the photocurability of the resin composition itself as well as by the action of the photopolymerization sensitizer.

Various photopolymerization sensitizers have been proposed in the past, but most of them are low molecular weight compounds, and they do not participate in chemical reactivity such as crosslinking or polymerization with the resin forming the film.

Furthermore, these photopolymerizable sensitizers, which are added in large amounts to meet the required curing speed, remain in the coating film after curing without being consumed by short-term ultraviolet irradiation.

Therefore, in addition to the problem of precipitation from the coating film or being eluted by solvents, further problems such as deterioration of the physical properties of the coating film had to be solved.

In order to solve these problems, the present inventors have invented an invention (specifically Application No. 49148703) has been completed.

However, polyepoxy compounds are expensive and at the same time have a large molecular weight per epoxy group, which limits the density of sensitive double bonds that can be introduced, and therefore poses some difficulties in photopolymerizability.

As a result of intensive research, the present inventors obtained resins with desired OH equivalents by various combinations of polyhydric alcohols and polybasic acids, and esterified these with unsaturated fatty acids such as dialkylaminobenzoic acid and acrylic acid. The above-mentioned problems can be solved by using the photopolymerizable sensitizing compound (vAA) in combination with the photopolymerizable sensitized resin (B), which is obtained by esterifying the OH-containing resin with a carboxyl group-containing benzophenone derivative and an unsaturated fatty acid such as acrylic acid. The inventors have discovered that the problem can be solved, leading to the present invention.

That is, the present invention provides O which is obtained by esterifying dialkylaminobenzoic acid, a polybasic acid, and optionally a fatty acid having 9 or more carbon atoms, and a polyhydric alcohol by a conventional method.
A photopolymerizable sensitizing compound obtained by esterifying an unsaturated fatty acid such as acrylic acid or methacrylic acid with a resin having an H equivalent of 150 to 500, a carboxyl group-containing benzophenone derivative, a polybasic acid, and optionally a carbon number 9.
A photopolymerizable sensitizing compound B) obtained by esterifying an unsaturated fatty acid such as acrylic acid or methacrylic acid to a resin having an OH equivalent of 150 to 500 obtained by esterifying the above fatty acids and a polyhydric alcohol by a conventional method. The present invention provides a photocurable resin composition containing the following.

In the present invention, dialkylaminobenzoic acids include dialkylaminobenzoic acids having 5 or less carbon atoms, such as dimethylaminobenzoic acid, diethylaminobenzoic acid, and dipropylaminobenzoic acid, or substituted products thereof.

In this case, it is obvious that even if the dialkylaminobenzoic acid is a methyl or ethyl ester, this does not pose any problem in carrying out the present invention.

In the present invention, examples of the carboxyl group-containing benzophenol/derivative include penzoyl benzoic acid, chlorobenzoyl benzoic acid, methylbenzoyl benzoic acid, methoxybenzoyl benzoic acid, benzophenone tetracarboxydian hydride, etc. As mentioned above, may be a methyl or ethyl ester.

Examples of polybasic acids include phthalic anhydride, isophthalic acid, adipic acid, and trimellitic acid, and examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, tetramethylene glycol, trimethylolethane, and trimethylolpropane. , pentaerythritol, dipentaerythritol, and the like.

Fatty acids with 9 or more carbon atoms include lauric acid, palmitic acid, stearic acid, tung oil fatty acid, linseed oil fatty acid, etc., and each is used when flexibility of the film or compatibility with other components is required. may be introduced arbitrarily depending on the purpose.

Esterification of dialkylaminobenzoic acid, polybasic acids, polyhydric alcohols, and fatty acids having 9 or more carbon atoms used as necessary is usually carried out at a temperature of about 150 to 230°C in the presence of an acid catalyst, and the OH equivalent is 150. What is necessary is just to determine the addition amount so that it becomes a resin of ~500.

Generally, the above esterification may be carried out at the same time, but it is also possible to esterify the polybasic acid and the polyhydric alcohol first, and then add the dialkylaminobenzoic acid thereto.

The same applies to the case of carboxyl group-containing benzophenone.

The esterification reaction between the resin having an OH equivalent of 150 to 500 and the unsaturated fatty acid suppresses the thermal polymerization of the unsaturated group, and is performed at a relatively low temperature in the presence or absence of a thermal polymerization inhibitor.
The temperature is about 0 to 130°C.

Examples of unsaturated fatty acids include acrylic acid, methacrylic acid, and crotonic acid.

If a resin with an OH equivalent of 150 or less is used, there will be a problem in miscibility with other components, and if a resin with an OH equivalent of 500 or more is used, the sensitive double bond density will become small.

The photopolymerizable sensitizing compound used in the present invention becomes an essential component of the photocurable resin composition together with other photopolymerizable monomers and/or prepolymers, and is photocured at a practical speed.

However, if more rapid curing is required, other conventionally known sensitizers may be added.

Known sensitizers include benzoin, benzoin alkyl ether, decyl chloride, decyl bromide, acetophenone, benzophenone, benzyl, N-N'-
Examples include tetraalkylbenzophenone and azobisisobutyronitrile.

Although photopolymerizable monomers and/or prepolymers are essential components of the photocurable resin composition according to the present invention,
This monomer includes styrene, styrene derivatives, (
Methyl acrylate, ethyl (meth)acrylate,
Butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ethylene glycol di(meth)acrylate, 1゜3-butanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate,
Examples include pentaerythritol tri(meth)acrylate, and examples of the prepolymer include acrylic acid or methacrylic acid adducts of unsaturated polyester or epoxy compounds.

Furthermore, various additives such as colorants and fillers may be added to the photopolymerizable resin composition depending on the purpose.

The photopolymerizable sensitizing compound blade/(B) in the photopolymerizable resin composition according to the present invention preferably has a weight ratio of about 3/1 to 1/20, and both are contained in an amount of 1 to 90% by weight in the resin composition. , preferably in a range of 10 to 70% by weight.

When the photopolymerizable resin composition according to the present invention is used as a paint or printing ink, it has excellent properties such as rapid curing, physical properties of the film, and no precipitation or elution of sensitizer from the film as in the past. It has the following.

Examples are shown below.

Example "Central part" refers to parts by weight. Example 1 82.5 parts of paradimethylaminobenzoic acid, 140 parts of linseed oil fatty acid, 148 parts of phthalic anhydride, and 202 parts of trimethylolpropane in a four-bottle flask equipped with a thermometer, water separator, and gas blowing device. was reacted at 230° C. for 5 hours under a carbon dioxide gas flow to give an acid value of 5 or less, and an esterified product with a hydroxyl equivalent of 357 was obtained.

Next, 110 parts of benzene, 2.5 parts of para-toluenesulfonic acid
Add 0.5 parts of hydroquinone, heat to 80°C while blowing air, drop 97 parts of acrylic acid, and after the dropwise addition, gradually raise the temperature while being careful not to generate heat.
The temperature was maintained at ~120°C, and after incubation for 35 hours, a photopolymerizable sensitized compound 4 having an acid value of 20 was obtained.

In a reactor similar to the previous one, orthobenzoyl benzoic acid, 113 parts, linseed oil fatty acid, 140 parts,
48 parts of "phthalic anhydride", 2'0 parts of trimethylolpropane
2 parts, 97 parts of acrylic acid, 110 parts of benzene as a refluxing solvent, and 2.5 parts of para-toluenesulfonic acid as a catalyst.
A photopolymerization sensitizing compound (8) having an acid value of 12 was obtained using 0.5 parts of hydroquinone as a polymerization inhibitor.

30 parts (8) 30 parts 1,6-hexanethiol diacrylate A mixture of 40 parts rate was applied to a steel plate to a thickness of 50μ, and 2 was irradiated with a high-pressure mercury lamp from a distance of 15C1rL. Hardened.

For comparison, a mixture of 60 parts of diacrylate, 40 parts of 1,6-hexanethiol diacrylate, and 60 parts of (8), 1,6-
A mixture of 40 parts of hexanediol diacrylate was cured under the above conditions, but it took 25 seconds and 20 seconds to cure, respectively.

Example 2 In the same manner as in Example 1, 140 parts of linseed oil fatty acid, 148 parts of phthalic anhydride, 202 parts of trimethylolpropane and 159 parts of acrylic acid were reacted in the presence of para-toluenesulfonic acid and hydroquinone using benzene as a refluxing solvent. A prepolymer was obtained.

30 parts of this prepolymer, 15 parts of the polymer from Example 1, (Bl
) and 40 parts of trimethylolpropane triacrylate was applied and irradiated in the same manner as in Example 1, and cured in 5 seconds.

For comparison, a coating agent was prepared by adding 3 parts of benzoin ethyl ether as a photopolymerization sensitizer to a mixture of 60 parts of this prepolymer and 40 parts of trimethylolpropane triacrylate, and the mixture was similarly coated and irradiated. When I tried it, it hardened to 10
It took several seconds, and the physical properties of the cured coating film were poor.

Example 3 A mixture of 30 parts of [J of Example 1, 30 parts of (8), and 40 parts of the following monomers was applied and irradiated under the conditions of Example 10, and cured in the time shown in the table.

Claims (1)

[Claims] 1 OH equivalent 150 to 5 obtained by esterifying dialkylaminobenzoic acid, a polybasic acid, and optionally a fatty acid having 9 or more carbon atoms, and a polyhydric alcohol by a conventional method
Photopolymerizable sensitizing compound '1, which is made by esterifying unsaturated fatty acids such as acrylic acid or methacrylic acid to 00 resin.
Acrylic acid or A photocurable resin composition containing a photopolymerizable sensitizing compound B) obtained by esterifying an unsaturated fatty acid such as methacrylic acid.