JPS5850612B2 - Photocurable resin composition - Google Patents

Description

Detailed Description of the Invention The present invention relates to a photocurable resin composition, and more particularly to a photocurable resin composition containing a so-called built-in type photopolymerizable sensitizing compound that is self-photopolymerizable and has a photosensitizing function. Regarding the 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. 148703 (1973) 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.

The present inventors conducted research in order to solve the above problems, and created a resin with a desired OH equivalent through an esterification reaction between various polyhydric alcohols, especially polyhydric alcohols having 3 or more hydroxyl groups, and polybasic acids. This was then esterified with dialkylaminobenzoic acid, a carboxyl group-containing benzophenone derivative, and an ethylenically unsaturated fatty acid to obtain a photopolymerizable sensitizing compound that satisfies both photopolymerizability and photosensitization properties.

That is, the present invention provides an OH equivalent of 150 OH obtained by esterifying dialkylaminobenzoic acid, a carboxyl group-containing benzophenone derivative, a polybasic acid, and optionally a fatty acid having 9 or more carbon atoms, and a polyhydric alcohol by a conventional method.
The present invention provides a photocurable resin composition containing a photopolymerizable sensitizing compound obtained by esterifying an ethylenically unsaturated fatty acid such as acrylic acid or methacrylic acid in a resin of No. 500 to 500.

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 carboxyl group-containing benzophenone derivatives include benzoyl benzoic acid, chlorbenzoyl benzoic acid, methylbenzoyl benzoic acid, methoxybenzoyl benzoic acid, penzophenone tetralupoxydianno hydride, and the like. As mentioned above, these may be methyl or ethyl esters.

Polybasic acids include phthalic anhydride, isophthalic acid, adipic acid, trimellitic acid, etc., and polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, tetramethylene glycol, trimethylolethane, and trimethylol. Propane, pentaerythritol, dipentaerythritol, etc. can be mentioned.

Fatty acids with 9 or more carbon atoms include lauric acid, palmitic acid, stearic acid, tung oil fatty acid, and linseed oil fatty acid. It can be introduced arbitrarily depending on the purpose.

Esterification of dialkylaminobenzoic acid, carboxyl group-containing benzophenone derivatives, polybasic acids, polyhydric alcohols, and optional fatty acids having 9 or more carbon atoms is usually carried out at a temperature of about 150 to 230'C in the presence of an acid catalyst. The addition amount may be determined so that the resin has an OH equivalent of 150 to 500.

Generally, the above esterification may be carried out all at once, but it is also acceptable to first esterify the polyhydric acid and polyhydric alcohol, and then add dialkylaminobenzoic acid and a carboxyl group-containing benzophenone derivative. do not have.

The esterification reaction of the above-mentioned resin with an OH equivalent of 150 to 500 and an 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.
It is carried out at a temperature of 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, tenruchloride, decyl bromide, acetophenone, benzophenone, benzyl, N-N'-
Examples include tetraalkylaminobenzophenone 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 can be added to the photopolymerizable resin composition as necessary.

In the present invention, the photopolymerizable sensitizing compound is 1 to 90% by weight, preferably 10 to 70% by weight in the photopolymerizable resin composition.
It is.

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 In a four-eye flask equipped with a thermometer, a water separator, a gas blower, and a stirrer, 41 parts of paradimethylaminobenzoic acid, 56 parts of orthobenzoylbenzoic acid, 280 parts of soybean oil fatty acid, and phthalic anhydride were added. 74 parts of pentaerythritol and 136 parts of pentaerythritol were reacted for 5 hours at 230°C under a stream of carbon dioxide gas to give an acid value of 5 or less and a resin with an OH equivalent of about 300. Add 0.0 part of hydroquinone and 0.5 part of hydroquinone, heat to 80°C while blowing air, drop 97 parts of acrylic acid, and gradually raise the temperature while paying attention to sudden heat generation after the dropwise addition.
After reaction for 35 hours while maintaining the temperature at 110 to 120°C, benzene was distilled off to obtain a photopolymerizable sensitizing compound 'tXA) having an acid value of 15.

A mixture of 60 parts of this (A) and 40 parts of ethylene glycol diacrylate was applied to a steel plate to a thickness of 50μ, and 2K
When irradiated with a W high-pressure mercury lamp from a distance of 15 cIIL, it cured in 2 seconds and a strong film was formed.

Example 2 In Example 1, 41 parts of para-diethylaminobenzoic acid was replaced with 48 parts of para-diethylaminobenzoic acid to obtain a photopolymerizable sensitizing compound (4MB), which was tested in the same manner. A film was formed.

Example 3 In the same manner as in Example 1, a prepolymer was obtained by esterification using 140 parts of linseed oil fatty acid, 148 parts of phthalic anhydride, 202 parts of trimethylolpropane, and 129 parts of acrylic acid.

The curing speed of a mixture of 30 parts of this prepolymer, 30 parts of (A) from Example 1, and 40 parts of trimethylolpropane triacrylate under the same conditions as in Example 1 was 5 seconds.

Comparative Example 1 In Example 3, for a mixture of 60 parts of prepolymer, 4 o parts of trimethylolpropane triacrylate, and 3 parts of benzoin ethyl ether, the curing speed under the same conditions as in Example 1 was 10 seconds, The physical properties of the cured coating are poor.

Comparative Example 2 82.5 parts of paradimethylaminobenzoic acid, 140 parts of linseed oil fatty acid, 148 parts of phthalic anhydride, and 202 parts of trimethylolpropane were added in a four-eye flask equipped with a thermometer, a water separator, and a gas blowing device. Under carbon dioxide gas flow, 230°
C for 5 hours to reduce the acid value to 5 or less, and the hydroxyl equivalent to 357.
Obtain the esterified product of.

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.
After reaction for 35 hours while maintaining the temperature at ~120°C, a photopolymerizable sensitizing compound q having an acid value of 20 was obtained.

For a mixture of 30 parts of the prepolymer in Example 3, 30 parts of the above (030 parts), and 40 parts of trimethylolpropane triacrylate, the curing rate under the same conditions as in Example 1 was approximately 2
It was 5 seconds.

Comparative Example 3 In a reactor similar to Comparative Example 2, orthobenzoyl benzoic acid, 113 parts, linseed oil fatty acid, 140 parts, phthalic anhydride, 148 parts, trimethylolpropane, 20 parts
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 having an acid value of 12 was obtained using 0.5 parts of hydroquinone as a polymerization inhibitor.

30 parts of the prepolymer in Example 3, 30 parts of the above-mentioned song,
The cure rate under conditions similar to Example 1 for a mixture of 40 parts of trimethylolpropane triacrylate was approximately 20 parts.
It was a nickname.

Example 4 A mixture of 30 parts of the photopolymerizable sensitizing compound A) in Example 1, 30 parts of the Flepolymer in Example 3, and 40 parts of the monomer in Table 1 was applied under the same conditions as in Example 1, and the curing time was irradiated with ultraviolet rays. It was as shown in Table 1.

Claims (1)

[Claims] 1 To a resin having an OH equivalent of 150 to 500 obtained by esterifying dialkylaminobenzoic acid, a carboxyl group-containing benzophenone derivative, a polybasic acid, and optionally a fatty acid having 9 or more carbon atoms, and a polyhydric alcohol by a conventional method, A photocurable resin composition containing a photopolymerizable sensitizing compound obtained by esterifying an ethylenically unsaturated fatty acid such as acrylic acid or methacrylic acid.