JPS5947246A - Photo-curable composition - Google Patents

Abstract

PURPOSE:To provide a photo-curable compsn. which gives a photo-cured film having excellent resistance to soldering heat, electrical insulating properties, etc. as well as excellent adhesion to copper and solder, containing a specific unsaturated polymer having phenyl groups and (meth)acryloyl groups on its side chain, a photopolymerizable monomer and a photopolymerization initiator as main components. CONSTITUTION:A photo-curable compsn. is formed by using an unsaturated polymer, a photopolymerizable monomer and a photopolymerization initiator as main components. The unsaturated polymer in the compsn. is an addition copolymer obtd. from an unsaturated monomer having phenyl groups and other unsaturated monomer or its modified copolymer, and has (meth)acryloyl groups and phenyl groups on its side chain in such a proportion as to give 500-30,000g of the unsaturated polymer weight per gram equivalent of (meth)acryloyl group and 150-305g of the unsaturated polymer weight per gram equivalent of phenyl group.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention comprises a specific unsaturated polymer having a phenyl group and a (meth)acryloyl group in its side chain, a photo(1) polymerizable monomer, and a photopolymerization initiator as main components. It concerns the photocurable composition that is blended.

The photocurable composition of the present invention can be printed on the surface of metal or synthetic resin moldings as printing ink, paint, or clear varnish (phenol that serves as a surface protective coating).

It can be applied or coated and photocured.

In particular, the photocurable composition of the present invention can be overcoated onto the surface of a rigid printed wiring (circuit) board, a flexible printed wiring (circuit) board, an integrated circuit chip carrier tape, etc. and photocured.

It has excellent adhesion to metals such as copper and solder, synthetic resins, etc., and can form a photocured film with excellent solder heat resistance that does not cause unevenness or blistering when immersed in a high-temperature solder bath. Furthermore, the photocuring process of this photocurable composition is as follows:
It has a high level of hardness, bending resistance, chemical resistance, water resistance, etc., and has excellent electrical insulation properties, so it can be used for electrical parts.

Conventionally, heat-resistant photocurable 2 varnish for electrical parts has been used.
Those described in Japanese Patent Laid-Open No. 6688, Japanese Patent Application Laid-Open No. 1983-145'i'l'7, etc. are known.

These have disadvantages such as unsatisfactory solder heat resistance in a solder bath, strong odor that adversely affects the working environment, and poor adhesion to copper and solder.

The inventors have developed heat resistance, chemical resistance, water resistance,
As a result of extensive research into photocurable compositions that can form flexible photocured films that have excellent electrical insulation properties and adhesion to copper, nada, and synthetic resins, we have found that phenyl groups and In a photocurable composition containing as main components an unsaturated polymer having a (meth)acryloyl group in its side chain, a photopolymerizable monomer, and a photopolymerization initiator, the phenyl group of the unsaturated polymer and the (meth) The present invention was completed based on the discovery that the above object can be achieved depending on the content of acryloyl groups.

That is, the present invention relates to a photocurable composition containing an unsaturated polymer, a photopolymerizable monomer, and a photopolymerization initiator as main components.

The unsaturated polymer is a modified product of a copolymer obtained from an unsaturated monomer having a phenyl group and the unsaturated monomer.

Moreover, the unsaturated polymer has a (meth)acryloyl group and a phenyl group in the side chain.

The ratio is such that the weight of the unsaturated polymer per gram equivalent of the C meth)acryloyl group is 500 to 30,000 grams, and the weight of the unsaturated polymer per gram equivalent of the phenyl group is 150 to 305 grams. The present invention relates to a photocurable composition characterized in that the proportion is such that the amount is in grams.

The photocurable film of the photocurable composition of this invention is made of copper or...
In addition to exhibiting excellent adhesion to the surface of conductors, it is also suitable for glass/epoxy resin plates used in electrical circuit boards, phenolic resin/paper laminates, as well as polyester, polyimide,
It also exhibits excellent adhesion to the surface of synthetic resins such as polyamide. In addition, the photocured film of the photocurable composition (4) of the present invention, which is photocured on a solder-covered surface, does not change in appearance, such as blisters and wrinkles, even when immersed in a molten high-temperature solder bath. It exhibits excellent adhesion and has excellent heat resistance.

Furthermore, the photocurable film of this photocurable composition has excellent water resistance at high temperatures and chemical resistance against chemicals such as organic solvents (e.g., trichlene, dichloroethane, etc.) that have high solubility. Excellent, highly flexible,
The volume resistance may be at least 1.0 x 1013Ω.
It has excellent electrical insulation properties.

It was a long time ago. Furthermore, since the photocurable composition of the present invention does not contain any compound having a peculiar odor, it does not generate any bad odor that would deteriorate the working environment during coating and photocuring processes.

The unsaturated polymer used in this invention is an addition copolymer obtained from an unsaturated monomer having a phenyl group and another unsaturated monomer, or a modified product of the copolymer, and The unsaturated polymer (5) has a (meth)acryloyl group and a phenyl group in the side chain.

In this invention, it is important that the unsaturated polymer, which is the main component, has a (meth)acryloyl group and a phenyl group simultaneously in the side chain in a specific ratio.
The acryloyl group mainly provides adhesiveness and chemical resistance to the photocured film of the photocurable composition of the present invention.
-4, the above-mentioned phenyl group mainly provides heat resistance and adhesiveness to the above-mentioned photocured film.

The unsaturated polymer has one unsaturated monomer having, for example, a phenyl group and at least two (meth)acryloyl groups.
In the presence of a polymerization initiator in an organic polar solvent, can be obtained by a direct copolymerization method in which addition copolymers having (meth)acryloyl groups and phenyl groups are directly produced by copolymerizing at a polymerization temperature of about 5 to 150°C, especially 20 to 120°C. , or (6) the unsaturated monomers having an enyl group and the unsaturated monomers having one reactive functional group (10 unsaturated monomers) are polymerized in an organic polar solvent. C2 in the presence of an agent, about 5 to 1
50+C, especially at a polymerization temperature of 20-120°C (7) to form an addition copolymer having a reactive functional group and a phenyl group. 1 in the presence of a reaction catalyst, about 30 to 200°C, especially 50°C.
--A compound capable of introducing a (meth)acryloyl group at a reaction temperature of 120 °C (e.g., acrylic acid,
methacrylic acid, 2-hydroxyalkyl acrylate, etc.) to produce a modified product obtained by modifying the addition copolymer.

Examples of the unsaturated monomer having a phenyl group used in the production of the unsaturated copolymer include 2, for example, styrene,
Styrenic derivatives such as p-chlorostyrene, p-methylstyrene, p-inglobylstyrene, 2,5-dimethoxystyrene, m-methylstyrene, α-methylstyrene, benzyl (7) (meth)acrylate, phenoxyethyl ( meth]acrylate, phenoxyargyl(meth)acrylate-l-compounds such as 3-phenoxy-2-hydroxypropyl acrylate, N-phenylmaleimide, N(p-
Preferred examples include N-phenylmaleimides such as hydroxyphenyl]maleimide.

At least two (meth)acryloyl groups used in the method for producing an unsaturated copolymer by direct copolymerization
Examples of unsaturated monomers having two monomers include glycols such as triethylene glycol, tetraethylene glycol, polyethylene glycol, tripropylene glycol and polypropylene glycol
Mention may also be made of di(meth)acrylate compounds of diol compounds such as meth)acrylate and 1,6-hexanediol, 1,5-pentanediol.

In the production of unsaturated copolymers by the direct copolymerization method, the ratio of the unsaturated monomer having a phenyl group to the unsaturated monomer having at least two (meth)(8) acryloyl groups should be The ratio of the (meth)acrylate monomer to the monomer is preferably 0.1 to 10 mol, particularly 0.5 to 8 mol. In the production of the unsaturated copolymer, if the acrylate monomer exceeds 10 molar proportion to the total monomers, the copolymerization reaction may occur.

This is not suitable because crosslinking reactions tend to occur and the copolymer gels.

The unsaturated monomer having a reactive functional group used in the method of producing an unsaturated copolymer by a modification method is 1
For example, glycidyl compounds such as glycidyl (meth)acrylate and allyl glycidyl ether, hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxyethyl (meth)propyl acrylate, and (meth)acrylic acid. Examples include unsaturated carboxylic acids, maleic anhydride, and the like.

The unsaturated (9) polymer used in the photocurable composition of the present invention is prepared in the above-mentioned production method by combining an unsaturated monomer having a phenyl group and an unsaturated monomer having at least two (meth)acryloyl groups. a monomer or an unsaturated monomer having both a vinyl group and a (meth)acryloyl group, and a third
as an unsaturated monomer.

It may also be a copolymer using an ethylene monomer 2, such as methyl (meth)acrylate, butyl (meth)acrylate, acrylonitrile, etc., or an unsaturated monomer having a phenyl group. A copolymer obtained by modifying a copolymer using an unsaturated monomer having one reactive functional group and an ethylene monomer as described above as a third unsaturated monomer. It may also be a modified product.

Examples of the organic solvent for polymerization used in the production of the unsaturated copolymer include tetrahydrofuran, benzene, toluene, dioxane, dimethylformamide, and dimethylacetamide.

Further, as the polymerization initiator used in the production of the unsaturated copolymer, it is possible to produce a copolymer by adding (10) the above-mentioned unsaturated monomer.

Any type of polymerization initiator known in the art may be used.2 For example, organic peroxides such as benzoyl peroxide, lauroyl peroxide, dicumyl peroxide, and the like.

Azo compounds such as azobisisobutyronitrile, methyl azobisisobutyrate, )IJ phenylazobenzene, n-
Examples include polymerization initiators such as organic alkali metal compounds such as butyl lithium, sodium naphthalene, and strium methoxy.

In the method of producing an unsaturated copolymer by a modification method, a copolymer having two reactive functional groups and a phenyl group,
A modified product is produced by reacting with a reactive compound capable of introducing a (meth)acryloyl group, and the reactive compound capable of introducing the (meth)acryloyl group into a copolymer includes: When the reactive functional group of the copolymer is a grindyl group, 1, for example, (meth)acrylic acid, an acidic phosphoric acid ester having a (meth)acryloyl group, etc. are preferable, and 2, the reactive functional group is hydroxyl, etc. When the reactive functional group is a carboxyl group, acrylic acid chloride, methacrylic acid chloride, (meth)acrylic acid, etc. are light and heavy, and when the reactive functional group is a carboxyl group, glycidyl (meth)azilylate, etc. are light and heavy.
When the reactive functional group is an acid anhydride group, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate-1, etc. are preferable.

As the reaction solvent in the above-mentioned modification reaction of the addition copolymer, the same organic polar solvent as used in the above-mentioned addition copolymerization can be used.

As a catalyst for the reaction, an esterifying agent such as a quaternary ammonium salt or a tertiary amine can be used.

Also, in the modification reaction of the aforementioned addition copolymer.

hydroquinone, hydroquinone monomethyl ether,
A polymerization inhibitor such as 2.5-t-butyl-p-cresol can also be used.

Furthermore, in the modification reaction of the addition copolymer, it is necessary to use a reactive compound capable of introducing a (meth)acryloyl group into the copolymer in a very large excess because the modification reaction described in section 2 is slow. can be.

For example, the amount used is preferably 2 to 20 times the amount required to modify all the reactive functional groups of the copolymer.

The unsaturated polymer used in this invention has a proportion such that the weight of the unsaturated polymer per gram of (meth)acryloyl group in its side chain is 500 to 30,000 grams, preferably 600 to 20,000 grams. Moreover, the ratio must be such that the weight of the unsaturated polymer per gram equivalent of phenyl group in the side chain is 150 to 305 grams, preferably 155 to 300 grams.

The weight of the unsaturated polymer per gram equivalent of the (meth)acryloyl group type or phenyl group in the side chain of the unsaturated polymer is generally the weight of the unsaturated polymer per gram equivalent of the (meth)acryloyl group type or phenyl group in the side chain of the unsaturated polymer. When an unsaturated polymer has an average of N (meth)acryloyl groups or phenyl groups (13), which is called phenyl group equivalent and has a weight average molecular weight of The (meth)acryloyl group type or phenyl group equivalent is calculated using the formula p = MW/N (grams).

In this invention, the unsaturated polymer has a (meth)acryloyl group equivalent weight of less than 500 grams.

The photocured film of the photocurable composition obtained by blending such an unsaturated polymer has poor adhesion to metal surfaces such as copper and solder, and also has poor chemical resistance. On the other hand, if the unsaturated polymer has a (meth)acryloyl group equivalent of more than 30,000 grams, the photocurable film of the photocurable composition obtained by blending such an unsaturated polymer will be It is not suitable because it has low chemical resistance to solvents (eg, halogenated hydrocarbons, etc.).

In this invention, the unsaturated polymer has a phenyl group equivalent weight of more than 305 grams.

A photocured film of a photocurable composition obtained by blending such an unsaturated polymer has poor adhesion to metal surfaces such as copper and solder, which is not suitable.

(14) If the amount of phenyl group is less than 150 grams, the compatibility with the photopolymerizable intermediate of 111L may decrease when preparing a photocurable composition, or such immiscibility may decrease by 1 inch. When a photocurable composition containing a saturated polymer is coated on steel and photocured, the appearance of the photocured film as determined by the boiling water resistance test'! , or the adhesion will deteriorate, so it is not appropriate.

The unsaturated polymer used in this invention has a weight average molecular weight of 5X103 to 1X10', particularly light and heavy, 1
It is preferable that it is about Xl0' to 5X105. If the average molecular weight per weight of the unsaturated polymer is too small, the photocured film of the photocurable composition containing such an unsaturated polymer will lack flexibility, so it is not preferred. If the weight average molecular weight becomes too large, the photocurable composition containing such an unsaturated copolymer will have an extremely high viscosity, which will impede coating and photocuring operations, which is not preferable.

The photocurable composition of the present invention is a composition containing the aforementioned unsaturated polymer, photopolymerizable monomer, and photopolymerization initiator as components.

The photopolymerizable monomer may be any compound that has a photopolymerizable unsaturated bond and is compatible with the unsaturated polymer. .

Examples of photopolymerizable monomers include fenoquine ethyl acrylate, 3-phenoxy-2-hydroxyglobyl acrylate-1., 2-hydroxypropyl (meth)
Mono(meth)acrylates such as acrylate, 2-hydroxyethyl(meth)acrylate, 2-ethylhegicyl(meth)acrylate, lauryl(meth)acrylate, and cyclohexyl(meth)acrylate!・Di(meth)acrylates of oligoesters of aromatic dicarboxylic acids and glycols or dihydroxy hydrocarbons, diacrylates of bisphenol-type epoxy resins, as described in the specification of Japanese Patent Application No. 54-44297; Di(meth)acrylates such as tetraethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate), and 1,6-hexanethiol di(meth)acrylate; Polyvalent (meth)acrylates such as methylolpropane tri(meth)acrylate and pentaerythritol tri(meth)acrylate.

Examples include acidic phosphoric acid esters having a (meth)acryloyl group.

In this invention, when the unsaturated copolymer has a large phenyl group equivalent, it is preferable to use a (meth)acrylate compound having a phenyl group as the photopolymerizable monomer.

In this invention, the blending ratio of the photopolymerizable monomer is 30 to 800 parts by weight per 100 parts by weight of the unsaturated polymer;
Particularly preferably, the ratio is such that 50 to 700 parts by weight of the photopolymerizable monomer is obtained.

Said photoinitiator may be any type of known photoinitiator conventionally used in photocurable compositions, in particular one such as benzoin, benzoin methyl ether, benzoin ethyl nitride (17 ) benzoins such as chil, penzoin isoglobyl ether, benzoin butyl ether, and α-methylbenzoin, benzophenone, dimethoxyphenylacetophenone, 4. ．． Benzophenones such as 4'-bis(dimethylamino)benzophenone.

Thioxanthone or its derivatives (e.g. 2-chlorothioxanthone, methylthioxanthone) and N,N-dimethylane! - Mixtures in combination with amine compounds such as methyl ranilate, ethyldimethylaminebenzoic acid, and dimethylaminoethanol can be used.

In this invention, the blending ratio of the photopolymerization initiator is 0.25 to 25 parts by weight, preferably 0.5 to 20 parts by weight of the photopolymerization initiator per 100 parts by weight of the unsaturated polymer. It is preferable that the ratio is such that

In addition to the above-mentioned unsaturated polymer, photopolymerizable monomer, and photopolymerization initiator, the photocurable composition of the present invention also includes fillers, additives, etc., which are blended into conventionally known photocurable compositions. may be blended in small amounts.

(18) The photocurable composition of this invention includes, as a thermal polymerization stabilizer,
Hydroquinone, 2,5-di-t-butyl para-cresol, hydroquinone monomethyl ether, etc. are used in a proportion of 5% by weight or less, particularly preferably 3% by weight or less based on the total photocurable composition. It is preferable.

The photocurable composition of the present invention may contain a small amount of an organic solvent such as benzene, tetrahydrofuran, xylene, or acetone as a viscosity modifier, as well as a modifier, a coupling agent, and silicone oil.

Inorganic pigments such as waxes, silicic anhydride, talc, and mica, and organic pigments such as phthalocyanine green may be blended.

Examples and comparative examples are shown below.

In the Examples and Comparative Examples, the substrate on which the photocured film of the photocurable composition is formed is an electrolytic copper foil for printed circuit boards (manufactured by Fukuda Metal Foil and Powder Industries Co., Ltd.), or a substrate whose entire surface is coated with solder in advance. A glass/epoxy resin copper-clad laminate was used.

In Examples and Comparative Examples, the photocuring speed of the photocurable composition was determined by coating the photocurable composition on the surface of the copper or solder layer of the above-mentioned substrate with a bar coater to a thickness of about 20 to 30μ. The coated substrate is cut into 2 pieces with a length of 25 cm.
KW High pressure mercury lamp (manufactured by Iwasaki Electric Co., Ltd., U B
The photocurable composition was placed on the belt of an ultraviolet irradiator equipped with a belt that moves horizontally under the vertical position of an O31-L A, -1 type mercury lamp, and the belt was run at a speed of 6 m/min. It is expressed as the number of times of light irradiation necessary for the paint film to be photocured until no tank or cloudiness occurs on the surface of the paint film by irradiating the paint film with light and repeating the light irradiation several times. .

The flexibility, adhesion, pencil hardness, powder heat resistance, and chemical resistance of the photocured film were measured using a substrate coated with the photocurable composition in the same way as when measuring the photocuring speed. Then, the substrate was placed on the belt of an ultraviolet irradiator, and while the belt was moving at a speed of 6 m/min, the coating film was irradiated with light six times, and the resulting photocured film was measured.

The flexibility was measured using the method specified in JIS-5400 on the photocured film that was photocured on the copper foil substrate. Flexibility is shown by the diameter of the bar used in the above test method, but for bars with a minimum diameter of 2 mm, there is no abnormality.

Furthermore, the copper foil having the photocured film was folded back to 180°, and the bent surface was also observed, and the diameter when there was no abnormality was indicated as 0 Ifi.

The adhesive properties described above are applied to a photocured film that is photocured on the surface of each substrate having a copper foil and a solder layer.

Linear cuts were made at intervals of 2 squares in each direction to form 100 goblets, and adhesive tape [5chotch (registered trademark) manufactured by Minnesota Mining and Manufacturing Co., transparent tapeNα] was prepared.
610 (manufactured by Hightach)] was applied to the grids, and then the tape was peeled off, and the average number of grids remaining on the substrate was shown.

The pencil hardness of the photocured film was determined to be 5400-6 in JIS- using the photocured film photocured on the copper foil substrate.
．． Measurements were made in accordance with the regulations of 14.

Solder heat resistance is determined by applying a photocured film that has a copper foil or solder layer (21) by photocuring it on a substrate in a melting bath at 270°C with the photocured zero layer facing down. After that, the adhesion was measured using the same method as the above-mentioned adhesion test method, and the results were expressed as the average number of dots.

The chemical properties of the photocured film are determined by boiling resistance, which is obtained by immersing the photocured film photocured on the copper foil substrate in boiling water for 2 hours, and then observing whether there are any abnormalities in the appearance of the photocured film. Aqueous test, alkaline resistance test in which the photocured film is immersed in a 3% by weight aqueous solution of caustic soda for 5 hours and then observed for any abnormality in appearance;
An abrasion IPA property test in which the photocured film is immersed for an hour and then observed for any abnormality in appearance, and a trichlene resistance test in which the photocured film is immersed in water for 1 hour and then observed for any abnormality in the appearance. Those that did not show any abnormality were marked as "excellent," those with slight cracks observed were marked as "good," and those with considerable soldering were marked as "solder." The photocured film bulged (22) was indicated as "blister".

The volume electrical resistance of the photocured film is 0.1 mm thick and 10 mm in diameter.
0 mm photocured film (formed by performing light irradiation 6 times to form a photocured film similar to that shown in the adhesion test)
, a microcurrent potentiometer (manufactured by Takeda Riken Co., Ltd., TI (
-50) are shown.

[Polymerization examples 1 to 14] Production of addition copolymers.

In a 200 d three-north flask equipped with a reflux condenser, a stirrer, and a thermometer, the types and amounts of polymerizable monomers shown in Table 1 and benzene as a solvent (however, only in 2-polymerization example 8, tetrahydrofuran was used) were added. ) 1 Aisobisisobutyronitrile (AIB) was used as a polymerization initiator.
(abbreviated as N) was added in the amount shown in Table 1 to make a homogeneous solution.

Replace the inside of the flask with nitrogen gas and raise the temperature of one reaction system to 60℃.
The temperature was raised to 1, and stirring was continued, and copolymerization was carried out for the time shown in Table 1 (2). After that, one reaction solution was cooled to room temperature, and methanol was added to one reaction solution to precipitate a copolymer. After dissolving the polymer in acetone and making it homogeneous, hexano was added to reprecipitate it. By vacuum drying, a white copolymer was obtained in the amount shown in Table 1. Calculated from the elemental analysis value of the copolymer. Table 1 shows the ratio (mol %) of each structure (repeating unit corresponding to monomer) constituting the copolymer and the molecular weight determined by high performance chromatography.

The copolymer obtained in Polymerization Example 14 has an acryloyl equivalent of 12,000 according to nuclear magnetic resonance analysis, and a phenyl group equivalent of 15 from the ratio of each structure of the copolymer.
It was 8.

[Modification Examples 1 to 14] Production of modified copolymers.

The copolymer obtained in each polymerization example, acrylic acid (reactive compound), dioxane (solvent), 1-IJ ethylbenzylammonium chloride (catalyst, sometimes abbreviated as TEBAC), methoxyethylhydroquinone (thermal Polymerization inhibitor (sometimes abbreviated as MEHQ) was added in the amount shown in Table 2 in a 2007 four-hole round bottom flask (a stirrer, a reflux condenser, and a thermometer).

Make a homogeneous solution in Pano 1 (with an air blowing pipe installed), stir and blow air, then raise the temperature to 90°C, and at that temperature for the time shown in Table 2. A denaturation reaction was carried out. Table 2 shows the acid values before and after the reaction.

Distilled water was then added to the first reaction solution to precipitate a modified copolymer. This modified product was purified by dissolving it in acetone and adding distilled water again. After dehydration and drying, a modified copolymer with a slightly yellow color of firefly shown in Table 2 was obtained.

The weight of the modified copolymer based on 1 gram equivalent of acryloyl group determined by nuclear magnetic resonance analysis, and
The weight of the modified product per 1 gram equivalent of phenyl group determined from the ratio of each structure of the copolymer for producing a modified copolymer is shown in Table 2. [Modification Example 15] Modification of Copolymer manufacturing of things.

Copolymer 5.0 obtained in Polymerization Example 13 using the same reactor as in the modification example described above. ! ? ,,2-hydroxy(25
) Diethyl acrylate) 5.0y, dioxane 2o,
52, catalyst (TEBAO) 30CII+9. and 30 mg of thermal polymerization inhibitor (M E H went. Thereafter, 2.6 g of a modified light yellow copolymer was obtained by the same operation as in Modification Example 1.

The modified product was determined by nuclear magnetic resonance analysis to have a weight of 42% of the modified copolymer per 1 gram equivalent of acryloyl group.
00, and the weight of the modified product per 1 gram equivalent of phenyl group was 165 based on the ratio of each structure in the copolymer used to produce the modified product.

\ Examples 1 to 14 and Comparative Examples 1 to 7 Copolymers or modified copolymers of the types and amounts shown in Table 3 and photopolymerizable monomers were mixed to form a uniform solution. Thereafter, a photopolymerization initiator of the type and amount shown in Table 3 was added to prepare a photocurable composition.

Table 3 shows the photocuring speed and physical properties of photocuring of these photocurable compositions.

The composition of the photocurable composition of the comparative example and the results of photocuring of the composition are shown in Table 3.

In Table 3, the abbreviations that appear are as follows:

CTX; 2-chlorothioxanthone EDMAB; ethyldimethylaminobenzoate NPG
DA; neopentyl glycol diacrylate TMPTA; trimethylolpropane triacrylate ux-2; oligoester diacrylate (manufactured by Osaka Organic Co., Ltd.) (30) 401- (29) Continued from page 1 0 Author Toshikazu Hayashi Ichihara City Goi South Coast 8-1 Ube Industries Co., Ltd. Polymer Research Institute

Claims (1)

[Scope of Claim] A photocurable composition containing as main components an unsaturated polymer, a photopolymerizable monomer, and a photopolymerization initiator. The unsaturated polymer is obtained from an unsaturated monomer having a phenyl group and another unsaturated monomer (-1 addition copolymer or a modified product of the copolymer). The saturated polymer has a (meth)acryloyl group and a phenyl group in the side chain, and the ratio is such that the weight of the unsaturated polymer is 500 to 30,000 grams per gram equivalent of the (meth)acryloyl group. Moreover, the photocurable composition is characterized in that the proportion is such that the weight of the unsaturated polymer per gram equivalent of the phenyl group is 150 to 305 grams.