JP2006052356A - Ultraviolet-curable coating composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-quality heat transfer recording sheet providing good image; and to provide a silicone composition for a release film. <P>SOLUTION: The ultraviolet-curable coating composition comprises (A) a urethane (meth)acrylate resin obtained by reacting (a) a polyisocyanate compound, (b) a polyester polyol and (c) a hydroxy group-containing (meth)acrylate, or by reacting the components (a), (b) and (c) and (d) a hydroxy-substituted organic group-containing organopolysiloxane, (B) a photopolymerizable monomer, (C) a hydroxy-substituted organic group-containing organopolysiloxane, (D) a photopolymerization initiator and (E) an organic solvent. According to the invention, a cured film having excellent adhesion to a base material compared to that of a conventional silicone composition for a release sheet is obtained, and the adhesion is improved almost without affecting the release characteristics. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to compositions useful for forming coating layers on paper and film substrates.
More specifically, process release papers used in the production of synthetic leather, ceramic release sheets, process release films useful for the production of ceramic green sheets, marking films, etc., liquid crystal displays (hereinafter abbreviated as LCD) The present invention relates to a coating composition suitable for a release film for protecting a pressure-sensitive adhesive layer such as a polarizing plate and a retardation plate used in the above. The present invention also relates to a thermal transfer recording sheet such as a video printer, a facsimile machine, and a word processor used in a system for recording an image by heating with a thermal head, and a coating composition suitable for a back agent for obtaining the recording sheet.

Conventionally, synthetic leather and the like are manufactured by a casting method or the like, and polyurethane resin, vinyl chloride resin, polyamide resin, amino resin, and the like are used for manufacturing.
In this production, a resin composition for process release paper is used to make the surface of the substrate peelable. As typical resin compositions for this process release paper, polypropylene-based, aminoalkyd-based, and silicone-based resin compositions are known.

  However, polypropylene-based materials are excellent in the durability of releasability when used repeatedly, but their use at relatively high temperatures is limited. In this case, the peeled surface is easily damaged, and enamel (high gloss) ) There were difficulties such as not being able to obtain type products. In addition, aminoalkyd type has excellent gloss but poor peelability, and silicone type has excellent drawback in peelability but poor gloss.

  As a solution to the above drawback, a resin composition for process release paper comprising a silicone-modified acrylic resin and a polyisocyanate compound is disclosed. Here, the silicone-modified acrylic resin is an organopolyester in which 15 to 50% of organic groups bonded to silicon atoms in one molecule are phenyl groups, and at least one of the remaining organic groups is a hydroxy group-substituted organic group. Acrylic resin is modified with siloxane. In the present invention, by using a hydroxyl group-substituted organic group, a process release paper having excellent heat resistance, good gloss, and good releasability can be obtained. (See Patent Document 1)

  Japanese Patent Publication No. 58-53680 (Patent Document 2) discloses a resin composition for process release paper comprising a silicone-modified alkyd resin and a polyisocyanate compound, and Japanese Patent Publication No. 61-13507 (Patent Document 3). A resin composition for process release paper comprising a silicone-modified acrylic resin, an alkanol-modified amino resin, and an acidic catalyst is disclosed in JP-B-4-20954 (Patent Document 4) as a silicone-modified alkyd resin, an alkanol-modified amino resin, And a resin composition for process release paper comprising an acidic catalyst. In these inventions as well, there is disclosed a technique capable of obtaining a process release paper having excellent heat resistance, good gloss, and good releasability.

  However, the resin composition for process release paper disclosed in these documents has a large variation in the content of hydroxy group-substituted organic groups bonded to silicon atoms, so the peel force varies greatly, and the quality varies greatly. There was a drawback.

In order to solve this drawback, in a resin composition for process release paper comprising an alkyd resin or an acrylic resin, an organopolysiloxane, an alkanol-modified amino resin, and an acidic catalyst, the hydroxy-substituted organic group contained in the organopolysiloxane is changed to —CH. _{2 CH 2 CH 2 -O- (C} 2 H 4 O) structure specific to the technology represented by n -H are disclosed. (See Patent Document 5) The process release paper thus obtained was superior in peelability and heat resistance, had good gloss, and could suppress variations in quality compared to the previous one.

  As for the improvement in production efficiency by repeated usability improvement, JP 2000-95929 A (Patent Document 6) discloses an alkyd resin, an amino resin containing a methylol group-containing methylated melamine resin as a main component, and a reaction with these resins. A release agent composition comprising a silicone resin containing a functional group having a property is disclosed in Japanese Patent Application Laid-Open No. 2002-47476 (Patent Document 7). A release agent composition that is excellent in repeated usability by imparting antistatic performance is disclosed.

As described above, excellent process release paper resin compositions have come to be supplied by many improvements. However, when these compositions are applied to form a release layer, they are cured and dried at 150 ° C. or higher. There is no change in the situation where temperature is required. The deterioration of the texture of the release paper due to heat is a cause of deteriorating the value of the obtained synthetic leather, and there is a problem that the production cost is increased in terms of increasing energy consumption.
From these things, the resin composition for process release paper which can be hardened at low temperature is calculated | required.

  For the production of ceramic green sheets used for multilayer ceramic substrates, multilayer ceramic capacitors, etc., a release film in which a release agent such as silicone is coated on one side of a plastic film such as a polyester film, a polyimide film or a polymethylpentene film is used. It is used. A ceramic slurry is applied on the release layer with an appropriate thickness, and this is heat dried.

  This ceramic slurry is composed of ceramic powder, plasticizer, binder, and the like, and many combinations are possible. However, the ceramic slurry is roughly classified into an organic solvent system and an aqueous system based on the type of binder and its dissolution performance.

  In this case, the organic solvent-based slurry uses, for example, polyvinyl butyral or ethyl cellulose as a binder and a solvent such as toluene or ethanol. Although this organic solvent-based slurry can obtain a thin and tough green sheet from the viscosity characteristics of the slurry, etc., it has difficulty in safety and workability, and has problems in terms of environmental hygiene.

  On the other hand, the aqueous slurry generally uses polyvinyl alcohol or acrylic resin as a binder, and polyethylene glycol is used as a plasticizer. Although this water-based slurry has no problems such as safety, it has a drawback that it is difficult to obtain a high-quality ceramic green sheet as compared with a solvent-based one because of poor coating properties and quality. This is also a problem that occurs when a resin sheet is molded from an aqueous resin.

  The cause of the problem that occurs when such an aqueous slurry is used is that the release film provided with a thermosetting silicone on the surface as a release layer easily repels the aqueous coating liquid when it is applied, and agglomeration occurs and cannot be used. This is probably because of this. Similarly, polyvinyl carbamate, polyethyleneimine, and the like containing a long-chain alkyl group are repelled, and a uniform coating film cannot be formed.

  As a solution to these problems, a release layer is formed in Japanese Patent Application Laid-Open No. 11-300894 (Patent Document 8), Japanese Patent No. 2932911 (Patent Document 9), and Japanese Patent No. 3457722 (Patent Document 10). A composition in which main resin components are alkyd resin, amino resin and acrylic resin is disclosed. According to this method, it is possible to obtain a release film for a process which is not only uniformly coated even with an aqueous ceramic slurry but also excellent in the peelability of the green sheet after drying.

  Recently, however, multilayer ceramic substrates and capacitors have been required to be smaller and have larger capacities, and ceramic layers have been increasingly multilayered and thinned. For this reason, the surface smoothness required for the release film itself is increased, and thermal deformation during the formation of the release layer has become a problem as an adverse effect. From the viewpoint of cost, the thickness of the release film has been reduced, and the heat resistance has been reduced. Therefore, a mold release agent that can be cured at a lower temperature is demanded.

  Looking at other applications in which a release film is used, a release film mainly composed of a polyester film is used for protecting an adhesive layer such as a liquid crystal polarizing plate and a retardation plate. As the recent trend toward larger screens and higher quality image quality is required, high accuracy is required for the shape of the release film in order to achieve the required processing accuracy. Here again, heating during the formation of the release layer is one of the problems because it can cause a decrease in accuracy due to deformation, and a release agent that can be cured at a lower temperature has been demanded. ing.

  Another use for release films can be found in the information industry. As many information processing systems have been developed with the rapid development of the information industry in recent years, various recording systems have been adopted. Among various recording methods, the thermal recording method is widely used because the apparatus is light in weight, the sound during printing is small, and the maintenance is excellent.

  In this thermal recording system, a heat transfer recording type using a heat transfer recording sheet in which a color material layer is composed of a heat melting material and a pigment, and a sublimation using a heat transfer recording sheet in which a color material layer is composed of a sublimation dye. There is a type. The former hot-melt transfer type is characterized by being capable of color development at low energy, while the latter sublimation type requires high energy, but it is easy to reproduce halftones due to the difference in applied energy, and full color. There is an advantage that an image can be easily obtained.

  In any type of thermal recording system, a great amount of heat is applied from the thermal head to the thermal transfer recording sheet for color development, and particularly in the sublimation type, the heat becomes high. Therefore, there is a problem that a so-called sticking phenomenon or thermal deformation is likely to occur, and in an image that requires a high density, the image is distorted and it is difficult to obtain a good image.

  Furthermore, in recent years, there is a tendency to make the base material thinner in order to increase the printing speed and enable transfer with a low energy amount, and thus it is necessary to improve the heat transfer recording sheet characteristics such as heat resistance and slipperiness. Has arisen.

  As an improvement measure for these problems, the back coating layer of the thermal transfer recording sheet is formed of a silicone composition. For example, JP-A 63-210160 (Patent Document 11) discloses siloxane / styrene / (meth) acrylic acid. It has been proposed as a coating agent mainly composed of an ester copolymer.

Japanese Patent Publication No.57-48013 Japanese Patent Publication No. 58-53680 Japanese Patent Publication No. 61-13507 Japanese Patent Publication No. 4-20954 Japanese Patent Publication No. 7-53820 JP 2000-95929 A JP 2002-47476 A Japanese Patent Application Laid-Open No. 11-300894 Japanese Patent No. 2932911 Japanese Patent No. 3457722 JP 63-210160 A

Since the conventional silicone composition requires heating during curing, for example, when an ultra-thin film of 10 μm or less is used as the thermal transfer recording sheet substrate, the film is easily deformed during coating and curing is obtained. Properties such as solvent resistance of the film were hardly sufficient.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-quality thermal transfer recording sheet and a release film silicone composition that hardly give the above problems and give a good image.

  As a result of intensive studies to solve this problem, a. A polyisocyanate compound having two or more isocyanate groups per molecule; b. A polyester polyol, c. Hydroxyl group-containing (meth) acrylate, d. (A) Urethane (meth) acrylate resin having a (meth) acryloyl group obtained by reacting with an organopolysiloxane having one or more hydroxy-substituted organic groups per molecule, (B) a photopolymerizable monomer (C) An organopolysiloxane having at least one hydroxy-substituted organic group per molecule and (D) a UV curable coating composition containing a photopolymerization initiator can satisfy this problem. I found.

  This composition is used in the above composition without solvent, but is used as (E) a solvent type diluted with a solvent and (F) an emulsion type dispersed in water with a surfactant. be able to.

(A) Urethane (meth) acrylate resin having a (meth) acryloyl group obtained by reacting a, b, c or a, b, c, d described below 100 parts by mass a. A polyisocyanate compound having two or more isocyanate groups per molecule b. Polyester polyol c. Hydroxyl-containing (meth) acrylate d. Organopolysiloxane having one or more hydroxy-substituted organic groups per molecule (wherein the amount of each component is b, c or the number of moles of isocyanate groups possessed by component a relative to the total number of moles of hydroxyl groups of b, c, d) The ratio is adjusted to 1.0: 1.0 to 1.0: 1.1.)
(B) 10 to 400 parts by mass of a photopolymerizable monomer (C) Organopolysiloxane having one or more hydroxy-substituted organic groups per molecule
0 to 150 parts by mass (D) Photopolymerization initiator 1 to 50 parts by mass (E) Organic solvent Knowing that an ultraviolet curable coating composition containing an arbitrary amount can be provided, the present invention is made. It came.

  By blending a siloxane-based compound having two or more polycyclic hydrocarbon groups containing an addition-reactive carbon-carbon double bond in one molecule with a conventional silicone composition for release paper, A cured film having excellent adhesion can be obtained, and the adhesion can be improved with little influence on the peeling properties.

The present invention will be described in detail below.
In the present invention, the urethane (meth) acrylate resin having a (meth) acryloyl group at the terminal which is the component (A) comprises: a. A polyisocyanate compound having two or more isocyanate groups per molecule; b. A polyester polyol, c. A hydroxyl group-containing (meth) acrylate; d. Obtained by reacting with an organopolysiloxane having one or more hydroxy-substituted organic groups per molecule

  (A) a raw material for component a. As described above, the polyisocyanate compound having two or more isocyanate groups per molecule is b. Polyester polyols and c. A hydroxyl-containing (meth) acrylate, and optionally d. This is reacted with an organopolysiloxane having one or more hydroxy-substituted organic groups per molecule or a mixture thereof, and known ones can be used for this, for example, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, water 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate, cyclohexane-1,4-diisocyanate, etc. Can be mentioned.

  Furthermore, a burette type polyisocyanate compound obtained by reacting the above various diisocyanate compounds with water, or an adduct type polyisocyanate compound obtained by reacting the above various diisocyanate compounds with a polyhydric alcohol such as trimethylolpropane. Alternatively, a multimer obtained by converting the above-mentioned various diisocyanate compounds into an isocyanurate can be used.

  a. The amount (in moles) of the polyisocyanate compound having two or more isocyanate groups per molecule of the component is the isocyanate that the component a has with respect to the total number of moles of hydroxyl groups of b, c or b, c, d. The ratio of the number of base groups is selected to be in the range of 1.0: 1.0 to 1.0: 1.1 (excess of isocyanate). When the ratio is less than 1.0: 1.0, unreacted products of b, c, and d increase. When the ratio exceeds 1.0: 1.1, an excessive isocyanate group decreases storage stability, which is not preferable.

  b. As the polyester polyol of the component, conventionally known ones can be used, which can be produced by polycondensation of unsaturated polyvalent carboxylic acid, saturated polyvalent carboxylic acid and polyhydric alcohol by a conventionally known method.

  Examples of the unsaturated polycarboxylic acid include fumaric acid, maleic acid, maleic anhydride, itaconic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, and the like. Two or more types may be used in combination.

  Examples of the saturated polyvalent carboxylic acid include conventionally known ones such as adipic acid, sebacic acid, succinic acid, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, Two or more types may be used in combination.

  Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl 1,5-pentanediol, and bisphenol A ethylene. Conventionally known compounds such as oxide or propylene oxide adduct, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, dimethylolpropionic acid, dimethylolbutanoic acid may be used alone or in combination of two or more.

  The ratio of unsaturated polyvalent carboxylic acid, saturated polyvalent carboxylic acid, and polyhydric alcohol is not particularly limited, but the molar ratio of unsaturated polyvalent carboxylic acid / saturated polyvalent carboxylic acid is preferably 20/80 or less. If it exceeds 20/80, the adhesiveness tends to decrease, and if an unsaturated polyvalent carboxylic acid is not used, the curability decreases.

In the present invention, such b. Specific examples of components include diol compounds such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, and neopentyl glycol. Reaction product of diol compound and dibasic acid such as succinic acid, adipic acid, phthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid; addition reaction product of ε-caprolactone or β-methyl-δ-valerolactone; A ternary reaction product of the diol compound, the dibasic acid, and ε-caprolactone or β-methyl-δ-valerolactone. Among these, it is preferable industrially to use the reaction material of ethylene glycol and adipic acid as a main component.

  c. A well-known thing can be used as a hydroxyl-containing (meth) acrylate of a component. This includes 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, butanediol mono (meth) acrylate, caprolactone modified product of 2-hydroxyethyl (meth) acrylate, glycidol di (meth) acrylate, penta Examples include erythritol tri (meth) acrylate. Among these, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate are preferable.

  What is necessary is just to make it the usage-amount (number of moles) of a hydroxyl-containing (meth) acrylate be equimolar with a residual isocyanate group, or a little insufficient. Specifically, the ratio of the number of moles of isocyanate groups of the component a to the total number of moles of hydroxyl groups of b, c or b, c, d described above is 1.0: 1.0 to 1.0: 1. It is chosen to be in the range of 1. The urethanization reaction and the urethanation reaction of the polyester polyol with polyisocyanate can be carried out in an inert organic solvent or without solvent at room temperature to 150 ° C., but particularly mild conditions of room temperature to about 80 ° C. The reaction is preferably carried out without solvent. Moreover, an organic tin compound, an amine, etc. can also be used as a reaction promoting catalyst.

  The urethane (meth) acrylate resin as the component (A) may be one obtained by reacting the components a, b and c as described above. However, a silicone-modified urethane having a (meth) acryloyl group (meta ) It can also be used as an acrylate resin. In this case a. A polyisocyanate compound having two or more isocyanate groups per molecule, b. Polyester polyol, c. In addition to the hydroxyl group-containing (meth) acrylate, d. An organopolysiloxane having at least one hydroxy-substituted organic group per molecule is reacted. This d component is the same as the component (C) described later, and a. It can be combined with other components via a polyisocyanate compound. In this way, by combining a part or all of the component (C) in the component (A) in advance, an effect of maintaining the release property of the coating film can be expected.

  In order to obtain the urethane (meth) acrylate resin as component (A), b. A polyester polyol, c. A hydroxyl group-containing (meth) acrylate; d. The hydroxyl group of the organopolysiloxane having at least one hydroxy-substituted organic group per molecule; Bonding via a polyisocyanate compound.

  One specific method is that b. Polyester polyol alone or b and d. A mixture with an organopolysiloxane having at least one hydroxy-substituted organic group per molecule; a. After reacting the polyisocyanate compound to give an isocyanate at the end, c. This is a method of reacting a hydroxyl group-containing (meth) acrylate. B. Polyester polyols and d. An organopolysiloxane having at least one hydroxy-substituted organic group per molecule; c. To a mixture of hydroxyl group-containing (meth) acrylates, a. A method of adding a polyisocyanate compound may also be used. In addition, it is also possible to coexist the photopolymerizable monomer of (B) component in these reactions.

  Examples of the (B) photopolymerizable monomer used in the present invention include styrene, vinyl toluene, vinyl acetate, N-vinyl pyrrolidone, N-vinyl formamide, N-vinyl caprolactam, (meth) acryloylmorpholine, cyclohexyl ( (Meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-hexyl acrylate, cyclohexyl acrylate, isobornyl acrylate, phenoxyethyl acrylate, diethylene glycol diacrylate, 1,6-hexanediol diacrylate , Neopentyl glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol Le tetraacrylate, dipentaerythritol hexaacrylate, and the like. Among these, styrene and acryloylmorpholine are preferable.

  (B) As for the usage-amount of a component, 10-400 mass parts is preferable with respect to 100 mass parts of urethane (meth) acrylate resin of (A) component, More preferably, it is 10-300 mass parts. When the component (B) is 10 parts by mass or less, the coating property is unfavorable, and when it exceeds 400 parts by mass, the curability is unfavorable.

  The component (C) used in the present invention is an organopolysiloxane having at least one hydroxy-substituted organic group per molecule for bonding with the component (A) or these raw material components via an isocyanate group. Must. When the average number of hydroxy-substituted organic groups is less than 1 per molecule, the tendency of organopolysiloxanes that cannot be bonded to bleed and migrate from the coating film becomes strong, and the releasability also decreases with time.

  The structure of the hydroxy-substituted organic group is not particularly limited. For example, an organic group in which a hydrogen atom of an alkyl group, an alkenyl group, or an aryl group is substituted with a hydroxyl group, and an ether bond, an ester bond, a urethane bond, It may contain a carbonyl bond or the like.

  The remaining organic groups other than the hydroxy-substituted organic group possessed by this organosiloxane are alkyl groups such as methyl group, ethyl group, propyl group, butyl group and octyl group, alkenyl groups such as vinyl group, allyl group and butenyl group, phenyl group Aryl groups, or substituted alkyl groups such as chloromethyl, trifluoropropyl, and cyanoethyl groups in which some or all of the hydrogen atoms bonded to carbon atoms of these groups are substituted with halogen atoms, cyano groups, etc. It is supposed to be.

  However, considering that it is easily dispersed during the production of the composition, easily reacts with the component (A), and easily reacts with other raw materials when preparing the component (A), these remaining organic groups are aryl groups. It is desirable to include an aromatic organic group. When an organopolysiloxane that does not contain any aromatic organic groups is used, the appearance of the composition becomes cloudy and the migration of the organopolysiloxane from the coating film increases. Although it depends on the structure of the remaining organic groups, it is more desirable that 10 to 50 mol% of all organic groups possessed by the organosiloxane are aromatic organic groups. If it is less than 10 mol%, repellency is likely to occur when it is made into a process release paper or process film, and if it exceeds 50 mol%, the releasability tends to decrease.

  The skeleton structure of the organopolysiloxane may be either a linear structure or a branched structure, and the degree of polymerization is not particularly specified, but a range of 30 to 1000 is preferably used. If it is less than 30, the releasability is insufficient, and if it exceeds 1000, the appearance of the composition may be poor.

  This type of organopolysiloxane can be obtained by, for example, treating a cyclic organosiloxane containing a dimethylsiloxane group, a cyclic organosiloxane containing a diphenylsiloxane group, and an organosilane forming a terminal group containing a hydroxy-substituted organic group. It can be obtained by charging in such a manner that it is obtained and polymerizing in the presence of an alkali such as KOH or CsOH. can get

  Specific examples of the organopolysiloxane of component (C) include those represented by the following general formula (1).

（式中、Ｒは置換又は非置換の１価炭化水素基を表し、Ｘはヒドロキシ置換有機基を含有する１価有機基を表し、ｎ及びｍは合計で３０〜１０００の整数を表す。α、βはそれぞれ０、１、２または３である。）

(In the formula, R represents a substituted or unsubstituted monovalent hydrocarbon group, X represents a monovalent organic group containing a hydroxy-substituted organic group, and n and m represent an integer of 30 to 1000 in total. , Β is 0, 1, 2 or 3, respectively.

  R in the formula represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and is an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, or an n-hexyl group. And aryl groups such as phenyl group and tolyl group, aralkyl groups such as benzyl group and phenethyl group, alkenyl groups such as vinyl group and allyl group, etc., but methyl group and phenyl group are preferred industrially. . Moreover, it is preferable that 10-50 mol% in all R is a phenyl group.

X represents a monovalent organic group containing a hydroxy-substituted organic group having 3 to 50 carbon atoms, such as 3-hydroxypropyl group, 4-hydroxybutyl group, 4-methyl-4-hydroxybutyl group, 3-aminopropyl group, Examples include 2-carboxyethyl group, 3-mercaptopropyl group, 10-carboxydecyl group, 3- (β-aminoethylamino) propyl group, and a group represented by the following formula (2).
—CH ₂ CH ₂ CH ₂ —O— (C ₂ H ₄ O) _a —H (2)
(A is an average value of 1 to 3)

  N and m representing the number of repeating siloxane units are desirably 30 or more and 1000 or less in total, but 40 or more and 900 or less are more preferable. This is because when n and m are less than 30 in total, the effect of imparting releasability to the cured film is reduced, and when it exceeds 1000, the migration is enhanced.

  The compounding amount of the organopolysiloxane having a hydroxy-substituted organic group is 0 to 150 parts by mass with respect to 100 parts by mass of the component (A). The smaller the compounding amount, the lower the releasability and the higher the peel strength. It is desirable to adjust the blending amount according to the purpose. If it exceeds 150 parts by mass, the adhesiveness is lowered, which is not desirable.

  The composition of the present invention is cured by irradiation with active energy rays. Examples of active energy rays that can be used include ultraviolet rays, electron beams, and X-rays, and ultraviolet rays are generally used. In terms of energy, an energy ray having a wavelength of 400 nm or less can be used. When cured by ultraviolet irradiation, it is 1 to 50 parts by mass with respect to 100 parts by mass of the component (A), preferably 100 parts by mass in total of the component (A) and the photopolymerizable monomer (B). On the other hand, it is necessary to add 1-10 mass parts (D) photoinitiator.

  (D) When the usage-amount of a photoinitiator is less than 1 mass part, sclerosis | hardenability is not enough, and when it exceeds 50 mass parts, it will become the tendency for the physical property of the coating film obtained to fall.

  Known photopolymerization initiators can be used such as 4-dimethylaminobenzoic acid, 4-dimethylaminobenzoic acid ester, 2,2-dimethoxy-2-phenylacetophenone, acetophenone diethyl ketal, alkoxyacetophenone. , Benzyldimethyl ketal, benzophenone, 3,3-dimethyl-4-methoxybenzophenone, 4,4-dimethoxybenzophenone, benzophenone derivatives such as 4,4-diaminobenzophenone, benzoyl alkyl benzoate, bis (4-dialkylaminophenyl) ketone Benzyl derivatives such as benzyl and benzylmethyl ketal, benzoin derivatives such as benzoin and benzoin isobutyl ether, benzoin isopropyl ether, 2-hydroxy-2-methylpropion Non, 1-hydroxycyclohexyl phenyl ketone, xanthone, thioxanthone and thioxanthone derivatives, fluorene, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1,2-benzyl-2-dimethylamino-1- (morpholinophenyl) -butanone-1 and the like.

  If necessary, various additives other than those mentioned above, such as hydroquinone, hydroquinone monomethyl ether, benzoquinone, pt-butylcatechol, 2,6-dibutyl-4-methylphenol as polymerization inhibitors, antioxidants, Foaming agents, leveling agents, ultraviolet absorbers, pigments and the like can also be added.

  This composition can be used not only as a solventless type but also as a solvent type composition diluted with an organic solvent, or as an emulsion type composition dispersed in water for convenience in use.

  When used as a solvent type, an organic solvent that dissolves the components well as the component (E) and has no reactivity with them may be used. Preferred solvents include, for example, toluene, xylene, hexane, heptane, methyl ethyl ketone, acetone, ethyl acetate, butyl acetate, diethyl ether, dibutyl ether, tetrahydrofuran and the like, or a mixture of two or more thereof. The solid content is preferably in the range of 5 to 50%.

  Moreover, when using as an emulsion type | mold, the composition of this invention can be disperse | distributed or emulsified in water by a well-known method. For example, emulsification can be performed using a homomixer, but a surfactant is used as necessary to obtain good stability and coating properties. Although a commercially available surfactant can be used, the usage-amount is 0.1-10 mass parts with respect to 100 mass parts of ultraviolet curable compositions. If the amount is less than 0.1 part, the stability of the emulsion may be insufficient. If the amount exceeds 10 parts by weight, the adhesiveness of the cured film to the substrate is lowered.

The composition of the present invention uses, for example, a bar coater, gravure coater, reverse coater or the like on the surface of a paper substrate or plastic film substrate, or a film having a solid content of about 0.05 to 5 g / m ² by spraying. After applying so that it may become thick, it can be set as a release paper or a release film by irradiating this with radiation.

  Here, as the radiation, for example, an ultraviolet ray generated from an electron beam, a mercury arc, a medium pressure mercury lamp, a high pressure mercury lamp, or the like can be used. Further, the radiation dose is not limited as long as the above-mentioned coating can be cured, and varies depending on the type of radiation. However, in the case of ultraviolet rays, for example, when a 2 KW high-pressure mercury lamp (80 W / cm) is used, the radiation dose is reduced to 0. What is necessary is just to irradiate for 1 to 10 seconds. In the case of using the emulsion type, moisture may be dried to some extent by air drying or heating before ultraviolet irradiation.

  Moreover, if the composition of this invention is apply | coated and hardened using a plastic film as a base material, the release film excellent in peelability, wettability, solvent resistance, etc. can be obtained similarly. Examples of the plastic film include a polyimide film such as a polyester film, a polyimide film, and a polyimide ether film, and a polyamide film. In particular, a polyester film is preferably used in terms of cost performance. Although thickness is not specifically limited, 20-200 micrometers is preferable from heat resistance, workability | operativity, etc.

  The release film thus obtained can be usefully used as a manufacturing process film for multilayer ceramic substrates, multilayer ceramic capacitors, and the like, and for protecting adhesive layers such as liquid crystal polarizing plates and retardation plates.

  Further, if the composition of the present invention is applied to a plastic film substrate and cured for a thermal transfer recording sheet, a back coat layer having excellent heat resistance and slipperiness can be formed.

  When coating using the composition of the present invention, the composition of the present invention is diluted directly or with an appropriate organic solvent, and then coated with a bar coater, roll coater, reverse coater, gravure coater, air knife coater, or thin film. The coating is applied to a substrate such as a plastic film by a known coating method such as a high-precision offset coater or a multi-stage roll coater.

The amount of the composition of the present invention applied to the substrate varies depending on the type of material of the substrate to be coated, but the solid content is preferably in the range of 0.05 to 5 g / m ² . By heating the substrate coated with the composition of the present invention as described above at 80 to 150 ° C. for 60 to 5 seconds, a cured film can be formed on the surface of the substrate to obtain a release film.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

[Preparation Example 1] (Synthesis of urethane acrylate resin A1)
A flask equipped with a stirrer, thermometer, cooler and nitrogen vent was charged with 388.7 parts by mass of ethylene glycol, 753.5 parts by mass of adipic acid, and 56.2 parts by mass of maleic acid, and gradually heated to 140 ° C. And kept warm for 1 hour. Thereafter, the temperature was raised to 200 ° C. Thereafter, esterification was performed under reduced pressure to obtain a polyester polyol.

  Thereafter, the mixture was cooled to 40 ° C., charged with 173.7 parts by mass of tolylene isocyanate, heated to 80 ° C., and kept warm for 4 hours. Thereafter, 115.8 parts by mass of 2-hydroxyethyl acrylate was added, and the mixture was kept warm for 9 hours. After confirming that the isocyanate group had disappeared by IR, urethane acrylate resin A1 was obtained.

[Preparation Example 2] (Synthesis of silicone-modified urethane acrylate resin A2)
In the same synthesis apparatus as Production Example 1, 388.7 parts by mass of ethylene glycol, 753.5 parts by mass of adipic acid, 56.2 parts by mass of maleic acid, carbinol-modified polysiloxane at both ends (containing 30 mol% of phenyl groups, viscosity of 4500 cp) ) 145.8 parts by mass were charged, the temperature was gradually raised to 140 ° C., and the temperature was kept for 1 hour. Thereafter, the temperature was raised to 200 ° C. Thereafter, esterification was performed under reduced pressure to obtain a polyester polyol.

  Thereafter, the mixture was cooled to 40 ° C., charged with 173.7 parts by mass of tolylene isocyanate, heated to 80 ° C., and kept warm for 4 hours. Thereafter, 115.8 parts by mass of 2-hydroxyethyl acrylate was added, and the mixture was kept warm for 9 hours. After confirming that the isocyanate group had disappeared by IR, a silicone-modified urethane acrylate resin A2 was obtained.

[Example 1]
Photopolymerization of 100 parts by mass of urethane acrylate resin A1 of Preparation Example 1, 40 parts by mass of acryloylmorpholine, 10 parts by mass of terminal carbinol-modified polysiloxane (containing 30 mol% of phenyl groups, viscosity 4500 mPa · s at 25 ° C.) 7.5 parts by mass of an agent (manufactured by Ciba Geigy Co., Darocur 1173) was added and mixed uniformly to prepare a solventless composition.

Thereafter, the above composition was applied to a 38 μm polyester film with a printing suitability tester at 0.5 g / m ² (solid content), ^two high-pressure mercury lamps (80 W / cm), an irradiation distance of 8 cm, and a line speed of 20 m / min. A release film was obtained by UV irradiation under the following conditions.

[Example 2]
100 parts by mass of silicone-modified urethane acrylate resin A2 of Preparation Example 2 and 40 parts by mass of acryloylmorpholine, 7.0 parts by mass of a photopolymerization initiator (Ciba Geigy, Darocur 1173) are added and mixed uniformly to obtain a solvent-free type. A composition was prepared.

Thereafter, the above composition was applied to a 38 μm polyester film with a printing suitability tester at 0.5 g / m ² (solid content), ^two high-pressure mercury lamps (80 W / cm), an irradiation distance of 8 cm, and a line speed of 20 m / min. A release film was obtained by UV irradiation under the following conditions.

[Example 3]
100 parts by mass of urethane acrylate resin A1 of Preparation Example 1, 40 parts by mass of acryloylmorpholine, and 7.5 parts by mass of a photopolymerization initiator (Darocur 1173 manufactured by Ciba Geigy Co., Ltd.) are added and mixed uniformly to obtain a solvent-free composition. A product was prepared.

Thereafter, the above composition was applied to a 38 μm polyester film with a printing suitability tester at 0.5 g / m ² (solid content), ^two high-pressure mercury lamps (80 W / cm), an irradiation distance of 8 cm, and a line speed of 20 m / min. A release film was obtained by UV irradiation under the following conditions.

[Example 4]
100 parts by mass of urethane acrylate resin A1 of Preparation Example 1, 400 parts by mass of acryloylmorpholine, 150 parts by mass of a terminal carbinol-modified polysiloxane (containing 30 mol% of phenyl groups, viscosity 4500 mPa · s at 25 ° C.) A solvent-free composition was prepared by adding 32.5 parts by mass (Darocur 1173, manufactured by Ciba-Geigy Corporation) and mixing uniformly.

Thereafter, the above composition was applied to a 38 μm polyester film with a printing suitability tester at 0.5 g / m ² (solid content), ^two high-pressure mercury lamps (80 W / cm), an irradiation distance of 8 cm, and a line speed of 20 m / min. A release film was obtained by UV irradiation under the following conditions.

[Example 5]
100 parts by mass of urethane acrylate resin A1 of Preparation Example 1, 40 parts by mass of acryloylmorpholine, 10 parts by mass of a terminal carbinol-modified polysiloxane (containing 30 mol% of phenyl groups, viscosity 4500 mPa · s at 25 ° C.) 7.5 parts by mass (Darocur 1173 manufactured by Ciba-Geigy Corporation) was added and mixed uniformly.

  37.5 parts by weight of HLB15 nonionic surfactant is added to 157.5 parts by weight of this mixture, and 1414.5 parts by weight of water is gradually added and emulsified while stirring using a homomixer, and the emulsion type has a solid content of 10%. 1575 parts by weight of the composition was prepared.

Thereafter, the above composition was applied to a 38 μm polyester film at a rate of 0.5 g / m ² (solid content) using a wire bar, and the hot air circulating dryer was used at 100 ° C. for 10 seconds to remove water. After drying, UV irradiation was performed under the conditions of two high-pressure mercury lamps (80 W / cm), an irradiation distance of 8 cm, and a line speed of 20 m / min to obtain a release film.

Comparative Example 1
A solventless composition was obtained in the same manner as in Example 1 except that terminal carbinol-modified dimethylpolysiloxane (viscosity at 25 ° C. of 40 mPa · s) was used as the both-end carbinol-modified siloxane of Example 1.

Thereafter, the above composition was applied to a 38 μm polyester film with a printing suitability tester at 0.5 g / m ² (solid content), ^two high-pressure mercury lamps (80 W / cm), an irradiation distance of 8 cm, and a line speed of 20 m / min. A release film was obtained by UV irradiation under the following conditions.

Comparative Example 2
Palm oil-modified alkyd resin 65 parts by mass, methylated melamine resin 15 parts by mass, butylated urea melamine resin 20 parts by mass with toluene-methyl ethyl ketone mixed solvent (mass ratio 1: 1) to 2 mass% (solid content) Then, 0.1 parts by mass of a 50% methanol solution of p-toluenesulfonic acid was added to 100 parts by mass of this solution to obtain a solvent-type composition that was cured by heating.

Since this composition is not cured by ultraviolet rays, it is uniformly applied to a 38 μm polyester film at 0.5 g / m ² (solid content) using a wire bar, and then dried and cured at 140 ° C. for 30 seconds in a hot air circulating dryer. Then, a release film was created.

<Evaluation method>
The properties of the release films obtained in the above examples and comparative examples were evaluated by the following methods. The results are shown in Table-1.

Curability According to the description in the Examples and Comparative Examples, the composition is applied to a 38 μm polyester film at 0.5 g / m ² (solid content). Regarding UV irradiation conditions, two high-pressure mercury lamps (80 W / cm), irradiation The distance of 8 cm was the same, and the line speed was changed from 20 m / min to 50 m / min in steps of 10 m / min, and the curing speed was examined. This determination of curing was made at the time when the coated surface did not fall off and did not cloud even when the coated surface was rubbed with a finger.

Adhesiveness A release film prepared according to the description of the examples and comparative examples was used as a test piece. The test piece was left at 25 ° C. for 1 week and then rubbed with a finger to examine the adhesion.
○: No dropout △: Partial dropout ×: Full dropout

Peel strength The release film prepared according to the description of the examples and comparative examples was used as a test piece. Knit polyester tape No. on the release surface. 31B (product name of Nitto Denko Co., Ltd.) was pasted and pressed once with a 2 kg pressure roller and left at 70 ° C. for 20 hours under a load of 20 g / cm ^2. The peel strength was measured with a tensile tester at a rate of minutes.

Residual Adhesion Rate A release film prepared in accordance with the description in Examples and Comparative Examples was used as a test piece. The test piece was allowed to stand at room temperature of 25 ° C. for 24 hours, and then knit polyester tape No. 31B was bonded and left at 70 ° C. for 20 hours under a load of 20 g / cm ² , and then the adhesive tape was peeled off, and this was attached to a stainless steel plate. A value obtained by measuring the peel strength by the same method as the peel strength was defined as f. Also, the same polyester tape No. 31B was stuck, this was processed like the above, the peeling force of this was measured, and this was made into the blank f0. Based on these measured values, the residual adhesion rate was determined by the following formula.
Residual adhesion rate (%) = f / f0 × 100

Wetability A release film prepared according to the description of the examples and comparative examples was used as a test piece. After this test piece was left at room temperature of 25 ° C. for 24 hours, the wettability test reagent was applied according to the JIS K 6768 wet tension test method to examine the wettability of the surface.

Wetability of water-based paint The components shown below were sufficiently mixed by a ball mill to prepare a ceramic slurry.
(A) Barium titanate 100 parts by weight (b) Acrylic emulsion 10 parts by weight (c) Polyurethane emulsion 1 part by weight (d) Ammonium polycarboxylate 1 part by weight (e) Water 15 parts by weight (f) Ammonia water 1 part by weight A release film prepared according to the description of Examples and Comparative Examples was used as a test piece. The above slurry was applied onto the test piece using an applicator, dried at 140 ° C. for 1 minute, observed for the degree of repellency, and evaluated for wettability according to the following criteria.
○: No repellency (good wettability)
Δ: Some repelling (slightly good wettability)
X: There is a repellency (poor wettability)

Film Base Shrinkage A release film prepared in accordance with the description in Examples and Comparative Examples was used as a test piece, and it was visually determined whether there was any shrinkage or distortion in appearance.
○: No shrinkage or distortion is seen ×: Shrinkage or distortion is seen

Evaluation results

注１：加熱硬化のため熱風乾燥器中１４０℃×３０秒で硬化

Note 1: Cured in a hot air dryer at 140 ° C for 30 seconds for heat curing

Claims (3)

(A) Urethane (meth) acrylate resin having a (meth) acryloyl group obtained by reacting a, b, c or a, b, c, d described below 100 parts by mass a. A polyisocyanate compound having two or more isocyanate groups per molecule b. Polyester polyol c. Hydroxyl-containing (meth) acrylate d. Organopolysiloxane having one or more hydroxy-substituted organic groups per molecule (wherein the amount of each component is b, c or the number of moles of isocyanate groups possessed by component a relative to the total number of moles of hydroxyl groups of b, c, d) The ratio is adjusted to 1.0: 1.0 to 1.0: 1.1.)
(B) 10 to 400 parts by mass of a photopolymerizable monomer (C) 0 to 150 parts by mass of an organopolysiloxane having one or more hydroxy-substituted organic groups per molecule (D) 1 to 50 parts by mass of a photopolymerization initiator ( E) Organic solvent An ultraviolet curable coating composition containing an arbitrary amount. The emulsion type ultraviolet curable coating composition obtained by adding 0.1-10 mass parts of (F) surfactant to 100 mass parts of ultraviolet curable compositions of Claim 1, and disperse | distributing to water. A release material provided with a release layer by ultraviolet curing the composition according to claim 1 on various substrates.