JP2006176926A - Embossed release paper and synthetic leather using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide embossed release paper having heat resistance, capable of being easily peeled from a polyurethane adhesive of two-pack curing type, excellent in emboss formability, capable of maintaining peelability, even when repeatedly used, and capable of being given at a low cost. <P>SOLUTION: This embossed release paper for producing a synthetic leather is equipped with at least paper used as a support and an ionizing radiation cured film formed on the paper and formed by subjecting the cured film to emboss processing, wherein a coating liquid containing at least a predetermined ionizing radiation curing composition is cured by irradiation with ionizing radiation, so as to form the cured film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

Field of Invention

  The present invention relates to an embossed release paper and a synthetic leather using the same, and more particularly to an embossed release paper using an ionizing radiation curable coating material having a specific composition.

  Conventionally, a release paper with an emboss is used as a process release paper for synthetic leather. As materials for synthetic leather, polyurethane (hereinafter abbreviated as PU), vinyl chloride (hereinafter abbreviated as PVC), a combination of PU and PVC, and the like are known.

  As a method for producing PU leather, for example, a paste-like PU resin for a skin layer is applied on a release paper, dried and solidified at a temperature of 90 to 140 ° C., and then a two-component curable PU adhesive is used as a base. There is a method in which PU leather is produced by peeling the release paper after reacting with a cloth and reacting in an aging room at 40 to 70 ° C. for 2 to 3 days. These PU resins are generally dissolved in organic solvents, but recently, water-based types are also being used due to environmental problems. In that case, drying is performed at a high temperature of 150 to 180 ° C. There is also.

  In addition, as a method for producing PVC leather, a PVC sol is coated on a release paper, heated and gelled at 200 to 250 ° C., then a PVC foam layer is formed and bonded to the base fabric, and then the release paper. There is a method of manufacturing PVC leather by peeling off.

  Furthermore, as a method for producing leather (also called semi-synthetic leather) in which PU and PVC are combined, a paste-like PU resin for skin layer is applied on a release paper, dried and solidified, and then a PVC foam layer There is a method in which the substrate is bonded to the base fabric and then the release paper is peeled off.

  Furthermore, a split leather in which these synthetic leathers are bonded to natural leather is also known.

  In the production of PVC leather or semi-synthetic leather, a release paper coated with a silicone resin and further provided with an uneven pattern by embossing is usually used. However, since the film-forming temperature of PVC is relatively high, embossing properties are poor and gloss unevenness tends to occur, and it has been difficult to repeatedly use release paper.

  On the other hand, in the production of PU leather, since the film forming temperature of PU is lower than that of PVC, it was extruded and coated with a thermoplastic resin such as polypropylene or 4-methyl-1-pentene, and further embossed. Release paper is used. The release paper for PU leather is excellent in embossing property, and there is no problem in peeling even in the processing of two-component curable PU, and it is excellent in repeated use. However, since the release paper is made of a thermoplastic resin, it has poor heat resistance and cannot be used for PVC leather.

  Because of these problems, release papers that are extrusion-coated with thermoplastic resin are only partially used for PVC leather and semi-synthetic leather, and there is no release paper that can be used for both PVC leather and PU leather. It was.

  In recent years, an embossed pattern cast using an electron beam curable resin such as isodecyl acrylate has been used for both PU and PVC because of its excellent embossability and heat resistance. (Japanese Patent Publication No. 63-2780; Patent Document 1).

  However, as a drawback of the type using an electron beam curable resin, there is a drawback that the isocyanate of the curing agent used in the two-component curable PU reacts with the surface of the release paper and is difficult to peel.

  Further, since the strength of the paper is deteriorated by the electron beam irradiation, the durability of the release paper is lowered and there is a problem that it cannot be used repeatedly.

Furthermore, since the coating amount of the electron beam curable resin is as large as 40 to 150 g / m ² , the production cost of the release paper is very high.

  In addition, the main component is a compound having an ethylenically unsaturated bond, such as an epoxy acrylate resin, and a solid resin is applied to paper at room temperature to form an uncured coating, embossing, and irradiation with ionizing radiation A release paper that has been cured in this way has also been proposed (Japanese Patent Publication No. 64-10626; Patent Document 2).

  However, as described above, it is not easy to peel off the two-component curable PU material, and it has not yet been put into practical use.

  Further, a method using a silicone resin having an acryloyl group has been proposed in order to improve the above problems, that is, the heat resistance of the release paper and the releasability when using a two-component curable PU (Japanese Patent Laid-Open No. Hei 5). -269931; Patent Document 3).

However, the resin raw material is not only expensive but also inferior in peelability and workability, and has not yet been put into practical use.
Japanese Patent Publication No. 63-2780 Japanese Patent Publication No. 64-10626 JP-A-5-269931

  The present inventors have found that by using a specific ionizing radiation curable resin, the release paper can be easily peeled from a two-component curable PU adhesive having heat resistance. Obtained. Moreover, even if it used for manufacture of a synthetic leather repeatedly by adjusting content of a silicone compound, the knowledge that the outstanding peelability was maintained was acquired. The present invention is based on this finding.

  Accordingly, an object of the present invention is a release paper with embossing that has heat resistance and can be easily peeled off even with a two-component curable PU adhesive, has excellent embossing property, and is used repeatedly. Is to provide an inexpensive embossed release paper that can maintain the peelability.

An embossed release paper according to the present invention comprises at least a paper as a support and an ionizing radiation cured film provided on the paper, and an emboss for producing synthetic leather, which is embossed on the cured film. Release paper,
The ionizing radiation cured film is
A reaction product comprising an isocyanate compound and a (meth) acrylic compound having a (meth) acryloyl group and capable of reacting with the isocyanate compound, or an isocyanate compound, having a (meth) acryloyl group and reacting with the isocyanate compound A reaction product comprising a (meth) acrylic compound to be obtained and a compound having no (meth) acryloyl group and capable of reacting with an isocyanate group,
A coating liquid comprising at least an ionizing radiation curable composition having a softening point of 40 ° C. or higher is cured by irradiation with ionizing radiation.

  Further, the synthetic leather as another embodiment of the present invention is a synthetic leather produced using the above release paper, and the silicon-derived silicon present on the release surface of the synthetic leather obtained by peeling the release paper The ratio is 20% or less.

  By forming an ionizing radiation-cured film (embossed film) using such a coating solution, it has heat resistance and can be easily peeled off from a two-component curable PU adhesive. An inexpensive embossed release paper that is excellent in moldability and can maintain releasability even after repeated use can be realized.

  Further, the synthetic leather as another embodiment of the present invention is a synthetic leather produced using the above release paper, and the silicon-derived silicon present on the release surface of the synthetic leather obtained by peeling the release paper The ratio is 20% or less.

  By using the release paper, even when the synthetic leather is repeatedly produced, the excellent peelability of the release paper is maintained, so that the synthetic leather can be easily obtained.

  An embossed release paper according to the present invention comprises at least a paper as a support and an ionizing radiation cured film provided on the paper, and an emboss for producing synthetic leather, which is embossed on the cured film. A release paper, which is obtained by curing the coating liquid by irradiation with ionizing radiation. First, the coating solution will be described.

Coating liquid The coating liquid used in the present invention comprises a reaction product comprising an isocyanate compound and a (meth) acrylic compound having a (meth) acryloyl group and capable of reacting with the isocyanate compound, or an isocyanate compound and (meth) A softening point comprising a reaction product comprising a (meth) acrylic compound having an acryloyl group and capable of reacting with an isocyanate compound, and a compound not having a (meth) acryloyl group and capable of reacting with an isocyanate group. It is a composition containing an ionizing radiation curable composition at 40 ° C. or higher.

  In the present specification, the (meth) acryloyl group means an acryloyl group and / or a methacryloyl group, the (meth) acrylic compound means an acrylic compound and / or a methacrylic compound, and the (meth) acrylate means an acrylate and // means methacrylate, and (meth) acrylic acid means acrylic acid and / or methacrylic acid.

  The isocyanate compound used in the present invention is a compound having at least one isocyanate group, and preferably a compound having two or more isocyanate groups. For example, aliphatic isocyanates such as phenyl isocyanate, xylyl isocyanate, naphthyl isocyanate, hexamethylene diisocyanate, lysine methyl ester diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate) Such as cycloaliphatic isocyanate such as alicyclic isocyanate, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthalene-1,5'-diisocyanate, and tolylene diisocyanate trimer and tolylene diisocyanate A hydrogen compound such as a reaction product of 3: 1 (molar ratio) with trimethylolpropane can be used.

  Further, a compound having an isocyanate group bonded to a non-aromatic hydrocarbon ring, a so-called alicyclic isocyanate compound trimer, a reaction product with an active hydrogen compound, or the like is preferably used. As the alicyclic isocyanate compound, isophorone diisocyanate which is easily available in the market is preferably used, but hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate and the like can also be used.

  A trimer of isophorone diisocyanate or a reaction product of 3: 1 (molar ratio) of isophorone diisocyanate and trimethylolpropane is preferable as the isocyanate compound used in the present invention, and among them, a trimer of isophorone diisocyanate is more preferable. Several isocyanate compounds may be used in combination.

  Examples of the (meth) acrylic compound having a (meth) acryloyl group and capable of reacting with an isocyanate compound include a (meth) acrylic compound having a hydroxyl group and / or a carboxyl group. Hereinafter, the “(meth) acrylic compound having a (meth) acryloyl group and capable of reacting with an isocyanate compound” may be abbreviated as “specific (meth) acrylic compound”.

  A reaction product of an isocyanate compound and a specific (meth) acrylic compound having a hydroxyl group is usually referred to as “urethane acrylate”. The reaction product of the isocyanate compound and the specific (meth) acrylic compound having a carboxyl group is a compound having a structure in which a polymerizable (meth) acryloyl group is bonded via an amide group. These will be described below.

  As a specific (meth) acrylic compound having a hydroxyl group, a hydroxy ester which is a reaction product of (meth) acrylic acid and a polyhydroxy compound is a typical compound. Furthermore, the compound etc. which added ethylene oxide, propylene oxide, caprolactone, etc. to the hydroxyl group of this hydroxy ester are mentioned. Furthermore, the compound which esterified a part of hydroxyl group of this hydroxy ester with monocarboxylic acid is also mentioned.

  Some examples are hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate Such as hydroxy (meth) acrylate, isocyanuric acid diacrylate, pentaerythritol diacrylate monostearate, 2-hydroxy-3-phenoxypropyl acrylate, and these caprolactone adducts, ethylene oxide adducts, propylene oxide adducts, ethylene oxide Examples include propylene oxide adducts.

  Moreover, the hydroxyl group of epoxy acrylate can also be utilized. Specific examples of the compound include 2 in 1 molecule such as neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and the like. Mention may be made of epoxy acrylates obtained by reacting a compound having one epoxy with acrylic acid. Since these components have two (meth) acryloyl groups in one molecule, they also have an effect of improving the crosslinking density.

  Specific (meth) acrylic compounds having a carboxyl group include (meth) acrylic acid itself and the above hydroxy (meth) acrylate, carboxylic acid anhydrides such as maleic anhydride, succinic anhydride, phthalic anhydride, tetrahydro Examples include compounds obtained by reacting phthalic anhydride and the like.

  Some examples are pentaerythritol triacrylate succinic acid monoester, dipentaerythritol pentaacrylate succinic acid monoester, pentaerythritol triacrylate maleic acid monoester, dipentaerythritol pentaacrylate maleic acid monoester, pentaerythritol triacrylate phthalate Acid monoester, dipentaerythritol triacrylate phthalic acid monoester, pentaerythritol triacrylate tetrahydrophthalic acid monoester, dipentaerythritol pentaacrylate tetrahydrophthalic acid monoester and the like.

  In the reaction between the isocyanate compound and the specific (meth) acrylic compound, other active hydrogen compounds capable of reacting with the isocyanate compound can be used in combination. That is, a compound that does not have a (meth) acryloyl group and can react with an isocyanate group may be used in combination.

  When such an active hydrogen compound is selected and used according to the purpose, the softening point of the resulting curable composition is increased, or the flexibility of the finally obtained cured coating film is increased. As such an active hydrogen-containing compound, a hydroxyl group-containing compound is usually used, but an amino group-containing compound or a carboxyl group-containing compound can also be used.

  Examples of the hydroxyl group-containing compound include glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 2-hydroxyethyl-1,6-hexanediol, 1,2,4-butanetriol, erythritol, sorbitol, Polyhydric alcohols having three or more hydroxyl groups such as pentaerythritol and dipentaerythritol; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3- Propanediol, 2-buty 2-ethyl-1,3-propanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 1,6-hexanediol, 2- Ethyl-1,3-hexanediol, neopentyl glycol, 1,3,5-trimethyl-1,3-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,8-octanediol, Aliphatic glycols such as 1,9-nonanediol and 2-methyl-1,8-octanediol, alicyclic glycols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, xylylene glycol, bishydroxy Aromatic glycols such as ethoxybenzene are used.

  High molecular weight polyols such as polyether polyols, polyester polyols, polyether ester polyols, polycarbonate polyols, and polyacryl polyols can also be used. Polyether polyols include glycols such as bisphenol A, ethylene glycol, propylene glycol and diethylene glycol, polyols having three or more hydroxyl groups such as glycerin, trimethylolethane, trimethylolpropane and pentaerythritol, or ethylenediamine and toluene. Examples include polyamines such as diamines obtained by addition polymerization of alkylene oxides such as ethylene oxide and propylene oxide, and polytetramethylene ether glycols obtained by ring-opening polymerization of tetrahydrofuran.

  Polyester polyols include dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid and phthalic acid, or carboxylic acids such as tri- and tetracarboxylic acids such as trimellitic acid and pyromellitic acid, and ethylene glycol and propylene glycol. 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2-diethylpropanediol, 2-ethyl-2-butylpropanediol, 1,6-hexanediol Diols such as neopentyl glycol, diethylene glycol, 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, triols such as trimethylolpropane and glycerin, or aromatic polyhydroxylation such as bisphenol A and bisphenol F Those obtained by the polycondensation reaction between objects.

  Examples of the polyether ester polyol include those obtained by reacting polyester glycol with an alkylene oxide, or those obtained by reacting the above-mentioned dicarboxylic acid or anhydride thereof with an ether group-containing diol or a mixture thereof with another glycol. (Polytetramethylene ether) adipate and the like. Polycarbonate polyol is obtained by dealcoholization condensation reaction between polyhydric alcohol and dialkyl carbonate such as dimethyl or diethyl, dephenol condensation reaction between polyhydric alcohol and diphenyl carbonate, deethylene glycol condensation reaction between polyhydric alcohol and ethylene carbonate, etc. A polycarbonate polyol is mentioned. Examples of the polyhydric alcohol used in this condensation reaction include 1,6-hexanediol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, and 3-methyl-1,5-pentane. Aliphatic diols such as diol, 2,2-diethylpropanediol, 2-ethyl-2-butylpropanediol and neopentyl glycol, or alicyclics such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol Diols can be mentioned.

  Examples of the amino group-containing compound (amine compound) include hexamethylenediamine, xylylenediamine, isophoronediamine, N, N-dimethylethylenediamine, and the like. Also, amino alcohols such as monoethanolamine and diethanolamine can be used as the active hydrogen-containing compound.

  Examples of the carboxyl group-containing compound (organic carboxylic acid) include lauric acid, stearic acid, oleic acid, palmitic acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, and the like.

  These active hydrogen compounds other than the specific (meth) acryl compound are active against the reactive group of the specific (meth) acryl compound so as not to impair the properties of the reaction product of the isocyanate compound and the specific (meth) acryl compound. It is preferable to use such that the molar ratio of the reactive group of the hydrogen compound is 50% or less, particularly 40% or less.

  The reaction between the isocyanate compound and the specific (meth) acrylic compound is preferably performed using a solvent. By using a solvent, the reaction can be easily controlled, and the viscosity of the reaction product can be adjusted. Examples of the solvent include inert solvents commonly used for this type of reaction, for example, aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, ethyl acetate, butyl acetate, and isobutyl acetate. Ester solvents, glycol ether ester solvents such as diethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, ethyl-3-ethoxypropionate, ether solvents such as tetrahydrofuran and dioxane, An aprotic polar solvent such as N-methylpyrrolidone is used.

  In the reaction, the reaction raw material is added to a solvent so that the concentration of the reaction product in the reaction product solution is 30 to 80% by weight, and if necessary, 0.01 to 0.1% by weight of organic tin based on the reaction raw material What is necessary is just to make it react at 50-80 degreeC in presence of a system catalyst. The charging ratio of the isocyanate compound to the specific (meth) acrylic compound and other active hydrogen compound used in combination with the specific (meth) acrylic compound which can react with the isocyanate group of the isocyanate compound and other It is preferable that the functional group of the active hydrogen compound is 0.5 mol or more, particularly 1 mol or more. The reaction time is usually about 3 to 8 hours, but it is preferable to monitor the content of isocyanate groups in the reaction product solution by analysis and stop the reaction when this reaches a target value.

  As the ionizing radiation curable composition of the present invention, a reaction product of the isocyanate compound thus prepared and a specific (meth) acrylic compound having a softening point of 40 ° C. or higher is used. The softening point of the ionizing radiation curable composition is preferably 50 ° C. or higher, more preferably 60 ° C. or higher. When the softening point of the ionizing radiation curable composition is lower than 40 ° C., the coating film before curing is blocked or the embossing moldability is poor.

In addition, the softening point prescribed | regulated to this invention means what was measured on condition of the following about what removed the solvent from the reaction product.
Equipment used: ARES-2KFRTNI manufactured by Rheometrics
Measurement mode: Temperature dependence test of dynamic viscoelasticity, 25 mm parallel plate Measurement temperature range: −50 to 150 ° C.
Vibration frequency: 1 rad / sec The temperature at which the melt viscosity is 5000 Pa · sec when measured under the above conditions is defined as the softening point.

  In addition, the (meth) acryl group in the ionizing radiation curable composition of the present invention is preferably 5% by weight or more, more preferably calculated by calculating the molecular weight of the olefinic double bond (—C═C—) as 24. Is 10% by weight or more. When the (meth) acrylic group content is low, the crosslink density after ionizing radiation curing is lowered, solvent resistance, heat resistance, etc. are insufficient, resulting in poor peeling and shaping sagging during vinyl chloride film formation.

  In addition, although content of an olefinic double bond is measured by IR, NMR, etc., when a manufacturing process is known, it is calculated | required also by calculation from preparation amount.

  In addition to the above components, the coating liquid used in the present invention preferably contains a silicone compound in order to impart releasability to the surface of the ionizing radiation cured film. When the silicone compound is contained, the silicon-derived silicon content in the surface of the ionizing radiation-cured film (ie, the peeled surface from the synthetic leather) is 5 to 30%, and synthetic leather is produced using release paper. It is preferable that the silicon-derived silicon existing ratio on the surface of the ionizing radiation-cured film when the step of repeating is repeated 5 times is 5% or more. In this specification, “silicon-derived silicon abundance ratio” means atomic% of the silicon atoms among the atoms detected from the release paper surface by X-ray photoelectron spectroscopy (hereinafter referred to as XPS) analysis (however, Ignore hydrogen atoms). By making the silicon presence ratio on the surface of the ionizing radiation cured film 5 to 30%, excellent peelability can be maintained even when used for the production of synthetic leather. In addition, when the ratio of silicon-derived silicon on the surface of the ionizing radiation cured film is 5% or more when the process of producing synthetic leather using the release paper of the present invention is repeated 5 times, the release paper is repeatedly used. It has been found that even when synthetic leather is produced by using it, the release paper can be sufficiently maintained.

  The content of the silicone compound contained in the ionizing radiation cured film is usually 20% by weight or less, preferably 0.5 to 20% by weight, and more preferably 1 to 15% by weight. When the amount of the silicone compound is more than 20% by weight, the coating film becomes sticky or the cost increases. When the amount is less than 0.5% by weight, the effect of improving the peelability is not sufficient.

  The silicone compound used in the present invention may be reactive or non-reactive. Examples of the reactive silicone compound include (meth) acryloyl-modified, vinyl-modified, amino-modified, mercapto-modified, epoxy-modified, carboxyl-modified, phenol-modified, and alcohol-modified silicone compounds.

  Specific examples of the (meth) acryloyl-modified silicone include X-22-164B, X-22-164C (manufactured by Shin-Etsu Chemical Co., Ltd.), FM-0711, FM-0721, FM0725 (manufactured by Chisso Corporation), As vinyl-modified silicone, XF40-A1987 (manufactured by Toshiba Silicone), and as amino-modified silicone, TSF4700, TSF4702, TSF4705 (manufactured by Toshiba Silicone), X-22-161AS, KF393, KF864 (manufactured by Shin-Etsu Chemical Co., Ltd.) BY16-208, SF8417 (manufactured by Toray Dow Corning Silicone), X-22-167B, KF-2001 (manufactured by Shin-Etsu Chemical Co., Ltd.) as the mercapto-modified silicone, YF3965, TSF4730 (manufactured by Shin-Etsu Chemical Co., Ltd.) Toshiba silicone Manufactured), KF105, X-22-169AS (manufactured by Shin-Etsu Chemical Co., Ltd.), SF8421, SF8413 (manufactured by Toray Dow Corning Silicone), carboxyl-modified silicone, TSF4770, XF-A9248 (manufactured by Toshiba Silicone), X-22-162A, X-22-3701E (manufactured by Shin-Etsu Chemical Co., Ltd.), SF8418, BY16-750 (manufactured by Toray Dow Corning Silicone Co., Ltd.), phenol modified silicones, X-22-165B (Shin-Etsu Chemical Co., Ltd.) BY16-752, BY16-150C (manufactured by Toray Dow Corning Silicone), alcohol-modified silicones such as TSF4750, TSF4751 (manufactured by Toshiba Silicone), BY16-848, BY16-201 (Toray Dow Corning)・ Silicone ), FM-4411, FM-4425, FM-0411, FM-0425, FM-DA21 (Chisso Corporation), and the like.

  Moreover, you may use the silicone compound synthesize | combined using these reactive silicones. The synthesized silicone compound may or may not further have a reactive group. Silicone compounds synthesized using reactive silicone include silicone-modified (meth) acrylic polymer and silicone-modified (meth) acrylate using (meth) acryloyl-modified silicone, silicone-modified epoxy acrylate using epoxy-modified silicone, alcohol-modified Examples include silicone-modified urethane polymers and silicone-modified urethane acrylates using silicone. Of these, silicone-modified urethane acrylate is particularly preferable.

  Examples of the non-reactive silicone compound include silicone compounds that do not have the above reactive group. Specific examples of the compound include TSF451, YF3800 (manufactured by Toshiba Silicone), dimethylpolysiloxane, KF96A (manufactured by Shin-Etsu Chemical Co., Ltd.), SH200 (manufactured by Toray Dow Corning Silicone), and TSF433 as methylphenylpolysiloxane. , TSF434 (manufactured by Toshiba Silicone), SH510, SH702 (manufactured by Dow Corning Toray), polyether-modified silicones TSF4440, TSF4445 (manufactured by Toshiba Silicone), KF-351, KF-353 (Shin-Etsu Chemical) SH3746, SH3748 (made by Toray Dow Corning Silicone), SS-2803, SS-2801 (made by Nihon Unicar).

  These silicone compounds may be used alone or in combination of two or more, and both reactive and non-reactive compounds may be used. From the viewpoint of compatibility with other components, the silicone compound preferably has a ring structure such as an aromatic, alicyclic, or isocyanuric acid skeleton. Examples of the silicone compound having a ring structure include a silicone compound such as methylphenyl silicone in which a phenyl group is introduced into the side chain, and a method of introducing a ring structure using a reactive silicone. As a method for introducing a ring structure using a reactive silicone, diphenylmethane diisocyanate is added to a silicone compound in which (meth) acryloyl-modified silicone and styrene are copolymerized to introduce a phenyl group, a silicone-modified urethane polymer or a silicone-modified urethane acrylate. Examples thereof include silicone compounds in which a ring structure is introduced using a monomer of naphthalate, naphthalene diisocyanate, isophorone diisocyanate or a trimer thereof. These silicone compounds having a ring structure may or may not have a reactive group.

  In the present invention, pinholes are further reduced by using two or more ionizing radiation-cured film layers. Therefore, it is preferable to use two or more layers. It is preferable that the silicone compound is contained in an amount of 0.5 to 20% by weight in at least one of the two or more layers. More preferably, the uppermost layer (that is, the peeled surface of the synthetic leather) disposed on the side opposite to the support side contains 0.5 to 20% by weight of a silicone compound. Thus, by including a silicone compound in the uppermost layer surface, the releasability can be improved, and even when synthetic leather is produced using repetitive release paper, the releasability of the release paper can be sufficiently maintained. When the ionizing radiation curable film is composed of a plurality of layers, the layers other than the uppermost layer may not contain a silicone compound.

  In addition to the silicone compound, the coating liquid used in the present invention may contain, as an optional component, a resin having a film-forming property, an inorganic pigment, etc., in order to modify the curing characteristics of the reaction product.

  In this case, it is more preferable that the lowermost layer contains an inorganic pigment in an amount of 0.5 to 50% by weight, particularly 1 to 10% by weight. Inorganic pigments used for this include talc, kaolin, silica, calcium carbonate, barium sulfate, titanium oxide, and zinc oxide.

  In a more preferred embodiment, the lowermost layer disposed on the support side contains 0.5 to 50% by weight of inorganic pigment, and the uppermost layer disposed on the side opposite to the support side contains 0.5 to 20% by weight of silicone compound. % Is included. Thus, excellent releasability can be imparted by including the inorganic pigment in the layer on the support side and the silicone compound in the layer opposite to the support side (layer on the release surface side of the synthetic leather). The reason for this is not clear, but for example, when an inorganic pigment and a silicone compound are contained in the same ionizing radiation cured film layer, the silicone compound may be affected by the inorganic pigment depending on the film formation conditions (for example, From the adsorption of silicone compounds to inorganic pigments). For example, when emphasizing a design effect such as imparting a matte feeling to the surface of the release paper, an inorganic pigment may be added to the uppermost layer disposed on the side opposite to the support side.

  As the resin having film-forming properties, methacrylic resin, chlorinated polypropylene, epoxy resin, polyurethane resin, polyester resin, polyvinyl alcohol, polyvinyl acetal, and the like can be used. Further, these resins having film-forming properties may or may not have reactive groups. Examples of the reactive group include (meth) acryloyl group, vinyl group, amino group, mercapto group, epoxy group, carboxyl group, phenol group, hydroxyl group and the like. A methacrylic resin is preferable from the viewpoint of adhesion to a substrate, film-forming property, etc., but from the viewpoint of embossability, a methacrylic resin having a glass transition temperature (Tg) of 40 ° C. or higher is preferable, and Tg is 50 ° C. or higher In addition to ordinary methacrylic compounds, maleic anhydride, methacrylic acid, styrene, hydroxyethyl methacrylate, maleimide group-containing methacrylate, isobornyl group-containing methacrylate, and the like can also be used as a copolymerization component.

  The amount of the resin having a film-forming property is usually 70% by weight or less, preferably 1 to 70% by weight, more preferably 20 to 60% by weight as the content in the coating liquid. When the resin having a film-forming property exceeds 70% by weight, that is, when the ionizing radiation curable composition is less than 30% by weight, the heat resistance after ionizing radiation curing becomes insufficient. By blending an appropriate amount of a resin having a film-forming property, there is an effect that the adhesion to the substrate, the film-forming property, etc. are improved.

  Furthermore, in addition to or in place of the above-mentioned resin and silicone compound having a film-forming property, the coating liquid includes a reactive monomer, a reactive oligomer, a pigment, a photopolymerization initiator, a polymerization inhibitor, a colorant, A surfactant or the like may be contained.

  Reactive monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, ethylhexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, tridecyl ( It is preferable to use (meth) acrylate, trimethylolpropane triacrylate, tris (acryloxyethyl) isocyanurate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, or the like.

  As the reactive oligomer, it is preferable to use epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, or the like.

  Examples of the photopolymerization initiator include benzoin ethyl ether, acetophenone, diethoxyacetophenone, benzyldimethyl ketal, 2-hydroxy-2-methylpropiophenone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino Propane-1, 1-hydroxycyclohexyl phenyl ketone, benzophenone, p-chlorobenzophenone, Michler's ketone, isoamyl N, N-dimethylaminobenzoate, 2-chlorothioxanthone, 2,4-diethylthioxanthone and the like are preferably used.

  In addition, the solvent is appropriately added so that the viscosity is easy to apply. Examples of the solvent include aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ester solvents such as ethyl acetate, butyl acetate and isobutyl acetate, diethylene glycol ethyl ether acetate, propylene Glycol ether ester solvents such as glycol methyl ether acetate, propylene glycol monomethyl ether, 3-methyl-3-methoxybutyl acetate, ethyl-3-ethoxypropionate, ether solvents such as tetrahydrofuran and dioxane, N-methylpyrrolidone, etc. These aprotic polar solvents are used.

Support will now be described support used in the present invention. Support materials include fine paper, kraft paper, glossy kraft paper, pure white roll paper, glassine paper, and uncoated paper such as base paper for cups, art paper with inorganic pigment coating layers, coated paper, and cast coat. Coated paper such as paper, synthetic paper that does not use natural pulp, and the like can also be used. In particular, when used for the production of PVC leather, it is necessary to use neutral paper rather than acidic paper because heat resistance to processing at a high temperature of 200 ° C. or higher is required. For acidic paper, a rosin-based sizing agent using a sulfuric acid band as a fixing agent is used as a sizing agent, but for neutral paper, a neutral rosin-based sizing agent that does not use a sulfuric acid band as a fixing agent, alkyl ketene dimer (AKD), Neutral sizing agents such as alkenyl succinic anhydride (ASA) are used.

Moreover, in embossing, in order to have good moldability, sufficient strength, and moderate smoothness, the pulp is a mixed system of softwood pulp and hardwood pulp, and contains at least 20% of softwood pulp. The basis weight is preferably 80 to 250 g / m ² .

  Furthermore, when a sealing layer made of the above-mentioned resin having the film-forming property and those obtained by adding an inorganic pigment to these resins is applied on these supports, the generation of pinholes due to the penetration of the coating liquid is suppressed. And smoothness is also imparted.

  Examples of the resin having a film-forming property used for forming the sealing layer include polyvinyl alcohol, acrylic resin, styrene acrylic resin, cellulose derivative, polyester resin, polyurethane resin, melamine resin, alkyd resin, aminoalkyd resin, polychlorinated resin. There are vinyl resin, polyvinylidene chloride resin, and the like, and these may be used in combination.

Inorganic pigments to be added include talc, kaolin, silica, calcium carbonate, barium sulfate, titanium oxide, zinc oxide, etc., and are usually blended so as to be 0.5 to 70% by weight with respect to the resin having film-forming properties. To do. The amount of the sealing layer may be 0.5 to 20 g / m ^2. If the amount is too small, the sealing effect is not exhibited. If the amount is too large, the embossing property is hindered. The sealing material is applied in the same manner as the ionizing radiation curable resin composition described later.

Ionizing radiation curable film The ionizing radiation curable film constituting the release paper of the present invention is formed by applying and curing the above coating liquid. As the coating liquid, a solution diluted with 10 to 1000 parts by weight of a solvent based on 100 parts by weight of the solid content can be used. By diluting the solvent, an appropriate viscosity is applied to the coating, for example, a viscosity of 10 to 3000 mPa · sec at 25 ° C., and the silicone compound can be transferred to an appropriate surface in the drying step.

  Coating methods for the coating liquid include direct gravure coating, reverse gravure coating, gravure offset coating, micro gravure coating, direct roll coating, reverse roll coating, curtain coating, knife coating, air knife coating, bar coating, die coating, spray coating, etc. The known method is used, and after coating on a paper substrate, the solvent is evaporated in a drying furnace to form a coating film.

If the coating liquid is applied so that the dry weight after evaporation of the solvent is 1 to 40 g / m ² , preferably 5 to 20 g / m ² , good embossing property can be obtained.

  Moreover, it is preferable to use two or more ionizing radiation cured film layers, and pinholes are further reduced by using two or more layers. When two or more ionizing radiation-cured film layers are used, the lowermost ionizing radiation-cured film layer preferably contains 0.5 to 50% by weight, particularly 1 to 10% by weight, of an inorganic pigment. As the inorganic pigment, the same pigments as those used for the filler layer can be used, and talc, kaolin, silica, calcium carbonate, barium sulfate, titanium oxide, zinc oxide and the like can be preferably used.

  Further, the ionizing radiation cured film layer may contain a silicone compound. In that case, the silicone compound may be contained only in the uppermost layer of the ionizing radiation curable film layer, or may be contained in each layer.

  Since the above coating liquid is coated on a support and the dried coating film is tack-free, it can be wound up without blocking the whole paper substrate after drying, and post-processing embossing can be performed offline. . Furthermore, by appropriately setting the embossing roll temperature and the softening temperature of the coating liquid, good moldability can be obtained without the coating liquid adhering to the embossing roll.

  Embossing is generally performed by transferring and embossing a metal emboss roll having a concavo-convex pattern, but a belt-type or lithographic-type press apparatus may be used. When the embossing roll is used, there are a double-sided embossing in which the backup roll is a female type and a single-sided embossing with no unevenness in the backup roll, in contrast to the male type of the embossing roll.

  When forming using the embossing apparatus on the support on which the coating liquid has been applied, the ionizing radiation curable composition is heated to a temperature of 50 to 150 ° C. This temperature is preferably higher than the softening point of the ionizing radiation curable composition contained in the coating solution and lower than the temperature at which the resin melts. In the heating method, the roll itself is usually heated by passing steam through the embossing roll, but a preheating method in which the coating liquid is heated in advance just before embossing is also possible.

  In order to obtain the above-mentioned good tack-free properties and moldability, the softening point of the ionizing radiation curable composition is 40 ° C. or higher, preferably 50 ° C. or higher, as described above. When the softening point is less than 40 ° C., tack-free property and formability become insufficient.

  After embossing, the curable coating film to which the coating liquid has been applied is cured by irradiating ultraviolet rays or electron beams from the side of the curable coating film. As the ultraviolet light source, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, a xenon lamp, a tungsten lamp, or the like is used. As an electron beam irradiation method, a scanning method, a curtain beam method, a broad beam method, or the like is used, and an acceleration voltage of the electron beam is appropriately 50 to 300 kV.

Method for Producing Synthetic Leather Using Release Paper FIG. 1 is a diagram showing an example of a production process for release paper of the present invention. In the figure, 1 is a drawing roll, 2 is an embossing roll, 3 is a backup roll, 4 is a winding roll, 5 is a paper with a curable coating film, 6 is a paper with a curable coating film with an embossing, and 7 is a release paper with an embossing. Respectively. A represents an embossing process, and B represents an ionizing radiation irradiation process.

  Next, a method for producing synthetic leather using the release paper obtained in the present invention will be described. Any known method can be used. For example, as a method for producing PU leather, a paste-like PU resin for skin layer is applied on release paper, dried and solidified at a temperature of 110 to 140 ° C., and then a two-component curable PU adhesive. Then, after bonding to the base fabric and reacting in an aging chamber at 40 to 70 ° C. for 2 to 3 days, the release paper is peeled off to produce PU leather. As a method for producing PVC leather, a paste-like PVC sol is applied on release paper, heated and gelled, and then a PVC sol containing a foaming agent is applied and heated to form a foam layer. There is a method of manufacturing PVC leather by laminating with a base fabric and then peeling off the release paper.

  The synthetic leather obtained in this way has a silicon-derived silicon content of 20% or less on the surface on the side from which the release paper has been peeled. When the release paper is peeled to produce a synthetic leather, a certain amount of silicone compound transferred from the release paper is present on the surface of the obtained synthetic leather. The present inventors confirmed this fact by XPS analysis of the release paper surface and the synthetic leather surface. That is, it means that the amount of the silicone compound transferred from the release paper (silicon-derived silicon existing ratio) is at most smaller than the silicone-derived silicon existing ratio on the surface of the release paper. The present inventors have obtained the knowledge that even when synthetic leather is produced using releasable release paper, the silicon-derived silicon content on the surface from which the release paper has been peeled is 30% or less. It is a thing.

  Moreover, even when synthetic leather is repeatedly produced using the release paper of the present invention as described above, the silicon-existing ratio of silicon on the release surface of the synthetic leather is 30% or less. Therefore, even when the release paper is used repeatedly, the excellent release property of the release paper is maintained.

  EXAMPLES Next, although an Example demonstrates this invention in detail, this invention is not limited to a following example, unless the summary is exceeded.

1. Synthesis of ionizing radiation curable compositions Two types of ionizing radiation curable compositions were synthesized as follows.

<Ionizing radiation curable composition A>
A reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 206.1 g of ethyl acetate and 133.5 g of isophorone diisocyanate trimer (Degussa, VESTANAT, T1890) and heated to 80 ° C. Warm to dissolve. After blowing air into the solution, 0.38 g of hydroquinone monomethyl ether, 249.3 g of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Osaka Organic Chemical Co., Ltd., Biscoat 300) and 0.38 g of dibutyltin dilaurate were added. Prepared. After reacting at 80 ° C. for 5 hours, 688.9 g of ethyl acetate was added and cooled.

  As a result of infrared absorption spectrum analysis, it was confirmed that the obtained ionizing radiation curable composition A was extinguished by isocyanate groups. When the ethyl acetate was distilled off from the ionizing radiation curable composition A, the softening temperature was 43 ° C.

<Ionizing radiation curable composition B>
A reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 256.67 g of methyl ethyl ketone and 110 g of isophorone diisocyanate trimer and heated to 80 ° C. for dissolution. After blowing air into the solution, 0.20 g of hydroquinone monomethyl ether, 146.65 g of a mixture of pentaerythritol tetraacrylate and pentaerythritol triacrylate, 30.08 g of epoxy acrylate (manufactured by Kyoeisha Chemical Co., Ltd., epoxy ester 70PA), and dibutyltin dilaurate 0.20 g was charged. After reacting at 80 ° C. for 5 hours, 412.37 g of methyl ethyl ketone was added and cooled.

  As a result of infrared absorption spectrum analysis, it was confirmed that the obtained ionizing radiation curable composition B was extinguished by isocyanate groups. The softening temperature of the product obtained by distilling off methyl ethyl ketone from the ionizing radiation curable composition B was 68 ° C.

2. Synthesis of resin having film-forming property A resin having a film-forming property was obtained by synthesis as follows.

<Resin a>
When a solution equipped with 30 g of isobornyl methacrylate, 65 g of methyl methacrylate, 5 g of glycidyl methacrylate, and 200 g of toluene was heated in a reactor equipped with a stirrer, reflux condenser, dropping funnel and thermometer, and the temperature was raised to 65 ° C. 2 hours after reaching 65 ° C., 0.5 g of 2,2′-azobis (2,4-dimethylethylvaleronitrile) was added and reacted at 65 ° C. for 5 hours to obtain a copolymer. It was. Then, while blowing air, the temperature was raised intermittently to 108 ° C., 0.2 g of hydroquinone monomethyl ether and 0.2 g of triphenylphosphine were added, 2.5 g of acrylic acid was added and reacted for 5 hours to react with acryloyl group. A resin a having a film forming property was obtained.

3. Preparation of Silicone Compound Two types of silicone compounds were prepared as follows.

<Silicone compound α>
To a reactor equipped with a stirrer, reflux condenser, dropping funnel and thermometer, 23.3 g of methyl ethyl ketone and 10 g of isophorone diisocyanate, 20.4 g of a mixture of pentaerythritol tetraacrylate and pentaerythritol triacrylate, and 0.10 g of dibutyltin dilaurate, After adding 0.10 g of hydroquinone monomethyl ether, blowing air into the solution, reacting at 25 ° C. for 3 hours, and then reacting for 5 hours while intermittently raising the temperature to 80 ° C., the alcohol-modified silicone (FMDA21 manufactured by Chisso Corporation) 240.8 g was added and reacted for another 5 hours, and then 609.3 g of methyl ethyl ketone was added and cooled to obtain a silicone-modified urethane acrylate (silicone compound α) containing an acryloyl group and silicone. .

<Silicone compound β>
In a reactor equipped with a stirrer, reflux condenser, dropping funnel and thermometer, a solution of 10 g of 2-hydroxyethyl methacrylate, 40 g of styrene, 40 g of methacryl-modified silicone (FM0711 manufactured by Chisso) and 2 g of lauryl mercaptan in 200 g of methyl ethyl ketone. When heated to 65 ° C. and 2 hours after reaching 65 ° C., 0.6 g of 2,2′-azobis (2,4-dimethylethylvaleronitrile) was added, and 65 ° C. For 5 hours to obtain a copolymer. This was obtained by reacting 22.2 g of isophorone diisocyanate, 57.1 g of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate at 25 ° C. for 3 hours, and then reacting for 5 hours while intermittently raising the temperature to 80 ° C. 79.3 g of an adduct was added and reacted at 80 ° C. for 5 hours to obtain a copolymer having an acryloyl group and silicone (silicone compound β).

4). Pretreatment of the support Using neutral paper with a basis weight of 125 g / m ² as the support, an acrylic resin containing the following composition silica as a covering material for the sealing layer, and a coating thickness after drying with a bar coater of 5 g The coating was performed so as to be / m ² . After coating, it was dried at 110 ° C. for 1 minute.

[acrylic resin]
Styrene / acrylic emulsion (manufactured by Seiko Polymer Co., Ltd., X-436) 25 parts by weight Water-soluble acrylic resin (manufactured by Johnson Polymer Co., Ltd., PDX-6102) 25 parts by weight Silica (manufactured by Fuji Silysia Chemical Ltd., Cycilia 350) 10 parts by weight Isopropyl alcohol 25 parts by weight water 25 parts by weight

5. Preparation of coating solution 30 parts by weight of the above-mentioned ionizing radiation curable composition A, 60 parts by weight of resin a having a film-forming property, and 10 parts by weight of silicone compound β (the above-mentioned parts by weight are solid parts by weight). Composition 1 was prepared by mixing. A part of the composition was sampled and the softening temperature was measured.

  In the same manner as described above, 80 parts by weight of the ionizing radiation curable composition B, 10 parts by weight of the resin a having a film-forming property, and 10 parts by weight of the silicone compound α (the above-mentioned parts by weight are all solid parts by weight). The composition 2 was prepared by mixing. A part of the composition was sampled and the softening temperature was measured.

6). Production of release paper 3 parts by weight of photopolymerization initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., Irgacure 907) with respect to 100 parts by weight of the solid content of composition 1, and the solid content concentration of methyl ethyl ketone as a diluent solvent It added so that it might become 30 weight%. The obtained mixture is applied to neutral paper without a sealing layer with a bar coater, and is applied so that the coating thickness is about 5 to 10 g / m ² after drying. Evaporated to dryness by heating.

  Next, 3 parts by weight of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., Irgacure 907) was added to 100 parts by weight of the solid content of Composition 2, and methyl ethyl ketone was added as a dilution solvent so that the solid content concentration was 30% by weight. . The obtained mixture was applied onto the coating film made of the above composition 1 in the same manner as described above, and then heated and evaporated to dryness.

  Thereafter, the coating surface was embossed. The embossing was performed by pressing a paper roll with a female mold as a backup roll against a metal embossing roll having an uneven pattern.

At this time, the embossing roll temperature is 120 ° C., and the support and the dried coating film are embossed at the same time. It was confirmed that the unevenness was sufficiently formed even on the back side of the paper. Next, using a high-pressure mercury lamp with an output of 120 W / cm, ultraviolet irradiation at 600 mj / cm ² was performed to cure the coating film, thereby obtaining a release paper.
Example 1

  For the resin that becomes the skin layer of the synthetic leather, the following substances were weighed and mixed to prepare an ester polyurethane solution.

<Composition of ester polyurethane solution>
Ester-based polyurethane resin (Crisbon NB-637N, manufactured by Dainippon Ink & Chemicals, Inc.) 100 parts by weight Color (Dailac TV-COLOR, manufactured by Dainippon Ink & Chemicals, Inc.) 15 parts by weight Methyl ethyl ketone 20 parts by weight Dimethylformamide 10 Parts by weight

  The prepared ester polyurethane solution was applied onto the release paper obtained above with a knife coater so as to have a dry thickness of 20 μm, and dried with hot air at 100 ° C. for 2 minutes to form a polyurethane skin layer. Next, as an adhesive layer on the polyurethane skin layer, a two-component curable polyester polyurethane adhesive 1 having the following composition was applied with a knife coater so as to have a dry thickness of 40 μm, and a knitted fabric was bonded.

<Composition of adhesive 1>
Main agent Two-part curable ester polyurethane resin (Dai Nippon Ink Chemical Co., Ltd., Chrisbon 4070) 100 parts by weight Curing agent Two-part curable urethane resin hardener (Dainippon Ink Chemical Co., Ltd., Crisbon NX ) 13 parts by weight Accelerator Two-part curable urethane resin curing accelerator (Dai Nippon Ink Chemical Co., Ltd., Chrisbon Accel HM) 3 parts by weight Solvent Methyl ethyl ketone 30 parts by weight

The bonded product was dried with hot air at 100 ° C. for 5 minutes, and further aged for 48 hours to react and solidify the adhesive. Then, in order to evaluate the suitability of the release paper by repeated use, when producing dry PU synthetic leather by peeling it from the release paper, (1) peel strength between the release paper and synthetic leather, and (2) the release paper surface after peeling And the ratio of silicone on the surface of the leather side was measured. In addition, this operation was performed 5 times and the change by repeated use was confirmed.
Example 2

  A synthetic leather was produced and evaluated in the same manner as in Example 1 except that the adjustment of the adhesive 1 in Example 1 was as follows.

<Composition of adhesive 2>
Main agent Two-part curable ester polyurethane resin (Dainippon Ink & Chemicals Co., Ltd. Chris Bon TA-265) 100 parts by weight Curing agent Two-part curable urethane resin curing agent (Dainippon Ink & Chemicals, Inc. Crisbon NX) 13 parts by weight Accelerator Two-part curable urethane resin curing accelerator (Dainippon Ink & Chemicals, Inc. Chrisbon Accel HM) 3 parts by weight Solvent Toluene / ethyl acetate (1/1) 25 parts by weight
Example 3

  A synthetic leather was manufactured and evaluated in the same manner as in Example 1 except that the adjustment of the adhesive 1 in Example 1 was as follows.

<Composition of adhesive 3>
Main component Two-component curable ester polyurethane resin (Dainippon Ink & Chemicals Co., Ltd. Chris Bon TA-205) 100 parts by weight Curing agent Two-component curable urethane resin curing agent (Dainippon Ink & Chemicals, Inc. Crisbon NX) 13 parts by weight Accelerator Two-part curable urethane resin curing accelerator (Dainippon Ink & Chemicals, Inc. Crisbon Accel HM) 3 parts by weight Solvent Toluene / ethyl acetate (1/1) 30 parts by weight

6). Evaluation (1) Repeated peelability With respect to the peelability when peeling the manufactured synthetic leather and the release paper, using a tensile testing machine (Tensilon RTC-1310A manufactured by Orientec Co., Ltd.), the speed of the synthetic leather 15 mm width is 300 mm / min. Was peeled from the release paper at 180 ° C., and the peel strength was measured. Using similar release paper, synthetic leather was repeatedly produced in the same manner as in the above example, and the peelability when peeling the synthetic leather and release paper was also measured. The results were as shown in Table 1 below.

(2) Silicon-derived silicon abundance ratio Silicone-derived silicon abundance ratio of release paper before producing synthetic leather and synthetic leather produced as described above using the release paper was measured. The measurement was performed as follows.

  First, as a surface analyzer, an X-ray photoelectron spectrometer (XPS, device name: ESCALAB 220i-XL (Thermo VG Scientific)) was used, and release paper and synthetic leather were cut into 1 cm squares at arbitrary positions, and the stage And pre-treatment was performed.

As the X-rays used, non-monochromatic Al-Kα rays were used (output: 300 W), the sample was set at a photoelectron capture angle of 90 degrees, and the silicon surface analysis of the release paper and synthetic leather was conducted, and the silicone present on the surface Origin silicon abundance was measured. The background processing conditions of the measurement results were performed by the Shirley method. Similarly to the above, using the same release paper, a synthetic leather was repeatedly produced in the same manner as in the above Example, the synthetic leather and the release paper were peeled off, and the respective silicon abundances were measured. The results were as shown in Table 2 below.

It is a figure which shows an example of the manufacturing process of the release paper of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pulling roll 2 Embossing roll 3 Backup roll 4 Winding roll 5 Paper with curable coating film 6 Paper with curable coating film with embossing 7 Release paper with embossing A Embossing process B Irradiation process of ionizing radiation

Claims (15)

An embossed release paper for producing synthetic leather, comprising at least paper as a support and an ionizing radiation cured film provided on the paper, and embossed on the cured film,
The ionizing radiation cured film is
A reaction product comprising an isocyanate compound and a (meth) acrylic compound having a (meth) acryloyl group and capable of reacting with the isocyanate compound, or an isocyanate compound, having a (meth) acryloyl group and reacting with the isocyanate compound A reaction product comprising a (meth) acrylic compound to be obtained and a compound having no (meth) acryloyl group and capable of reacting with an isocyanate group,
An embossed release paper, wherein the coating liquid comprising at least an ionizing radiation curable composition having a softening point of 40 ° C. or higher is cured by irradiation with ionizing radiation.   The release paper with embossing according to claim 1, wherein the ionizing radiation-cured film comprises a silicone compound.   Silicone on the surface of the ionizing radiation-cured film when the silicon-containing ratio of silicon derived from the surface of the ionizing radiation-cured film is 5 to 30% and the process of producing synthetic leather using a release paper is repeated 5 times. The release paper with embossing according to claim 2, wherein the silicon content is 5% or more.   The release paper with embossing of Claim 2 or 3 whose content of the silicone compound contained in the said ionizing radiation cured film is 0.5 to 20 weight%.   The release paper with embossing as described in any one of Claims 1-4 in which the said ionizing radiation hardening film further contains 1-70weight% of resin which has film forming property.   The release paper with embossing as described in any one of Claims 1-5 by which the sealing layer which consists of resin which has an inorganic pigment and film forming property is given to the surface of the said support body.   The release paper with embossing according to any one of claims 1 to 6, wherein the ionizing radiation-cured film is composed of at least two layers.   8. The embossed release paper according to claim 7, wherein the ionizing radiation curable film having two or more layers contains at least one or more inorganic pigments in an amount of 0.5 to 50% by weight.   The release paper with embossing according to claim 8, wherein the ionizing radiation curable film having two or more layers comprises 0.5 to 50 wt% of an inorganic pigment in the lowermost layer disposed on the support side.   The release sheet with embossing according to any one of claims 7 to 9, wherein in the ionizing radiation curable film having a structure of two or more layers, at least one layer contains a silicone compound in an amount of 0.5 to 20% by weight. .   The said ionizing radiation hardening film which consists of a structure of two or more layers WHEREIN: A silicone compound is contained in 0.5-20 weight% in the uppermost layer arrange | positioned on the opposite side to a support body side. The release paper with embossing as described in one item | term. In the ionizing radiation cured film comprising two or more layers,
The lowermost layer arranged on the support side contains 0.5 to 50% by weight of an inorganic pigment,
The release paper with embossing according to any one of claims 7 to 11, wherein the uppermost layer disposed on the side opposite to the support side contains 0.5 to 20% by weight of a silicone compound. In the ionizing radiation cured film comprising two or more layers,
The lowermost layer arranged on the support side contains 0.5 to 50% by weight of an inorganic pigment,
The release paper with embossment according to any one of claims 7 to 11, wherein each layer contains 0.5 to 20% by weight of a silicone compound.   A synthetic leather produced using the release paper according to any one of claims 1 to 13, wherein the silicon-derived silicon present in the release surface of the synthetic leather obtained by peeling the release paper is present. A synthetic leather characterized by being 20% or less.   The synthetic leather according to claim 14, wherein the release paper is used a plurality of times.

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