JP4984799B2 - Embossed process release paper - Google Patents

Description

  The present invention relates to an embossed process release paper, and more particularly to an embossed process release paper that is excellent in formability and heat resistance during embossing.

  Conventionally, synthetic leather made of vinyl chloride resin or polyurethane resin as a main raw material has been widely used. Such synthetic leather is often manufactured using process release paper. For example, in order to produce polyurethane leather, a paste-like polyurethane resin is applied on a process release paper, dried and solidified, and then bonded to a base fabric and peeled from the process release paper. If a drawing pattern or other irregularities similar to those of natural leather are formed on the process release paper, a good pattern can be imparted to the surface of the resulting synthetic leather. Based on the same principle, a paste-like polyurethane resin may be applied onto the process release paper, dried and solidified, and then a vinyl chloride foam layer may be formed and bonded to the base fabric, and then released from the process release paper. Also, as a method for producing vinyl chloride leather, after applying vinyl chloride sol on the process release paper, heating and gelling, forming a vinyl chloride foam layer and bonding it to the base fabric, and then peeling it from the process release paper There is also.

  The process release paper used for the production of such synthetic leather is generally prepared by applying a release layer made of a resin to a paper substrate and then embossing a specific pattern on the release layer. The process release paper is to transfer the surface pattern to form the surface pattern on the synthetic leather, and it is necessary to have a surface state suitable for the formation of the concavo-convex pattern. As a method of obtaining, a laminating method in which a resin composition composed of polypropylene and polyethylene and a polypropylene homopolymer are coextruded on a substrate is disclosed (Patent Document 1). The laminate laminated with polypropylene has severe extrusion unevenness because it is extruded at a temperature at which lamination is possible. However, in order to improve this, when low density polyethylene is mixed, uneven compatibility and rough skin occur. Therefore, the surface condition is improved by co-extruding a resin composition comprising polypropylene having a specific melt flow rate and polyethylene having a specific structure and a polypropylene homopolymer having a specific melt flow rate onto a substrate. It is what. According to the above-mentioned patent document 1, unevenness of extrusion is eliminated in order to use a specific resin composition by co-extruding the resin composition and a polypropylene homopolymer to make the resin composition the base material side. The use of polypropylene homopolymer provides excellent surface conditions without heat resistance, uneven gloss and rough skin. In the examples, the surface state is evaluated together with the laminate properties such as extrusion unevenness, and a laminate having excellent surface gloss and smoothness is obtained.

In addition, in order to produce a polyurethane-based synthetic leather bonded on the back surface with a cloth as a base material, a polyurethane resin is applied to the process release paper and dried, and then an isocyanate group is formed on the polyurethane layer in order to bond the cloth base material. A polyurethane two-component adhesive comprising a first liquid containing a component having a functional group and a second liquid composed of a polyol is used. This two-component adhesive has a strong adhesive force and is frequently used for furniture such as sofas and shoes that have a long use period or are used frequently. In the above process, an isocyanate group having high reactivity is used. The process may be shifted to a process release paper, which may impair the peelability of the process release paper and reduce the productivity. As a process release paper that can be easily peeled from such a polyurethane two-component adhesive and has excellent heat resistance, there is an embossed release paper composed of a paper and an ionizing radiation cured film (Patent Document 2). In Patent Document 2, the cured film does not have an isocyanate compound, a (meth) acryloyl group that has an (meth) acryloyl group and can react with the isocyanate compound, and no (meth) acryloyl group. And a reaction product of a compound capable of reacting with an isocyanate group, which is obtained by curing an ionizing radiation curable composition containing an ionizing radiation curable composition having a softening point of 40 ° C. or higher with ionizing radiation. Yes. In the examples, an ionizing radiation curable film is formed by coating the ionizing radiation curable composition twice on a paper base material provided with a sealing layer, and embossing having excellent embossing property, heat resistance, and repeated peelability. Manufactures attached release paper.
JP-A-5-82806 JP 2005-186516 A

  Synthetic leather manufactured using process release paper is manufactured in accordance with the application and consumer preference in addition to a matte type whose surface is matte, and a gloss type that is excellent in smoothness and gloss. In the laminate obtained by laminating polypropylene described in Patent Document 1, since polypropylene is thermoplastic, it has excellent embossing properties during embossing, and the emboss contrast is clear and glossy. Therefore, heat resistance is not enough. For this reason, the emboss may be melted by heat during drying of the synthetic resin due to repeated use, and the number of repeated use is limited. Therefore, a process release paper having excellent heat resistance and embossing property and high mechanical strength is desired.

  The process release paper described in Patent Document 2 is excellent in mechanical strength because it has an ionizing radiation curable film. However, the ionizing radiation curable film is formed by laminating two layers of the ionizing radiation curable composition. . Although the ionizing radiation curable composition is extremely expensive, if the amount used is reduced, the resin layer becomes thin, so that deep embossing cannot be performed, and it is difficult to ensure a deep texture. Therefore, if the amount of expensive ionizing radiation curable composition used can be reduced while ensuring embossability, the process release paper can be produced at low cost, which is advantageous.

  In addition, as shown in Patent Document 2, the process release paper using a paper base material is a paper base that has been previously treated with an acrylic resin containing silica in order to prevent the release agent from penetrating into the paper base material. Although the material is used, the embossing contrast is reduced by the silica or the like included in the sealing treatment, and the resulting process release paper tends to be matte, making it impossible to produce gloss type process release paper. In particular, the process release paper using the ionizing radiation curable composition tends to be a mat type. Therefore, a process release paper that is a gloss-type process release paper even when an ionizing radiation curable composition is used and that can prevent penetration of the release agent without a sealing layer is desired.

  In addition, it is preferable that the process release paper can be reused. For this purpose, it is preferable to improve the adhesion between the paper substrate and the release layer laminated thereon, and the machine is sufficient for reuse. A process release paper having the desired strength is desired.

  Under such circumstances, the present invention is capable of repeatedly producing synthetic leather made of a resin composition having a high melting point such as vinyl chloride leather, and is excellent in heat resistance, mechanical strength, and embossability. The purpose is to provide paper.

  As a result of detailed examination of the structure of the embossed process release paper, the present inventor has excellent adhesion to the paper base material and embossing property when the cross-linked polyolefin resin is laminated on the paper base material. It is suitable as a gloss-type process release paper because of its excellent contrast, and when an ionizing radiation-curing resin layer is laminated on a cross-linked polyolefin resin, it is excellent in heat resistance, so it can prevent fine deformation of the mold due to heat. Moreover, the amount of ionizing radiation curable resin used can be reduced, and further, when a thermosetting silicone layer is laminated, it is possible to ensure releasability even when a highly reactive adhesive such as a polyurethane two-component adhesive is used. The present invention was completed.

  The embossed process release paper of the present invention does not have a sealing layer in which silica or the like is blended, and thus can be suitably used as a gloss type process release paper.

  In the embossed process release paper of the present invention, the embossing forming layer is composed of a cross-linked polyolefin resin and an ionizing radiation curable resin layer, so that the thickness of the layer can be secured. A feeling can be formed. In addition, excellent embossability can be ensured by the cross-linked polyolefin resin.

  The embossed process release paper of the present invention has high mechanical strength and can be reused multiple times in the synthetic leather manufacturing process, which is economical.

  The present invention is an embossed process release paper in which a paper base material, a cross-linked polyolefin resin layer, an ionizing radiation curable resin layer, and a thermosetting silicone layer are laminated in this order and have embossing. Cross-linked polyolefin resin can be molded under the same molding conditions as polyolefin resin, and by cross-linking, heat characteristics such as heat resistance, low temperature characteristics, chemical characteristics such as oil resistance, impact resistance, friction resistance, and creep characteristics And other mechanical properties are improved. Moreover, it is crosslinked by being immersed in warm water or exposed to a hot and humid atmosphere and contacting with moisture. Therefore, in this invention, the process release paper which is excellent in embossing property and heat resistance can be manufactured by including this bridge | crosslinking type polyolefin resin in a peeling layer, without requiring a specific process. The present invention will be described in detail with reference to FIG. 1 showing an example of a preferred embodiment of the present invention.

(1) Embossed process release paper As shown in FIG. 1, the embossed process release paper comprises a thermosetting silicone layer (10), an ionizing radiation curable resin layer (20), and a crosslinkable polyolefin resin layer ( 30) and a paper substrate (40) are laminated in this order and embossed. The cross-linked polyolefin resin layer (30) is excellent in adhesion to paper substrate and embossing property, and the ionizing radiation curable resin layer (20) has high mechanical strength to prevent deformation of the molding process. Enables paper reuse. In addition, peelability is ensured by providing a thermosetting silicone layer (10) in the uppermost layer.

(2) Paper Base The paper base of the present invention has a strength that can withstand the process of laminating the cross-linked polyolefin resin layer (30), the ionizing radiation curable resin layer (20), and the thermosetting silicone layer (10). Further, it is necessary to have properties such as heat resistance and chemical resistance as a release paper for a process at the time of coating and forming synthetic leather, and to be easily embossed. In addition to non-coated paper such as kraft paper, high-quality paper, single gloss kraft paper, pure white roll paper, glassine paper, and cup base paper, synthetic paper that does not use natural pulp can also be used. For the processability of synthetic leather, it is preferable to use paper made of natural pulp in terms of durability and heat resistance.

In the present invention, the paper used as the base material layer has a basis weight of 15 to 300 g / m ² , preferably 100 to 180 g / m ² . If it is this range, embossing will be easy. The paper is preferably neutral paper. Acidic paper containing a sulfuric acid band or the like is subject to thermal degradation when used repeatedly in the synthetic leather manufacturing process, which may make it difficult to reuse it early. If it is a neutral paper, such thermal deterioration can be prevented.

  The paper used in the present invention may use neutral rosin, alkyl ketene dimer, alkenyl succinic anhydride as a sizing agent, and use cationic polyacrylamide or cationic starch as a fixing agent. Also good. Moreover, although it is most preferable not to use a sulfuric acid band for the said reason, it is also possible to make paper in a neutral region of pH 6-9 using a sulfuric acid band. In addition to the above sizing agents, as well as fixing agents, various papermaking fillers, yield improvers, dry paper strength enhancers, wet paper strength enhancers, binders, dispersants, flocculants, plastics An agent and an adhesive may be appropriately contained.

(3) Crosslinkable polyolefin resin layer The crosslinkable polyolefin resin constituting the crosslinkable polyolefin resin layer of the present invention can be obtained, for example, by crosslinking a polyolefin polymer by a conventional method. Examples of polyolefin polymers used include ethylene, propylene, 1-butene, 2-methyl-1-butene, 1-pentene, 2-methyl-1-pentene, 1-hexene, and 2,2-dimethyl-1-butene. 2-methyl-1-hexene, 4-methyl-1-pentene, 1-heptene, 2-methyl-1-hexene, 3-methyl-1-hexene, 2,2-dimethyl-1-pentene, 3,3 -Dimethyl-1-pentene, 2,3-dimethyl-1-pentene, 3-ethyl-1-pentene, 2,2,3-trimethyl-1-butene, 1-octene, 2,2,4-trimethyl-1 -Homopolymers of α-olefins such as octene, and copolymers of these α-olefins and other polymerizable monomers.

  Examples of other polymerizable monomers include vinyl compounds such as vinyl acetate, styrene, acrylonitrile, methacrylonitrile, and vinyl ketone; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; methyl acrylate, ethyl acrylate, acrylic Examples thereof include unsaturated carboxylic acid esters such as acid n-propyl, methyl methacrylate, ethyl methacrylate, and n-propyl methacrylate; unsaturated carboxylic acid amides such as acrylamide and methacrylamide. These polymerizable monomers can be used alone or in combination of two or more.

  Examples of a method for crosslinking a polyolefin polymer include (i) a method for chemically crosslinking a polyolefin polymer using a radical generator, (ii) a method for radiation crosslinking using an electron beam, etc., and (iii) a molecule. Examples thereof include a method of crosslinking a crosslinked olefin polymer having an unsaturated bond or an alkoxysilane group with heat or water by catalytic action. Among these, the method (iii) is preferable from the viewpoint of not requiring special and expensive crosslinking equipment.

  The crosslinked olefin polymer used in the above method (iii) contains a polymerizable double bond and / or alkoxysilane group in the molecule, and the polymers are separated from each other by the polymerizable double bond and / or alkoxysilane group. It is a crosslinked polymer. In the present invention, a vinylsilane-modified olefin polymer such as a polymer obtained by graft copolymerization of a vinylsilane compound to a polyolefin polymer or a polymer obtained by random copolymerization of a vinylsilane compound and an olefin is used. preferable. Examples of the vinylsilane-modified olefin polymer include polymers described in JP-B-48-1711, JP-A-59-36115, JP-A-55-9611, JP-A-11-181187, and the like. . More specifically, for example, various vinyl silane-modified olefin polymers commercially available under the trade name of Wrinklon (manufactured by Mitsubishi Chemical Corporation) can be used.

  The method for curing the cross-linked polyolefin resin is not particularly limited. For example, a method of leaving at room temperature, a method of heating to a predetermined temperature, a method of feeding a dry gas of a predetermined temperature to the surface of the resin composition layer, silanol Examples thereof include a method of crosslinking in the presence of a condensation catalyst. Among these methods, when a vinylsilane-modified olefin polymer is used, a method using a silanol condensation catalyst is preferable. By using a silanol condensation catalyst, the crosslinking reaction can easily proceed with water or moisture in the air, and a crosslinked polyolefin resin layer having a desired gel fraction can be formed. Therefore, it is preferable that the cross-linked polyolefin resin layer contains at least a vinylsilane-modified olefin polymer and a silanol condensation catalyst.

  As the silanol condensation catalyst to be used, for example, metal carboxylates such as tin, zinc, iron, lead and cobalt, organometallic compounds such as titanate and chelate, organic bases, inorganic acids, organic acids and the like are used. Can do. More specifically, dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, stannous acetate, stannous caprylate, lead naphthenate, zinc caprylate, cobalt naphthenate, tetrabutyl titanate, titanate Examples thereof include inorganic acids such as tetranonyl ester, ethylamine, dibutylamine, hexylamine, pyridine, sulfuric acid and hydrochloric acid, and organic acids such as toluenesulfonic acid, acetic acid, stearic acid and maleic acid. In order to allow the silanol condensation catalyst to be present in the reaction system when the layer of the cross-linked polyolefin resin is cured, (a) a method of blending as a master batch in which the silanol condensation catalyst is previously melt-kneaded with the polyolefin polymer, (B) A method in which the silanol condensation catalyst is directly blended with the resin as it is produced. The usage-amount of a silanol condensation catalyst is 0.001-10 mass parts normally with respect to 100 mass parts of vinylsilane modified olefin polymers, Preferably it is the range of 0.01-5 mass parts.

  The gel fraction (degree of crosslinking) of the vinylsilane-modified olefin polymer is preferably 40% or more, and more preferably 45% or more. A crosslinkable polyolefin resin layer containing a crosslinkable polyolefin resin having a gel fraction of 40% or more exhibits excellent strength over a long period of time.

  The gel fraction (%) can be determined as follows. (1) About 50 mg of a cross-linked polyolefin resin layer portion is collected, and the mass of the sample is accurately weighed. This value is A (mg). Next, (2) the sample bubbles are crushed and placed in a test tube, immersed in 10 ml of xylene, and the test tube is left in an oil bath at 120 ° C. for 24 hours. (3) Thereafter, the mixture is filtered through a container having a 200 mesh stainless steel wire mesh, the insoluble portion on the wire mesh is taken out, vacuum dried at 80 ° C. for 4 hours (pressure 10 mmHg), and then the dry mass B (mg ). (4) The obtained A and B are substituted into the formula: gel fraction (%) = (B / A) × 100.

  The gel fraction after curing of the crosslinkable polyolefin resin can be changed by changing the graft ratio of the vinylsilane compound of the crosslinkable polyolefin resin, the type and amount of the silanol condensation catalyst, and the conditions (temperature, time) for crosslinking. Can be adjusted.

  Further, an additive may be further added to the cross-linked polyolefin resin as desired. Examples of additives include antioxidants, light stabilizers, UV absorbers, heavy metal deactivators, metal soaps, epoxy compounds, pigments, dyes, flame retardants, antistatic agents, lubricants, processing aids, Examples include nucleating agents, plasticizers, fillers, and foaming agents.

  The melt flow rate value (MFR value) before curing of the cross-linked polyolefin resin is preferably in the range of 5 to 40 g / 10 min. By using a crosslinkable polyolefin resin having an MFR value in this range, a crosslinkable polyolefin resin layer having an easy and uniform thickness can be formed. Here, the MFR value (g / 10 minutes) is a flow rate for 10 minutes expressed in grams when a cross-linked polyolefin resin melted at a constant temperature is extruded from a circular die having a specified length and diameter. It is also called a melt index. The MFR value can be measured according to JISK6922-2 (temperature 190 ° C., load 2.16 kg).

  Examples of the coating / molding method of the cross-linked polyolefin resin include an extrusion molding method. Examples of the extrusion molding method include a blow molding method, an injection blow molding method, a pipe molding method, a film molding method, and a sheet molding method. More specifically, a method of extrusion molding (melt extrusion molding) of a melt of the resin composition on a base sheet using a known molding machine is preferable. Although the molding temperature at the time of extrusion molding depends on the melting temperature of the resin to be molded, it is usually in the range of 100 to 300 ° C, preferably 140 to 240 ° C.

  The thickness of the cross-linked polyolefin resin layer is preferably 3 to 40 μm, more preferably 5 to 20 μm. If it is thinner than 3 μm, the peelability after the production of synthetic leather may be lowered, whereas if it exceeds 40 μm, the curl of the process release paper may be increased.

  Since the cross-linked polyolefin resin layer is excellent in adhesiveness with an ionizing radiation curable resin layer described later, it can be adhered to the cross-linked polyolefin resin layer without performing surface treatment or the like. In the present invention, the cross-linked polyolefin resin layer may have a surface treatment layer. Such surface treatments include corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, etc., and other pretreatments, etc. is there.

(4) Ionizing radiation curable resin layer The ionizing radiation curable resin layer used in the present invention is a reaction product of an isocyanate compound and a (meth) acrylic compound having a (meth) acryloyl group and capable of reacting with the isocyanate compound. The reaction product having a softening point of 40 ° C. or higher, or an isocyanate compound, a (meth) acryloyl group that can react with the isocyanate compound, and a (meth) acryloyl group. In addition, an ionizing radiation curable composition comprising a reaction product with a compound capable of reacting with an isocyanate group and having a softening point of 40 ° C. or higher is cured by ionizing radiation. 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 is 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 mass, and if necessary, 0.01 to 0.1% by mass 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.

  The ionizing radiation curable composition of the present invention is a reaction product of the isocyanate compound thus prepared and a specific (meth) acrylic compound, and has a softening point of 40 ° C. or higher. Is 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 measurement of the softening point prescribed | regulated to this invention shall be measured by the method as described in the Example mentioned later.

  Further, the (meth) acryl group in the ionizing radiation curable composition of the present invention is preferably 5% by mass or more, more preferably calculated by calculating the molecular weight of the olefinic double bond (—C═C—) as 24. Is 10% by mass 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.

  The ionizing radiation curable composition used in the present invention may be used as a reaction product of an isocyanate compound and a specific (meth) acrylic compound itself, but it modifies the curing characteristics of the reaction product. Therefore, a resin having a film forming property, a silicone compound, an inorganic pigment, and the like may be included as an optional component.

  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. From the viewpoint of embossability, a methacrylic resin having a glass transition temperature (Tg) of 40 ° C. or higher is preferable, and a Tg of 50 ° C. or higher is preferable. 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 film-forming property is 70% by mass or less, preferably 1 to 70% by mass, more preferably 20 to 60% by mass as the content in the ionizing radiation curable composition comprising the reaction product. is there. When the resin having a film-forming property exceeds 70% by mass, that is, when the reaction product is less than 30% by mass, the heat resistance after ionizing radiation curing may be 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.

  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.

  Content of the silicone compound in an ionizing radiation-curable composition is 0-20 mass%, Preferably it is 0.5-20 mass%, More preferably, it is 1-15 mass%. When the silicone compound is more than 20% by mass, the coating film may become sticky or the cost may increase. However, the content of the reaction product in the ionizing radiation curable composition should not be less than 30% by mass.

  Furthermore, in the ionizing radiation curable composition used in the present invention, in addition to the resin having a film-forming property and the silicone compound described above, a reactive monomer, a reactive oligomer, a pigment, a photopolymerization initiator, a polymerization inhibitor, Coloring agents, surfactants, and the like may be included within a range that does not impair the characteristics.

  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.

  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.

  This ionizing radiation curable composition may be diluted with 10 to 1000 parts by mass of solvent with respect to 100 parts by mass of the solid content. 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.

  As the coating method, known as direct gravure coat, reverse gravure coat, gravure offset coat, micro gravure coat, direct roll coat, reverse roll coat, curtain coat, knife coat, air knife coat, bar coat, die coat, spray coat, etc. A method is used, and after coating on a cross-linked polyolefin resin film, drying and heating are performed, and the solvent is evaporated in a drying furnace to thermally cure the ionizing radiation curable composition. This temperature is a range higher than the softening point of the ionizing radiation curable composition and lower than the temperature at which the ionizing radiation curable composition melts.

  The thermosetting ionizing radiation curable composition can be cured with ionizing radiation by irradiating ultraviolet rays or electron beams from the thermosetting silicone layer side after embossing. 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.

(5) Thermosetting silicone layer The thermosetting silicone layer used in the present invention is formed by thermosetting a thermosetting silicone composition comprising an alkenyl group-containing organopolysiloxane, an organohydrogenpolysiloxane and a platinum-based curing catalyst. It is.

  Examples of the alkenyl group-containing organopolysiloxane include the following compounds.

以上のアルケニル基含有オルガノポリシロキサンの分子量は特に限定されないが、一般的には３，５００〜２０，０００の範囲が好適である。これらのアルケニル基含有オルガノポリシロキサンは市場から入手でき本発明で容易に使用することができる。

The molecular weight of the above alkenyl group-containing organopolysiloxane is not particularly limited, but is generally in the range of 3,500 to 20,000. These alkenyl group-containing organopolysiloxanes are commercially available and can be easily used in the present invention.

Organohydrogenpolysiloxane used in the present invention are those -R ¹ -X, at least one of -R ² -Z, and -R ³ -Y in the general formula is a hydrogen atom, the other The substituent, the arrangement of siloxane units, the molecular weight and the like are the same as in the general formula. These alkenyl group-containing organopolysiloxanes are commercially available and can be easily used in the present invention.

  The proportion of the alkenyl group-containing organopolysiloxane and the organohydrogenpolysiloxane is determined by the molar ratio of the reactive groups of the both, and the ratio of the former to the latter is 4: 1 to 1: 4, particularly 1: 1 to 1. : 3 is preferred, and if it is outside this range, satisfactory performance cannot be obtained in terms of reduction in releasability, reduction in coating film strength, deterioration in storage stability due to unreacted reactive groups, and the like.

  In the present invention, a platinum-based curing catalyst is further used. The catalyst is preferably used in an amount of about 5 to 200 parts by mass per 100 parts by mass of the alkenyl group-containing organopolysiloxane and organohydrogenpolysiloxane.

  The thermosetting silicone composition composed of the above alkenyl group-containing organopolysiloxane, organohydrogenpolysiloxane, and platinum-based curing catalyst, the reaction proceeds even at room temperature, and the progress of the reaction in the coating solution is degraded. In addition, a problem arises in the storage and handling properties of the coating liquid. In the present invention, in order to solve such a problem, a reaction inhibitor that has a reaction suppressing effect on the thermosetting silicone composition at normal temperature and that eliminates the suppressing effect at the time of heat treatment may be used. Specifically, the reaction inhibitor used in the present invention, in the state of the solvent solution, suppresses the action of the curing catalyst on the thermosetting silicone composition described above, the heated state and the state where the solvent is volatilized, That is, it is a material that does not suppress the action of the curing catalyst in the heated or dried state, but rather promotes it. Examples of such a curing inhibitor include silylated products of acetylene alcohol. These reaction inhibitors can be obtained from the market and used. Such a reaction inhibitor is preferably used at a ratio of about 5 to 100 parts by mass per 100 parts by mass of the thermosetting silicone composition.

  As such a thermosetting silicone composition, a commercially available product may be used. For example, a main component of an addition polymerization type silicone material (Shin-Etsu Chemical Co., Ltd.) composed of a mixture of an alkenyl group-containing organopolysiloxane and an organohydrogenpolysiloxane. It can be prepared by mixing a curing agent comprising a platinum-based curing catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., CA T-PL-50T) with Kogyo Co., Ltd. (KS-3603).

  The thermosetting silicone composition is a material that is in a solid state at room temperature but changes to a liquid state by heating during processing.

  The thermosetting silicone composition of the present invention requires curability in order to fix a fine uneven pattern formed by embossing and to obtain sufficient film properties such as strength.

  The method of forming the thermosetting silicone layer of the present invention itself may be the same as the formation of the dye-receiving layer such as application of the thermosetting silicone composition, drying and heating, and aging, and the thickness of the thermosetting silicone layer to be formed is The range of 0.01-20 micrometers is preferable.

(6) Method for producing embossed process release paper The embossed process release paper of the present invention is a laminate in which a cross-linked polyolefin resin layer, an ionizing radiation curable resin layer, and a thermosetting silicone layer are laminated on a paper substrate. And if it is embossed, there will be no restriction | limiting in the manufacturing method. In particular, a crosslinkable polyolefin resin layer is laminated on a paper substrate, an ionizing radiation curable composition is coated on the crosslinkable polyolefin resin layer, dried and thermally cured to form an ionizing radiation curable composition film. Heat cure. Next, the thermosetting silicone composition is applied onto the heat-cured ionizing radiation composition film and dried by heating to form a thermosetting silicone film, whereby a pre-embossed laminate can be produced.

  Next, the laminate before embossing is embossed to form a concavo-convex pattern having a specific pattern. This is because, if, for example, a drawing pattern similar to that of natural leather is formed on the process release paper, synthetic leather that is more similar to natural leather can be produced. Further, if a pattern such as a grain or a leaf or other design irregularities is formed on the process release paper, a pattern having a matte tone and a specific pattern can be transferred onto the surface of the obtained synthetic leather. In order to form a concavo-convex pattern on the surface of the embossed process release paper by such embossing, for example, an embossing roll having a concavo-convex pattern mold on the surface and a paper roll or metal roll receiving the concavo-convex of this embossing roll are opposed to each other. The embossing machine provided with, or the embossing machine provided with the embossing roll and the metal roll having the surface unevenness corresponding to the uneven shape of the embossing roll, the above-mentioned matte embossed process release paper is poured, Pressure is applied by a heated embossing roll to form an uneven pattern on the embossed process release paper. Usually, the heating temperature of the embossing roll is 50 to 150 ° C. and the pressure is 40 to 100 kgf / cm. This temperature is in a range higher than the softening point of the ionizing radiation curable composition and lower than the temperature at which the resin melts. As the heating method, the roll itself is usually heated by passing steam through the embossing roll, but a preheating method in which the ionizing radiation curable composition is heated in advance just before embossing is also possible. In addition, you may emboss by a flat press using a flat embossing plate, without using an embossing roll.

  Next, the cross-linked polyolefin resin layer is cross-linked and subjected to a radiation curing treatment.

  The method for curing the cross-linked polyolefin resin is not particularly limited. For example, a method of leaving at room temperature, a method of heating to a predetermined temperature, a method of feeding a dry gas at a predetermined temperature to the surface of the resin composition layer, a silanol condensation catalyst And a method of crosslinking in the presence of. Among these methods, when a vinylsilane-modified olefin polymer is used, a method using a silanol condensation catalyst is preferable. By using a silanol condensation catalyst, the crosslinking reaction can easily proceed with water or moisture in the air, and a crosslinked polyolefin resin layer having a desired gel fraction can be formed.

  Specifically, as a method of curing a cross-linked polyolefin resin using a silanol condensation catalyst, (i) a cross-linked polyolefin resin blended with a silanol condensation catalyst is formed on a substrate by an extrusion method. Examples include a method in which a layer of a resin based resin is formed and then exposed to a water atmosphere, or (ii) a layer of a cross-linked polyolefin resin coated or impregnated with a silanol condensation catalyst is exposed to a water atmosphere. The conditions for exposing the cross-linked polyolefin resin layer in a water atmosphere are usually in the range of room temperature to 200 ° C. for 10 seconds to 1 week, preferably from normal temperature to It is in the range of 1 minute to 100 hours at a temperature of 130 ° C. Further, immediately after the layer of the cross-linked polyolefin resin is formed by the extrusion molding method, it can be performed simultaneously with the step of cooling the layer of the cross-linked polyolefin resin through a water tank.

  Further, the gel fraction (degree of crosslinking) of the crosslinkable polyolefin resin layer is preferably 40% or more, and more preferably 45% or more. The gel fraction after curing of the crosslinkable polyolefin resin can be changed by changing the graft ratio of the vinylsilane compound of the crosslinkable polyolefin resin, the type and amount of the silanol condensation catalyst, and the conditions (temperature, time) for crosslinking. Can be adjusted.

  The ionizing radiation curable resin is cured by irradiating ultraviolet rays or electron beams from the thermosetting silicone film side. 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. As described above, the ionizing radiation curable composition can be thermally cured before the embossing, thereby improving the coating property of the thermosetting silicone composition, and the embossing can be applied by curing the ionizing radiation after the embossing. The type can be secured.

  In the embossed process release paper of the present invention, the total thickness of the cross-linked polyolefin resin layer (30) and the ionizing radiation curable resin layer (20) is preferably 6 to 80 μm, more preferably. Is 10-40 μm. When the thickness is less than 6 μm, when the process release paper is repeatedly used, the paper base of the embossed process release paper and the cross-linked polyolefin resin layer may vary depending on the plasticizer contained in the raw material resin of the synthetic leather and the high temperature environment. May peel. On the other hand, when it exceeds 80 μm, the width curl of the embossed process release paper becomes large, and the workability may deteriorate.

(7) Method for Producing Synthetic Leather Synthetic leather can be produced in the same manner by using the process release paper with embossing of the present invention and using conventional process release paper.

  First, the resin composition for synthetic leather is apply | coated on the thermosetting silicone layer of the embossed process release paper. On the resin layer applied on the thermosetting silicone layer, a pattern (unevenness pattern) corresponding to the uneven pattern shape of the thermosetting silicone layer is formed. Thereafter, a base fabric (for example, woven fabric, non-woven fabric, etc.) is bonded to this, the resin layer is dried and cooled, and then the process release paper is peeled off to obtain a synthetic leather. Resins such as polyurethane and polyvinyl chloride can be used for the above resin composition for synthetic leather. When using polyurethane, it is preferable to make solid content of a resin composition into about 20-50 mass%. When polyvinyl chloride is used, it is preferable to use a resin composition mixed and dispersed with a plasticizer such as dioctyl phthalate or dilauryl phthalate, a foaming agent, a stabilizer, or the like. Examples of the coating method of the resin composition include conventionally known coating methods such as knife coating, roll coating, and gravure coating. In the production of synthetic leather using the embossed process release paper of the present invention, the release between the paper substrate and the cross-linked polyolefin resin layer even in the case of vinyl chloride leather production performed at high temperature. Is prevented, and the presence of the ionizing radiation curable resin layer having excellent heat resistance and high mechanical strength and the presence of the thermosetting silicone layer having excellent peelability enable repeated stable production.

  Next, the present invention will be described in more detail by showing specific examples. In the present invention, the specified softening point is measured by the following method.

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 When measured as described above, the temperature at which the melt viscosity is 5000 Pa · sec is defined as the softening point.

Synthesis Example 1: Synthesis of ionizing radiation curable composition 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. And dissolved. After blowing air into the solution, 0.30 g of hydroquinone monomethyl ether, 381.2 g of a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPHA), 1,4-butanediol 21 .2 g and dibutyltin dilaurate 0.30 g were charged. After reacting at 80 ° C. for 5 hours, 939.02 g of methyl ethyl ketone was added and cooled. As a result of infrared absorption spectrum analysis, it was confirmed that the reaction product solution had extinguished isocyanate groups. The softening temperature of the product obtained by distilling off methyl ethyl ketone from the reaction product liquid was 42 ° C.

Synthesis Example 2: Synthesis of resin having film-forming property A solution in which 30 g of isobornyl methacrylate, 65 g of methyl methacrylate, 5 g of glycidyl methacrylate, and 200 g of toluene were dissolved in a reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer. Was heated to 65 ° C., and 2 hours after reaching 65 ° C., 0.5 g of 2,2′-azobis (2,4-dimethylethylvaleronitrile) was added in portions of 65 g. The copolymer was obtained by reacting at 5 ° C. for 5 hours. 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 having a film forming property was obtained.

Synthesis Example 3: Preparation of thermosetting silicone ionizing radiation curable composition Main component of addition polymerization type silicone material comprising a mixture of alkenyl group-containing organopolysiloxane and organohydrogenpolysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., KS-3603) ) 5 parts by mass of a curing agent (Shin-Etsu Chemical Co., Ltd., CAT-PL-50T) comprising 100 parts by mass and a platinum-based curing catalyst, and toluene as a diluent solvent were added so that the solid content concentration was 10% by mass.

Example 1
3 photopolymerization initiators (Irgacure 907, manufactured by Ciba Specialty Chemicals Co., Ltd.) per 100 parts by mass of the solid content of the composition with respect to 40 parts by mass of the ionizing radiation curable composition and 60 parts by mass of the resin having film-forming properties. An ionizing radiation curable composition was prepared by adding methyl ethyl ketone as a part by mass and a diluent solvent so that the solid content concentration was 30% by mass.

Neutral paper (basis weight 130 g / m ² ) is used as the base paper, and water-crosslinkable polyolefin (product name: Linkron, XPM800HM (manufactured by Mitsubishi Chemical)), density 0.91, MFR16, Extrusion thickness: 30 μm) and catalyst master batch PZO1OS (added at a ratio of 0.5 parts by mass with respect to 100 parts by mass of XPM800HM) as a reaction catalyst were mixed and extruded to prepare a paper / water crosslinkable polyolefin substrate. Next, an ionizing radiation curable composition is applied to the upper part of the water-crosslinkable polyolefin with a bar coater, and is applied so that the coating thickness is about 5 g / m ² after drying. Evaporation drying was carried out for minutes to obtain an ionizing radiation curable composition film.

A thermosetting silicone composition is applied onto the obtained ionizing radiation curable coating film with a bar coater, and is applied so that the coating thickness becomes 0.5 g / m ² after drying. Heat-cured silicone film was formed by heating, evaporating, drying and heat-curing for minutes.

  Thereafter, embossing was performed. 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. The embossing roll temperature at this time is 120 ° C., and the support, the thermosetting silicone film, and the dry coating film of the ionizing radioactive resin are embossed simultaneously, and not only the dry coating film surface but also the back surface side of the support is good. Forming was performed, and it was confirmed that the unevenness was sufficiently formed not only on the coating surface but also on the back side of the paper.

Subsequently, 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 ionizing radiation curable composition film. Thereafter, in order to crosslink the water-crosslinkable polyolefin resin, it was stored at room temperature (about 23 ° C., humidity about 40% Rh) for 2 weeks, and finally an embossed release paper was obtained.

The obtained release paper is heated at 230 ° C. for 3 minutes, and the surface roughness (irregularities of specific portions (3 mm × 3 mm) are measured with a three-dimensional surface roughness measuring machine (Surfcom 590A manufactured by Tokyo Seimitsu Co., Ltd.)) is heated. The heat resistance was confirmed compared to the previous one. The results are shown in Table 1.

(Example 2)
Instead of extruding a water-crosslinkable polyolefin by the extrusion coating, the water-crosslinkable polyolefin (product name: Linkron, XPM800HM (manufactured by Mitsubishi Chemical)), density 0.91, MFR16) and the same catalyst as in Example 1 PZO1OS is mixed at a ratio of 0.5 part by mass with respect to 100 parts by mass of XPM800HM, and a resin obtained by dry blending 1: 1 with polypropylene (product name: PHA03A (manufactured by Sun Allomer), density 0.90, MFR42) is used. A release paper was produced in the same manner as in Example 1 except that the extrusion thickness was 30 μm.

The obtained release paper was evaluated for heat resistance in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
Polypropylene (product name: PHA03A (manufactured by Sun Allomer Co., Ltd.), density 0.90, MFR42) was extruded on the same paper substrate as in Example 1 to an extrusion film thickness of 30 μm and embossed at 120 ° C. with the same embossed pattern as in Example 1. Molding was performed at the roll temperature to obtain a release paper.

Attaching to this release paper, the heat resistance was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2)
XPM800HM100 mass of the same catalyst PZO1OS as in Example 1 and water-crosslinkable polyolefin (product name: Linklon, XPM800HM (manufactured by Mitsubishi Chemical)), density 0.91, MFR16) by extrusion coating on the same paper substrate as in Example 1. What was mixed at a ratio of 0.5 parts by mass with respect to the part was an extruded film thickness of 30 μm, and was molded at an embossing roll temperature of 120 ° C. with the same embossed pattern as in Example 1, and then a water-crosslinkable polyolefin resin was used. In order to crosslink, it was stored at room temperature (about 23 ° C., humidity 40% Rh) for 2 weeks to obtain release paper.

  Attaching to this release paper, the heat resistance was evaluated in the same manner as in Example 1. The results are shown in Table 1.

（結果）
実施例は、加熱前後でＲａ、Ｒｚの変化が殆ど無いが、比較例１は加熱により６割程維持率が低下しており、殆ど耐熱性は無いと判断できる。一方、比較例２もＲａ、Ｒｚ共に４〜５％程度低下しており、例えば、この様な高温条件下で繰返し使用した場合、賦型性の維持率の差が大きく影響してくると考えられる。

(result)
In Examples, there is almost no change in Ra and Rz before and after heating, but it can be judged that Comparative Example 1 has almost 60% of the maintenance rate decreased by heating, and hardly has heat resistance. On the other hand, in Comparative Example 2, both Ra and Rz are reduced by about 4 to 5%. For example, when repeatedly used under such a high temperature condition, it is considered that the difference in the maintainability of moldability greatly affects. It is done.

FIG. 1 is a view for explaining the laminated structure of the embossed process release paper of the present invention. FIG. 2 is a diagram showing a process for producing an embossed process release paper of the present invention.

Explanation of symbols

10 ... thermosetting silicone layer,
20 ... ionizing radiation curable resin layer,
30 ... cross-linked polyolefin resin layer,
40: Paper base material.

Claims (5)

  An embossed process release paper in which a paper substrate, a cross-linked polyolefin resin layer, an ionizing radiation curable resin layer, and a thermosetting silicone layer are laminated in this order and have embossing.   The process release paper according to claim 1, wherein the cross-linked polyolefin resin layer contains at least a vinylsilane-modified olefin polymer and a silanol condensation catalyst. The ionizing radiation cured film is
A reaction product of an isocyanate compound and a (meth) acrylic compound having a (meth) acryloyl group and capable of reacting with the isocyanate compound, the reaction product having a softening point of 40 ° C. or higher, or an isocyanate compound; A reaction product of a (meth) acrylic compound having a (meth) 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, A reaction product having a softening point of 40 ° C. or higher,
The process release paper with an embossing of Claim 1 or 2 which hardens | cures the ionizing radiation-curable composition which consists of these by ionizing radiation.   The process release paper with embossing in any one of Claims 1-3 in which the said ionizing radiation composition contains 1-70 mass% of resin which has film forming property.   The thermosetting silicone layer is formed by heat-curing a thermosetting silicone composition comprising an alkenyl group-containing organopolysiloxane, an organohydrogenpolysiloxane, and a platinum-based curing catalyst. Process release paper with embossing according to crab.

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