JP2012251253A - Release paper for producing synthetic leather and synthetic leather produced using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release paper for producing a synthetic leather, which sharpens mat feeling of a mat tone in the synthetic leather and easily produces the synthetic leather.SOLUTION: The release paper for producing the synthetic leather comprises: a paper substrate layer 4; a filling layer 3 provided on the paper substrate layer 4; and a release layer 2 formed on the filling layer 3. The filling layer 3 comprises a thermoplastic resin or thermosetting resin, and a silicone composite powder. In the filling layer 3, the silicone composite powders having an average particle diameter of 0.5-30 μm are blended in a range of 10-70 mass%.

Description

  The present invention relates to a release paper and a synthetic leather for producing synthetic leather, and more particularly relates to a release paper for producing a synthetic leather excellent in matte tone and a synthetic leather produced using this release paper.

  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 release paper. For example, in order to manufacture polyurethane leather, a paste-like polyurethane resin is applied on a release paper, dried and solidified, and then a base fabric is bonded and peeled off from the release paper. If a drawing pattern similar to natural leather or other irregularities are formed on the 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 a release paper, dried and solidified, and then a vinyl chloride foam layer may be formed and bonded to the base fabric and peeled off from the release paper. As a method for producing vinyl chloride leather, there is a method in which a vinyl chloride sol is applied on release paper, heated and gelled, a vinyl chloride foam layer is formed, bonded to a base fabric, and peeled off from the release paper. is there.

  In such a release paper, a pigment coated paper having an oil absorption of 200 to 1000 seconds based on JIS P-3001 is used as a support for a release paper for synthetic leather, and a styrene-butadiene copolymer is used as the pigment coated paper. A latex having a gel weight fraction with respect to toluene of 80% or more is applied, the release agent layer contains an inorganic pigment having an average particle diameter of 0.5 to 40 μm as a matting agent, and the surface of the release paper There is a release paper for synthetic leather, characterized in that the Oken type smoothness is in the range of 100 to 500 seconds (Patent Document 1). As release paper used for surface formation of matte type synthetic leather, a release layer is formed by adding an inorganic pigment such as silica to the support, which has high gloss and smoothness. The color is pale and jet black is low. However, according to the said structure, it is said that high jetness and uniformity can be provided to synthetic leather.

  There is also a release paper in which an ionizing radiation curable resin layer and a thermosetting silicone layer are laminated in this order and have embossing (Patent Document 2). By using a specific ionizing radiation curable resin layer, a release paper which is excellent in heat resistance, solvent resistance and mechanical strength and can be reused is provided.

  Furthermore, a silicone composition for release paper (organopolysiloxane having at least two alkenyl groups directly bonded to silicon atoms in one molecule and at least three hydrogen atoms (SiH groups) directly bonded to silicon atoms in one molecule) By adding silicone rubber fine powder to the organohydrogenpolysiloxane), the coating surface obtained by applying this composition to various substrates can extremely reduce the gloss, and the surface is glossy. Since there is no so-called matte tone and is excellent in uniformity, there is also one that uses this to easily produce a synthetic resin sheet having a matte surface (for example, Patent Document 3).

JP 2000-328464 A JP 2009-101685 A JP 2004-107642 A

In Patent Document 1, a matting agent having a specific average particle size is blended in the release layer to ensure jet blackness. In addition to the release paper for synthetic leather described in Patent Document 1, Patent Document 2 When inorganic particles such as glass are added to the release layer of the release paper described above, it is necessary to add a dispersant, which requires use of raw materials and manufacturing processes, and skill is required for uniform dispersion. Inexpensive and simple manufacturing is difficult.
In the release paper described in Patent Document 3, silicone rubber fine powder is directly added to the silicone layer (silicone composition for release paper), and the silicone rubber fine powder is transferred to the urethane resin side of the synthetic leather side body. Therefore, since this urethane resin becomes whitish, it is not possible to increase the blending amount of the silicone rubber fine powder used for suppressing the gloss value (the degree of gloss). Therefore, the gloss value cannot be lowered, and there is a problem in that synthetic leather that emphasizes the matte feeling according to the needs of consumers cannot be manufactured.
Under such circumstances, the present invention provides a release paper for producing synthetic leather that makes the matte feel of the synthetic leather clearer and easier to produce.

  For this reason, the invention according to claim 1 is a synthesis comprising a paper base layer, a sealing layer provided on the paper base layer, and a release layer formed on the sealing layer. A release paper for producing leather, wherein the eye stop layer is composed of a thermoplastic resin or a thermosetting resin and a silicone composite powder.

  The invention according to claim 2 is the release paper for manufacturing synthetic leather according to claim 1, wherein the silicone composite powder having an average particle size of 0.5 to 30 μm is contained in the filler layer in an amount of 10 to 70 mass. It is characterized by blending in the range of%.

  The invention according to claim 3 is the release paper for producing synthetic leather according to claim 1, characterized in that the thermoplastic resin is polyvinyl chloride acetate.

  Invention of Claim 4 is the synthetic leather manufactured using the release paper for synthetic leather manufacture of Claim 1 or 2.

  According to the invention described in claim 1, for manufacturing synthetic leather comprising a paper base material layer, a sealing layer provided on the paper base material layer, and a release layer formed on the sealing layer. In the release paper, the filler layer is made of a thermoplastic resin or a thermosetting resin and a silicone composite powder, so that the matte tone can be clearly exposed on the surface of the synthetic leather. In addition, the silicone composite powder allows the silicone composite powder to be uniformly dispersed in the sealing layer without using a dispersant during the production of synthetic leather, thereby simplifying the production process of the release paper for synthetic leather production. .

  According to the second aspect of the present invention, the silicone composite powder having an average particle size of 0.5 to 30 μm is blended in the filler layer in the range of 10 to 70% by mass in the eye stop layer. The matte tone can be clearly displayed on the leather surface.

  According to the invention described in claim 3, since the thermoplastic resin is polyvinyl chloride, it is a heat-resistant resin, so that it can be heated and deformed at the time of embossing but at the time of high-temperature drying at the time of synthetic leather production. Since it does not melt or liquefy and has flexibility, it can be smoothly wound on a roll, and the productivity of synthetic leather can be improved.

  According to the invention described in claim 4, since the synthetic leather is produced using the release paper for producing synthetic leather according to claim 1 or 2, synthetic leather excellent in matte tone can be efficiently produced, The quality and productivity of synthetic leather can be improved.

It is a figure explaining the release paper for synthetic leather manufacture of this invention which laminated | stacked the paper base material layer, the eye stop layer, and the thermosetting silicone layer. It is a figure explaining the structure of silicone composite powder. It is the figure explaining the sedimentation state of the silicone composite powder in a liquid with time. It is the figure explaining the sedimentation state of the silicone resin powder in a liquid with time. It is the figure explaining the sedimentation state of the silica fine particles in a liquid over time. It is an enlarged view (290 times and 720 times) of the peeling layer of the release paper for synthetic leather manufacture using silicone composite powder. It is an enlarged view (290 times and 720 times) of the peeling layer of the release paper for synthetic leather manufacture using silicone resin powder.

The best mode for carrying out the present invention will be described below with reference to the drawings. FIG.
FIG. 2 is a view for explaining a release paper for producing synthetic leather according to the present invention in which a paper base material layer, a sealing layer and a thermosetting silicone layer are laminated, and FIG. 2 is a view for explaining the structure of the silicone composite powder.

  As shown in FIG. 1, a release paper 1 for producing synthetic leather according to the present invention is a laminate in which a release layer 2, a sealing layer 3, and a paper base material layer 4 are laminated in order from the produced synthetic leather side. It consists of Note that an intermediate layer made of a thermoplastic resin may be laminated between the paper base material layer 4 and the sealing layer 3. Such an intermediate layer may improve the adhesion between the paper base material layer 4 and the sealing layer 3.

  The eye stop layer 3 is obtained by blending silicone composite powder (particles) having an average particle size of 0.5 to 30 μm in a dry polyvinyl chloride layer in the range of 10 to 70% by mass. The unevenness of the particles of the composite powder gives fine unevenness to the thermosetting silicone layer 2 which is also a release layer, and becomes a matte tone.

  The paper base material layer 4 used in the release paper for producing synthetic leather of the present invention is a step of laminating the sealing layer 3 and the thermosetting silicone layer 2, and a step of embossing the release paper with an uneven pattern (embossing). It has the strength to withstand, and has properties such as heat resistance and chemical resistance during embossing when it is subjected to heating / drying treatment during the application and formation of synthetic leather. 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 paper base layer 4 has a basis weight of 15 to 300 g / m ² , preferably 100 to 180 g / m ² . In addition, as a paper base material layer used in the present invention, for example, general, clay-coated paper, fine-coated printing paper, coated printing paper, resin-coated paper, processed base paper, release base paper, double-sided coat release base paper, etc. You may use the commercial item in which the sealing layer etc. were formed previously.

Next, the sealing layer 3 is made of a resin having a film- forming property and a silicone composite powder which is a feature of the present invention described later. The sealing layer 3 is applied on the paper base material layer 4. If so, the generation of pinholes due to the penetration of the coating liquid of the thermosetting silicone layer 2 to be described later is suppressed, and fine irregularities that give a matte tone are also imparted.

  As the resin having film formability used for forming the sealing layer 3, a thermoplastic resin or a thermosetting resin can be used. Examples of the thermoplastic resin include polyvinyl alcohol, acrylic resin, styrene acrylic resin, cellulose derivative, polyester resin, polyurethane resin, alkyd resin, aminoalkyd resin, polyvinyl chloride resin, polyvinylidene chloride resin, and polyvinyl chloride acetate resin. Can be used.

  Moreover, as a thermosetting resin, a melamine resin, a phenol resin, etc. can be used, for example. Moreover, you may mix and use arbitrary resin from the mixture of each resin of the illustrated thermoplastic resin, the mixture of each resin of a thermosetting resin, or each of a thermoplastic resin and a thermosetting resin.

  As the resin for the sealing layer 3 of the present invention, it is more preferable to use a polyvinyl chloride resin. This is because during the production of synthetic leather, while being able to be deformed by heating, it does not melt or liquefy at the time of high-temperature drying, and is flexible so that it can be smoothly wound on a roll. This is because productivity can be improved.

  And in the release paper for synthetic leather manufacture of this invention, silicone composite powder is mix | blended with the polyvinyl chloride acetate resin used for the sealing layer 3. FIG. This silicone composite powder is obtained by coating the surface of a silicone rubber powder, which is a fine powder with each other, as shown in the structure of FIG. 2, for example, with a silicone resin powder. Silicone rubber powder is a compound having a structure in which vinyl group-containing dimethylsilicone oil is crosslinked with hydrogen silicone oil in the presence of a platinum catalyst. Silicone resin powder is obtained by hydrolyzing methyltrialkoxysilane. The resulting compound has a structure crosslinked in a three-dimensional network.

  As will be described later, the average particle size of the silicone composite powder used in the present invention is 0.5 to 30 μm, preferably 5 to 12 μm. Within the above range, a matte-like synthetic leather with more jetness can be obtained, which is preferable. Further, in the present invention, this silicone composite powder is blended in a concentration range of 10 to 70% by mass with respect to the solid content after drying in the polyvinyl chloride solution, preferably 25 to 65% by mass, More preferably, it is 25-55 mass%.

  Conventionally, in the production of release paper for synthetic leather production, some curable resin compositions use inorganic particles such as glass particles, but these glass particles are difficult to disperse in the curable resin composition. It is necessary to add a dispersant separately. In addition, skill is required for uniform dispersion, and a special process for kneading the particles into the curable resin composition is required. However, since the silicone composite powder particles used in the present invention can disperse the particles in the polyvinyl chloride resin without using a dispersant, the manufacturing process can be simplified and the matte tone can be achieved. It turned out that it was very excellent in expression.

  Here, it will be described that the silicone composite powder has high dispersion stability in liquid. FIG. 3 is a diagram illustrating the sedimentation state of the silicone composite powder in the liquid over time, FIG. 4 is a diagram illustrating the sedimentation state of the silicone resin powder in the liquid over time, and FIG. 5 is the sedimentation of silica fine particles in the liquid. FIG. 6 is an enlarged view (290 times and 720 times) of a release layer of a release paper for synthetic leather production using a silicone composite powder, and FIG. 7 is a synthetic leather production using a silicone resin powder. It is an enlarged view (290 times and 720 times) of the peeling layer of the release paper for use.

  First, in each beaker, silicone composite powder, silicone resin powder and silica fine particles are added in an amount of 65% by mass with respect to the dry solid content of the solution, and the state of the solution in each beaker is observed over time. did. As the solution in the beaker, polyvinyl chloride resin (manufactured by DIC Graphics Co., Ltd., trade name “XS-870”, solid content 25% by mass), silicone composite powder, Shin-Etsu Chemical Co., Ltd. Product name “KMP-600”, average particle size of about 5 μm, silicone resin powder manufactured by Shin-Etsu Chemical Co., Ltd., product name “X-52-1621”, average particle size of about 5 μm, silica fine particle A product name “X-60” manufactured by Tokuyama Corporation and a particle size of about 5 μm were used.

  As shown in FIG. 3, it was found that the silicone composite powder was stably dispersed in the liquid without being settled in the liquid in the beaker even after 3 hours from the start of charging.

  On the other hand, as shown in FIG. 4, in the silicone resin powder, it was found that the particles of the silicone resin powder separated from the liquid and settled within about 30 minutes to 1 hour from the start of charging. Further, in the silica fine particles, as shown in FIG. 5, the liquid gelled soon after the start of addition, and thixotropic properties could be confirmed. Therefore, from these results, it was found that the silicone composite powder is excellent in dispersion stability and coating property in the liquid.

Next, a paper base layer having a basis weight of about 157 g / m ² (made by Daio Paper Co., Ltd., trade name “Utrilogros Mat”) and a silicone composite powder (Shin-Etsu Chemical Co., Ltd., trade name “KMP”). -600 ", average particle size of about 5 μm), polyvinyl chloride resin (manufactured by DIC Graphics, trade name“ XS-870 ”, solid content 25% by mass), the other is silicone resin powder (Shin-Etsu Chemical Co., Ltd.) Made by company, trade name “X-52-1621”, average particle diameter of about 5 μm) and polyvinyl chloride resin (made by DIC Graphics, trade name “XS-870”, solid content 25 mass%) The eye stop layer 3 is coated using Meyer bar count: # 14 and dried by heating at 130 ° C. for 30 seconds, and the eye stop layer 3 is thermally cured to obtain a thermosetting composition film. It was.

Then, a release agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KS-830”) was coated with Mayer bar number: # 8 so that the coating thickness was 0.4 g / m ² after drying. In the same manner, the silicone layer was thermally cured by heating and drying at 130 ° C. for 30 seconds. The layer structure of this release paper for synthetic leather production is Utrilogros mat / KMP600 + XS-870 / KS-830.

  Enlarged views (magnifications of 290 times and 720 times) of the release layer of the release paper 1 for producing synthetic leather obtained as described above are shown in FIGS.

  As shown in FIG. 6, the release paper 1 using the silicone composite powder was dispersed without aggregation of the silicone composite powder. However, as shown in FIG. 7, the release paper 1 using the silicone resin powder is not dispersed. Many of the silicone resin powders aggregated to form a sea-island structure, indicating low dispersibility. Therefore, from these results, it was found that the dispersibility of the silicone composite powder was excellent. In addition, all the surface enlarged views in this specification are observed using the Keyence Corporation laser microscope VK-9510.

  In addition, as a method of coating the sealing layer 3 on the paper base material layer 4, blade coater, air knife coater, roll coater, comma coater, brush coater, kiss coater, squeeze coater, curtain coater, bar coater, gravure coater, spray It can select suitably from the methods using well-known coating machines, such as a coater.

  The average particle diameter of the silicone composite powder used in the present invention is preferably 5 to 12 μm as described above. This is because, within this range, the dispersibility with respect to the polyvinyl chloride resin is excellent, and a matte release paper can be formed. In the present specification, “average particle size” means that a silicone composite powder is observed / photographed with a scanning electron microscope at an arbitrary magnification, 500 particles are randomly selected from the photograph, and digital calipers are selected. Is used to measure the major axis of each particle, and the number average value is taken as the average particle size.

  Further, the shape of the silicone composite powder used is not limited to a perfect circle having a sphericity (minor axis / major axis) of 1, but is preferably 0.5 or more, more preferably It is 0.7 or more, particularly preferably 0.9 or more. The sphericity is the average sphericity of the silicone composite powder.

  Further, the particle size distribution of the silicone composite powder is not limited to monodispersion. The variation coefficient of the particle size distribution is preferably 0.65 or less, and more preferably 0.6 or less. This is because within this range, the dispersibility in the polyvinyl chloride resin is excellent. The variation coefficient of the particle size distribution is a numerical value obtained by dividing the standard deviation σ of the particle diameter by the average value and expressed as a percentage.

  The silicone composite powder used in the present invention needs to have heat resistance to form a matte tone on the synthetic leather by being blended with the polyvinyl chloride resin in the sealing layer 3. The melting point of the silicone composite powder used in the present invention is 200 ° C. or higher, more preferably 200 to 300 ° C.

  In the present invention, a commercially available product may be used as the silicone composite powder. As such a silicone composite powder, “KMP-600” from Shin-Etsu Chemical Co., Ltd. can be used.

  Next, the release layer 2 is preferably formed by thermosetting a thermosetting silicone composition comprising an alkenyl group-containing organopolysiloxane, an organohydrogenpolysiloxane and a platinum-based curing catalyst as the thermosetting silicone layer 2. Can be used for In addition, as such a thermosetting silicone composition, you may use a commercial item, for example, the main ingredient of the addition polymerization type silicone material (for example, the mixture of an alkenyl group containing organopolysiloxane and organohydrogenpolysiloxane ( It can be prepared by mixing a curing agent comprising a platinum-based curing catalyst (CAT-PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd., KS-3603) manufactured by Shin-Etsu Chemical Co., Ltd. Moreover, the product name "X-62-9214" by Shin-Etsu Chemical Co., Ltd. can also be used conveniently.

  The thermosetting silicone composition used in the present invention has curability to obtain sufficient film properties such as strength. The thermosetting silicone layer 2 can be prepared by applying the thermosetting silicone composition and drying and heating. The thickness of the thermosetting silicone layer 2 to be formed is preferably in the range of 0.01 to 20 μm.

  The manufacturing method of the release paper 1 for synthetic leather manufacture of this invention is demonstrated. The release paper 1 for producing synthetic leather is coated on the paper base layer 4 with the sealing layer 3 made of the above-mentioned silicone composite powder and polyvinyl chloride resin, and the sealing layer 3 is dried and thermally cured. Then, a thermosetting silicone composition is applied on the thermosetting sealing layer 3 and dried by heating to form a thermosetting silicone film. It can be produced by curing the layer 3.

  The filler layer 3 is prepared by, for example, diluting a polyvinyl chloride resin preliminarily blended with a thermal polymerization initiator (peroxide, azo compound, triethylborane, etc.) with a solvent, and adding the silicone composite powder to this while stirring. Can be prepared. When diluting with a solvent, it can be diluted with 10 to 1000 parts by mass, more preferably 100 to 700 parts by mass with respect to 100 parts by mass of the polyvinyl chloride resin. Within this range, the silicone composite powder can be dispersed without settling, and an appropriate viscosity for coating, for example, a viscosity of 10 to 3000 mPa · sec at 25 ° C. is given, and in the step of drying it, the silicone compound is appropriate. The transition to a smooth surface.

  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. The silicone composite powder used in the present invention has excellent affinity for polyvinyl chloride resin and is dispersed in the composition without settling.

  This eye stop layer 3 is a well-known 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. It can coat on the paper base material layer 4 by the method of this. This is coated on the paper base material layer 4, dried and heated at a temperature of 90 to 190 ° C., the solvent is evaporated in a drying furnace, and the sealing layer 3 is thermally cured. This temperature is higher than the softening point of the polyvinyl chloride acetate resin and lower than the temperature at which the polyvinyl chloride acetate resin melts.

  Next, a thermosetting silicone is applied on the sealing layer 3, dried by heating at a temperature of 90 to 190 ° C., and cured in a drying oven to form a thermosetting silicone film. From the thermosetting silicone layer 2 side, By heating, the thermosetting silicone film is cured to form the thermosetting silicone layer 2.

  In the release paper 1 for producing synthetic leather of the present invention, the thickness of the sealing layer 3 is 1 to 50 μm, and the thickness of the thermosetting silicone layer 2 is 0.01 to 20 μm. When the silicone composite powder is blended with the polyvinyl chloride resin, the unevenness due to the silicone composite powder is exposed on the surface of the release layer, and the release paper for producing synthetic leather can be matte.

  Next, the manufacturing method of synthetic leather is demonstrated. By using the release paper 1 for producing synthetic leather of the present invention, synthetic leather can be produced in the same manner as using conventional release paper. First, the resin composition for synthetic leather is apply | coated on the thermosetting silicone layer 2 of the release paper 1 for synthetic leather manufacture. Next, this resin composition is heated and dried to be thermally cured. A matte tone is formed on the resin layer applied on the thermosetting silicone layer 2. A synthetic leather can be obtained by bonding a base fabric (for example, woven fabric, non-woven fabric, etc.) to this, drying and cooling the resin layer, and then peeling the release paper 1.

  Resins such as polyurethane and polyvinyl chloride can be used for the above resin composition for synthetic leather. 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 release paper 1 for producing synthetic leather according to the present invention, even in the case of vinyl chloride leather production performed at a high temperature, the gap between the paper base material layer 4 and the sealing layer 3 is obtained. Is prevented from being peeled off, and the stable presence of the sealing layer 3 having excellent heat resistance and high mechanical strength and the presence of the thermosetting silicone layer 2 having excellent peelability enable repeated stable production.

Next, the present invention will be described in detail by showing specific examples.
Example 1
Polyvinyl acetate resin (manufactured by DIC Graphics, trade name “XS-870”) on a paper base layer (made by Daio Paper Co., Ltd., trade name “Utrilogros Mat”) having a basis weight of about 157 g / m ² , Each silicone composite powder (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KMP-600”, average particle diameter of about 5 μm) is in the range of 5 to 70% by mass with respect to the solid content of 25% by mass. Using a Meyer bar number: # 14, a coating liquid (liquid component is 125 parts by mass with respect to 100 parts by mass of “XS-870”) mixed with a mixture whose amount is changed The coating layer was heated and dried at 130 ° C. for 30 seconds, and the sealing layer 3 was thermally cured to obtain a thermosetting composition film.

A thermosetting silicone composition (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KS-830”) was applied to the obtained thermosetting composition film using a Meyer bar number: # 8, and the coating thickness was reduced to 0. The coating was applied to 4 g / m ^2, and heat-dried at 130 ° C. for 30 seconds to thermally cure the silicone layer. The layer structure of this release paper for synthetic leather production is Utrilogros mat / KMP-600 + XS-870 / KS-830.

Next, the thermosetting composition film was cured by heating to obtain a release paper for producing synthetic leather. About the obtained release paper for synthetic leather production, black pigment (manufactured by Dainichi Seika Co., Ltd.) with respect to 100 parts by mass of non-yellowing carbonate-based polyurethane (manufactured by Dainichi Seika Co., Ltd., product name “Rezamin NE8811”), (Product name “Seika Seven NET-5794”) 33.3 parts by weight of a polyurethane resin composition was prepared and coated using a Mayer bar number: # 18 so that the dry thickness basis weight was about 36 g / m ^2. This was cured by heating at 70 ° C. for 600 seconds. The same polyurethane resin composition as above was applied onto this thermosetting composition film, and this layer was used as an adhesive layer, and a base fabric was affixed to form a base fabric having a polyurethane skin layer. Then, after heat-curing similarly, the base fabric which has a polyurethane skin layer was peeled from the release paper for synthetic leather, and it was set as the synthetic leather.

  And about the synthetic leather manufactured using this release paper for synthetic leather and a release paper, the gloss value (60 degree reflection) was evaluated by HORIBA, Ltd. glossiness meter IG-320. The results are shown in Table 1. The peelability of the synthetic leather from the release paper was also visually evaluated, and the results are also shown in Table 1. The case where there is no transfer of particles to each coating film is marked with ◯, the case where there is a partial transfer of particles to each coating film, △, and the case where there is a transfer to each coating film or where it does not peel off did.

(Example 2)
Polyvinyl acetate resin (manufactured by DIC Graphics, trade name “XS-870”) on a paper base layer (made by Daio Paper Co., Ltd., trade name “Utrilogros Mat”) having a basis weight of about 157 g / m ² , Each silicone composite powder (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KMP-601”, average particle diameter of about 12 μm) is in the range of 5 to 70% by mass with respect to the solid content of 25% by mass. Using a Meyer bar number: # 14, a coating liquid (liquid component is 125 parts by mass with respect to 100 parts by mass of “XS-870”) mixed with a mixture whose amount is changed The coating layer was heated and dried at 130 ° C. for 30 seconds, and the sealing layer 3 was thermally cured to obtain a thermosetting composition film.

  And about the synthetic leather manufactured using this release paper for synthetic leather and release paper, it carried out similarly to Example 1, and evaluated the gloss value and peelability. The results are shown in Table 2.

(Example 3)
Polyvinyl acetate resin (manufactured by DIC Graphics, trade name “XS-870”) on a paper base layer (made by Daio Paper Co., Ltd., trade name “Utrilogros Mat”) having a basis weight of about 157 g / m ² , Each silicone composite powder (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KMP-602”, average particle size of about 30 μm) is in the range of 5 to 70% by mass with respect to the solid content of 25% by mass. Using a Meyer bar number: # 14, a coating liquid (liquid component is 125 parts by mass with respect to 100 parts by mass of “XS-870”) mixed with a mixture whose amount is changed The coating layer was heated and dried at 130 ° C. for 30 seconds, and the sealing layer 3 was thermally cured to obtain a thermosetting composition film.

  And about the synthetic leather manufactured using this release paper for synthetic leather and release paper, it carried out similarly to Example 1, and evaluated the gloss value and peelability. The results are shown in Table 3.

Example 4
Polyvinyl acetate resin (manufactured by DIC Graphics, trade name “XS-870”) on a paper base layer (made by Daio Paper Co., Ltd., trade name “Utrilogros Mat”) having a basis weight of about 157 g / m ² 5 to 70 masses of each silicone composite powder (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “X-52-7030”, average particle diameter of about 0.8 μm) with respect to the solid content of 25 mass%). % Coating solution (liquid component is 125 parts by mass of solvent with respect to 100 parts by mass of “XS-870”) mixed with a mixture whose amount is changed in the range of%. 14 was applied and dried by heating at 130 ° C. for 30 seconds to thermally cure the sealing layer 3 to obtain a thermosetting composition film.

  And about the synthetic leather manufactured using this release paper for synthetic leather and release paper, it carried out similarly to Example 1, and evaluated the gloss value and peelability. The results are shown in Table 4.

(Comparative Example 1)
Polyvinyl acetate resin (manufactured by DIC Graphics, trade name “XS-870”) on a paper base layer (made by Daio Paper Co., Ltd., trade name “Utrilogros Mat”) having a basis weight of about 157 g / m ² , Each silicone resin powder (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “X-52-1621”, average particle diameter of about 5 μm) is 5 to 70% by mass based on the solid content of 25% by mass. A coating liquid obtained by mixing a mixture whose amount is changed in the range (the liquid component is 125 parts by mass of a solvent with respect to 100 parts by mass of “XS-870”). The coating layer was heated and dried at 130 ° C. for 30 seconds, and the sealing layer 3 was thermally cured to obtain a thermosetting composition film.

  And about the synthetic leather manufactured using this release paper for synthetic leather and release paper, it carried out similarly to Example 1, and evaluated the gloss value and peelability. The results are shown in Table 5.

(Comparative Example 2)
Polyvinyl acetate resin (manufactured by DIC Graphics, trade name “XS-870”) on a paper base layer (made by Daio Paper Co., Ltd., trade name “Utrilogros Mat”) having a basis weight of about 157 g / m ² Each silicone resin powder (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “X-52-854”, average particle size of about 0.8 μm) is 5 to 70 mass based on the solid content of 25 mass% solid content. % Coating solution (liquid component is 125 parts by mass of solvent with respect to 100 parts by mass of “XS-870”) mixed with a mixture whose amount is changed in the range of%. 14 was applied and dried by heating at 130 ° C. for 30 seconds to thermally cure the sealing layer 3 to obtain a thermosetting composition film.

  And about the synthetic leather manufactured using this release paper for synthetic leather and release paper, it carried out similarly to Example 1, and evaluated the gloss value and peelability. The results are shown in Table 6.

  From the above results, when the silicone composite powder (Examples 1 to 4) having an average particle size of 0.8 μm to 12 μm was used for the sealing layer, and the silicone resin powder (Comparative Example 1) having an average particle size of 5 μm was used. In some cases, it was found that when the blending amount with respect to the polyvinyl chloride resin becomes approximately 50% by mass or more, the gloss value becomes 1 or less, and so-called glossiness for enhancing the matte tone is lowered.

  In addition, in the release paper in which the blending amount of the silicone resin powder in Comparative Example 1 was further increased, the gloss value was further decreased. However, as described above, the silicone resin powder has poor dispersibility compared to the silicone composite powder, so that even if it has a low gloss value, a uniform matte tone cannot be expressed and coating suitability may be poor. found. In addition, even when using a silicone resin powder having an average particle size of 0.8 μm (Comparative Example 2), since the dispersibility is poor, a uniform matte tone cannot be expressed even with a low gloss value. It was found that the coating suitability was poor.

  On the other hand, it was found that the release papers using the silicone composite powders of Examples 1 to 4 are excellent in coating suitability because of good dispersion stability in liquid. Furthermore, in the release paper using the silicone composite powder having an average particle diameter of around 5 to 12 μm in Examples 1 and 2, it was also found that the gloss value is significantly lowered with the increase in the amount of the compounded paper. From this, the matte tone of the synthetic leather can be expressed uniformly and clearly by the release paper using the silicone composite powder with excellent dispersion stability in the liquid, and the dispersant can also be used in the production of the release paper. A simplified manufacturing process can be realized. Moreover, as an optimal silicone composite powder used in this case, the average particle diameter is preferably 0.5 to 30 μm, more preferably 5 to 12 μm, and the blending amount with respect to the polyvinyl chloride resin is preferably 10 to 10 μm. The said effect can be exhibited to the maximum by mix | blending with a filler layer in 70 mass%, More preferably, 25-65 mass%. This is not preferable because the low gloss value cannot be obtained when the blending amount of the silicone composite powder is less than 10% by mass. Moreover, even if the blending amount of the silicone composite powder is more than 70% by mass, there is no significant change in the low gloss value, and conversely, the cost increases due to the increased consumption of the silicone composite powder, and the peelability also deteriorates. It is not preferable.

  Note that the release papers of Examples 1 to 4 and Comparative Examples 1 and 2 described above and synthetic leather using the release paper (in the peelability evaluation in Tables 1 to 6, examples of blending amounts near the upper limit indicating ◯) Table 7 shows a comparison of gloss value, peelability, and dispersion stability in liquid. Regarding the dispersion stability in liquids in the table, a solution system in which particles do not aggregate and settle even after standing for 3 hours after preparation is evaluated as x, while a particle system in which particles aggregate and settle within 3 hours is evaluated as x. did. As is clear from Table 7, the dispersion using the silicone composite powder having an average particle diameter of 5 to 12 μm shown in Examples 1 and 2 is stable in dispersion in the liquid of the silicone composite powder (as a result, coating suitability). ), The peelability of the synthetic leather, the low gloss value of the release paper and the synthetic leather, and all the aspects were found to be excellent.

  As described above in detail, the release paper 1 for producing synthetic leather in this example includes a paper base layer 4, a sealing layer 3 provided on the paper base layer 4, and a sealing layer 3. The sealing layer 3 is formed of a thermoplastic resin or a thermosetting resin and a silicone composite powder. The sealing layer 3 has an average particle size of 0.5 to 30 μm. The silicone composite powder is blended in the range of 10 to 70% by mass.

  The release paper for producing synthetic leather of the present invention is useful because it can produce a uniform and clear matte synthetic leather at low cost.

1 Release paper for synthetic leather production 2 Release layer (thermosetting silicone layer)
3 Eye stop layer 4 Paper base material layer

Claims (4)

A paper base layer;
An eye stop layer provided on the paper base layer;
A release paper for producing synthetic leather comprising a release layer formed on the sealing layer,
The release layer for producing synthetic leather, wherein the sealing layer comprises a thermoplastic resin or a thermosetting resin and a silicone composite powder.   2. The release paper for producing synthetic leather according to claim 1, wherein the silicone composite powder having an average particle size of 0.5 to 30 μm is blended in the filler layer in a range of 10 to 70 mass%. .   The release paper for manufacturing synthetic leather according to claim 1, wherein the thermoplastic resin is polyvinyl chloride.   A synthetic leather produced using the release paper for producing synthetic leather according to claim 1 or 2.