JP2005171439A - Embossed release paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an embossed release paper in hot embossing type, providing a high shapable rate in both of the machine direction and the cross direction, hardly getting wrinkles caused by the difference of elongation at the surface of the release paper, and having good feeling on the embossed surface. <P>SOLUTION: The embossed release paper is obtained by attaching a hot-melt resin film on one surface of paper, and embossing the paper having the hot melt resin film. The paper has ≤3.5 ratio of elongation in the cross direction to elongation in the machine direction, measured based on the regulations of JIS P8132. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mold release with embossing, and more particularly to a mold release paper with emboss used for manufacturing synthetic leather or the like.

Conventionally, as an embossed process release paper that requires heat resistance and a smooth surface state, a laminate formed by co-extrusion of a polypropylene and a homopolymer on a paper substrate, and a resin composition composed of polyethylene having a long chain branch Is known (see, for example, Patent Document 1). Further, there is known an embossed release paper in which an ionizing radiation curable film is provided on one side of the paper, and the paper provided with the ionizing radiation curable film is embossed (see, for example, Patent Document 2). Moreover, in the conventional release paper with embossing, the hot-embossing roll dissolves the hot-melt resin on the surface of the release paper, and at the same time softens the paper as the support, thereby making the embossing roll mold three-dimensionally release paper. (See, for example, Patent Document 2). Therefore, it is very important to examine the paper that is the support for the release paper with embossing in terms of the molding rate of the hot embossing roll to the release paper.
Japanese Patent Publication No. 5-82806 Japanese Patent Publication No. 64-10626

However, the release paper has not been studied with respect to the forming rate.
SUMMARY OF THE INVENTION An object of the present invention is to provide a heat embossed release paper with embossing that has a high forming ratio in both the vertical direction and the horizontal direction, and is less likely to cause wrinkles due to the difference in paper elongation on the surface of the release paper.

  The invention according to claim 1 solves the above-mentioned problem, and is provided with a hot melt resin film provided on one side of the paper, and the paper provided with the hot melt resin film is embossed. The gist is a release paper with embossing, characterized in that the paper has a ratio of the elongation in the horizontal direction / the elongation in the vertical direction of 3.5 or less measured according to JISP8132 as the paper.

  In the release paper with embossing of the present invention, the forming ratio can be increased by using a paper having a ratio of the elongation in the horizontal direction / the elongation in the vertical direction of 3.5 or less as measured according to JISP8132. In addition, the generation of wrinkles due to the difference between the elongation in the horizontal direction and the elongation in the vertical direction of the paper can be reduced.

  In the release paper with embossing of the present invention, a heat-melting resin such as polypropylene and an ionizing radiation-curable resin can be used as the heat-melting resin, but by using the ionizing radiation-curable resin, there is an appropriate release property. In addition, it is possible to obtain an embossed release paper that is excellent in terms of heat resistance, weather resistance, chemical resistance, wear resistance, and the like.

  The embossed release paper of the present invention is characterized in that a paper having a ratio of lateral elongation / longitudinal elongation measured in accordance with JISP8132 of 3.5 or less is used. In addition to having an embossed surface embossed with an embossing roll more faithfully than before, there is less wrinkling due to the difference between the elongation in the horizontal direction and the elongation in the vertical direction of the paper. Further, the texture of the embossed surface is good. Therefore, using the release paper with embossing according to the present invention, it is possible to produce synthetic leather or the like which is embossed with a higher forming rate than before and which has a good texture.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an embossed release paper 4 of the present invention. A hot melt resin film 2 is provided on one side of the paper 1, and an emboss 3 is provided on the paper 1 provided with the hot melt resin 2.

  Thus, in the release paper 4 with embossing of the present invention, as the paper 1, a paper having a ratio of the lateral elongation / longitudinal elongation measured in accordance with JISP8132 of 3.5 or less can be applied. By using paper having a ratio of the elongation in the horizontal direction / the elongation in the vertical direction of 3.5 or less, generation of wrinkles when embossing the release paper with the embossing roll can be reduced. Moreover, the vertical molding rate and the horizontal molding rate can be made substantially the same.

Further, as a paper, the ratio of the elongation in the transverse direction / the elongation in the longitudinal direction measured according to the provision of JISP8132 is 3.5 or less, and the moisture (%) measured according to the provision of JISP8127 is 4. By using paper having a density of 5% or more and a density measured in accordance with the provisions of JISP8118 of 0.95 g / cm ³ or less, the forming rate can be further increased. When the moisture (%) of the paper is 4.5% or more, the paper can be sufficiently softened by the embossing heat, and when the paper density is 0.95 g / cm ³ or less, the paper is softened. When embossed paper is embossed, the embossing pressure is sufficiently absorbed, and as a result, the release paper is embossed with a high shaping rate.

  Such paper is not only uncoated paper, but also clay coated paper obtained by applying clay and other pigments together with adhesive on the base paper surface, or organic materials such as polyvinyl alcohol. Resin-coated paper imparted with heat resistance and water resistance can also be used. When the surface layer is a resin-coated paper made of an organic material such as polyvinyl alcohol, surface treatment such as corona treatment may be performed.

  As the heat-melting resin constituting the heat-melting resin film 2, a heat-melting resin such as polypropylene and ionizing radiation irradiation curable resin can be used, and among them, it has moderate releasability and heat resistance, weather resistance, An ionizing radiation curable resin that is excellent in terms of chemical resistance, abrasion resistance, and the like is particularly preferable. The hot melt resin film 2 made of ionizing radiation curable resin is mainly composed of a compound having an ethylenically unsaturated bond, and if necessary, a coating material containing a photoinitiator is coated on the surface of the paper 1, It is cured by irradiation with radiation such as ultraviolet rays having a short wavelength after embossing, an electron beam by an accelerator, and X-rays. Even if the release paper with embossing provided with the hot melt resin film 2 made of ionizing radiation curable resin is used repeatedly, the surface layer does not fall off or the surface gloss does not decrease.

  An embossed release paper can be made by coating one side of a coating material paper 1 made of a hot melt resin such as polypropylene to form a coat layer and embossing the paper provided with the coat layer with a hot emboss roll. . However, desirably, a coating material containing an ionizing radiation curable resin as a main component is coated on one side of the paper 1 to form an uncured coat layer, and then a hot embossing roll is applied to the paper provided with the uncured coat layer. The embossed hot melt resin film 2 made of an ionizing radiation cured film formed by irradiating the coating layer with radiation such as an electron beam or ultraviolet rays and then curing is preferably formed. The reason why the embossing is performed before irradiation with radiation is that if the embossing is performed after curing, the coat layer is broken. The embossing is generally performed by an embossing roll, but other methods such as a belt method and a die pattern pressing method can also be applied.

  In addition, as an ultraviolet irradiation device used for curing a heat-melting resin layer made of ionizing radiation curable resin, a light source having a quartz mercury lamp, an ultraviolet curable carbon arc, a high flash lamp, or the like that emits light having a wavelength of 1800 to 4000 mm. Moreover, as an electron beam irradiation apparatus, an apparatus having an energy of 50 to 2000 KcV is suitable.

  The surface layer is formed by a method in which a coating layer containing a compound having an ethylenically unsaturated bond is cured at a low temperature in a short time by irradiation with an electron beam or ultraviolet rays, and the embossing is caused by heat in the process of curing the coating layer. The coating layer can be cured without any loss.

  Here, as a compound having an ethylenically unsaturated bond, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, acrylamide Monofunctional monomers such as methacrylamide, methylol acrylamide, methylol methacrylamide, butoxymethyl acrylamide, butoxymethyl methacrylamide, ethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, Trifunctional glycol monomers such as triethylene glycol diacrylate Trifunctional monomers such as roll propane triacrylate, urethane acrylate, urethane methacrylate, epoxy acrylate, epoxy methacrylate, polyether acrylate, polyether methacrylate, polyester acrylate, polyester methacrylate ethylene acrylamide, N, N '-(oxydimethylene) bismethacryl Examples thereof include oligomers and prepolymers such as amide-unsaturated polyester, and one or a mixture of two or more of these and a reaction product can be used. In addition, it is necessary that the coating material coating material containing the compound having an ethylenically unsaturated bond does not flow during embossing and does not adhere to the embossing roll. Sometimes, a coating material that softens and spreads by heating and pressurization is preferable, and a coating material that is solid at room temperature and has a softening point of 50 ° C. or higher is particularly preferable.

  Since the compound having an ethylenically unsaturated bond is curable by electron beam irradiation as it is, it may be used alone in the case of electron beam irradiation. However, in the case of ultraviolet irradiation, acetophenone, benzophenone can be used as a photoinitiator. , Benzoin alkyl ether, azobisisobutyronitrile, 4,4′-dichlorobenzophenone, etc. blended at a concentration of 0.5 to 5% by weight with respect to the compound having an ethylenically unsaturated bond as a coating material Use.

  Any coating method such as bar coating, knife coating, roll coating, curtain flow coating, spray coating, extrusion coating, etc. can be applied to coating of a coating material containing a compound having an ethylenically unsaturated bond as a main component. .

The coating amount of the coating material is suitably ^{0.1g / m 2 ~100g / m 2} , and preferably from ^{0.5g / m 2 ~50g / m 2} .

Paper (basis weight; 125 g / m ² , longitudinal elongation measured according to JISP8132; 8.2%, transverse elongation; 17.4%, transverse elongation / longitudinal elongation ratio 2.12) was subjected to extrusion coating with polypropylene resin (Montel SDK Sunrise, grade; PH943B, melting point; 134 ° C.) to a thickness of 30 μm to prepare a release substrate before embossing of hot embossing type. . Then, the release paper with an emboss was created through the hot embossing roll heated at 120 degreeC of the embossing machine (product made from a Yuri roll). Next, about the formability of the embossed surface of the obtained release paper with emboss, using a three-dimensional roughness measuring machine, the ten-point average roughness (Rz) of the embossed surface in the vertical direction and the ten points of the embossed surface in the horizontal direction The average roughness (Rz) was measured, and a ten-point average roughness (Rz) of 50.4 on the embossed surface in the vertical direction and a ten-point average roughness (Rz) of 54.8 on the embossed surface in the horizontal direction were obtained. Further, the ten-point average roughness (Rz) in the vertical direction of the embossing roll used at this time was 56.3, and the ten-point average roughness (Rz) of the embossed surface in the horizontal direction was 58.9. The ten-point average roughness (Rz) in the vertical direction and the horizontal direction of the obtained release paper with embossing is compared with the ten-point average roughness (Rz) of the roll surface of the embossing roll, and the forming ratio in the vertical direction and the horizontal direction. Asked. As a result, the molding rate in the vertical direction is 89.6%, the molding rate in the horizontal direction is 93.0%, the co-molding rate in both the vertical and horizontal directions is extremely high, and the molding in the vertical and horizontal directions is performed. The rate was found to be almost identical. The formula for calculating the molding rate is: molding rate = (10-point average roughness (Rz) of the embossed surface of the release paper with embossing / 10-point average roughness (Rz) of the roll surface of the embossed roll) × 100 ( %). Moreover, the texture of the embossed surface of the obtained release paper with emboss was good, and the surface flaw was not seen.

Paper (basis weight: 125 g / m ² , longitudinal elongation measured in accordance with JISP8132; 8.2%, transverse elongation; 17.4%, transverse elongation / longitudinal elongation ratio ; 2.12) a coating material comprising a trimethylolpropane triacrylate resin as a main component and a reaction initiator (manufactured by Ciba Geigy) in a proportion of 2% by weight with respect to the resin by a reverse coater. By applying about 21 g / m ² , a release substrate before embossing was prepared. Thereafter, embossing was performed through a hot embossing roll heated to 80 ° C. of an embossing machine (manufactured by Yuri Roll Co., Ltd.). Thereafter, a 160 W / cm high-pressure mercury ultraviolet lamp was used to irradiate the resin on the surface with ultraviolet rays to cure the resin, thereby producing an embossed release paper. Next, about the formability of the embossed surface of the obtained release paper with emboss, using a three-dimensional roughness measuring machine, the ten-point average roughness (Rz) of the embossed surface in the vertical direction and the ten points of the embossed surface in the horizontal direction The average roughness (Rz) was measured to obtain 10-point average roughness (Rz) 51.8 of the embossed surface in the vertical direction and 10-point average roughness (Rz) 55.1 of the embossed surface in the horizontal direction. Further, the ten-point average roughness (Rz) in the vertical direction of the embossing roll used at this time was 56.3, and the ten-point average roughness (Rz) of the embossed surface in the horizontal direction was 58.9. The ten-point average roughness (Rz) in the vertical direction and the horizontal direction of the obtained release paper with emboss is compared with the ten-point average roughness (Rz) of the roll surface of the embossing roll, and the forming ratio in the vertical direction and the horizontal direction. Asked. As a result, the molding rate in the vertical direction is 92.0%, the molding rate in the horizontal direction is 93.5%, the co-molding rate in both the vertical and horizontal directions is extremely high, and the molding in the vertical and horizontal directions is performed. The rate was found to be almost identical. Moreover, the texture of the embossed surface of the obtained release paper with emboss was good, and the surface flaw was not seen.

[Comparative Example 1]
Paper (basis weight: 125 g / m ² , longitudinal elongation measured according to JISP8132; 5.3%, transverse elongation; 18.9%, transverse elongation / longitudinal elongation ratio 3.56) was extrusion coated with polypropylene resin (Montel SDK Sunrise, grade; PH943B, melting point; 134 ° C.) to a thickness of 30 μm to prepare a release substrate before embossing of hot embossing type. . Then, the release paper with an emboss was created through the hot embossing roll heated at 120 degreeC of the embossing machine (product made from a Yuri roll). Next, about the formability of the embossed surface of the obtained release paper with emboss, using a three-dimensional roughness measuring machine, the ten-point average roughness (Rz) of the embossed surface in the vertical direction and the ten points of the embossed surface in the horizontal direction The average roughness (Rz) was measured to obtain 10-point average roughness (Rz) 60.5 of the embossed surface in the vertical direction and 10-point average roughness (Rz) 53.8 of the embossed surface in the horizontal direction. Further, the ten-point average roughness (Rz) in the vertical direction of the embossing roll used at this time was 56.3, and the ten-point average roughness (Rz) of the embossed surface in the horizontal direction was 58.9. The ten-point average roughness (Rz) in the vertical direction and the horizontal direction of the obtained release paper with emboss is compared with the ten-point average roughness (Rz) of the roll surface of the embossing roll, and the forming ratio in the vertical direction and the horizontal direction. Asked. As a result, it was found that the molding rate in the vertical direction was 60.5%, the molding rate in the horizontal direction was 91.5%, and the molding rate in the horizontal direction was poor. Further, the texture of the embossed surface of the obtained release paper with emboss was poor, and surface defects were partially observed.

  Next, Table 1 shows the ten-point average roughness (Rz) of the embossing roll, the ten-point average roughness (Rz) of the embossed release papers of Examples 1 and 2 and Comparative Examples 1 and 2, and the forming rate.

  As can be seen from Examples 1 and 2 and Comparative Examples 1 and 2, the ratio of lateral elongation / longitudinal elongation measured according to JISP 8132 is 3.5 or less to increase the forming rate. It was found that the texture of the embossed surface can be made good and the generation of surface flaws can be suppressed.

[Application example]
A polyurethane resin was applied to the surface of the release paper with embossing of Examples 1 and 2, and after drying, an adhesive was applied, and then bonded to a substrate made of a nonwoven fabric and dried, followed by curing at 40 ° C. for 2 days. Thereafter, the release paper was peeled off, and surface treatment such as printing and gloss adjustment was performed to obtain a synthetic leather. In this synthetic leather, the embossing of the embossing roll was faithfully reproduced at a higher molding rate than before, and the texture was good.

  The release paper with embossing of the present invention can be used not only for the production of synthetic leather but also as an embossing shaping film used in the production of a decorative board, and can form an embossed decorative board.

It is sectional drawing of the release paper with embossing of this invention.

Explanation of symbols

1 paper 2 heat melt resin 3 emboss 4 release paper with emboss

Claims (3)

  In a release paper with an emboss, in which a hot melt resin film is provided on one side of the paper and the paper provided with the hot melt resin film is embossed, the lateral elongation measured in accordance with the provisions of JISP8132 / An embossed release paper, wherein a paper having a longitudinal elongation ratio of 3.5 or less is used.   The release paper with embossing according to claim 1, wherein the hot-melt resin is an ionizing radiation curable resin. As paper, in addition to the ratio of the lateral elongation / longitudinal elongation measured in accordance with JISP8132 being 3.5 or less, the moisture (%) measured in accordance with JISP8127 is 4.5%. The embossed release paper according to claim 1 or 2, wherein a paper having a density measured in accordance with the provisions of JISP8118 of 0.95 g / cm ³ or less is used.

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