JP4445080B2 - Process release paper - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a process release paper, and more particularly to a process release paper used for the production of synthetic leather.
[0002]
[Prior art]
Conventionally produced synthetic leather includes polyurethane (PU) leather, semi-synthetic leather, and vinyl chloride (PVC) leather. As a method for producing PU leather, for example, there is a method in which a paste-like PU resin is applied on a process release paper, dried and solidified, and then bonded to a base fabric and peeled off from the process release paper.
[0003]
Moreover, as a semi-synthetic leather manufacturing method, a paste-like PU resin is applied onto a process release paper, dried and solidified, then a PVC foam layer is formed and bonded to a base fabric, and then peeled off from the process release paper. There is a way.
[0004]
Conventionally used process release paper is a process release paper in which polypropylene (PP) is coated on a substrate having a pH of 3 to 8 and a release resin layer having a thickness of about 20 to 50 μm is provided for PU leather production. (PP type). Also, for the production of semi-synthetic leather or PVC leather, a process release paper in which a methylpentene polymer is applied to a substrate having a pH of 3 to 8 and a single-layer release resin layer having a thickness of about 20 to 50 μm is provided. (Methylpentene polymer type) or process release paper (acrylic resin type) in which an acrylic resin is applied to a substrate having a pH of 3 to 8 and a release resin layer having a thickness of about 20 to 50 μm is provided. .
[0005]
In addition, as other types of process release paper, process release paper in which a melamine alkyd resin having a smooth surface of about 4 to 15 μm and a release resin layer is provided on the substrate, UV curable resin or There is a process release paper provided with a releasable resin layer made of an ionizing radiation curable resin.
[0006]
[Problems to be solved by the invention]
However, when ordinary paper is used as the base of the process release paper as described above, static electricity is likely to be generated during the formation of the release resin layer, and in the production of synthetic leather using the process release paper, Since there is a process of peeling the synthetic leather from the process release paper, the generation of static electricity was inevitable. As described above, when static electricity is generated during the production of the process release paper and during the production of the synthetic leather, there is a problem that cracks occur in the releasable resin layer and the synthetic leather of the process release paper.
[0007]
As measures for preventing the occurrence of static electricity as described above, there are means such as installing a mall or making a humid atmosphere. However, such measures are not sufficient particularly during drying in winter. In addition, if the amount of static electricity increases, there is a risk of fire, and there is a demand for sufficient measures against static electricity.
[0008]
The present invention has been made in view of such circumstances, and does not have defects such as cracks due to the generation of static electricity in the releasable resin layer, and suppresses the generation of static electricity and does not have defects such as cracks. It is an object of the present invention to provide a process release paper that enables the production of leather.
[0009]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a process release paper is a laminate of a release resin layer provided on at least one surface of the substrate and said substrate, the substrate surfaces of the base paper and are those of the conductive agent therein was contained in a range of 0.05~3.00g / m ^2, the surface resistance of its (Omega) and / or volume resistivity (Ω · cm) is 0.1 × 10 ¹⁰ ~6.0 × Ri 10 ¹⁰ range near of the conductive agent is an organic polymeric conductive agent and / or an inorganic conductive material, said organic polymeric conductive agent, nonionic polymers, anionic polymers, at least one cationic polymer, wherein the inorganic conductive agent, calcium oxide, sodium aluminate, calcium chloride, lithium chloride, potassium chloride, magnesium chloride, and with at least Tanedea so that configuration of sodium chloride.
[0011]
In the process release paper as described above, the release resin layer has an alkyd resin, an acrylic resin, a polyethylene resin, a polypropylene resin, a polymethylpentene resin, a silicone resin, an ultraviolet curable resin, an ionization resin. It consists of any of radiation curable resin etc., and it was set as the structure which has thickness in the range of 4-50 micrometers, and also the said releasable resin layer was a multilayer structure.
[0012]
In the present invention as described above, the substrate acts to prevent the generation of static electricity during the production of the process release paper and during the production of synthetic leather using the process release paper.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic sectional view showing an example of the process release paper of the present invention. In FIG. 1, the process release paper 1 includes a base 2 and a release resin layer 3 provided on one surface of the base 2, and a surface smooth pattern 4 is formed on the surface of the release resin layer 3. Is provided.
[0014]
FIG. 2 is a schematic sectional view showing another example of the process release paper of the present invention. In FIG. 2, the process release paper 11 includes a base 12 and a release resin layer 13 provided on one surface of the base 12, and an uneven pattern 14 is provided on the surface of the release resin layer 13. It has been.
[0015]
In the process release papers 1 and 11 of the present invention, the surface resistance value (Ω) and / or the volume resistance value (Ω · cm) of the substrates 2 and 12 are 0.1 × 10 ^{10 to} 6.0 × 10 ^10. It is in the range of. When the surface resistance value (Ω) and / or the volume resistance value (Ω · cm) are within the above range, the effect of preventing electrostatic charging is obtained, and the formation of the releasable resin layers 3 and 13 as will be described later. At the time of manufacturing synthetic leather using the process release papers 1 and 11, it is possible to prevent cracks due to the generation of static electricity from occurring in the peelable resin layers 3 and 13 and the synthetic leather.
[0016]
In the present invention, the method for measuring the surface resistance value and volume resistance value of the substrates 2 and 12 is defined as follows. That is, one sample was sampled at each of three locations, the center and both ends in the width direction of the substrate, and the sample was left in an environment of 20 ° C. and 65% RH for 1 hour, and then an electrical resistance measuring device (Yokogawa Hured). Measured by Packer 4329A + 16008A cell).
[0017]
As the substrates 2 and 12 constituting the process release papers 1 and 11, paper such as kraft paper or high-quality paper can be used. The thicknesses of the substrates 2 and 12 are preferably set to such a thickness that the concavo-convex pattern 14 can be formed on the surface of the releasable resin layer 13 by embossing as will be described later in consideration of the materials used. For example, it can set in the range of about 50-200 micrometers. In addition, the surface of the base 2 on the side where the release resin layer 3 is formed and the surface of the base 12 on the side where the release resin layer 13 is formed are heated in advance in order to improve the adhesion between the base and the release resin layer. Alternatively, corona discharge treatment or the like may be performed.
[0018]
The main ingredients of the substrates 2 and 12 can be mixed as follows. As the pulp blending, L-BKP and N-BKP are mainly used as pulp fibers, and waste paper and waste paper pulp are blended appropriately. Moreover, as an additive, an internally added sizing agent, cationized starch, a defoaming agent such as a fatty acid ester or a special paraffin can be used.
[0019]
In the size press process for manufacturing the substrate, a size press solution containing corn starch, a surface sizing agent, a conductive agent and the like is applied to the base paper. By passing through this size pressing step, the size press solution is applied to both sides of the substrate and impregnated inside the substrate.
[0020]
The conductive agent used is an organic polymer conductive agent and / or an inorganic conductive agent. Examples of the organic polymer conductive agent include nonionic polymers such as polyvinyl alcohol, polyacrylamide and polyethylene glycol, polymers having an anionic polar group such as sulfonated styrene resin, and quaternary ammonium salts such as quaternary ammonium chloride. A certain cationic polymer etc. are mentioned. Examples of the inorganic conductive agent include calcium oxide, sodium aluminate, zinc oxide, tin oxide, calcium chloride, lithium chloride, potassium chloride, magnesium chloride, sodium chloride, and carbon black.
[0021]
The content of the conductive agent as described above in the substrates 2 and 12 or the coating amount on the surfaces of the substrates 2 and 12 is 0.05 to 3.0 g / m ² , preferably 0.2 to 2.0 g / m. It can be within the range of ² . When the amount of the conductive agent is less than 0.05 g / m ² , the surface resistance value (Ω) and / or the volume resistance value (Ω · cm) of the substrates 2 and 12 are likely to be less than 0.1 × 10 ¹⁰ , and electrostatic charging When the release resin layers 3 and 13 to be described later are formed and the synthetic leather is manufactured using the process release papers 1 and 11, cracks due to the generation of static electricity are caused by the peelable resin layer 3. , 13 and synthetic leather. Moreover, even if the amount of the conductive agent exceeds 3.0 g / m ² , further improvement in the effect of preventing electrostatic charging cannot be obtained, which is disadvantageous in terms of material cost.
[0022]
The release resin layers 3 and 13 constituting the process release papers 1 and 11 are alkyd resins, acrylic resins, polyethylene resins, polypropylene resins, polymethylpentene resins, silicone resins, UV curable resins, Known resins such as ionizing radiation curable resins can be used, and can be selected in consideration of peelability from resins for synthetic leather, especially polymethylpentene resins, polypropylene resins, and alkyd resins. Is preferred.
[0023]
The releasable resin layers 3 and 13 are formed by applying the above resin on the substrates 2 and 12 by a method such as roll coating, gravure coating, extrusion coating, knife coating, Mayer bar coating, dipping coating, or adhesive coating. It can be performed by a film laminating method or the like by laminating or hot-melt laminating. The curing method of the resin may be any method such as a thermosetting method or a curing method such as ultraviolet rays or ionizing radiation. Further, the releasable resin layers 3 and 13 may have a multilayer structure in consideration of the peelability of synthetic leather, processes, and the like. In the process of forming the releasing resin layer, the surface resistance of the substrate 2 and 12 as described above (Omega) and / or volume resistivity (Ω · cm) is 0.1 × ^{10 10} ~6.0 × ¹⁰ Since it is within the range of ^10, the effect of preventing electrostatic charging is sufficiently exhibited, and cracking due to the generation of static electricity is prevented from occurring in the releasable resin layer.
[0024]
The thickness of the releasable resin layers 3 and 13 can be about 3 to 100 μm, preferably about 4 to 50 μm. When the thickness of the releasable resin layer is less than 3 μm, the peelability from the synthetic leather is deteriorated during the production of synthetic leather, and when it exceeds 100 μm, the curl of the process release paper increases and the depth of the uneven pattern 14 Is not preferable because it becomes difficult to make the thickness sufficiently deep (depth exceeding 50 μm).
[0025]
The process release paper 1 having the surface-smooth pattern 4 on the releasable resin layer 3 is obtained by the process as described above. On the other hand, the process release paper 11 having the concavo-convex pattern 14 on the releasable resin layer 13 takes the following embossing process. That is, the embossing machine provided with the embossing roll formed with concavity and convexity and the paper roll or metal roll that receives the concavity and convexity or the metal roll having the surface concavity and convexity corresponding to the concave and convex shape of the embossing roll. The process release paper is poured so that the moldable resin layer 13 comes into contact with the embossing roll, and pressure is applied by the heated embossing roll to form the uneven pattern 14 on the moldable resin layer 13. Usually, the heating temperature of the embossing roll is preferably about 80 to 150 ° C. and the pressure is about 40 to 100 kg / cm.
[0026]
Next, the production of synthetic leather using the process release paper of the present invention will be described.
First, the resin composition for synthetic leather is apply | coated on the releasable resin layer of process release paper. On the resin layer applied on the releasable resin layer, a pattern (uneven pattern) corresponding to the surface pattern shape of the releasable resin layer is formed. Thereafter, a base fabric (for example, woven fabric, non-woven fabric, etc.) is bonded thereto, the resin layer is dried and cooled, and then peeled off to obtain a synthetic leather.
[0027]
In the synthetic leather manufacturing method using the process release paper of the present invention, the surface resistance value (Ω) and / or the volume resistance value (Ω · cm) of the substrate is 0.1 × 10 ^{10 to} 6.0 ×. Since it is within the range of 10 ¹⁰ , a good effect of preventing electrostatic charge can be obtained, and cracking due to the generation of static electricity can be prevented from occurring in the synthetic leather and the release resin layer of the process release paper.
[0028]
In addition, resin, such as a polyurethane and a polyvinyl chloride, can be used for said resin composition for synthetic leather. When using polyurethane, the solid content of the resin composition is preferably about 20 to 50%. 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 application method of such a resin composition include conventionally known application methods such as knife coating, roll coating, and gravure coating.
[0029]
【Example】
Next, the present invention will be described in more detail by showing specific examples.
[0030]
[Example 1]
N-BKP 22.5 wt.%, L-BKP 67.5 wt.%, And 0.7% by weight of cationized starch with respect to pulp slurry containing 10% by weight of waste paper generated from the process and beaten. 0.15% by weight of rosin emulsion as an agent was added. Then papermaking base paper by adjusting the pulp slurry pH 5.5, by applying corn starch, the size press solution containing a combination of surface sizing agent and a conductive agent to the base paper in the size press step, US basis weight 125 g / m ² The paper was made into a substrate. In addition, quaternary ammonium chloride was used as the conductive agent, and the conductive agent content of the substrate was 2.0 g / m ² .
[0031]
Next, with respect to the above-mentioned substrate, a sample was sampled at each of three points at the center and both ends in a direction (width direction) perpendicular to the papermaking flow direction, and this was sampled for 24 hours in an environment of 20 ° C. and 65% RH. After leaving, the surface resistance value (Ω) and the volume resistance value (Ω · cm) were measured with an electric resistance measuring device (4329A + 16008A cell manufactured by Yokogawa Hured Packer Co., Ltd.) and found to be 0.2 × 10 ¹⁰ . .
[0032]
A polypropylene resin (FW163 manufactured by Chisso Co., Ltd.) was applied to the substrate thus made by extrusion coating and dried to form a release resin layer having a thickness of 30 μm.
Next, the embossing machine provided with the embossing roll and the paper roll formed with concavities and convexities are passed through the embossing machine so that the above-mentioned releasable resin layer comes into contact with the embossing roll, and the unevenness pattern is formed on the releasable resin layer. The process release paper of this invention was obtained. In addition, the temperature of the embossing roll was set to 120 ° C., and the pressure applied to the releasable resin layer by the embossing roll was set to 60 kg / cm.
[0033]
The release resin layer was formed in an environment at a temperature of 25 ° C. and a humidity of 20%. However, the release resin layer was not affected by static electricity, and no defects such as cracks were observed in the release resin layer. .
[0034]
Synthetic leather was produced using the process release paper produced as described above. That is, first, a polyurethane resin composition for synthetic leather skin having a solid content of 30% is applied to the release resin layer side of the process release paper by a knife coat method (clearance 150 μm), and after drying, a polyurethane resin adhesive is applied. It was applied and dried by a knife coat method, a base fabric was bonded to the adhesive surface, dried and aged, and then peeled off from the process release paper to obtain a synthetic leather having an uneven pattern corresponding to the uneven pattern.
[0035]
The above synthetic leather was produced in an environment of a temperature of 25 ° C. and a humidity of 20%. However, the synthetic leather was not affected by static electricity, and no defects such as cracks were observed in the synthetic leather.
[0036]
[Example 2]
A substrate was prepared in the same manner as in Example 1 except that magnesium chloride was used as the conductive agent used and the conductive agent content of the substrate was 0.1 g / m ² . The substrate was measured for surface resistance (Ω) and volume resistance (Ω · cm) in the same manner as in Example 1. As a result, it was 1.0 × 10 ¹⁰ and 1.4 × 10 ¹⁰ , respectively.
[0037]
A release resin layer having a thickness of 30 μm was formed on the paper substrate thus produced in the same manner as in Example 1, and an uneven pattern was provided to obtain a process release paper. The release resin layer was formed in an environment at a temperature of 25 ° C. and a humidity of 20%. However, the release resin layer was not affected by static electricity, and no defects such as cracks were observed in the release resin layer. .
[0038]
Synthetic leather was produced in the same manner as in Example 1 using the process release paper produced as described above. As a result, synthetic leather having an uneven pattern corresponding to the uneven pattern could be obtained, and no defects such as cracks were found in the synthetic leather without being affected by static electricity.
[0039]
[Example 3]
A substrate was prepared in the same manner as in Example 1 except that polystyrene sulfonate was used as the conductive agent used and the conductive agent content of the substrate was set to 3.0 g / m ² . This substrate, the surface resistance value in the same manner as in Example 1 (Omega), volume resistivity (Ω · cm) was measured. As a result, each 1.8 × ¹⁰ 10, was 2.6 × 10 ^10.
[0040]
A release resin layer having a thickness of 30 μm was formed on the paper substrate thus produced in the same manner as in Example 1, and an uneven pattern was provided to obtain a process release paper. The release resin layer was formed in an environment at a temperature of 25 ° C. and a humidity of 20%. However, the release resin layer was not affected by static electricity, and no defects such as cracks were observed in the release resin layer. .
[0041]
Synthetic leather was produced in the same manner as in Example 1 using the process release paper produced as described above. As a result, synthetic leather having an uneven pattern corresponding to the uneven pattern could be obtained, and no defects such as cracks were found in the synthetic leather without being affected by static electricity.
[0042]
[Comparative example]
A substrate was produced in the same manner as in Example 1 except that the size press solution used for production of the substrate did not contain a conductive agent. With respect to this substrate, the surface resistance value (Ω) and the volume resistance value (Ω · cm) were measured in the same manner as in Example 1. As a result, they were 2.0 × 10 ¹¹ and 4.5 × 10 ¹¹ , respectively.
[0043]
A release resin layer having a thickness of 30 μm was formed on the paper substrate thus produced in the same manner as in Example 1, and an uneven pattern was provided to obtain a process release paper. The release resin layer was formed in an environment at a temperature of 25 ° C. and a humidity of 20%. However, although static electricity was generated, no defects such as cracks were observed in the release resin layer.
[0044]
Next, using the process release paper produced as described above, a synthetic leather was produced in an environment of a temperature of 25 ° C. and a humidity of 20% in the same manner as in Example 1. As a result, a synthetic leather having an uneven pattern corresponding to the uneven pattern could be obtained. However, static electricity was generated, and defects due to cracks occurred in the release resin layer of the process release paper and the synthetic leather.
[0045]
【The invention's effect】
As described above in detail, according to the present invention, the process release paper is composed of a laminate of a substrate and a release resin layer provided on at least one surface of the substrate, and the substrate has a surface resistance value. (Ω) and / or volume resistance value (Ω · cm) is in the range of 0.1 × 10 ^{10 to} 6.0 × 10 ¹⁰ , so that the releasable resin layer is cracked by static electricity during its formation In the manufacture of synthetic leather using the process release paper of the present invention, high quality without defects such as cracks by suppressing the generation of static electricity, regardless of the humidity of the atmosphere. Of synthetic leather.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an example of a process release paper of the present invention.
FIG. 2 is a schematic sectional view showing another example of the process release paper of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,11 ... Process release paper 2,12 ... Base | substrate 3,13 ... Releasing resin layer 4 ... Surface smooth pattern 14 ... Uneven | corrugated pattern

Claims (3)

In a process release paper that is a laminate of a substrate and a releasable resin layer provided on at least one surface of the substrate,
The base are those obtained by incorporating both sides and internally a conductive agent 0.05~3.00g / m ² range of the base paper, the surface resistance of its (Omega) and / or volume resistivity (Omega · cm ) is Ri range near the ^{0.1 × 10 10 ~6.0 × 10 10} , the conductive agent is an organic polymeric conductive agent and / or an inorganic conductive material, said organic polymeric conductive agent, nonionic At least one of a conductive polymer, an anionic polymer, and a cationic polymer, and the inorganic conductive agent is at least one of calcium oxide, sodium aluminate, calcium chloride, lithium chloride, potassium chloride, magnesium chloride, and sodium chloride. Process release paper characterized by the above. The releasable resin layer is composed of any one of alkyd resin, acrylic resin, polyethylene resin, polypropylene resin, polymethylpentene resin, silicone resin, ultraviolet curable resin, ionizing radiation curable resin, The process release paper according to claim 1 , wherein the thickness is in the range of 4 to 50 μm. The process release paper according to claim 2 , wherein the releasable resin layer has a multilayer structure.

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