JP6673982B2 - Process paper for forming polyurethane coat layer - Google Patents

Description

  The present invention relates to a process paper for forming a polyurethane coat layer.

  Synthetic leather having a polyurethane coat layer is produced by applying a resin composition for forming a polyurethane coat layer onto a process paper having releasability, curing the resin composition, and then peeling the process paper.

  As the process paper used in the production process of the polyurethane coat layer, conventionally, a paper obtained by laminating a release layer on the surface of a base material layer made of kraft paper or the like in order to easily peel off the cured resin of the resin composition is used. (See Japanese Patent Application Laid-Open No. 2013-147764).

JP 2013-147764 A

  In such a process paper, if air bubbles, irregularities, unevenness, surface defects such as scratches, etc. are present in the release layer, the shape is transferred to the surface of the cured body of the applied resin composition, and the shape of the product is reduced. There is a risk of failure. In particular, in the case of process paper used for producing an enamel-like polyurethane coat layer, surface defects of the release layer directly lead to poor appearance of the product, which causes a reduction in product yield.

  Generally, the process paper is repeatedly used a plurality of times. However, in the case of the process paper used for producing the enamel-like polyurethane coat layer, the smoothness of the product surface is particularly important, and the dimethylformamide (DMF) contained in the resin composition for forming the polyurethane coat layer is important. ), Etc., the process paper is easily degraded by erosion of the process paper, so that there is a problem that it is difficult to use the process paper a plurality of times.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a process paper for forming a polyurethane coat layer that can suppress occurrence of poor appearance of a polyurethane coat layer even when used repeatedly.

  In order to solve the above problems, a process paper for forming a polyurethane coat layer according to the present invention includes a process for forming a polyurethane coat layer including a base material layer and a release layer laminated on a surface side of the base material layer. The paper is further provided with an intermediate layer disposed between the base layer and the release layer and containing a synthetic resin as a main component, wherein the release layer and the intermediate layer contain a fluorine-based compound.

  In the process paper for forming a polyurethane coat layer, since the intermediate layer has a synthetic resin as a main component and a fluorine-based compound, the surface of the intermediate layer has high smoothness. Therefore, the process paper for forming a polyurethane coat layer can sufficiently increase the smoothness of the surface of the release layer laminated on the surface side of the intermediate layer. Further, in the process paper for forming a polyurethane coat layer, since the release layer contains a fluorine-based compound, the smoothness of the surface of the release layer can be enhanced and the surface of the release layer can be prevented from being damaged. Further, in the process paper for forming a polyurethane coat layer, the release layer and the intermediate layer both contain a fluorine-based compound, so that the mold release is performed by a solvent such as DMF contained in the resin composition for forming a polyurethane coat layer. The layer and the intermediate layer are hardly deteriorated. Therefore, the process paper for forming a polyurethane coat layer can be repeatedly used for the production of the polyurethane coat layer, and suppresses the occurrence of poor appearance of the polyurethane coat layer even when repeatedly used for the production of the polyurethane coat layer. be able to.

  The content of the fluorine-based compound in the release layer is preferably from 0.01% by mass to 1.0% by mass, and the content of the fluorine-based compound in the intermediate layer is preferably from 0.01% by mass to 1.0% by mass. 0 mass% or less is preferable. As described above, when the content of the fluorine-based compound in the release layer and the content of the fluorine-based compound in the intermediate layer are within the above ranges, the surface of the release layer can be prevented from being damaged, and the release property can be improved. The peel strength of the release layer and the intermediate layer can be increased while improving the smoothness of the mold layer surface and the intermediate layer surface and the durability of the release layer and the intermediate layer.

The ratio of the content of the fluorine compound in the intermediate layer to the content of the fluorine compound in the release layer is preferably 0.5 or more and 5.0 or less. As described above, the ratio of the content of the fluorine-based compound in the intermediate layer to the content of the fluorine-based compound in the release layer is within the above range, thereby preventing the surface of the release layer from being scratched. The peel strength of the release layer and the intermediate layer is easily increased while improving the smoothness of the surface of the release layer and the surface of the intermediate layer, and the durability of the release layer and the intermediate layer.

  The main component of the intermediate layer is preferably an acrylic resin or an alkyd resin. As described above, when the main component of the intermediate layer is an acrylic resin or an alkyd resin, it is easy to increase the peel strength of the release layer and the intermediate layer while promoting the smoothing of the surface of the release layer. Further, the acrylic resin and the alkyd resin are easily deteriorated by a solvent such as DMF. However, when the intermediate layer contains a fluorine compound, the deterioration caused by the solvent can be sufficiently suppressed.

  The main component of the release layer is preferably a silicone resin, a fluorine resin, a wax resin or an alkyd resin. As described above, the main component of the release layer is a silicone resin, a fluorine resin, a wax resin or an alkyd resin, so that the release layer and the polyurethane coat layer can be separated from each other while ensuring release properties of the release layer. Easy to increase smoothness.

  In the present invention, the “surface side” refers to a side on which a resin composition for forming a polyurethane coat layer is applied. The “main component” refers to a component having the largest content ratio in terms of mass, for example, a component having a content ratio of 50% by mass or more.

  As described above, the process paper for forming a polyurethane coat layer of the present invention can suppress occurrence of poor appearance of the polyurethane coat layer even when used repeatedly.

It is a typical sectional view showing the process paper for polyurethane coat layer formation concerning one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view illustrating a process paper for forming a polyurethane coat layer according to a form different from the process paper for forming a polyurethane coat layer of FIG. 1.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[First embodiment]
The polyurethane coated layer forming process paper 1 of FIG. 1 includes a base layer 2 and a release layer 4 laminated on the surface side of the base layer 2. The polyurethane coat layer forming process paper 1 further includes an intermediate layer 3 disposed between the base material layer 2 and the release layer 4 and containing a synthetic resin as a main component. The process paper 1 for forming a polyurethane coat layer has flexibility as a whole. The release layer 4 and the intermediate layer 3 contain a fluorine compound. The base layer 2 and the intermediate layer 3 are directly laminated without any other layers. Further, the intermediate layer 3 and the release layer 4 are directly laminated without interposing any other layer. The release layer 4 forms the outermost layer of the process paper 1 for forming a polyurethane coat layer. The polyurethane coating layer forming process paper 1 is used as a polyurethane coating layer forming process paper which forms the surface of, for example, shoes or bags and exhibits an enamel tone.

(Base material layer)
The base material layer 2 is a sheet-like member constituting the polyurethane coat layer forming process paper 1. The material used for the base layer 2 is not particularly limited. For example, paper made by a known method (acid paper, neutral paper, coated paper, glassine paper, etc.), polyethylene terephthalate film, etc. Synthetic resin film, synthetic paper, nonwoven fabric and the like. Among them, paper is preferred from the viewpoint of durability and heat resistance.

  Paper used for the base layer 2 includes additives such as a sizing agent, a paper strength agent, a fixing agent, a retention agent, a dye, calcium carbonate, kaolin, titanium dioxide, talc, aluminum hydroxide, and white carbon. Can be appropriately compounded. Further, in the papermaking process, a surface treatment can be appropriately performed by applying a paper strength improver (starch, polyvinyl alcohol, etc.), a surface sizing agent, a dye, and the like. As a method of applying these additives and the like, a known method can be used, and examples thereof include a method using a size press coater, a gate roll coater, and the like.

The lower limit of the basis weight of the paper used for the substrate layer 2, preferably 50 g / ^{m 2,} more preferably ^{75g / m 2, 90g / m} 2 is more preferred. On the other hand, the upper limit of the basis weight is preferably from 300 g / ^{m 2,} more preferably ^{200g / m 2, 120g / m} 2 is more preferred. If the basis weight is less than the lower limit, the stiffness and strength of the base material layer 2 may be reduced, and the polyurethane coated layer forming process paper 1 may be easily broken, wrinkled, or curled. Conversely, if the basis weight exceeds the upper limit, the productivity of the process paper 1 for forming a polyurethane coat layer may be reduced.

  As a minimum of average thickness of substrate layer 2, 50 micrometers is preferred, 100 micrometers is more preferred, and 150 micrometers is still more preferred. On the other hand, the upper limit of the average thickness of the base material layer 2 is preferably 500 μm, more preferably 300 μm, and still more preferably 200 μm. When the average thickness of the base material layer 2 is less than the above lower limit, handling of the process paper 1 for forming a polyurethane coat layer may be difficult. Conversely, if the average thickness of the base layer 2 exceeds the upper limit, the cushioning property of the polyurethane coat layer forming process paper 1 may be insufficient, and the production cost of the polyurethane coat layer forming process paper 1 may be insufficient. May increase. The “average thickness” refers to the average value of the thickness at any 10 points.

(Intermediate layer)
The intermediate layer 3 is an anchor layer that makes the base layer 2 and the release layer 4 adhere to each other. Further, the intermediate layer 3 is interposed between the base material layer 2 and the release layer 4 to enhance the smoothness of the surface of the release layer 4.

  The intermediate layer 3 is formed, for example, by applying a coating liquid for forming an intermediate layer containing a synthetic resin (main component resin) and a fluorine-based compound contained as main components to the surface side of the base material layer 2. After forming a coating film on the side, the film is formed by drying the coating film. Examples of the coating method of the intermediate layer forming coating liquid include known coating methods such as a roll coater, a bar coater, a blade coater, a spin coater, a gravure coater, a flow coater, an air knife coat, a spray coat, and screen printing. Can be Since the intermediate layer 3 contains a fluorine-based compound in addition to the main component resin, the coating film has a high leveling property. Therefore, the process paper 1 for forming a polyurethane coat layer has high surface smoothness of the intermediate layer 3 obtained by curing the coating film. As a result, the process paper 1 for forming a polyurethane coat layer is formed by laminating a release layer 4 to be described later on the surface side of the intermediate layer 3 so as to smooth the surface of the release layer 4 and to form the polyurethane coat layer. The surface of the process paper 1 can be smoothed.

  Examples of the synthetic resin include acrylic resins, aliphatic polyesters, aromatic polyesters, alicyclic polyesters, polyesters such as alkyd resins, cellulose derivatives such as methyl cellulose and ethyl cellulose, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, and polybutene. And the like, and these can be used alone or as a mixture of two or more. Among them, an acrylic resin and an alkyd resin, which can easily increase the peel strength of the release layer 4 and the intermediate layer 3 while promoting the smoothing of the surface of the release layer 4 by enhancing the leveling property of the coating film, are preferable. When the intermediate layer 3 contains one of an acrylic resin and an alkyd resin as a main component, the intermediate layer 3 preferably further contains the other of the acrylic resin and the alkyd resin.

  In general, when the main component of the intermediate layer is an acrylic resin or an alkyd resin, the intermediate layer is likely to be deteriorated by a solvent such as DMF contained in the resin composition for forming the polyurethane coat layer during the production of the polyurethane coat layer. On the other hand, in the process paper 1 for forming a polyurethane coat layer, since the intermediate layer 3 contains a fluorine-based compound, the solvent resistance of the intermediate layer 3 can be improved. Therefore, the process paper 1 for forming a polyurethane coat layer can be repeatedly used for producing a polyurethane coat layer, and can be used, for example, 20 times or more for producing a polyurethane coat layer having an enamel tone.

As the fluorine-based compound, for example, a known fluorine-based surfactant of an anionic type, a nonionic type, a cationic type, or an amphoteric type can be used. Specifically, as the fluorine-based compound, for example, a fluoroalkyl carboxylic acid or a salt thereof, a perfluoroalkyl carboxylic acid or a salt thereof, a perfluoroalkyl sulfonic acid or a salt thereof, N-perfluorooctanesulfonyl glutamic acid or a salt thereof, 3- [fluoroalkyloxy] -1-alkylsulfonic acid or a salt thereof, 3- [ω-fluoroalkanoyl-N-ethylamino] -1-propanesulfonic acid or a salt thereof, perfluoroalkyl-N-ethylsulfonylglycine or Salt, perfluoroalkylethylene oxide adduct, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl) perfluorooctanesulfonamide, bis (N-perfluorooctylsulfonyl-N-phosphate) Butylaminoethyl), perfluoroalkylsulfonamidopropyltrimethylammonium salt, monoperfluoroalkylethylphosphate N- [3- (perfluorooctanesulfonamido) propyl] -N, N-dimethyl-N-carboxymethyleneammonium betaine Etc. can be used. Among them, a nonionic perfluoroalkylethylene oxide adduct and perfluorooctanesulfonic acid diethanolamide are preferable.

  The lower limit of the content of the fluorine-based compound in the intermediate layer 3 in terms of solid content is preferably 0.01% by mass, more preferably 0.05% by mass, and still more preferably 0.1% by mass. On the other hand, the upper limit of the content is preferably 1.0% by mass, more preferably 0.4% by mass, and still more preferably 0.2% by mass. If the content ratio is less than the lower limit, the solvent resistance of the intermediate layer 3 is insufficient, the intermediate layer 3 is likely to be deteriorated by DMF or the like, and the surface smoothness of the intermediate layer 3 is insufficient. There is a risk. Conversely, if the content exceeds the upper limit, the fluorine-based compound may penetrate into the center of the intermediate layer 3 and the intermediate layer 3 may not be sufficiently cured. Peeling strength may be insufficient. In the process paper 1 for forming a polyurethane coat layer, the fluorine-based compound is preferably arranged in a layer on the surface side of the intermediate layer 3 from the viewpoint of easily and surely curing the main component resin of the intermediate layer 3. In this respect, when the content ratio is equal to or less than the upper limit, the fluorine-based compound easily gathers in a layer on the surface side of the intermediate layer 3, and the fluorine-based compound does not easily hinder the curing of the main component resin of the intermediate layer 3. . Therefore, in the process paper 1 for forming a polyurethane coat layer, when the content is within the above range, the solvent resistance and the curing strength of the intermediate layer 3 can be sufficiently increased.

  The content ratio of the fluorine-based compound may change gradually or stepwise in the thickness direction of the intermediate layer 3. For example, the content of the fluorine-based compound increases gradually or stepwise from the back side of the intermediate layer 3 (the side opposite to the side on which the resin composition forming the polyurethane coat layer is applied) to the front side. You may. Thus, by changing the content ratio of the fluorine-based compound in the thickness direction of the intermediate layer 3, the solvent resistance and the curing strength of the intermediate layer 3 can be sufficiently increased. In addition, as a method of changing the content ratio of the fluorine-based compound in the thickness direction of the intermediate layer 3, for example, a plurality of intermediate layer forming coating liquids having different fluorine-based compound content ratios are prepared, and the fluorine-based compound A method of applying the coating liquid for forming the intermediate layer having a low content ratio to the surface side of the base material layer 2 in order and drying the coating liquid may be mentioned.

  As described above, the intermediate layer 3 enhances the adhesion between the base material layer 2 and the release layer 4 and enhances the smoothness of the surface of the release layer 4. The intermediate layer 3 may contain other additives such as a pigment. However, from the viewpoint of increasing the adhesion between the intermediate layer 3 and the base layer 2 and the release layer 4, the intermediate layer 3 contains the pigment. It is preferable not to contain. Since the intermediate layer 3 contains the synthetic resin and the fluorine-based compound, the smoothness of the surface of the release layer can be sufficiently increased without separately containing a pigment.

  The lower limit of the average thickness of the intermediate layer 3 is preferably 0.1 μm, more preferably 1.0 μm. On the other hand, the upper limit of the average thickness of the intermediate layer 3 is preferably 20 μm, more preferably 10 μm. If the average thickness is less than the lower limit, smoothing of the surface of the intermediate layer 3 may not be sufficiently promoted. On the other hand, when the average thickness exceeds the upper limit, the intermediate layer 3 becomes unnecessarily thick, and the production cost of the process paper 1 for forming the polyurethane coat layer may increase.

(Release layer)
The release layer 4 constitutes the outermost layer of the polyurethane coat layer forming process paper 1, and the polyurethane coat layer forming process paper 1 and the polyurethane coat layer manufactured using the polyurethane coat layer forming process paper 1. And enhance the releasability. As described above, the polyurethane coating layer forming process paper 1 is suitably used as an enamel-like polyurethane coating layer forming process paper for forming the surface of shoes, bags, and the like. Therefore, the surface of the release layer 4 is preferably a smooth surface having no unevenness.

  The lower limit of the 60 ° glossiness of the surface of the release layer 4 is preferably 90, more preferably 95, and even more preferably 98. If the glossiness is less than the lower limit, it may be difficult to produce an enamel-like polyurethane coat layer. On the other hand, the upper limit of the 60 ° glossiness of the surface of the release layer 4 is not particularly limited, but may be, for example, 200. When the glossiness exceeds the upper limit, the releasability from the polyurethane coat layer may not be sufficiently improved. The “glossiness” refers to a value based on JIS-Z8741: 1997.

  The release layer 4 contains, for example, a synthetic resin as a main component. The release layer 4 is coated on the surface of the intermediate layer 3 with a coating liquid for forming a release layer containing, for example, a synthetic resin (main resin) and a fluorine compound contained as main components. After forming a coating film on the side, the film is formed by drying the coating film. Examples of the method for applying the coating liquid for forming a release layer include the same methods as the above-described methods for applying the coating liquid for forming an intermediate layer used for forming the intermediate layer 3.

  Examples of the synthetic resin (a main component resin of the release layer 4) include a silicone resin, a fluorine resin, a wax resin, and an alkyd resin. When the synthetic resin is a silicone resin, a fluorine resin, a wax resin, or an alkyd resin, it is easy to increase the smoothness of the surface of the release layer 4 while securing the releasability of the release layer 4 from the polyurethane coat layer. Above all, a silicone resin which has a low peeling power and is excellent in the releasability from the polyurethane coat layer is preferable.

  Examples of the silicone resin include Si-H group-containing silicone, dimethylpolysiloxane, methylphenylpolysiloxane, alkoxy group-containing silicone, silanol group-containing silicone, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, vinyl silicone, and alkyd-modified. Silicone, polyether modified silicone, polyglycerin modified silicone, amino modified silicone, epoxy modified silicone, mercapto modified silicone, methacryl modified silicone, carboxylic acid modified silicone, fatty acid ester modified silicone, alcohol modified silicone, alkyl modified silicone, fluoroalkyl modified silicone And the like, and these can be used alone or in combination of two or more. Among them, alkyd-modified silicone is preferable.

  As the silicone resin, a curable silicone is preferable. By using the curable silicone, the releasability of the process paper 1 for forming a polyurethane coat layer can be improved, and the deterioration with time of the peel strength can be suppressed. As the curable silicone, one that has been cured using, for example, heat, ultraviolet light, an electron beam, or the like can be used. More specifically, for example, addition-curable silicone using Si-H group-containing silicone and vinyl silicone, condensation-curing silicone using Si-H group-containing silicone and silanol group-containing silicone, and UV curing using photopolymerizable functional group-modified silicone Mold silicone and the like.

  Examples of the fluororesin include polytetrafluoroethylene (PTFE), perfluoroalkoxy fluororesin (PFA) composed of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, and copolymer of tetrafluoroethylene and hexafluoropropylene (FEP) Copolymer of tetrafluoroethylene, perfluoroalkyl vinyl ether and hexafluoropropylene (EPE), copolymer of tetrafluoroethylene and ethylene or propylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene and chlorotrifluoroethylene Copolymer (ECTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and the like.

  Examples of the wax resin include olefin waxes such as polyethylene wax, polypropylene wax, and ethylene-vinyl acetate copolymer wax, paraffin wax, and microcrystalline.

  Examples of the fluorine-based compound contained in the release layer 4 include the above-described fluorine-based compound that can be contained in the intermediate layer 3.

  The lower limit of the content of the fluorine-based compound in the release layer 4 in terms of solid content is preferably 0.01% by mass, more preferably 0.05% by mass, and still more preferably 0.1% by mass. On the other hand, the upper limit of the content is preferably 1.0% by mass, more preferably 0.4% by mass, and still more preferably 0.2% by mass. When the content is less than the lower limit, the solvent resistance of the release layer 4 becomes insufficient, and the release layer 4 may be easily deteriorated by DMF or the like, or the surface of the release layer 4 may not be smooth. May be sufficient. If the content is less than the lower limit, the surface of the release layer 4 may be insufficiently prevented from being damaged. Conversely, if the content exceeds the upper limit, the fluorine-based compound may penetrate into the center of the release layer 4 and the release layer 4 may not be sufficiently cured, or the intermediate layer 3 and the release layer 4 may not be sufficiently cured. The peel strength between them may be insufficient. If the content exceeds the upper limit, the fluorine-based compound contained in the release layer 4 is transferred to the surface of the polyurethane coat layer, and the surface properties of the polyurethane coat layer may be insufficient.

  The lower limit of the ratio of the content of the fluorine-based compound in the intermediate layer 3 to the content of the fluorine-based compound in the release layer 4 is preferably 0.5, and more preferably 1.0. On the other hand, the upper limit of the content ratio is preferably 5.0, and more preferably 3.0. If the ratio of the content is less than the lower limit, the content of the fluorine-based compound in the intermediate layer 3 may be too small, and the surface smoothness of the intermediate layer 3 may be insufficient. If the ratio of the content is less than the lower limit, the content of the fluorine-based compound in the release layer 4 becomes too large, and the fluorine-based compound enters the center of the release layer 4 and is released. The layer 4 may not be sufficiently cured, the peel strength between the intermediate layer 3 and the release layer 4 may be insufficient, or the fluorine-based compound contained in the release layer 4 may be a surface of the polyurethane coat layer. And the surface properties of the polyurethane coat layer may be insufficient. Conversely, if the ratio of the content exceeds the upper limit, the content of the fluorine-based compound in the release layer 4 becomes too small, and the solvent resistance of the release layer 4 becomes insufficient. May be easily deteriorated by DMF or the like, the smoothness of the surface of the release layer 4 may be insufficient, or the surface of the release layer 4 may be insufficiently prevented from being damaged. If the ratio of the content exceeds the upper limit, the content of the fluorine-based compound in the intermediate layer 3 becomes too large, and the fluorine-based compound penetrates to the center of the intermediate layer 3 and the intermediate layer 3 is sufficiently formed. There is a possibility that curing may be difficult, and a peel strength between the intermediate layer 3 and the release layer 4 may be insufficient.

  Waxes, surface modifiers, and the like can be added to the release layer 4 for the purpose of improving releasability. In addition, additives such as a pigment, a catalyst, a dye, and a dispersant may be added to the release layer 4. Examples of the pigment include silica, titanium oxide, calcium carbonate, talc, and mica. However, it is preferable that the release layer 4 does not contain a pigment from the viewpoint of improving the adhesion to the intermediate layer 3 while ensuring the surface smoothness and the anti-scratch property. In the process paper 1 for forming a polyurethane coat layer, for example, by adjusting the content ratio of the fluorine-based compound in the intermediate layer 3 and the release layer 4, the intermediate layer 3 and the release layer 4 contain an additive such as a pigment. Even without this, it is possible to sufficiently enhance the smoothness of the surface of the release layer 4 while securing the releasability of the release layer 4.

  The lower limit of the average thickness of the release layer 4 is preferably 0.1 μm, more preferably 1.0 μm. On the other hand, the upper limit of the average thickness of the release layer 4 is preferably 20 μm, more preferably 10 μm. If the average thickness is less than the lower limit, the peelability between the polyurethane coating layer-forming process paper 1 and the polyurethane coating layer may be insufficient. Conversely, if the average thickness exceeds the upper limit, the release layer 4 becomes unnecessarily thick, and the production cost of the polyurethane coat layer forming process paper 1 may increase.

<Production method>
The polyurethane paper layer forming process The paper 1 is produced by, for example, preparing a base layer 2 by papermaking or extrusion (base layer preparing step) and preparing the base layer prepared in the base layer preparing step. (Intermediate layer laminating step) and a step of laminating the release layer 4 on the surface side of the intermediate layer 3 laminated in the intermediate layer laminating step (release layer laminating step). ). In the method for producing a paper for forming a polyurethane coat layer according to the present embodiment, the intermediate layer 3 is directly laminated on the surface of the base material layer 2 in the intermediate layer laminating step, and the release layer 4 is intermediately laminated in the release layer laminating step. Laminated directly on the surface of layer 3.

(Base layer preparation process)
When paper is used as the material of the base material layer 2 in the base material layer preparation step, a method of making the paper constituting the base material layer 2 is not particularly limited, and a known method can be used. . Specifically, for example, a fourdrinier system, a twin-wire system, a gap former system, a round net system, and the like can be given.

(Intermediate layer lamination process)
In the intermediate layer laminating step, a coating liquid for forming an intermediate layer containing a synthetic resin (a main component resin) and a fluorine-based compound constituting the intermediate layer 3 is applied to the surface side of the base layer 2 to form the base layer 2. After forming a coating film on the surface side of the above, the coating film is dried.

(Release layer lamination process)
In the release layer laminating step, a coating liquid for forming a release layer containing a synthetic resin (a main component resin) and a fluorine-based compound constituting the release layer 4 is applied on the surface side of the intermediate layer 3 to form an intermediate layer. After forming a coating film on the surface side of No. 3, this coating film is dried. The release layer laminating step is a state in which the intermediate layer 3 is laminated on the surface side of the base material layer 2 by the intermediate layer laminating step (that is, a coating film formed by applying a coating liquid for forming an intermediate layer). (Dry state).

<Advantages>
Since the intermediate layer 3 of the process paper 1 for forming a polyurethane coat layer has a synthetic resin as a main component and contains the above-mentioned fluorine-based compound, the surface of the intermediate layer 3 has high smoothness. Therefore, the process paper 1 for forming a polyurethane coat layer can sufficiently enhance the smoothness of the surface of the release layer 4 laminated on the surface side of the intermediate layer 3. In the process paper 1 for forming a polyurethane coat layer, since the release layer 4 contains the above-mentioned fluorine compound, the smoothness of the surface of the release layer 4 is improved and the surface of the release layer 4 is prevented from being damaged. can do. Further, the process paper 1 for forming a polyurethane coat layer is characterized in that the release layer 4 and the intermediate layer 3 both contain the above-mentioned fluorine-containing compound, and thus the solvent such as DMF contained in the resin composition for forming a polyurethane coat layer. The release layer 4 and the intermediate layer 3 are hardly deteriorated. Accordingly, the process paper 1 for forming a polyurethane coat layer can be repeatedly used for producing the polyurethane coat layer, and even when repeatedly used for producing the polyurethane coat layer, the occurrence of poor appearance of the polyurethane coat layer is suppressed. can do.

  The method for producing the polyurethane coat layer forming process paper can be repeatedly used for producing the polyurethane coat layer, and suppresses the occurrence of poor appearance of the polyurethane coat layer even when repeatedly used for producing the polyurethane coat layer. The possible process paper 1 for forming a polyurethane coat layer can be easily and reliably manufactured.

[Second embodiment]
The process paper 11 for forming a polyurethane coat layer in FIG. 2 is used as a process paper for forming an enamel-like polyurethane coat layer, for example, similarly to the process paper 1 for forming a polyurethane coat layer in FIG. The process paper 11 for forming a polyurethane coat layer is provided with a base layer 2, a release layer 4 laminated on the surface side of the base layer 2, and disposed between the base layer 2 and the release layer 4, And an intermediate layer 3 containing a synthetic resin as a main component. The release layer 4 and the intermediate layer 3 contain a fluorine compound. Further, the polyurethane coated layer forming process paper 11 further includes a filling layer 12 disposed between the base material layer 2 and the intermediate layer 3. The base material layer 2 and the sealing layer 12, the sealing layer 12 and the intermediate layer 3, and the intermediate layer 3 and the release layer 4 are directly laminated without any other layers. The release layer 4 constitutes the outermost layer of the polyurethane coat layer forming process paper 11. The base material layer 2, the intermediate layer 3, and the release layer 4 in the process paper 11 for forming a polyurethane coat layer are the same as those in the process paper 1 for forming a polyurethane coat layer in FIG. Omitted.

(Filler layer)
The filling layer 12 suppresses the components contained in the intermediate layer 3 from penetrating into the base material layer 2. The filling layer 12 is formed by applying a coating liquid for forming a filling layer containing a main component resin of the filling layer 12 such as a water-soluble polymer or polyethylene to the surface side of the base material layer 2 and drying. It is formed. As a method for applying the coating liquid for forming the filling layer, the same method as the method for applying the coating liquid for forming the intermediate layer used for forming the intermediate layer 3 may be used.

  Examples of the water-soluble polymer include polyacrylamide, polyacrylic acid, polymethacrylic acid, polyitaconic acid, polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, polyvinyl methyl ether, polyethylene glycol, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, hydroxymethyl cellulose, and alginic acid. Examples thereof include sodium, starch, casein, and gelatin. These can be used alone or in combination of two or more.

  A curing agent can be added to the filling layer 12 within a range that does not impair the adhesiveness to the intermediate layer 3. This curing agent is used when the sheet in which the filler layer 12 is laminated on the surface side of the base material layer 2 is made into a roll in the polyurethane paper layer forming process paper manufacturing process before the intermediate layer 3 is laminated. Is added to prevent blocking from occurring due to moisture absorption. As the curing agent, for example, chromic acid, glyoxal, or the like can be used. In addition, the filling layer 12 may contain an ultraviolet inhibitor, an antistatic agent, and the like as long as the adhesiveness to the base layer 2 is not impaired. Furthermore, a small amount of a release agent having a silicone group may be added to the filling layer 12 in order to improve the adhesion to the intermediate layer 3.

  It is preferable that the filling layer 12 be subjected to a surface treatment on the surface of the base material layer 2 and then be laminated on the surface side of the base material layer 2. Thereby, the adhesion between the base material layer 2 and the filling layer 12 can be improved. Examples of such surface treatments for improving adhesion include corona treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, etc., anchor coat treatment, and the like. Can be Among them, corona treatment and anchor coat treatment which improve the adhesive strength between the base material layer 2 and the sealing layer 12 and contribute to the formation of the dense and uniform sealing layer 12 are preferable.

<Production method>
The method for producing the paper 11 for forming the polyurethane coat layer includes a step of preparing the base layer 2 (base layer preparation step) and a step of filling the front side of the base layer 2 prepared in the base layer preparation step. A step of laminating the layer 12 (filler layer laminating step), a step of laminating the intermediate layer 3 on the surface side of the filler layer 12 laminated by the above filler layer laminating step (intermediate layer laminating step), A step of laminating the release layer 4 on the surface side of the intermediate layer 3 laminated in the layer laminating step (release layer laminating step). In the method for producing a paper for forming a polyurethane coat layer according to the present embodiment, the sealing layer 12 is directly laminated on the surface of the base material layer 2 in the sealing layer laminating step, and the intermediate layer 3 is formed in the intermediate layer laminating step. The release layer 4 is directly laminated on the surface of the intermediate layer 3 by the above-described release layer laminating step. The base layer preparing step, the intermediate layer laminating step, and the release layer laminating step in the method for producing the polyurethane coat layer forming process paper are the same as those described in the method for producing the polyurethane coat layer forming process paper 1 in FIG. Since the same method can be used, the description is omitted.

(Filling layer lamination process)
In the filling layer laminating step, a coating liquid for forming a filling layer for forming the filling layer 12 is applied to the surface side of the base material layer 2 to form a coating film on the surface side of the base material layer 2. After this, the coating is dried.

<Advantages>
The process paper 11 for forming a polyurethane coat layer is provided with a base layer 2, a release layer 4 laminated on the surface side of the base layer 2, and disposed between the base layer 2 and the release layer 4, Since the intermediate layer 3 containing a synthetic resin as a main component is provided, and the release layer 4 and the intermediate layer 3 contain the fluorine-based compound, the production of the polyurethane coat layer is repeated as described in the first embodiment. Even when used, the occurrence of poor appearance of the polyurethane coat layer can be suppressed. Further, in the process paper 11 for forming a polyurethane coat layer, since the filling layer 12 is provided between the base layer 2 and the intermediate layer 3, the components contained in the intermediate layer 3 penetrate into the base layer 2. , And thereby smoothness on the surface side of the intermediate layer 3 can be more easily increased.

  In the method for producing the process paper for forming a polyurethane coat layer, the smoothness of the surface side of the intermediate layer 3 is further improved, and even when the polyurethane coat layer is repeatedly used for the production of the polyurethane coat layer, the appearance of the polyurethane coat layer becomes poor. The polyurethane coated layer forming process paper 11 that can be more accurately suppressed can be easily and reliably manufactured.

[Other Embodiments]
The above embodiments do not limit the configuration of the present invention. Therefore, in the above embodiment, it is possible to omit, replace, or add the components of each part of the embodiment based on the description of the present specification and common technical knowledge, and all of them are interpreted as belonging to the scope of the present invention. Should.

  For example, the process paper for forming a polyurethane coat layer may further include a layer other than the above-described base layer, intermediate layer, release layer, and sealing layer. For example, the process paper for forming a polyurethane coat layer may include an antistatic layer or the like on the back side of the base layer (the side opposite to the side on which the resin composition forming the polyurethane coat layer is applied). Further, another resin layer or the like may be provided between the intermediate layer and the release layer.

  The process paper for forming a polyurethane coat layer is suitable for producing an enamel-like polyurethane coat layer as described above, but can also be used for producing other polyurethane coat layers.

  Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[Example]
[No. 1]
A solution containing 75% by mass of an acrylic resin “P-2075” manufactured by Dainichi Seika Kogyo Co., Ltd. and 25% by mass of a sulfonic acid compound “MPAC NO3” manufactured by Dainichi Seika Kogyo Co., Ltd. as a curing agent is prepared. A fluorine-based compound “F-553” manufactured by DIC was added in an amount of 0.10% by mass in terms of solid content to obtain a coating liquid for forming an intermediate layer. This intermediate layer forming coating liquid is applied to the surface of a cast-coated paper “Esprit C” manufactured by Nippon Paper Industries, dried at 190 ° C. for 30 seconds, and an acrylic resin is applied to the surface of the base layer made of the cast-coated paper. An intermediate layer which is a main component and contains a fluorine compound as an additive was laminated. A solution containing 75% by mass of an alkyd-modified silicone “KS-883” manufactured by Shin-Etsu Chemical Co., Ltd. and 25% by mass of para-toluenesulfonic acid “PS-80” manufactured by Shin-Etsu Chemical Co., Ltd. as a curing agent was prepared. To this solution, a fluorine-based compound “F-556” manufactured by DIC was added in an amount of 0.10% by mass in terms of solid content to obtain a coating liquid for forming a release layer. This coating liquid for forming a release layer is applied to the surface of the intermediate layer, and dried at 200 ° C. for 60 seconds. The surface of the intermediate layer contains an alkyd-modified silicone as a main component and contains a fluorine-based compound as an additive. Release layers were laminated. Thereby, No. 1 in which the base material layer, the intermediate layer and the release layer were laminated in this order. Thus, a process paper for forming a polyurethane coat layer No. 1 was obtained. The average thickness of the base layer was 180 μm, the average thickness of the intermediate layer was 4 μm, and the average thickness of the release layer was 4 μm. In addition, No. The 60 ° glossiness of the release layer surface of the polyurethane coating layer forming process paper of No. 1 was measured using “Gloss Mobile GM-1” manufactured by Suga Test Instruments Co., Ltd. in accordance with JIS-Z8741 to 96.8. Met.

[No. 2]
No. 6 except that “F-557” manufactured by DIC was used as the fluorine-based compound contained in the coating liquid for forming a release layer. In the same manner as in No. 1, A process paper for forming a polyurethane coat layer No. 2 was produced.

[No. 3]
No. 5 except that “F-571” manufactured by DIC was used as the fluorine-based compound contained in the coating liquid for forming a release layer. In the same manner as in No. 1, A process paper for forming a polyurethane coat layer No. 3 was produced.

[Comparative example]
[No. 4]
No. 4 except that a silicone-based compound “BYK-377” manufactured by BYK Japan KK was included in the coating liquid for forming a release layer instead of the fluorine-based compound. In the same manner as in No. 1, A process paper for forming a polyurethane coat layer No. 4 was produced.

[No. 5]
No. 3 except that a silicone-based compound “BYK-378” manufactured by BYK Japan KK was included in the coating liquid for forming a release layer instead of the fluorine-based compound. In the same manner as in No. 1, The process paper for forming a polyurethane coat layer of No. 5 was produced.

[No. 6]
No. 1 except that the coating liquid for forming a release layer contained an organic peroxide “Perbutyl (registered trademark) C” manufactured by NOF Corporation instead of the fluorine-based compound. In the same manner as in No. 1, A process paper for forming a polyurethane coat layer No. 6 was produced.

[No. 7]
No. 4 except that the coating liquid for forming a release layer contained an organic peroxide “Perhexa (registered trademark) 25B” manufactured by NOF Corporation instead of the fluorine-based compound. In the same manner as in No. 1, The process paper for forming a polyurethane coat layer of No. 7 was produced.

[No. 8]
No. 4 except that the coating liquid for forming a release layer did not contain a fluorine-based compound. In the same manner as in No. 1, No. 8 was prepared.

[No. 9]
No. 2 except that the coating liquid for forming an intermediate layer did not contain a fluorine compound. In the same manner as in No. 2, Ninety-four process papers for forming a polyurethane coat layer were produced.

[No. 10]
No. 2 except that neither the coating liquid for forming an intermediate layer nor the coating liquid for forming a release layer contained a fluorine-based compound. In the same manner as in No. 1, Ten process papers for forming a polyurethane coat layer were produced.

<Surface properties>
No. 1 to No. For No. 10, the gloss of the release layer surface was visually evaluated according to the following criteria. Table 1 shows the evaluation results.
A: No surface roughness, and no uneven mixing of the main component and the additive in the release layer.
B: Surface roughness due to the additive and uneven mixing of the main component and the additive in the release layer are observed.

<DMF resistance>
Using a 120 mm × 215 mm Kimwipe soaked with 1 ml of DMF, 1 to No. The surface of the 10 release layers was rubbed 40 times with a load of 0.5 N and a stroke distance of 18 cm. The glossiness of the surface of the release layer before and after rubbing was measured by "HG-268" manufactured by Suga Test Instruments Co., Ltd. in accordance with JIS-Z8741 and evaluated according to the following criteria. Table 1 shows the evaluation results.
A: The reduction in gloss is less than 0.5%.
B: The reduction in glossiness is 0.5% or more.

<Repeatability>
No. 1 to No. Using 10 polyurethane coat layer forming process papers, the same conditions were repeated 15 times to produce a polyurethane coat layer. The glossiness of the surface of the release layer before and after the production of the polyurethane coat layer was measured by "HG-268" manufactured by Suga Test Instruments Co., Ltd. in accordance with JIS-Z8741 and evaluated according to the following criteria. Table 1 shows the evaluation results.
A: The reduction in gloss is less than 0.5%.
B: The reduction in glossiness is 0.5% or more.

[Evaluation results]
As shown in Table 1, both of the intermediate layer and the release layer contained a fluorine-based compound. 1 to No. No. 3 is excellent in surface properties, DMF resistance and repetitive useability.

  As described above, the process paper for forming a polyurethane coat layer of the present invention is suitable as a process paper for producing an enamel-like polyurethane coat layer since the occurrence of poor appearance of the polyurethane coat layer can be suppressed.

1,11 Polyurethane coating layer forming process paper 2 Base layer 3 Intermediate layer 4 Release layer 12 Filler layer

Claims (2)

A base coat, a polyurethane coat layer forming process paper comprising a release layer laminated on the surface side of the base coat,
Further comprising an intermediate layer disposed between the base layer and the release layer,
The release layer and the intermediate layer contain a fluorine-based surfactant,
Main component of the release layer is alkyd-modified silicone, the main component of the intermediate layer is Ri der acrylic resin,
The content ratio of the fluorine-based surfactant in the release layer is 0.01% by mass or more and 1.0% by mass or less, and the content ratio of the fluorine-based surfactant in the intermediate layer is 0.01% by mass or more and 1% by mass. Process paper for forming a polyurethane coat layer of not more than 0.0% by mass . The polyurethane coat layer according to claim 1, wherein a ratio of a content ratio of the fluorine-based surfactant in the intermediate layer to a content ratio of the fluorine-based surfactant in the release layer is 0.5 or more and 5.0 or less. Process paper for forming.

Images