WO2019240069A1

WO2019240069A1 - Process paper for forming polyurethane coating layer

Info

Publication number: WO2019240069A1
Application number: PCT/JP2019/022896
Authority: WO
Inventors: 大平鈴木
Original assignee: 恵和株式会社
Priority date: 2018-06-11
Filing date: 2019-06-10
Publication date: 2019-12-19
Also published as: JP6673982B2; JP2019214136A

Abstract

This process paper for forming a polyurethane coating layer comprises a base material layer and a release layer that is layered on the obverse-surface side of the base material layer, wherein: the process paper furthermore comprises an intermediate layer containing a synthetic resin as a main component, the intermediate layer being disposed between the base material layer and the release layer; and the release layer and the intermediate layer contain a fluorine-based compound.

Description

Polyurethane coat layer forming process paper

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 polyurethane coat layer forming resin composition onto a process paper having a peelability, 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, in order to facilitate the release of the resin composition from the cured body, a paper having a release layer laminated on the surface of a base material layer made of kraft paper or the like is used. It is used (see JP 2013-147774 A).

Japanese Unexamined Patent Publication No. 2013-147764

In such process paper, if there are surface defects such as bubbles, unevenness, unevenness, scratches, etc. in the release layer, the shape is transferred to the cured body surface of the coated resin composition, and the shape of the product There is a risk of failure. In particular, in the process paper used for the production of the enamel-like polyurethane coat layer, the surface defect of the release layer is directly connected to the appearance defect of the product, which causes a decrease in the product yield.

In general, the process paper is used repeatedly several times. However, in the process paper used for the production of the enamel-like polyurethane coat layer, the smoothness of the surface of the product is particularly important, and dimethylformamide (DMF) contained in the polyurethane coat layer forming resin composition ) Or the like erodes the process paper, and the process paper is likely to deteriorate, so that it is difficult to use multiple times.

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

The process paper for forming a polyurethane coat layer according to the present invention made to solve the above-mentioned problems is a process for forming a polyurethane coat layer comprising a base material layer and a release layer laminated on the surface side of the base material layer. It is paper, It is arrange | positioned between the said base material layer and a mold release layer, and further comprises the intermediate | middle layer which contains a synthetic resin as a main component, and the said mold release layer and an intermediate | middle layer contain a fluorine-type compound.

In the process paper for forming a polyurethane coat layer, the intermediate layer has a synthetic resin as a main component and a fluorine-based compound, so that the surface of the intermediate layer has high smoothness. Therefore, the process paper for forming a polyurethane coat layer can sufficiently enhance the smoothness of the surface of the release layer laminated on the surface side of the intermediate layer. Moreover, since the said release layer contains the fluorine-type compound, the said polyurethane coat layer formation process paper can suppress the damage | wound of the release layer surface while improving the smoothness of this release layer surface. Further, the process paper for forming the polyurethane coat layer is such that 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 polyurethane coat layer forming resin composition. Layers and intermediate layers are difficult to deteriorate. Therefore, the process paper for forming the polyurethane coat layer can be used repeatedly for the production of the polyurethane coat layer, and even when it is repeatedly used for the production of the polyurethane coat layer, the appearance defect of the polyurethane coat layer is suppressed. be able to.

The content ratio of the fluorine compound in the release layer is preferably 0.01% by mass or more and 1.0% by mass or less, and the content ratio of the fluorine compound in the intermediate layer is 0.01% by mass or more and 1. 0 mass% or less is preferable. Thus, when the content ratio of the fluorine-based compound in the release layer and the content ratio of the fluorine-based compound in the intermediate layer are within the above ranges, the scratch prevention property on the surface of the release layer, the release 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 peel strength of the release layer and the intermediate layer can be increased.

The ratio of the content ratio of the fluorine compound in the intermediate layer to the content ratio of the fluorine compound in the release layer is preferably 0.5 or more and 5.0 or less. Thus, the ratio of the content ratio of the fluorine compound in the intermediate layer to the content ratio of the fluorine compound in the release layer is within the above range, thereby preventing the release layer surface from being scratched. While improving the smoothness of the release layer surface and the intermediate layer surface and the durability of the release layer and the intermediate layer, it is easy to increase the peel strength 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, the main component of the intermediate layer is an acrylic resin or an alkyd resin, so that it is easy to increase the peel strength of the release layer and the intermediate layer while promoting smoothing of the surface of the release layer. Acrylic resins and alkyd resins are easily deteriorated by a solvent such as DMF. However, when the intermediate layer contains a fluorine-based compound, deterioration due to the solvent can be sufficiently suppressed.

The main component of the release layer is preferably a silicone resin, a fluororesin, a wax resin, or an alkyd resin. As described above, the main component of the release layer is a silicone resin, a fluororesin, a wax resin, or an alkyd resin. Easy to improve smoothness.

In the present invention, the “surface side” refers to the side on which the resin composition forming the 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 the 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. It is typical sectional drawing which shows the process paper for polyurethane coat layer formation which concerns on the form different from the process paper for polyurethane coat layer formation of FIG.

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

[First embodiment]
The process paper 1 for forming a polyurethane coat layer in FIG. 1 includes a base material layer 2 and a release layer 4 laminated on the surface side of the base material layer 2. The process paper 1 for forming a polyurethane coat layer 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 polyurethane coat layer forming process paper 1 has flexibility as a whole. The release layer 4 and the intermediate layer 3 contain a fluorine compound. The base material layer 2 and the intermediate layer 3 are directly laminated without interposing other layers. Further, the intermediate layer 3 and the release layer 4 are directly laminated without interposing other layers. The release layer 4 constitutes the outermost layer of the polyurethane coat layer forming process paper 1. The process paper 1 for forming a polyurethane coat layer is used as a process paper for forming a polyurethane coat layer that 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 material 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, and non-woven fabric. Among these, paper is preferable from the viewpoint of durability and heat resistance.

The paper used for the base material layer 2 includes additives such as a sizing agent, paper strength enhancer, fixing agent, yield improver, dye, calcium carbonate, kaolin, titanium dioxide, talc, aluminum hydroxide, white carbon, etc. These internal additives can be appropriately blended. Furthermore, in the paper making process, a surface treatment can be appropriately performed by coating 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.

As a minimum of the basic weight of paper used for substrate layer 2, 50 g / m ² is preferred, 75 g / m ² is more preferred, and 90 g / m ² is still 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 coating layer forming process paper 1 may be easily broken, wrinkled, curled, or the like. Conversely, when the basis weight exceeds the upper limit, the productivity of the polyurethane coat layer forming process paper 1 may be reduced.

The lower limit of the average thickness of the base material layer 2 is preferably 50 μm, more preferably 100 μm, and even more preferably 150 μm. 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 even more preferably 200 μm. If the average thickness of the base material layer 2 is less than the above lower limit, it may be difficult to handle the polyurethane coat layer forming process paper 1. On the other hand, if the average thickness of the base material layer 2 exceeds the above upper limit, the cushioning property of the polyurethane coat layer forming process paper 1 may be insufficient, or the manufacturing cost of the polyurethane coat layer forming process paper 1 may be insufficient. May increase. Note that “average thickness” refers to an average value of thicknesses at arbitrary 10 points.

(Middle layer)
The intermediate layer 3 is an anchor layer that adheres the base material layer 2 and the release layer 4. Further, the intermediate layer 3 is interposed between the base material layer 2 and the release layer 4, thereby enhancing the smoothness of the surface of the release layer 4.

The intermediate layer 3 is, for example, coated on the surface side of the base layer 2 with a coating solution for forming an intermediate layer containing a synthetic resin (main component resin) included as a main component and a fluorine-based compound. After the coating film is formed on the side, the coating film is formed by drying. Examples of the coating method for the intermediate layer forming coating liquid include known coating methods such as roll coater, bar coater, blade coater, spin coater, gravure coater, flow coater, air knife coat, spray coat, and screen printing. It is done. Since the intermediate layer 3 contains a fluorine compound in addition to the main component resin, the leveling property of the coating film is high. 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 the polyurethane coat layer is formed by laminating a later-described release layer 4 on the surface side of the intermediate layer 3, thereby smoothing the surface of the release layer 4 and thus forming 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 methylcellulose and ethylcellulose, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, and polybutene. And the like, and these can be used alone or in admixture of two or more. Among them, an acrylic resin and an alkyd resin that 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 increasing the leveling property of the coating film are preferable. In addition, when the intermediate layer 3 includes one of an acrylic resin and an alkyd resin as a main component, the intermediate layer 3 preferably further includes 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 polyurethane coat layer forming resin composition when the polyurethane coat layer is produced. In contrast, in the process paper 1 for forming a polyurethane coat layer, since the intermediate layer 3 contains a fluorine compound, the solvent resistance of the intermediate layer 3 can be improved. Therefore, the process paper 1 for forming the polyurethane coat layer can be used repeatedly for the production of the polyurethane coat layer. For example, it can be used 20 times or more for the production of the polyurethane coat layer exhibiting an enamel tone.

As the fluorine compound, for example, anionic, nonionic, cationic or amphoteric known fluorine surfactants can be used. Specifically, as the fluorine-based compound, for example, fluoroalkylcarboxylic acid or a salt thereof, perfluoroalkylcarboxylic acid or a salt thereof, perfluoroalkylsulfonic acid or a salt thereof, N-perfluorooctanesulfonylglutamic 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 Its salts, perfluoroalkylethylene oxide adduct, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl) perfluorooctanesulfonamide, bis (N-perfluorooctylsulfonyl-N-) phosphate Tilaminoethyl), perfluoroalkylsulfonamidopropyltrimethylammonium salt, monoperfluoroalkylethyl phosphate N- [3- (perfluorooctanesulfonamido) propyl] -N, N-dimethyl-N-carboxymethyleneammonium betaine Etc. can be used. Among these, nonionic perfluoroalkylethylene oxide adduct and perfluorooctanesulfonic acid diethanolamide are preferable.

The lower limit of the content ratio in terms of solid content of the fluorine compound in the intermediate layer 3 is preferably 0.01% by mass, more preferably 0.05% by mass, and further 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 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 smoothness of the surface of the intermediate layer 3 is insufficient. There is a fear. Conversely, if the content ratio exceeds the upper limit, the fluorine-based compound may enter the center of the intermediate layer 3 and the intermediate layer 3 may not be sufficiently cured, or between the intermediate layer 3 and the release layer 4. Peel strength may be insufficient. In the process paper 1 for forming the polyurethane coat layer, the fluorine-based compound is preferably arranged in a layered manner on the surface side of the intermediate layer 3 from the viewpoint of easily and reliably curing the main component resin of the intermediate layer 3. In this respect, when the content ratio is less than or equal to the upper limit, the fluorine-based compound tends to gather in a layered manner on the surface side of the intermediate layer 3, and the fluorine-based compound does not easily prevent the main component resin of the intermediate layer 3 from being cured. . Therefore, the polyurethane coat layer forming process paper 1 can sufficiently enhance the solvent resistance and the curing strength of the intermediate layer 3 when the content ratio is within the above range.

The content ratio of the fluorine-based compound may be changed in an inclined or stepwise manner in the thickness direction of the intermediate layer 3. For example, the content ratio of the fluorine-based compound increases gradually or stepwise from the back side of the intermediate layer 3 (opposite to the side on which the resin composition forming the polyurethane coat layer is applied) from the back side. May be. Thus, by changing the content ratio of the fluorine 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 compound in the thickness direction of the intermediate layer 3, for example, a plurality of intermediate layer forming coating liquids having different content ratios of the fluorine compound are prepared. Examples of the method include a method in which coating is sequentially performed on the surface side of the base material layer 2 from a coating solution for forming an intermediate layer having a low content ratio and then dried.

As described above, the intermediate layer 3 increases the adhesion between the base material layer 2 and the release layer 4 and increases the smoothness of the surface of the release layer 4. The intermediate layer 3 may contain other additives such as a pigment, but from the viewpoint of enhancing the adhesion between the intermediate layer 3 and the base material layer 2 and the release layer 4, the intermediate layer 3 contains a 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 enhanced without containing a separate 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 and 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 be increased.

(Release layer)
The release layer 4 constitutes the outermost layer of the polyurethane coat layer forming process paper 1, and the polyurethane coat layer is produced using the polyurethane coat layer forming process paper 1 and the polyurethane coat layer forming process paper 1. And exfoliation. As described above, the polyurethane coat layer forming process paper 1 is suitably used as an enamel-like polyurethane coat layer forming process paper that forms the surface of shoes, bags, and the like. Therefore, it is preferable that the surface of the release layer 4 is a smooth surface with no irregularities.

The lower limit of the 60 ° gloss on 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 200, for example. When the glossiness exceeds the upper limit, the peelability from the polyurethane coat layer may not be sufficiently improved. “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 formed by, for example, applying a release layer forming coating solution containing a synthetic resin (main component resin) and a fluorine-based compound as main components to the surface side of the intermediate layer 3. After the coating film is formed on the side, the coating film is formed by drying. Examples of the coating method for the release layer forming coating solution include the same methods as those for the intermediate layer forming coating solution used for forming the intermediate layer 3.

Examples of the synthetic resin (the main component resin of the release layer 4) include silicone resin, fluorine resin, wax resin, alkyd resin, and the like. When the synthetic resin is a silicone resin, a fluororesin, a wax resin, or an alkyd resin, it is easy to improve the smoothness of the surface of the release layer 4 while ensuring the peelability of the release layer 4 from the polyurethane coat layer. Among these, a silicone resin having a low peel strength and excellent peelability 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 These can be used, and these can be used alone or in combination of two or more. Among these, alkyd-modified silicone is preferable.

As the silicone resin, curable silicone is preferable. By using the curable silicone, it is possible to improve the peelability of the process paper 1 for forming the polyurethane coat layer, and to suppress the deterioration of the peel strength over time. As this curable silicone, what hardened | cured using the heat | fever, an ultraviolet-ray, an electron beam etc. can be used, for example. Specifically, for example, addition-curing silicones with Si-H group-containing silicone and vinyl silicone, condensation-curing silicones with Si-H group-containing silicones and silanol group-containing silicones, UV curing with photopolymerizable functional group-modified silicones Examples of the type include silicone.

Examples of the fluororesin include polytetrafluoroethylene (PTFE), perfluoroalkoxy fluororesin (PFA) made of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, and a copolymer of tetrafluoroethylene and hexafluoropropylene (FEP). , Copolymers of tetrafluoroethylene, perfluoroalkyl vinyl ether and hexafluoropropylene (EPE), copolymers of tetrafluoroethylene and ethylene or propylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene and chlorotrifluoroethylene A copolymer (ECTFE), a polyvinylidene fluoride (PVDF), a polyvinyl fluoride (PVF), etc. are mentioned.

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

The lower limit of the content ratio in terms of solid content of the fluorine compound in the release layer 4 is preferably 0.01% by mass, more preferably 0.05% by mass, and further 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 release layer 4 becomes insufficient, the release layer 4 may be easily deteriorated by DMF, and the smoothness of the surface of the release layer 4 is not good. May be sufficient. Moreover, when the said content rate is less than the said minimum, there exists a possibility that the damage prevention property of the surface of the release layer 4 may become inadequate. On the other hand, if the content ratio exceeds the upper limit, the fluorine-based compound may enter the central portion 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. There is a possibility that the interlaminar peel strength is insufficient. Moreover, when the said content rate exceeds the said upper limit, the said fluorine-type compound contained in the mold release layer 4 will be transcribe | transferred to the surface of a polyurethane coat layer, and there exists a possibility that the surface property of a polyurethane coat layer may become inadequate.

The lower limit of the ratio of the fluorine compound content in the intermediate layer 3 to the fluorine compound content in the release layer 4 is preferably 0.5, 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 ratio is less than the lower limit, the content ratio of the fluorine-based compound in the intermediate layer 3 may be too small, and the smoothness of the surface of the intermediate layer 3 may be insufficient. If the content ratio is less than the lower limit, the content ratio of the fluorine compound in the release layer 4 becomes too large, and the fluorine compound enters the center of the release layer 4 to release the mold. There is a risk that the layer 4 will not be sufficiently cured, there is a risk that the peel strength between the intermediate layer 3 and the release layer 4 will be insufficient, and the fluorine compound contained in the release layer 4 is the surface of the polyurethane coat layer. The surface property of the polyurethane coat layer may be insufficient. On the contrary, when the ratio of the content ratio exceeds the upper limit, the content ratio of the fluorine-based compound in the release layer 4 becomes too small, the solvent resistance of the release layer 4 becomes insufficient, and the release layer 4 May be easily deteriorated by DMF or the like, the smoothness of the surface of the release layer 4 may be insufficient, and the damage prevention property of the surface of the release layer 4 may be insufficient. Further, if the ratio of the content ratio exceeds the upper limit, the content ratio of the fluorine compound in the intermediate layer 3 becomes too large, and the fluorine compound enters the center of the intermediate layer 3 so that the intermediate layer 3 is sufficiently There exists a possibility that it may become difficult to harden | cure and there exists a possibility that the peeling strength between the intermediate | middle layer 3 and the release layer 4 may become inadequate.

In the release layer 4, waxes, surface modifiers and the like can be added for the purpose of improving peelability. Moreover, you may add additives, such as a pigment, a catalyst, dye, and a dispersing agent, to the mold release layer 4. FIG. 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 adhesion with the intermediate layer 3 while ensuring surface smoothness and scratch resistance. The process paper 1 for forming the polyurethane coat layer, for example, by adjusting the content ratio of the fluorine compound in the intermediate layer 3 and the release layer 4, the intermediate layer 3 and the release layer 4 contain additives such as pigments. Even if it does not do, the smoothness of the surface of the mold release layer 4 can fully be improved, ensuring the peelability of the mold release layer 4. FIG.

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

<Manufacturing method>
The manufacturing method of the process paper 1 for forming the polyurethane coat layer includes, for example, a process of preparing the base material layer 2 by paper making or extrusion molding (base material layer preparation process), and a base material layer prepared in the base material layer preparation process. The step of laminating the intermediate layer 3 on the surface side of 2 (intermediate layer laminating step) and the step of laminating the release layer 4 on the surface side of the intermediate layer 3 laminated by the intermediate layer laminating step (release layer laminating step) ). In the manufacturing method of the process paper for forming a polyurethane coat layer in this embodiment, the intermediate layer 3 is directly laminated on the surface of the base material layer 2 by the intermediate layer lamination step, and the release layer 4 is intermediated by the release layer lamination step. Laminate directly on the surface of layer 3.

(Base material layer preparation process)
When paper is used as the material of the base material layer 2 in the base material layer preparation step, the 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, there are a long net method, a twin wire method, a gap former method, a round net method, and the like.

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

(Release layer lamination process)
In the release layer laminating step, a release layer forming coating solution containing a synthetic resin (main component resin) and a fluorine-based compound constituting the release layer 4 is applied to the surface side of the intermediate layer 3 and the intermediate layer After forming a coating film on the surface side of 3, this coating film is dried. In the release layer laminating step, the intermediate layer 3 is laminated on the surface side of the base material layer 2 in the intermediate layer laminating step (that is, a coating film formed by applying an intermediate layer forming coating solution is formed. In a dried state).

<Advantages>
In the process paper 1 for forming the polyurethane coat layer, since the intermediate layer 3 contains a synthetic resin as a main component and contains the fluorine 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. Moreover, since the release layer 4 contains the above-mentioned fluorine-based compound, the polyurethane coat layer forming process paper 1 improves the surface smoothness of the release layer 4 and suppresses the surface of the release layer 4 from being scratched. can do. Further, the process paper 1 for forming the polyurethane coat layer is such that the release layer 4 and the intermediate layer 3 both contain the above-mentioned fluorine-based compound, so that a solvent such as DMF contained in the resin composition for forming the polyurethane coat layer is used. The release layer 4 and the intermediate layer 3 are not easily deteriorated. Therefore, the process paper 1 for forming the polyurethane coat layer can be used repeatedly for the production of the polyurethane coat layer, and even when it is used repeatedly for the production of the polyurethane coat layer, the appearance defect of the polyurethane coat layer is suppressed. can do.

The process for producing the process paper for forming the polyurethane coat layer can be used repeatedly for the production of the polyurethane coat layer, and even when it is used repeatedly for the production of the polyurethane coat layer, the occurrence of poor appearance of the polyurethane coat layer is suppressed. The possible process paper 1 for forming a polyurethane coat layer can be produced easily and reliably.

[Second Embodiment]
The process paper 11 for forming a polyurethane coat layer in FIG. 2 is used as, for example, an enamel-like process paper for forming a polyurethane coat layer, similarly to the process paper 1 for forming a polyurethane coat layer in FIG. The polyurethane coat layer forming process paper 11 is disposed between the base material layer 2, the release layer 4 laminated on the surface side of the base material layer 2, and the base material 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. Furthermore, the polyurethane coat layer forming process paper 11 further includes a sealing 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 polyurethane coat layer forming process paper 11 are the same as the polyurethane coat layer forming process paper 1 in FIG. Omitted.

(Sealing layer)
The sealing layer 12 prevents the component contained in the intermediate layer 3 from penetrating into the base material layer 2. The sealing layer 12 is formed by, for example, applying a coating liquid for forming a sealing layer containing the main component resin of the sealing layer 12 such as a water-soluble polymer or polyethylene onto the surface side of the base material layer 2 and drying it. It is formed. Examples of the method for applying the sealing layer forming coating solution include the same method as the method for applying the intermediate layer forming coating solution used for forming the intermediate layer 3.

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. Sodium, starch, casein, gelatin and the like can be mentioned, and these can be used alone or in combination of two or more.

A curing agent can be added to the sealing layer 12 within a range that does not impair the adhesion with the intermediate layer 3. In the manufacturing process of the process paper for forming the polyurethane coat layer before the intermediate layer 3 is laminated, this curing agent is used when a sheet having the sealing layer 12 laminated on the surface side of the base material layer 2 is rolled. , Added to prevent blocking due to moisture absorption. As the curing agent, for example, chromic acid, glyoxal, or the like can be used. Moreover, you may mix | blend the anti-UV agent, an antistatic agent, etc. with the sealing layer 12 in the range which does not impair the adhesiveness with the base material layer 2. FIG. Furthermore, in order to improve the adhesion with the intermediate layer 3, a slight amount of a release agent having a silicone group may be added to the sealing layer 12.

Moreover, it is preferable that the sealing layer 12 is laminated on the surface side of the base material layer 2 after surface treatment is performed on the surface of the base material layer 2. Thereby, the adhesiveness of the base material layer 2 and the sealing layer 12 can be improved. Examples of such surface treatment for improving adhesion include corona treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, anchor coating treatment, and the like. It is done. Among these, corona treatment and anchor coat treatment that improve the adhesive strength of the base material layer 2 and the sealing layer 12 and contribute to the formation of a dense and uniform sealing layer 12 are preferable.

<Manufacturing method>
The manufacturing method of the process paper 11 for forming the polyurethane coat layer is based on the step of preparing the base material layer 2 (base material layer preparation step) and the surface side of the base material layer 2 prepared in the base material layer preparation step. A step of laminating the layer 12 (sealing layer laminating step), a step of laminating the intermediate layer 3 on the surface side of the sealing layer 12 laminated by the above-mentioned sealing layer laminating step (intermediate layer laminating step), and the above intermediate 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 manufacturing method of the process paper for forming a polyurethane coat layer in the present embodiment, the sealing layer 12 is directly laminated on the surface of the base material layer 2 by the sealing layer laminating step, and the intermediate layer 3 is identified by the intermediate layer laminating step. The release layer 4 is directly laminated on the surface of the intermediate layer 3 by directly laminating on the surface of the stop layer 12 and the release layer lamination step. The base material layer preparing step, intermediate layer laminating step and release layer laminating step in the process for producing the polyurethane coat layer forming process paper are the same as described in the method for producing the polyurethane coat layer forming process paper 1 in FIG. The description can be omitted because it can be performed in the same manner.

(Sealing layer lamination process)
In the sealing layer laminating step, a coating liquid for forming a sealing layer for forming the sealing 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 that, the coating film is dried.

<Advantages>
The polyurethane coat layer forming process paper 11 is disposed between the base material layer 2, the release layer 4 laminated on the surface side of the base material layer 2, and the base material layer 2 and the release layer 4. An intermediate layer 3 containing a synthetic resin as a main component, and the release layer 4 and the intermediate layer 3 contain the above-mentioned fluorine-based compound, so as described above in the first embodiment, the production of the polyurethane coat layer is repeated. Even when it is used, it is possible to suppress the appearance failure of the polyurethane coat layer. Furthermore, since the sealing layer 12 is disposed between the base material layer 2 and the intermediate layer 3 in the process paper 11 for forming the polyurethane coat layer, the components contained in the intermediate layer 3 penetrate into the base material layer 2. This can easily suppress the surface side smoothness of the intermediate layer 3.

The process for producing the process paper for forming the polyurethane coat layer improves the smoothness of the surface side of the intermediate layer 3, and even when it is repeatedly used in the production of the polyurethane coat layer, the appearance of the appearance of the polyurethane coat layer is reduced. The polyurethane coat layer forming process paper 11 that can be more accurately suppressed can be easily and reliably manufactured.

[Other Embodiments]
The said embodiment does not limit the structure of this invention. Therefore, in the above-described embodiment, the components of each part of the above-described embodiment can be omitted, replaced, or added based on the description and common general knowledge of the present specification, and they are all 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 base material layer, the intermediate layer, the release layer, and the sealing layer. For example, the polyurethane coat layer forming process paper may include an antistatic layer or the like on the back side of the base material layer (the side opposite to the side on which the resin composition for 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 with reference to examples, but the present invention is not limited to these examples.

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

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

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

[Comparative example]
[No. 4]
In place of the fluorine-based compound, No. 1 except that the release layer forming coating solution contains a BYK-377 silicone-based compound “BYK-377”. In the same manner as in No. 1, 4 process paper for forming a polyurethane coat layer was produced.

[No. 5]
Instead of the fluorine-based compound, No. 1 was used except that the release layer forming coating solution contained BYK-378, a silicone-based compound manufactured by Big Chemie Japan. In the same manner as in No. 1, 5 process paper for forming a polyurethane coat layer was produced.

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

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

[No. 8]
No. except that the release layer forming coating solution did not contain a fluorine compound. In the same manner as in No. 1, 8 process paper for forming a polyurethane coat layer was produced.

[No. 9]
No. except that the coating liquid for forming the intermediate layer did not contain a fluorine compound. In the same manner as in No. 2, 9 process paper for forming a polyurethane coat layer was produced.

[No. 10]
No. except that neither the intermediate layer forming coating solution nor the release layer forming coating solution 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 property>
No. 1-No. For No. 10, the gloss of the release layer surface was visually evaluated according to the following criteria. The evaluation results are shown in Table 1.
A: There is no surface roughness and no uneven mixing of the main component and additive in the release layer is observed.
B: Surface roughness caused by the additive and mixing unevenness between the main component and the additive in the release layer are observed.

<DMF resistance>
A 120 mm × 215 mm Kimwipe dipped in 1 ml of DMF was used. 1-No. The surface of 10 mold 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. according to JIS-Z8741, and evaluated according to the following criteria. The evaluation results are shown in Table 1.
A: The decrease in glossiness is less than 0.5%.
B: The decrease in glossiness is 0.5% or more.

<Repeatability>
No. 1-No. Using 10 process papers for forming a polyurethane coat layer, a polyurethane coat layer was produced by repeating 15 times under the same conditions. 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. according to JIS-Z8741, and evaluated according to the following criteria. The evaluation results are shown in Table 1.
A: The decrease in glossiness is less than 0.5%.
B: The decrease in glossiness is 0.5% or more.

[Evaluation results]
As shown in Table 1, each of the intermediate layer and release layer contains a fluorine compound. 1-No. No. 3 has excellent surface properties, DMF resistance and repeated use.

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

1,11 Process paper for forming polyurethane coating layer 2 Base material layer 3 Intermediate layer 4 Release layer 12 Sealing layer

Claims

A process paper for forming a polyurethane coat layer comprising a base material layer and a release layer laminated on the surface side of the base material layer,
An intermediate layer that is disposed between the base material layer and the release layer and contains a synthetic resin as a main component,
A process paper for forming a polyurethane coat layer, wherein the release layer and the intermediate layer contain a fluorine compound.
The content of the fluorine compound in the release layer is 0.01% by mass or more and 1.0% by mass or less, and the content of the fluorine compound in the intermediate layer is 0.01% by mass or more and 1.0% by mass. The process paper for forming a polyurethane coat layer according to claim 1, wherein:
The polyurethane coat layer according to claim 1 or 2, wherein a ratio of a content ratio of the fluorine compound in the intermediate layer to a content ratio of the fluorine compound in the release layer is 0.5 or more and 5.0 or less. Forming process paper.
The process paper for forming a polyurethane coat layer according to claim 1, 2 or 3, wherein the main component of the intermediate layer is an acrylic resin or an alkyd resin.
The process paper for forming a polyurethane coat layer according to any one of claims 1 to 4, wherein a main component of the release layer is a silicone resin, a fluororesin, a wax resin or an alkyd resin.