WO2010137264A1

WO2010137264A1 - Method for producing polyurethane laminate, and polyurethane laminate obtained by the production method

Info

Publication number: WO2010137264A1
Application number: PCT/JP2010/003393
Authority: WO
Inventors: 米田久夫; 井上和正; 芦田哲哉
Original assignee: 株式会社クラレ
Priority date: 2009-05-29
Filing date: 2010-05-20
Publication date: 2010-12-02
Also published as: CN102448695B; JP5622724B2; CN102448695A; TWI466778B; TW201105509A; JPWO2010137264A1

Abstract

Disclosed is a method for producing a polyurethane laminate, which comprises: a melt-mixing step in which a urethane resin composition is formed by heating and melt-mixing a urethane prepolymer that is in a semi-solid state or in a solid state at room temperature, a chain extender and a temperature-sensitive urethanization catalyst exhibiting a specific exothermic peak temperature, within a temperature range lower than the exothermic peak temperature by 10-30˚C; a resin layer-forming step in which a urethane resin layer is formed on a sheet surface using the urethane resin composition; and a heating step in which the urethane resin layer is heated at a temperature not less than the exothermic peak temperature. Also disclosed is a polyurethane laminate that is a laminate of a composite fiber sheet, which is obtained by integrating a fiber sheet and a polymer elastic material by impregnation and has a plurality of pores in the surface layer, and a polyurethane resin layer that is arranged on the composite fiber sheet. The polyurethane laminate has a mixed layer having a thickness of not less than 10 μm. In the mixed layer, some parts of the polyurethane resin layer and the surface layer of the composite fiber sheet are present in an incompatible state since the parts of the polyurethane resin layer have entered into the pores.

Description

Method for producing polyurethane laminate and polyurethane laminate obtained by the production method

The present invention relates to a method for producing a polyurethane laminate and a polyurethane laminate obtained by the production method.

Conventionally, polyurethane laminates have been widely used as surface materials for footwear, clothing, bags, furniture, and the like.

A typical structure of such a polyurethane laminate is a structure in which a polyurethane layer is laminated on the surface of a composite fiber base material in which a fibrous base material such as nonwoven fabric, woven fabric, or knitted fabric is impregnated with polyurethane. Is mentioned. The polyurethane layer may be formed by applying a solvent-type polyurethane or water-based polyurethane to the surface of the composite fiber substrate and then drying, or by applying a polyurethane film previously formed on the surface of the release paper on the surface of the composite fiber substrate with an adhesive. It is formed using a method of bonding.

Incidentally, in recent years, in order to reduce the environmental burden, a process using a solventless urethane prepolymer that does not use an organic solvent is required in the production of a polyurethane laminate.

For example, in Patent Document 1 below, an isocyanate group-containing urethane prepolymer that is semi-solid or solid at room temperature as an A component, and a compound capable of reacting with an isocyanate group and / or a urethane curing catalyst as a B component are heated and melted. Thereafter, a method for producing a polyurethane porous body by stirring and mixing and mechanical foaming is disclosed. And it is described that according to such a method, a high intensity | strength polyurethane porous body can be manufactured efficiently, without using a solvent and a dryer.

Also, conventionally, leather-like sheets using polyurethane laminates have been widely used as surface materials resembling leather used in bags, footwear, clothing, furniture, and the like.

A typical configuration of such a polyurethane laminate includes a configuration in which a polyurethane resin layer is laminated on the surface of a composite fiber sheet obtained by impregnating a porous base material with a fibrous base material such as a nonwoven fabric. As a specific example of the manufacturing method, for example, as disclosed in Patent Document 2 below, a polyurethane resin layer is obtained by pressure-bonding a thermoplastic polyurethane film immediately after being extruded using a T die to the surface of a composite fiber sheet. A method of forming is known. As another method, as disclosed in Patent Document 3 below, a polyurethane resin layer is formed by applying and drying a solvent-type urethane resin on the surface of a release paper, and the resulting polyurethane resin layer is used as a solvent. There is also known a method for producing a leather-like sheet by laminating and drying using a mold urethane adhesive. As another method, for example, as disclosed in Patent Document 4 below, a polyurethane resin layer is formed by applying a water-based urethane resin to the surface of a release paper and then drying it, and the resulting polyurethane resin layer There is also known a method for producing a leather-like sheet by laminating and drying a composite fiber sheet using a water-based urethane adhesive. Further, for example, a method of forming a polyurethane resin layer by applying a melted hot-melt urethane resin to the surface of a composite fiber sheet as disclosed in Patent Document 5 below and then crosslinking it is also known. Yes.

JP 2002-249534 A Japanese Patent Laid-Open No. 9-24590 JP 2005-113318 A JP 2005-264371 A International Publication WO2005 / 083173 Pamphlet

In the method for producing a polyurethane porous body as described in Patent Document 1 above, it is possible to achieve solvent-free. However, according to the study by the present inventors, there were the following problems when industrially producing a polyurethane laminate continuously using the above method.

A urethane prepolymer that is semi-solid or solid at room temperature as described in Patent Document 1 has a low viscosity when heated to a relatively high temperature, and is adjusted to a viscosity that allows mechanical foaming. When a urethane resin composition containing a urethane prepolymer and a urethane curing catalyst is heated to such an extent that mechanical foaming is possible, the urethane curing catalyst is activated to cause a crosslinking reaction. When the urethane resin composition is heated to a temperature at which mechanical foaming is possible as described above, the crosslinking reaction of the urethane prepolymer proceeds and the melt viscosity gradually rises. There was a problem that it became short and continuous production for a long time was difficult.

Furthermore, in the case of producing a polyurethane porous body by a method as described in Patent Document 1, the porous body obtained by using mechanical foaming becomes communication holes, and has uniform independent pores. There was also a problem that could not be obtained.

In the case of forming a polyurethane layer formed by using a urethane prepolymer that is semi-solid or solid at room temperature on a sheet, the present invention continuously maintains the pot life of the applied urethane resin composition for a long time. Thus, it is possible to stably form an uncrosslinked polyurethane layer, and to improve productivity by rapidly crosslinking the applied uncrosslinked polyurethane layer by heat treatment.

The method for producing a polyurethane laminate, which is one aspect of the present invention, is a sensitivity that shows a predetermined exothermic peak temperature by differential scanning calorimetry with a urethane prepolymer (A) that is semi-solid or solid at room temperature and a chain extender (B). A melt-mixing step of forming a urethane resin composition by heating and melt-mixing the warm urethanization catalyst (C) at a temperature in the range of 10 to 30 ° C. lower than the exothermic peak temperature; and the urethane resin composition A resin layer forming step for forming a urethane resin layer on a sheet surface such as a release paper or a fiber base material, and a heat treatment step for heat-treating the urethane resin layer at a temperature equal to or higher than the exothermic peak temperature. And

Further, according to the study by the present inventors, the polyurethane resin layer is formed by pressure-bonding a thermoplastic polyurethane film immediately after being extruded by a T die, as disclosed in Patent Document 2, to the surface of the composite fiber sheet. According to the forming method, since the thermoplastic polyurethane film is rapidly cooled when it comes into contact with the surface of the composite fiber sheet, it is pressure-bonded in a state where solidification has progressed to some extent. Therefore, the interface between the composite fiber sheet and the thermoplastic polyurethane film is a two-dimensional planar interface. For this reason, when the polyurethane laminate is bent, the difference between the elastic modulus and the stretchability of the composite fiber sheet and the polyurethane film causes deviation or peeling at the interface between the composite fiber sheet and the thermoplastic polyurethane film. Such a shift or delamination between layers at the interface causes the following problems. Specifically, for example, in the case of a polyurethane laminate obtained by the above-described method, a crease generated when a leather is bent is compared with the generation of fine wrinkles as shown in FIG. As shown in FIG. 8, a large wrinkle is generated as if the corrugated cardboard is folded. In addition, after folding, there is also a problem that many creases remain.

Further, according to the study by the present inventors, according to the method of forming a polyurethane resin layer by applying and drying a solvent-type urethane resin on the surface of the release paper, as disclosed in Patent Document 3, the application is performed. If the drying process is not repeated many times, there is a problem that a sufficiently thick polyurethane resin layer having smoothness on the surface cannot be obtained. Moreover, the polyurethane resin layer thus formed on the release paper is bonded to the surface of the composite fiber sheet using a solvent-type urethane adhesive. According to such a method of laminating by adhesion, an adhesive layer exists between the polyurethane resin layer and the composite fiber sheet. For this reason, since the polyurethane resin layer hardly permeates and fills the voids in the surface layer portion of the composite fiber sheet, a sense of unity between the polyurethane resin layer and the composite fiber sheet cannot be obtained. Therefore, it tended to be inferior in leather-like texture and crease. Furthermore, as another problem, there was a problem that pore structure of porous polyurethane impregnated in the composite fiber sheet was dissolved by the solvent in the adhesive to destroy the pore structure, and the texture and surface smoothness were lowered. .

Furthermore, according to the study by the present inventors, as disclosed in the above-mentioned Patent Document 4, after applying a water-based urethane resin to the surface of the release paper, the method of forming a polyurethane resin layer by drying, If the coating and drying steps are not repeated many times, there is a problem that a sufficiently thick polyurethane resin layer having smoothness on the surface cannot be obtained. Moreover, such a polyurethane resin layer is laminated | stacked through the contact bonding layer using the water-system urethane adhesive on the composite fiber sheet surface. Therefore, a sense of unity between the polyurethane resin layer and the composite fiber sheet could not be obtained.

Further, according to the study by the present inventors, the polyurethane resin layer is formed by applying a molten hot melt urethane resin to the surface of the composite fiber sheet as disclosed in Patent Document 5 and then crosslinking the resin. Since the polyurethane resin layer is simply laminated by simply applying a melted hot melt urethane resin on the surface of the composite fiber sheet, the composite fiber sheet and the polyurethane resin layer The problem of slippage and peeling at the interface has not been solved.

The present invention has been made in view of the above-described problems, and is a polyurethane laminate that is similar to leather and has a solid texture and a good feeling of folding when folded, and it is difficult for creases to remain after folding. The purpose is to provide a body.

A method for producing a polyurethane laminate, which is another aspect of the present invention, is a coating film forming step of forming a release paper-coating laminate by applying a molten crosslinkable hot melt urethane resin to the surface of the release paper. And a heat treatment step for partially cross-linking the crosslinkable hot-melt urethane resin, and a release paper in the void of the composite fiber sheet having a large number of voids in the surface layer, in which the fiber sheet and the polymer elastic body are impregnated and integrated. A laminating process for laminating a coating film on the surface of the composite fiber sheet with a pressure at which a part of the coating film of the coating film laminate enters, and a cooling process for cooling and solidifying the crosslinkable hot-melt urethane resin are provided. Is preferred.

In addition, the coating film forming step has a sensitivity that exhibits a predetermined exothermic peak temperature by differential scanning calorimetry with a hot melt urethane prepolymer (A) having a melt viscosity at 100 ° C. of 10,000 mPa · sec or less and a chain extender (B). A melt-mixing step of forming a crosslinkable hot-melt urethane resin by heat-melting and mixing with the temperature urethanization catalyst (C) at a temperature in the range of 10-30 ° C. lower than the exothermic peak temperature; A coating film forming step of forming a release paper-coating laminate by applying a crosslinkable hot-melt urethane resin in a molten state, and the heat treatment step makes the release paper-coating laminate above the exothermic peak temperature. It is preferable to be a step of partially cross-linking the coating film by heat treatment at the temperature.

A polyurethane laminate according to yet another aspect of the present invention is a composite fiber sheet having a large number of voids in the surface layer, in which a fiber sheet and a polymer elastic body are impregnated and integrated, and laminated on the composite fiber sheet. 10 μm in which a part of the polyurethane resin layer and a surface layer of the composite fiber sheet are mixed in an incompatible state when a part of the polyurethane resin layer enters the gap. As described above, it is preferable to have a mixed layer having a thickness of 30 μm or more.

The objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

FIG. 1 is a schematic process diagram illustrating a method for producing a polyurethane laminate according to Embodiment 1 of the present invention. FIG. 2 is a schematic cross-sectional view of a polyurethane laminate obtained by the production method of Embodiment 1 according to the present invention. FIG. 3 is a schematic cross-sectional view of a polyurethane laminate obtained by the method for producing a polyurethane laminate of Embodiment 2 according to the present invention. FIG. 4 is an explanatory view for explaining an example of the production process of the polyurethane laminate of Embodiment 2 according to the present invention. FIG. 5 is an SEM photograph of a cross section of the leather-like sheet obtained in Example 2-1. FIG. 6 is an SEM photograph of a cross section of the leather-like sheet obtained in Comparative Example 2-1. FIG. 7 is a schematic diagram for explaining a state of a crease and wrinkle generated when leather is folded. FIG. 8 is a schematic diagram for explaining the appearance of a crease and wrinkle generated when a conventional leather-like sheet is folded.

[Embodiment 1]
The method for producing the polyurethane laminate of Embodiment 1 includes a urethane prepolymer (A) that is semi-solid or solid at room temperature, a chain extender (B), and a temperature-sensitive urethane that exhibits a predetermined exothermic peak temperature by differential scanning calorimetry. A melting and mixing step in which a urethane resin composition is formed by heating and melting and mixing the catalyst (C) at a temperature in the range of 10 to 30 ° C. lower than the exothermic peak temperature; and using the urethane resin composition A resin layer forming step of forming a urethane resin layer on the surface of the sheet such as a pattern paper or a fiber base; and a heat treatment step of heat-treating the urethane resin layer at a temperature equal to or higher than the exothermic peak temperature.

First, the urethane prepolymer (A), the chain extender (B), and the temperature-sensitive urethanization catalyst (C) that are semi-solid or solid at room temperature used in this embodiment will be described.

The urethane prepolymer (A) used in the present embodiment is a urethane prepolymer having an isocyanate group obtained by reacting a polyol and a polyisocyanate, and is a substantially solvent-free type that is semisolid or solid at room temperature. This is a polyurethane-forming component. Such a urethane prepolymer is a solid or a semi-solid property having a viscosity that is difficult to apply at room temperature, but the viscosity is reduced to a level that allows application by heating.

Specific examples of the polyol include high molecular weight polyols such as polyester polyols, polyether polyols, and polycarbonate polyols; ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene. Glycol, 1,4-butylene glycol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, 1,4 -Bis (hydroxyethoxy) benzene, 1,3-bis (hydroxyisopropyl) benzene, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4-di Ethanol, glycerol, trimethylol propane, trimethylol ethane, hexane triol, pentaerythritol, sorbitol, low-molecular-weight polyol such as methyl glycoside. These may be used alone or in combination of two or more.

Specific examples of the polyisocyanate include aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, naphthalene diisocyanate, and xylylene diisocyanate; hexamethylene diisocyanate. , Lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, aliphatic diisocyanate such as tetramethylxylylene diisocyanate, or cycloaliphatic diisocyanate; Etc. These may be used alone or in combination of two or more.

The production of the urethane prepolymer can usually be carried out in the absence of a solvent, but it may be carried out in an organic solvent. In the case of producing in an organic solvent, an organic solvent such as ethyl acetate, n-butyl acetate, methyl ethyl ketone, and toluene that does not inhibit the reaction between the chain extender and polyisocyanate can be used. After completion of the reaction, it is necessary to remove the organic solvent by a method such as heating under reduced pressure.

The reaction ratio between the polyol and the polyisocyanate is preferably such that the equivalent ratio [NCO / OH] of the isocyanate group in the polyisocyanate to the hydroxyl group in the polyol is in the range of 1.1 to 5.0. More preferably, it is within the range of 2 to 3.0.

The number average molecular weight of the urethane prepolymer is in the range of 500 to 30,000, more preferably in the range of 1000 to 10,000. The melt viscosity can be easily adjusted, and excellent flexibility, mechanical strength, and wear resistance are obtained. It is preferable from the point that the polyurethane layer which has the property and hydrolysis resistance can be formed.

The melt viscosity of the urethane prepolymer is such that the melt viscosity at 120 ° C. measured with a cone plate viscometer is in the range of 500 to 100,000 mPa · s, more preferably 1000 to 10,000 mPa · s. Is preferable because it is easy.

Commercially available products of such urethane prepolymers include DIC Corporation's trade names Task Force KMM-100, Tyforce NH-122A, NH-200, NH-300, H-1041, and Takeda Pharmaceutical Co., Ltd. Takedamelt SC-13, SL-01, SL-02, SL-03, SL-04 and the like.

In the urethane prepolymer (A), the reaction between the isocyanate group in the urethane prepolymer (A) and the hydroxyl group or amino group in the chain extender (B) described later is promoted by the urethanization catalyst to increase the molecular weight. The polymer having a high molecular weight further undergoes a crosslinking reaction by reacting with an isocyanate group present in the system.

The chain extender (B) used in the present embodiment is a compound having two or more functional groups having active hydrogen such as a hydroxyl group and an amino group that can react with the isocyanate group of the urethane prepolymer (A).

Specific examples of the chain extender include, in addition to the above-mentioned various polyols, ethylenediamine, 1,3-propylenediamine, 1,2-propylenediamine, hexamethylenediamine, norbornenediamine, hydrazine, piperazine, N, N′— Diaminopiperazine, 2-methylpiperazine, 4,4'-diaminodicyclohexylmethane, isophoronediamine, diaminobenzene, diphenylmethanediamine, methylenebisdichloroaniline, triethylenediamine, tetramethylhexamethylenediamine, triethylamine, tripropylamine, trimethylaminoethylpiperazine And polyamines such as N-methylmorpholine, N-ethylmorpholine, and di (2,6-dimethylmorpholinoethyl) ether. These may be used alone or in combination of two or more.

The temperature-sensitive urethanization catalyst (C) exhibiting a predetermined exothermic peak temperature by differential scanning calorimetry used in this embodiment is from 0 ° C. to 200 ° C. at a temperature rising rate of 10 ° C./1 minute under a nitrogen seal. It is a urethanization catalyst which shows a predetermined exothermic peak temperature when differential scanning calorimetry is measured in the range up to. The exothermic peak temperature is preferably in the range of 50 to 160 ° C., and more preferably in the range of 80 to 140 ° C., from the viewpoint of excellent treatment efficiency and stabilization of urethanization.

Specific examples of such a urethanization catalyst include an organic acid salt of 1,8-diazabicyclo (5,4,0) -undecene-7 (DBU), specifically a phenol salt of DBU (exothermic peak temperature of 88 ° C. ), DBU octylate (99 ° C.), DBU phthalate (138 ° C.), DBU oleate (110 ° C.), and the like. Such a urethanization catalyst is appropriately selected in consideration of the softening temperature of the urethane prepolymer (A) to be used.

In this embodiment, in order to make the resulting polyurethane layer porous, it is preferable to blend a foaming agent in the applied urethane resin composition as necessary. The type of foaming agent is not particularly limited, but it is preferable to use thermally expandable microcapsules from the viewpoint of easy control of pore uniformity. As such a heat-expandable microcapsule, for example, the encapsulated hydrocarbon expands by heating, and at the same time, the thermoplastic resin forming the outer shell softens to start expansion, and the internal pressure and the external pressure of the microcapsule are increased. Examples thereof include a temperature-sensitive foaming agent for forming uniform closed cells by expanding to a balanced predetermined expansion ratio, preferably twice or more. Specific examples of such thermally expandable microcapsules include Matsumoto Microsphere F series manufactured by Matsumoto Yushi Seiyaku Co., Ltd.

In the present embodiment, in addition to the various components described above, additives such as colorants such as pigments, thickeners, and antioxidants may be blended as necessary.

An example of a method for producing a polyurethane laminate according to this embodiment, which is performed using the various components described above, will be described with reference to FIG.

FIG. 1 is a schematic process diagram for explaining a method for producing a polyurethane laminate according to this embodiment. In FIG. 1, 1 is a release paper, 2 is a urethane prepolymer that is semi-solid or solid at room temperature, 3 is a chain extender, 4 is a temperature-sensitive urethanization catalyst having a predetermined exothermic peak temperature, and 5 is a thermal expansion property. It is a microcapsule. The mixing head 6 is composed of a first nozzle 6a for supplying a urethane prepolymer, a second nozzle 6b for supplying a chain extender, and a mixing chamber 6c. Note that 6a, 6b, and 6c are each provided with a heater (not shown). Further, 7 is a base sheet, 8 is a delivery reel of the

base sheet

7, 9a is a touch roll, 9b is a reverse roll, 10 is a urethane resin composition (urethane resin layer), 11 is a delivery roll, 12 is a heating device, 13 is a polyurethane laminate, 14 is a take-up reel of the

polyurethane laminate

13, 16 is a cooling roll, and PR is a press roll. In FIG. 1, a reverse roll coater is constituted by a combination of a touch roll 9a and a reverse roll 9b.

In the method for producing a polyurethane laminate of the present embodiment, first, the urethane prepolymer 2, the chain extender 3, the temperature-sensitive urethanization catalyst 4, and the thermally expandable microcapsule 5 are added to the exothermic peak temperature by 10 to 10 times. Heat melting and mixing at a temperature in the range of 30 ° C. lower (melt mixing step).

As a specific example of the heating and melting and mixing method, for example, the following method may be mentioned.

In the mixing method, the urethane prepolymer 2 is heated to a predetermined viscosity, while the chain extender 3, the temperature-sensitive urethanization catalyst 4, and the heat-expandable microcapsule 5 are kept warm, A method of stirring after mixing or mixing using a known mixing head as shown in FIG. 1 that mixes by jetting high pressure and colliding is used, or a method of simply stirring and mixing in a molten state is adopted. .

As shown in FIG. 1, the mixing method using the mixing head is performed by atomizing the urethane prepolymer 2 from the first nozzle 6a in a heated and melted state by pressure injection and supplying it to the mixing chamber 6c. The urethanizing catalyst 4 and the thermally expandable microcapsule 5 are mixed with the chain extender 3, and are sprayed from the second nozzle 6b to be atomized and supplied to the mixing chamber 6c. And each component atomized in the mixing chamber 6c is collided and mixed. The heat-expandable microcapsule 5 is blended as necessary when the purpose is to form a porous urethane layer. In this case, the first nozzle 6a and the second nozzle of the mixing head are mixed so that the temperature of the urethane resin composition formed by mixing is heated and melted and mixed at a temperature in the range of 10 to 30 ° C. lower than the exothermic peak temperature. The temperature of 6b and the mixing chamber 6c is controlled. According to the mixing method using such a mixing head, more uniform mixing is possible.

Also, as a simple stirring method in the molten state, the following methods can be mentioned.

First, the urethane prepolymer 2 is heated to a predetermined viscosity and stored in a predetermined container. On the other hand, the chain extender 3, the temperature-sensitive urethanization catalyst 4, and the heat-expandable microcapsule 5 are not activated by the temperature-sensitive urethanization catalyst 4 in another container, and the heat-expandable microcapsule 5 Keep at a temperature that does not swell. And the mixture containing the urethane prepolymer 2, the temperature-sensitive urethanization catalyst 4, the thermally expansible microcapsule 5, and the chain extender 3 is supplied to the container provided with the heater and the stirring apparatus. In the container, the urethane prepolymer 2, the chain extender 3, the temperature-sensitive urethanization catalyst 4, and the thermally expandable microcapsule 5 are 10 to 10 times the exothermic peak temperature of the temperature-sensitive urethanization catalyst 4. It is heated, melted and mixed at a temperature in the range of 30 ° C. lower.

In the melt mixing step, the urethane prepolymer 2 and the chain extender are heated at a temperature in the range of 10 to 30 ° C., preferably in the range of 10 to 25 ° C. lower than the exothermic peak temperature at which the temperature-sensitive urethanization catalyst 4 is activated. 3, the temperature-sensitive urethanization catalyst 4 and the thermally expandable microcapsule 5 are heated, melted and mixed. The progress of the cross-linking reaction is suppressed by heat-melt mixing at such a temperature. Therefore, the pot life of the urethane resin composition prepared in the mixing chamber 6c can be extended. When the thermally expandable microcapsule 5 is blended, it is preferable to select a thermally expandable microcapsule that does not substantially expand to the target expansion ratio in the melt mixing step.

On the other hand, as shown in FIG. 1, the release paper 1 is continuously fed from a sheet delivery reel (not shown), and the release paper 1 that is continuously fed is fed by a feed roll 11 that rotates in the direction of the arrow. After that, a continuous line of the release paper 1 is formed in advance by the take-up reel 14.

And as shown in FIG. 1, the urethane resin composition 10 prepared in the mixing chamber 6c is formed between the touch roll 9a and the reverse roll 9b toward the release paper 1 continuously conveyed. It flows down toward the clearance, and is applied to the surface of the release paper 1 with a uniform thickness by the reverse roll 9b to form the urethane resin layer 10 (resin layer forming step). The coating thickness is controlled by a clearance interval formed between the reverse roll 9b and the touch roll 9a.

The release paper 1 may be a release paper having an embossed pattern for the purpose of imparting surface design, in addition to a release paper having a smooth surface. Furthermore, a layer of a known polymer elastic body represented by polyurethane resin or acrylic resin may be formed in advance on the surface of the release paper. When a layer of a polymer elastic body is previously formed on the surface of the release paper, it can be obtained by heat-melt mixing the urethane prepolymer (A), the chain extender (B), and the temperature-sensitive urethanization catalyst (C). Since the surface of the layer made of the urethane resin composition is coated with the polymer elastic body layer, it is preferable in that the surface properties can be modified. In particular, when coated with the polymer elastic body layer, it is possible to prevent a decrease in adhesiveness with other resin layers due to the surface of the urethane resin composition having a crosslinked structure.

When the surface of the layer made of the urethane resin composition is coated with the polymer elastic body layer, the layer made of the urethane resin composition is coated with the polymer elastic body layer in a state where the layer is not sufficiently crosslinked, Adhesiveness between the layer made of the urethane resin composition and the polymer elastic body layer is improved, and the surface embossing (providing the uneven pattern) is further improved.

Further, it is preferable in that it is possible to suppress surface tack by being covered with the polymer elastic body layer.

Furthermore, it is possible to produce a polyurethane laminate consisting of a solvent-free process by previously forming a layer comprising a known water-dispersed polymer elastic body or a solvent-free cured polymer elastic body as a surface layer. And more preferable.

In addition, as a specific example of an application mechanism for applying the heated and melted urethane resin composition 10 to the surface of the release paper 1, for example, a knife coater, a roll coater, a reverse coater may be used instead of the reverse roll coater as shown in FIG. A coater, kiss roll coater, spray coater, T-die coater, comma coater, or the like may be used. In addition, in these application | coating mechanisms, the application | coating mechanism provided with the heating means is preferable from the point which can control the melt viscosity of a urethane resin composition.

The thickness of the urethane resin layer 10 to be formed is preferably in the range of 5 to 800 μm, more preferably 10 to 500 μm, from the viewpoint of obtaining a polyurethane laminate excellent in flexibility and mechanical strength.

And the polyurethane laminated body 13 in which the urethane resin layer 10 was formed in the surface of the base material sheet 7 is formed by bonding the base material sheet 7 to the surface of the urethane resin layer 10 formed in the surface of the release paper 1 .

Specifically, the bonding of the urethane resin layer 10 and the base sheet 7 is performed, for example, as shown in FIG. 1, when the base sheet 7 is sent out from the feed reel 8, and the urethane resin layer 10 is melted or softened. In this state, they are bonded together by a press roll PR.

Specific examples of the substrate sheet 7 used in the present embodiment include, for example, fiber substrates generally used for leather-like sheets such as nonwoven fabrics, woven fabrics, and knitted fabrics; And composite fiber base materials impregnated with water-based, emulsion-based or solvent-free polyurethane resin, acrylic resin, butadiene-based resin (SBR, NBR, MBR) and the like. In these, the composite fiber base material which impregnated the nonwoven fabric formed from the ultrafine fiber with the polyurethane is especially preferably used from the point from which the polyurethane laminated body which has a soft texture and more excellent mechanical strength is obtained. As the nonwoven fabric, a conventionally known short fiber web, a web obtained by a known method such as a spunbond method or a melt blow method can be used without any particular limitation. Moreover, after forming a web as needed, you may obtain by laminating | stacking several webs and making it intertwined by a needle punch process etc. Specific examples of the fibers forming the nonwoven fabric include, for example, polyurethane fibers, polyethylene terephthalate (PET) fibers, various polyamide fibers, polyacrylic fibers, various polyolefin fibers, and polyvinyl alcohol fibers. The fibers forming the nonwoven fabric are preferably ultrafine fibers having a fiber diameter of 0.1 to 50 μm, more preferably 1 to 15 μm. Such ultrafine fibers have low rigidity and are soft, which is preferable from the viewpoint of obtaining a polyurethane laminate having a soft texture. The basis weight of the nonwoven fabric is preferably in the range of 50 to 2000 g / m ² , more preferably in the range of 100 to 1000 g / m ² , from the viewpoint of obtaining a polyurethane laminate having a soft texture.

Next, the polyurethane laminate 13 having the urethane resin layer 10 formed on the surface of the base sheet 7 is heat-treated at a temperature equal to or higher than the exothermic peak temperature of the temperature-sensitive urethanization catalyst (C) (heat treatment step). Thus, the urethane resin layer 10 formed on the surface of the release paper 1 is heat-treated at a temperature higher than the exothermic peak temperature of the temperature-sensitive urethanization catalyst (C), whereby the urethane resin layer 10 formed by coating is formed. Cross-linking is promoted.

The heat treatment temperature is not particularly limited as long as the temperature of the urethane resin layer 10 is higher than the exothermic peak temperature of the temperature-sensitive urethanization catalyst (C) and does not deteriorate the polyurethane layer formed by curing. Specifically, heat treatment is performed in a temperature range 0 to 30 ° C higher than the exothermic peak temperature of the temperature-sensitive urethanization catalyst (C), and further in a temperature range 0 to 15 ° C higher than the exothermic peak temperature. It is preferable to do.

Further, as a specific example of the heat treatment time, for example, about 15 seconds to 10 minutes, further about 30 seconds to 5 minutes, the crosslinking reaction can be sufficiently promoted without lowering the productivity. To preferred.

The heat treatment is performed by a heating device 12 such as a hot air heating dryer.

Then, the bonded body of the urethane resin layer 10 and the base sheet 7 in the state covered with the release paper 1 thus obtained is forcibly cooled using the cooling roll 16 and then wound by the take-up reel 14. take. Then, by aging the wound polyurethane laminate 13 for a predetermined time, the crosslinking reaction of the urethane resin layer 10 proceeds to increase the molecular weight.

As the aging conditions for the polyurethane laminate 13, aging is preferably performed for about 20 to 50 hours under the conditions of a temperature of 20 to 40 ° C. and a relative humidity of 50 to 80%. Thereby, the polyurethane laminated body excellent in mechanical strength and water resistance is obtained.

FIG. 2 shows a schematic cross-sectional view of the polyurethane laminate 13 obtained by such a process.

As shown in FIG. 2, the polyurethane laminate 13 is completed by peeling the release paper 1 coated on the surface. Uniform closed cells 21 are formed in the crosslinked polyurethane layer 20 in the polyurethane laminate 13.

In this embodiment, a continuous line of the release paper 1 is formed in advance, the urethane resin layer 10 is formed on the surface of the release paper 1 that is continuously fed out, and the surface of the formed urethane resin layer 10 is formed. The process of laminating the base sheet 7 has been described as a representative. However, the order of laminating the release paper 1 and the base sheet 7 is changed to form a continuous line of the base sheet 7 in advance. Alternatively, the urethane resin layer 10 may be formed on the surface of the base sheet 7 to be fed out, and the release paper 1 may be bonded to the surface of the formed urethane resin layer 10. Moreover, in this embodiment, the process which forms the urethane resin layer 10 in the surface of the release paper 1, and bonds the base material sheet 7 on the surface of the formed urethane resin layer 10, and heat-processes it is typical. As described above, heat treatment may be performed before the base sheet 7 is bonded to the urethane resin layer 10.

In addition, for the obtained polyurethane laminate, in order to impart surface designability, tactile sensation, or color correction by a publicly known and commonly used method, the surface layer portion is solvent-based, water-based, emulsion It is also possible to coat a system or solventless polyurethane resin or acrylic resin, or to perform post-processing such as buffing or embossing as appropriate.

The polyurethane laminate thus obtained can be preferably used as a leather-like sheet that becomes a surface material for footwear, clothing, bags, furniture, and the like.

[Embodiment 2]
The method for producing a polyurethane laminate of Embodiment 2 preferably includes a coating film forming step of forming a release paper-coating laminate by applying a meltable crosslinkable hot-melt urethane resin to the surface of the release paper. A release paper-coating is applied to the voids of the composite fiber sheet having a large number of voids in the surface layer, in which a heat treatment step for partially crosslinking the crosslinkable hot-melt urethane resin and the fiber sheet and the polymer elastic body are impregnated and integrated. A laminating step of laminating the coating film on the surface of the composite fiber sheet with a pressure that allows a part of the coating film of the film laminate to enter, and a cooling step of cooling and solidifying the crosslinkable hot-melt urethane resin are provided.

That is, in the method for manufacturing a polyurethane laminate of Embodiment 2, the coating film forming step corresponds to the resin layer forming step in the manufacturing method of Embodiment 1 described above, and the heat treatment step in Embodiment 2 is the same as that of Embodiment 1. It preferably corresponds to a heat treatment step. At the same time, in the manufacturing method of Embodiment 2, it is preferable to newly include the specific laminating step and the cooling step.

In the second embodiment, the melt mixing step in the first embodiment described above is preferably a hot melt type urethane prepolymer (A) having a melt viscosity of 10000 mPa · sec or less at 100 ° C. and a chain extender (B). The crosslinkable hot melt is heated and melt mixed with a temperature-sensitive urethanization catalyst (C) exhibiting a predetermined exothermic peak temperature by differential scanning calorimetry at a temperature in the range of 10 to 30 ° C. lower than the exothermic peak temperature. This is a melt mixing process for forming a mold urethane resin. Further, the resin layer forming process in the first embodiment is preferably the second embodiment, in which the release paper-coating laminate is formed by applying the molten cross-linkable hot-melt urethane resin to the release paper surface. This is a coating film forming step. In the second embodiment, the heat treatment step in the first embodiment is preferably a heat treatment step in which the release paper-coating laminate is heat-treated at a temperature equal to or higher than the exothermic peak temperature to partially crosslink the coating film. is there.

Referring to the drawings, an example of a preferred method for producing the polyurethane laminate of Embodiment 2 will be described in detail.

First, the crosslinkable hot-melt urethane resin used in this embodiment will be described.

The crosslinkable hot-melt urethane resin used in the present embodiment is a urethane prepolymer having an isocyanate group obtained by reacting a polyol and a polyisocyanate, and, if necessary, for curing and crosslinking the urethane prepolymer. It is a composition containing a chain extender and a catalyst, and is a solvent-free polyurethane-forming component that is semi-solid or solid at room temperature. Such a crosslinkable hot-melt urethane resin is solid or semi-solid having a viscosity that is difficult to apply at room temperature. After the work, it is re-solidified or thickened by cooling.

Specific examples of the polyol include the polyol described in Embodiment 1 above. These may be used alone or in combination of two or more.

Further, specific examples of the polyisocyanate include, for example, the polyisocyanate described in the first embodiment. These may be used alone or in combination of two or more.

The urethane prepolymer can be usually produced in the absence of a solvent, but may be produced in an organic solvent. When manufacturing in an organic solvent, an organic solvent such as ethyl acetate, n-butyl acetate, methyl ethyl ketone, and toluene can be used, but the organic solvent is removed by a method such as heating under reduced pressure during or after the reaction. It is necessary to.

The reaction ratio between the polyol and the polyisocyanate is preferably such that the equivalent ratio [NCO / OH] of the isocyanate group in the polyisocyanate to the hydroxyl group in the polyol is in the range of 1.1 to 5, More preferably, it is within the range of ˜3.

The number average molecular weight of the urethane prepolymer is in the range of 500 to 30,000, more preferably in the range of 1000 to 10,000. The melt viscosity can be easily adjusted, and excellent flexibility, mechanical strength, and wear resistance are obtained. It is preferable from the viewpoint that a polyurethane resin layer having heat resistance and hydrolysis resistance can be formed.

Examples of such commercially available urethane prepolymers include DIC Corporation's trade names Task Force KMM-100, KMM-100LV, Tyforce NH-122A, NH-200, NH-300, H-1041, and Takeda. Takeda Melt SC-13, SL-01, SL-02, SL-03, SL-04, etc. manufactured by Kogyo Co., Ltd. may be mentioned.

The chain extender is a compound having two or more functional groups having an active hydrogen such as a hydroxyl group or an amino group that can react with an isocyanate group of the urethane prepolymer. In the urethane prepolymer, the reaction between the isocyanate group in the urethane prepolymer and the hydroxyl group or amino group in the chain extender, which will be described later, is accelerated by the urethanization catalyst to increase the molecular weight. The polymer having a high molecular weight further undergoes a crosslinking reaction by reacting with an isocyanate group present in the system.

Specific examples of the chain extender include the polyamines described in Embodiment 1 in addition to the various polyols described above. These may be used alone or in combination of two or more.

Among the crosslinkable hot melt type urethane resins, a moisture curable hot melt type urethane resin having heat melting property and moisture curable property is particularly preferable.

The moisture (moisture) curability of the moisture curable hot-melt urethane resin is cured by reacting the isocyanate group terminal in the urethane prepolymer with moisture (water) to form a urethane bond or urea bond. . Further, the formed urethane bond or urea bond further undergoes a crosslinking reaction by reacting with an isocyanate group present in the system. Through such a curing reaction and a crosslinking reaction, the urethane prepolymer has a high molecular weight, whereby a polyurethane resin having excellent mechanical properties and water resistance is formed.

The crosslinkable hot-melt urethane resin of the present embodiment preferably contains a urethanization catalyst, particularly a temperature-sensitive urethanization catalyst. The temperature-sensitive urethanization catalyst is a urethanization catalyst that exhibits a predetermined exothermic peak temperature when differential scanning calorimetry is performed in a temperature range of 0 ° C. to 200 ° C. at a rate of temperature increase of 10 ° C./1 minute under a nitrogen seal. It is. The exothermic peak temperature is preferably in the range of 50 to 160 ° C., and more preferably in the range of 80 to 140 ° C., from the viewpoint of excellent treatment efficiency and stabilization of urethanization.

Specific examples of such a temperature-sensitive urethanization catalyst include an organic acid salt of 1,8-diazabicyclo (5,4,0) -undecene-7 (DBU), specifically a phenol salt of DBU (exothermic peak). Temperature 88 ° C), DBU octylate (99 ° C), DBU phthalate (138 ° C), DBU oleate (110 ° C), and the like. Such a temperature-sensitive urethanization catalyst is appropriately selected in consideration of the softening temperature of the urethane prepolymer used.

The crosslinkable hot-melt urethane resin preferably contains a foaming agent as necessary in order to make the resulting polyurethane resin layer porous. The type of foaming agent is not particularly limited, but it is preferable to use thermally expandable microcapsules from the viewpoint of easy control of pore uniformity. As such a heat-expandable microcapsule, for example, the encapsulated hydrocarbon expands by heating, and at the same time, the thermoplastic resin forming the outer shell softens to start expansion, and the internal pressure and the external pressure of the microcapsule are increased. Examples thereof include a temperature-sensitive foaming agent for forming uniform closed cells by expanding to a balanced predetermined expansion ratio, preferably twice or more. Specific examples of such thermally expandable microcapsules include Matsumoto Microsphere F series manufactured by Matsumoto Yushi Seiyaku Co., Ltd.

The crosslinkable hot-melt urethane resin of this embodiment may contain additives such as colorants such as pigments, thickeners, and antioxidants as necessary, in addition to the various components described above.

As the melt viscosity of such a crosslinkable hot-melt urethane resin, the melt viscosity at 100 ° C. measured with a cone plate viscometer is in the range of 500 to 12000 mPa · s, more preferably 1000 to 10,000 mPa · s. This is preferable from the viewpoint of excellent coating properties and easy adjustment of the film thickness.

A method for producing a polyurethane laminate according to this embodiment, which is performed using the above-described crosslinkable hot-melt urethane resin, will be described with reference to FIG.

FIG. 4 is a schematic explanatory diagram for explaining the method for producing the polyurethane laminate of the present embodiment. In FIG. 4, 120 is a crosslinkable hot-melt urethane resin, 121 is a release paper, 122 is a urethane prepolymer, 123 is a chain extender, 124 is a temperature-sensitive urethanization catalyst having a predetermined exothermic peak temperature, and 125 is heat. Expandable microcapsules. In addition, the chain extender of 123 may contain a polyol for imparting a desired color tone or a polyol as long as necessary so as not to impair the effects of the present invention. . Further, a mixing head 136 includes a first nozzle 136a for supplying the urethane prepolymer 122, a second nozzle 136b for supplying the chain extender 123 and the like, and a mixing chamber 136c. Note that 136a, 136b, and 136c are each provided with a heater (not shown). Also, 103 is a composite fiber sheet, 138 is a feed reel of the

composite fiber sheet

103, 139a is a touch roll, 139b is a reverse roll, 140 is a release paper-coating laminate, 141 is a feed roll, 142 is a heating device, and 143 is A polyurethane laminate precursor, 144 is a take-up reel of the

polyurethane laminate precursor

143, 146 is a cooling roll, and PR is a press roll. In FIG. 4, a reverse roll coater is configured by a combination of a touch roll 139a and a reverse roll 139b.

In the method for producing a polyurethane laminate of this embodiment, first, a release paper-coating laminate 140 is formed by applying a meltable crosslinkable hot-melt urethane resin 120 to the surface of the release paper 121 (coating). Film formation step).

As a method for preparing the crosslinkable hot-melt urethane resin 120 (melt mixing process), for example, a urethane prepolymer 122, a chain extender 123, a temperature-sensitive urethanization catalyst 124, and a thermally expandable microcapsule 125 are temperature-sensitive. And heat melting and mixing at a temperature at which the urethanizing catalyst 124 is not activated.

As the heat-melt mixing method, for example, the urethane prepolymer 122 is heated at a temperature that has a predetermined viscosity, while the chain extender 123, the temperature-sensitive urethanization catalyst 124, and the thermally expandable microcapsule 125 are added. A method of stirring after mixing or mixing using a mixing head as shown in FIG. 4 that mixes by injecting and colliding them with high pressure after they are kept warm, or simply in a molten state in a container equipped with a heating device A method such as stirring and mixing is employed.

As shown in FIG. 4, the mixing method using the mixing head is performed by atomizing the urethane prepolymer 122 from the first nozzle 136a in a heated and melted state by pressure injection and supplying it to the mixing chamber 136c. The urethanizing catalyst 124 and the heat-expandable microcapsule 125 are mixed with the chain extender 123, sprayed from the second nozzle 136b, atomized, and supplied to the mixing chamber 136c. And each component atomized in the mixing chamber 136c collides and mixes. The thermally expandable microcapsule 125 is a component that is blended as necessary when forming a porous polyurethane resin layer. In this case, the first nozzle 136a and the first nozzle of the mixing head are set so that the temperature of the crosslinkable hot-melt urethane resin 120 prepared by mixing is lower than the temperature at which the temperature-sensitive urethanization catalyst 124 is activated. The temperatures of the two nozzles 136b and the mixing chamber 136c are controlled. According to the mixing method using such a mixing head, more uniform mixing is possible.

First, the urethane prepolymer 122 is heated and stored in a predetermined container at a melting temperature. On the other hand, the chain extender 123, the temperature-sensitive urethanization catalyst 124, and the heat-expandable microcapsule 125 are not activated in the other container, and the heat-expandable microcapsule 125 is not activated. Keep at a temperature that does not swell. And the mixture containing the urethane prepolymer 122, the temperature-sensitive urethanization catalyst 124, the thermally expansible microcapsule 125, and the chain extender 123 is supplied to the container provided with the heater and the stirring apparatus. In the container, the urethane prepolymer 122, the chain extender 123, the temperature-sensitive urethanization catalyst 124, and the thermally expandable microcapsule 125 are heated at a temperature that does not activate the temperature-sensitive urethanization catalyst 124. Melt mixed.

In the melt mixing step, the urethane prepolymer 122 is at a temperature in the range of 10 to 30 ° C. lower than the exothermic peak temperature, preferably in the range of 10 to 25 ° C., which is the temperature at which the temperature-sensitive urethanization catalyst 124 is activated. It is preferable that the chain extender 123, the temperature-sensitive urethanization catalyst 124, and the thermally expandable microcapsule 125 are heated and melt mixed. The progress of the cross-linking reaction is suppressed by heat-melt mixing at such a temperature. Thereby, the coating stability of the crosslinkable hot-melt urethane resin 120 prepared in the mixing chamber 136c can be improved. In addition, when mix | blending the thermally expansible microcapsule 125, it is preferable to select the thermally expansible microcapsule which starts expansion | swelling in a melt mixing process.

On the other hand, as shown in FIG. 4, the release paper 121 is continuously sent out from a sheet delivery reel (not shown), and the release paper 121 that is continuously sent out is sent by a delivery roll 141 that rotates in the direction of the arrow. After that, a continuous line of the release paper 121 is formed in advance by the take-up reel 144.

As shown in FIG. 4, the crosslinkable hot-melt urethane resin 120 prepared in the mixing chamber 136c is placed between the touch roll 139a and the reverse roll 139b toward the release paper 121 that is continuously conveyed. It flows down toward the clearance to be formed, and is applied to the surface of the release paper 121 with a uniform thickness by the reverse roll 139b to form the release paper-coating laminate 140. The coating thickness is controlled by the clearance interval formed between the reverse roll 139b and the touch roll 139a.

As the release paper 121, a release paper having an embossed pattern may be used in addition to a smooth release paper for the purpose of imparting surface design.

In addition, as a specific example of an application mechanism for applying the crosslinkable hot melt urethane resin 120 in a heated and melted state to the surface of the release paper 121, for example, a knife coater, a roll may be used instead of the reverse roll coater as shown in FIG. A coater, reverse coater, kiss roll coater, spray coater, T-die coater, or comma coater may be used. In addition, in these application mechanisms, the application mechanism provided with the heating means from the point which can control the molten state of the crosslinkable hot-melt-type urethane resin 120 is preferable.

The thickness of the coating film 132 of the release paper-coating laminate 140 is preferably in the range of 10 to 1000 μm, more preferably 50 to 500 μm from the viewpoint of obtaining a polyurethane laminate excellent in flexibility and mechanical strength. .

Next, the crosslinkable hot melt urethane resin 120 is partially crosslinked (heat treatment step). Specifically, the release paper-coating laminate 140 is heat-treated at a temperature at which the temperature-sensitive urethanization catalyst 124 contained in the crosslinkable hot-melt urethane resin 120 is activated, thereby forming the coating film 132. Crosslinking of the crosslinkable hot-melt urethane resin 120 is promoted. Thereby, the viscosity of the coating film 132 rises to some extent. When a foaming agent such as the thermally expandable microcapsule 125 is contained in the crosslinkable hot-melt urethane resin 120, it is preferable to foam in the heat treatment step.

The heat treatment temperature is not particularly limited as long as the temperature of the coating film 132 is higher than the exothermic peak temperature of the temperature-sensitive urethanization catalyst 124 and does not deteriorate the polyurethane resin layer that is cured and formed, Specifically, heat treatment is preferably performed in a temperature range of 0 to 30 ° C. higher than the exothermic peak temperature of the temperature-sensitive urethanization catalyst 124, and further in a temperature range of 0 to 15 ° C. higher than the exothermic peak temperature. .

Further, as a specific example of the heat treatment time, for example, about 15 seconds to 10 minutes, further about 30 seconds to 5 minutes, the crosslinking reaction can be sufficiently promoted without lowering the productivity. To preferred. In this embodiment, the heat treatment step is provided after the release paper-coating laminate is formed, but the heat treatment step is provided immediately before the application of the crosslinkable hot-melt urethane resin, and partial crosslinking is started before the application. You may provide in any step.

The heat treatment is performed by a heating device 142 such as a hot air heating dryer.

Next, pressure is applied to the surface of the composite fiber sheet 103 under such a pressure that a part of the partially cross-linked coating film 132 of the release paper-coating laminate 140 enters the numerous voids on the surface layer of the composite fiber sheet 103 described above. The coating film 132 is laminated (lamination process).

Specifically, the release paper-coating laminate 140 and the composite fiber sheet 103 are bonded together, for example, as shown in FIG. Although the coating film 132 on the surface of the laminate 140 is partially crosslinked, it is bonded by the press roll PR while being softened to some extent.

In addition, the pressure applied at the time of bonding between the release paper-coating laminate 140 and the composite fiber sheet 103 is appropriately set according to the viscosity of the coating film 132 during press roll. This pressure can be adjusted, for example, by adjusting the clearance clearance between the rolls of a press roll formed by combining two rolls. The clearance interval between the two rolls is adjusted according to the total thickness of the release paper-coating laminate 140 and the composite fiber sheet 103, and for example, the following clearance interval is preferably employed. The clearance between the two rolls is about 70 to 99%, more preferably about 80 to 97% of the total thickness of the release paper-coating laminate 140 and the composite fiber sheet 103 before the press roll. It is preferable to set to.

In the present embodiment, a manufacturing method of performing a laminating step of bonding the release paper-coating laminate 140 and the composite fiber sheet 103 after performing a heat treatment step of partially cross-linking the crosslinkable hot-melt urethane resin 120 is performed. However, the laminating step may be performed before the heat treatment step.

The polyurethane laminate precursor 143, which is a laminate of the release paper-coating laminate 140 and the composite fiber sheet 103, obtained as described above is forcibly cooled using a cooling roll 146 (cooling step). In the cooling step, the crosslinkable hot melt urethane resin 120 is solidified or thickened.

Then, after the cooling process, the film is taken up by the take-up reel 144. Then, the wound polyurethane laminate precursor 143 is aged for a predetermined time as necessary, so that the crosslinking reaction of the polyurethane resin layer further proceeds to increase the molecular weight and cure. Further, when a moisture curable hot melt urethane resin is used as the crosslinkable hot melt urethane resin, moisture curing proceeds.

As the aging conditions for the polyurethane laminate precursor 143, aging is preferably performed for about 20 to 50 hours under the conditions of a temperature of 20 to 40 ° C. and a relative humidity of 50 to 80%. Thereby, the polyurethane laminated body excellent in mechanical strength and water resistance is obtained.

After aging, the release paper 121 is peeled off from the polyurethane laminate precursor 143 to obtain a polyurethane laminate.

In addition, in order to impart surface designability to the obtained polyurethane laminate by a known and conventional method, the surface layer portion is made of a solvent-based, water-based, emulsion-based or solvent-free urethane resin or acrylic resin. A skin layer may be provided by coating, or post-processing such as buffing or embossing may be appropriately performed.

The polyurethane laminate thus obtained can be used as a leather-like sheet used for bags, footwear, clothing, furniture and the like.

[Embodiment 3]
In Embodiment 3, the polyurethane laminate obtained by the method for producing a polyurethane laminate of Embodiment 2 will be described. The polyurethane laminate according to Embodiment 3 is preferably a composite fiber sheet having a large number of voids in the surface layer, in which a fiber sheet and a polymer elastic body are impregnated and integrated, and a polyurethane resin laminated on the composite fiber sheet And a mixed layer having a thickness of 10 μm or more formed by intruding into a void in the surface layer of the composite fiber sheet.

The polyurethane laminate according to the present embodiment will be described in detail with reference to the drawings. FIG. 3 is a schematic cross-sectional view of the

polyurethane laminate

110, 101 is a fiber sheet, 102 is a porous polyurethane (polymer elastic body), and the fiber sheet 101 is impregnated with the porous polyurethane 102 and integrated. Thereby, the composite fiber sheet 103 is formed. Reference numeral 104 denotes a polyurethane resin layer, and the lower layer of the polyurethane resin layer 104 enters and mixes with the gap 106 in the upper layer of the composite fiber sheet 103, whereby the mixed layer 105 is formed.

Specific examples of the fiber sheet 101 include, for example, fiber base materials generally used for leather-like sheets such as nonwoven fabrics, woven fabrics, and knitted fabrics. In these, the nonwoven fabric formed from the ultrafine fiber or the ultrafine fiber bundle is used preferably from the point from which the composite fiber sheet which has a soft texture and the outstanding mechanical strength is obtained. As such a nonwoven fabric, a conventionally known short fiber web, a web obtained by a known method such as a spunbond method or a melt blow method can be used without particular limitation. Moreover, after forming a web as needed, it may be obtained by accumulating a plurality of webs and intertwining them by a needle punching process or the like. Specific examples of the fibers forming the nonwoven fabric include, for example, polyester fibers such as polyurethane fibers and PET fibers, polyamide fibers, polyacrylic fibers, polyolefin fibers, and polyvinyl alcohol fibers. The fibers forming the nonwoven fabric are preferably fine fibers or ultrafine fibers having a fiber diameter of 0.1 to 50 μm, more preferably 1 to 15 μm. Such a fine fiber or ultrafine fiber has a low rigidity and is soft, so that a composite fiber sheet having a soft texture can be obtained. Further, as the cross-sectional shape of the fiber, in addition to a normal circular or elliptical cross-section, a star-shaped one may be used, and from the point of obtaining a composite fiber sheet having both lightness and mechanical strength, it is hollow or A lotus-type multi-cavity hollow shape may be used.

The basis weight of the nonwoven fabric is preferably in the range of 50 to 2000 g / m ² , and more preferably in the range of 100 to 1000 g / m ² from the viewpoint of obtaining a composite fiber sheet having a soft texture.

Also, the fiber sheet 101 of this embodiment is impregnated with porous polyurethane 102 as a polymer elastic body. The polymer elastic body is not limited to a porous material. Instead of polyurethane, acrylonitrile-butadiene copolymer, styrene-butadiene copolymer, acrylic ester or methacrylic ester copolymer, silicon rubber, or the like may be used. Polyurethane is particularly preferable in that a good texture can be obtained.

Specific examples of the porous polyurethane 102 include a porous polyurethane resin obtained by solidifying or solidifying a solvent-based, water-based, emulsion-based or solvent-free urethane resin. The composite fiber sheet 103 formed by impregnating the fiber sheet 101 with the porous polyurethane 102 and being integrated is impregnated with the porous polyurethane 102 in the gaps formed between the fibers or fiber bundles constituting the fiber sheet 101. And a large number of voids that are not impregnated with the porous polyurethane 102. As will be described later, the lower layer of the polyurethane resin layer 104 penetrates into a large number of voids 106 existing on the surface layer to form a mixed layer 105.

The thickness of the composite fiber sheet 103 is not particularly limited, but is preferably in the range of 100 to 2000 μm, and more preferably in the range of 200 to 1500 μm, because the texture becomes soft and the rubber-like texture does not easily occur.

Further, the porosity of the composite fiber sheet 103 before the mixed layer 105 is formed is preferably 20 to 85% by volume, more preferably 35 to 80% by volume, and particularly preferably 40 to 80% by volume. In the case of such a porosity, it is preferable from the point that the crease / protrusion of the obtained polyurethane laminate is particularly fine, the balance of texture is excellent, and the peel strength is excellent. In addition, the porosity is calculated | required from the following formula.
Porosity (%) = [1−density of composite fiber sheet ÷ {specific gravity of fibers constituting composite fiber sheet × (mass ratio of fibers in composite fiber sheet) + polymer elastic body constituting composite fiber sheet] Specific gravity x (mass ratio of polymer elastic body in composite fiber sheet)}] × 100

On the other hand, specific examples of the polyurethane resin layer 104 include a layer made of a polyurethane resin obtained by coagulating or solidifying a hot-melt urethane resin, a thermoplastic polyurethane resin, a solvent-based urethane resin, a water-based urethane resin, or an emulsion-based urethane resin. Is mentioned. Among these, a polyurethane resin layer derived from a hot-melt urethane resin is particularly preferably used from the viewpoint of excellent industrial productivity.

The polyurethane resin layer 104 including the thickness of the mixed layer 105 has a thickness of 30 to 1000 μm, more preferably 100 to 800 μm, particularly 150 to 700 μm, and a polyurethane laminate excellent in flexibility and mechanical strength. Is preferable from the point that can be obtained.

The polyurethane resin layer 104 is preferably a porous resin layer. The average diameter of the porous voids formed in the polyurethane resin layer 104 is preferably 10 to 500 μm, more preferably 20 to 200 μm, from the viewpoint of excellent processing stability, resin layer smoothness and surface touch. Further, the porosity of the polyurethane resin layer 104 is 10 to 90% by volume, more preferably 20 to 80% by volume, and particularly 30 to 70% by volume. This is preferable from the viewpoint of fineness and physical properties.

As shown in FIG. 3, the polyurethane laminate 110 includes a composite fiber sheet 103 and a polyurethane resin layer 104 laminated on the surface of the composite fiber sheet 103, and a part of the polyurethane resin layer 104 is a surface of the composite fiber sheet 103. The mixed layer 105 is formed by entering and filling the void 106. Such a mixed layer 105 is a layer having a thickness of 10 μm or more formed when a part of the polyurethane resin layer 104 enters a large number of voids 106 of the composite fiber sheet 103, and is combined with a part of the polyurethane resin layer 104. It is a layer having a three-dimensional thickness formed by mixing a part of the fiber sheet 103 in an incompatible state. In addition, when the polyurethane resin layer 104 enters the gap 106 of the composite fiber sheet 103, the bottom surface 107 of the mixed layer 105 exists in a deep portion from the surface layer of the polyurethane laminate 110. Then, the voids of the composite fiber sheet 103 are intruded and filled with polyurethane constituting the polyurethane resin layer 104, and the polymer elastic body and the fiber sheet constituting the composite fiber sheet 103 are mixed. As a result, the interface between the polyurethane resin layer and the composite fiber sheet does not exist in the vicinity of the surface layer, so that the influence of the interface is less likely to appear on the surface layer of the polyurethane laminate 110.

The thickness of the mixed layer 105 is preferably 10 to 800 μm, more preferably 30 to 500 μm from the viewpoint of exhibiting a high anchor effect. When the thickness of the mixed layer 105 is too thin, the anchor effect is weakened, the adhesion between the polyurethane resin layer 104 and the composite fiber sheet 103 is not sufficiently improved, the crease feeling is inferior, and the crease tends to remain. Yes, if the mixed layer 5 is too thick, the texture tends to be hard.

Further, the ratio of the thickness of the mixed layer 105 to the total thickness of the entire polyurethane resin layer 104 is preferably 10 to 80%, more preferably 30 to 70%, from the viewpoint of exhibiting a high anchor effect. When the ratio of the thickness of the mixed layer 105 is too low, the adhesive force between the polyurethane resin layer 104 and the composite fiber sheet 103 tends not to be sufficiently improved, and the interface 107 of the mixed layer becomes close to the surface layer. Tend. When the ratio of the thickness of the mixed layer 105 is too high, the texture tends to be hard rubber-like.

In the mixed layer 105, the porous polyurethane 102 and the polyurethane resin layer 104 exist in a substantially incompatible state. By forming such a mixed layer 105, a higher anchor effect is exhibited. Further, since the partition walls forming the porous structure formed in the porous polyurethane 102 are maintained as they are, the mechanical characteristics of the mixed layer 105 are excellent.

For the polyurethane laminate 110, the surface layer thereof is coated with a solvent-based, water-based, emulsion-based or solvent-free polyurethane resin or acrylic resin in order to impart surface designability by a known and conventional method. The outer skin layer may be laminated or post-processing such as buffing or embossing may be appropriately performed.

The total thickness of the polyurethane laminate 110 is preferably 100 to 3000 μm, more preferably 200 to 2000 μm, and particularly preferably 500 to 1500 μm from the viewpoint of obtaining a texture similar to leather.

Such a polyurethane laminate can be preferably used as a leather-like sheet similar to natural leather that becomes a surface material of footwear, clothing, bags, furniture, and the like.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples.

First, Examples 1-1 to 1-5 corresponding to Embodiment 1 will be described.

[Raw materials used in Examples 1-1 to 1-5]
<Urethane prepolymer>
Task Force KMM-100 (Hot melt type urethane prepolymer manufactured by DIC Corporation, melt viscosity at 120 ° C. is 3200 mPa · s)
<Chain extender>
Polyol (pigment-dispersed polyol manufactured by DIC Corporation, Black Exp. 7457, polyol 70% by mass, pigment 30% by mass)
<Temperature sensitive urethane catalyst>
DBU oleate (San Apro Co., Ltd., exothermic peak temperature 110 ° C)
<Thermal expandable microcapsule>
Matsumoto Microsphere F-36 (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., outer shell softening temperature 80-90 ° C)
<Base material sheet>
Thickness 1 mm, basis weight 550 g / m ² , specific gravity 0.55 g / cm ³ impregnated with a water-soluble polyurethane (Hydran WLI612 manufactured by DIC Corporation) in an entangled nonwoven fabric made of ultrafine fibers having an average fineness of 0.07 dtex Base fabric.
<Release paper>
Release paper R-8 with wrinkles made by Lintec Corporation

[Example 1-1]
A polyurethane laminate was produced using a production process as shown in FIG.

Specifically, first, the urethane prepolymer 2 was atomized by pressure injection from the first nozzle 6a in a heated and melted state kept at 100 ° C. and supplied to the mixing chamber 6c, while keeping the temperature at 50 ° C. 16. A mixture obtained by mixing 0.9 parts by mass of the temperature-sensitive urethanization catalyst 4 and 0.8 parts by mass of the thermally expandable microcapsule 5 with respect to 2 parts by mass of the chain extender 3 is pressurized from the second nozzle 6b. The mixture was sprayed, atomized, and supplied to the mixing chamber 6c kept at 100 ° C. And each component atomized in the mixing chamber 6c was collided and mixed. The mixing ratio was 15 parts by mass of a mixture of the chain extender 3, the temperature-sensitive urethanization catalyst 4, the thermally expandable microcapsule 5 and 2100 parts by mass of the urethane polymer. The urethane resin composition 10 prepared by collision mixing was further stirred in the mixing chamber 6c. Stirring was performed at 4000 rpm for 15 seconds using a stirrer (TK homodisper prime) provided in the mixing chamber 6c. It was 100 degreeC when the surface temperature of the urethane resin composition 10 was measured with the non-contact-type thermometer after stirring.

Next, as shown in FIG. 1, the release paper 1 that is continuously fed from a release paper feed reel (not shown) is fed by a feed roll 11 that rotates in the direction of the arrow, and is then wound by a take-up reel 14. Thus, a continuous line of the release paper 1 was formed.

And as shown in FIG. 1, the reverse roll 9b and the touch roll 9a which heated the urethane resin composition 10 melt-mixed in the mixing chamber 6c at 100 degreeC toward the release paper 1 sent out continuously, The urethane resin layer 10 was formed by applying the reverse flow 9b onto the surface of the release paper 1 so that the application amount was 500 g / m ² . At this time, the coating thickness of the urethane resin layer 10 on the substrate was about 300 μm.

Next, the base material sheet 7 was sent out from the feed reel 8 toward the surface of the urethane resin layer 10 formed on the surface of the release paper 1 and bonded by the press roll PR.

Next, in order to activate the temperature-sensitive urethanization catalyst 4 and expand the thermally expandable microcapsules 5, treatment was performed with a heating device 12 at 115 ° C. for 60 seconds.

Then, the bonded body of the urethane resin layer 10 and the base sheet 7 covered with the release paper 1 thus obtained was wound up by the take-up reel 14. And in the wound state, after making it age | cure | ripen in a 40 degreeC aging room | chamber 48 hours, the black polyurethane laminated body 13 was obtained by peeling the release paper 1. FIG.

When the polyurethane laminate 13 is continuously produced by the method as described above, the urethane resin composition 10 in the mixing chamber 6c maintains a viscosity in a range where it can be continuously applied for at least about 3 hours, and the pot life is reduced. It was excellent. Further, when the cross section of the obtained polyurethane laminate 13 was observed with a scanning electron microscope, uniform independent pores having an average diameter of about 80 μm were formed.

[Example 1-2]
A polyurethane laminate 13 was continuously produced in the same manner as in Example 1-1 except that the polyurethane resin composition in the mixing chamber 6c was kept at 80 ° C. instead of keeping at 100 ° C.

When the polyurethane laminate 13 was continuously produced by the method as described above, the viscosity of the resin was somewhat high, and the applicability was somewhat lower than in Example 1, but there was no problem in continuous productivity. Further, the urethane resin composition in the mixing container maintained a viscosity range that could be applied continuously for at least about 4 hours, and was excellent in pot life.

[Example 1-3]
Instead of performing a heat treatment process in which the substrate sheet 7 is bonded to the urethane resin layer 10 formed on the surface of the release paper 1 and then heated at 115 ° C. for 60 seconds, the same process is performed before the substrate sheet 7 is bonded. A polyurethane laminate 13 was continuously produced in the same manner as in Example 1-1, except that the heat treatment step was performed under the conditions, and then the base sheet 7 was bonded. When a cross section of the obtained polyurethane laminate 13 was observed, uniform independent pores were formed.

[Example 1-4]
Example 1 except that instead of forming a continuous line of the release paper 1, a line of the base sheet 7 is first formed and the urethane resin layer 10 is formed on the surface of the base sheet 7 that is continuously fed out. In the same manner as in No. 3, a urethane resin layer 10 was formed.

Next, the release paper 1 was fed out from the feed reel 8 toward the surface of the urethane resin layer 10 formed on the surface of the base sheet 7 and bonded by the press roll PR.

Then, in order to activate the temperature-sensitive urethanization catalyst 4 and expand the heat-expandable microcapsule 5, it was treated with a heating device 12 at 115 ° C. for 60 seconds.

And after forcibly cooling to near room temperature using the cooling roll 16, it wound up. And in the wound state, after making it age | cure | ripen in a 40 degreeC aging room | chamber 48 hours, the black polyurethane laminated body 13 was obtained by peeling the release paper 1. FIG. When a cross section of the obtained polyurethane laminate 13 was observed, uniform independent pores were formed.

[Example 1-5]
Epidermis blended in advance with water-dispersible polyurethane resin D-6065 (manufactured by Dainichi Seika Kogyo Co., Ltd.) / Thickener D-890 (manufactured by Dainichi Seika Kogyo Co., Ltd.) = 100/2 on the surface of release paper 1 A release liquid with a skin layer is prepared by coating the liquid mixture for drying so that the thickness after drying is 10 μm and drying at 120 ° C. for 2 minutes to form a skin layer made of a polymer elastic body on the surface of the release paper. A multilayer polyurethane laminate was continuously produced in the same manner as in Example 1-1 except that the urethane resin layer 10 was formed on the release paper with the skin layer. When a cross section of the obtained multilayer polyurethane laminate was observed, uniform independent pores were formed in the urethane resin layer 10. And the skin part had a smooth touch.

[Comparative Example 1-1]
A polyurethane laminate was produced using a production process as shown in FIG.

Specifically, first, the urethane prepolymer 2 is atomized by pressure injection from the first nozzle 6a in a heated and melted state kept at 120 ° C. and supplied to the mixing chamber 6c, while keeping the temperature at 50 ° C. 16. A mixture obtained by mixing 0.9 parts by mass of the temperature-sensitive urethanization catalyst 4 and 0.8 parts by mass of the thermally expandable microcapsule 5 with respect to 2 parts by mass of the chain extender 3 from the second nozzle 6b. The mixture was supplied to the mixing chamber 6c which was atomized by pressure injection and kept at 110 ° C. And each component atomized in the mixing chamber 6c was collided and mixed. The mixing ratio is a ratio of 15 parts by mass of a mixture of the chain extender 3, the temperature-sensitive urethanization catalyst 4 and the thermally expandable microcapsule 5 supplied from the second nozzle 6b with respect to 2100 parts by mass of the urethane polymer. Mixed. The urethane resin composition 10 prepared by collision mixing was further stirred in the mixing chamber 6c. After stirring, the surface temperature of the urethane resin composition 10 was 110 ° C. when measured with a non-contact type thermometer. At this time, the thermally expandable microcapsule was expanded more than twice.

In the subsequent steps, a polyurethane laminate was formed in the same manner as in Example 1-1 except that no heat treatment was performed.

When the polyurethane laminate was continuously produced by the above-described method, the viscosity of the urethane resin composition in the mixing container rose to a viscosity that would make it difficult to apply within about 5 minutes.

From the results of Examples 1-1 to 1-5 and Comparative Example 1-1, the following can be understood.

A polyurethane resin composition to be applied at a temperature lower by 10 to 30 ° C. than the exothermic peak temperature of the temperature-sensitive urethanization catalyst as in Examples 1-1 to 1-4 according to the present invention was prepared. In this case, it can be seen that the pot life of the prepared polyurethane resin composition is very long and the continuous productivity is excellent. On the other hand, in the case of Comparative Example 1-1 in which the polyurethane resin composition was prepared at the exothermic peak temperature of the temperature-sensitive urethanization catalyst, the pot life of the prepared polyurethane resin composition was very short, and the continuous production It was scarce. Then, by adding a heat treatment step of heat-treating the urethane resin layer at a temperature equal to or higher than the exothermic peak temperature, the resin layer formation speed can be optimized and productivity can be improved.

Next, Examples 2-1 to 2-5 corresponding to Embodiments 2 and 3 will be described.

[Raw materials used in Examples 2-1 to 2-5]
<Urethane prepolymer>
Task Force KMM-100LV (Moisture curable hot-melt urethane prepolymer manufactured by DIC Corporation, melt viscosity at 100 ° C. is 2500 mPa · s)
<Chain extender>
Butanediol (Mitsubishi Chemical Corporation)
<Temperature sensitive urethane catalyst>
DBU oleate (San Apro Co., Ltd., U-CAT SA-106, exothermic peak temperature 110 ° C)
<Thermal expandable microcapsule>
Matsumoto Microsphere F-36 (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., outer shell softening temperature 80-90 ° C)
<Pigment>
Dirac black RHM-7944 (made by DIC Corporation)
<Composite fiber sheet>
An entangled nonwoven fabric composed of lotus root type nylon ultrafine fibers (specific gravity: 1.14) having an average fineness of 2 dtex and a polyether-based porous polyurethane (specific gravity: 1.2) 12 are compounded at a weight ratio of 1: 1. A composite fiber sheet having a thickness of about 800 μm, a basis weight of 250 g / m ² , a density of 0.315 g / cm ³ , and a porosity of about 73% by volume.
<Release paper>
Release paper R-70N (thickness 200μm) manufactured by Lintec Corporation

[Example 2-1]
A polyurethane laminate was produced using a production process as shown in FIG.

Specifically, first, a crosslinkable hot-melt urethane resin 120 was prepared using a mixing head (manufactured by Maruka Chemical Co., Ltd., MEG-HK-55S type). Specifically, 100 parts of urethane prepolymer maintained at 115 ° C. (mass part, the same applies hereinafter) is atomized by pressure injection from the first nozzle 136a and supplied to the mixing chamber 136c, while 15.7 parts of pigment. A mixture of 0.8 parts of thermally expandable microcapsules, 0.25 parts of a temperature-sensitive urethanization catalyst, and 0.25 parts of a chain extender at 50 ° C. is sprayed from the second nozzle 136b under pressure and atomized. Each atomized component was allowed to collide and be mixed. In addition, the mixing ratio was mixed at a ratio of 17 parts by mass with respect to 100 parts by mass of the urethane prepolymer.

Next, the release paper 121 delivered from the unillustrated release paper delivery reel at a line speed of 5 m / min is delivered by a delivery roll 141 that rotates in the direction of the arrow, and is then taken up by a take-up reel 144 and released. 121 continuous lines were formed.

Then, a reverse roll 139b and a touch roll rotating at 12 m / min heated to 100 ° C. for the crosslinkable hot-melt urethane resin 120 melted and mixed in the mixing chamber 36c toward the release paper 121 that is continuously fed out. flows down toward a clearance formed between the 139a, the coating film 132 was formed by coating so that the coating amount of 280 g / m ² release paper 121 surface by reverse roll 139b, the release paper surface A release paper-coating laminate 140 formed with the coating 132 was formed. At this time, the thickness of the coating film 132 was about 450 μm.

Next, in order to activate the temperature-sensitive urethanization catalyst 124 to partially crosslink the urethane prepolymer and complete the expansion of the thermally expandable microcapsule 125, the release paper-coating laminate 140 is heated to 125 ° C. It processed for 90 second with the heating apparatus 142. FIG.

Next, the composite fiber sheet 103 was fed from the feed reel 138 toward the surface of the coating film 132 formed on the release paper-coating laminate 140, and bonded by a press roll PR composed of two rolls. At this time, the clearance interval between the two rolls was 1410 μm.

The polyurethane laminate precursor 143, which is a laminate of the release paper-coating laminate 140 and the composite fiber sheet 103 in a state covered with the release paper 121 thus obtained, is forced to use a cooling roll 146. After cooling, the film was taken up by a take-up reel 144. And in the wound state, after making it age | cure | ripen in the aging room | chamber temperature of 40 degreeC for 48 hours, the black polyurethane laminated body was obtained by peeling the release paper 121. FIG.

On the surface of the polyurethane laminate thus obtained, a skin layer having a thickness of 20 μm mainly composed of carbonate-based non-yellowing urethane (NES9950 manufactured by Dainichi Seika Kogyo Co., Ltd.) is applied as a urethane-based adhesive (Daiichi Seika). A cord-burn leather-like sheet 117 was obtained by bonding with ME8116 manufactured by Kogyo Co., Ltd. And the cross section of the leather-like sheet | seat 117 was observed with the scanning electron microscope (SEM) (refer FIG. 5).

From the obtained SEM photograph, the leather-like sheet 117 is composed of a skin layer 109 having a thickness of about 20 μm, a polyurethane resin layer 114 having a thickness of about 650 μm, and a composite fiber sheet 113 having a thickness of about 800 μm, which are laminated in order from the surface layer. The lower layer of the polyurethane resin layer 114 entered and filled the upper space 116 of the composite fiber sheet 113 to form a mixed layer 115 having a thickness of about 300 μm. Further, uniform independent pores having an average diameter of about 180 μm were formed in the polyurethane resin layer 114. Furthermore, in the mixed layer 115, the porous polyurethane and the polyurethane resin layer 114 exist in an incompatible state. In addition, each said thickness is an average value measured from the SEM photograph in 10 cross sections arbitrarily chosen of the obtained leather-like sheet | seat 117. FIG. A typical photomicrograph at this time is shown in FIG.

Also, the texture when the leather-like sheet obtained in this way was folded was evaluated. Specifically, creases and creases generated when a leather-like sheet cut into a square shape with a side of 200 mm was folded in half were observed. At this time, fine wrinkles similar to the case of leather as shown in FIG. 7 occurred. In addition, even after opening the crease by bending and holding it with a finger strongly, no crease remains and a smooth surface is maintained.

[Example 2-2]
A leather-like sheet was produced and evaluated in the same manner as in Example 2-1, except that the clearance interval between the two rolls of the press roll PR was changed from 1410 μm to 1310 μm. And the cross section of the obtained leather-like sheet | seat was observed with the scanning electron microscope (SEM). The obtained leather-like sheet is composed of a skin layer having a thickness of about 20 μm, a polyurethane resin layer having a thickness of about 650 μm, and a composite fiber sheet having a thickness of about 800 μm, which are laminated in order from the surface layer. However, a mixed layer having a thickness of about 400 μm was formed by invading and filling the voids in the upper layer of the composite fiber sheet. Further, when the texture of the leather-like sheet obtained as described above was evaluated, fine wrinkles as shown in FIG. 7 were generated. In addition, even after opening the crease by bending and holding it with a finger strongly, no crease remains and a smooth surface is maintained.

[Example 2-3]
A leather-like sheet was produced and evaluated in the same manner as in Example 2-1, except that the clearance interval between the two rolls of the press roll PR was changed from 1410 μm to 1450 μm. And the cross section of the obtained leather-like sheet | seat was observed with the scanning electron microscope (SEM). The obtained leather-like sheet is composed of a skin layer having a thickness of about 20 μm, a polyurethane resin layer having a thickness of about 650 μm, and a composite fiber sheet having a thickness of about 800 μm, which are laminated in order from the surface layer. However, a mixed layer having a thickness of about 40 μm was formed by entering and filling the voids in the upper layer of the composite fiber sheet. Further, when the texture of the leather-like sheet obtained as described above was evaluated, fine wrinkles as shown in FIG. 7 were generated. Further, even when the crease was made by bending and holding it tightly with a finger, when it was opened, no crease remained and a smooth surface was maintained. The leather-like sheet 117 was slightly inferior.

[Example 2-4]
A leather-like sheet was produced and evaluated in the same manner as in Example 2-1, except that the clearance interval between the two rolls of the press roll PR was changed from 1410 μm to 1200 μm. And the cross section of the obtained leather-like sheet | seat was observed with the scanning electron microscope (SEM). The obtained leather-like sheet is composed of a skin layer having a thickness of about 20 μm, a polyurethane resin layer having a thickness of about 650 μm, and a composite fiber sheet having a thickness of about 800 μm, which are laminated in order from the surface layer. However, a mixed layer having a thickness of about 600 μm was formed by invading and filling the voids in the upper layer of the composite fiber sheet. Further, when the texture of the leather-like sheet obtained as described above was evaluated, fine wrinkles as shown in FIG. 7 were generated. In addition, even after opening the crease by folding and restraining it with a finger, the crease was not left and the smooth surface was maintained. However, the texture was better than that of Example 2-1. It was hard.

[Example 2-5]
Epidermis previously blended on the surface of release paper 121 with water-dispersible polyurethane resin D-6065 (manufactured by Dainichi Seika Kogyo Co., Ltd.) / Thickener D-890 (manufactured by Dainichi Seika Kogyo Co., Ltd.) = 100/2 The liquid mixture for coating was applied so that the thickness after drying was 10 μm, and dried at 120 ° C. for 2 minutes to prepare a release paper with a skin layer in which a skin layer made of a polymer elastic body was formed on the surface of the release paper. . A multilayer polyurethane laminate was continuously produced in the same manner as in Example 2-1, except that a layer made of the crosslinkable hot-melt urethane resin 120 was formed on the release paper with the skin layer. The obtained multilayer polyurethane laminate was able to produce a leather-like sheet continuously without a solvent without forming a skin layer later as in Example 2-1. When the cross section of the obtained leather-like sheet was observed, it was composed of a skin layer, a polyurethane resin layer, and a composite fiber sheet laminated in order from the surface layer, and the lower layer of the polyurethane resin layer was a void in the upper layer of the composite fiber sheet As a result, a mixed layer having a thickness of about 300 μm was formed. In addition, uniform independent pores having an average diameter of about 180 μm were formed in the polyurethane resin layer. Furthermore, in the mixed layer, the porous polyurethane and the polyurethane resin layer exist in an incompatible state. Further, the texture, crease, crease feeling and smoothness when bent were the same evaluations as in Example 2-1.

[Comparative Example 2-1]
After dry blending 100 parts of thermoplastic polyurethane resin (Kuraray Co., Ltd. Kuramylon U3119-000) and 3 parts of black pigment, a thermoplastic polyurethane film was removed from an extruder equipped with a T-die set at a cylinder temperature of 230 ° C. The polyurethane resin layer was manufactured by extruding and crimping | bonding to the surface of a composite fiber sheet immediately after that. The press bonding was performed using a press roll PR having the same clearance interval as that used in Example 2-1. A leather-like sheet was produced by forming a skin layer on the surface of the obtained polyurethane resin layer in the same manner as in Example 2-1. Evaluation was performed in the same manner as in Example 2-1. The SEM photograph of the cross section of the obtained leather-like sheet 118 is shown in FIG. The leather-like sheet 118 was composed of a skin layer 109 having a thickness of about 20 μm, a polyurethane resin layer 111 having a thickness of about 350 μm, and a composite fiber sheet 113 having a thickness of about 800 μm, which were laminated in order from the surface layer. The mixed layer as formed in the polyurethane laminate of -1 to 2-5 was not formed. Further, when the texture of the leather-like sheet obtained as described above was evaluated, large wrinkles as shown in FIG. 8 were generated. In addition, when the crease was attached by bending and holding it with a finger, many fine creases remained when opened.

[Comparative Example 2-2]
After applying a solvent-type polyurethane liquid containing a black pigment (solid content: 15% by mass) onto the release paper, drying was repeated three times to form a polyurethane resin layer having a thickness of 300 μm. Then, the obtained polyurethane resin layer was bonded to the surface of the composite fiber sheet using a solvent-based two-component polyurethane adhesive. And the polyurethane laminated body was obtained by ageing | curing | ripening. The polyurethane resin layer of the obtained polyurethane laminate is a continuous layer having a thickness of about 10 μm and extending so as to slightly penetrate into the composite fiber sheet, but the entry portion has a thickness. It wasn't. Moreover, it was not what was filled in the space | gap of the composite fiber sheet. Furthermore, the porous structure of the porous polyurethane contained in the composite fiber sheet in the entry portion is dissolved and destroyed by the solvent in the solvent-type polyurethane liquid, and the polyurethane and the porous polyurethane constituting the polyurethane resin layer form an interface with each other. It was not compatible.

[Comparative Example 2-3]
By repeating the coating and drying of the aqueous polyurethane dispersion (solid content concentration 45%) instead of the solvent-based polyurethane solution of Comparative Example 2-2 on the release paper so as to have almost the same thickness as Comparative Example 2-2, A polyurethane resin layer having a thickness of 350 μm was formed. And the obtained polyurethane resin layer was bonded together to the composite fiber sheet 3 through the water-based polyurethane adhesive. And the polyurethane laminated body was obtained by ageing | curing | ripening. The polyurethane resin layer of the obtained polyurethane laminate had a portion extending so as to slightly penetrate from the surface of the composite fiber sheet at a depth of about 10 μm, as in Comparative Example 2-2. The gaps in the fiber sheet were not filled, and the entry portion was not a continuous layer having a thickness.

From the results of Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-3 described above, the following can be understood.

When the leather-like sheets mainly composed of the polyurethane laminates obtained in Examples 2-1 to 2-5 according to the present embodiment were folded, fine creases and wrinkles similar to leather were generated, and the folds were bent. There was no crease when it was opened after shaping. This is because the composite fiber sheet and the polyurethane resin layer have high adhesion because a mixed layer having a certain thickness is formed by integrating the upper layer of the composite fiber sheet and the lower layer of the polyurethane resin layer. This is probably due to the formation of a solid laminated structure.

On the other hand, leather mainly composed of the polyurethane laminate obtained in Comparative Example 2-1 obtained by extruding a thermoplastic polyurethane film from an extruder equipped with a T-die and pressing the thermoplastic polyurethane film on a composite fiber sheet When the thermoplastic polyurethane membrane comes into contact with the surface of the composite fiber sheet, the surface suddenly thickens or solidifies. The thermoplastic polyurethane film did not penetrate, and a mixed layer formed by the polyurethane laminate of the example was not formed. Further, in the polyurethane laminates obtained in Comparative Examples 2-2 and 2-3, the mixed layer as formed by the polyurethane laminate of the example was not formed. For this reason, in Comparative Examples 2-1 to 2-3, high adhesion and a sense of unity between the composite fiber sheet and the polyurethane resin layer are not obtained, and a solid texture similar to leather when folded is obtained. It was not obtained.

As described above, one aspect of the present invention is a temperature sensitivity that shows a predetermined exothermic peak temperature by differential scanning calorimetry with a urethane prepolymer (A) that is semi-solid or solid at room temperature and a chain extender (B). A melt-mixing step of forming a urethane resin composition by heat-melting and mixing the urethanizing catalyst (C) at a temperature in the range of 10 to 30 ° C. lower than the exothermic peak temperature, and using the urethane resin composition A polyurethane layered product comprising: a resin layer forming step of forming a urethane resin layer on a sheet surface such as a release paper and a fiber substrate; and a heat treatment step of heat-treating the urethane resin layer at a temperature equal to or higher than the exothermic peak temperature. It is a manufacturing method.

According to such a production method, the urethane prepolymer (A), the chain extender (B), and the chain extender (B) are at a temperature in the range of 10 to 30 ° C. lower than the exothermic peak temperature at which the temperature-sensitive urethanization catalyst (C) is activated. In order to prepare a urethane resin composition by heat-melting and mixing with the temperature-sensitive urethanization catalyst (C), the progress of the crosslinking reaction of the urethane resin composition to be applied is suppressed. Therefore, the pot life of the urethane resin composition used for application is extended. The urethane resin layer formed on the surface of the base material is later heat-treated at a temperature higher than the exothermic peak temperature at which the temperature-sensitive urethanization catalyst (C) is activated, thereby quickly crosslinking and producing Improves.

When the temperature-sensitive urethanization catalyst is an organic acid salt of 1,8-diazabicyclo (5,4,0) -undecene-7, the predetermined exothermic peak temperature by differential scanning calorimetry becomes sharp. This is preferable from the viewpoint of easy control of the crosslinking reaction.

Further, in the melt mixing step, the heat-expandable microcapsules are further mixed in the urethane resin composition, and the heat-expandable microcapsules are expanded at an expansion ratio of 2 times or more in the heat treatment step. preferable. By mixing such thermally expandable microcapsules in the urethane resin composition, a polyurethane layer having uniform closed cells can be formed.

In addition, the melt mixing step is performed by pressure-injecting the urethane prepolymer (A) in a heat-melted state atomized by pressure-injecting from the first nozzle of the mixing head and the second nozzle. By melting the atomized mixture containing the chain extender (B) and the temperature-sensitive urethanization catalyst (C), the mixture is heated and melted at a temperature in the range of 10 to 30 ° C. lower than the exothermic peak temperature. A mixing step is preferred. According to such a method, more uniform mixing is possible.

Further, the polyurethane laminate of the present invention is preferably a polyurethane laminate obtained by any one of the above production methods.

Another aspect of the present invention is a coating film forming step of forming a release paper-coating laminate by applying a molten crosslinkable hot melt urethane resin to the surface of the release paper, and a crosslinkable hot melt. The release paper-coating laminate is applied to the voids of the composite fiber sheet having a large number of voids in the surface layer, in which the fiber sheet and the polymer elastic body are impregnated and integrated, and the heat treatment step for partially crosslinking the mold urethane resin. A method for producing a polyurethane laminate comprising a laminating step of laminating a coating film on the surface of a composite fiber sheet at a pressure at which a part of the membrane enters, and a cooling step of cooling and solidifying a crosslinkable hot-melt urethane resin. is there.

According to such a production method, the polyurethane laminate having the mixed layer as described above can be easily produced.

In addition, the coating film forming step is a temperature sensitivity which shows a predetermined exothermic peak temperature by differential scanning calorimetry with a hot melt urethane prepolymer (A) having a melt viscosity at 100 ° C. of 10,000 mPa · sec or less and a chain extender (B). Melting and mixing step of forming a crosslinkable hot-melt urethane resin by heat melting and mixing with the heat-resistant urethanization catalyst (C) at a temperature in the range of 10-30 ° C. lower than the exothermic peak temperature, and melting on the release paper surface And a coating film forming step of forming a release paper-coating laminate by applying a crosslinkable hot-melt urethane resin in a state, wherein the heat treatment step makes the release paper-coating laminate above the exothermic peak temperature. It is preferably a step of partially crosslinking the coating film by heat treatment at a temperature.

According to such a production method, the urethane prepolymer (A), the chain extender (B), and the chain extender (B) are at a temperature in the range of 10 to 30 ° C. lower than the exothermic peak temperature at which the temperature-sensitive urethanization catalyst (C) is activated. In order to prepare a crosslinkable hot-melt urethane resin by heat-melting and mixing with the temperature-sensitive urethanization catalyst (C), the progress of the crosslinking reaction of the crosslinkable hot-melt urethane resin used for coating is suppressed. . Therefore, the viscosity required for application is maintained. The coating film formed on the release paper surface is heat-treated at a temperature higher than the exothermic peak temperature at which the temperature-sensitive urethanization catalyst (C) is activated, so that the coating film is partially crosslinked to adjust the viscosity. Is done. And the quantity of the coating film which penetrate | invades into the space | gap of the surface layer part of a composite fiber sheet can be easily adjusted by pressing the coating film adjusted to moderate viscosity.

As the temperature-sensitive urethanization catalyst, for example, an organic acid salt of 1,8-diazabicyclo (5,4,0) -undecene-7 is preferably used.

In the melt mixing step, the heat-expandable microcapsules are further mixed in the crosslinkable hot-melt urethane resin so that the heat-expandable microcapsules have an expansion ratio of 2 times or more in the melt-mixing step and / or heat treatment step. It is preferable that it expand | swells. A polyurethane resin layer having uniform closed cells can be formed by mixing such thermally expandable microcapsules in a crosslinkable hot melt urethane resin.

Also, the melt mixing step is performed by pressure injection from the first nozzle of the mixing head and the hot melt urethane prepolymer (A) in a heated and melted state atomized by pressure injection from the first nozzle of the mixing head. The mixture containing the chain extender (B) and the temperature-sensitive urethanization catalyst (C) atomized by the above is collided with heat to melt and mix at a temperature in the range of 10-30 ° C. lower than the exothermic peak temperature. It is preferable that it is a process. According to such a method, more uniform mixing is possible.

Still another aspect of the present invention is a composite fiber sheet having a large number of voids in a surface layer, in which a fiber sheet and a polymer elastic body are impregnated and integrated, and a polyurethane resin layer laminated on the composite fiber sheet 10 μm or more, preferably a part of the polyurethane resin layer and a surface layer of the composite fiber sheet are mixed in an incompatible state when a part of the polyurethane resin layer enters the gap. Is a polyurethane laminate having a mixed layer having a thickness of 30 μm or more.

According to such a polyurethane laminate, the interface between the composite fiber sheet and the polyurethane resin layer is not two-dimensional like the polyurethane laminate obtained by the conventional method, but as shown in FIG. The polyurethane constituting the polyurethane resin layer can permeate deeply and randomly in the thickness direction of the composite fiber sheet, and can exist as a mixed layer 105 formed three-dimensionally having a sufficient thickness. In addition, since such a mixed layer is formed so that a part of the polyurethane resin layer penetrates into and fills the voids of the composite fiber sheet, the polyurethane resin layer is supported by the composite fiber sheet with a high anchor effect. Is done. Furthermore, when the polyurethane resin layer enters the composite fiber sheet, the bottom surface of the mixed layer is located in a deep portion from the surface layer of the polyurethane laminate (for example, the bottom surface 107 in FIG. 3). This makes it difficult for the influence of mismatch at the interface between the polyurethane resin layer and the composite fiber sheet, which has been a problem in the past, to appear on the surface layer of the polyurethane laminate. By providing such a mixed layer on the polyurethane laminate to improve the adhesion between the composite fiber sheet and the polyurethane resin layer, it has a solid texture similar to leather and a good feeling of folding when folded. Thus, after folding, a polyurethane laminate in which no creases remain is obtained. In the mixed layer, the polymer elastic body and the polyurethane resin layer exist in a substantially incompatible state. Here, the incompatible state means a state in which the polymer elastic body constituting the composite fiber sheet and the polyurethane resin constituting the polyurethane resin layer are mutually melted and are not substantially mixed. The polymer elastic body and the polyurethane resin layer may be in close contact or cross-linked, may be simply filled in the voids of the polymer elastic body, or may exist so as to cover the polymer elastic body. Good. On the other hand, when a solvent-type urethane adhesive is applied to the surface of the composite fiber sheet, the polymer elastic body in the composite fiber sheet is dissolved by the solvent, so that the applied polyurethane and the high level in the composite fiber sheet are dissolved. Molecular elastic bodies are easily mixed and become compatible. And when it will be in a compatible state, when the polymeric elastic body in a composite fiber sheet is a porous state especially, a porous state collapse | crumbles and there exists a tendency for it to be inferior to a feeling and a crease feeling.

Further, the thickness ratio of the mixed layer in the total thickness of the polyurethane resin layer is preferably 10 to 80%. Thus, when the mixed layer whose thickness ratio with respect to the total thickness of a polyurethane resin layer is comparatively high is formed, the unity feeling of a polyurethane resin layer and a composite fiber sheet becomes higher. Note that the total thickness of the polyurethane resin layer can be determined by referring to FIG. 3 from the surface of the polyurethane resin layer 104 when the cross section parallel to the thickness direction of the polyurethane laminate is observed with a scanning electron microscope. Is the thickness of the composite fiber sheet 103 up to the deepest part of the composite fiber sheet 103, and the thickness of the mixed layer is the part of the composite fiber sheet 103 where the polyurethane resin layer 104 enters the composite fiber sheet 103 deepest. The thickness is up to.

In addition, the polyurethane resin layer is a layer formed of a crosslinkable hot-melt urethane resin, so that the mixed layer has excellent penetration and filling properties and is incompatible with the polymer elastic body constituting the composite fiber sheet. It is preferable from the viewpoint of easily obtaining the state.

In addition, it is preferable that at least one of the polyurethane resin layer and the polymer elastic body is porous in terms of being able to suppress a soft texture, a natural leather-like crease feeling, and generation of arabi during fishing.

Further, when the porosity of the composite fiber sheet is in the range of 30 to 85% by volume, it is preferable from the viewpoint that the resulting polyurethane laminate has finer wrinkles, excellent texture balance, and excellent peel strength.

According to the method for producing a polyurethane laminate of the present invention, when a polyurethane layer is formed on a substrate surface without a solvent, the polyurethane layer is continuously stabilized by maintaining the pot life of the urethane resin composition to be applied for a long time. In addition, the productivity of the polyurethane laminate is improved by rapidly crosslinking the applied uncrosslinked polyurethane layer by heat treatment.

Moreover, according to the method for producing a polyurethane laminate of the present invention, a polyurethane laminate that exhibits a texture similar to leather when folded can be obtained. In particular, it is possible to obtain a polyurethane laminate in which fine creases similar to leather are generated, and creases after folding are less likely to remain.

Claims

A urethane prepolymer (A) that is semi-solid or solid at room temperature, a chain extender (B), and a temperature-sensitive urethanization catalyst (C) that exhibits a predetermined exothermic peak temperature by differential scanning calorimetry are used as the exothermic peak temperature. On the other hand, a melt mixing step of forming a urethane resin composition by heating and mixing at a temperature in the range of 10-30 ° C. and a resin layer forming step of forming a urethane resin layer on the sheet surface using the urethane resin composition And a heat treatment step of heat-treating the urethane resin layer at a temperature equal to or higher than the exothermic peak temperature.
The method for producing a polyurethane laminate according to claim 1, wherein the sheet is a release paper.
The said sheet | seat is a sheet | seat which consists of a release paper and the polymeric elastic body layer previously formed in the surface of this release paper, Comprising: The urethane resin layer is formed in the surface of the said polymeric elastic body layer. Process for producing a polyurethane laminate.
The method for producing a polyurethane laminate according to claim 1, wherein the sheet is a fiber base material.
The method for producing a polyurethane laminate according to any one of claims 1 to 4, wherein the temperature-sensitive urethanization catalyst is an organic acid salt of 1,8-diazabicyclo (5,4,0) -undecene-7.
In the melt mixing step, thermally expandable microcapsules are further mixed into the urethane resin composition,
The method for producing a polyurethane laminate according to any one of claims 1 to 5, wherein the thermally expandable microcapsule expands at an expansion ratio of 2 or more in the heat treatment step.
In the melt mixing step, the urethane prepolymer (A) in a heated and melted state atomized by pressure injection from the first nozzle of the mixing head and the atomization by pressure injection from the second nozzle. The mixture containing the chain extender (B) and the temperature-sensitive urethanization catalyst (C) is made to collide with heat to melt and mix at a temperature in the range of 10 to 30 ° C. lower than the exothermic peak temperature. The method for producing a polyurethane laminate according to any one of claims 1 to 6, which is a step.
A polyurethane laminate obtained by the production method according to any one of claims 1 to 7.
The manufacturing method of the polyurethane laminated body including the process which the sheet | seat of the said Claim 1 is a release paper, and it is further bonded to the fiber base material on the surface of the obtained said urethane resin layer.
In the manufacturing method of the polyurethane laminated body of Claim 1,
A coating film forming step of forming a release paper-coating laminate by applying a crosslinkable hot-melt urethane resin in a molten state to the surface of the release paper;
A heat treatment step of partially crosslinking the crosslinkable hot-melt urethane resin;
The pressure is such that a part of the coating film of the release paper-coating laminate enters the void of the composite fiber sheet having a large number of voids on the surface layer, in which the fiber sheet and the polymer elastic body are impregnated and integrated. A laminating step of laminating the coating film on the surface of the composite fiber sheet;
And a cooling step of cooling and solidifying the crosslinkable hot-melt urethane resin.
11. The polyurethane according to claim 10, wherein the release paper has a polymer elastic layer formed in advance on the surface thereof, and a molten crosslinkable hot-melt urethane resin is applied to the surface of the polymer elastic layer. A manufacturing method of a layered product.
In the manufacturing method of the polyurethane laminated body of Claim 1,
In the melt mixing step, a hot-melt urethane prepolymer (A) having a melt viscosity at 100 ° C. of 10,000 mPa · sec or less, a chain extender (B), and a temperature-sensitive urethane exhibiting a predetermined exothermic peak temperature by differential scanning calorimetry. A melt-mixing step of forming the crosslinkable hot-melt urethane resin by heating and melt-mixing the catalyst (C) at a temperature in the range of 10-30 ° C. lower than the exothermic peak temperature,
The resin layer forming step is a coating film forming step of forming a release paper-coating laminate by applying the crosslinkable hot-melt urethane resin in a molten state to the surface of the release paper;
The method for producing a polyurethane laminate, wherein the heat treatment step is a heat treatment step of partially crosslinking the coating film by heat-treating the release paper-coating laminate at a temperature equal to or higher than the exothermic peak temperature.
In the manufacturing method of the polyurethane layered product according to claim 12,
After the heat treatment step,
The pressure is such that a part of the coating film of the release paper-coating laminate enters the void of the composite fiber sheet having a large number of voids on the surface layer, in which the fiber sheet and the polymer elastic body are impregnated and integrated. A laminating step of laminating the coating film on the surface of the composite fiber sheet;
And a cooling step of cooling and solidifying the crosslinkable hot-melt urethane resin.
The method for producing a polyurethane laminate according to any one of claims 10 to 13, wherein the temperature-sensitive urethanization catalyst is an organic acid salt of 1,8-diazabicyclo (5,4,0) -undecene-7.
In the melt mixing step, thermally expandable microcapsules are further mixed into the crosslinkable hot melt urethane resin,
The method for producing a polyurethane laminate according to any one of claims 10 to 14, wherein the thermally expandable microcapsule expands at an expansion ratio of 2 times or more in the melt mixing step and / or the heat treatment step.
In the melt mixing step, the hot melt urethane prepolymer (A) in a heated and melted state atomized by pressure injection from the first nozzle of the mixing head, and pressure injection from the second nozzle. The mixture is heated at a temperature in the range of 10-30 ° C. lower than the exothermic peak temperature by colliding with the mixture containing the chain extender (B) and the temperature-sensitive urethanization catalyst (C) atomized by The method for producing a polyurethane laminate according to any one of claims 10 to 15, which is a step of melt-mixing.
A polyurethane laminate obtained by the production method according to any one of claims 10 to 16,
A laminate of a fiber sheet and a polymer elastic body impregnated and integrated, a composite fiber sheet having a large number of voids in the surface layer, and a polyurethane resin layer laminated on the composite fiber sheet,
A polyurethane having a mixed layer having a thickness of 10 μm or more in which a part of the polyurethane resin layer and the surface layer of the composite fiber sheet are mixed in an incompatible state when a part of the polyurethane resin layer enters the gap. Laminated body.
The polyurethane laminate according to claim 17, wherein the mixed layer has a thickness of 30 μm or more.
The polyurethane laminate according to claim 17 or 18, wherein a thickness ratio of the mixed layer in the total thickness of the polyurethane resin layer is 10 to 80%.
The polyurethane laminate according to any one of claims 17 to 19, wherein the polyurethane resin layer is a layer formed of a crosslinkable hot-melt urethane resin.
The polyurethane laminate according to any one of claims 17 to 20, wherein at least one of the polyurethane resin layer and the polymer elastic body is porous.
The polyurethane laminate according to any one of claims 17 to 21, wherein the composite fiber sheet has a porosity of 30 to 85% by volume.