JP7355671B2 - Multilayer sheet and its manufacturing method - Google Patents

Description

The present invention relates to a polyurethane multilayer sheet, and more particularly to a multilayer sheet used for manufacturing shoes by laminating textiles and hot press molding.

Hot-melt sheets made of polyurethane have traditionally been used for a variety of purposes. In recent years, shoe production has begun to use heat press molding to directly shape textiles into shoe shapes, without using the traditional sewing process using sewing machines. The sheet is increasingly used by being attached to textiles (for example, Patent Document 1).

On the other hand, for the purpose of decorating shoes, one side of a polyurethane sheet is colored or patterned, and the other side is provided with a polyurethane layer (melt-adhesive base material layer) for melt-bonding textiles using heat. It is also known to attach a design to shoes by attaching this surface to textiles and hot-press molding them into the shape of shoes. In this method, a polyurethane sheet with a low flow initiation temperature is used for adhesion to textiles.

A polyurethane sheet needs to have a certain amount of basis weight in order to provide sufficient strength to the adhesive surface of the textile when it is formed into a shoe shape by hot press molding to infiltrate the polyurethane into the textile. . For this reason, as a polyurethane sheet for hot press molding, a thermoplastic polyurethane sheet with a high basis weight is separately prepared using a calendar method, etc., and this is used by bonding it to a polyurethane layer for decorative purposes. .

Special Publication No. 2012-504067

A polyurethane adhesive using a two-component crosslinking agent is usually used to bond a polyurethane sheet for hot press molding and a polyurethane layer for decorative purposes. However, there is a problem in that the crosslinking agent in the adhesive causes the physical properties of polyurethane to change over time, resulting in a drop in adhesive performance when it is later bonded to textiles and hot press-molded into the shape of a shoe.

The present invention is a multilayer urethane sheet including a melt-adhesive base layer, which is used to manufacture shoes by heat press molding by laminating it onto textiles, and which improves the adhesive performance of the melt-adhesive base layer over time. An object of the present invention is to provide a multilayer sheet with less deterioration.

That is, the present invention comprises a sheet-like melt-adhesive base material layer obtained by thermally melting and shaping thermoplastic polyurethane, and a polyurethane skin layer provided on one surface of the base material layer via an adhesive layer. The thermoplastic polyurethane of the melt-adhesive base layer has a flow start temperature of 100 to 120°C, the polyurethane of the skin layer has a flow start temperature of 150°C or higher, and the adhesive layer has a flow start temperature of 150°C or higher. This is a multilayer sheet made of liquid polyurethane, characterized in that the one-component polyurethane has a flow initiation temperature of 120 to 140°C.

According to the present invention, there is provided a multilayer sheet of urethane comprising a melt-adhesive base material layer, which is used for manufacturing shoes by heat press molding by laminating it to textiles, wherein the adhesiveness of the melt-adhesive base material layer increases over time. A multilayer sheet with less deterioration in performance can be provided.

The present invention will be explained in detail below.

[Melt-adhesive base material layer]
As the thermoplastic polyurethane for the melt-adhesive base material layer, one having a flow initiation temperature of 100 to 120° C. is used. When the flow start temperature is within this range, good workability can be obtained in bonding with textiles. If the flow start temperature is less than 100°C, the strength of the shoes will decrease when the shoes obtained by hot press molding using the multilayer sheet of the present invention are placed in a high temperature place such as the trunk of a car for a long time. This will cause a decline in the temperature. On the other hand, if the flow start temperature exceeds 120°C, processing becomes difficult.

When the laminated sheet of the present invention is thermally bonded to a textile, the thermoplastic polyurethane constituting the melt-adhesive base material melts and penetrates into the textile due to heat and pressure, allowing the textile to be hot-press molded. This has the effect of allowing it to be molded into the shape of a shoe. In order to achieve high adhesive strength that will not peel off even when the molded shoe is for sports shoes at a reasonable cost, the thickness of the melt-adhesive base material is preferably 100 to 200 μm. From the viewpoint of adhesive strength, a thickness of 100 μm or more is preferable, whereas a thickness exceeding 200 μm is not preferable because the adhesive strength reaches a ceiling and only the cost increases.

The thermoplastic polyurethane of the melt-adhesive base layer is preferably a thermoplastic polyurethane whose main diol component is polyester polyol. "Main" means, for example, 70% by weight or more, preferably 80% by weight of the total diol component. This thermoplastic polyurethane is particularly preferably a thermoplastic polyurethane whose polyol component is a polyester polyol. By using this thermoplastic polyurethane, flexibility suitable for shoe molding can be obtained. Hot-melt polyurethane, which is generally used for adhesion to textiles, is available in many types of polyester polyols, and these can be used in the present invention.

In the present invention, a sheet-like melt-adhesive base material layer obtained by heat-melting and shaping thermoplastic polyurethane is used. Since the melt-adhesive base layer is bonded to the textile by hot press processing, if it is manufactured by coating with a polyurethane solution, a sufficient amount of thermoplastic polyurethane cannot penetrate into the textile.

The melt-adhesive base material layer is preferably manufactured by a T-die method, an inflation method, or a calendar method, and particularly preferably by a calendar method. By using a melt-adhesive base layer produced by these methods, particularly the calendering method, a sufficient amount of thermoplastic polyurethane can be infiltrated into the textile when it is laminated to the textile.

To be more specific, the T-die method uses an extruder equipped with a slit-shaped mold called a T-die at its tip. Hot-molten thermoplastic polyurethane is extruded into a sheet from a T-die, cooled by a cooling roller, and wound up.

In the inflation method, an extruder equipped with an annular mold is used. Heat-molten thermoplastic polyurethane is continuously extruded into a tube shape from a tubular mold, and air is blown into the tube-shaped excipient through an air hole installed in the center of the mold, creating a balloon shape. It is expanded, cooled and rolled up while being pulled by rollers. Just before being rolled up, it is rolled up into a flat sheet, usually by cutting open one end.

In the calender method, a calender roll is used. Hot-molten thermoplastic polyurethane is sandwiched between a plurality of calendar rolls and rolled into a sheet, which is further cooled on the surface of a cooling roller and wound up. The calendar method may be combined with the T-die method or the inflation method.

[Adhesive layer]
The adhesive layer serves to adhere the melt-adhesive base layer and the skin layer.
The adhesive layer is made of one-component polyurethane. In the present invention, a two-component type polyurethane using a crosslinking agent is not used as the polyurethane of the adhesive layer, but a one-component type polyurethane is always used. If a two-component type polyurethane is used, the crosslinking agent used in the two-component type will penetrate into the melt-adhesive base material layer due to the influence of the solvent, causing the textile and the multilayer sheet of the present invention to be bonded by heat. The physical properties of the polyurethane in the melt-adhesive base layer change over time, making it impossible to maintain adhesive properties. In the present invention, since a one-component type polyurethane is used for the adhesive layer, when the molten adhesive base material layer and the skin layer to be bonded are bonded together, heat is applied after applying the polyurethane for the adhesive layer. The melt-adhesive base material layer and the skin layer can be bonded together while applying the adhesive.

The flow initiation temperature of this one-component polyurethane is 120 to 140°C. The fluidization start temperature is preferably lower than the fluidization start temperature of the polyurethane in the skin layer and higher than the fluidization start temperature of the polyurethane in the melt-adhesive base layer. If the flow start temperature is less than 120°C, adhesion becomes easier, but when the multilayer sheet of the present invention is laminated with textiles and used for forming shoes, the thermoplastic polyurethane of the melt adhesive base layer is The adhesive layer melts first before melting, and it begins to melt from the edges of the parts cut to form the shoe shape, spoiling the appearance. Furthermore, if shoes obtained by hot press molding using the multilayer sheet of the present invention are left in a high-temperature place such as the trunk of a car for a long time, the quality may deteriorate. On the other hand, if the flow start temperature exceeds 140° C., it is difficult to melt and high adhesive strength cannot be obtained.

The thickness of the adhesive layer is preferably 50 to 150 μm. By having a thickness within this range, the melt-adhesive base material layer and the skin layer are firmly adhered, and the polyurethane of the adhesive layer does not flow out from the cross section when thermoformed into the shape of the shoe, resulting in a good appearance. Shoes can be molded.

As the one-component polyurethane of the adhesive layer, a conventionally known thermoplastic polyurethane obtained by a polymerization reaction of an organic diisocyanate, a polymeric diol, and a chain extender can be used.

The one-component polyurethane for the adhesive layer is preferably a polyurethane containing polyester polyol and polyether polyol as diol components. This is a mixed type polyurethane of polyester polyol and polyether polyol. By using polyether polyol in combination, the surface tackiness increases during adhesion, making it easier to adhere to the melt-adhesive base layer.

[Epidermal layer]
The skin layer serves as a surface protector and protects the final product of the shoe from deteriorating its appearance due to abrasion.

As the polyurethane for the skin layer, a conventionally known thermoplastic polyurethane obtained by a polymerization reaction of an organic diisocyanate, a polymeric diol, and a chain extender can be used.

The polyurethane of the skin layer has a flow initiation temperature of 150°C or higher, preferably 170 to 190°C. By having a flow start temperature within this range, when the multilayer sheet of the present invention and textile are thermally bonded together by heat press in the shoe manufacturing process, the skin layer is maintained as a protective layer without being thermally melted. .

From the viewpoint of excellent mechanical strength and production cost, the polyurethane of the skin layer should be a polyurethane whose main diol component is polyester polyol or polyether polyol, or a polyurethane whose main diol component is polyester polyol and polyether polyol. is preferred. "Main" means, for example, 70% by weight or more, preferably 80% by weight of the total diol component.

It is preferable to use water-based polyurethane for the polyurethane skin layer because the skin layer can be efficiently formed by applying a polyurethane solution to the release paper and drying it. That is, the skin layer is preferably a sheet-like skin layer formed from water-based polyurethane.

The thickness of the epidermal layer is preferably 20 to 80 μm. By having a thickness within this range, it is possible to obtain flexibility that follows the mold during hot press molding of the shoe, and a protective function for the surface of the shoe.

The polyurethane of the skin layer preferably has a 100% modulus of 2 to 20 MPa. If the modulus is less than 2 MPa, the surface abrasion strength tends to be insufficient, which is not preferable. On the other hand, if it exceeds 20 MPa, it tends to become hard and inflexible, making it unsuitable and undesirable for use in shoes.

[Microcapsules, etc.]
The skin layer or adhesive layer contains hollow microcapsules with an average particle size of 10 to 100 μm, preferably 1% by weight or more, more preferably 3 to 5% by weight based on the weight of the skin layer or adhesive layer containing the hollow microcapsules. %contains. By containing hollow microcapsules in any layer, the weight can be reduced. When the adhesive layer contains hollow microcapsules, the interlayer adhesive strength between the skin layer and the melt-adhesive base layer can be improved.

As hollow microcapsules, for example, those whose outer shells are made of thermoplastic resin such as acrylonitrile or vinylidene chloride resin can be used. There are two types of hollow microcapsules: a thermal expansion type that foams when exposed to heat, and a type that does not change in volume due to heat. Whichever hollow microcapsules are used, weight reduction and improvement in interlayer adhesion can be expected, but it is preferable to use thermal expansion type ones because high interlayer adhesion can be obtained. When a thermal expansion type is used, the hollow microcapsules are destroyed after thermal expansion, and the polyurethane of the adhesive layer enters the cavity created at that time, improving adhesive strength.

The skin layer or adhesive layer is preferably colored with a pigment or metallized powder. When colored with a pigment, shoes made using the multilayer sheet of the present invention can be colored. When colored with metallized powder, shoes made using the multilayer sheet of the present invention can be colored with metallic luster.

[Manufacturing method of multilayer sheet]
The multilayer sheet of the present invention can be manufactured, for example, by the following method.
(1) A step of applying a solution of polyurethane with a flow start temperature of 150°C or higher onto a release paper to obtain a sheet-like skin precursor layer, and (2) A sheet made of thermoplastic polyurethane with a flow start temperature of 100 to 120°C. The step of adhering a melt-adhesive base material layer of A method for producing a multilayer sheet, comprising an organic solvent having a boiling point higher than the flow initiation temperature of a type polyurethane.

That is, the present invention includes the above manufacturing method.

The production of the multilayer sheet of the present invention includes the steps (1) and (2) above, and is preferably carried out as a continuous sheet production that can be continuously produced, for example, preferably using a transfer lamination method. Note that, for convenience, the layer that is formed on the release paper and later becomes the skin layer is referred to as a skin precursor layer.

In this transfer lamination method, first, a polyurethane solution, which is a raw material for the skin precursor layer, is applied onto a release paper flowing on the production line, and the solution is placed in a drying chamber and dried to obtain the skin precursor layer. Next, an adhesive layer is provided and laminated by bonding to a melt-adhesive base material layer, or laminated by bonding to a melt-adhesive base material layer on which an adhesive layer has been provided in advance. The laminated sheet obtained by this lamination includes a release paper, a skin precursor layer, an adhesive layer, and a melt-adhesive base material layer laminated in this order. The release paper may be left unremoved until after it is laminated with the textile used as the material for the shoe, or it may be peeled off before lamination. By peeling off the release paper, the epidermis precursor layer appears on the surface and becomes the epidermis layer. The resulting laminated sheet has a skin layer, an adhesive layer, and a melt-adhesive base material layer laminated in this order.

A specific example of the method for manufacturing the multilayer sheet of the present invention is as follows. First, a polyurethane solution having a flow start temperature of 150° C. or higher for the raw material for the skin layer is applied once or twice onto the release paper. This is dried through a drying chamber to obtain a laminate of release paper and skin precursor layer. Then, a one-component polyurethane solution having a flow start temperature of 120° C. to 140° C. of the raw material for the adhesive layer is applied onto the skin precursor layer of this laminate and dried through a drying chamber. Immediately after that, a thermoplastic polyurethane sheet with a flow start temperature of 100°C to 120°C for the melt-adhesive base material layer is superimposed on this, and in this state, two thermo rolls with at least one heated to 100°C or higher are used. Glue them together by applying heat through the gaps.

[Shoe manufacturing]
The multilayer sheet of the present invention is layered with a textile material for shoes, and then processed into the shape of a shoe by hot press molding. At this time, the thermoplastic polyurethane of the melt-adhesive base layer is fluidized and permeated into the textile, serving as an adhesive that maintains the shape of the shoe.

Note that a press machine equipped with upper and lower heating plates is used to bond the multilayer sheet and textile of the present invention. In this lamination, the textile and the multilayer sheet of the present invention are stacked together and heat and pressure are applied using a press. At this time, the thermoplastic polyurethane of the melt-adhesive base layer is fluidized, soaks into the textile, and adheres to it. According to the present invention, high productivity and high yield can be obtained in bonding with this textile. The multilayer sheet of the present invention may be cut into a desired shape according to the shape of the shoe before being laminated with the textile, or may be cut into a desired shape according to the shape of the shoe after being laminated with the textile. Good too.

The present invention will be explained below using examples. Physical properties were measured by the following method. "Parts" means "parts by weight." Note that methyl ethyl ketone is sometimes abbreviated as "MEK" and dimethyl formamide is sometimes abbreviated as "DMF".
(1) Peel strength According to the JIS K6301 method, 100 mm was peeled at a tensile speed of 50 mm/min, and the average value of the minimum value of 5 points every 20 mm was expressed in N/cm and was defined as the peel strength.
(2) Flow Start Temperature When MFR was measured using a Koka type flow tester described in JIS K7210, the temperature at which the flow rate value was detected for the first time was defined as the flow start temperature.

[Example 1]
A 152 cm wide release paper ("UM32" manufactured by Dai Nippon Printing Co., Ltd.) was flowed on the transfer bonding line at a line speed of 7 m/min, and a polyurethane coating liquid was applied to the release paper at a basis weight of 150 g/m ² at 100°C. The process of drying in a chamber was repeated twice to form a skin layer (polyurethane layer) made of an elastic polymer having a thickness of 0.05 mm.

The polyurethane coating liquid is polyurethane ("PERMUTEX RU-43-006" manufactured by Stahl). This is an aqueous dispersion with a polyurethane concentration of 35% by weight, and the polyurethane flow initiation temperature after drying is 175 ° C. (100% modulus is 5.0 MPa), 1 part of thermal expansion type microcapsules ("Matsumoto Microsphere F-36" manufactured by Matsumoto Yushi Co., Ltd.), 1 part of microcapsules without thermal expansion ("Matsumoto Microspheres F-36" manufactured by Matsumoto Yushi Co., Ltd.) ``Matsumoto Microsphere F-80ED'' and 2 parts of a crosslinking agent (XR-5588 manufactured by Stahl) were prepared by adjusting and mixing them with a thickener, a leveling agent, and an antifoaming agent.At this time, the thickener, The leveling agent and antifoaming agent were 5 parts, 0.5 parts, and 0.3 parts, respectively.

As an adhesive layer, a one-component solvent-based polyurethane ("Crisbon OA320" manufactured by DIC Corporation) with a flow start temperature of 125 ° C. is applied as an adhesive layer. 100 parts of polyurethane (100% modulus after drying is ^3.0 MPa. Immediately after heating and drying through a drying chamber, immediately after the temperature does not drop, a polyurethane sheet (polyester polyol, 300% modulus (10 MPa) and were pressed together by passing through two rolls with a gap of 0.1 mm. Thereafter, it was wound up and allowed to stand for one day in an atmosphere at room temperature to cool down, and then the release paper was peeled off to obtain Sheet-1.

After cutting this sheet-1 into the shape of shoe parts, it was layered on textiles and bonded together using a heat press machine at 120°C for 30 seconds. After cooling, the peel strength was measured, and the result was 5.4 kg/cm. This was a high number. Three months after the sheet was created, it was laminated to textiles in the same manner to check for changes over time, and its peel strength was measured, and the peel strength was as high as 5.2 kg/cm.

[Example 2]
A skin layer (polyurethane layer) made of an elastic polymer having a thickness of 0.05 mm was formed on the release paper in the same manner as in Example 1 except that microcapsules were not blended into the polyurethane coating liquid, and this was used to conduct the Examples. Sheet-1 was obtained in the same manner as in Example 1.

After cutting this sheet-1 into the shape of shoe parts, it was layered on textiles and bonded together using a heat press machine at 120°C for 30 seconds. After cooling, the peel strength was measured and found to be 5.7 kg/cm. This was a high number.

[Example 3]
A skin layer (polyurethane layer) made of a polymeric elastomer with a thickness of 0.05 mm was formed on the release paper in the same manner as in Example 2, except that 10 parts of a water-based white pigment was further added and stirred to the polyurethane coating solution, Using this, sheet-1 was obtained in the same manner as in Example 2.

After cutting this sheet-1 into the shape of shoe parts, it was layered on textiles and bonded together using a heat press machine at 120°C for 30 seconds. After cooling, the peel strength was measured and found to be 5.7 kg/cm. This was a high number.

[Comparative example 1]
In the same manner as in Example 1, a skin layer (polyurethane layer) made of an elastic polymer having a thickness of 0.05 mm was formed on the release paper.

A two-component polyurethane adhesive ("Crisbon TA-365FT" manufactured by DIC Corporation) is used as an adhesive layer on the surface. This is a solution with a polyurethane concentration of 65% by weight (the solvent is a mixture of DMF and MEK at a ratio of 1:2 (weight ratio)). A solution containing 100 parts of polyurethane (solvent), and the 100% modulus of polyurethane after drying is 2.0 MPa, 20 parts of DMF, 20 parts of MEK, and 15 parts of the crosslinking agent "Coronate HL" was applied at a basis weight of 150 g/ ^m2 . After drying by heating through a drying chamber set at 100°C, a polyurethane sheet (made of polyester polyol, 300% (modulus is 10 MPa) and passed through two rolls with a gap of 0.1 mm to press them together. Thereafter, it was wound up and left in an atmosphere of 80° C. for 2 days to complete the crosslinking reaction of the two-component polyurethane, and then cooled, and the release paper was peeled off to obtain Sheet-2.

This sheet-2 was cut into shoe parts, layered on textiles, and bonded together using a heat press at 120°C. When the peel strength was measured, it was as high as 5.6 kg/cm. Further, in order to confirm the change over time, this sheet-2 was laminated to a textile and the peel strength was measured in the same manner 3 months after its creation, and the peel strength was as low as 2.8 kg/cm.

[Comparative example 2]
In the same manner as in Example 1, a skin layer (polyurethane layer) made of an elastic polymer having a thickness of 0.05 mm was formed on the release paper.

As an adhesive layer on the surface, 100 parts of one-component polyurethane ("NB140" manufactured by DIC Corporation. This is an aqueous dispersion with a polyurethane concentration of 40% by weight, and the polyurethane flow start temperature after drying is 160 ° C.), A solution containing 50 parts of DMF and 50 parts of MEK was applied at 150 g/m ² and dried through a drying chamber set at 100°C. Immediately after the temperature did not drop, the thickness was prepared by the T-die method as a melt-adhesive base layer. The sheet was laminated with a polyurethane sheet (made of polyester polyol and has a 300% modulus of 10 MPa) having a diameter of 150 μm and a flow start temperature of 120° C., and was pressed together by passing through two rolls with a gap of 0.1 mm. Thereafter, after cooling by leaving it for one day in an atmosphere at room temperature, the release paper was peeled off to obtain Sheet-3.

This sheet-3 was cut into shoe parts, layered on textiles, and bonded together at 120°C using a heat press machine. When the peel strength was measured, it was as low as 1.2 kg/cm. The peeling point was between the adhesive layer and the polyurethane sheet (melt adhesive base layer) produced by the T-die method.

[Comparative example 3]
In the same manner as in Example 1, a skin layer (polyurethane layer) made of an elastic polymer having a thickness of 0.05 mm was formed on the release paper.

As an adhesive layer on the surface, a one-component solvent-type polyurethane ("Crisbon OA320" manufactured by DIC Corporation) with a flow start temperature of 125 ° C. The 100% modulus of polyurethane after drying is 3.0 MPa), 20 parts of DMF, and 20 parts of MEK were applied at 150 g/m ² and dried at 100°C. After heating and drying through a chamber, a polyurethane sheet (made of polyester polyol) with a thickness of 150 μm and a flow start temperature of 150° C. (made of polyester polyol) prepared by the T-die method was layered as a melt-adhesive base layer to form a 0.1 mm adhesive base layer. The material was passed through two rolls in the gap and crimped. Thereafter, after cooling by leaving it for one day in an atmosphere at room temperature, the release paper was peeled off to obtain Sheet-4.

After cutting this sheet-4 into shoe parts, it was layered on textiles and bonded together at 120°C using a heat press machine. As the bottom layer (melt-adhesive base material layer) did not melt, it was not possible to adhere it to the textiles. could not. Furthermore, when the temperature setting of the heat press machine was increased to perform bonding at 140° C. and 150° C., the polyurethane of the adhesive layer oozed out around the cut parts in both cases, and the appearance was not desirable.

The multilayer sheet of the present invention is used in the manufacture of shoes by hot press molding, particularly in the manufacture of upper parts of shoes. The multilayer sheet of the present invention is bonded to a textile material for shoes by heat press to obtain a multilayer sheet for shoe molding, which is cut into a desired shape and molded into the shape of a shoe by heat press molding.

Claims (12)

A multilayer sheet consisting of a sheet-like melt-adhesive base layer obtained by thermally melting and shaping thermoplastic polyurethane, and a polyurethane skin layer provided on one side of the base layer through an adhesive layer. , the thermoplastic polyurethane of the melt-adhesive base layer has a flow start temperature of 100 to 120°C, the polyurethane of the skin layer has a flow start temperature of 150°C or higher, and the adhesive layer is made of one-component polyurethane; A multilayer sheet, characterized in that the one-component polyurethane has a flow initiation temperature of 120 to 140°C. The multilayer sheet according to claim 1, wherein the type 1 polyurethane of the adhesive layer is a polyurethane containing polyester polyol and polyether polyol as diol components. The multilayer sheet according to claim 1 or 2, wherein the thermoplastic polyurethane of the melt-adhesive base layer is a thermoplastic polyurethane containing polyester polyol as a main diol component. The multilayer sheet according to any one of claims 1 to 3, wherein the melt-adhesive base layer is obtained by shaping by a T-die method, an inflation method, or a calendar method. 5. The multilayer sheet according to claim 1, wherein the polyurethane skin layer is a sheet-like skin layer formed from water-based polyurethane. The multilayer sheet according to any one of claims 1 to 5, wherein the melt adhesive base layer has a thickness of 100 to 200 μm, the skin layer has a thickness of 20 to 80 μm, and the adhesive layer has a thickness of 50 to 150 μm. . The multilayer sheet according to any one of claims 1 to 6, wherein the skin layer or the adhesive layer is colored with a pigment or metallized powder. The multilayer sheet according to claim 6, wherein the skin layer or adhesive layer contains hollow microcapsules with an average particle size of 10 to 100 μm at 1% by weight or more based on the weight of the skin layer or adhesive layer containing the microcapsules. . The multilayer according to any one of claims 1 to 8, wherein the polyurethane of the skin layer is a polyurethane whose main diol component is a polyester polyol or a polyether polyol, or a polyurethane whose main diol components are a polyester polyol and a polyether polyol. sheet. The multilayer sheet according to any one of claims 1 to 9, which is used for manufacturing shoes by hot press molding. (1) A step of applying a solution of polyurethane with a flow start temperature of 150°C or higher onto a release paper to obtain a sheet-like skin precursor layer, and (2) A sheet made of thermoplastic polyurethane with a flow start temperature of 100 to 120°C. The step of adhering a melt-adhesive base material layer of A method for producing a multilayer sheet, comprising an organic solvent having a boiling point higher than the flow initiation temperature of a type polyurethane. 12. The method for producing a multilayer sheet according to claim 11, wherein the sheet-shaped melt-adhesive base layer is produced by a calendar method.