JP2022089715A - Pearl-feeling leather-like sheet - Google Patents

Abstract

To provide a pearl-feeling leather-like sheet hard to discolor at a fold line part when the fold line part receives friction in the pearl-feeling leather-like sheet having high pearl feeling.MEANS: A pearl-feeling leather-like sheet is a leather-like sheet including: a fiber substrate; and a resin layer laminated on the fiber substrate, where the resin layer includes an intermediate layer including a first polyurethane, a skin layer laminated on the intermediate layer, and a surface coat layer that the skin layer is coated with, the skin layer is a layer of a thickness of 10-30 μm including a second polyurethane, and 30-45 pts.mass of a pearl pigment to 100 pts.mass of the second polyurethane, and the surface coat layer is a layer of a thickness of 2-5 μm including a third polyurethane having a 10% modulus of 5 MPa or more, and has a surface of Flop Index of 10 or more.SELECTED DRAWING: Figure 1

Description

The present invention relates to a leather-like sheet having a pearl-like grain layer that is excellent in both high pearliness and abrasion resistance.

Leather-like sheets such as artificial leather having a grain-like resin layer are used as materials for bags, clothing, shoes, and the like. The grain-like resin layer of the leather-like sheet is usually colored and used. As a variation of coloring, a pearl-like leather-like sheet having a grain-like resin layer which gives a metallic feeling by using a pearl pigment is known.

For example, Patent Document 1 below describes a substrate layer (a) composed of a fiber aggregate or a fiber aggregate filled with a polymer mainly composed of a polyurethane elastomer and a porous coating layer of the polymer mainly composed of a polyurethane elastomer. , A colored layer (b) composed of a polymer mainly composed of a polyurethane elastomer having a thickness of 0.1 to 10 μm and containing 3% by weight to 500% by weight of a pigment or dye with respect to the polymer. On the other hand, a pearl layer (c) composed of a polymer mainly composed of a polyurethane elastomer having a thickness of 0.2 to 10 μm and containing 10% by weight to 500% by weight of a pearl pigment and 0% by weight to 300% by weight of a dye. Also disclosed is a porous sheet having a good pearly feel, which is composed of a clear layer made of a polymer mainly composed of a polyurethane elastomer having a thickness of 0.5 to 100 μm.

Further, in Patent Document 2 below, a base coat layer, a first color coat layer, a second color coat layer and a top coat layer, all of which are mainly composed of synthetic resin, are sequentially laminated on the surface of a natural leather base material. The first color coat layer contains 8 to 16% by weight of chromatic pigment, and the second color coat layer contains 3 to 8% by weight of bright pigment and 1 to 5 by weight of chromatic pigment. Disclosed is a brilliant natural leather comprising weight% and a cross-linking agent and having a topcoat layer containing the cross-linking agent.

Further, Patent Document 3 below is a silver-coated leather-like sheet containing a fiber base material and a polyurethane surface film laminated on the surface layer directly on the fiber base material or via another polyurethane layer, and is a polyurethane surface film. Contains at least one diketopyrrolopyrrole red pigment or α-type phthalocyanine blue pigment, further comprises a clear polyurethane film layer that coats the polyurethane surface coating, and the clear polyurethane film layer is silvered with silicone-modified polyurethane. Disclose a leather-like sheet.

Japanese Unexamined Patent Publication No. 51-002785 Japanese Unexamined Patent Publication No. 2013-023646 WO2020 / 195850

In the pearl-like leather-like sheet, a higher pearly feeling is required in order to further improve the design. In order to improve the pearly feeling, it is necessary to add more pearl pigment. However, when a large amount of pearl pigment is blended, there is a problem that the wear resistance of the surface is lowered. In particular, there is a problem that the wear resistance of the creases is lowered and the creases are discolored when the creases are rubbed.

It is an object of the present invention to provide a pearl-like leather-like sheet having a high pearly feeling, in which the fold portion is less likely to be discolored when the fold portion is rubbed.

One aspect of the present invention is a leather-like sheet including a fiber base material and a resin layer laminated on the fiber base material, and the resin layer is an intermediate layer containing a first polyurethane and a skin laminated on the intermediate layer. The thickness includes a layer and a surface coat layer adhered to the skin layer, and the skin layer contains a second polyurethane and 30 to 45 parts by mass of a pearl pigment with respect to 100 parts by mass of the second polyurethane. It is a layer having a thickness of 10 to 30 μm, and the surface coat layer is a layer having a thickness of 2 to 5 μm containing a third polyurethane having a 10% modulus of 5 MPa or more, and has a Flop Index of 10 or more. It is a sheet. Such a pearl-like leather-like sheet can maintain a surface having a high pearly feeling, in which the folds are less likely to be discolored when the folds are rubbed.

Here, Flop Index is a quantified value of the flip-flop phenomenon, which is a phenomenon in which the brightness changes with the change of the viewing angle. Flop Index uses the brightness (L ^* _{15 °} , L ^* _{45 °} and L ^* _{110 °} ) at 15 degrees, 45 degrees and 110 degrees to formula (I):

Is required from.

Further, it is preferable that the resin layer further includes a cushion layer mainly made of porous polyurethane adhered to the fiber base material, from the viewpoint of maintaining high surface characteristics such as wear resistance and bending resistance.

Further, it is preferable that the intermediate layer contains 10 to 50 parts by mass of a coloring pigment with respect to 100 parts by mass of the first polyurethane because it is easy to form a colored surface having a high pearly feeling.

For the pearl-like leather-like sheet, the edge portion folded in half is pressed against the pressing plate to which the plain weave cotton cloth 79A is attached by using a castom type textile abrasion tester with a load of 2 lb, and the sample table is reciprocated 1000 times. When the creases are rubbed when the difference in brightness ΔL ^* between L ^* a ^* b ^* and the brightness L ^* in the color system before friction is 3 or less when friction is performed by exercising. It is preferable because a pearl-like leather-like sheet whose folds are not easily discolored can be obtained.

According to the present invention, in a pearl-like leather-like sheet having a high pearly feeling, it is possible to obtain a pearl-like leather-like sheet in which the creases are less likely to be discolored when the folds are rubbed.

FIG. 1 is a schematic cross-sectional view of the pearl-like leather-like sheet 10 of the embodiment.

Hereinafter, the pearl-like leather-like sheet according to the present invention will be described in detail along with the manufacturing method of the embodiment.

FIG. 1 is a schematic cross-sectional view illustrating the layer structure of the pearl-like leather-like sheet 10, which is an example of the pearl-like leather-like sheet of the present embodiment. The pearl-like leather-like sheet 10 is a leather-like sheet provided with a fiber base material 1 and a resin layer 2 laminated on the fiber base material 1, and the resin layer 2 is adhered to and laminated on the fiber base material 1. The cushion layer 3 mainly composed of porous polyurethane, the intermediate layer 4 mainly composed of the first polyurethane, the skin layer 5 laminated on the intermediate layer 4, and the surface coat layer 6 adhered to the skin layer 5 The polyurethane adhesive layer 7 for adhering the cushion layer 3 and the intermediate layer 4 is further provided. The skin layer 5 is a layer having a thickness of 10 to 30 μm and containing a second polyurethane and 30 to 45 parts by mass of the pearl pigment 8 with respect to 100 parts by mass of the second polyurethane, and is a surface coat layer. Reference numeral 6 is a layer having a thickness of 2 to 5 μm, which comprises a third polyurethane having a 10% modulus of 5 MPa or more. Further, the skin layer 5 may contain a coloring pigment 9 other than the pearl pigment 8 if necessary. And, such a pearl-like leather-like sheet 10 has a surface with a high pearly feeling showing 10 or more Flop Indexes. The pearl-like leather-like sheet is not limited to such a layer structure, and is a resin layer including a fiber base material, an intermediate layer as described above, a skin layer, and a surface coat layer laminated on the fiber base material. The layer structure is not particularly limited as long as it is a leather-like sheet provided with.

As the fiber base material, it is used for conventionally known artificial leather base materials used for manufacturing artificial leather such as non-woven fabrics, textiles, knitted fabrics, or base materials impregnated with polyurethane impregnated therein, and synthetic leather. The synthetic leather base material used is not particularly limited. The thickness of the fiber base material is also not particularly limited, but is preferably, for example, about 0.3 to 3 mm, more preferably about 0.5 to 1.5 mm. Further, the type of fiber forming the fiber base material is not particularly limited, and is not particularly limited, for example, nylon-based fiber, polyester-based fiber, polyolefin-based fiber, polyurethane-based fiber, and the like.

Further, the fineness and morphology of the fiber are not particularly limited. For example, the fineness may be a regular fiber having a fineness of more than 1 dtex, or an ultrafine fiber having a fineness of less than 1 dtex, and further may be 0.0001 to 0.5 dtex. Further, the form of the fiber may be a solid fiber or a fiber having voids such as a hollow fiber or a lotus root-like fiber.

The first polyurethane contained in the intermediate layer, the second polyurethane contained in the epidermis layer, the third polyurethane contained in the surface coat layer, the porous polyurethane contained in the cushion layer, and the adhesive layer contained in the polyurethane adhesive layer 7. Polyurethane for use is obtained by reacting a urethane raw material containing a high molecular weight polyol, an organic polyisocyanate, and a chain extender. Each polyurethane is prepared as an organic solvent solution (eg, a solution of an organic solvent such as dimethylformamide, methylethylketone, acetone, toluene), an aqueous dispersion, an emulsion, or a melt in the production of pearl-like leather-like sheets. ..

Specific examples of the high molecular weight polyol include polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and poly (methyltetramethylene glycol); polyhexamethylene carbonate diol, poly (3-methyl-1, 5-Pentylene carbonate) diols, polypentamethylene carbonate diols, polytetramethylene carbonate diols and other polycarbonate-based polyols; polyethylene adipate diols, polybutylene adipate diols, polypropylene adipate diols, polybutylene sebacate diols, polyhexamethylene adipate diols, Poly (3-methyl-1,5-pentylene adipate) diols, poly (3-methyl-1,5-pentylene sebacate) diols, polyester-based polyols such as polycaprolactone diols, or copolymers thereof, etc. Can be mentioned. These may be used alone or in combination of two or more.

Specific examples of the organic polyisocyanate include aromatic diisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate polyurethane. Yellowing diisocyanate; examples thereof include an aliphatic diisocyanate such as hexamethylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, and 4,4′-dicyclohexylmethane diisocyanate, or non-yellowing diisocyanate such as alicyclic diisocyanate. Further, if necessary, a polyfunctional isocyanate such as a trifunctional isocyanate or a tetrafunctional isocyanate may be used in combination. These may be used alone or in combination of two or more.

Specific examples of the chain extender include diamines such as hydrazine, ethylenediamine, propylenediamine, hexamethylenediamine, nonamethylenediamine, xylylenediamine, isophoronediamine, piperazine and its derivatives, adipic acid dihydrazide, and isophthalic acid dihydrazide. Classes; triamines such as diaminetriamines; tetramines such as triethylenetetramines; ethyleneglycols, propylene glycols, 1,4-butanediols, 1,6-hexanediols, 1,4-bis (β-hydroxyethoxy) benzenes, 1 , Diamines such as 4-cyclohexanediol; Triols such as trimethylolpropane; Pentaols such as pentaerythritol; Amino alcohols such as aminoethyl alcohol and aminopropyl alcohol. These may be used alone or in combination of two or more. In addition, during the chain extension reaction, monoamines such as ethylamine, propylamine, and butylamine; carboxyl group-containing monoamine compounds such as 4-aminobutanoic acid and 6-aminohexanoic acid; and methanol, ethanol, propanol, butanol, etc. Monoamines may be used in combination.

In the pearl-like leather-like sheet 10, the resin layer 2 includes a cushion layer 3 mainly composed of porous polyurethane, an intermediate layer 4 mainly composed of the first polyurethane, and a skin layer 5 laminated on the intermediate layer 4. A polyurethane adhesive layer 7 for adhering the cushion layer 3 and the intermediate layer 4 is further provided, including the surface coat layer 6 adhered to the skin layer 5.

The cushion layer is formed, for example, by applying a wet-solidifying polyurethane solution to the surface of the fiber substrate and then immersing it in an aqueous coagulation bath to coagulate the porous polyurethane. Further, the cushion layer may be permeated into the inside of the fiber base material for the purpose of imparting morphological stability to the fiber base material. In this case, the fiber base material is impregnated with the polyurethane solution in advance, further coated with the polyurethane solution, and then immersed in an aqueous coagulation bath to coagulate the inside of the fiber base material. Also can be imparted with porous polyurethane. The thickness of the cushion layer is not particularly limited, but is preferably, for example, about 100 to 600 μm, more preferably about 200 to 400 μm. The cushion layer may be a non-porous polyurethane layer.

The intermediate layer 4 and the skin layer 5 are formed by adhering to the surface of the cushion layer 3 by, for example, a method using the following drywall method.

A polyurethane film for forming the skin layer 5 is formed on the release paper. Then, a polyurethane film for forming the intermediate layer 4 is formed on the polyurethane film of the skin layer 5. In this way, the intermediate layer 4 formed on the release paper and the skin layer 5 laminated on the intermediate layer 4 are formed. The intermediate layer 4 may be a layer composed of only a single layer, or may have a laminated structure in which a plurality of layers containing different polyurethanes are laminated.

Then, a polyurethane-based adhesive is applied to the intermediate layer 4, the solvent is completely or incompletely removed and dried to form a semi-cured adhesive layer, and the semi-cured adhesive layer is applied to the surface of the cushion layer 3. By curing the semi-cured adhesive layer, a laminated structure of the cushion layer 3, the intermediate layer 4, and the skin layer 5 is formed via the polyurethane adhesive layer 7. Then, by peeling the release paper from the surface of the skin layer 5, the pearl-like leather-like sheet including the fiber base material, the cushion layer 3 laminated on the fiber base material, the intermediate layer 4, and the skin layer 5 is provided. A substrate is obtained.

The skin layer 5 is a layer having a thickness of 10 to 30 μm and containing a second polyurethane and 30 to 45 parts by mass of a pearl pigment with respect to 100 parts by mass of the second polyurethane, and imparts a pearly feeling to the surface. It is a polyurethane layer for the purpose. When the skin layer is such a polyurethane layer, as will be described later, it is possible to obtain a pearl-like leather-like sheet having a surface exhibiting a high pearly feeling showing 10 or more Flop Indexes.

The type of the second polyurethane is not particularly limited, but is a polycarbonate-based polyurethane containing a polycarbonate-based polyol as a polymer polyol unit and a aliphatic diisocyanate as an organic polyisocyanate unit, particularly a silicone-modified polycarbonate-based polyurethane. This is preferable from the viewpoint of excellent wear resistance. Further, the modulus of the second polyurethane is not particularly limited, but for example, 100% modulus is preferably about 2 to 8 MPa.

The pearl pigment is a thin plate-like pigment that exhibits a pearly luster accompanied by an interference color due to multi-layer reflection of light. As a specific example, for example, a thin plate-shaped mica-based pearl pigment formed by coating the surface of thin plate-like particles of natural mica or synthetic mica with a metal oxide such as titanium dioxide, silicon oxide, or iron oxide (for example, manufactured by Merck Co., Ltd.). (Iriodin (registered trademark)), resin-based pearl pigments obtained by laminating two or more resin layers having different light refractive elements, pearl powder, shell inner wall powder, fish scale foil, and the like. The particle size of the pearl pigment is not particularly limited, but it is preferable that the median diameter D50 is selected from the range of 4 to 20 μm, for example.

The content of the pearl pigment in the skin layer is 30 to 45 parts by mass, preferably 35 to 40 parts by mass with respect to 100 parts by mass of the second polyurethane. By containing the pearl pigment in such a relatively high proportion in the epidermis layer, it is possible to impart a pearly feeling exhibiting 10 or more Flop Index as described above to the surface of the pearl-like leather-like sheet. When the content of the pearl pigment in the skin layer is less than 30 parts by mass with respect to 100 parts by mass of the second polyurethane, it becomes difficult to obtain a surface showing Flop Index of 10 or more, and when it exceeds 45 parts by mass. Reduces bending resistance and surface wear resistance.

The epidermis layer has a thickness of 10 to 30 μm, preferably 15 to 25 μm. If the thickness of the epidermis layer exceeds 30 μm, the colored intermediate layer is concealed and the color becomes whitish, and if it is too thin, the wear resistance is lowered and the surface showing 10 or more Flop Index is formed. It becomes difficult to obtain.

By providing such a skin layer, the pearl-like leather-like sheet of the present embodiment can realize a surface showing 10 or more Flop Indexes. Flop Index is high when the thin plate-shaped pearl pigment covers the inside of the surface of the epidermis layer to a high extent, and the pearl pigment has high smoothness without forming irregularities on the surface of the epidermis layer. In order to obtain such a surface, the thickness of the epidermis layer described above and the blending ratio of the pearl pigment are adjusted.

The content of the pearl pigment in the epidermis layer per unit area is 3 to 10 g / m ² , and further, 5 to 8 g / m ² makes it easy to obtain a surface showing Flop Index of 10 or more. preferable.

The epidermis layer may contain other coloring pigments other than the pearl pigment as long as the effects of the present invention are not impaired. The types of other coloring pigments are not particularly limited, but organic pigments that do not impair the brightness of the pearl pigments are preferable. Specific examples thereof include diketopyrrolopyrrole pigments such as diketopyrrolopyrrole red pigments, anthracinone pigments, perylene pigments, and phthalocyanine pigments such as α-type phthalocyanine blue pigments. When the skin layer contains a coloring pigment, the total content of the coloring pigment and the pearl pigment in the skin layer may be 50 parts by mass or less, and further 45 parts by mass or less with respect to 100 parts by mass of the second polyurethane. , It is preferable because it does not easily reduce the wear resistance.

Further, the intermediate layer 4 is a layer containing the first polyurethane, preferably a coloring pigment. Such an intermediate layer is a layer for adjusting the color visible from the surface or imparting cushioning property without adding a large amount of coloring pigment to the epidermis layer.

The type of the first polyurethane is also not particularly limited, but it is flexible and durable that it is a refractory polyether polyurethane containing a polyether polyol as a polymer polyol unit and an aromatic diisocyanate as an organic polyisocyanate unit. It is preferable from the viewpoint of sex. Further, the modulus of the second polyurethane is not particularly limited, but for example, 100% modulus is preferably about 2 to 5 MPa.

When the intermediate layer contains a coloring pigment, the type of the coloring pigment contained in the intermediate layer is not particularly limited. Specific examples thereof include diketopyrrolopyrrole pigments such as diketopyrrolopyrrole red pigments, anthracinone pigments, perylene pigments, and phthalocyanine pigments such as α-type phthalocyanine blue pigments.

When the intermediate layer contains a coloring pigment, it is sufficient to contain the coloring pigment in an amount of 10 to 50 parts by mass and further 20 to 30 parts by mass with respect to 100 parts by mass of the first polyurethane to obtain a color visually recognizable from the surface. It is preferable because it can be toned to.

The thickness of the intermediate layer is not particularly limited, but is preferably 10 to 50 μm, more preferably 20 to 30 μm.

Further, the polyurethane adhesive layer 7 is a layer containing polyurethane for adhering the cushion layer 3 and the intermediate layer 4. The thickness of the polyurethane adhesive layer is not particularly limited, but it is preferable to have a thickness of 20 to 60 μm, preferably 30 to 50 μm in order to obtain sufficient adhesiveness.

Then, 10% modulus is applied to the surface of the epidermis layer obtained by peeling the release paper on the surface of the base material of the pearl-like leather-like sheet thus obtained by using a coating means such as gravure printing. By applying and drying an ink containing a third polyurethane of 5 MPa or more, a surface coat layer having a thickness of 2 to 5 μm adhered to the skin layer is formed.

The surface coat layer is a clear polyurethane layer coated on the epidermis layer, which is substantially free of coloring pigments and pearl pigments and is mainly composed of a third polyurethane having a 10% modulus of 5 MPa or more, and has a thickness of 2 to 5 μm. Has a pearl. Since such a surface coat layer is adhered to the epidermis layer, even if the epidermis layer contains a high proportion of pearl pigment, the folds are less likely to be discolored when the creases are rubbed. A leather-like sheet can be obtained.

The type of the third polyurethane is not particularly limited as long as its 10% modulus is 5 MPa or more. The 10% modulus of the third polyurethane is preferably 5 to 15 MPa. The 100% modulus of the third polyurethane is preferably 8 to 20 MPa, more preferably 9 to 17 MPa. Since the 10% modulus of the third polyurethane is 5 MPa or more, even if the epidermis layer contains a pearl pigment in a high proportion, the crease portion is less likely to be discolored when the crease portion is rubbed. On the other hand, when the 10% modulus of polyurethane contained in the surface coat layer is less than 5 MPa, the crease portion is likely to be discolored when friction is applied to the crease portion.

The surface coat layer has a thickness of 2-5 μm. When the thickness of the surface coat layer is less than 2 μm, the effect that the crease portion is less likely to be discolored when friction is applied to the crease portion is reduced. Further, when the surface coat layer exceeds 5 μm, the texture becomes hard and the bending resistance deteriorates.

In this way, the pearl-like leather-like sheet of the present embodiment is obtained. The pearl-like leather-like sheet of the present embodiment is provided with a resin layer having the above-mentioned layer structure, so that even if the Flop Index on the surface is 10 or more, the folds are creases when the creases are rubbed. The part is less likely to discolor.

Here, the surface showing Flop Index of 10 or more means that the surface of the surface coat layer of the pearl-like leather-like sheet is measured from angles of 15 degrees, 45 degrees, and 110 degrees using a multi-angle spectrocolorimeter. Using the brightness L ^* values (L ^* _{15 °} , L ^* _{45 °} and L ^* _{110 °} ) calculated from the coordinate values of the L ^* a ^* b ^* color system obtained by

It is a value obtained from. The Flop Index on the surface of the pearl-like leather-like sheet of the present embodiment is 10 or more, preferably 10.5 or more. It should be noted that the thin plate-shaped pearl pigment covers the inside of the surface of the epidermis layer to a high extent, and the pearl pigment has high smoothness without forming irregularities on the surface of the epidermis layer, so that Flop Index is high.

The pearl-like leather-like sheet of the present embodiment is provided with a resin layer having the above-mentioned layer structure, so that the pearl-like leather-like sheet having a high pearly feeling is creases when the creases are rubbed. The part is less likely to discolor.

To the extent that the creases are less likely to discolor when rubbed against the creases, for example, the edges of the folds of the pearl-like leather-like sheet when folded in half are made of cotton thick weave (plain woven cotton cloth 79A). ^{) Is applied to the pressing plate with a load of 2 lb, and the sample table is reciprocated 1000 times to perform friction. The brightness difference ΔL * of the brightness L * in the color system} is 3 Hereinafter, it is preferably 2 or less. The pearl-like leather-like sheet of the present embodiment is adjusted so as to show a small brightness difference ΔL ^* in such a test, so that the crease portion is less likely to be discolored when the crease portion is rubbed. Become.

Leather-like sheets are processed to be bent into a box shape or molded into a pipe shape in products of various shapes. The fold portion formed by being processed in this way has a problem that discoloration is conspicuous when it is rubbed against the floor, clothes, other parts of the product, or the like, and the product quality is easily impaired. According to the pearl-like leather-like sheet of the present embodiment described above, a bag like a school bag is required to have a high pearly feeling, and it is preferable that the folds do not discolor when the folds are rubbed. It is preferably used as a material for.

Hereinafter, the present invention will be described in more detail with reference to Examples. The scope of the present invention is not limited to these examples.

[Example 1]
After melt-spinning a sea-island type composite fiber containing 45 parts by mass of 6-nylon (sea component) and 55 parts by mass of polystyrene (island component), stretching it three times, applying a fiber oil agent, and mechanically crimping it. , Dry. The obtained crimped fiber was cut into 51 mm to form a staple of 3 dtex, and after forming a web, needle punching of about 500 punches / cm ² was performed alternately from both sides to obtain an entangled nonwoven fabric. The basis weight of this entangled nonwoven fabric was 350 g / m ² , and the apparent specific gravity was 0.17. This entangled nonwoven fabric was treated with a 4% aqueous solution of polyvinyl alcohol, compressed and fixed to a thickness of about 1.3 mm, and the surface was buffed and smoothed. Then, it was impregnated with a dimethylformamide (hereinafter referred to as DMF) solution of polyurethane mainly composed of polyester-based polyurethane having a concentration of 13%. Further, the same polyurethane solution was applied to the surface in an amount of 100 g / m ² in solid content, and then the porous polyurethane was wet-coagulated by immersing it in a mixed solution of DMF / water. Then, the island component was eluted and removed in hot toluene to convert the sea-island type composite fiber into a hollow fiber. In this way, a fiber base material having a cushion layer permeated into the surface layer laminated was obtained. The thickness of the cushion layer was 300 μm.

Next, a polyurethane composition solution containing 100 parts by mass of a 20% solution of the second polyurethane, 8 parts by mass of a pearl pigment, and 0.2 parts by mass of a red pigment on the surface of a release paper (R-70 manufactured by Lintec Co., Ltd.). Was applied so that the thickness after drying was 20 μm, and dried to form a skin layer. The second polyurethane was a silicone-modified polycarbonate-based polyurethane containing a polycarbonate-based polyol as a polymer polyol unit and a fatty diisocyanate as an organic polyisocyanate unit.

Then, on the surface of the skin layer formed on the release paper, 100 parts by mass of a 30% solution of the first polyurethane, 30 parts by mass of a red vehicle containing 10% by mass of anthracinone pigment, and 10 parts by mass of a white vehicle containing titanium dioxide. , 30 parts by mass of DMF and 30 parts by mass of methyl ethyl ketone were applied so as to have a thickness of 20 μm after drying, and dried to form an intermediate layer having a thickness of 20 μm. The first polyurethane was a refractory polyether polyurethane containing a polyether polyol as a polymer polyol unit and an aromatic diisocyanate as an organic polyisocyanate unit.

Then, a polyurethane-based adhesive is applied to the surface of the intermediate layer formed on the release paper and dried at 120 ° C. for 2 minutes to evaporate the solvent to form a semi-cured adhesive layer having a thickness of 50 μm. did. Then, the semi-cured adhesive layer formed on the release paper was bonded to the cushion layer laminated on the fiber base material to produce a laminated intermediate. The polyurethane-based adhesive contains 100 parts by mass of a cross-linking polyurethane-based adhesive plus a cross-linking agent and a cross-linking accelerator as an adhesive component, and contains 5 parts by mass of DMF and 10 parts by mass of ethyl acetate as a solvent. .. Then, the semi-cured adhesive layer was infiltrated into the cushion layer while being pressure-bonded by pressing with a roll provided with a clearance of about 65% of the total thickness of the laminated intermediate of 1.6 mm. Then, after drying at 130 ° C. for 3 minutes and aging at 50 ° C. for 3 days, the release paper was peeled off to obtain a base material of a pink pearl-like leather-like sheet.

Then, a coating liquid containing a third polyurethane is applied to the surface of the epidermis layer of the base material of the pearl-like leather-like sheet so that the thickness after drying is about 2 μm, and the surface coat layer is dried. Formed. As the coating liquid containing the third polyurethane, SP-215NS manufactured by Dainichiseika Kogyo Co., Ltd. containing a refractory polyester polyurethane having a 10% modulus of 5.4 MPa was used. In this way, a pearl-like leather-like sheet was obtained.

Then, the obtained pearl-like leather-like sheet was evaluated as follows.

(Measurement of polyurethane modulus)
A film having a thickness of about 400 μm of polyurethane used in each Example and Comparative Example was prepared, and a film cut out to a width of 2.5 cm was measured for high elongation with a precision universal testing machine (autograph). Read the elongation 10%, 20%, and 100% strength of the resulting SS curve and divide by the film thickness and the cross-sectional area obtained from the 2.5 cm width, 10% modulus, 20% modulus, 100% modulus ( MPa) was calculated.

(Measurement of thickness of each layer)
The cross section of the pearl-like leather-like sheet in the thickness direction was observed with a scanning electron microscope at a magnification of 800, and the image at that time was preserved. The photographs were taken at 5 randomly selected locations. Then, the thickness of each layer was measured for the obtained five images.

(Measurement of Flop Index)
L ^* a ^* b ^* Coordinates of the color system obtained by measuring the surface of the surface coat layer of the pearl-like leather-like sheet from angles of 15 degrees, 45 degrees and 110 degrees using a multi-angle spectrocolorimeter. Using the brightness L ^* values (L ^* _{15 °} , L ^* _{45 °} and L ^* _{110 °} ) calculated from the values, the following formula (I):

I asked for it.

(Measurement of L ^* value of crease wear)
For the measurement of crease wear, refer to the JIS L1096 general woven fabric test method, and use a castom type woven fabric wear tester to fold the edges of the pearl-like leather-like sheet in half and use a cotton thick weave (plain weave cotton cloth 79A). A load of 2 lb was applied to the attached pressing plate and pressed, and the sample table was reciprocated 1000 times to perform friction.

The color is measured by using a spectrocolorimeter according to JIS Z 8722: 2009 (color geodesy method-reflection and transmission object color, 5. spectroscopic color measurement method), and JIS Z 8781-4: 2013. (Color measurement-Part 4: CIE 1976 L ^* a ^* b ^* color space) L ^* a ^* b ^* using the equations (1) to (9) shown in "4.1 Basic coordinates". Calculated. The number of measurements was 3 times, and the average value was shown as a result.

(Bending resistance)
Using a pearl-like leather-like sheet, a flexibility test was conducted with a flexometer in an environment of 20 ° C., and it was confirmed whether or not cracks were generated on the surface every 100,000 cycles of bending. The cracks were confirmed visually using a loupe. Then, when cracks were confirmed in 100,000 cycles, it was determined as "less than 100,000 cycles", when cracks were confirmed in 200,000 cycles, it was determined as "100,000 cycles", and similarly, it was determined for each "100,000 cycles". .. The test was completed in 500,000 cycles, and those in which no crack was confirmed were judged to be 500,000 cycles or more.

(Abrasion resistance)
A double-sided tape was attached to the back surface of the pearl-like leather-like sheet to prepare a measuring piece cut into a circle with a diameter of 10.6 cm, and the measurement piece was precisely weighed with a predetermined balance. Next, the measuring piece was set on the turntable and attached to the vertical drive shaft of the Taber Ablation Tester. Then, an arm equipped with a wear ring (H-22 (manufactured by Dite Electron)) was lowered onto the measurement surface, and the pearl-like surface of the measurement piece was worn under the conditions of a load of 1 kg and a rotation speed of 1000 times. After abrading up to 1000 rpm, the measuring piece was removed, the wear debris adhering to the measuring piece was well removed with a brush, and the balance was precisely weighed to measure the wear loss (mg). Abrasion weight loss was calculated as the difference in weight before and after wear. The average value of the results of the three measurements was taken as the wear reduction of the pearl-like leather-like sheet.

The above results are shown in Table 1 below.

[Example 2]
In Example 1, a coating liquid containing a non-yellowing polycarbonate-based polyurethane having a 10% modulus of 12.3 MPa (SSTC-7 manufactured by Dainichiseika Kogyo Co., Ltd.) was used as the coating liquid containing the third polyurethane. A pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 1 except for the above. The results are shown in Table 1.

[Example 3]
In Example 1, as a coating liquid containing a third polyurethane, a coating liquid containing a non-yellowing silicone-modified polycarbonate-based polyurethane having a 10% modulus of 6.9 MPa (Rezaroid LU-587 manufactured by Dainichi Seika Kogyo Co., Ltd.). A pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 1 except that the above was used. The results are shown in Table 1.

[Example 4]
In Example 1, a pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 1 except that the thickness of the surface coat layer was changed from 2.3 μm to 5 μm. The results are shown in Table 1.

[Example 5]
In Example 2, a pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 2 except that 40 parts by mass of the pearl pigment was changed to 45 parts by mass. The results are shown in Table 1.

[Example 6]
In Example 2, a pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 2 except that 40 parts by mass of the pearl pigment was changed to 30 parts by mass. The results are shown in Table 1.

[Example 7]
In Example 1, a pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 1 except that the thickness of the epidermis layer was changed from 20 μm to 10 μm. The results are shown in Table 1.

[Example 8]
In Example 1, a pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 1 except that the thickness of the epidermis layer was changed from 20 μm to 30 μm. The results are shown in Table 1.

[Comparative Example 1]
In Example 1, a pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 1 except that the surface coat layer was not formed. The results are shown in Table 1.

[Comparative Example 2]
In Example 1, a coating liquid containing a non-yellowing silicone-modified polycarbonate-based polyurethane having a 10% modulus of 2.2 MPa (NY-324 manufactured by DIC Corporation) was used as the coating liquid containing the third polyurethane. Obtained and evaluated a pearl-like leather-like sheet in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3]
In Example 1, a coating liquid containing a non-yellowing polycarbonate-based polyurethane having a 10% modulus of 2.7 MPa (NY-360 manufactured by DIC Corporation) was used as the coating liquid containing the third polyurethane. A pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 4]
In Example 1, a coating liquid containing a non-yellowing polycarbonate-based polyurethane having a 10% modulus of 1.4 MPa (SSTC-8014 manufactured by Dainichiseika Kogyo Co., Ltd.) was used as the coating liquid containing the third polyurethane. A pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 1 except for the above. The results are shown in Table 1.

[Comparative Example 5]
In Example 2, a pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 1 except that the thickness of the surface coat layer was changed from 2.5 μm to 1.0 μm. The results are shown in Table 1.

[Comparative Example 6]
In Example 1, artificial leather was obtained and evaluated in the same manner as in Example 1 except that 40 parts by mass of the pearl pigment was changed to 20 parts by mass. The results are shown in Table 1.

[Comparative Example 7]
In Example 1, artificial leather was obtained and evaluated in the same manner as in Example 1 except that 40 parts by mass of the pearl pigment was changed to 50 parts by mass. The results are shown in Table 1.

[Comparative Example 8]
In Example 1, a pearl-like leather-like sheet was obtained and evaluated in the same manner as in Example 1 except that the thickness of the surface coat layer was changed from 2.3 μm to 8 μm. The results are shown in Table 1.

Referring to Table 1, the pearl-like leather-like sheets obtained in Examples 1 to 8 all have a surface having a high pearly feeling with Flop Index of 10 or more, and the brightness difference (ΔL) in the crease wear test. ^* ) Was small, and it was difficult for the creases to discolor when the creases were rubbed.

On the other hand, any of the pearl-like leather-like sheets obtained in Comparative Example 1 in which the surface coat layer was not formed and Comparative Examples 2 to 4 in which the 10% modulus of the third polyurethane contained in the surface coat layer was less than 5 MPa. Also, Flop Index has a surface with a high pearly feeling of 10 or more, but the difference in brightness (ΔL ^* ) in the crease wear test is large, and the crease portion is easily discolored when friction is applied to the crease portion. In addition, the pearl-like leather-like sheet obtained in Comparative Example 5 in which the surface coat layer is too thin also has a large difference in brightness (ΔL ^* ) in the crease wear test, and the crease portion is discolored when friction is applied to the crease portion. It was easy. Further, the pearl-like leather-like sheet obtained in Comparative Example 6 in which the content ratio of the pearl pigment in the epidermis layer is low has a small difference in brightness (ΔL ^* ) in the crease wear test, but has a high Flop Index of 10 or more. I didn't have it. Further, the pearl-like leather-like sheet obtained in Comparative Example 7 in which the content ratio of the pearl pigment in the epidermis layer was too high had low wear resistance. Further, the pearl-like leather-like sheet obtained in Comparative Example 8 in which the surface coat layer was too thick had a hard surface and low bending resistance.

1 Fiber base material 2 Resin layer 3 Cushion layer 4 Intermediate layer 5 Skin layer 6 Surface coat layer 7 Polyurethane adhesive layer 8 Pearl pigment 9 Color pigment 10 Pearl-like leather-like sheet

Claims (4)

A leather-like sheet comprising a fiber base material and a resin layer laminated on the fiber base material.
The resin layer includes an intermediate layer containing the first polyurethane, a skin layer laminated on the intermediate layer, and a surface coat layer adhered to the skin layer.
The skin layer is a layer having a thickness of 10 to 30 μm containing a second polyurethane and 30 to 45 parts by mass of a pearl pigment with respect to 100 parts by mass of the second polyurethane.
The surface coat layer is a layer having a thickness of 2 to 5 μm containing a third polyurethane having a 10% modulus of 5 MPa or more.
A leather-like sheet with pearl-like silver, characterized in that Flop Index has a surface of 10 or more. The leather-like sheet with pearl-like silver according to claim 1, wherein the resin layer further includes a cushion layer mainly made of porous polyurethane adhered to the fiber base material. The leather-like sheet with pearl-like silver according to claim 1 or 2, wherein the intermediate layer contains 10 to 50 parts by mass of a coloring pigment with respect to 100 parts by mass of the first polyurethane. Using a castom type woven fabric wear tester, the edge part folded in half was pressed against a pressing plate to which a plain weave cotton cloth 79A was attached with a load of 2 lb, and the sample table was reciprocated 1000 times to perform friction. , L ^* a ^* b ^* The leather-like sheet with pearl-like silver according to any one of claims 1 to 3, wherein the difference in brightness ΔL ^* between the lightness L ^* and the lightness before friction in the color system is 3 or less.

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