Synthetic leather with concave pattern and preparation method thereof

Abstract

The present invention relates to a synthetic leather with a concave pattern, which is characterized in that: a plurality of expansion areas are distributed on the back of the synthetic leather, the expansion areas are coated with expansion materials, the expansion areas expand outward and bulge, and after the expansion materials are solidified, the front side of the synthetic leather shrinks toward the back side to form a concave pattern, and the concave pattern corresponds to the position of the expansion area on the back side of the synthetic leather. The concave pattern of the synthetic leather has a strong three-dimensional sense, clear lines, and a relatively soft feel.

Description

Technical Field

[0001] The invention relates to the technical field of synthetic leather production, in particular to synthetic leather with a concave pattern. Background Art

[0002] The surface pattern of existing synthetic leather can only be achieved by changing the thickness and texture of the leather grain on the surface of the veneer layer, which is relatively monotonous, causing visual fatigue to people and failing to meet people's increasingly improved aesthetic taste.

[0003] Therefore, the synthetic leather is pressed by high temperature and external force to produce a concave pattern, but the synthetic leather softens under high temperature, and the leather texture on the surface of the synthetic leather is flattened or collapsed under the action of pressure. Although the surface presents a concave pattern, the texture of the synthetic leather itself is flattened and disappears, which reduces the grade and texture of the synthetic leather. At the same time, for the sake of production efficiency, the rotation speed of the pressing roller with a three-dimensional pattern is relatively fast when preparing the concave pattern. The concave pattern pressed only by high temperature and external force will rebound a lot, resulting in a weak three-dimensional sense of the concave pattern, and the bubbles inside the wet bass in the middle of the synthetic leather are flattened, making it hard to touch. Therefore, it is necessary to design a synthetic leather with a concave pattern with a strong three-dimensional sense and a soft touch. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention aims to provide a synthetic leather with a concave pattern. The concave pattern on the surface of the synthetic leather makes the synthetic leather surface more three-dimensional, with clear leather texture and soft and comfortable feel.

[0005] The present invention is completed by adopting the following technical scheme: a synthetic leather with a concave pattern, wherein a plurality of expansion areas with patterns are distributed on the back of the synthetic leather, and the expansion areas are coated with expansion materials. After the expansion areas expand and bulge and the expansion materials are solidified, the front side of the synthetic leather shrinks toward the back side to form a concave pattern, and the concave pattern corresponds to the position of the expansion area on the back side of the synthetic leather.

[0006] Furthermore, the expansion material comprises heat-expandable plastic microspheres and resin, the resin is polyurethane resin or acrylic resin, the polyurethane resin is solvent-based polyurethane resin or water-based polyurethane resin, and the acrylic resin is solvent-based acrylic resin or water-based acrylic resin.

[0007] Furthermore, the expansion area is divided into a plurality of isolation lines, and the isolation lines divide the expansion area into a plurality of small blocks, and the blocks are coated with expansion material.

[0008] Furthermore, the isolation line is a continuous isolation line or a discontinuous isolation line. When the isolation line is a continuous isolation line, the continuous isolation line is not coated with expansion material. When the isolation line is a discontinuous isolation line, the broken part is coated with expansion material, and the continuous part is not coated with expansion material.

[0009] Furthermore, the isolation lines are distributed in a staggered manner horizontally and vertically.

[0010] Furthermore, the width or length of the block is between 1-3 mm, and the width of the isolation line is between 0.05-0.3 mm.

[0011] Furthermore, the synthetic leather is composed of a base fabric, a wet-fabric base and a dry-fabric veneer, the expansion material is coated on several expansion areas of the base fabric, the surface of the dry-fabric veneer has texture, the width of the concave pattern is greater than the width of the texture, and the expansion areas are distributed on the back of the synthetic leather in a regular or irregular pattern.

[0012] Furthermore, the weight ratio of the resin to the heat-expandable plastic microspheres is 100:3-7.

[0013] Furthermore, the method for preparing the synthetic leather having a concave pattern is as follows:

[0014] 1) preparing an expansion material by mixing heat-expandable plastic microspheres and resin; the resin is a solvent-based resin or a water-based resin;

[0015] 2) Printing the expansion material on the back base fabric of the synthetic leather to form a number of expansion areas on the base fabric;

[0016] 3) The synthetic leather printed with the expansion material is heated in an oven, and the expansion material expands due to the heat. The expansion area on the base fabric bulges up and after the expansion material solidifies, a concave pattern is formed on the front side of the synthetic leather, and the concave pattern corresponds to the position of the expansion area on the back side of the synthetic leather.

[0017] Furthermore, in the above step 2, the expansion material is rolled onto the base fabric using a gravure printing wheel, the gravure printing wheel is provided with a plurality of gravure patterns, the gravure patterns are provided with a plurality of isolation lines, the isolation lines divide the gravure patterns into a plurality of small blocks, during printing, the expansion material is adhered to the blocks of the gravure printing wheel, and the expansion material on the blocks is rolled onto the base fabric by the gravure printing wheel to form an expansion area with a plurality of isolation lines.

[0018] Beneficial effects of the present invention:

[0019] 1. The base fabric on the back of the synthetic leather is printed with a pattern of expansion material composed of heat-expandable plastic microspheres and polyurethane resin. The expansion material of the printed pattern expands when heated and bulges toward the back of the synthetic leather. The bulging pattern pulls the base fabric, wet-fabricated bass, and dry-fabricated veneer with texture on the surface to move toward the back, and produces depressions in the style of the printed pattern on the back. Compared with the synthetic leather with heat-pressed concave patterns, the synthetic leather manufactured in this way has a strong three-dimensional depression, clear textures, and a relatively soft feel.

[0020] 2. After the expansion material is heated and expanded and solidified, the pattern area of ​​the expansion material will become harder than the original leather. The expansion material is divided with fine isolation lines, which isolate the expansion material pattern into small blocks, and there are gaps between adjacent small blocks, so there are movable gaps between the small blocks, making the pattern area of ​​the expansion material softer.

[0021] 3. The isolation line is in an intermittent shape, which is conducive to the expansion and protrusion of the pattern area of ​​the expansion material on the base fabric without affecting the soft feel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of a front side of a synthetic leather having a concave pattern;

[0023] Figure 2 The figure is a schematic diagram of the structure of the back side of a synthetic leather having a concave pattern.

[0024] Figure 3 It is a schematic diagram of a partially enlarged structure of a continuous isolation line with a concave pattern.

[0025] Figure 4 It is a schematic diagram of a partially enlarged structure of an intermittent isolation line with a concave pattern.

[0026] Figure 5 The present invention is a schematic diagram of a partially cutaway structure of a synthetic leather having a concave pattern.

[0027] Figure 6 The diagram is a structural diagram of an irregular pattern front surface of synthetic leather with a concave pattern.

[0028] Figure 7 The diagram is a partially enlarged structural diagram of a synthetic leather back expansion material with a concave pattern after printing.

[0029] In the figure, the front side of the synthetic leather 1; the back side of the synthetic leather 2; the expansion area 3; the concave pattern 4; the leather grain 5; the isolation line 6; the fine block 7; the wet base 8; the dry veneer 9; the base fabric 10; the expansion material 11, the place where the isolation line is disconnected 12, and the place where the isolation line is continued 13. DETAILED DESCRIPTION

[0030] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation method, structure, characteristics and effects of the present invention are described in detail below in combination with the preferred embodiments.

[0031] according to Figure 1-Figure 7As shown, the present invention provides a synthetic leather with a concave pattern, wherein a plurality of expansion areas 3 with patterns are distributed on the back side 2 of the synthetic leather, and the expansion areas 3 are coated with an expansion material 11. After the expansion areas 3 expand and bulge and the expansion material 11 is cured, the front side 1 of the synthetic leather shrinks toward the back side 2 to form a concave pattern 4, and the concave pattern 4 corresponds to the position of the expansion areas 3 on the back side 2 of the synthetic leather, and the expansion areas 3 are regularly or irregularly distributed on the back side 2 of the synthetic leather.

[0032] The expansion material 11 of the expansion zone 3 comprises heat-expandable plastic microspheres and resin. The resin is polyurethane resin or acrylic resin, the polyurethane resin is solvent-based polyurethane resin or water-based polyurethane resin, the acrylic resin is solvent-based acrylic resin or water-based acrylic resin, preferably water-based polyurethane resin. The weight ratio of the polyurethane resin with a solid content of about 30% and the heat-expandable plastic microspheres is 100:3-7.

[0033] The synthetic leather is composed of a base fabric 10, a wet base 8 and a dry veneer 9, an expansion material 11 is distributed on a plurality of expansion areas 3 of the base fabric 10, the outer surface of the dry veneer 9 has a leather grain 5, and the width of the concave pattern 4 is greater than the width of the grain 5. The width of the leather grain 5 is preferably 0.1-0.2 mm, and the width of the concave pattern 4 is preferably 1-15 mm. The depth of the concave bottom of the leather grain 5 is preferably less than 0.2 mm, and the depth of the concave pattern 4 is preferably greater than 0.3 mm and less than 1.5 mm.

[0034] Working principle: A plurality of expansion materials 11 composed of heat-expandable plastic microspheres and polyurethane resin are printed on the base fabric 10 of the back side 2 of the synthetic leather. The printed expansion material 11 expands thermally under heat and bulges toward the back side 2 of the synthetic leather to form an expansion area 3. Under the action of the foaming stress, the bulging expansion area 3 pulls the base fabric 10, the wet-fabric base 8, and the dry-fabric veneer 9 with the surface texture 5 toward the back side 2, so that the front side 1 of the synthetic leather presents a concave pattern 4, which is the same as the pattern style of the expansion area 3 printed on the back side 2. The heat-expandable plastic microspheres in the expansion material 11 begin to expand when heated to the expansion starting temperature. There is solvent or water in the expansion material 11, which evaporates during the heating process, and the expansion material 11 forms a firm shape after solidification. The manufactured synthetic leather has a strong three-dimensional sense of the concave pattern 4, clear texture 5, and a relatively soft feel. The combination of the concave pattern 4 and the texture of the front side 1 of the synthetic leather improves the texture and grade of the finished product.

[0035] The expansion area 3 is provided with a plurality of isolation lines 6, and the isolation lines 6 are distributed in a staggered manner horizontally and vertically. The isolation lines 6 divide the expansion area 3 into a plurality of fine blocks 7, and the blocks 7 are coated with expansion material 11. The width or length of the blocks 7 is between 1-3 mm, and the width of the isolation lines 6 is between 0.05-0.3 mm. The isolation lines 6 are continuous isolation lines 6 or intermittent isolation lines 6. When the isolation lines are continuous isolation lines, the continuous isolation lines are not coated with expansion material, and the expansion material is distributed in the block positions. When the isolation lines are intermittent isolation lines, the disconnected parts 12 and the block positions are coated with expansion material, and the continuous parts 13 are not coated with expansion material. The isolation lines 6 are preferably intermittent isolation lines, and the isolation lines are in an intermittent shape, which is conducive to the expansion protrusion of the expansion material pattern area on the base cloth without affecting the soft feel.

[0036] After the expansion material 11 is heated and expanded and solidified, the expansion area 3 becomes harder than the original synthetic leather. The expansion material is divided with fine isolation lines 6, which isolate the expansion material 11 pattern into small blocks 7, and gaps are generated between adjacent small blocks 7, so that there are movable gaps between the small blocks 7, making the expansion area 3 softer, while not affecting the presentation of the concave pattern 4 on the surface of the synthetic leather, so that the overall feel of the synthetic leather is softer.

[0037] The preparation method of the above-mentioned synthetic leather with a concave pattern:

[0038] 1) Prepare a synthetic leather with a base fabric 10, a wet-fabric base 8 and a dry-fabricated veneer 9, preferably a soft synthetic leather.

[0039] 2) Prepare an expansion material by mixing heat-expandable plastic microspheres and resin; the resin is a solvent-based resin or a water-based resin. The resin can be a polyurethane resin or an acrylic resin. For a soft feel, a water-based polyurethane resin is preferred, and the modulus is less than 5kgf / cm2. The weight ratio of the polyurethane resin with a solid content of 30% and the heat-expandable plastic microspheres is 100:3-7. According to the viscosity and color required for printing, an appropriate amount of N,N-dimethylformamide and color powder can be added to the expansion material.

[0040] 3) Printing the expansion material 11 on the back base fabric 10 of the synthetic leather to form a plurality of expansion areas on the base fabric. The expansion material printing method is as follows: the expansion material is rolled on the base fabric using a gravure printing wheel, wherein the gravure printing wheel is provided with a plurality of gravure patterns, and the gravure patterns are provided with a plurality of isolation lines, and the isolation lines divide the gravure patterns into a plurality of fine blocks. During printing, the expansion material is adhered to the blocks of the gravure printing wheel, and the expansion material on the blocks is rolled and brushed on the base fabric by the gravure printing wheel to form an expansion area with a plurality of isolation lines.

[0041] The isolation line 6 is a continuous isolation line 6 or a discontinuous isolation line 6. When the isolation line is a continuous isolation line, the continuous isolation line is not coated with expansion material, and the expansion material is distributed in the block position. When the isolation line is a discontinuous isolation line, the discontinuous part and the block position are coated with expansion material, and the continuous part is not coated with expansion material. The isolation line 6 is preferably a discontinuous isolation line.

[0042] 4) The synthetic leather printed with the expansion material 11 is placed in an oven and heated to a temperature greater than the expansion start temperature of the heat-expandable plastic microspheres and less than the end temperature. The expansion start temperature of the heat-expandable plastic microspheres is preferably less than 100 degrees, and the end temperature is preferably greater than 120 degrees.

[0043] The mixed expansion material 11 expands when heated, and the expansion area 3 on the base fabric 10 expands outward and bulges. After the expansion material 11 is cured, a concave pattern 4 is formed on the front side of the synthetic leather, and the concave pattern 4 corresponds to the shape and position of the expansion area 11 on the back side of the synthetic leather. The expansion area is regular or irregular in shape, so that a regular or irregular concave pattern is formed on the front side.

[0044] Wherein, the weight parts of the slurry of the expansion material are as follows:

[0045] 100 parts of polyurethane resin solvent liquid with a modulus of 5kgf / cm2 and a solid content of 30%;

[0046] 3-7 parts of heat-expandable plastic microspheres with a particle size of 10-20 microns, a starting temperature of 90 degrees and an end temperature of 130 degrees.

[0047] 100-200 parts of N,N-dimethylformamide.

[0048] Another weight portion of the slurry of the expansion material is as follows:

[0049] 100 parts of polyurethane resin solvent liquid with a modulus of 5kgf / cm2 and a solid content of 30%;

[0050] 3-7 parts of heat-expandable plastic microspheres with a particle size of 10-20 microns, a starting temperature of 90 degrees and an ending temperature of 130 degrees;

[0051] 100-200 parts of N,N-dimethylformamide;

[0052] Color paste 0.5-3 parts.

[0053] Another weight portion of the slurry of the expansion material is as follows:

[0054] 100 parts of polyurethane resin solvent liquid with a modulus of 5kgf / cm2 and a solid content of 30%;

[0055] 3-7 parts of heat-expandable plastic microspheres with a particle size of 10-20 microns, a starting temperature of 90 degrees and an ending temperature of 130 degrees;

[0056] 100-200 parts of N,N-dimethylformamide;

[0057] 3-10 parts of silicone softener

[0058] Another weight portion of the slurry of the expansion material is as follows:

[0059] 100 parts of waterborne polyurethane resin with a modulus of 5kgf / cm2 and a solid content of 30%;

[0060] 3-7 parts of heat-expandable plastic microspheres with a particle size of 10-20 microns, a starting temperature of 90 degrees and an ending temperature of 130 degrees;

[0061] 50-100 parts water;

[0062] 0.5-1 part of water-based thickener;

[0063] Color paste 0.5-3 parts.

[0064] Another weight portion of the slurry of the expansion material is as follows:

[0065] 100 parts of water-based acrylic resin with a modulus of 5kgf / cm2 and a solid content of 30%;

[0066] 3-7 parts of heat-expandable plastic microspheres with a particle size of 10-20 microns, a starting temperature of 90 degrees and an ending temperature of 130 degrees;

[0067] 50-100 parts of water;

[0068] 0.5-1 part of water-based thickener;

[0069] Color paste 0.5-3 parts.

[0070] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A synthetic leather having a concave pattern, characterized in that: The back of the synthetic leather is provided with a plurality of expansion zones, the expansion zones are coated with expansion materials, the expansion zones expand outward and bulge, and after the expansion materials are solidified, the front side of the synthetic leather shrinks toward the back side to form a concave pattern, the concave pattern corresponds to the position of the expansion zones on the back side of the synthetic leather, and the expansion zones are distributed on the back side of the synthetic leather in a regular or irregular pattern; The expansion material includes heat-expandable plastic microspheres and resin.

2. The synthetic leather with a concave pattern according to claim 1, characterized in that: The resin is a polyurethane resin or an acrylic resin, the polyurethane resin is a solvent-based polyurethane resin or a water-based polyurethane resin, and the acrylic resin is a solvent-based acrylic resin or a water-based acrylic resin.

3. The synthetic leather with a concave pattern according to claim 1 or 2, characterized in that: The expansion area is divided into a plurality of isolation lines, and the isolation lines divide the expansion area into a plurality of fine blocks, and the blocks are coated with expansion material.

4. The synthetic leather with a concave pattern according to claim 3, characterized in that: The isolation line is a continuous isolation line or a discontinuous isolation line. When the isolation line is a continuous isolation line, no expansion material is applied to the continuous isolation line. When the isolation line is a discontinuous isolation line, the discontinuous part has the expansion material, and the continuous part does not have the expansion material.

5. The synthetic leather with a concave pattern according to claim 4, characterized in that: The isolation lines are distributed in a staggered manner horizontally and vertically.

6. The synthetic leather with a concave pattern according to claim 5, characterized in that: The width or length of the block is between 1-3 mm, and the width of the isolation line is between 0.05-0.3 mm.

7. The synthetic leather with a concave pattern according to claim 1 or 2 or 5 or 6, characterized in that: The synthetic leather is composed of a base fabric, a wet-fabric base and a dry-fabricated veneer. The expansion material is coated on several expansion areas of the base fabric. The surface of the dry-fabricated veneer has textures, and the width of the concave pattern is greater than the width of the textures.

8. The synthetic leather with a concave pattern according to claim 2, characterized in that: The weight ratio of the resin to the heat-expandable plastic microspheres is 100:3-7.

9. The method for preparing a synthetic leather having a concave pattern according to claim 1, characterized in that: 1) preparing an expansion material by mixing heat-expandable plastic microspheres and a resin, wherein the resin is a solvent-based resin or a water-based resin; 2) Printing the expansion material on the back base fabric of the synthetic leather to form a number of expansion areas on the base fabric; 3) The synthetic leather printed with the expansion material is heated in an oven, the expansion material expands due to the heat, the expansion area on the base fabric expands outward and bulges, and after the expansion material solidifies, a concave pattern is formed on the front side of the synthetic leather, and the concave pattern corresponds to the position of the expansion area on the back side of the synthetic leather.

10. The method for preparing a synthetic leather having a concave pattern according to claim 9, characterized in that: In the above step 2, the expansion material is rolled onto the base fabric using a gravure printing wheel, the gravure printing wheel is provided with a plurality of gravure patterns, the gravure patterns are provided with a plurality of isolation lines, the isolation lines divide the gravure patterns into a plurality of small blocks, during printing, the expansion material is adhered to the blocks of the gravure printing wheel, and the expansion material on the blocks is rolled onto the base fabric by the gravure printing wheel to form an expansion area with a plurality of isolation lines.

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