Fabric and Synthetic Resin Leather

Abstract

To provide a plain knit fabric having equal elongation percentage in warp direction and weft direction, which is used as a base cloth of a synthetic resin leather and the like.SOLUTION: A knit fabric has a first layer 1 formed by plain knitting, a second layer 2 formed by plain knitting in substantially parallel with the first layer, and a third layer 3 formed by plain knitting across the first layer and the second layer. The third layer is formed across stitches in warp direction of the first layer and the second layer and knitted so as to form a space between the first layer and the second layer. It is preferable that the first layer has a plurality of first loops 1L knitted so as to be aligned in the warp direction continuously in weft direction; the second layer has a plurality of second loops 2L knitted so as to be aligned in the warp direction continuously in the weft direction; and the third layer has a third front loop 3F, which is knitted in the weft direction between the plurality of first loops adjacent in the warp direction on the first layer, a third back loop 3B knitted between the plurality of second loops adjacent in the warp direction on the second layer, and a curve portion 3C linking the third front loop and the third back loop.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a knitted fabric knitted in a knitted pattern used for a base fabric of synthetic resin leather or the like, and a synthetic resin leather joined with this knitted fabric.

Background Art

[0002] Conventionally, synthetic resin leather used for seats of vehicles such as automobiles, airplanes, ships, other chairs, or bags, clothes, etc. has a laminated structure that is stretchable with a base fabric bonded to its back surface. As the base fabric, single-sided knitted rib or double-sided knitted rib is used. In addition, as a synthetic resin leather with a reduced difference in elongation rate between the warp (lengthwise) direction and the weft (crosswise) direction, Patent Document 1 proposes devising a method for forming loops in a plain knitted rib, and Patent Document 2 proposes devising the number of loops in a double-sided knitted rib.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, single-sided knitted rib and double-sided knitted rib have extremely large elongation in the weft direction compared to the elongation in the warp direction, and the tensile strength in the weft direction is weak compared to the tensile strength in the warp direction. For this reason, synthetic resin leather using single-sided knitted rib or double-sided knitted rib as the base fabric is also the same, with the weft direction being easily stretchable and having inferior tensile strength, and the warp direction being difficult to stretch and having excellent tensile strength. As a result, when a product such as a seat (chair), a bag, or clothing is sewn and tailored using a synthetic resin leather of single-sided knitted jersey or double-sided knitted jersey as the base fabric, it is restricted in the cutting direction, resulting in an increase in cutting scraps, a waste of the fabric, and a decrease in work efficiency during cutting due to this directionality. Furthermore, the tailored product also has problems such as a low strength in the transverse direction of the base fabric, resulting in breakage, or distortion and a short lifespan of the entire product. Particularly in applications where a load is repeatedly applied, such as in automotive seats, this tendency is particularly prominent. In addition, there is also a problem that wrinkles are likely to occur in the sewing part, reducing the sewing efficiency. Also, the synthetic resin leather described in Patent Document 1 is single-sided knitted jersey, so there is a problem that the base fabric has no thickness and lacks the texture as leather. Also, the synthetic resin leather described in Patent Document 2 is knitted with yarns that are difficult to stretch, such as cotton, rayon, polyester, nylon, and vinyl chloride fibers. Therefore, it has a small elongation in the transverse direction and a large tensile strength in the transverse direction, and it is impossible to achieve a natural softness and suppleness, lacking the texture as leather.

Means for Solving the Problems

[0005] In order to achieve such problems, the knitted fabric according to the present invention includes a first layer knitted in jersey, a second layer knitted in jersey substantially parallel to the first layer, and a third layer knitted in jersey across the first layer and the second layer. The third layer is knitted between the warp stitches in the first layer and the second layer so as to form a gap between the first layer and the second layer. Also, in order to achieve such problems, the synthetic resin leather according to the present invention is a synthetic resin leather using the knitted fabric as a base fabric, characterized in that a synthetic resin sheet is joined to at least one side of the base fabric.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0007] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 to 2, the knitted fabric A according to the embodiment of the present invention is a fabric having a multi-layer structure knitted in a plain weave (flat knitting, single jersey knitting), and is mainly used for the base fabric 10 of the synthetic resin leather B and the like. More specifically, the knitted fabric A according to the embodiment of the present invention includes a first layer 1 knitted in a plain weave, a second layer 2 knitted in a plain weave substantially parallel to the first layer 1, and a third layer 3 knitted in a plain weave across the first layer 1 and the second layer 2 as main components. The first layer 1, the second layer 2, and the third layer 3 are arranged so as to face each other in one direction (the vertical direction in the illustrated example), and this facing direction is hereinafter referred to as the "thickness direction (T direction)". The direction intersecting the T direction is hereinafter referred to as the "weft (horizontal) direction (We direction), warp (vertical) direction (Wa direction)".

[0008] The first layer 1 is a single-sided knitted plain weave in which a plurality of first loops 1L continuous in the weft direction (We direction) are knitted in a plurality of rows in the warp direction (Wa direction) to form a structure. The first layer 1 is composed of one or more first yarns 1a, 1b. In the illustrated example, each row of first loops 1L continuing in the weft direction (We direction) is formed by knitting two first yarns 1a, 1b so that they are alternately arranged in the weft direction (We direction). The second layer 2 is a single-sided knitted fabric formed by knitting a plurality of second loops 2L continuous in the weft direction (We direction) so that they are arranged in multiple rows in the warp direction (Wa direction). The second layer 2 is composed of one or more second yarns 2a, 2b. In the illustrated example, each row of second loops 2L continuing in the weft direction (We direction) is formed by knitting two second yarns 2a, 2b so that they are alternately arranged in the weft direction (We direction).

[0009] The third layer 3 is a double-sided knitted fabric formed by knitting together the stitches of the first loops 1L in each row arranged in the warp direction (Wa direction) in the first layer 1 and the stitches of the second loops 2L in each row arranged in the warp direction (Wa direction) in the second layer 2. The third layer 3 is composed of one or more third yarns 3a, 3b, and is knitted together so as to form gaps S between the first layer 1 and the second layer 2 and the third yarns 3a, 3b. In the illustrated example, each row continuing in the weft direction (We direction) is formed by knitting two third yarns 3a, 3b so that they are alternately arranged in the weft direction (We direction). That is, the third layer 3 has third front loops 3F knitted together in the weft direction (We direction) between the first loops 1L in each row adjacent in the warp direction (Wa direction) in the first layer 1, third back loops 3B knitted together between a plurality of second loops 2L adjacent in the warp direction (Wa direction) in the second layer 2, and a curved portion 3C connecting the third front loops 3F and the third back loops 3B.

[0010] The first yarns 1a, 1b constituting the first layer 1, the second yarns 2a, 2b constituting the second layer 2, and the third yarns 3a, 3b constituting the third layer 3 are made of one kind of synthetic fiber yarn such as polyethylene terephthalate (PET), rayon, nylon, or a blended yarn of PET and rayon. The thicknesses of the first yarns 1a, 1b, the second yarns 2a, 2b, and the third yarns 3a, 3b are preferably set to about 50 to 150 deniers (D), more specifically 70 to 80 D. When used as the base fabric 10 of the synthetic resin leather B, if the thicknesses of the first yarns 1a, 1b, the second yarns 2a, 2b, and the third yarns 3a, 3b are less than about 50 D, the yarns are too thin and the strength of the yarns becomes weak, so the natural softness and flexibility of the base fabric 10 are impaired, which is not preferable. Conversely, if the thicknesses of the first yarns 1a, 1b, the second yarns 2a, 2b, and the third yarns 3a, 3b exceed about 150 D, the yarns are too thick and the elongation of the yarns becomes small, so the base fabric 10 becomes hard and the natural softness and flexibility are impaired, which is not preferable.

[0011] When shown in FIGS. 1 to 2 as a specific example of the knitted fabric A, it is formed in a three-layer structure having an intermediate third layer 3 between the front first layer 1 and the back second layer 2. The thickness of the third layer 3 (void S) in the thickness direction (T direction) of these three-layer structures is preferably set to 10 to 80%. When the thickness of the three-layer structure is about 0.5 mm to 1.0 mm, the thickness of the third layer 3 (void S) is set to about 0.30 to 0.60 mm. Thereby, by having the third layer 3 with the void S formed between the front first layer 1 and the back second layer 2, the structure is different from that of the conventional double-sided knitted wool in which the front layer and the back layer are joined. Also, although not shown as other examples, it is possible to change to a laminated structure of four or more layers, change the thickness, change the first yarns 1a, 1b, the second yarns 2a, 2b, and the third yarns 3a, 3b to three or more, and so on.

[0012] Next, the synthetic resin leather B according to the embodiment of the present invention will be described in detail with reference to FIG. 3. More specifically, the synthetic resin leather B according to the embodiment of the present invention includes, as main components, a knitted fabric A used as the base fabric 10 and a synthetic resin sheet 20 joined to at least one side of the base fabric 10. Furthermore, it is preferable to include an adhesive layer 30 formed between the base fabric 10 and the synthetic resin sheet 20 and an epidermis layer 40 formed on the surface side of the synthetic resin sheet 20.

[0013] The synthetic resin sheet 20 is made of a material mainly composed of a synthetic resin such as polyvinyl chloride (PVC: vinyl chloride resin) or polyurethane resin such as thermoplastic polyurethane (TPU), and is formed to an appropriate thickness (0.20 to 1.00 mm, specifically 0.32 to 0.81 mm). As necessary, the main component constituting the synthetic resin sheet 20 may contain conventionally known additives, such as colorants, plasticizers, stabilizers, fillers, lubricants, paints, foaming agents, flame retardants, release agents, etc. These can be used alone or in combination of two or more.

[0014] The adhesive layer 30 is formed by applying an adhesive to the back surface 20a of the synthetic resin sheet 20. As the adhesive for the adhesive layer 30, it is preferable to use a hot melt type made of a material having high affinity with the main component of the synthetic resin sheet 20. In particular, it is preferable to use a reactive hot melt adhesive whose viscosity can be relatively easily adjusted according to the heating temperature. It is also possible to blend a thermally expandable foaming agent into the adhesive layer (adhesive) 30 and disperse it in the adhesive, and expand the bubbles 31 generated with the heating of the adhesive and the foaming agent. As the application method of the adhesive layer 30, it is preferable to transfer the adhesive along the back surface 20a of the synthetic resin sheet 20 by printing or the like.

[0015] The skin layer 40 is formed with a predetermined thickness along the surface 20b of the synthetic resin sheet 20. Examples of the skin layer 40 include a process for adjusting the gloss using a matting agent or a brightening agent, and a process for creating a protective film on the outer surface. Examples of the formation method of the skin layer 40 include printing or coating of a surface treatment agent, and it is preferable to apply by printing using a printing machine such as a gravure printer or an inkjet printer, spray coating with a spray gun, or the like. Furthermore, embossing for attaching a predetermined uneven pattern such as a rib pattern is performed on the skin layer 40.

[0016] When shown in Fig. 3 as a specific example of the synthetic resin leather B, a knitted fabric A serving as the base fabric 10 on the back side, a synthetic resin sheet 20 joined via a foamable adhesive layer 30 to one side of the base fabric 10, and a skin layer 40 formed on the surface side of the synthetic resin sheet 20 are integrally laminated to form a four-layer structure. The thickness of the third layer 3 (void S) in the thickness direction (T direction) of these four-layer structures is preferably set to 10 to 50%. When the thickness of the four-layer structure is about 0.90 to 1.20 mm, the thickness of the third layer 3 (void S) is set to about 0.20 to 0.50 mm. As a result, by joining the base fabric 10 (knitted fabric A) having the third layer 3 in which the void S is formed along the back surface 20a of the synthetic resin sheet 20, the structure is different from that of the conventional synthetic resin leather to which single-sided knitted rib or double-sided knitted rib is joined. Also, although not shown as other examples, it is possible to change to a three-layer structure without the skin layer 40, join the synthetic resin sheet 20 via a non-foamable adhesive layer 30 to one side of the base fabric 10, change the thickness, etc.

[0017] Then, the above-described four-layer-structured synthetic resin leather B (Example) and a synthetic resin leather (Comparative Example) obtained by joining conventional double-sided knitted rib were prepared, and a tensile test was conducted on the elongation in the warp direction and the weft direction. The tensile tests in the warp direction and the weft direction were measured by a test method conforming to JIS K6772. The results of the tensile test were that the elongation at break in the warp direction in the comparative example was 31% and the elongation at break in the weft direction was 196%, the elongation at a constant load in the warp direction was 9% and the elongation at a constant load in the weft direction was 77%. On the other hand, in the example, the elongation at break in the warp direction was 112% and the elongation at break in the weft direction was 113%, the elongation at a constant load in the warp direction was 52% and the elongation at a constant load in the weft direction was 54%. From the results of this peeling test, it was demonstrated that the elongation rates in the warp direction and the weft direction in the example were improved until they became equivalent. Furthermore, with respect to the thicknesses of the examples and the comparative examples, evaluation samples of the same weight (700 g) were prepared from the examples and the comparative examples, and their respective thicknesses were compared. As a result, the thickness of the examples increased by 10 to 20% compared to the thickness of the comparative examples. As a result, it was demonstrated that the examples increased the volume in the thickness direction without increasing the overall weight compared to the comparative examples, and were relatively lightweight. In addition, when comparing the surface morphology of the example and the comparative example, the surface morphology of the comparative example tended to show the uneven patterns formed on the surface of the double-sided knitted wool. On the other hand, in the example, since the third layer 3 in which the gap S was formed was provided between the first layer 1 on the front side and the second layer 2 on the back side in the base fabric 10 (knit A), the uneven patterns formed on the first layer 1 on the front side were deformed toward the gap S with the joining of the synthetic resin sheet 20. Thereby, it was demonstrated that the surface morphology of the example did not show the uneven patterns formed on the first layer 1 protruding to the surface side of the synthetic resin sheet 20. An enlarged cross-sectional photograph of the example taken for reference is shown in FIG. 4, and an enlarged cross-sectional photograph of the comparative example taken is shown in FIG. 5.

[0018] According to the knitted fabric A according to the embodiment of the present invention as described above, the third layer 3 is knitted between the stitches adjacent in the warp direction (Wa direction) in the first layer 1 and between the stitches adjacent in the warp direction (Wa direction) in the second layer 2 so that the gap S is formed between the first layer 1 and the second layer 2, and the first layer 1 and the second layer 2 are knitted together. Thereby, a laminated structure of three or more layers is formed with the gap S sandwiched between the first layer 1 and the second layer 2. Therefore, even when a tensile force in the warp direction (Wa direction) acts on the laminated structure of three or more layers, the third layer 3 is likely to stretch and deform. Therefore, the elongation rates in the warp direction (Wa direction) and the weft direction (We direction) can be made equal. As a result, compared to single-sided knitted wool or double-sided knitted wool that is easily stretched in the transverse direction and easily stretched in the longitudinal direction, cutting and sewing can be performed without worrying about the difference in elongation rates between the warp direction (Wa direction) and the weft direction (We direction). Thereby, great improvement in sewability and yield can be expected. Furthermore, since it has a laminated structure of three or more layers with a gap S formed between the first layer 1 and the second layer 2, it is possible to increase the volume in the thickness direction T without increasing the overall weight. As a result, compared with single-sided knitted fabric or double-sided knitted fabric that is easy to stretch in the transverse direction and easy to stretch in the longitudinal direction, the texture is improved, and weight reduction and texture improvement can be achieved.

[0019] In particular, the first layer 1 has a plurality of first loops 1L that continue in the weft direction (We direction) and are arranged in the warp direction (Wa direction), and the second layer 2 has a plurality of second loops 2L that continue in the weft direction (We direction) and are arranged in the warp direction (Wa direction). The third layer 3 preferably includes a third surface loop 3F that is knitted in the weft direction (We direction) between a plurality of first loops 1L adjacent to each other in the warp direction (Wa direction) in the first layer 1, a third back loop 3B that is knitted between a plurality of second loops 2L adjacent to each other in the warp direction (Wa direction) in the second layer 2, and a curved portion 3C that connects the third surface loop 3F and the third back loop 3B. In this case, when a tensile force acts in the warp direction (Wa direction), the third surface loop 3F and the third back loop 3B extend and deform in a V shape in the warp direction (Wa direction). At the same time, with the extension and deformation of the third surface loop 3F and the third back loop 3B, the curved portion 3C is pulled in the thickness direction T, and the third yarns 3a, 3b can be drawn out in the warp direction (Wa direction) by linear deformation. Therefore, with the addition of the third layer 3, it can be surely stretched in the warp direction (Wa direction). As a result, the elongation rate in the warp direction (Wa direction) can be surely increased to the elongation rate in the weft direction (We direction).

[0020] Furthermore, it is preferable to knit the first yarns 1a, 1b of the first layer 1, the second yarns 2a, 2b of the second layer 2, and the third yarns 3a, 3b of the third layer 3 so that a plurality of each are alternately arranged in the weft direction (We direction). In this case, it can be industrially mass-produced using a machine knitting machine such as a weft knitting machine. As a result, a high-precision knitted fabric A can be produced at low cost.

[0021] Also, it is preferable that a synthetic resin leather B using the knitted fabric A as the base fabric 10 has a synthetic resin sheet 20 joined to at least one side of the base fabric 10. According to such a synthetic resin leather B according to an embodiment of the present invention, the base fabric 10 joined to the synthetic resin sheet 20 extends between the stitches adjacent in the warp direction (Wa direction) in the first layer 1 and between the stitches adjacent in the warp direction (Wa direction) in the second layer 2, and the third layer 3 is knitted in a rib stitch so that a gap S is formed between the first layer 1 and the second layer 2, and the first layer 1 and the second layer 2 are knitted together. Thereby, a laminated structure of three or more layers is formed with the gap S sandwiched between the first layer 1 and the second layer 2. Therefore, even when a tensile force in the warp direction (Wa direction) acts on the laminated structure of three or more layers, the third layer 3 is likely to stretch and deform. Therefore, it is possible to provide a synthetic resin leather B having the same elongation rate in the warp direction (Wa direction) and the weft direction (We direction). As a result, compared with the conventional synthetic resin leather using single-sided knitted rib or double-sided knitted rib as the base fabric, the tensile strength in the longitudinal direction and the transverse direction is averaged. Therefore, even when sewing and making products such as seats (chairs), bags, and clothes, there is no restriction on the cutting direction of the fabric, and waste of the fabric can be reduced. In particular, even in applications where a load is repeatedly applied, such as the seat of an automobile, it is difficult for the shape to collapse, and wrinkles are likely to occur in the sewing part, improving the sewing efficiency. Furthermore, since the base fabric 10 has a laminated structure of three or more layers with a gap S formed between the first layer 1 and the second layer 2, the volume in the thickness direction T can be increased without increasing the overall weight. As a result, compared with the conventional synthetic resin leather using single-sided knitted rib or double-sided knitted rib as the base fabric, the touch is improved, and weight reduction and texture improvement can be achieved. Thereby, natural softness and suppleness can be produced, and the texture as leather is excellent. In addition, since the uneven pattern generated on the front-side first layer 1 is deformed toward the gap S along with the joining with the synthetic resin sheet 20, the uneven pattern generated on the first layer 1 does not protrude on the surface of the synthetic resin sheet 20. Thereby, a high-quality synthetic resin leather B can be easily produced.

[0022] In addition, in the above-described embodiment, only the case where the knitted fabric A is used as the base fabric 10 of the synthetic resin leather B has been described, but the present invention is not limited thereto, and it is also possible to use it in addition to the base fabric 10 of the synthetic resin leather B.

Explanation of Signs

[0023] A Knitted fabric 1 First layer 1L First loop 1a, 1b First thread 2 Second layer 2L Second loop 2a, 2b Second thread 3 Third layer 3F Third front loop 3B Third back loop 3C Curved portion 3a, 3b Third thread S Gap B Synthetic resin leather 10 Base fabric 20 Synthetic resin sheet

Claims

1. a first layer knitted in a knitted fabric pattern, a second layer knitted in a knitted fabric pattern substantially parallel to the first layer, and a third layer knitted in a knitted fabric pattern across the first layer and the second layer, wherein the third layer is knitted between the warp stitches in the first layer and the second layer so as to form a gap between the first layer and the second layer, the first layer has a plurality of first loops knitted so as to be arranged in the warp direction continuously in the weft direction, and the first loops for each column following in the weft direction are knitted such that two or more first yarns are alternately arranged in the weft direction, the second layer has a plurality of second loops knitted so as to be arranged in the warp direction continuously in the weft direction, and the second loops for each column following in the weft direction are knitted such that two or more second yarns are alternately arranged in the weft direction, the third layer has a third front loop knitted in the weft direction between the plurality of first loops adjacent to each other in the warp direction in the first layer, a third back loop knitted between the plurality of second loops adjacent to each other in the warp direction in the second layer, and a curved portion connecting the third front loop and the third back loop, and for each column following in the weft direction, two or more third yarns are knitted such that they are alternately arranged in the weft direction, a knitted fabric characterized in that the thicknesses of the knitted first layer, the second layer, and the third layer are 0.5 mm to 1.0 mm, and the thickness of the third layer is 0.30 mm to 0.60 mm.

2. A synthetic resin leather using the knitted fabric according to Claim 1 as a base fabric, characterized in that a synthetic resin sheet is joined to at least one side of the base fabric.

Images