JP7095967B2 - Composite fiber and molded body - Google Patents

Description

The present invention relates to a composite fiber and a molded product using the composite fiber. More specifically, the present invention relates to a technique for forming a fabric-like molded body using a woven fabric, a knitted fabric, or a braided fabric in which threads are arranged in two or more directions.

Fabric-like resin molded bodies (hereinafter referred to as fabric-like molded bodies) that have a fabric-like appearance are interior parts for vehicles such as automobiles and trains, interior materials for buildings such as houses and offices, furniture, and interiors. It is used in various fields such as miscellaneous goods and daily necessities. Conventionally, as a method of forming a fabric-like molded body, for example, there are a method of fixing short fibers to the surface of a resin molded body (see Patent Document 1) and a method of forming a fabric pattern by printing (see Patent Document 2). ..

Further, in order to realize a more natural woven fabric pattern, a decorative material in which a woven fabric-like uneven pattern is formed on the surface of the base material has also been proposed (see Patent Document 3). Furthermore, in order to realize surface characteristics with less fraying and wear while having the appearance image peculiar to woven fabrics made of natural fibers, a fabric-like heat-shielding film material in which both sides of the fiber fabric are impregnated with a resin layer has been proposed. (See Patent Document 4). In the heat shield film material described in Patent Document 4, core-sheath spun yarns are used for at least one of the warp and wefts constituting the fiber fabric.

Japanese Unexamined Patent Publication No. 8-117681 Japanese Unexamined Patent Publication No. 10-414186 Japanese Unexamined Patent Publication No. 2001-113894 Japanese Unexamined Patent Publication No. 2015-83725

However, the above-mentioned conventional fabric-like molded product has the following problems. In the fabric-like molded product described in Patent Document 1, the step of fixing the single fiber to the surface of the molded product is complicated and time-consuming. Further, the fabric-like molded body described in Patent Document 2 is easy to manufacture because a sheet on which a fabric pattern is printed may be laminated on a substrate sheet, but it can be seen as a real fabric from any direction by printing. It is difficult to obtain the same luster and texture.

Further, in the fabric-like molded body described in Patent Document 3, a fiber-like pattern is formed by finely engraving the surface of the sheet-like material, but in this method, the glossiness peculiar to the fiber changes depending on the viewing angle. It is impossible to produce a texture, and it is difficult to make the texture look like a real textile material. On the other hand, the fabric-like molded body described in Patent Document 4 has an appearance close to that of a real cloth because the molded body is formed by using a fiber cloth, but includes a plying / impregnation step. Therefore, it is inferior in processability, and it is inferior in shapeability after molding into a film material because plying or impregnated resin is used.

Therefore, an object of the present invention is to provide a composite fiber capable of obtaining a fabric-like molded body having a fiber texture and a fabric-like molded body using the composite fiber.

As a result of diligent experimental studies in order to solve the above-mentioned problems, the present inventor heat-molds a woven fabric, a knitted fabric or a braided fabric formed by using a composite fiber having specific optical characteristics. We have found that a fabric-like molded body having a texture closer to that of real fiber can be obtained, and have reached the present invention. In the present invention, "texture" is a visual impression received by the color tone, pattern, gloss, etc. of the fiber, and "having the texture of the fiber" means, for example, a woven fabric composed of fibers having two vertical and horizontal axes. The difference in lightness between the warp and weft caused by the optical anisotropy of the fiber can be visually recognized, and when rotated by 90 °, the light and darkness of each thread is switched as in the case of real fabric.

The composite fiber according to the present invention is made of a second thermoplastic resin having a cross section perpendicular to the longitudinal direction and having a melting point higher than that of the first thermoplastic resin in the sea component made of the first thermoplastic resin. A composite fiber having a sea-island structure in which a plurality of island components are scattered, the first thermoplastic resin is a propylene copolymer , polyethylene, or a polymer alloy in which these are mixed, and has a parallel light transmittance of 5. % Or more of the resin , the second thermoplastic resin is polyethylene, polypropylene, polyethylene terephthalate , polybutylene terephthalate, or a polymer alloy in which these are mixed, and the island component indicates a temperature rise rate of 30 ° C./min. The degree of crystallization measured by the scanning calorimeter is 10% or more, and the ratio of the island components is 50 to 90% by volume.
In the composite fiber of the present invention, for example, the crystallinity of the island component can be 60% or more.
The first thermoplastic resin is, for example, a resin having a parallel light transmittance of 13% or more .

The molded body according to the present invention is a molded body formed by heat-molding a woven fabric, a knitted fabric, or a braided fabric in which threads are arranged in two or more directions, and is the same as the woven fabric, the knitted fabric, or the braided fabric. The composite fiber described above is used for two or more axes.
In the molded body of the present invention, in each composite fiber used for the woven fabric, knitted fabric or braid, for example, only the sea component is melted by the thermoforming, and the island component exists as it is. ing.

According to the present invention, since the composite fiber having a specific optical property is used, it is possible to realize a fabric-like molded body having the texture of the fiber.

It is a figure which shows typically the example of the cross-sectional structure of the composite fiber of 1st Embodiment of this invention. It is a figure which shows typically the example of the cross-sectional structure of the undrawn yarn used for the composite fiber 10 shown in FIG. 1.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments described below.

(First Embodiment)
First, the composite fiber according to the first embodiment of the present invention will be described. FIG. 1 is a diagram schematically showing an example of a cross-sectional structure of a composite fiber of the present embodiment, and is a cross-sectional view in a direction perpendicular to a longitudinal direction (stretching direction). As shown in FIG. 1, the composite fiber 10 of the present embodiment has a structure in which a plurality of island components 2 are interspersed in a sea component 1 having a cross section perpendicular to the longitudinal direction, and the island components 2 are continuous in the length direction. It is a sea-island type composite fiber.

[Sea component 1]
The sea component 1 is a binder (matrix) component for integrating a plurality of island components 2, is made of a thermoplastic resin (hereinafter referred to as a first thermoplastic resin), and has a parallel light transmittance of 5% or more. be. The "parallel light transmittance" referred to here is a value measured by a haze meter using a sheet-shaped sample having a thickness of 0.70 ± 0.05 mm.

As will be described later, when the fabric-like molded body is formed by using the composite fiber 10 of the present embodiment, the color tone and the pattern of the fibers constituting the fabric pattern are expressed by the island component 2. However, when the parallel light transmittance of the sea component 1 is less than 5%, the island component 2 becomes difficult to see, and the color tone and pattern of the fibers constituting the fabric pattern become unclear when the molded body is formed. The sea component 1 preferably has a parallel light transmittance of 13% or more, whereby a texture closer to that of a real fabric can be obtained when a molded product is formed.

Examples of the first thermoplastic resin constituting the sea component 1 include a propylene copolymer (co-PP) such as an ethylene-propylene random copolymer and a linear low density polyethylene (LLDPE). It is not limited to this, and any thermoplastic resin having a parallel light transmittance of 5% or more may be used. The first thermoplastic resin may be a polymer alloy in which two or more kinds of polymers are mixed, and may be an antioxidant, a neutralizing agent, a light stabilizer, as long as the above-mentioned range of parallel light transmittance can be maintained. Various additives such as lubricants and antistatic agents and pigments for coloring may be blended.

[Island component 2]
The island component 2 is a component that expresses the color tone and pattern of fibers when a fabric-like molded product is formed, and is a thermoplastic resin having a higher melting point than the above-mentioned first thermoplastic resin (hereinafter referred to as a second thermoplastic resin). ), And the degree of crystallization is 10% or more. When the melting point of the second thermoplastic resin constituting the island component 2 is equal to or lower than the melting point of the first thermoplastic resin, the island component 2 is melted during spinning or drawing, and the island component 2 is scattered in the sea component 1. The composite fiber 10 having a sea-island structure cannot be obtained. From the viewpoint of ease of manufacturing the composite fiber 10 and the fabric-like molded body, the melting point of the second thermoplastic resin is preferably 20 ° C. or higher higher than the melting point of the first thermoplastic resin.

Further, when the fabric-like molded body is formed by using the composite fiber 10, the color tone and the pattern of the fiber are expressed by the orientation of the crystalline resin constituting the island component 2. Therefore, if the oriented crystals of the second thermoplastic resin constituting the island component 2 are insufficient, the difference in brightness between the warp and weft becomes small, and the pattern of the fabric pattern becomes difficult to see. Specifically, when the crystallinity of the island component 2 is less than 10%, the difference in brightness between the warp and the weft becomes small when the fabric-like molded body is formed, and the visibility of the color tone and the pattern is lowered. Therefore, the crystallinity of the island component 2 is set to 10% or more. Further, from the viewpoint of improving the texture when the fabric-like molded product is formed, the crystallinity of the island component 2 is preferably 60% or more.

The crystallinity of the island component 2 can be measured with a differential scanning calorimeter (DSC). Generally, when measuring the melting point of a resin using DSC, the temperature rise rate is set to 10 ° C./min, but the amount of heat of melting is measured for fibers that have oriented crystallization such as drawn products. When determining the difference in the inherent crystallization degree, if the temperature rise rate is slow, crystallization proceeds during the temperature rise, and the amount of heat of fusion different from that before the measurement is measured. Therefore, in the present invention, the crystallinity of the island component is defined by a value measured at a temperature rising rate of 30 ° C./min.

Examples of the second thermoplastic resin constituting the island component 2 include crystalline polyesters and nylons such as polypropylene (PP), potiethylene (PE), polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). However, the present invention is not limited to these, and any thermoplastic resin having a higher melting point than the first thermoplastic resin and having a crystallinity of island component 2 of 10% or more when drawn into a composite fiber may be used. .. The second thermoplastic resin may be a polymer alloy in which two or more kinds of polymers are mixed, and is an antioxidant, a neutralizing agent, a light stabilizer, a lubricant and a lubricant as long as the effect of the present invention is not affected. Various additives such as antistatic agents and pigments for coloring may be blended.

[Component ratio]
In the composite fiber 10 of the present embodiment, the component ratio (sea component / island component) of the sea component 1 and the island component 2 is 50/50 to 10/90 in volume ratio. That is, the ratio of the island component 2 in the composite fiber 10 is 50 to 90% by volume. When the ratio of the island component 2 in the composite fiber 10 is less than 50% by volume, the thickness of the sea component 1 from the surface of the composite fiber 10 increases, and the color tone and pattern of the fiber expressed by the island component 2 become difficult to see. On the other hand, when the ratio of the island component 2 in the composite fiber 10 exceeds 90% by volume, the sea component 1 which is a binder component is insufficient, and it becomes difficult to shape the composite fiber into a molded product such as a sheet by heat processing.

[Production method]
Next, a method for producing the composite fiber 10 of the present embodiment will be described. FIG. 2 is a diagram schematically showing an example of a cross-sectional structure of an undrawn yarn used for the composite fiber 10 shown in FIG. The composite fiber 10 of the present embodiment can be formed, for example, by using an undrawn yarn having a sheath core structure having a cross-sectional structure as shown in FIG. In that case, since the sheath portion 11 of the undrawn yarn becomes the sea component 1 of the composite fiber 10 and the core portion 12 becomes the island component 2, the sheath portion 11 is formed of the first thermoplastic resin, and the core portion 12 is the second. Formed from thermoplastic resin.

About 10 to 1000 undrawn threads having this sheath core structure are focused, and the resin (second thermoplastic resin) constituting the core portion 12 has a melting point equal to or higher than the melting point of the resin (first thermoplastic resin) constituting the sheath portion 11. It is stretched and integrated while being heated at a temperature below the melting point. As a result, the composite fiber 10 in which a plurality of island components 2 are scattered in the sea component 1 is obtained. The method for producing the composite fiber 10 of the present embodiment is not limited to the above-mentioned method, and for example, the drawing step and the integration step may be performed separately.

As described in detail above, the composite fiber of the present embodiment has a sea island structure having a cross section perpendicular to the longitudinal direction, a parallel light transmittance of the sea component of 5% or more, and a crystallization degree of the island component of 10% or more. Since the ratio of the island component is 50 to 90% by volume, the visibility of the color tone and the pattern is improved when the fabric-like molded body is formed. Then, by using the composite fiber of the present embodiment, it is possible to realize a fabric-like molded body having the texture of the fiber.

(Second embodiment)
Next, the molded body according to the second embodiment of the present invention will be described. The molded body of the present embodiment is a fabric-like molded body formed by heat-molding a woven fabric, a knitted fabric, or a braided fabric in which threads are arranged in two or more directions. The composite fiber 10 of the first embodiment described above is used for two or more axes in the woven fabric, knitted fabric, and braid used for the molded body of the present embodiment.

The "woven cloth", "knitted cloth" and "knitted cloth" used in the molded body of the present embodiment are cloths in which threads of two or more axes are combined, and have a certain angle among the constituent raw threads. There are two or more intersecting threads. For example, in the case of woven cloth, plain weave cloth, twill woven cloth, satin woven cloth, etc. consisting of two or more threads are applicable, and in the case of knitted cloth, three-axis knitted cloth, etc. are applicable. The methods for producing these woven fabrics, knitted fabrics and braided fabrics are not particularly limited, and can be produced by known methods.

The molded body of the present embodiment is manufactured by thermoforming a woven fabric, a knitted fabric, or a braided fabric in which the composite fiber 10 of the first embodiment described above is used for two or more axes. The thermoforming method is not particularly limited, and can be appropriately selected depending on the purpose and shape, such as a molding method using a non-contact heating method such as infrared heating, in addition to heat press molding. The heating temperature at that time is higher than the melting point of the sea component 1 (first thermoplastic resin) and the island component 2 (second thermoplastic resin) is higher than the melting point of the sea component 1 (first thermoplastic resin) from the viewpoint of improving moldability and visibility of color tone and pattern. It is preferably lower than the melting point. As a result, only the sea component 1 of the composite fiber 10 is melted, and the island component 2 is not melted and exists as it is. As a result, the difference in brightness between the warp and weft expressed by the island component 2 imparts a texture close to that of a real fiber material to the molded product.

The shape of the molded body of the present embodiment is not particularly limited, and various shapes such as a sheet shape, a substantially box shape, and a curved surface shape can be adopted.

As described in detail above, since the molded body of the present embodiment is a heat-molded woven fabric, knitted fabric or braided fabric formed by using the composite fiber of the first embodiment, it can be made into a real fabric. A fabric-like molded body having similar colors and patterns and reproducing the texture of fibers can be obtained.

Hereinafter, the effects of the present invention will be specifically described with reference to Examples and Comparative Examples. In this example, sheet-shaped molded bodies (hereinafter, simply referred to as sheets) of Examples and Comparative Examples were produced by the following methods, and their textures were evaluated.

<Example 1>
240 undrawn yarns with a sheath core structure are focused and made of homo-PP (Y2000GV manufactured by Prime Polymer Co., Ltd., melting point 165 ° C.), an island component having a crystallinity of 62.1%, and PE (manufactured by Prime Polymer Co., Ltd.). A composite fiber having a sea-island structure having a parallel light transmittance of 13.3% and a sea component / island component of 35/65 by volume was produced.

This composite fiber was woven to obtain a plain weave cloth, which was thermoformed to obtain the sheet of Example 1. For thermoforming, a woven cloth is sandwiched between iron plates to which a fluororesin sheet is attached, set in a hot press machine heated to 140 ° C, heated at 140 ° C for 1 minute to melt the sea components, and then 140 ° C. It was carried out by pressurizing at 1 MPa for 1 minute while still being heated in. The thermoformed sheet was cooled to 50 ° C. or lower by water-cooling the hot press machine while being pressurized, and then taken out from the hot press machine.

<Example 2>
The island component is composed of a resin obtained by adding 2% by mass of a red pigment (PPM (F) 27961 red manufactured by Tokyo Ink Co., Ltd.) to homo PP (Y2000GV manufactured by Prime Polymer Co., Ltd., melting point 165 ° C.), and the sea component is PE (stock). A composite fiber was produced by the same method and conditions as in Example 1 described above, except that it was composed of SP1071C manufactured by Prime Polymer Co., Ltd., melting point 100 ° C.). In this composite fiber, the crystallinity of the island component was 65.4%, and the parallel light transmittance of the sea component was 24.4%. Then, this composite fiber was woven to obtain a plain weave cloth, which was thermoformed by the same method and conditions as in Example 1 to obtain a sheet of Example 2.

<Example 3>
Except for the fact that the island component was composed of a resin obtained by adding 2.5% by mass of a black pigment (TPM 9BB019 manufactured by Tokyo Ink Co., Ltd.) to homoPP (Y2000GV manufactured by Prime Polymer Co., Ltd., melting point 165 ° C.), the same as Example 2 described above. Composite fibers were prepared by the same method and conditions. The crystallinity of the resin forming the island component was 66.8%. Then, this composite fiber was woven to obtain a plain weave cloth, which was thermoformed by the same method and conditions as in Example 1 to obtain a sheet of Example 3.

<Example 4>
The island component is composed of a resin containing homo PP (Y2000GV manufactured by Prime Polymer Co., Ltd., melting point 165 ° C.) and homo PP (S135 manufactured by Prime Polymer Co., Ltd., melting point 165 ° C.), and the sea component is co-PP (Prime Co., Ltd.). A composite fiber was produced by the same method and conditions as in Example 1 described above, except that the polymer was made of Y2045GP and had a melting point of 131 ° C.). In this composite fiber, the crystallinity of the island component was 62.1%, and the parallel light transmittance of the sea component was 65.6%. Then, this composite fiber was woven to obtain a plain weave cloth, which was thermoformed by the same method and conditions as in Example 1 to obtain a sheet of Example 4.

<Example 5>
Same as Example 1 described above except that the island component is composed of homoPP (Y2000GV manufactured by Prime Polymer Co., Ltd., melting point 165 ° C.) and the sea component is composed of PE (SP1071C manufactured by Prime Polymer Co., Ltd., melting point 100 ° C.). The composite fiber was prepared according to the method and conditions of the above. In this composite fiber, the crystallinity of the island component was 62.1%, and the parallel light transmittance of the sea component was 24.4%. Then, this composite fiber was woven to obtain a triaxial braid, which was thermoformed by the same method and conditions as in Example 1 to obtain a sheet of Example 5.

<Example 6>
Same as Example 1 described above except that the island component is composed of PET (NEH2050 manufactured by Unitika Ltd., melting point 252 ° C.) and the sea component is composed of co-PP (WFW4 manufactured by Japan Polypropylene Corporation, melting point 125 ° C.). The composite fiber was prepared according to the method and conditions of the above. In this composite fiber, the crystallinity of the island component was 13.4%, and the parallel light transmittance of the sea component was 65.6%. Then, this composite fiber was woven to obtain a plain weave cloth, which was thermoformed by the same method and conditions as in Example 1 to obtain a sheet of Example 6.

<Example 7>
Same as Example 1 described above except that the island component is composed of homoPP (Y2000GV manufactured by Prime Polymer Co., Ltd., melting point 165 ° C.) and the sea component is composed of HDPE (S6932 manufactured by Keiyo Polyethylene Co., Ltd., melting point 131 ° C.). The composite fiber was prepared according to the method and conditions of the above. In this composite fiber, the crystallinity of the island component was 62.1%, and the parallel light transmittance of the sea component was 6.8%. Then, this composite fiber was woven to obtain a plain weave cloth, which was thermoformed by the same method and conditions as in Example 1 to obtain a sheet of Example 7.

<Comparative Example 1>
The island component is composed of a resin obtained by adding 2.5% by mass of a black pigment (TPM 9BB019 manufactured by Tokyo Ink Co., Ltd.) to Homo PP (Y2000GV manufactured by Prime Polymer Co., Ltd., melting point 165 ° C.), and the sea component is PE (Prime Co., Ltd.). A composite fiber was produced by the same method and conditions as in Example 1 described above, except that the resin was composed of a polymer SP1071C (melting point 100 ° C.) and a black pigment (EPE-K522432 manufactured by Polycol Kogyo Co., Ltd.) added in an amount of 6% by mass. did. Since this composite fiber has a lower draw ratio than the composite fiber used in Example 3, the crystallinity of the island component containing the black pigment is 61.2%, and the parallel light transmittance of the sea component containing the black pigment is high. It was 0%. Then, this composite fiber was woven to obtain a plain weave cloth, which was thermoformed by the same method and conditions as in Example 1 to obtain a sheet of Comparative Example 1.

<Comparative Example 2>
The island component is composed of PET (NEH2050 manufactured by Unitika Co., Ltd., melting point 252 ° C.), and the sea component is co-PP (WFW4 manufactured by Nippon Polypro Co., Ltd., melting point 125 ° C.) and white pigment (TPM 1BB111 WHITE MF manufactured by Tokyo Ink Co., Ltd.). A composite fiber was produced under the same method and conditions as in Example 1 described above, except that the resin was composed of 5% by mass of AL). In this composite fiber, the crystallinity of the island component was 13.4%, and the parallel light transmittance of the sea component containing the white pigment was 4.1%. Then, this composite fiber was woven to obtain a plain weave cloth, which was thermoformed by the same method and conditions as in Example 1 to obtain a sheet of Comparative Example 2.

<Comparative Example 3>
Composite fibers were produced by the same methods and conditions as in Example 6 described above, except that the draw ratio in the drawing step was reduced. In this composite fiber, the crystallinity of the island component was 9.5%, and the parallel light transmittance of the sea component was 65.6%. Then, this composite fiber was woven to obtain a plain weave cloth, which was thermoformed by the same method and conditions as in Example 1 to obtain a sheet of Comparative Example 3.

The "crystallinity" and "parallel light transmittance" of the thermoplastic resins used in Examples 1 to 7 and Comparative Examples 1 to 3 were measured by the following methods.

[Crystallinity]
The crystallinity of the island component was measured with a differential scanning calorimeter (DSC). Specifically, 5 mg of sample raw yarn (composite fiber) was set in a DSC device, heated at a heating rate of 30 ° C./min, and melted at a temperature of 300 ° C. Then, the mixture was cooled at a temperature lowering rate of 100 ° C./min, reached a temperature of 30 ° C., and then kept at an isothermal state for 5 minutes. This sample was heated again to 300 ° C. at 30 ° C./min.

Then, the measured melting peak area (J) of the island component is divided by the mass (g) of the island component to calculate the melting heat amount (J / g), and the melting heat amount (ΔHm) at the time of the first temperature rise is calculated. The degree of crystallization of the island component was determined from the amount of heat of melting (ΔHc) and the amount of heat of complete crystal melting (ΔHm ₀ ) at the time of the second temperature rise based on the following formula 1.

[Parallel light transmittance]
After uniformly arranging the resins (raw material pellets) that form the sea component on the iron plate to which the fluororesin sheet is attached, surround it with an iron plate frame with a thickness of 0.70 mm, and then place the iron plate to which the fluororesin sheet is attached. I put it. In that state, the sample was set in a hot press heated to a temperature equal to or higher than the melting point of the sample to be measured, heated for 1 minute to melt the resin, and further heated at 1 MPa for 1 minute. Then, the sample was taken out from the heat press machine, and the whole iron plate was put into water and rapidly cooled. By the above procedure, a resin sheet having a thickness of 0.70 ± 0.05 mm was produced. Using this measuring resin sheet, the parallel light transmittance was measured with a haze meter (NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd., light source halogen lamp).

Next, the glossiness, color tone and pattern of each sheet of Examples and Comparative Examples produced by the above-mentioned method were evaluated by the methods shown below.

[Glossiness]
The composite fibers used in Examples and Comparative Examples were arranged on a flat plate without gaps so as to be parallel to each other. At this time, the composite fibers sometimes overlapped with each other, but since there was no problem, they were left as they were. Then, the composite fibers arranged substantially in parallel were pressed while heating at a temperature at which only the sea component was melted to obtain a sheet-shaped molded body in which the island components were arranged on one axis. Then, using a gloss meter (manufactured by Suga Test Instruments Co., Ltd., a light source tungsten bulb), the glossiness in the longitudinal direction and the width direction of this sheet-shaped molded body was measured.

[Color tone / pattern]
Each sheet of the example and the comparative example was placed under a lamp of 20 lux and visually observed by a panel of 5 people, and the difference in brightness between the fibers of different axes (difference in brightness between the warp and weft) was observed. It was judged whether the generated pattern and the color tone of the fiber could be identified. As a result, those judged to be identifiable by all (5 people) are marked with ○, those judged to be identifiable by 3 or 4 people are marked with △, and those judged to be identifiable by 2 or less are marked with ×. did.

The above results are summarized in Table 1 below.

As shown in Table 1 above, in the sheets of Comparative Example 1 and Comparative Example 2 in which the parallel light transmittance of the sea component was less than 5%, the fiber pattern was visible, but the color tone was difficult to see. Further, the sheet of Comparative Example 3 in which the parallel light transmittance of the sea component is 5% or more but the crystallization degree of the island component is less than 10% has a small difference in brightness between the warp and weft, and the fiber pattern and color tone. Was inferior in visibility.

On the other hand, the sheets of Examples 1 to 7 produced within the scope of the present invention had excellent visibility in both the fiber pattern and the color tone, and had a color tone and a pattern close to those of real cloth. In particular, the sheets of Examples 1 to 5 having a crystallinity of the island component of 60% or more and a high parallel light transmittance of the sea component obtained a texture closer to that of real fiber. From the above results, it was confirmed that according to the present invention, a fabric-like molded product having a fiber texture can be obtained.

1 Sea component 2 Island component 10 Composite fiber 11 Sheath 12 Core

Claims (5)

A plurality of island components composed of a second thermoplastic resin having a melting point higher than that of the first thermoplastic resin are scattered in the sea component having a cross section perpendicular to the longitudinal direction made of the first thermoplastic resin. A composite fiber with a sea-island structure
The first thermoplastic resin is a propylene copolymer , polyethylene, or a polymer alloy in which these are mixed, and has a parallel light transmittance of 5% or more .
The second thermoplastic resin is polyethylene, polypropylene, polyethylene terephthalate , polybutylene terephthalate, or a polymer alloy in which these are mixed.
The island component has a crystallinity of 10% or more measured by a differential scanning calorimeter at a heating rate of 30 ° C./min.
A composite fiber having an island component ratio of 50 to 90% by volume. The composite fiber according to claim 1, wherein the island component has a crystallinity of 60% or more. The composite fiber according to claim 1 or 2, wherein the first thermoplastic resin has a parallel light transmittance of 13% or more. A molded body formed by heat-molding a woven fabric, knitted fabric, or braided fabric in which threads are arranged in two or more directions.
The woven fabric, knitted fabric, or braided fabric is a fabric-like molded body in which the composite fiber according to any one of claims 1 to 3 is used for two or more axes. The fabric according to claim 4, wherein in each of the composite fibers used in the woven fabric, the knitted fabric, or the braided fabric, only the sea component is melted by the thermal molding, and the island component exists as it is. Tone molded body.

Images