JP2944780B2 - Manufacturing method of sheet material for molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a sheet material for molding such as a camera case, a vehicle interior material, a bag, a marking material, and a clothing material.

[0002]

2. Description of the Related Art Artificial leather and synthetic leather are used for molded articles such as camera cases, vehicle interior materials, and bags. These can be formed by thermoforming or high-frequency molding.
The feeling is also luxurious and preferable.

[0003] However, these materials are expensive because they are impregnated with a polyurethane resin or the like into a nonwoven fabric or a woven or knitted fabric, and are heavy. It is difficult to obtain satisfactory products.

[0004] Further, there is a vehicle using a non-woven fabric or the like as an interior material for a vehicle. In this case, however, there are many raised materials, which are different from artificial leather.

When such a nonwoven fabric is to be formed, the edges of the nonwoven fabric are partially thinned due to the low density of the nonwoven fabric. Is not preferred. Further, a backing material is required for maintaining the form.

[0006]

SUMMARY OF THE INVENTION The present invention is a new material which solves the drawbacks of these conventional artificial leathers, synthetic leathers and nonwoven fabrics, has a high-grade appearance, is excellent in feel and formability, and is lightweight. A sheet is obtained.

[0007]

According to the present invention, a high-shrinkable polyester fiber having a shrinkage of at least 35% in hot water at 70 ° C. or more is 30% by weight or more, and a heat-fusible fiber is 5% or more.
After mixing and mixing at a ratio of about 30% by weight to prepare a web and performing an entanglement treatment, the high-shrinkable polyester fiber is shrunk, and the area of the obtained sheet is shrunk to an area shrinkage rate of 25% or more. A sheet material for forming, characterized in that the sheet material is subjected to surface processing after being pressurized at 180 ° C. and higher than the shrinkage temperature to increase the apparent density by 30% or more to at least 0.20 g / cm ³ or more. Manufacturing method. ".

The highly shrinkable polyester fiber used in the present invention is a polyester fiber which shrinks greatly by heat treatment and has a shrinkage of 35% or more in 70 ° C. hot water.

This polyester fiber can be produced by appropriately selecting spinning conditions (cooling conditions, take-off speed), drawing conditions, heat treatment conditions, and the like.

The heat-fusible fiber used in the present invention is composed of two kinds of thermoplastic synthetic polymers having different melting points, with a high melting point polymer as a core and a low melting point polymer as a sheath. Although a core-sheath type composite fiber is preferable, a single fiber composed of only a polymer having a low melting point may be used. The melting point of the low melting point component, which is the adhesive component of the heat fusible fiber, is preferably 180 ° C. or less.

The high-shrinkable polyester fiber having a shrinkage ratio of at least 35% in hot water of 70 ° C. or more is 30% by weight or more, and the heat-fusible fiber is 3-35% by weight, preferably,
It is preferable that the high-shrinkable polyester fiber is mixed in a proportion of 50% by weight or more and the heat-fusible fiber is mixed in a proportion of 5 to 25% by weight.

If the high-shrinkable polyester fiber is less than 30% by weight, the shrinkage (area shrinkage) of the non-woven fabric is insufficient and the non-woven fabric is buckled. It will be.

When the amount of the heat-fusible fiber is less than 5% by weight, the shape-retaining properties of the molded article are poor, and when it exceeds 35% by weight, the molded article becomes a film, which is not preferable because it has no bulk.

In forming the web, two kinds of high-shrinkable polyester fiber and heat-fusible fiber may be used, but low-shrinkable fiber which does not substantially shrink at 130 ° C. or lower is used by mixing. In addition, the bulkiness of the finally obtained nonwoven fabric increases, the relative movement between the fibers increases in the steps of shrinkage, pressurization, etc., the entanglement of the fibers generated by needle punching is released, and the fiber density decreases. This is preferable because it becomes easier to be uniform and the generation of wrinkles during the bending process is eliminated.

Examples of the low-shrinkable fiber which does not substantially shrink at a temperature of 130 ° C. or lower include polyester fiber and polyamide fiber. These low-shrinkage fibers can also be formed by spinning conditions (cooling conditions, take-off conditions, etc.), drawing. It can be manufactured by appropriately selecting conditions, heat treatment conditions, and the like.

It is desirable that both the heat fusible fiber and the low shrinkage fiber are polyester fibers.

The high-shrinkage polyester fiber, the heat-fusible fiber and the low-shrinkage fiber may use a raw material-colored polymer.

The web is prepared by opening the high-shrinkable polyester fiber and the heat-sealable fiber or the high-shrinkage polyester fiber, the heat-sealable fiber and the low-shrinkable fiber using an ordinary roller card or the like. Then, the spun fibers can be mechanically laminated or laminated by using an air flow or the like.

In order to perform the entanglement treatment on the web, it is most efficient to perform punching with a barbed needle using a needle rocker or the like. However, a method using a high-pressure water flow or the like may be employed.

Next, the entangled web thus obtained is shrunk so that the surface area of the web is reduced by 30% or more.

When the shrinkage ratio of the web surface area is less than 30%, the fiber density is insufficiently uniform, the uniformity of the surface after pressurization is insufficient, and wrinkles occur during molding. It is not preferable because it is easy to perform and the bulkiness is poor.

It is particularly preferred that the shrinkage ratio of the web surface area be 35 to 60%.

To shrink the web, any method such as a method of immersing the web in warm water and a method of exposing the web to warm air can be adopted. The way to do it is excellent.

The web having been subjected to the shrinkage treatment is further pressurized at a temperature of 70 to 180 ° C. while keeping the web surface area substantially constant, so that the apparent density of the nonwoven fabric becomes 3%.
Increase by at least 0% to at least 0.20 g / cm ³ or more.

If the temperature during pressurization is lower than 70 ° C., it is difficult to increase the apparent density of the web to 0.20 g / cm ³ or more.

If the temperature is higher than 180 ° C., the nonwoven fabric becomes a film-like shape and loses bulkiness, which is not preferable.

As a method of pressing the web, a method of compressing between flat plates having a smooth surface, between a cylinder roll and a belt, between cylinder rolls, or the like, such as a flat plate press, a cylinder belt press, and a roller press, may be employed. is necessary.

In this pressing operation, it is necessary to increase the apparent density of the web by at least 30% or more, preferably 50 to 200%, based on the apparent density of the web after the shrinkage treatment. In addition, there is an effect that unevenness of the web surface caused by entanglement processing such as needle punching is flattened by pressing, and a uniform appearance can be obtained at the time of finishing.

Further, at the time of the entanglement treatment, there is an effect of breaking the fiber bundle which is hooked on the barb of the needle and pushed in the thickness direction of the web, thereby reducing the density unevenness in the web.

When the apparent density of the web is increased by 30% or more by pressurization, these effects are small and the fiber density unevenness of the web is not sufficiently reduced, and the problem that wrinkles are generated during bending cannot be solved.

Further, unevenness of colorant application in the finishing process,
Problems such as poor adhesion of the film layer and unevenness in appearance occur.

Further, the apparent density of the nonwoven fabric is at least 0.
It is necessary to increase it to 20 g / cm ³ or more.

If the content is not increased to 0.20 g / cm ³ or more, it tends to have corners at the time of molding, the molded article is not round, and it is difficult to maintain the shape.

Preferably, 0.30 to 0.70 g / cm ³
Is good.

Next, the nonwoven fabric is finished without being impregnated with a polyurethane resin or the like.

In the finishing process, embossing is performed at a temperature and pressure at which a pattern can be sufficiently formed on the surface to form a desired pattern on the surface.

Alternatively, a colored surface is formed by applying a polymer composition containing a coloring agent to the nonwoven fabric by a gravure printing method or a spraying method until a desired colored layer is applied.

More preferably, embossing makes the appearance more similar to artificial leather.

Alternatively, after a release paper having a desired pattern is coated with a polymer containing a colorant, an adhesive is coated, the polymer film layer is laminated on a nonwoven fabric, and the release paper is peeled off. It is also possible to carry out finishing processing. Furthermore, dyeing processing etc. may be performed,
Other finishing methods can also be used.

Hereinafter, the present invention will be further described with reference to examples.

[0041]

Example 1 An undrawn yarn obtained by melt-spinning polyethylene terephthalate containing 3% by weight of carbon black at 280 ° C. was drawn 2.5 times in warm water at 55 ° C., passed through a crimper, coated with an oil agent, and cut. 2.5 denier 51mm
Was obtained.

This fiber is a highly shrinkable polyester fiber having a shrinkage of 52% in hot water at 70 ° C.

A sheath made of a polyethylene terephthalate copolymer having a melting point of 130 ° C. obtained by copolymerizing an isophthalic acid component at 35 mol%, and a polyethylene terephthalate containing 2% by weight of carbon black disposed at a core portion are 2 denier and a fiber length of 51 mm. Was used as the heat fusible fiber.

The carbon black-containing polyester unstretched tow used in the production of the high shrinkable polyester fiber is stretched 4 times in hot water at 93 ° C. and further stretched 2.1 times in warm water at 60 ° C. The tow having an average denier of 1.8 denier was set at 180 ° C. under tension and heat, then an oil agent was applied, crimped, and then cut into 51 mm. The obtained short fiber had a shrinkage ratio of 1% under a dry heat of 130 ° C.

The above three types of fibers were obtained by dividing the high shrinkage polyester fiber / heat fusible fiber / low shrinkage fiber = 70/10/2
0, then carding and laminating with a card and a cross layer to obtain a web of 200 g / m ² , and then 800 pieces / piece in a needle room equipped with a needle.
Punching of cm ² was performed.

Next, this was immersed in warm water of 68 ° C. for 2 minutes, and contracted by 38% with respect to the original web surface area.

Thereafter, the water content was reduced to 10 with a suction dehydrator.
It was reduced to 0% or less, and then dried under pressure with a cylinder press while keeping the web surface area substantially constant, followed by hot air drying to obtain a nonwoven fabric.

The apparent density of the web is 0.19 g / cm ³
The density of the nonwoven fabric was 0.37 g / cm ³ , and the increase rate of the apparent density was 95%.

Next, a N, N'-dimethylformamide solution containing 5% by weight of a polyurethane containing black pigment was sprayed onto the non-woven fabric to carry out color coating, and then heated and embossed with an embossing roll having a mature cowhide pattern.

This sheet was cut into a square, and was molded using a high-frequency welder for a camera case under the conditions of 12 KW, 1 A, and 3 seconds.

The obtained molded product of the camera case had no sag and had the same appearance as that of artificial leather without corners. Further, the basis weight was as light as 560 g / m ² .

[0052]

Comparative Example 1 The high-shrinkage polyester fiber / low-shrinkage fiber used in Example 1 was mixed at a weight ratio of 70/30, and needle processing, shrinkage processing, and the like were performed under the same conditions as in Example 1.
Pressure drying and hot air drying were performed.

The area shrinkage of the obtained sheet is 32% shrinkage relative to the original web surface area, and the apparent density is 0.1%.
17 g / cm ³ , the apparent density of the nonwoven fabric after processing is 0.32
g / cm ³ . The increase rate of the apparent density was about 88%.

Next, the same finishing and forming processes as in Example 1 were performed. The obtained molded product had the same appearance as that of artificial leather, but could not maintain the form as a camera case, had a large set, and could not be used as a camera case.

[0055]

Comparative Example 2 The same nonwoven fabric as in Example 1 was impregnated with an N, N'-dimethylformamide solution of 7% by weight of a polyurethane resin obtained by adding 2.5 parts of carbon black to 100 parts of a polyurethane resin. And then immersed in warm water at 40 ° C., coagulated, washed and dried.

When the same finishing and molding processes as those of Example 1 were performed, a camera case having a firm shape and an excellent appearance was obtained, but the basis weight was 900 g / m ² , which was heavy.

[0057]

Example 2 An undrawn yarn obtained by melt-spinning polyethylene terephthalate containing 5% by weight of carbon black at 290 ° C. was drawn 2.3 times in hot water at 63 ° C., passed through a crimper and coated with an oil agent. After cutting, short fibers of 2.0 denier 51 mm were obtained. This fiber was a highly shrinkable polyester fiber having a shrinkage of 50% in hot water at 70 ° C.

A single-filament fineness of 3 in which a polyethylene terephthalate copolymer having a melting point of 130 ° C. obtained by copolymerizing 35% by mole of an isophthalic acid component is provided in a sheath portion and polyethylene terephthalate containing 3% by weight of carbon black is provided in a core portion. A denier core-sheath composite fiber having a fiber length of 51 mm was used as the heat-fusible fiber.

The carbon black-containing polyester undrawn tow used in the production of the above high shrinkable polyester fiber is drawn 3.6 times with a hot pin, further heat-set on a heat plate at 180 ° C., then applied with an oil agent and crimped. And then cut to 51 mm (2.5 denier). The shrinkage of the obtained short fibers under dry heat at 130 ° C. was 2%.

The above three types of fibers were obtained by combining high-shrinkable polyester fiber / heat-fusible fiber / low-shrinkable fiber = 65/20/1.
5 and then carding and lamination with a card and a cross layer to prepare a 170 g / m ² web, and 800 needles / cm 2 in a needle room equipped with a needle.
² punching was performed.

Next, this was immersed in warm water at 70 ° C. for 2 minutes, and shrunk by 40% with respect to the original web surface area.

Thereafter, the water content was reduced to 10 by a suction dehydrator.
It was reduced to 0% or less, and then dried under pressure with a cylinder press while keeping the web surface area substantially constant, followed by hot air drying to obtain a nonwoven fabric.

The apparent density of the web was 0.20 g / cm ³ , the density of the nonwoven fabric was 0.40 g / cm ³ , and the increase rate of the apparent density was 100%.

Next, 10% by weight of polyurethane containing black pigment was used.
The N, N'-dimethylformamide solution was color-coated on the nonwoven fabric by a gravure method, and then heated and pressed with a leather-shaped embossing roll.

This sheet was cut into squares, and a thermoformed lithographic plate for marking with the company name was used.
Pressed for a second to obtain a marking material with a clear letter shape. This marking material did not lose characters even when it was bent, and was a marking material having high form stability.

[0066]

Comparative Example 3 The same non-woven fabric after drying with hot air as in Example 2 was subjected to finishing by the same gravure method as in Example 2, but uniform coating could not be performed due to unevenness on the surface.

Further, the resultant was pressed by heating using an embossing roll. As a result, only a part having a poor appearance was obtained due to the presence of a partially convex part having fluff or a film-like corner part.

[0068]

The sheet material obtained by the present invention can be finished in the same manner as artificial leather by forming a uniform and high-density non-woven fabric using high-shrinkable polyester fibers and heat-fusible fibers. It is a lightweight sheet material having a high-grade appearance, excellent feeling and formability.

──────────────────────────────────────────────────の Continuation of front page (51) Int.Cl. ⁶ identification code FI D06N 7/00 D06N 7/00 (58) Field surveyed (Int.Cl. ⁶ , DB name) D04H 1/00-18/00 D01F 8/14

Claims (1)

(57) [Claims] 1. A hot-shrinkable polyester fiber having a shrinkage ratio of at least 35% in hot water of 70 ° C. or more is mixed at a ratio of 30% by weight or more, and a heat-fusible fiber is mixed at a ratio of 3 to 35% by weight. After being formed and entangled, the high-shrinkable polyester fiber is shrunk to shrink the area of the obtained sheet to an area shrinkage of 25% or more, and then at 70 to 180 ° C and a temperature higher than the shrinkage temperature. A method for producing a sheet material for molding, comprising applying pressure to increase the apparent density by 30% or more to at least 0.20 g / cm ³ or more, and then subjecting the sheet material to surface treatment.