JPS6039488A - Manufacture of artificial leather sheet - Google Patents

Abstract

PURPOSE:To obtain the titled high-quality sheet having flexible and tough texture, by applying a specific aqueous emulsion of a polymeric elastomer to a nonwoven sheet composed of a fiber capable of forming ultrafine fibrils, needling the sheet to obtain a composite sheet, and subjecting to the heat-shrinkage treatment and the fibrillation treatment. CONSTITUTION:For example, a web is manufactured with a composite fiber capable of forming ultrafine fibrilas of <=0.3d, e.g. oriented polymer fiber having sea-and-island structure, and the web is needled to obtain a nonwoven sheet. An aqueous emulsion of a polymeric elastomer, e.g. a polyurethane having a swelling ratio in trichloroethylene of >=20 (by weight), a melting point of >=190 deg.C and Young's modulus of <=150kg/cm<2> is applied to the nonwoven sheet, and needled in undried state to obtain a composite sheet. The sheet is subjected to the heat- shrinkage treatment (shrinkage of >=30%) and then to the fibrillation treatment. A flexible and tough high-quality artificial leather sheet can be manufactured even by using the polymeric elastomer in the form of an aqueous emulsion by suppressing the migration of said elastomer during solidification.

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to ultra-thin fibers (those made of an elastic polymeric material).
-Relating to a method for manufacturing leather.

(Prior Art and Its Disadvantages) It has been well known to manufacture artificial leather using a composite sheet made of ultrafine fibers and an elastomer polymer.

There are two types of polymeric elastomer binders: a solvent type in which the polymeric elastomer is dissolved in an organic solvent, and a water emulsion type in which the polymeric elastomer is dispersed in water. are commonly used, while the latter is rarely used despite its great advantages of being safe and easy to handle.

The reason for this is that the former is wet-coagulated after being applied to the l1lff sheet, so that it is uniformly distributed inside the fiber sheet.
However, since it can be applied with a porous structure, it is flexible and has good surface quality.

This is because the latter is difficult to perform wet solidification, and furthermore, when dry solidified, a so-called migration phenomenon occurs in which the binder migrates to both the front and back surfaces during assimilation. Due to this migration phenomenon, the interior of the sheet 1 becomes hollow and the texture hardens, making it extremely unsuitable as an artificial leather sheet.

On the other hand, in order to take advantage of the advantages of water emulsion type binders, many proposals have been made to suppress the McGration phenomenon during dry assimilation, but no satisfactory method has yet been found. Moreover.

Conventional water emulsion binders are generally heat resistant, t
Due to poor I4 solvent titre, flexibility, etc., there are many problems with processability and physical properties, and these points have also been cited as reasons why it is not suitable for use in artificially grown seedling sheets.

(Object of the Invention) An object of the present invention is to provide a method for manufacturing a flexible and tough high-grade artificial leather sheet by solidifying a 44im II It receipt water emulsion type binder while preventing migration.

(Structure of the Invention) The present invention provides that a trichlorethylene swelling ratio of 20 times or less (f
II ratio), I! The point is over 190℃? N'J rate is 150
kq10 (A composite sheet is created by attaching the following water emulsion type polymeric elastomer and needling in an undried state)
The present invention relates to a method for producing an artificial leather sheet, which is then subjected to a heat shrinkage treatment and an ultrafine treatment.

The present invention uses Kyoku 111 fiber generation type fiber, uses a water emulsion type binder which has excellent heat resistance, solvent resistance and flexibility as a polymeric elastic body, and uses a water emulsion type binder for the fiber sheet. After applying the binder, needling is performed in a bed-dried state to form a sheet, and furthermore, the composite sheet undergoes heat shrinkage 51!11! I! It consists of a combination of

The present invention cannot be achieved without these combinations.

(Available range for epidemic prevention) The ultrafine fiber-generated binding cord used in the present invention is as follows.

There are no particular limitations. For example, seabird-shaped polymer array chicks,
#2 Combined spun yarn mH, various split type binding cords, especially polymer array $
1$1 [is a fiber suitable for the present invention. As the ultrafine fiber component, melt f1 linear polymers having fiber-forming ability such as polyester, polyamide, polypropylene, and polyethylene are suitable, and one or more of these can be used. In particular, polyethylene terephthalate, nylon 6, and nylon 66 are preferred because of the physical properties and practical performance of the resulting product. These poles 1111'Iff
Liquid bath, steam or dry heat stretching using generated fibers,
Processes such as crimping, cutting, and opening are performed to produce raw cotton. There are no particular limitations to this method; use short fibers! ! All known methods can be applied.

The thickness of the composite I1M after stretching used in the present invention is 0.3 to 1
Preferably it is 0 denier.

Particularly preferably, it is 1 to 6 denier, and after ultrafine treatment, the single yarn is 0.7 denier or less, preferably 0.3 denier or less.

As the water J-mulsion type binder used in the present invention, one or more types of polyurethanes, polybutadiene, polyisobutane, polyacrylic, etc. can be used, but from the viewpoint of practical performance of the resulting product, and polyacrylics are suitable water emulsion binders for this invention.

In order for the product to withstand dry cleaning, such a water emulsion type binder must have a trichlorethylene swelling ratio of 20 times or less (weight ratio), preferably 1.5 to 1.
In order to withstand high-temperature dyeing or ironing, the melting point should be 190°C or higher, and to obtain a flexible product, the Young's modulus should be 150 kIJ/- or lower. The present invention cannot be achieved without a binder having all of these properties. The swelling rate of trichlorethylene refers to the weight of a polyurethane dry film of approximately 5 cm square with a thickness of approximately 0.5 (foundation) immersed in trichlorethylene for 1 day at room temperature. This is the value divided by The melting point is the temperature at which a section of rimple is placed in a thin capillary and raised to a high temperature, and the section begins to lose its shape.

Young's modulus is obtained by performing a conventional tensile test.

A water emulsion binder that satisfies the following properties at the same time is, for example, a propylene oxide adduct of trimethylolpropane as the polyol component,
Diols such as propylene oxinoid adducts of glycerin include polycaprolactone diol and polytetramethylene glycol, and hydrogenated P as isocyanate components.

Chain extension components such as P'-diphenylmethane diisocyanate and inphorone diisocyanate contain water and/or
Alternatively, a water emulsion type polyurethane made of hexamethylene diamine, hydrazine, isophorone diamine, etc. may be used.

Next, sea urchin 1 is made using the above-mentioned raw cotton, and known methods such as card, cross wrapper, random sea urchin, etc. can be applied to the raw cotton.

This web is subjected to LIv needling to achieve initial entanglement to the extent that a water-one-water emulsion binder can be applied in the second step. Thereafter, a water emulsion binder is applied to the initial entangled sheets 1 to 1 by spraying, coating, dipping, etc., and needling is performed in an undried state. The reason why needling is performed while the binder is in an undried state is to push the binder into the sheet as soon as the fibers are entangled, and to suppress the so-called migration phenomenon in which the binder moves to the front and back sides as the moisture dries. V) which caused entanglement of the Si film and solidification of the binder.

In such needling, the needling resistance increases as fiber entanglement or binder solidification progresses, so it is preferable to complete the needling when the binder is semi-solidified. The needle density at this time is preferably 200 to 4000 needles/d, particularly preferably 500 to 3000 needles/aI. The amount of binder applied is preferably 2 to 80% (weight ratio) in terms of solids to the IIN sheet, particularly preferably 5 to 80% (weight ratio).
~60% (weight ratio). If the target amount is not reached in one binder application process, it is preferable to perform the application process two or more times and repeat the combination process of needling/binder application. A lubricant may be applied to the needling before or during sheet formation to reduce needle resistance.

Note that although the fiber sheet of the present invention is mainly composed of nonwoven fabric, it can also have a structure that uses woven or knitted fabric in some cases.

This composite sheet is wet-shrinked and/or dry-shrinked to form a high-density rIXm composite sheet. The area shrinkage rate at this time is preferably at least 20%, particularly preferably 30% or more.

After that, the composite sheet is subjected to ultrafine treatment,
Ultra-fine silk-generated IJ [artificial leather sheet 1]
~. This ultra-fine treatment is achieved by physical and chemical treatment for split-type composite binding strings, and for composite fibers where ultra-fine fibers become apparent by removing one component, unnecessary components are removed using a solvent. Which method do you use? Such ultra-fine treatment may be performed after applying a shape fixing agent such as polyvinyl alcohol depending on the case.

The thus obtained artificial leather sheet has ultrafine fibers intertwined with each other at a high density, and the dry binder is evenly adhered to the inside of the sheet, making it woven (intervening in 1gm or bonded to fiber intersections/intertwining points). It can be made into something strong and flexible. Depending on the purpose and use, this artificial leather sheet is further subjected to conventionally known application processes such as puffing, heat treatment, pressing, II surface application, dyeing, slicing, and reapplication of water or solvent type binder. By doing so, it is possible to process the product into suede-like artificial leather having raised naps, rooted artificial leather having a silver surface, and the like. The artificial leather obtained through this process is flexible and strong, and has a luxurious quality that cannot be obtained with conventional water emulsion type binders.

<Effects> According to the present invention, the following effects can be obtained when producing an artificial leather sheet using a water emulsion as the main binder.

(1) Flexible and tough artificial leather can be obtained.

(2) Since it can be processed without solvent, it is safe and easy to handle.

(3) The migration phenomenon of the water emulsion binder during assimilation can be suppressed.

(4) The manufacturing process can be simplified.

Next, examples according to the present invention will be shown.

However, the measurement of the product in the present invention is carried out by the following method.

(1) Tensile strength crab JIS-11079 5.12.1
(2) Tear-resistant crab JIS-L1079 5.14 C
Method (3) Rigid pox: Method A of 5.17 of JIS-L1079 In addition, "1%" and "percentage" t in the examples are all based on weight ak:.

Example 1 The island component is Borini 1-ethylene terephthalate, the sea component is polystyrene, and the ratio of the island component to the sea component is 50:50.
The number of Shimaki is 16, the thickness is 3.5 denier, the cut is 51, and the number of crimps is 15 to 1 B +1. A tube of □I' 605 CJ/rn' was made using a polymer array fiber (1) of 605 CJ/rn' by passing it through a card and a cross wrapper. After initial entanglement by needling, the polyol component was mixed with glycol (a mixture of 20 parts of propylene A oxide adduct of Ryorin/67 parts of polycaprolactone glycol and 13 parts of poly[Delta]xy[brene glycol]).

Isocyanate 1 ~ Using a water emulsion polyurethane with a concentration of 30% consisting of isophorone diisocyanate as a component and isoborone diamine as a chain extension component, the first 1
! A spray was applied to both surfaces of the sheet containing No. 11. The polyurethane had a tric 1] ethylene ['l ratio of 4.8 times, a melting point of 03° C., and a Young's modulus of 90 kq/ωr. Next, needling was performed at 200 needles/d, and the water emulsion polyurethane was again sprayed onto both surfaces of the sheet, and needling was performed at 1000 needles/J to obtain a composite sheet. The amount of polyurethane binder applied at this time was 20.5% in terms of solid content based on the fiber sheet. After drying the composite sheet with hot air.

It was shrunk by passing it through hot water at 90°C. The area shrinkage rate at this time was /10.7%. Afterwards, this shrink sheet was washed with trichlorethylene to remove the sea components.
Heat treatment was performed at 150° C. for 5 minutes. The basis weight of the sheet at this time is 719Q/m', and the apparent density is 0.282
0/a+! Met. Run this sheet through a slicing machine to make two sheets.

One of the sheets was subjected to a puff machine to form naps on both surfaces, and then Na flow dyed using 9 disperse dye at 120° C. for 60 minutes. The obtained suede-like artificial leather has an extremely good surface despite being made of water emulsion polyurethane.
It was flexible and strong. The tensile strength of this artificial leather is 6.7 ks/cm in the vertical direction.

The horizontal strength is 5.1 kq/c11, and the vertical tear strength is 2.5.
-, extremely strong with a width of 2.21, and a bending resistance of 42 m in length.
It was flexible with a length of 38 mm and a width of 38 mm. Furthermore, it was sufficiently resistant to chlorine-based dry cleaning, and it was also possible to use normal ironing.

Comparative Example 1 The raw cotton of Example 1 was used to make a web, and the needle density was further increased to lff2.
00(')/- needling and fabric weight 570
Q/Tr12. Seams 1~ with an apparent density of 1'ff0.1820/- were produced. This sheet was passed through hot water at 90° C. to shrink it. The area shrinkage rate at this time was 41.7%. Next, the shrink sheet was impregnated with a 20% water-mulsion polyurethane consisting of polyoxybutylene glycol as the polyol component, tolylene diisocyanate as the isocyanate component, and hexamebendiamine as the chain extension component.

Dry in a pre-dryer. This polyurethane had a trichlorT dylene swelling ratio of 23 times and a melting point of 179°C. At this time, the f'N1 contribution of the polyurethane binder was 21.4% in terms of solid content based on the fiber sheet 1~. The polynuclear sheet was washed with trichlorethylene to remove sea components. In sheets 1 to 1, the polyurethane was significantly swollen or partially dissolved by trichlorethylene, so the shape of the sheet was distorted and post-processing could no longer be performed.

Comparative example 2 Using the needle punch sheet of Comparative Example 1.

It was shrunk by passing it through hot water at 90°C. The area shrinkage rate at this time was 40.9%. Next, 20 used in Example 1
% of water emulsion polyurethane was impregnated into the sheets 1 to 1, and then dried in a hot air dryer. The amount of polyurethane binder applied at this time was 22.3% in terms of solids based on the woven sheet. The polynuclear sheet was washed with trichlorethylene to remove sea components, and then heated at 150°C.
Heat treatment was performed for 5 minutes. The basis weight of the sheet at this time is 6'
96g/m2. See m'f13m is 0.268g/a+
There was a tr. The sheet was then sliced into two pieces, and one of the sheets was puffed to form naps on both surfaces. Furthermore, this raised sheet was dyed using disperse dyeing n.
A liquid-liquid process was carried out at 20°C for 60 minutes. The obtained product had abnormally long raised hairs on the sliced surface, but the density of the raised hairs was extremely coarse, and the non-sliced surface was hard because polyurethane was concentrated on the surface layer.

The surface did not have any raised edges, and the texture as a whole was hard (and could not be called high-quality artificial leather).

Patent applicant Higashi Shikikai Co., Ltd.

Claims (1)

[Claims] Non-woven fabric uA navy blue receipt made of ultra-fine textured fibers [1 helical] Water emulsion type polymer elastic with ethylene swelling rate of 20 times or less (weighted), melting point of 190°C or higher, and Young's modulus of 1501/J or lower 1. A method for producing an artificial leather sheet, which comprises needling the composite sheet in an undried state while avoiding adhesion to the composite sheet, and then subjecting it to a heat shrinkage treatment and an ultrafine treatment.