JPS6134287A - Production of flexible sheet like leather - Google Patents

Abstract

PURPOSE:To produce a flexible artificial leather, by coagulating or solidifying a high polymer elastic material applied to a fibrous sheet, subjecting the sheet to high-speed fluid treatment. CONSTITUTION:A fibrous sheet consisting of nonwoven fabric obtained by needle punching conjugated fibers forming <=0.3d extremely thin fibers made of especially polyester, nylon, etc. is provided with a high polymer elastic material such as polyurethane, etc., the elastic material solution is coagulated or solidified, a high-speed fluid jetted from an orifice is hit to a layer in which the high polymer elastic material exists, so that structure of the sheet is changed in a very small unit, and made flexible. A sheet like leather having an arbitrary feeling can be obtained by changing the jetting condition of the high-speed flow. A sheet like leather having flexibility and draping properties which have never existed before can be obtained by this method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a highly flexible leather-like sheet. More specifically, the present invention relates to a method for producing a highly flexible leather-like sheet by treating a fiber sheet containing an elastic polymer with a high-speed fluid.

[Conventional technology]

The fiber C-I, which has traditionally been used as a material to obtain flexible leather-like leather similar to natural leather, has a high density and
Moreover, a soft non-woven fabric, a 11-knit fabric, or a combination of a woven fabric or a knitted fabric with a soft non-woven fabric is used, and the fibers constituting the sheet are also extremely coarse. In addition, in order to obtain mechanical strength and a satisfying feel, flexible and high-performance polymer elastic materials such as polyurethane have been simultaneously added to fiber sheets. For this reason, relatively high quality leather-like sheets can now be obtained.

However, since this leather-like sheet contains an elastic polymer, it inevitably has a hard, rubber-like texture, and is therefore clearly inferior to natural leather in terms of flexibility and drapability. .

In recent years, demands on the demand side have become increasingly diverse, and in fields where dressy silhouettes are required, flexibility and drapability are especially important and necessary characteristics. For this reason, these properties, which are inferior to those of natural leather, have long been an issue to be improved.

In order to eliminate the drawbacks of such leather-like sheets, various proposals have been made and improvements have been made to some extent, but they are still far from satisfactory. Proposals for softening and improving hand feel include, for example, using porous polyurethane, or adding softeners and porosity agents to polyurethane (
Special Publications No. 45-20790, No. 46-2593, No. 48-
4940, 52-49042, etc., 1! A method of adding a smoothing agent or a release agent to a fiber sheet, a method of adding polyurethane (Japanese Patent Publications No. 58-45502, No. 59-21989, etc.), and a method of adding a polyurethane to a fiber sheet (Japanese Patent Publication No. 58-45502, No. 59-21989, etc.). A method of applying polyurethane to a sheet of m1M fiber-generating composite glint and then removing the -component (Japanese Patent Publications No. 41-9315, No. 51-32681, etc.)
, Method of adding a softener to a leather-like sheet (Special Publication No. 1973-
19922), and a method of mechanically kneading a leather-like sheet.

However, these softening methods may not be sufficient to soften polyurethanes, or may only be effective for certain types of polyurethane, or even if they can be softened, the resulting leather-like sheet may have poor mechanical strength. In addition, it was accompanied by some difficulties such as unstable workability.

(Problems to be Solved by the Invention) The present inventors have worked diligently to solve such drawbacks, namely, the problems of conventional leather-like sheets, such as insufficient flexibility, drapability, and unstable workability. As a result of research, we finally discovered an effective method as in the present invention.

[Means for solving problems]

The gist of the present invention is as follows. That is, in a method of manufacturing a leather-like sheet by adding a polymeric elastic material to a fiber sheet, a solution and/or dispersion of a polymeric elastic material is applied to a fiber sheet, coagulated or solidified, and then treated with a high-speed fluid. A method for producing a leather-like sheet is provided.

The present invention involves applying a fluid injected at high speed to the layer where the polymeric elastic material is present on a fiber sheet provided with a polymeric elastic material.
The structure of the sheet is changed in minute units to make it more flexible. Therefore, even if the influence of the high-speed fluid on the processing sheet is too small, the object of the present invention cannot be achieved. Therefore, it is preferable that the high-speed fluid is sprayed uniformly onto the sheet, and that the effective depth of the high-speed fluid to the sheet is at least 1/4 or more of the elastomer adhesive layer. The effective reaching depth here refers to the shape or large serrations of the elastic polymer material fixed in the sheet, I! It refers to the depth at which some phenomenon changes due to the injected high-speed fluid, such as fiber bundles, the direction of the tJR strip, the state of entanglement of the fibers, the positional relationship between the fibers and the polymeric elastic body, and other traces of the passage of the high-speed fluid.

If the reaching depth is too small, the softening effect will be reduced.

The fiber sheet used in the present invention is not particularly limited (i.e., a needle-punched nonwoven fabric manufactured by a conventionally known method, a water-jet punched nonwoven fabric, a sheet made by intertwining short fibers with a woven or knitted fabric, and a sheet made by fusion of fibers). The sheet I wore,
It can be applied to flocked sheets, long fiber nonwoven fabrics, woven fabrics, knitted fabrics, etc. The present invention can be particularly effectively achieved with a nonwoven fabric having a sheet structure in which flexibility and drapability are difficult to obtain due to the form of intertwined fibers.

Furthermore, there are no particular limitations on the fibers that make up the sheet, such as polyamide (nylon), polyester,
Any of synthetic fibers such as polyacrylonitrile, polyethylene, and polypropylene, regenerated fibers such as viscose rayon and cupro, semi-synthetic mM such as acetate, and natural IIN such as wool, cotton, and hemp can be used. Among these, synthetic fibers that can be easily made into fine fibers are particularly desirable, and from the standpoint of practical performance, nylon and polyester are particularly suitable fibers.

The thickness of IIH is 1 for general clothing! There is no particular limitation as long as it is coarse, but from the point of view of flexibility, the single yarn of the fiber is preferably 1 d or less, particularly preferably 0.3 d or less. This is because the sheet itself can be easily softened, and at the same time, the ultrafine fibers become delicately entangled with each other due to high-speed fluid treatment, so that it is possible to prevent the strength of the sheet from decreasing even when treated with high-speed fluid. Preferably used ultrafine fibers are obtained from the following composite machine string.

For example, a polymer array consisting of two types of polymers with different solubility and having a sea-island relationship with each other in a cross section perpendicular to the fiber axis! ! ! fiber (Japanese Patent Publication No. 44-18369), blended spun fiber (Japanese Patent Publication No. 41-11632), easily splittable composite fiber cord made of two adjacent polymers having low compatibility with each other (Japanese Patent Publication No. 48-28005), is that.Also,
There are ultrafine fibers such as acrylic fibers obtained by wet spinning with a spinneret made of 11 sets of sintered metal sheets and then drawing, polyester fibers obtained by ultra-stretching, and polyester m-fibers obtained by melt blowing.

When sea-island type or easily split type composite fibers are used, processing the composite Jl fiber into tim ss m can be carried out at any stage of the process, but it is particularly preferable for the present invention to process the composite Jl fiber into ti m ss m. It is best to do this before processing.

The fabric weight of the fiber sheet can be any size as long as it can be used for practical purposes, but it is usually between 70 and 50 in terms of actual residual fiber content.
0g/1112 is suitable. The LLN sheet before being coated with the polymeric elastic material may be subjected to shrinkage processing or compression processing in order to give the leather-like sheet a sense of fullness. In order to further improve the properties, water-soluble polymers such as polyvinyl alcohol and carboxymethyl cellulose may be added.

Examples of the polymeric elastic body imparted to the fibers 1 to 1 include polyurethane, nitrile butadiene rubber, styrene butadiene rubber, butyl rubber, neoprene, acrylic rubber, silicone rubber, natural rubber, and polyamide copolymers. One example is the body. High-speed fluid processing makes it easy to make flexible structures of polymeric elastomer-imparted sheets, making it possible to choose a wider range of polymeric elastomers than ever before. From the side,
Particularly preferred is polyurethane. The polymeric elastomer may be in the form of a solution, a colloid, or a dispersion such as an emulsion or latex-as-absorption.

Moreover, the polymeric elastomer may be used alone or in combination of two or more. Furthermore, pigments and their additives can also be added to the polymer elastomer.

The manner in which the polymeric elastomer is attached to the fiber sheet can be applied to the present invention, such as to the entire sheet, to only the surface layer on both sides, or to only one side, for example, the back side. However, from the viewpoint of ease of softening control through high-speed fluid processing, etc., it is more preferable to adhere to the entire sheet.

The method of applying the polymeric elastomer to the fiber sheet is carried out by conventionally known methods such as impregnation, coating, and spraying. The fixing of the elastic polymer to the am sheet is carried out by wet coagulation or dry solidification depending on the type and form of the elastic polymer.

When the polymeric elastomer is polyurethane, the most preferred embodiment of the present invention is that the polyurethane is a solution type, impregnated throughout the fiber sheet, and wet-coagulated.

The amount of the polymeric elastic material applied to the fiber sheet may be appropriately selected depending on the type of elastic material and the use of the product sheet, but it is usually 5 to 150% in terms of solid content, preferably 10 to 150% based on the actual remaining fibers. ~100%.

After solidifying or assimilating the polymer elastomer, the treatment is performed using a high-speed fluid injected from an orifice, and the present invention is applicable whether the sheet to be treated is wet or dry. The fluid to be injected may be of any type as long as it does not denature or dissolve the fiber J5 and the n-molecular elastomer (Jtl (Ei), but from the viewpoint of ease of handling and economical efficiency, water or dry water is usually used. This is a method suitable for the present invention.Of course, additives may be added to the fluid for the purpose of preventing *1g loss or increasing the jetting effect.

The hole shape of the injection orifice is not particularly limited, and any shape is applicable, but it is generally circular. In the case of a circular hole, the hole diameter is 0.05 to 3 mn+, and 0.1 to 1.0 m is particularly preferably used. The 110% pressure of the fluid can be adjusted as appropriate depending on the orifice hole diameter, the distance between the orifice and the processing section, the processing speed of the sheet, the basis weight fflNffl and thickness of the sheet, the type and amount of adhesion of the polymer elastic body, the adhesion state, the type of fluid, etc. However, it is generally between 5 and 500 km/lffl. When the fluid is aqueous, the range preferably used is 10 to 300 km.
/cJ.

If the jetting pressure is too low, the object of the present invention cannot be achieved, and if the jetting pressure is too high, it not only causes a decrease in the mechanical strength of the treated sheet, but also makes fluid jetting marks noticeable and impairs the surface quality of the sheet, which is not preferable. The distance between the orifice and the treated sheet surface is usually 1
0 to 100 works.

If the distance is too large, the energy loss of the ejected fluid will be large and the processing efficiency will be degraded, while if the distance is too small, it will cause fluid ejection marks. Usually, a plurality of orifices are arranged in the width direction of the processing sheet, and the orifice is a swinging mechanism for uniform processing. As for rocking, XY-axis rocking that is performed not only in the width direction but also in the traveling direction is particularly preferable.

In addition, the jetting angle of the high-speed fluid is usually 9
Although the angle is 0 degrees ±45 degrees, it may be adjusted as appropriate depending on the processing effect or the use of the processing sheet.

The treatment of the polymer elastomer-applied sheet with a high-speed fluid may be performed only on one side, or may be performed on both sides.

Furthermore, when the sheet is made of a nonwoven fabric base, the sheet may be processed after being sliced into a plurality of sheets along the sheet surface.

In this way, the sheet treated with high-speed fluid becomes a highly flexible leather-like sheet, but it can also be dyed by raising it with a puff or brushing machine, or it can be coated with a film such as polyurethane on the surface. By processing, it can be made into a raised-type leather-like sheet or a grain-faced leather-like sheet with added flexibility, drapeability, etc., and an elegant appearance and good texture.

Note that the high-speed fluid treatment of the present invention can also be applied to sheets that have been subjected to a napping process using a puff machine or the like, or to sheets that have been dyed. Furthermore, as an effect other than imparting flexibility or drapeability, the sheet can also be processed into a fuzz chamber by appropriately adjusting the jetting center and jetting angle of the fluid.

Previous examples of application of high-speed fluid processing to mN sheets include methods of entangling webs to form non-silk fabrics (Japanese Patent Publications No. 47-18069, No. 48-13749, No. 57-59).
348), a method of entangling and integrating short fibers in a woven or knitted fabric (
Special Publications No. 54-27402, No. 55-26222, No. 58
-13661), in an aqueous coagulation bath, to relieve tension, promote solvent replacement with water, and reduce contact with rolls, etc.
Method for coagulating polyurethane-impregnated sheets for transportation purposes (Japanese Patent Publications No. 48-9233, No. 55-26224, No. 5)
6-16222), but the present invention is completely different from the conventional methods both in purpose and in the manner in which sheets are processed by high-speed fluid.

〔Example〕

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples.

The physical properties were measured using the following method.

Bending resistance: 5.17 for J 1s-L1079 A method drape coefficient: 5.17 for J 15-L1079 F method Tensile strength and elongation: 5.12.1 Example 1 for J 15-L1079, Comparative example 1 Sea component is copolymerized polystyrene of 2-ethylhexyl acrylate, island component is polyethylene terephthalate, sea/
Island ratio 50150. Number of islands: 36, composite fiber denier: 3d,
Using a sea-island type composite navy blue raw cotton with a fiber length of 51 mm and crimps of 615 threads/inches, we made sea urchin whelks through the carding and cross-wrapping processes, and produced 3,000 pieces.
Perform 11 needle punches and make a fabric weight type fit 550
CJ/tn' nonwoven fabric was used.

When this nonwoven fabric was subjected to shrinkage treatment with hot water at 85° C., the fabric weight became 716 g/m 2 . Next, it is impregnated with polyvinyl alcohol (PVA), and the solid content is 35% of the island component.
After applying weight percent and drying, the sea component was removed using trichloroethylene and ultrafine fiber processing was performed. Next, polyurethane containing 1% pasty black pigment based on polyurethane solid content, 5% dimethylformamide (DMF)
The solution was impregnated into the sheet and the polyurethane was coagulated in a water bath. This sheet was further soaked in hot water and squeezed repeatedly to remove PVA and DMF.

The a-law of polyurethane to fiber was 40% by weight. Moreover, the basis weight mff1 and thickness of the sheet were 500 g/T112.1.76 mm, respectively.

Next, this sheet was subjected to high-speed water jet treatment by passing it through a high-speed water jet jet device with orifices with a hole diameter of 0.25 rrn arranged at 2.5 mm intervals in a straight line in the width direction of the process line once on each side under the following conditions. . A comparative example was prepared by performing the polyurethane processing in the same manner as in the example, but omitting the high-speed water treatment.

Water pressure: Condition A, 100 kg/a (, Condition B, 501
oi/cnf Swing width of orifice in width direction: 10 m Swing cycle of orifice = 3 times/sec Distance between orifice and processing sheet: 50 m Water jet angle to processing surface: 90 degrees Moving speed of processing sheet r9I: 0.25 m The sheet obtained by high-speed water jet treatment at a speed of 1/2 min and drying had some shrinkage in the vertical direction, but was highly flexible. On the other hand,
The sheet of the comparative example had strong rubber-like properties and was rough and hard. It should be noted that although there was initially concern that the strength of the sheet treated with high-speed fluid would be significantly reduced, the reduction was not that large.

Table 1 shows the properties and physical properties of the sheet.

Table 1 Example 2, Comparative Example 2 The sheets of Example 1 and Comparative Example 1 were each sliced into two sheets each having a thickness in half. Next, 15
Using a puffing machine equipped with a sand vapor of 0 mesh, the surface opposite to the sliced surface was mainly puffed. Next, it was dyed using a disperse dye at 120°C for 50 minutes, and then finished through a reduction process and an antistatic agent application process.

As a result, the seeds of Examples were extremely flexible, had good drape properties, and were leather-like sheets with a good texture that closely resembled napped type natural leather. In contrast, the sheet of Comparative Example was a leather-like sheet with a hard texture. The physical properties of the leather-like sheet are shown in Table 2.1゜Example 3, Comparative Example 3 Using nylon 6 raw cotton consisting of 1 d of single yarn, 51 m of fiber length, and 13 crimps/inch, the process of carding and cross-wrapping was carried out. A web was then created and needle punched at 2000 threads/d to obtain a nonwoven fabric with a basis weight of mff 141C1/m2. This nonwoven fabric was shrink-treated with boiling water and hot-pressed at 150°C. The fabric weight of the shrinkage weld was 456 Q/m2. Next, impregnate it with PVA! A solid content of 30 ftIrrI% was applied to each fiber. The sheet was then impregnated with a 12% DMF solution of polyurethane containing 1% pasty black pigment based on polyurethane solids, and the polyurethane was coagulated in a water bath. Then soaked in hot water,
PVA and DMF were removed by repeated squeezing.

l! The adhesion of polyurethane to dirt was 39% by weight. Further, the basis weight and thickness of this sheet were 630Q/m'' and 2.5m, respectively.

Next, this sheet was heated to a water pressure of 100 and 9/a# in Example 1.
High-speed water treatment was performed in the same manner as above. Next, the float was sliced into two sheets, and the opposite side to the sliced side was mainly puffed using a buffing iron equipped with a 100 mesh sand vapor.

After this, dyeing was carried out using an acid dye at 100°C for 45 minutes.
Finished through a fixing process and an antistatic agent application process. The sheet weight 111t was 215Q/tn2, and the thickness was 0.95++wn. Because the fibers used were thicker, the resulting sheet had longer naps and was coarser and harder than the sheet of Example 2. However, the high-speed water treatment was omitted and the other steps were the same as in Example 2. Comparative example (fabric weight ff
However, it was clearly softer and had a better texture compared to the 212g/ln', thickness 0892m).

Example 4, Comparative Example 4 Sea component is polystyrene, island component is polyethylene terephthalate, sea/island ratio 30/70, number of items 16.12 111
1 m (0 teny) Lt3, 5 d, ilI[tJ
%51 trtn, spun using sea-island composite fiber raw cotton with 13 crimps/inch (1/60 meter), fabric weight with tricot knitting machine! ! ! ff1150g
/m2 meridian. Next, the sea component of this knitted fabric yarn was removed using trichlorethylene, and the yarn was subjected to ultra-fiber treatment. The weight of the knitted fabric was 106 g/m''.

Next, the polyurethane was impregnated with a 16% DMFwj solution containing 3% of a pasty brown pigment based on the solid content of the polyurethane, and the polyurethane was coagulated in a water bath. Then 8 due to hot water! The DMF was removed by repeating the clearing and squeezing. Wffl with polyurethane for the knitted fabric sheet was 44%. In addition, the basis weight of this sheet is 153Q/m",
The thickness was 0.47++n.

Next, this sheet was applied to Example 1 at a water pressure of 75 kg/car.
High-speed water treatment was performed in the same manner as above. This treatment made the sheet surface fluffy and extremely flexible.

Next, a one-component polyurethane solution containing 5% of a paste-like brown pigment based on the polyurethane solid content was applied onto a separately prepared release paper with grained sheepskin, and dried to form a 5-micron film. did. Next, on top of this, 2 containing a pasty brown pigment of 10% based on the solid content of the polyurethane.
A solution of liquid polyurethane (DMF/methyl elketone/ethyl acetate) is applied so that the skin Rn is 40 microns, and in a semi-dry state, it is laminated to a sheet that has been previously subjected to high-speed water jet processing and cleared. It was passed between rolls of 0.2 nwn to be crimped and then dried. After aging at 40°C for 24 hours, the release paper was peeled off. What was obtained was a silver type leather-like sheet that was extremely soft and had good drapability.

On the other hand, the comparative example, which was processed in the same manner as the example except that only the high-speed water treatment was omitted, had a leather-like sheet with poor flexibility.

〔Effect of the invention〕

The effects of the present invention are listed below.

(1) By changing the jetting conditions of high-speed fluid, it is possible to produce a leather-like sheet with any texture.

(2) In order to improve binding efficiency, using an elastic polymer that has good adhesion to fibers, or increasing the amount of elastic polymer to give a sense of fullness, generally gives the sheet a hard texture. According to the present invention, even for such purposes, it is possible to create a soft texture without making it hard.

(3) While high-speed fluid processing does not involve entanglement of fibers,
Since the continuous polymeric elastic mass that inhibits the flexibility of the fibers is appropriately divided, flexibility can be imparted to the sheet while maintaining strength.

(4) The surface of the sheet can be fluffed by increasing the jetting conditions of the high-speed fluid or by changing the jetting angle with respect to the treated sheet.

Claims (1)

[Claims] In a method for producing a leather-like sheet by adding a polymer elastic material to a fiber sheet, after applying a solution and/or dispersion of the polymer elastic material to the fiber sheet and coagulating or solidifying it,
A method for producing a leather-like sheet characterized by processing with a high-speed fluid.