JPS6022107B2 - Manufacturing method of firm and flexible leather-like sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a firm and flexible leather-like sheet or a substrate for a leather-like sheet.

Research has been carried out to create leather-like sheets that have the texture of leather-like sheets, especially those that have the firmness and flexibility of natural leather, especially cowhide. When impregnating and coagulating the emulsion, it is possible to change the type of impregnated polymeric substance, change the fiber form, or add a coagulation regulator such as an activator to the impregnated polymeric substance, especially the polyurethane elastomer solution. Methods have been proposed and implemented, such as changing the sponge structure during coagulation or dispersing rigid polymers etc. in polyurethane solution and coagulating them, but each method has its advantages and disadvantages, and the effects are sufficiently satisfactory. It has not been.

In particular, a leather-like sheet with a well-balanced performance, which satisfies both the sensory performance of a firm, flexible texture and solid feel, as well as the basic physical and mechanical performance, has not been obtained. The present inventors have conducted extensive research into creating a leather-like sheet with well-balanced performance, and as a result, have arrived at the present invention. An object of the present invention is to produce a leather-like sheet or a substrate for a leather-like sheet, which has a firm, flexible texture and a solid feel similar to natural leather, and which satisfies basic physical and mechanical performance.

That is, in the method of the present invention, when producing a leather-like sheet or a substrate of a leather-like sheet by incorporating a resin composition into a fiber structure, the main resin (2) in the resin composition has a glass transition temperature (Tg) of - Tensile strength (Temi) below 20℃
remodulus ASTM D-638) is 0.9×1
A flexible resin with a property of 0-4dy female/base temperature or less is used, and the resin 'B} blended with resin ■ has a glass transition temperature (
Tensile modulus (Tg) is higher than room temperature.
It is a rigid resin with a ASTM D-6 spot) of 1.1 x 1 pid skin e/ or more, and the blending ratio of resin wind and legs is wind: {B} of 95:5 to 65:35. The resin composition has a certain composition, and the resin composition is mixed with the fiber component as a resin composition dispersion dispersed in a dispersion chamber, coagulated by a green method or a dry method, and then washed and dried as necessary. It is characterized by post-finishing.

The method of the present invention is characterized by the resin composition contained in the fiber structure and the use of a dispersion of the resin composition.

That is, by mixing the dispersion of the resin example and the dispersion of the resin legs, or by dispersing and mixing the resin legs with the dispersion of the resin, the dispersion molding state of the resin sticks in the coagulated resin composition can be changed. In addition to being included in the resin, resin 'B} is dispersed in the form of a lump or film, or by forming a small independent region or a mixture of both, the initial stage as a leather-like sheet composition is The initial behavior of deformation, such as bending, compression, extension, and rebound, can be handled by the flexible resin, and the large deformation behavior after mid-term deformation can be shared by the mutual effects of the resin and the resin. As a result, we were able to provide sensory performance that combines a firm, flexible texture with a solid feel. The resin composition used in the present invention is extremely important in its composition.

First of all, resin (■) plays an important role in controlling flexibility and solidity.Therefore, the performance of resin (■) is that the glass transition temperature (Tg) is -20℃ or less, and the film formed with it
% crystallinity measured by x-ray method in the stretched state is 15%
Below is the tensile strength (Tensile module ship AST
It is desirable that the ball has a performance condition of less than 0.9×1 pid pitch e/ball, preferably 0.8 to 0.02×1 pid pitch e/ball (MD-16 paper). Examples of such resins include various polyacrylates such as polyethyl acrylate, polybutyl acrylate, and polyisobutyl acrylate. Polyvinylidene halides such as polyvinylidene fluoride and polyvinylidene chloride. Low-density polyethylene, polyethylene. Or styrene-butadiene,
Tetrafluoroethylene-hexafluoropropylene,
Copolymers such as ethylene-vinyl acetate. There are various ethylene-acrylate copolymers such as ethylene-ethyl acrylate and ethylene-butyl acrylate. Among these, particularly preferred polymers are those mainly composed of polyacrylic acid esters or derivatives thereof. In addition, the resin {B' added to the resin is required to have rigidity in order to play a role in providing a firm texture and a solid feel. Therefore, the performance as a resin {B' is determined by the glass transition temperature (T
g) is above room temperature, and its tensile strength (Temilem
odulus ASTM MD-6 paper) is 1.1 x 1 dyM
/, preferably 1.3 to 6.9×1 dyme/
It is desirable that the material meets the performance requirements of the earth. Examples of such resins include 6-nylon, 6-nylon,
8-nylon, 9-nylon, 11-nylon, 8.1
Various polyamides such as 0-nylon, 12-nylon, etc. Various polyvinyl carboxylic acid esters such as polyvinyl acetate, polyvinyl chloroacetate, and polyvinyl butyrate. Various polyacrylates such as polymethyl acrylate, polymethyl methacrylate, polyethyl methacrylate, various polymethacrylates, or copolymers of acrylate or methacrylate with other copolymerizable vinyl monomers. Various polyesters such as polyhexamethylene terephthalate and polydecamethylene terephthalate. Phenol resin, melamine resin, fluorine resin, polycarbonate. A polymer glycol selected from polyester glycol, polyether glycol, polyester ether glycol, polylactone glycol obtained by ring polymerization, etc. having a molecular weight of 500 to 3000, an alicyclic or ring-containing polyisocyanate, and at least two active hydrogen atoms. Rigid polyurethane obtained by chain extension with a low molecular weight compound. Polypinyl chloride or its copolymer.
Polystyrene or its copolymers or derivatives. 1 type or 2 that satisfies the above specific conditions selected from etc.
It is a more rigid resin than other types. The method of blending resin 'B-Z into the dispersion of resin (2) is to blend resin {B} as a dispersion liquid in a dispersion medium, or to mix fine powder of resin legs into a dispersion of resin W. A blending method such as adding and dispersing is used, but it is preferable to blend Z as a resin dispersion, especially as an emulsion. It's convenient to take. However, depending on the bending stiffness of the fibers or fiber components used, a larger block may provide a more balanced texture, so research should be conducted in advance regarding the selection of the type of resin [B] and the blending form. Set optimal conditions. In addition, if the amount of resin (B) is small, the resulting sheet will be flexible but lack firmness and lack a sense of solidity, and as the amount increases, it will feel hard. : side is 95:5 to 65:35 preferably 90:10
A composition of ~70:30 is used. In addition, prior to impregnating the fiber composition, the resin composition dispersion may be heat-sensitively formulated so that it gels at a constant temperature, as necessary.
A preferred method is to increase the viscosity to adjust the impregnation properties.

The resin composition dispersion impregnated into the fiber composition is then heated and gelled using the so-called dry method, or soaked in an ionic coagulating liquid or hot water to gel it using the so-called wet method. Contains. If there are any undesirable substances in the resin composition, such as activators, heat-sensitive additives, and other impurities, they are removed by washing. The fiber structures used in the present invention are structures obtained from loosely woven fabrics such as woven fabrics, knitted fabrics, knitted fabrics having napped on at least one surface, nonwoven fabrics or entangled nonwoven fabrics, and nonwoven fabrics combined with knitted fabrics. The fibers that make up the fiber structure are naturally thin fibers such as cotton, linen, and wool. Regenerated fibers such as rayon and acetate. Polyolefins such as polyethylene and polypropylene. Polyethylene terephrate or modified or cocondensed polyester. Polyamides such as 6-nylon, 66-nylon, and 6.10-nylon.

Polyacrylonitrile, polyvinyl alcohol, and other chemical fibers. In the case of chemical fibers, there are fibers obtained from ordinary grade yarns, irregular cross-section fibers that can be deformed by the shape of the holes in the spinneret, mixed fibers or composite fibers spun by combining at least two types of polymers with different properties, and mixed fibers or composite fibers. Composite fibers can be treated with solvents, swelling agents or/and
Fibers whose fiber structure has been modified by mechanical or physical treatment to have at least a plurality of fine fibers arranged in a cluster or a pore array are used. In the present invention, the sheet obtained by incorporating the resin composition into the fiber structure may be such that the impregnated resin composition is too soft and the hardness cannot be balanced with the fiber structure, or when trying to improve solvent resistance or heat resistance. If desired, melamine resin or melamine derivative,
Treatment with a solution or dispersion of a condensing or crosslinking organic compound such as formalhyde or its precondensate, an organic polyisocyanate or a crosslinking-reactive organic polyisocyanate. After the treatment, the material is heat treated and hardened as required. In addition, as a conventional method, it is also useful to perform a functionalization treatment in advance so that a crosslinking reaction can be caused by a simple treatment after the resin ① and/or resin '811 is impregnated and solidified. . 0
An example of the functionalization treatment is a method of copolymerizing a monomer that causes a crosslinking reaction with resin A and/or resin B by heating or the like.

This method is based on the technique used in general polymer chemistry, and is obtained by copolymerizing a monomer having a carboxylta group such as methacrylic acids with a monomer having a glycidyl group. However, the present invention is not limited to this, and polymer reactions can also be used. The surface of the sheet obtained by the present invention is buffed to make it smooth,
Alternatively, it can be finished as a fluffed surface, or a porous or non-porous layer of resin can be formed on the smooth surface, and it can be finished as a leather-like sheet by applying treatments such as coloring and embossing.

The sheet obtained here is an excellent sheet that satisfies the sensory performance of a firm, flexible texture and solid feel similar to that of cow grass, and also satisfies the basic physical and mechanical performance of a leather-like sheet. Obtained. Next, embodiments of the present invention will be explained using specific examples, but the present invention is not limited to these examples.

Note that parts and percentages in the examples are by weight unless otherwise specified. Example 1 Polyethyl acrylate aqueous emulsion with a concentration of 35% (trade name Primal HA-24).

Manufactured by Rohm and Hass Co., Ltd.) (Tg: -23qo, tensile strength 0
．． Add 2 parts of nonionic activator and mix thoroughly, and then add polyvinyl chloride emulsion with a concentration of 35% (Tg: 81°C; tensile strength 2.4~ 4.
1×1 Bid skin e/ground) 1 anchor part was mixed to form a homogeneous dispersion system, and then calcium chloride was added to prepare a heat-sensitive formulation composition liquid having a gelation temperature of 40° C. of the polymer composition. on the other hand,
Consisting of 5 polyethylene anchors, 6 nylon 5 anchors, 6
- An entangled non-woven fabric with a fabric weight of 950 mm/m is made using a multi-core nylon mixed fiber, and this entangled non-woven fabric is impregnated with the polymer composition liquid prepared above to increase the adhesion rate of the impregnated liquid to 140%. Next, the polymer-impregnated entangled nonwoven fabric is routinely soaked in hot water at a temperature of 95 oo to gel the polymer composition, and further washed to remove calcium chloride, activating agent, etc.
After removing the moisture, the sheet is soaked without drying in a composition solution with a resin concentration of 15% mainly consisting of a melamine initial condensate, and 9 parts of the polymer composition are mixed with 1 part of the melamine resin.
Adjust with adhesion liquid so that the ratio is 1 part, and then reduce the temperature to 1 part.
Drying and curing were performed using a hot air dryer at 35°C.

The obtained sheet was treated to extract the polyethylene component constituting the fibers with a solvent, and the fiber form was modified to 6-nylon fine fibers condensed to form a flexible sheet.

The surface of this sheet is ground with sandpaper to make it smooth and then polished, giving it a firm and flexible texture.
It was a leather-like sheet similar to soft cowhide products with a rich sense of solidity that cannot be obtained with conventional sheets and excellent drapability. 4. For comparison, all other impregnated polymer compositions were processed under the same conditions except for polyvinyl chloride, and the sheet obtained by manipulation had a soft texture but no leather-like stiffness. , anti-twill properties and elastic recovery properties were extremely poor, the texture did not feel heavy, and the texture was thin, and the commercial value was low. Example 2 To 85 parts of the same 35% concentration polyethyl acrylate aqueous emulsion used in Example 1, 2.5 parts of a nonionic activator was added and thoroughly mixed, and then a hard polyurethane containing many hard components (35% concentration) was added. Tg: 520: Tensile strength 2.7 x 1 dyne/base)
15 parts of the aqueous dispersion were mixed to form a homogeneous dispersion, and then an acid was added to bring the gelling temperature of the polymer composition to about 45%.
A heat-sensitive composition liquid of qo was prepared.

On the other hand, using polyethylene terephthalate fibers with a weave of 0.8 denier, we made an entangled nonwoven fabric with a fabric weight of 350 tano.
This composite nonwoven fabric was impregnated with the polymer composition liquid prepared above to increase the adhesion rate of the impregnation liquid to 165%, and then the polymer-impregnated entangled nonwoven fabric was sequentially impregnated in 95 qo hot water to remove the polymer composition. After gelling, washing, and drying, the polyisocyanate-containing resin composition (trade name: Crispon,
(manufactured by Dainippon Ink Industries, Ltd.), dried, and cured at 50 qo.

Buff the surface of the obtained sheet with sandpaper,
The processed material had a firm, flexible texture and a rich polymeric feel, and a leather-like sheet with a leather-like slimy feel was obtained. Example 3 Polyethyl acrylate emulsion with a concentration of 35% (trade name Primal HA-24 manufactured by Rohm and Haas)
8 Add 2 parts of nonionic activator and mix thoroughly.
Furthermore, 2$ of polyvinyl chloride emulsion with the same concentration of 35% as used in Example 1 was mixed to create a uniform dispersion system.
Next, calcium chloride was added to prepare a heat-sensitive composition liquid having a gelling temperature of 40 qo.

On the other hand, the same entangled nonwoven fabric used in Example 1 was impregnated with the polymer composition liquid prepared above, and the adhesion rate of the impregnating liquid was reduced to 1.
40%, then polymer-impregnated entangled nonwoven fabric at temperature 9
The sheet was sequentially immersed in hot water at 5°C to gel the polymer composition, and then washed to remove calcium chloride, activators, etc., and after removing moisture, the sheet was dried in a hot air dryer at 135°C. Drying and curing were carried out.

The polyethylene component constituting the fibers of the obtained sheet was extracted with a solvent, and the fiber form was modified to 6-nylon fine fibers condensed to form a flexible sheet.

The surface of this sheet was ground with sandpaper to make it a smooth surface, and then processed to produce a leather-like sheet with a firm drape that cannot be obtained with conventional sheets. Example 4 Copolymer consisting of 95 parts of ethyl acrylate and 5 parts of methacrylic acid (Resin A: Tg = -21.7q0; tensile strength = 0
．． 85×IQd beaten e/ground) aqueous dispersion (resin concentration 40%
) 6 base part and 95 parts of methyl methacrylate and 5 parts of glycidyl methacrylate (resin B: Tg = 29
A homogeneous dispersion was prepared from 4 parts of an aqueous dispersion (resin concentration 30%), tensile strength = 3.3
A heat-sensitive composition liquid at 0°C was prepared.

Next, the same entangled nonwoven fabric used in Example 1 was impregnated with the above composition solution, the adhesion rate of the impregnation solution was increased to 165%, and then the polymer composition was immersed in 95 oo hot water to gel. I let it happen. After washing and drying this sheet, it was
The impregnated polymer composition was crosslinked by heat treatment for a minute. The obtained sheet was treated with hot toluene to extract and remove the polyethylene component constituting the fibers, thereby obtaining a flexible sheet.

The obtained sheet had a good balance between the fiber structure and hardness, and was a leather-like sheet with high commercial value that had both a solid feel and a soft texture with excellent solvent resistance. For comparison, a solution with a resin concentration of 15% (resin A content: 10%, resin B content: 5%) was prepared by dissolving the above resins A and B in ethyl acetate, which is a common solvent, and this solution was mixed with the above solution. The same nonwoven fabric was soaked with the same nonwoven fabric, and the impregnation solution was soaked so that the adhesion rate was 396% (the amount of resin adhesion was the same as above), and then the solvent ethyl acetate was evaporated by leaving it in hot air.
As a result, a sheet was produced which was exactly the same as the above sheet in that resin A and resin B were deposited and coagulated in a nonwoven fabric of nylon 6 fine fibers.

Claims (1)

[Scope of Claims] 1. When producing a leather-like sheet or a substrate of a leather-like sheet by incorporating a resin composition into a fiber component, the main resin (A) in the resin composition has a glass transition temperature (Tg
) is -20℃ or less, the tensile modulus (Tensile modulus
lus ASTM D-638) is 0.9×10^4d
A flexible resin having a property of not more than
dulus ASTM D-638) is 1.1 x 10^
It is a rigid resin with a density of 4 dyne/cm^2 or more, and the blending ratio of resins (A) and (B) is (A):(B) is 95
:5 to 65:35, the resin composition is impregnated into a fiber component as a resin dispersion dispersed in a dispersion medium, coagulated by a wet method or dry method, and then, if necessary, A method for producing a firm and flexible leather-like sheet characterized by washing, drying, and finishing. 2. A firm and flexible leather-like sheet according to claim 1, characterized in that the resin composition impregnated and coagulated into a fiber component is further treated with a condensing or crosslinking organic substance and then finished. manufacturing method. 3. The fiber composition is characterized by using a fiber composition mainly composed of bundled fibers made of at least three artificially produced fine denier fibers of 1 denier or less and/or porous arrayed fibers. A method for producing a firm and flexible leather-like sheet according to claim 1. 4. The method for producing a firm and flexible leather-like sheet according to claim 1, wherein the resin (A) is a dispersion of polyacrylic acid ester or a derivative thereof. 5. Claim 2, wherein the condensable or crosslinkable organic substance is a solution or dispersion of a melamine resin or a derivative thereof, formaldehyde or an initial condensate thereof, an organic polyisocyanate, or a crosslinking-reactive organic polyisocyanate. A method for producing a firm and flexible leather-like sheet as described in Section 1.