JPH0742653B2 - Functional leather and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a functional leather made of vinyl chloride resin used for surface materials of furniture, bags, vehicles, etc., shoe coverings, bags, etc., and a method for producing the leather. In particular, the present invention relates to the above-mentioned functional leather which is excellent in stain resistance, abrasion resistance, chemical resistance and the like, and is also excellent in texture and feel, and a method for producing the leather.

[0002]

2. Description of the Related Art Conventionally, vinyl chloride leather called vinyl chloride leather has been widely used in various fields as described above. Such a vinyl chloride leather is generally formed by laminating a foam layer on a fiber base cloth and laminating an upper coating layer made of a vinyl chloride resin on the foam layer. By the way, as is well known, a vinyl chloride resin is used with a large amount of a plasticizer mixed therein for the purpose of imparting workability and cold resistance, changing hardness, and the like. The vinyl chloride resin forming the above-mentioned overcoat layer also contains a large amount of a plasticizer.
During the use of the leather, the plasticizer gradually migrates to the surface side of the leather and forms a film of the plasticizer everywhere on the surface of the leather (this phenomenon is called bleed). When the plasticizer bleeds, stains are easily attached due to the oiliness of the plasticizer, and a sticky feeling occurs.

In order to deal with the above drawbacks, a technique for treating the leather surface with a surface treatment agent has been developed. According to this technology, adhesion of dust and dirt is prevented,
Even if it adheres, it is easy to fall off, and it is possible to obtain some effects such as eliminating the sticky feeling. However, it is not a complete countermeasure against oily stains, and it is not possible to prevent the adhesion itself, and once it adheres, it is difficult to remove, and it is not limited to the adhesion on the leather surface, vinyl chloride resin It penetrates even into the inside of the fine concavo-convex pattern (called grain) formed by embossing in the layer, and further penetrates into the vinyl chloride resin layer, and cannot be removed. Moreover, the surface
The treating agent also has a drawback that it tends to flow out due to water or a solvent.

Therefore, in recent years, in place of the above-mentioned treatment technique using a surface active agent, a technique for adhering a fluororesin film onto a vinyl chloride resin layer as an upper coating layer with an adhesive has been developed and is being widely adopted. is there. According to this technique, it exerts a good effect even on oily stains as described above,
In addition to sufficient stain resistance, the fluororesin film also imparts properties such as wear resistance, chemical resistance, and durability. Therefore, a leather having a fluororesin film adhered to its surface is expected to be used in a wide range as a so-called functional leather excellent in stain resistance, abrasion resistance, chemical resistance and durability.

[0005]

However, in the case of the above-mentioned functional leather, the following problems newly occur due to the fluororesin film adhered to the surface. (1) Since the fluorine resin film has a high degree of gloss,
Matte-like leather cannot be obtained, and it becomes glossy leather, which limits its use. (2) Since the fluorine-based resin film is hard, the texture of the leather is hard, and it cannot be said that the feel is excellent. (3) Due to the above (1) and (2), the above-mentioned functional leather is inferior in appearance or touch to natural leather and has a low commercial value.

In consideration of the above points, the present invention is a furniture, bag,
It is a functional leather with excellent stain resistance, abrasion resistance, chemical resistance, etc. used for surface materials such as vehicles, shoe coverings, bags, etc., and it is matte and has a texture etc. It is an object of the present invention to provide a functional leather which is more similar to the natural leather in terms of the feel of, and a method for producing the leather.

[0007]

In the functional leather of the present invention, a foam layer is formed on a base fabric, and a fluororesin film is provided directly on the foam layer or through an upper layer made of vinyl chloride resin. Is laminated, and is characterized in that at least the surface layer of the fluororesin film is formed with fine unevenness patterns of uneven sizes. Also,
The production method of the present invention is a foam layer on a base cloth, or after laminating a foam layer and an overcoat layer made of a vinyl chloride resin, a fluororesin film on the foam layer or the overcoat layer. It is characterized in that it is adhered and then subjected to a kneading process under a moist heat condition, and an embossing process is performed prior to the kneading process under the moist heat condition.

As the base cloth in the leather of the present invention, the base cloth materials usually used for this kind of leather such as woven cloth, non-woven cloth and knitted cloth made of natural or synthetic fibers can be preferably used, and the leather of the present invention is particularly preferable. A raised cloth is suitable for providing a soft texture. The thickness of the base fabric is not particularly limited, and an appropriate thickness is selected according to the purpose of use of the leather of the present invention. Examples of the foam layer on such a base cloth include ordinary synthetic resins such as vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin and acrylic resin, and a foaming agent which are used in this type of leather. Examples of the foam layer include various additives such as a plasticizer, a colorant, a stabilizer, an antifouling agent, an antifungal agent, a lubricant, and a flame retardant which are used as necessary.

The expansion ratio of this foam layer is such that at least the surface layer of the fluororesin film described later has a fine uneven pattern of uneven size, called a grain, to make the leather of the present invention flexible. It is one of the important factors for the texture, and if the expansion ratio is too low, a good texture cannot be obtained. Further, the higher the expansion ratio, the softer the texture, and the lighter the leather of the present invention, the higher the probability of foaming failure, resulting in poor adhesion of the fluororesin film, and its mechanical strength. Lower. Therefore, 130 to 250%, preferably 150 to 200% is suitable for the leather of the present invention.

A vinyl chloride resin is used as the upper coating layer in the leather of the present invention. Examples of the vinyl chloride resin include polyvinyl chloride, copolymers with other monomers capable of copolymerizing with vinyl chloride monomer, and blends of these resins, which are conventionally used as a leather of this type. Can be used. Examples of the other monomer copolymerizable with the vinyl chloride monomer include ethylene, propylene, vinyl acetate, vinylidene chloride, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, maleic acid, and acrylonitrile fumarate. Can be mentioned. Divinyl phthalate, diisobutyl phthalate, dioctyl phthalate, didodecyl phthalate, butylbenzyl phthalate, diisodecyl phthalate, dihexyl phthalate, diisononyl phthalate, dioctyl adipate, diisodecyl adipate, dibutyl sebacate, dioctyl are used as plasticizers for such vinyl chloride resins. In addition to sebacate, tributyl phosphate, tricresyl phosphate, triphenyl phosphate, trichloroethyl phosphate, trioctyl phosphate, diphenyl cresyl phosphate, trimellitic acid ester plasticizer, epoxy plasticizer, The polyester-based plasticizer and the like are blended alone or as a mixture of two or more. The blending ratio of these plasticizers is
The optimum ratio is selected according to the type of plasticizer,
Generally, it is preferable that the amount of the plasticizer is about 50 to 150 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. In addition to these plasticizers, an appropriate amount of additives such as colorants, stabilizers, antifouling agents, antifungal agents, lubricants, and flame retardants are added to the above-mentioned overcoat layer. May be. If the thickness of the upper coating layer is too thick, the texture becomes hard. Therefore, it is preferable that the thickness is thin in order to obtain a soft texture, but if it is too thin, the mechanical strength tends to be low, and the application tends to be narrow. Therefore, in the leather of the present invention, the lower limit is about 0.1 mm,
The upper limit is preferably about 0.2 mm.

Examples of the fluorine-based resin film on the above-mentioned upper layer (or foam layer) include tetrafluoroethylene, trifluoroethylene chloride, vinylidene fluoride, vinyl fluoride, propylene hexafluoride, and perfluoropini. Homopolymers or copolymers of fluorine-containing monomers and other fluorine-containing monomers, or copolymers of these fluorine-containing monomers and monomers containing no fluorine, such as ethylene-tetrafluoroethylene copolymers and ethylene-trifluoride. Ethylene chloride copolymer or the like is used. Such fluorine-based resin film, an ultraviolet absorber if necessary, colorants, stabilizers, soil release agents, antifungal, lubricants, and additives such as a flame retardant may be obtained by adding an appropriate amount , Resins other than fluorine-based resins
Is substantially not included. If the thickness of the fluororesin film is too thick, the leather surface becomes too hard, resulting in a soft texture and poor texture formation, and in addition, the material cost increases significantly. On the other hand, if it is too thin, the surface strength is lowered, and the wear resistance and durability are not improved, and further the chemical resistance is not improved. Therefore, in the leather of the present invention, about 5 to 50 μm, preferably 10 to 20 μm
m is suitable.

The leather of the present invention is one in which wrinkles are formed on at least the surface layer of the above-mentioned fluororesin film, and the wrinkles are formed on at least the entire surface layer of the film as uniformly as possible. It is preferable for improving the yield of the leather of the present invention. However, the height of the fine irregularities of the grain and the size of the area may be uneven, and rather the unevenness gives a texture closer to that of natural leather. Further, the texture may be formed not only in the surface layer of the above-mentioned fluororesin film but also in the above-mentioned overcoat layer or foam layer. When the wrinkles are formed even in the top-coating layer and the foam layer, the texture becomes more soft, the appearance and the touch become better, and the commercial value of the leather of the present invention is enhanced.

In the leather of the present invention, the above-mentioned overcoat layer has a pattern such as a so-called cloud pattern, which is similar to the surface pattern of natural leather, or any other suitable pattern, as in the case of ordinary vinyl chloride leather. It may be printed.

The leather of the present invention having the above-mentioned configuration,
It can be manufactured by the manufacturing method of the present invention described in detail below. In the method of the present invention, the foam layer and the overcoat layer (or only the foam layer) are formed on the above-mentioned base fabric in the same manner as in the usual method for producing vinyl chloride leather. After that, a fluororesin film is attached on the upper layer (or on the foam layer) with an adhesive. As the adhesive, any adhesive can be used as long as it can firmly bond both the vinyl chloride resin (or the resin forming the foam layer) forming the upper coating layer and the fluororesin film. Well, for example, a vinylidene chloride-based, acrylic-based, acrylic-epoxy-based, acrylphenol-modified vinyl-based, polyester-based temperature-sensitive adhesive or the like is used. The adhesive may be applied in advance to the surface of the fluororesin film that contacts the upper coating layer (or the foam layer), or the adhesive layer may be applied to the upper coating layer (or the foam layer) before the film is attached. ) May be applied on top. In the case of using the temperature-sensitive adhesive as described above, the heated upper coating layer (or the foam layer) and the fluororesin film are brought into contact with each other,
Then, the two are firmly bonded by thermocompression bonding such as passing between rolls. If the adhesion between the two is insufficient, steam enters between the two during the rubbing process under the moist heat condition described later, causing a problem such as peeling of the fluororesin film. In this way, the adhesive layer on the fluororesin film
As a means for laminating the sheets into a multilayer sheet, coextrusion or the like is used.
Known laminating method of
The agent layer may be multi-layered. Such a multi-layer system
Specific examples of the sheet include fluororesin film / acrylic
Resin layer, fluorine resin film / acrylic resin layer
/ A vinyl chloride resin layer or the like.

After sticking the fluororesin film as described above, a rubbing process is performed under wet heat conditions. The rubbing process in the method of the present invention is performed by mechanically picking up and down the functional leather to which the fluororesin film is attached as described above,
It is reciprocally moved in various directions such as left and right, front and back, or by tumbler processing that is performed in the field of synthetic leather. However, the former rubbing process by mechanical reciprocating motion may cause a breakage of the thin fluorine-based resin film, and therefore delicate adjustments such as pinching and pulling during reciprocating motion are required. In the method of the present invention, the above tumbler processing is performed by, for example, cutting the functional leather into an appropriate length (for example, about 20 to 30 m) and putting it in a tumbler having a plurality of baffle plates installed therein. , By rotating the tumbler. With the rotation of the tumbler, the functional leather is lifted above the tumbler by the action of the baffle and falls from above the tumbler to below. By repeating this operation, wrinkles are formed on the surface layer of the fluororesin film, or on the upper layer and the foam layer.

In order to improve the formation of the texture, in other words, to form fine texture close to that of natural leather and to give a soft texture, the method of the present invention performs the rubbing process under wet heat conditions. When the humidity and temperature are too low, the wet heat conditions in the method of the present invention are such that the formation of wrinkles cannot be formed or the formation thereof is too small, and a soft texture like natural leather cannot be obtained. On the other hand, if the humidity and the temperature are too high, such problems as peeling of the base cloth and secondary foaming of the foam layer occur. In addition, when the humidity is low and the temperature is high, only extremely fine grain is formed, and it does not become uneven grain of size such as height and area, and it does not look like natural leather, nor does it have a soft texture. . On the contrary, when the humidity is high and the temperature is low, the wrinkles are not sufficiently formed. Therefore, in the method of the present invention, the humidity is set to 70 to 100%, preferably 90 to 100%.
And the temperature is 40 to 100 ° C., preferably 85 to 95 ° C.
Is suitable.

In the case of the above tumbler processing, the vinyl chloride leather is dipped in water, appropriately squeezed and put into a heated tumbler, and steam is generated from the vinyl chloride leather to cause the above-mentioned wet heat condition to appear. The above-mentioned moist heat condition may be introduced into the tumbler by sending heated steam into the tumbler, or by sending steam and heating the tumbler. Further, in the case where the kneading is performed by mechanically reciprocating, it is preferable to perform the kneading under the moist heat conditions of the above humidity and temperature. If the kneading time under wet heat conditions is too short, sufficient wrinkles will not be formed, and areas where no wrinkles will be formed will remain. Not only is it uneconomical, but it also causes inconveniences such as excessive shrinkage of the base fabric, so in the method of the present invention, 0.5 to 2 hours, preferably 1 to 1.5 hours is suitable.

When the above steps are completed, natural drying or forced drying and natural cooling or forced cooling are performed. As a result, at least the fine and uneven grain sizes formed on the surface layer of the fluororesin film are fixed, and the above-described leather of the present invention is manufactured.

Further, in the method of the present invention, embossing may be performed prior to the rubbing under the above-mentioned wet heat conditions. This embossing may be the same as the embossing applied to ordinary vinyl chloride leather. If you apply embossing before rubbing under the above humid heat conditions, the grain forming effect by the rubbing process is improved, and a fine and uneven grain size that is closer to natural leather is formed,
The texture becomes even better. The embossing is
It is important to do this after sticking the fluororesin film. Because, when embossing is performed on the upper coating layer before sticking the film, the grain formed in the upper pulling layer by the processing hinders the sticking property of the thin fluororesin film,
This is because it is impossible to attach them uniformly. Further, in the method of the present invention, the cloud pattern and other patterns can be printed before the above-mentioned fluororesin film is attached.

[0020]

In the leather of the present invention, at least the unevenness of light is caused by the fine unevenness formed on the surface layer of the fluororesin film, which is uneven in size such as height and area, and is unique to the fluororesin film. The high-grade luster is diminished, and it becomes matte. Further, the above-mentioned texture has an effect of providing a soft texture, and makes the leather of the present invention feel like natural leather. Further, the above-mentioned texture does not impair the inherent properties of the fluororesin film, such as abrasion resistance, chemical resistance and durability, and the bleeding of the plasticizer from the upper coating layer by the film. It does not impair the shielding effect. As described above, the leather of the present invention has a matte tone and a soft texture while maintaining the characteristics of the conventional functional leather.
It has a feeling closer to that of natural leather.

Further, in the production method of the present invention, the vinyl chloride leather to which the fluororesin film is adhered is subjected to a kneading process under moist heat conditions. The humidity and temperature at this time make the fluororesin film at least soft, By improving the rubbing effect, the fine and different grain sizes that have the above-mentioned effects,
It is formed well on at least the surface layer of the film. The humidity and temperature also soften the upper coating layer and the foam layer existing under the fluororesin film and exert the effect of rubbing on these layers, and these layers also have the above-mentioned texture. Are formed well. In addition, the above humidity and temperature are
The base cloth is also contracted to some extent, and the contraction of the base cloth also has the effect of making the texture of the product leather as a whole soft and matte and approximating that of natural leather.

Furthermore, in the production method of the present invention, the embossing performed prior to the above-mentioned kneading under the moist heat condition has the effect of improving the texture forming effect of the kneading.
That is, fine embossing is also formed by embossing. The texture that is formed by rubbing under moist heat conditions is added to the texture, and the texture becomes complicated.
It more closely resembles the texture of natural leather. In addition, the embosses formed by embossing also have the effect of softening the PVC leather, and when the soft leather is kneaded under wet heat conditions, the embossing is performed in a better condition.

Further, in the leather of the present invention, a structure having no upper layer is suitable for a field where the texture is particularly important. The method of manufacturing the leather having such a structure simply omits the step of forming the upper coating layer in the step of manufacturing the leather having the upper coating layer.

[0024]

【Example】

Example 1 An example of the leather of the present invention shown in FIG. 1 was produced by an example of the production method of the present invention. That is, first, a napped cloth (thickness: 0.6 m
m) 1 on top of which is a foam layer (thickness 0.4
mm, foaming ratio of 180%) 2 and the upper layer 3 having the composition shown in Table 2. Next, the laminated body and a fluororesin film (thickness 20 μm) 5 having an adhesive (acrylic resin) 4 applied to the back surface (that is, the contact surface with the upper coating layer 3) are heated to 110 ° C. After heating to secure the adhesiveness of the adhesive 4, the adhesive layer 4 of the fluororesin film 5 is brought into contact with the upper coating layer 3 of the laminate, and sandwiched between the rolls to apply pressure to both (laminate And the fluororesin film 5) were firmly adhered by the adhesive 4.

[0025]

[Table 1]

[0026]

[Table 2]

The functional leather thus obtained is
Cut to 30m and immerse in water, water content 30wt%
Lightly squeeze it to a certain extent and put it in the tumbler.
The inside of this tumbler was heated so that the inside temperature was 100 ° C., the water contained in the introduced functional leather was evaporated, and the inside of the tumbler was kept at a relative humidity of 95 to 100%. Under this moist heat condition, tumbler 30-6
It was rotated at 0 rpm and kneaded for about 1 hour. As a result, as shown in FIG. 1, the fluororesin film 5,
In both the top-coating layer 3 and the foam layer 2, fine and uneven unevenness S of size was uniformly formed on the entire surface.

Regarding the leather of the present invention (hereinafter referred to as the leather 1 of the present invention) obtained as described above and the functional leather before tumbling (hereinafter referred to as the comparative leather 1), oily stains (magic) Resistance to ink),
When the transfer resistance to dye, abrasion resistance, and chemical resistance (methanol, toluene, cosmetics, etc.) when contacted with natural leather were examined, both leathers showed similar performance. Further, when the gloss and the flexibility are compared, the gloss of the invention leather 1 is a good matte tone, whereas the comparison leather 1 has a high gloss, and the flexibility is the leather 1 of the invention.
Was sufficiently soft, while Comparative Leather 1 had a hard feel.

Example 2 The leather of the present invention (hereinafter referred to as the leather 2 of the present invention) was produced in the same manner as in Example 1 except that the embossing of the texture of the leather was applied prior to the tumbling under the heat and humidity condition. did.
With respect to the leather 2 of the present invention and the comparative leather after embossing but before tumbling (hereinafter referred to as comparative leather 2), the same stain resistance, migration resistance, abrasion resistance and resistance as in Example 1 were obtained. When examined for chemical properties, both leathers showed similar performance. Further, when the gloss and the flexibility were compared in the same manner as in Example 1, the gloss of the present leather 2 was a good matte tone, whereas the comparison leather 2 had a high gloss, Regarding the flexibility, the leather 2 of the present invention was sufficiently soft, while the comparative leather 2 had a hard feel. Furthermore, when the present invention leather 1 and the present invention leather 2 were compared with each other in terms of gloss and flexibility as in Example 1 in the same manner as in Example 1, the present invention leather 1 showed that the present invention leather 1 had the same gloss. The leather 2 of the present invention had a slightly softer feel than the leather 1 of the present invention.

Example 3 The leather of the present invention was prepared in the same manner as in Example 1 except that the fluororesin film 5 was directly adhered to the foam layer 2 of the laminate in which the upper coating layer 3 was not laminated. Hereinafter, the present invention leather 3) was produced. Regarding the leather 3 of the present invention, the same stain resistance, migration resistance, and wear resistance as in Example 1 were obtained.
When the chemical resistance was examined, it exhibited the same performance as that of the leather 1 of the present invention, the gloss was also the same as that of the leather 1 of the present invention, and the flexibility of the leather 3 of the present invention was superior in flexibility.

[0031]

As described above in detail, according to the leather of the present invention, while retaining the functions such as the stain resistance, migration resistance, abrasion resistance, chemical resistance and durability of the fluororesin film, At least due to the grain formed on the surface layer of the film, it has a matte tone and a soft texture, and it has a look and feel similar to that of natural leather, greatly expanding its applications. Greatly improve the value. Further, in the production method of the present invention, the formation of the wrinkles that bring about the above effects can be performed very well by the rubbing process under the wet heat condition. Furthermore, by performing embossing prior to this rubbing, it is possible to further improve the texture formation.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the leather of the present invention manufactured by an embodiment of the manufacturing method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base cloth 2 Foam layer 3 Topcoat layer 4 Adhesive layer 5 Fluorine-based resin film layer S Concavo-convex pattern

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B32B 33/00 7148-4F

Claims (3)

[Claims] 1. A functional leather in which a foam layer is laminated on a base cloth, and a fluororesin film is laminated on the foam layer directly or via an overcoat layer made of a vinyl chloride resin,
A functional leather characterized in that at least a surface layer of the fluorine-based resin film is provided with fine unevenness patterns of non-uniform size. 2. A foam layer, or a foam layer and a vinyl chloride resin topcoat layer are laminated on a base fabric, and then a fluororesin film is attached onto the foam layer or topcoat layer. The method for producing a functional leather according to claim 1, wherein the kneading process is performed under moist heat conditions. 3. The manufacturing method according to claim 2, wherein embossing is performed before the rubbing under wet heat conditions.