JPH04343772A - Functional leather and production thereof - Google Patents

Abstract

PURPOSE:To provide a functional leather used for the surface materials of furnitures, bags, motor vehicles, etc., and for the insteps of shoes, bags, etc., being excellent in resistance to stain, abrasion chemicals, etc., and in delustering appearance, touch, etc., and further having functions similar to natural leathers, and to provide a method for producing the leather. CONSTITUTION:A foam layer 2 is formed on a base fabric 1. A fluororesin film 5 is formed on the foam layer 2 directly or through a vinyl chloride resin cover layer 3, and a fine uneven pattern S having depressions and projections with different sizes is formed at least on one surface of the film 5. The uneven pattern irregularly reflects light to give a delustered appearance, and gives a soft touch. According to the method, aforestated the foam layer or both the foam layer and the cover layer are laminated to the base fabric, and the fluororesin film is adhesively bonded to the foam layer or the cover layer, followed by subjecting the laminated product to a crumpling process under a wet-heating condition. An embossing process may be applied to the laminated product prior to the crumpling process. The crumpling process and the embossing process form the uneven pattern at least on the surface of the film.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to functional leather made of vinyl chloride resin used as surface materials for furniture, bags, vehicles, etc., shoe covers, bags, etc., and a method for manufacturing the leather. In particular, the present invention relates to the above-mentioned functional leather that has excellent stain resistance, abrasion resistance, chemical resistance, etc., and is also excellent in feel such as texture, and a method for producing the leather.

0002

2. Description of the Related Art Conventionally, vinyl chloride leather, referred to as vinyl chloride leather, has been widely used in the various fields mentioned above. Such PVC leather is generally constructed by laminating a foam layer on a base cloth made of fiber, and laminating a top layer made of vinyl chloride resin on the foam layer. By the way, as is well known, vinyl chloride resin is used with a large amount of plasticizer mixed therein for the purpose of imparting processability and cold resistance, changing hardness, and the like. The vinyl chloride resin constituting the above-mentioned top layer also contains a large amount of plasticizer. During use of the leather, this plasticizer gradually migrates to the surface of the leather, forming a plasticizer film all over the surface of the leather (this phenomenon is called bleed). When the plasticizer bleeds, dirt tends to adhere due to the oiliness of the plasticizer, resulting in a sticky feeling.

[0003] In order to address the above-mentioned drawbacks, techniques have been developed in which the surface of the leather is treated with a surfactant. According to this technique, it is possible to obtain certain effects such as preventing the adhesion of dust, dust, etc., making it easy to remove even if it does adhere, and eliminating the sticky feeling. However, it is not a complete countermeasure against oil-based stains, and not only is it impossible to prevent the adhesion itself, but once it adheres, it is difficult to remove, and it does not only stick to the leather surface. It penetrates into the fine uneven patterns (called grains) formed on the layer by embossing, and even seeps into the vinyl chloride resin layer, making it impossible to remove. Moreover, surfactants also have the disadvantage of being easily washed out by water, solvents, and the like.

[0004] Therefore, in recent years, instead of the above-mentioned treatment technology using a surfactant, a technology has been developed in which a fluororesin film is adhered onto the vinyl chloride resin layer, which is the top layer, using an adhesive, and is being widely adopted. be. According to this technology, it is also effective against oil-based stains such as those mentioned above.
In addition to sufficient stain resistance, the fluororesin film also provides properties such as abrasion resistance, chemical resistance, and durability. Therefore, leather with a fluororesin film adhered to its surface is expected to be used in a wide range of areas as a so-called functional leather with excellent stain resistance, abrasion resistance, chemical resistance, and durability.

[0005]

[Problems to be Solved by the Invention] However, in the case of the above-mentioned functional leather, the following new problems have arisen due to the fluororesin film adhered to the surface. (1) Because fluororesin film has a high degree of gloss,
It is not possible to obtain a matte-like leather, and all leather becomes glossy, which limits the areas where it can be used. (2) Since the fluororesin film is hard, the texture of the leather is hard and cannot be said to have an excellent feel. (3) Due to (1) and (2) above, the functional leather described above is inferior in appearance or feel to the skin and has a lower commercial value than natural leather.

[0006] The present invention takes the above points into consideration and provides furniture, bags,
It is a functional leather with excellent stain resistance, abrasion resistance, chemical resistance, etc., used as surface materials for vehicles, shoe covers, bags, etc., and has a matte finish and texture. The purpose of the present invention is to provide functional leather that has an excellent feel and is closer to natural leather, and a method for producing the leather.

[0007]

[Means for Solving the Problems] The functional leather of the present invention has a foam layer on a base fabric, and a fluororesin film on the foam layer either directly or through a top layer made of vinyl chloride resin. The functional leather is characterized in that fine irregularities of uneven size are formed on at least the surface layer of the fluororesin film. In addition, in the manufacturing method of the present invention, after laminating a foam layer, or a foam layer and a vinyl chloride resin top layer on a base fabric, a fluorine resin is laminated on the foam layer or top layer. It is characterized in that a film is attached and then subjected to a rolling process under moist heat conditions, and is also characterized in that embossing is performed prior to the rolling process under moist heat conditions.

As the base fabric for the leather of the present invention, base fabric materials normally used for this type of leather, such as woven fabrics, non-woven fabrics, and knitted fabrics made of natural or synthetic fibers, can be preferably used. Raised fabric is suitable for giving it a flexible texture. The thickness of the base fabric is not particularly limited, and an appropriate thickness is selected depending on the intended use of the leather of the present invention. The foam layer on the base fabric is made of ordinary synthetic resins and foaming agents used in this type of leather, such as vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, acrylic resin, etc. , a foam layer containing 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 foaming ratio of this foam layer is determined by forming fine irregularities of non-uniform size called grains on at least the surface layer of the fluororesin film, which will be described later, to make the leather of the present invention flexible. This is one of the important factors in obtaining a good texture, and if the expansion ratio is too low, a good texture cannot be obtained. In addition, the higher the foaming ratio, the softer the texture and the lighter the leather of the present invention, but on the other hand, the probability of foaming failure is higher, which makes the adhesion of the fluororesin film poor, and the mechanical strength is also reduced. decrease. Therefore, in the leather of the present invention, 130 to 250%, preferably 150 to 200% is suitable.

[0010] A vinyl chloride resin is used as the top layer in the leather of the present invention. The vinyl chloride resin includes resins conventionally used for this type of leather, such as polyvinyl chloride, copolymers of vinyl chloride monomers and other copolymerizable monomers, or blends of these resins. Can be used. Examples of other monomers that can be copolymerized with the above vinyl chloride monomer include ethylene, propylene, vinyl acetate, vinylidene chloride, acrylic acid, acrylic ester, methacrylic acid, methacrylic ester, maleic acid, and acrylonitrile fumarate. Can be mentioned. Such vinyl chloride resins contain dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, didodecyl phthalate, butylbenzyl phthalate, diisodecyl phthalate, dihexyl phthalate, diisononyl phthalate, dioctyl adipate, diisodecyl adipate, dibutyl sebacate, dioctyl. In addition to sebacate, tributyl phosphate, tricresyl phosphate, triphenyl phosphate, trichloroethyl phosphate, trioctyl phosphate, diphenyl cresyl phosphate, etc., trimellitic acid ester plasticizers, epoxy plasticizers, A polyester plasticizer or the like may be blended singly or in combination. The optimum blending ratio of these plasticizers is selected depending on the type of plasticizer, but in general, it is about 50 to 150 parts by weight of plasticizer per 100 parts by weight of vinyl chloride resin. preferable. In addition,
In addition to these plasticizers, appropriate amounts of additives such as colorants, stabilizers, antifouling agents, antifungal agents, lubricants, and flame retardants may be added to the above-mentioned top layer. good. Regarding the thickness of the top layer, if it is too thick, the texture will be hard, so in order to obtain a flexible texture, the thinner the layer, the better, but if it is too thin, the mechanical strength will decrease and the applications will tend to be narrowed. Therefore, in the laser of the present invention, it is preferable that the lower limit is about 0.1 mm and the upper limit is about 0.2 mm.

[0011] The fluororesin film on the above-mentioned top layer (or foam layer) includes tetrafluoroethylene, trifluorochloroethylene, vinylidene fluoride, vinyl fluoride, hexafluoropropylene, perfluorovinyl ether. ，
Homopolymers or copolymers of other fluorine-containing monomers, or copolymers of these fluorine-containing monomers with non-fluorine-containing monomers, such as ethylene-tetrafluoroethylene copolymers, ethylene-trifluoroethylene chloride Copolymers etc. are used. Such fluororesin films are coated with ultraviolet absorbers, colorants, stabilizers,
Appropriate amounts of additives such as antifouling agents, antifungal agents, lubricants, and flame retardants may be added. If the fluororesin film is too thick, the leather surface will become too hard and the leather will not have a soft texture, and the grain formation will also be poor, and in addition, the material cost will increase significantly. On the other hand, if it is too thin, the surface strength will decrease and the abrasion resistance and durability will not improve, and furthermore, the chemical resistance will not improve. Therefore, in the leather of the present invention, 5 to
A suitable thickness is about 50 μm, preferably about 10 to 20 μm.

[0012] In the laser of the present invention, grains are formed at least on the surface layer of the above-mentioned fluororesin film. This is preferable for improving the yield of the laser of the present invention. However, the height, area, etc. of the fine unevenness of the grain may be non-uniform, and if it is non-uniform, the texture will be closer to that of natural leather. Furthermore, the grains may be formed not only on the surface layer of the fluororesin film but also on the above-mentioned top layer or foam layer. When grains are formed even in the top layer and the foam layer, the leather has a softer texture, has a better appearance and feel, and increases the commercial value of the leather of the present invention.

[0013] In the leather of the present invention, the above-mentioned upper layer has a pattern such as a so-called cloud pattern that approximates the surface pattern of natural leather, as well as other appropriate patterns, as in the case of ordinary PVC leather. It may be printed.

The laser of the present invention having the above structure can be manufactured by the manufacturing method of the present invention described in detail below. In the method of the present invention, the above-mentioned foam layer and top coat layer (or only the foam layer) are formed on the above-mentioned base fabric in the same manner as in the usual manufacturing method of PVC leather. Thereafter, a fluororesin film is attached onto the top layer (or onto the foam layer) using an adhesive. Any adhesive can be used as long as it can firmly bond both the vinyl chloride resin that makes up the top layer (or the resin that makes up the foam layer) and the fluororesin film. For example, temperature-sensitive adhesives such as vinylidene chloride, acrylic, acrylic epoxy, acrylic phenol-modified vinyl, and polyester adhesives are used. The adhesive is used as a top layer (or foam layer) of fluororesin film in advance.
It may be coated on the contact surface with the film, or it may be coated on the top layer (or foam layer) prior to the application of the film. In addition, when using a temperature-sensitive adhesive such as the one described above, a heated top layer (or foam layer) is brought into contact with a fluororesin film, and then heat is applied, such as by passing it between rolls. Firmly bond the two together by crimping or the like. If the adhesion between the two is insufficient, steam will enter between the two during the rolling process under moist heat conditions described below, causing problems such as peeling of the fluororesin film.

After the fluororesin film is attached as described above, it is rubbed under moist heat conditions. The rubbing process in the method of the present invention involves mechanically pinching the functional leather to which the fluororesin film has been attached as described above.
This is done by making small reciprocating movements in various directions such as left and right, front and back, or by tumble processing, which is used in the field of synthetic leather. However, in the former method of rolling by mechanical reciprocating motion, there is a possibility that the thin fluororesin film may break, so delicate adjustments such as the amount of pinching and the amount of tension during reciprocating motion are required. In the method of the present invention, the above-mentioned tumbler processing is performed by, for example, cutting the above-mentioned functional leather into an appropriate length (for example, about 20 to 30 m) and putting it into a tumbler equipped with a plurality of baffle plates inside. , by rotating the tumbler. As the tumbler rotates, the functional leather is lifted above the tumbler by the action of the baffle plate and falls downward from above the tumbler. By repeating this operation, grains are formed on the surface layer of the fluororesin film or even on the top layer and foam layer.

In order to improve the formation of this grain, in other words, to form fine grains similar to those of natural leather and to provide a soft texture, in the method of the present invention, the rolling process is carried out under moist heat conditions. When the humidity and temperature conditions in the method of the present invention are too low, grains may not be formed or grains may be formed too little, and a soft texture similar to natural leather cannot be obtained. On the other hand, if both the humidity and temperature are too high, problems such as peeling of the base fabric and secondary foaming of the foam layer will occur. In addition, if the humidity is low and the temperature is high, only very fine grains will be formed, and the grains will not be uneven in height or area, and not only will it not look like natural leather, but it will not have a soft texture. . Conversely, if the humidity is high and the temperature is low, grains will not be sufficiently formed. Therefore, in the method of the present invention, it is suitable that the humidity is 70 to 100%, preferably 90 to 100%, and the temperature is 40 to 100°C, preferably 85 to 95°C.

[0017] In the case of the above-mentioned tumbler processing, the PVC leather is soaked in water, squeezed appropriately, and placed in a heated tumbler to generate water vapor from the PVC leather to create the above-mentioned moist heat conditions. The above-mentioned moist heat conditions may be created in the tumbler by introducing heated steam into the tumbler, or by introducing steam and heating the tumbler. Furthermore, even when the kneading process is performed by mechanically reciprocating, it is of course preferable to perform the kneading process under the moist heat conditions of the above-mentioned humidity and temperature. Note that if the kneading time under moist heat conditions is too short, sufficient grain will not be formed and some areas will remain where no grain will be formed, and even if the kneading time is too long, the processing effect will be saturated. Since this is not only uneconomical but also causes disadvantages such as excessive shrinkage of the base fabric, the method of the present invention is suitable for about 0.5 to 2 hours, preferably about 1 to 1.5 hours.

After the above steps are completed, natural or forced drying and natural or forced cooling are performed. As a result, the fine grains of non-uniform size formed on at least the surface layer of the fluororesin film are fixed, and the leather of the present invention described above is manufactured.

Furthermore, in the method of the present invention, embossing may be performed prior to the rolling under the above-mentioned moist heat conditions. This embossing may be similar to the embossing applied to ordinary PVC leather. If embossing is performed before rolling under the above-mentioned moist heat conditions, the effect of forming grains by rolling will be improved, and fine grains of uneven size will be formed that are even closer to those of natural leather.
The texture also becomes even better. In addition, embossing is
It is important to perform this after pasting the fluororesin film. This is because if the top layer is embossed before the film is applied, the grains formed on the top layer by the process will impede the adhesion of the thin fluororesin film, making it difficult to apply the film uniformly. This is because it makes it impossible to wear clothes. Furthermore, in the method of the present invention, before pasting the above fluororesin film,
The aforementioned cloud pattern and other patterns can also be printed.

[0020]

[Function] In the laser of the present invention, the fine grains of uneven height and area formed on at least the surface layer of the fluororesin film have a diffused reflection effect on light, which is unique to fluororesin films. The high gloss is reduced and the color becomes matte. Furthermore, the grains described above also have the effect of providing a soft texture, giving the leather of the present invention a feel similar to that of natural leather. The above-mentioned grains do not impair the inherent properties of the fluororesin film, such as abrasion resistance, chemical resistance, durability, etc., and prevent the plasticizer from bleeding from the top layer due to the film. It also does not impair the shielding effect. As a result, the leather of the present invention has a matte and flexible texture while maintaining the characteristics of conventional functional leather.
It has a feel that is even closer to natural leather.

Furthermore, in the manufacturing method of the present invention, the PVC leather to which the fluororesin film is attached is rubbed under humid heat conditions, and the humidity and temperature at this time at least soften the fluororesin film, By improving the rolling effect, fine grains having the above-mentioned effect and having different sizes can be formed satisfactorily on at least the surface layer of the film. This humidity and temperature also soften the top layer and foam layer that exist under the fluororesin film, and the effect of the rolling process is also exerted on these layers, causing the above-mentioned texture to occur in these layers as well. form well. In addition, the above humidity and temperature also cause the base fabric to shrink somewhat, and the shrinkage of the base fabric also makes the overall texture of the product leather soft and matte, making it similar to natural leather. have

Furthermore, in the manufacturing method of the present invention, the embossing performed prior to the rolling under the above-mentioned moist heat conditions has the effect of improving the effect of forming grains by the rolling. That is, fine grains are also formed by embossing. On top of this grain, grains formed by rolling under moist heat conditions are added, making the condition of the grain complicated.
More closely resembles the texture of natural leather. In addition, the grain formed by embossing also has the effect of making the PVC leather soft, and if the soft leather is rubbed under moist heat conditions, the grain will be formed in a better condition.

[0023] Furthermore, in the leather of the present invention, one having a structure in which no top layer is provided is suitable for fields where texture is particularly important. The method for manufacturing a leather having such a structure simply omits the step of forming a top layer in the process of manufacturing a leather having a top layer.

[0024]

【Example】

Example 1 An example of the leather of the present invention shown in FIG. 1 was manufactured by an example of the manufacturing method of the present invention. That is, first, a raised cloth (thickness 0.6 m
m) A foam layer having the composition shown in Table 1 (thickness 0.4
mm, foaming ratio 180%) 2 and a top layer 3 having the assembly properties shown in Table 2 was laminated. Next, this laminate and a fluororesin film (thickness: 20 μm) 5 having an adhesive (acrylic resin) 4 coated on the back surface (that is, the surface in contact with the above-mentioned top layer 3) were heated to 110°C. After ensuring the adhesive properties of the adhesive 4 by heating, the adhesive layer 4 of the fluororesin film 5 is brought into contact with the top layer 3 of the laminate, and is sandwiched between rolls and pressurized. and fluororesin film 5) were firmly adhered with adhesive 4.

[0025]

[Table 1]

[0026]

[Table 2]

[0027] The functional leather obtained in this way,
Cut into 30m lengths and immerse in water, water content 30wt%
The mixture was squeezed lightly to the desired consistency and placed in a tumbler. The inside of this tumbler was heated to 100° C., and the moisture contained in the functional leather put into it evaporated, and the inside of the tumbler was maintained at a relative humidity of 95 to 100%. Under this moist heat condition, the tumbler is heated to 30~6
It was rotated at 0 rpm and rubbed for about 1 hour. As a result, as shown in FIG.
In both the top layer 3 and the foam layer 2, fine grains S of non-uniform size were uniformly formed over the entire surface.

[0028] The leather of the present invention obtained as described above (
Regarding the functional leather before tumble processing (hereinafter referred to as Inventive Leather 1) and the functional leather before tumble processing (hereinafter referred to as Comparative Leather 1), the stain resistance against oil-based stains (magic ink) and the resistance when brought into contact with natural leather were determined. When we investigated resistance to dye migration, abrasion resistance, and chemical resistance (methanol, toluene, cosmetics, etc.), both leathers showed similar performance. In addition, when comparing gloss and flexibility, inventive leather 1 had a good matte tone, while comparative leather 1
had a high degree of luster, and while Inventive Leather 1 was sufficiently soft, Comparative Leather 1 had a hard feel.

Example 2 A leather of the present invention (hereinafter referred to as "leather of the present invention 2") was produced in the same manner as in Example 1, except that the leather was embossed to give it a textured texture prior to tumble processing under moist heat conditions. did. The present invention leather 2 and the comparative leather after embossing and before tumble processing (hereinafter referred to as comparative leather 2) had the same stain resistance, migration resistance, abrasion resistance, and resistance as in Example 1. When chemical properties were investigated, both leathers showed similar performance. Furthermore, when the gloss and flexibility were compared in the same manner as in Example 1, it was found that the inventive leather 2 had a good matte tone, while the comparative leather 2 had a high level of gloss. In terms of flexibility, Inventive Leather 2 was sufficiently soft, whereas Comparative Leather 2 had a hard feel. Furthermore, when the present invention leather 1 and the present invention leather 2 were compared in the same way as in Example 1 in terms of gloss and flexibility, the present invention leather 1 had a higher gloss than the present invention leather 2. In terms of flexibility, Invention Leather 2 had a softer feel than Invention Leather 1.

Example 3 The fluororesin film 5 was directly adhered to the foam layer 2 of the laminate on which the top layer 3 was not laminated.
A leather of the present invention (hereinafter referred to as "leather of the present invention 3") was produced in the same manner as in Example 1. When the stain resistance, migration resistance, abrasion resistance, and chemical resistance of the leather 3 of the present invention were examined in the same manner as in Example 1, it showed the same performance as the leather 1 of the present invention.
The gloss was also the same as that of Inventive Leather 1, and the flexibility of Inventive Leather 3 was superior to that of Inventive Leather 3.

[0031]

[Effects of the Invention] As detailed above, according to the leather of the present invention, while retaining the functions of the fluororesin film such as stain resistance, migration resistance, abrasion resistance, chemical resistance, and durability, Due to the grains formed on at least the surface layer of the film, it has a matte and flexible texture, and has an appearance, feel, etc. similar to natural leather, which greatly expands the range of uses and products. It also significantly increases value. Further, in the manufacturing method of the present invention, by rolling under moist heat conditions, it is possible to form grains that bring about the above-mentioned effects very well. Furthermore, by performing embossing prior to this rolling process, it is possible to further improve the grain formation.

[Brief explanation of drawings]

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

[Explanation of symbols]

1 Base fabric 2 Foam layer 3 Top layer 4 Adhesive layer 5 Fluorine resin film layer S　Uneven pattern

Claims (3)

[Claims] 1. A functional leather comprising a foam layer on a base fabric, and a fluororesin film on the foam layer either directly or via a vinyl chloride resin top layer, comprising:
A functional leather characterized in that fine irregularities of uneven size are formed on at least the surface layer of the fluororesin film. 2. After laminating a foam layer, or a foam layer and a vinyl chloride resin top layer on a base fabric, a fluororesin film is attached on the foam layer or top layer. 2. The method for producing functional leather according to claim 1, wherein the leather is then rubbed under moist heat conditions. 3. The manufacturing method according to claim 2, wherein embossing is performed prior to rolling under moist heat conditions.