JPS6142032B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for imparting a surface finish resembling the appearance of natural leather to the surface of a polymer sheet, particularly a leather-like sheet. [Prior Art] Leather-like sheet materials have been produced on fiber base materials such as nonwoven fabrics, woven fabrics, and knitted fabrics, or on these fiber base materials impregnated with elastic polymers such as polyurethane elastomers. A porous layer of a flexible polymer such as polyurethane elastomer, polyamide, or polyvinyl chloride is formed thereon. Various surface finishing methods have been developed to make such leather-like sheet materials resemble natural leather in appearance. For example, by spraying small droplets of a polymer solution containing a pigment onto the surface of a porous polymer using a spray method or the like, and creating many independent small mounds based on the droplets, the water vapor permeability of the porous polymer can be improved. There are known methods of patterning without damaging the
(see, for example, British Patent No. 1325850). In addition, various coloring methods have been proposed to improve the disadvantages of the gravure method compared to the spray method and to make the appearance more similar to leather. For example, there is a method of applying an easily dyeable polymer to the surface of a polymer sheet for dyeing (Japanese Patent Publication No. 48-28041), and a method of applying a composition in which a dye is added to an easily dyeable polymer (Japanese Patent Publication No. 48-28041).
48-28042). [Problems to be Solved by the Invention] The conventional method of spraying small droplets of a polymer solution containing a pigment onto a surface is superior in that it can be colored without impairing the water vapor permeability of the porous polymer. However, since the droplets contain a polymer, the droplets tend to become large, and the colored part becomes bulging, resulting in a rough surface pattern.Since the colorant is a pigment, the pattern is extremely rough. It becomes superficial, causing differences in gloss, the abrasion resistance of the pattern is low, and the leather-like sheet material obtained using this method has unevenness on the surface due to the porous layer. Because of this, it has drawbacks such as giving a cheap impression.
The leather-like sheet material obtained by this method cannot be said to have an appearance similar to natural leather. In addition to coloring by such a spray method, a method is known in which the surface of a leather-like sheet is colored by gravure printing. This method has the advantage of being able to mass-produce various patterns, but the resulting surface pattern only has regular colors or patterns, and does not have a solid appearance. However, it has the disadvantage that only a product can be obtained that gives an extremely artificial and cheap impression with a so-called vinyl feel. In addition, Special Publication No. 48-28041 or Special Publication No.
The method described in Publication No. 48-28042 has the advantage that a leather-like sheet material with a deep color can be obtained, but the leather-like sheet material obtained by this method has a uniform surface pattern. For that reason,
It also has the disadvantage of giving the impression of being artificial. [Means for Solving the Problems] The first object of the present invention is to provide a leather-like sheet material having a porous polymer layer on the surface with an appearance similar to that of natural leather and having a solid appearance and an elegant appearance. It is an object of the present invention to provide a method for coloring and finishing a surface, which has natural deep coloration and is excellent in abrasion resistance. The second object of the present invention is to use such a surface coloring method to improve the surface properties of the leather-like sheet material without impairing its feel, abrasion strength, scratch strength, etc. When the resulting leather-like sheet material is folded, wrinkles (hereinafter referred to as
The purpose of the present invention is to provide a finishing method in which the folding wrinkles (referred to as folding wrinkles) are fine and extremely similar to the folding wrinkles of high-grade natural leather. A third object of the present invention is to provide a finishing method that is extremely simple and has good workability. That is, the present invention provides a method for applying the polymer forming the non-porous polymer layer to the surface of a polymer sheet product in which a uniformly colored non-porous polymer layer is laminated on the surface of a porous polymer substrate. A dye solution in which a dye is dissolved in a swelling agent having a linear swelling rate of at least 15% at a temperature of 30°C, or a swelling agent for the polymer in the non-porous part, or a solvent for the polymer in the non-porous part. is irregularly applied as mist-like droplets to the surface of the homogeneous colored non-porous polymer layer, so that the total patterned area of the micro-area colored parts is 15% of the sheet surface area.
A process for producing a polymer sheet product similar to the appearance of natural leather, characterized in that the coloring is ~80% and the swelling agent is evaporated to allow the dye to penetrate at least into the non-porous polymer layer. The purpose will be achieved. A polymer sheet product in which a colored non-porous polymer layer is laminated on the surface of a porous polymer substrate by applying surface finishing by the method of the present invention; A colored part with a minute area of 0.002 to 0.25 mm ² is colored with different dyes.
500 or more per cm ² , and the total area of the colored minute area portions is 15 to 80% of the sheet surface area, the colored minute area portions have no periodicity, and the colored portions have no periodicity. It penetrates at least into the non-porous polymer layer without rising to the surface of the polymer layer, resulting in a polymer sheet material that has an appearance similar to natural leather. A feature of the present invention is that it uses a polymer-free dye solution in which the dye is dissolved in a polymer swelling agent that forms a non-porous layer, so the viscosity of the dye solution is low, and it can be sprayed into small atomized droplets. The coated surface can form a small colored area. Furthermore, by using a swelling agent for the polymer forming the non-porous layer, dye molecules can be easily penetrated into the non-porous polymer layer without dissolving the non-porous polymer layer. ,
Coloring can be done without the colored portion rising up on the surface of the polymer layer. In addition, the porous surface does not have the diffused reflection of light, has a subdued luster similar to the luster of natural leather, has a surface pattern with excellent abrasion resistance, and has excellent abrasion and scratch resistance. But it will be excellent. Furthermore, due to the relationship between the non-porous layer and the porosity existing thereunder, the folding wrinkles are fine and very similar to the folding wrinkles of high-grade natural leather. The polymer sheet material to be surface-finished in the present invention is mainly made of fibrous base materials such as non-woven fabrics and knitted fabrics, or elastic polymers such as polyurethane elastomers, acrylonitrile-butadiene copolymers, and styrene-butadiene copolymers. Uniformly coloring the surface of a porous polymer substrate, which is obtained by adding a porous layer or a non-porous layer of a polymer such as polyurethane elastomer, polyamide, or polyvinyl chloride to at least one side of a fibrous substrate containing a polymer. It is a sheet-like product made of laminated non-porous polymer layers.
Specific examples of the polymer for the uniformly colored non-porous polymer layer forming the surface of the polymer sheet include polyurethane elastomer, acrylonitrile-butadiene copolymer, polyvinyl chloride, and polyamide. Among these, polyurethane elastomer is preferred. In particular, the weight percentage (hereinafter referred to as N%) of nitrogen atoms constituting isocyanate groups in the diisocyanate compound used to synthesize the polyurethane elastomer is 3 to 7.
% by weight of a polyurethane elastomer or a polymer composition based on this polyurethane elastomer. If N% is less than 3% by weight, wear resistance and scratch resistance will be poor; on the other hand, if N% is 7% by weight
If it exceeds this, the bending fatigue resistance will decrease and the creases will become rough. These polymers are prepared by adding a coloring agent to a solution dissolved in a solvent or a dispersion dispersed in a dispersant to form a colored composition liquid, and a liquid is applied to the surface of the porous polymer substrate to a thickness of 2 μm to 10 μm after drying. of the polymer to form a non-porous polymer layer. Further, the coloring agent used to form the colored non-porous layer may be a dye, a pigment, or a mixture of both. As the dye, metal complex dyes, acid dyes, disperse dyes, etc. can be used, but solvent-soluble dyes are preferable. Examples of pigments include carbon black, chrome yellow, cadmium yellow, iron oxide, amber, red lead, cobalt purple, ultramarine blue, cobalt blue,
Inorganic pigments such as cerulean blue, chrome green, chromium oxide, and various metal powder pigments, and organic pigments such as azo compounds, phthalocyanines, and metal chelate compounds are preferably used. Note that if a white pigment such as titanium oxide or zinc oxide is used alone as a coloring agent, the object of the present invention cannot be achieved in such a case because it cannot be colored. Moreover, as a solvent which is one component constituting the coloring composition liquid, it is preferable to use a solvent that is compatible with the above-mentioned polymer constituting the coloring composition liquid. Among them,
It is particularly preferable that a solvent that dissolves the porous polymer constituting the leather-like sheet material is contained. When such a solvent is used, a non-porous polymer layer is provided on the porous polymer of the leather-like sheet, and the surface layer of the porous polymer is dissolved by the solvent and becomes non-porous. The adhesion between the porous polymer and the non-porous layer becomes stronger, and the scratch resistance and bending fatigue resistance are improved. When polyurethane elastomer is used as the polymer in the color sweeping composition, N・N'-dimethylformamide (hereinafter referred to as DMF) is used as the solvent.
), formamide-based solvents such as N·N'-diethylformamide, sulfoxide-based solvents such as dimethyl sulfoxide (hereinafter abbreviated as DMSO), and tetrahydrofuran (hereinafter abbreviated as THF). In addition, when polyamide is used as the polymer in the coloring composition liquid, phenols, benzyl alcohol, etc. can be used as the solvent, and when polyvinyl chloride is used, DMF, THF, cyclohexane, etc. can be used as the solvent. Can be used. The ratio of the colorant to the polymer in the coloring composition liquid is preferably in the range of 0.01 to 5 in terms of weight ratio. If the colorant is used in an amount exceeding this range, the adhesion to the porous polymer will be reduced, resulting in the disadvantage that folding wrinkles will become coarse. If the amount of the coloring agent used is too small to fall within this range, there will be a drawback that the unevenness on the surface of the porous polymer layer cannot be concealed. Furthermore, the ratio of solvent to polymer in the coloring composition liquid is 5 to 5 in terms of polymerization ratio.
A range of 20 is preferred. If a large amount of solvent is used in excess of this range, a coating film with an orange skin pattern is likely to be formed during the drying process of the solvent. Furthermore, if the amount of solvent used is too small to fall within this range, interference-like color spots are likely to occur. The coloring composition liquid may also contain fillers, stabilizers, gloss control agents, etc. within a range that does not impair the appearance or physical properties of the product. A non-solvent may be included as long as the combination does not precipitate as a solid. Examples of methods for applying the colored composition liquid onto the porous surface of the leather-like sheet include a gravure method and a transfer method. When the coated leather-like sheet material is dried, a uniformly colored non-porous coating layer is formed on the surface. The thickness of the non-porous coating layer to be formed is preferably 2 to 10 μm. If the thickness of the non-porous coating layer exceeds this range,
The disadvantage is that the bending fatigue resistance decreases and the bending wrinkles become coarse. Conversely, if the thickness is less than this range, fine bending wrinkles cannot be obtained and the surface of the porous polymer layer becomes rough. This results in the drawback that the unevenness is not sufficiently concealed, and the abrasion resistance and scratch resistance are further reduced. If simply applying a coloring composition solution does not reach this range, or if you want to add a natural leather-like uneven pattern to the surface,
By heating and embossing the surface of the non-porous coating layer, the thickness of the non-porous layer can be increased, and
A desired embossed pattern can be obtained. The swelling agent used to create the dye solution used to form the microscopic area of colored areas in the homogeneously colored non-porous polymer is then the same as that of the polymer forming the non-porous layer. A liquid whose linear expansion coefficient in the thickness direction of the film is at least 15% when the polymer is made into a dry film with a thickness of 5 μm and the film is immersed in a liquid maintained at 30°C for 5 minutes. Alternatively, the liquid composition is referred to as a swelling agent. Linear expansion rate is 15%
If the dye molecules dissolved in the swelling agent hardly penetrate into the interior of the leather-like sheet, the surface pattern of the obtained leather-like sheet will look superficial and cheap. At the same time, the abrasion resistance of the surface pattern is also inferior. On the other hand, when a liquid that provides a coefficient of linear expansion exceeding 200% is used as a swelling agent, the surface of the resulting product becomes uneven, giving it a cheap impression. This swelling agent may be a liquid that has a swelling effect by itself, but for polymers forming a non-porous layer, the liquid that acts as a solvent and the liquid that acts as a non-solvent can be used to achieve the desired linear swelling rate. It is also possible to use a composition liquid that has been adjusted by mixing in proportions. In particular, it is preferable to use a mixture of a liquid that will serve as a solvent and a liquid that will serve as a non-solvent, since the coefficient of linear expansion, drying rate, etc. can be arbitrarily selected. However, when a mixture of a solvent liquid and a non-solvent liquid is used as a swelling agent, the solvent liquid and the non-solvent liquid must be mutually soluble. When the polymer forming the non-porous layer is a polymer mainly composed of polyurethane elastomer, the solvent liquid may be, for example, DMF,
Examples include formamide solvents such as N·N'-diethylformamide, sulfoxide solvents such as DMSO, and THF and cellosolve solvents. However, some of these solvents
Some polyurethane elastomers are non-solvents due to their molecular structure. In addition, non-solvents include ketones such as dioxane, cyclohexanone, methyl ethyl ketone (hereinafter abbreviated as MEK), and acetone.
Representative examples include esters such as ethyl acetate and butyl acetate, aromatic hydrocarbons such as toluene, xylene and benzene, and alcohols such as methanol, ethanol, butanol and isopropyl alcohol. In addition, when the polymer forming the non-porous layer is a polymer mainly composed of polyamide, phenols, benzyl alcohol, etc. can be used as a solvent, and ethers, acetone, benzene, etc. can be used as a non-solvent. etc. can be used. In addition, if the polymer forming the non-porous layer is a polymer mainly composed of polyvinyl chloride, use DMF, THF, cyclohexanone, etc. as a solvent, or alcohols, ethers, acetone, benzene, etc. can be used as a non-solvent. Further, as the dye used in the dye solution, it is preferable to use a dye that has affinity with the polymer forming the non-porous layer. However, it does not necessarily have to have affinity with the polymer of the non-porous layer, as long as the dye permeates and adheres to the dye as well as the swelling agent permeates. Examples of the dye include dyes selected from metal complex dyes, acid dyes, disperse dyes, etc., and which are soluble in the swelling agent. The dye may be used alone or in a mixture of two or more. The ratio of dye to swelling agent depends on the desired density of the surface pattern, but is generally between 0.2 and 25.
% by weight, especially in the range 0.5-20% by weight,
If the dye concentration is increased beyond this range, the penetration of the dye into the non-porous layer may be insufficient, resulting in uneven gloss, and if a dye solution with a concentration below this range is used, the resultant product will be The surface pattern does not have the effect of applying the dye liquid, and becomes a monotonous artificial surface pattern. Further, in the present invention, a spray method is used as a method for applying the dye liquid to the surface of the leather-like sheet material. When the spray method is used, the dye liquid is applied in the form of atomized droplets to the surface of the leather-like sheet material. Moreover, in the present invention, when the surface of the obtained product is enlarged, it is clearly seen that the atomized droplets of the dye liquid have been applied, and the pattern is created by minute colored parts that are different in color from the surrounding area. It is necessary that it be attached. On the surface of the leather-like sheet obtained by the present invention, there are areas where a large number of these droplets are applied and areas where relatively few droplets are applied, so that they do not have periodicity and exist irregularly. Adjust the spray driver, air pressure, running speed of the sheet material, etc. Further, when applying the dye liquid to the surface of a leather-like sheet by a spray method, the amount of liquid applied at one time is 5 to 100 g/m ² , preferably 5 to 80 g/m ² . If more than 100 g/m ² is applied at one time, the amount of liquid present on the surface of the sheet material will vary depending on the rate at which the dye liquid permeates into the non-porous polymer layer and the rate at which the swelling agent in the dye liquid evaporates. become more,
As a result, the applied dye liquid may not exist as droplets and may flow on the surface of the sheet-like object. In such a case, the surface pattern becomes rough and extremely artificial, and it is impossible to obtain a surface pattern similar to natural leather. Therefore, by adjusting the air pressure of the spray, the flow rate of the dye liquid, the viscosity of the dye liquid, etc., the size of the small droplets of the dye liquid scattered from the nozzle can be adjusted so that the area of the minute colored part is within the range of 0.002 to 0.25 ^mm2 . and the minute colored part is at least 500 per ^cm2 .
The number of particles, preferably 700 to 5,000, is dispersed, and the total area of the colored minute areas on the surface of the sheet-like article is in the range of 15 to 80%. A preferred method of spraying to achieve this condition is achieved by reducing the amount of sprayed dye from the nozzle to reduce the droplet size and repeating the number of sprays multiple times. Furthermore, after spraying, the surface of the sheet material is treated under dry conditions at a temperature of 130°C or less, so that the swelling agent is evaporated and removed, but at least the dye penetrates into the inside of the non-porous polymer layer. go. If necessary, iron the surface of the leather-like sheet material patterned by the method of the present invention,
It is also good to perform finishing treatments such as sanding, and softening treatments such as rubbing and staking. Furthermore, embossing may be performed to provide surface irregularities similar to natural leather, or to smooth the surface. Furthermore, the surface gloss and surface strength can be improved by applying a transparent or lightly colored polymer solution to the surface of the leather-like sheet obtained by the method of the present invention. [Example] Next, the embodiments of the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the examples, parts and percentages are by weight unless otherwise specified. Example 1 50 parts of polyethylene terephthalate chips and 50 parts of polyethylene chips were mixed, melted using the same screw, polyethylene terephthalate was spun as an ultrafine denier fiber component, and stretched, crimped, and cut to a fineness of 6.0 denier and fiber length. A 51mm mixed spun fiber was produced. Next, a web is made from the mixed spun fibers and needle punched to give a fabric weight of approximately 1000 g/
An entangled nonwoven fabric of m ² was prepared. After heat-setting the nonwoven fabric by leaving it at a temperature of 135°C for 6 minutes, 18% of a polyurethane elastomer with an N% of 4.5% consisting of polyethylene adipate glycol, 1,4-butanediol and diphenylmethane-4,4'-diisocyanate was added. The heat-set nonwoven fabric was impregnated with a solution consisting of 82% DMF and 82% DMF, squeezed, immersed in a coagulation bath of 50% DMF and 50% water at a temperature of 50°C for 30 minutes to coagulate, and then washed with water and dried. The obtained sheet was immersed in heated toluene to extract and remove the polyethylene component in the mixed spun fibers to obtain a polymer sheet. In this polymer sheet, 105 g of porous polyurethane elastomer was present inside the nonwoven fabric per 100 g of fiber. On the other hand, the same polyurethane elastomer 12% and DMF88 used in the above polymer sheet
% on a polyethylene sheet at a liquid volume of 80 g/m ² as a solid content, then 40%
The density of approximately 0.32 g/cm ³ was obtained by treating with an aqueous solution containing DMF at 30°C for 30 minutes, then peeling it off from the polyethylene sheet, removing the solvent, and drying it.
A porous film was obtained. This porous film was bonded to the polymer sheet using a polyurethane solution as an adhesive to obtain a leather-like sheet material (A). On the porous film surface of this leather-like sheet material (A), 5% of the same polyurethane as the above polyurethane elastomer, 7% of brown pigment, 22% of DMF,
A colored composition liquid for undercoating consisting of 66% MEK was applied with a 200-mesh stamped gravure roll, and then polyethylene glycol, diphenylmethane-4,
150 meshes of 7% polyurethane with N% 5.5% consisting of 4'-diisocyanate and ethylene glycol, 1% brown metal complex dye (manufactured by Civer Geigy; Orazol Brown 2GL), 21% DMF, and 71% MEK. Leather-like sheet-like material (B) that is coated with an engraved gravure roll and then heated and embossed with an emboss roll with an adult cowhide pattern to form a non-porous layer with a thickness of approximately 5 μm on the surface.
I got it. Next, a dye solution consisting of 240 parts of ethyl cellosolve, 50 parts of DMF, and 10 parts of a metal complex dye (Orazol Brown 3RG, manufactured by Civer Geigy) was prepared. This dye solution was applied to the colored non-porous surface of the leather-like sheet material (B) in an amount of 50 g/m ² by a spray method and dried. The polyurethane used in the coloring composition liquid for the undercoat and the polyurethane used in the coloring composition liquid for the topcoat were each made into dry films with a thickness of 5 μm, and these films were mixed with 240 parts of ethyl cellosolve and 50 parts of DMF, and When immersed in a composition solution kept at 30°C for 5 minutes, the coefficients of linear expansion in the thickness direction were 35% and 30%, respectively. When observing the surface of a leather-like sheet colored by the above method using a micrograph, it is found that the areas where the amount of dye solution adhered is relatively small have an area in the range of approximately 0.002 mm ² to approximately 0.034 mm ² . . Approximately 1400 minute colored areas on average with different shades of color from the surrounding areas/
cm ² , and the total area of these minute colored areas corresponds to approximately 17% of the sheet surface area in the range where these minute colored areas exist, and the areas where the amount of dye liquid attached is relatively large. On average, about 3,150 minute colored portions/cm ² were present, and the total area of these minute colored portions corresponded to about 61% of the sheet surface area in the range where these minute colored portions were present.
When this sheet-like material was viewed as a whole, its appearance was extremely similar to that of natural leather. In addition, the surface color of this colored leather-like sheet has extremely good abrasion resistance, and the abrasion strength and scratch strength of the surface layer are also higher than those of the leather-like sheet (A).
It was far superior. Furthermore, the folding wrinkles of this colored leather-like sheet were also fine. Comparative Example 1 The same dye solution as in Example 1 was applied to the non-porous surface of the leather-like sheet material (B) obtained in Example 1 using a 150-mesh stamped gravure roll. The surface of the obtained leather-like sheet-like material has a regular pattern, and the leather-like sheet-like material has an artificial, so-called vinyl-like feel.
This leather-like sheet-like material did not have the solid feeling that natural leather has. Examples 2, 3 and Comparative Examples 2 to 7 Polybutylene adipate gelicol, 1.4-
Butanediol and diphenylmethane-4,4'-
A DMF solution containing 20% polyurethane with an N% of 4.0% made of diisocyanate was applied to an entangled nonwoven fabric made of nylon fibers with a basis weight of 550 g/m ² at a solid content of 300.
After impregnating with an amount of solution applied in the amount of g/m ² and then applying the same solution on one side with an amount of solution giving a solid content of 110 g/m ² , a temperature of 40% DMF - 60% water was applied.
After treatment in a coagulation bath at 40°C for 30 minutes, solvent removal and drying were performed to obtain a leather-like sheet material (C). On the polyurethane-coated side of this leather-like sheet, there are many microholes with pore diameters of about 0.7 μm to about 25 μm, which communicate with the pores existing inside the nonwoven fabric, resulting in air permeability. It greatly contributes to increasing moisture permeability. This leather-like sheet material (C) is coated with polyester polyurethane (manufactured by Dainichiseika Kagyo KK; Rezamin TC).
-31) 3%, tea coloring agent (Dainichiseika Kakkyo K.
A coloring composition liquid consisting of 8% (manufactured by K.; M-1801), 30% isopropyl alcohol, 30% toluene, and 29% DMF was applied using a gravure roll with a 150-mesh stamp, and then heated using an embossing roll with a hard-like pattern. Press the surface to approximately 7μm.
A leather-like sheet material (D) was obtained by forming a non-porous portion having a thickness of . Next, the non-porous surface of this leather-like sheet material (D) was sprayed with 40 g of various dye solutions shown in Table 1.
It was applied in an amount of m ² and dried. The dye used in each of the dye solutions was metal complex dye Solvent Yellow 90 (manufactured by Civer Geigy; Irgasset Yellow 2GL). In addition, a dry film with a thickness of 5 μm of polyurethane used for the coloring composition was prepared, and
The film was immersed for 5 minutes in each dye-free solvent kept at 0.degree. C., and the coefficient of linear expansion in the thickness direction of the film was measured. The results are shown in Table 1. The abrasion resistance and surface roughness of the surface color of leather-like sheet materials colored with each dye solution were investigated. The results are also shown in Table 1. In addition, when observing the surfaces of these products by taking microscopic photographs, the areas where the amount of dye liquid adhered is relatively small are found to have a different shade of color from the surrounding area, which has a microscopic area ranging from approximately 0.009 mm ² to 0.04 mm ² . On average, there are approximately 1750 different colored microscopic areas/cm ² , and the total area of these microscopic colored areas is 15 to 35% of the sheet surface area in the range where these micro colored areas exist,
In addition, in areas where a relatively large amount of dye liquid was deposited, there were an average of about 3,650 minute colored areas/cm ² as described above, and the total area was about 45 to 75%. When these sheets were viewed as a whole, irregular surface patterns were obtained. However, when using a dye liquid with a coefficient of linear expansion of less than 15% or a dye liquid that dissolves a non-porous layer, as shown in Table 1, the abrasion resistance or surface smoothness of the surface color Because it was inferior, it had no commercial value. In particular, when a dye solution with a coefficient of linear expansion of less than 15% was used, the dye did not penetrate sufficiently into the non-porous layer, resulting in poor color depth. On the other hand, when dye liquids with linear expansion coefficients of 18.2% and 20.0% were used, they had excellent abrasion resistance, no surface roughening, and the dye molecules sufficiently penetrated into the non-porous layer. As a result, a leather-like sheet material with excellent color depth was obtained. In Table 1, ECS is ethyl cellosolve,
EAC stands for ethyl acetate. Regarding the abrasion fastness, ◯ indicates that it is very good, △ indicates that the color fades slightly, and × indicates that the color fades so much that it cannot be used as a product. Regarding surface roughness, ◯ indicates that there is no surface roughness at all, and × indicates that many irregularities caused by application of the dye liquid are present on the surface.

【table】

〔Effect of the invention〕

The polymer sheet obtained by the present invention, especially the leather-like sheet, has many colored parts with a small area that differ in color tone from the homogeneously colored non-porous polymer layer as the base, and it is similar to natural leather. It has a natural deep color resembling its appearance, has a colored finish on an elegant surface with a solid appearance, and has excellent stain resistance, abrasion resistance, and surface feel. becomes. Furthermore, the sheet-like material had naturally fine wrinkles similar to those of natural leather when folded and was visually flexible.

Claims (1)

[Scope of Claims] 1. A polymer sheet product in which a colored non-porous polymer layer is laminated on the surface of a porous polymer substrate, wherein the non-porous polymer layer is a uniformly colored polymer layer. At least on its surface, there are 500 or more colored parts ^per 1 ^cm2 of minute areas of 0.002 to 0.25 mm2 colored with dyes of different tones, and the total area of the minute colored parts is 15 of the surface area of the sheet. ~80%, and the colored micro-area part has no periodicity, and furthermore, the colored part does not bulge on the surface of the polymer layer, but at least penetrates into the non-porous polymer layer. A polymer sheet material that resembles the appearance of natural leather. 2. The polymer sheet product according to claim 1, wherein the non-porous polymer layer is a polymer mainly composed of polyurethane elastomer. 3. Temperature is applied to the surface of a polymer sheet formed by laminating a uniformly colored non-porous polymer layer on the surface of a porous polymer substrate, with respect to the polymer constituting the non-porous polymer layer. A dye solution in which a dye is dissolved in a swelling agent having a composition having a linear swelling rate of at least 15% at 30°C or a solvent for the non-porous polymer is sprayed onto the surface of the homogeneous colored non-porous polymer layer. The total area of the colored micro-area is 15-80% of the sheet surface area.
By coloring and removing the swelling agent by evaporation,
A method for producing a polymer sheet product having an appearance similar to natural leather, characterized by impregnating a dye into at least a non-porous polymer layer. 4. The manufacturing method according to claim 3, wherein the non-porous polymer is a polymer mainly composed of a polyurethane elastomer based on isocyanate groups and having a nitrogen content of 3 to 7% by weight. 5. Claim 3, wherein the solvent of the swelling agent having a composition containing a polymer solvent in the non-porous portion is at least one type selected from N.N'-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, and cellosolve. The manufacturing method according to item 4 or item 4. 6. The manufacturing method according to claim 3 or 4, wherein the dye is at least one type of dye selected from metal complex dyes, acid dyes, and disperse dyes.