JP4255746B2 - Manufacturing method of silver-like artificial leather - Google Patents

Description

【００５０】
【発明の効果】
本発明の製造方法は、良好なしぼ感と風合に優れ、靴、衣料用の天然皮革代替物に好適に用いられる銀付調人工皮革の製造方法である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a silver-tone artificial leather, and more particularly, to a method for producing a silver-tone artificial leather having a good feeling of feeling and texture.
[0002]
[Prior art]
In recent years, as a substitute for natural leather, silver-coated artificial leather with a coat layer laminated on the surface of a base material consisting of a fiber assembly and a polymer elastic body has been used for apparel because of its lightness, easy care, low price, etc. Widely used in general materials and sports fields.
[0003]
And, it is known that the polymer elastic body contained in the base material is excellent in terms of texture if micropores exist, and is generally manufactured by a method called a wet coagulation method. There are many. However, a long time is required for wet coagulation, and there is a problem that a large and expensive dedicated equipment is inevitably required from the point of using an organic solvent.
[0004]
Therefore, recently, an attempt has been made to form a porous layer by improving a water-based polyurethane thermal coagulation method, which has been conventionally only a solid layer, instead of a solvent-based wet coagulation method. For example, Patent Document 1 discloses a method of treating a composition containing a water-based heat-sensitive coagulable polyurethane emulsion and a heat-expandable plastic microballoon in water at 40 to 190 ° C. or water vapor. However, this method has a problem that porosity is generated in the entire impregnated layer, and the thickness becomes 3 to 5 times that before treatment due to foaming. .
[0005]
[Patent Document 1]
Japanese Examined Patent Publication No. 6-60260 [0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is excellent in feeling of feeling and texture, and is used as a natural leather substitute for shoes and clothing. It is in providing the manufacturing method of.
[0007]
[Means for Solving the Problems]
The method for producing silver-finished artificial leather according to the present invention comprises a polymer elastic emulsion and a thermally expandable capsule having a shell wall softening temperature of 80 ° C. or higher on a fibrous base material pretreated with amino-modified silicone. The impregnating liquid is applied from the surface side, and pre-dried at a temperature lower than the shell wall softening point temperature a plurality of times, and then the thermally expandable capsule is foamed at a temperature equal to or higher than the shell wall softening point. It is characterized in that it is dried and subsequently a coating layer made of a polymer elastic body is applied on the surface side.
[0008]
Furthermore, it is preferable that the fibrous base material is made of ultrafine fibers of 0.5 dtex or less, and the diameter of the thermally expandable capsule is 5 to 50 μm.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
In the production method of the present invention, first, an impregnating liquid containing a polymer elastic emulsion and a thermally expandable capsule is applied onto a fibrous base material from the surface side.
[0010]
Although the fiber which comprises a fibrous base material may be a fiber of normal thickness, it is preferable that it is an ultrafine fiber from the feel surface. The fineness of the ultrafine fiber is preferably 0.5 dtex or less, and more preferably 0.001 to 0.3 dtex. Moreover, as such a fiber used for preparing the fibrous base material, it is preferable that the fiber finally becomes an ultrafine fiber as described above, and a sea-island type mixed spinning is used as the fiber before the ultrafine fiber. Any of fiber, composite spun fiber, and the like can be applied, but it is particularly preferable that the fiber is a peeled split type composite fiber.
[0011]
As such fibers used in the present invention, one of conventionally known synthetic resins capable of forming fibers such as polyester, polyamide, polyacryl and polyolefin, or synthetic fibers composed of two or more resins can be used. Among these, it is particularly preferable to use a polyester, polyamide, or polyester / polyamide. Examples of the polyester used as the fiber include polyethylene terephthalate, polybutylene terephthalate, and polypropylene terephthalate. Examples of the polyamide include nylon-6, nylon-66, and nylon-12. Among these, polyethylene terephthalate, nylon-6, and the like are preferable from the viewpoint of process stability and cost.
[0012]
Moreover, in this invention, it is preferable to make a sheet | seat with the fiber before ultrathinning, and to use as a fibrous base material through an ultrathinning process. Further, at this time, it is preferable that the fibers before the ultra-thinning constituting the sheet contain heat-shrinkable fibers. By shrinking the fiber by heat after forming the sheet shape, the density of the fiber can be increased before impregnation with the polymer elastic body, and the texture is improved. Such a heat-shrinkable fiber is particularly preferably a high-shrinkage polyester fiber having a large shrinkage stress. For example, a heat-shrinkable fiber obtained by spinning a fiber-forming polymer containing polyethylene terephthalate as a main component and then drawing at a low magnification in warm water. Furthermore, the heat-shrinkable fiber is preferably one that exhibits shrinkage characteristics at 50 ° C. or higher and 100 ° C. or lower by controlling stretching conditions and the like. Those exhibiting characteristics at a temperature lower than 50 ° C. cause quality variation, and those exhibiting characteristics at a temperature higher than 100 ° C. require a large amount of heat, resulting in poor productivity. After the sheet is formed, the shrinkage rate until it becomes a fibrous base material is preferably 5 to 50%, particularly preferably 20 to 40%.
[0013]
Most preferably, the fiber constituting the sheet is a composite fiber that is composed of heat-shrinkable fibers and can be further divided into two or more types of single fibers. Thus, when the heat shrinkability of each single fiber generated by dividing the composite fiber is different from each other, the composite fiber is further divided during the shrinkage treatment, and a more dense and homogeneous structure can be obtained. For example, a peelable split type composite fiber that is finally split into ultrafine fibers into polyester fibers with high heat shrinkability and polyamide fibers with low heat shrinkability is preferable.
[0014]
The sheet made of these fibers is most preferably a non-woven fabric in terms of texture. As a method for forming such a nonwoven fabric, conventionally known methods such as a method of carding from short fibers and entanglement treatment, or a method of forming a long fiber into a direct sheet and entanglement treatment can be employed. Furthermore, in order to obtain a dense and homogeneous fibrous base material, a method of using an exfoliated split type composite fiber that is made into ultrafine fibers and entangled with a high-pressure water flow is preferable.
[0015]
In the method for producing silver-finished artificial leather of the present invention, the fibrous base material needs to be treated with amino-modified silicone in advance. Generally, an amino-modified silicone is attached and dried. In the present invention, the amino-modified silicone acts between the fibers before impregnation of the polymer elastic body, so that the adhesion between the fiber and the polymer elastic body is prevented and the structure becomes more flexible.
[0016]
In the production method of the present invention, the preferred adhesion amount of the amino-modified silicone component is 0.1 to 2% by weight, more preferably 0.5 to 1% by weight, based on the weight of the fibrous base material. As a treatment method, it can be obtained by impregnating a fibrous base material with a solution prepared by diluting with water to a concentration of 0.1 to 1% by weight, controlling the amount of squeezed adhesion with a nip roll, and then drying. The drying method may be hot air drying, but the surface smoothness can be obtained at the same time by drying by contacting with a heating roll. Further, in the present invention, since the treatment is performed before impregnation with the resin, a high effect is obtained despite such a small amount of adhesion, and the fall off from the finally obtained leather-like sheet is very small. .
[0017]
In the production method of the present invention, an impregnating liquid containing a polymer elastic emulsion and a thermally expandable capsule having a shell wall softening point temperature of 80 ° C. or higher is applied from the surface side to the fiber substrate thus treated. .
The polymer elastic emulsion used in the present invention may be any as long as it exhibits elastomeric properties after removing water, but polyurethane emulsion is particularly preferred from the viewpoints of flexibility, strength, weather resistance and the like.
[0018]
Furthermore, in the present invention, it is preferable that the elastic polymer emulsion has a heat-sensitive coagulation property. The temperature at which the coagulation characteristic of the polymer elastic emulsion is developed is preferably a temperature at which the coagulation characteristic is exhibited at a temperature lower than the expansion start temperature of the thermally expandable capsule. The temperature at which the solidification characteristics of the polymer elastomer emulsion are expressed is the temperature at which the emulsion loses its fluidity and solidifies when the temperature of the emulsion containing various additives is increased while stirring.
[0019]
Examples of the thermally expandable capsule used in the present invention include those in which a thermoplastic resin is used as a shell, and an organic compound having a specific boiling point is encapsulated and encapsulated as an expander. For example, a vinylidene chloride-acrylonitrile copolymer as a shell, and isobutane encapsulated and encapsulated. The diameter is preferably 5 to 50 μm. In the thermally expandable capsule of the present invention, the shell is softened by heating, and the encapsulated organic compound expands as a gas. The expansion start temperature and the maximum expansion point can be changed depending on the kind of the thermoplastic resin, the thickness of the shell, the diameter of the capsule, and the like.
Further, as the impregnating liquid to be treated, the solid content weight of the thermally expandable capsule is preferably 2 to 10% by weight with respect to the solid content weight of the polymer elastic body.
[0020]
Furthermore, for the purpose of improving various durability such as light resistance, heat resistance, water resistance and solvent resistance of the emulsion, stabilizers such as antioxidants, ultraviolet absorbers, hydrolysis inhibitors, epoxy resins, melamine resins, A crosslinking agent such as an isocyanate compound, an aziridine compound, or a polycarbodiimide compound can also be blended and used. Furthermore, various inorganic or organic pigments that are water-soluble or water-dispersible can be blended for the purpose of coloring.
[0021]
The method of impregnating the fibrous base material with the impregnation liquid of the present invention is a method of coating from the surface side, and a gravure coating method is preferably used. The number of times of application may be two times or more, but it is sufficient if it is not more than 10 times from an industrial point of view, and is generally within 5 times. The adhesion amount (solid content) by one application is preferably 5 to 15% by weight of the fiber weight after drying, and the total application amount is preferably 50% by weight or less. Thus, when apply | coating several times, while making the adhesion amount per time into 15 weight% or less, it is preferable to reduce an adhesion amount whenever it repeats the frequency | count. Thus, by applying in several times, the impregnation layer which consists of a polymeric elastic body and a fiber is formed in the surface side, and a thermally expansible capsule can be unevenly distributed in the outermost surface side. This is because the first application reduces the voids on the surface of the fibrous base material, and only the polymer elastic body penetrates into the interior by the second application, and the thermally expandable capsule having a relatively large diameter remains on the surface.
[0022]
In order to apply more stably, it is preferable to perform additional preliminary drying during application to volatilize unnecessary moisture. For example, after repeating the application and preliminary drying a plurality of times, additional preliminary drying is performed, and then the coating and preliminary drying are further repeated a plurality of times, so that the time for preliminary drying is shortened to about 5 to 60 seconds. Can be suppressed. At this time, the additional preliminary drying is preferably performed for a long time of about 2 to 30 minutes.
[0023]
The adhesion amount of the polymer elastic body in the impregnation stage is preferably 3 to 50% by weight with respect to 100 parts by weight of the fibrous base material. When there is little adhesion amount (solid content) of a polymeric elastic body, the fullness of the sheet | seat obtained will fall, and conversely when it is large, there exists a tendency which becomes hard.
[0024]
In the present invention, it is necessary to apply the impregnating liquid from the surface after the coating predrying step in which the impregnating liquid is applied from the surface and preliminarily dried at a temperature lower than the shell wall softening temperature. In order to stabilize the coating amount, it is preferable to apply in small portions in two or three times as described above.
[0025]
When the polymer elastic body used has a heat-sensitive coagulation property, the predrying temperature is preferably equal to or higher than the heat-sensitive coagulation temperature. By performing such preliminary drying, excessive penetration of the polymer elastic body due to migration can be prevented, and the foam is unevenly distributed on the surface because it is applied in a plurality of times. Almost does not exist.
After the impregnation liquid is applied again in this way, the thermally expandable capsule is foamed at a temperature equal to or higher than the shell wall softening point, and at the same time, the impregnation liquid is dried.
[0026]
In the present invention, it is further necessary to provide a coating layer made of a polymer elastic body on the surface side coated with the polymer elastic body and dried. Although there is no restriction | limiting in particular as a polymeric elastic body used at this time, It is most preferable that it is a polyurethane resin from the feel surface.
[0027]
In this case, a heat-expandable capsule may be included in a small amount, but it is preferably not included in order to obtain smoothness. Moreover, a conventionally well-known method can be used as a coating method, However, It is preferable that it is the laminating method which is easy to satisfy surface smoothness and a pattern. For example, a film layer of a polymer elastic body is formed on a release paper, and a binder layer of a polymer elastic body is applied and bonded to an impregnated substrate. When using an aqueous laminating method, it is preferable to nip with a heat cylinder.
[0028]
Thus, the silver-finished artificial leather obtained by the production method of the present invention is suitable because there are voids in the polymer elastic body, and there are few in the interior of the substrate and many in the portion immediately below the coat layer. It becomes a texture, excellent in feeling and feel, and becomes a silver-tone artificial leather suitably used as a substitute for natural leather for shoes and clothing.
[0029]
【Example】
The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples. In the examples and comparative examples, “parts” and “%” are based on weight unless otherwise specified.
[0030]
In the examples, “wrinkle feeling” and “texture” are judged in the order of good, ○, Δ, ×, “Uki” is judged by the presence or absence of the occurrence of itch when bent, and the occurrence of itch The case where no wrinkles occurred was marked with ◯, the case where small wrinkles occurred was marked with △, and the case where large wrinkles occurred was marked with ×. The “impregnated polyurethane coating amount” is a value obtained by dividing the penetration distance of the polymer elastic body from the surface by the total thickness of the section (%) "R / F" was determined for the ratio (%) of the polymer elastic body / fiber of the entire fiber composite sheet without separating the unimpregnated portion and the impregnated portion.
[0031]
[Example 1]
(Create fiber base material)
A peeled split type composite fiber having a cross section of a 16 split gear type with polyethylene terephthalate having shrinkage characteristics as the first component and nylon-6 as the second component and having a main yarn fineness of 4.4 dtex is obtained by needle punching and high-pressure hydroentanglement treatment. The fiber is entangled and divided to form a nonwoven fabric having a thickness of 1.05 mm and a basis weight of 241 g / m ² , and then the nonwoven fabric after the division treatment is immersed in a 75 ° C. hot water tank for 20 seconds, The polyethylene terephthalate fiber was shrunk, and the whole area was shrunk by 21% to obtain a nonwoven fabric to be a fibrous base material.
[0032]
(Silicone treatment)
To the non-woven fabric obtained in Reference Example 1, Polon MF-14 (amino-modified silicone softener, manufactured by Shin-Etsu Chemical Co., Ltd., solid content concentration 15% by weight) / water = 2/98 (parts by weight), a wet pickup, A nonwoven fabric was obtained by softening at 200% by weight and drying at 120 ° C. for 5 minutes.
[0033]
(Preparation of impregnation solution)
V-2114 (water-based polyurethane resin, manufactured by Dainippon Ink & Chemicals, Inc., solid concentration 40% by weight) / DISPERSE HG-950 (water-dispersible black pigment, manufactured by Dainippon Ink & Chemicals, Inc.) / Hydran WL Assister T2 (urethane thickener, manufactured by Dainippon Ink & Chemicals, Inc.) / F-90N (water proofing agent, manufactured by Meisei Chemical Co., Ltd.) / SD-8i (hydrophobic agents, Dainippon Ink & Chemicals, Inc. ( Co., Ltd.) / Matsumoto Microsphere-F-50 (low-boiling hydrocarbon-containing thermally expandable microcapsules, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) / Water = 70/1/1/1/1/26 (parts by weight) ) And an impregnating solution (720 mPa · s, 20 ° C.) for gravure coating was prepared.
[0034]
(Create fiber composite sheet)
The process of apply | coating with the gravure roll (# 110) and pre-drying (110 degreeC, 20 second) to the said shrink nonwoven fabric which carried out the silicone treatment was repeated for 4 rolls. Further, preliminary drying at 90 ° C. for 10 minutes was added to the intermediate step after coating for 2 rolls. All four rolls were coated and foamed and dried at 130 ° C. for 5 minutes after preliminary drying to obtain a fiber composite sheet.
[0035]
When the cross section and surface state were observed with an electron microscope, the foaming agent was present only in the surface layer portion, the size was 100 μm or less, and the foaming agent and fibers were observed on the surface.
[0036]
(Creation of coat layer)
Hydran WLS211 (water-based polyurethane resin, manufactured by Dainippon Ink & Chemicals, Inc., solid concentration 35% by weight) / DISPERSE HG (water dispersible black pigment, manufactured by Dainippon Ink & Chemicals, Inc.) / Hydran WL Assistor T1 (Urethane-based thickener, manufactured by Dainippon Ink & Chemicals, Inc.) / Hydran WL Assister C2 (Isocyanate-based crosslinking agent, manufactured by Dainippon Ink & Chemicals, Inc.) / Hydran WL Assister W1 (Leveling agent, Dainippon Ink) Chemical Industry Co., Ltd.) / Hydran Assista D1 (Antifoamer, Dainippon Ink & Chemicals Co., Ltd.) = 100/5 / 0.25 / 4 / 0.2 / 5 (parts by weight) The layered solution was applied to release paper (AR-144SM, thickness 0.25 mm, manufactured by Asahi Roll Co., Ltd.) at a coating thickness of 100 μm (wet). 2 min at 0 ° C., then subjected to drying in two stages for four minutes at 110 ° C., to form a polyurethane resin film (hereinafter referred to as the film layer).
[0037]
In addition, Hydran WLA311 (aqueous polyurethane resin, manufactured by Dainippon Ink & Chemicals, Inc., solid concentration 45% by weight) / DISPERSE HG (water dispersible black pigment, manufactured by Dainippon Ink & Chemicals, Inc.) / Hydran WL Assister T1 (urethane thickener, manufactured by Dainippon Ink & Chemicals, Inc.) / Hydran WL Assister C2 (isocyanate-based crosslinking agent, manufactured by Dainippon Ink & Chemicals, Inc.) = 100/5 / 0.0. An adhesive compounded liquid compounded at 1/10 (part) was applied at a coating thickness of 150 μm (wet) to create a laminate layer. The water content of the coating solution on the release paper was measured and found to be 45.8%.
[0038]
(Create silver-tone artificial leather 1)
The above coating layer is immediately bonded to the fiber composite sheet 1, brought into contact with a heat cylinder (surface temperature 130 ° C.), preheated for 15 seconds, and then heated using the heat cylinder under the condition of clearance 1.0 mm. Nipped and further cured at 120 ° C. for 2 minutes. The moisture content of the base material after curing was 4.1%. Furthermore, aging was performed at 50 ° C. for 24 hours, and the release paper was peeled off to obtain a silver-tone artificial leather 1.
Table 1 shows the physical properties and the like.
[0039]
[Example 2]
Silver as in Example 1 except that the silicone treatment in Example 1 was changed to Polon MF-14 (amino-modified silicone softener, manufactured by Shin-Etsu Chemical Co., Ltd.) / Water = 3/97 (parts by weight). Toned artificial leather was created.
[0040]
When the cross section and surface state of the fiber composite sheet before application of the coating layer were observed with an electron microscope, the foaming agent was present only in the surface layer part, the size was 100 μm or less, and the foaming agent and fibers were observed on the surface.
The physical properties and the like are also shown in Table 1.
[0041]
[Example 3]
Silver as in Example 1 except that the silicone treatment in Example 1 was changed to Polon MF-14 (amino-modified silicone softener, manufactured by Shin-Etsu Chemical Co., Ltd.) / Water = 4/96 (parts by weight). Toned artificial leather was created.
[0042]
When the cross section and surface state of the fiber composite sheet before application of the coating layer were observed with an electron microscope, the foaming agent was present only in the surface layer part, the size was 100 μm or less, and the foaming agent and fibers were observed on the surface.
The physical properties and the like are also shown in Table 1.
[0043]
[Comparative Example 1]
A silver-tone artificial leather was prepared in the same manner as in Example 1, except that the silicone treatment in Example 1 was not performed.
[0044]
When the cross-section of the fiber composite sheet before applying the coating layer and the surface state are observed with an electron microscope, the foaming agent is present only in the surface layer part, the size is 100 μm or less, and the foaming agent and fibers are observed on the surface, The texture was inferior.
The physical properties and the like are also shown in Table 1.
[0045]
[Comparative Example 2]
Except not performing preliminary drying of Example 1, the silver-tone artificial leather was created similarly to Example 1.
[0046]
The impregnated polyurethane penetrated into the interior, and further became a cardboard structure when dried, resulting in poor texture. The physical properties and the like are also shown in Table 1.
[0047]
[Comparative Example 3]
Instead of the gravure coating of Example 1, a fiber base sheet having an R / F of 35% was prepared by immersing the fiber base material in an impregnating solution and nipping, and thereafter, a coating layer was formed in the same manner as in Example 1. Granted.
[0048]
The impregnated polyurethane and the foaming agent penetrated into the interior, and the texture was poor. The physical properties and the like are also shown in Table 1.
[0049]
[Table 1]

[0050]
【The invention's effect】
The production method of the present invention is a method for producing a silver-tone artificial leather that is excellent in a good texture and feel and is suitably used as a substitute for natural leather for shoes and clothing.

Claims (5)

An impregnating solution containing a water-based polymer elastic emulsion and a thermally expandable capsule having a shell wall softening point temperature of 80 ° C. or higher is applied from the surface side onto a fibrous base material pretreated with amino-modified silicone. After repeating the preliminary drying at a temperature lower than the wall softening point multiple times, the thermally expandable capsule is foamed at a temperature higher than the shell wall softening point and the impregnating solution is dried, and then the polymer elastic body on the surface side. A method for producing a silver-tone artificial leather, comprising providing a coat layer comprising:   The method for producing silver-finished artificial leather according to claim 1, wherein the fibrous base material is made of ultrafine fibers of 0.5 dtex or less.   The method for producing artificial leather with a silver tone according to claim 1 or 2, wherein the thermally expandable capsule has a diameter of 5 to 50 µm. The coating amount for a single impregnation solution, the weight after drying is 5-15 wt% of the fiber weight, and the total coating amount of any one of claims 1 to 3 is 50 wt% or less A method for producing artificial leather with silver. The method for producing a silver-finished artificial leather according to claim 4, wherein the amount of the impregnating liquid applied is reduced every time the coating is repeated.