JP2674806B2 - Synthetic leather and manufacturing method thereof - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a supple synthetic leather having a base of a cloth or a non-woven fabric made of an ultrafine thread of 0.005 to 1.0 denier, on which a thin coating layer or laminate layer is placed. Therefore, it is particularly related to synthetic leather that improves the coloring property of the ultrafine yarn that constitutes the base fabric and is markedly darkened, and also prevents migration and sublimation of the disperse dye when the base fabric is colored with the disperse dye. The present invention relates to synthetic leather having excellent effects.

(Prior Art) Conventional synthetic leather has a problem in that it is significantly inferior in color development of dark color to natural leather. In particular, the thinner the single yarn denier of the yarn used for the cloth or nonwoven fabric in order to make the leather supple, and even if the laminate layer or coating layer is colored, make this layer thin and supple. The poorer the coloration of the base fabric, the more it leads to the poor coloration of the synthetic leather.

In order to improve the color developability of this synthetic leather, even if the surface is coated with a darkening agent made of a low refractive index polymer which is commercially available as a darkening agent for cloth, the color developability is not improved. It gets worse. This is considered to be because the refractive index of the conventional thickening agent is not low enough to make the leather dark, and furthermore, it cannot be applied in a uniform thin film form.

Further, conventionally, when a so-called coated cloth or laminated cloth in which a resin or rubber such as urethane, acrylic, or vinyl chloride is coated or laminated on the base cloth, the base cloth is mainly made of a nylon material. This is a polyester-based fiber, dyed with a disperse dye, when printing, the dye migrates to the coating layer or laminate layer, further migrates from the coating layer or laminate layer to the outermost surface and discolors, This is because there is a problem of disperse dye transfer sublimation that contaminates other materials in contact therewith.

(Problems to be Solved by the Invention) As described above, according to the present invention, by using the ultrafine yarn in the synthetic leather that has the flexibility or flexibility, the coating layer or the laminate layer is placed on the cloth or the nonwoven fabric made of the ultrafine yarn. It is intended to obtain a synthetic leather which is capable of improving the underlying poor coloring property and preventing the disperse dye from being contaminated with other materials even when the basic material is a polyester type.

(Means for Solving Problems) That is, according to the present invention, 1) a dyed or printed cloth or nonwoven fabric containing 30% by weight or more of ultrafine fibers having a single fiber denier of 0.005 to 1.0 denier, a colored resin or a A coating layer or laminating layer made of rubber is laminated, and a thin film having a refractive index of 1.35 to 1.45 and a thickness of 0.02 to 0.2 micron (μ) is 0.9a to 1.1a of an average thickness a (μ) on the surface. Synthetic leather characterized by being present as a uniform film.

2) A single fiber denier 0.005 to 1.0 denier fiber is used so as to be 30% by weight or more of the fiber constituting the base fabric to form a cloth or a non-woven fabric, or the base cloth is subjected to an ultrafine fiber treatment, By forming a cloth or non-woven fabric composed of ultrafine fibers having a single yarn denier of 0.005 to 1.0 denier in which 30% by weight or more of fibers constituting the cloth are formed, by dyeing or printing at the same time as or after the formation of the cloth or non-woven fabric made of the ultrafine fibers. A coloring treatment is performed, and then the colored cloth or nonwoven fabric is coated or laminated with a colored resin or rubber, and the cloth or nonwoven fabric is coated or laminated to form a thin film having a refractive index of 1.35 to 1.45. Is formed by plasma polymerization to a thickness of 0.02 to 0.2 micron (μ), a method for producing synthetic leather.

About.

In the present invention, a fabric or a non-woven fabric made of ultrafine fibers having a single fiber denier of 0.005 to 1.0 denier means that the fabric or the non-woven fabric, as a result of which the fibers constituting the single fiber denier are the ultrafine denier described above. It means good. That is, an ultrafine yarn is directly produced by spinning, and a fabric, a non-woven fabric is produced by using the ultrafine yarn, or an ultrafine yarn is directly produced by a melt blow method or the like.
Alternatively, it also includes the case where the mixed spun fiber is used to form a cloth or a non-woven fabric and then the composite or mixed spun fiber is subjected to an ultrafine treatment to obtain a cloth or a non-woven fabric made of an ultrafine fiber. As typical examples of the latter, there are, for example, a type for weight reduction division with an alkali, a type for division with a solvent or mechanically, or a type for solvent extraction of sea components of sea-island fiber.

The monofilament denier of the fibers constituting the base fabric is 0.005 denier or less and becomes stiff when made into leather, and the fineness of the constituent fibers is 0.005 to 1.0 denier, and more preferably 0.05, because it becomes supple when it is 1.0 denier or more. ~
0.5 denier is preferable. Of course, cloth and non-woven fabric do not have to be made of 100% ultrafine threads, at least 30
Any material containing wt% may be used. A polyester-based material is typically used as a material that can easily obtain ultrafine fibers, but is not limited to polyester.

By the way, when polyester is used, a disperse dye is often used for coloring, and in this case, the disperse dye is apt to migrate after coating or lamination, which has the above-mentioned serious problem. Resins used for coating or laminating include dry urethane, wet urethane, vinyl chloride, acrylic and rubber, but the thinner the thickness of these layers, the more flexible the synthetic leather can exhibit. Therefore, 50μ
Hereafter, it is more preferably 10 μm or less. The coating layer or laminate layer preferably has wrinkles or wrinkles on the surface thereof in order to have the fine surface change of natural leather. Further, in order to increase the peel strength between the coating layer or the laminate layer and the base cloth, at least the coating layer or the laminate layer side of the cloth or the non-woven fabric may be feathered by a conventional method, and the coating or laminating may be performed thereon. It is also desirable to add inorganic fine particles to the coating layer or laminate layer to enhance the matte effect, or to add a dye or pigment for coloring. Furthermore, a resin such as silicon may be attached to the coating surface and the laminated surface to improve the feel, slipperiness and gloss.

The present invention has a refractive index of 1.35 to 1.45 and a thickness of 0.02 to 0.2 on the surface of such a coated article or laminate.
The feature is that a micron (μ) thin film exists as a uniform film. The lower the refractive index of the thin film is, the more preferable it is, but a plasma polymer having a refractive index of less than 135 cannot be formed. If it is greater than 1.45, the improvement of the dark color effect is small as described above. The film thickness should be 0.02-0.2μ. 0.02μ
When it is less than 1, the dark color effect is small, and the effect of preventing dye transfer sublimation when dyed with a disperse dye is small. If it exceeds 0.2μ, the productivity will decrease. The above effect becomes remarkable only when the thin film becomes a film having a uniform thickness, and the uniformity is preferably 0.9a to 1.1a of the average film thickness a (μ), and more preferably 0.95a to 1.05. is a. A film having such uniformity is only possible by the plasma polymerization technique.

The plasma polymerization referred to in the present invention refers to a polymerization method utilizing low-temperature plasma discharge, in which one or more monomers are supplied at the time of discharge to perform one-step polymerization in the presence or absence of non-polymerizable or polymerizable gas. Say

The fluorine-based compound monomer used in the plasma polymerization method is a CnHmClpf _2n-mp type (n ≧ ₃₎ represented by C ₂ F ₄ and C ₃ F _6.
2, m ≧ 0, p ≧ 0, 2n−m−p ≧ 1 integer), CF ₄ , C
CnHmClpBrqF _{2n + 2-mpq} type represented by ₂ F ₆ and C ₃ F ₈ (n ≧ 1, m ≧ 0, p ≧ 0, q ≧ 0, 2n + 2-m−p−
q ≥ 1), CnHmClpF _2n-mp ring type represented by C ₄ F ₈ (n ≧
3, m ≧ 0, p ≧ 0, an integer of 2n−m−p ≧ 1, and a cyclic type having a double bond of CnHmClpF _2n-2-mp represented by C ₄ F ₆ (n ≧ 4, m ≧) 0, p ≧ 0, 2n-2-m-p
There are various types such as a type represented by C ₃ F ₆ O, a type represented by NF ₃ , SF ₆ , and WF ₆ , and the like.

Deposition rate among these large industrial preferred are _{C 2 F 4, C 3 F} 6, C 3 F 8, C 4 F 8, C 3 F 6 O, in C ₂ H ₄ F ₂ or the like However, C ₃ F ₆ , C ₄ F ₃ , and C ₃ F ₆ O are more preferable in terms of transportation safety, film formation rate, and the like.

The fluorine-based compound may contain elements such as hydrogen, chlorine and bromine.

What is a silicon compound monomer? (However, R _{1 to} R ₄ are OCH ₃ , CC ₂ H ₅ , CH ₃ , C ₂ H ₃ , CH ₂ = CH,
H, An alkoxysilane silicon compound represented by any of (However, R _{1 to} R ₃ are H, CH ₃ , CH ₂ = CH, Chlorosilane-based silicon compound represented by either Cl or ClCH ₂ ), or (Wherein Y is _{CH 2 = CH, CH 2 -CHCH} 2 O, NH 2, SH, Cl, A silane-cutting silicon compound represented by any of NHR'NH ₂ (R ': alkyl group), R is an alkyl group, and X is any of OCH ₃ and OC ₂ H _5. (However, R ₁ -R ₂ is H, CH ₃ , C ₂ H ₃ , Si (CH ₃ ) ₃ , , R is CH ₃ COSi (CH ₃ ) ₃ , CF ₃ COSi (CH ₃ ) ₃
A silazane-based silicon compound that is (However, R is an alkyl group, X is Cl, NH ₂ , Of any of the above), a reactive siloxane oligomer-based silicon compound. Typical examples include trimethoxysilane, trimethoxyvinylsilane, triethoxysilane, triethoxyvinylsilane, trimethoxychlorosilane, trimethylmethoxysilane, dimethoxyvinylsilane, dimethylmethoxyvinylsilane, trimethylvinylsilane, triethylvinylsilane, vinyltrichlorosilane, hexamethyldisilane. Silazane, dimethyltrimethylsilylamine,
Amino siroxine, chlorosiloxane, etc. are available.

There is no particular limitation on the silicon compound used in the plasma polymerization method.

In addition to fluorine-based and silicon-based, acrylic acid, methacrylic acid or their esters can be used.

The low-temperature plasma is the plasma generated during discharge with an average quantum energy of 10 eV (10 ⁴ to 10 ⁵ K) and an electron density of 10 ^{9 to} 12
It is characterized by ¹² cm ^-3 and is also called non-equilibrium plasma because it does not have an equilibrium between electron temperature and gas temperature. Electrons, ions, atoms, molecules, etc. are mixed in the plasma generated by the discharge.

As a power source for applying a voltage, one having an arbitrary frequency can be used. From the viewpoint of discharge continuity and uniformity, 1KHz to 10GH
z is desirable. From the viewpoint of plasma uniformity in the width direction of the electrode, 1 KHz to 1 MHz is preferable, and if it is 1 MHz or more and the length of the electrode exceeds 1 m, treatment unevenness is likely to occur in the length direction. At 100 Hz or less, the edge effect of the electrode is likely to occur, and arc discharge is likely to occur at the edge portion. As the current, alternating current, direct current, biased alternating current, pulse wave or the like can be used. Electrodes are divided into an internal electrode system arranged inside the vacuum system and an external electrode system arranged outside the vacuum system. In the external electrode system, when the size of the device becomes large, plasma moves especially to the surface of the object to be processed. The treatment effect is small because the activity is lost in the meantime or the plasma is scattered and the plasma concentration is diluted. On the other hand, in the internal electrode method, the discharge electrode can be installed near the object to be processed, and therefore the processing effect is large as compared with the external electrode method.

The electrode shape is divided into symmetrical and asymmetrical. In the case of a large-sized plasma processing apparatus, which has a large processing width of an object to be processed and thus requires a large electrode, the symmetrical electrode has more demerits. For example, it is almost impossible to evenly flow the gas between the large electrodes, and the electric field is disturbed at the ends of the larger electrodes, so that processing spots are likely to occur. Therefore, in the case of a large-sized plasma processing apparatus, an asymmetrical electrode is preferable. Although the object to be processed can be set and moved to any position between the electrodes, contact with one of the electrodes may result in less wrinkling and a greater processing effect.

The shape of the electrode on the side that does not come into contact with the object to be processed can be arbitrarily set to one or more such as a columnar shape or a rod shape with a polygonal cross section having an acute angle cross section, but the processing effect depends on the number of electrodes. In contrast, if it is too small, the treatment effect will be small. The shape is preferably cylindrical. As the shape of the electrode on the side with which the object to be processed may come into contact, a drum shape, a plate shape, or a deformed shape thereof can be used. It is not limited to these. The material of the electrode may be metal such as stainless steel, copper, iron and aluminum, and may be coated with glass, ceramics or the like, if necessary. Of course, these electrodes may be water-cooled if necessary, and the cooling temperature is appropriately selected depending on the object to be treated. The cooling water is preferably water containing as few impurities as possible, but this is not particularly the case when electric leakage due to these impurities is not a serious problem.

The gas to be introduced into the vacuum system should be introduced while being distributed as needed by providing a supply port as far as possible from the exhaust port of the vacuum pump. It may also be introduced between the electrodes. This is important in the sense of avoiding the short path of the gas in the vacuum system, and at the same time, it is important not to cause the processing unevenness of the object to be processed.

The gas containing the monomer introduced into the vacuum system may be any of a monomer gas, a monomer gas and a non-polymerizable gas, and a monomer gas and a polymerizable gas. The monomer gas may be either a gas or a liquid at room temperature. The mixture of the non-polymerizable gas or the polymerizable gas and the monomer gas can be arbitrarily selected depending on the reactivity of the monomer gas, the performance of the formed thin film and the like. The monomer gas and the monomer gas and other gases are separately introduced into the vacuum system and mixed in the system, or they are mixed in advance,
It does not matter if they are introduced at the same time, or the monomer gas may be introduced under discharge with a non-polymerizable gas.

The degree of vacuum that causes low-temperature plasma is usually 0.00
Although 1 to 50 Torr is used, 0.01 to 5.0 Torr is preferable according to the results of studies by the present inventors. When the degree of vacuum is 0.01 Torr or less, the mean free path of ions and electrons increases and the energy of accelerated particles increases, but the total number of accelerated particles that reach the object to be processed is small, and the efficiency of processing becomes slightly low. Moreover, while introducing gas into the large processing chamber, 0.01 Torr
A vacuum pump with a very large displacement is required to keep the value below, which is not desirable from the viewpoint of equipment cost.
When the degree of vacuum is 5 Torr or more, the mean free path of ions, electrons, etc. becomes small, the energy of accelerating particles becomes small, and the processing efficiency becomes low despite the large number of accelerating particles.

Further, although the relative position of the cloth arranged between the electrodes has been described above, the processing efficiency is generally good when the cloth is arranged in contact with one of the electrodes. Also, if you do not want to apply much tension to the cloth or if you do not want to wrinkle the cloth, you can move the cloth and the electrode together, for example, place the cloth on the drum electrode and place the cloth in contact with the drum, and rotate the drum. It is desirable that the cloth be moved while being moved.
In fact, minute wrinkles often cause treatment spots.
If you don't have to pay much attention to tension or wrinkles,
For example, the cloth may be placed in contact with the plate electrode, and the cloth may be slid on the electrode and moved. Of course, after the one-sided treatment, the two-sided treatment can be performed by passing the electrode on the opposite side of the cloth. In the usual case, the treatment effect on only one side is often sufficient, so this type is desirable from the viewpoint of treatment efficiency. However, if it is inevitable to obtain the treatment effect on both surfaces with only one pair of electrodes, the cloth may be arranged at a position between the electrodes and the cloth may be moved. In this case, the theory effect is generally smaller than that in the case of being arranged in contact with the electrode.

Next, in terms of processing uniformity, both electrodes must be held in parallel and must be arranged at right angles to the direction of travel of the fabric. If this condition is not satisfied,
This causes processing unevenness in the width direction of the cloth.

Furthermore, the width of both electrodes must be at least 5 cm longer than the width of the cloth. This is to eliminate the non-uniformity of the electric field at the ends of the electrodes. If the length is 5 cm or less, the treatment effect is different as compared with the width direction of the cloth, especially on both sides near the center, which is not preferable.

The equipment is such that the fabric in the atmosphere can be continuously moved into the vacuum system for processing, the fabric is placed in the preliminary vacuum system and can be moved to the processing chamber, and further, the fabric is partitioned and arranged in the processing chamber. What is meant is, as long as the cloth can move continuously. The plasma output is preferably 0.1 to 5 watts / cm ² as the output acting on the discharge part. In this case, as the area of the discharge part, when the value of the plasma discharge part output is divided by the surface area of the cloth existing in the discharge part or the surface area of either of the counter electrodes, one of the numerical values is 0.
It should be 1 to 5 watts / cm ² . The output of the discharge part can be easily calculated by measuring the voltage and current of the discharge part, but as one guide, it may be considered to be 30 to 70% of the output of the plasma power supply. When the plasma output is less than 0.1 watt / cm ^2, the processing takes time and the film thickness is not sufficient. When the plasma output is 5 watts / cm ² or more, the discharge becomes a little unstable and etching other than polymerization is likely to occur. From the viewpoint of long-term discharge stability of plasma polymerization and discharge grafting, it is 0.
Most preferred is 1 watt / cm ² or more and 2 watts / cm ² or less.

The processing time is preferably about 5 to 600 seconds, but is not necessarily limited to this range. If the treatment is performed for less than 5 seconds, the thickness of the polymer film will be slightly low, and if it exceeds 600 seconds, the thickness of the polymer film will be sufficient, but coloring, slightly hard surface, and brittleness will result in the original performance of the fiber. May be different.

To measure the film thickness, a polyester film was placed in a plasma polymerization atmosphere, a cover glass was placed on the film, the cover glass was removed, and the step was measured by a multiple interference microscope or an electron microscope.

Fluorine-based, plasma-based polymers of silicon-based compounds or plasma-based polymers of acrylic acid, methacrylic acid or their esters have a low refractive index.
Plasma-polymerized products composed of silicon compounds are low.

(Example) An example will be described below. In the following, dye transfer sublimation is carried out by bringing the thin film polymerized surface of the fabric into close contact with the white polyurethane film and sandwiching it between the stainless steel plates as it is, immersing the adhered product in water, and removing excess water from the paper. Although it may be sandwiched between the stainless steel plates after being removed by the method described above, the degree of contamination of the white background film was judged with a gray scale at 80 ° C for 120 minutes under an atmosphere of 120 ° C under a load of 100 g / cm ² . The former case is called the dry method, and the latter case is called the wet method.

The dark color effect was determined by L ^* a ^* b ^* by Hitachi spectrophotometer.

The plasma processing device was a parallel plate internal electrode type, and the power supply used was a frequency of 13.56 MHz.

Example 1 A stretched yarn of polyethylene terephthalate 75 denier / 144 filament was used as a warp yarn and a weft yarn to prepare a twill fabric, which was processed by a usual process, and one face was raised by a needle cloth raising machine. Then, it was dyed with a black disperse dye, and coated with dry polyurethane colored black on the raised surface. Further, vinyltrimethoxysilane monomer was flown on the coating surface at a flow rate of 30 cc / min, and plasma polymerization treatment was carried out at a voltage of 4 KV for 80 seconds while maintaining the vacuum degree at 0.6 Torr.

The transfer of disperse dyes before plasma polymerization is 2-3 in the dry method.
The wet method was the second grade, but after the plasma polymerization, the dry method was the fourth to fifth grade, and the wet method was the fourth grade. The average film thickness of the thin film at this time was 0.07 μm. At this time, the uniformity of the film was 0.067μ to 0.071μ.

Further, the degree of darkening is L ^* = 23 before plasma polymerization,
After plasma polymerization, L ^* = 18, which was so-called crow's wet feather black color.

Example 2 Composed of polyethylene terephthalate and nylon-6
A vertical knitted fabric was formed by using a drawn yarn of 75 denier / 24 filament having an 11-layer laminated cross-section and processed by a conventional method. Sodium hydroxide 4%, 10% by weight in a bath at 98 ° C. After the weight reduction treatment, dyeing was performed with a jet dyeing machine using a disperse dye, and at the same time, the bonded portions were divided to prepare a knitted fabric composed of divided yarns.

After that, polyurethane containing a red dye was prepared on one surface by a wet method and laminated. This surface was coated with methanol-dispersed silicon to improve the texture. 20cc / min of C ₂ F ₄ fluorine gas and a vacuum degree of 0.3 Torr are applied to this laminated surface.
A voltage of 3 KV was applied for 60 seconds to form a plasma polymerized thin film.

The disperse dye transfer fastness of this product was 5 in the dry method, 4 to 5 in the wet method, and 2 in the dry method before plasma polymerization.
The grade and wet method are remarkably improved as compared with the grade 1 and grade 2.

The dark color effect is L ^* = 28 to L ^* = 23 before and after plasma.
By contrast, it was possible to obtain a synthetic leather-like product that was remarkably improved and had a lustrous gloss.

At this time, the average thickness of the thin film was 0.9μ, the uniformity of the film was 0.96μ to 0.91μ, and the refractive index of the thin film was 1.36.

Example 3 A 50-denier / 24-filament stretched yarn having a cross-section of 9 layers made of polyester copolymerized with polyethylene terephthalate and 5 mol% sodium sulfoisophthalate was used as a warp yarn, and a weft yarn was a 75-denier / 36 filament poly. A plain woven fabric made of drawn butylene terephthalate yarn is processed by a conventional method to hydrolyze and remove a polyester obtained by copolymerizing 5 mol% of sodium sulfoisophthalate at 4% with sodium hydroxide at 98 ° C and containing 35% by weight of divided ultrafine yarn. Fabric was created.

After dyeing with a disperse dye, 5 μm thick polyurethane was laminated by a dry method. This urethane contained a dye having a color similar to that of the base cloth and calcium carbonate.

C ₃ F ₆ 30cc / min to the laminate surface, in vacuum 0.5Torr
A plasma-polymerized thin film was formed by applying a voltage of 4 KV for 80 seconds.
Further, silicon dispersed in methanol was applied to the plasma-polymerized surface to give a feeling and slipperiness.

This synthetic leather-like base cloth is supple and has vivid color development, and the transfer sublimation fastness is 5 in both the dry method and the wet method.
The grade was maintained, and it was markedly improved from each grade 2 before plasma treatment.

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Claims (2)

(57) [Claims] 1. A single fiber denier of 30% by weight or more is 0.005-1.0.
A dyed or printed cloth or non-woven fabric made of denier ultrafine fibers, a coating layer or laminate layer made of colored resin or rubber is laminated, and the surface has a refractive index of 1.35 to 1.45 and a thickness of 0.02 to 0.2 microns. A synthetic leather characterized in that the thin film of (μ) is present as a uniform film of 0.9a to 1.1a having an average film thickness a (μ). 2. A single fiber denier of 0.005 to 1.0 denier is used so as to be 30% by weight or more of the fibers constituting the base fabric to form a cloth or a non-woven fabric, or the base fabric is subjected to an ultrafine fiber treatment. Dyeing is carried out to form a cloth or non-woven fabric composed of ultrafine fibers having a single yarn denier of 0.005 to 1.0 denier in which 30% by weight or more of the fibers constituting the base cloth are formed, and dyed at the same time as or after the formation of the cloth or non-woven fabric made of the ultrafine fibers. Alternatively, a coloring treatment by printing is performed, and then a colored resin or rubber is coated or laminated on the colored cloth or non-woven fabric, and the refractive index of 1.35 to
A method for producing synthetic leather, characterized in that a thin film of 1.45 is formed by plasma polymerization to a thickness of 0.02 to 0.2 micron (μ).