JP2001140129A - Joined type conjugate fiber and method for producing leathery sheet using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a sueded leathery sheet excellent in color developing properties and color fastness from joined type conjugate fibers favorable from the aspects of environment and equipment and to produce the fibers used therein. SOLUTION: A nonwoven fabric is obtained from joined type conjugate fibers comprising a polyester and a specific semiaromatic polyamide and having a fiber cross section in which the whole outer periphery of the fiber cross section is covered with either one of resins of the polyester or the polyamide and the conjugate fibers are then split and peeled to produce the leathery sheet having ultrafine fiber naps on the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a leather-like sheet having excellent coloring properties and color fastness, and a bonded conjugate fiber used therefor.

[0002]

2. Description of the Related Art Conventionally, as a suede-like leather-like sheet, there has been known a sheet in which microfiber naps are present on the surface of a base obtained by applying a polymer elastic body to a nonwoven fabric made of microfibers. As a method for producing ultra-fine fibers constituting such a nonwoven fabric, direct spinning tends to cause breakage due to too thin a single fiber, and there is a limit as a method for obtaining a fiber having a fineness of 0.1 denier or less. Uses a composite spinning method. In the composite spinning method, the cross section of the fiber is classified into a junction type (multilayer type, petal type, etc.) in which two components are highly divided and arranged, and a sea-island type in which one component is highly dispersed in other components. When sea-island fibers are used, a large amount of extracted components is involved, and a facility for recovering the extracted components is required, and a large amount of waste is generated. This is an undesirable method from the viewpoint of facilities and the environment. On the other hand, from such a viewpoint, the above-mentioned bonded conjugate fiber is a preferable method, but has a problem to be solved as described below.

[0003] In the joint type composite fiber, an ultrafine fiber is formed only by exfoliation of its components. Therefore, it is necessary to select two potentially peelable components. Polyamides such as nylon 6, nylon 66, nylon 11, nylon 12, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene, polyethylene, etc.
Two types of combinations selected from polyolefins such as polypropylene, thermoplastic elastomers such as polyester elastomers, polyamide elastomers, and urethane elastomers are already known. However, most of the combinations of polyesters represented by polyethylene terephthalate and other polymers require dyeing with two or more dyes twice or more, or it is difficult to dye deeply. Furthermore, there is a problem that the color fastness is poor.

In the case of producing a nonwoven fabric using a bonded composite fiber composed of two components that are potentially peelable, the fiber is not peeled off in a nonwoven fabric production process such as drawing, crimping, carding, and needle punching. Going through the process,
It is important in terms of productivity. In other words, when drawing, crimping, and card processing cause the separation of the components of the bonded conjugate fiber and the fineness is reduced, a nep occurs in the card processing step, and the fibers are entangled in the card machine, and the card processing is performed. Ability gradually decreases. In addition, if the fineness is reduced in the needle punching process or the previous process, there is a problem that the single fibers are not easily entangled by the needle punch, and the peel strength of the nonwoven fabric does not increase. As an effort to solve such problems,
In the combination of polyethylene terephthalate and nylon 6, a resin in which 5-sodium sulfoisophthalic acid is copolymerized with polyethylene terephthalate may be selected in order to improve mutual adhesion. There is also an attempt to increase the spinning speed and perform spinning in a region where the shrinkage behavior of polyethylene terephthalate and nylon 6 is very similar to reduce the peeling during the spinning process. However, such a peeling measure has not been sufficient in the production of nonwoven fabrics.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a conjugated conjugate fiber which is preferable from the viewpoint of environment and equipment, from a color developing property,
An object of the present invention is to provide a method for producing a leather-like sheet having excellent color fastness, and a fiber used for the method.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, a polyamide having a specific structure which is well dyed with polyester and a disperse dye, and has excellent coloring properties and color fastness. In a potentially strippable combination of the above, the above object can be achieved if the basic technical idea of manufacturing a nonwoven fabric using a contact type composite fiber having a specific fiber cross section that does not substantially peel in a nonwoven fabric manufacturing process is used. Was found.

That is, the present invention relates to a specific fiber used in such a method, that is, the fiber cross section is such that polyester and polyamide are alternately arranged, and the entire outer circumference of the fiber cross section is made of polyester or polyamide. The thickness of the polyester coating covering the polyamide portion or the thickness of the polyamide coating covering the polyester portion is 0.05 to 2.0 μm.
m, and under the following conditions (1) and (2), in the polyamide, 60 to 100 mol% of dicarboxylic acid units are aromatic dicarboxylic acid units, and 60 to 100 mol% of diamine units are aliphatic diamine units. And the logarithmic viscosity is 0.1.
(2) The weight ratio of polyester / polyamide in the fiber is 90/10 to 10/90.
And the bonded composite fiber satisfies the following condition. The fiber cross section in the present invention means a cross section of the fiber in a plane perpendicular to the fiber axis direction.

[0008] The present invention also relates to a method for producing a leather-like sheet from the above-mentioned bonded conjugate fiber, that is, to form a non-woven fabric from the contact-type conjugate fiber, and then to form a bonded-type non-woven fabric constituting the non-woven fabric. A method for producing a leather-like sheet, comprising separating fibers, separating the fibers, and fuzzing the surface of the nonwoven fabric, or forming a resin layer on the surface of the nonwoven fabric.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. It is important that the bonded conjugate fiber according to the present invention has a coating covering the entire outer periphery of the cross section of the fiber. If the coating is not formed, the fibers are separated and split in the longitudinal direction after the card treatment and the needle punch treatment. For the formation of a coating, the weight ratio of polyester to polyamide is preferably in the range of 90/10 to 10/90, more preferably in the range of 85/15 to 15/85. 10% by weight of polyester or polyamide
If less than, when alternately arranging polyester and polyamide before discharging from the die, it is difficult to form the desired cross-section because the amount of polyester or polyamide is small, or the cross-section of the fiber It becomes difficult to form a coating covering the entire outer periphery, or the thickness of the coating becomes thin.

In order to maintain good processability in processing steps such as carding and needle punching, the thickness of the coating made of polyamide or polyester on the polyester or polyamide portion is 0.05 to 2.0 μm.
m, more preferably in the range of 0.1 to 1.5 μm. That is, when the coating is thinner than 0.05 μm, the coating is rubbed in the carding and needle punching steps, and is separated in the longitudinal direction of the fiber and is divided by splitting, resulting in poor processability. When the thickness exceeds 2.0 μm, there is no problem in the steps of carding and needle punching, and the processability is good. However, it is exfoliated and split by treatments such as high-pressure water flow, shrinkage, and alkali reduction to make it ultrafine. When doing, it becomes difficult to split.

The cross-sectional shape of the bonded conjugate fiber in which the entire outer periphery of the fiber of the present invention is covered with polyester or polyamide can be a multilayer type, a petal type, a hollow petal type, or the like. In order to obtain fibers of each cross-sectional shape, a corresponding nozzle nozzle hole structure may be used. As the number of bonding layers of the bonding type composite fiber, the total number of polyester layers and polyamide layers is preferably 4 to 200 in terms of the texture and color development of the leather-like sheet obtained, and more preferably 6 to 200.
It is 100 layers, and more preferably 8 to 50 layers. The fineness of each layer is preferably in the range of 0.01 to 1.0 decitex in terms of color development and texture, and particularly preferably in the range of 0.05 to 0.6 decitex.
Further, as the fiber cross-sectional shape after splitting, the flatness is 2 to 15
It is preferable that the fibers have a flat cross section in the range of from the viewpoint of flexibility and splitting property.

The polyester used in the bonded conjugate fiber of the present invention must be a polyester which can be dyed with a disperse dye and has good coloring properties and color fastness. Specific examples thereof include a crystalline polyester obtained by combining a dicarboxylic acid unit such as a terephthalic acid unit and a 2,6-naphthalenedicarboxylic acid unit with a glycol unit such as ethylene glycol, propylene glycol, and butylene glycol.

Further, if necessary, it may have a small amount of other dicarboxylic acid units or oxycarboxylic acid units together with terephthalic acid units and 2,6-naphthalenedicarboxylic acid units. Other dicarboxylic acid units and oxycarboxylic acid units include isophthalic acid, sodium sulfoisophthalate, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, β-hydroxyethoxybenzoic acid, p
-A unit composed of an aromatic dicarboxylic acid or an aromatic oxycarboxylic acid such as -oxybenzoic acid; an aliphatic dicarboxylic acid such as adipic acid, sebacic acid or 1,4-cyclohexanedicarboxylic acid, or an alicyclic dicarboxylic acid. it can.

Further, the polyester constituting the present invention may have a small amount of other glycol units in addition to the above-mentioned glycol units. Other glycol units include diols such as cyclohexane-1,4-dimethanol, neopentyl glycol, bisphenol A and bisphenol S; and polyoxyalkylene glycol units.

In the polyester constituting the present invention, a polycarboxylic acid such as trimellitic acid; and a polyol such as glycerin, trimethylolpropane and pentaerythritol are used as long as the linear structure is not substantially impaired. Is also good.

Among the above-mentioned polyesters, crystalline polyesters having a glass transition temperature of 50 ° C. or higher, particularly 60 ° C. or higher, are preferable from the viewpoint of improving the color fastness of the leather-like sheet. The glass transition temperature is measured by a differential calorimeter (DSC).

The intrinsic viscosity of the polyester constituting the present invention is determined by using a mixed solvent of phenol / tetrachloroethane (1/1).
0.50-1.
It is preferably in the range of 00 dl / g. More preferably, it is in the range of 0.55 to 0.80 dl / g. If the intrinsic viscosity of the crystalline polyester is less than 0.50 dl / g, the mechanical properties of the leather-like sheet are inferior, which is not preferable.
On the other hand, if it exceeds 1.00 dl / g, the spinnability of the bonded conjugate fiber of the present invention is undesirably reduced.

The polyamide used in the bonded conjugate fiber of the present invention substantially comprises a dicarboxylic acid unit and a diamine unit. As the dicarboxylic acid unit, 60 to 100% by mole is composed of an aromatic dicarboxylic acid unit, and preferably contains 60% by mole or more, more preferably 75% by mole or more of a terephthalic acid unit as an aromatic dicarboxylic acid unit. And more preferably 90% by mole or more. Dicarboxylic acid unit content of 60
If the amount is less than mol%, the obtained leather-like sheet is inferior in dyeability, or deteriorates in chemical resistance, strength and the like.

The dicarboxylic acid unit other than the terephthalic acid unit includes, for example, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dimethylmalonic acid, 3,3- Aliphatic dicarboxylic acids such as diethylsuccinic acid, 2,2-dimethylglutaric acid, 2-methyladipic acid and trimethyladipic acid; 1,3-cyclopentanedicarboxylic acid;
Alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; isophthalic acid, 2,6-naphthalenedicarboxylic acid,
2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid,
1,3-phenylenedioxydiacetic acid, diphenic acid, 4,
4'-biphenyldicarboxylic acid, 4,4'-oxydibenzoic acid, diphenylmethane-4,4'-dicarboxylic acid,
One or more units derived from an aromatic dicarboxylic acid such as diphenylsulfone-4,4'-dicarboxylic acid can be included. From the viewpoint of dyeing fastness, chemical resistance, strength, etc., among the above dicarboxylic acid units,
It is preferred to include an aromatic dicarboxylic acid unit.

In the polyamide constituting the present invention, a unit derived from a polycarboxylic acid such as trimellitic acid, trimesic acid or pyromellitic acid is used as long as the linear structure is not substantially impaired. May

The diamine unit must contain an aliphatic diamine unit in an amount of 60 mol% to 100 mol%, preferably at least 75 mol%.
More preferably, the content is 90 mol% or more. When the content of the aliphatic diamine unit is less than 60 mol%,
Inferior dyeability of the leather-like sheet obtained, chemical resistance,
It is not preferable because the strength is reduced.

As the diamine unit, the spinnability of the contact type conjugate fiber, the coloring property of the leather-like sheet, the color fastness, the heat resistance,
For good chemical resistance and the like, it is preferably a 1,9-nonanediamine unit and / or a 2-methyl-1,8-octanediamine unit. And the diamine unit is a 1,9-nonanediamine unit and 2-methyl-
When a 1,8-octanediamine unit is contained, the spinning properties of the contact-type conjugate fiber, the physical properties such as tensile strength and tear strength of the sheet, heat resistance, chemical resistance, and the like are good. Nonanediamine unit and 2-methyl-1,8
The molar ratio of octanediamine units is from 40/60 to 99 /
1, preferably 50/50 to 99/1, and more preferably 70/30 to 95/5.

Examples of other diamine units other than the 1,9-nonanediamine unit include ethylenediamine, propylenediamine, 1,4-butanediamine, 1,6-hexanediamine, 1,7-heptanediamine, and 1,8-diamine.
Octanediamine, 1,10-decanediamine, 1,1
1-undecanediamine, 1,12-dodecanediamine, 1-butyl-1,2-ethanediamine, 1,1-dimethyl-1,4-butanediamine, 1-ethyl-1,4
-Butanediamine, 1,2-dimethyl-1,4-butanediamine, 1,3-dimethyl-1,4-butanediamine, 1,4-dimethyl-1,4-butanediamine, 2,
3-dimethyl-1,4-butanediamine, 2-methyl-
1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,5-dimethyl-1,6-hexanediamine, 2,4-dimethyl-1,6-hexanediamine, 3,3-dimethyl- 1,6-hexanediamine,
2,2-dimethyl-1,6-hexanediamine, 2,
2,4-trimethyl-1,6-hexanediamine, 2,
4,4-trimethyl-1,6-hexanediamine, 2,
4-diethyl-1,6-hexanediamine, 2,2-dimethyl-1,7-heptanediamine, 2,3-dimethyl-1,7-heptanediamine, 2,4-dimethyl-1,
7-heptanediamine, 2,5-dimethyl-1,7-heptanediamine, 2-methyl-1,8-octanediamine, 3-methyl-1,8-octanediamine, 4-methyl-1,8-octanediamine , 1,3-dimethyl-
1,8-octanediamine, 1,4-dimethyl-1,8
-Octanediamine, 2,4-dimethyl-1,8-octanediamine, 3,4-dimethyl-1,8-octanediamine, 4,5-dimethyl-1,8-octanediamine, 2,2-dimethyl-1 , 8-octanediamine,
3,3-dimethyl-1,8-octanediamine, 4,4
-Dimethyl-1,8-octanediamine, 5-methyl-
Aliphatic diamines such as 1,9-nonanediamine; alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine, isophoronediamine, norbornanedimethylamine, tricyclodecanedimethylamine;
-Phenylenediamine, m-phenylenediamine, p-
Xylylenediamine, m-xylylenediamine, 4,
Examples include units derived from aromatic diamines such as 4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, and 4,4'-diaminodiphenylether, and one or more of these units are used. be able to.

The logarithmic viscosity of the polyamide used in the present invention is in the range of 0.4 to 2.0, and if it is less than 0.4, pelletization cannot be performed. When it is larger than 2.0, polymerization is difficult. Preferably it is 0.6 to 1.4, more preferably 0.7 to 1.2.

The method for producing the polyamide constituting the present invention is not particularly limited, and any production method known as a method for producing a crystalline polyamide can be used.
For example, it can be polymerized by a solution polymerization or an interfacial polymerization method using acid chloride and diamine as raw materials, a melt polymerization method using dicarboxylic acid and diamine as raw materials, a solid phase polymerization method, a melt extruder polymerization method, or the like.

The polyester and polyamide constituting the present invention can be used by blending various additives as necessary. For example, catalysts, color inhibitors, heat-resistant agents, flame retardants, fluorescent brighteners, matting agents, coloring agents, gloss improvers, antistatic agents, fragrances, deodorants, antibacterial agents, anti-mite agents, inorganic fine particles Etc. may be included. Further, the additives may be blended on one side of polyester or polyamide, or on both sides.

The leather-like sheet of the present invention can be obtained by performing the following steps in combination. That is, it can be obtained by sequentially performing the following steps (a) to (d). (A) In the fiber cross section, polyester and polyamide are alternately arranged, and the entire outer circumference of the fiber cross section is coated with polyester or polyamide, and the thickness of the polyester coating covering the polyamide portion or the polyamide covering the polyester portion The thickness of the coating of 0.05 ~
A contact type composite structure having a thickness of 2.0 μm;
Producing a contact type composite fiber satisfying (2) and
(B) a step of producing an entangled nonwoven fabric comprising the fibers;
(C) a step of separating and separating the fibers, (2) a step of forming nap of the fiber bundle on at least one surface, or a step of forming a resin layer on at least one surface, and the steps (b) and (c). Between steps (c) and (2), the following steps (e) to (g) may be added as necessary, or the following step (h) may be added after the above step (d). May be. (E) a step of shrinking the nonwoven fabric, (f) a step of temporarily fixing the nonwoven fabric with a water-soluble glue or the like, (g) a step of impregnating, coagulating, and drying a polymer liquid to impart a polymer to the nonwoven fabric; H) Dyeing the obtained sheet

Next, the process of the present invention will be described in detail below. First, in order to produce a bonded conjugate fiber in which the entire outer periphery of the cross section used in the present invention is covered with polyester, the polyester and polyamide are made into a molten state, and these are alternately arranged by a conventional method. And discharge from the nozzle hole. That is, polyester and polyamide are arranged alternately,
By the surface tension of the polyamide, the end is rounded in the part that comes into contact with the metal of the die and the die during discharge until it is discharged from the pores inside the die, and the polyester flows into the gap there, A joined conjugate fiber having a coating in which the entire outer periphery of the cross section is covered with polyester can be obtained. In addition, the production of the bonded conjugate fiber in which the entire outer periphery of the cross section is coated with polyamide is performed by adjusting the balance of the apparent melt viscosities at the time of spinning the polyester and the polyamide, and spinning similarly to obtain the desired bonded conjugate fiber. Obtainable.

The obtained conjugated composite fiber is drawn and, if necessary, subjected to processing steps such as crimping, heat setting, and cutting to obtain a fiber having a fineness of 2 to 15 denier.

[0030] The bonded conjugate fiber is defibrated with a card and formed through a webber to form a random web or a cross-wrap web. If necessary, other fibers may be mixed.
The resulting fibrous web is laminated to the desired weight and thickness. Next, a needle punching process is performed by a known method,
Needle punched nonwoven fabric. The number of punches is usually 200 ~
The range is 2500 punches / cm ² .

It is necessary to peel and split the bonded conjugate fiber constituting the fiber entangled nonwoven fabric to make it ultrafine. The methods of peeling and splitting include physical impact such as weight loss by an alkali solution and high pressure liquid flow. And a method utilizing the difference in shrinkage between the polyamide component and the polyester component of the bonded conjugate fiber.

Then, the fiber entangled nonwoven fabric is heated to 50 to 150 ° C.
, And more preferably, the fiber-entangled nonwoven fabric is heated in a hot water tank at 50 to 95 ° C to shrink the fiber-entangled nonwoven fabric. By shrinking,
The feeling of fulfillment of the obtained leather-like sheet is remarkably improved. The shrinkage rate is determined by the types of polyester and polyamide, the weight ratio, spinning conditions, stretching conditions, and the like.
It is preferably in the range of 60%, more preferably in the range of 20 to 50%.

If necessary, a non-woven fabric may be provided with a resin which can be dissolved and removed, for example, a water-soluble glue such as a polyvinyl alcohol resin, and the non-woven fabric may be temporarily fixed.

Further, the leather-like sheet of the present invention may be provided with a polymer liquid in order to supplement the surface appearance of the sheet, the feeling such as the fullness, and the mechanical properties. As the polymer liquid to be used, a polymer liquid obtained by dissolving a urethane polymer or an acrylic polymer in a solvent or dispersing in a non-solvent such as water is impregnated into a fiber-entangled nonwoven fabric and treated with a resin non-solvent. Then, wet coagulation, or heat treatment, dry coagulation, or heat treatment, hot water treatment, steam treatment, and heat-sensitive coagulation. The polymer used may be solidified so as to be uniformly applied to the entire nonwoven fabric, or may be migrated to the surface and applied with a gradient in the thickness direction. After impregnating, coagulating, and drying the polymer liquid, the polymer may be adhered to the fibers, or a space may be formed between the polymer and the fibers. The amount of the polymer to be applied is as follows.
The amount of the polymer to be added is 120 parts by weight or less, preferably 100 parts by weight or less, more preferably 80 parts by weight or less based on 0 parts. If the amount exceeds 120 parts by weight, the resulting leather-like sheet is unfavorably soft, resulting in a rubber-like sheet.

Next, at least one surface of a sheet comprising the ultrafine fiber entangled nonwoven fabric and the above-mentioned polymer to be used as necessary is subjected to a raising treatment to form a fiber fiber raised surface mainly composed of ultrafine fibers, thereby producing suede-like leather. Or a laminated resin layer on at least one side to form a leather-like sheet with a silver surface. As a method for forming the fiber raised surface, a method of buffing using a sandpaper or the like is used after adjusting the thickness of the fibrous substrate to a desired thickness or before adjusting the thickness. If the thickness has not been adjusted, the thickness is adjusted to a desired thickness. Similarly, in the case of a leather-like sheet on which a resin layer is laminated, the thickness is adjusted. As the resin layer laminated on the surface, an elastic polymer layer represented by a polyurethane layer is preferably used. The surface of the nonwoven fabric can be melted by heating the surface and pressing the smooth surface to form a resin layer. Next, the obtained suede-like leather-like sheet or grain-like leather-like sheet is dyed as necessary. Dyeing is carried out with a dye mainly composed of a disperse dye or the like by a usual dyeing method. Further, the leather-like sheet can be subjected to finishing treatment such as kneading softening treatment and brushing as necessary to obtain a leather-like sheet.

The leather-like sheet obtained by the present invention has extremely good color fastness and color development and excellent texture, and is used as a suede type or a type with silver as well as for clothing, ornaments and interiors. For, shoes, car seats,
Suitable for bags, various gloves, and the like.

[0037]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, parts and% relate to weight unless otherwise specified.

[Glass Transition Temperature] The glass transition temperature of the polyester was measured using a differential scanning calorimeter (DSC) manufactured by Mettler (TA-3000) under a nitrogen gas stream as shown in Table 1 below.
Steps 1 to 3 shown below were sequentially performed, and the glass transition temperature was determined from the transition point at that time.

[0039]

[Table 1]

[Logarithmic viscosity of polyamide] Calculated from a value measured using a Ubbelohde type viscosity system in a constant temperature bath at 30 ° C. using concentrated sulfuric acid.

[Measurement of Coating Thickness] In a state where both ends of the spun and drawn raw cotton fiber are fixed and tensioned, they are placed in a hot water bath at 100 ° C. for 10 minutes, and the bonded surface is determined by the difference in shrinkage ratio between polyester and polyamide. After the cracks were formed, the cross section was cut, and the thickness of the film of the polyester portion or the polyamide portion was measured with a scanning electron microscope.

[Lightfastness to Light Dyeing] After the leather-like sheet was irradiated with a fade tester (UV long life fade meter FAL-5H / B / BL, UV carbon arc lamp, 63 ° C., manufactured by Suga Test Instruments Co., Ltd., 63 ° C.) for 80 hours. The degree of discoloration was determined by gray scale.

The resins used in the following Examples and Comparative Examples are shown in Table 2 below.

[0044]

[Table 2]

Example 1 PET (1) was used as polyester and polyamide (1) was used as polyamide, and the layers were alternately arranged in 11 layers at a weight ratio of 70/30. The apparent melt viscosities during spinning are 950 respectively.
Poise was 1220 poise. After spinning, the fiber was drawn to obtain a bonded composite fiber. The obtained bonded conjugate fiber has a single yarn fineness of 3.8 dtex, the fineness of the stratum corneum constituting the bonded conjugate fiber is 0.34 dtex on average, and the flatness of the cross section of each layer is about 7. there were. 5 cut every 5m
The thickness of the polyester coating covering the outer peripheral surface of the fiber at the cut surface was 0.4 μm. A mechanical crimp was applied to the bonded conjugate fiber, then cut into 51 mm, defibrated with a card, and formed into a web with a cross wrapper webber. Next, needle punching was performed to obtain a fiber-entangled nonwoven fabric. No split fibers were observed in the fibers after the card treatment and the knee pan treatment. 90 ° C. sodium hydroxide aqueous solution (concentration: 4
0 g / l) of the fiber-entangled nonwoven fabric,
The sodium hydroxide was washed in a bath containing hot water at 0 ° C. The fiber-entangled nonwoven fabric shrinks by these treatments, and the shrinkage ratio [(length of nonwoven fabric after shrinkage / length of nonwoven fabric before shrinkage) ×
100] was 19% in the vertical direction and 20% in the horizontal direction. After drying the contracted nonwoven fabric, the nonwoven fabric is impregnated with an aqueous urethane emulsion so that 5 parts of a solid content of an aqueous emulsion (Bondick 1310 manufactured by Dainippon Ink and Chemicals, Inc.) is added to the nonwoven fabric. And dried with hot air. After buffing one surface of the fibrous substrate with sandpaper and adjusting the thickness to 0.80 mm,
The other side is treated with an emery buffing machine to form a very fine nap, and after being dyed brown using a disperse dye with a circular jet dyeing machine, a leather-like sheet having a specific gravity of 0.41 is finished. Obtained. Staining color evenly dark color, which is the reduction treatment, further, light fastness properties were as good as No. 4-5.

Example 2 Using polyethylene terephthalate (1) as the polyester and polyamide (2) as the polyamide,
After alternately arranging 11 layers at a weight ratio of 70/30, the mixture was discharged from a die and spun. The apparent melt viscosities during spinning were 950 poise and 1180 poise, respectively. After spinning, the yarn was drawn to obtain a joint type composite fiber. The obtained bonded type composite fiber has a single yarn fineness of 3.6 dtex,
The fineness of the stratum corneum constituting the bonded composite fiber is 0.3 on average.
3 decitex, and the flatness of the cross section of each layer was about 7. The thickness of the polyester coating wrapping the outer surface of the fiber at five cut surfaces where the fiber was cut every 5 m was 0.5.
μm. A mechanical crimp was applied to the bonded conjugate fiber, then cut into 51 mm, defibrated with a card, and formed into a web with a cross wrapper webber. Next, needle punching was performed to obtain a fiber-entangled nonwoven fabric. No split fibers were observed in the fibers after the card treatment and the knee pan treatment. 9
0 ° C sodium hydroxide aqueous solution (concentration: 40 g / l)
Then, the fiber-entangled nonwoven fabric was soaked, and then sodium hydroxide was washed in a bath containing hot water at 90 ° C. By these treatments, the fiber-entangled nonwoven fabric shrinks, and the shrinkage ratio [(length of nonwoven fabric after shrinkage / length of nonwoven fabric before shrinkage) × 100] is 20% in the vertical direction and 21% in the horizontal direction. . After drying the contracted non-woven fabric, an aqueous emulsion was applied to the non-woven fabric (Bondick 1310 manufactured by Dainippon Ink and Chemicals, Inc.).
The nonwoven fabric was impregnated with an aqueous urethane emulsion so as to give 5 parts of a solid content of, and dried with hot air at 130 ° C.
After buffing one surface of the fibrous base material with sandpaper and adjusting the thickness to 0.80 mm, the other surface is treated with an emery buffing machine to form an extremely fine nap surface, and further a disperse dye is formed with a circular jet dyeing machine. After dyeing into brown and reducing, the leather-like sheet having a specific gravity of 0.43 was obtained. Are dyed in the color evenly dark color, further, light fastness properties were as good as No. 4-5.

Comparative Example 1 Using polyethylene terephthalate (2) as the polyester and polyamide (2) as the polyamide,
After alternately arranging 11 layers at a weight ratio of 70/30, the mixture was discharged from a die and spun. The apparent melt viscosities during spinning were 1600 poise and 1180 poise, respectively. After spinning, the yarn was drawn to obtain a joint type composite fiber. The obtained bonded conjugate fiber had a single-fiber fineness of 3.5 dtex and had no polyester coating on the outer peripheral surface of the fiber at five cut surfaces cut every 5 m. A mechanical crimp was applied to this bonded conjugate fiber, then cut to 51 mm, and the fiber was defibrated with a card. However, most of the fiber was split, and a web was not obtained.

Comparative Example 2 Using polyethylene terephthalate (1) as the polyester and polyamide (3) as the polyamide,
After alternately arranging 11 layers at a weight ratio of 70/30, the mixture was discharged from a die and spun. The apparent melt viscosities during spinning were 950 poise and 1250 poise, respectively. After spinning, the yarn was drawn to obtain a joint type composite fiber. The obtained bonded conjugate fiber had a single yarn fineness of 3.2 denier and a length of 5 m.
The thickness of the polyester coating covering the outer peripheral surface of the fiber at the five cut surfaces cut every other time was 0.5 μm. A mechanical crimp was applied to the bonded conjugate fiber, then cut into 51 mm, defibrated with a card, and formed into a web with a cross wrapper webber. Next, needle punching was performed to obtain a fiber-entangled nonwoven fabric. No split fibers were observed in the fibers after the card treatment and the knee pan treatment. This fiber entangled nonwoven fabric was immersed in a 90 ° C. aqueous sodium hydroxide solution (concentration: 40 g / l), and then the sodium hydroxide was washed in a bath containing hot water at 90 ° C. By these treatments, the fiber-entangled nonwoven fabric shrinks, and the shrinkage ratio [(length of nonwoven fabric after shrinkage / length of nonwoven fabric before shrinkage) × 100] is 10% in the vertical direction and 12% in the horizontal direction. . After drying the contracted nonwoven fabric, the nonwoven fabric is impregnated with an aqueous urethane emulsion so that 5 parts of a solid content of an aqueous emulsion (Bondick 1310 manufactured by Dainippon Ink and Chemicals, Inc.) is added to the nonwoven fabric. And dried with hot air. After buffing one surface of the fibrous base material with sandpaper and adjusting the thickness to 0.80 mm, the other surface is treated with an emery buffing machine to form an extremely fine nap surface, and further a disperse dye is formed with a circular jet dyeing machine. After dyeing brown and reducing, a finishing process was performed to obtain a leather-like sheet having a specific gravity of 0.32. Since the color of the polyamide fiber was light, the color of the sheet surface was very light, and there was color unevenness. Furthermore, the result of light fastness was 2-3.
No. was inferior.

[0049]

The present invention provides a suede-like leather-like sheet dyed with a disperse dye in a dark color without unevenness in color and having excellent color fastness.

[Brief description of the drawings]

FIG. 1 is a schematic view of one example of a cross section of a multicomponent fiber of the present invention.

[Explanation of symbols]

 1: Polyester 2: Polyamide

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D06N 3/00 DAA D06N 3/00 DAA F-term (Reference) 4F055 AA01 BA12 BA16 CA16 EA04 EA05 EA13 EA14 EA24 EA31 4L041 AA07 BA04 BA05 BA13 BA23 BA24 BA34 BA49 BA59 BC20 BD11 BD15 CA06 CA23 CA30 DD01 DD04 DD15 EE06 EE15 EE20 4L047 AA21 AA23 AA27 AB02 AB08 AB09 BA03 BA05 BA09 BA22 BB09 CA08 CC01 CC09 CC16 DA00

Claims (3)

[Claims] (1) polyester and polyamide are alternately arranged in a cross section of the fiber, and the entire outer periphery of the cross section of the fiber is coated with polyester or polyamide;
The thickness of the polyester coating over the polyamide portion or the thickness of the polyamide coating over the polyester portion is 0.
05 to 2.0 μm, under the following conditions (1) and (2):
In the polyamide, 60 to 100 mol% of dicarboxylic acid units are composed of aromatic dicarboxylic acid units, 60 to 100 mol% of diamine units are composed of aliphatic diamine units, and the logarithmic viscosity is 0.4 to 2.0. (2) The weight ratio of polyester / polyamide in the fiber is 90/10
In the range of 〜１０10 / 90. 2. The polyamide according to claim 1, wherein the dicarboxylic acid units of the polyamide are terephthalic acid units, and the diamine units are 1,9-nonanediamine units and / or 2-methyl-1,8-octanediamine units. Bonded composite fiber. 3. A non-woven fabric is formed from the contact-type composite fiber according to claim 1 or 2, and thereafter, the bonded conjugate fiber constituting the non-woven fabric is separated and separated, and the surface of the non-woven fabric is fluffed. Alternatively, a method for producing a leather-like sheet, comprising forming a resin layer on the surface of the nonwoven fabric.