JP3015124B2 - PROCESS FOR PRODUCING SHEET-FREE YELLOW WHITE SUEDE TONE SHEET HAVING GOOD HAND - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to have good texture and fine appearance, weatherability, resistance to NO _x yellowing, a method for manufacturing a white suede sheet excellent in such hydrolysis resistance as It is.

[0002]

2. Description of the Related Art Conventionally, as a suede-like artificial leather, a sheet-like material having ultrafine fibers such as polyester fibers on the surface of a fibrous base material containing a porous polymer mainly composed of an elastic polymer is a unique material. It is particularly preferably used because it has a lighting effect and a good feeling. Generally, polyurethane is often used as the elastic polymer used for the base layer.

As a method for producing artificial leather having good nap, a method of raising the apparent density of a fiber-entangled body by a needle punch and then applying a polymer elastic body to raise the hair is disclosed in Japanese Patent Application Laid-Open No. 57-171772. No. 1993. In addition, as a method for producing a flexible sheet, a method of shrinking a high apparent density fiber entangled body by heat treatment, applying a viscoelastic material and a temporary filler, and removing the temporary filler after the fiber is thinned is featured. Kaisho 5
It is proposed in Japanese Patent Application Laid-Open No. 7-117681. Furthermore, as a method for producing a suede-like sheet made of polyester ultrafine fiber nap, which has a good appearance and is excellent in color development and dyeing fastness, 1,9-nonanediol and / or 2-methyl 1 Japanese Patent Application Laid-Open No. HEI 2 (1996) -197686 discloses a method in which a polyester diol obtained by condensation polymerization of 8,8-octanediol and dicarboxylic acid is impregnated with polyurethane using a soft segment as a soft segment, raised, and then dyed with a jet dyeing machine and washed with alkali reduction. No. 289187.

However, within the range of the above-mentioned technology, there is a difficulty in obtaining a non-yellowing white suede-like sheet which is particularly demanded recently in high-end sports shoes and the like. As the polyurethane satisfying the severe weather resistance and NO _x yellowing resistance required for these uses, a polyurethane using isophorone diisocyanate or hydrogenated diphenylmethane diisocyanate (hereinafter referred to as hydrogenated MDI) as an isocyanate component. You need to use Since such a polyurethane has a hard texture after coagulation and does not have high solvent resistance, there is a difficulty in obtaining a good texture and a high-grade appearance.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention, weather resistance, resistance to NO _x yellowing, excellent like hydrolysis resistance, and good feeling and white suede sheet having fine appearance It is to provide a manufacturing method.

[0006]

[Means for Solving the Problems]

The present invention provides a process of three-dimensionally entangled a polyester ultrafine fiber-generating fiber web to form a nonwoven fabric having a delamination strength of 6 kg / 2.5 cm or more.
Shrinking; generating ultrafine polyester fibers having a single fiber fineness of 0.001 to 0.3 denier; 1,9-nonanediol and / or 2-methyl 1,8-octanediol and dicarboxylic acid Polyester diol obtained by condensation polymerization with an acid,
Alternatively, polycarbonate todiol or poly (β
-Methyl δ-valerolactone) diol, a polyol containing at least one member selected from the group consisting of isophorone diisocyanate or hydrogenated diphenylmethane diisocyanate, and a compound having two active hydrogen atoms. Impregnated with polyurethane obtained by reacting as an elongation agent,
Wet coagulation; raising the surface of the sheet obtained in step 1 to form polyester microfiber naps; using a high-temperature high-pressure liquid dyeing machine having a rubbing function;
And a step of performing flexible processing in hot water at a temperature of 10 ° C. or more and 130 ° C. or less.

The polyester ultrafine fiber-generating fiber used in the present invention is a mixed spun fiber or a composite spun fiber composed of polyester and one or more kinds of spinnable synthetic polymers having different properties with respect to a solvent and a decomposer. Such a fiber can be spun by a conventionally known method such as mixing and melting each component in the same melting system, or melting and melting the components in separate melting systems, repeating division-integration, or regulating with a spinning nozzle.

[0008] The reason why polyester is used as the ultrafine fiber component is the whiteness of the fiber nap and the non-yellowing property when white suede is used. Further, in order to increase the apparent density and the degree of entanglement of the nonwoven fabric by the shrinkage treatment following the three-dimensional entanglement treatment, it is necessary to use polyester. When a polyamide fiber or the like is used, a suede-like sheet having excellent flexibility can be obtained, but it is inferior to yellowing.

The proportion of the polyester microfiber component in the microfiber-generating fiber is not particularly limited, but it is 50% or more, preferably 60 to 85%, in that the apparent density of the nonwoven fabric can be increased when it is modified into microfiber. It is. The fineness of the single yarn of the ultrafine polyester is 0.001 to 0.
It is in the range of 3 denier. If the single-filament fineness is out of this range, it becomes larger or smaller, which adversely affects the physical properties such as the strength and elongation of the product, the appearance, the texture, etc., the polyurethane impregnation, and the formation of polyurethane sponge during coagulation. Exert.

A single fiber of the above fibers is formed into a web by using a card or the like, and a three-dimensional entangled nonwoven fabric is formed by a method such as a needle punch method or a water entanglement method. The basis weight of the nonwoven fabric is 300 to 800 by the basis weight when the polyester microfiber nonwoven fabric is used.
The range of g / m ² is a guide. It is necessary to perform the three-dimensional entanglement until the delamination strength becomes 6 kg / 2.5 cm or more. Here, the delamination strength is a force required to peel the nonwoven fabric into two pieces in the thickness direction. By performing such three-dimensional entanglement, the apparent density and the degree of fiber entanglement of the nonwoven fabric are increased, and sufficient strength and morphological stability that can withstand the polyurethane impregnation step when the fibers are extremely fine can be obtained. In addition, a suede-like sheet-like material having a high surface nap density and a flexible and strong sheet can be obtained.

Next, the entangled nonwoven fabric is shrunk in warm water of 70 ° C. or more by changing the area by 25 to 50%. By this shrinkage treatment, the apparent density and the degree of fiber entanglement of the nonwoven fabric are further increased, and the form stability is also increased. If the area shrinkage is less than 25%, the increase in apparent density is not sufficient. If the area shrinkage is more than 50%, the above-mentioned three-dimensional entanglement treatment is insufficient or the suede density is too high. The texture of the sheet-like material becomes hard. Further, if necessary, a treatment such as hot pressing is performed to improve the permeability of the polyurethane impregnation step and the state of the polyurethane impregnation.

The shrink-treated non-woven fabric is treated with a solvent or a decomposer of a component other than the polyester of the constituent fibers to obtain a non-woven fabric made of ultrafine polyester fibers having a single fiber fineness of 0.001 to 0.3 denier. Isophorone diisocyanate or hydrogenated MDI-based hardly yellowed polyurethane used for impregnation in the present invention does not have very high solvent resistance. Therefore, it is necessary to ultrafine the nonwoven fabric constituent fibers prior to the polyurethane impregnation. is there.

Polyurethane used for the [0013] present invention is wet-coagulable, with advantages such as light resistance, and further hot water resistance, hydrolysis resistance, excellent in such resistance NO _x yellowing.

The polyurethane elastomer used for impregnation in the present invention is a polymer diol having an average molecular weight of 500 to 5000 and having good hydrolysis resistance, an aliphatic or alicyclic diisocyanate, and an activity having a molecular weight of 500 or less. It is obtained by reacting a compound having two hydrogen atoms. Examples of the polyester diol include 1,9-nonanediol and / or
Or a polyesterdiol obtained by condensation polymerization of 2-methyl-1,8-octanediol and dicarboxylic acid.
Le. Polycarbonate diols such as 1,5-pentanediole, 1,6-hexanediol, 1,9-nonanediol and / or 2-methyl 1,8-octanediol and ethylene carbonate Bonnet
Alkylene carbonates such as dialkyl carbonate, diphenyl carbonates such as diphenyl carbonate, and carbonates such as dialkyl carbonates such as diethyl carbonate. And polycarbonates produced by reacting the diols and phosgene in desired proportions. Further, poly (β-methylδ-valerolactone) diol obtained by ring-opening polymerization of β-methylδ-valerolactone using ethylene glycol as a polymerization initiator is also used as a soft segment.

The diisocyanate used in the polyurethane of the present invention is an aliphatic or alicyclic diisocyanate, and isophorone diisocyanate or hydrogenated MDI is preferably used. Examples of the chain extender containing a compound having two active hydrogen atoms include aliphatic diols such as ethylene glycol, propylene glycol, and butanediol, and 1,
Alicyclic diols such as 4-cyclohexanediol, divalent aromatic alcohols such as xylylene glycol, diethylene glycol, dipropylene glycol, dibutylene glycol, triethylene glycol; Polyalkylene glycols such as diols, diols such as carboxylic acid-containing diols such as dimethylolpropionic acid, ethylenediamine, propylenediamine, xylylenediamine,
Aliphatic, alicyclic or aromatic diamines such as isophorone diamine, phenylenediamine, tolylenediamine,
A heterocyclic compound containing two imino groups in a cyclic structure such as piperazine is preferably used. Preferably,
From the viewpoint of both physical properties and flexibility, a polyurethane having a stress at 100% elongation of 20 to 100 kg / cm ² is used.

The polyurethane is dissolved in an appropriate solvent, for example, dimethylformamide, impregnated into a fiber-entangled nonwoven fabric by a conventionally known method, and coagulated with a non-solvent or a mixed solvent of a non-solvent and a solvent. The amount of polyurethane occupied in the sheet-like substrate is in the range of 10 to 30% by weight, preferably 10 to 20% by weight as a solid content. If the content of polyurethane in the sheet-like substrate is outside the above range,
It is not preferable because the waist is lost, the elastic behavior becomes large, and the feeling becomes hard.

Next, at least one surface of the sheet-like substrate made of the ultrafine fiber entangled nonwoven fabric and the polyurethane is formed with a fiber raised surface mainly composed of polyester ultrafine fibers. That is, after the sheet-shaped substrate is adjusted to a desired thickness or before the thickness is adjusted, at least one surface of the sheet-shaped substrate is raised by a raising machine, buffing by sandpaper, or the like. By the treatment or the like, a nap surface mainly composed of fiber nap is formed to obtain a suede nap hair sheet. If the thickness of the sheet is not adjusted, the back surface is processed to a desired thickness and the thickness is adjusted. The product thickness of the suede-like sheet is 0.35-1.
It is desirable to be in the range of 50 mm.

The suede-like sheet of the present invention is further subjected to soft working in hot water at 110 ° C. to 130 ° C. using a high-temperature high-pressure jet dyeing machine. It is necessary to carry out mechanical rubbing by a method such as passing through a narrow nozzle using a liquid jet dyeing machine in order to obtain a soft feeling with a rounded feeling.
Further, when the hot water temperature is within the above range, effective flexible working can be performed without physical damage. Further, it is preferable to perform a hair styling treatment such as brushing after softening and drying in order to improve the appearance.

[0019]

Next, the present invention will be described with reference to specific examples, but the present invention is not limited to the description of the examples. In the examples, parts and percentages relate to weight unless otherwise specified.

Example-1 75 parts of polyethylene terephthalate (island component), 25 parts of low-density polyethylene (sea component), and 5 islands
Zero needle punching is applied to a web of sea-island type mixed fibers with an average fineness of about 0.08 denier after removing the sea component after removing the sea component, and the strength when peeled in a direction perpendicular to the thickness direction. Is 7 kg / 2.5 cm. 9
Shrink by 30% in area shrinkage rate in hot water of 0 ° C, 120 ° C
After hot-pressing with a heat roll and temporarily fixing the mixture, the mixture was treated in toluene at 85 ° C. to remove polyethylene from sea components and to make polyethylene terephthalate fibers ultrafine.

[0021] 1,9-
Polyesterdiol having an average molecular weight of 2,000, obtained by condensation polymerization of a mixture of nonandiol and 2-methyl-1,8-octanediol (molar ratio 50/50) with adipic acid, isophorone diisocyanate Then, a 10% by weight dimethylformamide solution of polyurethane obtained by reacting the compound with isophoronediamine at a molar ratio of 2: 5: 3 was impregnated, wet coagulated, and then subjected to solvent removal and drying treatment.
After the obtained sheet was adjusted to a thickness of 1.0 mm, the surface was buffed by sandpaper to raise the surface.

Further, the obtained fiber napping sheet is subjected to soft working in hot water at 110 ° C. for 1 hour by using a high-temperature and high-pressure liquid jet dyeing machine, and after drying, the napping of the surface is adjusted by a nylon brush. And The resulting product has a flexible feeling with appearance and rounded a classy, and light resistance, NO _x yellowing extremely excellent flame yellowing of white Sue - was de. The results are shown in Table 1.

[0023]

[Table 1]

Note 1) The light resistance was evaluated according to JIS L-084.
1 "Testing method for color fastness to carbon arc light"
Discoloration degree, carbon arc lamp light fastness 1 to
Evaluated at 8th grade. Note 2) resistance to NO _x yellowing evaluation is sufficiently has internal volume, after fixing the specimen in a glass container with lid with a stirring device capable of internal agitation in a substantially vertical state, JIS L-085
5 Inject a fixed amount (50 ppm) of NO _x gas generated based on the “Dyeing Fastness Test Method for Nitric Oxide Gas” into a closed glass container, leave it indoors for 5 days, and then measure the degree of discoloration of the sample. Is determined by instrumental colorimetry using the reflectance at a specific wavelength.
IS Z-8729 "L ^* a ^* b ^* color system and L ^* u ^* v ^*
It was evaluated by the color difference [Delta] b ^* values of [Delta] b ^* values determined in the display method "of the object color by color system. Note 3) Hand feeling evaluation ◎ Very good ΔNormal × Bad

[0025]

[Comparative example]

Comparative Example-1 The same procedure as in Example was carried out except that polybutylene adipate having an average molecular weight of 2,000 was used as the soft segment as the impregnating polyurethane, and 4,4-diphenylmethane diisocyanate was used as the diisocyanate component. To give a white suede-like sheet. However, this product suffered severe damage to the polyurethane during the flexible processing using a jet dyeing machine, resulting in a loose feeling, and did not have the necessary strength as a commercial product. Furthermore, light resistance, NO resistance
_x Inferior to yellowing.

Comparative Example 2 A white suede-like sheet was obtained in the same manner as in the Example except that the ultrafine polyethylene terephthalate fiber was treated after impregnation with polyurethane. However, this product had a hard feeling due to the structural destruction of the polyurethane sponge due to the solvent during the ultrafine treatment, and did not have the quality in terms of sensitivity required as a product.

Comparative Example 3 A white suede-like sheet was obtained in the same manner as in the example except that the shrinkage treatment of the entangled nonwoven fabric was not performed. However, since the fiber density in the sheet was low and the entanglement was insufficient, the texture had a rubber-like resilience and the nap density was slightly lower and did not have the quality in terms of sensitivity required as a product. .

[0028]

According to the method of the present invention, it has a high-grade appearance, a rounded and soft feel, and is light- and N-resistant.
O _x yellowing extremely excellent flame yellowing of white Sue - de tone sheet - DOO-like material can be produced.

Claims (1)

(57) [Claims] 1. A three-dimensionally entangled polyester ultrafine fiber generating fiber web having a delamination strength of 6 kg / 2.5 cm.
The above-mentioned nonwoven fabric process, 25 to 50% of the area change of the above nonwoven fabric in warm water
Shrinking; generating ultrafine polyester fibers having a single fiber fineness of 0.001 to 0.3 denier; 1,9-nonanediol and / or 2-methyl 1,8-octanediol and dicarboxylic acid Polyester diol obtained by condensation polymerization with an acid,
Alternatively, polycarbonate todiol or poly (β
-Methyl δ-valerolactone) diol, a polyol containing at least one member selected from the group consisting of isophorone diisocyanate or hydrogenated diphenylmethane diisocyanate, and a compound having two active hydrogen atoms. Impregnated with polyurethane obtained by reacting as an elongation agent,
Wet coagulation; raising the surface of the sheet obtained in step 1 to form polyester microfiber naps; using a high-temperature high-pressure liquid dyeing machine having a rubbing function;
A process of softening in hot water at a temperature of 10 ° C. or more and 130 ° C. or less.