JP3373403B2 - Method for producing suede-like artificial leather - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing suede-like artificial leather. In particular, a suede-like artificial leather made of polyamide and / or polyester ultrafine fibers of 0.3 de or less and polyurethane is kneaded to release the sticking of the fibers or fiber bundles on the surface and at the same time impart flexibility to the base material layer. The goal is to produce suede-like artificial leather that is soft and has good chalk mark properties.

[0002]

2. Description of the Related Art A composite material in which polyurethane is added to a fiber is used in an extremely wide variety of fields, especially as artificial leather, and has been well received. For example, in recent years, the demand for silver-coated artificial leather and suede-like artificial leather in the fields of sports shoes, bags, clothing, etc. has been increasing. 0.3 among them
Suede-like artificial leather using ultrafine fibers of de or less is particularly excellent in strength, flexibility, suppleness and choke mark property, and is therefore being actively developed. In particular, there are high demands for flexibility and choke mark properties.

Regarding the flexibility, it has been proposed to achieve softness from the viewpoint of the structure of the base material. For example, in Japanese Examined Patent Publication No. 51-32681, a non-woven fabric is made by using fibers obtained by mixing and spinning two kinds of polymer substances having different solubilities, polyvinyl alcohol is added to the non-woven fabric, and then hydroxyl groups are added to both ends. Having an average molecular weight of 1200 to 2500
Polyvinyl alcohol is removed after impregnation with a solution of a polyurethane elastomer having a nitrogen content of 3.0 to 4.0% obtained from the polymer glycol of P, P'-diphenylmethane diisocyanate and a diol compound as a chain extender, and coagulating. In addition, a method for producing a flexible sheet-like product is proposed, which comprises extracting and removing at least one polymer substance in the mixed spun fiber. This method is certainly an effective method because it can form a space between the ultrafine fibers and the polyurethane, and is sufficiently satisfactory for applications such as shoes and bags. However, kneading has been unavoidable in fields requiring super-softness such as clothing and clothing accessories.

Further, in JP-A-60-126384, as a method of softening a fibrous material and a sheet material mainly composed of a polymeric elastic material, a chemical bondable chemical agent is added to the fibrous material and reacted. It is shown that a highly flexible sheet-like material can be obtained. However, this method has the drawback that the fibrous substance is dissolved by the drug, and the flexibility is not so excellent. Therefore, rubbing after the treatment is necessary. As described above, there was a limit in the study on the structure of the base material.

On the other hand, various methods of softening by rubbing have been proposed. For example, a tumbler method and a method of kneading in a tensionless state by air flow conveyance have been proposed. In Japanese Examined Patent Publication No. 6-37752, a suede-like sheet is treated in water or an aqueous dye solution, and after drying, it is treated in a treatment apparatus having a kneading mechanism in an organic liquid that does not dissolve the constituent materials of the sheet, and the treatment liquid is removed. After that, a method of drying while giving a rubbing action has been proposed. A so-called tumbler system has been proposed in the embodiment as a method for giving this kneading effect.

Although this method can soften the material to a considerable extent, this method alleviates the tension state generated in the previous processing step, and rather performs the rubbing processing while shrinking the base material, and in terms of yield. It also decreases and wrinkles are unavoidable.

The so-called Yamasa kneading method, in which both ends are held and kneaded, is also suitable for softening, but it has drawbacks such as slow processing speed and wrinkles remaining on the surface. A method of hitting the surface of the base material with a stake is also performed with natural leather or the like. Since this method has a weak rubbing force, it has a drawback that the artificial leather is gradually hardened after the treatment. As a method of imparting and improving the choke mark property, a method of rubbing and then brushing the suede surface is generally used. However, in the case of an ultrafine fiber of 0.3 de or less, the fiber is stuck and entangled especially after dyeing, and brushing is required many times. It was re-polished to improve the chalk mark property.

[0008]

SUMMARY OF THE INVENTION In view of these points, the present inventors have made it simple to provide a fiber base sheet having a polyamide of at least 0.3 de and / or polyester and polyurethane having napped ultrafine fibers on at least one surface. We thoroughly studied a method of making suede-like artificial leather that is flexible, supple, and has excellent chalk mark properties by various processing methods.

[0009]

Means for Solving the Problems That is, before rubbing a fibrous base sheet made of polyamide and / or polyester and polyurethane of 0.3 de or less, a fluorine-based water repellent having no film-forming property and / or a softening agent is used. By impregnating the base material with 0.1 to 10% of the base material and drying the base material, the base material is beaten from the top and bottom of the base material while being spread and stretched by 0.5% or more of the base material width in the width direction of the base material. , And found that it can be made into a suede-like artificial leather with excellent chalk mark properties that is unprecedentedly flexible, supple, and wrinkle-free. The present invention will be described in detail below.

As the fibers that can be used in the present invention, polyamide includes nylon 6, nylon 66, nylon 610,
Nylon 12 or the like can be used. Nylon 6 is preferable. As the polyester, polyethylene terephthalate, polybutylene terephthalate, or the like can be used.

As a method of making such fibers into ultrafine fibers of 0.3 de or less, a method of spinning, stretching and crimping polyamide and / or polyester to obtain 0.3 de by a super draw method, or polyamide and / or polyester There is a method in which a fiber-forming polymer having a different solvent solubility, for example, a polyolefin and a sea-island fiber are used, and then components other than polyamide and / or polyester are extracted with a solvent to form a fiber bundle of 0.3 de or less. . In addition, after polyamide and polyester are laminated to form a composite fiber, a non-woven fabric is formed, and then 0.3 de
There is a method such as disassembling to make it ultrafine.

When the fineness of the fiber is 0.3 de or more,
The base material treated with a water-repellent agent and / or a softening agent having no film-forming property proposed by the present invention has a 0 . In that for beating the vertical of more than 5% with open-width extension, increased flexibility and chalk marks improvement is small. 0 . The effect of the present invention is greater as the ultrafine fibers are 3 de or less. Ultrafine fibers of 0.1 to 0.001 de are preferable. 0.001
If it is less than de, in the case of suede, the fibers on the surface fall off and the fastness is deteriorated.

Usually these fibers are impregnated with polyurethane,
Alternatively, in the case of a two-component fiber, a nonwoven fabric is prepared before extracting one component. As a method for forming a nonwoven fabric, raw cotton is made into a web by a card, a random weber, a cross layer, etc., and a needle punch of 800 to 3000 pieces / cm ² is applied to make a nonwoven fabric, or after being made into a web, a high-pressure water stream is used instead of the needle punch. There are various methods such as the method of dividing and entanglement the surface fibers with. All of these employ the method of the present invention.

The polyurethane with which the nonwoven fabric is impregnated contains at least one polymer diol selected from the group consisting of polyester diol having an average molecular weight of 500 to 2500, polyether diol, polyester ether diol, polylactone diol and polycarbonate diol, and an aromatic ring. A polyurethane obtained by reacting at least one kind of organic diisocyanate selected from the group including diisocyanates and alicyclic diisocyanates, which is contained, with a compound having two active hydrogen atoms as a chain extender. 100% M
Those having d of 40 to 150 kg / cm ² can be used. It is preferably 60 to 100 kg / cm ² . 40 kg /
cm ² something soft and Do Ri solvent resistance below is reduced,
If it is 150 kg / cm ² or more, the effect of rubbing decreases.

The ratio of polyurethane to non-woven fabric is important, especially polyurethane (PU) and fiber (F) in the fibrous layer.
It is necessary that the ratio of is within a certain range.

The range of PU / F × 100 = 30 to 65 is suitable. When the ratio is 30 or less, the ratio of fibers is large and the amount of polyurethane as a binder is small, so that the waist is lost,
The rubbing process deteriorates the physical properties. On the contrary, the proportion of polyurethane having a ratio of more than 65 is large, and even if it is kneaded, it has a strong rubber elasticity and cannot obtain softness. It is preferably in the range of 45 to 55.

In the case of using suede, the resin on the surface of the non-woven fabric is removed so that the thickness can be reduced to 70 to 80% of the thickness.

The polyurethane is then solidified in the fibrous layer . As a coagulation method, a wet coagulation method is preferable in terms of imparting softness. However, in recent years, the quality of water-based urethane has been improved, and it is possible to impregnate the water-based urethane with a formulation that prevents migration and dry it to form a solidified structure with a good texture.

Thus, a composite fibrous sheet of non-woven fabric and polyurethane is completed, and if necessary, the fibers can be subjected to an ultrafine treatment. The solvent varies depending on the type of fiber used, but the solvent composition does not dissolve the residual fiber component and polyurethane.

In the case of a suede tone, a liquid that dissolves polyurethane is applied to the solidified surface, and then the surface can be polished. Solvents for polyurethane include dimethylformamide, diethylformamide, and diethyl acetate.
Seto, dimethyl sulfoxide, a solvent such as tetrahydrofuran, or can be used as a mixture of water, alcohol, and methyl ethyl ketone thereto. As a coating method, a gravure coater, a spray, or the like can be used. Usually, it is desirable to perform the nip of the substrate with a gravure roll.

As polishing, sandpaper having a fine mesh is desired when short naps are desired, and sandpaper having a coarse mesh is appropriately selected and combined when long naps are desired. Normally, use a 150-800 mesh one
Polish ~ 3 times.

These substrates can be dyed if necessary. When polyamide is used as the fiber, it can be dyed at 80 ° C. or higher by mainly using a metal-containing dye and an acid dye.

In the case of polyester, disperse dyes can be used for high-pressure dyeing. There are various dyeing methods such as a circular method, a jigger method, a wind method, and a pad jig method, and the method is appropriately selected depending on the application and rod size. Circular is preferable for the uniformity and stability of the surface dyeing.

The fibrous sheet thus obtained is processed by the method of the present invention. That is, a fluorine-based water repellent and / or a softening agent having no film-forming property was added to a fibrous sheet base material composed of a polyamide and / or polyester ultrafine fiber of 0.3 de or less and polyurethane, respectively. It is a method of impregnating the base material from above and below while impregnating 1 to 10% of the base material and drying it, and then spreading and extending the base material width by 0.5% or more in the width direction of the base material.

Here, it is necessary to add 0.1 to 10% of each of the fluorine-based water repellent and / or the softener having no film forming property.

[0026] The no film-forming, solid content after drying at 100 ° C., refers to those or a liquid, or a mass shape as easily into powder by hand. As the fluorine-based water repellent, there are fluorine water repellents such as perfluoroacrylate (water repellents such as Asahi Glass, Dainippon Ink and Sumitomo 3M), which can be easily determined by obtaining them and drying. As the softener, any general softener may be used,
For example, there are amine salt type softeners, quaternary ammonium salt type softeners, silicone type softeners, lanolin type softeners, phosphate ester type softeners, etc., but it is necessary that they have no film forming property. The spreading ratio in the width direction is 0.
5% or more is required, and if it is less than 5%, satisfactory flexibility and choke mark property cannot be obtained.

When the rubbing process is carried out by the above-mentioned method of the present invention, the sued-like sheet not only has the fibrous layer appropriately rubbed to improve the flexibility, but also the napped fibers are beaten from the surface by the impact of beating. Choke mark property is improved at once by the variation.

The effect can be achieved by using a stretching machine manufactured by CARTIGLIANO, for example.

If brushing is further applied, turbulence is adjusted and an elegant suede-like surface is obtained. The reason why the method of the present invention is effective is to estimate that
For the fibrous sheet impregnated with a water-repellent agent and / or a softening agent having no film-forming property, since it is stretched in the width direction at the same time as beating, the interface between the fiber / fiber and the fiber / polyurethane is stretched, and the adhesion point It is considered that the water-repellent agent and / or the softening agent covers the adhesion points and the flexibility is improved as the resin comes off. Further, since it is an ultrafine fiber of 0.3 de or less, it is presumed that the bonding point easily comes off with a small force, and therefore an effect that cannot be obtained with ordinary fiber is exerted. Fiber / fiber, fiber /
It is believed that polyurethane has a large effect of breaking adhesive points and softening. In a rubbing process using a tumbler method or air flow transfer, this stretching force in the width direction does not work,
Flexibility is limited.

The choke mark property is 0.3d.
Since the ultrafine fibers of e or less have a significantly low fiber modulus, the napped fibers are laid face down on the surface, especially after dyeing, or they tend to stick like a brush tip after use. . If a beating effect is exerted from the surface while spreading and stretching 0.5% or more in the width direction in such a state, it is possible to easily fluff or disperse. In particular, it is considered that the treatment of a fluorine-based water repellent or a softening agent having no film-forming property lowers the coefficient of friction between fluffs and improves the choke mark property.

As described above, when processed by the method of the present invention, a suede-like artificial leather excellent in flexibility and chalk mark property can be obtained.

The method of the present invention is a method that has not been used in suede-like artificial leather until now, is completely unpredictable, and is based on a new idea.

[0033]

EXAMPLES Next, specific examples will be described, but the invention is not limited thereto. The percentages used here are based on the weight of the substrate.

[Example 1] Nylon 6 and low density polyethylene chips were mixed at 50:50.
Of was molten mixed spun at a ratio, stretching, crimping, cutting, 7.
5 de x 51 mm raw cotton was made. Stacked with cards and cross layers, 1400 needles with 3 barbs /
Needle punch with a needle density of cm ² and a basis weight of 570 g /
A non-woven fabric having a thickness of m ² and a thickness of 2.5 mm was prepared. This non-woven fabric was heated in a dryer at 150 ° C. and fixed by cooling nip with a metal roll at 90 ° C. The basis weight of this product is 565 g / m.
^{2. The} thickness was 1.75 mm.

Next, 920 g / cm ^{2 of} a polyurethane DMF solution prepared by adding a coagulation modifier to a 15% polyurethane concentration of 100% Md = 110 kg / cm was impregnated, and the surface was squeezed to 75% of the substrate thickness to form a polyurethane. After removing the resin, the resin was coagulated in a 10% DMF water bath and dried at 140 ° C. Thereafter, dipping and nip were repeated with toluene at 80 ° C. to extract polyethylene. Unit weight is 440g / c
It was m ² . This product had PU / F × 100 = 48.

One roll of DMF of 200 mesh was coated on both sides of this substrate, dried and then both sides were ground with 320 mesh sandpaper, and further polished with 180 mesh sandpaper from the opposite direction to form a fine ultrafine surface. A suede-like base material having napped nylon fibers was prepared.

[0037] The substrate was sliced into half the thickness was 1 roll coating a 200 mesh grayed Labia role of solvent DMF / MEK = 70/30 to the slice plane.

This product was dyed in beige with a metal-containing dye. However, it was bone-like, paper-like, and had almost no chalk mark. In addition to this, as a fluorine-based water repellent, Dickguard F-90C (manufactured by Dainippon Ink and Chemicals) and as a silicone-based softener, Silcoat F
ZS (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd.) was added to each base material in an amount of 0.
It was made to adhere so that it might be 35% and 0.9%, and was dried. This base material was placed on a stretching machine manufactured by CARTIGLIANO, and was stretched by spreading and beaten from the surface, and the conditions were set as follows. Width before processing = 138 cm Width after processing = 140 cm Spreading ratio = 1.4% When brushed on this material, it had good flexibility and very good choke mark property.

[Comparative Example 1] Dyeing-water repellent, softener treatment,
Drying was carried out in the same manner as in Example 1, and brushing was performed without using a stretching machine. This product had bone tension and had almost no chalk mark property.

COMPARATIVE EXAMPLE 2 Nylon 6 and low density polyethylene chips were mixed at 50:50.
And molten mixed spun at a ratio of stretching, crimping, and cutting, 8d
An e × 51 mm raw cotton was made. Stacked with cards and cross layers, 1400 needles / cm with 3 barb needles
And needle-punched by ^two needle density, basis weight 650 g / m ^2,
A non-woven fabric having a thickness of 3.5 mm was prepared. This non-woven fabric 15
It was heated in a dryer at 0 ° C. and fixed by cooling nip with a metal roll at 90 ° C. The basis weight of this product was 653 g / m ² , and the thickness was 1.60 mm.

Then, 1050 g / cm ^{2 of} a polyurethane DMF solution prepared by adding a coagulation modifier to a 15% polyurethane concentration of 100% Md = 270 kg / cm was impregnated, and the surface was squeezed to 75% of the substrate thickness to form polyurethane. After removing the resin, the resin was coagulated in a 10% DMF water bath and dried at 140 ° C. Thereafter, dipping and nip were repeated with toluene at 80 ° C. to extract polyethylene. Unit weight is 480g /
It was cm ² . This product had PU / F × 100 = 48.

Two rolls of DMF with 200 mesh were coated on both sides of this base material, dried, and then both sides were polished with 600 mesh sandpaper, and further polished with 1000 mesh sandpaper from the opposite direction to form a fine ultrafine surface. A suede-like base material having napped nylon fibers was prepared.

This product was dyed brown with a metal-containing dye. Furthermore, DIC GUARD F-90C (manufactured by Dainippon Ink and Chemicals Co., Ltd.) as a fluorine-based water repellent and Silcoat FZS (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd.) as a softening agent were used in amounts of 0.3% and 1%, respectively. Dip and nip were carried out so that it might be set to 0.0%, it was made to adhere, and it dried.

This base material is put on a stretching machine,
Along with the spreading and stretching, the material was beaten from the surface and processed under the same conditions as in Example 1. The processing result of the product itself was as follows. Width before processing = 140 cm Width after processing = 140.5 cm Spreading ratio = 0.35% When this was brushed, it had little flexibility and poor choke mark property.

Comparative Example 3 A nonwoven fabric having a basis weight of 560 g / m ² and a thickness of 1.90 mm was prepared in the same manner as in Example 1. Next, 1060 g / cm of a polyurethane DMF solution prepared by adding a white toner and a silicone-based coagulation regulator to a 15% polyurethane concentration of 100% Md = 110 kg / cm.
^{2. After} impregnation, the surface was squeezed to 70% of the substrate thickness to remove the polyurethane resin, then coagulated in a 10% DMF concentration water bath, and dried at 140 ° C. Thereafter, dipping and nip were repeated with toluene at 80 ° C. to extract polyethylene. The basis weight was 445 g / cm ² . Two rolls of DMF with 200 mesh were applied on the surface of this substrate, and after drying, 3
Polish with 20 mesh sandpaper, then 400
Polishing from the opposite direction with a sandpaper of mesh, a suede-like base material having fine ultrafine nylon fibers raised on the surface was prepared. Teflon ZON with film forming properties
YL7040 / Beckamine AMP / Catalyst 376
Prepare an aqueous dispersion of 70% to 80% with dips and nips
Impregnation was performed so that the adhesion rate was achieved. Teflon ZONYL70
The adhered amount of 40 was 1.6%. This thing 150 ℃
It was dried for 4 minutes with the dryer. This product had a sticky surface and had no suede feeling. This was subjected to a rubbing process under the same conditions as in Example 1, but there was no flexibility and the chalk mark property was hardly recovered.

[0046]

If processing is performed by the method of the present invention,
The ultrafine fiber napped sheet composed of polyamide and / or polyester fiber of 0.3 de or less and polyurethane is not only capable of removing the sticking of the ultrafine fibers on the surface, but also greatly improved in flexibility, is super soft and has a chalk mark property. Can be made of good suede- like artificial leather.

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-56-68171 (JP, A) JP-A-56-159369 (JP, A) JP-A-56-154581 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) D06N 3/00-3/18

Claims (4)

(57) [Claims] 1. A suede-like artificial leather which is flexible and has good choke mark properties is produced by rubbing a fibrous sheet substrate made of polyamide and / or polyester ultrafine fibers of 0.3 de or less and polyurethane having naps on at least one side. In the method described above, a fibrous sheet base material having naps before rubbing is impregnated with a fluorine-based water repellent and / or softening agent having no film-forming property in an amount of 0.1 to 10%, and dried. Then, 0.5% of the width of the base material in the width direction of the base material
A method for producing a suede-like artificial leather, which comprises beating from above and below a substrate while spreading and stretching. 2. A weight ratio (hereinafter referred to as PU / F × 100) of polyurethane (hereinafter referred to as “PU”) and fibers (hereinafter referred to as “F”) as a base material before rubbing is 30 to 65. The method for producing a suede-like artificial leather according to claim 1, wherein 3. A 100% elongation modulus (hereinafter referred to as "Md") of the polyurethane impregnated in the base material before the rubbing process.
Say. ) Is Suedo adjustment process for producing an artificial leather according to claim 1 or 2, wherein it is 40~150kg / cm ^2. 4. The method for producing a suede-like artificial leather according to claim 1, wherein the base material before rubbing is a dyed base material.