JPS5911713B2 - Suede-like artificial leather with excellent mottling effect and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a suede-like artificial leather with excellent mottling effect and a method for producing the same.

Natural suede leather has a unique texture and appearance due to its internal structure made up of collagen fibers and the surface hair layer, and has an elegant appearance due to its chalk mark properties.

Chalk mark property here refers to the property that when the surface of suede is touched, the luster and color tone of that area changes.

This is said to be due to the fact that the naps of the ultra-fine collagen fibers on the suede surface easily change their direction due to external force.

Due to this chalk mark property, natural suede has a so-called mottle effect (with a natural depth and three-dimensional feel) where areas of different luster and tones are mottled at first glance.
It has a surface appearance with a rich mottled pattern effect.

A number of methods have been proposed for producing human varnished suede, which has a texture and appearance similar to natural suede, and the necessity of a surface layer made of ultra-fine fibers as a technical element has been clarified.

For example, Special Publication No. 49-48583, Special Publication No. 51-626
The techniques disclosed in Japanese Patent Laid-Open No. 48-92650 and the like are representative examples.

However, although the human varnished suede created by these techniques does have some chalk mark characteristics, its appearance is inferior when compared to natural suede, especially when it comes to creating depth and three-dimensionality due to the mottle ring effect. In order to compensate for the lack of mottle ring effect of Nisneed,
From the beginning, an attempt has been proposed to produce this effect by creating patches of long fluff and short fluff in the surface hair layer of human varnished hair (Special Publication No. 48-20286).゜20287).

Although this method does provide a mottled appearance, the following problems have been pointed out.

When human varnished needles are impregnated with a large amount of polyurethane, the polyurethane at the base of the raised hairs may be exposed in the partial areas formed from short fluffs of the surface hair layer, damaging the appearance. It was also found that when woven fabrics were made from human varnished needles, the woven structure became more visible.

Also, the distribution of the piloerection length should not be sufficiently controlled (and the mottling effect will become too strong, giving an unnatural feel).

The present invention was completed as a result of extensive research into imparting an elegant mottling effect to human varnish needs.

The suede-like artificial leather of the present invention having an excellent mottle ring effect includes a base layer made of a sheet-like fiber material and at least one layer thereof.
It has a raised layer formed on the surface mainly consisting of ultrafine fibers of 0.01 to 0.4 denier, and the raised layer has a large number of parts each adjacent to the other and each having an arbitrary shape and area. The direction of the nap of the ultrafine fibers in each subarea is different from the nap direction of the ultrafine fibers in other subareas adjacent to this subarea. It is characterized by exhibiting a light reflection/absorption property different from that of the partial region.

In addition, in the method of manufacturing suede-like artificial leather with excellent mottling effect according to the present invention, the method of manufacturing suede-like artificial leather with excellent mottling effect mainly includes applying a 0.01 to 0.4
Forming a sheet-like body having a napped layer made of ultrafine denier fibers, and forming a sheet-like body having a napped layer made of ultrafine fibers of denier, and forming a plurality of partial areas of the napped layer, each adjacent to the other and each having an arbitrary shape and area,
The ultrafine fibers in each partial area are given a different napped direction from the ultrafine fibers in other partial areas adjacent to this area, and then this napped layer is subjected to heat treatment or resin processing to make each ultrafine fiber napped. It is characterized by fixing the direction of.

The artificial leather of the present invention is characterized by the fact that the direction of the raised naps on the suede surface differs from region to region, so that the effect of reflection and absorption of light rays differs from region to region, resulting in a mottled luster and color tone. This is a point that brings about change.

This effect is very similar to the mottling effect observed in natural suede leather, and as a result, the product of the present invention has a natural depth and three-dimensional appearance, and is of high quality.

The sheet-like body used in the method of the present invention has a surface of 0.
Any material having a nap layer mainly composed of ultrafine fibers of 0.01 denier to 0.4 denier may be used.

Generally, a non-woven fabric or knitted fabric made of ultra-fine fibers or so-called latent ultra-fine fibers that can be developed into ultra-fine fibers through processing such as extraction or splitting is used as a base material, and this is treated with a napping process or, if necessary, elastic material such as polyurethane. It is obtained by impregnating with resin.

A specific example of such a sheet-like body is the Japanese Patent Publication No. 49-4858
No. 3, JP-A-48-92650, JP-A-52-107
368, JP-A-53-78373, JP-A-53-318
It is disclosed in No. 66, etc.

The mottled pattern in the artificial leather of the present invention is imparted due to the difference in the direction of the raised naps.

Conventional suede-like napped sheets have a very uniform surface when the napped hair is smoothed in one direction, for example in the grain direction, with a brush or the palm of the hand, exhibiting uniform color tone and luster, and a flat, flat appearance. .

Also, brushing in the opposite direction will result in a very rough surface.

This is because all the fibers are directionally raised in a certain direction during the raising process using a cloth raising machine, a sandpaper puff machine, or the like.

In the present invention, the direction of the nap is different and fixed for each partial area on the sheet surface, so even if the sheet is brushed in a fixed direction, the direction of the nap for each partial area will be normal or reverse. Since these partial areas with different directions of raised hair are mixed together, the gloss and color tone change for each partial area, so that it does not give the impression of being flat.

In the present invention, the directionality of the raised hair is not temporary but durable, and even if brushing is repeated, the mottling effect continues.

The sheet-like material used in the present invention is capable of forming ultrafine naps of 0.01 to 0.4 denier on the surface by puffing or raising, and is composed of interlaced nonwoven fabrics mainly composed of ultrafine fibers, and mainly those with excellent napping properties. Typical examples are woven and knitted fabrics made of ultrafine fibers.

Further, the sheet of the present invention may be a composite impregnated with an elastic polymer such as polyurethane. Examples include polyvinyl alcohol-based fibers and cellulose-based fibers, which are made into ultrafine fibers by known methods.

In the present invention, these fibers form naps on the sheet-like surface as ultrafine fibers of 0.01 d to 0.4 d.

It is important that the thickness of the fibers be within this range.

If it is too thick, it will give a rough and hard surface, which is not desirable as artificial leather.

It also tends to deteriorate the feel and make it difficult to provide good chalk mark properties.

On the other hand, if it is less than 0.01 d, the fibers will become too fine and will be difficult to cut during raising to give a good nap, and the fibers will become tangled easily, which is not preferable.

The sheet-like product of the present invention includes a step of raising a base sheet, a step of changing the direction of the raised ends of the raised surface in a mottled manner for each region,
Next, this directionality can be obtained by taking a step of fixing it by heat treatment or resin processing.

When the base sheet is a nonwoven fabric, raising with a puff is suitable.

In addition, in the case of knitted or woven fabrics, raising using cloth is appropriate.

Bringing the raised surface into contact with a flat or curved surface having an uneven pattern, or randomly and intermittently colliding the raised surface with air flow or liquid ejected from a nozzle, or Vigorous rubbing in the liquid creates a mottled disorder on the piloerection surface.

Further, it is also possible to perform heat treatment at the same time when giving a mottled disorder and forming fiber napped regions with different napped directions.

When a flat or curved surface having the above-mentioned uneven pattern is heated, and when the fluid ejected from the nozzle is a heated fluid, the napped fibers are directed at the same time as they are heat-fixed in that direction. A mottled orientation of durable napped fibers can be obtained.

The mottled disturbance is caused by the difference in the directionality of the raised hair in each partial area, and the pattern and degree of strength are set by appropriately selecting the above-mentioned processing conditions.

By these treatments, only the direction of the nap is changed, and the nap itself is rarely damaged or cut.The obtained mottled pattern is then fixed by heat treatment or resin processing.

Heat treatment is particularly effective when the ultrafine fibers that form the napped fibers are made of thermoplastic polymers such as polyester or polyamide, and the temperature is generally higher than the secondary rearrangement temperature of the napped fibers.
Treated under temperature conditions below the softening temperature.

For the treatment, it is appropriate to bring the napped layer into contact with a heating roll or to heat it with hot air.

The processing time is set arbitrarily. For example, in the case of raising polyethylene terephthalate, the heat treatment temperature is 150-190.
℃, and the appropriate treatment time is 1 to 10 seconds when using heated rolls, and 10 to 120 seconds when using hot air.

Fixation by resin processing is effective for raising the nap of all materials, including cellulose fibers that cannot be heat fixed.

Resin processing is carried out by impregnating the patterned base material with a resin solution, resin emulsion, or tispersion, and then solidifying and fixing it.

The resin suitable for this resin processing is preferably one made of an elastomer polymer, and for example, polyurethane, acrylic rubber, butadiene rubber, polyester elastomer, nylon nystomer, etc. can be used as appropriate.

The important point in this case is to protect the nape from the resin.

If too much resin is attached to the nap, the original suede effect of the nap layer made of ultrafine fibers will be impaired.

For this purpose, there are two methods: applying resin impregnation from the back side and attaching it only to the roots of the nape, or applying a protective glue to the nape layer in advance, impregnating it with resin, and removing the glue after solidification. It is preferable.

The amount of resin can be arbitrarily adjusted depending on the type and use of the base material, but a range of 2 to 100% by weight is applied to the base material.

If the base material is a nonwoven fabric, the weight ratio is 20 to 100, knitted fabric,
In the case of textiles, a weight ratio of 2 to 20 is preferred.

The artificial leather obtained by the present invention can be used for clothing, shoes, bags, interior goods, building materials, etc., and gives products with a three-dimensional effect.

Further, depending on the intended use, known processing such as dyeing can be performed.

Next, the present invention will be explained in more detail by giving examples.

Example 1 Polyethylene terephthalate chips having an intrinsic viscosity of 0.66 (0-chlorophenol at 35°C) were melt-spun by a conventional method to obtain an undrawn yarn of 480 denier/266 filaments.

This undrawn yarn was stretched 3.5 times while heating at 130°C,
The film was further stretched 2.6 times on a roller at 75°C, then heat-treated on a hot plate at 150°C, and then rolled up.

The unstretched supply speed was 9 ml/min.

The obtained drawn yarn has a single yarn fineness of 0.2 denier, a number of filaments of 266, and a strength of 2.5? /denier, elongation was 36.

The filaments were gathered into a tow shape and cut into short fibers with a length of 4M using a cutter.

The short fibers were dispersed in water to form a slurry with a concentration of 0.1.

This slurry was added to the middle layer using a two-layer paper machine.
? /rr? A coarse woven fabric (polyethylene terephthalate 75d/36f, 1.000 T/m strong twist yarn warp) is inserted into the paper sheet to produce short fiber paper sheets/woven fabrics/
A three-layer laminated sheet of short fiber paper sheets was obtained.

The fabric weight of both the upper and lower layers in this paper-made sheet is 80 g/rr.
? Closed.

Next, apply 0.2r to the entire front and back surfaces of this three-layer sheet.
A high-pressure columnar water stream ejected at 8 KV/crA from a nozzle with a diameter of rarL was applied, and the entire surface of the front and back of the sheet was treated with a high-pressure water stream of 25 K4/crA to obtain an entangled sheet.

Next, the surface of the interlaced sheet was puffed and raised with 240 mesh sandpaper.

Next, it was impregnated with a 10% aqueous solution of polyvinyl alcohol and dried to provide PVA with a solid content of 10%.

Furthermore, a 20% aqueous solution of carboxymethyl cellulose was coated on the raised surface and dried.

The amount of CMC applied to the entangled sheet is 30% as solid content.
f/? ? It was Z2.

Furthermore, it was impregnated with a 15 DMF solution of polyurethane elastomer, then coagulated in water, and then washed in hot water to dissolve and remove soluble components.

A leather-like sheet containing 40 parts of polyurethane di-stomer and having uniform raised naps on the surface was obtained.

After brushing the resulting leather-like sheet in a certain direction to straighten the raised hairs, place a paper pattern perforated in a random pattern on the raised surface, and brush the paper pattern from above in the opposite direction to the direction of the hair arrangement. The paper pattern was brushed to make the direction of the nap in the hole area of the pattern opposite to the direction of the nap in other areas, and then the sheet was brought into contact with a roll heated to 185° C. for 5 seconds.

Next, it was dyed with disperse dye and further reduced and washed.
A suede-like artificial leather with a motu ring effect corresponding to the paper pattern was obtained.

On the other hand, the leather-like sheet was vigorously rubbed in hot water at 130°C for 30 minutes, dried, and then heat-treated for 45 seconds using a pin tenter at 185°C.

Next, it was dyed with a disperse dye at 130°C, and the excess dye was further decomposed and removed by reduction washing.

In the napped layer of the obtained sheet, the napped direction differs from region to region, and speckled glossy spots with an average size of about 3c4 were observed over the entire surface of the sheet, and an extremely favorable mottle tone was observed, giving a three-dimensional effect. It was a suede-like sheet with a rich appearance.

Example 2 Nylon 6 as island component (relative sulfuric acid viscosity ηr=8.2
) and 60 parts by weight of polystyrene (Styron GP-679 manufactured by Asahi Dow Co., Ltd.) as the sea component to obtain sea-island fibers.

The sea component of this sea-island fiber was extracted with chloroform at 50°C, and the single yarn denier was 0.3 d and the fiber bundle denier was 15 d.
An ultrafine fiber bundle was obtained.

Next, this ultrafine fiber bundle was treated with steam at 3 kg/crA to fuse the single fibers together, and then cut into 35 pieces using a drawing machine to avoid crimping. It was a table.

This stable is made into a random web using a card machine and cross-layered with a basis weight of 100 g/lr? and 50g/r
r? Two types of cross-laid webs were made, and a woven fabric made of gauze-like polyester fibers of 30 d/24 f with a basis weight of 45 f/m was sandwiched between the two types of cross-laid webs to form a sheet with a three-layer structure.

This three-layered sheet was needle-punched 1500 times/1nch2, and then a high-pressure water stream of 60 Kq/crA was ejected from a nozzle with a pore diameter of 0.10%, and was sprayed all over the front and back of the sheet, so that the fibers were mutually bonded. were sufficiently confounded.

The resulting interlaced sheet was puffed with 240 mesh sandpaper to raise it.

After brushing the brushed surface to evenly condition the hair, apply 0.5%
A pattern was created by intermittently blowing an air stream at a pressure of IKf/cni onto the surface of one sheet from a nozzle with a hole diameter of 1,000 psi, and randomly changing the direction of the nap in each partial area.

Next, the sheet was impregnated with a 10% polyvinyl alcohol aqueous solution.

The sheet was suctioned from the back side, the liquid was squeezed out, and the sheet was dried.

The amount of PVA attached was 9.5, and the raised surface was further coated with carboxymethyl cellulose in the same manner as in Example 1, and polyurethane was similarly impregnated and coagulated, followed by hot water extraction.

The obtained sheet was dyed with a disperse dye at 130° C., and then subjected to reduction cleaning using a conventional method.

The resulting sheet was an elegant suede-like artificial leather with a fixed direction of raised naps that varied randomly in each partial region, and an excellent appearance with a mottle-like appearance.

Claims (1)

[Scope of Claims] 1. A base layer made of a sheet-like fiber material, and a napped layer formed on at least one surface of the base layer and mainly made of ultrafine fibers of 0.01 to 0.4 denier, the napped layer comprising: It has a large number of partial regions, each adjacent to the other, and each having an arbitrary shape and area, and the direction in which the ultrafine fibers in each partial area are raised is the same as the napped direction of the ultrafine fibers in the other partial areas adjacent to this partial area. A suede-like artificial leather having an excellent mottle ring effect, characterized in that each partial region exhibits a light reflection/absorption property different from that of other adjacent partial regions. 2. A sheet-like body having a nap layer mainly made of ultrafine fibers of 0.01 to 0.4 denier is formed on at least one side of a base layer made of a sheet-like fiber material, and each of the nap layers is adjacent to the other. and for a large number of partial regions each having an arbitrary shape and area, giving the ultrafine fiber napped in each partial area a different direction of napped ultrafine fibers from the ultrafine fiber napped in other partial areas adjacent to this partial area. A method for producing suede-like artificial leather with an excellent mottle ring effect, which is characterized in that the napped layer is then subjected to heat treatment or resin processing to fix the direction of each ultrafine fiber napped layer.