JPH0995700A - Production of soft leather product and treating agent for soft leather - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a soft leather product prevented in the generation of deformation and creases and improved in shape retainability. SOLUTION: This method for producing the soft leather product comprises preparing the solution of a norbornene polymer, coating the front and back surfaces of a leather with the prepared solution as a shape-retaining agent in a solid content rate of 80-200g/m<2> , cutting the treated leather, sewing the cut leather, hanging the sewed product in a wooden mold, heating the hung product at 100-150 deg.C, once gradually cooling the leather product, and subsequently treating the cooled leather product with 120-180 deg.C air.

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 soft leather product and a treatment material for soft leather, and more particularly to a method for producing a soft leather product which prevents deformation and wrinkles which are likely to occur in the production process. The present invention relates to a processing material for soft leather.

[0002]

2. Description of the Related Art When manufacturing leather products such as shoes and bags, wrinkles are easily formed when sewing after cutting leather.
In addition, wrinkle recovery due to water absorption can be easily caused by an aqueous finish after sewing. Further, since the thickness, elasticity and flexibility of the leather are different depending on the cut portion of the leather, deformation such as depression is likely to occur due to these differences. In particular, soft leather products often suffer from deformation and wrinkles.

Conventionally, a coating film of an acrylic resin emulsion is formed on the back surface of leather, and the strength of the resin coating film holds the shape of the leather product. Alternatively, a method is known in which an acrylic resin emulsion is penetrated into the leather to fix the leather fibers.

[0004]

In the conventional method using a coating film of an acrylic resin emulsion, since it is a partial shape-retaining for increasing the strength of the resin coating film, a uniform shape-retaining property is obtained over the entire mold. However, it is used only for the partial hardness adjustment of leather products.

Further, although the method of permeating the acrylic resin emulsion can prevent the deformation of the leather to some extent, the leather becomes hard. In particular, soft leather loses its flexibility and loses its unique texture.

Therefore, in the production of soft leather products,
A technical problem to be solved occurs in order to prevent deformation and wrinkling and improve the shape retention, and the present invention aims to solve this problem.

[0007]

The present invention has been proposed in order to achieve the above object, and a solution of a norbornene-based polymer is applied to the back surface of leather as a solid content of 80 to 200 g /
After coating at a ratio of m ^2, the leather is cut and sewn, fished into a wooden mold, heated at 100 to 150 ° C., and the leather is allowed to cool once and then treated with hot air at 120 to 180 ° C. Method for producing soft leather product and 1 to 6% by weight
The present invention provides a treatment material for soft leather, which comprises the norbornene-based polymer solution.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The norbornene-based polymer used in the present invention is
It is a high molecular weight polymer obtained by ring-opening polymerization of a norbornene-based polymer such as norbornene, methylnorbornene, ethylnorbornene, and ethylidenenorbornene according to a conventional method, and has a characteristic of retaining a shape. Deformation is given in the flow region above the glass transition temperature (Tg), and when the temperature is below the glass transition temperature (Tg), the deformation is maintained.

For example, "Nosolex" (manufactured by Nippon Zeon Co., Ltd.), which is commercially available as a ring-opening polymer of norbornene.
Has a glass transition temperature (Tg) of about 35 ° C,
When it is deformed at a higher temperature and cooled to room temperature, it retains the deformed shape.

Therefore, it is intended to prevent the deformation and wrinkling of the leather product by applying the norbornene-based polymer as a solution to the leather. Also,
It may be used as a mixture with other polymers as long as the above properties are not impaired.

In the present invention, the norbornene-based polymer is used as a solution by dissolving it in a solvent such as benzene, toluene or xylene. The norbornene-based polymer solution is preferably used in an amount of 1 to 6% by weight. this is,
If the amount is less than 1% by weight, the effect of the present invention cannot be achieved.
This is because it is difficult to adjust the solution and the effect cannot be expected for the cost.

Now, 1 to 6% by weight of a norbornene-based polymer solution is prepared as a shape stabilizer (hereinafter, this concentration of the norbornene-based polymer solution is simply referred to as a "shape stabilizer"), and this shape stabilizer is used as a calf or a sheep. The amount of 80 to 200 g / m ² in terms of solid content is applied to the back surface of the soft leather. By applying the shape stabilizer, the resin component penetrates into the leather and is entangled and fixed to the leather fibers.

This is because when it is 80 g / m ² or less, there is little improvement in shape retention such as product deformation and wrinkling, and 200 g / m 2
^{Even if it is 2} or more, there is no result of improvement for the cost, and workability and texture are inferior.

After being left for several hours to 2 days,
The leather is cut and sewn and fished into a wooden mold. While fixed in a wooden mold, heating is usually performed at 100 to 150 ° C. for 3 to 10 minutes to form a leather product. Further, this leather product is once allowed to cool at room temperature and then treated with hot air at 120 to 180 ° C. for usually 10 to 60 seconds.

This is because the coating effect becomes weaker at the above temperature or lower, and the product quality may be adversely affected at the temperature or higher. And after the hot air treatment,
In order to improve the surface appearance (glossiness) of leather products such as shoes, an aqueous finishing treatment is performed with a known finishing agent such as wax or lacquer.

The soft leather product manufactured through the above steps remembers its shape and is stably retained, so that deformation such as sagging is less likely to occur, and even if it is subjected to an aqueous finish, it has a moisture content. Very little wrinkle return due to absorption.

[0017]

Example Here, "Nosolex" (manufactured by Zeon Corporation) commercially available as a ring-opening polymer of norbornene was dissolved in toluene to prepare a 2% by weight polynorbornene solution. 70 g / m ² , 85 g / m ² , 100 g / m of this solution as polynorbornene on the back side of the sheep leather for shoes.
The coating solution was applied so as to have a m ² of 125 g / m ² and left at room temperature for 1 day. For comparison, a sample prepared by not applying the polynorbornene solution at all was also prepared.

The above sheep leather was tested for hemispherical plasticity (J
The test was performed according to IS K-6546). (1) Each of the above sheep leathers was punched out into a circle having a diameter of 9 cm to obtain a test piece. (2) Each test piece was pushed up to a height of 13 mm with a hemispherical plasticity tester. (3) Then, with each test piece pushed up by 13 mm, 12
The mixture was heated in a constant temperature bath at 0 ° C. for 5 minutes, taken out from the constant temperature bath, and then left at room temperature for 3 hours. 13mm for each test piece
A sample was also prepared which was left at room temperature for 3 hours without being heated while being pushed up. (4) The test piece heat-treated in (3) above was further processed for 150
Hot air treatment was performed at 30 ° C. for 30 seconds. (5) Each test piece taken out from the hemispherical plasticity tester was applied with a mixed finishing agent of an acrylic resin emulsion and a wax emulsion for aqueous finishing. still,
The one without the water-based finish was also prepared. (6) The drop in height of each of these test pieces is measured, and the drop rate from the initial height of 13 mm is calculated by the following formula.

[0019]

[Equation 1]

Table 1 shows the results of measuring the drop rate on the 21st day when no change was observed after setting.

[0021]

[Table 1]

The test pieces coated with the shape stabilizer in an amount of 200 g / m ² or more did not differ much from the test pieces according to the present invention in the drop rate, but they were prone to stains during coating and became too hard and had a poor texture. There are problems such as deterioration and distortion of the figure.

As shown in Table 1, the test piece to which the shape stabilizer was not applied had a large drop rate, that is, a large amount of deformation and wrinkles due to the drop even when the heat treatment according to the present invention was performed. It did not reach far below the target value of 25% (the test piece of Comparative Example 2).

On the other hand, even when the shape stabilizer was applied, the drop rate did not reach the target value of 25% when the heat treatment according to the present invention was not performed (Comparative Example 4).
Test piece).

Further, while the test pieces according to Comparative Example 1 did not reach the target value, the test pieces according to Examples 1 to 3 were not significantly affected by the presence or absence of the aqueous finish, and any of them fell. The target rate was 25% or less.

That is, when the shape stabilizer treatment and the heat treatment are performed in the manufacturing process, the drop rate is 2 as described above.
It becomes 5% or less, and the drop rate can be reduced by 10% or more compared to the conventional case. For this reason, the work of reworking the leather product has been required at a considerably high rate in the past, but the rework work of the present invention can be reduced to 1/10 or less of the conventional work, and the workability can be greatly improved.

As a result, for example, a shoe manufactured by applying a shape stabilizer and then subjecting it to a heat treatment step has less drop in the boundary between the leather of the toecap portion of the shoe and the toecap material and the surrounding leather, and There is no wrinkle and deformation of the mouth, so it can be prevented from deforming, further, without losing the texture of soft leather,
It has been found that a stable shape can be retained.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0029]

As described above, according to the present invention, in the production of soft leather products, preferably 1 to 6% by weight of a norbornene-based polymer solution is prepared as a shape stabilizer, and the shape stabilizer is used as the back surface of the soft leather. The shape of the leather product is memorized and stably maintained by applying a heat treatment under specific conditions after the application to the. Therefore, deformation such as wrinkles and sagging does not occur, and wrinkles are not returned by absorption of water even when an aqueous finish is performed.

Thus, the shape retention and the commercial value of the soft leather product can be improved without impairing the texture of the soft leather.

Claims (2)

[Claims] 1. A norbornene-based polymer solution is applied as a solid content to the back surface of leather at a rate of 80 to 200 g / m ² , and then the leather is cut and sewn and fished into a wooden mold.
A method for producing a soft leather product, which comprises heating at 0 to 150 ° C., allowing the leather to cool once, and then treating with hot air at 120 to 180 ° C. 2. A treatment material for soft leather comprising a norbornene-based polymer solution of 1 to 6% by weight.