JPH0250233B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a synthetic leather that is bulky, voluminous, and lightweight, and more specifically, has characteristics of being bulky, voluminous, yet lightweight, and has sufficient physical properties to withstand processing and use. This relates to synthetic leather that has both.

Generally, synthetic leather is made by forming a coating film of synthetic resin such as nylon or polyurethane on a substrate such as knitted fabric, woven fabric, or nonwoven fabric. By the way, these conventional synthetic leathers use ordinary fabrics such as knitted fabrics and raised fabrics as their base materials, and in some cases, in order to meet physical property requirements, the base material itself is impregnated with a synthetic resin.
Synthetic leather in general has a dense structure, is bulky, and is lightweight.

The uses of synthetic leather are extremely wide, including clothing,
This includes shoes, bags, bags, furniture upholstery such as sofas, automobile interiors, and other miscellaneous goods. These items are usually handled carelessly, rarely used with care, and are subject to considerable force such as pulling and stretching during processing and sewing. Synthetic leather is originally intended for these uses, and therefore requires physical properties that can withstand processing and usage conditions. Therefore, as mentioned above, ordinary synthetic leather attempts to satisfy these conditions by forming it into a tight structure.

By the way, some of the items for each purpose are bulky, lightweight,
There are also items that require materials with excellent heat retention. Synthetic leather having such characteristics can be obtained in appearance by forming a synthetic resin coating on a bulky nonwoven fibrous sheet without a binder as a base material. However, the bulky nonwoven fibrous sheet without a binder used here is generally one in which the fibers are entangled with each other by moderate needle punching without impairing the bulkiness, and this is used as a base material. Although synthetic resin coatings are bulky and lightweight, on the other hand, they are not satisfactory in terms of physical properties such as tensile strength and modulus for processing, sewing, and use.

In view of the current situation as described above, the present inventor completed the present invention as a result of research in order to provide synthetic leather that has both characteristics such as bulkiness, light weight, and heat retention, and physical properties such as tensile strength and modulus. This is what I did.

The present invention is based on one or both sides of a woven fabric woven with yarns of 60 denier or more and 450 denier or less in both warp and warp directions of 8 or more and 50 or less yarns/cm and a projected area fiber dot area ratio of 90% or less. A foamed synthetic resin layer is formed on one side of a bulky non-woven fibrous substrate, which has been laminated with non-woven fibrous webs and then needle-punched on one or both sides at a rate of 50 punches/cm ² or more and 300 punches/cm ² or less. and a non-foamed synthetic resin surface layer thereon, weighing 400 g/m ² or less, thickness 1.2
The present invention relates to lightweight, bulky synthetic leather having an apparent density of 0.3 g/cm ³ or less, a 20% modulus of 8 kg/3 cm or more, and a tensile strength of 10 kg/3 cm or more.

That is, in the present invention, by using a bulky nonwoven fibrous sheet as a base material by sandwiching and integrating a certain woven fabric between layers of a nonwoven fibrous web with a certain punch density, an unspecified needle can be simply formed. Even if the base material is a non-woven fibrous sheet that has just been punched, the lightweight and bulky properties of synthetic leather are not impaired in any way, and the defects in its physical properties have been successfully resolved. As a result, it has become possible to provide lightweight, bulky synthetic leather that has certain physical properties that are extremely useful for a variety of uses.

In the present invention, the strength aspects such as modulus and tensile strength have been improved by adopting a method of sandwiching and integrating the woven fabric between the layers of the nonwoven fiber web. 60
It is limited to yarns of denier or more and 450 denier or less in both warp and warp of 8 or more and 50 or less yarns/cm, and the projected area fiber space factor is 90% or less, and the nonwoven fiber web of the woven fabric is Needle punching of 50 punches/ ^cm2 or more for interlayer integration.
By limiting the number of punches to 300 punches/cm ² or less, it was possible to maintain the characteristics of light weight and bulk for the first time. In other words, the object of the present invention cannot be achieved if the inherent characteristics of light weight and bulk of the nonwoven fiber web are impaired due to the sandwiching of the woven fabric between the layers of the nonwoven fiber web and the needle punching. Depending on the structure of the woven fabric and the conditions of needle punching, it may be difficult to improve the strength.

First, the thread used to weave the woven fabric is
If it is larger than 450 denier, the bulkiness and soft feel will be lost, if it is smaller than 60 denier, there will be no reinforcing effect in terms of physical properties, and the number of yarns will be less than 50 threads/cm for both warp and weft. If there are many,
Even if the thickness of the thread is less than 450 denier, the soft feel will be lost, and on the other hand, there will be 8 threads per warp and 8 threads per weft.
This is because if the thickness is less than cm, there will be no reinforcing effect in terms of physical properties even if the thickness of the thread is 60 denier or more. On the other hand, even if the above number of implants is satisfied, if the projected area fiber space factor is not 90% or less,
Needling, which will be explained in detail below, is difficult to perform smoothly.

Next, in needle punching, if the number is more than 300 punches/ ^cm2 , the bulkiness and soft feel will be lost, and if it is less than 50 punches/ ^cm2 , the entanglement and integration of the woven fabric and nonwoven fiber web will be weak. , sufficient physical properties cannot be obtained in synthetic leather using this as a base material. Note that the needle for needle punching used in the present invention is preferably #36 to #42.

The woven fabric used in the present invention is not particularly limited as long as it satisfies the conditions for its composition; for example, it may be woven from synthetic resins such as nylon, polyester, rayon, cotton, or natural fibers alone or in combination. is raised. In addition, the constituent fibers of the non-woven fiber web to be entangled and integrated with these woven fabrics are not limited to these, and synthetic fibers, natural fibers alone or in blends may be used,
The web formation is carried out, for example, by a conventional card method.

In the present invention, the first layer of the synthetic resin layer formed on the bulky non-woven fibrous substrate is a foam layer, which hides the unevenness of the substrate surface and is suitable for use as synthetic leather. It smoothes the outermost surface and gives it a soft feel, and the thickness of the foamed synthetic resin layer in this case is preferably 0.1 to 0.3 mm. This foamed synthetic resin layer can be formed by either a so-called wet film forming method or a dry film forming method (by foaming with a foaming agent or by mechanical foaming). A non-foamed synthetic resin surface area is provided on the foamed synthetic resin layer, which is important for reinforcing surface strength such as scratch resistance.

By the way, the synthetic resin used is not particularly limited; for example, polyurethane resin,
Polyacrylic resin, polyamide resin, etc. are used, but polyurethane is the most common among them.

The synthetic leather of the present invention is particularly useful as a material for shoes, upholstery, etc. due to its bulky, soft feel, light weight, and heat retention properties.

The present invention will be described in more detail below with reference to Examples.

Example: 177 denier yarn made of polyester/cotton blend.
140g/m 2 made of 3 denier, 51 mm polyester and rayon blend on a plain woven cloth woven with 17 threads/cm, 133 denier threads at a weft of 22 threads/cm ^.
A bulky nonwoven fibrous substrate was obtained by stacking the nonwoven fibrous webs and needle-punching the nonwoven fibrous web at 200 punches/cm ² using a #40 needle.

Separately, a solution of polyurethane elastomer of the following formulation A was applied to process paper at a concentration of 100 g/m ² ,
This was made into a dry film.

Furthermore, a heat-foamable urethane prepolymer paint having the following formulation B was applied onto this film at a coating density of 200 g/m ² , and then heat-foamed at 120°C for 2 minutes. A foamed polyurethane paint layer is laminated to the surface, and this is heated to 70℃.
After heating for 1 hour, it was cooled and the process paper was peeled off to obtain synthetic leather.

Combination A pedal 4933 100 (Toyo Polymer Awasou ▲ Kaihoori

Claims (1)

[Claims] 1. Threads of 60 denier or more and 450 denier or less are warp,
A nonwoven fiber web is layered on one or both sides of a woven fabric woven with 8 fibers/cm or more and 50 fibers/cm or less in both weft and projected area fiber space factor of 90% or less, and then a nonwoven fiber web is layered on one or both sides. A foamed synthetic resin layer is provided on one side of a bulky nonwoven fibrous substrate that has been needle-punched at a rate of 50 punches/cm ² or more and 300 punches/cm ² or less, and a non-foamed synthetic resin surface layer is provided on top of that. A lightweight, bulky product with a weight of 400g/ ^m2 or less, a thickness of 1.2mm or more, an apparent density of 0.3g/ ^cm3 or less, a 20% modulus of 8Kg/3cm or more, and a tensile strength of 10Kg/3cm or more. Synthetic leather.