JPS609976A - Preparation of impregnated composite material - Google Patents

Abstract

PURPOSE:To obtain an impregnated composite material having sufficient flexibility and sufficient rigidity, by pretreating a fibrous structure with a specific mixed treatment solution to improve it, impregnating it with a specific polyurethane composition. CONSTITUTION:A fibrous structure such as a woven or knitted material consisting of natural or synthetic fiber is pretreated with a mixed solution of colloidal or synthetic fiber is pretreated with a mixed solution of colloidal silica and alumina zol, so that it is provided with 0.1-8wt% (solid content) of both the components, respectively. It is then impregnated with a W/O emulsion type polyurethane composition wherein water is dispersed into a solution of polyurethane in an organic solvent such as methyl ethyl ketone, etc., to give an impregnaged composite material having sufficient flexibility and rigidity useful as a simulated synthetic leather substitute.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for producing an impregnated composite used for artificial leather and the like. More specifically, the present invention is directed to the production of a leather-like impregnated composite having good flexibility and stiffness, which is composed of a fibrous structure whose fiber surface has been modified with a specific treatment agent and a specific polyurethane composition. It is about the method.

PRIOR ART Methods for producing flexible leather-like sheets have been studied for a long time. It is known to obtain a flexible leather-like sheet material using a copolyester obtained from a polyalkylene ether, a low-molecular diol, and a dicarboxylic acid or its ester as shown in No. 50-105876.

Also, use water-repellent silicone! It is also known to be used as aUa surface modifier for IN-like structures to obtain flexible leather-like sheets.

However, although this method provides flexibility, it does not provide the stiffness characteristic of natural leather, and when used as a leather substitute for footwear, it has poor wearing comfort.

Some drawbacks have been pointed out, such as poor appearance when worn.

In addition, as shown in Japanese Patent Application No. 52-121526, a large amount of colloidal silica is applied to the fibrous base fabric to prevent direct adhesion between the impregnated polymer and the fibers, and to prevent the fabric from being rubbed after impregnation. A method of softening colloidal silica by powdering it is known.

However, in such a method, the required softening effect cannot be obtained unless a large amount of colloidal silica is used.

Purpose As a result of intensive research into a method for obtaining a leather-like sheet material that has sufficient flexibility and sufficient stiffness found in natural leather, the present inventor has developed a method for obtaining a leather-like sheet material that has sufficient flexibility and sufficient stiffness found in natural leather. The inventors discovered that the objective could be achieved by impregnating a shaped structure with a specific polyurethane composition, and thus arrived at the present invention.

Components of the Invention In other words, the present invention involves, when producing an impregnated composite by impregnating a fibrous structure with a W10 emulsion type polyurethane composition, the fibrous structure is previously treated with a mixed solution of colloidal silica and alumina sol. Then, 0.1 to 8.0% by weight of colloidal silica solid content and 0.1 to 8.0% by weight of alumina sol solid content were added to the fiber heavy eel, and then a W10 emulsion type polyurethane composition was added. This is a method for producing an impregnated composite material.

The fibrous structure used in the present invention refers to a woven fabric or a nonwoven fabric made of natural fibers, synthetic fibers, etc.
Of course, this also includes items that have undergone conventional processing such as dyeing and shrinkage processing.

A feature of the present invention is that the fibrous structure is previously treated with a mixture of colloidal silica and alumina sol before being impregnated with the polyurethane composition, and by doing so, when impregnated with the W10 emulsion type polyurethane composition, , it is possible to obtain an impregnated structure having sufficient flexibility and sufficient stiffness.

The reason for this is that the V of the polyurethane used as the impregnating liquid
The water held by the JlO type emulsion and the hydrophilic power of the colloidal silica and alumina sol treated on the fiber surface of the fibrous structure have an appropriate balance of affinity, and the colloidal silica and alumina sol have an affinity of W10.
Due to its affinity with the polyurethane in the mold emulsion. That is, at the interface between the fiber surface of the fibrous structure and the W10 emulsion impregnated with hydrophilic colloidal silica and alumina sol treated on the 1ef surface, part of the water dispersed in the W10 emulsion becomes water. A film is formed, and this water film prevents adhesion between the polyurethane and the fibers of the fibrous structure, resulting in sufficient flexibility. Although such a phenomenon occurs with hydrophilic fiber surface modifiers or water-repellent silicones other than those of the present invention, the feature of the present invention is that the organic solvent for polyurethane in the W10 emulsion impregnated into the fibrous structure is evaporated. In the step of forming, the impregnated W10 type emulsion gradually gels while retaining the dispersed water.
Polyurethane tends to block due to large shrinkage forces, but the polyurethane is retained on the fiber surface by colloidal silica and alumina sol that have an affinity for polyurethane treated on the fiber surface, and the polyurethane is retained on the fiber surface by the previously known fiber surface modifiers mentioned above. It is less likely to block compared to
As a result, an impregnated structure having sufficient stiffness can be obtained.

The alumina sol used in the present invention is generally hydrated and dispersed on the acidic side, but colloidal silica is hydrated and dispersed on the acidic side and hydrated and dispersed on the basic side. Either can be used. However, when using a mixture of colloidal silica hydrated and dispersed on the basic side and alumina sol, care must be taken as there is a tendency for coagulation and separation. The amount of colloidal silica and alumina sol applied to the fibrous structure is determined based on the solid fiber N weight.
0.1 to 8 respectively. O-type tank%. If either of these amounts is less than 0.1%, the effect of increasing flexibility and waist strength of the present invention cannot be obtained. That is, the present invention is characterized in that the combined use of colloidal silica and alumina sol provides a greater effect than when either of them is used alone. In addition, the applied amount was 8 for both colloidal silica and alumina sol.
．． Must not exceed 0%. If either of them exceeds 8.0% by weight, silica or alumina tends to fall off from the treated fibrous structure or the final impregnated structure, causing problems in handling and degrading the quality of the final product. So I don't like it.

These processing amounts can be controlled using colloidal silica,
This can be easily achieved by preparing a mixed treatment solution in which the concentration of each active ingredient of the alumina sol is adjusted, and adjusting the wet pickup arrangement using normal dip and nip treatments. Thereafter, it is dried in a dryer, and then impregnated with a W10 emulsion type polyurethane composition.

The W10 emulsion type polyurethane composition of the present invention refers to a type of emulsion in which water is dispersed in a polyurethane organic solvent solution or slurry. It is difficult to obtain the effects of the present invention in a type in which water is solubilized in a polyurethane-organic solvent solution or slurry. To obtain such a composition, as a solvent for polyurethane,
Organic solvents that are miscible with water in any proportion cannot be used, and polyurethanes preferably having appropriate hydrophilic groups in their molecular chains are preferred from the viewpoint of emulsion stability. The organic solvent for polyurethane is
In order to better exhibit the effects of the present invention, it is preferable that the fresh water is lower than water.

Examples of such organic solvents include methyl edyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl fomate, n-propyl fomate, methyl acetate, ethyl acetate,
Examples include isopropyl acetate and isobutyl acetate. Of course, a mixed solvent of two or more of these can also be used. Organic solvents that are miscible with water in any proportion, such as acetone and tetrahydrofuran, are also organic solvents that hardly dissolve water.

For example, it can be used as a mixed solution by mixing with benzene, toluene, n-hexane, etc. to reduce the solubility in water.

As described above, due to the principles of the hydrophilic balance between the W10 emulsion and the fiber surface modifier and the affinity balance between polyurethane and the fiber surface a-quality 11J, the objective of the present invention is to achieve sufficient flexibility and A leather-like impregnated structure having firmness can be obtained.

1E1 Below, the present invention will be specifically explained by giving examples to further clarify the present invention. All parts in the examples indicate parts by weight. Note that the characteristics in the present invention were measured as follows.

1) Bending resistance (Re) Grip the 2cR portion of one end of a test piece with a width of 2.5ffi and a length of 9DR, and hold the I! ! Radius of curvature approximately 2α at position 21 from tin
Measure the repulsive force when folded into a 1/4 semicircle shape, and the width is 1α.
It is converted into a value and used as a substitute for flexibility.

2) Bending compressive stress (Ps) A test piece with a width of 2.5 (21 x length 9 α) was bent in half,
It is compressed until the thickness of the curved part becomes 5 m/m, and the stress at that time is measured, converted to the value of width 1a*, and shown as a substitute characteristic for the strength of the waist.

3) Leather-like property It is expressed as the value obtained by dividing the bending compressive stress (Ps) by the bending resistance (Re), and the larger this value is, the more the structure is characteristic of natural leather.

Example 1 A needle-punched nonwoven fabric made of latent shrinkable polyester lIN with a fineness of 2 de and a length of 51 am was shrunk to 40% of its original area in warm water at 68° C., and a nonwoven fabric obtained by applying pressure (fabric weight 4505 F/Wt, thickness (L7 m/m ) was immersed in an aqueous solution containing colloidal silica (Snowtex-20 manufactured by Yasan Kagaku) with a concentration of 0.5% of the active ingredient and alumina sol (manufactured by San San Kagaku) with a concentration of 0.5% of the active ingredient, After completely infiltrating, squeeze the wet pickup with a nip roll so that it is 200% of the weight of the m-fiber, and dry it in a hot air dryer at 130°C for 15 minutes. A nonwoven fabric was obtained which had a solid content of 1.0% by weight and an alumina sol solid content of i and ol of 1%. Note that this mixed solution of colloidal silica and alumina sol produced some sediment during mixing, so it was passed through the mouth before use.

Next, a 20% concentration obtained by polymerization of ρ,p'-diphenylmethane diisocyanate, polybutylene adipate having a terminal -○H group with an average molecular weight of 2000, polyoxyethylene glycol with an average molecular weight of 1600, and 1,4-butanediol 30 parts of water was dispersed in 100 parts of the polyurethane-methylene ethyl ketone solution of W.
A nonwoven fabric to which the colloidal silica and alumina sol were applied was impregnated with a Type 10 emulsion type polyurethane composition, and after scraping off the excess liquid on the surface, it was dried at 50°C for 30 minutes and at 110°C for 10 minutes. The obtained impregnated structure had good flexibility and stiffness, and its properties as a natural leather substitute were unprecedented.

This characteristic is shown in Table-1.

Example 2 The needle-punch-shrink-pressure nonwoven fabric used in Example 1 (fabric weight 450!?/m, thickness 1-77 rL/m) was mixed with colloidal silica at a concentration of 0.2% active ingredient and 2.0% active ingredient.
Immerse it in an aqueous solution containing alumina sol at a concentration of %.After completely permeating it, wet pickup is performed using a nip roll! 1it (200% of the weight of f), dried in a hot air dryer at 130°C for 15 minutes, and the solid content of colloidal silica was 0.
4% by weight, and a nonwoven fabric having an alumina sol solid content of 4.0% by weight was obtained.

This nonwoven fabric was impregnated with the W10 emulsion type polyurethane composition used as the polyurethane impregnation liquid in Example 1, and the same procedure as in Example 1 was performed to obtain an impregnated structure. Table 1 shows the properties of the obtained impregnated structure.

Example 3 The needle-punch-shrink-pressure nonwoven fabric (fabric weight: 450 g/rd, thickness: 1.7 m/m) used in Example 1 was mixed with colloidal silica at a concentration of 2.0% of the active ingredient and 0.0% of the active ingredient.
After immersing the fiber in an aqueous solution containing 2% alumina sol and allowing it to completely penetrate, the fiber was squeezed with nip rolls so that the wet pickup was 200% of the fiber weight, and then dried in a hot air dryer at 130°C for 1S minutes. Dry and add 4.0 ffl of colloidal silica solids to the fibers.
%, and a nonwoven fabric having an alumina sol solid content of 0.4% by weight was obtained.

This nonwoven fabric was prepared by polymerizing p,p'-diphenylmethane diisocyanate, polyethylene adipate having a terminal -○H group with an average molecular weight of 1t1700, polyoxyethylene glycol with an average molecular weight of 1400, and 1,4-butanediol at a concentration of 20%. polyurethane
Add 25 parts of water to 100 parts of ethyl acetate slurry solution.
After impregnating the partially dispersed W10 emulsion type polyurethane composition and scraping off the excess liquid on the surface,
It was dried at 0°C for 30 minutes and at 110°C for 10 minutes. The obtained impregnated structure had good flexibility and stiffness.

Table 1 shows the properties of the obtained impregnated structure.

Comparative Example 1 The needle-punch-shrinkage-pressure nonwoven fabric (fabric weight 450 g/m, thickness 1.7 m/7 rL) used in Example 1 was coated with
Using the same treatment method as in Example 1, the solid content of colloidal silica was 0.05% and the solid content of alumina sol was 0.05% based on the fiber weight.
05% by weight was added. This nonwoven fabric was impregnated with the W10 emulsion type polyurethane composition used as the polyurethane impregnating liquid in Example 1, and the same procedure as in Example 1 was performed to obtain an impregnated structure. The obtained impregnated structure is
It did not have satisfactory flexibility. This characteristic is shown in Table-1.

Comparative Example 2 The needle-punch-shrinkage-pressure nonwoven fabric (fabric weight 450 g/TIi, thickness 1.7 m/m) used in Example 1 was
A colloidal silica solid content of 10.0% by weight and an alumina sol solid content of 10.0% by weight were applied to the fiber llt ia i using the same treatment method as in Example 1. This nonwoven fabric was impregnated with the W10 emulsion type polyurethane composition used as the polyurethane impregnating liquid in Example 1, and the same procedure as in Example 1 was performed to obtain an impregnated structure. Although the impregnated structure had satisfactory flexibility, silica and alumina powder fell off when it was bent or rubbed, and it had no commercial value. Furthermore, when the nonwoven fabric is impregnated with the polyurethane composition, silica and alumina powders fall off during handling, which poses operational problems.

Comparative Example 3 A nonwoven fabric to which a colloidal silica solid content of 1.0 wt % and an alumina sol solid content of 1.0 wt % were added to the llff weight in Example 1 (date 450y/'nt, thickness 1.7
TrL/m) was impregnated into the 20% concentration polyurethane-methyl ethyl ketone solution obtained in Example 2 (the solution before making the W10 type emulsion), and an impregnated structure was created in the same manner as in Example 1. . The obtained impregnated structure was hard, as shown in Table 1, and was significantly different from that of the present invention.

Comparative Example 4 In Example 1, the solid content of colloidal silica was 1.
Non-woven fabric with 0 weight% and 1.0 weight% alumina sol solid content (fabric weight 450g/nt, thickness 1.7TrL/
711L) was impregnated into a polyurethane aqueous emulsion (Izerax S-4040, manufactured by Hodogaya Chemical Co., Ltd.), and an impregnated structure was created in the same manner as in Example 1. The obtained impregnated structure was hard as shown in Table 1,
This was significantly different from the present invention.

Comparative Example 5 The needle pan day shrinkage-pressure nonwoven fabric (fabric weight 450!?/m, thickness 1.7 m/m) used in Example 1 was
Using the same treatment method as in Example 1, silicone (Boron MNK, manufactured by Shin-Etsu Chemical) was added to 0.5% of the amount of fiber (in terms of active ingredient).
Weight i% was given. This nonwoven fabric was impregnated with the W10 emulsion type polyurethane composition used as the polyurethane impregnation liquid in Example 1, and an impregnated structure was obtained in the same manner as in Example 1. Although the obtained impregnated structure had good flexibility, it felt stiff and unwieldy. This characteristic is shown in Table-1.

Comparative Example 6 A colloidal silica hardener was added to the needle-punch-shrink-pressure nonwoven fabric (fabric weight 450 g/rd, thickness 1.7 m/m) used in Example 1 for the amount of fiber i using the same treatment method as in Example 1. A mold content of 2.0% by weight was applied. This nonwoven fabric was impregnated with the W10 emulsion type polyurethane composition used as the polyurethane impregnating solution in Example 1, and the same procedure as in Example 1 was carried out to obtain an impregnated I transparent body. Although the obtained impregnated structure had some flexibility, it could not achieve the object of the present invention. This characteristic is shown in Table-1.

Comparative Example 7 The needle punch-shrinkage-pressure nonwoven fabric (fabric weight 4509/yyf, thickness 1.7 m/m) used in Example 1 was treated with colloidal for m and ii weight by the same treatment method as in Example 1. A silica solids content of 30.0 ffl 1% was applied.

This nonwoven fabric was hard and became soft when bent or rubbed, but a large amount of silica powder fell off. This nonwoven fabric was impregnated with the W10 emulsion type polyurethane composition used as the polyurethane impregnation liquid in Example 1, and the same procedure as in Example 1 was performed to obtain an impregnated structure. The obtained impregnated MI4 structure had a plate-like shape, and although it became soft when rubbed, it also became stiff (which was different from the object of the present invention. The characteristics are shown in Table 1. show.

(Leave blank below) Table 1: Characteristics of leather-like sheet material -"L As detailed above, the method of the present invention has a leather-like material that has better flexibility and stiffness than the conventional method. An impregnated structure can be provided. That is, it is possible to increase the stiffness/flexibility (Ps/Re) value, which is a measure of natural leather-likeness, and to provide a leather-like impregnated structure with unprecedented properties.

Claims (1)

[Claims] When manufacturing an impregnated composite by impregnating a mH-like product with a W10 emulsion type polyurethane composition, the fibrous structure is treated in advance with a mixed solution of colloidal silica and alumina sol to reduce the fiber density. .1-8
．． 0 weight percent colloidal silica solids and 0.1 to 8
．． Add 0% by weight of alumina sol solid content, then W
A method for producing an impregnated composite by impregnating it with a Type 10 emulsion type polyurethane composition.