JPS6021982A - Preparation of impregnated composite material - Google Patents

Abstract

PURPOSE:To obtain an impregnated composite material having sufficient suppleness and sufficient rigidity, by pretreating a fibrous structure with a specific mixed treatment solution to modify it, impregnating it with a specified polyurethane composition. CONSTITUTION:A fibrous structure such as knitted or woven cloth, etc. consisting of naturally occurring or synthetic fiber is pretreated with a mixed solution containing colloidal silica, and alumina sol and a urethane bond-containing surface active agent as main components, so that it is provided with 0.1-8wt% solid content of colloidal silica, 0.1-8wt% solid content of alumina sol, and 0.1- 6wt% solid content of the surface active agent. It is then impregnaged with a polyurethane composition of W/O type wherein water is dispersed into a solution of polyurethane in an organic solvent such as methyl ethyl ketone, etc., to give a leather sheet like naturally occurring leather. The surface active agent preferably has urethane group in the molecular chain, 30-80wt% polyoxyethylene segment as a hydrophilic group component, 2,500-30,000 molecular weight, and water solubility or water dispersibility.

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 copolymerized polyester obtained from a polyfulkylene ether, a low-molecular diol, and a dicarboxylic acid or its ester as shown in No. 50-105876.

It is also known to use water-repellent silicone as a fiber surface modifier for fibrous structures to obtain flexible leather-like sheet materials.

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, there are problems such as poor wearing comfort and appearance. Shortcomings have been pointed out.

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.
A method of softening colloidal silica by powdering it by processing such as impregnation molding and edge rolling is known. However, in such a method, the required softening effect cannot be obtained without using a large amount of colloidal silica.

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 present invention was achieved by finding out that the objective can be achieved by impregnating a fibrous structure with a specific polyurethane composition.

View L11 That is, in the present invention, when manufacturing an impregnated composite by impregnating a fibrous structure with a KWIO emulsion type polyurethane composition, the fibrous structure is preliminarily coated with colloidal silica, alumina sol, and an interface having urethane bonds. A mixture containing an activator as a main component is processed to produce fibers * * IC
colloidal silica solid content of 0.1 to 8.0% by weight of alumina sol solid content of 0.1 to 8.0% by weight and 0.1 to 8.0% by weight of colloidal silica solid content of oil
This is a method for producing an impregnated composite, in which a surfactant solid content having urethane bonds of 1 to 6.0% by weight is applied, and then a W10 emulsion type polyurethane composition is impregnated.

The fibrous structure used in the present invention refers to a woven fabric, a knitted fabric, or a non-woven fabric made of natural fibers, navy blue, synthetic fibers, etc., and which has been subjected to conventional treatments such as dyeing and shrinkage treatments. Of course, σ) is also included.

A feature of the present invention is that before impregnating the fibrous structure with the polyurethane composition, the fibrous structure is treated in advance with a liquid mixture mainly composed of colloidal silica, alumina sol, and a surfactant having a urethane bond. When impregnated with a W10ffl emulsion type polyurethane composition, an impregnated composite having sufficient flexibility and sufficient stiffness can be obtained.

The reason for this is that the polyurethane W used as the impregnating liquid
The water held by the Type 10 emulsion and the hydrophilic power of the colloidal silica, alumina sol and urethane bond-containing surfactant treated on the fiber surface of the fibrous structure have an appropriate balance and affinity; This is because colloidal silica, alumina sol, and a surfactant having a urethane bond have affinity with the polyurethane in the W10 emulsion. That is, W1 is impregnated with hydrophilic colloidal silica, alumina sol, and a surfactant having urethane bonds treated on the fiber surface.
At the interface between the type 0 emulsion and the fiber surface of the fibrous structure,
Part of the water dispersed in the W10 emulsion forms a water film, which prevents adhesion between the polyurethane and the fibers of the fibrous structure, resulting in sufficient flexibility. become. 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 W impregnated into a fibrous structure
At the stage of evaporating the organic solvent for the polyurethane in the type 10 emulsion, the impregnated WZO type emulsion gradually gels while retaining the dispersed water, and the polyurethane tends to be blocked by large shrinkage molds, but the fibers Colloidal silica, alumina sol, and surfactants with urethane bonds, which have an affinity for the surface-treated polyurethane, allow the polyurethane to be retained on the fiber surface and block it compared to the previously known fiber surface modifiers mentioned above. As a result, an impregnated composite with sufficient stiffness can be obtained.

The surfactant having a urethane bond used in the present invention is a water-soluble or water-dispersible surfactant having substantially a urethane group in its molecular chain.

To give one example, a glycol selected from the group consisting of polyoxyethylene glycol as a hydrophilic group and polyalkylene glycols other than polyoxyethylene glycol, aliphatic polyester diols, and mixtures thereof as a hydrophobic group is used as a conventional organic diisocyanate. such as surfactants bonded with The molecular weight of these surfactants is preferably in the range of SOO to 30,000.

When the molecular weight exceeds 30,000, the resulting impregnated composite tends to become hard, which is contrary to the purpose of the present invention.
If it is less than 500, it is not preferred because it tends to bleed onto the surface of the product in the presence of heat or organic solvents. In addition,
In these surfactants, the polyoxyethylene segment, which is the hydrophilic group component, accounts for 30% of the total surfactant.
~80% by weight and must be water-soluble or water-dispersible. A material that satisfies the above conditions and has a larger number of urethane bonds is more effective for the present invention. The amount of colloidal silica and alumina sol applied to the fibrous structure is 0.1 to 8.0% of the solid content based on the fiber weight, respectively.
% by weight, and the amount of surfactant having urethane bonds is from 0.1 to 6.0% by weight. If any of these applied amounts are less than 0.1% by weight, the desired effect of increasing flexibility and stiffness cannot be obtained. That is, the present invention is characterized in that the combined use of colloidal silica, alumina sol, and a surfactant having a urethane bond provides a greater effect than when any of these is used alone. Also, the amount applied is 418. Do not exceed OM bone width. If either of them exceeds 8.0% by weight, silica or alumina tends to fall off from the treated delicate structure or the final impregnated composite, causing problems in handling and degrading the quality of the final product. So I don't like it. The applied amount of surfactant with urethane bond is 6.0 weight'! If the amount exceeds , the above-mentioned effect as a fiber surface modifier can be obtained, but too much K is also unsuitable because the amount of treatment is too large and the surfactant appears on the product surface, impairing the feel of the product. be. To control these processing amounts, prepare a mixed processing solution with adjusted concentrations of each active ingredient of colloidal silicate force, alumina sol, and a surfactant with urethane bond, and adjust the wet pick-up amount using normal dip and nip processing. This can be easily accomplished. Thereafter, it is dried in a dryer, and then impregnated with a W10 emulsion type polyurethane composition.

The W10 emulsion type polyurethane composition as used in the present invention refers to a type of emulsion in which millet 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 or slurry.

To obtain such a composition, it is necessary to avoid using organic solvents that are miscible with water in any proportion as the solvent for the polyurethane, and the polyurethane preferably contains an appropriate amount of hydrophilic acid in its molecular chain. Those having a group are preferable from the viewpoint of emulsion stability. In order to better exhibit the effects of the present invention, the organic solvent for polyurethane is preferably one whose water production is lower than that of water. Examples of such organic solvents include methyl ethyl ketone, methyl-n-propyl ketone, methyl isonotyl ketone, diethyl ketone, methylfomate, n-7' lobilfomate, methyl acetate, ethyl acetate, isopropyl acetate, and imbutyl acetate. It will be done.

Of course, a mixed solvent of two or more of these can also be used.

Also, organic solvents that are miscible with water in any proportion 2
For example, acetone, tetrahydrofuran, etc. can be mixed with an organic solvent that hardly dissolves water, such as benzene, toluene, or n-hexane, to reduce the solubility under water pressure and used as a mixed solution.

As mentioned above, the original IJ, which has a hydrophilic balance between the W10 emulsion and the fiber surface modifier, and an affinity balance between the polyurethane and the fiber surface modifier, provides unprecedented flexibility and sufficient It is possible to obtain a leather-like impregnated composite having excellent elastic strength.

EXAMPLES Below, examples for further clarifying the present invention will be specifically described. All parts in the examples indicate parts by weight. Note that the characteristics in the present invention were measured as follows.

] Bending resistance (RB) Width 2.5cIIL x Length 9 (one end of 17+1 test piece)
The repulsive force when gripping a part of - cm and bending it into a semicircular shape with a curved radius of about 2 c + u l / 4 at a position 2 cfrL from the other end is shown by converting it to a C width i cmO value,
Used as a proxy characteristic for flexibility.

2) Bending compressive stress (P,) A test piece of width 2.5 (1) x length 9 cnl was bent by hand and compressed until the thickness of the curved part became 5 m/m. The stress is measured and converted to a value of width 1cIrL, which is shown as , and is used 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 (P, ) by the bending resistance (RB), and the larger this value is, the more the structural characteristics are similar to natural leather! ! 'Taste.

Example 1 A needle-punch nonwoven fabric made of latent shrinkable polyester fibers with a fineness of 2de and a length of 51 mm was shrunk to 4% of its original area in warm water at 68°C, and then pressurized to obtain a nonwoven fabric (fabric weight 45
0j9/rn', thickness 1.7mm) as the active ingredient o,
Colloidal silica with SR4 concentration (Snowtex-2O manufactured by Ichisan Kagaku), alumina sol with 0.5T concentration of active ingredient (
After soaking in an aqueous solution containing Nippon Chemical Co., Ltd. and a surfactant with the following composition with an active ingredient concentration of 0.5% and allowing it to completely penetrate, use a nip meal to make the wet pick-up amount 20ocID based on the weight of the fiber. Squeezing, hot air drying! l
! The fibers were dried under the conditions of 130"QX for 15 minutes, and the solid content of colloidal silica (i), the amount of oi (oi), the alumina sol solid content (1.0 weight), and the surfactant solid content (1.0 weight) were added to the fiber weight. A nonwoven fabric was obtained.This mixed treatment solution produced some sediment during mixing, so it was filtered and used.
.

<Urethane group-containing surfactant composition>P,P'-dicyclohexylmethane diisocyanate
3 molar average molecular weight [2,000 polyoxyethylene glycol 2 molar average molecular weight 2. Polyoxyethylene glycol of Q OO 2 molar order 1c, P, P'-diphenylmethane diincyanate, polybutylene adipate with terminal -〇H'1& of average molecular weight 2000, polyoxyethylene glycol of average molecular weight J 600 and 1.4 - W10 emulsion type polyurethane prepared by dispersing 30 parts of water in 100 parts of a polyurethane-methylene ethyl ketone solution with a 2O4 concentration obtained by polymerization of butanediol, 1i
A nonwoven fabric to which a surface modifier was applied was impregnated with the ll product, 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 composite had good flexibility and stiffness, and its properties as a natural leather substitute were unprecedented. This characteristic is shown in Table IK.

Example 2 Needle bunch-shrinkage-pressure nonwoven fabric used in Example 1 (fabric weight 450 ft/tn', thickness t, 7 m/m
) was immersed in an aqueous solution containing colloidal silica with a concentration of 0.2% active ingredient, alumina sol with a concentration of 2.0% active ingredient, and a surfactant having a urethane bond used in Example 1 with a concentration of o, z%, After completely infiltrating the fiber, it is squeezed with a nip roll so that the wet pickup is 200% of the fiber weight, and dried in a hot air dryer at 130°C for 15 minutes to reduce the colloidal silica solid content relative to the fiber weight. 0.4% by weight, aluminium/L solid content 4.0% by weight,
A nonwoven fabric to which a surfactant solid content of 0.4% by weight was provided was obtained.

This nonwoven fabric was impregnated with the W10 emulsion type polyurethane composition used as the polyurethane impregnating liquid in Example 5, and an impregnated composite was obtained in the same manner as in Example 1. The properties of the obtained impregnated composite are shown in Table 1.

Example 3 Needle pan 1,000-shrinkage-pressure nonwoven fabric used in Example 1 (fabric weight 450II/rrII, thickness 1.7 m/m)
was immersed in an aqueous solution containing colloidal silica with a concentration of 2.0% of the active ingredient, alumina sol with a concentration of 0.2% of the active ingredient, and a surfactant having a urethane bond used in Example 1 with a concentration of 0.4%. After infiltrating it, squeeze it with a nip roll so that the wet pickup is 200% of the weight of the line drawing, and dry it in a hot air dryer at 130°C for 15 minutes. # Colloidal silica solid content 4.0% by weight, alumina sol solid content 0.4% by weight fl:%
, surfactant solid content 0. A nonwoven fabric to which f1 weight and t% was imparted was obtained.

This nonwoven fabric was obtained by polymerizing P,P'-diphenylmethane diincyanate, polyethylene adipate having an average molecular weight of 1700 and a terminal -○H group, polyoxyethylene glyfur and 1,4-butanediol with an average molecular weight of -)it4oo. 20% polyurethane
It was impregnated with a W10 emulsion type polyurethane composition in which 100 parts of ethyl 7-cetate slurry solution was dispersed with 25 parts of water, and after scraping off the excess liquid on the surface, it was heated at 50°C for 30 minutes and at 110°C. Allowed to dry for 10 minutes.

The obtained impregnated composite had good flexibility and stiffness.

The properties of the obtained impregnated composite are shown in Table-i.

Comparative Example 1 Needle bunch-shrinkage-pressure nonwoven fabric used in Example 1 (fabric weight 45077/rrf, thickness 1.7 m/m) K,
Using the same treatment method as in Example 1, the solid content of colloidal silica was 0.05% by weight and the solid content of Fluminasol was 0.05% by weight based on the fiber weight.
05 weight, surfactant solid content used in Example 1 0.0
5% by weight was added.

This nonwoven fabric was impregnated with the W10 emulsion type polyurethane composition used as the polyurethane impregnation liquid in Example 1, and an impregnated composite was obtained in the same manner as in Example 5. The resulting impregnated composite did not have satisfactory flexibility. This characteristic is shown in Table IK.

Comparative Example 2 The needle pan thousand-shrink pressurized nonwoven fabric (450 g/rrf, thickness 1.7 m/m) used in Example 1 was treated with a core a based on the fiber weight using the same treatment method as in Example 1. Idal silica solid content 10.0 weight ratio, alumina sol solid content 1
O00 weight, surfactant solid content used in Example 1 8
．． 0% by weight was added. 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 composite. The resulting impregnated composite is
Although the flexibility was satisfactory, it was difficult to bend or knead it. The silica and alumina powder fell off and 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 In Example 1, the solid content of colloidal silica was 1.
Nonwoven fabric (fabric weight 450,
9/moromi, thickness 1.7 m/m) obtained in Example 2.
Polyurethane-methyl ethyl ketone solution (W
Type 10 emulsion (before pressing) was impregnated with K, and an impregnated composite was prepared in the same manner as in Example 1. The obtained impregnated composite was hard as shown in Table 1,
This was significantly different from the object of the present invention.

Comparative Example 4 In Example 1, the fiber weight was 1. ．． Non-woven fabric (fabric weight 45
Q1//m, thickness z, 7 m/m) was impregnated into a polyurethane aqueous emulsion (Izerax S-4040 manufactured by Hodogaya Chemical Co., Ltd.), and an impregnated composite was prepared in the same manner as in Example 1.

The obtained impregnated composite was hard as shown in Table 1, and was significantly different from the object of the present invention.

Comparative Example 5 The needle-punch-shrinkage-pressure nonwoven fabric (fabric weight 450 g/rrf, thickness s, rm/m) K used in Example 1 was treated with silicone (
Poron MNK (manufactured by Shin-Etsu Chemical Co., Ltd.) was added in an amount of 0.5 weight in terms of active ingredient. This nonwoven fabric was impregnated with the W10 emulsion type polyurethane composition used as the polyurethane impregnating liquid in Example 1 (I2), and an impregnated composite was obtained in the same manner as in Example 1. The obtained impregnated composite had good flexibility, but felt stiff and unsteady, which was significantly different from the object of the present invention. This characteristic is shown in Table-1.

Comparative Example 6 The needle bread cow-shrinkage-pressure nonwoven fabric (4s 09/rrf-thickness t, 7 m/m) used in Example 1 was treated with colloidal fibers in the same manner as in Example 1. A silica solids 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 liquid in Example 1, and an impregnated composite was obtained in the same manner as in Example 1. Although it 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/n1'-thickness t, 7 m/m) used in Example 1 was treated with colloidal for MIi fibers using the same treatment method as Example 1. A silica solid content of 30.0 weight -9'li 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 emulsion type polyurethane composition used as the polyurethane impregnating solution in Example 1.
Thereafter, an impregnated composite was obtained in the same manner as in Example 1.

The obtained impregnated composite was in the form of a hard plate, which became soft when manipulated, but at the same time lost its stiffness, which was different from the object of the present invention.

This characteristic is shown in Table-1.

(Leave blank below) Table 1 Characteristic effects of leather-like sheet material As detailed above, the method of the present invention provides a leather-like impregnated composite material with better flexibility and stiffness than the conventional method. I can give you my body. That is, it is possible to increase the stiffness/flexibility (P, /RB) value, which is a measure of natural leather-likeness, and to provide a leather-like impregnated composite having unprecedented properties.

Patent applicant Teijin Ltd.

Claims (1)

[Claims] When producing an impregnated composite by impregnating a fibrous structure with a W10 emulsion type polyurethane composition, the fibrous structure is preliminarily mixed with colloidal silica, alumina sol, and a surfactant having a urethane bond as a main component. The mixed solution is treated to give a colloidal silica solid content of 0.1 to 8.0% by weight, 0.1 to 8.0% by weight based on the fiber weight.
A method for producing an impregnated composite comprising applying an alumina sol solid content of 0.1 to 6.0 weight and a surfactant solid content having urethane bonds of 0.1 to 6.0 weight, and then impregnating with a W10 emulsion type polyurethane composition.