JPS5845502B2 - Hikakuyoushi - Tojiyoubutsunoseizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a leather-like sheet material that is highly flexible and has excellent processability.

Natural leather has excellent mechanical properties and durability, is highly flexible, and has excellent processability, so it has traditionally been used favorably for shoes, bags, bags, and clothing.

However, since natural leather is expensive and limited in production, so-called artificial leather has recently been developed as an alternative material.

As a result of various improvements, it has become possible to obtain artificial leather that has properties comparable to natural leather in terms of mechanical strength, durability, and flexibility.

However, a material that has both the flexibility and processability of natural leather has not yet been developed.

The inventor has found that it has mechanical strength and durability comparable to natural leather,
Moreover, as a result of intensive research on the production method of artificial leather, i.e., leather-like sheet-like material, which has both the flexibility and processability of natural leather, we have added rubber-like elasticity to the fibrous base material and produced leather-like sheet-like material. When producing a rubber-like elastic body, if a specific amount of polyethylene glycol-polypropylene glycol block copolymer is attached to the fibrous base material before applying the rubber-like elastic body to the fibrous base material, the rubber-like elastic body and the fibers can be bonded together. Because the fibers do not form strong bonds, a flexible sheet can be obtained, and the solid frictional resistance between fibers and between the fibers and the rubber-like elastic body increases, reducing the repulsive elasticity of the sheet and making it difficult to process. The present invention was achieved based on the findings that the mold retention property after molding is improved due to improved properties and moderate plasticity.

That is, the present invention provides a method for producing a leather-like sheet material by applying a solution or dispersion of a rubber-like elastic body to a fibrous base material, and then removing a solvent or dispersion medium from the base material. This is a method for producing a leather-like sheet material, characterized in that a polyethylene glycol-polypropylene glycol block copolymer is previously attached to a base material in an amount of 0.4 to 10% by weight of the base material.

Polyethylene glycol-polypropylene glycol block copolymer (hereinafter referred to as PE) used in the present invention
G-PPG block copolymer) is (PEG)-(PPG)-(PEG).

(PPG) - (PEG) - (PPG) and (PPG)
Although there are block copolymers such as the -(PEG) type, those having a hydrophilic PEG component at the end are preferred.

Molecular weight of PEG component (total amount): 300 to 600oo1
Preferably, the molecular weight of the PPG component (total amount) is 300 to 600,001, preferably 1,000.
~10,000 is suitable.

Particularly preferably, the melting point of the PEG-PPG block copolymer is 10°C to 80°C, and PEG=P
The cloud point of the aqueous solution or dispersion of the PG block copolymer is 80.
It is below 0C.

PEG and PPG can be bonded by linear ether bonds, ester bonds by dibasic acids such as adipic acid and sepatic acid, urethane bonds by polyisocyanates such as phenylene diisocyanate, or ethylene diamine and hexamethylene diamine. may include a bond such as an alkylene amino group.

The fibrous base material used in the present invention may be in any form such as nonwoven fabric, woven fabric, or knitted fabric, and its material may be made of natural fibers, synthetic fibers, or mixed fibers thereof.

Preferably, polyester fibers such as polyethylene terephthalate, polybutylene terephthalate, and polybutylene naphthalate, or copolymerized polyesters containing appropriate amounts of copolymerized components such as isophthalic acid, benzoic acid, and sulfoisophthalic acid in these dicarboxylic acid components. These include polyester fibers, mixed spun fibers, and composite spun fibers containing 50% by weight or more of these polyesters.

In the present invention, in order to make the PE()-PP() block copolymer adhere to the fibrous base material, it is preferably made into an organic solvent solution or an aqueous dispersion. You may add additives such as agents.

When used as an aqueous dispersion, the emulsifier used is preferably a nonionic activator with a cloud point of 60° C. or lower.

The attachment may be carried out by any means such as dipping, spraying, transfer coating, etc., but it is preferable to remove the solvent or dispersion medium after attachment.

The amount of the PEG-PPG block copolymer (solid content) attached to the fibrous base material is 0.4 to 10%, preferably 0.6 to 6%, based on the weight of the base material.

If the amount of adhesion is less than 0.4%, the effect of preventing bonding between the rubber-like elastic body and the fibers will be insufficient, and the material will be hard and have high rebound, which is not preferable.

If it is more than 10%, bonding by the rubber-like elastic body is inhibited and durability against repeated bending etc. is impaired.

In the present invention, the fibrous base material to which the PEG-PPG block copolymer is adhered as described above is then applied with a solution or dispersion of a rubber-like elastomer.

The rubber-like elastic material used in the present invention refers to polyurethane elastomer, polyester elastomer, synthetic rubber, etc., but for leather-like sheet materials, JIS
20 ± 2°C, 60 ± 5% RH, elongation rate 100 with 2-place dumbbell test piece shown in K6301 Vulcanized Rubber Test Method
%/ When measured with rattan, the load at 5% elongation is o, oi
~0.40kg/1rL/ft is suitable.

More specifically, polyurethane elastomers include:
polyethylene glycol with a molecular weight of 800 to 5,000,
Polyalkylene ether glycols such as polyethylene propylene ether glycol and polytetramethylene ether glycol, or polyester diols such as polyethylene adipate, polybutylene adipate, and polycaprolactone, alone or in mixtures, and diisocyanates such as diphenylmethane diisocyanate, tolylene diisocyanate, and xylene diisocyanate. A prepolymer consisting of ethylene glycol, 1,4--j tandiol, xylene glycol, propylene diamine, hexamethylene diamine, hydrazine, dicarboxylic acid hydrazide, aminocarboxylic acid hydrazide, etc. is subjected to a chain extension reaction with a chain extension agent, etc. can be used.

Examples of polyester elastomers include terephthalic acid,
Consists of a condensate of aromatic dicarboxylic acids such as isophthalic acid and naphthalene dicarboxylic acid, or their methyl esters, and diols such as ethylene glycol, 1,4-butanediol, 6-hexanediol, cyclohexanediol, and xylene glycol. crystalline polyester segment and polytetramethylene ether glycol,
Polyalkylene ether glycol such as polypropylene glycol, polyoxyethylene ether glycol, or polyethylene adipate, polybutylene adipate,
It consists of a non-grade polyether or polyester segment made of polyester diol such as polycaprolactone.

Synthetic rubbers include 5BR1NBR, chloroprene rubber,
Such as isoprene rubber.

These rubber-like elastic bodies can be used as a solution by dissolving the polymer in a solvent, or can be used in the form of a dispersion (including an emulsion).

However, the solvent used must be selected so that it does not dissolve or significantly swell the fibrous base material.

In particular, in the present invention, P E to be attached to a fibrous base material
Since the G-P P G block copolymer contains a hydrophilic polyethylene glycol component, the treatment liquid containing the rubber-like elastic material is a dispersion in which an appropriate amount of water is mixed in advance with a solution in which the rubber-like elastic material is dissolved. When an aqueous emulsion of a liquid or a rubber-like elastic body is used, water in the treatment liquid containing the elastic body becomes PE with hydrophilic groups attached to the fiber surface.
Coordinates with the G-P P G block copolymer, effectively prevents adhesion between the elastic body and the fibrous base material during the coagulation and drying process, and produces sheet-like materials with particularly excellent flexibility and rebound properties. Can be manufactured.

Such an effect can also be achieved by a method in which the elastic body is dissolved in a water-miscible solution and applied to a fibrous base material, and then the base material is immersed in water to extract and remove the solvent.

P containing the hydrophilic polyethylene glycol component of the present invention
Since the fibrous base material to which the EG-PPG block copolymer is attached has a high affinity with aqueous elastomer dispersions or emulsions, it can be used as a fibrous base material containing hydrophobic synthetic fibers or conventional flexible sheet-like materials. When immersing an aqueous elastomer dispersion or emulsion into a fibrous base material treated with silicone softeners, fluororesin softeners, paraffin softeners, etc. that have been used in the production of When applied, there are no disadvantages such as poor penetration and uneven impregnation caused by low affinity with these processing solutions, and the processing is uniform.
The performance and operability are significantly improved.

Any conventionally known method may be used to remove the solvent or dispersion medium from the fibrous base material to which the solution or dispersion of the rubbery elastic body has been applied.

For example, a method of extracting and removing the elastic material using a non-solvent, and a method of removing by evaporation using dry heat can be adopted.

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

The percentages and parts in the examples are based on weight unless otherwise specified.

Moreover, the measurement items shown in the examples were measured as follows.

(1) Apparent density (g/1) A sample of 5C7ILX5α was measured at a temperature of 20 ± 2°C and a humidity of 60 ±
After conditioning for 24 hours under the condition of 5% RH, the weight is measured, and the thickness is determined from the thickness measured under a load of 500 g/- by the following formula.

Weight of sample [g] Mitsura 1 density = 5 x 5 x thickness) (2) Thickness The thickness measured in step 1) is expressed in units of 鈜.

(3) Weight The weight measured in step 1) is converted to the weight of In and expressed as 〆1.

(4) Tensile strength and elongation J Is-6505 according to the artificial leather test method for shoe uppers.

(5) Bending rigidity A rectangular sample with a width of 25crrL and a length of 30Crrt is protruded from a horizontal table, and the length of the protruding part is determined by 1) crrL and the protrusion angle (an extension line on the horizontal plane and the origin of the protruding part (of the horizontal table). The angle between the line connecting the end) and the tip) θ degree, the weight of the sample W (El /CrIL) and 500 g/cy
The thickness h (mm) under yt load is measured and calculated using the following formula.

The smaller the value, the more flexible it is, 9/- from 70 to 85.
If so, it exhibits flexibility comparable to that of natural leather.

(6) Rebound elasticity modulus A test piece with width ICIIL and length 9CIrL was folded in half with the skin layer on the outside, a load of 5 kg per crrL width was applied, and the load was left standing for 2 hours.The load was removed and the opening angle after 5 minutes. When is θ (degrees), it is expressed as rebound modulus - (θ/180) x 100 (equity).

If this value is too high, processability and texture will be poor, and natural leather will be
Indicates a value of 0 to 60%.

(7) Flexing resistance The leather is bent an appropriate number of times according to the leather bending test method of JIS-6545, and judged according to 5.2 of JIS-6505.

The higher the grade, the better the bending resistance.

(8) Height of Ise Mountain (See Figure 1) A circular sample with a diameter of 6 crrL is placed concentrically between two plates (with a gap of 5 cm) having a circular hole with a diameter of 4 crrL.

Next, this was set in a device equipped with a hemispherical dome-shaped push-up part with a radius of curvature of 1.75 CrIL so that the center of the circle of the sample coincided with the center of the circle of the support plate and the apex of the hemisphere. The hemispherical push-up device is 1.5 (
11771 Push up (see Figure 1a).

At this time, the sample is deformed so as to be squeezed into a hemispherical shape by the support disk and the hemispherical push-up device, but wrinkles that cannot be completely absorbed by the squeeze deformation occur in the test piece.

Draw on the surface of the test piece the line where the apex of this wrinkle and the test piece are in contact with the support disk.

Then, with the test piece laid flat, measure the distance (h) between the apex of the wrinkle and the line that was in contact with the support disk, and calculate the maximum h that occurred within the test piece to the height of the wrinkle. Satoru (1st
(see figure).

A smaller value indicates better workability.

(9) Set rate width 1 crn, length 30 crrL test piece 25 crr
Insert gauge lines at L intervals.

Then, after fixing both ends to the gripping tool, the mark interval was 27.5.
Elongate until it becomes CrrL, and in this state, heat at 110℃ xio
Perform heat treatment for a minute.

Then leave it at room temperature (temperature 20±2℃, humidity 60±5%R) for 30 minutes.
After cooling in H), the elongation is released, and the distance between the gauge lines is measured after being allowed to recover for 24 hours in the same room, and determined by the following formula.

1, -25.0 Set rate = X100 (to) 2.5 11 Distance between marked lines after 24 hours of recovery after heat treatment.

The setting rate is a measure of the plasticity of the sheet-like material, and the larger the value, the better the mold retention after processing.

Natural leather shows a value of 40-60%.

Example 1 [Manufacture of fibrous base material] A needle-punched mat of shrinkable polyethylene terephthalate fibers (0.5 denier x 38 mm) was heated at 70°C.
The sample was immersed in warm water to shrink to 60% of its original area, the water was sucked out with a suction drum, and the sample was dried under pressure at 120° C. for 2 minutes through a belt pressure machine.

The weight of the obtained nonwoven fabric was 220 g/m, and the apparent density was 0.2.
It was 1g/tone.

(Production and attachment treatment of PEG-PPG block copolymer) 800 parts of PPGI with a molecular weight of 3600, 168 parts of hexamethylene diisocyanate and 0.002 parts of dibutyltin dilaurate were mixed, and the mixture was heated at 70°C in a nitrogen stream for 600 parts.
Allowed to react for minutes.

Next, 2000 parts of PEG having a molecular weight of 2000 was added and the reaction was further carried out for 60 minutes.

Next, 1,000 parts of methyl ethyl ketone was gradually added to the above reaction mixture, and then 20,000 parts of water was gradually added to emulsify the mixture, and the mixture was vacuumed at 20° C. to remove most of the methyl ethyl ketone.

The resulting aqueous emulsion of PEGPPG block copolymer had a concentration of 19.8%.

This was further diluted with water to 5%.

The fibrous base material was immersed in a 5% aqueous emulsion of the PEG-PPG block copolymer, the wet pickup was set to 150 g/m' using an air knife, and then dried at 130°C for 5 minutes. .

The amount of the PEG-PPG block copolymer (solid content) adhered to the fibrous base material was 3.4%.

[Production of polyurethane elastomer]

Polyethylene adipate (molecular weight 1500>280 parts,
4,4'-Diphenylmethane diisocyanate 177.
5 parts, polyethylene glycol (molecular weight 1500) 20
1 part, 0.1 part of triethylene amine, and 119 parts of methyl ethyl ketone were mixed and reacted at 50°C for 90 minutes to obtain a prepolymer.

Next, 45 parts of tetramethylene glycol, 230 parts of methyl ethyl ketone, and 1.0 part of triethylene amine were added to the mixture to start the reaction at 50°C, and the temperature was gradually raised to 80°C. When the temperature reached 80°C, methyl ethyl ketone was appropriately added dropwise to dilute the mixture. The reaction was carried out to obtain a methyl ethyl ketone dispersion of polyurethane with a concentration of 20%.

Next, 0.2 parts of carbon black was added to 100 parts of the polyurethane dispersion, and while stirring with a homomixer, 25 parts of water was added to obtain a mixed dispersion.

[Production method of leather-like sheet material]

The fibrous base material to which the PEGPPG block copolymer was adhered was immersed in the polyurethane mixed dispersion liquid to be evenly encapsulated, and after scraping off the excess liquid through a squeeze roll, the temperature was 40°C and the humidity was 85°C. % high humidity dryer for 15 minutes and then dried at 100° C. for 10 minutes.

Next, one side was buffed with sandpaper to create a raised surface.

The obtained sheet-like material had a feel similar to natural leather with high flexibility and low repulsion land, and it became similar to natural leather by simple kneading.

The properties of the obtained sheet are shown in Table 1.

Example 2 The PEG-PPG attached fibrous base material obtained in Example 1 was immersed in a 10% solution of polyurethane DMF solution (Crisbon 6666HV, manufactured by Dainippon Ink), uniformly impregnated, and then squeezed with a squeeze roll. Then DMF/Wed = 70/30
The husband and wife were immersed in a 30/70 bath for 30 minutes each to solidify, then thoroughly washed with water and dried at 100°C.

I then puffed one side of the sheet with sandpaper.

The properties of the obtained sheet are shown in Table 1.

Example 3 Approximately 50% of ethylene oxide was added to PPG with a molecular weight of 4000.
A 5% aqueous emulsion of the PEG-PPG block copolymer obtained by molar addition was applied to the fibrous base material prepared in Example 1 so as to have a solid content of 1.2%.

Then, the base material was treated with 100 parts of 25% NBR latex solution,
It was immersed in a mixture of 25 parts of a latex heat sensitizing agent, 2 parts of zinc oxide, 0.1 part of colloidal sulfur, and 0.1 part of a vulcanization accelerator to be uniformly impregnated.

The latex was then passed through an infrared heater for 2 minutes to solidify the latex, and then vulcanized at 150'C for 2 minutes.

Then, it was washed with water, dried, and one side was puffed with sandpaper.

The obtained sheet had excellent flexibility and low rebound resilience, and had properties suitable for use as a leather material.

The properties of the obtained sheet are shown in Table 1.

Comparative Example 1, 2.3 Comparative Example 1 shows the characteristics of a sheet-like product made using a fibrous base material to which no PEG-PPG block copolymer is attached in accordance with Examples 1 and 2.3. , 2.3 in Table 1.

Claims (1)

[Claims] 1. In a method for producing a leather-like sheet material by applying a solution or dispersion of a rubber-like elastic body to a fibrous base material and then removing a solvent or dispersion medium from the base material, the fibrous base material is coated in advance with: 1. A method for producing a leather-like sheet material, which comprises adhering a polyethylene glycol-polypropylene glycol block copolymer in an amount of 0.4 to 10% based on the weight of the substrate.