JPS5920029B2 - Method for manufacturing leather-like sheet material - 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 found that we can create leather-like sheet-like material by adding rubber-like elasticity to the fibrous base material. During production, if a specific amount of a specific copolymerized polyester is attached to the fibrous base material before applying the rubbery elastic body to the fibrous base material, the rubbery elastic body and the fibers can form a strong bond. Because the material is not produced, a flexible sheet-like product can be obtained, and solid frictional resistance between fibers and between the fibers and the rubber-like elastic body increases, reducing the rebound resilience of the sheet-like material and improving processability. The present invention was achieved based on the finding that the mold retainability after molding is improved because the material has appropriate 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. The molecular weight is 500 to 6 on the base material in advance.
0,000 polyalkylene ether glycol, a low molecular weight diol having a molecular weight of 60 to 450, a dicarboxylic acid or its ester, and the copolymerized polyester obtained by Kami et al.
This is a method for producing a leather-like sheet material, characterized in that the weight of the base material is 04 to 10 degrees, and 10 degrees is adhered to the base material.

The copolymerized polyester used in the present invention has a molecular weight of 500 to 60,000, preferably 1,500 to 8,000.
polyalkylene ether glycol and molecular weight 60-4
50, preferably 60 to 200, is a copolymerized polyester obtained from a low molecular weight diol and a dicarboxylic acid or an ester thereof.

Copolyesters obtained from materials outside the above range cannot achieve the object of the present invention.

As the polyalkylene ether glycol, polyoxyethylene glycol, polypropisone glycol, and polytetramethylene ether glycol can be used, and as the low molecular weight diol, ethylene glycol, propylene gellicol, tetramethylene glycol, hexitemethylene glycol, and xylene glycol can be used. Cyclohexane diol, cyclohexanedimethanol, etc. are used.

As dicarboxylic acids, terephthalic acid, isophthalic acid/4,
Aromatic dicarboxylic acids such as naphthalene dicarboxylic acid, aliphatic dicarboxylic acids such as oxalic acid and adipic acid can be used.

The ester of dicarboxylic acid refers to methyl ester, ethyl ester, etc. of the dicarboxylic acid.

In order to fully achieve the object of the present invention, at least 60% of the weight of polyoxyalkylene ether glycol in the copolymerized polyester is polyoxyethylene glycol, and [number of moles of low molecular weight diol component]/[
The value of the number of moles of polyalkylene ether glycol is 0
．． 5 to 2.0 is preferable.

Furthermore, in order to sufficiently maintain the durability of the leather-like sheet according to the present invention, the composition of the copolymerized polyester must be such that its melting point is 30 to 140°C and it has crystalline block polyester segments. It is preferable to select.

Crystalline block polyester segments are polyester segments consisting of dicarboxylic acids and low molecular weight diols, such as aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, ethylene glycol, tetramethylene glycol, and 6-hexane. These include diols, xylene glycol, cyclohexanediol, and other diols.

In particular, when a copolyester having an aromatic crystalline block polyester segment having the same chemical structure as the fibrous base material used is selected, the effects of the present invention will be even more excellent.

Such a copolyester can be produced by a known method.

For example, dicarboxylic acid or its ester, low molecular weight diol, and polyalkylene ether weighed in a predetermined ratio are mixed, calcium acetate is added as an esterification reaction catalyst, and antimony oxide is added as a polymerization catalyst.
℃ reaction method, or first synthesize an ester from a dicarboxylic acid or its ester (for example, methyl ester) and a low molecular weight diol, and then melt-react it with an appropriate amount of polyalkylene ether glycol to partially remove the low molecular weight diol. A method such as depressurizing removal can be used.

The fibrous base material used in the present invention may be in the form of nonwoven fabric, woven fabric, knitted fabric, etc., 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. Polyester fibers and 50 ijt% of these polyesters
These are mixed spun fibers and composite spun fibers containing the above.

In the present invention, since the copolymerized polyester is attached to the fibrous base material, it is preferably made into an organic solvent solution or an aqueous dispersion.Additives such as emulsifiers and dispersion stabilizers are added to make the aqueous dispersion. It's okay (・.

The adhesion may be carried out by means that produce a temperature of °C.
It is preferable to remove the solvent or dispersion medium after deposition.

The amount of copolymerized polyester (solid content) attached to the fibrous base material is 04 to 10%, preferably 0.6 to 6%, based on the weight of the base material.

If the adhesion amount is less than 0.4%, the effect of preventing bonding between the rubber-like elastic body and the fibers is insufficient, and the hard and rebound-resilient thick ℃・
This is not desirable.

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 copolyester is adhered as described above is then applied with a solution or dispersion of a rubbery elastic material.

The rubber-like elastic material used in the present invention refers to polyurethane-based nydistomers, polyester-based elastomers, synthetic rubbers, etc.;
When measured at 20°C ± 2°C, 60% RH ± 5% RH, and an elongation rate of 100%/- using a two-place dumbbell test piece shown in ISK6301 Vulcanized Rubber Test Method, the load at 5% elongation is 0.01~ A material in the range of 0.40 kg/ma is suitable.

More specifically, polyurethane elastomers include:
Polyalkylene ether glycols such as polyethylene glycol, polyethylene propylene ether glycol, and polytetramethylene ether glycol having a molecular weight of 800 to 5,000, or polyester diols such as polyethylene adipate, polybutylene adipate, and polycaprolactone, alone or in mixtures, and diphenylmethane diisocyanate, tolylene diisocyanate. , a prepolymer consisting of a diisocyanate such as xylene diisocyanate, and a chain extender such as ethylene glycol, 1,4-butanediol, xylene glycol, propylene diamine, hexamethylene diamine, hydrazine, dicarboxylic acid hydrazide, or aminocarboxylic acid hydrazide. It is possible to use products subjected to a chain extension reaction at °C.

Examples of polyester elastomers include terephthalic acid,
Aromatic dicarboxylic acids such as inphthalic acid and naphthalenedicarboxylic acid, or their methyl esters, and diols such as ethylene glycol, Non-quality products consisting of crystalline polyester segments consisting of condensates and polyalkylene ether glycols such as polytetramethylene ether glycol, polypropylene glycol, and polyoxyethylene ether glycol, or polyester diols such as polyethylene adipate, polybutylene adipate, and polycaprolactone. It consists of polyether or polyester segments.

Synthetic rubbers include SBR, NBR, 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, when a copolymerized polyester containing a hydrophilic polyoxine ethylene glycol component is used as the copolymerized polyester to be adhered to the fibrous base material in the present invention, the treatment liquid containing the rubbery elastic body may be prepared by dissolving the rubbery elastic body. When using a dispersion in which an appropriate amount of water is mixed in the solution or an aqueous emulsion of @rubber-like elastic material, the water in the treatment liquid containing the elastic material transforms into a copolymerized polyester with hydrophilic groups attached to the fiber surface. Coordination, coagulation, and adhesion between the elastic body and the fibrous base material during the drying process can be effectively prevented, and a sheet-like article with particularly excellent flexibility and rebound properties can be produced.

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.

Furthermore, when a copolymerized polyester containing a hydrophilic polyoxyethylene glycol component is attached to a fibrous base material, it has a high affinity with an aqueous elastomer dispersion or emulsion.

Therefore, fibrous base materials containing hydrophobic synthetic fibers or fibrous base materials treated with silicone-based softeners, fluororesin-based softeners, paraffin-based softeners, etc. that have been conventionally used in the production of flexible sheet materials. When applying an aqueous elastomer dispersion or emulsion to materials by immersion treatment, the present invention eliminates the drawbacks such as poor permeability and uneven impregnation caused by low affinity with these treatment solutions, and improves the uniformity of the treatment. - 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 ('?/crA) A sample of 5 cIrL x 5 cIrL was conditioned for 24 hours at a temperature of 20°C ± 2°C and a temperature of 60°C ± 5% RH, and then its weight was measured, and a load of 5009/crA was measured. It is determined by the following formula from the thickness (CWt) measured below.

(2) Thickness The thickness measured in step 1) is expressed in mm.

(3) Weight: Convert the weight measured in 1) to the weight of 1 m', and convert it to 2 parts m'.
It is expressed as

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

(5) Protrude a rectangular sample with a bending rigidity width of 2.5 cm and a length of 30 CTL from a horizontal table, and calculate the length of the protruding part.1) CrrL and the protrusion angle (the extension line on the horizontal plane and the origin of the protruding part) angle) θ (degrees) between the line connecting the end of The thickness h (mm) under a load of /crA is measured and calculated using the following formula.

A lower value indicates more flexibility, 70-85 kg
/cyst exhibits flexibility comparable to natural leather.

Bending rigidity = 12 ・Rc / h” (kg/r
sl ) (6) Rebound modulus A test piece with a width of 1crIl and a length of 9cIrL was folded in half with the skin layer on the outside, a load of 5kg per 1crfL width was applied, and the load was left to stand for 2 hours, then the load was removed and 0.5 If the opening angle after minutes is θ (degrees), the rebound elasticity modulus is expressed as (θ/180)×100(%).

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) Bending 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 K6505.

The higher the grade, the better the bending resistance.

(8) Height of the rocky mountain (See Figure 1) A circular sample with a diameter of 6 crrL is placed concentrically between two plates (gap of 5 rnm) with a circular hole of 4 crfL in diameter.

Next, this was set in a device equipped with a hemispherical dome-shaped push-up part with a radius of curvature of 1.75 crrL so that the center of the circle of the sample, the center of the circle of the support plate, and the apex of the hemisphere coincided. 1.5c from the top surface of the hemisphere push-up device
IrL is pushed 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.

Mark the top of this wrinkle and the line where the test piece touches the support disk on the surface of the test piece.

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: 25 cTr for a test piece with a width of 1 cyrt and a length of 30 cTrL
Insert gauge lines at L intervals.

Then, after fixing both ends to the gripping tool, the gauge line spacing is 275c.
It is elongated until it becomes In, and in this state, heat treatment is performed at 110° C. for 10 minutes.

Then leave it at room temperature for 30 minutes (temperature 20℃±2℃, humidity 60%±5
%RH), then solve (Fl'1-1j) and recover in the same room for 24 hours. The distance between the gauge lines is measured and determined by the following formula.

11 The distance setting rate between the marked lines after 24 hours of recovery after heat treatment 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 60-80%.

Example 1 [Production of copolymerized polyester] 39 parts of dimethyl terephthalate, 6 parts of ethylene glycol
1 part of calcium acetate was added to 56 parts of polytetramethylene ether glycol (molecular weight 2,800) and 320 parts of polyoxyethylene ether glycol (molecular weight 4,000), and the mixture was reacted at normal pressure at 180 to 190°C for 2 hours. The mixture was allowed to react for an additional 2 hours under vacuum.

The melting point of the obtained copolymerized polyester is 60 to 70°C, and the ratio of the number of moles of ethylene glycol to the number of moles of polyalkylene ether glycol is about 1.

The obtained copolymerized polyester was mixed with Butylceron Lube 250.
0 parts, and heated and dissolved at 150° C. for 30 minutes.

Next, 15 parts of nonionic activator nonylphenyl ether (POEIO mole addition) was added thereto and uniformly dissolved, and then cooled to 30° C., and water was added thereto with continued stirring to obtain an emulsified dispersion.

[Production and adhesion treatment of fibrous base material]

Next, a shrinkable polyethylene terephthalate fiber mat (0
, 5 denier x 38 mm) at 70°C.
Soak it in warm water, shrink it to 60% of its original area and squeeze out the water.
Next, the copolymerized polyester dispersion obtained by the above method was immersed in a solution diluted to 2% with water, and after uniform impregnation,
The amount of impregnation was adjusted by passing it through a squeeze roll, and it was roughly dried by passing it through a belt pressure machine at 120°C for 2 minutes, and then heat-treated at 130°C for 5 minutes.

The obtained fibrous base material has a weight of 220 P/m' and an apparent density of 0.
．． 21? /ca, and the amount of copolymerized polyester adhered to the fibrous base material was 3.2%.

[Manufacture of polyurethane elastomer and tomer]

280 parts of polyethylene adipate (molecular weight 1500),
4,4'-cyphenylmethane 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 poured 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.

[Manufacture of leather-like sheet material]

The fibrous base material to which the copolymerized polyester has been adhered is immersed in the mixed dispersion liquid to uniformly enclose it, and then passed through a squeeze roll to scrape off the excess liquid. Run in the dryer for 15 minutes, then at 100°C for 1
Drying was performed for 0 minutes.

Puff one side with sandpaper to make the surface fluffy.

The obtained sheet-like material had a feel similar to natural leather with high flexibility and low rebound, and was suitable as a velor-like shoe sheet material.

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

Example 2 The copolymerized polyester-attached fibrous base material obtained in Example 1 was
It was immersed in a solution containing 100 parts of a 25% NBR latex solution, 2.5 parts of a latex heat sensitizing agent, 2 parts of zinc oxide, 0 and i parts of colloidal sulfur, and 0 and i parts of a vulcanization accelerator to be uniformly impregnated. .

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

Next, it was thoroughly 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.

Example 3 The copolymerized polyester-attached fibrous base material obtained in Example 1 was
After soaking in a 10% solution of polyurethane DMF solution (Crisbon 6666HV, manufactured by Dainippon Ink) and impregnating it uniformly, it was squeezed with a squeeze roll, and then DMF/Beau 70 was applied.
After coagulating by immersing in /30 and 30/70 baths for 30 minutes each, the samples were 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.

Comparative Examples 1 to 3 Corresponding to Examples 1.2.3, the characteristics of sheet-like products made using a fibrous base material to which no copolymerized polyester is attached are as Comparative Examples 1.2.3 and 1. Shown in the table.

The leather-like sheet material of the present invention is softer than conventional artificial leather and exhibits flexibility comparable to natural leather (see flexural rigidity).

It also has better processability than conventional artificial leather (see rebound modulus and height of burrs), and shape retention after processing is better than conventional artificial leather (see set rate).

Example 4 Polyethylene terephthalate (inphthalic acid) 10ml
% copolymerization, molecular weight approx. 40,000) and 200 parts of polyoxyethylene ether glycol (molecular weight 20,000) were melted and mixed, the mixture was reacted until the melt viscosity decreased and equilibrium was reached, and then butyl cellosolve was added to this. Add 300 parts of
The mixture was heated and dissolved at 150°C.

Next, 20 parts of nonylphenyl ether added with 10 moles of pQE was added and dissolved therein, and the mixture was cooled to 20° C., homogenized, and 1400 parts of water was added to prepare an emulsion.

This was then dipped into a raised cloth (fibrous base material) made of polyester fibers and cotton so that the amount was 6% of the weight of the fibers, and then dried.

Further, this was immersed in a liquid having the same composition as the polyurethane mixed dispersion prepared in Example 1, squeezed with two doctor knives, immersed in methanol for 30 seconds, and immediately heated to 60°C.
The mixture was treated in a dryer for 30 minutes, and then dried at 100°C for 10 minutes to obtain a sheet-like product.

The obtained sheet-like material had a thickness of 0.8 mm, a polyurethane adhesion amount of 60% of the weight of the base material, and a bending rigidity of 32 kg/
ca, rebound resilience was 68%, it was flexible, had low rebound resilience, and had the feel of natural leather for clothing.

[Brief explanation of drawings]

Figures 1a and 1) are explanatory diagrams of a method for measuring the height of a rocky mountain.

Claims (1)

[Claims] 1. 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 the solvent or dispersion medium from the base material at a temperature of
Polyalkylene ether glycol with a molecular weight of 500 to 60,000 and a molecular weight of 60 to 45 are added to the fibrous base material in advance.
1. A method for producing a leather-like sheet material, which comprises adhering a copolyester obtained from a low molecular weight diol of 0.0 and a dicarboxylic acid or an ester thereof in an amount of 0.4 to 10% of the weight of the substrate.