JPS5821932B2 - Polyurethane elastomer solution composition for wet synthetic leather - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyurethane elastomer solution composition for wet synthetic leather.

More specifically, it has a fast coagulation rate during wet coagulation, a fast solvent removal rate during water washing, excellent moisture permeability and hydrolysis resistance, can form synthetic leather that is flexible, lightweight, and has a uniform microporous structure, and has good storage stability. The present invention relates to a polyurethane elastomer solution composition (mixture).

Conventionally, synthetic leather produced by the wet method involves wet coagulation by coating and impregnating a base fabric or membrane plate with a solution of a polymer such as polyurethane in a water-miscible organic solvent or a mixture thereof, and then immersing it in a coagulating liquid such as water. After that, the solvent remaining in the coagulated product is removed by washing with water and dried.
The solidification rate is fast, the solvent can be removed in a short time when washing with water, the porous sheet after drying has good high humidity and hydrolysis resistance, and is flexible and lightweight. It is important that the polyurethane solution or its mixture has a stable, uniform and fine porous structure without large pores (cavities), and that the polyurethane solution or its mixture has good storage stability.

This is because if even one giant pore exists in a porous sheet, stretching stress will be generated there during stretch molding during shoe manufacturing, and the giant pore will easily dent or break, making it difficult to improve moisture permeability and molding process. This is because even if the product has good properties, it is treated as having low commercial value.

In addition, if the coagulation rate or solvent removal rate during water washing is slow, the ability to produce porous sheets will be reduced, and if solvent remains after washing with water, the heat during drying will cause the polyurethane to swell and soften, crushing micropores and reducing moisture permeability.

Among the above-mentioned problems, methods for producing uniform microporous sheets without large pores include methods such as changing the composition of coagulation rate retarders and coagulants, and methods for speeding up the removal rate of solvents by washing with water include using a special polyurethane elastomer solution. Although methods using such compositions have been proposed, a method that can satisfy all of the above-mentioned problems (necessary conditions) has not yet been found.

For example, an opaque solution composition produced by mixing a polyvinyl chloride solution with a polyurethane solution in which a prepolymer consisting of polyethylene butylene adipate and diphenylmethane diisocyanate is chain-extended with hydrazine and ethylenediamine is described in Japanese Patent Publication No. 50-28977. Although it has good solvent removal properties, it has poor storage stability and cannot form a flexible porous film with high moisture permeability.

Furthermore, the composition liquid produced by mixing an emulsion of an elastic polymer with a homogeneous solution of a polyurethane elastomer described in JP-A-52-28906 has poor storage stability;
When coagulated with water, it forms a porous film with large pores, and the rate of solvent removal by water washing is also relatively slow.

Also, JP-A-51-111264 and JP-A-51-1
In the polyurethane composition solution described in Japanese Patent Publication No. 11265, which is made by dissolving a blend of two polyurethanes of the same type that have polylactone glycol, polycarbonate, or polyether glycol as soft segments and have different nitrogen content, water When coagulated with water, it forms a sheet with large pores and low moisture permeability, and the rate at which the solvent is removed by water washing is also slow.

As a result of intensive research to solve the above-mentioned problems, the present inventor found that all of the specific polyurethane elastomer solutions mentioned below have poor solvent removal properties, moisture permeability, and uniformity of porous structure during wet (water) coagulation. However, as described below, the elastomer solution composition (liquid) produced by mixing in a specific combination is stable and solidifies quickly, and when washed with water, the solvent can be easily and quickly removed, increasing manufacturing efficiency. The present invention was completed after discovering that all of the above-mentioned problems could be easily solved by producing a sheet with excellent moisture permeability and hydrolysis resistance, being flexible, lightweight, and having a uniform fine porous structure without large pores. did.

The purpose of the present invention is to be stable even when stored for a long period of time, to solidify quickly when applied to a synthetic leather substrate, impregnated, and wet solidified.
A polyurethane elastomer solution composition that allows the solvent to be removed in a short time when washed with water, has high moisture permeability, hydrolysis resistance, flexibility, and lightness, and can easily produce a leather-like sheet with a uniform fine porous structure without large pores. It's about providing things.

That is, the present invention provides a polyurethane solution composition produced by mixing at least two solutions in which a polyurethane elastomer consisting of a polymeric diol, an organic diisocyanate, and a chain extender is dissolved in a water-miscible organic solvent. One polyurethane elastomer solution A to be mixed contains polymethylene glycol adipate diol alone or 7
Turbidity 0.05 in which polymethylene glycol adipate-based polyurethane elastomer made of a diol mixture of polydiethylene glycol adipate diol of 0 weight coefficient or more and 30 weight coefficient or less is dissolved as a polymer diol.
The other polyurethane elastomer solution B is a transparent solution containing a polymeric diol selected from the group consisting of polydiethylene glycol adipate diol, polyε-caprolactone glycol, and polydipropylene glycol adipate diol alone or in an amount of 70% by weight. 30
A polydiethylene glycol adipate-based polyurethane elastomer, a polyε-caprolactone-based polyurethane elastomer, or a polydipropylene glycol adipate-based polyurethane elastomer, which is made of a diol mixture with polymethylene glycol adipate diol or polyalkylene ether glycol below the weight ratio, is dissolved. and the composition produced by mixing the polyurethane elastomer solution is a cloudy white liquid with a turbidity of 0.2 to 1.5. This is a polyurethane elastomer solution composition for wet synthetic leather.

Hereinafter, embodiments of the present invention will be explained in detail.

Polyurethane elastomer a dissolved in the one polyurethane elastomer solution A used in the present invention
has an average molecular weight of 500 to 3000 (preferably 1000
-2000) alone or a mixture of polydiethylene glycol adipate diol of 70% to 30% by weight, an organic diisocyanate and a chain extender (diamine, low molecular weight glycol, etc.) using a one-shot method. Alternatively, it is a single or a mixture of polyurethane or polyurethane urea synthesized by a prepolymer method without a solvent (bulk polymerization) or in a solvent (solution polymerization method).

(This polyurethane elastomer a was referred to as a polymethylene glycol adipate-based polyurethane elasmer for convenience because the soft segment constituting it is mainly composed of polymethylene glycol adipate diol.

) In this case, if the amount of polymethylene glycol adipate diol used is less than 70% by weight, the coagulation rate and solvent removal rate of the composition will be slow, and a flexible porous sheet with high moisture permeability and no macropores will be formed. Can not do it.

The polymethylene glycol adipate diol referred to in N means an adipate diol obtained by condensing adipic acid with at least one glycol having a methylene group (-CH2 group), such as polyethylene glycol adipate diol, polypropylene glycol adipate diol, polybutylene. Glycol adipate diol, polyhexamethylene adipate diol, polyneopetyl glycol adipate diol, polycyclohexane (
1,4) Homopolymerized adipate diols such as glycol adipate diol, and copolymerized adipate diols such as polyethylene butylene glycol adipate diol and polyethylene propylene glycol adipate diol.

The polyurethane elastomer B dissolved in the upper part of the other polyurethane elastomer solution B is a polymeric diol selected from the group consisting of polydiethylene glycol adipate diol, polyε-caprolactone glycol, and polydipropylene glycol adipate diol alone or in the amount of 70% by weight. % or more and 30% by weight or less of polymethylene glycol adipate diol or polyalkylene ether glycol, an organic diisocyanate, and a chain extender by a one-shot method or a prepolymer method, and without a solvent (bulk polymerization) or with a solvent. Polyurethane or polyurea synthesized by solvent polymerization (solvent polymerization method) alone or as a mixture.

These polyurethane elastomers b1. b2 or b
At least the first amount of polydiethylene glycol adipate diol or polymethylene glycol adipate diol used as the polymer glycol in step 3 is 7
If it is less than 0% by weight, the hydrolysis resistance tends to deteriorate, the coagulation rate of the composition becomes slow, and the solvent removal properties, moisture permeability, flexibility, etc. of the coagulated product decrease, which is not preferable.

The polymethylene glycol adipate diol having a weight ratio of 30 or less is the same as the polymethylene glycol adipate diol that is used as a solvent in one of the polyurethane elastomers A.

Examples of the polyalkylene ether glycol include polyethylene ether glycol, polypropylene ether glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, and polycyclohexyl 4,4'-methyl ether glycol.

Examples of the organic diisocyanate include tolylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, naphthylene diisocyanate, xylylene diisocyanate, 4,4'-dodecahydrodiphenylmethane diisocyanate, isophorone diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, and the like. can.

Among these, aromatic diisocyanates are particularly preferred.

Examples of chain extenders include low molecular weight glycols with a molecular weight of 500 or less, such as ethylene glycol propylene glycol, phethylene gelicol, hexamethylene glycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexane glycol, and 1,4-cyclohexane dimetatool. , ethylenediamine, hydrazine, 1,2
- Diamines such as propylene diamine, hexamethylene diamine, phenylene diamine, tolylene diamine, 4,4-diaminodiphenylmethane, naphthylene diamine, cyclohexylene diamine, isophorone diamine 4,4'-diaminododecahydrodiphenylmethane, water, amino alcohol , dihydrazide, and the like.

One or more types of chain extenders are used.

The polyurethane elastomer obtained by polymerization without a solvent is dissolved in an appropriate amount of a water-miscible organic solvent to prepare each of the polyurethane elastomer solutions A and B at an appropriate concentration, and the polyurethane elastomer is obtained by solution polymerization. The polyurethane elastomer solution can be used as it is or diluted to an appropriate concentration.

Generally, solution polymerization is preferable because it is easier to obtain a transparent solution and the above-mentioned effects can be sufficiently exhibited.

The concentration of the polyurethane elastomer a or b in the polyurethane elastomer solution A or B used in the present invention is usually 20 to 40 parts by weight, preferably 20 to 35 parts by weight.

If it is less than 20% by weight, the coagulation rate of the mixed composition liquid will be slow, and the moisture permeability and storage stability may tend to decrease.If it is more than 40% by weight, defoaming will be difficult and the mixed composition liquid will be Solvent removal properties and moisture permeability of the coagulated product may be reduced.

The polyurethane elastomer solution A or B used in the present invention is a water-miscible organic solvent solution in which the above-mentioned specific polyurethane elastomer is dissolved, and the turbidity (
It is important that the material be substantially transparent (transparent when observed with the naked eye) with an optical turbidity of 0.05 or less.

When the turbidity is greater than 0.05, it gives a slightly cloudy to white turbid appearance, and moreover, the turbidity of the composition liquid produced by mixing both polyurethane elastomer solutions A and B is 0.2 to 1.5.
Even if it is within the range, the storage stability of the composition liquid decreases,
This is not preferred because it tends to form large pores and the solvent removal properties and moisture permeability of the coagulated product deteriorate.

The water-miscible organic solvent in the polyurethane elastomer solution A or B (the water-miscible organic solvent used for dissolving the polyurethane elastomer obtained by solvent-free polymerization or solvent polymerization) may include ordinary water for polyurethane. Miscible organic solvents include, for example, amide solvents such as N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, tetramethylurea, dioxane, and gamma-based solvents. Examples include butyrolactone, cyclohexanone, methyl ethyl ketone, etc., and they may be used alone or in combination.

Among the above solvents, amide solvents, especially N. N-dimethylformamide is preferred.

The polyurethane elastomer solution composition of the present invention is produced by mixing one of the polyurethane elastomer solutions A and the other polyurethane elastomer solution B, or by adding an appropriate solvent after mixing as necessary to adjust the concentration. Ru.

It is necessary that the turbidity of the polyurethane elastomer solution composition of the present invention to be produced is within the range of 0.2 to 1.5.

If the turbidity is outside the above range, phase separation, polymer precipitation, gelation, etc. will occur during storage, resulting in poor storage stability, lower coagulation speed, and lower solvent removal properties, resulting in a film with high density and low moisture permeability. This is not desirable because it generates

The mixing ratio and mixing amount of A and B in the polyurethane elastomer solution are relatively wide, and usually the polyurethane elastomer a in the polyurethane elastomer solution composition is
and b are mixed in a weight ratio of 90:10 to 10:90.

Usually, the solutions A and B are mixed so that the total concentration of both polyurethane elastomers in the solution composition A is 20 to 38 weight percent (preferably 25 to 35 weight percent).

Outside the above range, the storage stability, solvent removal properties, and moisture permeability tend to decrease, and large pores tend to be generated. 3-polydipropylene glycol adipate-based polyurethane elastomer, polytetramethylene ether glycol-based polyurethane elastomer, and polyε - Caprolactone-based polyurethane elastomers have good hydrolysis resistance. Therefore, the polyurethane elastomer solution composition of the present invention containing a large amount of these polyurethane elastomers or their residues can be used as a porous sheet etc. with excellent hydrolysis resistance. can be formed.

The polyurethane solution composition of the present invention produced by mixing the aforementioned polyurethane elastomer solutions A and B is a substantially cloudy homogeneous liquid with a turbidity of 0.2 to 1.5 (
The viscosity is usually 5000 to io, oo.

cps/30°C), but stability against temperature changes.

It has excellent storage stability and can be stored (stored) stably for a long period of time without any change in quality, making it convenient and suitable for industrial applications.

The solution composition of the present invention is used in the production of wet synthetic leather.
After impregnating and applying resin to woven fabrics, knitted fabrics, non-woven fabrics, or at least one surface of a fibrous substrate or membrane plate (e.g. glass plate, metal plate) to which they are attached, the resin is first wetted and coagulated with a coagulating liquid (bath). However, in this case, a coagulant such as water or alcohol (non-solvent for polyurethane elastomer) alone or in a mixture, or a water-polyurethane elastomer solvent (e.g. I) MF mixture mainly composed of water can be used relatively quickly and homogeneously. Upon solidification, a stable leather-like porous sheet material with no skin or wrinkles on the surface and excellent moisture permeability can be produced.

Also, JP-A-52-111264, JP-A-52-111
One of the features of the present invention is that there is no decrease in stability during storage and no selectivity of coagulating liquid (agent) as with urethane-based lastomer solution compositions such as those disclosed in Japanese Patent Publication No. 265-265 and Japanese Patent Application Laid-Open No. 52-28905. It is.

In general, with polyurethane elastomer solutions that have a fast solidification rate and good solvent removal properties when washed with water, the surface of the solution coating film solidifies rapidly to form a skin, and the unsolidified portion inside the coating film is delayed considerably. However, the polyurethane solution composition of the present invention solidifies relatively quickly, and the solvent can be easily and quickly removed during washing with water. The uniqueness of the action and effect is remarkable in that it improves productivity and forms a leather-like sheet with high moisture permeability and a uniform microporous structure free of large pores.

Examples will be described below.

In the examples, part means part by weight, and part means weight %.

The methods for measuring or testing turbidity, solvent removal, 100% modulus, density, moisture permeability, and stability are as follows.

(1) Turbidity Turbidity is defined by the following formula.

Tu-1m1x-(■1・a1+■2・a2+...music・+■n-an) where Tu: Turbidity lm1x: Components 1, 2...,.

Absorbance of the mixed solution in which al, a2, river...an are dissolved in each weight ratio In = Absorbance of a solution of component n as a single solution at the same concentration as in the mixed solution All: Absorbance of the solute in the mixed solution The weight fraction of component n, therefore a1+a2+...+an=1.0.

Absorbance was measured using a double-beam spectrophotometer (e.g. Hitachi 624).
(type digital spectrophotometer), optical path length is 1.0 cIfL.
Measurements are performed using a quartz cell using the following steps.

That is, the quartz cell filled with only a solvent is placed in the optical path on the control side, and the same quartz cell filled with the sample solution is placed in the optical path on the sample side, and the absorbance at a wavelength of 400 nm (nanometers) is read.

Note that the room temperature at the time of measurement is 25° C., and the sample solution is stored under the measurement temperature condition for 24 hours after preparation, and then the measurement is performed according to the above-mentioned procedure.

Furthermore, when transferring a sample solution to a quartz cell for absorbance measurement, extreme care must be taken to prevent not only foreign matter such as dust but also air bubbles from entering the sample solution.

(2) Solvent removal (residual solvent) A solution of the sample polyurethane in N,N-dimethylformamide is placed on a glass plate in a thickness of 1.0 mm and an area of 100 cI? L
After coating the sample solution in the form of a thin film (10 crrL x 10 crrL), the sample solution is immersed for 30 minutes in a solution of 30° C. water (coagulation liquid) for 30 minutes.

After that, the glass plate was taken out, the coagulated film formed on the glass plate was peeled off, and then this coagulated film was left at 60°C.
water (washing water) for 30 minutes to elute (natural washing) the N,N-dimethylformamide solvent contained in the coagulated film.

After soaking, take out the film, wipe off the water adhering to its surface with P paper, bend the film slightly from the center, and press it firmly with pliers to remove the remaining liquid (N) inside the film. : If N-dimethylformamide remains, it is an aqueous solution; if not, it is a liquid consisting only of water). Squeeze 1 to 2 drops of N-dimethylformamide onto the sample plate of the Atsube refractometer.

Next, measure the refractive index of the liquid.

(This operation and measurement are performed in a constant temperature room at 25°C.

) On the other hand, create a calibration curve graph showing the relationship between the concentration of N,N-dimethylformamide and the refractive index in an N,N-dimethylformamide aqueous solution, and use this graph and the refractive index of the squeeze fluid measured previously to calculate the Determine the concentration (by weight) of N,N-dimethylformamide contained in the upper part of the liquid.

The lower the concentration, the better the sample polyurethane elastomer solution has a better desolvation property after wet coagulation (the solvent in the wet coagulation product is easily removed by washing with water). This means that it was completely eluted and removed by washing with water and rinsing.

(3) The 100% modulus (hereinafter abbreviated as 100%M) coagulated film was immersed in water at 60°C for 120 minutes and then dried with hot air at 80°C, but in the same manner as in the solvent removal test. Create a sample film.

The stress of this sample film at an elongation rate of 100 degrees was measured according to the method of JIS-6650, and the stress was determined as a modulus of 100.

The unit is 9/1! It, the smaller the value, the softer the touch.

(4) Using the same sample film as in the case of density 100% modulus,
The density was determined from its volume and weight.

The lower the density, the lighter the weight.

(5) The same sample film as in the case of 100% moisture permeability modulus was
-The moisture permeability was measured according to the method of -6549.

The unit is 1n9/cTL/hr, and fabrication humidity with a large value is good.

(6) Presence or absence of giant pores (cavities) formed inside the film100
The cut surface of the same sample film as in the case of % modulus and the surface where the film was folded in two were shaved with a razor, and the surfaces were observed under a microscope to determine the presence or absence of large pores (cavities).

(7) Using the same sample film as in the case of 100% hydrolysis resistant modulus,
JIS-6552 in a constant temperature room at 0℃ and relative humidity of 90%
The strength and elongation was measured according to the method described in 2007, and the strength retention rate was expressed as the number of days elapsed when the strength retention rate became smaller than the initial factor of 50.

The longer the number of days, the better the hydrolysis resistance.

Example 1 49.5 parts of polybutylene glycol adipate diol with a molecular weight of 1970, 30.0 parts of 4.4'-diphenylmethane diisocyanate, 8.3 parts of 1.4-butanediol
1 part and 2.05 parts of NN-dimethylformamide (hereinafter referred to as DMF) were placed in a polymerization machine, and the polymerization reaction was carried out at 60°C for 6 hours while stirring in a nitrogen gas atmosphere, and then 0.3 part of ethanolamine was added as a polymerization terminator. One of the polyurethane elastomer solutions described above (hereinafter referred to as elastomer solution A) was obtained.

Its solid content concentration is 29.9%, and its viscosity is 79,000 cps/
The turbidity at 30°C was 0.013 and the appearance was transparent.

Next, the other polyurethane elastomer solution M (hereinafter referred to as elastomer solution B) was obtained in the same manner as above except that polydipropylene glycol adipate diol having a molecular weight of 1970 was used instead of polybutylene glycol adipate diol.

Its solid concentration is 30%, and the viscosity is 81,000 cps/30°C.
The turbidity was 0.051 and the appearance was transparent.

A polyurethane elastomer solution composition of the present invention (hereinafter referred to as composition solution A+B1) was prepared by using 50 parts each of the thus obtained one elastomer solution A and the other elastomer solution B1 and thoroughly mixing them with stirring. .

The solid content concentration was 301%, the turbidity was 0.7'), and the appearance was a milky white homogeneous liquid.

This composition was left in the back of a constant temperature chamber for 6 months, which was kept reciprocating between .±.45.degree. C., but it remained stable without any abnormalities.

Next, the above-mentioned solution composition (composition solution of A + B1), the stability of the above-mentioned elastomer solutions A and B1, 100% M of the removable (residual solvent) produced film in wet coagulation, density, moisture permeability, presence or absence of macropores. I looked into it.

As is clear from these results, one elastomer solution A (a solution of a polyurethane elastomer in which the polymer diol constituting the soft segment is composed of polybutylene glycol adipate diol alone) and the other elastomer solution Bl (a solution of a polyurethane elastomer in which the polymer diol constituting the soft segment is polybutylene glycol adipate diol alone) and The solution composition of the present invention, which is obtained by mixing a solution of a polyurethane elastomer in which the diol is polydipropylene glycol adipate diol alone, has better properties as a de-lodging agent for wet coagulation products, solution storage stability, etc. than each elastomer solution. It is possible to obtain a leather-like sheet-like material that is lightweight, has excellent moisture permeability and flexibility, and has a uniform porous structure without large internal pores.

Example 2 Instead of polybutylene glycol adipate diol,
A polyurethane elastomer solution (hereinafter referred to as elastomer solution B2) was obtained in the same manner as in Example 1 except that polydiethylene glycol adipate diol having a molecular weight of 1970 was used.

The solid content concentration is 29.9%, and the viscosity is 80,000 cps/3.
The temperature was 0°C, the turbidity was 0.010, and the appearance was transparent.

Next, using 50 parts each of this elastomer solution B2 and the elastomer solution A used in Example 1, Example 1
A polyurethane elastomer solution composition of the present invention was prepared by mixing in the same manner as above.

Its solid concentration is 3'0, and its viscosity is 80,000 cps/30°C.
The turbidity was 0.623, and it was a milky white homogeneous liquid.

This composition was stored for 6 months in the same manner as in Example 1, but it was extremely stable without any abnormalities.

The elastomer solution composition (elastomer solution A+B
2) and the results of wet coagulation using each of the elastomer solution B2 and elastomer solution A
The results of Example 1 are shown in Table 2.

As is clear from these results, one elastomer solution A (a solution of a polyurethane elastomer in which the polymer diol constituting the soft segment is composed of polydipropylene glycol adipate diol alone) and the other elastomer solution B2 (a solution of a polyurethane elastomer in which the polymer diol constituting the soft segment is polydipropylene glycol adipate diol alone) The solution composition of the present invention obtained by mixing a solution of a polyurethane elastomer in which the diol is composed of polyε-caprolactone glycol alone can be obtained by mixing each elastomer solution A or B.
To obtain a leather-like sheet-like material that is superior in solvent removal properties of a wet coagulation product, etc., is lightweight, has better moisture permeability, and flexibility than No. 2, and has no large internal pores and has a uniform porous structure. I can do it.

Example 3 Instead of polybutylene glycol adipate diol,
A polyurethane elastomer solution (hereinafter referred to as elastomer solution B) was obtained in the same manner as in Example 1, except that polyε-caprolactone diol having a molecular weight of 1970 was used.

Its solid concentration is 30.11%, and its viscosity is 80,000 cp.
The temperature was s/30°C, the turbidity was 0.035, and the appearance was transparent.

Next, 50 parts each of this elastomer solution B3 and the elastomer solution A used in Example 1 were mixed in the same manner as in Example 1 to prepare a polyurethane elastomer solution composition of the present invention.

Its solid concentration is 30% and viscosity is 80,000 cps/30
℃, turbidity was 1.230, and it was a milky white homogeneous liquid.

This composition was stored for 6 months in the same manner as in Example 1, and was stable without any abnormalities.

The elastomer solution composition (elastomer solution A and B)
Table 3 shows the results of wet coagulation using the elastomer solution B3) and the elastomer solution B3 of Example 1.

As is clear from this result, the polyurethane elastomer solution (elastomer solution B3) in which the polymeric diol constituting the soft segment is solely polytetramethylene ether glycol adipate diol is mixed with the elastomer solution A of Example 1. The solution composition of the invention has superior solvent removal properties and hydrolysis resistance for wet coagulation products than elastomer solutions A or B3, is lightweight, flexible, has better moisture permeability, and is uniform without large pores. A leather-like sheet material with a porous structure can be obtained.

Example 4 Solution composition AB1B2 mixed liquid in which 50 parts each of elastomer solution A of Example 1, elastomer solution B1 of Example 1, and elastomer solution B2 of Example 2 were mixed (turbidity 0.60)
) and a solution composition obtained by mixing 500 parts each of the elastomer solutions A and B2 and the elastomer solution B3 of Example 3 (mixture of AB2B2) (turbidity 0.781), and the elastomer solutions A, B1, and B3. (AB1B3 mixture) (turbidity 0.950)
Table 4 shows the results of wet coagulation using each of the above.

Example 5 Instead of polybutylene glycol adipate diol,
Same as Example 1 except that each elastomer solution obtained by solution polymerization using the following diols alone or in a mixture (abbreviated as diol) in the same manner as in Example 1 was used instead of elastomer solution A. I went to

The results are shown in Table 5. /161: Polyethylene glycol adipate diol (PEGAD) with a molecular weight of 1970
) alone.

A2: Single adipate diol copolymerized with polyethylene glycol (20 mol %) and butylene glycol (80 mol %).

A3: Single polyhexamethylene glycol adipate diol having a molecular weight of 1970.

A4: A mixture of 85% polybutylene glycol adipate diol (PBGAD) with a molecular weight of 1970 and 15% diethylene glycol adipate diol (DEGAD) of Example 2.

A5: The above PBGAD70 and the above DEGAD30
Mixture with attendant.

Fu 6: The above PBGAD65 and the above DEGAD15
Mixture with attendant.

Example 6 Solution polymerization was carried out in the same manner as in Example 1, using diols /161 to /166 of Example 5 instead of polybutylene glycol adipate diol, and each of the obtained elastomer solutions A was used instead.

Table 6 shows the results obtained in the same manner as in Example 2, and Table 7 shows the results obtained in the same manner as in Example 3.

Example 7 Solution polymerization was carried out in the same manner as in Example 1 except that the polybutylene glycol adipate diol mixture of Example 1 was used, and each of the obtained elastomer solutions was used as a single elastomer solution B.
Example 1 was carried out in the same manner as in Example 1, except that Example 1 was used instead of Example 1.

The results are shown in Table 8.

Fu 1: Polydipropylene glycol adipate diol CPDPGAD85 with a molecular weight of 1970 and a molecular weight of 197
0 polybutylene glycol adipate diol (PBGA115).

/1622 70% of the above PDPGAD and the above PBGA
A mixture with D30.

43: PDPGAD65 above and PBGAD3 above
Mixture of 5 parts.

Fu 4: Above (7) PDPGAD 85% and molecular weight 2100
mixture with polypropylene ether glycol (PPEG) 15%.

A5: The above PDPGAD70 section and the above PPEG30
Mixture with attendant.

A6: A mixture of the above PDPGAD65 East and the above PPEG35.

Example 8 ・□ Polybutylene glycol adipate of Example 1 The following diol mixture was used in place of glycol adipate, solution polymerization was carried out in the same manner as in Example 1, and each of the obtained elastomer solutions was used in place of one elastomer solution B1. The same procedure as in Example 1 was carried out except that the sample was used in the following manner.

The results are shown in Table 9. /161: Mixture of Example 3 ε-caprolactone glycol (PεCLG) 85% and polybutylene glycol adipate diol (PBGAD) of Example 1, 15%.

Rot 2: A mixture of the above PεCLG76 and PBGAD30.

A3: A mixture of the above PεCLG65 and PBGAD35.

A4: A mixture of the above PεCLG85aI) and polytetramethylene ether glycol (PTMEG) 15 having a molecular weight of 1970.

A5: A mixture of the above PεCLG70 and the above PTMEG 30%.

/I66: The above PεCLG65 section and the above PTMEG
A mixture with section 35.

Example 9 A of the polyurethane elastomer solution used in Example 1
The same procedure was carried out except that each elastomer solution composition containing B1 and B1 mixed at the mixing ratio shown in Table 9 was used instead of the elastomer solution composition of Example 1.

As is clear from these results, the mixing ratio of polyurethane elastomers (a) and (b) is 90:10 to 10.
90 is preferred.

Example 10 Polyurethane elastomer concentration was 38%, obtained by solution polymerization in the same manner as in Example 1 while varying the amount of DMF.
Each composition obtained by mixing 50 parts each of elastomer solutions A and B1 of 35 parts, 25 parts, 20 parts, and 12 parts was used.

The rest was carried out in the same manner as in Example 1.

The results are shown in Table 11.

Example 11 Terminal NC obtained by reacting 49.5 parts of polybutylene glycol adipate diol with a molecular weight of 1970 and 30 parts of 4,4-diphenylmendiisocyanate at 80°C for 2 hours.
After cooling the prepolymer having O groups, DMF20
After dissolving in 4 parts, 8.2 parts of 1,4-butanediol was added as a chain extender and solution polymerization was carried out (60°C, 4 hours), and 0.3 parts of ethanolamine as a polymerization terminator was added. , a polyurethane elastomer solution A1o was obtained.

Its solid content concentration is 30.1%, and its viscosity is 82,000 cps.
/30°C, turbidity 0.029, transparent liquid.

A polyurethane elastomer solution B1o was obtained by the prepolymer method in the same manner as described above, except that polydipropylene glycol adipate diol having a molecular weight of 1970 was used instead of polybutylene glycol azbate diol.

The solid content concentration of this solution is 30%, and the viscosity is 82,000 cps.
/30°C, and the turbidity was 0.015.

Next, 50 parts each of Alo and Blo of the polyurethane elastomer solution obtained by the prepolymer method were used and mixed with thorough stirring to form an elastomer solution composition (Alo +B).

) was obtained. This turbidity is 0.958. It is a milky white homogeneous liquid.

In addition, A1 of the elastomer solution obtained by the prepolymer method
A composition obtained by mixing 850 parts of elastomer solution B by the one-shot method of Example 1 (A10+
B1) was a milky white homogeneous liquid with a turbidity of 0.810.

Table 12 shows the results of wet coagulation of these elastomer solutions alone and as a composition.

Example 12 Same as in the case of elastomer solution A in Example 1 except that a specific amount of each chain extender shown below (Scrap 1 to A5) is used instead of 8.2 parts of 1,4-butanediol as the chain extender. Table 13 shows the results of each composition (liquid) produced by mixing each elastomer solution obtained in step 1 and the other elastomer solution B1.

Claims (1)

[Claims] 1. A polyurethane elastomer solution composition produced by mixing at least two solutions in which a polyurethane elastomer comprising a polymeric diol, an organic diisocyanate, and a chain extender is dissolved in a water-miscible organic solvent. One of the polyurethane elastomer solutions A to be mixed with polymethylene glycol adipate diol alone or
A substantially transparent solution with a turbidity of 0.05 or less in which a polymethylene glycol adipate-based polyurethane elastomer made of a mixture of polydiethylene glycol adipate diol of 0 weight coefficient or more and 30 weight coefficient or less as a polymer diol is dissolved, The other polyurethane elastomer solution B is a polymeric diol selected from the group consisting of polydiethylene glycol adipate diol, poly ε-caprolactone glycol, and polydipropylene glycol adipate diol alone or with a weight ratio of 70 and polymethylene glycol of 30 or less. Turbidity 0.05 in which polydiethylene glycol adipate-based polyurethane elastomer, polyε-caprolactone-based polyurethane elastomer, or polydipropylene glycol adipate-based polyurethane elastomer is dissolved, which is made of a diol mixture with adipate diol or polyalkylene ether glycol as a polymeric diol. A polyurethane elastomer for wet synthetic leather, which is a substantially transparent solution as described below, and the composition produced by mixing the polyurethane elastomer solution is a cloudy white liquid with a turbidity of 0.2 to 1.5. Solution composition. 2. The composition according to claim 1, wherein the polyurethane elastomer solution to be mixed has a concentration of 20 to 40% by weight of each polyurethane elastomer. 3. Claim 1, wherein one polyurethane elastomer solution A and the other polyurethane elastomer solution B are mixed such that the weight ratio of one polyurethane elastomer to the other polyurethane elastomer is 90:10 to 10:90. Compositions as described. 4. The composition according to claim 1, wherein one polyurethane elastomer solution and the other polyurethane elastomer solution are mixed such that the content concentration of the total amount of polyurethane elastomer is 20 to 38% by weight. 5. The composition according to claim 1, wherein the chain extender is a diamine, a low molecular glycol having a molecular weight of 500 or less, an amino alcohol, water, or a combination thereof. 6. The composition according to claim 1, wherein the water-miscible organic solvent is an amide solvent. 7. The composition according to claim 1, wherein the polyurethane elastomer solution to be mixed is a polyurethane elastomer solution obtained by a solution polymerization method.