JPS602783A - Manufacture of semigloss deep-grained flexible leather sheet - Google Patents

Abstract

PURPOSE:To manufacture the titled flexible leather sheet, by using a porous polyurethane elastomer as the coating layer of a conventional leather sheet, and coating the product successively with a specific elastic clear layer, a masking layer of colored elastomer and a topping layer made of a specific elastomer. CONSTITUTION:A porous polyurethane elastomer having an apparent density of 0.3-0.45g/cm<3> is used as the coating layer of a leather sheet obtained by impregnating and coating a fibrous base cloth with an elastic plymer. The product is coated with a clear layer composed of a polyurethane elastomer having a 10% elongation stress of 20-150kg/cm<2> and composed of an alicyclic diisocyanate, a polymeric diol having a molecular weight of 600-4,000, and a compound selected from low-molecular diols, aliphatic diamines, etc. The objective semigloss deep-grained flexible leather sheet can be manufactured by coating the product with a masking layer having a solid content of 0.5-10g/m<2>, containing a colorant and composed of a polyurethane elestomer having a 10% elongation stress of 20-150kg/cm<2>, and then with a topping layer composed of a polyurethane elastomer having a 10% elongation stress of 100-400kg/cm<2> and containing a clear colorant only or free from colorant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a leather-like sheet product that has a luster similar to that of enamel, that is, semi-gloss, forms deep grains when folded, and has a soft feel. A method of imparting an enamel-like luster to a leather-like sheet product is to coat a sheet structure with a resin film on release paper, etc., apply adhesive to the sheet structure, and then bond it together.Then, the release paper is removed and the enamel-like luster is applied. There are methods such as applying a thick layer of resin solution using methods such as gravure to create a glossy finish.

However, in the former case, a thick film of resin is formed, making it difficult to obtain a glossy finish, and it is only possible to create a certain level of luster, that is, an enamel-like one.Moreover, the appearance is a resin luster, and it has a cold feel. It was inevitable to give. In addition, in terms of physical properties, there was a drawback that there was almost no air permeability or moisture permeability, and the bending resistance was also significantly reduced. In the latter method, a colored paint is applied to the surface of the sort using gravure caulk, etc., and then clear paint is applied over the surface. I couldn't get the shine.

Moreover, in all of the above methods, the wrinkles that occur on the leather sort when folded are small or do not occur at all, and making shoes, two bags of cases, etc. from the curl sheet does not give a luxurious look. I only got what was missing.

Purpose of the Invention The present invention has been made against the background of the above circumstances,
The purpose is to give leather-like sheets a high-quality luster similar to enamel, that is, semi-gloss, and to make the semi-gloss more effective by deepening the grain that occurs when folding. be.

In the leather sheet-like article of the invention, which is obtained by impregnating and impregnating a high-molecular-weight elastic polymer on a purchased fibrous base material, the coating layer of the leather sheet-like article has an apparent density of 0.30 to 0.451/crl. It is formed of a porous polyurethane elastomer, and on the surface of the coating layer, (a) an alicyclic diincyanate, (b) a molecular weight of 60
0 to 4000 polymer diols and (cl) selected from the group consisting of low molecular weight diols, aliphatic diamines and alicyclic diamines,
A clear layer made of polyurethane elastomer (A) having a % elongation stress of 20 to 150'rg/crA and containing no colorant or extender is formed, and then a 10% elongation stress of 2.0 to 150' is formed on the surface of the clear layer. kl? /7 polyurethane elastomer [B] with a solid content of 0.
5~1og/rt? and a colorant-containing shielding layer is formed, and the 10φ elongation stress is 100 to 400 kg/
This is a method for producing a semi-gloss textured soft leather notebook material, which is characterized by forming a top layer made of CNI polyurethane elastomer [C] and containing only a transparent colorant or no colorant at all. .

The leather sheet used in the present invention has a structure in which a fiber base is impregnated with an elastic polymer and has a microporous layer on the surface. The fibrous base material is a fibrous sheet such as a non-woven fabric or a woven fabric, and the fibers used may optionally be natural N&fiber 1 synthetic gauze, fiber, or recycled fiber.

Examples of the elastic polymer to be impregnated into the fibers include polyurethane and polyurea.

Examples include 5BR (styrene 7 rubber), NBR (acrylonitrile-butadiene rubber), acrylic branched ester polymers, and vinyl chloride polymers.

The microporous layer forming the coating layer is preferably a polyurethane elastomer, and is coated with a solution or dispersion, and then coated with an arbitrary method.
For example, it can be formed by applying a porous method such as a wet or dry coagulation method, a chemical foaming method, or a one-mechanism foaming method.

In order to achieve the object of the present invention, the apparent density of the coating layer needs to be in the range of 0.30 to g, 4s, 9/cn. If this density is less than 0.30 glcr&, the folding grain of the sheet material produced by the method of the present invention will become extremely rough (and the appearance will lose its luxurious appearance. Moreover, the strength of the coating layer will decrease significantly, making it difficult to make shoes, bags, etc.). etc., it becomes impossible to meet the practical strength at the time of creation.

On the contrary, 0-451/c++! If it exceeds this, the bending grain will become small and it will not be possible to obtain a product with a coarse grained deep grain, which is the object of the present invention, and the appearance will not be good.

0) A clear layer of polyurethane elastomer (A) is applied to the surface of the sheet-like product thus prepared. This polyurethane elastomer [A] contains (a) an alicyclic diisocyanate, (b) a polymer diol with a molecular weight of 600 to 4,000, (c) a low molecular diol, an aliphatic diamine and/or an alicyclic diamine (a), fb ), (c>).

Here, examples of the alicyclic diisocyanate include cyclohexane diisocyanate, cyclohexyl isocyanate, cyclohexylmethane-4,4'-diisocyanate, and cyclohexyldimethylmethane-44'-diisocyanate.

Also (bl polymer diols include polyethylene glycol, boli-a-pyrene glycol.

Ether polyols such as polytetramenalene glycol and polyhexamethine/glycol, or ester thread polyols such as polyethine ambate and polybutylene ambate, may be used alone or in mixtures.

Furthermore, (c) aliphatic diamines include ethylene diamine, 1-2 propylene diamine, hexamethylene diamine, etc. (Cl alicyclic diamines include piperazine and inphorone diamine.

It can be obtained by reacting with 4.4'-diaminodicyclohexylmethane by a known method.

The reason why an alicyclic diincyanate, an aliphatic diamine and/or an alicyclic diamine is used in the present invention is that it is necessary to use a soft ruben to dissolve the polyurethane.

That is, polyurethane using an aromatic diisocyanate and an aromatic diamine generally does not form a uniform solution and is difficult to coat unless a so-called donlebento, which is mainly an amide solvent, is used as a solvent.

However, amide solvents have a high boiling point and a slow evaporation rate, so if a paint containing a large amount of amide solvents is used, it will dissolve the porosity of the coating layer, resulting in a loss of surface smoothness and, as a result, less gloss. As a result, the density of the porous material increases, resulting in a lack of softness and difficulty in forming deep grains (as a result, the object of the present invention cannot be achieved).

Regarding the hardness of the polyurethane CA) used in the present invention, it is necessary that the 10 inch elongation stress is in the range of 20 to 150 to 9/crl, and if it is less than about 20 kg/d, the physical properties, especially the heat resistance, will deteriorate. If the pressure exceeds about 15 kg/i, the surface becomes hard and the sheet material becomes wrinkled and wrinkled, which does not give it a luxurious feel. The bending durability force is weakened by 1, which causes a practical problem.

The solvent for dissolving the polyurethane elastomer (A) of the present invention contains at least 80% by weight of a solvent selected from the group consisting of ketones, esters, alcohols, and hydrocarbon solvents having a boiling point of 60 to 120°C, alone or in combination. 120℃
It is preferable to use a solvent obtained by mixing the above amide solvents in a proportion of 20% by weight or less.

Ketones include acetone and methyl ethyl ketone.

Methyl isobutyl ketone, etc. can be used, esters include ethyl acetate, butyl acetate, etc., cyclic ethers include tetrafuran, furfural, etc., and alcohols include ethyl alcohol.

n-propyl alcohol, isopropyl alcohol'S
, hydrocarbon l Y: is benzene, toluene.

Hexane etc. can be used.

Dimethylformamide, dimethylacetamide, etc. can be used as the amide solvent.

In the mixed solvent system, a solvent with a boiling point of 60 to 120°C is
These solvents are important for maintaining the porosity of the coating layer. boiling point 12
Approximately 20% by weight of the amide solvent having a temperature of 0° C. or higher is required to form a uniform urethane film. If the weight greatly exceeds 20 weights, the porosity will be damaged and it will not be possible to obtain a sorted material with the desired appearance.

The polymer solution consisting of the above polyurethane elastomer [A] and a solvent has a concentration of 5 to 15 and a weight coefficient of 100 to 100 s.
It is appropriate to adjust the temperature to 0 o cps/2 o°C.

It is preferable that the thus prepared paint containing no colorant or extender pigment is applied as a first layer over the entire surface of the sheet-like article by overfeeding. Overfeed spreading coating refers to fixing the excess paint on the surface of the sheet material and then scraping it off with a doctor grade, rondo, etc. to form a uniform paint film, or applying it to the sorted material between the chive rolls. This refers to a method in which a large amount of paint is supplied, spread uniformly on the surface of the object to be treated before squeezing, and then squeezed to control the applied amount.

Polyurethane elastomer-7-(
The adhesion amount of A) is 1-10 l/i, preferably 2
~8. ! 7/m, and if it is less than about 11/rr1, it will not be possible to form a uniform film, resulting in glossy spots, which will be a drawback. Necessary to give shine.

On the other hand, if it greatly exceeds about 10 g/rl, the amount of coating per coat increases, which tends to be affected by the solvent, and properties such as air permeability and moisture permeability are greatly reduced, which is undesirable.

Further, it is necessary that the paint does not contain a coloring agent or an extender pigment. Containing pigments causes the surface roughness to increase rapidly, making it impossible to increase the level of gloss.

In short, the first layer coating must form a smooth film without roughening the porous surface.

Next, a polyurethane elastomer (B) with a 10% elongation stress of 20 to 150 9/cra and a coloring agent of 3
The solid content of the shielding layer containing ~200% by weight is o, s ~1o
A masking layer of i/rrt, preferably 1 to 81//m' is formed.

The polyurethane elastomer (B) used here may be the above-mentioned soft solvent type, or a hard solvent type using aromatic diisocyanate.

The amount of the colorant is 3 to 200% by weight, preferably 5 to 150% by weight, based on the polyurethane elastomer [B]. When the amount of the colorant is less than about 3%, the O layer has poor shielding properties and embedding occurs.

On the other hand, if the weight factor exceeds H') 20 o, the mechanical properties of the sheet material, especially the durability of the bent surface, deteriorate, so that it cannot be used.

The solid content of this shielding layer is 0.5 to 10jj/n? A range of 1 to 8 is required, preferably 1 to 8/d. Approximately 0.
5. If it is less than about 10 g/m", uniform coloring is impossible and embedding occurs, whereas if it exceeds about 10 g/i, it becomes difficult to create minute creases, and the softness in Table 1111 becomes thicker (decreased). However, the moisture permeability decreases significantly, which is undesirable.

Next, a 10% elongation stress of 100
~4ooQ/7, with a third layer of polyurethane elastomer (rc) containing no opaque colorant, only transparent colorant, or no colorant at 0.5~101/r
Apply l. The hardness of this polyurethane (C) must be such that the 1° elongation stress is 100 to 400 kg/crj, preferably 150 to 380 kg/cIl, and if it is less than about 100 kg/i, the surface The adhesiveness is high, which poses a practical problem, and in terms of appearance, the appearance of bending wrinkles is extremely poor and does not give a high-quality appearance. On the other hand, about 4o
When it exceeds okg/7, the number of folding grains becomes extremely small, resulting in a shape similar to that of folded cardboard, which loses its high-quality appearance, and its practical durability, particularly its resistance to bending fatigue, decreases significantly.

In addition, N IQ and r'i! when a transparent colorant is included. I
For example, a metal-containing complex salt material soluble in an organic solution 111], a transparent extender pigment such as silicon oxide, etc. can be used. The amount of coloring agent is adjusted appropriately depending on the depth of color, but is usually 5 to 100% by weight. In particular, when adding silicon oxide, etc., it is necessary to keep it in a very small amount because if it is added too much, the luster will be lost.

The amount of polyurethane [C] is 0.5 to 10 g/m,
The desirable range is 1-8! ? /nl.

If it is less than about 0.5 g/m', it is impossible to obtain a semi-glossy high-quality gloss, and on the other hand, if it is about 101/rr? If it exceeds this value, the bending durability of the surface will decrease, and at the same time, the appearance will go beyond the semi-gloss, luxurious luster and become enamel-like, losing its luxurious appearance.

The leather sheet obtained in this way does not have the glare of enamel, has a subdued glossy surface, has moderately rough folds (and is deep and has a soft texture). It is highly durable.

EXAMPLES The present invention will be specifically explained with reference to Examples below. The various physical properties shown in the Examples were measured using the following methods.Table 1 shows the physical properties of the sheet products prepared in the Examples and Comparative Examples, and Table 2 shows the properties of the sheet materials prepared in the Examples and Comparative Examples. The main specifications that make up the groove are shown below.

1) 10% elongation stress of polyurethane elastomer Based on the vulcanized rubber tensile test method of JISK-6301-3.

After making size 2 dumbbells and storing them at 2°±2°C for 24 hours, they were tested using an Instron tensile tester at a tensile rate of 200/min.
Measured in mm.

li) Bending resistance A bending test of 200,000 times was conducted according to the leather bending test method of JISK-6545. And JIS-ni-6505
Judgment was made according to 5.2. The larger the value, the better the bending resistance.

The low-temperature flexibility is the value obtained when the material is bent 100,000 times at -1.0'C by the method described above.

111) Moisture permeability JIS-650Fi-5-2-1317) Method 61]1 was carried out.

Example 1 [Manufacture of fibrous base material] Polyethylene terephthalate 1-41 fibers (single fiber fineness 2.5 denier, length 51 ni) having a shrinkage rate of 45 in hot water at 70°C were used. , the weight is 2 due to the 7 rat car 1°
009/d web was created.

It was passed through this web-like needle locker room, needle punched at 800 needles/d, and then immersed in warm water at 68°C for 5 minutes to shrink to 62 times its original area.

This shrink web is dried using a belt press dryer.
It was dried at 130° C. while being pressurized at a pressure of 0 kg/i to obtain a nonwoven fabric (fiber member base) having a weight of 2909/rrj, a thickness of 1 nm, and a density of 0.26971 i.

[Manufacture of impregnated base fabric]

The obtained nonwoven fabric was impregnated with a dimethylpolamide solution (Part 15) of a polyurethane resin polymerized with the following composition, squeezed, coagulated by immersion in water, extracted and removed from the solvent, and dried to prepare a polyurethane-impregnated base fabric.

Composition of polyurethane pp'-diphenylmethane diincyane) 367
．． 5 parts polybutylene adipate (molecular weight 2000)
263.0 parts polytetranotylene glycol (molecular weight 2
000) 263.0 parts 1.4 phthanediol 106.5 parts dimethylformamide 4000 parts [Production of leather-like sheet with porous coating layer] A polyurethane solution prepared with the above composition was applied to the surface of the obtained impregnated base fabric. Adjusted with the composition shown in F, and M of about 5oo, V/m'
4 containing 10% dimethylformamide.
After coagulating in a coagulation bath at 0° C., the sheet was washed with water to remove most of the solvent, and then dried to produce a sheet having a porous layer about 0.2 mm thick.

The dense layer of the porous coating layer created in this way was 0.3 s.
, 9/cJ.

Composition of polyurethane for producing porous coating layer Polyurethane 750 parts Lamifuto F-62 3.75 parts (manufactured by Dai-Kogyo Seiyaku) Dimethylformamide 250 Zheng [Synthesis of polyurethane elastomer A] Molecule i 282
209.5 parts of polytetramethylene glycol 751-88r dicyclohexylmethanediyneane) were placed in a stirred reactor purged with nitrogen, and after reacting at 90°C for 80 minutes, tetrahydrofuran/dimethylformamide = 9/1 was added. Add 3845.2 parts of the heated solvent at the same ratio and cool it to 40°C while dissolving it to make a 20% by weight liquid.1 Next, 38.7 parts of 1,2 propylene diamine was dissolved in 154.8 parts of the same mixed solvent. The mixture was separated little by little to carry out a chain elongation reaction, and after reacting for 8 hours, 3.5 parts of dibutylamine was added to stop the reaction, and a solution of 1200 voids was obtained at 30°C.

The obtained polymer was diluted to a concentration of 10% with dimethylformamide, poured onto a glass plate, and roughly dried at 50°C for about 12 hours, and then vacuum-dried at 80°C for 2 hours to create a transparent polyurethane film. did. The 10% elongation stress of this film measured after conditioning the humidity in a room at 20°C x 60% RH for one day was 25 kg/ci, and the intrinsic viscosity determined at 1 lllll in dimethylformamide at 30°C was 1.
．． It was 02.

[Synthesis of polyurethane elastomer B] Molecule 12012
5.97.5 parts of polytetramethylene glycol and 297.0 parts of diphenylmethane diisocyanate were placed in a stirred reactor purged with nitrogen and reacted at 70°C for 60 minutes, followed by methyl ethyl ketone/dimethylformamide.
3,578 parts of a mixed solvent of No. 515 was separated and dissolved while cooling to obtain a 20% by weight liquid. Next, 0.2 parts of dibutyltin dilaurate was added, followed by 90 parts of 1,4 phthanediol.
1 part was dissolved in 360 parts of the same mixed solvent as above, poured into the solution for 1 hour, and reacted for 6 hours. 3.5 parts of heptadipylamine was added to stop the reaction.

The resulting polymer solution had a temperature of 1050 poise at 30°C, and the 10 modulus elongation stress measured in the same manner as above was 40'.
9/c++! , the intrinsic viscosity was 0.90.

[Synthesis of polyurethane elastomer C] Molecule ft158
0 polytetramethylene glycol 6142 parts and 3.3
．． 5) Riftyl. 5 Isocyanate 257.7 parts of methyl cyclohexyl incyanate were placed in a nitrogen-substituted reactor equipped with a stirrer and reacted at 90°C for 80 minutes, and then 3488 parts of a mixed solvent of tetrahydrofuran/dimethylformamide = e/4 was added while cooling. Dissolve at 40℃
Cooled to . Then 3, 3, 5)! j Methyl, 128.1 parts of 5-aminomethylcyclohexylamine was dissolved in 512 parts of the above-mentioned mixed solvent, and a solution of 40 to 50
The chain elongation reaction was carried out at °C for 8 hours, and finally 3.5 parts of di-n-7-ethylamine was added to stop the reaction. The resulting polymer solution had an intrinsic viscosity of 980 poise and 0.8 at 30°C.
5.10% elongation stress was 150 Yu/d.

[Manufacture of leather sheets]

Polyurethane elastomer A was diluted to 10% by weight with a solvent mixed with isopropyl alcohol/methyl ethyl ketone/dimethyl formamide-s/4/l on the surface of the sheet having the porous coating layer obtained as described above, and heated at 20°C. I made 200 centipoise clear paint.

The solid content is 3. Using a gravure roll with a line count of 150 lines/inch to give ¥/7/d, overfeed the paint without using a doctor blade to make the excess paint adhere to the surface of the sheet and squeeze it with a nip meal. A uniform coating was formed on the entire surface.

Then, using polyurethane elastomer B (tetrahydrofuran/methyl ethyl ketone/dimethyl formamide-S/4/1 mixed solvent), a coloring point pigment was added as shown in the following composition to prepare a paint having a strength of 150 centipoise at 20°C.

UST27907' Lucknia 0g (manufactured by Inuichi Coffin Ka)
Polyurethane 33: 150 g tetrahydrofuran /: 230 g methyl ethyl ketone / dimethyl formamide / = 5/4/1 This paint was applied to the surface of the sheet with a gravure roll of 110 lines/inch for 3.0 mm. A sheet with a uniformly colored surface was obtained.

Next, polyurethane C was mixed with isopropyl alcohol/toluene/methyl ethyl ketone/dimethylformamide=
10M in a/3/3/1 mixed solvent
A clear paint was prepared by diluting it to 2.0 El/m by the same coating method as the colored paint.

The appearance of the leather-like sheet product thus obtained was extremely glossy, the creases were coarse and rough, similar to shrink leather, and the surface had a soft texture.

The sheet also had extremely excellent bending resistance.

Table 1 shows data on appearance and physical properties.

Example 2 [Production of leather-like sheet with porous coating layer] Example 15
Use the polyurethane prepared in Example 1 as it is [Production of polyurethane A'] Use the polyurethane of Example [Production of polyurethane B] Use the polyurethane of Example 1 [Production of polyurethane C] Polytetramethylene glycol with a molecular weight of 801 446.
3 parts and 3.3.5) Limethyl, 5-incyanate Methyl hexyl isocyanate 369.9 parts were placed in a reactor equipped with a stirrer purged with nitrogen and reacted at 90°C for 80 minutes, and then tetrahydrofuran/dimethyl Formamide-6
Add 3265 parts of a /4 mixed solvent and dissolve while cooling.
3,3,5 trimethyl without cooling to 40°C.

183.8 parts of 5-aminomethylcyclohexylamine was dissolved in 735 parts of the above mixed solvent,
The chain extension reaction was carried out at 0°C for 8 hours, and finally 3.5 parts of :/n-butylamine was added to stop the reaction.

The resulting polymer solution had an intrinsic viscosity of 980 poise at 30° C., an intrinsic viscosity of 0.85.10, and an elongation stress of '340 Yu/d.

[Manufacture of leather sheets]

The surface of the sheet having the porous coating layer obtained as described above was coated with polyurethane silastomer A in the same manner as in Example 1, and a sheet having a diameter of 200 centipoise was prepared at 20°C. Using a rod wrapped with lO mill stainless steel, this was a.
A uniform film was created by applying a uniform coating. Next, polyurethane elastomer B was made into a colored paint in exactly the same manner as in Example 1, and 7. oi/11 was attached. Furthermore, the polyurethane elastomer C prepared as described above was diluted with a mixed solvent of inpropyl alcohol/toluene/methyl ethyl ketone/dimethyl formamide = 3/3/37 for 10 minutes.
% diluted with a gravure roll. o! j/rr? A leather-like sheet-like material was prepared by coating.

The sheets thus produced were extremely smooth, had deep creases similar to those of Example 1, and had a soft surface feel.

The main physical properties are shown in Table 1.

Comparative Example 1 [Manufacture of fibrous base material] Use the material of Example 1 [Manufacture of impregnated base fabric] Use the material of Example 1 [Manufacture of leather-like sort with porous coating layer] Example 1
A 12% solution of the polyurethane prepared in Example 1 with the following composition was applied to the surface of the impregnated base fabric prepared in Example 1, and approximately 500.9 parts mJ
After casting and coagulating in a coagulation bath containing 10% dimethylformamide at 40°C, washing with water to remove most of the solvent, drying to form a porous coating with a thickness of about 0.2 mm. A leather-like sheet material was created. The apparent density of the porous material thus produced was 0.2 g, 9/i.

Polyurethane (20% liquid) 600 parts Lami-Ufusofu 62 4.5 parts (manufactured by Dai-Kogyo Seiyaku) Dimethylformamide 400 parts [Manufacture of leather sheet-like products] Using the sort prepared above, the same procedure as in Example 1 was carried out. When a colored sheet was prepared, the surface gloss was almost the same as that of Example 1, but the creases were extremely coarse, similar to those that occur when cardboard is folded, and the appearance was not noticeable. It's Shiri. Furthermore, the bending resistance was poor and did not have practical strength.

Comparative Example 2 [Manufacture of fibrous base fabric] Use the product of Example 1 [Production of impregnated base fabric] Use the product of Example 1 [Production of leather-like sheet with porous coating layer] Example 1
The polyurethane prepared in Example 1 was applied to the surface of the impregnated base fabric prepared in Example 1 as a dimethylformamide solution with the following composition, about 7oo11/n? The weight of the sample was cast to form a porous structure in the same manner as in Example 1. The thickness of the porous material at this time is 0.
23mm.

The apparent density was 0.50 g/crA.

[Manufacture of leather sheets]

When a colored sheet was made in exactly the same manner as in Example 1 using the sheet prepared as described above, it obtained almost the same level of gloss as in Example 1, but the creases were delicate and it looked like shrink leather. Example 3 [Preparation of a leather-like sheet with a porous coating layer] The sheet was made and used using the same materials and under the same conditions as in Example 1 [Polyurethane elastomer] Production of A] Molecule R3250
701 parts of polybutylene adipate and 190.9 parts of inholotincea were placed in a stirred reactor purged with nitrogen and reacted at 90°C for 80 minutes. -4/4/2
3,567.6 parts of a solvent mixed in the ratio of 2ON was added and cooled to 40° C. while dissolving to obtain a 2ON solution.

Next, a solution of 107.3 parts of inphorondiamine dissolved in 429.2 parts of the same mixed solvent was added little by little to carry out a chain elongation reaction. After reacting for 8 hours, dibutylamine 3.
The reaction was stopped by adding 5 parts, and a solution of 200 poise was obtained at 30''C.

A film was prepared from the obtained polymer by the method described in Example 1, and the measured 10% elongation stress was 130 kg/
c++! Met.

[Synthesis of polyurethane elastomer B] Molecule r20
] 2 polytetramethylene glycol 58: L6
3. Diphenylmethane diisocy7-1-326,3
1 part was placed in a reactor equipped with a stirrer purged with nitrogen and heated at 70"C.
After reacting for 0 minutes, 3640 parts of a mixed solvent of methyl ethyl ketone/dimethylformamide = 515 was added and dissolved while cooling to give a liquid weight ratio of 20.

Next, 0.2 parts of dibutyltinine laurate was added, and 90.1 parts of 1.4 phthanediol was dissolved in 360 parts of the same mixed solvent as above and added over 1 hour, followed by a reaction for 6 hours to add 3.5 parts of dibutylamine. was added to stop the reaction. The obtained polymer has 800 voids at 30°C, intrinsic viscosity 0.90°, 10 inch elongation Jk stress of 130 kg'/c++
! Met.

[Manufacture of leather sheets]

The porous 51 holes obtained by K as described above and R-J are
The above polyurethane elastomer A is applied to the surface of the leather sheet to be coated with isopropyl alcohol/toluene/methyl ethyl ketone/dimethylborumamide-3/a/3.
/ diluted to 10.5% by weight with a solvent mixed with 1,
I made clear paint with a 250cm voice using 20"C.

This was coated by the method of Example 1 to a ratio of 311/rr to form a uniform coating film.

Then, using polyurethane elastomer B, tetrahydrofuran/dioxane/dimethylform 7mide
A 150 centipoise paint at 20"C was prepared using a mixed solvent of 1/4/1 and a coloring pigment having the following composition.

UST2692 Tsuno l;-1o ogram polyurethane B 1so duram tetrahydrofura//dioxane/dimethylformamide 200 grams = 5/4
/1 Using this paint, a solid content of 7 mm/rrl was applied to the surface of the sheet using a 110 line/inch gravure roll to obtain a sort with a uniformly colored surface.

Then, the polyurethane elastomer C used in Example 1 was applied in the same manner as the polyurethane elastomer B so that the coating was applied at a rate of 4 ji/m.

The sheet thus obtained had the extremely deep luster of a semi-gloss enamel, and had a soft texture with deep creases similar to shrink leather as in Example 1. The main properties are shown in Table 1.

Example 4 In place of the polyurethane elastomer 〇 in Example 3, the tensile stress used in Example 2 was 3.40 kg/c.
I used one from td. The other materials used were the same as in Example 3.

The coating method for polyurethane A, B, and C was the same as in Example 2, and polyurethane A was applied at 7 g/rrl.

Polyurethane B was applied at 3F/m, and polyurethane C was applied at 2/d.

The resulting leather-like sheet was substantially the same as that of Example 2, and had a semi-gloss gloss and deep creases. The main properties are shown in Table 1.

Comparative Example 3 [Production into polyurethane elastomer 9 molecules i290
57 parts of polytetramethaneglycolure of Q and 205.2 parts of cyclohexylmethane diisocyanate were placed in a stirred reactor purged with nitrogen and reacted at 90°C for 80 minutes, and then tetrahydrofuran/dimethylformamide = 9 3848 parts of a solvent mixed at a ratio of 1/l was added and cooled to a melting point of 40'C to form a 2ON liquid.

Next, 1.5% of the same mixed solvent was added to 152 parts. A solution of 37.9 parts of 2-propylene diamine was added little by little to carry out a chain elongation reaction. After reacting for 8 hours, dibutylamine 3
．． The reaction was stopped by adding 5 parts, and a solution of 650 poise was obtained at 30°C. The tensile elongation stress of a film of this polymer measured by the measuring method shown in Example] was xskg/c.
It was nI.

[Manufacture of leather sheets]

A sheet was manufactured using the same material as in Example 1 except for polyurethane elastomer A, but after applying polyurethane A, even after drying the solvent, there was insufficient narrow surface smoothness, and polyurethane elastomer Before applying elastomer B, a part of the surface stuck to the kite roll etc., causing gloss spots, and a uniform semi-gloss appearance of a practical level could not be obtained. In addition, there were almost no creases, and the sheet had a very soft, vinyl-leather feel.

Comparative Example 4 A second layer was formed by substituting polyurethane elastomer B for polyurethane elastomer A in Comparative Example 3. A leather-like sheet was prepared using the same other materials as in Example 1, but as in Comparative Example 3, a uniform sort with a semi-glossy appearance could not be obtained. In addition, the folded grain was also poor, similar to Comparative Example 3, and it lacked a luxurious feel. On the outside of the surface, a mottled appearance was felt, which was thought to be due to the mottling of the gloss.

Comparative Example 5 [Polyurethane elastomer A 117] IA m
: 1 minute - Pii: 614.2 parts of polytetramethylene glycol of 1580, 257 parts of inphorone diisocyanate
．． 7 parts were placed in a stirred reactor purged with nitrogen and reacted at 90°C for 80 minutes, followed by a mixture of solvent 348 in a ratio of 9/1 of tetrahytronane/dimethylformamide.
7.6 parts were added and dissolved, and the mixture was cooled to 40° C. to make a 20% solution. Next, a solution of 128.1 parts of inphorondiamine dissolved in 512.4 parts of the same mixed solvent was added little by little to carry out a chain extension reaction, and after reacting for 8 hours, 3.5 parts of diptylamine was added to stop the reaction. A solution of 500 voids was obtained at 30°C. The resulting polymer had a 10 inch elongation stress of 180 kg/i.

[Manufacture of leather sheets]

Polyurethane elastomer A obtained as described above
A leather sheet was prepared using the method of Example 1. The same fibrous base material and polyurethane B and polyurethane C as in Example 1 were used, and the conditions were also the same.

The appearance of the sheet made in this way was almost the same as in Example 1, with a semi-gloss luster and a rich sense of luxury. However, when it was folded, no wrinkles appeared and there were buckling wrinkles, resulting in a lack of a sense of luxury. Ta. This is the polyurethane elastomer A forming the first M.
This occurred because the 10% elongation stress was too high. Regarding other physical properties, the bending resistance was inferior to Examples 1 to 4.

Example 5 [Fibrous base material] The same material as in Example 1 was used.The material prepared in Example 1 was used. Polyurethane made in step 1
An 8-chi solution was prepared with the following composition, and a porous layer was formed according to the method of Example 1.

The apparent density of the porous material at this time was 0.44j//yl.

Polyurethane 900 parts Lami-Ufusofu 627 parts (manufactured by Dai-Kogyo Seiyaku) Dimethylform 7mide 100 parts [Production of leather sorted product] 1 used in Example 1 for the sheet produced as described above
A polyurethane elastomer [A] with a 0% elongation stress of 25 kg/cTI was used, and the diluting solvent was methylethylgtone/ethyl acetate/Normanpropyl alcohol/hexane/
Two coats were applied as in Example 1 using DMF = 2/2/2/2/2 to give a solids content of 7 g/rt. Next, the polyurethane elastomer B used in Example 3 and having a 10 modulus elongation stress of 130 kg/C1d
3.0 using the gravure method. li'/m", the same (10% elongation stress used in Example 3 is 1 s Okg/c)
4. Adding 5 parts by weight of silicon oxide for matting to Td polyurethane elastomer; A sheet was prepared by depositing a solid content of oM/m'.

The sheet produced in this way has a semi-gloss gloss, and the gloss is softened by silicon oxide, giving it a calm and glossy feel. Flexibility was also good.

Example 6 Apparent density of I and porous σ layer used in Example 5 0-44
Polyurethane A using g/d sorting.

B also has a 10% elongation stress of 25 kg/c++f and 130 kg/cff, respectively, as in Example 5.
1 was used. The coating amount was 311/rr when polyurethane A was applied once using the method of Example 1. solid content was deposited. Polyurethane B was prepared as 711 in the same manner as in Example 3.
/rri'' solid content was applied.

The polyurethane elastomer C used in Examples 2 and 4 and having a 10 Llb elongation stress of 350 kg/cffl was used, and a solid content of 2-01/rrl was adhered by the gravure method.

The leather-like sheet thus produced had a semi-gloss glossy feel, had deep creases similar to Examples 1 to 5, and had good physical properties such as bending resistance.

Comparative Example 6 The 10% elongation stress created in Comparative Example 5 was 180 kg/c
Polyurethane A of rl was used in place of polyurethane B and a solids content of 511/crd was applied. As polyurethane A, l used in Example 1.

3. Using the method of Example 1, using a material with a tensile stress of 25 y/d. ! i'/m was applied. Polyurethane C is 10%
5,9/1 with elongation stress of 150 kg/cr/I
n? Gravure coated.

As with Comparative Example 5, the sheet produced in this manner had a bent texture due to the hard resin applied to the second layer, resulting in poor appearance and poor bending resistance compared to Example 6. was.

Example 7 The same porous coating layer used in Example 5 had an apparent density of 0,
44. Using a sheet of i17/c++l, polyurethane A had a tensile stress of 130 to 9/9, the same as in Example 3.4.
CR! 7 g/in the same manner as in Example 5 using
m solid content was applied.

The polyurethane B used was the same as that used in Example 1.2, and had an lO tensile stress of 2sky, /7.
As in 3, a solid content of 7&/mJ was applied.

Polyurethane C was prepared in Example 1 and had a lo% elongation stress of 150 kl? /c++! A semi-gloss sheet was prepared by applying a solid content of zg/rrt using the gravure method.

The sheets thus produced had a deep luster similar to those produced in Examples 1 to 6, and the creases were similar to shrink leather, with deep folds and excellent bending resistance.

Comparative Example 7 A sheet was prepared by applying 5 #/m of polyurethane A in Example 3 with a lo% elongation stress of 6 ok/d in place of polyurethane C in Example 7, with a slightly different composition. As a result, the sheet had a vinyl-like appearance with insufficient gloss and without the deep creases that are an effect of the present invention.

This is because the hardness of the third layer of polyurethane C was insufficient compared to that of the present invention.

Example 8 Apparent density o of the porous coating layer used in Examples 5 to 7, 4
Using a sheet of 4.9/crI, polyurethane A had a 10-inch elongation stress of 130 kg/c++!
A solid content of 3, li'/nl was applied in the same manner as in Example 3. Polyurethane B had a to% elongation stress of 25 ky/d, which was used in Example 1.2, and was processed using the method of Example 1 in 3. o9/m was applied.

Polyurethane C was the same as in Example 2 and had a) 10% elongation stress of 350 kllllcr&, and the solid content of <4-01/cni as in Example 2 was applied.

The sheet thus produced had a semi-gloss, high-quality gloss, deep creases, and excellent bending resistance.

Comparative Example 8 In place of polyurethane C in Example 8, a product was prepared in substantially the same manner as in Example 2. A 10-inch elongation stress of 420 kg/crl was used and applied by a 41/m gravure method. Although this sheet had a glossy feel, it had wrinkles due to bending and bending, and the leather texture was poor. Moreover, the bending resistance was also poor.

Comparative Example 9 The first layer of polyurethane A used in Example 1 was diluted with DMF to prepare a clear paint with 200 centivoids at 20° C., and applied by the method of Example 5. The second layer, the 31st layer, was the same as in Example 1.

The sheet thus produced had a large amount of DMF in the first layer, which damaged the porous polymer, resulting in no gloss (almost no creases or wrinkles), and the moisture permeability was also significantly reduced. It was inferior to other examples.

Comparative Example 10 Using the same materials according to the method of Example 1, the first layer of polyurethane A was 11/m + the second layer of polyurethane B was O-5 g/m + the third layer of polyurethane C was 0
．． When a 51/m"m cloth sheet was prepared, the gloss described in the present invention could not be obtained because the amount of adhesion was insufficient in each layer.
Also, the folded grain was insufficient.

Table 1 Effects on physical properties of leather-like sheets As detailed above, the leather sheets produced by the method of the present invention have a rich luster and a deep shrink leather-like appearance compared to conventional colored sheets. It has folded texture and is highly durable.

Claims (1)

[Scope of Claims] A leather sheet material obtained by impregnating and coating a fibrous base material with an elastic polymer, wherein the ω layer of the leather sheet material has an apparent density of 0.30 to 0.45 fl/ It is formed of a porous polyurethane elastomer of cnI, and on the surface of the layer, (a) an alicyclic diynethiaide, (b) a molecular weight 6
10 obtained from a polymer diol of 00 to 4000 and (c) at least one compound selected from the group consisting of low molecular diols, aliphatic cyamines, and alicyclic diamines.
A clear layer made of polyurethane elastomer (A) containing no colorant or extender pigment and having a lo% elongation stress of 20 to 150 kg/cyl is formed, and then a lo% elongation stress of 20 to 150 kg/cyl is formed on the surface of the clear layer. /'d polyurethane elastomer CB) with a solid content of 0.5~
10 g/m' and a colorant-containing shielding layer, and the lO elongation stress is 100 to 400 kg/crI.
A method for producing a semi-gloss textured soft leather sheet, which comprises forming a top layer made of a polyurethane elastomer [C] containing only a transparent colorant or no colorant at all.