KR101195808B1 - Skin-material-forming composition for fibrous layered product, synthetic leather or artificial leather made with the same, and process for producing synthetic leather or artificial leather - Google Patents

Abstract

The present invention has an object of providing a surface layer forming composition for a fiber laminate and a synthetic leather using the same, which is excellent in balance between strength and flexibility and is environmentally friendly during production, and is composed of a main material (A) and a hardener (B). In the surface layer forming composition for a fiber laminate to be used, the main component (A) is PCD obtained from 1,6-HD and low molecular carbonate, and the curing agent (B) has a number average molecular weight of 350 to 500 and an average number of functional groups (f). Is composed of a modified polyisocyanate (B1) of HDI having 2 ≦ f <3 and an isocyanurate modified polyisocyanate (B2) of HDI having f ≧ 3, wherein B1: B2 = 50: 50 to 95: 5 (mass ratio ), And the problem of the present invention is solved by the surface layer material-forming composition for fiber laminates, which contains no organic solvent in both the main body (A) and the curing agent (B).

Description

Surface-layer-forming composition for fiber laminates, and synthetic leather or artificial leather using the same, and a method for producing synthetic leather or artificial leather. (SKIN-MATERIAL-FORMING COMPOSITION FOR FIBROUS LAYERED PRODUCT, SYNTHETIC LEATHER OR ARTIFICIAL LEATHER MADE WITH THE SAME, AND PROCESS FOR PRODUCING SYNTHETIC LEATHER OR ARTIFICIAL LEATHER}

The present invention relates to a surface layer forming composition for a fiber laminate, a synthetic leather or artificial leather using the same, and a method for producing a synthetic leather or artificial leather. More specifically, the present invention relates to a surface layer-forming composition for fiber laminates, which is excellent in balance between strength and flexibility, and which is environmentally friendly in production, and synthetic or artificial leather using the same, and a method for producing synthetic leather or artificial leather. .

Synthetic leather and artificial leather are used for a bag, shoes, etc., for example. Synthetic leather is required for flexibility, resilience, strength, elasticity, and breathability according to its use environment and conditions.

On the other hand, in the manufacturing method of such synthetic leather or artificial leather, a method of directly coating a base cloth or the like or coating on a release paper and then transferring to the base fabric is common. Therefore, if the organic solvent is increased during the coating of the coating resin composition, environmental problems, labor safety and hygiene problems occur, and equipment for countermeasures is required, thus increasing equipment investment. There is.

Therefore, Patent Document 1 proposes coating an aqueous polyurethane coating agent on synthetic leather and the like.

However, production systems using aqueous coatings suffer from high energy costs due to the high evaporation energy of water. Therefore, a coating agent for synthetic leather that satisfies all productivity, strength, and environmental response could not be obtained.

Patent Document 1: Japanese Patent Application Publication No. 2006-104251

An object of the present invention is to provide a surface layer forming composition for a fiber laminate, which is excellent in balance between strength and flexibility, and is environmentally friendly during production, and a synthetic leather or artificial leather using the same, and a method for producing the synthetic leather or artificial leather. It is done.

That is, this invention is as showing to the following (1)-(7).

(1) In the surface layer material forming composition for fiber laminates which consists of a main body (A) and a hardening | curing agent (B), main body (A) is a polycarbonate diol obtained from 1, 6- hexanediol and low molecular carbonate, B) isocyanurate of the modified polyisocyanate (B1) of hexamethylene diisocyanate whose number average molecular weight is 350-500, and average number of functional groups (f) is 2 <f <3, and hexamethylene diisocyanate of f≥3. Fiber which consists of modified polyisocyanate (B2), and is B1: B2 = 50: 50-95: 5 (mass ratio), and does not contain an organic solvent in both a main body (A) and a hardening | curing agent (B). Surface layer forming composition for laminated bodies.

(2) B1 is an allophanate-modified isocyanate obtained from monool and hexamethylene diisocyanate, The surface layer material forming composition for fiber laminated bodies of said (1) characterized by the above-mentioned.

(3) Synthetic leather which consists of a surface layer formed from the surface layer forming composition for fiber laminated bodies of said (1) or (2), and a fiber cloth layer.

(4) An artificial leather comprising a surface layer and a fiber cloth layer formed of the surface layer forming composition for a fiber laminate of (1) or (2).

(5) The liquid containing the above-mentioned main ingredient (A) and the curing agent (B) of (1) or (2) is applied to a release support, and first cured, then adhered to a fiber cloth, and then secondary cured. A method for producing a synthetic leather or artificial leather, characterized by removing the post-release support.

(6) A method for producing a synthetic leather or artificial leather, wherein the liquid containing the main ingredient (A) and the curing agent (B) of the above (1) or (2) is directly applied to a fiber cloth and heat cured. .

(7) The liquid which mix | blended the main body (A) of said (1) or said (2), and a hardening | curing agent (B) WHEREIN: The molar ratio of the hydroxyl group and the isocyanate group of the said mixture liquid is hydroxyl group / isocyanate group = 90/100- The manufacturing method of the synthetic leather or artificial leather of said (5) or (6) characterized by the ratio of 110/100.

According to the present invention, there is provided an excellent balance of productivity, strength and flexibility, and a surface layer forming composition for a fiber laminate in consideration of the global environment, a synthetic leather or artificial leather using the same, and a method for producing a synthetic leather or artificial leather. I can do it.

In the present invention, the subject (A) is a specific polycarbonate diol (hereinafter abbreviated as PCD), and the curing agent (B) is a hexamethylene diisocyanate having a number average molecular weight of 350 to 500 and a low functional group (hereinafter abbreviated as HDI). It is a surface layer material formation composition for fiber laminated bodies which consists of a modified polyisocyanate (B1) of) and an isocyanurate modified polyisocyanate (B2) of HDI.

PCD in the subject (A) used for this invention is PCD which can be obtained by de-alcohol reaction and dephenol reaction of 1, 6-hexanediol (henceforth abbreviated as 1, 6-HD) and low molecular carbonate. to be. The preferable number average molecular weight of this PCD is 500-5,000, More preferably, it is 1,000-3,000. When the number average molecular weight is too low, the flexibility of the coating agent decreases, and the touch when touched and the followability with the substrate decrease. On the other hand, when the number average molecular weight is too high, the film strength tends to be insufficient.

At the time of manufacture, PCD obtained using low molecular weight polyols other than 1, 6-HD can also be used together with the main ingredient (A) of the coating agent of this invention. As such low molecular polyols other than 1,6-HD, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5 -Pentanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 2-ethyl-4-butyl-1,3-propanediol, diethylene glycol, dipropylene Glycol, neopentyl glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, dimer acid diol, ethylene oxide or propylene oxide adduct of bisphenol A, bis (β-hydroxyethyl) benzene, Low molecular polyols, such as xylene glycol, glycerin, trimethylol propane, pentaerythritol, etc. are mentioned.

As low molecular carbonate, ethylene carbonate, diethyl carbonate, diphenyl carbonate, etc. are mentioned.

The use of the chain extender is not a problem in that it is mixed and used immediately before the blending of the main agent and the curing agent. However, when the polyol premix is used in advance, the transesterification reaction occurs during storage, which is not preferable.

The hardening | curing agent (B) in this invention consists of modified polyisocyanate (B1) of HDI which is a number average molecular weight 350-500, and low functional group number, and isocyanurate modified polyisocyanate (B2) of HDI.

The modified polyisocyanate (B1) of HDI which is a number average molecular weight 350-500 and low functional group number gives a film | membrane flexibility, and also brings the effect of improving workability at the time of surface-layer material formation.

When the number average molecular weight of B1 is less than a lower limit, the odor problem may arise at the time of surface layer material formation work. When exceeding an upper limit, since a viscosity becomes high, productivity at the time of surface layer material formation operation | work will fall.

The average functional group f of B1 is 2 <f <3. When f is less than the lower limit, the crosslinking effect is insufficient, and the film physical properties are lowered. Above the upper limit, the flexibility of the coating is reduced.

As a specific example of B1, 1: 2 (molar ratio) addition product of low molecular glycol (molecular weight 62-164) and HDI, the allophanate modified body of 1: 2 (molar ratio) of low molecular monool (molecular weight 32-164) and HDI, etc. For example. In the present invention, a 1: 2 (molar ratio) allophanate modified product of low molecular weight monool and HDI, which has a low viscosity, is preferable.

Low molecular monools include methanol, ethanol, propanol (including various isomers), butanol (including various isomers), pentanol (including various isomers), hexanol (including various isomers), heptanol ( Saturated aliphatic monools such as various isomers), octanol (including various isomers), nonanol (including various isomers), unsaturated aliphatic monools having 2 to 9 carbon atoms, and the like. The low molecular weight monool which is preferable in this invention is isopropanol which has a small molecular weight and high shielding effect.

In the method for producing an allophanate modified product of HDI, an allophanate reaction of HDI and a monool at least two molar equivalents with respect to a hydroxyl group is carried out in the presence of an allophanate catalyst, followed by addition of a catalyst poison. , A method of removing unreacted HDI.

Isocyanurate-modified polyisocyanate (B2) of HDI is obtained by removing the unreacted HDI through the isocyanurate reaction of the partial urethane prepolymer of HDI or HDI. Here, the partial urethane prepolymer of HDI is obtained by carrying out urethanation reaction of excess HDI and low molecular glycol with respect to a hydroxyl group, and the preparation molar ratio of HDI: low molecular glycol = 5: 1-100: 1 is preferable. In addition, the low molecular glycol is preferably 1,3-butanediol in consideration of the compatibility of the polyisocyanate obtained and the isocyanate content of the polyisocyanate to be obtained.

Polyisocyanate other than B1 and B2 can be used together for a hardening | curing agent (B) as needed. Specifically, diphenylmethane diisocyanate (including various isomers), tolylene diisocyanate (including various isomers), xylene diisocyanate (including various isomers), tetramethylxylene diisocyanate (containing various isomers) ), Aliphatic diisocyanates such as phenylene diisocyanate (including various isomers), tetramethylene diisocyanate, 3-methyl-1,5-pentane diisocyanate, lysine diisocyanate, isophorone diisocyanate, hydrogen Alicyclic diisocyanate, such as added tolylene diisocyanate, hydrogenated xylene diisocyanate, and hydrogenated diphenylmethane diisocyanate, etc. are mentioned. Moreover, these polymers, urethane, urea, allophanate, biuret, carbodiimide, uretonimide, uretdione, isocyanurate, etc. are mentioned, and these are also mentioned, for example. 2 or more types of mixtures are mentioned.

10-25 mass% is preferable, and, as for the isocyanate content of the hardening | curing agent (B) obtained in this way, 13-22 mass% is especially preferable. When there is too much isocyanate content, since there is much free isocyanate content, there arises a problem in workability, such as a bad smell. Moreover, when too low, since a crosslinking density falls, the strength and durability of the formed surface layer material for fiber laminated bodies tend to be inadequate.

In the present invention, additives may be used for the main or curing agent or both. Examples of the additive include plasticizers, fillers, colorants, flame retardants, organic fillers or inorganic fillers, antioxidants, ultraviolet absorbers, pigments, dyes, antibacterial agents and antifungal agents.

The synthetic leather or artificial leather of the present invention comprises a surface layer and a fiber fabric layer formed of the surface layer forming composition for a fiber laminate described above.

Synthetic leather or artificial leather using the surface layer forming composition for a fiber laminate of the present invention, after applying the liquid containing the above-described main ingredient (A) and the curing agent (B) to the release support, and the primary curing, fiber fabric To a secondary fabric, and then to a secondary curing method, and then to a releasing support, or a production method in which the liquid containing the above-described main ingredient (A) and the curing agent (B) is directly applied to the fiber fabric and heated and cured. Obtained.

In order to form the liquid (the following abbreviated as a compounding liquid) which mix | blended the above-mentioned main body (A) and hardening | curing agent (B) on a mold release support body, it apply | coats using a normal coating method, for example, a knife overall roll, etc., What is necessary is just to adhere to a fiber cloth, and to harden | cure it secondaryly after primary hardening, and to remove a mold release support body after that. Or in order to apply | coat a compounding liquid directly to a fiber cloth, you may carry out by the coating method using a knife coater, a comma coater, etc., for example. In the present invention, the fiber laminate and the synthetic leather generally indicate that the surface of the surface material is used on the surface side of the final product, but in the same manufacturing method, a moisture-permeable waterproof coating agent in which the surface of the surface material is used on the back side; and A moisture-permeable waterproof material can also be used similarly.

As said release support body, a release paper, a polyester film, etc. can be used, for example. As the fiber fabric, for example, natural fibers or all synthetic fibers can be used. Specific examples may be cotton, artificial fibers, polyester, nylon, acrylic and a mixture of two or more thereof. Examples of the form include woven fabrics, knitted fabrics, nonwoven fabrics, brushed fabrics, and the like. Moreover, the laminated base material which has porous membranes, such as a polyurethane resin, on one side of a fiber cloth may be sufficient. In addition, these fiber fabrics may be water-repellent treated with a silicone resin, a fluororesin or the like.

Examples of the coating method in the case of direct coating include knife coating, wire bar coating, doctor blade coating, reverse roll coating, calendar coating, and the like. After the coating is coated on the synthetic leather surface, it is heat cured to form a coating.

1-200 micrometers is preferable and, as for the film thickness of the surface layer material layer for fiber laminated bodies, 5-100 micrometers is more preferable.

At this time, the composition which mix | blended the above-mentioned main body (A) and hardening | curing agent (B) with the fiber cloth in the ratio of hydroxyl group / isocyanate group in the ratio of hydroxyl group / isocyanate group = 90 / 100-110 / 100 is a mold release support body. It is preferable to apply | coat to or to a fiber cloth, and to heat and harden | cure after that. When the molar ratio of the hydroxyl group and the isocyanate group deviates from the aforementioned ratio, the strength and durability of the coating layer tend to be insufficient.

As for the heating temperature at the time of hardening, 50-150 degreeC is preferable. The heating time is preferably 2 minutes to 2 hours. If the temperature is too low or if the time is too short, curing will be insufficient. On the other hand, when the temperature is too high or the time is too long, unnecessary heat history is given to the film or the substrate.

When mix | blending a main body (A) / hardening | curing agent (B), a catalyst can be added for the purpose of shortening a hardening process and improving reaction rate. As the urethane-forming catalyst, the catalyst is a tertiary amine catalyst such as triethylamine, tetramethylpropylenediamine, tetramethylhexamethylenediamine, tolylenediamine, or tin octoate, tin oleate, dibutyltin dilaurate, Metal catalysts represented by the same tin catalyst are exemplified, and these are each used alone or in combination.

Synthetic leather or artificial leather manufactured using the surface layer forming composition for a fiber laminate of the present invention is useful for clothing, shoes, bags, bags and the like. Moreover, the surface layer forming composition for fiber laminated bodies of this invention can be used also as coating agents, such as for moisture-permeable waterproof clothing.

Example

Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to these. And in an Example and a comparative example, "%" represents the "mass%."

[Production of Modified Polyisocyanate of HDI]

Production Example 1

Capacity with a stirrer, a thermometer, a cooler, and a nitrogen gas introduction tube: 950 g of HDI and 50 g of isopropanol were charged into a 1 L reactor, and the urethanation reaction was performed at 90 ° C for 2 hours. The reaction product was analyzed by FT-IR and the hydroxyl group was lost. Next, 0.2 g of 2-ethylhexanoic acid zirconium was added and reacted at 90 ° C for 3 hours. The reaction product was analyzed by FT-IR and ¹³ C-NMR, and the urethane group was lost. Subsequently, 0.1 g of phosphoric acid was added, and the reaction was stopped at 50 ° C for 1 hour. The isocyanate content of the reaction product after the stop reaction was 42.1%. The reaction product was subjected to thin film distillation at 130 ° C. to 0.04 kPa, and free HDI was removed. Polyisocyanate P having an isocyanate content of 19.4%, a viscosity of 100 mPa · s at 25 ° C., 0.1% of free HDI content and a color number of 10 APHA. -1 was obtained. When P-1 was analyzed by FT-IR and ¹³ C-NMR, the presence of the urethane group was not recognized, and the presence of the allophanate group was confirmed. Also, uretdione and isocyanurate groups were recognized as traces. When the number average molecular weight of P-1 was calculated | required, it was 433 and the average number of functional groups computed from this number average molecular weight and isocyanate content was 2.0.

Production Example 2

Capacity with stirrer, thermometer, cooler and nitrogen gas introduction tube: 600 parts of HDI, 5 parts of 1,3-butanediol, 0.1 part of potassium capricate as catalyst, 0.6 part of phenol as promoter Then, the air in the flask was replaced with nitrogen, heated to a reaction temperature of 70 ° C. while stirring, and the reaction was carried out at this temperature for 4 hours. 0.2 part of phosphoric acid was added to the reaction solution as a terminator, and after stirring for 1 hour at this reaction temperature, the reaction product was thin-film distilled at 130 ° C to 0.04 kPa, free HDI was removed, and the isocyanate content was 20.8%, 25 Polyisocyanate P-2 which is a viscosity of 2500 mPa * s, 0.3% of free HDI content, and 20APHA of color number was obtained. As a result of analyzing P-2 by FT-IR and ¹³ C-NMR, isocyanurate groups were identified, but traces of allophanate and uretdione groups were recognized. The number average molecular weight of P-2 was determined, and it was 747. The average number of functional groups calculated from this number average molecular weight and isocyanate content was 3.7.

[Film Evaluation]

Examples 1-9, Comparative Examples 1-4

In the combinations shown in Tables 1 and 2, the main body and the room temperature curing agent heated and dissolved at 60 ° C. were mixed so that the isocyanate group and the hydroxyl group were equivalent, and applied to the release paper by a bar coater so as to have a thickness of 100 μm. After heating at 60 degreeC for 30 minutes, it heated at 120 degreeC for 1 hour and hardened | cured. And the compounding ratio of a main body and a hardening | curing agent is an equivalent equivalent of an isocyanate group and a hydroxyl group. Then, after standing at room temperature for 24 hours, various physical properties were evaluated. The results are shown in Tables 1 and 2.

In Tables 1 and 2

PCD-1000: PCD obtained by reacting diethyl carbonate with 1,6-HD

Number average molecular weight = 1,000

PCD-2000: PCD obtained by reacting diethyl carbonate with 1,6-HD

Number average molecular weight = 2,000

PCD-3000: PCD obtained by reacting diethyl carbonate with 1,6-HD

Number average molecular weight = 3,000

Property evaluation test method

Tensile Properties (each modulus, strength at break, increased at break)

The sample was punched by the No. 4 dumbbell cutter, and this was measured according to JISK7311. Tensile velocity was 200 mm / min, and measurement temperature was 23 degreeC.

Hysteresis Los

The sample was punched out by the No. 4 dumbbell cutter, and the tensile velocity was measured at 200 mm / min and the measurement temperature of 23 ° C. until the elongation was 300%, and then the load was removed.

As shown in Tables 1 and 2, the film formed from the surface layer forming composition for a fiber laminate of the present invention was excellent in balance between strength and flexibility. On the other hand, Comparative Examples 1 and 3 were films that lacked flexibility, had small strength, and had no physical properties. In Comparative Examples 2 and 4, the strength was sufficient, but the hysteresis loss was large and the elasticity was insufficient. And there was no odor at the time of making all the films, and workability was favorable.

[Manufacture of Synthetic Leather]

Example 10

Synthetic leather was manufactured in the following procedure.

1) The combination of Example 3 was used, but the mixing ratio of the isocyanate group and the hydroxyl group of the main body and the room temperature curing agent heated and dissolved at 60 ° C was the same equivalent, and dioctyltin dilaurate was used as the catalyst to the main body / curing agent mixture. 300 ppm was added, the main body, the hardening | curing agent, and the catalyst were mixed uniformly, and degassed under reduced pressure.

2) Next, this compound was applied to a release paper such that the thickness was 15 µm and heated at 120 ° C. for 5 minutes.

3) Thereafter, polyester taffeta was superimposed and crimped as a base fabric thereon.

4) After aging at 50 to 60 ° C for 48 hours, release paper was peeled off to obtain synthetic leather.

The obtained synthetic leather was flexible and the touch was also favorable. In addition, at the time of production, there was no odor, and it considered productivity and the environment.

Example 11

Synthetic leather was manufactured in the following procedure.

1) The combination of Example 3 was used, but the mixing ratio of the isocyanate group and the hydroxyl group of the main body and the room temperature curing agent heated and dissolved at 60 ° C was the same equivalent, and dioctyltin dilaurate was used as the catalyst to the main body / curing agent mixture. 300 ppm was added, the main body, the hardening | curing agent, and the catalyst were mixed uniformly, and degassed under reduced pressure.

2) Next, this compounding solution was applied as a base cloth by a bar coater on a polyester taffeta so as to have a thickness of 15 µm.

3) After heating at 120 degreeC for 5 minutes, it aged at 50-60 degreeC for 48 hours, and obtained the synthetic leather.

The obtained synthetic leather was flexible and the touch was also favorable. In addition, at the time of production, there was no off-flavor and was considering productivity and environment.

[Manufacture of Artificial Leather]

Example 12

Artificial leather was manufactured according to the following procedures.

1) The combination of Example 3 was used, but the mixing ratio of the isocyanate group and the hydroxyl group of the main body and the room temperature curing agent heated and dissolved at 60 ° C was the same equivalent, and dioctyltin dilaurate was used as the catalyst to the main body / curing agent mixture. 300 ppm was added, the main body, the hardening | curing agent, and the catalyst were mixed uniformly, and degassed under reduced pressure.

2) Next, this compound was applied to a release paper such that the thickness was 15 µm and heated at 120 ° C. for 5 minutes.

3) After that, a three-dimensional entangled nonwoven fabric made of polyester was superimposed thereon and pressed.

4) After aging at 50 to 60 ° C. for 48 hours, release paper was peeled off to obtain artificial leather.

The obtained artificial leather was flexible and had good texture. In addition, at the time of production, there was no off-flavor and was considering productivity and environment.

Example 13

Artificial leather was manufactured according to the following procedures.

1) The combination of Example 3 was used, but the mixing ratio of the isocyanate group and the hydroxyl group of the main body and the room temperature curing agent heated and dissolved at 60 ° C was the same equivalent, and dioctyltin dilaurate was used as the catalyst to the main body / curing agent mixture. 300 ppm was added, the main body, the hardening | curing agent, and the catalyst were mixed uniformly, and degassed under reduced pressure.

2) Next, this compounding liquid was apply | coated with the bar coater on the polyester three-dimensional entangled nonwoven fabric so that thickness might be set to 15 micrometers.

3) It heated at 120 degreeC for 5 minutes, and aged at 50-60 degreeC after that for 48 hours, and obtained artificial leather.

The obtained artificial leather was flexible and had good texture. In addition, at the time of production, there was no off-flavor and was considering productivity and environment.

Claims (7)

In the surface layer forming composition for fiber laminated bodies which consists of a main body (A) and a hardening | curing agent (B),
Main (A) is polycarbonate diol obtained from 1, 6- hexanediol, and the carbonate selected from 1 or more types from ethylene carbonate, diethyl carbonate, and diphenyl carbonate,
Allophanate-modified polyisocyanate (B1) obtained from monool and hexamethylene diisocyanate whose hardening | curing agent (B) is number average molecular weight 350-500, and average number of functional groups (f) is 2 <f <3, and f≥3 It consists of the isocyanurate modified polyisocyanate (B2) of phosphorus hexamethylene diisocyanate, It is B1: B2 = 50: 50-95: 5 (mass ratio), It is an organic solvent in both a main body (A) and a hardening | curing agent (B) The surface layer forming composition for fiber laminated bodies which does not contain. Synthetic leather which consists of a surface layer formed from the surface layer forming composition for fiber laminated bodies of Claim 1, and a fiber cloth layer. An artificial leather comprising a surface layer and a fiber fabric layer formed of the surface layer forming composition for a fiber laminate according to claim 1. The synthesis | combination which apply | coated the liquid which mix | blended the main ingredient (A) and hardening | curing agent (B) of Claim 1 to a mold release support body, and after it hardened | cured primarily, adheres to a fiber cloth for secondary hardening, and then removes a mold release support body. Method of manufacturing leather or artificial leather. The manufacturing method of synthetic leather or artificial leather which apply | coats the liquid which mix | blended the main ingredient (A) and hardening | curing agent (B) of Claim 1 to a fiber cloth directly, and heat-hardens. The method according to claim 4 or 5,
The liquid which mix | blended the main ingredient (A) and hardening | curing agent (B) of Claim 1 WHEREIN: Let molar ratio of the hydroxyl group and the isocyanate group of the said compounding liquid be a ratio of hydroxyl group / isocyanate group = 90/100-110/100, Method of manufacturing synthetic leather or artificial leather. delete