JPS60239573A - Production of leather-like substance - Google Patents

Abstract

PURPOSE:A fibrous base is impregnated with a solution of high polymeric elastomer containing a flourine-containing urethane and the solution is coagulated by the wet method, the base is brought into contact with a heater on its surface, then a microporous layer is formed by the wet method on the surface whereby the titled sheet of high smooth surface is obtained. CONSTITUTION:A solution of high polymeric elastomer containing a fluorine- containing urethane (preferably of 12-35wt% fluorine content) which has been obtained by reaction between an urethane prepolymer and a compound containing perfluoroalkyl groups, is used to impregnated a fibrous base. Then, the base is dipped in a nonsolvent medium mainly consisting of water to effect the wet coagulation of the elastomer. Then, the base is brought into contact with the surface of a heater on at least one surface of the base of remove the nonsolvent near the surface layer. The surface treated with the heater is coated with an elastomer solution and coagulated by the wet method to form a microporous layer. The base becomes water-repellent on the whole and the penetration of water into the base is inhibited on the formation of the microporous layer, thus the air bubbles in the base are not pushed out thereby forming dense and uniform foam structure.

Description

[Detailed description of the invention] The present invention provides a leather-like sheet material having excellent surface uniformity.

Regarding the manufacturing method.

A conventional method for manufacturing a leather-like sheet material is to impregnate the voids of an L fibrous base material with a solution of an elastic polymer such as polyurethane in a hydrophilic organic solvent.

For example, the base material is immersed in water, the organic solvent is dissolved and removed in water, and the elastic polymer is wet-coagulated.7 Next, a solution of a high-molecular elastic polymer such as polyurethane is applied to the surface of the base material, and then applied to the surface. A method is known in which a microporous layer is formed by wet-coagulating an elastomeric polymer. deer【
However, according to this method, water, etc. penetrates into the base material during the wet coagulation process when forming the microporous layer, and air bubbles in the base material are extruded and enter the microporous layer during the solidification process, resulting in the microporous layer being formed. There was a drawback that coarse air bubbles were generated in the porous layer, and a microporous layer with uniform and dense air cells was not formed, resulting in a decrease in surface smoothness of the obtained sheet-like product.

On the other hand, after the back side of the base material has been treated to be water repellent, a solution such as polyurethane is applied to the opposite side to the treated side.

A method of forming a microporous layer by wet coagulating polyurethane is also known (Japanese Patent Laid-Open No. 51-616).
05), in this method, only the back side of the base material is treated to be water repellent, and the front side of the base material is not treated to be water or oil repellent, so water from the back side of the base material during the wet coagulation process. However, when a solution such as polyurethane is applied in the previous step, the solution such as polyurethane penetrates into the base material and forms a coating on the surface of the base material to replace the air in the base material. There was a problem that air bubbles were extruded into the polyurethane film, making it difficult to form a microporous layer with excellent smoothness, and a new process called water removal treatment was required, making manufacturing complicated. .

The present invention was made in view of the above points, and it is possible to form a microporous layer with a dense and uniform cell structure without the bubbles in the base material transferring to the microporous layer during the solidification process when forming the microporous layer. .

An object of the present invention is to provide a method for producing a leather-like sheet material that can obtain a leather-like sheet material with excellent surface smoothness.

That is, the present invention involves impregnating a fibrous base material with an elastomeric polymer solution containing a fluorine-containing urethane compound, and then immersing the base material in an aqueous solvent to wet-coagulate the elastomeric polymer. After removing the aqueous solvent near the surface layer of the base material by bringing at least one of the surfaces of the base material into contact with the surface of the heating element having a surface temperature equal to or higher than the boiling point of the aqueous solvent, A leather-like material characterized by applying an elastomeric polymer solution to the surface of the material, and then immersing it in an aqueous solvent to wet-coagulate the elastomeric polymer applied to the surface to form a microporous layer. The gist is a method for manufacturing sheet-like products.

The fibrous base material used in the present invention includes:

Examples include base materials having voids inside, such as woven fabrics, cotton fabrics, and nonwoven fabrics. In addition, examples of elastic polymers containing fluorine-containing urethane compounds include polyurethane, polyacrylonitrile, polyacrylic acid ester, etc.; Thermoplastic polyurethanes are most preferred, especially those with a softening point of 1
Polyurethane having a temperature of 40 to 220°C is preferred.

In the method of the present invention, Fi is first applied to the above-mentioned fibrous base material.

After impregnating with a solution of the above elastic polymer containing a fluorine-containing urethane compound, the fluorine-containing urethane compound and the elastic polymer are wet coagulated. At this time, as a solvent for the high molecular weight elastic polymer solution.

A hydrophilic organic solvent is used to dissolve both the fluorine-containing urethane compound and the elastomeric polymer. Examples include dimethylformamide, dioxane, tetrahydrofuran, acetone, etc., but dimethylformamide is the most suitable. preferable.

Also, for wet coagulation of high molecular weight elastic polymers.

An aqueous solvent containing water as a main component is used, which dissolves the above-mentioned organic solvent but does not dissolve the elastic polymer.

In the present invention, examples of the fluorine-containing urethane compound contained in the elastic polymer include addition reaction products of a urethane prepolymer having an isocyanate group at the end and a perfluoroalkyl group-containing compound having an active hydrogen group. I get kicked.

The above urethane prepolymer polyethylene adipate,
Polyester polyols such as polybutylene adipate and poly-ε-caprolactone, polyethylene glycol,
Polypropylene glycol.

A polyether polyol such as polytetramethylene glycol and 2.4-)lylene diisocyanate.

2.6-) lylene diisocyanate, 4.4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isoporone diisocyanate.

It is obtained by reacting polyisocyanates such as xylene diisocyanate and 4,4'-dicyclohexylmethane diincyanate, but polyols such as polyester polyols and polyether polyols have molecular weights of 400 to 400.
4000 is preferred. An example of a compound containing an active hydrogen group and a sulperfluoroalkyl group that can be subjected to an addition reaction with the urethane prepolymer is as follows.

RIOH, R15O2NHz, RISO!・N・CH
t (Jb OH.

■ 2 R+ Soz・NCR1C City OCR no CI(, OI(,
Examples include compounds represented by the general formula R, ・O・C CH, OH2 (wherein R1 represents a perfluoroalkyl group and R2 represents an alkyl group). Preferably.

The urethane prepolymer is prepared such that the fluorine content in the fluorine-containing urethane compound obtained by the reaction between the urethane prepolymer and the perfluoroalkyl group-containing compound acid 2 is 12 to 35% by weight.

It is preferable to select and use nine types of molecular weight compounds containing perfluoroalkyl groups. The amount of the fluorine-containing urethane compound added to the elastic polymer is such that the fluorine content in the elastic polymer and the fluorine-containing urethane compound is 0.0.
An amount of 2 to 0.30% by weight, particularly 0.03 to 0.20% by weight is preferred. When the fluorine content of the fluorine-containing urethane compound is out of the range of 12 to 35% by weight, the water repellency of the fluorine-containing urethane compound decreases or the fluorine-containing urethane compound escapes from the elastic polymer into the aqueous solvent. Problems such as these are likely to occur. Furthermore, if the content of the fluorine-containing urethane compound in the elastic polymer is such that the fluorine content is less than 0.02% by weight, it is difficult to obtain sufficient water repellency.
Even if the fluorine-containing urethane compound is contained in an amount exceeding 30% by weight, the effect of the addition of the fluorine-containing urethane compound is not in an equilibrium state, and further improvement cannot be expected.

It is preferable that the elastomeric polymer solution containing the fluorine-containing urethane compound does not contain a surfactant. When a surfactant is added to the base material, it is preferable to wet-coagulate the elastomeric polymer 9 and then thoroughly wash the base material with water to remove the surfactant remaining in the base material. In addition, in order to improve the light resistance and hydrolysis resistance of the elastic polymer, light resistance improvers such as hindered phenol, benzotriazole, benzophenone, and hindered amine, and hydrolysis inhibitors such as polycarbodiimide are used. There is no problem even if it is added and used as long as it does not cause a decrease in water repellency, and if necessary, a pigment for coloring the fibrous base material can also be used in combination.

The base material is filled with wet coagulated elastomeric polymer.
Although the excess aqueous solvent in the base material is removed, it is preferable that the aqueous solvent contained in the base material is not completely removed at this time, and that the aqueous solvent is contained in the voids in the base material. The dry weight of the base material filled with the solidified elastic polymer is 1
The amount of aqueous solvent contained in the base material when 00 is 30-2
Preferably it is 00.

Next, at least one surface of the base material is brought into contact with the surface of a heating element having a surface temperature equal to or higher than the boiling point of the aqueous solvent to remove the aqueous solvent near the surface layer of the base material, and then brought into contact with the surface of the heating element. Apply an elastic polymer solution to the optical surface of the @ base material. By bringing the surface of the base material into contact with the surface of the heating element and removing the aqueous solvent on the surface, the adhesive strength with the elastomeric polymer applied to the core surface is improved, and the fibers protruding from the surface are brought down and the two surfaces are This has the effect of further improving smoothness. In addition, the surface that is brought into contact with the surface of the heating element is hydrophobic υ. Therefore, not only the surface on which the elastomeric polymer that forms the microporous layer is coated, but also the elastomeric polymer solution should not be applied. It is preferable to bring the surface of the base material into contact with the surface of the heating element to remove the aqueous solvent near the surface layer, and by bringing both the front and back surfaces of the base material into contact with the surface of the heating element, the hydrophobicity is further enhanced.

Furthermore, a microporous layer with a uniform and dense cell structure is formed.

The elastic polymer to be applied to the above surface is as follows.

Preferably, an elastic polymer containing a polyurethane elastomer as a main component, and examples of the polyol constituting the polyurethane elastomer include polyethylene adipate and polyethylene butylene adipate.

Polyester polyols such as polybutylene adipate and poly-ε-caprolactone, polyether polyols such as polypropylene glycol and polytetramethylene ether glycol, or ethylene glycol, 1.4
Examples include low molecular weight glycols such as -butanediol and 1,3-butanediol, and polycarbonate polyols. Examples of the polyisocyanate include 4,4'-diphenylmethane diisocyanate, 2.4-)lylene diisocyanate, 2.6-)lylene diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, etc. 4,4'-diphenylmethane diisocyanate is particularly preferred. As a solvent for these high-molecular elastic polymers mainly composed of polyurethane entomers, after applying the impregnated solution to the base material, one layer is formed in an aqueous solvent mainly composed of water, and a leather-like material is formed. A sheet-like product is obtained.

As described above, according to the present invention, since the elastic polymer filled in the base material contains a fluorine-containing urethane compound, the entire base material has excellent water repellency, and therefore the polymer forming the microporous layer This is because it is difficult for water etc. to penetrate into the base material during wet coagulation of elastic polymers.

Since there is very little risk that air bubbles in the base material will be extruded into the elastomeric polymer during the solidification process due to the penetration of water into the base material, coarse air bubbles will not be contained in the formed microporous layer. As a result, a leather-like sheet material with an extremely smooth surface is obtained as a result of the formation of a microporous layer having a dense and uniform cell structure. In addition, the surface to which the elastomeric polymer solution forming the microporous layer is applied is
By contacting the heated body surface in advance, the aqueous solvent near the surface layer is removed and the fibers on the surface are collapsed, which improves the adhesive strength between the base material and the microporous layer and further improves the planar smoothness. It has various effects such as

The present invention will be described in further detail with reference to Examples and Comparative Examples below.Example 1: 30% polyurethane terephthalate fiber with a fiber length of 33 m and a fineness of 1.5 denier and a fiber length of 51 mm.

Consists of 70% 6-nylon fibers with a fineness of 1.5 denier. A short fiber entangled body having a thickness of 1.3 mm and a basis weight of z5o1/d is used as a base material, and the base material is made of polyurethane polyurea (product name: Crisbon, manufactured by Dainippon Ink and Chemicals: softening point 1).
94℃, 100% modulus 40kg/cd) 1
9.8%, fluorine-containing urethane (fluorine content 32% by weight) 0
．． The sample was immersed in a dimethylformamide solution containing 0.044% (the fluorine content in the total solid content of polyurethane polyurea and fluorine-containing urethane was approximately 0.070%). Next, after squeezing the solution so that the ratio of the substrate to the dimethylformamide solution was 100:97, the substrate was immersed in an aqueous solvent at 20°C consisting of 97% water and 3% dimethylformamide to remove fluorine. A polyurethane polyurea containing urethane was coagulated. Next, after squeezing the liquid using a squeezing roll so that the weight of the aqueous solvent contained in the base material is 68 when the dry weight of the base material is 100, the surface of the base material is heated to a surface temperature of 160°C.
After contacting the surface with a metal roll, polyurethane polyurea (product name: Sanprene, Sanyo Kasei M: softening point 98°C, 100% modulus 125 to 9/c+J) 2
3.5%, castor oil 0.65%, and polyethylene glycol lauryl ether 1.3%.
Thereafter, the substrate was immersed in water at 20° C. to coagulate the polyurethane polyurea. After this, wash thoroughly with water at 120°C.
Ventilated and dried.

A leather-like notebook material with a uniform and dense microporous layer and excellent surface smoothness was obtained.

In addition, the above-mentioned Fluorine Urethane Co., Ltd. polyethylene adipate (MW
556),) lylene diisocyanate and C8F17
Obtained by reacting 5OzN (CHs ) CHt CH20H in dimethylformamide. It is a fluorine-containing urethane with a perfluorooctyl group at the end.

Comparative Example 1 A leather-like sheet material was obtained in the same manner as in Example 1 except that fluorine-containing urethane was not used, but the microporous layer contained coarse air bubbles and the surface smoothness was poor. Ta.

Comparative Example 2 The same base material as in Example 1 was impregnated with a dimethylformamide solution of polyurethane polyurea containing the same fluorine-containing urethane as in Example 1.

The substrate was immersed in water to solidify the polyurethane polyurea. Next, without bringing the substrate surface into contact with the surface of the heating element, a dimethyl formamide solution containing polyurethane polyurea as a main component similar to Example 1 was immediately applied, and then immersed in water to coagulate the polyurethane polyurea to form a microporous layer. A leather-like sheet material was obtained.

The obtained sheet-like material 1 had poor surface smoothness and was also poor in adhesive strength of the microporous layer.

Procedural author's letter (spontaneous) June 16, 1980 Director General of the Patent Office Mr. Kazuinu Wakasugi 1, Indication of the case 1982 Patent Application No. 93795 2, Name of the invention Process for manufacturing leather-like sheet material 3, Relationship with the case of the person making the amendment Patent applicant address 5 name, 22 Daikyo-cho, Shinjuku-ku, Tokyo (007)
) Achilles Co., Ltd. Representative Masao Tonooka 4, Agent ■101 Address 2-7 Kanda Sakuma-cho, Chiyoda-ku, Tokyo Voluntary amendment 6, "Claims" column of the specification subject to amendment and "Details of the invention 1,
The scope of claims in the scope of claims section of the specification is amended as follows.

[(1) After impregnating a fibrous base material with an elastomeric polymer solution containing a fluorine-containing urethane compound, the base material is immersed in a non-solvent mainly composed of water to form an elastomeric polymer. is wet-coagulated, and then at least one of the surfaces of the base material is brought into contact with the surface of the heating element to remove non-mK near the surface layer of the base material, and then a polymer is applied to the surface of the base material on the side that has been brought into contact with the surface of the heating element. Leather characterized in that a microporous layer is formed by applying an elastomeric polymer solution and immersing the elastomeric polymer solution in a non-solvent containing water as a main component to wet-coagulate the elastomeric polymer applied to the surface. A method for producing a similar sheet-like product.

(2) Fluorine content in the fluorine-containing urethane compound is 12 to 3
The method for producing a leather-like sheet material according to claim 1, wherein the content is 5% by weight.

(3) Claims in which the elastic polymer containing a fluorine-containing urethane compound contains the fluorine-containing urethane compound in an amount such that the fluorine content in the polymer is 0.02 to 0.30% by weight. The method for producing a leather-like sheet material according to item 1 or 2.

(4) The method for producing a leather-like sheet material according to any one of claims 1 to 3, wherein the surfaces of the base material that are brought into contact with the heating body surface are both the front and back surfaces. 2. Detailed explanation of the invention in the specification (1) On page 2, line 17 of the specification, change ``in water'' to ``hydrophilic organic solvents such as water dissolve, but the high molecular weight elastic polymer does not dissolve.'' Correct as "in a non-solvent."

(2) Correct "to water" in the same sentence to "to non-solvent such as water."

(3) “Aqueous solvent” on page 4, line 15 and page 5, line 1
is corrected to ``a nonsolvent whose main component is water.''

(4) Delete "having the temperature of the aqueous solvent" in lines 17-18 of the same page.

(5) Page 4, line 19, page 6, line 6, page 8, line 13, page 9, lines 17, 18, and 19, page 10, lines 2, 6, and 9
line, line 18, page 12, line 6, page 13, line 5, page 14, line 7
Correct “aqueous solvent” in line 10 to “non-solvent”.

The temperature above the boiling point of the water-distributing solvent is changed to the temperature above the boiling point of the non-solvent.
"..." is corrected.

(7) "Water, etc." on page 12, lines 15 and 16 is corrected to "non-solvent such as water."

(Spontaneous) February 10, 1980 Manabu Shiga, Commissioner of the Patent Office 93795-No. 2, Name of the invention, Method for manufacturing a leather-like sheet-like product 3, Lottery IF, Relationship to the case. Patent applicant address: 5 name, 22 Daikyo-cho, Shinjuku-ku, Tokyo (007)
) A; Representative of Torres Co., Ltd. fl Masa Mataoka h1 (.

4), 101 Address: 2-75 Kanda Sakuma-cho, Tokyo, 2-75 Kanda Sakuma-cho, Voluntary amendment 6, Detailed description of the invention column 7 of the specification to be amended, Contents of Supplement II- W iJG / rl Niili M (1) On page 5, line 7 of the specification: ``...Car Z7f Gerane.
Ru. Insert the following sentence between -1 and "Also contains fluorine...1.

r IN m Stilts 1; Materials impregnated with water-soluble polymers such as myrrhinyl alcohol, hydroxycellulose, methylcellulose, etc. and treated with ζ can also be used. r-rt=:ε乎市i-1之-木-(Spontaneous) Patent 1'+
'J Official Shiga '7 Indication of 111-1'1 Showa 59 Guide 1 Tokuko No. 1 No. 93795 2, Name of invention 3 Process for manufacturing leather-like sheet-like article 3 Person making the amendment (Relationship with 1) Patent applicant address: 5 name, 22 Daikyocho, Shinjuku-ku, Tokyo (007)
) Achilles Co., Ltd. representative hitter Masao Crotch 4 agent 101 I1 2-75 Kanda Sakuma-cho, Chiyoda-ku, Tokyo, ``1 attachment of 1 toe order, subject to voluntary amendment 6 supplementary iE, 1982 Mobilized Petition No. 93795 8th year of 1982
Month 10 "] Ikij-'fVE, Attachment 7 of Sodeichisho, Contents of amendment

Claims (1)

[Scope of Claims] (11) After impregnating a fibrous base material with a solution of an elastomeric polymer containing a fluorine-containing urethane compound. Solidification 1 Then, at least one of the surfaces of the base material is brought into contact with the surface of a heating body having a surface temperature equal to or higher than the boiling point of the aqueous solvent to remove the aqueous solvent near the surface layer of the base material, and then brought into contact with the surface of the heating body. A microporous layer is formed by applying an elastomeric polymer solution to the surface of the base material on the other side, and then immersing it in an aqueous solvent to wet-coagulate the elastomeric polymer applied to the surface. A method for producing a leather-like sheet material. (2) The fluorine content in the fluorine-containing urethane compound is from 12 to
The method for producing a leather-like sheet material according to claim 1, which has a weight of 35% by weight. (3) The elastic polymer containing a fluorine-containing urethane compound contains the fluorine-containing urethane compound in an amount such that the fluorine content in the polymer is 0.02 to 0.30% by weight. A method for producing a leather-like sheet material according to item 1 or 2. (4) The leather-like sheet form according to any one of claims 1 to 3, wherein the surfaces of the base material that are brought into contact with the surface of the heating element having a surface temperature equal to or higher than the boiling point of the aqueous solvent are both the front and back sides. How things are manufactured.