JPH0784710B2 - Flame-retardant synthetic leather and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a flame-retardant synthetic leather, particularly to a synthetic leather suitable as a vehicle seat material.

[Prior Art] In recent years, as a method of imparting flame retardancy to synthetic leather, in particular, synthetic leather according to a dry manufacturing method, it is known to add various flame retardants to each layer constituting the synthetic leather.

In addition, synthetic leather generally causes the brittleness and deterioration of the polyurethane resin by adding a flame retardant,
It cannot withstand long-term use under normal use conditions.

On the other hand, the flame-retardant treatment of the synthetic leather according to the wet manufacturing method has technical difficulties more than that of the dry synthetic leather, and this is unsolved.
To date, synthetic leather with durability and flame retardancy has not been obtained.

The specific contents of the technical difficulty of the flame-retardant treatment of wet synthetic leather are as follows. That is, even if the fiber substrate is subjected to flame-retardant treatment, the flame-retardant agent is dissolved in water during solvent removal coagulation to form a microporous substrate in the wet treatment and loses its effect, and a microporous layer is formed. Three points: even if a flame retardant is added to polyurethane, the flame retardant is likewise dissolved in water during solvent coagulation and the effect disappears. Furthermore, the addition of a flame retardant significantly reduces wet film forming performance. Is mentioned.

BACKGROUND ART Polyurethane synthetic leather has been excellent in texture and appearance, and has been widely used as a material for bags, bags, shoes, clothing, belts and the like. However, conventionally, in most cases, a glycol having 2 to 4 carbon atoms has been used as the raw material,
Since polyurethane that uses polyester with dibasic acid such as adipic acid as a polyol component is used, it is inferior in hydrolysis resistance, and it is extremely suitable for products that require long-term use such as furniture and vehicle seats. It was not usable.

Of course, adding an anti-hydrolysis agent, such as polycarbodiimide, to the component can make some improvement, but cannot expect substantial improvement. Especially when it is applied mainly to interior materials such as clothing, furniture, vehicle materials, etc., it is not practically applicable except for special ones because the legal regulations are strict because human damage in a fire is great. The legal regulations include, for example, automotive interior materials such as FMVSS-302 and JIS / D-1201 in Japan, and JIS / A-1321 for wall coverings, which pass the regulations. There must be. In addition, automobile manufacturers often set their own standards that are stricter than legal regulations. In addition, in order to impart flame retardancy to synthetic leather as a composite material composed of fibers and synthetic resins, it is necessary to treat the fibers and synthetic resins having different combustion mechanisms with flame retardant treatment. It is necessary to add a large amount of flame retardant in order to be satisfied, but the resulting hardening of the texture, deterioration of durability, and sticky feeling. The flame retardant is easy to migrate and sticky on the surface. It is also necessary to eliminate problems such as the occurrence of bleeding or blooming to the surface and deterioration of surface quality.

An object of the present invention is to provide a flame-retardant synthetic leather which is capable of imparting flame-retardant properties without any loss of texture, feel, etc. of the synthetic leather, and which is excellent in hydrolysis resistance and light resistance. It is in.

[Means for Solving the Problems] The present invention relates to at least one or more polyurethane coating layers obtained by laminating a polyurethane microporous structure on a microporous fiber substrate formed on a fibrous substrate via a polyurethane adhesive layer. And the microporous structure is composed of a polycarbonate polyurethane having a bromine-containing modified urethane compound with a 100% modulus of 20 to 120 Kg / cm ² , and the microporous fiber substrate has a halogenated phosphate ester compound and / or a surface. A thickness including a phosphorus-containing nitrogen-containing compound and the polyurethane adhesive layer including an antimony trioxide and a bromine-containing modified urethane compound.
10～60Myu, 100% modulus 20~60Kg / cm consists of ^two polycarbonate-based polyurethane, thickness 20~80μ one layer of the polyurethane coating layer as mesothelial layer or the outermost layer, 100
Flame-retardant synthetic leather characterized by being composed of a polycarbonate-based polyurethane having a% modulus of 40 to 180 kg / cm ² , and a method for producing this synthetic leather, that is, a fibrous base material such as cotton cloth, woven cloth, and non-woven cloth. , A polycarbonate-based polyurethane solvent solution containing a bromine-containing modified urethane compound is applied and adhered by means such as impregnation, and then wet coagulation treatment is performed to form a microporous structure of the polycarbonate-based polyurethane on a fibrous base material. A halogenated phosphoric acid ester-based compound and / or a phosphorus-containing nitrogen-containing compound is adhered to the microporous fiber substrate thus formed, and then an antimony trioxide- and bromine-containing modified urethane compound is attached to the surface of the microporous fiber substrate. Flame-retardant characterized by sequentially laminating an adhesive layer containing at least one polycarbonate-based polyurethane film layer It is a manufacturing method of forming leather.

The microporous fiber base material as referred to in the present invention means that the surface of the fibrous base material is raised and impregnated with a solvent solution of a polycarbonate-based polyurethane, and / or a solvent solution of the same polycarbonate-based polyurethane is applied on the raised surface. After coating so as to cover the raised surface, the polycarbonate-based polyurethane is laminated and formed as a microporous body by a wet coagulation treatment.

The fibrous base material is a knitted or woven fabric made of natural fibers such as cotton and hemp, regenerated fibers such as rayon, suf, acetate and the like, synthetic fibers such as polyester, polyamide, polyacrylonitrile and the like, or a mixture of various fibers. It is a non-woven fabric or the like.

First, a knitted fabric, a woven fabric, a non-woven fabric or the like used as a fibrous base material is impregnated with polycarbonate polyurethane. The polyurethane impregnation amount is preferably within the range of 100% based on the weight of the fiber.

The microporous fiber substrate may be the above-mentioned impregnated cloth, but it is also possible to form a microporous coating layer of polycarbonate-based polyurethane on the impregnated cloth by wet treatment on the surface of the base material. A nonionic surfactant is generally known to be most effective as a coagulation regulator for forming fine cells in a wet cell formed in a microporous coating layer. It should be noted that cellulose fine powder, calcium carbonate colorant, various stabilizers and the like can be added for the purpose of improving wet film-forming property and feeling of this polycarbonate-based polyurethane. Careful determination is necessary in relation to the physical properties of the porous fiber substrate. A solvent solution of polycarbonate-based polyurethane containing these additives is applied on a fibrous base material impregnated with polycarbonate-based polyurethane, coagulated and desolvated in water, and then repeatedly washed in warm water, dehydrated and dried. A microporous fibrous substrate having micropores is formed.

Of course, it is possible to obtain a microporous fiber substrate by forming a microporous coating layer of polycarbonate polyurethane on a knitted fabric, a woven fabric, or a non-woven fabric not impregnated with the polycarbonate polyurethane in the same manner as described above. Polycarbonate polyurethane used for impregnation and coating has 100% modulus of 2
It is 0 to 120 Kg / cm ² .

Although the 100% modulus is feeling becomes soft at 20 Kg / cm ² or less, not practical physical properties are weakened, Although the 120 kg / cm ² or more physical properties is improved unfavorably hardened is feeling.

The density of the microporous coating layer is preferably 0.3 to 0.7 g / cc.

If the density is 0.3 g / cc or less, the physical properties are weak and not practical, and if the density is 0.7 g / cc or more, the texture becomes hard and it is not preferable.

Further, the thickness of the microporous coating layer is preferably 100 μ to 1000 μ. When the thickness is 100 μm or less, it is not preferable because it lacks flexibility and the volume feeling is poor, and when it is 1000 μm or more, the thickness becomes thick and wrinkles become large, which is not preferable.

Further, the polycarbonate-based polyurethane used in the present invention is a polymer of a polycarbonate-based polyol, a diisocyanate compound and a chain extender, the polycarbonate-based polyol is generally preferably a polyalkylene polycarbonate-based polyol, specifically 1,6 -Hexane polycarbonate based polyols are preferred.

Further, a part of the polyalxin polycarbonate-based polyol is a polyoxyalkylene polyol, for example,
A copolymer substituted with a modified polycarbonate such as polypropylene glycol or polytetramethylene glycol can also be used. Further, as the diisocyanate compound to be reacted with this polycarbonate-based polyol, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate and the like can be used.

As the chain extender, low molecular weight glycols such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol and neopentyl glycol, or piperazine, ethylenediamine, hexamethylenediamine, propylene-1,2-diamine. , N-methyl-bis- (3-aminopropyl) amine, 1,4-diaminocyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, etc. primary or secondary Can be used.

The flame retardant added to the impregnated and applied polycarbonate-based polyurethane elastomer solvent solution uses a bromine-containing modified urethane compound having a urethane bond in the molecule.

The amount of the flame retardant having a bromine content of 30 to 40% is preferably 10 to 30% by weight based on the polyurethane solid content.

If the amount added is less than 10%, flame retardant effects cannot be expected, and
If it is 30% by weight or more, the wet film forming performance is remarkably reduced.

Further, as a method of post-treating the microporous fiber substrate with a halogenated phosphoric acid ester compound and a phosphorus-containing nitrogen-containing compound alone or in a mixture, any processing method such as impregnation method, coating method and gravure method may be used. .

The rate of adhesion of the flame retardant to the microporous fiber substrate is preferably 5 to 20% by weight. The reason for limiting the adhesion rate is that the flame retardant may indirectly cause deterioration of the polyurethane elastomer.

As the flame retardant added to the polyurethane adhesive layer, a bromine-containing modified urethane compound having the same composition as the flame retardant added to the polyurethane which is previously impregnated or coated on the substrate is used.

The amount of the flame retardant having a bromine content of 30 to 40% is preferably 10 to 30% by weight based on the polyurethane solid content.

When antimony dioxide is used in combination with a bromine-containing modified urethane compound, it is combined with a bromine-based flame retardant at the time of combustion and is used in order to exert high flame retardancy due to a synergistic effect. Further, this also binds with a halogenated phosphoric acid ester-based compound during combustion to exert a synergistic effect.

Antimony trioxide is used for bromine-containing modified urethane compounds
It is preferable to add 30 to 60%.

The outermost layer of the present invention, when the 100% modulus was polyurethane film layer of 40~18Kg / cm ^2, although there are some drawbacks in that it is applied the appearance of natural leather with a fine wrinkles, mesothelial layer it Used on the surface of the
Providing a polyurethane film layer with a yield value of 200 to 600 Kg / cm ^{2 as} a% modulus, and subjecting the formed polyurethane film layer to a kneading process, it has more wrinkle residue and more closely resembles natural leather. Can be configured to look like.

In this case, the film layer used for the inner skin layer is colored with a coloring agent,
It is preferable that the outermost coating layer is a transparent layer without being colored. The reason is that the outermost layer has the above wrinkle residue,
By not coloring the coating layer, there is an advantage that the discoloration and fading of the colorant due to light can be remarkably improved.

The synthetic leather having flame retardancy according to the present invention is a polycarbonate having 100% modulus 20-60 kg / cm ² containing antimony trioxide and a bromine-containing modified urethane compound on a flame-retardant microporous fiber substrate as described above. Based polyurethane,
A polycarbonate-based polyurethane adhesive layer is formed by laminating with a thickness of 10 to 60 μ, and in this case, the polycarbonate-based polyurethane used for the adhesive layer is such that a part of the polycarbonate-based polyol in the constituent components is a polyether-based polyol such as polytetrahydrofuran. It may be a copolymer substituted with methylene glycol, polypropylene glycol or the like.

Further, a polycarbonate-based polyurethane having a 100% modulus of 40 to 180 kg / cm ² is laminated on the surface of the adhesive layer as a coating layer with a thickness of 20 to 80 μm. Further, when this is used as the inner skin layer and the outermost layer is separately provided, the polycarbonate-based polyurethane adhesive layer and the polycarbonate-based polyurethane inner skin layer are configured to have the same modulus and thickness as those of the polyurethane adhesive layer and the polyurethane coating layer, and further, the outermost layer is formed on the inner skin layer surface. As the outer layer, a polycarbonate-based polyurethane film layer having a yield value of 100% modulus of 200 to 600 Kg / cm ² and having a thickness of 5 to 10 μ is laminated.

The polycarbonate layer polyurethane used for the inner skin layer and the outermost layer may be any of yellowing type, hardly yellowing type and non-yellowing type as a diisocyanate that reacts with a polycarbonate type polyol, Considering the required light resistance, it is preferable to use a non-yellowing type diisocyanate.

When coloring the polyurethane film layer as the inner skin layer, it is possible to add colorants such as pigments and dyes, and various other stabilizers and fillers to this layer and, if necessary, to the adhesive layer for coloring. it can.

[Effects of the Invention] According to the present invention, by changing the hardness of each constituent layer, it is possible to have a texture, feel and wrinkle that closely resemble natural leather, and it is excellent in hydrolysis resistance and light resistance. Synthetic leather can be obtained.

If a fire accident occurs when used as a surface material for automobile seats, halogen gas is generated from the fiber base material and bromine gas is generated from polyurethane and reacts immediately with antimony trioxide in polyurethane. Therefore, a remarkable flame retardant effect can be exhibited.

Further, according to the present invention, when a polycarbonate-based polyurethane having a yield value is laminated on the outermost layer of the structure, the texture and feel of the leather are very similar to those of natural leather, and it is excellent in wrinkle residue and hydrolysis resistance. , Synthetic leather with excellent light resistance can be obtained.

[Examples] Examples of the present invention will be given below, but the present invention is not limited to these examples.

(Example 1) A double-sided brushed fabric in which polyester fibers and rayon fibers were mixed-spun on a 1,6-hexanediol polycarbonate-based polyurethane solvent solution having 100% modulus of 60 kg / cm ² (solvent (DM
F) is impregnated with an impregnating liquid consisting of the following composition, and the polyurethane solid content is 30% per weight of fiber with a squeeze roll.
%, Then immersed in water at 20 ° C., coagulated, desolvated, dehydrated, and dried under hot air at 130 ° C. to obtain an impregnated cloth.

<Impregnation liquid formulation> parts by weight Polyurethane solvent solution (solid content 30%) 100 Bromine-containing modified urethane compound (solid content 70%) (DFR-10
02S Bromine content 31%: manufactured by Dainichiseika) 10 Colorant 5 Nonionic surfactant 1.5 DMF 200 Next, as a coating solution for forming a microporous coating layer, 100% modulus 1,6-hexanediol polycarbonate with a modulus of 40 Kg / cm ^2. The following compounded solution consisting of a system polyurethane solvent solution (solvent DMF) was prepared and applied to the impregnated cloth at a thickness of 1.0 m / m.

<Coating liquid formulation> parts by weight Polyurethane solvent solution (solid content 30%) 100 Modified bromine-containing urethane compound (solid content 70%) (DFR-10
02S Bromine content 31%: manufactured by Dainichiseika) 10 Colorant 5 Nonionic surfactant 1.5 DMF 80 After applying the above coating solution to the impregnated cloth, solidify in water at 20 ° C,
Desolvate, dehydrate, and dry under hot air at 130 ° C to a thickness of 1.2
A microporous fiber substrate having an extremely smooth surface of m / m was obtained.

Then, the above-mentioned microporous fiber substrate was impregnated with a flame retardant consisting of the following compounding solution, squeezed so that the wet pickup ratio was 80%, dried at 130 ° C for 3 minutes, and further heat-treated at 150 ° C for 2 minutes. The polyester fiber and rayon fiber were flame-retarded.

<Flame retardant compound> Weight part Halogenated phosphate ester compound (frame guard
5316-S: Dainippon Ink) 15 Phosphorus-containing nitrogen-containing compound (Frame Guard VF-74: Dainippon Ink) 10 Melamine resin 2 Catalyst 0.2 Water 75 On the other hand, 100% modulus 90 Kg on release paper with squeeze / cm ²
A 1,6-hexanediol polycarbonate-based polyurethane solution (containing 25 parts by weight of colorant) was applied with a knife coater to a dry thickness of 40μ, and this was dried with hot air at 100 ° C for 3 minutes to form a polycarbonate-based polyurethane film layer. Formed.

Furthermore, the 100% modulus on the surface of the coating layer is 25 kg / cm ²
1,6-hexanediol polycarbonate-polytetramethylene glycol copolymer polyurethane adhesive (antimony trioxide 5 parts by weight and bromine-containing modified urethane compound 15 parts by weight to polyurethane solution (solid content 40%, 100 parts by weight)) Part) is applied by a knife coater to a dry thickness of 30 μm and dried with hot air at 100 ° C. for 3 minutes, and then the surface of the microporous coating layer of the above-mentioned microporous fiber substrate is applied to the upper surface of the polyurethane adhesive layer. After bonding by thermocompression bonding at ℃, the release paper was peeled off after curing the adhesive to obtain synthetic leather.

The obtained synthetic leather passed the American combustion standard FMVSS-302,
Moreover, it was excellent in hydrolysis resistance and light resistance, and the texture and appearance were very similar to natural leather, and it was suitable as a vehicle seat material.

(Example 2) 100% modulus 5 on a raised fabric made of polyester fiber
The following coating liquid consisting of 0 kg / cm ² of 1,6-hexanediol polycarbonate-based polyurethane solvent solution (solvent DMF) was prepared, and this was applied to a thickness of 1. m / m.

<Coating liquid formulation> parts by weight Polyurethane solvent solution (solid content 30%) 100 Modified bromine-containing urethane compound (solid content 70%) (DFR-10
01S Bromine content 35%: made by Dainichiseika) 8 Colorant 5 Nonionic surfactant 1.5 DMF 100 After applying the above coating solution on a brushed cloth, coagulate and desolvate in water at 20 ° C. It was dried in hot air at 130 ° C to obtain a microporous fiber substrate having a thickness of 1.0 m / m and having extremely excellent surface smoothness.

Then, the above microporous fiber substrate was impregnated with a flame retardant consisting of the following liquid mixture, squeezed so that the wet pickup rate was 90%, dried at 130 ° C for 3 minutes, and then heat-treated at 150 ° C for 2 minutes to make a polyester. The fibers were flame retarded.

<Flame retardant compound> parts by weight Phosphorus-containing nitrogen-containing compound (Frameguard VF-74: Dainippon Ink & Chemicals Co., Ltd.) 10 Melamine resin 1.5 Catalyst 0.1 Water 90 On the other hand, 100% modulus 250Kg with yield value on squeezed release paper. / cm ² 1,6-hexanediol polycarbonate polyurethane solution (clear liquid containing no colorant)
Was coated with a knife coater to a dry thickness of 6 μm, and this was dried with hot air at 100 ° C. for 2 minutes to form a polycarbonate-based polyurethane film layer.

Next, 100% modulus of 70 kg / cm ² of 1,6
-Hexanediol polycarbonate-based polyurethane solution (containing 20 parts by weight of colorant) was applied with a knife coater to a dry thickness of 35μ, and this was dried with hot air at 100 ° C for 3 minutes to form a polycarbonate-based polyurethane inner skin layer. .

Furthermore, 100% modulus is 17 kg / cm ^{2 on the} surface of the mesothelial layer.
The 1,6-hexanediol polycarbonate-polytetramethylene glycol copolymer polyurethane adhesive was coated with a knife coater in the following composition so that the dry thickness was 40 μm.

<Adhesive formulation> Parts by weight Polyurethane solution (solid content 40%) 100 Antimony trioxide 6 Bromine-containing modified urethane compound (solid content 70%) (DFR-10
01S Bromine content 35%: made by Dainichiseika) 14 After hot-air drying this at 100 ° C for 3 minutes, the microporous coating layer surface of the above-mentioned microporous fiber substrate is thermocompression bonded to the upper surface of the polyurethane adhesive layer at 130 ° C. Then, after the adhesive was cured, the release paper was peeled off to obtain a synthetic leather.

When the obtained synthetic leather is wrinkled with a kneading machine, it has good wrinkling and not only keeps the wrinkles for a long time, but its texture and appearance are very similar to those of natural leather. It passed FMVSS-302, was excellent in hydrolysis resistance and light resistance, and was suitable as a vehicle seat material.

Comparative Example 1 Synthetic leather was obtained by processing in the same manner as in Example 1 except that the bromine-containing modified urethane compound was not added to the impregnating solution formulation and the coating solution formulation.

(Comparative Example 2) In Example 2, in a coating solution formulation composed of a polyurethane solvent solution, a halogen-containing condensed organophosphate ester (trade name CR-505: manufactured by Daihachi Chemical Co., Ltd.) was used instead of the bromine-containing modified urethane compound in the polyurethane solvent solution. 10 for 100 parts by weight
By adding parts by weight, coagulation, desolvation and dehydration drying were carried out in the same manner as in Example 2 to obtain a microporous fiber substrate.

The obtained microporous fiber substrate had a thickness of 0.83 m / m and was extremely inferior in surface smoothness, and had a hard texture.

The microporous fiber substrate was further treated in the same manner as in Example 2 to obtain a synthetic leather.

(Comparative Example 3) In Example 1, a halogenated phosphoric acid ester compound (trade name: Phylol FR-2: manufactured by Stoffa Chemical Co., Ltd.) was used as a flame retardant in place of the antimony trioxide and bromine-containing modified urethane compound in the adhesive layer. Synthetic leather was obtained by processing in the same manner as in Example 1 except that 20 parts by weight was added to 100 parts by weight of the polyurethane solution.

Regarding the synthetic leathers obtained in Examples 1 and 2 and Comparative Examples 1, 2 and 3, the American combustion standard FMVSS-
Table 1 shows the combustion test results and hydrolysis resistance and light resistance test results according to 302.

Combustion test method Combustion speed (inch / inch) that complies with American combustion standard FMVSS-302
Min) was measured.

Method of measuring hydrolysis resistance Synthetic leather sample pieces are left under conditions of 95% relative humidity and 70 ° C for 4 weeks, and then the resin layer of the sample pieces is loaded with a Taber abrasion tester under a load of 1 Kg and an abrasion count of 2000. The surface condition was observed by turning.

Light resistance measurement method Synthetic leather sample pieces were irradiated with a black panel temperature of 83 ° C for 200 hours with a fade meter, and then the resin layer of the sample pieces was surface-treated with a Taber type abrasion tester under a load of 1 Kg and 2000 wear cycles. The condition was observed.

As is apparent from Table 1 above, according to the present invention, it was possible to obtain a synthetic leather having excellent hydrolysis resistance and light resistance, and particularly excellent flame retardancy.

Claims (2)

[Claims] 1. A microporous fiber substrate having a microporous structure of polyurethane formed on a fibrous substrate and having at least one or more polyurethane coating layers laminated via a polyurethane adhesive layer on the microporous fiber substrate, Tissue contains bromine-containing modified urethane compound
Polycarbonate polyurethane with 100% modulus 20-120 kg / cm ² is used, the microporous fiber substrate contains halogenated phosphoric ester compound and / or phosphorus-containing nitrogen-containing compound on the surface, and the polyurethane adhesive layer is antimony trioxide. And a bromine-containing modified urethane compound having a thickness of 10 to 60 μ, consisting of a polycarbonate polyurethane having a 100% modulus of 20 to 60 Kg / cm ² , and one of the polyurethane film layers having a thickness of 20 to 80 μ as a middle skin layer or an outermost layer, 100 Flame-retardant synthetic leather characterized by being composed of polycarbonate-based polyurethane having a% modulus of 40 to 180 kg / cm ² . 2. A fibrous base material such as cotton cloth, woven cloth, non-woven cloth,
After applying a solution of a polycarbonate-based polyurethane solvent containing a bromine-containing modified urethane compound using a means such as coating or impregnation, a wet coagulation treatment is performed to form a microporous structure of the polycarbonate-based polyurethane on a fibrous base material. ,
Adhesion of halogenated phosphoric acid ester compound and / or phosphorus-containing nitrogen-containing compound to the obtained microporous fiber substrate, and then adhesion containing antimony trioxide and bromine-containing modified urethane compound on the surface of the microporous fiber substrate A method for producing a flame-retardant synthetic leather, which comprises sequentially laminating layers and at least one or more polycarbonate-based polyurethane coating layers.