JPWO2015166659A1 - Flame retardant synthetic leather and method for producing the same - Google Patents

Abstract

Provided is a synthetic leather having good flame retardancy, which does not cause a decrease in flame retardancy when a yellow pigment is blended. The flame retardant synthetic leather is a synthetic leather formed by laminating a skin layer made of polyurethane resin on a fibrous base material, and the skin layer contains a composite oxide pigment containing titanium oxide as a yellow pigment. To do. The composite oxide pigment containing titanium oxide includes a composite oxide pigment containing titanium oxide together with one or two metals selected from the group consisting of antimony, nickel, chromium, iron, zinc, molybdenum, tungsten, and niobium. Is mentioned.

Description

  The present invention relates to a synthetic leather having high flame retardancy and particularly suitably used as an interior material and a vehicle interior material, and a method for producing the same.

  Conventionally, synthetic leather has been used as a substitute for natural leather, or as a leather material with better physical properties than natural leather, for various uses such as clothing, bags, shoes, interior materials, and vehicle interior materials. Yes. Among these materials, interior materials and vehicle interior materials are strictly regulated in consideration of human damage in the event of a fire, and synthetic leather is required to have high flame retardance that satisfies this standard.

  Synthetic leather is generally known as having a form in which a skin layer made of polyurethane resin is laminated on a fibrous base material. As a method of making the synthetic leather flame-retardant, there are cases where each layer constituting the synthetic leather (for example, a fibrous base material, a polyurethane resin layer, and an adhesive layer is provided between the fibrous base material and the polyurethane resin layer). ) (PTLs 1 to 4), a method of newly providing a flame retardant layer (PTL 5), and the like are disclosed.

  However, although the flame retardancy of synthetic leather is improved by these methods, there is a problem that the flame retardancy is lowered in the case of a color of synthetic leather, in particular, a color containing many yellow pigments such as beige and brown. .

Japanese Patent Laid-Open No. 2-264081 Japanese Unexamined Patent Publication No. 58-144184 Japanese Unexamined Patent Publication No. 2005-344224 Japanese Unexamined Patent Publication No. 2003-89986 Japanese Patent Laid-Open No. 6-146174

  An object of the present invention is to provide a synthetic leather having good flame retardancy, which does not cause a decrease in flame retardancy when a yellow pigment is blended.

  The present inventor has found that the decrease in flame retardancy caused by the color of synthetic leather, particularly in the case of a color containing many yellow pigments such as beige and brown, is caused by the yellow pigment. Conventionally, hydrous iron oxide is generally used as a yellow pigment for synthetic leather. Since iron oxide itself is also used as a flame retardant, it does not inhibit flame retardancy. However, since iron oxide is highly oil-absorbing, the skin layer containing it has a high viscosity in the molten state, and the ignition part is less likely to drop during combustion (the fire type is less likely to fall down). This has found that flame retardancy is inhibited. Further, the hydrous iron oxide undergoes a dehydration reaction at 200 to 300 ° C., and depending on the type of the flame retardant used in combination, particularly in the type that imparts flame retardancy by charring at 400 to 600 ° C., It was also found that the endothermic effect of the dehydration reaction hinders char formation and inhibits flame retardancy. Here, charring means carbonization of the flame contact portion of the resin. The present embodiment is based on such knowledge.

  In the present embodiment, first, in a flame-retardant synthetic leather obtained by laminating a skin layer made of a polyurethane resin on a fibrous base material, the skin layer is a composite oxide containing titanium oxide as a yellow pigment. A flame-retardant synthetic leather characterized by containing a pigment.

  The composite oxide pigment containing titanium oxide includes titanium oxide together with one or two metals selected from the group consisting of antimony, nickel, chromium, iron, zinc, molybdenum, tungsten, and niobium It is preferable that

  This embodiment is secondly a method for producing a flame-retardant synthetic leather obtained by laminating a skin layer made of a polyurethane resin on a fibrous base material, and a composite oxide pigment containing titanium oxide as a yellow pigment The polyurethane resin composition mixed with (1) is applied to a fibrous base material, or (2) is applied onto a releasable base material, and the fibrous base material is bonded to the coated surface. This is a method for producing a flame-retardant synthetic leather.

  According to this embodiment, it is possible to provide a synthetic leather with good flame retardancy that does not cause a decrease in flame retardancy when a yellow pigment is blended.

  The flame-retardant synthetic leather according to the present embodiment is a flame-retardant synthetic leather obtained by laminating a skin layer made of polyurethane resin on a fibrous base material, and a composite containing titanium oxide as a yellow pigment in the skin layer. It contains an oxide pigment (hereinafter also referred to as a complex oxide yellow pigment).

  The fibrous base material used in the present embodiment is not particularly limited, and examples thereof include fabrics such as woven fabrics, knitted fabrics, and nonwoven fabrics, and natural leather (including floor leather). In addition, a cloth which is coated or impregnated with a liquid mainly composed of a conventionally known solvent-free, solvent-based or water-based polymer compound, for example, polyurethane resin or a copolymer thereof, and is dry-coagulated or wet-coagulated. Can also be used. In addition, the material of the fibers constituting the fibrous base material is not particularly limited, and examples thereof include conventionally known fibers such as natural fibers, regenerated fibers, semi-synthetic fibers, and synthetic fibers. It may be combined. Of these, synthetic fibers are preferable and polyester fibers are more preferable from the viewpoints of strength and processability.

  The fibrous base material may be colored with a dye or a pigment. In addition, although the dye and pigment used for coloring are not specifically limited, When using a yellow pigment, it is preferable to use the complex oxide pigment containing a titanium oxide like a skin layer.

  As the fibrous base material, a flame retardant material may be used. The method of flame retardancy is not particularly limited. For example, it is difficult to use flame retardant fibers for the fibers constituting the fibrous base material, or to treat the fabric constituting the fibrous base material with a flame retardant. A flame retardant may be attached. It does not specifically limit as a flame retardant, For example, a phosphorus flame retardant can be used. Examples of the phosphorus-based flame retardant include ammonium polyphosphate, aluminum phosphate, phosphate ester, guanidine phosphate, and organic phosphine oxide. These may be used alone or in combination of two or more. Can be used.

  The flame-retardant synthetic leather according to this embodiment is obtained by laminating a skin layer made of a polyurethane resin as a resin layer on the above-described fibrous base material.

  The polyurethane resin used for forming the skin layer is not particularly limited, and examples thereof include a polyether-based polyurethane resin, a polyester-based polyurethane resin, and a polycarbonate-based polyurethane resin. These can be used alone or in combination of two or more. Of these, polycarbonate polyurethane resins are preferred from the viewpoints of flame retardancy, abrasion resistance and light resistance. Polycarbonate-based polyurethane resin forms a relatively large amount of char (carbide) during combustion and covers the surface, so the supply of cracked gas generated inside the resin to the combustion field and the supply of oxygen from the outside to the combustion field By blocking, flame retardancy can be imparted.

  Moreover, you may make it exhibit a further flame-retardant effect by adding a phosphorus flame retardant etc. to a polyurethane resin. That is, the skin layer made of a polyurethane resin may contain a flame retardant such as a phosphorus flame retardant. As the phosphorus-based flame retardant, as described above, for example, at least one selected from the group consisting of ammonium polyphosphate salt, aluminum phosphate salt, phosphate ester, guanidine phosphate, and organic phosphine oxide is used. be able to.

  The form of the polyurethane resin can be used regardless of whether it is solventless, hot-melt, solvent-based, water-based, etc., and it can be used regardless of one-pack type or two-pack curable type. can do.

  For coloring the skin layer of the flame-retardant synthetic leather according to the present embodiment, a composite oxide pigment containing titanium oxide as a main component, that is, a composite oxide yellow pigment containing titanium oxide is used as a yellow pigment. The pigment other than the yellow pigment is not particularly limited. In addition, since content of this complex oxide yellow pigment is suitably set by the color calculated | required by a skin layer, it is not specifically limited, For example, with respect to 100 mass parts (solid content) of the polyurethane resin which forms a skin layer 1-50 mass parts (solid content) may be sufficient, and 5-40 mass parts (solid content) may be sufficient.

  According to the present embodiment, a composite oxide pigment mainly composed of titanium oxide is used as the yellow pigment for the skin layer. The skin layer containing such a titanium oxide-based composite oxide yellow pigment does not have a high viscosity in the molten state, and the ignition part tends to drop during combustion, so that it has excellent flame retardancy. Moreover, since it can prevent preventing charring, it is excellent in flame retardancy.

  The composite oxide yellow pigment is mainly composed of titanium oxide (more specifically, titanium dioxide), and one or more selected from the group consisting of antimony, nickel, chromium, iron, zinc, molybdenum, tungsten, and niobium Examples include composite oxide pigments containing two kinds of metals. Among these, from the viewpoint of versatility and environmental burden, it is preferable to use chromium titanium yellow and / or composite oxide pigments in which iron and zinc are contained in titanium oxide. Examples of chrome titanium yellow include Ti—Cr—Sb, Ti—Cr—W, and Ti—Cr—Nb, and these may be used alone or in combination. Here, the Ti—Cr—Sb system is a complex oxide pigment in which a part of tetravalent titanium ions in the crystal lattice of titanium oxide is substituted with pentavalent antimony ions and trivalent chromium ions.

  The above complex oxide yellow pigments can be used alone or in combination of two or more. In addition, when using the complex oxide pigment which has titanium oxide as a main component and contains iron, it is important that it is the content which does not inhibit the effect of this embodiment.

  The viscosity of the complex oxide yellow pigment at a measurement temperature of 23 ° C. is preferably 500 to 10,000 mPa · s, more preferably 1,000 to 5,000 mPa · s. When the viscosity is 500 mPa · s or more, the storage stability of the pigment is improved. When the viscosity is 10,000 mPa · s or less, the skin layer containing this is less likely to have a high viscosity in the molten state, and the ignited portion is likely to drop during combustion, thereby providing excellent flame retardancy.

  In the present specification, the viscosity of the composite oxide yellow pigment is determined at a measurement temperature of 23 ° C. of a pigment liquid having a solid content concentration (pigment concentration) of 35 mass% using dimethylformamide (hereinafter referred to as DMF) as a dispersion medium. Viscosity, measured as follows. That is, when the solid content concentration of the pigment liquid used is 35% by mass, the viscosity of the pigment liquid is measured as it is. In this type of pigment product (pigment liquid), since the dispersion medium is mainly DMF, if the solid content concentration of the pigment liquid is 35% by mass, the viscosity may be measured as it is. On the other hand, when the solid content concentration exceeds 35% by mass, it is diluted with DMF as a dispersion medium. When the solid content concentration is less than 35% by mass, the dispersion medium (DMF) is vaporized so that the solid content concentration becomes 35% by mass. The viscosity of the obtained pigment solution is measured. The viscosity is measured using a BM viscometer (rotor: No. 3, 12 rpm, 23 ° C.).

  Moreover, it is preferable that PVI (Printing Viscosity Index) value in the measurement temperature of 23 degreeC of the said complex oxide yellow pigment is 0.3-0.8, More preferably, it is 0.3-0.6. When the PVI value is 0.3 or more, the skin layer containing the PVI value is less likely to have a high viscosity in the molten state, and the ignition part is likely to drop during combustion, so that the flame retardancy is excellent. When the PVI value is 0.8 or less, the color stability is good (color unevenness is eliminated).

In the present specification, the PVI value of the composite oxide yellow pigment is a PVI value at a measurement temperature of 23 ° C. of a pigment liquid having a solid content concentration of 35 mass% using DMF as a dispersion medium, and is measured as follows. . That is, when the solid content concentration of the pigment liquid used is 35% by mass, the viscosity of the pigment liquid is measured as it is. On the other hand, when the solid content concentration exceeds 35% by mass, it is diluted with DMF as a dispersion medium. After preparing the liquid, the viscosity of the obtained pigment liquid is measured. The viscosity is measured using a BM type viscometer (rotor: No. 3, 23 ° C.) at rotation speeds of 6 rpm and 60 rpm, and the PVI value is calculated using the following equation.
PVI value = (viscosity at 60 rpm [mPa · s]) ÷ (viscosity at 6 rpm [mPa · s])

  For the skin layer, if necessary, within the range that does not impair the effects of the present embodiment, conventionally known additives such as urethanization catalysts, crosslinking agents, heat stabilizers, light stabilizers, thermoplastic resins, heat Curable resin, dye, pigment, moisture permeability improver, water repellent, oil repellent, hollow foam, water absorbent, moisture absorbent, deodorant, defoamer, antifungal agent, antiseptic, pigment dispersant, blocking An inhibitor, a hydrolysis inhibitor, a leveling agent, etc. can be used. The thickness of a skin layer is not specifically limited, For example, 10-50 micrometers may be sufficient.

  In the flame-retardant synthetic leather according to this embodiment, a skin layer made of a polyurethane resin is laminated as a resin layer on the above-described fibrous base material. Typically, a skin layer made of a polyurethane resin is laminated on at least one surface of a fibrous base material directly or via an adhesive layer. Although it does not specifically limit as an adhesive agent used as a contact bonding layer, A polyurethane resin is used preferably and resin similar to the resin used for a skin layer can be used. Therefore, the adhesive layer is preferably made of a polycarbonate-based polyurethane resin from the viewpoint of flame retardancy. In order to enhance the flame retardant effect, the adhesive layer may contain a flame retardant such as a phosphorus flame retardant. The thickness of the adhesive layer is not particularly limited, and may be, for example, 50 to 300 μm.

  The flame retardant synthetic leather according to the present embodiment may include a flame retardant such as a phosphorus flame retardant. The flame retardant can be contained in one or more of the layers constituting the synthetic leather. For example, when the synthetic leather is composed of a fibrous base material and a skin layer, it can be contained in either or both of the fibrous base material and the skin layer, and the synthetic leather is bonded to the fibrous base material and the skin layer. When it consists of layers, it can be contained in one or more of the fibrous base material, the skin layer and the adhesive layer. The content of the flame retardant is not particularly limited. For example, when giving to a fibrous base material, 5-20 mass% may be sufficient as the adhesion amount of the flame retardant with respect to a fibrous base material. When giving to a skin layer, 5-40 mass parts may be sufficient as the addition amount of a flame retardant with respect to 100 mass parts (solid content) of the polyurethane resin which forms a skin layer. When imparted to the adhesive layer, the amount of the flame retardant added may be 5 to 40 parts by mass with respect to 100 parts by mass (solid content) of the polyurethane resin forming the adhesive layer.

  Next, the manufacturing method of the flame-retardant synthetic leather which concerns on this embodiment is demonstrated. The manufacturing method includes a step of preparing a polyurethane resin composition in which a composite oxide pigment mainly composed of titanium oxide as a yellow pigment is mixed, and (1) whether the polyurethane resin composition is applied to a fibrous base material. Or (2) a process of laminating a skin layer made of a polyurethane resin on a fibrous base material by applying it onto a releasable base material and bonding the fibrous base material to the coated surface. .

  In more detail, the said flame-retardant synthetic leather can be manufactured by the following method, for example.

  (1) A polyurethane resin composition mixed with a composite oxide pigment containing titanium oxide as a yellow pigment is applied to at least one surface of a fibrous base material, and then solidified by dry coagulation, wet coagulation, etc. A skin layer is directly formed and laminated on a porous substrate. (Uniform of (1) above)

  (2) A polyurethane resin composition in which a composite oxide pigment containing titanium oxide as a yellow pigment is mixed is applied to a releasable substrate and then solidified to form a skin layer, which is formed into at least one of the fibrous substrates. The surface layer is directly laminated on the fibrous base material by pasting to the surface by pressure bonding and finally peeling the releasable base material. (Uniform of (2) above)

  (3) A polyurethane resin composition mixed with a composite oxide pigment containing titanium oxide as a yellow pigment is applied to a releasable substrate, and then a solid state that is not completely solidified is applied to at least one surface of the fibrous substrate. The skin layer is directly laminated on the fibrous base material by pasting and finally peeling the releasable base material. (Uniform of (2) above)

  (4) A polyurethane resin composition in which a composite oxide pigment containing titanium oxide as a yellow pigment is mixed is applied to a releasable substrate and then solidified to form a skin layer, which is formed into at least one of the fibrous substrates. A surface layer is laminated on the fibrous base material by laminating to the surface using an adhesive and finally peeling the releasable base material. (Uniform of (2) above)

  A conventionally known method can be used as a method for applying the polyurethane resin composition mixed with the composite oxide pigment to a fibrous base material or a releasable base material, and is not particularly limited. For example, the method using apparatuses, such as a knife coater, a roll coater, a gravure coater, a spray coater, can be mentioned. In particular, coating with a knife coater is preferable in that a uniform thin film layer can be formed.

  The releasable substrate used in the present embodiment is not particularly limited, and may be any substrate that has a releasability with respect to polyurethane resin or a substrate that has been subjected to a release treatment. Examples thereof include a pattern paper, a release treatment cloth, a water repellent treatment cloth, an olefin sheet or film made of polyethylene resin or polypropylene resin, a fluororesin sheet or film, and a plastic film with release paper.

  What is necessary is just to set the application | coating thickness of a polyurethane resin composition suitably.

  Next, heat treatment is performed as necessary. The heat treatment accelerates the reaction when the solvent in the polyurethane resin composition is evaporated and the resin is dried, and when a crosslinking agent that causes a crosslinking reaction by the heat treatment is used, or when a two-component curable resin is used. And is performed to form a film having sufficient strength. It is preferable that the heat processing temperature is 50-150 degreeC, More preferably, it is 60-120 degreeC. When the heat treatment temperature is 50 ° C. or higher, the heat treatment does not take time, so the process load is not increased, and the resin is sufficiently dried and crosslinked, so that a sufficient coating strength can be obtained. When the heat treatment temperature is 150 ° C. or lower, the texture of the resulting synthetic leather is excellent. The heat treatment time is not particularly limited, but is preferably 2 to 20 minutes, more preferably 2 to 10 minutes. When the heat treatment time is 2 minutes or longer, the resin is sufficiently dried and crosslinked, so that sufficient coating strength can be obtained. If the heat treatment time is 20 minutes or less, the heat treatment does not take time, so the process load does not increase.

  Thus, the flame retardant synthetic leather according to this embodiment is obtained. However, the method for producing the flame-retardant synthetic leather according to the present embodiment is not limited to the above method.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. “Parts” in the examples are based on mass. Moreover, evaluation of the obtained flame-retardant synthetic leather followed the following method.

[Flame retardance]
Evaluation was performed in accordance with the test method of the US automobile safety standard FMVSS302.
On the back of the resulting synthetic leather, a 1.3 mm thick flexible urethane foam (EL68F, manufactured by Inoac Corporation, specific gravity 0.03 g / cm ³ ) and nylon half tricot as a backing cloth are laminated together by frame lamination method. To a composite laminate, and an ignition operation is performed by indirect flame for 15 seconds with a gas burner at the end of the test piece obtained by cutting the composite laminate to a width of 100 mm and a length of 350 mm. The distance and time until the fire was extinguished after exceeding the marked line provided at a position of 38 mm were measured. Five points were measured in each of the vertical and horizontal directions, the combustion rate was calculated, and the most burned one was determined according to the following criteria.
A: The specimen did not ignite or the ignited flame was extinguished before the mark B: The maximum value of the burning rate was 80 mm / min or less C: The maximum value of the burning rate was 80 mm / min Beyond

[Example 1]
Formula 1
Polycarbonate polyurethane resin: 100 parts by mass (Chrisbon NY-328, solid content 20% by mass, manufactured by DIC Corporation)
Yellow pigment: 16 parts by mass (complex oxide yellow pigment mainly composed of titanium oxide and containing iron and zinc, L-7875S, solid content 35% by mass, viscosity 2,300 mPa · s, PVI value 0.43, DIC Corporation)
White pigment (titanium oxide): 1.5 parts by mass (L-1781S, solid content 40% by mass, manufactured by DIC Corporation)
Brown pigment (iron oxide): 3 parts by mass (L-1777S, solid content 30% by mass, manufactured by DIC Corporation)
・ Solvent (dimethylformamide): 40 parts by mass

  The polyurethane resin composition for the skin layer having a viscosity of 2,000 mPa · s (B-type viscometer, rotor: No. 4, 60 rpm, measurement temperature 23 ° C.) prepared according to the above-mentioned prescription 1 was wetted using a knife coater. It was applied to release paper so that the coating thickness was 200 μm, and heat-treated at 100 ° C. for 2 minutes in a dryer to dry and solidify, thereby forming a skin layer having a thickness of 45 μm. Here, the thickness of the skin layer was calculated as follows. That is, the vertical cross section of the flame retardant synthetic leather was observed with a microscope (manufactured by Keyence Corporation, Digital HF microscope VH-8000), and the height difference between the top of the convex portion and the lowest part of the skin layer was measured at any 10 locations. The average value of the value and the value obtained by measuring the height difference between the bottom of the recess and the lowest part of the skin layer at any 10 locations was taken as the thickness of the skin layer.

Next, on the skin layer, 100 parts by mass of a polycarbonate-based polyurethane resin (Chrisbon TA-205, solid content 70% by mass, manufactured by DIC Corporation) and a phosphorus flame retardant (ATC powder, solid content 100% by mass, ARCROMA JAPAN) Dimethylformamide was added to a mixture of 8 parts by mass of a product of Co., Ltd., and an adhesive adjusted to a viscosity of 5,000 mPa · s (B-type viscometer, rotor: No. 4, 60 rpm, measurement temperature 23 ° C.) Using a coater, the wet coating thickness was applied to 200 μm, pre-dried by heat treatment at 100 ° C. for 1 minute in a dryer, and 4 kgf / cm ² (39.2 N / cm ²⁾ on the polyester tricot cloth. ) For 1 minute to obtain a flame-retardant synthetic leather. The evaluation of the flame retardancy of the obtained synthetic leather was “A”, and it had good flame retardancy.

[Example 2]
In the above formulation 1, the yellow pigment is changed to chrome titanium yellow (L-8299S, Ti—Cr—Sb, solid content 35% by mass, viscosity 2,400 mPa · s, PVI value 0.49, manufactured by DIC Corporation). Except that, flame retardant synthetic leather was obtained in the same manner as in Example 1. The evaluation of the flame retardancy of the obtained synthetic leather was “A”, and it had good flame retardancy.

[Example 3]
Example 1 except that a polyester tricot cloth was treated with a flame retardant (HF-2300, triphenylphosphine oxide, solid content 50 mass%, manufactured by Nikka Chemical Co., Ltd.) at 130 ° C. for 30 minutes at 7% owf. In the same manner as above, a flame-retardant synthetic leather was obtained. The evaluation of the flame retardancy of the obtained synthetic leather was “A”, and it had good flame retardancy.

[Comparative Example 1]
Example 1 except that the yellow pigment was changed to iron oxide (L-1778S, solid content 30% by mass, viscosity 19,000 mPa · s, PVI value 0.20, manufactured by DIC Corporation) in the above formula 1. In the same manner, a synthetic leather was obtained. The evaluation of flame retardancy of the obtained synthetic leather was “C”.

[Comparative Example 2]
Example 3 in Example 1 except that the yellow pigment was changed to iron oxide (L-1778S, solid content 30% by mass, viscosity 19,000 mPa · s, PVI value 0.20, manufactured by DIC Corporation). In the same manner, a synthetic leather was obtained. The flame retardant evaluation of the obtained synthetic leather was “B”.

Claims (7)

  In a flame-retardant synthetic leather obtained by laminating a skin layer made of a polyurethane resin on a fibrous base material, the skin layer contains a composite oxide pigment containing titanium oxide as a yellow pigment. Fire retardant synthetic leather.   The composite oxide pigment containing titanium oxide includes titanium oxide together with one or two metals selected from the group consisting of antimony, nickel, chromium, iron, zinc, molybdenum, tungsten, and niobium The flame-retardant synthetic leather according to claim 1, wherein   2. The flame retardant synthetic leather according to claim 1, wherein the composite oxide pigment containing titanium oxide is chromium titanium yellow and / or a composite oxide pigment containing titanium and iron and zinc.   The composite oxide pigment containing titanium oxide has a viscosity of 500 to 10,000 mPa · s measured at a temperature of 23 ° C. with respect to a pigment liquid having a solid content concentration of 35% by mass. The flame retardant synthetic leather as described.   5. The composite oxide pigment containing titanium oxide has a PVI (Printing Viscosity Index) value of 0.3 to 0.8 measured at a temperature of 23 ° C. with respect to a pigment liquid having a solid content concentration of 35 mass%. The flame-retardant synthetic leather according to any one of the above.   The flame-retardant synthetic leather according to any one of claims 1 to 5, wherein the polyurethane resin comprises a polycarbonate-based polyurethane resin.   A method for producing a flame-retardant synthetic leather obtained by laminating a skin layer made of a polyurethane resin on a fibrous base material, wherein a polyurethane resin composition in which a composite oxide pigment containing titanium oxide as a yellow pigment is mixed, (1) A method for producing a flame-retardant synthetic leather, which is applied to a fibrous base material, or (2) is applied onto a releasable base material, and the fibrous base material is bonded to the coated surface. .