WO2016059882A1

WO2016059882A1 - Flame-retardant polyurethane resin and flame-retardant synthetic leather

Info

Publication number: WO2016059882A1
Application number: PCT/JP2015/074033
Authority: WO
Inventors: 中村　隆; 雄介河内
Original assignee: 大和化学工業株式会社
Priority date: 2014-10-15
Filing date: 2015-08-26
Publication date: 2016-04-21
Also published as: CN106574112A; CN106574112B; JP6151678B2; JP2016079375A

Abstract

Provided are: a flame-retardant polyurethane resin which exhibits extremely high flame retardancy, while having both hydrolysis resistance and bleed-out resistance even under high temperature and high humidity conditions without inhibiting coloring of a product, and which is able to suppress increase in the cost; and a flame-retardant synthetic leather. A flame-retardant polyurethane resin which is obtained by mixing (a) a metal phosphinate salt and (b) a polyurethane resin, and which is characterized in that the mixing ratio (a)/(b) in terms of a weight ratio is within the range from 5/95 to 50/50; and a flame-retardant synthetic leather which is formed of the flame-retardant polyurethane resin.

Description

Flame retardant polyurethane resin and flame retardant synthetic leather

The present invention relates to a flame retardant polyurethane resin and a flame retardant synthetic leather having a remarkably high flame retardant performance equal to or better than that of a halogen flame retardant and having good physical properties.

Conventionally, polyurethane resin has been used for various uses such as clothing, bags, shoes, furniture, interior materials for vehicles, interior materials for aircraft, interior materials for ships, etc. as a synthetic leather, which is one main application. Among these, fields requiring high flame retardancy include furniture, vehicle interior materials / aircraft interior materials, marine interior materials, and the like.

Synthetic leather is generally formed by impregnating or laminating a polyurethane resin on a fiber base material such as nonwoven fabric, woven fabric, or knitted fabric. However, it is known that the synthetic leather is very difficult to be flame-retardant because the combustion mechanism of the polyurethane resin constituting the synthetic leather and the fiber base material are different.

As a flame retardant for synthetic leather as described above, an additive-type flame retardant added to a polyurethane resin and imparting flame retardant performance is copolymerized as one of the resin components when the polyurethane resin is synthesized. Reactive flame retardants that have become flame retardant when incorporated have been reported. However, additive-type flame retardants that are cheaper in production cost, can freely adjust the type and amount of flame retardants in the post-production process according to the application desired by the producer, and are more suitable for the production of a small variety of products. Due to its ease of use, it dominates the current market.

As a flame retardant, a bromine-based halogen compound, in particular, a combination formulation of decabromodiphenyl ether and antimony trioxide has been widely used since it exhibits excellent flame retardancy. However, it has been pointed out that halogen compounds generate toxic gases such as hydrogen halides and dioxins during combustion. For this reason, in order to protect the environment, there is a great demand for non-halogen flame retardants that do not use halogen compounds, particularly phosphorus flame retardants, and various phosphorus flame retardants have been developed. As the phosphorus flame retardant, many flame retardants such as ammonium polyphosphate, melamine polyphosphate, red phosphorus, organic phosphorus metal salt, phosphate ester and phosphate amide are known.

Various flame retardant methods using these phosphorus flame retardants have been proposed. For example, Patent Document 1 below discloses a leather-like sheet-like product formed by attaching a polycarbonate-based polyurethane solution containing a red phosphorus flame retardant to a fiber base material.

Patent Document 2 below discloses the production of a flame retardant polyurethane resin composition containing a polyurethane resin, a phosphorus-nitrogen flame retardant (surface-treated ammonium polyphosphate), a polyhydric alcohol or derivative thereof, and a silicon compound (alkoxysiloxane). A method is disclosed.

As another example, Patent Document 3 below discloses a polyurethane synthetic leather composed of a polyurethane resin layer containing a fiber base material and a phosphate ester flame retardant.

Furthermore, Patent Document 4 below discloses a flame retardant polyurethane resin in which the phosphorus-containing chain extender in the polyurethane resin is a special phosphaphenanthrene derivative.

Japanese Patent Laid-Open No. 5-163683 Japanese Patent No. 5246101 JP 2013-189736 A Japanese Patent No. 5405383

However, the red phosphorus flame retardant used in the method of Patent Document 1 has a high phosphorus content and high flame retardancy, but has a unique red color, and therefore imparts an undesirable color to the product. There is a risk that. In addition, in order to balance coloring suppression and flame retardancy, it is necessary to blend a considerable amount of achromatic agent, which may cause problems such as degradation of flame retardancy and poor light resistance of the achromatic agent. is there.

In the method using ammonium polyphosphate that is difficult to hydrolyze as in Patent Document 2, the phosphorus content is relatively high, about 30%, and the flame retardancy is easy to be obtained. However, temporarily coated ammonium polyphosphate However, it is difficult to sufficiently prevent hydrolysis under high temperature and high humidity conditions. As a result, polyphosphoric acid generated not only deteriorates the physical properties of the product, but also causes a whitening phenomenon called so-called bleedout on the product surface. There is a risk of causing stickiness and degrading the quality of the product. In fact, the patent literature evaluates the flame retardancy and mechanical properties of the resin composition, but does not verify the bleed out.

Moreover, although the phosphoric acid ester is used in patent document 3, in order to respond to the hydrolyzability and bleed-out which are the problems of a phosphoric acid ester similarly to the above, the acid value and molecular weight of a phosphoric acid ester are restrict | limited. ing. However, under high temperature and high humidity conditions, it is difficult to sufficiently prevent bleed out.Furthermore, in order to improve the hydrolysis resistance of phosphate ester, it is necessary to increase the molecular weight to a condensation type, Thereby, the phosphorus content rate in phosphate ester will fall. As a result, there is a problem that the flame retardancy performance is generally lowered.

On the other hand, as in Patent Document 4, in a method of incorporating a phosphorus-containing chain extender composed of a special phosphaphenanthrene derivative as a reactive flame retardant into a polyurethane resin, the flame retardant is a strong chemical bond in the resin, so-called Since they are integrated by covalent bonding, the flame retardant does not bleed out even under high temperature and high humidity conditions. However, according to the examples of the patent document, in order to synthesize the above-mentioned special flame retardant, a very complicated process of 10 hours at 150 ° C., 10 hours at 180 ° C., and further 10 hours at 200 ° C. Therefore, the increase in cost is unavoidable and has the disadvantage of being difficult to use in practice. Furthermore, there is a limit to the phosphorus concentration that can be contained in the polyurethane resin, and when the upper limit is exceeded, not only the texture is lowered, but the flame resistance performance is evaluated only by the limiting oxygen index (LOI value), and flame retardancy It cannot be properly judged whether or not a sufficiently high level of flame retardancy can be exhibited at the phosphorus concentration contained as a synthetic leather.

As described above, the conventional technology has the problem to be solved as described above, that is, has extremely high flame retardant performance equivalent to or higher than that of the halogen-based flame retardant, does not impair the colorability of the product, There are no flame retardant polyurethane resins and flame retardant synthetic leathers that have hydrolysis resistance and bleed-out resistance even under wet conditions, and that can suppress the increase in cost. Yes.

Therefore, the present invention has been made in consideration of the above-mentioned problems, that is, it has a remarkably high flame retardancy equivalent to or higher than that of a halogen-based flame retardant, does not hinder the colorability of the product, An object of the present invention is to provide a flame-retardant polyurethane resin and a flame-retardant synthetic leather that have both hydrolysis resistance and bleed-out resistance even under high-humidity conditions and that can suppress an increase in cost.

As a result of intensive studies to achieve the above object, the inventors of the present invention imparted a flame retardant represented by the following formula (1) to synthetic leather, thereby achieving an extremely high level equivalent to or higher than that of a halogen flame retardant. Flame retardant polyurethane resin that has excellent flame retardant performance, does not hinder product coloration, has hydrolysis resistance and bleed out resistance even under high temperature and high humidity conditions, and can suppress cost increase And it discovered that a flame-retardant synthetic leather was obtained and came to complete this invention.

(Wherein R ₁ is hydrogen, a phenyl group, or a linear alkyl group having 1 to 6 carbon atoms, M is Mg, Al, Ca, Ti, or Zn, and m is 2, 3, or 4) is there.)

That is, the present invention
(1) A flame retardant polyurethane resin obtained by mixing a flame retardant (a) represented by the following formula (1) and a polyurethane resin (b), wherein the mixing ratio is (a) / (b) = Flame retardant polyurethane resin characterized by being in the range of 5/95 to 50/50,

(Wherein R ₁ is hydrogen, a phenyl group, or a linear alkyl group having 1 to 6 carbon atoms, M is Mg, Al, Ca, Ti, or Zn, and m is 2, 3, or 4) is there.)
(2) Flame retardant represented by the above formula (1) (a) 100 parts by weight of melamine phosphate, melamine pyrophosphate, melamine polyphosphate, ammonium polyphosphate, phosphate ester amide, melamine phthalate, melamine The total of one or more flame retardant aids (c) selected from the group consisting of melamine cyanurate, benzoguanamine, expandable graphite, aluminum hydroxide and magnesium hydroxide is 0 to 200 parts by weight, The mixing ratio of the flame retardant (a) represented by the formula (1), the polyurethane resin (b) and the flame retardant aid (c) is {(a) + (c)} / (b) = 5 The flame retardant polyurethane resin according to claim 1, wherein the flame retardant polyurethane resin is in the range of / 95 to 50/50,
(3) The synthetic leather is composed of a non-woven fabric, a woven fabric, a fiber substrate including knitted fabric, and at least one polyurethane resin layer, and the polyurethane resin layer is flame retardant as described in (1) and / or (2) above. Flame retardant synthetic leather, characterized in that it is formed using a heat-resistant polyurethane resin,
Is a summary.

According to the present invention, it has remarkably high flame retardant performance equal to or better than that of halogen flame retardants, does not impair product colorability, and is resistant to hydrolysis and bleed out even under high temperature and high humidity conditions. Further, it is possible to provide a flame retardant polyurethane resin and a flame retardant synthetic leather capable of suppressing an increase in cost.

Furthermore, since the present invention uses a non-halogen phosphorus flame retardant, it is more environmentally friendly than conventional flame retardant synthetic leather using a halogen flame retardant.

Hereinafter, embodiments of the flame-retardant polyurethane resin and the flame-retardant synthetic leather of the present invention will be described.
[Flame Retardant {Formula (1)} below]
The flame retardant used in the present invention is a compound represented by the following formula (1).

R _{1 in} the above formula (1) is preferably hydrogen, a phenyl group, a methyl group or an ethyl group, and M in the above formula (1) is preferably aluminum or zinc.

Specific examples of the flame retardant represented by the above formula (1) include zinc phosphinate (phosphorus content 31.7%), zinc phenylphosphinate (phosphorus content 17.8%), and methyl methylphosphinate (phosphorus). Content 27.7%), zinc ethylphosphinate (phosphorus content 24.6%), aluminum phosphinate (phosphorus content 41.9%), phenyl phenylphosphinate (phosphorus content 20.6%), methyl Examples include aluminum phosphinate (phosphorus content 35.2%) and ethyl ethylphosphinate (phosphorus content 30.4%). Since these phosphinic acid metal salts are usually colorless or white powders, they can be used without impairing the colorability of the product. The phosphorus content will be described later.

The flame retardant represented by the above formula (1) is any one of phosphinic acid, phenylphosphinic acid, methylphosphinic acid and ethylphosphinic acid, or an alkali metal salt of phosphinic acid, phenylphosphinic acid, methylphosphinic acid and ethylphosphinic acid. One and any one of aluminum, zinc nitrate, sulfate, carbonate and hydroxide are heated and reacted in an aqueous solution state. This is a kind of acid-base reaction or salt reaction in an aqueous solution. Since the reaction proceeds rapidly, the target compound is produced in a relatively short time of 1 to 3 hours, so that an increase in cost can be suppressed. It is similar to the manufacturing method.

The average particle size of the flame retardant of the present invention is preferably 1 to 50 μm, particularly preferably 2 to 20 μm. If the average particle size exceeds 50 μm, the dispersion stability of the flame-retardant polyurethane resin composition may be deteriorated. If the average particle size is less than 1 μm, the generation of aggregates in the resin composition or extremely There is a risk of thickening of the film.

The flame retardant of the present invention can exhibit extremely high flame retardant performance without using any other flame retardant or flame retardant aid. The following two points can be considered as the reason.
(A) High phosphorus content (B) Reducing action by P—H bond

(A) About high phosphorus content, it is well-known as one of the elements which improves a flame retardance performance. That is, phosphorus can achieve flame retardancy by suppressing the combustion of combustible materials such as synthetic resins and fiber base materials in both the gas phase and the solid phase. In the gas phase, OH radicals that cause expansion of combustion are trapped by phosphorus-derived PO chemical species, and combustion is suppressed. In the solid phase, polyphosphoric acid generated by thermal decomposition of phosphorus promotes carbonization of the resin and is dense. It is considered that the combustion is suppressed by blocking the resin from heat by forming a carbonized film. Therefore, from the above theory, it is considered that the higher the phosphorus content, the higher the flame retardant performance. The phosphorus content of the flame retardant of the present invention is preferably 30 to 50%.

(B) About having the reducing action by the P—H bond, it is not within the scope of the author's guess, but can be considered as a new theory for improving the flame retardancy in the present invention. That is, by having a P—H bond, it is positively combined with oxygen present on the surface of a very narrow range of a combustible material such as a synthetic resin, thereby reducing the surrounding oxygen concentration and suppressing combustion. So why does the P—H bond actively associate with oxygen? It is considered that this is due to the high reducibility of the P—H bond. The reducibility is a scale that expresses the degree to which an object is oxidized by being bound to oxygen and is generally reduced, and is generally known as a redox potential. In fact, sodium phosphinate has a strong reducing ability and is widely used as a reducing agent for metal plating. In other words, high reducibility means high ability to bind to oxygen, and high reducibility is considered to contribute to flame retardancy. In this case, it is considered that the P—H bond of the flame retardant of the present invention is combined with oxygen to form a P—OH bond, thereby reducing the surrounding oxygen concentration. This new theory for improving the flame retardant performance in the present invention is unique to the flame retardant of the present invention, and is different from the organophosphorus metal salts that are generally commercially available, ie, dialkylphosphinic acid metal salts. To do.
As a supplement, there is a theory that generally the more easily oxidized (strong reducing agent) is more flammable, this is the case where the substance exists alone, and in the present invention, the flame retardant is combined with a polyurethane resin or a synthetic resin. It is reasonable to think that this theory is not applicable because of the coexistence of leather components. In fact, as shown in Example 1, when the flame retardant performance test as a synthetic leather is performed, it is clear from the fact that it exhibits extremely high performance.

In addition to the flame retardant of the present invention, melamine phosphate, melamine pyrophosphate, melamine polyphosphate, ammonium polyphosphate, phosphate ester amide, melamine phthalate, melamine, melamine cyanurate, benzoguanamine for further flame retardant performance improvement In addition, expansive graphite, aluminum hydroxide and magnesium hydroxide may optionally be used in combination as flame retardant aids. The amount used is 0 to 200 parts by weight of the total of at least one compound of the above flame retardant aid with respect to 100 parts by weight of the flame retardant of the present invention.

The mixing ratio of the flame retardant of the present invention and the polyurethane resin is preferably 5/95 to 50/50, more preferably 10/90 to 35/65, by mass ratio. In addition, when a flame retardant aid is included, the mixing ratio of the total of the flame retardant of the present invention and the flame retardant aid and the polyurethane resin is preferably 5/95 to 50/50 by mass ratio. More preferably, it is 10/90 to 35/65. If the mixing ratio exceeds 50/50, the synthetic leather may have a texture hardening or a decrease in tensile strength, and if the mixing ratio is less than 5/95, sufficient flame retardancy may not be obtained.

[Flame-retardant synthetic leather]
The flame-retardant synthetic leather of the present invention comprises a nonwoven fabric, a woven fabric, a fiber base material including a knitted fabric, and at least one polyurethane resin layer, and any one of the polyurethane resin layers is a flame-retardant material of the present invention. It is formed using a conductive polyurethane resin.

[Fiber base]
Nonwoven fabrics, woven fabrics, knitted fabrics and the like are used as the fiber base material used in the present invention. The type of fiber material is not particularly limited, and synthetic fibers such as polyester, nylon, polyacrylonitrile, polypropylene and aramid, semi-synthetic fibers such as diacetate and triacetate, and cellulosic fibers such as rayon, cotton and hemp Further, animal fibers such as wool, silk and feathers, or inorganic fibers such as glass fibers and carbon fibers may be used alone or in combination.

[Polyurethane resin]
As the polyurethane resin used in the present invention, those synthesized from polyols, isocyanates, and chain extenders can be used.

Examples of the polyol include polycarbonate polyol, polyester polyol, polyether polyol, polycaprolactone polyol, polyolefin polyol, vegetable oil-based polyol, and the like. These polyols may be used alone or in combination of two or more. The number average molecular weight is preferably in the range of 1000 to 3000.

Examples of the polycarbonate polyol include one or two alkanediols such as 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentanediol, and 1,12-dodecanediol. The above and the copolymer with 1 type, or 2 or more types of carbonate compounds, such as dialkyl carbonate, alkylene carbonate, and diphenyl carbonate, are mentioned.

Examples of the polyester polyol include one or two low molecular diols such as ethylene glycol, 1,4-butylene glycol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, and diethylene glycol. Examples thereof include polycondensation products of at least one species with one or more low-molecular dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and phthalic acid.

Examples of the polyether polyol include polypropylene ether polyol, polytetramethylene ether polyol, hexamethylene ether polyol, and the like.

Examples of the vegetable oil-based polyol include castor oil-modified polyol, dimer acid-modified polyol, soybean oil-modified polyol, and the like.

Examples of the isocyanate used include aliphatic diisocyanates such as methylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, and trimethylhexamethylene diisocyanate, and alicyclic groups such as 4,4′-dicyclohexylmethane diisocyanate, isophorone diisocyanate, and norbornene diisocyanate. Aromatic diisocyanates such as diisocyanate, 4,4′-diphenylmethane diisocyanate, tolylene diisocyanate, 1,5-naphthalene diisocyanate and the like can be mentioned. These isocyanates can be used alone or in combination of two or more.

A low molecular weight diol having 2 to 10 carbon atoms used as a chain extender is preferable, such as ethylene glycol, diethylene glycol, 1,4-butylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, Examples thereof include aliphatic glycols such as neopentyl glycol and low-molecular alicyclic diols such as cyclohexanediol. These polyols can be used alone or in combination of two or more. These polyols preferably have an average number of functional groups of 2 or more and an average molecular weight in the range of 50 to 400.

The polyurethane resin used for the synthetic leather 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 may be used alone or in combination of two or more. They can be used in combination. Especially, it is preferable to use a polycarbonate-type polyurethane resin at the point which is excellent in durability, heat resistance, and a weather resistance of the polyurethane resin obtained.

[Method for producing flame-retardant synthetic leather]
The method for producing the flame-retardant synthetic leather of the present invention is not particularly limited, and can be produced by either a wet method or a dry method.

The wet method is a method in which a base polyurethane resin mixed with a water-soluble solvent (hereinafter referred to as a base resin) is coated on a fiber base material and immersed in a coagulation bath containing water. In this method, the water-soluble solvent is eluted, the polyurethane resin is precipitated and solidified to form a porous microporous layer having a large number of voids, and the product is then washed and dried to obtain a product. A flame retardant may be blended in the base resin, and a skin layer containing a pigment that has been embossed or the like may be laminated on the base resin.

The dry method is a direct coating method in which a polyurethane resin mixed with a solvent is directly coated on a fiber substrate, and the solvent is evaporated by a dryer to cure, or for a skin layer containing a pigment on a release paper. A polyurethane resin is coated and dried to form a skin resin layer, and then a polyurethane resin for an adhesive layer is coated on the skin resin layer, bonded and bonded to a fiber substrate, and dried to obtain a product. is there. In addition, an aging treatment may be performed to complete the curing reaction. Finally, the release paper is peeled off to complete. A flame retardant may be blended in the polyurethane resin for the adhesive layer.

Specifically, it can be produced by the following method, but is not limited thereto.
A composition containing the polyurethane resin for the skin layer is coated on the release paper, and if necessary, heat treatment is performed to form the skin layer. Next, a composition containing a flame retardant polyurethane resin in which the flame retardant of the present invention is blended in advance as an adhesive layer is coated on the skin layer, and the fiber base material and the roll are in a state where the composition has adhesiveness. Alternatively, they are bonded together by pressure bonding such as a hot roll, cooled to room temperature, and subjected to aging treatment to form an adhesive layer. Finally, the release paper is peeled to obtain the flame-retardant synthetic leather of the present invention.

As a method for coating the flame retardant polyurethane resin composition, various conventionally known methods can be employed and are not particularly limited. Examples thereof include a method using an apparatus such as a reverse roll coater, spray coater, roll coater, gravure coater, kiss roll coater, knife coater, comma coater, or T-die coater.

The thickness of the adhesive layer is preferably 50 to 400 μm, more preferably 100 to 300 μm, in a wet state immediately after coating. If it is less than 50 μm, the adhesive strength may not be sufficient, and if it exceeds 400 μm, the texture of the synthetic leather may become hard.

The thickness of the skin layer is preferably 5 to 200 μm, more preferably 10 to 100 μm, in a wet state immediately after coating. If it is less than 5 μm, the abrasion resistance may not be sufficient, and if it exceeds 200 μm, the texture of the synthetic leather may become hard.

[Other additives]
You may mix | blend another additive with the flame-retardant synthetic leather of this invention in the range which does not impair the physical property and flame-retardant performance of synthetic leather. For example, antibacterial and antifungal agents, antistatic agents, lubricants, light stabilizers such as UV absorbers and hindered amines, antioxidants, water repellents, plasticizers, colorants, foaming agents, antifoaming agents, urethanization catalysts And surface treatment agents.

The usage application of the flame-retardant polyurethane resin obtained in the present invention is not particularly limited. For example, a seat sheet material, a floor carpet, and a ceiling material used as interior materials for vehicles, railways, aircrafts, and ships. Etc., furniture carpets, chair seats, curtains, blinds, notebooks, outdoor tents, car covers and the like.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples. In the following examples, “%” refers to wt% and “parts” refers to parts by weight unless otherwise specified. Each synthetic leather was evaluated by the following method.

[Flame retardant performance test]
FMVSS (US Automotive Safety Standards) No. In accordance with 302 automotive interior material combustion test standards, flame retardancy was evaluated according to the following criteria.
・ When it disappeared before reaching the A marked line, the judgment category was “NB (Non Burning)”.
-When self-extinguishing exceeds the mark A, and the combustion distance is within 50 mm and the combustion time is within 60 seconds, the judgment category is "SE (Self-Extinction)".
-When the burning speed between the marked lines is 102 mm / min or less, the judgment category is “slow flammability”.
-When the burning speed between marked lines exceeded 102 mm / min, the judgment category was set to “Fail”.
In addition, flame retardance performance is high in the order of “NB”>“SE”> “slow flame retardance”, and all three points pass.
Furthermore, in order to make it easy to compare the difference in flame retardant performance, the combustion distance from the flame contact portion in each sample was represented by an average value of four points. The smaller the value of the combustion distance, the better the tendency.

[Hydrolysis resistance test]
Evaluation of the flame retardant powder (hereinafter referred to as powder) was performed. As a test method, about 5 g of powder was put in a beaker, left uncovered in a constant temperature and humidity chamber adjusted to 70 ° C. and 90% relative humidity for 500 hours, and the state of the powder before and after the test changed. It was evaluated by appearance (presence / absence of discoloration), FT-IR (Fourier transform infrared spectroscopy) and TGA (thermogravimetric analysis), and judged according to the following criteria.
○: No clear change is observed in the powder before and after the test in all the above three evaluation methods. X: Clear change is observed in the powder before and after the test in any one of the above three evaluation methods. (If discoloration, different peaks in FT-IR, or differences in thermal decomposition curves in TGA are seen, it is suggested that the flame retardant has hydrolyzed and the chemical structure has changed.)

[Bleed resistance test]
The synthetic leather was evaluated. As a test method, synthetic leather cut to 18 × 25 cm is placed in a thermo-hygrostat adjusted to 70 ° C. and relative humidity 90%, and the surface condition of the synthetic leather after 500 hours is visually observed, and the following criteria are used. Judged according to.
○: The surface of the synthetic leather is not whitened Δ: The surface of the synthetic leather is slightly whitened ×: The surface of the synthetic leather is clearly whitened

[Moist heat aging test]
The synthetic leather was evaluated. As a test method, synthetic leather cut to 18 × 25 cm is placed in a constant temperature and humidity chamber adjusted to 70 ° C. and relative humidity 90%, and the above flame retardant performance test is performed on the synthetic leather after 500 hours. Judgment was made according to the criteria.
○: After the wet heat aging test, no decrease in flame retardancy is observed compared to before the test.
X: After the wet heat aging test, compared with before the test, the flame-resistant performance is clearly reduced.

[Example 1]
A polyurethane resin composition for the skin layer was prepared according to the following formulation.
<Prescription 1>
-Polycarbonate polyurethane resin (solid content 25%, solvent DMF) 100 parts-Dimethylformamide (DMF) 40 parts-Carbon black pigment 12 parts

A polyurethane resin composition for the adhesive layer was prepared according to the following formulation.
<Prescription 2>
・ Polycarbonate polyurethane resin (solid content 70%, solvent MEK) 100 parts ・ Methyl ethyl ketone (MEK) 50 parts ・ Urethane curing agent (polyisocyanate) 10 parts ・ Urethane catalyst 2 parts ・ Ethylphosphinic acid aluminum (average particle size 5 μm) 15 copies

The resin composition for skin layer of the above formulation 1 was coated on a release paper so as to have a thickness of 150 μm, and dried for 2 minutes with a dryer at 100 ° C. to form a skin layer. Next, on this skin layer, the resin composition for the adhesive layer of the above formulation 2 is coated to a thickness of 250 μm, dried for 3 minutes in a dryer at 120 ° C., bonded to a polyester tricot cloth, and pressed with a mangle. Then, the flame-retardant synthetic leather of Example 1 was obtained by aging at 40 ° C. for 72 hours and peeling off the release paper.

[Example 2]
Flame retardant in the same manner as in Example 1 except that the flame retardant of <Prescription 2> of Example 1 was a mixture of 10 parts of aluminum ethylphosphinate (average particle diameter 5 μm) and 5 parts of benzoguanamine (average particle diameter 10 μm). Sexual synthetic leather was obtained.

[Comparative Example 1]
A flame retardant synthetic leather was obtained in the same manner as in Example 1 except that no flame retardant was added to the adhesive layer.

[Comparative Example 2]
A flame-retardant synthetic leather was obtained in the same manner as in Example 1 except that the flame retardant of <Prescription 2> in Example 1 was changed to 15 parts of a mixture of decabromodiphenyl ether and antimony trioxide (average particle size: 4 μm).

[Comparative Example 3]
A flame-retardant synthetic leather was obtained in the same manner as in Example 1 except that 15 parts of the flame retardant of <Prescription 2> in Example 1 was changed to 15 parts of ammonium polyphosphate (average particle size: 15 μm).

Table 1 shows the evaluation results of the synthetic leathers of Examples and Comparative Examples for the flame retardant performance test.

Table 2 shows the evaluation results of the synthetic leathers of Examples and Comparative Examples for other evaluation items.

Since the hydrolysis resistance test and the bleed resistance test of Comparative Example 1 did not contain a flame retardant, the wet heat aging test was originally rejected because the flame retardant performance was originally unacceptable.

From Tables 1 and 2, the flame retardant synthetic leather made of polyurethane resin using the flame retardant of the present invention has the same or better advanced flame retardant performance than the synthetic leather using halogenated flame retardant, but synthetic leather. As a result, various physical properties were maintained in good condition.

Claims

A flame retardant polyurethane resin obtained by mixing a flame retardant (a) represented by the following formula (1) and a polyurethane resin (b), wherein the mixing ratio is (a) / (b) = 5 / A flame-retardant polyurethane resin characterized by being in the range of 95 to 50/50.

(Wherein R 1 is hydrogen, a phenyl group, or a linear alkyl group having 1 to 6 carbon atoms, M is Mg, Al, Ca, Ti, or Zn, and m is 2, 3, or 4) is there.)
For 100 parts by weight of the flame retardant (a) represented by the above formula (1), melamine phosphate, melamine pyrophosphate, melamine polyphosphate, ammonium polyphosphate, phosphate ester amide, melamine phthalate, melamine, cyanuric acid The total of one or more flame retardant aids (c) selected from the group consisting of melamine, benzoguanamine, expandable graphite, aluminum hydroxide and magnesium hydroxide is 0 to 200 parts by weight, and the above formula (1 The mixing ratio of the flame retardant (a), the polyurethane resin (b) and the flame retardant aid (c) represented by {) is expressed as {(a) + (c)} / (b) = 5 / 95- The flame-retardant polyurethane resin according to claim 1, which is in a range of 50/50.
The synthetic leather is composed of a nonwoven fabric, a woven fabric, a fiber substrate including a knitted fabric, and at least one polyurethane resin layer, and any one of the polyurethane resin layers is a flame retardant polyurethane according to claim 1 and / or 2. A flame-retardant synthetic leather characterized by being formed using a resin.