Flame-retardant polyurethane resin composition and synthetic artificial leather using same

Abstract

[Problem] The present invention addresses the problem of providing: a polyurethane resin composition which has excellent flame retardancy and flexibility and in which the amount of flame retardant is low; and a synthetic artificial leather which is formed from the polyurethane resin composition. [Solution] A polyurethane resin composition which contains a flame retardant and a reaction product of a polyurethane resin raw material component that contains a polyisocyanate compound and a polyol compound, in which the polyisocyanate compound, the polyol compound, the polyisocyanate compound, the polyol compound, and the polyurethane resin raw material component are bonded together. A modified isocyanurate-type polyisocyanate compound having an average number of isocyanate groups of 1.7 to 2.3 is used. A synthetic artificial leather is obtained by forming a skin layer on a support such as a fiber fabric using the obtained flame-retardant polyurethane resin composition.

Description

Technical Field

[0001] The present invention relates to a new flame-retardant polyurethane resin composition having excellent flame retardancy and flexibility, and a synthetic leather (imitation leather) using the composition. Furthermore, it relates to a flame-retardant polyurethane resin composition having a high biomass ratio using plant-derived components. Background Art

[0002] As a sheet material for automobiles, synthetic leather using a polyurethane resin is mostly used. Polyurethane resins for such applications generally require high flexibility and flame retardancy.

[0003] As a method for imparting flame retardancy to a polyurethane resin, a method of mixing a flame retardant is known. For example, in Patent Document 1, a method of using a liquid flame retardant containing a phosphate ester or the like is used.

[0004] However, in the case of using a liquid flame retardant, depending on the usage environment of the product, a so-called "bleeding" phenomenon in which the flame retardant bleeds out occurs. In the case of being used for an automobile sheet material, there are also problems such as evaporation of the bleeding flame retardant and fogging of the automobile glass. There is also a method of mixing a solid flame retardant, but the obtained polyurethane resin has a tendency to become hard. In addition, the amount of the flame retardant also needs to be very large, dozens of % relative to the mass of the polyurethane resin.

[0005] It is known that a flame-retardant polyurethane resin can be obtained by using an isocyanurate-type polyisocyanate component (for example, Patent Documents 2 to 6). However, a polyurethane resin using a large amount of a polyfunctional isocyanate component such as an isocyanurate has a tendency to have a high hardness, and is generally used as a hard board such as a building material, and is sometimes not suitable for a relatively soft material such as an automobile sheet material.

[0006] On the other hand, in recent years, many biomass polyurethane resins obtained by using a plant-derived polyol component have been developed, and furthermore, it has been proposed to also use a plant-derived substance as the polyisocyanate component to obtain a polyurethane resin having a higher biomass ratio (Patent Documents 7 to 12).

[0007] In the process of repeated studies by the present inventors to contribute to carbon neutrality for the purpose of global warming countermeasures and reduction of environmental load, they have also focused on obtaining an environmentally friendly flame-retardant biomass polyurethane resin by using an isocyanurate obtained by trimerizing plant-derived pentamethylene diisocyanate.

[0008] It should be noted that it is known to modify an isocyanurate-type polyisocyanate by reacting it with a short-chain monohydric alcohol or the like (Patent Document 13), but it is not known to obtain a polyurethane resin having a good balance between flame retardancy and flexibility using it. Prior Art Documents

[0009] Patent Documents Patent Document 1: Japanese Patent Laid-Open No. 2022-056074 Patent Document 2: Japanese Patent Laid-Open No. 2019-090038 Patent Document 3: International Publication WO2016 / 010042 Patent Document 4: Japanese Patent Laid-Open No. 2022-022919 Patent Document 5: Japanese Patent Laid-Open No. 2020-063410 Patent Document 6: Japanese Patent Laid-Open No. 2017-043667 Patent Document 7: Japanese Patent Laid-Open No. 2011-226047 Patent Document 8: Japanese Patent Laid-Open No. 2019-199498 Patent Document 9: Japanese Patent Laid-Open No. 2019-199499 Patent Document 10: International Publication WO2019 / 221090 Patent Document 11: Japanese Patent Laid-Open No. 2011-241528 Patent Document 12: International Publication WO2015 / 011921 Patent Document 13: Japanese Patent Laid-Open No. 2008-101087 Summary of the Invention Problems to be Solved by the Invention

[0010] The problem of the present invention is to develop a polyurethane resin product having excellent flexibility, high flame retardancy, and no bleeding problem. Means for Solving the Problems

[0011] The present inventors conducted intensive studies and found that by using, as at least a part of the polyisocyanate component in the polyurethane resin raw material component, a modified isocyanurate-type polyisocyanate compound having a specific number of isocyanate groups obtained by blocking at least one functional group (isocyanate group) contained in the isocyanurate-type polyisocyanate compound with a monohydric alcohol or the like, flexibility and flame retardancy can be improved simultaneously, and thus the present invention was completed.

[0012] That is, the present invention relates to the following flame-retardant polyurethane resin composition, compounding mixture for flame-retardant polyurethane resin, synthetic leather, and method for producing the same. (1) A flame-retardant polyurethane resin composition comprising a reaction product of a polyurethane resin raw material component and a flame retardant, the polyurethane resin raw material component containing a polyisocyanate component and a polyol component, wherein the polyisocyanate component contains a modified isocyanurate-type polyisocyanate compound having an average number of isocyanate groups of 1.7 to 2.3.

[0013] (2) The flame-retardant polyurethane resin composition according to (1), wherein the content ratio of the flame retardant is 15% by mass or less based on the total amount of the flame-retardant polyurethane resin composition. (3) The flame-retardant polyurethane resin composition according to (1), wherein the modified isocyanurate polyisocyanate compound contains a partially blocked isocyanurate polyisocyanate in which at least one of the isocyanate groups of the isocyanurate polyisocyanate is blocked with a monohydric alcohol.

[0014] (4) The flame-retardant polyurethane resin composition according to (3), wherein the monohydric alcohol is selected from monohydric alcohols having 6 to 12 carbon atoms and monohydric alcohols derived from castor oil. (5) The flame-retardant polyurethane resin composition according to (1), wherein the content ratio of the modified isocyanurate polyisocyanate compound is 60 to 100% by mass based on the total amount of the polyisocyanate component.

[0015] (6) The flame-retardant polyurethane resin composition according to (1), wherein the polyisocyanate component further contains a diisocyanate compound. (7) The flame-retardant polyurethane resin composition according to (6), wherein in the polyisocyanate component, the ratio of the diisocyanate compound (a) to the modified isocyanurate polyisocyanate compound (b) is (a):(b) = 1:99 to 40:60 (molar ratio).

[0016] (8) The flame-retardant polyurethane resin composition according to (1), wherein the modified isocyanurate polyisocyanate compound is 3 parts by mass or more based on 100 parts by mass of the flame-retardant polyurethane resin composition.

[0017] (9) The flame-retardant polyurethane resin composition according to (1), wherein the polyisocyanate component contains a modified isocyanurate polyisocyanate compound derived from 1,5-pentamethylene diisocyanate of plant origin. (10) The flame-retardant polyurethane resin composition according to (1), wherein the polyol component contains a polyol compound of plant origin.

[0018] (11) A polyurethane resin blend for the flame-retardant polyurethane resin composition according to (1), which comprises a polyurethane resin raw material component and a flame retardant, the polyurethane resin raw material component containing a polyisocyanate component and a polyol component, wherein the polyisocyanate component contains a modified isocyanurate polyisocyanate compound having an average number of isocyanate groups of 1.7 to 2.3.

[0019] (12) The flame-retardant polyurethane resin blend according to (11), wherein the content ratio of the flame retardant is 15% by mass or less. (13) A synthetic artificial leather, which comprises a support and an epidermis layer, characterized in that at least the epidermis layer is composed of the flame-retardant polyurethane resin composition described in any one of (1) to (10). (14) The synthetic artificial leather as described in (13), which is an interior material for vehicles.

[0020] (15) A method for manufacturing a synthetic artificial leather, the synthetic artificial leather comprising a support and an epidermis layer, the manufacturing method comprising a step of laminating the flame-retardant polyurethane resin blend described in (11) or (12) on the support and performing heat treatment to form the epidermis layer. Advantages of the Invention

[0021] The flame-retardant polyurethane resin composition obtained by the present invention uses a specific polyisocyanate compound in the polyurethane resin itself and has high flame retardancy. Therefore, the content of the flame retardant can be suppressed to a low level. In addition, the hardness of the polyurethane resin does not become too high, so sufficient flexibility can be achieved.

[0022] Therefore, a polyurethane resin composition with excellent flexibility, high flame retardancy and no exudation problem can be obtained, and it can be applied to synthetic leather or artificial leather such as synthetic artificial leather with both flexibility and flame retardancy, such as sheet materials for automobiles.

[0023] In addition, by using a specific polyisocyanate component or polyol component of plant origin as a raw material component of the polyurethane resin, a synthetic artificial leather composed of an environmentally friendly polyurethane resin material with not only flexibility and flame retardancy but also a high biomass ratio can be obtained. Detailed Embodiments

[0024] I. Flame-Retardant Polyurethane Resin Composition The flame-retardant polyurethane resin composition of the present invention comprises a reaction product of polyurethane resin raw material components and a flame retardant, the polyurethane resin raw material components containing a polyisocyanate component and a polyol component, wherein the polyisocyanate component contains a modified isocyanurate-type polyisocyanate compound having an average number of isocyanate groups of 1.7 to 2.3.

[0025] (1) Isocyanurate-Type Polyisocyanate The above-mentioned modified isocyanurate-type polyisocyanate compound is a compound obtained by modifying an isocyanurate-type polyisocyanate having one or more isocyanurate rings in one molecule.

[0026] As an isocyanurate type polyisocyanate having one or more isocyanurate rings in one molecule, it is preferable to use an isocyanurate type polyisocyanate having one isocyanurate ring in one molecule as the main component. However, as a by-product in the production stage of the isocyanurate type polyisocyanate, the case where a small amount of an isocyanurate type polyisocyanate having two or more isocyanurate rings in one molecule is contained is not excluded.

[0027] The above-mentioned isocyanurate type polyisocyanate can be synthesized from diisocyanates such as aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates.

[0028] As the aliphatic or alicyclic diisocyanate that can be used, an aliphatic or alicyclic diisocyanate having 4 to 30 carbon atoms is preferable. Examples of the aliphatic diisocyanate include tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), 2,2,4-(or 2,4,4-)trimethyl-1,6-hexamethylene diisocyanate, and lysine diisocyanate.

[0029] Examples of the alicyclic diisocyanate include isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, norbornane diisocyanate, 1,4-diisocyanatocyclohexane, 1,3-bis(diisocyanatomethyl)cyclohexane, and 4,4'-dicyclohexylmethane diisocyanate.

[0030] Examples of the aromatic diisocyanate include 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, dimethyldiphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, and polymethylene polyphenyl polyisocyanate.

[0031] These diisocyanates can be used alone or in combination. Among them, from the viewpoints of weather resistance and easy industrial availability, it is preferable to use 1,6-hexamethylene diisocyanate. In addition, considering the environmental impact, it is preferable to use an isocyanate of plant origin, that is, an environmentally friendly 1,5-pentamethylene diisocyanate.

[0032] (2) Synthesis of isocyanurate type polyisocyanate The isocyanurate type polyisocyanate can be obtained by subjecting a diisocyanate to an isocyanuration reaction in the presence of an isocyanuration catalyst. Examples of the isocyanuration catalyst include a trimerization catalyst that causes the isocyanate groups contained in the diisocyanate to react and trimerize, thereby promoting the formation of an isocyanurate ring.

[0033] As the isocyanuric acid esterification catalyst, the following can be used: nitrogen-containing aromatic compounds such as tris(dimethylaminomethyl)phenol, 2,4-bis(dimethylaminomethyl)phenol, 2,4,6-tris(dialkylaminoalkyl)hexahydro-S-triazine, potassium acetate, potassium 2-ethylhexanoate, potassium octanoate and other alkali metal carboxylates, tertiary ammonium salts such as trimethylammonium salt, triethylammonium salt, triphenylammonium salt, and quaternary ammonium salts such as tetramethylammonium salt, tetraethylammonium salt, tetraphenylammonium salt, etc. They can be used alone or in combination of two or more.

[0034] The addition amount of the isocyanuric acid esterification catalyst is preferably in the range of 0.001 parts by mass to 0.1 parts by mass, and most preferably in the range of 0.005 parts by mass to 0.05 parts by mass, based on 100 parts by mass of the diisocyanate.

[0035] As specific examples of the isocyanurate-type polyisocyanate (the number of isocyanurate rings is 1) of the present invention, the following examples can be cited. HDI3N: Isocyanurate-type triisocyanate synthesized from hexamethylene diisocyanate HTMDI3N: Isocyanurate-type triisocyanate synthesized from trimethylhexamethylene diisocyanate PDI 3N: Isocyanurate-type triisocyanate synthesized from pentamethylene diisocyanate IPDI3N: Isocyanurate-type triisocyanate synthesized from isophorone diisocyanate HTDI3N: Isocyanurate-type triisocyanate synthesized from hydrogenated toluene diisocyanate HXDI3N: Isocyanurate-type triisocyanate synthesized from hydrogenated xylylene diisocyanate NBDI3N: Isocyanurate-type triisocyanate synthesized from norbornane diisocyanate HMDI3N: Isocyanurate-type triisocyanate synthesized from hydrogenated diphenylmethane diisocyanate MDI 3N: Isocyanurate-type triisocyanate synthesized from diphenylmethane diisocyanate TDI 3N: Isocyanurate-type triisocyanate synthesized from toluene diisocyanate XDI 3N: Isocyanurate-type triisocyanate synthesized from xylylene diisocyanate

[0036] Each of the above triisocyanurates can be used alone or in combination.

[0037] (3) Modified isocyanurate-type polyisocyanate compound (i) Average number of isocyanate groups The modified isocyanurate polyisocyanate compound used in the present invention is a compound obtained by modifying the above isocyanurate polyisocyanate to have an average number of isocyanate groups of 1.7 to 2.3.

[0038] Specifically, the modified isocyanurate polyisocyanate compound of the present invention contains a partially blocked isocyanurate polyisocyanate in which at least one of the isocyanate groups of the above isocyanurate polyisocyanate is blocked with a monohydric alcohol or the like. Preferably, it contains a partially blocked isocyanurate polyisocyanate in which at least one of the three isocyanate groups of the above isocyanurate polyisocyanate having one isocyanurate ring is blocked with a monohydric alcohol or the like.

[0039] Regarding the partially blocked isocyanurate polyisocyanate modified with an isocyanurate polyisocyanate having one isocyanurate ring, examples include: a partially blocked isocyanurate type in which one of the three isocyanate groups is blocked (blocking number is 1), a partially blocked isocyanurate type in which two of the three isocyanate groups are blocked (blocking number is 2), and a blocked isocyanurate type in which all three isocyanate groups are blocked (blocking number is 3). In addition, it also includes an unmodified isocyanurate polyisocyanate in which none of the isocyanate groups are blocked.

[0040] Among the above, the preferred is a partially blocked isocyanurate type in which one of the three isocyanate functional groups is blocked (blocking number is 1). However, in practice, there are cases where a mixture mainly composed of a partially blocked isocyanurate type with a blocking number of 1 contains isocyanurate types with blocking numbers of 0 to 3. That is, the modified isocyanurate polyisocyanate compound of the present invention is sometimes a mixture of compounds with different remaining isocyanate group numbers after partial blocking.

[0041] The proportion of the isocyanurate types (isocyanurate bodies) with different blocking numbers relative to the entire mixture constituting the modified isocyanurate polyisocyanate compound of the present invention is not particularly limited. By specifying the average value of the number of isocyanate groups per molecule in the mixture (average number of isocyanate groups), it can be used as a reference for the composition of the isocyanurate types with different blocking numbers in the mixture.

[0042] The average number of isocyanate groups of the modified isocyanurate polyisocyanate compound can be determined by methods known to those skilled in the art for measuring the number of isocyanate groups by chemical titration methods. For example, by using known methods such as the method for measuring the isocyanate group content based on JIS-K-1603-1, those skilled in the art can determine the average number of isocyanate groups of the obtained modified isocyanurate polyisocyanate compound.

[0043] Generally, when the modified isocyanurate type polyisocyanate compound contains only the partially blocked isocyanurate type with a blocking number of 1 (the remaining number of isocyanate groups is 2), the average number of isocyanate groups is 2. On the other hand, in the case of containing a small amount of each isocyanurate type with a blocking number of 0 (the remaining number of isocyanate groups is 3), a blocking number of 2 (the remaining number of isocyanate groups is 1), and a blocking number of 3 (the remaining number of isocyanate groups is 0), depending on their ratios, the average number of isocyanate groups sometimes shows a value lower than 2 and sometimes shows a value higher than 2.

[0044] The number of isocyanate groups in one molecule of the modified isocyanurate type polyisocyanate compound of the present invention is 1.7 to 2.3 on average, preferably 1.8 to 2.2, and it is desirable to be based on such a ratio. If the average number of isocyanate groups is too small, the flexibility is too high and the durability is reduced. If the average number of isocyanate groups is too large, the flexibility is reduced and the touch feel becomes poor.

[0045] As for the specific content ratio of the partially blocked isocyanurate type with each blocking number (blocking numbers of 0, 1, 2, 3) relative to the total amount of the above mixture constituting the modified isocyanurate type polyisocyanate compound of the present invention, there is no particular limitation. However, from the chemical reaction principle when a monohydric alcohol reacts with isocyanurate in a molar ratio of 1:1, it is considered that the isocyanurate type with a blocking number of 1 (the remaining number of isocyanate groups is 2) is produced the most as the main product, and the amounts of the partially blocked isocyanurate types with blocking numbers of 0, 2, and 3 are generated in amounts of by-products.

[0046] The content ratio of the partially blocked isocyanurate type with a blocking number of 1 (the remaining number of isocyanate groups is 2) as the main component is preferably 50% by mass or more, more preferably 70% by mass or more, and the total content ratio of the isocyanurate types with blocking numbers of 0, 2, and 3 is preferably less than 50% by mass, more preferably less than 30% by mass.

[0047] The polyurethane resin which is a reaction product using the polyisocyanate component containing such a modified isocyanurate type polyisocyanate compound as a raw material component of the polyurethane resin has high flame retardancy and can also satisfy the flexibility as a material for synthetic leather.

[0048] (ii) Modification method (partial blocking method) In order to partially block the isocyanate groups of the isocyanurate type polyisocyanate, it is preferred to react the isocyanurate type polyisocyanate with a monohydric alcohol. As the monohydric alcohol for partial blocking, an organic compound having 1 hydroxyl group in one molecule can be cited. More preferably, a linear monohydric alcohol, a branched monohydric alcohol, etc. can be cited.

[0049] As linear monohydric alcohols, examples include: methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, n-undecanol, n-dodecanol (lauryl alcohol), n-tridecanol, n-tetradecanol, n-pentadecanol, n-hexadecanol, n-heptadecanol, n-octadecanol (stearyl alcohol), n-nonadecanol, eicosanol, etc.

[0050] As branched-chain monohydric alcohols, for example, examples include: isopropanol, isobutanol, sec-butanol, tert-butanol, isopentanol, isohexanol, isoheptanol, isooctanol, 2-ethylhexane-1-ol, isononanol, isodecanol, 5-ethyl-2-nonanol, trimethylnonanol, 2-hexyldecanol, 3,9-diethyl-6-tridecanol, 2-isoheptylisoundecanol, 2-octyldodecanol, other branched-chain alkanols, etc. (carbon number 5 to 20), etc. In addition, monohydric alcohols derived from plants can also be used. For example, examples include: monohydric alcohols derived from castor oil, etc.

[0051] Among them, those preferably selected are monohydric alcohols having 6 to 12 carbon atoms and monohydric alcohols derived from plants. As preferred examples of monohydric alcohols having 6 to 12 carbon atoms, examples include: 1-hexanol, 1-dodecanol, etc. As monohydric alcohols derived from castor oil, examples include: monohydric alcohols having a biomass degree of 90% or more. These can be commercially available products.

[0052] The usage amount of the monohydric alcohol is preferably 0.7 to 1.2 moles, more preferably 0.8 to 1.1 moles, and further preferably 0.9 to 1.0 moles relative to 1 mole of the isocyanurate polyisocyanate. By using the monohydric alcohol within this range, a modified isocyanurate polyisocyanate compound having a desired average number of isocyanate groups can be obtained.

[0053] The partial blocking reaction using the monohydric alcohol is usually carried out under atmospheric pressure in an atmosphere of a gas such as dry air or nitrogen that does not contain moisture and is non-reactive with isocyanate. As the reaction conditions, the reaction temperature is, for example, 60°C or higher, preferably 80°C or higher, and for another example, 130°C or lower, preferably 100°C or lower, and the reaction time is, for example, 180 minutes or longer, preferably 210 minutes or longer, and for another example, 10 hours or shorter, preferably 6 hours or shorter.

[0054] (4) Other polyisocyanate components [[ID=*18]] As the polyisocyanate component used in the present invention, the above-mentioned modified isocyanurate polyisocyanate compound can be used, but other polyisocyanate compounds such as diisocyanate compounds can also be mixed according to other needs.

[0055] In the present invention, as the polyisocyanate component, it is most preferred to use only a modified isocyanurate type polyisocyanate compound. However, by using a diisocyanate compound in combination, the flexibility can be easily adjusted, and a sufficient balance between flame retardancy and flexibility can be maintained.

[0056] As the diisocyanate compound, aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, etc., which can be used as raw materials for the above-mentioned modified isocyanurate type polyisocyanate compounds, can be used.

[0057] (5) Composition of the polyisocyanate component With respect to the total amount of the polyisocyanate component used in the present invention, the content ratio of the modified isocyanurate type polyisocyanate compound is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 100%.

[0058] With respect to the total amount of the polyisocyanate component and the polyol component as the raw material components of the polyurethane resin of the present invention, the content ratio of the modified isocyanurate type polyisocyanate compound is preferably 5% by mass or more, more preferably 15% by mass or more, particularly preferably 25% by mass or more, and preferably 65% by mass or less, more preferably 55% by mass or less.

[0059] In order to maintain sufficient flame retardancy and flexibility simultaneously, it is preferred that the content of the modified isocyanurate type polyisocyanate compound is within the above range.

[0060] As the polyisocyanate component used in the present invention, when containing components such as diisocyanates other than the modified isocyanurate type polyisocyanate compound, the content ratio is preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 20% by mass or less, particularly preferably 5 - 15% by mass. If within this range, the cost can be reduced while maintaining a sufficient balance between flame retardancy and flexibility.

[0061] In the above polyisocyanate component, when a modified isocyanurate type polyisocyanate compound and a diisocyanate compound are used in combination, if the molar amount of the diisocyanate compound is (a) and the molar amount of the modified isocyanurate type polyisocyanate compound is (b), the ratio of (a) to (b) is preferably (a):(b) = 1:99 - 40:60 (molar ratio), more preferably (a):(b) = 5:95 - 40:60 (molar ratio), further preferably (a):(b) = 5:95 - 35:65 (molar ratio), and even more preferably (a):(b) = 10:90 - 25:75 (molar ratio).

[0062] By using a diisocyanate compound in combination, it is possible to adjust to obtain moderate softness. On the other hand, in order to obtain sufficient flame retardancy, it is desirable to set the content of the isocyanurate component within the above range.

[0063] The polyurethane resin obtained from the reaction product using such a polyisocyanate component as a raw material component of the polyurethane resin composition has high flame retardancy and also has excellent softness. Since the polyurethane resin itself has flame retardancy, a polyurethane resin composition with a low content of flame retardant can be prepared.

[0064] 2. Polyol component The polyol component is used as a raw material component of the reaction product constituting the flame-retardant polyurethane resin composition of the present invention.

[0065] Examples of the polyol component include: aromatic polyols, alicyclic polyols, aliphatic polyols, polyether polyols, polyester polyols, polylactone polyols, acrylic polyols, epoxy polyols, polycarbonate polyols, urethane polyols, etc. They can be used alone or in combination of two or more.

[0066] Examples of the aromatic polyol include: bisphenol A, bisphenol F, phenol novolac, cresol novolac, etc.

[0067] Examples of the alicyclic polyol include: cyclohexanediol, methylcyclohexanediol, isophorone diol, dicyclohexylmethane diol, dimethyldicyclohexylmethane diol, etc.

[0068] Examples of the aliphatic polyol include: ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, etc.

[0069] Examples of the polyether polyol include: a polymer obtained by ring-opening polymerization of at least one of alkylene oxides such as ethylene oxide, propylene oxide, and tetrahydrofuran in the presence of at least one of low-molecular-weight active hydrogen compounds having two or more active hydrogens. Examples of the low-molecular-weight active hydrogen compounds having two or more active hydrogens include: glycols such as bisphenol A, ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol, etc., triols such as glycerol, trimethylolpropane, etc., amines such as ethylenediamine, butylenediamine, etc.

[0070] As the polyester polyol, for example, there can be mentioned: polyester polyol resin obtained by the condensation reaction of a binary acid selected from carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, fumaric anhydride, isophthalic acid, terephthalic acid, etc. alone or as a mixture with a polyol such as ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, glycerol, etc. alone or as a mixture; polycaprolactone obtained by ring-opening polymerization of ε-caprolactone and a polyol; and esters formed from aliphatics having hydroxyl groups such as castor oil and polyols, etc.

[0071] As the polylactone polyol, for example, there can be mentioned: polypropylene lactone diol, polycaprolactone diol, polypentyl lactone diol, etc.

[0072] As the acrylic polyol, there can be mentioned: acrylic polyol obtained by copolymerizing a polymerizable monomer having one or more active hydrogens in one molecule with a monomer copolymerizable therewith. For example, there can be mentioned: an acrylic polyol resin obtained by polymerizing component (i) and component (ii) in the presence or absence of component (iii), where, (i) is selected from acrylic esters having active hydrogens such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, etc.; methacrylic esters having active hydrogens such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, etc.; a single or mixture of acrylic or methacrylic acid having polyvalent active hydrogens such as a monoacrylate or monomethacrylate of glycerol, a monoacrylate or monomethacrylate of trimethylolpropane, etc., (ii) is selected from acrylic esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, etc.; methacrylic esters such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, etc. alone or as a mixture, (iii) is selected from unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, etc., unsaturated amides such as acrylamide, N-hydroxymethylacrylamide, etc.; and polymerizable monomers such as styrene, vinyltoluene, vinyl acetate, acrylonitrile, etc. alone or as a mixture.

[0073] As the epoxy polyol, there can be mentioned: epoxy resins such as novolac type, β-methyl epichlorohydrin type, cyclic ethylene oxide type, glycidyl ether type, glycidyl ester type, diol ether type, epoxidized aliphatic unsaturated compound type, epoxidized aliphatic ester type, polycarboxylic acid ester type, amino glycidyl type, resorcinol type, etc.

[0074] Examples of the polycarbonate polyol include polyols obtained by a dealcoholization reaction of a hydroxyl group-containing compound such as ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, octylene glycol, and nonylene glycol with diethyl carbonate, dipropyl carbonate, etc. Further, examples include polycarbonate polyols obtained from aromatic polyols such as bisphenol A or aliphatic / alicyclic polyols such as 1,6-hexanediol as raw materials.

[0075] Examples of the urethane polyol include a compound having a urethane bond in a polymer formed by a polyaddition reaction of an aromatic, aliphatic, or alicyclic diisocyanate and an active hydrogen compound and having a hydroxyl group in the side chain or terminal of the polymer.

[0076] Examples of the polyol component other than the above include polybutadiene polyol, modified polyol of polyol, or a hydride thereof, etc.

[0077] Examples of the modified polyol of polyol include polyols modified by reacting a raw material polyol with an alkylene oxide. Examples of the polyol include trihydric alcohols such as glycerin and trimethylolpropane; tetra- to octahydric alcohols such as pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin, dipentaerythritol, etc., sucrose, glucose, mannose, fructose, methyl glucoside, and their derivatives; phenol polybutadiene polyols such as phenol, phloroglucinol, cresol, pyrogallol, catechol, hydroquinone, bisphenol A, bisphenol F, bisphenol S, 1-hydroxynaphthalene, 1,3,6,8-tetrahydroxynaphthalene, anthrol, 1,4,5,8-tetrahydroxyanthracene, 1-hydroxypyrene; castor oil polyol; polyfunctional (e.g., the number of functional groups is 2 to 100) polyols such as (co)polymers of (meth)acrylic acid hydroxyalkyl esters and polyvinyl alcohol, condensates of phenol and formaldehyde (novolac).

[0078] The method for modifying the polyol is not particularly limited, and a method of adding an alkylene oxide (hereinafter simply referred to as AO) is preferably used. Examples of the AO include AOs having 2 to 6 carbon atoms, such as ethylene oxide (hereinafter simply referred to as EO), 1,2-epoxypropane (hereinafter simply referred to as PO), 1,3-epoxypropane, 1,2-epoxybutane, 1,4-epoxybutane, etc. Among them, from the viewpoints of properties and reactivity, PO, EO, and 1,2-epoxybutane are preferred, and PO and EO are more preferred. As the addition method when using two or more kinds of AOs (e.g., PO and EO), it may be block addition, random addition, or these methods may be used in combination.

[0079] Among them, as the polyol component of the present invention, from the viewpoint of durability, polycarbonate polyol is preferably used. Polycarbonate diol is more preferably used, and polycarbonate diol having an average molecular weight of 500 to 4000 is particularly preferably used.

[0080] In addition, considering the environmental impact, it is also preferable to use sebacic acid-based polyols obtained from plant-derived sebacic acid or castor oil polyols derived from castor oil.

[0081] With respect to 100 parts by mass of the raw material components of the polyurethane resin of the present invention, the content ratio of the polyol component is preferably 35 parts by mass or more, more preferably 40 parts by mass or more, particularly preferably 45 parts by mass or more, and preferably 80 parts by mass or less, more preferably 75 parts by mass or less, and particularly preferably 70 parts by mass or less.

[0082] With respect to 100 parts by mass of the polyurethane resin composition of the present invention, the content ratio of the polyol component is preferably 30 parts by mass or more, more preferably 35 parts by mass or more, particularly preferably 40 parts by mass or more, and preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and particularly preferably 60 parts by mass or less.

[0083] 3. Other raw material components In the present invention, as the raw material components of the polyurethane resin, in addition to the above-mentioned polyisocyanate component and polyol component, a crosslinking agent, a chain extender, a curing accelerator (catalyst component), an organic solvent, etc. may be contained as needed. In addition, a foaming agent, an antifoaming agent, a thickening agent, a surface conditioner, a surfactant, a filler, a weather resistance improver, an ultraviolet absorber, water, a dispersant, a color pigment, a pH adjuster, etc. may also be included.

[0084] As the chain extender, there is no particular limitation, and generally diols having a low molecular weight are used. For example, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, hexylene glycol, PEG, etc. derived from petroleum, and 1,3-propanediol, 1,2-hexanediol, etc. diols derived from plants can be cited. These diols can be used alone or in combination of two or more as needed. In addition, diamines, etc. can also be used as needed. The amount of the chain extender used is not particularly limited, and is about 1 to 5 parts by mass with respect to 100 parts by mass of the polyurethane resin composition of the present invention.

[0085] In addition, a curing accelerator (catalyst component) can also be used. Specifically, metal-based catalysts such as titanium bis(ethyl acetoacetate) diisopropoxide, amine-based catalysts, DBU-based catalysts, etc. can be cited. The amount of the curing accelerator used is not particularly limited, and is about 0.01 to 1 part by mass with respect to 100 parts by mass of the flame-retardant polyurethane resin composition of the present invention.

[0086] As the organic solvent, there is no particular limitation, and polar solvents inert to isocyanate groups such as dimethylformamide (DMF) or dimethyl sulfoxide (DMSO), and organic solvents such as methyl ethyl ketone (MEK), toluene, xylene, etc. can be cited.

[0087] 4. Flame retardant As the flame retardant contained in the flame-retardant polyurethane resin composition of the present invention, known flame retardants can be exemplified. For example, as organic phosphorus compounds, the following can be cited: phosphate esters and their salts, phosphite esters and their salts, phosphonic acids and their derivatives (including salts), hypophosphonic acids and their derivatives (including salts), phosphines, phosphine oxides, diphosphines, salts, and phosphazenes, etc. As inorganic phosphorus compounds, the following can be cited: phosphates represented by ammonium polyphosphate. In addition to the above compounds, red phosphorus as a simple substance can also be used.

[0088] As flame retardants other than phosphorus compounds, the following can be cited: melamine cyanurate, melamine-based compounds such as melamine, metal hydrates such as aluminum hydroxide and magnesium hydroxide, and antimony compounds such as antimony trioxide and antimony pentoxide. Among them, hypophosphite salts are preferred for the reasons of good flame retardancy and little influence on physical properties.

[0089] With respect to the total amount of the flame-retardant polyurethane resin composition of the present invention, the content ratio of the flame retardant is preferably 15% by mass or less, more preferably 12.5% by mass or less, particularly preferably 10% by mass or less, and additionally preferably 0% by mass or more, more preferably 2.5% by mass or more, and particularly preferably 5% by mass or more.

[0090] The flame-retardant polyurethane resin composition of the present invention is mainly composed of a polyurethane resin obtained from a reaction product using a specific polyisocyanate component, and can ensure high flame retardancy without impairing flexibility, so the amount of the added flame retardant can be suppressed to a low level.

[0091] 5. Other additives In the flame-retardant polyurethane resin composition of the present invention, as needed, within the range not impairing the physical properties of the cured polyurethane resin, a foaming agent, a defoaming agent, a thickening agent, a surface conditioner, a surfactant, a filler, a weather resistance improver, an ultraviolet absorber, an organic solvent, water, a dispersant, a color pigment, a pH regulator, etc. can be contained.

[0092] In addition, a urethanation catalyst, a silane coupling agent, a thixotropy imparting agent, a tackifier, a wax, a heat stabilizer, a light stabilizer, a fluorescent brightening agent, a thermoplastic resin, a thermosetting resin, a dye, a pigment, a conductivity imparting agent, an antistatic agent, a moisture permeability improver, a waterproof agent, an oil-proof agent, a hollow foam, a compound containing crystal water, a water absorbent, a moisture absorbent, a deodorant, a foam stabilizer, a mildew-proof agent, a preservative, an algicide, a pigment dispersant, an inert gas, an anti-blocking agent, a hydrolysis inhibitor, etc. can be used as needed. These additives can be used singly or in combination of two or more.

[0093] 6. Reaction product The reaction product contained in the flame-retardant polyurethane resin composition of the present invention is a polyurethane resin obtained by subjecting polyurethane resin raw material components containing the above-mentioned polyisocyanate component, polyol component, and other raw material components used as needed to treatments such as drying, heating, and curing.

[0094] The molar ratio of the polyisocyanate component to the polyol component is preferably polyisocyanate component / polyol component = 0.6 / 1 to 1.8 / 1. If either the polyisocyanate component or the polyol component is excessive, it is difficult to obtain a resin layer exhibiting durability or toughness.

[0095] The number-average molecular weight of the polyurethane resin thus obtained is preferably 2000 or more, more preferably 2500 or more. The upper limit of the number-average molecular weight is not particularly limited, and is usually 200,000,000 or less, preferably 100,000,000 or less. When the number-average molecular weight of the polyurethane resin is within the above range, a resin suitable for forming a resin layer can be obtained.

[0096] 7. Method for producing flame-retardant polyurethane resin composition The flame-retardant polyurethane resin composition of the present invention is prepared by mixing polyurethane resin raw material components composed of the above-mentioned polyisocyanate component, polyol component, and other raw material components, a flame retardant, and other additives to form a flame-retardant polyurethane resin blend, and subjecting it to thermal curing after molding as needed.

[0097] As the conditions for thermal curing, treatment at a temperature of 80 to 140°C and a time of 1 to 10 minutes is preferred. In addition, it may include a step of drying and removing liquid components such as organic solvents contained as needed. For example, after mixing the polyurethane resin raw material components, the flame retardant, and other additives, it can be molded, dried, and thermally cured. The drying and thermal curing can be carried out in one step or in separate steps.

[0098] For example, as described later, in the case of forming a layer composed of a flame-retardant polyurethane resin composition on a support (base fabric, etc.) of a synthetic leather of the present invention, after coating the flame-retardant polyurethane resin blend on the support, treatments such as drying and thermal curing can be carried out.

[0099] In addition, it can also be obtained by allowing a part or all of the above-mentioned polyisocyanate component and polyol component to react in advance preferably in the presence of a chain extender, and then mixing the flame retardant and other additives. When allowing a part or all of the above-mentioned polyisocyanate component, polyol component, and other raw material components to react in advance before mixing with the flame retardant and other additives, an organic solvent may be contained.

[0100] II. Blending Composition for Flame-Retardant Polyurethane Resin The blending composition for flame-retardant polyurethane resin of the present invention is a raw material blending composition for the above-mentioned flame-retardant polyurethane resin composition, and contains a polyurethane resin raw material component containing a polyisocyanate component and a polyol component, and a flame retardant.

[0101] As the polyisocyanate component, polyol component, and flame retardant contained in the blending composition for flame-retardant polyurethane resin, the components blended for the above-mentioned flame-retardant polyurethane resin composition are used. In particular, the above polyisocyanate component contains a modified isocyanurate-type polyisocyanate compound having an average number of isocyanate groups of 1.7 to 2.3.

[0102] In addition, other raw material components such as a chain extender or a curing accelerator used as needed may be blended. In addition, the above other additives other than the flame retardant may be blended.

[0103] The flame-retardant polyurethane resin blending composition is obtained by stirring and mixing the above polyisocyanate component, polyol component, other raw material components used as needed, and the flame retardant and other additives by a conventionally known method.

[0104] In addition, it can also be obtained by previously reacting a part or all of the polyurethane resin raw material component containing the above polyisocyanate component, polyol component, and other raw material components used as needed, preferably in the presence of a chain extender, and then mixing the flame retardant and other additives. In addition, an organic solvent may be contained during this reaction.

[0105] The molar ratio of the polyisocyanate component to the polyol component is preferably polyisocyanate component / polyol component = 0.6 / 1 to 1.8 / 1. If either the polyisocyanate component or the polyol component is excessive, it is difficult to obtain a resin layer showing durability or toughness.

[0106] The flame-retardant polyurethane resin blending composition of the present invention can be made into the flame-retardant polyurethane resin composition of the present invention by thermal curing. As the conditions for thermal curing, it is preferably treated at a temperature of 80 to 140 °C for a time of 1 to 10 minutes. In addition, the solvent contained as needed can also be dried and removed and then heated and cured.

[0107] For example, as described later, in the case of forming a layer composed of the flame-retardant polyurethane resin composition on the support (base fabric, etc.) of the synthetic leather of the present invention, after coating the flame-retardant polyurethane resin blending composition on the support, treatments such as drying, heating, and curing can be performed.

[0108] When applying the flame-retardant polyurethane resin blend on the support, it is preferable to adjust the formulation so that it has a viscosity that can be applied even without a solvent. However, if necessary, the inclusion of organic solvents is not excluded to achieve a viscosity suitable for application.

[0109] III. Synthetic Leather The synthetic leather of the present invention comprises at least a support (base fabric) and a skin layer. In the present invention, as the so-called concept including synthetic leather and artificial leather, it is collectively referred to as synthetic leather. The synthetic leather of the present invention is excellent in softness and high in flame retardancy, and does not have the problem of bleeding, so it can be applied to seat materials for automobiles, etc., as synthetic leather or artificial leather having both softness and flame retardancy.

[0110] 1. Support As the support (base fabric) for the synthetic leather of the present invention, conventionally known substrates for synthetic leather can be used without particular limitation. For example, there can be mentioned: fibrous fabrics such as knitted or woven fabrics composed of twill fabrics, plain fabrics, etc., napped fabrics obtained by mechanically raising the cotton fabric of the fabric, rayon fabrics, nylon fabrics, polyester fabrics, Kevlar (Kevlar is a registered trademark), non-woven fabrics (polyester, nylon, various latexes, etc.), various synthetic resin films or sheets, natural leather, etc. These can be appropriately selected according to the purpose. Preferred examples include fibrous fabrics such as knitted fabrics, woven fabrics, and non-woven fabrics.

[0111] The thickness of the support can be appropriately set in consideration of the material, texture, feel of the resulting synthetic leather, use, etc., and is preferably 100 - 2000 μm, particularly preferably 200 - 1000 μm.

[0112] 2. Skin layer The synthetic leather of the present invention has a skin layer containing the flame-retardant polyurethane resin composition on at least one surface of the support. The skin layer can be a porous layer or a non-porous layer.

[0113] The thickness of the skin layer can be appropriately set in consideration of the feel and use of the resulting synthetic leather, the material and shape of the support, etc., and is preferably 5 - 300 μm.

[0114] In the present invention, in order to improve the surface strength and designability of the synthetic leather, etc., coloring, gloss adjustment, uneven patterns, etc. can also be applied to the skin layer. In addition, if necessary, it can be composed of two or more layers. When composed of two or more layers, examples of layers other than the layer composed of the flame-retardant polyurethane resin composition of the present invention include: heat-insulating layers, foaming layers, etc.

[0115] 3. Manufacturing method of synthetic leather The synthetic artificial leather of the present invention is manufactured by a method including a step of forming a skin layer by laminating the above-mentioned flame-retardant polyurethane resin blend on a support and performing heat treatment.

[0116] The skin layer can be formed by applying a flame-retardant polyurethane resin blend capable of forming the flame-retardant polyurethane resin composition on at least one surface of the support by a coating method. As the coating method, there can be mentioned: a method of directly applying the flame-retardant polyurethane resin blend on a fabric using a doctor blade coater, a comma coater, a roll coater, a slot coater or a lip coater, etc. The coating thickness of the polyurethane resin blend is not particularly limited, and is preferably 5 to 300 μm.

[0117] It should be noted that the polyurethane resin blend is preferably adjusted in formulation so that it can be coated even without a solvent, but if necessary for viscosity adjustment, it can contain a solvent. As the solvent, there can be mentioned: well-known organic solvents such as DMF, DMSO, MEK, toluene, xylene, etc. At this time, a solution dispersed at a concentration of about 60 to 100 mass% based on the solid content concentration is preferably used.

[0118] After the coating step, the formed coating layer is dried and heat-treated to thermally cure the flame-retardant polyurethane resin blend, thereby forming a layer composed of the flame-retardant polyurethane resin composition. The drying and thermal curing can be carried out in one step or in separate steps. For example, after the coating layer is formed, a treatment at a temperature of 80 to 140 °C and a time of 1 to 10 minutes is preferably carried out.

[0119] In addition, it can also be manufactured by an impregnation method in which the above-mentioned polyurethane resin blend is impregnated into the support.

[0120] Furthermore, it can also be manufactured by a lamination method in which a separately formed skin layer is laminated on the support. For example, there can be mentioned the following method: forming a skin layer by applying the above-mentioned polyurethane resin blend on a release substrate by coating or the like, and laminating the skin layer on the support and then peeling off the release substrate.

[0121] As the lamination method, in addition to the method using an adhesive or the like, there can be mentioned the following method: semi-curing the flame-retardant polyurethane resin blend of the present invention by heating, laminating it on the support in an adhesive state, and then heating the flame-retardant polyurethane resin blend again to make it fully cured.

[0122] As means for coating, known methods such as comma coating, knife coating, roll coating, gravure coating, slot coating, spraying, etc. can be cited. After forming the film, it is appropriately dried to form an epidermal layer. A fabric is directly pressure-bonded onto this epidermal layer, or an adhesive is coated by a known method, and then the epidermal layer is coated and pressure-bonded to the support. Then, heat treatment (drying or heating) is performed to thermally cure it, and then it is peeled off from the release substrate to obtain synthetic artificial leather.

[0123] Here, as the conditions for pressure bonding, it is preferable to perform treatment at a temperature of 20 to 140°C, a pressure of 0.1 to 10 MPa, and a time of 0.0005 to 3 minutes. As the conditions for heat treatment, it is preferable to perform treatment at a temperature of 80 to 140°C and a time of 1 to 10 minutes.

[0124] In the case where the epidermal layer is adhered to the support via an adhesive, as the adhesive to be used, in addition to the above-mentioned flame-retardant polyurethane resin composition, polyurethane resins formed from conventional petroleum-based raw materials, acrylic resins, epoxy resin-based adhesives, etc. can also be cited. The adhesive can be imparted to either the epidermal layer side or the support side.

[0125] The above-mentioned release substrate is not particularly limited. For example, a film composed of a resin having releasability with respect to the polyurethane resin (olefin resin, silicone resin, etc., hereinafter referred to as a release agent) itself, a release paper, a release cloth, a release film, etc. in which a release layer composed of a release agent is laminated on a substrate such as paper, fabric, or film can be cited.

[0126] The release substrate can have concavo-convex patterns. By using such a release substrate, a resin film having concavo-convex patterns can be formed on the surface, and a synthetic artificial leather with good touch can be obtained while preventing adhesion between film surfaces.

[0127] In the above method, from the viewpoints of the physical properties and feel of the obtained synthetic artificial leather, etc., it is preferable to use the lamination method (stacking method). However, the present invention is not limited to these methods.

[0128] The synthetic artificial leather of the present invention as described above is suitable for shoes, clothing, bags, furniture, vehicle interior materials (such as instrument panels, car doors, consoles, seats), etc.

[0129] 4. Physical properties, etc. of synthetic artificial leather The synthetic artificial leather thus obtained can be further subjected to post-processing such as surface treatment and kneading processing as needed. In addition, in addition to the above-mentioned support and epidermal layer, an adhesive layer and / or a surface protective layer, etc. can also be provided. The adhesive layer is provided between the support and the epidermal layer, etc. The surface protective layer can be provided on the outside of the epidermal layer. As the surface protective layer, a layer formed from a known polyurethane resin, etc. can be cited.

[0130] For example, a synthetic artificial leather having a surface protective layer as the outermost layer in addition to a support and an epidermal layer can be obtained by the following method: Coating a polyurethane resin as a surface protective layer (the outermost layer) on a mold-releasing substrate and drying it, then coating the flame-retardant polyurethane resin blend of the present invention thereon, semi-curing it by heating, and bonding the layer formed by the flame-retardant polyurethane resin blend to the support in an adhesive state, and then heat-treating the flame-retardant polyurethane resin blend layer to make it fully cured.

[0131] The physical properties of the film covering the epidermal layer composed of the above-mentioned flame-retardant polyurethane resin composition are preferably as follows: the 100% modulus satisfies 0.4 MPa to 2.0 MPa, the strength at break satisfies 2.0 to 6.0 MPa, and the elongation at break satisfies 150 to 500%. In addition, the flame retardancy measured according to the test method of the US automotive safety standard FMVSS302 preferably has a maximum burning rate of 80 mm / min or less. By providing an epidermal layer with film physical properties satisfying the above range, a synthetic artificial leather with good mechanical strength and feel (softness) and high flame retardancy can be obtained.

[0132] Regarding the flame retardancy of the synthetic artificial leather formed by the epidermal layer composed of the above-mentioned flame-retardant polyurethane resin composition and the support, as the flame retardancy measured according to the test method of the US automotive safety standard FMVSS302, the maximum burning rate is preferably 80 mm / min or less. The synthetic artificial leather with various physical properties satisfying the above range has high flame retardancy and good mechanical strength and feel (softness), etc. Examples

[0133] The present invention will be described below by way of examples, but the present invention is not limited by any of these examples. Each evaluation in the examples was carried out according to the following methods.

[0134] [Flame retardancy] The evaluation was carried out according to the test method of the US automotive safety standard FMVSS302. At the end of a test piece (synthetic artificial leather; thickness 1000 μm) cut to a width of 100 mm and a length of 350 mm, an ignition operation was carried out by indirectly burning with a gas burner for 15 seconds, and the distance and time from the ignition flame passing over a marking line set at a position 38 mm from the end to extinction were measured. The burning rate was calculated and judged according to the following criteria. 〇: The test piece was not ignited or the ignited flame extinguished before the marking line, or the maximum burning rate was less than 50 mm / min △: The maximum burning rate was 50 mm / min to 80 mm / min ×: The maximum burning rate exceeded 80 mm / min

[0135] [Softness] A test piece (polyurethane resin film) with a width of 30 mm, a length of 100 mm, and a thickness of 150 μm was installed on a precision universal testing machine (trade name “Autograph AG-100A”, manufactured by Shimadzu Corporation) at room temperature of 20 ± 2°C and humidity of 65 ± 5% RH with a gripping width of 30 mm and a gripping interval of 50 mm, and the test piece was broken at a moving speed of the gripper of 100 mm / minute. The load (MPa) at a stroke distance of 50 mm was measured, the 100% modulus was calculated, and evaluation was performed according to the following criteria. 〇: The 100% modulus is 0.6 MPa or more and less than 1 MPa △: The 100% modulus is 0.4 MPa or more and less than 0.6 MPa, or is 1 MPa or more and less than 2 MPa ×: The 100% modulus is less than 0.4 MPa, or is 2 MPa or more

[0136] [Average number of isocyanate groups] Refer to JIS K 1603-1:2007 and obtain by the following method. (1) Prepare 0.5M hydrochloric acid and 0.5M dibutylamine / toluene solution in 300 mL volumetric flasks respectively. Fill 0.5M hydrochloric acid into a 25 mL burette. Conduct a blank test and record the titration volume at that time. (2) In a 300 - 500 mL beaker, add dibutylamine / toluene solution using a 10 mL volumetric burette, and then add 0.5 g of the sample (each modified polyisocyanate synthesized in Synthesis Examples 1 - 5). Then add 20 mL of dehydrated toluene and stir for 1 hour. (3) Add 150 mL of DMF and 15 drops of bromocresol green solution to the stirred solution, stir well, and titrate with a standard hydrochloric acid solution. (4) According to the titration result, calculate the isocyanate group content rate (%) using the following formula (Equation 1), and then calculate the remaining number of isocyanate groups using the following formula (Equation 2) based on this isocyanate group content rate as the average number of isocyanate groups.

[0137] [Equation 1]

[0138] N1: Isocyanate group content rate (mass percentage; %) V1: Amount of hydrochloric acid used (mL) measured to 0.01 mL required for the blank test V2: Amount of hydrochloric acid used (mL) measured to 0.01 mL required for the sample titration 0.25: Concentration of hydrochloric acid (mol / L) m0: Mass of the sample (g) 42.02: Chemical equivalent weight of isocyanate group (g / mol) f: Factor of 0.5 mol / L hydrochloric acid standard solution

[0139] [Number 2]

[0140] N2: Number of remaining isocyanate groups m1: Total weight of synthesized modified polyisocyanate (g) N0: Number of moles of isocyanurate polyisocyanate used for synthesis 3: Number of functional groups of isocyanurate polyisocyanate

[0141] Partially blocked isocyanurate polyisocyanate is manufactured as follows. <Synthesis Example 1> To 50 parts by mass of 1,5-pentamethylene diisocyanate-derived isocyanurate (isocyanurate polyisocyanate; manufactured by Mitsui Chemicals, Inc., trade name "STABiO D-370N", biomass content 70%), 10 parts by mass of 1-hexanol (monohydric alcohol) was added, and the reaction was carried out at 80 °C for 4 hours under a nitrogen atmosphere (atmospheric pressure) to obtain partially blocked isocyanurate polyisocyanate 1. The average number of isocyanate groups (average number of NCO functional groups) of this substance was found to be 1.89. It should be noted that the amount of monohydric alcohol used was 0.33 moles per 1 mole of isocyanurate polyisocyanate.

[0142] <Synthesis Example 2> To 50 parts by mass of 1,5-pentamethylene diisocyanate-derived isocyanurate (manufactured by Mitsui Chemicals, Inc., trade name "STABiO D-370N", biomass content 70%), 34 parts by mass of castor oil monohydric alcohol (trade name "URIC H-31", manufactured by Ito Oil Co., Ltd., biomass content 98%) was added, and the reaction was carried out at 80 °C for 4 hours under a nitrogen atmosphere to obtain partially blocked isocyanurate polyisocyanate 2. The average number of isocyanate groups of this substance was 1.81. It should be noted that the amount of monohydric alcohol used was 0.33 moles per 1 mole of isocyanurate polyisocyanate.

[0143] <Synthesis Example 3> To 50 parts by mass of 1,5-pentamethylene diisocyanate-derived isocyanurate (manufactured by Mitsui Chemicals, Inc., trade name "STABiO D-370N", biomass content 70%), 12 parts by mass of 1-hexanol was added, and the reaction was carried out at 80 °C for 4 hours under a nitrogen atmosphere to obtain a partially blocked isocyanurate-type polyisocyanate 3. The average number of isocyanate groups of this substance was 1.78. It should be noted that the amount of the monohydric alcohol used was 0.39 mol relative to 1 mol of the isocyanurate-type polyisocyanate.

[0144] <Synthesis Example 4> To 50 parts by mass of 1,5-pentamethylene diisocyanate-derived isocyanurate (manufactured by Mitsui Chemicals, Inc., trade name "STABiO D-370N", biomass content 70%), 7 parts by mass of 1-hexanol was added, and the reaction was carried out at 80 °C for 4 hours under a nitrogen atmosphere to obtain a partially blocked isocyanurate-type polyisocyanate 4. The average number of isocyanate groups of this substance was 2.25. It should be noted that the amount of the monohydric alcohol used was 0.23 mol relative to 1 mol of the isocyanurate-type polyisocyanate.

[0145] <Synthesis Example 5> To 50 parts by mass of 1,5-pentamethylene diisocyanate-derived isocyanurate (manufactured by Mitsui Chemicals, Inc., trade name "STABiO D-370N", biomass content 70%), 4 parts by mass of 1-hexanol was added, and the reaction was carried out at 80 °C for 4 hours under a nitrogen atmosphere to obtain a partially blocked isocyanurate-type polyisocyanate 5. The average number of isocyanate groups of this substance was 2.40. It should be noted that the amount of the monohydric alcohol used was 0.13 mol relative to 1 mol of the isocyanurate-type polyisocyanate.

[0146] <Example 1> 60 parts by mass of the above-obtained <partially blocked isocyanurate-type polyisocyanate 1> as a polyisocyanate compound, 84 parts by mass of a polycarbonate polyol (number average molecular weight: 2000) as a polyol compound, 3 parts by mass of 1,4-butanediol as a crosslinking agent, 0.1 part by mass of titanium diisopropoxide bis(ethyl acetoacetate) (manufactured by Matsumotofine chemicals Co., Ltd., trade name "ORGATIX TC750") as a curing accelerator, and 4 parts by mass of a metal hypophosphite-based flame retardant (manufactured by Clariant Chemicals, trade name "Exolit OP930") were compounded and stirred to obtain a flame-retardant polyurethane compounding liquid 1. It should be noted that the polyisocyanate component / polyol component (molar ratio) = 1.20.

[0147] [Epidermal layer] With respect to 100 parts by mass of a polycarbonate-based polyurethane resin (manufactured by DIC Corporation, trade name "S-705"), 20 parts by mass of dimethylformamide, 25 parts by mass of methyl ethyl ketone, and 20 parts by mass of a black pigment were stirred and mixed, and the mixture was wet-coated on a flat release paper (manufactured by LINTEC Corporation, trade name "EV130TPD") to a wet coating thickness of 200 μm. It was dried and cured at 90°C for 1.5 minutes and then at 130°C for 1.5 minutes using a dryer to obtain a resin film (the polyurethane resin layer constituting the outermost layer) with a thickness of 30 μm.

[0148] The flame-retardant polyurethane compounding liquid 1 was wet-coated on the resin film formed on the release paper using a coater to a wet coating thickness of 250 μm. Then, it was pre-dried at 130°C for 3 minutes using a dryer to obtain an epidermal layer formed from a flame-retardant polyurethane resin composition.

[0149] [Synthetic leather production] The obtained epidermal layer was overlapped on a polyester tricot fabric (support: thickness 800 μm) in a semi-dry state such that the flame-retardant polyurethane resin composition layer was in contact with the fabric, and then they were laminated under the condition of a pressure of 0.5 MPa and officially cured at 130°C for 3 minutes using a dryer. The release paper was peeled off to obtain the synthetic leather of the present invention (thickness 1000 μm).

[0150] [Production of polyurethane resin film for flexibility evaluation] The obtained flame-retardant polyurethane compounding liquid 1 was wet-coated on a flat release paper (EV130TPD, manufactured by LINTEC Corporation) to a wet coating thickness of 250 μm. Then, it was pre-dried at 130°C for 3 minutes and officially cured at 130°C for 3 minutes using a dryer. The polyurethane resin film was aged at 80°C for 3 hours, and the release paper was peeled off to obtain a polyurethane resin film for flexibility evaluation (thickness 150 μm).

[0151] [Example 2] 84 parts by mass of the above-obtained <partially blocked isocyanurate type polyisocyanate 2> as a polyisocyanate compound, 84 parts by mass of a polycarbonate polyol (number average molecular weight: 2000) as a polyol compound, 3 parts by mass of 1,4-butanediol as a crosslinking agent, 0.1 part by mass of titanium bis(ethyl acetoacetate) diisopropoxide (manufactured by Matsumoto Fine Chemicals Co., Ltd., trade name "ORGATIX TC750") as a curing accelerator, and 4 parts by mass of a flame retardant (manufactured by Clariant Chemicals, trade name "Exolit OP930") were compounded and stirred to obtain a flame-retardant polyurethane compounding liquid 2. It should be noted that the polyisocyanate component / polyol component (molar ratio) = 1.20. Using the obtained flame-retardant polyurethane blend solution 2, the same operations as in Example 1 were carried out to obtain a synthetic leather and a polyurethane resin film.

[0152] <Example 3> 62 parts by mass of the above-obtained <partially blocked isocyanurate type polyisocyanate 3> as a polyisocyanate compound, 74 parts by mass of a polycarbonate polyol (number average molecular weight: 2000) as a polyol compound, 3 parts by mass of 1,4-butanediol as a crosslinking agent, 0.1 part by mass of diisopropoxybis(ethyl acetoacetate)titanium (manufactured by Matsumoto Fine Chemicals Co., Ltd., trade name “ORGATIX TC750”) as a curing accelerator, and 4 parts by mass of a flame retardant (manufactured by Clariant Chemicals Co., Ltd., trade name “Exolit OP930”) were compounded and stirred to obtain a flame-retardant polyurethane blend solution 3. It should be noted that the polyisocyanate component / polyol component (molar ratio) = 1.20. Using the obtained flame-retardant polyurethane blend solution 3, the same operations as in Example 1 were carried out to obtain a synthetic leather and a polyurethane resin film.

[0153] <Example 4> 57 parts by mass of the above-obtained <partially blocked isocyanurate type polyisocyanate 4> as a polyisocyanate compound, 102 parts by mass of a polycarbonate polyol (number average molecular weight: 2000) as a polyol compound, 4 parts by mass of 1,4-butanediol as a crosslinking agent, 0.1 part by mass of diisopropoxybis(ethyl acetoacetate)titanium (manufactured by Matsumoto Fine Chemicals Co., Ltd., trade name “ORGATIX TC750”) as a curing accelerator, and 5 parts by mass of a flame retardant (manufactured by Clariant Chemicals Co., Ltd., trade name “Exolit OP930”) were compounded and stirred to obtain a flame-retardant polyurethane blend solution 4. It should be noted that the polyisocyanate component / polyol component (molar ratio) = 1.20. Using the obtained flame-retardant polyurethane blend solution 4, the same operations as in Example 1 were carried out to obtain a synthetic leather and a polyurethane resin film.

[0154] <Example 5> In the above Example 1, 40 parts by mass of the <partially blocked isocyanurate type polyisocyanate 1> as a polyisocyanate compound was changed, and further 5 parts by mass of 1,5-pentamethylene diisocyanate (manufactured by Mitsui Chemicals, Inc., trade name “STABiO PDI”, biomass content 71%) was used. Otherwise, the same operations as in Example 1 were carried out to obtain a synthetic leather and a polyurethane resin film. It should be noted that the polyisocyanate component / polyol component (molar ratio) = 1.20.

[0155] <Comparative Example 1> In the above Example 1, <Partially blocked isocyanurate polyisocyanate 1> was changed to 1,5-pentamethylene diisocyanate (manufactured by Mitsui Chemicals, Inc., trade name “STABiO PDI”, biomass content 71%) at 14 parts by mass, and the flame retardant was changed to 3 parts by mass. Otherwise, the same operations as in Example 1 were performed to obtain a synthetic leather and a polyurethane resin film. It should be noted that the polyisocyanate component / polyol component (molar ratio) = 1.20. The evaluation results of flame retardancy and softness are shown in Table 1. It should be noted that when a flame retardant in an amount showing the same level of flame retardancy as in the Example was added in Comparative Example 1, it was found that the softness was significantly reduced.

[0156] <Comparative Example 2> 54 parts by mass of the above-obtained <Partially blocked isocyanurate polyisocyanate 5> as a polyisocyanate compound, 118 parts by mass of a polycarbonate polyol (number average molecular weight: 2000) as a polyol compound, 4 parts by mass of 1,4-butanediol as a crosslinking agent, 0.1 part by mass of titanium diisopropoxide bis(ethyl acetoacetate) (manufactured by Matsumotofine chemicals Co., Ltd., trade name “ORGATIX TC750”) as a curing accelerator, and 5 parts by mass of a flame retardant (manufactured by Clariant Chemicals, trade name “Exolit OP930”) were mixed and stirred to obtain a flame-retardant polyurethane blend liquid 5. It should be noted that the polyisocyanate component / polyol component (molar ratio) = 1.20. Using the obtained flame-retardant polyurethane blend liquid 5, the same operations as in Example 1 were performed to obtain a synthetic leather and a polyurethane resin film.

[0157] The evaluation results of the synthetic leathers of the above Examples and Comparative Examples are shown in Table 1. It should be noted that the numerical values of the components forming the skin layer in the table are represented in parts by mass. Industrial Applicability

[0159] The polyurethane resin using the specific polyisocyanate component of the present invention has excellent flame retardancy and softness, and can suppress the compounding amount of the flame retardant to a low level, so that there is no problem of bleeding. Therefore, a flame-retardant polyurethane resin composition suitable for synthetic leathers such as synthetic leather or artificial leather having both softness and flame retardancy can be obtained. The synthetic leather of the present invention can be used in various fields such as clothing, bags, shoes, and vehicle interior materials. For example, it can be applied to vehicle interior materials represented by automotive seat, roof panel material, dashboard, door lining material, and handle.

Claims

1. A flame-retardant polyurethane resin composition, which is a polyurethane resin composition containing a reaction product of polyurethane resin raw material components and a flame retardant, wherein the polyurethane resin raw material components contain a polyisocyanate component and a polyol component, and The polyisocyanate component contains a modified isocyanurate-type polyisocyanate compound having an average number of isocyanate groups of 1.7 to 2.

3.

2. The flame-retardant polyurethane resin composition according to claim 1, wherein, The content ratio of the flame retardant is 15% by mass or less.

3. The flame-retardant polyurethane resin composition according to claim 1, wherein, The modified isocyanurate-type polyisocyanate compound contains a partially blocked isocyanurate-type polyisocyanate in which at least one of the isocyanate groups of the isocyanurate-type polyisocyanate is blocked with a monohydric alcohol.

4. The flame-retardant polyurethane resin composition according to claim 3, wherein, The monohydric alcohol is selected from monohydric alcohols having 6 to 12 carbon atoms and monohydric alcohols derived from castor oil.

5. The flame-retardant polyurethane resin composition according to claim 1, wherein, The content ratio of the modified isocyanurate-type polyisocyanate compound is 60 to 100% by mass relative to the total amount of the polyisocyanate component.

6. The flame-retardant polyurethane resin composition according to claim 1, wherein, The polyisocyanate component further contains a diisocyanate compound.

7. The flame-retardant polyurethane resin composition according to claim 6, wherein, In the polyisocyanate component, the ratio of the diisocyanate compound (a) to the modified isocyanurate-type polyisocyanate compound (b) is (a):(b)=1:99 to 40:60 in terms of molar ratio.

8. The flame-retardant polyurethane resin composition according to claim 1, wherein, The modified isocyanurate-type polyisocyanate compound is 3 parts by mass or more relative to 100 parts by mass of the flame-retardant polyurethane resin composition.

9. The flame-retardant polyurethane resin composition according to claim 1, wherein, The polyisocyanate component contains a modified isocyanurate-type polyisocyanate compound derived from 1,5-pentamethylene diisocyanate of plant origin.

10. The flame-retardant polyurethane resin composition according to claim 1, wherein, The polyol component contains a polyol compound of plant origin.

11. A blend for a flame-retardant polyurethane resin, which is a blend for a polyurethane resin for the flame-retardant polyurethane resin composition according to claim 1, and which contains a polyurethane resin raw material component and a flame retardant, wherein the polyurethane resin raw material component contains a polyisocyanate component and a polyol component, and wherein, The polyisocyanate component contains a modified isocyanurate-type polyisocyanate compound having an average number of isocyanate groups of 1.7 to 2.

3.

12. The blend for a flame-retardant polyurethane resin according to claim 11, wherein, The content ratio of the flame retardant is 15% by mass or less.

13. A synthetic artificial leather, which comprises a support body and an epidermis layer, is characterized in that, At least the skin layer is composed of the flame-retardant polyurethane resin composition according to any one of claims 1 to 10.

14. The synthetic leather according to claim 13, which is an interior material for vehicles.

15. A method for manufacturing a synthetic leather, the synthetic leather including a support and a skin layer, the manufacturing method including a step of laminating the flame-retardant polyurethane resin blend according to claim 11 or 12 on the support and performing heat treatment to form the skin layer.

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