Flexible polyurethane foam

Abstract

To provide a flexible polyurethane foam that has an excellent balance between fire retardancy and compression hardness by containing vinyl chloride-based polymer particles and a phosphoric acid ester-based fire retardant, and is suitable for use as sheets or cushion material in bedding, automobiles, motorcycles, and the like.SOLUTION: A flexible polyurethane foam includes: at least vinyl chloride-based polymer particles corresponding to a chloride concentration of 0.5-5.0 wt.%; and a phosphorous acid ester-based fire retardant corresponding to a phosphorous concentration of 0.1-1.5 wt.%, where the 25% compression hardness conforming to JIS K6400-2 D method is 105-250 N / 314 cm2, further preferably the determination conforming to FMVSS No.302 ignition test is no ignition, or self extinguishment, and / or the apparent density is 15-40 kg / m3.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polyurethane foam containing vinyl chloride polymer particles, and particularly to a flexible polyurethane foam excellent in the balance between flame retardancy and compression hardness by containing vinyl chloride polymer particles and a phosphate ester flame retardant.

Background Art

[0002] Polyurethane foam is mainly produced by the reaction of isocyanate and polyol. Flexible polyurethane foam having interconnected pores and characterized by flexibility and resilience is used as a cushioning material such as for vehicle and furniture cushions. Rigid polyurethane foam having closed pores and characterized by light weight and heat insulation is used in a wide range of applications such as heat insulation materials and structural materials in architecture, storage tanks, ships, etc. Conventionally, in order to make polyurethane foam flame retardant, flame retardants have been used to enhance the flame retardant performance of the resin itself. As such flame retardants, liquid flame retardants at room temperature typified by phosphate ester monomers, and solid flame retardants such as red phosphorus, polyphosphates, and expanded graphite have been used.

[0003] However, generally when a phosphate ester monomer that is liquid at room temperature is used as a flame retardant, such a flame retardant has a plasticizing effect on polyurethane, so it is likely to cause a decrease in the compression hardness of the polyurethane foam. Also, when a solid flame retardant is used, the flexibility of the foam is likely to decrease. There are particularly significant problems in reducing the characteristics of flexible polyurethane foam, and reduction of the amount of phosphate ester flame retardant used and substitution with other flame retardants that do not adversely affect physical properties are being studied.

[0004] Furthermore, as a method for flame retarding polyurethane foam without using phosphate ester-based flame retardants, a method has been proposed in which a polyol containing polyvinyl chloride particles is used as a raw material. For example, a method for preparing a polyol in which polyvinyl chloride monomers are polymerized in a polyol to disperse polyvinyl chloride particles (see, for example, Patent Document 1), a method using polyvinyl chloride particles and a carbonyl group-containing compound as a stabilizer (see, for example, Patent Document 2), and a method using a polyol composition in which 0.05 μm to 1 μm polyvinyl chloride particles and / or vinyl chloride-unsaturated vinyl copolymer particles are dispersed (see, for example, Patent Document 3) have been proposed. In addition, as a method for using vinyl chloride polymer in combination with a phosphate ester-based flame retardant, a composition for rigid polyurethane foam containing an organic polyisocyanate, a polyol, a catalyst, a blowing agent, a foam stabilizer, and vinyl chloride polymer particles and a phosphate ester-based flame retardant as flame retardants, and a rigid polyurethane foam obtained therefrom have been proposed (see, for example, Patent Document 4). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 03-097715 [Patent Document 2] Japanese Patent Application Publication No. 09-059341 [Patent Document 3] Japanese Patent Publication No. 2010-31169 [Patent Document 4] Japanese Patent Publication No. 2017-171760 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, the proposals in Patent Documents 1 to 3 concern the flame retardancy of polyurethane and polyurethane foam, while the proposal in Patent Document 4 concerns rigid polyurethane foam with independent cells. Neither of these documents considers flexible polyurethane foam, which offers an excellent balance between compression hardness and flame retardancy.

[0007] Therefore, there is a need for a flexible polyurethane foam that offers an excellent balance between flame retardancy and compressive hardness. [Means for solving the problem]

[0008] As a result of diligent research into the above-mentioned problems, the inventors of the present invention have discovered that a flexible polyurethane foam containing a specific amount of phosphate ester-based flame retardant and vinyl chloride-based polymer particles exhibits an excellent balance of compression hardness and flame retardancy while maintaining the properties of a flexible polyurethane foam, thus completing the present invention.

[0009] In other words, the present invention contains vinyl chloride polymer particles corresponding to at least 0.5 to 5.0% by weight of chlorine concentration and a phosphate ester flame retardant corresponding to 0.1 to 1.5% by weight of phosphorus concentration, and has a 25% compression hardness of 105 to 250 N / 314 cm in accordance with JIS K6400-2 D method. 2 This concerns flexible polyurethane foam.

[0010] The present invention will be described in detail below.

[0011] The flexible polyurethane foam of the present invention is a flexible polyurethane foam containing vinyl chloride polymer particles equivalent to at least 0.5 to 5.0% by weight of chlorine concentration and a phosphate ester flame retardant equivalent to 0.1 to 1.5% by weight of phosphorus concentration. Examples of polyurethane foams constituting the flexible polyurethane foam include polyurethane foams obtained by foaming and molding a polyurethane foam composition containing a general isocyanate component (A), a polyol component (B), a catalyst (C), a blowing agent (D), and a flame retardant (E), and possibly at least a foam stabilizer (F). Polyurethane foams are broadly classified into flexible polyurethane foams and rigid polyurethane foams. Flexible polyurethane foams are characterized by flexibility and resilience, and structurally have a structure in which air bubbles are interconnected. On the other hand, rigid polyurethane foams are characterized by hardness, lightness, and heat insulation, and structurally have a structure in which air bubbles are independent.

[0012] Furthermore, the flexible polyurethane foam of the present invention has a 25% compression hardness of 105-250 N / 314 cm² in accordance with JIS K6400-2 D method. 2 It is particularly excellent as a soft foam with good flexibility and moderate hardness, making it an excellent flame-retardant cushioning and shock-absorbing material, with a rating of 105-135N / 314cm². 2 It is preferable that the 25% compression hardness is 105 N / 314 cm. 2 If the hardness is less than 250 N / 314 cm², the material will have low hardness and be unsuitable as a cushioning material. On the other hand, a 25% compression hardness of 250 N / 314 cm² is considered to be low. 2 If the hardness exceeds this value, it will be too hard and unsuitable as a cushioning material. Furthermore, because rigid polyurethane foam has independent air cells, it lacks flexibility and has high hardness, which can cause indentations when compressed, making it difficult to measure the 25% compression hardness itself.

[0013] The vinyl chloride polymer particles constituting the flexible polyurethane foam of the present invention may be any particles belonging to the category of vinyl chloride polymer particles. For example, particles composed of vinyl chloride polymers such as paste-processing vinyl chloride polymers and SUS-vinyl chloride polymers can be used. In particular, particles of paste-processing vinyl chloride polymers (hereinafter sometimes referred to as paste vinyl chloride) are preferred because they have excellent handling properties. Furthermore, in order to provide a flexible polyurethane foam with excellent handling properties and an excellent balance between compression hardness and flame retardancy, the volume average particle diameter (hereinafter sometimes referred to as [MV] value) is preferably 0.1 to 10 μm, particularly 0.1 to 5 μm, and even more preferably 0.1 to 2 μm. The [MV] value of the vinyl chloride polymer particles in this case can be measured using any particle size distribution analyzer based on the generally known laser diffraction method and dynamic light scattering method. For example, it can be measured using a disk centrifugal particle size distribution analyzer (CPSInstruments, (product name) CPSDiscCentrifuge).

[0014] Such vinyl chloride polymer particles can be prepared by copolymerizing vinyl chloride monomer alone or by copolymerizing vinyl chloride monomer with an unsaturated vinyl monomer copolymerizable with vinyl chloride monomer. Any generally known method for producing vinyl chloride polymer particles can be used, and the following is an example of a known method for producing paste vinyl chloride particles.

[0015] Examples include emulsion polymerization, in which vinyl chloride monomer alone or a mixture of vinyl chloride monomers copolymerizable with vinyl chloride monomer and vinyl chloride monomer together with deionized water, a surfactant, and a water-soluble polymerization initiator under gentle stirring; seed emulsion polymerization, in which particles obtained by emulsion polymerization are used as seeds; microsuspension polymerization, in which vinyl chloride monomer alone or a mixture of vinyl chloride monomers copolymerizable with vinyl chloride monomer and vinyl chloride monomer together with deionized water, a surfactant, an emulsifying aid such as a higher alcohol if necessary, and an oil-soluble polymerization initiator are mixed and dispersed in a homogenizer, etc., and then polymerized under gentle stirring; and seed microsuspension polymerization, in which seeds containing an oil-soluble polymerization initiator obtained by microsuspension polymerization are used for polymerization. The unsaturated vinyl monomer used in this case can be any monomer that forms a copolymer with vinyl chloride, and is not particularly limited. Examples include vinyl acetate monomer, styrene monomers such as styrene monomer, α-methylstyrene monomer, hydroxystyrene monomer, and chlorostyrene monomer; acrylonitrile monomers such as acrylonitrile monomer and methacrylonitrile monomer; (meth)acrylic acid ester monomers such as methyl (meth)acrylic acid ester monomer, ethyl (meth)acrylic acid ester monomer, and butyl (meth)acrylic acid ester monomer; (meth)acrylic acid monomer, alkali metal salts of (meth)acrylic acid, (meth)acrylamide, ethylene monomer, propylene monomer, and vinylidene chloride monomer. These unsaturated vinyl monomers may be used alone or in combination of two or more. Examples of commercially available paste vinyl include (product name) Ryuron Paste (manufactured by Tosoh Corporation), (product name) Kane Vinyl Paste (manufactured by Kaneka Corporation), and (product name) ZEST (manufactured by Shin-Daiichi Vinyl Chloride Co., Ltd.).

[0016] The content of the vinyl chloride polymer particles is equivalent to 0.5 to 5.0% by weight in terms of chlorine concentration, and is preferably 0.5 to 3.0% by weight, as this results in a flexible polyurethane foam with excellent handling properties and product appearance. If the content is less than 0.5% by weight, the hardness and flame retardancy of the foam will be reduced. On the other hand, if the content exceeds 5.0% by weight, continuous foaming will be difficult, the hardness will be high, and the foam will not be suitable as a flexible foam.

[0017] The phosphate ester-based flame retardant constituting the flexible polyurethane foam of the present invention is not particularly limited and includes, for example, tris(chloroethyl) phosphate, tris(2-chloropropyl) phosphate, tris(dichloropropyl) phosphate, tetrakis(2-chloroethyl)ethylenediphosphate, 2,2-bis(chloromethyl)-1,3-propanebis(chloroethyl) phosphate, tris(2,3-dibromopropyl) phosphate, tris(tribromoneopentyl) phosphate, 2,2-bis(chloromethyl)trimethylenebis(bis(2-chloroethyl) phosphate), polyoxyalkylene bisdichloroalkyl phosphate, halogenated phosphate phosphonate oligomer ester (manufactured by Daihachi Chemical Industry Co., Ltd., (product names) CR-504L, CR-530, CR-570, CR-509, etc.), trimethyl phosphate, triphenyl phosphate, tricresyl phosphate, cresyldiphenyl phosphate, tri-2 Examples include halogenated phosphate esters or non-halogenated phosphate esters and their oligomers, such as ethylhexyl phosphate, tributyl phosphate, trixylenyl phosphate, triethyl phosphate, trioctyl phosphate, dimethylmethyl phosphate, diethylphenyl phosphate, dimethylphenyl phosphate, resorcinol diphenyl phosphate, ethyl phosphate phosphate oligomers (ICL, (trade name) FR-PNX, etc.), aromatic phosphate oligomer esters (resorcinol bis-diphenyl phosphate, resorcinol bis-dixylenyl phosphate, bisphenol A bis-diphenyl phosphate, Daihachi Chemical Industry Co., Ltd., (trade name) CR-735, etc.), and so-called phosphate-containing polyols having hydroxyl groups in the phosphate compound (Adeka, (trade name) FC-450; ICL, (trade name) Phyrol 6; Clariant, (trade name) OP-550, etc.). Among these, tris(2-chloropropyl) phosphate and halogenated phosphate phosphonate oligomer esters are preferred due to their excellent hydrolysis resistance and processability.

[0018] The content of the phosphate ester flame retardant is an amount corresponding to a phosphorus concentration of 0.1 to 1.5% by weight, and particularly preferably an amount corresponding to a phosphorus concentration of 0.3 to 1.2% by weight because it results in a flexible polyurethane foam having an excellent balance between flame retardancy and compression hardness physical properties. Here, when the amount corresponds to less than 0.1% by weight of phosphorus concentration, the foam will be inferior in flame retardancy. On the other hand, when the amount corresponds to more than 1.5% by weight of phosphorus concentration, the compression hardness physical properties of the foam will decrease due to the plasticizing effect, causing a decrease in the compression hardness and shrinkage of the foam.

[0019] The flexible polyurethane foam of the present invention is particularly excellent as a seat cushion material for vehicles equipped with internal combustion engines such as automobiles and motorcycles. Therefore, it is preferable that the determination based on the FMVSS No. 302 combustion test does not catch fire or is self-extinguishing. Here, self-extinguishing does not simply mean being naturally extinguished, but means being naturally self-extinguished within a combustion distance of 51 mm or less and within 60 seconds.

[0020] The flexible polyurethane foam of the present invention is a flexible foam having an excellent balance between flame retardancy and hardness. Therefore, the apparent density is preferably in the range of 15 to 40 kg / m 3 and particularly preferably 25 to 35 kg / m 3 .

[0021] As a method for producing the flexible polyurethane foam of the present invention, a method known as a method for producing a polyurethane foam can be used. For example, a composition for a polyurethane foam containing an isocyanate component (A), a polyol component (B), a catalyst (C), a blowing agent (D), a flame retardant (E), and in some cases at least a foam stabilizer (F) is prepared, and the isocyanate component (A) and the polyol component (B) are polyadded to form a polyurethane while foaming is carried out by foam molding to obtain a flexible polyurethane foam.

[0022] Examples of the isocyanate component (A) include compounds having at least two isocyanate groups, such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, lysine diisocyanate, triphenylmethane triisocyanate, tetramethylxylylene diisocyanate, 1,6-hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, norbornane diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanatomethyloctane, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, trimethylhexamethylene diisocyanate, isocyanate-containing prepolymers obtained by the reaction of these with polyols, and mixtures of two or more of these. Further, modified products of these isocyanates (modified products containing urethane groups, carbodiimide groups, allophanate groups, urea groups, biuret groups, isocyanurate groups, amide groups, imide groups, uretonimine groups, uretdione groups or oxazolidone groups) and condensates such as polymethylene polyphenylene polyisocyanate (polymeric MDI, sometimes referred to as a polycondensate) can also be mentioned. Among them, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and modified products thereof are particularly preferable because they result in a flexible polyurethane foam having excellent compression hardness.

[0023] The polyol component (B) can be any polyol that forms polyurethane through polyaddition with the isocyanate component (A), and belongs to the category of polyols. Examples include conventionally known polyether polyols, polyester polyols, polycarbonate polyols, polymer polyols, etc. Among these, it is desirable that at least one is selected from the group consisting of polyether polyols and polyester polyols, as this results in a soft polyurethane foam with excellent flexibility and compressive hardness. Furthermore, it is more desirable that the polyol has a number-average molecular weight of 1000 to 10000 and a nominal number of functional groups of 2 or more, as this results in a foam with excellent compressive residual strain, which is an indicator of hardness and durability. Note that the nominal number of functional groups refers to the theoretical average number of functional groups (number of active hydrogen atoms per molecule) assuming that no side reactions occur during the polymerization reaction of the polyol.

[0024] Polyether polyols are not particularly limited, and examples include those produced by an addition reaction between a compound having at least two active hydrogen groups (such as polyhydric alcohols like ethylene glycol, propylene glycol, glycerin, trimethylolpropane, and pentaerythritol; amines like ethylenediamine; and alkanolamines like ethanolamine and diethanolamine) and an alkylene oxide (such as ethylene oxide or propylene oxide) as a starting material (see, for example, the method described in Gunter Oertel, "Polyurethane Handbook" (1985), Hanser Publishers (Germany), pp. 42-53).

[0025] Polyester polyols are not particularly limited and include, for example, those obtained from the reaction of dibasic acids and glycols, such as polyester polyols composed of adipic acid and ethylene glycol, which are polycondensation-type polyester polyols, as well as lactone-based polyester polyols such as polycaprolactone polyol, and polyester polyols derived from processed waste materials from nylon production, trimethylolpropane, pentaerythritol, phthalate-based polyesters, and other waste products (see, for example, Keiji Iwata, "Polyurethane Resin Handbook" (1987), Nikkan Kogyo Shimbun, p. 117).

[0026] The polymer polyol is not particularly limited, and examples include polymer polyols obtained by reacting the polyether polyol with an ethylenically unsaturated monomer (e.g., butadiene, acrylonitrile, styrene, etc.) in the presence of a radical polymerization catalyst.

[0027] Examples of commercially available polyols include Sannix (trade name, manufactured by Sanyo Chemical Industries, Ltd.), Exenol (trade name, manufactured by Asahi Glass Co., Ltd.), Actcol (trade name, manufactured by Mitsui Chemicals Polyurethane Co., Ltd.), and VORANOL (trade name, manufactured by DOW).

[0028] Furthermore, when preparing the flexible polyurethane foam of the present invention, it is preferable to handle the vinyl chloride polymer particles as dispersed in the polyol component (B) because of its excellent handling properties. It may also be a mixture in which a catalyst (C), a blowing agent (D), a flame retardant (E), a foam stabilizer (F), etc., are dispersed.

[0029] Examples of the catalyst (C) include various urethane catalysts, such as triethylamine, tripropylamine, tributylamine, N-methylmolypholine, N-ethylmolypholine, dimethylbenzylamine, N,N,N',N'-tetramethylhexamethylenediamine, N,N,N',N',N''-pentamethyldiethylenetriamine, bis-(2-dimethylaminoethyl) ether, triethylenediamine, 1,8-diazabicyclo[5.4.0]undecene-7, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, and more. Examples of catalysts include these organic salts; organometallic compounds such as stanus octoate and zinc naphthenate; and amine catalysts having active hydrogen such as dimethylethanolamine, N,N-dimethyl-N-hexanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, hydroxymethyltriethylenediamine, and N,N,N'-trimethyl-N'-hydroxyethyl-bisaminoethyl ether. Among these, triethylamine, tripropylamine, tributylamine, and triethylenediamine are preferred because they exhibit excellent reactivity in urethane formation and foaming properties. Furthermore, the amount of catalyst (C) in this case is preferably 0.01 to 10 parts by weight per 100 parts by weight of polyol component (B) because this allows for the efficient production of a flexible polyurethane foam with excellent foaming properties.

[0030] As the blowing agent (D), various known blowing agents can be used, and among them, water can be used as a blowing agent for polyurethane foam because it generates carbon dioxide gas through reaction with isocyanate groups, and this carbon dioxide gas enables carbon dioxide foaming. In addition, any blowing agent may be used in addition to water, for example, low boiling point organic compounds such as cyclopentane and isopentane. Furthermore, foaming can be achieved by mixing and dissolving air, nitrogen gas, or liquefied carbon dioxide into the stock solution using a gas loading device. When using water as the blowing agent (D), the amount is preferably 0.5 to 10 parts by weight per 100 parts by weight of polyol component (B), more preferably 4.0 to 8.0 parts by weight, and more preferably 5.0 to 8.0 parts by weight, as this makes it easy to stably provide a foam with a low apparent density.

[0031] Furthermore, the above-mentioned vinyl chloride polymer particles and phosphate ester flame retardant are used as the flame retardant (F), and other flame retardants may be used in combination if necessary. In this case, the amount of vinyl chloride polymer particles is preferably 1 to 10 parts by weight per 100 parts by weight of polyol component (B) because a soft polyurethane foam with excellent flame retardancy, foamability, and flexibility can be efficiently obtained. In addition, the amount of phosphate ester flame retardant is preferably 3 to 25 parts by weight per 100 parts by weight of polyol component (B) because a soft polyurethane foam with excellent flame retardancy, foamability, and flexibility can be efficiently obtained.

[0032] In some cases, a foam stabilizer (F) may be used, and a conventional surfactant is used, with organosilicon-based surfactants being particularly suitable. Examples include (product names) SRX-280A, SZ-1327, SZ-1325, SZ-1336, SZ-3601 (manufactured by Toray Dow Corning); (product names) Y-10366, L-5309 (manufactured by Momentive Corporation); (product names) B-8724LF2, B-8715LF2 (manufactured by Evonik Corporation); (product name) F-122 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these foam stabilizers (F) is preferably 0.1 to 3 parts by weight per 100 parts by weight of the polyol component (B).

[0033] Furthermore, anti-settling agents and, if necessary, various known additives such as anti-foaming agents, antioxidants, UV absorbers, plasticizers, pigments / dyes, antibacterial / antifungal agents can be used.

[0034] When preparing the composition for flexible polyurethane foam, the ratio of isocyanate component (A) to polyol component (B) is preferably 0.7 to 1.4 (isocyanate index (NCOINDEX) = 70 to 140) as the molar ratio (NCO / active hydrogen) of all isocyanate groups to all active hydrogen groups including water, in order to efficiently obtain a flexible foam with interconnected air bubbles. A more preferable ratio is 0.7 to 1.2 (NCOINDEX = 70 to 120) as it provides a good range for foam durability and molding cycles.

[0035] The present invention provides a method for producing flexible polyurethane foam, which involves subjecting the flexible polyurethane foam composition to known foaming methods such as slab foaming, injection mold foaming, spray foaming, and continuous production panel foaming. It can be used in a variety of general applications, such as insulation and structural materials in buildings and civil engineering; insulation for freezers, refrigerators, and refrigerated display cases in electrical equipment; insulation for LPG and LNG tankers and pipelines in plants and ships; insulation for refrigerated storage and refrigerated trucks in vehicles; and also for bedding, seats in automobiles, cushioning materials, sound-absorbing materials, vibration-damping materials, and construction flooring materials. In particular, it is used for bedding, seats in automobiles, and cushioning materials. [Effects of the Invention]

[0036] The present invention, in particular, contains vinyl chloride polymer particles and a phosphate-based ester flame retardant, resulting in a soft polyurethane foam with an excellent balance of flame retardancy and compressive hardness, which can be used in applications such as bedding, automobile seats, and cushioning materials. [Examples]

[0037] The present invention will be described in more detail by reference to examples, but the present invention is not limited in any way by these examples.

[0038] <Effervescence Evaluation> The foaming properties of the flexible polyurethane foam obtained in the examples were evaluated by visual observation. The evaluation criteria were as follows: ○; The polyurethane foam has not shrunk and there are no cracks inside. ×; A condition in which shrinkage or internal cracks have occurred in the polyurethane foam.

[0039] <Apparent density of forms> The flexible polyurethane foam obtained in the example was stored for one day, and then the core portion was cut to dimensions of 100 mm x 100 mm x 50 mm. The dimensions and weight were measured, and the apparent density was determined.

[0040] <Evaluation of dimensional stability> The flexible polyurethane foam obtained in the example was stored for one day, and then the core portion was cut into a rectangular parallelepiped measuring 50 (length) x 50 (width) x 30 (thickness) mm. The dimensions (T1) in each direction (length, width, and thickness) were measured, and the dimensions (T2) in each direction were measured after 20 hours under high temperature conditions (70°C). The dimensional change (T2-T1) was measured. The evaluation criteria were as follows. ○; 3.5% or less in both directions. ×; There is a 3.5% or greater chance of this happening.

[0041] <Evaluation of flame retardancy> The flexible polyurethane foam obtained in the examples was stored for one day, and then a 100 x 200 x 10 mm sample was cut out. The flame retardancy was measured according to the FMVSS No. 302 combustion test.

[0042] The evaluation criteria were as follows: ○; The test piece does not ignite, or it self-extinguishes within a burning distance of 51 mm or less and within 60 seconds. ×; Burning distance exceeds 51 mm, or burns for more than 60 seconds.

[0043] <25% Compression Hardness> The 25% compression hardness was measured using the flexible polyurethane foam obtained in the examples, in accordance with JIS K6400-2 Method D.

[0044] The following raw materials were used in the examples and comparative examples, respectively. Polyol A: Polyether polyol (manufactured by Sanyo Chemical Industries, Ltd., (product name) GP-3050V: 3 functional groups, hydroxyl value 56.4 mgKOH / g). Flame retardant A: Vinyl chloride polymer particles (manufactured by Tosoh Corporation, product name: Ryuron Paste 860). Flame retardant B: Halogen-containing condensed phosphate ester (manufactured by Daihachi Chemical Industry Co., Ltd., (product name) CR-504L: phosphorus concentration 10.8 wt%). Foaming agent A: Water. Foam stabilizer A: Silicone-based surfactant (manufactured by Toray Dow Corning, product name SRX280A). Catalyst A: Dipropylene glycol solution of triethylenediamine (manufactured by Tosoh Corporation, product name TEDA-L33). Catalyst B: Stannous octanoate (manufactured by EVONIK, product name DABCOT-9). Isocyanate: Tolylene diisocyanate (manufactured by Tosoh Corporation, product name Coronate T-80, NCO content = 48.2%).

[0045] Example 1 At room temperature (20-25°C), a polyol composition was prepared by mixing 100 parts by weight of polyol A with 0.24 parts by weight of catalyst A, 0.23 parts by weight of catalyst B, 1 part by weight of foam stabilizer A, 4.1 parts by weight of blowing agent A, 2.5 parts by weight of flame retardant A, and 18.5 parts by weight of flame retardant B, and the mixture was heated to 20°C. Then, 48.7 parts by weight of isocyanate heated to 20°C was added to 100 parts by weight of polyol A, and the mixture was stirred at a stirring speed of 3500 rpm for 10 seconds to obtain a composition for flexible polyurethane foam.

[0046] A composition for flexible polyurethane foam was poured into a 240 x 240 x 240 mm open-top container, and free foaming was performed to obtain a flexible polyurethane foam with interconnected air bubbles.

[0047] Table 1 shows the evaluation results for the flexible polyurethane foam. In all cases, the compression hardness, dimensional stability, and flame retardancy were good.

[0048] Examples 2-4 A flexible polyurethane foam was manufactured and evaluated using the same method as in Example 1, except that the blending ratio of the composition for the flexible polyurethane foam was as shown in Table 1.

[0049] Table 1 shows the evaluation results for the flexible polyurethane foam. In all cases, the compression hardness, dimensional stability, and flame retardancy were good.

[0050] Comparative Examples 1-3 Polyurethane foam was manufactured and evaluated using the same method as in Example 1, except that the blending ratio of the polyurethane foam composition was as shown in Table 1.

[0051] The evaluation results for urethane foam are shown in Table 1.

[0052] Polyurethane foam was manufactured and evaluated using the same method as in Example 1, except that the blending ratio of the polyurethane foam composition was as shown in Table 1.

[0053] The evaluation results for urethane foam are shown in Table 1.

[0054] The polyurethane foam of Comparative Example 1 lacked self-extinguishing properties and had poor flame retardancy. The polyurethane foam of Comparative Example 2 had a low amount of vinyl chloride polymer particles and had poor compression hardness and dimensional stability. The polyurethane foam obtained by Comparative Example 3 had a low amount of phosphate ester flame retardant and burned for more than 60 seconds, exhibiting poor flame retardancy.

[0055] [Table 1] [Industrial applicability]

[0056] This invention provides a flexible polyurethane foam with excellent compressive hardness and flame retardancy, and this flexible polyurethane foam is expected to be suitable for use in the polyurethane resin manufacturing industry and as a product thereof.

Claims

1. It contains vinyl chloride polymer particles equivalent to at least 0.5 to 5.0% by weight of chlorine and a phosphate ester flame retardant equivalent to 0.1 to 1.5% by weight of phosphorus, and has a 25% compression hardness of 105 to 250 N / 314 cm in accordance with JIS K6400-2 D method. ２ A flexible polyurethane foam characterized by a interconnected cell structure.

2. The flexible polyurethane foam according to claim 1, characterized in that the vinyl chloride polymer particles are vinyl chloride polymer particles having a volume average particle diameter of 0.1 to 10 μm.

3. The flexible polyurethane foam according to claim 1 or 2, characterized in that the result, in accordance with the FMVSS No. 302 combustion test, is that it does not ignite or self-extinguishes.

4. Apparent density is 15-40 kg / m³ ３ The flexible polyurethane foam according to claim 1 or 2, characterized in that it is the same as the one described above.

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