JP6125451B2 - Method for producing flexible polyurethane foam - Google Patents

Description

  The present invention relates to a flexible polyurethane foam.

  Flexible polyurethane foams are widely used for furniture and bedding mattresses, automotive seat cushions, clothing, and the like. Residual toluenediamine (hereinafter abbreviated as TDA) in urethane foam, especially for furniture, bedding mattresses and clothing. ) The amount is an important item, and CertiPUR, which is an international standard set by EURO PUR (European PU slab foam industry), has 2,4-TDA content of 5 ppm or less as an environmentally friendly grade.

In recent years, there has been a demand for lowering the density of flexible polyurethane foam for weight reduction.
In order to meet the demand for reducing the amount of residual TDA, there are a method of setting the isocyanate index to 100 or more (for example, see Patent Document 1) and a method of using a polyether polyol having a high oxyethylene ratio (for example, see Patent Document 2). However, in such a method, there is a problem that the mechanical properties such as durability and elongation and tensile strength of the flexible polyurethane foam are insufficient, and the foam density is high, and the durability is excellent even at a low density. A flexible polyurethane foam having a low TDA content capable of maintaining mechanical properties is desired.

JP 2010-6992 A JP 2012-167221 A

  An object of the present invention is to provide a low-density flexible polyurethane foam having excellent mechanical properties and low residual TDA content.

As a result of intensive studies to solve the above problems, the present inventors have reached the invention shown below. That is, the present invention comprises a polyol (composition) (A) [hereinafter referred to as a polyol composition (A)] and an organic polyisocyanate component (B), a foaming agent (C), a urethanization catalyst (D), and a foam stabilizer. A process for producing a flexible polyurethane foam obtained by reacting in the presence of an agent (E), wherein the total amount of 2,4-toluenediamine and 2,6-toluenediamine contained in the foam is 10 ppm or less, The density kg / m3 is 10 to 40, and the content of 2,4- or 2,6-tolylene diisocyanate based on the total weight of (B) in the organic polyisocyanate component (B) is 20 to 100. percent by weight, the polyol (composition) (a) is contained polyether polyol alkylene oxide to an active hydrogen-containing compound is formed by adding the following (1) to ( ) Is a method for producing a flexible polyurethane foam to meet the.
(1) The primary hydroxyl group ratio of the terminal hydroxyl group of (A) is 40 to 90%;
(2) The content of ethylene oxide units is 8% by weight or less based on the weight of (A);
(3) The hydroxyl value of (A) is 20 to 290 mgKOH / g.
(4) The isocyanate index is 80-100.

  The flexible polyurethane foam of the present invention exhibits excellent mechanical properties even when the density is low, and the amount of residual TDA is small.

  The flexible polyurethane foam of the present invention is obtained by reacting a polyol composition (A) and an organic polyisocyanate (B) in the presence of a foaming agent (C), a urethanization catalyst (D) and a foam stabilizer (E). It is done.

  The polyol composition (A) in the present invention preferably comprises a polyether polyol, and a 1,2-alkylene oxide having 3 or more carbon atoms (hereinafter, alkylene oxide is abbreviated as AO) is essential for the active hydrogen-containing compound. Polyether polyol (P-1) formed by adding AO that does not contain ethylene oxide (hereinafter abbreviated as EO), an active hydrogen-containing compound and 1,2-AO having 3 or more carbon atoms as an essential component A polyether polyol (P-2) in which EO is added to a block containing EO-free AO, and 1,2-AO having 3 or more carbon atoms and EO are essential for the active hydrogen-containing compound Polyether polyol (P-3) in which EO is block-added to a random addition of AO contained as a component, activity A compound containing 1,2-AO having 3 or more carbon atoms as an essential component in an element-containing compound, and 1,2-AO and EO having 3 or more carbon atoms as essential components in addition to AO not containing EO Polyether polyol (P-4) in which AO is randomly added and polyether polyol in which AO containing 1,2-AO having 3 or more carbon atoms and EO as essential components is added to an active hydrogen-containing compound ( More preferably, it contains at least one polyether polyol (P) selected from the group consisting of P-5).

  As the active hydrogen-containing compound, a compound having two or more active hydrogen-containing functional groups (hydroxyl group, amino group, carboxyl group, thiol group, phosphate group, etc.) in the molecule, such as a hydroxyl group-containing compound, an amino group-containing compound, Examples include thiol group-containing compounds, phosphoric acid compounds, and mixtures of two or more thereof.

Examples of the hydroxyl group-containing compound include water, divalent to octavalent polyhydric alcohols and polyhydric phenols. Specifically, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, 1,4-bis (hydroxymethyl) cyclohexane and 1,4-bis (hydroxyethyl) Dihydric alcohols such as benzene; trihydric alcohols such as glycerin and trimethylolpropane; 4- to 8-hydric alcohols such as pentaerythritol, sorbitol and sucrose; polyhydric phenols such as pyrogallol, catechol and hydroquinone; bisphenol A, bisphenol F And bisphenols such as bisphenol S; polybutadiene polyols; castor oil-based polyols; (co) polymers of hydroxyalkyl (meth) acrylates and polyfunctional (eg, functional groups) such as polyvinyl alcohol 2 to 100) a polyol, and the like.
(Meth) acrylate means methacrylate and / or acrylate, and the same applies hereinafter.

  Examples of the amino group-containing compound include amines, polyamines, amino alcohols and the like. Specifically, ammonia; monoamines such as C1-C20 alkylamine (butylamine and the like) and aniline; aliphatic polyamines such as ethylenediamine, hexamethylenediamine and diethylenetriamine; heterocyclics such as piperazine and N-aminoethylpiperazine Polyamines; alicyclic polyamines such as dicyclohexylmethanediamine and isophoronediamine; aromatic polyamines such as phenylenediamine, tolylenediamine and diphenylmethanediamine; alkanolamines such as monoethanolamine, diethanolamine and triethanolamine; dicarboxylic acids and excess polyamines Polyamines obtained by condensation with polyamines; polyether polyamines; hydrazines (such as hydrazine and monoalkylhydrazines), dihydrazides ( Etc. Haq acid dihydrazide and dihydrazide terephthalate), guanidine (butyl guanidine and 1-cyanoguanidine, etc.); dicyandiamide; and mixtures of two or more thereof.

  Examples of the carboxyl group-containing compound include aliphatic polycarboxylic acids such as succinic acid and adipic acid; aromatic polycarboxylic acids such as phthalic acid and trimellitic acid; carboxylic acid polymers such as (co) polymers of acrylic acid (functional Base number 2-100) etc. are mentioned.

Examples of the thiol group-containing compound include polythiol compounds, and examples include divalent to octavalent polyvalent thiols. Specific examples include ethanedithiol and 1,6-hexanedithiol.
Examples of phosphoric acid compounds include phosphoric acid, phosphorous acid, and phosphonic acid.

  Among these active hydrogen-containing compounds, from the viewpoint of mechanical properties of the obtained polyurethane foam, a hydroxyl group-containing compound and an amino group-containing compound are preferable, and water, alcohol, and amine are more preferable.

  Examples of AO added to the active hydrogen-containing compound include EO, 1,2-AO {1,2-propylene oxide (hereinafter abbreviated as PO), 1,2-butylene oxide and styrene oxide} having 3 or more carbon atoms. 2 or more may be used in combination. Of these, PO, EO, and 1,2-butylene oxide are preferable from the viewpoints of properties and reactivity. When two or more types of AO are used (for example, PO and EO), block addition or random addition may be used, or a combination thereof may be used.

  In (P-1) to (P-5), AO other than 1,2-AO and EO can be used as an alkylene oxide as an optional component. As AO other than 1,2-AO and EO, those having 4 to 8 carbon atoms are preferable, and examples thereof include 1,3-, 1,4- or 2,3-butylene oxide. Good. The amount of AO other than 1,2-AO and EO is preferably 10% by weight or less, more preferably 5% by weight or less in the total AO, and 0% by weight, that is, the total AO is derived from only the essential component AO. It is particularly preferred that

  As 1,2-AO having 3 or more carbon atoms used in (P-1) to (P-5), PO and 1,2-butylene oxide are preferable from the viewpoint of properties and reactivity, and more preferable is PO. It is.

The content of 1,2-AO having 3 or more carbon atoms used in (P-1) to (P-5) is preferably 10% by weight or more from the viewpoint of properties and reactivity based on the total weight of AO. More preferably, it is 50% by weight or more.
The content of EO in (P-1) to (P-5) is preferably 10% by weight or less, more preferably 8% by weight or less, particularly preferably 8% by weight or less from the viewpoint of properties and reactivity, based on the total weight of AO. Is 0.1 to 8% by weight.

  In the present invention, the average added mole number of EO per active hydrogen of the polyether polyol (P) is preferably 20 or less, more preferably 19 or less, particularly preferably 18 or less, particularly preferably 10 or less, most preferably. 9 or less. When the average added mole number of EO is from 0 to 20, mechanical properties such as wet heat compression residual strain of urethane foam are good.

  The primary hydroxyl group ratio of the terminal hydroxyl group of (P) (that is, the ratio of the hydroxyl group bonded to the primary carbon in the hydroxyl group located at the terminal) (%) is from the viewpoint of TDA reduction, cell shape and mechanical property improvement, 40-100 are preferable, More preferably, it is 50-90, Most preferably, it is 60-85, Most preferably, it is 65-80.

In the present invention, the primary hydroxyl group ratio of the terminal hydroxyl group is calculated by measuring by ¹ H-NMR method after esterifying the sample in advance.

The method for measuring the primary hydroxyl group ratio will be specifically described below.
<Sample preparation method>
About 30 mg of a measurement sample is weighed into an NMR sample tube having a diameter of 5 mm, and about 0.5 ml of deuterated solvent is added and dissolved. Thereafter, about 0.1 ml of trifluoroacetic anhydride is added to obtain a sample for analysis. Examples of the deuterated solvent include deuterated chloroform, deuterated toluene, deuterated dimethyl sulfoxide, and deuterated dimethylformamide, and a solvent that can dissolve the sample is appropriately selected.
<NMR measurement>
¹ H-NMR measurement is performed under normal conditions.

<Calculation method of primary hydroxyl group ratio>
By the pretreatment method described above, the terminal hydroxyl group of the polyether polyol reacts with the added trifluoroacetic anhydride to become a trifluoroacetic acid ester. As a result, a signal derived from a methylene group bonded with a primary hydroxyl group was observed at around 4.3 ppm, and a signal derived from a methine group bonded to a secondary hydroxyl group was observed at around 5.2 ppm (deuterated chloroform was used as a solvent). Used as). The primary hydroxyl group ratio is calculated by the following formula.
Primary hydroxyl group ratio (%) = [a / (a + 2 × b)] × 100
In the formula, a is an integral value of a signal derived from a methylene group to which a primary hydroxyl group is bonded in the vicinity of 4.3 ppm; b is an integrated value of a signal derived from a methine group to which a secondary hydroxyl group is bonded in the vicinity of 5.2 ppm. .

  The number average functional group number of (P) is preferably from 2 to 8, more preferably from 2.3 to 7.8, particularly preferably from 2.5 to 7.6, from the viewpoints of improvement in mechanical properties and handling properties. .

The number average molecular weight / number average functional group number of (P) is preferably from 500 to 3000, more preferably from 550 to 2800, and particularly preferably from 600 to 2500 from the viewpoint of improvement in tensile strength and mechanical properties.
The number average molecular weight is determined by GPC (gel permeation chromatography). The detector is a differential refractometer (RI), the flow rate is 0.6 ml / min, the sample concentration is 0.25 mg / ml, the eluent is tetrahydrofuran, and the standard substance is polystyrene.
Further, the number average functional group number is calculated from the amount of each polyol used, assuming that it is the same as the average functional group number of the active hydrogen-containing compound used in producing the average functional group number of each polyol.

The hydroxyl value (mgKOH / g) of (P) is preferably 20 to 170, more preferably 25 to 120, from the viewpoint of the viscosity of the polyether polyol and the elongation at break of the polyurethane foam.
In addition, the hydroxyl value in this invention is calculated | required by JISK-1557-1.

  Examples of the method for obtaining the polyether polyol (P) in the present invention include a method of adding AO to the active hydrogen-containing compound in the presence of a specific catalyst (α). (Α) is used when adding AO that generates a hydroxyl group bonded to a secondary carbon when added in the presence of other commonly used catalysts described later such as 1,2-AO having 3 or more carbon atoms, It is not always necessary to use it in all stages, and after adding a part of AO in the presence of other commonly used catalysts described later, the remaining AO may be added using (α) only in the later stage of the addition reaction. Good.

Examples of (α) include those described in JP-A No. 2000-344881, specifically, boron or aluminum compounds to which fluorine atoms, (substituted) phenyl groups and / or tertiary alkyl groups are bonded. , Triphenylborane, diphenyl-t-butylborane, tri (t-butyl) borane, triphenylaluminum, diphenyl-t-butylaluminum, tri (t-butyl) aluminum, tris (pentafluorophenyl) borane, bis (pentafluoro) Phenyl) -t-butylborane, tris (pentafluorophenyl) aluminum, bis (pentafluorophenyl) -t-butylaluminum and the like.
Among these, triphenylborane, triphenylaluminum, tris (pentafluorophenyl) borane, and tris (pentafluorophenyl) aluminum are preferable, and tris (pentafluorophenyl) borane and tris (pentafluorophenyl) aluminum are more preferable. It is.

  The addition conditions of AO may be the same as the method described in the above publication. For example, 0.0001 to 10% by weight is preferable with respect to the ring-opened polymer to be formed, and 0.001 to 1% by weight of the above is more preferable. The reaction is performed using a catalyst, preferably at 0 to 250 ° C, more preferably at 20 to 180 ° C.

  In (P-2) and (P-3), EO is further added to a 1,2-AO adduct having 3 or more carbon atoms and a random adduct of 1,2-AO and EO having 3 or more carbon atoms. A polyether polyol having a high primary hydroxylation rate can be obtained. A 1,2-AO adduct having 3 or more carbon atoms and a random adduct of 1,2-AO and EO having 3 or more carbon atoms in the catalyst (α), that is, a primary hydroxyl group of a terminal hydroxyl group before EO addition. Since the hydroxylation rate is as high as 40% or more, preferably 60% or more, more preferably 70% or more, the primary hydroxyl group ratio of the terminal hydroxyl group can be increased with a small amount of EO used.

The catalyst used for the block addition of EO may use the above boron or aluminum compound as it is, or may use another catalyst that is usually used instead.
Other catalysts include basic catalysts such as sodium hydroxide, potassium hydroxide, cesium hydroxide, potassium carbonate and triethylenediamine; acid catalysts such as boron trifluoride, tin chloride, triethylaluminum and heteropolyacid; zinc hexacyano Cobaltate; phosphazene compounds and the like. Of these, basic catalysts are preferred. Although the usage-amount of a catalyst is not specifically limited, 0.0001-10 weight% is preferable with respect to the polymer to produce | generate, More preferably, it is 0.001-1 weight%.

The polyol composition (A) of the present invention preferably satisfies the following (1) to (3).
(1) The primary hydroxyl group ratio of the terminal hydroxyl group of (A) is 40 to 90%.
(2) The content of EO units is 10% by weight or less based on the total weight of (A).
(3) The hydroxyl value of (A) is 20-290 mgKOH / g.

The primary hydroxyl group ratio of the polyol composition (A) in the present invention is preferably 40 to 90%, more preferably 42 to 85%, from the viewpoints of TDA reduction, urethane foam cell shape, mechanical properties and durability improvement. Especially preferably, it is 45 to 80%.
The primary hydroxyl group ratio can be determined by the method described above.

  The content of the EO unit based on the total weight of the polyol composition (A) is preferably 10% by weight or less, more preferably 8% by weight or less, particularly preferably from the viewpoint of improving the mechanical properties and durability of the urethane foam. Is 6% by weight or less.

  The hydroxyl value (mgKOH / g) of the polyol composition (A) is preferably 20 to 290, more preferably 22 to 170, and particularly preferably 25 to 120, from the viewpoint of the viscosity of the polyol and the elongation at break of the polyurethane foam. .

  The number average functional group number of the polyol composition (A) is preferably 2.5 to 5.0, more preferably 2.7 to 4.5, and particularly preferably 2.8 from the viewpoint of improvement in durability and handleability. ~ 4.0.

The inclusion of (P) in the polyol composition (A) includes the use of a polymer polyol obtained by polymerizing the vinyl monomer (g) in (P).
The polymer polyol is a polymer polyol in which polymer particles are dispersed in (P), and can be produced by polymerizing the vinyl monomer (g) in (P) by a known method. For example, in (P), (g) is polymerized in the presence of a radical polymerization initiator, and the obtained polymer (g) is stably dispersed. Specific examples of the polymerization method include those described in US Pat. No. 3,383,351 and Japanese Examined Patent Publication No. 39-25737.
(G) preferably contains styrene and / or acrylonitrile.

  In the present invention, the polyol composition (A) may contain other active hydrogen components in addition to the polyol (P). For example, polyether polyols, polyester polyols, and other polyols other than (P) , Monools, polyhydric alcohols, amines and mixtures thereof.

Examples of polyether polyols other than (P) include AO adducts of active hydrogen-containing compounds, other than (P).
Examples of the polyester polyol include the following (1) to (5).
(1) Esters of polyhydric alcohols and polycarboxylic acids or ester-forming derivatives thereof As polyhydric alcohols, dihydric alcohols (ethylene glycol, diethylene glycol, propylene glycol, 1,3- or 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, etc.), polyether polyols (preferably diols), and mixtures thereof with trihydric or higher polyhydric alcohols (glycerin, trimethylolpropane, etc.). Examples of acids or ester-forming derivatives thereof [acid anhydrides and lower alkyl (alkyl group having 1 to 4 carbon atoms) esters] include adipic acid, sebacic acid, maleic anhydride, phthalic anhydride, and dimethyl terephthalate. Can be mentioned.
(2) Active hydrogen-containing compound or AO adduct of active hydrogen-containing compound and reaction product of carboxylic anhydride and AO (3) AO (EO and PO etc.) adduct of (1) above (4) Polylactone Polyol [For example, obtained by ring-opening polymerization of a lactone (e.g., ε-caprolactone) using a polyhydric alcohol as an initiator]
(5) Polycarbonate polyol [for example, reaction product of polyhydric alcohol and alkylene carbonate]

Other polyols and monools include polydiene polyols such as polybutadiene polyol and hydrogenated products thereof; acrylic polyols, hydroxyl groups described in JP-A-58-57413 and JP-A-58-57414, etc. -Containing vinyl polymer; natural fat-based polyol such as castor oil; modified natural fat-based polyol such as castor oil-modified product (for example, polyhydric alcohol transesterification product, hydrogenated product); International Publication WO 98/44016 Described terminal hydrogen radical functional group-containing active hydrogen compound (including monools); modified polyol obtained by jumping polyether polyol with alkylene dihalide such as methylene dihalide; OH-terminated prepolymer of polyether polyol; etc. Is mentioned.
Examples of the polyhydric alcohol and amine include those described above.

  Among these other active hydrogen components, polyether polyol is preferable from the viewpoint of improving mechanical properties.

  In the present invention, the content (% by weight) of the polyol (P) is preferably 10 to 100, more preferably 20 to 100, from the viewpoint of cell shape and mechanical properties, based on the weight of the polyol composition (A). Especially preferably, it is 40-100.

  As the organic polyisocyanate component (B) in the present invention, those conventionally used in the production of polyurethane can be used. Examples of such isocyanates include aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, and modified products thereof (for example, urethane groups, carbodiimide groups, allophanate groups, urea groups, burettes). Group, an isocyanurate group, or an oxazolidone group-containing modified product) and a mixture of two or more thereof.

As aromatic polyisocyanate, C6-C16 aromatic diisocyanate, C6-C20 aromatic triisocyanate, and crude products of these isocyanates (excluding carbon in the NCO group; the following isocyanates are also the same), etc. Is mentioned. Specific examples include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4′- or 4,4′-diphenylmethane diisocyanate ( MDI) and polymethylene polyphenyl isocyanate (crude MDI).
Examples of the aliphatic polyisocyanate include aliphatic diisocyanates having 6 to 10 carbon atoms. Specific examples include 1,6-hexamethylene diisocyanate and lysine diisocyanate.

Examples of the alicyclic polyisocyanate include alicyclic diisocyanates having 6 to 16 carbon atoms. Specific examples include isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate, and norbornane diisocyanate.
Examples of the araliphatic polyisocyanate include araliphatic diisocyanates having 8 to 12 carbon atoms. Specific examples include xylylene diisocyanate and α, α, α ′, α′-tetramethylxylylene diisocyanate.
Specific examples of the modified polyisocyanate include urethane-modified MDI and carbodiimide-modified MDI.

Of these, TDI, crude TDI, MDI, crude MDI and modified products of these isocyanates are preferred from the viewpoint of mechanical properties and reactivity, and TDI, MDI and a mixture of TDI and MDI are more preferred. Particularly preferred is TDI.
The content of TDI in the organic polyisocyanate (B) is preferably 20 to 100% by weight, more preferably 30 to 100% by weight, particularly preferably from the viewpoint of mechanical properties and reactivity, based on the total weight of (B). Is 40 to 100% by weight.

As the foaming agent (C) in the present invention, water and liquefied carbon dioxide gas are preferable from the viewpoint of improving mechanical properties.
The amount of water used is preferably from 1 to 8 parts by weight, more preferably from 2.5 to 6.5 parts by weight, based on 100 parts by weight of the polyol composition (A), from the viewpoint of the calorific value and the expansion ratio.
The amount of liquefied carbon dioxide used is preferably 30 parts by weight or less, more preferably 25 parts by weight or less, per 100 parts by weight of the polyol composition (A) from the viewpoint of the calorific value and the expansion ratio.
Moreover, as a foaming agent (C), you may use together a hydrogen atom containing halogenated hydrocarbon, a low boiling point hydrocarbon, etc.

Specific examples of the hydrogen atom-containing halogenated hydrocarbon-based blowing agent include dichloromethane, HCFC (hydrochlorofluorocarbon) (HCFC-123, HCFC-141b, HCFC-22, HCFC-142b, etc.); HFC (hydrofluorocarbon) (for example, HFC-134a, HFC-152a, HFC-356mff, HFC-236ea, HFC-245ca, HFC-245fa, and HFC-365mfc).
Among these, HCFC-141b, HFC-134a, HFC-356mff, HFC-236ea, HFC-245ca, HFC-245fa and HFC-365mfc, and mixtures of two or more of these are preferred.
Among these, dichloromethane is preferable from the viewpoint of the calorific value and the expansion ratio.
The amount of hydrogen atom-containing halogenated hydrocarbon used as the blowing agent (C) is preferably 50 parts by weight or less, more preferably 5 to 45 parts by weight per 100 parts by weight of the polyol composition (A).

The low boiling point hydrocarbon is a hydrocarbon having a boiling point of −5 to 70 ° C., and specific examples thereof include butane, pentane, cyclopentane, and mixtures thereof.
The amount of low boiling point hydrocarbon used as the blowing agent (C) is preferably 30 parts by weight or less, more preferably 25 parts by weight or less per 100 parts by weight of the polyol composition (A).

As the urethanization catalyst (D), all usual catalysts for accelerating the urethanation reaction can be used. Tertiary amine {triethylenediamine, bis (N, N-dimethylamino-2-ethyl) ether and N, N, N ′, N′-tetramethylhexamethylenediamine, etc.}, tertiary amine carboxylates, carboxylic acid metal salts (potassium acetate, potassium octylate, stannous octoate, etc.) and organometallic compounds (stannous octylate) Stannic laurate, etc.).
The amount of the urethanization catalyst (D) used is preferably 0.01 to 1.5 parts by weight, more preferably 0.8 parts per 100 parts by weight of the total value of the polyol composition (A) and the organic polyisocyanate (B). 1 to 1.2 parts by weight.

As the foam stabilizer (E), all those used for the production of polyurethane foam can be used, and examples thereof include a silicone foam stabilizer.
Examples of silicone foam stabilizers include polyether-modified dimethylsiloxane foam stabilizers (“SZ-1346” and “SF-2962” manufactured by Toray Dow Corning Co., Ltd.) and “L-” manufactured by Momentive Performance Materials. 540 "etc.], dimethylsiloxane-based foam stabilizer [" SRX-253 "etc. manufactured by Toray Dow Corning Co., Ltd.] and the like.
The amount of the foam stabilizer used is preferably 0.3 to 3.0 parts by weight, more preferably 0.6 to 2 parts by weight with respect to a total of 100 parts by weight of the polyol composition (A) and the organic polyisocyanate (B). 5 parts by weight.

In the present invention, a crosslinking agent (K) can be used as necessary. Examples of the crosslinking agent (K) include amines such as monoethanolamine, diethanolamine, and triethanolamine, polyhydric alcohols such as ethylene glycol, glycerin, pentaerythritol, and sorbitol, and AO adducts using these as starting materials. . Of these, amines are preferable from the viewpoint of moldability and hardness of polyurethane foam, and diethanolamine is particularly preferable.
The amount of the crosslinking agent (K) used is preferably 0.1 to 4% by weight, more preferably 0.2 to 3% by weight, based on the total weight of the polyol composition (A) and the organic polyisocyanate (B). is there.

In the present invention, if necessary, a known auxiliary component such as a colorant, a flame retardant, an anti-aging agent and an antioxidant may be used and reacted in the presence thereof. Colorants include dyes and pigments. Examples of the flame retardant include phosphate esters and halogenated phosphate esters. Examples of the antiaging agent include triazole type and benzophenone type antiaging agents. Examples of the antioxidant include hindered phenol-based and hindered amine-based antioxidants.
The amount of these auxiliary components used is preferably 1 part by weight or less for the colorant, preferably 20 parts by weight or less, and more preferably 10 parts by weight or less for the colorant to 100 parts by weight of the polyol composition (A). The antioxidant is preferably 1 part by weight or less, more preferably 0.5 part by weight or less, and the antioxidant is preferably 1 part by weight or less, more preferably 0.01 to 0.5 part by weight. .

In the present invention, the isocyanate index [ratio of the equivalent of isocyanate group in (B) to equivalent of active hydrogen atom-containing group in (A) × 100] in the production of flexible polyurethane foam is the durability of the flexible polyurethane foam and 80-100 are preferable from a viewpoint of residual TDA reduction, More preferably, it is 85-100, Most preferably, it is 90-100.
The active hydrogen atom-containing group includes those derived from water as a foaming agent.

The core density (kg / m ³ ) of the flexible urethane foam in the present invention is usually 10 to 40, preferably 15 to 40, more preferably 20 from the viewpoints of weight reduction, durability, and residual TDA reduction of the flexible polyurethane foam. ~ 40.
The foam core density is measured by a method based on JIS K6400.

The total amount of 2,4-TDA and 2,6-TDA contained in the flexible polyurethane foam in the present invention is usually 10 ppm or less, preferably 5 ppm or less, more preferably from the viewpoint of influence on the environment and the human body. 1 ppm or less.
The residual TDA content in the foam is measured by a method based on EURO PUR (CertiPUR).

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited by this.

Examples 1-8 and Comparative Examples 1-7
In accordance with the formulation shown in Table 1 and Table 2, foamed under the following foaming conditions to produce a flexible polyurethane foam, the core density of the foam after standing for 24 hours at a settling rate of 25 ° C. and 50% humidity ( kg / m ³ ), air permeability (ml / cm ² / sec), foam hardness (25% ILD, N / 314 cm ² ), tensile strength (N / cm ² ), tear strength (N / cm), cut elongation (%), Compression residual strain (%), residual TDA content (ppm) and ΔYI were measured based on the following measurement methods. The results are shown in Tables 1 and 2. In addition, the numerical value of raw materials other than TDI in the compounding recipes of Tables 1 and 2 means parts by weight, and TDI was used in an amount that gives the isocyanate index shown in the compounding recipes.

(Foaming conditions)
Mold size: 250mm x 250mm x 250mm
Material: Wood Mixing method: Hand mixing (foaming method in which the required amount of reagent is charged in a given container, and then stirring blades are inserted into the container and stirred)
Mixing time: 6 to 20 seconds, stirring blade rotation speed: 5000 rotations / minute

The polyurethane foam raw materials in Examples 1 to 8 and Comparative Examples 1 to 7 are as follows.
(1) Polyol composition (p-1 to p-7)
p-1: 15.7 mol of PO with potassium hydroxide as a catalyst was added to 1 mol of glycerin [amount of catalyst used: 0.3 wt% (based on reaction product weight), reaction temperature: 95 to 105 ° C.] Potassium oxide was removed. Further, in the same manner as in Example 1 of Japanese Patent Laid-Open No. 2000-344881, 31.3 mol of PO was added using tris (pentafluorophenyl) borane as a catalyst [amount of catalyst: 50 ppm (based on weight of reaction product), reaction temperature: 75 ° C. Then, tris (pentafluorophenyl) borane was removed by a conventional method, and 4.1 mol of EO was added using potassium hydroxide as a catalyst [catalyst consumption 0.3 wt% (based on reaction product weight), reaction temperature 95 to 105 ° C.] and obtained by removing potassium hydroxide by a conventional method (hydroxyl value = 56.1 mgKOH / g, EO unit content = 6.0% by weight, 1 of terminal hydroxyl group) Grade hydroxyl group ratio = 85%, number average functional group number = 3.0).

p-2: 15.7 mol of PO with potassium hydroxide as a catalyst was added to 1 mol of glycerin [amount of catalyst used: 0.3 wt% (based on reaction product weight), reaction temperature: 95 to 105 ° C.] Potassium oxide was removed. Further, in the same manner as in Example 1 of Japanese Patent Laid-Open No. 2000-344881, 34.4 mol of PO was added using tris (pentafluorophenyl) borane as a catalyst [amount of catalyst 50 ppm (based on reaction product weight), reaction temperature 75 ° C. The polyoxyalkylene polyol obtained by removing tris (pentafluorophenyl) borane by a conventional method (hydroxyl value = 56.1 mgKOH / g, EO unit content = 0% by weight, primary hydroxyl group of terminal hydroxyl group) Ratio = 70%, number average functional group number = 3.0).

p-3: 49.4 mol of PO with potassium hydroxide as a catalyst was added to 1 mol of pentaerythritol [amount of catalyst used: 0.3 wt% (based on reaction product weight), reaction temperature: 95 to 105 ° C.] Potassium hydroxide was removed. Further, in the same manner as in Example 1 of JP-A-2000-344881, 49.8 mol of PO was added using tris (pentafluorophenyl) borane as a catalyst (amount of catalyst 50 ppm (based on the weight of the reaction product), reaction temperature 75). ℃], tris (pentafluorophenyl) borane was removed by a conventional method, and 11.6 mol of EO was added using potassium hydroxide as a catalyst [catalyst consumption 0.3 wt% (based on reaction product weight), reaction temperature 95 to 105 ° C.] and obtained by removing potassium hydroxide by a conventional method (hydroxyl value = 35.1 mgKOH / g, EO unit content = 8% by weight, primary hydroxyl group of terminal hydroxyl group) (Ratio = 82%, number average functional group number = 4.0).

p-4: 3 mol of PO was added to 1 mol of glycerin using potassium hydroxide as a catalyst (amount of catalyst used 0.3 wt% (based on reaction product weight), reaction temperature 95 to 105 ° C.), and then 4 EO was added. Polyoxyalkylene polyol obtained by adding 0.8 mol, further adding 13.1 mol of PO and removing potassium hydroxide by a conventional method (hydroxyl value = 56.1 mgKOH / g, content of EO unit = 7 0.0 wt%, terminal hydroxyl group primary hydroxyl group ratio = 2%, number average functional group number = 3.0).

p-5: 38.8 mol of PO was added to 1 mol of glycerol using potassium hydroxide as a catalyst (amount of catalyst used: 0.3 wt% (based on the weight of the reaction product), reaction temperature 95 to 105 ° C.), and then 15 EO was added. Polyoxyalkylene polyol obtained by adding 0.0 mol and removing potassium hydroxide by a conventional method (hydroxyl value = 56.1 mgKOH / g, EO unit content = 22.0% by weight, primary hydroxyl group of the terminal) Hydroxyl ratio = 84%, number average functional group number = 3.0).

p-6: Potassium hydroxide as a catalyst was added to 1 mol of glycerin 84.6 mol of PO (amount of catalyst used 0.3 wt% (based on reaction product weight), reaction temperature 95 ° C. to 105 ° C.). Polyoxyalkylene polyol obtained by removing potassium hydroxide (hydroxyl value = 33.7 mg KOH / g, EO unit content = 0 wt%, primary hydroxyl group ratio of terminal hydroxyl groups = 2%, number average functional group number = 3.0).

p-7: 9.0 mol of PO was added to 1 mol of propylene glycol using potassium hydroxide as a catalyst (amount of catalyst used: 0.3 wt% (based on reaction product weight), reaction temperature: 95 to 105 ° C.) The polyoxyalkylene polyol obtained by removing potassium hydroxide by (hydroxyl value = 187.0, EO unit content = 0% by weight, primary hydroxyl group ratio of terminal hydroxyl groups = 2%, number average functional group number = 2 0.0).

(2) Organic polyisocyanate component b-1: TDI trade name “Coronate T-80” [manufactured by Nippon Polyurethane Industry Co., Ltd.]
(3) Foaming agent c-1: Water c-2: Dichloromethane (4) Catalyst d-1: “TEDA-L33” manufactured by Tosoh Corporation (triethylenediamine / dipropylene glycol = 33/67 wt% solution)
d-2: “Neostan U-28” manufactured by Nitto Kasei Co., Ltd. (stannic octylate)
(5) Foam stabilizer e-1: “L-540” manufactured by Nippon Unicar Co., Ltd.
e-2: “SZ-1346” manufactured by Toray Dow Corning
(6) Cross-linking agent k-1: diethanolamine

<Test method>
The measurement method for each item is as follows.
Settling rate: Settling refers to the phenomenon that the molded foam sinks after reaching the maximum height, and the settling rate was calculated from the following formula.
Settling rate (%) = [(A−B) / A] × 100
However, in the formula, A means the maximum height (mm) of the foam, and B means the height (mm) when the foam sinks. The settling rate correlates with the closed cell rate, and the smaller the value, the higher the closed cell rate. That is, blending with a low settling rate is preferable because of good moldability.
-Core density: Conforms to JIS K6400 (unit: kg / m ³ ).
-Breathability: Conforms to JIS K6400 (unit: ml / cm ² / sec).
Foam hardness (25% -ILD): Conforms to JIS K6400 (unit: N / 314 cm ² ).
-Tensile strength: Conforms to JIS K6400 (unit: N / cm ² ).
-Tear strength: Conforms to JIS K6400 (unit: N / cm).
-Cutting elongation: Conforms to JIS K6400 (unit:%).
-Compression residual strain: Conforms to JIS K6400 (unit:%).
-Residual TDA content: A test piece of 5 g of urethane foam was prepared, and the test piece was extracted in 100 ml of 1% acetic acid aqueous solution while repeating compression for 3 minutes at room temperature. After this operation was performed 5 times every 15 minutes, the urethane foam was removed to obtain a sample solution. This sample solution was subjected to Shimadzu Corporation high performance liquid chromatography “LCMS-8030” (column: Inert Sustain C18, eluent: acetonitrile / 0.1 M ammonium acetate aqueous solution = 10/90, flow rate: 0.2 ml / min). Used and analyzed for 2,4-TDA and 2,6-TDA content (ppm).
ΔYI: The yellowness (YI) of the sample and blank was measured using “Spectro Photometer SD5000” manufactured by Nippon Denshoku Industries Co., Ltd., and the yellowing degree (ΔYI) was obtained by subtracting the YI of the sample from the blank YI. ).

  From the results shown in Tables 1 and 2, the foams of Examples 1 to 8 show excellent mechanical properties even with a lower density than the foams of Comparative Examples 1 to 7, and the residual TDA content is small.

  The flexible polyurethane foam of the present invention can be suitably used for applications such as bedding and furniture.

Claims (3)

Production of flexible polyurethane foam obtained by reacting polyol (composition) (A) and organic polyisocyanate component (B) in the presence of blowing agent (C), urethanization catalyst (D) and foam stabilizer (E) The total amount of 2,4-toluenediamine and 2,6-toluenediamine contained in the foam is 10 ppm or less, the core density kg / m3 is 10 to 40, and the organic polyisocyanate component ( The content of 2,4- or 2,6-tolylene diisocyanate based on the total weight of (B) in B) is 20 to 100% by weight, and the polyol (composition) (A) is active A method for producing a flexible polyurethane foam containing a polyether polyol obtained by adding an alkylene oxide to a hydrogen-containing compound and satisfying the following (1) to ( 4 ):
(1) The primary hydroxyl group ratio of the terminal hydroxyl group of (A) is 40 to 90%;
(2) The content of ethylene oxide units is 8% by weight or less based on the weight of (A);
(3) The hydroxyl value of (A) is 20 to 290 mgKOH / g.
(4) The isocyanate index is 80-100.   The polyol (composition) (A) is a polyether polyol (1) containing an active hydrogen-containing compound containing 1,2-alkylene oxide having 3 or more carbon atoms as an essential component and an alkylene oxide not containing ethylene oxide. P-1), a polyhydride comprising an active hydrogen-containing compound containing 1,2-alkylene oxide having 3 or more carbon atoms as an essential component, and an alkylene oxide not containing ethylene oxide added thereto, and a block addition of ethylene oxide Ethylene oxide is block-added to ether polyol (P-2), an active hydrogen-containing compound obtained by randomly adding alkylene oxide containing 1,2-alkylene oxide having 3 or more carbon atoms and ethylene oxide as essential components Polyether polyol (P-3), an active hydrogen-containing compound containing 1,2-alkylene oxide having 3 or more carbon atoms as an essential component, and an alkylene oxide not containing ethylene oxide added to 1,2 having 3 or more carbon atoms -Polyether polyol (P-4) obtained by random addition of alkylene oxide containing alkylene oxide and ethylene oxide as essential components, and active hydrogen-containing compound, 1,2-alkylene oxide and ethylene oxide having 3 or more carbon atoms are essential The manufacturing method of Claim 1 containing the at least 1 sort (s) of polyether polyol (P) chosen from the group which consists of the polyether polyol (P-5) formed by random addition of the alkylene oxide contained as a component. The production according to claim 1 or 2 , wherein the content of 2,4- or 2,6-tolylene diisocyanate based on the total weight of (B) in the organic polyisocyanate component (B) is 100% by weight. Method.