JP2020026501A - Flexible polyurethane foam - Google Patents

Abstract

To provide a flexible polyurethane foam which has high temperature dependence of rebound resilience at 25°C and 40°C, and has good air permeability.SOLUTION: A flexible polyurethane foam is formed of a reactant of a mixture (F) of a polyol component (A), an organic polyisocyanate component (D), a foaming agent (E), a catalyst (F) and a foam stabilizer (G), in which the polyol component (A) contains polyether polyol (B) and di- or hexa-valent aliphatic polyhydric alcohol (C) and satisfies the following conditions (1) and (2), in the organic polyisocyanate component (D), a ratio (x)/(y) of a molar number (x) of NCO groups to a molar number (y) of active hydrogen groups reacting with the NCO groups is 0.83-0.98, and a ratio (BR/BR) of a rebound resilience ratio BRat 40°C to a rebound resilience ratio BRat 25°C is 1.6-12.0. (1) A hydroxyl value of the polyol component (A) is 100-140. (2) The total weight of an oxyethylene unit contained in the polyol component (A) is 10-40 wt.% based on the weight of (A).SELECTED DRAWING: None

Description

The present invention relates to a flexible polyurethane foam.

Flexible polyurethane foams are widely used for furniture, bedding pillows, bedding mattresses, automobile seat cushions, clothing and the like. In particular, pillows and mattresses for bedding are preferred to have high air permeability and low resilience.

As for the low resilience of the flexible polyurethane foam, it is required that the foam exhibit excellent low resilience at room temperature and does not become hard even at a low temperature, that is, low temperature dependence of foam hardness. As a flexible polyurethane foam having a low temperature dependency of foam hardness, a polyol composition containing a polyester triol and having a specific range of an ester group concentration, a hydroxyl group concentration, and the like is used. There is known a flexible polyurethane foam obtained by reacting in the presence of an agent, a catalyst and a foam stabilizer (for example, Patent Document 1).

However, the polyurethane foam described in Patent Document 1 has a problem that air permeability is not sufficient. Furthermore, while the low-resilience mattress made of flexible polyurethane foam is easy to fit on the body, it is difficult to turn over, and the rebound resilience increases in a humid state due to sweat at a temperature around the body temperature at bedtime, that is, the temperature dependence of the rebound resilience It is required to be high.

JP 2014-185335 A

The problem to be solved by the present invention is to provide a flexible polyurethane foam having high temperature dependence of rebound resilience at 25 ° C. and 40 ° C. and good air permeability.

The present inventors have conducted intensive studies to solve the above problems, and as a result, have reached the invention described below.
That is, the flexible polyurethane foam of the present invention is obtained by reacting a mixture (H) containing a polyol component (A), an organic polyisocyanate component (D), a foaming agent (E), a catalyst (F), and a foam stabilizer (G). A flexible polyurethane foam made of a product, wherein the polyol component (A) contains a polyether polyol (B) and a divalent to hexavalent aliphatic polyhydric alcohol (C), and satisfies the following conditions (1) and (2): Satisfied, the ratio (x) / (y) of the number of moles (x) of NCO groups in the organic polyisocyanate component (D) to the number of moles (y) of active hydrogen groups reacting with the NCO groups is from 0.83 to 0.83. 0.98, the ratio between the modulus of repulsion elasticity _{BR 25} modulus of repulsion elasticity _{BR 40} of 40 ° C. and _{25 ℃ (BR 40 / BR 25} ) is 1.6 to 12.0.
(1) The polyol component (A) has a hydroxyl value of 100 to 140.
(2) The total weight of oxyethylene units contained in the polyol component (A) is 10 to 40% by weight based on the weight of (A).

The flexible polyurethane foam of the present invention has both high temperature dependence of rebound resilience and air permeability.
Furthermore, the foam does not become hard even at a low temperature, and has an effect that the temperature dependency of the foam hardness is low and an effect that the rebound resilience at 25 ° C. is low.

The flexible polyurethane foam of the present invention satisfies the following conditions (1) and (2), and comprises a polyether polyol (B) and a polyol component (A) containing a divalent to hexavalent aliphatic polyhydric alcohol (C). A flexible polyurethane foam comprising a reaction product of a mixture (H) containing an organic polyisocyanate component (D), a foaming agent (E), a catalyst (F), and a foam stabilizer (G).
(1) The polyol component (A) has a hydroxyl value of 100 to 140.
(2) The total weight of oxyethylene units contained in the polyol component (A) is 10 to 40% by weight based on the weight of (A).
Furthermore, the ratio (x) / (y) of the number of moles (x) of NCO groups in the organic polyisocyanate component (D) to the number of moles (y) of active hydrogen groups reacting with the NCO groups is 0.83 to 0. is .98, the ratio between the modulus of repulsion elasticity _{BR 25} modulus of repulsion elasticity _{BR 40} of 40 ° C. and _{25 ℃ (BR 40 / BR 25} ) is 1.6 to 12.0.

In the flexible polyurethane foam of the present invention, the polyol component (A) contains the polyether polyol (B) and the divalent to hexavalent aliphatic polyhydric alcohol (C), and satisfies the following conditions (1) and (2). .
(1) The polyol component (A) has a hydroxyl value of 100 to 140.
(2) The total weight of oxyethylene units contained in the polyol component (A) is 10 to 40% by weight based on the weight of (A).

Examples of the polyether polyol (B) include an alkylene oxide (hereinafter, sometimes abbreviated as AO) adduct of the active hydrogen group-containing compound (a). Alcohols (a1) (dihydric alcohols having 2 to 20 carbon atoms, trihydric alcohols having 3 to 20 carbon atoms, 4 to 8 alcohols having 4 to 20 carbon atoms, etc.), compounds containing polyhydric hydroxyl groups other than polyhydric alcohols ( a2), an amino group-containing compound (a3), a thiol group-containing compound (a4), and a phosphate group-containing compound (a5).
Note that active hydrogen refers to a hydrogen atom bonded to an oxygen atom, a nitrogen atom, a sulfur atom, and the like, and an active hydrogen group-containing compound refers to an active hydrogen-containing functional group (hydroxyl group, amino group, thiol group, Phosphoric acid group).

Among the polyhydric alcohols (a1), examples of the dihydric alcohol having 2 to 20 carbon atoms include aliphatic diols (ethylene glycol, propylene glycol, 1,3- or 1,4-butanediol, 1,6-hexanediol and Neopentyl glycol, etc.) and alicyclic diols (cyclohexanediol, cyclohexanedimethanol, etc.).

Examples of the trihydric alcohol having 3 to 20 carbon atoms include aliphatic triols (such as glycerin and trimethylolpropane).
Examples of the 4- to 8-hydric alcohol having 4 to 20 carbon atoms include aliphatic polyols (such as pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin and dipentaerythritol) and saccharides (sucrose, glucose, mannose, fructose, methyl glucoside and the like). Derivatives thereof).

Examples of the polyhydric hydroxyl group-containing compound (a2) other than the polyhydric alcohol include polyhydric phenols (hydroquinone, bisphenol A, bisphenol F, bisphenol S, 1,3,6,8-tetrahydroxynaphthalene, anthrol, 1,4, 5,8-tetrahydroxyanthracene, 1-hydroxypyrene, etc.), polybutadiene polyol, castor oil-based polyol, polymer of hydroxyl group-containing monomer [(co) polymer of hydroxyalkyl (meth) acrylate having 2 to 100 hydroxyl groups) And polyvinyl alcohol], condensates of phenol and formaldehyde (such as novolak), and polyphenols described in US Pat. No. 3,265,641.
In addition, (meth) acrylate means methacrylate and / or acrylate, and the same applies hereinafter.

Examples of the amino group-containing compound (a3) include ammonia, amine, polyamine, and amino alcohol. Specifically, ammonia, alkylamines having 1 to 20 carbon atoms (such as butylamine), aniline, aliphatic polyamines (such as ethylenediamine, hexamethylenediamine and diethylenetriamine), and heterocyclic polyamines (such as piperazine and N-aminoethylpiperazine) , Alicyclic polyamines (such as dicyclohexylmethanediamine and isophoronediamine), aromatic polyamines (such as phenylenediamine, tolylenediamine and diphenylmethanediamine), alkanolamines (such as monoethanolamine, diethanolamine and triethanolamine), and excess dicarboxylic acid Polyamines, polyether polyamines, hydrazines (such as hydrazine and monoalkylhydrazine), dihydrazides (succinic Etc. dihydrazide and dihydrazide terephthalate), guanidine (butyl guanidine and 1-cyanoguanidine, etc.) and dicyandiamide, and the like.

Examples of the thiol group-containing compound (a4) include a polythiol compound. Examples of the polythiol include polyvalent thiols having 2 to 8 valences. Specific examples include ethanedithiol and 1,6-hexanedithiol.

Examples of the phosphate group-containing compound (a5) include phosphoric acid, phosphorous acid, and phosphonic acid.

As AO to be subjected to addition polymerization to the active hydrogen group-containing compound (a), AO having 2 to 4 carbon atoms, for example, ethylene oxide (hereinafter abbreviated as EO), 1,2-propylene oxide (hereinafter abbreviated as PO), , 3-propylene oxide, 1,2-butylene oxide and 1,4-butylene oxide.
Among these, PO, EO and 1,2-butylene oxide are preferred from the viewpoint of properties and reactivity.
When two or more types of AOs are used, the addition format may be block addition, random addition, or a combination thereof.

The number average functional group number of the polyether polyol (B) is preferably 2.6 or more, more preferably 2.7 or more, and most preferably 2.8 or more from the viewpoint of durability.

The number average functional group number of the polyether polyol (B) is preferably 4.0 or less, more preferably 3.8 or less, and most preferably 3.6 or less from the viewpoint of air permeability.

The hydroxyl value of the polyether polyol (B) is preferably 103 or more, more preferably 105 or more, and most preferably 107 or more from the viewpoint of rebound resilience.

The hydroxyl value of the polyether polyol (B) is preferably 140 or less, more preferably 137 or less, and most preferably 135 or less from the viewpoint of temperature dependence of foam hardness.
The hydroxyl value is the number of mg of potassium hydroxide required to neutralize acetic acid bonded to a hydroxyl group when 1 g of a sample is acetylated, and is defined in JIS K1557-1 Plastic-Polyurethane Raw Material Polyol Test Method. -Part 1: Determination of hydroxyl value ".

The divalent to hexavalent aliphatic polyhydric alcohol (C) is not particularly limited as long as it is a saturated or unsaturated aliphatic alcohol having 2 to 6 hydroxyl groups, but from the viewpoint of handling, ethylene glycol, propylene glycol, , 4-butylene glycol, glycerin and the like are preferred.

The content of the divalent to hexavalent aliphatic polyhydric alcohol (C) is preferably 0.1 to 5.0% by weight based on the weight of the polyol component (A). If it is less than 0.1% by weight, the temperature dependence of the rebound resilience decreases, and if it exceeds 5.0% by weight, the air permeability decreases.

The hydroxyl value of the polyol component (A) is from 100 to 140, preferably from 105 to 138, and more preferably from 110 to 135. Within this range, the rebound resilience at 25 ° C is low, and the foam does not become hard even at 0 ° C, and the temperature dependence of the foam hardness decreases.
Examples of the polyol component (A) include not only polyether polyol (B) and divalent to hexavalent aliphatic polyhydric alcohol (C), but also polyester polyol (I) and polymer polyol (P) as optional components described later. ) And other compounds containing a hydroxyl group.

The hydroxyl value of the polyol component (A) is the same as the hydroxyl value of each of the polyether polyol (B), the divalent to hexavalent aliphatic polyhydric alcohol (C), the polyester polyol (I), and the polymer polyol (P). It is the total value (arithmetic mean value) of the values obtained by multiplying the content ratio by weight ratio. The weight of the polymer polyol (P) includes the weight of the polymer particles (J).
Specifically, it is measured in accordance with the above-mentioned "JIS K1557-1 Plastics-Polyurethane raw material polyol test method-Part 1: How to determine hydroxyl value".

On the other hand, the hydroxyl value of the polyol component (A) excluding the divalent to hexavalent aliphatic polyhydric alcohol (C) is preferably from 100 to 130, more preferably from 105 to 125. Within this range, the rebound resilience at 40 ° C. is high, and even at 0 ° C., the foam does not become hard and the temperature dependence of foam hardness decreases.

The total weight of the oxyethylene units contained in the polyol component (A) is 10 to 40% by weight based on the total weight of the polyol component (A) from the viewpoints of air permeability, reactivity, and compression set. , Preferably 14 to 36% by weight.

The total weight of the oxyethylene units of the polyol component (A) is based on the weight content of each of the oxyethylene units of the polyether polyol (B), the optional polyester polyol (I), and the polymer polyol (P). It is the total value (arithmetic mean value) of the values obtained by multiplying the content ratio by weight ratio. The weight of the polymer polyol (P) includes the weight of the polymer particles (J).
The amount of oxyethylene units contained in the polyol component (A), proton nuclear magnetic resonance analysis of ^{(1 H-NMR)} were measured, it can be calculated from the area ratio of the signals derived from oxyethylene units.

The number average functional group number of the polyol component (A) excluding the divalent to hexavalent aliphatic polyhydric alcohol (C) is preferably from 2.6 to 4.0 from the viewpoint of air permeability and durability, and more preferably from 2 to 4.0. 0.7 to 3.8.
The number average number of functional groups is the content ratio of the respective functional groups of the polyether polyol (B) contained in the polyol component (A), the optional component polyester polyol (I), and the polymer polyol (P) in the respective molar ratios. Is the total value (arithmetic mean value) of the values obtained by multiplying by.
The number-average number of functional groups of the polyol component (A) excluding the divalent to hexavalent aliphatic polyhydric alcohol (C) is the number-average number of functional groups per molecule of the polyol contained in the polyol component (A). It can be calculated from resonance analysis ¹³ C-NMR.

It is preferable that the polyol component (A) further contains the polyester polyol (I) from the viewpoint of the temperature dependence of foam hardness and the rebound resilience.

The polyester polyol (I) contained for this purpose includes a condensation reaction product (I1) of a polyhydric hydroxyl group-containing compound with a polycarboxylic acid (a transesterification reaction between the polyhydric hydroxyl group-containing compound and a lower alkyl ester of a polycarboxylic acid). Product), an ester group-containing reaction product (I2) obtained by further adding a carboxylic anhydride and AO to the polyether polyol (B), a polylactone polyol (I3) [for example, the polyhydric alcohol ( obtained by ring-opening polymerization of a lactone (e.g., ε-caprolactone) using a1) as an initiator], a polycarbonate polyol (I4) [for example, a reaction product of the above polyhydric alcohol (a1) and an alkylene carbonate], and Reaction products obtained by further adding AO to (I1) to (I4) are exemplified.

Examples of the polyhydric hydroxyl group-containing compound used for the polyester polyol (I1) include the above-mentioned polyhydric alcohol (a1) and the above-mentioned polyether polyol (B).

Examples of the polycarboxylic acid used for the polyester polyol (I1) include aromatic polycarboxylic acids, aliphatic polycarboxylic acids, and molecular cyclic anhydrides thereof. Examples of the lower alkyl esters of the polycarboxylic acids include aromatic polycarboxylic acids. An ester of an acid or an aliphatic polycarboxylic acid with an aliphatic alcohol having 1 to 4 carbon atoms may be used.

Examples of aromatic polycarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, 2,2′-bibenzyldicarboxylic acid, trimellitic acid, hemilitic acid, trimesic acid, pyromellitic acid, naphthalene-1,4 dicarboxylic acid, and naphthalene And aromatic polycarboxylic acids having 8 to 18 carbon atoms, such as -2,3,6-tricarboxylic acid, diphenic acid, 2,3-anthracene dicarboxylic acid, 2,3,6-anthracene carboxylic acid, and pyrene dicarboxylic acid. .
Examples of the aliphatic polycarboxylic acid include succinic acid, fumaric acid, sebacic acid and adipic acid.

Examples of the lower alkyl ester of polycarboxylic acid include dimethyl phthalate and dimethyl terephthalate.

The reaction product (I2) obtained by adding a carboxylic acid anhydride and AO to a polyether polyol is, for example, reacted with the polyether polyol (B) and an aromatic dicarboxylic anhydride to form an esterified product, and further obtained by PO, EO, or the like. Is a polyester polyol to which AO is added.

Among these polyester polyols (I), a condensation reaction product (I1) of a polyhydric hydroxyl group-containing compound with a polycarboxylic acid or a lower ester of a polycarboxylic acid, and the polyether polyol (B) with a carboxylic anhydride The reaction product (I2) to which AO is added is preferred.
More preferably, it is a reaction product obtained by adding an aromatic dicarboxylic anhydride (preferably phthalic anhydride) and PO to a trifunctional polyether polyol (preferably, a glycerin PO adduct of 20 to 50 mol).

The hydroxyl value of the polyester polyol (I) is preferably from 25 to 100, more preferably from 40 to 80, from the viewpoint of the handling of the polyol component (A) and the temperature dependence of the foam hardness.

The ester group concentration (mmol / g) of the polyester polyol (I) is 0.5 to 10 based on the weight of the polyester polyol (I) from the viewpoint of the handling of the polyol component (A) and the temperature dependency of the foam hardness. It is preferably 0.0 mmol / g, and more preferably 0.5 to 7.0 mmol / g.

When the polyol component (A) contains the polyester polyol (I), the concentration of the ester group contained in the polyol component (A) is 0.02 to 0.40 mmol / g based on the weight of the polyol component (A). Preferably, it is 0.05 to 0.40 mmol / g, more preferably.
When the polyester polyol (I) is contained, the rebound resilience at 25 ° C is low, and the foam does not become hard even at 0 ° C, and the temperature dependence of foam hardness is low. On the other hand, when the content of the polyester polyol (I) is large, the air permeability deteriorates.

The ester group concentration of the polyester polyol (I) and the ester group concentration of the polyol component (A) were determined by measuring the infrared spectroscopic analysis (IR) of the polyester polyol (I) and the polyol component (A). The intensity can be calculated using a calibration curve of the peak intensity and the ester group concentration prepared using a sample whose ester group concentration is known.

When the polyol component (A) contains the polyester polyol (I), the content of the polyester polyol (I) in the polyol component (A) depends on the temperature dependence of the foam hardness, the handling of the polyol component, and the moldability of the foam. From the viewpoint, it is preferably 1 to 20% by weight, more preferably 2 to 18% by weight based on the total weight of the polyol component (A), and particularly preferably 3 to 15% by weight from the viewpoint of handling of the polyol composition. %.

From the viewpoint of foam hardness, the polyol component (A) preferably further contains a polymer polyol (P) including polymer particles (J) containing an ethylenically unsaturated compound as a constituent monomer.

The polymer polyol (P) contains polymer particles (J) having an ethylenically unsaturated compound as a constituent monomer. The polymer polyol (P) is obtained by polymerizing an ethylenically unsaturated compound in a polyether polyol (B) in the presence of a radical polymerization initiator.
The polymer particles (J) polymerized in the polyether polyol (B) are preferable because they are stably dispersed and a homogeneous polymer polyol (P) can be obtained.

As the ethylenically unsaturated compound that is a constituent monomer of the polymer particles (J), a vinyl monomer described in JP-A-2006-176071 can be used, and among them, styrene and acrylonitrile are preferable.
When styrene and acrylonitrile are used in combination, the weight ratio of styrene is preferably 30 to 70% by weight based on the total weight of styrene and acrylonitrile from the viewpoint of the flame retardancy and foam hardness of the polyurethane foam.

When the polymer polyol (P) containing the polymer particles (J) is used as the polyol component (A), the content ratio of the polymer particles (J) contained in the polymer polyol is determined based on the viewpoint of foam hardness and the like. It is preferably from 35 to 55% by weight, more preferably from 38 to 50% by weight, based on the weight of the polyol (P).
The content of the polymer particles (J) contained in the polymer polyol (P) is measured by the following method.

<Content of polymer particles (J)>
Approximately 5 g of a polymer polyol is precisely weighed in a 50 ml centrifuge tube for centrifugation to obtain a weight (W1). Dilute with 50 g of methanol. Using a cooling centrifuge [Model: H-9R, manufactured by Kokusan Co., Ltd.], centrifuge at 18,000 rpm for 60 minutes at 5 ° C. The supernatant is removed using a glass pipette. The operation of adding 50 g of methanol to the remaining sediment to dilute it and centrifuging the same to remove the supernatant is repeated three more times. The residual sediment in the centrifuge tube is dried under reduced pressure at 3 to 4 kPa at 80 ° C. for 3 hours, and the dried sediment is weighed and designated as (W2).
The value calculated by the following equation is defined as the polymer particle content (% by weight).
Polymer particle content (% by weight) = (W2) × 100 / (W1)

The content of the polymer particles (J) contained in the polyol component (A) is 0.8 to 9.0% by weight based on the weight of the polyol component (A) from the viewpoint of foam hardness and the like. Is more preferable, and more preferably 1.3 to 5.0% by weight.
The content of the polymer particles (J) contained in the polyol component (A) is determined by using the polyol component (A) instead of the polymer polyol used in the method for measuring the content of the polymer particles (J). Measured.

The polyol component (A) is a mixture of a polyether polyol (B), a divalent to hexavalent aliphatic polyhydric alcohol (C), a polyester polyol (I), a polymer polyol (P), and other polyols used as required. Can be easily obtained.
As a mixing method at the time of mixing, a known mixing device (a container with a stirrer or the like) can be used. As the polymer particles (J), polymer particles contained in the polymer polyol (P) are used. It is preferable to mix with other raw materials to produce the polyol component (A) for producing a flexible polyurethane foam.
From the viewpoint of storage stability and the like, it is preferable to lower the oxygen concentration inside the container when mixing.

The flexible polyurethane foam of the present invention is a foam of the mixture (H) containing the polyol component (A), the organic polyisocyanate component (D), the foaming agent (E), the catalyst (F) and the foam stabilizer (G). Is a flexible polyurethane foam.

As the organic polyisocyanate component (D), all known organic polyisocyanates used for flexible polyurethane foams can be used, and aromatic polyisocyanates (D1), aliphatic polyisocyanates (D2), and alicyclic polyisocyanates (D3) ), Araliphatic polyisocyanates (D4), modified products thereof (D5) (modified products containing urethane group, carbodiimide group, allophanate group, urea group, buret group, isocyanurate group and oxazolidone group) and the like. Mixtures of more than one species.

As the aromatic polyisocyanate (D1), the carbon number excluding the carbon in the NCO group (in the following polyisocyanate, the carbon number in the NCO group is excluded when the carbon number is described) is 6 to 16. Examples thereof include aromatic diisocyanates, aromatic triisocyanates having 6 to 20 carbon atoms, and crude products of these isocyanates. 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), polymethylene polyphenylene polyisocyanate (crude MDI), naphthylene-1,5-diisocyanate and triphenylmethane-4,4 ′, 4 ″ -triisocyanate.

Examples of the aliphatic polyisocyanate (D2) include aliphatic diisocyanates having 6 to 10 carbon atoms. Specific examples include 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate.

Examples of the alicyclic polyisocyanate (D3) include an alicyclic diisocyanate having 6 to 16 carbon atoms. Specific examples include isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, and norbornane diisocyanate.

Examples of the araliphatic polyisocyanate (D4) include araliphatic diisocyanates having 8 to 12 carbon atoms. Specific examples include xylylene diisocyanate and α, α, α ′, α′-tetramethylxylylene diisocyanate.
Examples of the modified polyisocyanate (D5) include modification of urethane group, carbodiimide group, allophanate group, urea group, burette group, isocyanurate group and oxazolidone group, and specific examples include carbodiimide-modified MDI.

Among these organic polyisocyanate components (D), an aromatic polyisocyanate (D1) is preferred from the viewpoint of reactivity and rebound resilience, and more preferably, TDI, crude TDI, MDI, crude MDI, and these isocyanates. Modified products, particularly preferred are TDI, MDI and crude MDI.

The polyurethane foam is obtained by reacting the polyol composition with the organic isocyanate component (D). The amount of the organic isocyanate component (D) used is determined by the ratio of the isocyanate group (NCO group) to the active hydrogen atoms in the raw material. By adjusting, the physical properties of the polyurethane foam are adjusted.
In the flexible polyurethane foam of the present invention, the ratio (x) / (y) of the number of moles (x) of NCO groups in the organic polyisocyanate component (D) and the number of moles (y) of active hydrogen groups that react with the NCO groups. ) Is from 0.83 to 0.98, preferably from 0.84 to 0.97, more preferably from 0.85 to 0.96 from the viewpoint of rebound resilience.

Examples of the foaming agent (E) include water, liquefied carbon dioxide, and low-boiling compounds having a boiling point of -5 to 70 ° C.

Examples of the low-boiling compounds include halogenated hydrocarbons containing hydrogen atoms and low-boiling hydrocarbons. Specific examples of the hydrogen atom-containing halogenated hydrocarbon and the low boiling point hydrocarbon include methylene chloride, HCFC (hydrochlorofluorocarbon) (HCFC-123, HCFC-141b, HCFC-142b, etc.); HFC (hydrofluorocarbon) (HFC- 134a, HFC-152a, HFC-356mff, HFC-236ea, HFC-245ca, HFC-245fa and HFC-365mfc), butane, pentane and cyclopentane.

Among these, from the viewpoint of moldability, water, liquefied carbon dioxide, methylene chloride, cyclopentane, HCFC-141b, HFC-134a, HFC-356mff, HFC-236ea, HFC-245ca, HFC-245fa, HFC-365mfc, It is preferable to use a mixture of two or more of these as the blowing agent (E).

From the viewpoint of foam density, the amount of water used as the foaming agent (E) is preferably 1.0 to 8.0 parts by weight with respect to 100 parts by weight of the polyol component (A) used in producing the urethane foam. Preferably, it is 1.5 to 4.0 parts by weight.
The amount of the low boiling point compound used is preferably 30 parts by weight or less, more preferably 5 to 25 parts by weight, based on 100 parts by weight of the polyol component (A) from the viewpoint of molding failure.
The liquefied carbon dioxide gas is preferably 30 parts by weight or less, more preferably 1 to 25 parts by weight, based on 100 parts by weight of the polyol component (A).

As the catalyst (F), any catalyst that promotes the urethanization reaction can be used, but from the viewpoint of moldability, tertiary amine ｛triethylenediamine, N-ethylmorpholine, N, N-dimethylaminoethanol and N- (N ′, N ′,-2-dimethylaminoethyl) morpholine and the like and metal carboxylate (potassium acetate, potassium octylate, stannous octylate, dibutylstannic dilaurate and lead octylate, etc.) No.
Among these, triethylenediamine, stannous octylate, and dibutylstannate dilaurate are preferred from the viewpoints of foam hardness and rebound resilience.

From the viewpoint of moldability, the amount of the catalyst (F) used is preferably 0.01 to 5.0 parts by weight, more preferably 0.1 to 5.0 parts by weight, based on 100 parts by weight of the polyol component (A) used in the production of the urethane foam. 05 to 2.0 parts by weight. As the catalyst (F), one type may be used alone, or two or more types may be used in combination.

As the foam stabilizer (G), known foam stabilizers (silicone-based foam stabilizers and non-silicone-based foam stabilizers) used in the production of polyurethane foam can be used, and are manufactured by Toray Dow Corning Co., Ltd. "SZ-1959", "SF-2904", "SZ-1142", "SZ-1720", "SZ-1675t", "SF-2936F", "SZ-3601", "SRX-294A", "SH" -193 "," L-540 "and" L-3601 "manufactured by Nippon Unicar Co., Ltd.," L-626 "manufactured by Momentive Performance Materials Co., Ltd.," B8715 LF2 manufactured by Evonik Degussa Japan Ltd. " And the like that can be obtained from the market.

The amount of the foam stabilizer (G) to be used is preferably 0.4 to 5.0 parts by weight, more preferably 0.4 to 5.0 parts by weight, based on 100 parts by weight of the polyol component (A), from the viewpoint of moldability and resilience. To 3.0 parts by weight.

The flexible polyurethane foam of the present invention may be a foam that has been subjected to a urethanization reaction using other auxiliaries described below.
Other auxiliaries include colorants (dyes and pigments), plasticizers (phthalates and adipic esters, etc.), organic fillers (synthetic short fibers, hollow microspheres made of thermoplastic or thermosetting resin, etc.) And known auxiliary components such as flame retardants (such as phosphate esters and halogenated phosphate esters), antioxidants (such as triazole and benzophenone) and antioxidants (such as hindered phenol and hindered amine).

The amount of these auxiliaries is preferably 1 part by weight or less based on 100 parts by weight of the polyol component (A). The amount of the plasticizer is preferably 10 parts by weight or less, more preferably 5 parts by weight or less. The amount of the organic filler is preferably 50 parts by weight or less, more preferably 30 parts by weight or less. The amount of the flame retardant is preferably 30 parts by weight or less, and more preferably 2 to 20 parts by weight. The antioxidant is preferably used in an amount of 1 part by weight or less, more preferably 0.01 to 0.5 part by weight. The amount of the antioxidant is preferably 1 part by weight or less, more preferably 0.01 to 0.5 part by weight. The total amount of the auxiliaries is preferably not more than 50 parts by weight, more preferably 0.2 to 30 parts by weight.

The flexible polyurethane foam of the present invention can be produced by a known method.
As an example, first, a polyol component (A), a foaming agent (E), a catalyst (F), a foam stabilizer (G) and, if necessary, other additives are mixed in predetermined amounts to obtain a mixture (H).
Next, this mixture (H) and the organic polyisocyanate component (D) are rapidly mixed using a polyurethane foam foaming machine or a stirrer.
The resulting mixed solution (foaming stock solution) can be continuously foamed to obtain a flexible polyurethane foam.
In addition, a flexible polyurethane foam can be obtained by injecting into a closed or open mold (made of metal or resin), causing a urethanization reaction, curing for a predetermined time, and then removing the mold.

The 25 ° C. rebound resilience of the flexible polyurethane foam of the present invention is preferably from 5 to 15%, more preferably from 6 to 13%, from the viewpoint of sitting comfort and sleeping comfort. Within this range, the foam hardness is good, and the sitting comfort and the sleeping comfort are excellent.

From the viewpoint of impact resilience is high turn easily in humid conditions due to sweating at a temperature of at about body temperature bedtime, rebound resilience of BR ₄₀ of 40 ° C. of flexible polyurethane foam of the present invention and 25 ° C. modulus of repulsion elasticity BR ₂₅ (BR ₄₀ / BR ₂₅ ) is 1.6 to 12.0, preferably 1.7 to 10.0, more preferably 1.8 to 8.0, and particularly preferably 1.9 to 5. 0.0.

The flexible polyurethane foam of the present invention is used for pillows for furniture and bedding, mattresses for bedding, seat cushions for automobiles, clothing, and the like.

Hereinafter, the present invention will be further described by way of examples, but the present invention is not limited thereto.

<Preparation of polyol composition>
The components described in Tables 1 and 2 were uniformly mixed in a mixing vessel to prepare the polyol compositions of Examples 1 to 16 and Comparative Examples 1 to 8.

The components used in Examples 1 to 16 and Comparative Examples 1 to 8 described in Tables 1 and 2 are as follows, respectively.

<Polyether polyol (B)>
Polyether polyol (B-1)
The reaction temperature is 95 ° C. to 130 ° C. using potassium hydroxide as a catalyst [catalyst amount 0.3% by weight (based on the weight of the reaction product)] so that the molar ratio of glycerin and PO becomes 1: 83.8. PO addition of glycerin having a hydroxyl value of 34, a primary hydroxyl group ratio of 2%, and an Mn of 4950, obtained by adding PO to glycerin by a conventional method after adding PO to glycerin. Things.

Polyether polyol (B-2)
A reaction temperature of 95 was obtained by using potassium hydroxide as a catalyst [catalyst amount 0.3% by weight (based on the weight of the reaction product)] so that the ratio of PO was 16.6 moles and EO was 51.0 moles per mole of glycerin. After reacting a PO / EO mixture containing PO and EO with glycerin to glycerin at a temperature of from 130 ° C to 130 ° C, the hydroxyl value is 51 obtained by removing potassium hydroxide by an ordinary method, and is a primary hydroxyl group. It is a PO / EO random adduct of glycerin having a ratio of 36%, Mn of 3,300, and a weight ratio of oxyethylene units of 70% by weight.

Polyether polyol (B-3)
A reaction temperature of 95 using potassium hydroxide as a catalyst [catalyst usage 0.3% by weight (based on reaction product weight)] so that the ratio of PO 46.6 moles and EO 4.6 moles per mole of glycerin is 1 mole. A PO.EO mixture containing PO and EO is added to glycerin at a temperature of from 130 ° C. to 130 ° C., and the resulting mixture is reacted with glycerin and then potassium hydroxide is removed by a conventional method. It is a PO / EO random adduct of glycerin having a ratio of 2%, Mn of 3,000 and a weight ratio of oxyethylene units of 7% by weight.

Polyether polyol (B-4)
The reaction temperature is 95 ° C. to 130 ° C. using potassium hydroxide as a catalyst [catalyst amount 0.3% by weight (based on the weight of the reaction product)] so that the molar ratio of glycerin and PO becomes 1: 50.1. PO addition of glycerin having a hydroxyl value of 56, a ratio of primary hydroxyl groups of 2%, and an Mn of 3,000 obtained by removing potassium hydroxide by a conventional method after adding PO to glycerin. Things.

Polyether polyol (B-5)
The reaction temperature was raised to 95 ° C. to 130 ° C. using potassium hydroxide as a catalyst [catalyst amount 0.3% by weight (based on the weight of the reaction product)] so that the molar ratio of glycerin and PO became 1: 16.5. PO added to glycerin, and then obtained by removing potassium hydroxide by a conventional method. PO adduct of glycerin having a hydroxyl value of 160, a ratio of primary hydroxyl groups of 2%, and Mn of 1050. It is.

Polyether polyol (B-6)
The reaction temperature was raised to 95 ° C. to 130 ° C. using potassium hydroxide as a catalyst [catalyst amount 0.3% by weight (based on the weight of the reaction product)] so that the molar ratio of glycerin and PO became 1: 11.3. PO added to glycerin, and then obtained by removing potassium hydroxide by a conventional method. PO adduct of glycerin having a hydroxyl value of 224, a ratio of primary hydroxyl groups of 2%, and Mn of 750. It is.

Polyether polyol (B-7)
A reaction temperature of 95 ° C. to 130 ° C. using potassium hydroxide as a catalyst [catalyst amount 0.3% by weight (based on the weight of the reaction product)] so that the molar ratio of propylene glycol to PO becomes 1: 5.9. Of propylene glycol having a hydroxyl value of 270, a primary hydroxyl group ratio of 2%, and an Mn of 420, which is obtained by adding PO to propylene glycol by a conventional method and removing potassium hydroxide by a conventional method. PO adduct.

<Divalent to hexavalent aliphatic polyhydric alcohol (C)>
(C-1): glycerin (C-2): ethylene glycol

<Polyester polyol (I)>
Polyester polyol (I-1)
27.7 mol of PO was added to 1 mol of glycerin at a reaction temperature of 95 ° C. to 130 ° C. using potassium hydroxide as a catalyst [catalyst amount 0.3% by weight (based on the weight of the reaction product)] and then a conventional method. By removing potassium hydroxide, a PO adduct of glycerin having a hydroxyl value of 56 and Mn of 1700 was obtained. Next, 6 moles of phthalic anhydride was mixed with 1 mole of the PO adduct of glycerin, and further mixed with PO to obtain a polyester triol [proportion of primary hydroxyl group = 2% by weight, hydroxyl value = 56 mg KOH / G, ester group concentration = 2.0 mmol / g].

<Polymer polyol (P)>
Polymer polyol (P-1)
A polymer polyol (polymer content: 44.0%) obtained by copolymerizing styrene and acrylonitrile (weight ratio: 70/30) in the polyether polyol (B-3). The volume average particle size of the polymer particles is 0.5 to 0.7 μm.

<Blowing agent (E)>
(E-1): water

<Catalyst (F)>
(F-1): "DABCO-33LX" manufactured by Air Products Japan Co., Ltd.
(F-2): "DABCO-BL22" manufactured by Air Products Japan Co., Ltd.
(F-3): "Neostan U-28" manufactured by Nitto Kasei Corporation

<Foam stabilizer (G)>
(G-1): Silicone foam stabilizer "SF-2904" manufactured by Dow Corning Toray Co., Ltd.

<Organic polyisocyanate component (D)>
(D-1): Mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate (mixing ratio: 80/20) (TDI) [Product name: "Coronate T-80" manufactured by Tosoh Corporation (isocyanate group) Content = 48.3% by weight)]

<Production of flexible polyurethane foam (UF)>
Using the polyol compositions obtained in Examples 1 to 16 and Comparative Examples 1 to 8, TDI (D-1) of the organic isocyanate in the number of parts shown in Tables 1 and 2 was uniformly mixed, and under the following foaming conditions. It foamed and produced flexible polyurethane foam (UF-1)-(UF-16) and (UF'-1)-(UF'-8).
In addition, the numerical value of each component in Table 1 and Table 2 has described the weight part number, and about the organic polyisocyanate (D-1), the isocyanate index [(x) / (y)] is separately described. Parts by weight of organic isocyanate corresponding to the isocyanate index were used.

<Foaming conditions>
Mold size: 250mm x 250mm x 250mm
Material: Wood mixing method:
Hand mixing (a foaming method in which a required amount of a necessary reagent is charged into a predetermined container, and then a stirring blade is inserted into the container and the mixture is stirred at 5,000 rpm for 6 to 20 seconds).
Mixing time: 6 to 20 seconds Number of stirring blade rotations: 5000 rotations / minute

After the obtained flexible polyurethane foam was allowed to stand at a temperature of 25 ° C. and a humidity of 50% for 24 hours, the density, 25% compression hardness, force gauge hardness, air permeability, and rebound resilience of each flexible polyurethane foam were measured. The measurement was performed based on the following measurement method, and the results are shown in Tables 1 and 2.
Comparative Examples 5 and 8 contracted during standing after foaming, and Comparative Examples 3 and 7 had an apparent volume increase once due to foaming, but were immediately crushed. Was not measured.

<Testing method for flexible polyurethane foam>
The measuring method of each item is as follows.

<Density>
It was measured according to JIS K6400 (unit is kg / m ³ ).

<25% compression hardness of the foam at 25 ° C.>
Using a polyurethane foam temperature-controlled in an environment of 25 ° C., a 25% compression hardness was measured according to JIS K6400 (unit: N / 314 cm ² ).

<Ratio of force gauge hardness of foam at 0 ° C and 25 ° C>
Using a polyurethane foam whose temperature was controlled in an environment of 0 ° C. and 25 ° C., the stress (unit: N) was measured when the sample was pushed in with a force gauge by 20 mm, and the hardness ratio between 0 ° C. and 25 ° C. (0 ° C. hardness) / 25 ° C hardness).

<Breathability>
It was measured in accordance with JIS K6400 (unit is cc / cm ² / s). The air permeability of the flexible polyurethane foam measured by this method is generally preferably 40 cc / cm ² / s or more.

<Rebound resilience>
Using a polyurethane foam temperature-controlled at an environment of 25 ° C. and 40 ° C. at a humidity of 50%, a rebound resilience BR _{25 at 25} ° C. and a rebound resilience BR ₄₀ at 40 ° C. were measured in accordance with JIS K6400 ( Units%).
The ratio of rebound resilience between 40 ° C. and 25 ° C. (BR ₄₀ / BR ₂₅ ) was calculated.

As is clear from Tables 1 and 2, all of the flexible polyurethane foams of Examples 1 to 16 have a low rebound resilience BR ₂₅ at 25 ° C, and a ratio of rebound resilience between 25 ° C and 40 ° C BR ₄₀ / BR. ₂₅ was high, air permeability was good, and the hardness ratio between 0 ° C. and 25 ° C. was low.
On the other hand, in Comparative Examples 3 and 7, the flexible urethane foam collapsed, and in Comparative Examples 5 and 8, the physical properties could not be measured because the foam shrank.
The polyurethane foam of Comparative Example 1 had low air permeability, and also had a poor BR ₄₀ / BR _{25 of} less than 1.6. The polyurethane foam of Comparative Example 4 had almost no air permeability, had a poor BR ₄₀ / BR _{25 of} less than 1.6, and had a high hardness ratio between 0 ° C. and 25 ° C.
The polyurethane foams of Comparative Examples 2 and 6 had a failure ratio of BR ₄₀ / BR ₂₅ of less than 1.6, and also had a high resilience at 25 ° C. BR ₂₅ .

As described above, the flexible polyurethane foams of Examples 1 to 16 have low rebound resilience, a high ratio of rebound resilience between 25 ° C and 40 ° C, and a low ratio of force gauge hardness between 0 ° C and 25 ° C, Because of its good air permeability, it is considered to be particularly suitable for bedding (mattress, pillow, etc.).

The flexible polyurethane foam of the present invention is suitable for seat cushions, bedding, furniture and the like.

Claims (6)

A flexible polyurethane foam comprising a reaction product of a mixture (H) containing a polyol component (A), an organic polyisocyanate component (D), a foaming agent (E), a catalyst (F), and a foam stabilizer (G),
The polyol component (A) contains a polyether polyol (B) and a divalent to hexavalent aliphatic polyhydric alcohol (C), and satisfies the following conditions (1) and (2);
The ratio (x) / (y) of the number of moles (x) of NCO groups in the organic polyisocyanate component (D) to the number of moles (y) of active hydrogen groups reacting with the NCO groups is 0.83 to 0.98. And
40 ° C. The flexible polyurethane foam ratio _(BR 40 / BR ₂₅₎ is 1.6 to 12.0 and modulus of repulsion elasticity _{BR 40} and 25 ° C. modulus of repulsion elasticity _{BR 25} of.
(1) The polyol component (A) has a hydroxyl value of 100 to 140.
(2) The total weight of oxyethylene units contained in the polyol component (A) is 10 to 40% by weight based on the weight of (A). The flexible polyurethane foam according to claim 1, wherein the polyol component (A) excluding the divalent to hexavalent aliphatic polyhydric alcohol (C) has a hydroxyl value of 100 to 130. The flexible polyurethane foam according to claim 1 or 2, wherein the polyol component (A) excluding the divalent to hexavalent aliphatic polyhydric alcohol (C) has a number average functional group number of 2.6 to 4.0. Furthermore, the polyol component (A) contains the polyester polyol (I), and the content of the polyester polyol (I) is 1 to 20% by weight based on the weight of the polyol component (A). The flexible polyurethane foam as described. The flexible polyurethane foam according to claim 4, wherein the ester group concentration of the polyol component (A) is 0.02 to 0.40 mmol / g. Furthermore, the polyol component (A) contains a polymer polyol (P), and the polymer polyol (P) contains polymer particles containing an ethylenically unsaturated compound as a constituent monomer. Polyurethane foam.