JP6470707B2 - Method for producing flexible polyurethane mold foam - Google Patents

Description

  The present invention relates to a method for producing a flexible polyurethane mold foam, and more particularly to a production method for obtaining a flexible polyurethane mold foam suitable for applications such as a cushion for a vehicle seat.

A flexible polyurethane mold foam is generally used for a vehicle seat cushion such as an automobile. When producing a flexible polyurethane mold foam, molding in various mold shapes is required. In various mold shapes, air voids due to coalescence of bubbles in the late reaction, sinking after gas release, etc. This tends to cause molding defects.
By improving the stability of the foam, good moldability can be obtained, but the closed cell properties become stronger, causing problems such as deterioration in durability due to deterioration in physical properties and reduction in productivity due to difficulty in demolding. To do.
For this reason, a method for producing a flexible polyurethane mold foam having good moldability and low closed cell properties is desired, but it has been difficult to achieve both by conventional methods (see Non-Patent Document 1).

Keiji Iwata, "Polyurethane resin handbook", Nikkan Kogyo Shimbun, 1st edition, pages 183-185 (1987)

  An object of the present invention is to provide a method for producing a flexible polyurethane mold foam having good moldability and low closed cell property.

As a result of intensive studies to solve these problems, the inventor of the present invention uses a polyol component having a specific structure and uses a reactive amine catalyst and a non-reactive amine catalyst in combination. The present inventors have found that a flexible polyurethane mold foam having low closed cell properties can be produced, and the present invention has been achieved.
That is, the present invention relates to a method for producing a flexible polyurethane mold foam in which a polyol component (A) and an organic polyisocyanate component (B) are reacted in the presence of a foaming agent (C) and a catalyst (D). ) Contains a polyol (A2) other than the polymer polyol (A1) obtained by polymerizing the vinyl monomer (v) in the presence of a radical polymerization initiator in the polyol (a), and (A1), The polyol (A2) contains the following polyol (a1), and at least one of the polyol (a) and polyol (A2) contains the following polyol (a2), and at least one of the polyol (a) and polyol (A2) The following polyol (a3) is contained therein, and the catalyst (D) is a non-reactive amine catalyst (D1) and a reactive amine catalyst (D2) [ It is a manufacturing method of the flexible polyurethane mold foam characterized by including the said polyol component (A) is excluded] .
Polyol (a1): An amine-based diol represented by the following general formula (1).

[However, R ₁ and R ₂ are each independently an alkyl group having 1 to 4 carbon atoms, R ₃ is independently hydrogen or a methyl group, and G is a linear alkylene group having 2 to 4 carbon atoms. Yes, n is a number with an average of 1-4. ]
Polyol (a2): an alkylene oxide adduct of an active hydrogen-containing compound, wherein the content of ethylene oxide units exceeds 18% by weight and is 30% by weight or less, and 70% or more of the terminal hydroxyl groups are primary. A polyoxyalkylene polyol which is a hydroxyl group, has a hydroxyl value (mgKOH / g) of 20 to 45 and an unsaturation degree of 0.12 meq / g or less.
Polyol (a3): an alkylene oxide adduct of an active hydrogen-containing compound, wherein the content of ethylene oxide units is 5 to 18% by weight, and 70% or more of the hydroxyl groups located at the terminals are primary hydroxyl groups, A polyoxyalkylene polyol having a value (mgKOH / g) of 20 to 45 and an unsaturation degree of 0.12 meq / g or less.

  According to the method for producing a flexible polyurethane mold foam of the present invention, it is possible to obtain a flexible polyurethane foam having a low closed cell property and good moldability with various shapes of molds as compared with the conventional method. I can do it.

  The polyol component (A) used for producing the flexible polyurethane mold foam in the present invention is a polymer polyol (A1) obtained by polymerizing the vinyl monomer (v) in the presence of a radical polymerization initiator in the polyol (a), And polyol (A2) other than (A1) is contained.

The polyol (A2) contains the polyol (a1).
The polyol (a1) is an amine-based diol represented by the following general formula (1). Usually, N, N-dialkyl (1 to 4 carbon atoms) aminoalkyl (2 to 4 carbon atoms) amine oxide (hereinafter referred to as ethylene oxide) It is obtained by adding EO and / or propylene oxide (hereinafter abbreviated as PO).

However, R ₁ and R ₂ are independently an alkyl group having 1 to 4 carbon atoms (methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, etc.), preferably methyl group and ethyl It is a group. R ₃ is independently hydrogen or a methyl group. G is a linear alkylene group having 2 to 4 carbon atoms (ethylene group, propylene group, etc.), preferably an alkylene group having 2 to 3 carbon atoms. n is a number with an average of 1 to 4, preferably 1 to 3.
Specific examples of (a1) include N, N-dimethylaminopropylamine PO2-4 mol adduct, N, N-dimethylaminopropylamine EO2-4 mol adduct, N, N-diethylaminopropylamine PO2 -4 mol adduct, EO 2-4 mol adduct of N, N-diethylaminopropylamine EO 2-4 mol adduct of N, N-dimethylaminoethylamine, EO 2-4 mol adduct of N, N-dimethylaminoethylamine Preferable is a PO2 molar adduct of N, N-dimethylaminopropylamine.

In the polyol component (A), the following polyol (a2) is further contained in at least one of the polyol (a) which is a raw material of the polymer polyol (A1) and the polyol (A2) other than (A1), (a ) And (A2) contain the following polyol (a3) in at least one of them.
The polyol (a2) and the polyol (a3) may be contained in either the polyol (a) or the polyol (A2), respectively, and may be contained in both, but the polyol (a2) is the polyol (A2). It is preferable that the polyol (a3) is contained in the polyol (a).
Polyol (a2): an alkylene oxide adduct of an active hydrogen-containing compound, wherein the content of ethylene oxide units exceeds 18% by weight and is 30% by weight or less, and 70% or more of the terminal hydroxyl groups are primary. A polyoxyalkylene polyol which is a hydroxyl group, has a hydroxyl value (mgKOH / g) of 20 to 45 and an unsaturation degree of 0.12 meq / g or less.
Polyol (a3): an alkylene oxide adduct of an active hydrogen-containing compound, wherein the content of ethylene oxide units is 5 to 18% by weight, and 70% or more of the hydroxyl groups located at the terminals are primary hydroxyl groups, A polyoxyalkylene polyol having a value (mgKOH / g) of 20 to 45 and an unsaturation degree of 0.12 meq / g or less.

  The polyol (a2) and polyol (a3) are alkylene oxide adducts of active hydrogen-containing compounds. Examples of the active hydrogen compound include a hydroxyl group-containing compound, an amino group-containing compound, a thiol group-containing compound, a phosphate compound; a compound having two or more active hydrogen-containing functional groups in the molecule; and a mixture of two or more of these. It is done.

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-valent alcohols such as pentaerythritol, sorbitol and sucrose; pyrogallol, catechol and hydroquinone Polyphenols; bisphenols such as bisphenol A, bisphenol F and bisphenol S; polybutadiene polyols; castor oil-based polyols; hydroxyalkyl (meth) acrylate (co) polymers and polyfunctionals such as polyvinyl alcohol (for example, Functional group 2 to 100) a polyol, and the like.
(Meth) acrylate means methacrylate and / or acrylate, and the same applies hereinafter.

Examples of amine group-containing compounds include alkanolamines, polyamines, and monoamines.
Examples of the alkanolamine include mono-, di- and tri-alkanolamines having 2 to 20 carbon atoms (for example, monoethanolamine, diethanolamine, triethanolamine and isopropanolamine).
As a polyamine (the number of primary and secondary amino groups: 2 to 8), as an aliphatic amine, an alkylenediamine having 2 to 6 carbon atoms (for example, ethylenediamine, propylenediamine and hexamethylenediamine), 4 to 20 carbon atoms. Polyalkylene polyamines (dialkylene triamine having 2 to 6 carbon atoms in the alkylene group to hexaalkylene heptamine, for example, diethylenetriamine and triethylenetetramine).
Also, aromatic polyamines having 6 to 20 carbon atoms (for example, phenylenediamine, tolylenediamine, xylylenediamine, diethyltoluenediamine, methylenedianiline and diphenyletherdiamine); alicyclic polyamines having 4 to 20 carbon atoms (for example, Isophoronediamine, cyclohexylenediamine, and dicyclohexylmethanediamine); heterocyclic polyamines having 4 to 20 carbon atoms (for example, piperazine and aminoethylpiperazine) and the like.
As monoamine, ammonia; as aliphatic amine, alkylamine having 1 to 20 carbon atoms (for example, n-butylamine and octylamine); aromatic monoamine having 6 to 20 carbon atoms (for example, aniline and toluidine); -20 alicyclic monoamine (for example, cyclohexylamine); C4-C20 heterocyclic monoamine (for example, piperidine) and the like.

  Polyvalent (2-8 valent) phenols include monocyclic polyphenols such as pyrogallol, hydroquinone and phloroglucin; bisphenols such as bisphenol A, bisphenol F and bisphenol sulfone; condensates of phenol and formaldehyde (novolaks); Examples include polyphenols described in Japanese Patent No. 3265641.

Examples of the polycarboxylic acid include aliphatic polycarboxylic acids having 4 to 18 carbon atoms (succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, etc.), and aromatic polycarboxylic acids having 8 to 18 carbon atoms (phthalic acid, Terephthalic acid, isophthalic acid, trimellitic acid, etc.) and mixtures of two or more thereof.
Two or more of these active hydrogen-containing compounds may be used in combination. Of these, polyhydric alcohols are preferred.

  As the alkylene oxide (hereinafter referred to as AO) to be added to the active hydrogen-containing compound, PO and EO are preferable. AO preferably contains only these, but other AO may be used in combination within a range of 10% by weight or less (particularly 5% by weight or less) in AO. Other AOs are preferably those having 4 to 8 carbon atoms, such as 1,2-, 1,3-, 1,4- and 2,3-butylene oxide and styrene oxide. Also good.

The number average functional group number of the polyol (a2) and the polyol (a3) is preferably 2 to 4, and more preferably 3 to 4. Even if the number of functional groups outside this range is included, the number average functional group number may be 2 to 4 (the same applies to the number average functional group number of other polyols). In the present invention, the number of functional groups of the polyol is considered to be the same as the number of functional groups of the starting material.
When the number average functional group number of (a2) and (a3) is 2 or more, the curing time is shortened and the productivity is improved, and when it is 4 or less, the elongation property of the foam is improved.

The hydroxyl value (mgKOH / g) of the polyol (a2) and the polyol (a3) is 20 to 45, preferably 25 to 42, more preferably 30 to 40 from the viewpoint of moldability of the foam. When the hydroxyl value is 20 or more, the foam hardness is improved, and when it is 45 or less, the foam has less closed cells and the foam is difficult to shrink.
In addition, the hydroxyl value in this invention is measured by the method prescribed | regulated to JISK0070 (1992 edition).

  The content of the EO unit based on the weight of the polyol (a2) is more than 18% by weight and 30% by weight or less, preferably 18.5 to 25% by weight, from the viewpoint of mechanical properties of the polyurethane. Further, the content of the EO unit based on the weight of the polyol (a3) is 5 to 18% by weight, preferably 7 to 16% by weight from the viewpoint of the mechanical properties of the polyurethane.

  The ratio of primary hydroxyl groups (primary hydroxyl group ratio) in all terminal hydroxyl groups of polyol (a2) and polyol (a3) is 70% or more, preferably 75% or more from the viewpoint of the vibration characteristics of the foam.

In the present invention, the primary hydroxyl group ratio is determined by ¹ H—N after pre-treatment of the sample in advance of esterification.
Measure and calculate by MR method.

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 polyoxyalkylene 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 calculation 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 unsaturation degree (meq / g) of the polyol (a2) and the polyol (a3) is in the range of 0 to 0.12, preferably 0 to 0.09, from the viewpoint of the mechanical properties of the polyurethane.
The measurement method and unit of unsaturation in the present invention are shown below.
Unsaturation degree: Conforms to JIS K1557-3, unit is meq / g

  The number average molecular weights of the polyols (a2) and (a3) are appropriately selected depending on the use of the polyol component, for example, the required physical properties of the polyurethane foam to be produced, and are not particularly limited, but from the viewpoint of mechanical properties of the polyurethane, 400 to 100, 000 is preferable, and 400 to 20,000 is more preferable.

  Specific examples of the polyols (a2) and (a3) include water PO adducts, glycerin PO adducts, water PO / butylene oxide copolymer adducts, water PO / butylene oxide copolymer adducts, and glycerin. And PO / butylene oxide copolymer adducts of pentaerythritol and PO / EO copolymer adducts of pentaerythritol.

  As a catalyst for synthesizing polyols (a2) and (a3), basic catalysts such as sodium hydroxide, potassium hydroxide, cesium hydroxide, potassium carbonate, triethylenediamine; boron trifluoride, tin chloride, triethylaluminum And acid catalysts such as heteropolyacid, tris (pentafluorophenyl) borane and tris (pentafluorophenyl) aluminum; zinc hexacyanocobaltate; phosphazene compound 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 AO adduct to manufacture, More preferably, it is 0.0005-1 weight%.

  The polymer polyol (A1) can be produced by polymerizing the vinyl monomer (v) by an ordinary method in the presence of a radical polymerization initiator in the polyol (a). Specific examples of the polymerization method include those described in US Pat. No. 3,383,351, Japanese Examined Patent Publication No. 39-25737, and the like.

  As the radical polymerization initiator, those that generate a free radical to initiate polymerization can be used, for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile). ), Azo compounds such as 2,2′-azobis (2-methylbutyronitrile); organic peroxides such as dibenzoyl peroxide, dicumyl peroxide, benzoyl peroxide, lauroyl peroxide and persuccinic acid; Examples thereof include inorganic peroxides such as persulfate and perborate. In addition, these can use 2 or more types together.

As vinyl monomer (v), aromatic vinyl monomer (v1), unsaturated nitrile (v2), (meth) acrylic acid ester (v3), other vinyl monomers (v4), and two or more of these Of the mixture.
Examples of (v1) include styrene, α-methylstyrene, hydroxystyrene, chlorostyrene, and the like.
Examples of (v2) include acrylonitrile and methacrylonitrile.
(V3) includes those composed of C, H and O atoms, for example, (meth) acrylic acid alkyl ester (alkyl group having 1 to 24 carbon atoms) [for example, methyl (meth) acrylate, butyl (meta ) Acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, eicosyl (meth) acrylate, docosyl (meth) acrylate], hydroxyalkyl (2 to 5 carbon atoms) (meth) acrylate [for example, Hydroxyethyl (meth) acrylate] and hydroxypolyoxyalkylene mono (meth) acrylate [for example, an alkylene group having 2 to 4 carbon atoms and a polyoxyalkylene chain having a number average molecular weight of 200 to 1000].

(V4) includes ethylenically unsaturated carboxylic acids and derivatives thereof, specifically (meth) acrylic acid, (meth) acrylamide, etc .; aliphatic or alicyclic hydrocarbon monomers, specifically alkenes ( Ethylene, propylene, norbornene, etc.), alkadienes (butadiene, etc.); fluorinated vinyl monomers, specifically fluorine-containing (meth) acrylates (perfluorooctylethyl methacrylate, perfluorooctylethyl acrylate, etc.), etc .; chlorine -Based vinyl monomers, specifically vinylidene chloride, etc .; nitrogen-containing vinyl monomers other than those mentioned above, specifically nitrogen-containing (meth) acrylates (diaminoethyl methacrylate, morpholinoethyl methacrylate, etc.); and vinyl-modified silicones Etc.
Preferred among these (v) are (v1) and (v2), particularly styrene and / or acrylonitrile.

The weight ratio of (v1), (v2), (v3) and (v4) in the vinyl monomer (v) can be changed according to the required physical properties of the polyurethane and is not particularly limited. An example is as follows.
The total of (v1) and (v2) is preferably 50 to 100% by weight, more preferably 90 to 100% by weight. The weight ratio of (v1) and (v2) is not particularly limited, but is preferably 10/90 to 100/0. (V3) is preferably 0 to 50% by weight, more preferably 0 to 20% by weight. (V4) is preferably 0 to 10% by weight, more preferably 0 to 5% by weight.
In addition to these monofunctional monomers, a small amount (preferably 0.05 to 1% by weight) of a bifunctional or higher (preferably 2 to 8 functional) polyfunctional vinyl monomer (v5) is used in (v). As a result, the strength of the polymer can be further improved. Examples of (v5) include divinylbenzene, ethylene di (meth) acrylate, polyalkylene (alkylene group having 2 to 8 carbon atoms, degree of polymerization: 2 to 10) glycol di (meth) acrylate, pentaerythritol triallyl ether, Examples include methylolpropane tri (meth) acrylate.

  The content of styrene in (v) is 10 to 100% by weight, preferably 15 to 90% by weight, more preferably 26 to 60% by weight, based on the weight of (v), from the viewpoint of flame retardancy of the foam. 80% by weight.

  In the polymer polyol (A1), the content of the polymer (v) is 25 to 60% by weight, preferably 26 to 50% by weight, based on the weight of (A1). If the content of the polymer is less than 25% by weight, sufficient foam hardness cannot be exhibited, and if it exceeds 60% by weight, the viscosity of (A1) becomes low and handling is difficult.

In (A1), the volume average particle diameter (R) of the polymer particles is preferably 0.9 μm or less from the viewpoint of the mechanical properties of the foam. If it is 0.9 μm or less, the moldability of the foam is good.
Examples of a method of reducing the volume average particle diameter (R) of the polymer particles include a method of increasing the ratio of (v2) in the vinyl monomer (v) constituting the polymer particles.

A method for measuring the volume average particle diameter (R) of the polymer particles will be specifically described below.
The obtained polymer polyol was diluted with the polyol used so that the transmittance of the laser beam was 70 to 90%, and the content (volume%) of particles of 10 μm or more was measured with the following particle size distribution analyzer. And the volume average particle diameter (μm) was measured.
Equipment: LA-750, manufactured by HORIBA, Ltd.
Measurement principle: Mie scattering theory Measurement range: 0.04 μm to 262 μm
Solution injection amount: He-Ne laser Measurement time: 20 seconds

<Volume average particle diameter>
According to the following formula.
Volume average particle diameter (μm) = Σ [q (J) × X (J)] / Σ [q (J)]
J: Particle size division number (1 to 85)
q (J): Frequency distribution value (volume%)
X (J): Particle size division number J-th particle size (μm)

  In the polyol (A2) of the polyol component (A), in addition to the polyols (a1), (a2) and (a3), if necessary, other polyols (a4) and / or (a5) may be contained. Good.

  The polyol (a4) has a number average functional group number of 2 to 8, a hydroxyl value of 20 to 130 mgKOH / g, an oxyalkylene group having 2 and 3 carbon atoms, and an oxyethylene unit (EO adduct). Is a polyoxyalkylene polyol having an EO unit content of 50 to 80% by weight.

Examples of the polyol (a4) include compounds having a structure in which AO is added to divalent to octavalent compounds among the active hydrogen-containing compounds, and two or more kinds may be used in combination.
As AO, those containing only PO and EO are preferable, but other AOs may be contained within a range of 10% by weight or less (particularly 5% by weight or less) in AO.
The addition format of PO and EO may be PO or EO block addition or random addition, but random addition is preferable.

  The number average functional group number of a polyol (a4) is 2-8, Preferably it is 3-4. When the number average functional group number of (a4) is 2 or more, the curing time is shortened and the productivity is improved, and when it is 8 or less, the stretch physical property of the foam is improved.

  The hydroxyl value (mgKOH / g) of (a4) is 20 to 130, preferably 21 to 120, more preferably 22 to 100, and particularly preferably 22 to 40. When the hydroxyl value is 20 or more, the foam hardness is improved. When the hydroxyl value is 130 or less, the number of closed cells in the foam decreases and the foam is difficult to shrink.

  The content of the oxyethylene unit in (a4) is 50 to 80% by weight, preferably 55 to 78% by weight, and more preferably 60 to 76% by weight. When the content of the EO unit is 50% by weight or more, the curing time is shortened, and when it is 80% by weight or less, the foam has less closed cells and the foam is difficult to shrink.

  Among the polyols (a4), a polyoxyalkylene polyol having an oxyethylene unit content of 50 to 80% by weight and an EO / PO random adduct is preferred from the viewpoint of foam breathability.

  In the present invention, the polyol (a5) includes aliphatic amine AO adducts (a5-1), polyhydric alcohols, polyhydric phenols, and their AO adducts (a5-2), polyester polyols (a5-3). And polyols other than (a1), (a2), (a3) and (a4), and the like may be used in combination.

Examples of the aliphatic amine (a5-1) include primary and / or secondary amines, and the number of primary and / or secondary amino groups is preferably 1 to 4, more preferably 1 to 3. The number of active hydrogens derived from amino groups is preferably 2-8, and more preferably 2-4.
Specifically, as (a5-1), alkanolamine; A1 addition of C1-20 alkylamine, C2-6 alkylenediamine and alkylene group C = 2-6 polyalkylene polyamine (degree of polymerization 2-8) Thing etc. are mentioned. (A5-1) is preferably an AO adduct of alkanolamine and alkylenediamine.
As the AO to be added in (a5-1), from the viewpoint of mechanical properties of the flexible polyurethane foam, those containing PO and / or EO as the main component and optionally containing other AO of 20% by weight or less are particularly preferable. PO and a combination of PO and EO.

  Examples of the polyhydric alcohol and polyhydric phenol (a5-2) include the same as (a2) and (a3).

  The hydroxyl value (mgKOH / g) of the other polyol (a5) is preferably from 10 to 2000, more preferably from 20 to 1900, particularly preferably from 100 to 1850, from the viewpoint of mechanical properties of the flexible polyurethane foam.

  The content of the EO units based on the total weight of the polyol component (A) used in the present invention (excluding the weight of the polymer of the vinyl monomer (v)) is preferably 0 to 0 from the viewpoint of strain characteristics and durability characteristics. It is 18 weight%, More preferably, it is 5-16 weight%.

Regarding the content of each polyol based on the total weight of polyol (a1), polyol (a2) and polyol (a3) in the polyol component (A) [excluding the weight of the polymer of vinyl monomer (v)] It is as follows.
The polyol (a1) is preferably 0.01 to 5% by weight, more preferably 0.03 to 2% by weight, and particularly preferably 0.05 to 0.8% by weight from the viewpoint of moldability. The polyol (a2) is preferably 40 to 88% by weight, more preferably 50 to 78% by weight, from the viewpoint of moldability. The polyol (a3) is preferably 10 to 58% by weight, more preferably 20 to 48% by weight, from the viewpoint of mechanical properties. The polyol (a4) is preferably 0 to 10% by weight, more preferably 0.1 to 5% by weight, from the viewpoint of moldability. The polyol (a5) is preferably 0 to 20% by weight, more preferably 0.1 to 10% by weight, from the viewpoint of mechanical properties.

The total content of the polyols (a2) and (a3) based on the weight of the polyol component (A) [excluding the weight of the polymer of the vinyl monomer (v)] is 50 to 50 from the viewpoint of the mechanical properties of the flexible polyurethane foam. preferably 99.9 9 wt%, more preferably 70 to 99 wt%, particularly preferably 80 to 98 wt%.

  As the organic polyisocyanate component (B) used in the method for producing the flexible polyurethane mold foam of the present invention, those conventionally used for polyurethane production 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.

Examples of the aromatic polyisocyanate include C (excluding carbon in the NCO group; the same as the following isocyanates) 6 to 16 aromatic diisocyanates, C6 to 20 aromatic triisocyanates, and crude products of these isocyanates. . Specific examples include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4′- and / or 4, 4'-diphenylmethane diisocyanate (MDI), polymethylene polyphenyl isocyanate (crude MDI), and the like.
Examples of the aliphatic polyisocyanate include C6-10 aliphatic diisocyanate. Specific examples include 1,6-hexamethylene diisocyanate and lysine diisocyanate.

Examples of the alicyclic polyisocyanate include C6-16 alicyclic diisocyanate. Specific examples include isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and norbornane diisocyanate.
Examples of the araliphatic polyisocyanate include C8-12 araliphatic diisocyanate. Specific examples include xylylene diisocyanate, α, α, α ′, α′-tetramethylxylylene diisocyanate, and the like.
Specific examples of the modified polyisocyanate include urethane-modified MDI and carbodiimide-modified MDI.
Among these, aromatic polyisocyanates and modified products thereof are preferable.

In the method for producing a flexible polyurethane mold foam of the present invention, a foaming agent (C) is used in addition to the polyol component (A) and the organic polyisocyanate component (B). If necessary, other additives may be used.
As a foaming agent (C), it is preferable to contain water and to contain a well-known foaming agent. Examples of known foaming agents include hydrogen atom-containing halogenated hydrocarbons, low-boiling hydrocarbons, and liquefied carbon dioxide, and two or more of them may be used in combination.
Specific examples of the hydrogen atom-containing halogenated hydrocarbon include methylene chloride and HCFC (hydrochlorofluorocarbon) type (for example, HCFC-123 and HCFC-141b); HFC (hydrofluorocarbon) type (for example, HFC-245fa). And HFC-365mfc); HFO (hydrofluoroolefin) type (for example, HFO-1336mzzZ) and the like.
The low boiling point hydrocarbon is a hydrocarbon having a normal boiling point of −5 to 70 ° C., and specific examples thereof include butane, pentane, and cyclopentane.

  The amount of water used based on the weight of the polyol component (A) is preferably 1.0 to 6.0% by weight, more preferably based on the weight of the polyol component (A), from the viewpoint of moldability and density of the foam. Is 2.0 to 5.0% by weight.

In the method for producing a flexible polyurethane mold foam of the present invention, a catalyst (D) is used.
As the catalyst (D), a non-reactive amine catalyst (D1) and a reactive amine catalyst (D2) are used in combination from the viewpoints of fogging, polycarbonate contamination, and urethane foam moldability. If (D1) is not used, the foam cannot be molded. If (D2) is not used, the foaming reaction does not proceed sufficiently, the curing property is deteriorated, and the molding of the foam becomes difficult.

  Examples of the non-reactive amine catalyst (D1) include bis (N, N-dimethylamino-2-ethyl) ether, triethylenediamine, N, N, N ′, N′-tetramethylhexamethylenediamine, and N-ethylmorpholine. , Tertiary amine catalysts containing no active hydrogen, such as tetramethylethylenediamine, diaminobicyclooctane, 1,2-dimethylimidazole, 1-methylimidazole and 1,8-diazabicyclo- [5,4,0] -undecene-7 Is mentioned. Of these, triethylenediamine and bis (N, N-dimethylamino-2-ethyl) ether are preferred.

  Examples of the reactive amine catalyst (D2) include tertiary amine catalysts having active hydrogen (for example, a hydroxyl group, a thiol group, a carboxyl group, and preferably a hydroxyl group). Specific examples include dimethylethanolamine, diethylethanolamine, Dimethylhexanolamine, “DABCO NE300”, “DABCO1070” manufactured by Air Products Japan Co., Ltd., “Kaorizer No23NP”, “Kaorizer No25”, “Kaorizer No26”, “Kaorizer No27”, “Kaorizer No28” manufactured by Kao Corporation ”,“ Kaorizer P-200 ”,“ TOYOCAT HX63 ”,“ TOYOCAT HX70 ”,“ TOYOCAT RX20 ”,“ TOYOCAT RX21 ”,“ TOYOCAT RX24 ”,“ RZE ”manufactured by Tosoh Corporation A ", and the like. Among these, it is preferable to use “DABCO NE300” from the viewpoint of contamination to polycarbonate.

As the catalyst (D), in addition to the non-reactive amine catalyst (D1) and the reactive amine catalyst (D2), all the usual catalysts for promoting the urethanization reaction can be used. Examples thereof include carboxylates and organometallic compounds (D3).
Examples of (D3) include stannous octylate, dibutylstannic dilaurate, and lead octylate.

The amount of the catalyst (D) used is 0.01 to 5 with respect to 100 parts by weight of the polyol component (A) used in the production of the urethane foam from the viewpoint of improving mechanical properties (tensile strength, tear strength, compression hardness). 0.0 part by weight is preferable, and 0.1 to 2.0 parts by weight is more preferable.
Of the catalyst (D), the non-reactive amine catalyst (D1) is used in an amount of 0.001 to 0.20 with respect to 100 parts by weight of the polyol component (A) from the viewpoint of fogging and contamination to polycarbonate. Part by weight is preferable, and 0.01 to 0.17 part by weight is more preferable.
The amount of the reactive amine catalyst (D2) used is preferably 0.009 to 4.8 parts by weight, more preferably 0.09 to 1.83 parts by weight, based on 100 parts by weight of the polyol component (A). is there.

  Other additives include foam stabilizers (dimethylsiloxanes, polyether-modified dimethylsiloxanes, etc.), colorants (dyes and pigments), plasticizers (phthalates, adipates, etc.), organic fillers (synthesis) Short fibers, hollow microspheres made of thermoplastic or thermosetting resins, etc.), flame retardants (phosphate esters and halogenated phosphate esters, etc.), anti-aging agents (triazoles, benzophenones, etc.), antioxidants (hindered phenols) And hindered amines), and the like, and can be reacted in the presence of these known additives.

  Regarding the use amount of the other additives based on the weight of the polyol component (A), the foam stabilizer is preferably 10% by weight or less, more preferably 0.5 to 5% by weight. The colorant is preferably 1% by weight or less. The plasticizer is preferably 10% by weight or less, more preferably 5% by weight or less. The organic filler is preferably 50% by weight or less, more preferably 30% by weight or less. The flame retardant is preferably 30% by weight or less, more preferably 5 to 20% by weight. The anti-aging agent is preferably 1% by weight or less, more preferably 0.01 to 0.5% by weight. The antioxidant is preferably 1% by weight or less, more preferably 0.01 to 0.5% by weight. The total amount of other additives used is preferably 50% by weight or less, more preferably 0.2 to 30% by weight.

  In the method for producing a flexible polyurethane mold foam of the present invention, the isocyanate index (NCO INDEX) [(equivalent ratio of NCO group / active hydrogen atom-containing group) × 100] during foam production is preferably 60 to 150, more preferably. Is 70 to 135, particularly preferably 80 to 120.

Moreover, the conditions which make a polyol component (A) and an organic polyisocyanate component (B) react may be the well-known conditions normally used.
As an example, first, a predetermined amount of the polyol component (A), a foaming agent, and other additives as required is mixed. The mixture (polyol premix) and the isocyanate component are then rapidly mixed using a polyurethane low pressure or high pressure injection foamer or stirrer. The obtained mixed liquid is poured into a closed mold or an open mold (made of metal or resin) to cause urethanization reaction, and after curing for a predetermined time, it is demolded to obtain a polyurethane foam.

The flexible polyurethane mold foam obtained by the production method of the present invention preferably has a core density of 35 to 60 kg / m ³ . The core density can be measured based on the method of JIS K6401 relating to the measurement of physical properties of polyurethane foam.
The rebound resilience (%) is preferably 65% or more from the viewpoint of cushion feeling when the vehicle seat cushion material is used. The elongation (%) is preferably 100% or more from the viewpoint of the mechanical properties of the foam. The wet heat compression residual strain (%) is preferably 20% or less from the viewpoint of mechanical properties when used as a cushion material for a vehicle seat.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited by this. In Examples and Comparative Examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively, unless otherwise specified.

[Examples 1 to 9 and Comparative Examples 1 to 6]
A predetermined amount of organic polyisocyanate B is added to the number of parts of the polyol premix (mixture of components other than organic polyisocyanate) shown in Table 1 so as to have an NCO index of 100. After stirring at 4000 rpm for 6 seconds, it was poured into a 300 mm (length) x 300 mm (width) x 100 mm (height) aluminum mold whose temperature was adjusted to 65 ° C, and curing time (time from raw material injection to demolding) Molded in 4 minutes 30 seconds.
Table 1 shows the measurement results such as physical property values of each foam. The core density is a density measured by cutting out from the center of the foam into a size of 100 mm × 100 mm × 50 mm.

The polyurethane foam raw materials in Examples and Comparative Examples are as follows.
1. Polyol component (A)
(1) Polyol (a2-1): obtained by adding PO to glycerin using potassium hydroxide as a catalyst and then adding EO, hydroxyl value 33.5, content of terminal EO unit 20%, Polyoxyethylene polyoxypropylene polyol having a primary hydroxyl group ratio of 78% and a degree of unsaturation of 0.05 meq / g.
(2) Polyol (a2-2): Hydroxyl value 32.5, content of terminal EO unit 18.5 obtained by adding PO to glycerin using potassium hydroxide as a catalyst and then adding EO %, 79% of primary hydroxyl groups of terminal hydroxyl groups, polyoxyethylene polyoxypropylene polyol having an unsaturation degree of 0.06 meq / g.
(3) Polymer polyol (A1-1): obtained by blocking addition of PO and EO to pentaerythritol using potassium hydroxide as a catalyst, having a functional group number of 4.0, a hydroxyl value of 32, and a terminal EO unit PO and EO using 12% polyoxyethylene polyoxypropylene polyol (a3-1) having an amount of 12%, a terminal hydroxyl group ratio of 75%, an unsaturation of 0.08 meq / g, and glycerol with potassium hydroxide as a catalyst. Polyoxyethylene poly having a functional group number of 3.0, a hydroxyl value of 34, a terminal EO unit content of 14%, a terminal hydroxyl group ratio of 82%, and an unsaturation of 0.07 meq / g. In a mixture (weight ratio: 20/80) of two types of polyol (a3) which is oxypropylene polyol (a3-2), vinyl monomer (v-1) That styrene and acrylonitrile (weight ratio: 30/70) polymer polyols obtained by copolymerizing (polymer content 33.5%), the volume average particle (R) 0.4 .mu.m of the polymer particles.
(4) Polymer polyol (A1-2): Hydroxyl value 33.5, content of terminal EO unit 15 obtained by adding PO to glycerin using potassium hydroxide as a catalyst and then adding EO 15 %, In the polyol (a3) which is a polyoxyethylene polyoxypropylene polyol (a3-3) having a primary hydroxyl group ratio of 80% and a degree of unsaturation of 0.05 meq / g, the vinyl monomer (v-1) Polymer polyol (polymer content 33.5%) obtained by copolymerization of a certain styrene and acrylonitrile (weight ratio: 30/70), volume average particle (R) 0.4 μm of polymer particles.
(5) Polymer polyol (A1-3): hydroxyl group value 33.5, content of terminal EO unit 20 obtained by adding PO to glycerin using potassium hydroxide as a catalyst and then adding EO 20 %, In the polyol (a2) which is a polyoxyethylene polyoxypropylene polyol (a2-1) having a primary hydroxyl group ratio of 78% and a degree of unsaturation of 0.05 meq / g, the vinyl monomer (v-1) Polymer polyol (polymer content 33.5%) obtained by copolymerization of a certain styrene and acrylonitrile (weight ratio: 30/70), volume average particle (R) 0.4 μm of polymer particles.
(6) Polyol (a1-1): PO 2 mol adduct of N, N-dimethylaminopropylamine.

(7) Polyol (a4-1): 1 mol of EO was added to 1 mol of glycerol using potassium hydroxide as a catalyst, and then 99.9 mol of EO and 34.6 mol of PO were randomly added. Is a polyether polyol obtained by removing. Hydroxyl value = 24, EO unit content = 70.0%.
(8) Polyol (a5-1): Triethanolamine. Hydroxyl value = 1130.
(9) Polyol (a5-2): Polypropylene obtained by adding PO to sorbitol using potassium hydroxide as a catalyst and having a functional group number of 6.0, a hydroxyl value of 490, and a terminal hydroxyl group having a primary hydroxyl group ratio of 2% Polyol.

2. Foaming agent (C)
2. Foaming agent (C-1): water Catalyst (D)
Catalyst (D1-1): “DABCO 33LV” manufactured by Air Products Japan Co., Ltd .: (33% dipropylene glycol solution of triethylenediamine)
Catalyst (D2-1): “DABCO NE300” manufactured by Air Products Japan Co., Ltd.
4). Foam stabilizer (E)
Foam stabilizer (E-1): “DOW CORNING TORAY SZ-1346E” (polysiloxane foam stabilizer) manufactured by Toray Dow Corning
5. Organic polyisocyanate component (B)
Polyisocyanate (B-1): TDI-80 / crude MDI = 70/30 (weight ratio), NCO% = 42.8

The measurement method and unit of foam physical properties are shown below.
Core density: Conforms to JIS K6400, unit is kg / m ³
Foam hardness (25% -ILD): Conforms to JIS K6400, unit is N / 314 cm ²
Humid heat compression residual strain: Conforms to JIS K6400, temperature 50 ° C., humidity 95%. Units%
Rebound resilience: Conforms to JIS K6400, unit is%
Elongation: Conforms to JIS K6400, unit is%
Rise time: Time from the start of stirring to reaching the maximum height of foam when foaming is performed at 25 ° C. Curing property: After removing the foam, press the finger against the foam and leave the mark after 5 seconds. Was confirmed and evaluated according to the following criteria.
○: No finger marks remain.
X: Fingerprints remain.

Formability was evaluated by measuring the settling rate during free foaming.
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. In other words, a blended formulation with a low settling rate is preferable because of good moldability. If the settling rate is 5% or less, it is judged that the urethane foam has high cell stability and good moldability. If it exceeds 5%, the cell is unstable and the moldability is insufficient. Judgment can be made.

The closed cell property (single cell property) was evaluated as follows.
The polyurethane foam (test piece) after demolding was subjected to foam breaking treatment that passed between crushing rollers with a roller interval of 40 mm twice, and each load value (kN) was measured.
If the 1st time is 1 kN or less, and the 2nd time is 5 kN or less, it is judged that sufficient foam breaking treatment has been performed and the single bubble property is low.

From the results of Table 1, the same core density (kg / m ³ ) [range of (40.1 to 42.2)]
In contrast, in the examples, the curing property is satisfied, the settling rate of the free foam is low, the stability of the cell is high, and the moldability is good. Furthermore, in an Example, it turns out that the load value at the time of bubble breaking is low, and a single bubble property is low. On the other hand, Comparative Examples 1, 4 and 6 have high curing properties and moldability, but have high self-foaming properties, are difficult to remove during actual molding, and there is a possibility that cracking may occur at thick portions. Recognize. In Comparative Examples 2, 3, and 5, although the cell foam is low, the cell is unstable, the curing property is low, and the production efficiency may be reduced. It can be seen that only in the examples, a polyurethane foam having a curing property commensurate with the demolding time, having good moldability and having a stable cell, but having a low self-foaming property, which is the contradiction, is obtained. .

The flexible polyurethane mold foam obtained by the method for producing a flexible polyurethane mold foam of the present invention has a stable cell with good moldability and a soft polyurethane foam having low foamability as compared with the conventional method. Can do.
Because of the above effects, the polyurethane foam obtained by the production method of the present invention is useful as a sheet material. It is particularly useful as a cushion material for vehicle seats.

Claims (5)

In the method for producing a flexible polyurethane mold foam, the polyol component (A) and the organic polyisocyanate component (B) are reacted in the presence of the blowing agent (C) and the catalyst (D).
Polyol component (A) is a polymer polyol (A1) obtained by polymerizing vinyl monomer (v) in the presence of a radical polymerization initiator in polyol (a), and polyol (A2) other than (A1) The polyol (A2) contains the following polyol (a1), and at least one of the polyol (a) and polyol (A2) contains the following polyol (a2), and the polyol (a) and polyol (A2) ) Contains the following polyol (a3) in at least one of them, and the catalyst (D) contains a non-reactive amine catalyst (D1) and a reactive amine catalyst (D2) [excluding the polyol component (A)]. A method for producing a flexible polyurethane mold foam, comprising:

Polyol (a1): An amine-based diol represented by the following general formula (1).

[However, R ₁ and R ₂ are each independently an alkyl group having 1 to 4 carbon atoms, R ₃ is independently hydrogen or a methyl group, and G is a linear alkylene group having 2 to 4 carbon atoms. Yes, n is 1 on average
It is a number that becomes ~ 4. ]
Polyol (a2): an alkylene oxide adduct of an active hydrogen-containing compound, wherein the content of ethylene oxide units exceeds 18% by weight and is 30% by weight or less, and 70% or more of the terminal hydroxyl groups are primary. A hydroxyl group and a hydroxyl value (mgKOH / g) of 20 to 45,
A polyoxyalkylene polyol having an unsaturation degree of 0.12 meq / g or less.
Polyol (a3): an alkylene oxide adduct of an active hydrogen-containing compound, wherein the content of ethylene oxide units is 5 to 18% by weight, and 70% or more of the hydroxyl groups located at the terminals are primary hydroxyl groups, Value (mgKOH / g) of 20 to 45, unsaturation of 0.12
A polyoxyalkylene polyol having a meq / g or less. The method for producing a flexible polyurethane mold foam according to claim 1, wherein the polyol (a2) is contained in the polyol (A2) and the polyol (a3) is contained in the polyol (a).   The content of the non-reactive amine catalyst (D1) is 0.001 to 0.20 parts by weight with respect to 100 parts by weight of the polyol component (A), and the content of the reactive amine catalyst (D2) is polyol. The method for producing a flexible polyurethane mold foam according to claim 1 or 2, wherein the amount is 0.009 to 4.8 parts by weight per 100 parts by weight of the component (A). Based on the total weight of polyol (a1), polyol (a2) and polyol (a3), the content of polyol (a1) in polyol component (A) [excluding the weight of the polymer of vinyl monomer (v)] 0.01 to 5% by weight, the content of polyol (a2) is 40 to 88% by weight, the content of polyol (a3) is 10 to 58% by weight, and (a2) and (a3
The process for producing a flexible polyurethane molded foam according total content in any of claims 1 to 3 is 95 to 99.9 9 weight percent). The soft foam according to any one of claims 1 to 4, wherein the foam has a core density of 35 to 60 kg / m ³ , an elongation of 100% or more, a resilience of 65% or more, and a wet heat compression residual strain of 20% or less. Method for producing polyurethane mold foam.