JP2006104404A - Polyurethane pad for vehicle seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyurethane pad for a vehicle seat which has extremely high use percentage of a natural raw material, has excellent moldability and curing properties, and is especially excellent in physical properties of a core density, a modulus of elasticity in repulsion, and a compression residual strain rate (wet core). <P>SOLUTION: The pad for the vehicle seat consists of a polyurethane foam where a polyol component (A) and a polyisocyanate component (B) are reacted in the presence of a catalyst (D) and a foaming agent (E), wherein (A) consists of a castor oil type polyol (a2) obtained by adding a 2-4C alkylene oxide to castor oil and having a primary hydroxy group ratio of ≥10 mol% and a hydroxyl group value of 20-350, and a polyol (a1), other than the castor oil type polyol (a2), having an average functional group number of 2.0-6.0 and a hydroxyl group value of 20-800; and (B) consists of a diphenylmethane diisocyanate-based polyisocyanate (b1) and a tolylene diisocyanate-based polyisocyanate (b2). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polyurethane pad for a vehicle sheet having a remarkably high use rate of a natural raw material and excellent in moldability, curing properties, physical properties and the like.

Conventionally, flexible polyurethane foam is widely used for automobile seats as well as cushioning members such as heat insulating materials and furniture because of its excellent cushioning properties.
As a method for producing a flexible polyurethane foam excellent in foam physical properties, moldability and surface curing properties, specifically, for example, a polyhydroxyl compound, an organic polyisocyanate, a catalyst, a foam stabilizer, a foaming agent (water) and an additive are used. There has been proposed a method of reacting by using them (see Patent Documents 1 and 2). This additive is castor oil (specifically, refined castor oil, semi-refined castor oil, unrefined castor oil, hydrogenated castor oil, etc.) or fatty acid esters, and the amount used is based on the polyhydroxyl compound. It is in the range of 0.1 to 15% by mass.
Japanese Patent Laid-Open No. 5-59144 JP-A-7-206962

However, the flexible polyurethane foam produced according to Patent Documents 1 and 2 is particularly suitable for heat aging and long-term durability as a polyurethane pad used in vehicle seats such as recent automobile seats that require a high degree of comfort and safety. On the other hand, it is hard to say that the physical properties of the foam are still sufficient.
In addition, from the viewpoint of depetroducing chemical raw materials and carbon neutral in recent years, it is also required to further increase the amount of natural raw materials used.

  An object of the present invention is a polyurethane for vehicle seats in which the use ratio of natural raw materials is remarkably high, the moldability and curing properties are good, and the core density, rebound resilience, and compression residual strain (wet core) are particularly excellent. Is to provide a pad.

  In order to achieve the above object, the present invention provides a castor oil-based polyol (a2) having a hydroxyl group primary conversion of 10 mol% or more and a hydroxyl value of 20 to 350, which is obtained by adding a C2-4 alkylene oxide to castor oil, A polyol component (A) composed of a polyol (al) having an average functional group number of 2.0 to 6.0 and a hydroxyl value of 20 to 800 other than the castor oil-based polyol (a2), a diphenylmethane diisocyanate polyisocyanate (b1), It comprises a polyurethane foam obtained by reacting a polyisocyanate component (B) comprising tolylene diisocyanate polyisocyanate (b2) in the presence of a catalyst (D) and a foaming agent (E). It is a pad for a vehicle seat.

  The present invention relates to a castor oil-based polyol (a2) having a hydroxyl group primary ratio of 10 mol% or more and a hydroxyl value of 20 to 350 obtained by adding an alkylene oxide having 2 to 4 carbon atoms to castor oil, and the castor oil-based polyol (a2). A polyol component (A) composed of a polyol (al) having an average functional group number of 2.0 to 6.0 and a hydroxyl value of 20 to 800, a diphenylmethane diisocyanate polyisocyanate (b1), and a tolylene diisocyanate polyisocyanate ( characterized in that it comprises a polyurethane foam obtained by reacting a polyisocyanate component (B) consisting of b2) in the presence of a catalyst (D), a foaming agent (E) and a foam stabilizer (F). It is a pad for a vehicle seat.

  The present invention relates to a castor oil-based polyol (a2) having a hydroxyl group primary conversion ratio of 10 mol% or more and a hydroxyl value of 20 to 350 obtained by adding an alkylene oxide having 2 to 4 carbon atoms to castor oil, and the castor oil-based polyol (a2). A polyol component (A) composed of a polyol (al) having an average functional group number of 2.0 to 6.0 and a hydroxyl value of 20 to 800, a diphenylmethane diisocyanate polyisocyanate (b1), and a tolylene diisocyanate polyisocyanate ( characterized in that it comprises a polyurethane foam obtained by reacting a polyisocyanate component (B) comprising b2) with a crosslinking agent (C) in the presence of a catalyst (D) and a foaming agent (E). It is a pad for a vehicle seat.

  The present invention relates to a castor oil-based polyol (a2) having a hydroxyl group primary conversion ratio of 10 mol% or more and a hydroxyl value of 20 to 350 obtained by adding an alkylene oxide having 2 to 4 carbon atoms to castor oil, and the castor oil-based polyol (a2). A polyol component (A) comprising a polyol (al) having an average functional group number of 2.0 to 6.0 and a hydroxyl value of 20 to 800, a diphenylmethane diisocyanate polyisocyanate (b1), and a tolylene diisocyanate polyisocyanate ( Polyurethane foam obtained by reacting a polyisocyanate component (B) comprising b2) with a crosslinking agent (C) in the presence of a catalyst (D), a foaming agent (E) and a foam stabilizer (F) A vehicle seat pad characterized by comprising:

  This invention is each said vehicle seat pad whose compounding mass ratio of a polyol (a1) and a castor oil-type polyol (a2) is 84 / 16-30 / 70.

  This invention is each said vehicle seat pad whose compounding mass ratio of diphenylmethane diisocyanate type polyisocyanate (b1) and tolylene diisocyanate type polyisocyanate (b2) is 99 / 1-60 / 40.

Further, according to the present invention, each of the above vehicle seats has a density of a core portion of polyurethane foam of ³⁰ to 70 kg / m ³ , a rebound resilience of 40 to 65%, and a compressive residual strain (wet core) of 15% or less. Pad.

  For the first time according to the present invention, a polyurethane pad for a vehicle seat having a remarkably high use rate of natural raw materials, good moldability and curing properties, and particularly excellent core density, rebound resilience and compression residual strain (wet core) properties. It became possible to provide.

Further, the contents of the present invention will be described in detail.
First, the polyol component (A) used for the production of the polyurethane foam in the present invention comprises a castor oil-based polyol (a2) and a polyol (al) other than the castor oil-based polyol (a2). This polyol (a1) is a polyol having an average functional group number of 2.0 to 6.0 and a hydroxyl value of 20 to 800 other than castor oil-based polyol (a2). If the average number of functional groups is less than 2.0, the compressive residual strain becomes worse and the curing time becomes longer, so that the practicality is poor, and if it exceeds 6.0, the number of closed cells increases and the elongation becomes worse. If the hydroxyl value is less than 20, the compression residual strain is poor and the curing time becomes long, and if it exceeds 800, the number of closed cells increases, resulting in poor practicality.
In the present invention, when the polyol (a1) is a mixture, not only the case where all the individual polyols have an average functional group number of 2.0 to 6.0 and a hydroxyl value of 20 to 800, but the individual polyols have an average functional group. Even if the number of groups is 2.0 to 6.0 and the hydroxyl value is in the range of 20 to 800 or outside the range, the mixture as a whole satisfies the condition of the average functional group number of 2.0 to 6.0 and the hydroxyl value of 20 to 800. Including.

  Specific examples of the polyol (a1) include a polyester polyol, a polycarbonate polyol, a polyether polyol, a polymer polyol, a poly (meth) acryl polyol, a copolyol thereof, or a mixture of any two or more thereof. It is done. Of these polyol components, polyether polyols and / or polymer polyols are preferred.

Examples of the polyester polyol include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalenedicarboxylic acid, trimellitic acid One or more of polycarboxylic acid such as acid, acid ester or acid anhydride, and ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butane Diol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonane Diol, diethylene glycol, dipropylene glycol, 1 4-cyclohexanedimethanol, ethylene oxide of bisphenol A (hereinafter abbreviated as EO) or propylene oxide (hereinafter abbreviated as PO) adduct, low molecular alcohols such as trimethylolpropane, glycerin and pentaerythritol, hexamethylene Examples thereof include polyester polyols and polyester amide polyols obtained by a dehydration condensation reaction with one or more of low molecular weight amines such as diamine, xylylenediamine, and isophorone diamine, and low molecular weight amino alcohols such as monoethanolamine and diethanolamine.
Moreover, for example, lactone polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone, using low molecular alcohols, low molecular amino alcohols, and the like as initiators.

  Examples of the polycarbonate polyol include dehydrochlorination reaction of low molecular alcohols and phosgene used in the synthesis of the polyester polyol described above, or esters of the low molecular alcohols with diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and the like. What is obtained by an exchange reaction is mentioned.

As the polyether polyol, for example, low molecular alcohols, low molecular amines, low molecular amino alcohols used for the synthesis of the above-mentioned polyester polyols, and EO, PO, tetrahydrofuran, etc. are opened using phenols as initiators. Polymerized polyoxyethylene polyols, polyoxypropylene polyols, polytetramethylene ether polyols, polyoxyethylene polyoxypropylene polyols, and polyester ether polyols having the above-described polyester polyols and polycarbonate polyols as initiators may be mentioned. More specifically, those obtained by block addition of PO and EO and polyoxyethylene polyoxypropylene polyols having a content of oxyethylene units having EO added to the terminal and having a content of 5 to 50% by mass are preferred. When the content of the oxyethylene unit is less than 5% by mass, the curing property is deteriorated, and when it exceeds 50% by mass, closed cells are not preferable.
Of these, polyoxyethylene polyoxypropylene polyol is particularly preferable.

The polymer polyol includes a method of polymerizing an ethylenically unsaturated monomer in a polyether polyol, a method of mixing separately produced polymer fine particles into a polyether polyol, a macromonomer having an ethylenically unsaturated group and an ethylenically unsaturated monomer. It is produced by a method of polymerizing in a polyether polyol. This polymer polyol is also called polymer polyol-containing polyether polyol.
Examples of the ethylenically unsaturated monomer include styrene and acrylonitrile.
Of these, those obtained by polymerizing ethylenically unsaturated monomers in polyether polyol are preferred, and those obtained by polymerizing ethylenically unsaturated monomers in polyoxypropylene triol are more preferred.
The content of the polymer fine particles is preferably 50% by mass or less, particularly preferably 30% by mass or less, based on the total polyether polyol. When the content of the polymer fine particles exceeds 50% by mass, the viscosity of the polymer polyol is increased, and workability is deteriorated during molding.

  Examples of poly (meth) acrylic polyols include monomers of (meth) acrylic acid ester compounds containing hydroxyl groups such as 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, and hydroxypropyl methacrylate. And one or more other ethylenically unsaturated compounds in the presence or absence of a radical polymerization initiator and in the presence or absence of a solvent such as batch polymerization or continuous polymerization. The thing obtained by making it react by the method of radical polymerization is mentioned.

Moreover, if it has an alcoholic hydroxyl group, for example, in addition to dimer acid diol and hydrogenated dimer acid diol, epoxy resin, polyester resin, rosin resin, urea resin, melamine resin, phenol resin, polyvinyl alcohol, etc. These resins can also be used as the polyol (a1).
As described above, these can be used alone or in admixture of two or more.

The castor oil-based polyol (a2) is a polyol obtained by adding C2-C4 alkylene oxide to castor oil, and the primary ratio of the hydroxyl group must be 10 mol% or more from the viewpoint of curing properties. And the hydroxyl value is 20 to 350.
Examples of the alkylene oxide include EO, PO, and latrahydrofuran, which can be added to castor oil randomly or in blocks.
These can be used alone or in admixture of two or more.

  The blending mass ratio of the polyol (a1) and the castor oil-based polyol (a2) in the polyol component (A) is preferably 84/16 to 30/70, more preferably 80/20 to 40/60, and particularly preferably 70/30 to 50 / 50 is preferred. When the ratio of the castor oil-based polyol (a2) to the polyol (a1) is exceeded, the resilience and compression residual strain are likely to deteriorate, the curing time becomes longer, and the hardness is difficult to be obtained.

The polyisocyanate component (B) used in the production of the polyurethane foam in the present invention comprises diphenylmethane diisocyanate polyisocyanate (b1) and tolylene diisocyanate polyisocyanate (b2).
Specific examples of the diphenylmethane diisocyanate-based polyisocyanate (b1) include diphenylmethane diisocyanate (hereinafter referred to as 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate). Abbreviated as MDI), polymethylene polyphenylene polyisocyanate, modified urethane thereof, or a mixture of any two or more thereof, and 2,2′-MDI and 2,4′-MDI in total 5 to 20 mass % And 4,4′-MDI 95-80% by weight, MDI 80-30% by weight (particularly 2,2′-MDI and 2,4′-MDI 5-20% by weight and 4,4′-MDI 95-80% by mass) and polymethylene polyphenylene polyisocyanate 20% to 70% by weight of a mixture, these former and / or latter mixtures urethane-modified with the same compounds as those mentioned above as the polyol (a1) having a molecular weight of 1000 or more, or any two of these mixtures One or more blends, particularly a mixture of 2,2'-MDI and 2,4'-MDI in a total of 5-20% by weight and 4,4'-MDI 95-80% by weight with a polyether polyol having a molecular weight of 1000 or more. Partly urethane-modified and MDI 80-30% by mass (especially containing 2,2'-MDI and 2,4'-MDI 5-20% by mass and 4,4'-MDI 95-80% by mass) ) And a mixture of 20 to 70% by weight of polymethylene polyphenylene polyisocyanate. The isocyanate group content of this MDI polyisocyanate (b1) is preferably 23.2 to 32.5% by mass.
Examples of tolylene diisocyanate polyisocyanate (b2) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, modified carbodiimides thereof, and a mixture of two or more of these.

  The blending mass ratio of the MDI polyisocyanate (b1) to the tolylene diisocyanate polyisocyanate (b2) in the polyisocyanate component (B) is 99/1 to 60/40, more preferably 90/10 to 65/45, 80 / 20-70 / 30 is preferable. When the blending mass ratio of tolylene diisocyanate polyisocyanate (b2) to MDI polyisocyanate (b1) exceeds this range, the resilience and compression residual strain are liable to deteriorate, the curing time becomes longer, and the hardness is increased. It becomes difficult.

The crosslinking agent (C) in the present invention is preferably a low molecular active hydrogen compound having a molecular weight of less than 500, such as low molecular alcohols, low molecular amines, low molecular amino alcohols, etc. used for the synthesis of the above-mentioned polyester polyol. Can be mentioned.
Any of these may be used alone or in admixture of two or more.
Of these, low molecular amino alcohols and further diethanolamine are preferred from the viewpoint of slow reaction with isocyanate groups.
The amount of the crosslinking agent (C) used is preferably 10 g or less, more preferably 5.0 g or less, based on 100 g of the polyol component (A).

As the catalyst (D) in the present invention, any known catalyst used for polyurethane production can be used. Examples thereof include tertiary amines, diazabicycloalkenes and salts thereof, and organometallic compounds.
Examples of tertiary amines include triethylenediamine, triethylamine, tri-n-butylamine, bis (2-dimethylaminoethyl) ether, N, N, N ′, N′-tetramethylhexamethylenediamine, 1,2-dimethyl. Imidazole is mentioned.
Examples of organometallic compounds include metal salts of metals such as zinc, tin, lead, zirconium, bismuth, cobalt, manganese, iron and organic acids such as octenoic acid, naphthenic acid, dibutyltin dilaurate, dioctyltin dilaurate, Examples thereof include metal chelate compounds such as dibutyltin diacetylacetonate, zirconium tetraacetylacetonate, titanium acetylacetonate, acetylacetone aluminum, acetylacetone cobalt, acetylacetone iron, acetylacetone copper, and acetylacetone zinc.
Any of these may be used alone or in admixture of two or more.
Of these, tertiary amines are preferred.

As the foaming agent (E) in the present invention, other known materials can be used in addition to water. As this known foaming agent, for example, there are two kinds of inert low boiling point solvents and reactive foaming agents. As the former, dichloromethane, hydrochlorofluorocarbon, hydrofluorocarbon, acetone, hexane, isopentane, etc., nitrogen gas, Carbon dioxide and air can be mentioned. Examples of the latter include those that decompose at a temperature higher than room temperature to generate a gas, such as an azo compound.
These can be used alone or in admixture of two or more.
A particularly desirable blowing agent in the present invention is water (alone).

Examples of the foam stabilizer (F) in the present invention include silicones generally used for the production of polyurethane foam and other known ones. Examples thereof include polydimethylsiloxane-polyalkylene oxide block polymer and vinylsilane-polyalkylene polyol polymer.
These can be used alone or in admixture of two or more.

The usage-amount of a catalyst (D) is 0.1-5.0g with respect to 100g of polyol components (A), Furthermore, the range of 0.3-2.0g is preferable. If it is less than this range, curing is insufficient.
The amount of the foaming agent (E) used is preferably 0.5 to 10.0 g, more preferably 1.0 to 5.0 g, based on 100 g of the polyol component (A). If it is less than this range, it becomes a closed cell, and if it exceeds this range, the foam may be depressed.
The amount of the foam stabilizer (F) used is preferably 5.0 g or less, more preferably 3.0 g or less, based on 100 g of the polyol component (A) in order to form a uniform cell.

  In the production of the polyurethane foam in the present invention, an anti-aging agent such as an antioxidant or an ultraviolet absorber, a filler such as calcium carbonate or barium sulfate, an internal mold release agent, a flame retardant, a plasticizer, and a colorant. Various known additives and auxiliaries such as antifungal agents can be used as necessary.

The vehicle seat pad of the present invention can be suitably manufactured in the range of NCO index 70 to 140, and further in the range of 80 to 120, by means such as casting and injection (RIM technology). In this case, the reaction can be promoted by heating the raw material or the mold as necessary.
In the present invention, the raw material mixture is preferably introduced into (in each space of) a mold form coated with an external release agent via at least one mixing head, and is usually subjected to a foaming reaction at a temperature of, for example, room temperature to 70 ° C. (Cold cure) is performed.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited and limited by these.
In Examples and Comparative Examples, “%” indicates “% by mass” unless otherwise specified, except for foam physical properties.

Examples 1 to 17, Comparative Examples 1 and 2
The polyurethane foam was free-foamed in the mold with the composition shown in Tables 1, 2, 3 and 4, and then taken out from the mold, and the physical properties of the obtained flexible polyurethane foam were measured.
[Foaming conditions]
Mold temperature: 55-60 ° C
Mold shape: 100 × 300 × 300mm
Mold material: Aluminum Mixing method: High pressure machine mixing Raw material temperature: 25 ± 2 ℃
Cure conditions: 55-60 ° C x 6 minutes

[Raw materials]
Polyol with polyol component polyol a1-1: EO end content obtained by adding PO / EO (= 90/10) = 10%, average functional group number = 4.0, hydroxyl value = 28 (mgKOH / g) Ethylene polyoxypropylene polyol, Asahi Glass Urethane Co., Ltd. EL-838
Polyol a1-2: Polyoxyethylene polyoxypropylene polyol having an average number of functional groups obtained by random addition of PO / EO (= 60/40) = 3.0 and hydroxyl value = 48 (mgKOH / g), Asahi Glass Urethane Co., Ltd. Company EL-985
Polyol a1-3: Polymer polyol having an average number of functional groups of 3.0 and a hydroxyl value of 20 (mgKOH / g) obtained by subjecting PO to glycerin and polymerization of styrene and acrylonitrile monomer, Asahi Glass Urethane Co., Ltd. EL-937
Polyol a1-4: polyoxypropylene polyol having an average number of functional groups of 3.0 and a hydroxyl value of 732 (mgKOH / g) obtained by addition polymerization reaction of PO to glycerin, GE230 manufactured by Lion Corporation
Polyol a1-5: Polyoxyethylene polyoxypropylene polyol having an average functional group number of 4.0 and a hydroxyl value of 28 (mgKOH / g) obtained by random addition polymerization reaction of EO and PO with pentaerythritol polyol a2-1: Castor oil-based polyol obtained by adding EO to castor oil = 59 (mgKOH / g), average functional group number = about 3, terminal primary OH conversion ratio = 62 mol% Polyol a2-2: castor oil with EO, PO A castor oil-based polyol having a hydroxyl value of 40 (mg KOH / g), an average number of functional groups of about 3 and a terminal primary OH conversion ratio of 35 mol%

Polyisocyanate component Polyisocyanate b1-1: MDI mixture of 2,4′-MDI 11% and 4,4′-MDI 89%, PO / EO = 80/20 (mass ratio), average number of functional groups = 4.0, number MDI polyisocyanate obtained by reacting polyoxyethylene polyoxypropylene polyol having an average molecular weight of about 8,000 Polyisocyanate b1-2: 4.1% of 2,4′-diphenylmethane diisocyanate and 4,4′-diphenylmethane diisocyanate 32. Mixture of 9% and polymethylene polyphenylene polyisocyanate 63% Polyisocyanate b2: Tolylene diisocyanate

Catalyst catalyst D-1: 33% dipropylene glycol solution of triethylenediamine, TEDA-L33 manufactured by Tosoh Corporation
Catalyst D-2: 70% dipropylene glycol solution of bis (2-dimethylaminoethyl) ether, TOYOCAT ET manufactured by Tosoh Corporation
Catalyst D-3: 70% dipropylene glycol solution of 1,2-dimethylimidazole, DP70 manufactured by Tosoh Corporation

Foam stabilizer Foam stabilizer F-1: Silicone foam stabilizer, Nippon Unicar Co., Ltd. SZ-1306

  Castor oil: hydroxyl value = 160 (mgKOH / g), molecular weight = about 1000, average number of functional groups = about 3, terminal primary OH conversion rate = 0 mol%

[Method for measuring physical properties of polyurethane foam]
This was performed based on the method of JIS K6401.
Formability evaluation criteria;
Self-bubble feeling ○: Closed bubbles become continuous bubbles in several hands, and no problem occurs
×: Due to the strong closed cell, it does not become a continuous bubble in several hands, but the foam deforms. ○: No problem
X: Deformation when a load is applied to the molded foam These compositions and the results of physical properties measurement of the flexible polyurethane foam are summarized in Tables 1 to 4.

Example 18
The raw material mixture in Example 8 was introduced into a mold of an automobile seat (seat) shape (80 × 700 × 700 mm) by a mixing head, and the same foaming conditions as in Example 8 except for the shape of the mold After being cold-cured and foamed, it was removed from the mold to produce a pad for an automobile seat (seat).
The manufactured pad had good sitting comfort.
The physical properties were measured based on the method of JIS K6401.
The measurement results such as physical properties are summarized below.
Pad mass: 1500g
Density core 30 mm: 63.5 kg / m ³
Hardness 25% ILD: 190N / 314cm ²
Formability Single cell feeling: ○
Cure property: ○
Rebound resilience (core 50mm): 49%
Tensile strength: 152 kPa
Elongation rate: 80%
Tear strength: 6.0 N / cm
Compressive residual strain Dry core: 7.0%
Wet core: 14.9%
Resonance frequency: 4.05 Hz
Resonance magnification: 3.46

Claims (7)

A castor oil-based polyol (a2) having a primary hydroxylation ratio of 10 mol% or more and a hydroxyl value of 20 to 350 obtained by adding a C2-C4 alkylene oxide to castor oil, and an average functionality other than the castor oil-based polyol (a2) A polyol component (A) comprising a polyol (al) having a base number of 2.0 to 6.0 and a hydroxyl value of 20 to 800;
A polyisocyanate component (B) comprising diphenylmethane diisocyanate polyisocyanate (b1) and tolylene diisocyanate polyisocyanate (b2),
A vehicle seat pad comprising a polyurethane foam obtained by reacting in the presence of a catalyst (D) and a blowing agent (E). A castor oil-based polyol (a2) having a primary hydroxylation ratio of 10 mol% or more and a hydroxyl value of 20 to 350 obtained by adding a C2-C4 alkylene oxide to castor oil, and an average functionality other than the castor oil-based polyol (a2) A polyol component (A) comprising a polyol (al) having a base number of 2.0 to 6.0 and a hydroxyl value of 20 to 800;
A polyisocyanate component (B) comprising diphenylmethane diisocyanate polyisocyanate (b1) and tolylene diisocyanate polyisocyanate (b2),
A vehicle seat pad comprising a polyurethane foam obtained by reacting in the presence of a catalyst (D), a foaming agent (E) and a foam stabilizer (F). A castor oil-based polyol (a2) having a primary hydroxylation ratio of 10 mol% or more and a hydroxyl value of 20 to 350 obtained by adding a C2-C4 alkylene oxide to castor oil, and an average functionality other than the castor oil-based polyol (a2) A polyol component (A) comprising a polyol (al) having a base number of 2.0 to 6.0 and a hydroxyl value of 20 to 800;
A polyisocyanate component (B) comprising diphenylmethane diisocyanate polyisocyanate (b1) and tolylene diisocyanate polyisocyanate (b2);
A crosslinking agent (C),
A vehicle seat pad comprising a polyurethane foam obtained by reacting in the presence of a catalyst (D) and a blowing agent (E). A castor oil-based polyol (a2) having a primary hydroxylation ratio of 10 mol% or more and a hydroxyl value of 20 to 350 obtained by adding a C2-C4 alkylene oxide to castor oil, and an average functionality other than the castor oil-based polyol (a2) A polyol component (A) comprising a polyol (al) having a base number of 2.0 to 6.0 and a hydroxyl value of 20 to 800;
A polyisocyanate component (B) comprising diphenylmethane diisocyanate polyisocyanate (b1) and tolylene diisocyanate polyisocyanate (b2);
A crosslinking agent (C),
A vehicle seat pad comprising a polyurethane foam obtained by reacting in the presence of a catalyst (D), a foaming agent (E) and a foam stabilizer (F).   The vehicle seat pad according to any one of claims 1 to 4, wherein a blending mass ratio of the polyol (a1) and the castor oil-based polyol (a2) is 84/16 to 30/70.   The vehicle seat according to any one of claims 1 to 5, wherein a blending mass ratio of diphenylmethane diisocyanate polyisocyanate (b1) to tolylene diisocyanate polyisocyanate (b2) is 99/1 to 60/40. pad. The density of the core part of polyurethane foam is 30 to 70 kg / m ³ , the impact resilience is 40 to 65%, and the compressive residual strain (wet core) is 15% or less. The vehicle seat pad described in 1.