JP2002212254A - Raw material composition for manufacturing soft polyurethane foam, soft polyurethane foam and its manufacturing method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a raw material composition capable of manufacturing a soft polyurethane foam having good moldability and excellent physical properties even using water as a foaming agent, and to provide the foam and its manufacturing method using the same. SOLUTION: The raw material composition comprises polyols and isocyantates. The polyol has a viscosity of <=2500 mPa.s, and contains a specific polymeric component, two or three polyoxyalkylene polyols, a foaming agent, a catalyst and a foam stabilizer. The isocyanate having a viscosity of <=50 mPa.s, and contains a prepolymer having a terminal isocyanate group (NCO) and toluene diisocyanate which are obtained by reacting an isocyanate isomers mixture in a specific polyoxyalkylene polyol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polyol / isocyanate system for producing a flexible polyurethane foam, a flexible polyurethane foam using the same, and a production method. In detail, when producing flexible polyurethane foam using water as a foaming agent, it is possible to produce a flexible polyurethane foam with low density and a wide range of hardness under a wide range of discharge pressure conditions without being restricted by foaming equipment. The present invention relates to a method for producing an excellent polyol / isocyanate system, a flexible polyurethane foam using the same, and a production method.

[0002]

2. Description of the Related Art Flexible polyurethane foams have excellent elasticity and are widely used for automobile seats, furniture, bedding and the like. In recent years, the setting of the appearance and hardness of foams has been complicated in automobile seats due to the demand for sheet design and ergonomics with a low degree of fatigue. Further, weight reduction and cost reduction as a sheet have been demanded, and reduction in density of a flexible polyurethane foam has been studied. However, when the density of the flexible urethane foam is reduced, problems such as a decrease in mechanical strength of the foam and an increase in wet heat compression set are caused. For this reason, in the production of flexible polyurethane foam sheet products having a complicated shape, there is a demand for a technique for reducing the density while maintaining the foam properties. As a method for suppressing a decrease in physical properties due to a decrease in the density of a flexible polyurethane foam, for example, JP-A-10-25328 discloses that a method is realized by using a specific polyether polyol and a limited vinyl polymer. ing. However, in this method, toluene diisocyanate (hereinafter abbreviated as TDI) is used as an isocyanate in a ratio of 70% by mass or more, and there is a problem that the working environment conditions during the production of a flexible polyurethane foam are deteriorated because the TDI content is large. . In the method for producing a low-density and high-elasticity flexible polyurethane foam described in JP-A-9-176276, there is a similar problem since TDI is mainly used as a polyisocyanate.

Further, as documents describing a method for producing a flexible polyurethane foam using a predetermined polyisocyanate, Japanese Patent Application Laid-Open Nos. 44-16674 and 4-2 have been disclosed.
JP-A-11417, JP-A-4-8720, JP-A-3-200829, JP-A-4-185626 and JP-A-4-218520. In these production methods, the density of the foam is not sufficiently reduced, and both the foam properties and the moldability cannot be sufficiently realized.

On the other hand, JP-A-7-206961, JP-A-7-292065, and JP-A-9-176273
JP, JP-A-7-330850 and JP-A-11-330850
JP-A-255857 describes that a specific polyisocyanate capable of reducing problems in the working environment is used to realize a reduction in foam density and a balance between foam physical properties and moldability. However, in these, there are many unclear points in the physical properties of the foam such as mechanical strength and compression set.

[0005]

In such a situation, when the use of a chlorofluorocarbon is prohibited and the foaming agent is changed from chlorofluorocarbon to water, it is more difficult to reduce the weight of the foam. The reason is that when CFCs are used as a foaming agent, CFCs exhibit a viscosity-reducing effect and facilitate mixing of polyol and isocyanate, whereas when water is used as a foaming agent, on the contrary, the polyol has a thickening effect. And the isocyanate are difficult to mix, and the homogenization of the resulting foam is hindered. Therefore, it is difficult to increase the amount of the foaming agent to reduce the weight of the foam. In order to solve this problem and always obtain a stable foam, it is necessary to improve the foaming apparatus for mixing the polyol and the isocyanate to greatly change the use conditions. However, this comes at a great cost.

[0006] If the stability of foam production is low, it is difficult to produce a foam having a complicated structure. For example, when producing a foam product in which a plurality of flexible polyurethane foams having different hardnesses are produced, the foam to be produced is difficult. Due to the inhomogeneity, sinks occur in the resulting product, resulting in incomplete integration and shape of the foams.

[0007] Accordingly, an object of the present invention is to produce a flexible polyurethane foam capable of realizing a low-density flexible polyurethane foam and realizing good foam properties in production under a good working environment using a normal foaming apparatus. To provide a raw material system and a method for producing a flexible polyurethane foam.

It is another object of the present invention to provide a raw material system and a method for producing a flexible polyurethane foam which can realize weight reduction of a composite integrated foam product while using water as a foaming agent. .

Another object of the present invention is to provide an integrated flexible polyurethane foam product which uses water as a foaming agent and is reduced in weight.

[0010] In particular, it maintains high mechanical strength, suppresses an increase in permanent set under wet heat compression, and can produce a foam product having a complex shape with high molding efficiency and good production efficiency with a wide range of hardness. It is an object of the present invention to provide a raw material system for producing a flexible polyurethane foam which can be sufficiently handled by a conventional foaming apparatus, a production method using the same, and a foam product.

[0011]

Means for Solving the Problems As a result of intensive studies to solve these problems, the present inventors have found that the above problems can be solved by using a specific polyol and a specific isocyanate. It was confirmed that stable production was possible even under the production of flexible urethane foam, and the present invention was completed.

That is, the raw material system for producing a flexible polyurethane foam of the present invention is a raw material system comprising a polyol system and an isocyanate system for producing a flexible polyurethane foam in the presence of a catalyst and a foam stabilizer using water as a blowing agent. In the above polyol system, the polyoxyalkylene polyol composition (A) is mixed with water, a catalyst and a foam stabilizer, and has a viscosity of 25.
The isocyanate system is a mixture having a mass ratio of isocyanate group-terminated prepolymer (B2) obtained by reacting polyoxyalkylene polyol (A4) in isocyanate mixture (B1) with toluene diisocyanate (B3). 50 / 50-80 /
The polyoxyalkylene polyol composition (A) is a composition having a viscosity of 50 mPa · s or less compounded at a ratio of 20. The polyoxyalkylene polyol composition (A) has an average number of functional groups of 2 to 4 and a number average molecular weight of 4
The polymer component (P) is formed by polymerizing an ethylenically unsaturated monomer in a polyoxyalkylene polyol (A1) having a molecular weight of 2,000 to 6,000 and a terminal oxyethylene unit content of 12 to 25% by mass. Polymer polyol (A1 ′); having an average number of functional groups of 2
4, a polyoxyalkylene polyol (A2) having a number average molecular weight of 6,500 to 7,500, a terminal oxyethylene unit content of 14 to 20% by mass, and a terminal primary hydroxyl group conversion of 85% or more; And a polyhydroxy compound (A3) having a number average molecular weight of 40 to 1000 and a polyoxyalkylene polyol (A) of the polymer polyol (A1 ′).
The mass ratio to 2) is 80/20 to 70/30,
The mass ratio of the polyhydroxy compound (A3) to the total of the polyoxyalkylene polyols (A1 ′) and (A2) is 1/100 to 5/100, and the polymer component (P) is a polymer polyol (A1 ′) and (A
2) to 2% by mass of the total of 2), and the isocyanate mixture (B1) contains 2,2′- and 2,4′-
Diphenylmethane diisocyanate mixture (B1-1)
10 to 25% by mass, 4,4'-diphenylmethane diisocyanate (B1-2) 50 to 80% by mass and polymethylene polyphenylene polyisocyanate (B1-3) 1
0 to 25% by mass, wherein the polyoxyalkylene polyol (A4) has an average number of functional groups of 2 to 2.
4, the number average molecular weight is 1000 to 5000, and the content of the oxyethylene unit in the molecule is 60 to 85% by mass.

According to another aspect of the present invention, a raw material system for producing a flexible polyurethane foam is a polyol system for producing a flexible polyurethane foam in the presence of a catalyst and a foam stabilizer using water as a blowing agent. And a raw material system comprising an isocyanate system, wherein the polyol system is a mixture having a viscosity of 2500 mPa · s or less, in which water, a catalyst and a foam stabilizer are blended with the polyoxyalkylene polyol composition (a), The isocyanate system comprises a polyoxyalkylene polyol (A4) in the isocyanate mixture (B1).
Isocyanate group-terminated prepolymer (B)
2) and a mixture of toluene diisocyanate (B3) at a mass ratio of 50/50 to 80/20 and a viscosity of 50 m
A mixture of Pa · s or less, wherein the polyoxyalkylene polyol composition (a) has an average functional group number of 2 to 4;
By polymerizing an ethylenically unsaturated monomer in a polyoxyalkylene polyol (a1) having a number average molecular weight of 4000 to 6000 and a terminal oxyethylene unit content of 12 to 25% by mass, a polymer component ( polymer polyol (a1 ′) that produced p);
The number of average functional groups is 2 to 6 and the number average molecular weight is 40 to 100
A polyhydroxy compound (A3) that is 0, the mass ratio of the polyhydroxy compound (A3) to the polymer polyol (a1 ′) is 1/100 to 5/100, and the polymer component (p) is a polymer. The isocyanate mixture (B1) is contained at a ratio of 15 to 30% by mass of the polyol (a1 '), and the 2,2'- and 2,2'-
4'-diphenylmethane diisocyanate mixture (B1
-1) 10 to 25% by mass, 4,4'-diphenylmethane diisocyanate (B1-2) 50 to 80% by mass and polymethylene polyphenylene polyisocyanate (B1-
3) A mixture comprising 10 to 25% by mass, wherein the polyoxyalkylene polyol (A4) has an average number of functional groups of 2 to 4, a number average molecular weight of 1,000 to 5,000, and a content of oxyethylene units in the molecule. 60 to 85% by mass
The gist is that

The isocyanate group-terminated prepolymer (B2) preferably has an NCO group content of 30 to 32% by mass.

In the method for producing a flexible polyurethane foam according to the present invention, the polyol system and the isocyanate system of any one of the above-mentioned raw material systems are reacted using a mixing apparatus in which the discharge pressure is adjusted to 5 to 20 MPa. The main point is to produce a flexible polyurethane foam.

According to another aspect of the present invention, there is provided a process for producing a flexible polyurethane foam, comprising the steps of: The reactive mixture of the above-mentioned raw material system, which is intended to be formed into a different-hardness molded body in which flexible polyurethane foams having different hardnesses are integrated by being supplied to different parts in the mold and integrally molded, is not used as an auxiliary agent. An active gas can also be introduced.

According to the above manufacturing method, the core density is 27
~34kg / ^{m 3} at 25% hardness 60~140N / 31
4 cm ² of a first flexible polyurethane foam having a core density of 33 to 40 kg / m ³ and a 25% hardness of 130 to 26
A flexible polyurethane foam which is integrated with a second flexible polyurethane foam of 0N / 314 cm ² is produced.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In order to manufacture a molded article of different hardness in which a plurality of polyurethane foams having different hardnesses are integrated, raw materials of a plurality of polyurethane foams are supplied almost simultaneously into a molding die and sealed. Mold in the state. In this case, what is particularly important is the homogeneity of each polyurethane formed in the mold. If the homogeneity is low, the joining position of the foams is displaced due to fluctuations in the balance between the foams, and the molded body having a desired shape and structure I can't get the product. In order to increase the homogeneity of the produced polyurethane, it is necessary to easily mix the polyol and the isocyanate as the raw materials. For this purpose, it is important to keep the viscosity of the polyol and isocyanate low. However, since this also affects the material properties of the polyurethane foam to be produced, a different hardness molding having desired product structure and material properties is required. Body products are simply not available. In particular, when water is used as a foaming agent, the viscosity is significantly increased when mixed with a polyol, and the mixing property with isocyanate is deteriorated. Therefore, a desired foam cannot be obtained with a conventional mixing apparatus.

In the present invention, by devising the composition of the polyol and the isocyanate, the material properties of the obtained polyurethane foam are optimized while the viscosity of the raw material is kept low, and a product obtained by integrating a plurality of types of polyurethane foams having different hardnesses is obtained. Realize manufacturing. Hereinafter, a method for producing the flexible polyurethane foam of the present invention for realizing the above-described integrally molded product will be described.

In the present invention, a polyoxyalkylene polyol composition containing, as raw material polyols, a polyoxyalkylene polyol and a polymer component obtained by polymerizing an ethylenically unsaturated monomer in the polyoxyalkylene polyol ( A) and (a) are used. The polyoxyalkylene polyol is a compound obtained by adding an alkylene oxide to an active hydrogen atom compound (initiator), and the polyoxyalkylene polyol used varies depending on the hardness of the polyurethane foam to be produced. The polyoxyalkylene polyol composition (A) in the following description is used for producing a polyurethane foam having a relatively low hardness, and the polyoxyalkylene polyol composition (a) is used for producing a polyurethane foam having a relatively high hardness. Used. On the other hand, the same isocyanate can be used as the raw material isocyanate regardless of the hardness of the polyurethane foam to be produced. As components, diphenylmethane diisocyanate (isomer mixture), polymethylene polyphenylene polyisocyanate, isocyanate group-terminated prepolymer (hereinafter, referred to as NCO-terminated prepolymer) and toluene diisocyanate (B). NCO-terminated prepolymers are obtained by reacting a polyoxyalkylene polyol in a mixture of diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate. For the polyoxyalkylene polyol compositions (A) and (a) prepared according to the hardness of the polyurethane foam to be produced, a foaming agent (C), a catalyst (D), a foam stabilizer (E) and, if necessary, used. After the other auxiliary agent is added to form a polyol system, the mixture is reacted with an isocyanate system composed of the isocyanate composition (B) by using a mixing device (foaming device) to cause foaming and curing. When a polyurethane raw material is supplied into a mold and foamed and cured, a polyurethane foam molded body is obtained.

Hereinafter, the components and preparation of the raw materials will be described in detail.

[Polyoxyalkylene polyol] The polyoxyalkylene polyol is obtained by adding an alkylene oxide to an active hydrogen atom compound (initiator) using a polymerization catalyst such as an alkali metal catalyst. The components of the raw material polyol in the present invention include four types of polyols (A1), (A2), (A3), and (a1), and polyoxyalkylene polyol ( A1) and (A2) are polyoxyalkylene polyols (a) for the production of flexible polyurethane foams having relatively high hardness.
1) is used. In addition, polyhydroxy compounds (A
3) may be a polyoxyalkylene polyol or a polyfunctional compound described later. The polyoxyalkylene polyol (A4) is used in preparing the isocyanate composition (B).

The addition of the alkylene oxide to the initiator
It can be performed according to a commonly used method, for example,
After adding an alkali metal catalyst to the initiator, the mixture is dehydrated under reduced pressure at about 110 ° C. for about 4 hours.
Addition polymerization is carried out at 120 ° C.

(Initiator) Examples of the initiator include dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol and 1,6-hexanediol, glycerin, trimethylolpropane, trimethylolethane, Hexanetriol, trihydric alcohols such as triethanolamine, pentaerythritol, diglycerin, tetrahydric alcohols such as methylglucoside, sorbitol, mannitol, hexitol, pentahydric or higher alcohols such as sucrose, monoethanolamine, diethanolamine, Alkanolamines such as isopropanolamine, N-
Heterocyclic amines such as (2-aminoethyl) piperazine and N-aminomethylpiperazine; aliphatic amines such as ethylenediamine, propylenediamine and hexamethylenediamine; aromatic amines such as tolylenediamine and diaminodiphenylmethane; bisphenol And phenols such as A.

(Alkylene oxide) The alkylene oxide to be added to the initiator in the preparation of the polyoxyalkylene polyol is preferably an alkylene oxide having 2 or more carbon atoms, and specifically, ethylene oxide, propylene oxide, 1,2-butylene oxide , 2,3-
Butylene oxide and the like. Particularly, propylene oxide or a combination of propylene oxide and ethylene oxide is preferable.

(Molecular Weight / EO Content of Polyoxyalkylene Polyol) Polyoxyalkylene polyol (A
1) and (a1) have a number average molecular weight of 4000 to 6000
And the content of terminal oxyethylene units (hereinafter referred to as terminal E)
O content) is 12 to 25% by mass. Those having a number average molecular weight of 4500 to 5500 and a terminal EO content of 14 to 21% by mass are particularly suitable. When the average number of functional groups of the polyoxyalkylene polyols (A1) and (a1) is greater than 4, elongation in foam properties and mechanical strength decrease. When the average number of functional groups is smaller than 2,
The hardness and durability of the resulting foam are reduced. Further, polyoxyalkylene polyols (A1), (a
When the number average molecular weight of 1) is lower than 4000, the compression set and the elongation properties of the foam increase in physical properties. When the number average molecular weight is higher than 6000, the hardness decreases and the viscosity of the polyol increases to increase the foam viscosity. Poor mixing is likely to occur during molding. Further, the terminal EO content is 12% by mass.
If it is lower than this, the foaming stability at the time of urethane foam molding is insufficient, and a defect (partially collapsed) occurs at the time of molding. If it exceeds 25% by mass, the stability at the time of foaming is increased, but the compression set and the durability of the foam are increased in physical properties. Cracking is likely to occur during the process of impacting the cell membrane to force the cell membrane to break and communicate.

The above-mentioned polyoxyalkylene polyols (A1) and (a1) are prepared by adding propylene oxide using a trihydric alcohol or a combination of a plurality of alcohols having an average number of functional groups of 2 to 4 as an initiator. Thereafter, those obtained by adding ethylene oxide are preferable.

In the production of an integral molded article of polyurethane foams having different hardnesses, which will be described later, the same polyoxyalkylene polyol can be used as the polyoxyalkylene polyols (A1) and (a1).

Polyoxyalkylene polyol (A2)
Has a number average molecular weight of 6500 to 7500, a terminal EO content of 14 to 20% by mass, and a terminal primary hydroxyl group conversion (1 °
OH) is 85% or more. Number average molecular weight is 6800 or more
7200, and those having a terminal EO content of 15 to 18% by mass are particularly preferred. Polyoxyalkylene polyol (A
When the average number of functional groups in 2) is larger than 4, elongation and mechanical strength in foam physical properties decrease. When the average number of functional groups is smaller than 2, the hardness and durability of the obtained foam are reduced. When the number average molecular weight of the polyoxyalkylene polyol (A2) is smaller than 6500, the viscosity of the polyol decreases, but the elongation of the foam properties decreases. On the other hand, when it is larger than 7,500, the hardness of the foam is reduced, and the viscosity of the polyol is significantly increased, so that poor mixing is likely to occur during foam molding. On the other hand, if the terminal EO content is lower than 14% by mass, the foaming stability at the time of urethane foam molding is insufficient, and a failure (partial depression) occurs at the time of molding. Also, 20
When the amount is more than 100% by mass, the stability at the time of foaming increases, but an increase in compression set and a decrease in durability are caused in foam properties. Further, when the terminal primary hydroxyl grouping ratio is lower than 85%, the foaming stability at the time of urethane foam molding is lowered and the curing property at the time of molding is also lowered.

The polyoxyalkylene polyol (A2) as described above is prepared by using a trihydric alcohol or a combination of alcohols having an average number of functional groups of 2 to 4 as an initiator.
Those obtained by adding ethylene oxide after adding propylene oxide are preferable.

The polyhydroxy compound (A3) has an average number of functional groups of 2 to 6, and a number average molecular weight of 40 to 1,000. The average number of functional groups of the polyhydroxy compound (A3) is 6
If it is larger, elongation and mechanical strength are reduced in foam properties. When the average number of functional groups is smaller than 2, the hardness and durability of the obtained foam are reduced. Further, when the number average molecular weight is smaller than 40, the viscosity of the polyoxyalkylene polyol composition (A) or (a) is reduced, but the elongation property is reduced in the foam properties. Further, when the number average molecular weight is larger than 1000, particularly when the average number of functional groups is 6, the viscosity of the polyoxyalkylene polyol composition (A) or (a) is remarkably increased, and poor mixing occurs during urethane molding. It will be easier.

As the polyhydroxy compound (A3),
Alcohols and alkanolamines exemplified as the above-mentioned initiators themselves can be used. Also, polyoxyalkylene polyols can be used. At this time, the amount of terminal EO is preferably 0 to 50% by mass. When the terminal EO content is higher than 50% by mass, an increase in compression set in the physical properties of the foam and a decrease in durability occur.

[Polymer Component (P), (p)] Each of the polymer components (P), (p) is obtained by polymerizing an ethylenically unsaturated monomer. A polyoxyalkylene polyol composition (A) in the form of a polymer polyol (A1 ′), (a1 ′) polymerized in the polyol (A1) or (a1) and containing the polymer components (P) and (p); Used for the preparation of (a).
The polymerization of the ethylenically unsaturated monomer is carried out, for example, by feeding the monomer into the polyoxyalkylene polyol (A1) or (a1) heated to 100 to 120 ° C. and reacting for 2 to 10 hours. Do. When a vinyl polymerization reaction catalyst is used, it is supplied together with the monomer. The polymer component (P) is used for producing a polyurethane foam having relatively low hardness, and the polymer component (p) is used for producing a polyurethane foam having relatively low hardness. Compounds that can be used as the ethylenically unsaturated monomer include styrene,
Aromatic vinyl monomers such as α-methylstyrene and α-ethylstyrene; olefinic hydrocarbon monomers such as ethylene, propylene, butadiene and isobutylene; vinyl ester monomers such as vinyl acetate; vinyl chloride and vinylidene chloride Vinyl halide monomers such as vinyl methyl ether; unsaturated nitriles such as acrylonitrile and methacrylonitrile. Of these, acrylonitrile, methyl methacrylate, styrene and butadiene are preferred monomers, and particularly preferred are acrylonitrile, styrene, and a combination of acrylonitrile and styrene.

The polymer component (P) preferably has a number average molecular weight of about 200,000 to 400,000. Further, a polymer polyol (A1 ′) and a polyoxyalkylene polyol (A2)
And 2 to 8% by mass of the total amount. Therefore,
The amount of the polyoxyalkylene polyol (A1), (A2) and the amount of the ethylenically unsaturated monomer corresponding to 2 to 8% by mass relative to the total amount of 100% by mass of the monomer is added to the polyoxyalkylene polyol (A1). It can be produced by polymerizing in water. If the content is less than 2% by mass, the hardness of the obtained polyurethane foam does not reach the target range of 60 N / 314 cm ² , which is a relatively low hardness foam. On the other hand, if it is higher than 8% by mass, the viscosity of the whole polyoxyalkylene polyol composition (A) increases, so that poor mixing tends to occur at the time of urethane molding, and it is necessary to adjust a foaming device.

The polymer component (p) preferably has a number average molecular weight of about 200,000 to 400,000. Further, it is contained in the polymer polyol (a1 ′) at a ratio of 15 to 30% by mass. Therefore, the polyoxyalkylene polyol (a1)
It can be produced by polymerizing an amount of the monomer corresponding to 15 to 30% by mass in the polyoxyalkylene polyol (a1) with respect to 100% by mass of the total amount of the monomer and the ethylenically unsaturated monomer. If the amount is less than 15% by mass, the hardness of the obtained polyurethane foam is 130 N, which is the target range.
/ 314 cm ² . Further, when it is higher than 30% by mass, the polyoxyalkylene polyol composition (a)
As a result, the overall viscosity becomes large, poor mixing is likely to occur during urethane molding, and adjustment of the foaming apparatus is required.

When polymerizing the ethylenically unsaturated monomer to obtain polymer components (P) and (p),
A well-known catalyst for a vinyl polymerization reaction is used. For example, peroxides such as hydrogen peroxide, benzoyl peroxide, acetyl peroxide, t-butyl peroxide, di-t-butyl peroxide, azo compounds such as azoisobutyronitrile, and persulfates, peroxides Compounds of peracids such as succinic acid, di-isopropyl peroxydicarbonate and the like can be mentioned.

The polymerization catalyst is used in an amount of 0.01 to 5% by mass, preferably 0.1 to 5% by mass, based on the total amount of the polyoxyalkylene polyol (A1) or (a1) and the ethylenically unsaturated monomer.
It is added at a rate of 1 to 2% by mass. 100-
By stirring at 120 ° C. for about 4 hours and then reacting, the polyoxyalkylene polyol (A1), (a
Polymer polyols (A1 ′) and (a1 ′) in which polymer components (P) and (p) are dispersed in 1) are prepared.

[Preparation of Polyoxyalkylene Polyol Compositions (A) and (a)] The polyoxyalkylene polyol composition (A) of the present invention comprises polyoxyalkylene polyols (A1), (A2), (A3), And a polymer component (P) obtained by polymerizing an ethylenically unsaturated monomer in a polyoxyalkylene polyol (A1). Ratio of polymer polyol (A1 ′) and polyoxyalkylene polyol (A2) [hereinafter, (A1 ′)
/ (A2) is 80/20 to 70 / in mass ratio.
30 and the total of polymer polyol (A1 ′) and polyoxyalkylene polyol (A2) is 100
The polyoxyalkylene polyol (A
3) is 1 to 5 parts by mass, and the amount of the polymer component (P) is the sum of the polymer polyol (A1 ′) and the polyoxyalkylene polyol (A2) [= polyoxyalkylene polyol (A1), (A2) and polymer [Total amount of component (P)]].

In particular, the ratio of (A1 ') / (A2) exceeds the above range (excess of polymer polyol (A1'))
Then, the viscosity of the polyoxyalkylene polyol composition (A) decreases, but the wet heat compression set in the foam properties deteriorates. When the ratio is lower than the above range (the ratio of the polyoxyalkylene polyol (A2) becomes relatively high), the viscosity of the polyoxyalkylene polyol composition (A) increases, and molding defects during production increase.
When the amount of the polyoxyalkylene polyol (A3) is less than the above range, the obtained foam has a low crosslinking density and the durability is reduced. When the amount is too large, elongation is deteriorated in the properties of the obtained foam.

On the other hand, the polyoxyalkylene polyol composition (a) is
1), (A3), and a polymer component (p) obtained by polymerizing an ethylenically unsaturated monomer in a polyoxyalkylene polyol (a1). The polyoxyalkylene polyol (A3) is 1 to 5 parts by mass based on 100 parts by mass of the polymer polyol (a1 ′), and the amount of the polymer component (p) is the polymer polyol (a1 ′) [= polyoxyalkylene polyol (a1). ) And the polymer component (p)]. The proportion of the polyoxyalkylene polyol (A3) is 100%.
If the amount is less than 1% by mass relative to the mass%, the crosslink density of the foam becomes low, and the durability decreases. If the amount is more than 5% by mass, elongation in the properties of the foam decreases.

[Isocyanate Composition (B)] The isocyanate composition (B) is an isocyanate mixture (B1)
The NCO-terminated prepolymer (B2) obtained by reacting the polyoxyalkylene polyol (A4) with toluene diisocyanate (B3) in a mass ratio of 50/50.
It is contained at a ratio of ~ 80/20. The isocyanate mixture (B1) is diphenylmethane diisocyanate (2,
2'-, 2,4'- and 4,4'-isomers) and polymethylene polyphenylene polyisocyanates.

(Isocyanate mixture (B1)) The isocyanate mixture (B1) is a mixture of 2,2'- and 2,4'-diphenylmethane diisocyanate mixtures (B1-1) and 4,4'-
It contains diphenylmethane diisocyanate (B1-2) and further contains polymethylene polyphenylene polyisocyanate (B1-3). When the amount of the isocyanate mixture (B1) is 100% by mass, the ratio of the mass percentage of each component is diphenylmethane diisocyanate mixture (B1-1) / 4,4′-diphenylmethane diisocyanate (B1-2) / polymethylene polyphenylene. Polyisocyanate (B1-3) = 10-25 / 50-
80 / 10-25, preferably 10-20 / 55-75
/ 15 to 25.

When the amount of 4,4′-diphenylmethane diisocyanate (B1-2) is less than 50% by mass, the diphenylmethane diisocyanate mixture (B1-1) and / or
Alternatively, the polymethylene polyphenylene polyisocyanate (B1-3) exceeds the upper limit of the mass ratio. Diphenylmethane diisocyanate mixture (B1-
If 1) exceeds the above-mentioned mass ratio, the curing property of the foam decreases, and the productivity decreases. When the polymethylene polyphenylene polyisocyanate (B1-3) exceeds the above mass ratio, the wet heat compression set becomes large in the foam properties, and the elongation also decreases. On the other hand, when the content of 4,4′-diphenylmethane diisocyanate (B1-2) is higher than 80% by mass, the diphenylmethane diisocyanate mixture (B1-1) and / or the polymethylene polyphenylene polyisocyanate (B1-3) have the lower limit of the mass ratio. It will be below. When the diphenylmethane diisocyanate mixture (B1-1) is less than the above mass ratio, the stability during foam foaming is reduced, and the productivity is reduced. When the polymethylene polyphenylene polyisocyanate (B1-3) falls below the above mass ratio, the hardness of the foam decreases, and the stability during foaming also decreases. In particular, 4,4'-diphenylmethane diisocyanate (B1-2) includes 2,2'- and 2,4'-diphenylmethane diisocyanate (B1-1) and (B1-1).
Since the reaction with the polyoxyalkylene polyol compositions (A) and (a) is faster than 1-3), when the urethane foam is produced using water as the blowing agent (C), the isocyanate composition (B) The carbon dioxide gas generated by the reaction with is easily retained in the urethane. Therefore, the density of the foam can be reduced even with a small amount of water.

(Polyoxyalkylene polyol (A)
4)) The polyoxyalkylene polyol (A4) has 3
An alkylene oxide is added so that the content of oxyethylene units in the molecule (hereinafter referred to as EO amount) is 60 to 85% by mass using a combination of a monovalent alcohol or an alcohol having an average functional group number of 2 to 4 as an initiator. It is preferable to use one prepared in advance. If the average number of functional groups is greater than 4, the viscosity increase when reacted with isocyanate is large,
The viscosity of the polyisocyanate system increases, and poor mixing is likely to occur during urethane molding. When the average number of functional groups is smaller than 2, the stability during foam molding is reduced. Further, when the EO amount is less than 60% by mass, an increase in compression set and a decrease in durability occur in the foam physical properties, and when it is more than 85% by mass, the stability during foam molding decreases. In addition, the number average molecular weight is 1
If it is smaller than 000, the viscosity of the isocyanate is reduced, but the mechanical strength and elongation are reduced in the foam physical properties.If it is larger than 5,000, the increase in the viscosity when reacted with the isocyanate is increased. Failure is likely to occur, and adjustment of the foaming device is also required.

(NCO-terminated prepolymer) The NCO-terminated prepolymer is obtained by reacting a polyoxyalkylene polyol (A4) in the isocyanate mixture (B1). The reaction is carried out under commonly used reaction conditions. Specifically, the isocyanate mixture (B1) is heated to 40 to 60 ° C. with stirring, and then the polyoxyalkylene polyol (A4) is charged and the mixture is heated to 60 to 60 ° C. with stirring. By reacting at 100 ° C. for 3 to 6 hours, an NCO-terminated prepolymer (B2) is obtained.

NC in NCO-terminated prepolymer (B2)
The O group content is preferably from 30 to 32% by mass. When the content of the NCO group is lower than 30% by mass, the formation of the foam becomes unstable, the productivity is reduced, and the hardness of the foam decreases. The NCO group content is 32% by mass.
If it is higher, the wet heat compression strain deteriorates in the foam properties.

(Preparation of Isocyanate Composition (B))
When the total of the CO-terminated prepolymer (B2) and the toluene diisocyanate (B3) is 100% by mass, the ratio of the percentage of these components is NCO-terminated prepolymer (B3).
2) / Toluene diisocyanate (B3) = 50/50
８０80/20. In particular, (B2) / (B3) = 60
A mass ratio of / 40 to 70/30 is preferred. When the toluene diisocyanate (B3) exceeds the upper limit of the mass ratio, the working environment is reduced due to odor, and it is difficult to obtain the desired hardness of the foam. When the toluene diisocyanate (B3) falls below the lower limit of the mass ratio,
Elongation decreases in foam physical properties.

The viscosity of the isocyanate composition (B) is 50
It is essential that the pressure is not more than mPa · s. 50mPa ・
When the pressure is higher than s, the discharge pressure in the urethane foaming device increases, and equipment adjustment is required. In addition, the miscibility with the polyoxyalkylene polyol composition (A) deteriorates, and the productivity decreases.

[Urethane Reaction] The polyoxyalkylene polyol compositions (A) and (a) prepared as described above
Further comprises a blowing agent (C), a catalyst (D),
A polyurethane system is formed by adding a foam stabilizer (E) and, if necessary, other auxiliaries to a polyol system, and reacting the polyol system with an isocyanate system comprising the isocyanate composition (B). A blowing agent (C) is added to the polyoxyalkylene polyol composition (A) or (a).
The viscosity of the polyol system containing water, the catalyst (D) and the foam stabilizer (E) is 2500 mPa · s or less. The polyurethane foam obtained by using the polyoxyalkylene polyol composition (A) and the isocyanate composition (B) has a core density of 27 to 34 kg /.
The urethane foam obtained when the polyoxyalkylene polyol composition (a) and the isocyanate composition (B) are used is a soft urethane foam having a m ³ of 60 to 140 N / 314 cm ² and a core density of 33 to 40 k.
It is a soft urethane foam having a g / m ³ and a hardness of 130 to 260 N / 314 cm ² , each having good foam properties and moldability.

[Blowing Agent (C)] In the present invention, a low-viscosity polyol system can be constituted by using water as the blowing agent (C). Further, one or more kinds of various inert gases may be appropriately selected and used as a foaming agent in combination with water. Specific examples of the inert gas include air, nitrogen, and liquefied carbon dioxide. Blowing agent (C)
Is not particularly limited, and an appropriate amount is used depending on requirements such as the expansion ratio. From the viewpoint of operability and the like, when only water is used as the foaming agent (C), 10 parts by mass or less, particularly 4 parts by mass, is used for 100 parts by mass of the composition (A) or (a).
It is preferable that the amount be 7 to 7 parts by mass.

The inert gas such as liquefied carbon dioxide may be used in such a form that the polyol system and the isocyanate system are mixed and then introduced as an auxiliary agent.

[Catalyst (D)] As the catalyst (D), a catalyst generally used for a urethane reaction, that is, an amine catalyst and an organometallic catalyst can be used, and both catalysts may be used in combination. . Examples of the amine-based catalyst include triethylenediamine, N-methylmorpholine, N-ethylmorpholine, triethylamine, tetramethylhexamethylenediamine, bis- (dimethylaminoethyl) ether, and trimethylaminoethylpiperazine. For example, there are tin-based catalysts such as stannas octoate, stannas laurate and dibutyltin laurate, and lead-based catalysts such as lead octylate. The amount of the catalyst used can be appropriately varied depending on the reactivity (reaction rate), the physical properties of the foam to be obtained, the moldability, and the like. Usually, the polyoxyalkylene polyol compositions (A) and (a) and the isocyanate are used. 0.005 to 4 of the mixture with the composition (B)
Use an amount of about mass%.

[Foam stabilizer (E)] Examples of the foam stabilizer (E) that can be used in the present invention include a silicone-based foam stabilizer and a fluorine-containing compound-based foam stabilizer. Usually, an amount of about 0.5 to 1.5% by mass of the mixture of the polyoxyalkylene polyol compositions (A) and (a) and the isocyanate composition (B) is used.

In the present invention, auxiliary agents such as coloring agents and flame retardants can be used, if necessary, in addition to the above additives. Even when such an auxiliary is used, similarly to the above-mentioned additive, it is blended in the polyoxyalkylene polyol composition while paying attention so that the viscosity of the polyol system does not deviate from the aforementioned range.

[Foaming Apparatus] In the present invention, the viscosity of the polyol system is adjusted to 2 by preparing as described above.
The molecular weight, the number of functional groups, and the composition ratio of the constituent components of the raw material system are specified so that the viscosity of the isocyanate system is approximately 500 mPa · s or less and the viscosity of the isocyanate system is approximately 50 mPa · s or less. However, when a system is configured using components near the boundary of the above-mentioned specified range, depending on the situation, the viscosity may deviate from the above-described appropriate viscosity range, so it is necessary to confirm the viscosity of the prepared system. When the viscosity of the polyol system is higher than 2500 mPa · s and the viscosity of the polyisocyanate system is higher than 50 mPa · s, it is difficult to mix both uniformly with a normally used high-pressure foaming apparatus, and the surface of the foam product has stickiness. Problems, such as the occurrence of non-uniform foam products, and a decrease in productivity. In addition, capital investment such as improvement of the pump capacity of the high-pressure foaming device is required.

The polyurethane foam is produced by a method of directly injecting a reactive mixture obtained by mixing a raw material system (a polyol system and an isocyanate system) into a molding die (for example, a mold) (that is, a reaction injection molding method) or an open molding. It is preferably carried out according to the method of injecting the reactive mixture into the mold and sealing after injection. The mixing of the raw material systems is preferably performed by high-pressure stirring (collision stirring) using a normal high-pressure foaming apparatus that mixes two liquids.

However, the production of the polyurethane foam of the present invention is not limited to the above-mentioned embodiment, and the above-mentioned polyol system may be replaced with a polyoxyalkylene polyol composition (A),
The raw material system is divided into a foaming agent (C), a catalyst (D), a foam stabilizer (E), and a mixture of other additives, and the raw material system is configured into three systems, and these are mixed by a foaming device and cast. Is also possible. For example, there may be mentioned a mode in which a third system is constituted by a catalyst, a foaming agent (usually dispersed or dissolved in a part of a high molecular weight polyol), liquefied carbon dioxide gas and the like.

When the urethane foam is molded using a high-pressure foaming apparatus, it is preferable to produce the urethane foam by setting the discharge pressure of the isocyanate system and the polyol system in the range of 5 to 20 MPa. If the discharge pressure is lower than 5 MPa, the mixing property is reduced and the surface of the foam is defective, and the productivity is reduced. On the other hand, when the pressure is higher than 20 MPa, it becomes difficult to control the injection of the reactive mixture into the molding die, and the mixture is scattered to a part other than a predetermined portion, thereby lowering productivity.

The mixing ratio of the isocyanate system and the polyol system is determined by the isocyanate index value calculated from the compositions of the polyoxyalkylene polyol composition (A) and the isocyanate composition (B) (based on the number of active hydrogens in all active hydrogen-containing compounds). 80 to 120, preferably 85)
１１５115.

The reactive mixture obtained by mixing the raw material systems according to the above is heated in a mold at about 60 to 70 ° C. for about 4 to 8 minutes and cold-cured to obtain a flexible polyurethane foam molded article. The time from the start of the injection of the reactive mixture into the mold to the closing of the mold is preferably about 30 seconds or less. It is preferable that the reaction of the reactive mixture proceeds relatively slowly during the period from the injection to the sealing of the mold so that the mold does not overflow.

In order to produce a molded article of different hardness in which a plurality of types of polyurethane foams having different hardnesses are integrated, a plurality of polyurethane foams having different hardness are prepared by using each of the polyoxyalkylene polyol compositions (A) and (a). The seed systems may be provided, and two reactive mixtures may be prepared from each system using a mixing device, respectively, and supplied to different parts of one mold according to the product design and cold-cured. The feed rate and timing of the reactive mixture into the mold should be such that each reactive mixture is delivered to the appropriate location in the mold to form a foam conforming to the product design and the reactivity and volume balance of each mixture. It is adjusted in consideration of such factors. As described above, since the casting time of the reactive mixture is relatively short, about 30 seconds or less, the timing of casting each mixture is substantially substantially the same. The respective reactive mixtures in the closed mold are simultaneously cured / molded and united to form a molded body of different hardness. For example, in the manufacture of products such as automotive seat pads and headrests, the reactive mixture for high hardness is used for the frame parts that need supporting force, and the reactive mixture for low hardness is used for other parts that need flexibility. The supply of the mixture to the mold is controlled so that the mixture is arranged, and the mixture is suitably formed as an integrally molded article having partially different hardness.

[0062]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

(Preparation of Polyoxyalkylene Polyol) Polyol samples S1 to S14 prepared by adding ethylene oxide (EO) and / or propylene oxide (PO) as an alkylene oxide to the initiators shown in Table 1 were prepared. Polyoxyalkylene polyol (A1), (a1), (A2), (A4), polyhydroxy compound (A3), and a comparative polyol were used. Table 1 shows the number average molecular weight, the average number of functional groups, the terminal EO amount, the terminal primary hydroxyl group conversion rate, and the EO amount in the molecule of each of the samples S1 to S14.

(Preparation of Isocyanate Composition (B))
Mass ratio shown in Table 2 of 2,2'- and 2,4'-diphenylmethane diisocyanate mixture (B1-1), 4,4'-diphenylmethane diisocyanate (B1-2) and polymethylene polyphenylene polyisocyanate (B1-3) To prepare an isocyanate mixture (B1), and the sample S of the polyoxyalkylene polyol (A4) shown in Table 1 was added to the isocyanate mixture (B1).
9. The comparative sample S13 or S14 was added and reacted at 60 ° C. for 4 hours to prepare an NCO-terminated prepolymer (B2) having an NCO group content shown in Table 2. Toluene diisocyanate (B3) was added thereto so that the mass ratio of (B2) / (B3) became the value shown in Table 2, to obtain isocyanate samples I1 to I9. Used as The viscosity of the obtained isocyanate composition (B) was measured according to JIS K-1557. Table 2 shows the results.

[0065]

[Table 1]

[Table 2] (Production Examples 1 to 9) Samples S1 to S2 and S5 to S shown in Table 1
Using No. 7, a polyoxyalkylene polyol composition (A) was prepared by the following procedure.

First, acrylonitrile (AN) was added to polyoxyalkylene polyol (A1),
For 4 hours to obtain a polymer polyol (A) containing a polymer of acrylonitrile as a polymer component (P).
1 ′) was adjusted. Next, the polyols (A1 ′) and (A2) in parts by mass shown in Table 3 were mixed. The amount of acrylonitrile was adjusted such that the mass percentage of the polymer component (P) in the mixture of (A1 ′) and (A2) was as shown in Table 3. Further, a polyhydroxy compound (A
3) was added in parts by mass in Table 3 to obtain a polyoxyalkylene polyol composition (A). To this, the foaming agent (C), the catalyst (D) described in Table 3, and the foam stabilizer (E) were added in parts by mass in the table to adjust the polyol system. When the viscosity of the obtained polyol system was measured according to JIS K-1557, the values shown in Table 3 were obtained.
The details of the foaming agent (C), the catalyst (D) and the foam stabilizer (E) are as follows.

Blowing agent (C): distilled water Catalyst (D): TEDA L33, TOYOCAT T
F, TOYOCATET, TOYOCAT ETF
(Trade name, manufactured by Tosoh Corporation) Foam stabilizer (E): SF-2962 (trade name, manufactured by Toray Dow Corning Silicone Co., Ltd.) Further, according to the following foaming conditions, the polyol system and the samples I1 to I3 shown in Table 2 were used. The isocyanate composition (B) was charged into a high-pressure foaming apparatus, mixed at a ratio corresponding to an isocyanate index value shown in Table 3, and injected into an aluminum mold to perform foaming. On this occasion,
The discharge pressures of the polyol system and the isocyanate system were adjusted to the values shown in Table 3 by changing the orifice diameter in the mixing section head of the foaming apparatus. After being removed from the mold, the polyurethane foam cured in the mold was compressed to 50% to 90% of the foam thickness and subjected to a crushing treatment.

<Foaming Conditions> Foaming device: High-pressure foaming machine manufactured by Polyurethane Engineers Type of mixing section head: 3B type, discharge port diameter: 20 mm Raw material system temperature: 25 ± 2 ° C. Mold size: 400 mm × 400 mm × 70 mm Mold temperature : 63 ± 3 ° C Curing conditions: 63 ± 3 ° C, 6 minutes [Evaluation of moldability and cureability] The polyurethane foam molded under the above-mentioned foaming conditions was evaluated for moldability by observing the appearance and filling property. In addition, the cure property was evaluated based on the resilience of the foam thickness after crushing.

[Polymer Properties] A polyurethane foam molded under the above foaming conditions was subjected to a temperature of 23 ° C. and a relative humidity of 50%.
After curing for 24 hours in the atmosphere of JIS K-640
0, the physical properties of the foam (core density [kg / m ³ ],
25% hardness [N / 314 cm ² ], rebound resilience (%),
Tear strength [N / cm], tensile strength [kPa],
Elongation [%], compression set [%], wet heat compression set [%]) were measured. In addition, the combustion test (FMVSS-3
02), the flammability of the foam was confirmed. Table 3 shows the results.

[0070]

[Table 3] (Production Examples 10 to 17) Samples S3 to S4 and S6 shown in Table 1
Using S8, a polyoxyalkylene polyol composition (a) was prepared by the following procedure.

First, acrylonitrile (AN) and styrene (ST) having the mass ratios shown in Table 4 were added to the polyoxyalkylene polyol (a1) as an ethylenically unsaturated monomer and reacted at 105 ° C. for 4 hours. A polymer polyol (a1 ′) containing a polymer of acrylonitrile-styrene as the polymer component (P) was prepared. The amount of the ethylenically unsaturated monomer added is determined by the percentage by mass of the polymer component (P) in the polymer polyol (a1 ′).
Was adjusted so as to be the value shown in FIG. Next, (a1 ′) and the polyhydroxy compound (A3) were mixed in parts by mass in Table 4 to obtain a polyoxyalkylene polyol composition (a).
In the same manner as in Production Examples 1 to 9, the foaming agent (C), the catalyst (D) and the foam stabilizer (E) were added in parts by mass in Table 4 to adjust the polyol system. When the viscosity of the obtained polyol system was measured in accordance with JIS K-1557, the values shown in Table 4 were obtained.

Further, under the same foaming conditions as in Production Examples 1 to 9, the above polyol system and Sample I shown in Table 2 were used.
The isocyanate compositions (B) of Nos. 1 to 13 were charged into a high-pressure foaming apparatus, mixed at a ratio that would give an isocyanate index value shown in Table 4, and injected into a mold to foam. At this time, the discharge pressure of the polyol system and the isocyanate system was adjusted to the value shown in Table 4 by changing the orifice diameter in the mixing section head of the foaming apparatus. After being removed from the mold, the polyurethane foam cured in the mold was compressed to 50% to 90% of the foam thickness and subjected to a crushing treatment.

[Evaluation of Moldability and Cure Property], [Foam Physical Properties] Moldability and cure property were evaluated for urethane foams molded in the same manner as in Production Examples 1 to 9.

As for the physical properties of the foam, Production Example 1
As in the case of Nos. To 9, measurement was performed after curing treatment. Furthermore,
The flammability of the foam was confirmed according to a flammability test (FMVSS-302).

Table 4 shows the results.

[0076]

[Table 4] (Production Examples 18 to 28) Samples S1 to S2 and S5 shown in Table 1
Using S7, S12 and S13, a polyoxyalkylene polyol composition was prepared in the same procedure as in Production Examples 1 to 9, and a blowing agent (C), a catalyst (D) and a foam stabilizer (E) were added. To make a polyol system. The amount of each component used is as shown in Table 5 in parts by mass. When the viscosity of the obtained polyol system was measured according to JIS K-1557, the values shown in Table 5 were obtained.

Further, under the same foaming conditions as in Production Examples 1 to 9, the above polyol system and Sample I shown in Table 2 were used.
The isocyanate compositions (B) of Nos. 1, I4 to I9 were charged into a high-pressure foaming apparatus, mixed at a ratio having an isocyanate index value shown in Table 5, and injected into a molding die to perform foaming. At this time, the discharge pressure of the polyol system and the isocyanate system was adjusted to the value shown in Table 5 by changing the orifice diameter in the mixing section head of the foaming apparatus. After being removed from the mold, the polyurethane foam cured in the mold was compressed to 50% to 90% of the foam thickness and subjected to a crushing treatment.

[Evaluation of Moldability and Cure Property], [Foam Physical Properties] Moldability and cure property were evaluated for urethane foams molded in the same procedure as in Production Examples 1 to 9.

Further, regarding the physical properties of the foam, Production Example 1
As in the case of Nos. To 9, measurement was performed after curing treatment. Furthermore,
The flammability of the foam was confirmed according to a flammability test (FMVSS-302).

Table 5 shows the results.

(Production Example 28 ') Polymer polyol (A
1 ′) and 6% by mass of the polymer component (P) in the mixture of the polyoxyalkylene polyol (A2).
By repeating the same operation as in Production Example 28 except that the amount was changed to 10% by mass, a polyol system and an isocyanate system were prepared, and a polyurethane foam was produced. At this time, the viscosity of the polyol system is 3600
mPa · s, causing poor mixing during system mixing,
The resulting foam had cracks.

[0082]

[Table 5] (Production Examples 29 to 39) Samples S3 to S4 to S6 shown in Table 1
Using 7,10 to 13, a polyoxyalkylene polyol composition was prepared in the same procedure as in Production Examples 10 to 17, and a blowing agent (C), a catalyst (D) and a foam stabilizer (E) were added. A polyol system was made. The amount of each component used is as shown in Table 6 in terms of mass ratio. When the viscosity of the obtained polyol system was measured in accordance with JIS K-1557, the values shown in Table 6 were obtained.

Further, under the same foaming conditions as in Production Examples 1 to 9, the above polyol system and Sample I shown in Table 2 were used.
The isocyanate compositions (B) of Nos. 1, I4 to I9 were charged into a high-pressure foaming apparatus, mixed at a ratio of an isocyanate index value shown in Table 6, and injected into a molding die to perform foaming. At this time, the discharge pressure of the polyol system and the isocyanate system was adjusted to the values shown in Table 6 by changing the orifice diameter in the mixing section head of the foaming apparatus. After being removed from the mold, the polyurethane foam cured in the mold was compressed to 50% to 90% of the foam thickness and subjected to a crushing treatment.

[Evaluation of Moldability / Cureability], [Properties of Foam] Moldability and cureability were evaluated for urethane foams molded in the same procedure as in Production Examples 1 to 9.

Further, regarding the physical properties of the foam, Production Example 1
As in the case of Nos. To 9, measurement was performed after curing treatment. Furthermore,
The flammability of the foam was confirmed according to a flammability test (FMVSS-302).

Table 6 shows the results.

(Production Example 39 ') Polymer polyol (a
The same operation as in Production Example 39 was repeated except that the mass percentage of the polymer component (p) in 1 ′) was changed from 20% by mass to 32% by mass to prepare a polyol system and an isocyanate system. Created. At this time, the viscosity of the polyol system is 450
It was 0 mPa · s, mixing failure occurred during system mixing, and the resulting foam had cracks.

[0088]

[Table 6] As is evident from Tables 3 and 4, the specific polyoxyalkylene polyol compositions (A) and (a) are used in accordance with the provisions of the present invention, and the polyoxyalkylene polyol compositions are used in specific mixing ratios. The viscosity of the polyol composition and the polyol system can be reduced, and the viscosity can be reduced in the specific composition ratio and the structural ratio of the prepolymerized polyisocyanate and in the prepolymerization. Under a wide range of discharge pressure conditions, a flexible polyurethane foam having excellent moldability, low density and a wide range of hardness can be produced. In particular, the polyurethane foam produced by the present invention can be used for an automobile seat cushion and a seat back material.
The foam properties shown in Tables 3 and 4 are particularly suitable for an automobile seat back material.

On the other hand, in the production examples shown in Table 5, a polyoxyalkylene polyol (A) or an isocyanate composition (B) outside the range specified in the present invention is used. In such a case, it can be seen that the foam properties are deteriorated, and in particular, deviate from the foam property standards required for an automobile seat back material. As an automobile seat back material, it is generally required that the elongation property is 100% or more and the wet heat compression set is 25% or less. Production Examples 19 and 23 to 26 shown in Table 5 satisfy the above-mentioned standards. I'm not satisfied. Further, Production Examples 21 to 23 are not suitable for automobile seats because of poor moldability or cure property. Furthermore,
In Production Examples 18, 20, 27, and 28, since the structure of the polyoxyalkylene polyol, the viscosity of the polyol system, and the viscosity of the polyisocyanate are outside the specified limits, a polyurethane foam that is sufficiently satisfied can be obtained. Absent.

Similarly, in Table 6, Production Examples 30, 35
No.-37 do not satisfy the standards for automotive seat back materials. Further, Production Examples 32 to 34 are not suitable for automobile seats because of poor moldability or cure property. Further, for Production Examples 29, 31, 38, and 39, the polyoxyalkylene polyol structure, the viscosity of the polyol system,
When the viscosity of the polyisocyanate is out of the specified range, a polyurethane foam having a satisfactory content cannot be obtained.

(Production Examples 40 to 46) Internal dimensions are 400 mm
A slit with a height of 50 mm and a thickness of 2 mm is erected along a plane parallel to the side surface that equally divides the inside into two rectangular parallelepipeds at the bottom of a rectangular parallelepiped mold of × 400 mm × 70 mm and divided into two cavities. did.

From the set of the polyol system and the isocyanate system prepared according to the above production example, two sets were selected as shown in Table 7, and each set of the polyol system and the isocyanate composition was put into two high-pressure foaming apparatuses. Each set of reactive mixtures X and Y was injected into the two cavities of the mold. As for the discharge pressure of the polyol system and the isocyanate system at this time, the flow rate of the reactive mixture X to the mold was set to 280 g / s, the discharge time was set to 0.61 s, and the flow rate of the reactive mixture Y was set to 330 g in accordance with the description of the above production example. / S, and the ejection time was set to 0.67 s. Table 7 shows the time difference between the start of the injection of the reactive mixture X and the start of the injection of the reactive mixture Y. After the injection was completed, the mold was closed and cured under the same foaming conditions as in the above Production Example.

After taking out the obtained polyurethane foam from the mold, the moldability of the foam was observed. The moldability was evaluated as good (shown by ○ in the table) when the two polyurethane foams were well joined at the upper part of the slit and conformed to the cavity shape. (Indicated by x).

[0094]

Table 7-----------------------------Production example 40 41 42 43 44 45 46 47 48 49 50--- −−−−−−−−−−−−−−−−−−−−−−−−−−−− Reactive mixture X Production Example 1 2 4 5 1 1 21 21 1 22 22 −−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−− Reactive mixture Y Production Example 10 11 10 12 10 32 10 32 33 10 33 −−−−−−−−−− −−−−−−−−−−−−−−−−−−−−−− Injection time difference (sec) 5 5 5 5 10 5 5 5 5 5 −−−−−−−−−−−−−− −−−−−−−−−−−−−−−−−−− Moldability ○ ○ ○ ○ ○ × × × × × × −−−−−−−−−−−−−−−−−−−−− In Production Examples 45 to 47, the use of a high-viscosity system resulted in an inhomogeneous polyurethane foam and poor moldability. Shrinkage has occurred to the rules. Further, in Production Examples 48 to 50, although the viscosity of the system is not high, the system is homogeneous, but the molding property is poor due to the low curing property, and the spot at the corner portion in contact with the slit and the sink at the joint portion are formed. There has occurred. In contrast, Production Examples 40 to
For the polyurethane foam of No. 44, the two types of foams were bonded well and the moldability was also good.

As described above, the raw material system according to the present invention has good joining and formability in the production of a molded article of different hardness. Further, even if the above-described injection time difference occurs in the injection of the reactive mixture, it is possible to sufficiently cope with the difference, and it is possible to maintain good moldability.

[0096]

According to the present invention, it is possible to provide a polyol system and an isocyanate system having good moldability and proper viscosity while using water as a foaming agent. A flexible polyurethane foam having a complex shape and a molded article having a different hardness are produced. Therefore, the present invention is extremely useful industrially.

Continued on the front page (72) Inventor Takumi Mizuno 3-13-26 Kukuchi, Amagasaki-shi, Hyogo Sumitomo Bayer Urethane Co., Ltd. (72) Inventor Takayuki Sasaki 3-474-2 Tsukakoshi, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Asahi Glass Co., Ltd. (72) Inventor Yuji Kimura 3-474-2 Tsukakoshi, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Inside Asahi Glass Co., Ltd. (72) Inventor Hiroshi Wada 3-474-2 Tsukakoshi, Sai-ku, Kawasaki-shi, Kanagawa Asahi Glass Co., Ltd. (72) Inventor Hiromitsu Takeyasu 3-474-2 Tsukakoshi, Saiwai-ku, Kawasaki-shi, Kanagawa F-term (reference) 4J034 AA01 DA01 DB03 DC50 DG02 HA01 HA02 HA06 HA07 HA09 HC12 HC22 HC46 HC63 HC64 HC65 HC67 HC71 JA41 KD12 NA03 NA05 PA02 QA01 QB15 QC01

Claims (7)

[Claims] 1. A raw material system comprising a polyol system and an isocyanate system for producing a flexible polyurethane foam in the presence of a catalyst and a foam stabilizer using water as a foaming agent, wherein the polyol system is a polyoxyalkylene. A mixture of water, a catalyst and a foam stabilizer mixed with the polyol composition (A) and having a viscosity of 2500 mPa · s or less. The isocyanate system is a polyoxyalkylene polyol (A4) in the isocyanate mixture (B1).
Isocyanate group-terminated prepolymer (B)
2) and a mixture of toluene diisocyanate (B3) at a mass ratio of 50/50 to 80/20 and a viscosity of 50 m
A composition of Pa · s or less, wherein the polyoxyalkylene polyol composition (A) is:
The average number of functional groups is 2 to 4 and the number average molecular weight is 4000 to 6
000 and the content of terminal oxyethylene units is 12
A polymer polyol (A1 ′) obtained by polymerizing an ethylenically unsaturated monomer in a polyoxyalkylene polyol (A1) having a molecular weight of 2 to 25% by mass; 4, a polyoxyalkylene polyol (A2) having a number average molecular weight of 6,500 to 7,500, a terminal oxyethylene unit content of 14 to 20% by mass, and a terminal primary hydroxyl group conversion of 85% or more; Having a number average molecular weight of 40 to 1000 (A)
3) and wherein the mass ratio of the polymer polyol (A1 ′) to the polyoxyalkylene polyol (A2) is 80/2.
0 to 70/30, and the polyhydroxy compound (A
3) The mass ratio to the total of the polyoxyalkylene polyols (A1 ′) and (A2) is from 1/100 to 5/10.
0, the polymer component (P) is contained in a proportion of 2 to 8% by mass of the total of the polymer polyols (A1 ′) and (A2), and the isocyanate mixture (B1) is 2,2′- and 2 4,4'-diphenylmethane diisocyanate mixture (B1-1) 10 to 25% by mass, 4,4'-diphenylmethane diisocyanate (B1-2) 50 to 80% by mass
And polymethylene polyphenylene polyisocyanate (B1-3) in a mixture of 10 to 25% by mass. The polyoxyalkylene polyol (A4) has an average number of functional groups of 2 to 4 and a number average molecular weight of 1000 to 5000.
And the content of oxyethylene units in the molecule is 60 to 8
A raw material system characterized by being 5% by mass. 2. A raw material system comprising a polyol system and an isocyanate system for producing a flexible polyurethane foam in the presence of a catalyst and a foam stabilizer using water as a foaming agent, wherein the polyol system is a polyoxyalkylene. It is a mixture having a viscosity of 2500 mPa · s or less in which water, a catalyst and a foam stabilizer are blended with the polyol composition (a). The isocyanate system is a polyoxyalkylene polyol (A4) in the isocyanate mixture (B1).
Isocyanate group-terminated prepolymer (B)
2) and a mixture of toluene diisocyanate (B3) at a mass ratio of 50/50 to 80/20 and a viscosity of 50 m
A mixture of Pa · s or less, wherein the polyoxyalkylene polyol composition (a) is:
The average number of functional groups is 2 to 4 and the number average molecular weight is 4000 to 6
000 and the content of terminal oxyethylene units is 12
A polymer polyol (a1 ′) obtained by polymerizing an ethylenically unsaturated monomer in a polyoxyalkylene polyol (a1) of 平均 25% by mass and a polymer component (p); 6, a polyhydroxy compound (A3) having a number average molecular weight of 40 to 1000, and the mass ratio of the polyhydroxy compound (A3) to the polymer polyol (a1 ′) is 1/100 to 5/100.
And the polymer component (p) is contained in a proportion of 15 to 30% by mass of the polymer polyol (a1 ′). The isocyanate mixture (B1) is a mixture of 2,2′- and 2,4′-diphenylmethane diisocyanate. (B1-1) 10 to 25% by mass, 4,4'-diphenylmethane diisocyanate (B1-2) 50 to 80% by mass
And polymethylene polyphenylene polyisocyanate (B1-3) in a mixture of 10 to 25% by mass. The polyoxyalkylene polyol (A4) has an average number of functional groups of 2 to 4 and a number average molecular weight of 1000 to 5000.
And the content of oxyethylene units in the molecule is 60 to 8
A raw material system characterized by being 5% by mass. 3. The isocyanate group-terminated prepolymer (B2) has an isocyanate group content of 30 to 32% by mass.
The raw material system according to claim 1, wherein: 4. A reaction system wherein the polyol system and the isocyanate system of the raw material system according to claim 1 are adjusted to have a discharge pressure of 5 to 20 MPa, respectively. Of producing a flexible polyurethane foam. 5. The two kinds of reactive mixtures obtained by mixing the raw material system according to claim 1 and the raw material system according to claim 2 by using a mixing device, respectively, in different portions in one mold. A flexible polyurethane foam having a different hardness is formed into a unitary molded body of different hardness by supplying the same into a single molded body. 6. The method according to claim 4, wherein an inert gas is introduced as an auxiliary agent into the reactive mixture of the raw material system. 7. A flexible polyurethane foam produced by the production method according to claim 5, having a core density of 27 to 34 kg / m ³ and a 25% hardness of 60 to 140 N /.
314 cm ² of a first flexible polyurethane foam having a core density of 33 to 40 kg / m ³ and a 25% hardness of 130 to
A flexible polyurethane foam characterized by being integrated with a second flexible polyurethane foam of 260 N / 314 cm ² .