JP2003105050A - Method for manufacturing flexible polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flexible polyurethane foam excellent in impact resilience and durability, having a low density, reducing vibration transfer, having a small permeable gas volume and reduced in the volume of closed cells at the same time for improving productivity. SOLUTION: The method for manufacturing a flexible polyurethane foam comprises contacting together at least a polyol (A), an oxyethylene group- containing compound (B), a blowing agent (C), a silicone foam stabilizer (D) and a polyisocyanate (E), where the polyol (A) is a compound different from the oxyethylene group-containing compound (B), and the oxyethylene group- containing compound (B) contains in a ratio of at least 40 mole% of a constituting component obtained by random polymerization or block polymerization of oxyethylene, has a molecular weight in the range of 300-30,000 and is used in a ratio of at least 0.5 pt.mass and at most 20 pts.mass based on 100 pts.mass of the polyol (A).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a flexible polyurethane foam and a method for producing the same. More specifically, the present invention relates to a flexible polyurethane foam that provides excellent sitting comfort as a cushion for vehicles such as automobiles, and has improved productivity during manufacturing, and a method for manufacturing the same.

[0002]

BACKGROUND OF THE INVENTION Flexible polyurethane foams (hereinafter sometimes simply referred to as foams) are widely used mainly for cushions for vehicles such as automobiles due to their excellent cushioning properties. This seat cushion is required to have a comfortable cushioning feeling, an appropriate hardness, and a rebound resilience, and when it is used as a member of an automobile or the like, there is an increasing demand for weight reduction.

Further, in recent years, it has been required that a vehicle such as an automobile has a performance of preventing and reducing vibrations received from a road surface during traveling. However, a seat cushion using a flexible polyurethane foam is used for a human body. Since it is in direct contact with, the vibration transmission characteristics of the seat cushion are directly transmitted to the human body. Therefore, it is required to reduce the vibration transmission of the seat cushion to reduce or prevent the vibration transmission to the human body.

Generally, a flexible polyurethane foam amplifies vibrations from a vehicle in a frequency range of 1 to 5 Hz, and has a frequency of 5H.
It has the effect of damping vibrations at z or higher. Particularly, since the flexible polyurethane foam has a resonance magnification in a vibration region of about 3 to 4 Hz, it is necessary to reduce the resonance magnification of the seat cushion in order to reduce the vibration transmission to the human body.

As a method of reducing the resonance magnification, for example, there is a method of reducing the cell size of the flexible polyurethane foam. The cell size can be simply expressed by the air flow rate of the foam, and in general, there is a relation that the soft air foam having a small cell size has a low air flow rate. By the way, a flexible polyurethane foam for a vehicle usually employs a forming method called mold foaming. In mold foaming, a liquid in which a polyol and an auxiliary agent are mixed is stirred and mixed, and the liquid is put into a container with a sheet shape called a mold, sealed, and released after curing. Molded polyurethane foam.

[0006] In the production of such a flexible polyurethane foam product, there is a demand for an easy-to-remove product in which the number of closed-cell cells at the time of demolding is reduced so that the product can be produced more easily. Generally, when a seat cushion is molded by the cold cure method, there are many closed cells remaining in the obtained foam, and if left as it is, the foam shrinks, and there is a problem that dimensional stability cannot be maintained. . Therefore, usually, a method has been adopted in which the closed cells are continuously bubbled by mechanical crushing to maintain dimensional stability.

However, in the foam in which the closed cell remains too much, there is a problem that the cell skeleton is destroyed during the mechanical crushing and the foam is cracked.
For this reason, the activity of the foam stabilizer is reduced, and the cell size at the time of demolding is increased to reduce the number of closed-cells and prevent cracking during mechanical crushing. However, as described above, when the cell size is increased, the ventilation amount of the obtained foam is increased, and as a result, the resonance magnification is increased, and it is impossible to reduce the vibration transmission to the human body.

That is, if the cell size is reduced by increasing the activity of the foam stabilizer to reduce the air flow rate, the closed cell cannot be reduced, which adversely affects the productivity. On the other hand, if the activity of the foam stabilizer is weakened and the cell size at the time of demolding is increased, a flexible polyurethane foam having a favorable air flow rate can be obtained, but the higher air flow rate results in a higher resonance magnification. Therefore, there is a problem that the vibration transmission cannot be reduced.

On the other hand, JP-A-8-217844 and JP-A-8-23
1678, JP-A-8-239445, JP-A-8-245746, as a method of obtaining a flexible polyurethane foam that can be produced without carrying out mechanical crushing work, a specific polyoxygen as a defoaming agent. The use of ethylene polyoxypropylene polyols is described. However, in the present invention, when a specific polyol is used,
Although it is described that it is possible to reduce the number of closed cells, there is no description as to whether or not the air flow rate can be reduced at the same time, and the method cannot reduce the vibration transmission. there were.

A method for producing a flexible foam having a low air flow rate is described in Japanese Patent Application No. 2001-93112.
Flexible polyurethane foams produced using this method often have closed cells remaining during demolding, causing problems such as cracking during demolding and crushing, shrinkage after demolding, and there are still improvements in productivity. there were. Therefore, in order to improve the impact resilience and durability, reduce the vibration transmission, and improve the productivity, the amount of air permeation is small, and at the same time, the flexible polyurethane foam with a reduced number of closed cells and the manufacturing method thereof are desired. It was rare.

[0011]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, and has excellent impact resilience and durability, low density, reduced vibration transmission, and production. It is an object of the present invention to provide a flexible polyurethane foam having a small air flow rate and at the same time a reduced number of closed-cells in order to improve the property, and a method for producing the same.

[0012]

SUMMARY OF THE INVENTION In the method for producing a flexible polyurethane foam according to the present invention, at least a polyol (A), an oxyethylene group-containing compound (B), a foaming agent, a silicone foam stabilizer and a polyisocyanate are contacted. A method for producing a flexible polyurethane foam, wherein the polyol (A) is a compound different from the oxyethylene group-containing compound (B), and the oxyethylene group-containing compound (B) is a random oxyethylene compound. It contains a constituent component obtained by polymerization or block polymerization in a proportion of 40 mol% or more, has a molecular weight in the range of 300 to 30,000, and is 0.5 parts by mass or more and 20 parts by mass with respect to 100 parts by mass of the polyol (A). used in the following proportions, the resulting flexible polyurethane foam, air permeability be 5cc / cm ² / sec or more 45cc / cm ² / sec or less Spectrum measured by FT-IR has a peak in the range of 1660 cm ^-1 or less beyond 1645 cm ^-1, 50 immediately after the flexible polyurethane foam demoulding
It is characterized in that the resistance value at the time of% compression is 1300 N / 314 cm ² or less. However, the resistance value at 50% compression immediately after demolding the flexible polyurethane foam means that the flexible polyurethane foam has a thickness of 30 seconds after demolding, and a thickness of the flexible polyurethane foam is 250 mm / min. It is the resistance value when compressed to 50%.

The oxyethylene group-containing compound (B)
Has one or more hydroxyl groups and has a hydroxyl value of 20 mgKOH / g
It is preferable that the alcohol is in the range of 500 mgKOH / g or less and the primary hydroxyl value is 20% or more and 80% or less. The polyisocyanate contains toluylene diisocyanate in an amount of 50-100 in all polyisocyanates.
It is preferable that the polyisocyanate is contained by weight%.

[0014] The flexible polyurethane foam according to the present invention, aeration is less 5cc / cm ² / sec or more 45cc / cm ² / sec, the spectrum measured by FT-IR is 1660 cm ^-1 or less exceed 1645 cm ^-1 The soft polyurethane foam having a peak in the range of 1 is characterized in that the resistance value at 50% compression immediately after demolding the soft polyurethane foam is 1300 N / 314 cm ² or less. However, the resistance value at the time of 50% compression immediately after defoaming the foam means that the foam is demolded for 30 seconds and then 250 mm / min.
It is a resistance value when the flexible polyurethane foam is compressed to 50% of the thickness at the speed of.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be specifically described below. [Flexible Polyurethane Foam] The flexible polyurethane foam according to the present invention is a flexible polyurethane foam which is excellent in impact resilience, durability and the like, and has a specific low air permeability and a specific reduced closed cell.

The remaining condition of the closed cell is called "closed cell" and can be measured by various methods. The following method is preferably adopted as one of the methods for measuring the foamability, and the evaluation of the foamability is also based on this method in the present specification. After the curing, the soft foam taken out from the mold is allowed to stand in a hardness tester. 30 seconds after demolding, using a disk with a diameter of 20 cm, 250 mm / min.
Push the flexible polyurethane foam at the speed of. The resistance value at the time when the thickness of the flexible polyurethane foam is compressed by 50% is measured.

At this time, the thickness of the flexible polyurethane foam is not particularly limited, but it is desirable to measure it at 94 to 100 mm. This measurement method is called "Force-to-cru
The measurement method is almost the same as the method called "sh". For example, JD Tobias, Polyurethanes Expo '98, Septem
The measurement method is described in ber, 1998, p445. Such a "Force-to-crush" method is an index similar to the "drag value at 50% compression immediately after demolding the foam" used in the present invention.

In the flexible polyurethane foam of the present invention, the air permeability is 5 cc / cm ² / sec or more and 45 cc / cm ² / sec or less, preferably 10 cc / cm ² / sec or more and 40 cc / cm ² / sec or less, more preferably Is preferably 15 cc / cm ² / sec or more and 35 cc / cm ² / sec or less. If the ventilation amount is within the above range,
It exhibits a good resonance magnification and improves riding comfort.

The flexible polyurethane foam according to the present invention has a 50% compression resistance value of 130 immediately after the foam is removed from the mold.
0 N / 314 cm ² or less, preferably 200 N / 314 cm ^{2 to} 1200
N / 314 cm ² , more preferably 300 N / 314 cm ^{2 to} 1100
N / 314 cm ² is desirable. Further, the resonance magnification of the flexible polyurethane foam according to the present invention is preferably 3.2 times or less, more preferably 2.8 times or less.

Wet-heat compression set (hereinafter sometimes referred to as "WS") of the flexible polyurethane foam according to the present invention.
Is preferably 15% or less, more preferably 3% or more and 14% or less, and particularly preferably 5% or more and 13% or less. When the wet heat compression set is in such a range, a flexible polyurethane foam having excellent durability can be obtained.

The impact resilience of the flexible polyurethane foam according to the present invention is preferably 50 or more and 78 or less, more preferably 55 or more and 75 or less, particularly preferably 58 or more 73.
The following is desirable. When the impact resilience is within the above range, a soft polyurethane foam having a comfortable sitting comfort can be obtained. The elongation of the flexible polyurethane foam according to the present invention is preferably 100% or more and 300% or less, more preferably 105% or more and 250% or less, and particularly preferably 110% or more and 220% or less.

The core density of the flexible polyurethane foam according to the present invention is preferably 47 kg / m ³ or more, more preferably 50 kg / m ³ or more, particularly preferably 52 kg / m ³ or more when the impact resilience is less than 65%. Is desirable. When the impact resilience is 65% or more, the core density is preferably 4
It is desirable that the amount is ³ kg / m ³ or more, more preferably 45 kg / m ³ or more, and particularly preferably 47 kg / m ³ or more. When the density is within the above range, a flexible polyurethane foam having a comfortable sitting comfort can be obtained.

Such a flexible polyurethane foam is
When producing the cold cure molded foam method, spectrum measured by using a flexible polyurethane foam by FT-IR has a peak at 1660 cm ^-1 in the range beyond the 1645 cm ^-1. The raw materials and manufacturing method of such a flexible polyurethane foam according to the present invention will be described below.

[Polyol (A)] When producing the flexible polyurethane foam according to the present invention, the polyol to be reacted with polyisocyanate is obtained from a specific polyoxyalkylene polyether polyol or a specific polyoxyalkylene polyether polyol. Polymer polyol.

Polyoxyalkylene polyether polio
The polyoxyalkylene polyether polyol used in the present invention is an oligomer or polymer obtained by ring-opening polymerization of an alkylene oxide, and a polyoxy group having a specific hydroxyl value depending on the production method as described later. Alkylene polyether polyols are used. Such a polyoxyalkylene polyether polyol is usually obtained by ring-opening polymerization of an alkylene oxide with an active hydrogen compound as an initiator in the presence of a catalyst.

The polyoxyalkylene polyether polyol may also be referred to as "polyoxyalkylene polyol". When manufacturing flexible polyurethane foam by the cold cure mold foam method,
That is, the spectrum measured by FT-IR is 1645 cm ^-1
When a flexible polyurethane foam having a peak in the range of more than 1660 cm ^-1 is obtained, the polyoxyalkylene polyether polyol has a hydroxyl value of 20 mgKOH.
/ G or more and 80 mgKOH / g or less, preferably 24 mgKOH /
g or more and 70 mgKOH / g or less, more preferably 26 mgK
OH / g or more and 60 mgKOH / g or less is desirable.

When the hydroxyl value of the polyoxyalkylene polyether polyol used in the cold cure mold foam method is in such a range, a flexible polyurethane foam having excellent impact resilience and durability and a low density can be produced. Such polyoxyalkylene polyether polyol has a total degree of unsaturation of preferably 0.060.
meq / g or less, more preferably 0.045 meq / g
It is preferably g or less, and particularly preferably 0.025 meq / g or less.

When the total degree of unsaturation is within the above range, the monool content is low, so that a highly durable polyurethane foam can be obtained. These polyoxyalkylene polyether polyols may be used alone or in combination of 2
A combination of two or more species can be used. In the production of the polyoxyalkylene polyether polyol, the initiator and alkylene oxide may be used alone or in combination.

The polyoxyalkylene polyether polyol may contain an active hydrogen compound such as other alcohols, as long as it is not against the gist of the present invention. Examples of such active hydrogen compounds include dihydric alcohols such as ethylene glycol and propylene glycol,
Examples thereof include trihydric alcohols such as glycerin and trimethylolpropane, and tetrahydric alcohols such as pentaerythritol and diglycerin.

( Polyoxyalkylene polyether poly
Active hydrogen compounds for all production) Active hydrogen compounds used as an initiator in the production of polyoxyalkylene polyether polyols include active hydrogen compounds having an active hydrogen atom on an oxygen atom, and active hydrogen atoms on a nitrogen atom. Examples thereof include active hydrogen compounds. Among the active hydrogen compounds, as the active hydrogen compound having an active hydrogen atom on the oxygen atom, for example, water, the number of carbon atoms 1 to 20
Carboxylic acids, polyvalent carboxylic acids having 2 to 6 carboxyl groups having 2 to 20 carbon atoms, carbamic acids, alcohols having 1 to 20 carbon atoms, and 2 to 8 hydroxyl groups having 2 to 20 carbon atoms. Having polyhydric alcohols, sugars or derivatives thereof, aromatic compounds having 1 to 3 hydroxyl groups having 6 to 20 carbon atoms, polyalkylene having 2 to 8 terminals and 1 to 8 hydroxyl groups at the terminals Examples thereof include oxides.

As the carboxylic acid having 1 to 20 carbon atoms,
Examples thereof include formic acid, acetic acid, propionic acid, isobutyric acid, lauric acid, stearic acid, oleic acid, phenylacetic acid, dihydrocinnamic acid or cyclohexanecarboxylic acid, benzoic acid, paramethylbenzoic acid or 2-carboxyhydrophthalic acid. Examples of polyvalent carboxylic acids having 2 to 6 carboxyl groups having 2 to 20 carbon atoms include oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, adipic acid, itaconic acid, butanetetracarboxylic acid, and phthalic acid. Acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid and the like can be mentioned.

Examples of carbamic acids include N, N-
Examples thereof include diethylcarbamic acid, N-carboxypyrrolidone, N-carboxyaniline, N, N′-dicarboxy-2,4-toluenediamine and the like. As the alcohol having 1 to 20 carbon atoms, for example, methanol, ethanol,
Normal-Propanol, Iso-Propanol, Normal
-Butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, iso-pentyl alcohol, tert-pentyl alcohol, normal-octyl alcohol, lauryl alcohol, cetyl alcohol, cyclopentanol, cyclohexanol, allyl alcohol, crotyl alcohol, methyl Examples thereof include vinyl carbinol, benzyl alcohol, 1-phenylethyl alcohol, triphenyl carbinol, and cinnamyl alcohol.

Examples of the polyhydric alcohols having 2 to 8 hydroxyl groups having 2 to 20 carbon atoms include ethylene glycol, propylene glycol, diethylene glycol,
Dipropylene glycol, 1,3-propanediol, 1,3-
Examples thereof include butanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanediol, trimethylolpropane, glycerin, diglycerin, pentaerythritol and dipentaerythritol.

Examples of the sugar or its derivative include glucose, sorbitol, dextrose, fructose, sucrose and the like. Examples of the aromatic compounds having 1 to 3 hydroxyl groups having 6 to 20 carbon atoms include phenol, 2-naphthol, 2,6-dihydroxynaphthalene, bisphenol A and the like.

Examples of the polyalkylene oxides having 1 to 8 hydroxyl groups at the terminals include polyethylene oxide, polypropylene oxide and copolymers thereof. Further, among the active hydrogen compounds in the method of the present invention, as the active hydrogen compound having an active hydrogen atom on the nitrogen atom, for example, aliphatic or aromatic primary amines having 1 to 20 carbon atoms, 2 to carbon atoms 20 aliphatic or aromatic secondary amines, 2-3 with 2-20 carbon atoms
Polyvalent amines having a primary or secondary amino group,
Saturated cyclic secondary amines having 4 to 20 carbon atoms, 4 carbon atoms
~ 20 unsaturated cyclic secondary amines, 4-20 carbon atoms 2 ~
Cyclic polyamines containing secondary amino groups of 3, unsubstituted or N-monosubstituted acid amides having 2 to 20 carbon atoms, 5 to 7 membered cyclic amides, 4 to 10 carbon atoms Examples of the dicarboxylic acid imides include

Examples of the aliphatic or aromatic primary amines having 1 to 20 carbon atoms include methylamine, ethylamine, normal-propylamine, isopropylamine, normal-butylamine, isobutylamine, sec-
Examples thereof include butylamine, tert-butylamine, cyclohexylamine, benzylamine, β-phenylethylamine, aniline, o-toluidine, m-toluidine, p-toluidine and the like.

Examples of the aliphatic or aromatic secondary amine having 2 to 20 carbon atoms include dimethylamine, methylethylamine, diethylamine, di-normal-propylamine, ethyl-normal-butylamine, methyl-sec.
-Butylamine, dipentylamine, dicyclohexylamine, n-methylaniline, diphenylamine and the like can be mentioned.

Examples of polyamines having 2 to 3 primary or secondary amino groups having 2 to 20 carbon atoms include, for example,
Ethylenediamine, di (2-aminoethyl) amine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, tri (2-aminoethyl) amine, N, N'-dimethylethylenediamine, N, N'-diethylethylenediamine or di ( 2-methylaminoethyl) amine and the like can be mentioned.

Examples of the saturated cyclic secondary amine having 4 to 20 carbon atoms include pyrrolidine, piperidine, morpholine, 1,2,3,4-tetrahydroquinoline and the like. Examples of the unsaturated cyclic secondary amines having 4 to 20 carbon atoms include 3-pyrroline, pyrrole, indole, carbazole, imidazole, pyrazole and purine.

Examples of the cyclic polyvalent amines having 2 to 3 secondary amino groups having 4 to 20 carbon atoms include piperazine, pyrazine, 1,4,7-triazacyclononane and the like. Examples of the unsubstituted or N-monosubstituted acid amide having 2 to 20 carbon atoms include acetamide, propionamide, N-methylpropionamide, N-methylbenzoic acid amide, N-ethylstearic acid amide and the like. To be

The 5- to 7-membered cyclic amides include, for example, 2-pyrrolidone or ε-caprolactam. Examples of the dicarboxylic acid imides having 4 to 10 carbon atoms include succinimide, maleic imide, phthalimide and the like. Among these active hydrogen compounds, when the flexible polyurethane foam according to the present invention is produced by the hot cure mold foam method, it is preferably a polyhydric alcohol having 2 to 20 carbon atoms and 2 to 8 hydroxyl groups. And more preferably ethylene glycol, propylene glycol,
Examples include diethylene glycol, dipropylene glycol, glycerin, diglycerin, pentaerythritol, and the like.

Of these active hydrogen compounds, when a flexible polyurethane foam is produced by the cold cure mold foam method, it preferably has 2 to 20 carbon atoms and 2 to 8 hydroxyl groups. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, diglycerin, and pentaerythritol.

(Alkylene oxide compound) Examples of the alkylene oxide compound used in producing the polyoxyalkylene polyether polyol used in the present invention include ethylene oxide, propylene oxide, 1,2-butylene oxide and 2,3 -Butylene oxide,
Examples thereof include epoxy compounds such as styrene oxide, cyclohexene oxide, epichlorohydrin, epibromohydrin, methyl glycidyl ether, allyl glycidyl ether, and phenyl glycidyl ether. Among these alkylene oxide compounds, ethylene oxide, propylene oxide, 1,2-butylene oxide and styrene oxide are preferable, and ethylene oxide and propylene oxide are more preferable.

These compounds may be used alone or in combination of two or more. When these compounds are used in combination, a method of simultaneously using a plurality of alkylene oxide compounds, a method of sequentially using them, a method of repeating the order, or the like can be adopted. In such a polyoxyalkylene polyether polyol, the content of structural units derived from ethylene oxide (total oxyethylene group content) is such that the total amount of structural units derived from alkylene oxide constituting the polyoxyalkylene polyether polyol is 100 mass. %, Preferably 5% by mass or more and 30% by mass or less, more preferably 10% by mass.
It is desirable that the content is not less than mass% and not more than 20 mass%.

Polymer Polyol The polymer polyol used in the present invention is a polymer polyol obtained from the polyoxyalkylene polyether polyol. Specifically, when a flexible polyurethane foam is produced by the cold cure mold foam method, the hydroxyl value is 15 mgKOH / g or more 64
mgKOH / g or less, and the total degree of unsaturation is preferably 0.
It is a polymer polyol obtained from a polyoxyalkylene polyether polyol having a content of 060 meq / g or less.

In the present invention, the polymer polyol (hereinafter sometimes referred to as "polymer-dispersed polyol") means a compound having an unsaturated bond such as acrylonitrile or styrene, and a radical initiator such as azobisisobutyronitrile. Is a dispersion of vinyl polymer particles (hereinafter, may be simply referred to as “polymer fine particles”) obtained by dispersion polymerization in a polyol.

The vinyl polymer particles may be vinyl polymer particles composed of a homopolymer of a compound having an unsaturated bond, but in the present invention, at least a part of the compound having an unsaturated bond such as acrylonitrile is used during dispersion polymerization. It is preferable to graft to a polyol which is a dispersion medium. Thus, in the present invention, the polyol may be used as a non-reaction solvent or a reaction solvent.

When the polymer-dispersed polyol is used in the present invention, the amount of the polyol and the polymer polyol used is 1
When set to 00, the proportion of polymer fine particles (sometimes referred to as "vinyl polymer content") is preferably 5 to 3.
It is desirable that the content is 0% by mass, more preferably 5 to 20% by mass. The compound having an unsaturated bond is a compound having an unsaturated bond in the molecule, and examples thereof include acrylonitrile, styrene and acrylamide. These compounds having an unsaturated bond can be used alone or in combination of two or more. In the present invention, it is preferable to use a mixture of two or more compounds having an unsaturated bond.

When producing the polymer-dispersed polyol, a dispersion stabilizer or a chain transfer agent may be used in combination with the compound having an unsaturated bond. [Oxyethylene group-containing compound (B)] The oxyethylene group-containing compound (B) used in the present invention has a molecular weight of 300 to 3000 having an oxyethylene group skeleton obtained by random or block polymerization of oxyethylene in the molecule.
0, preferably 500 to 10000, more preferably 1000 to 600
0 compound, wherein the oxyethylene group-containing compound contains the oxyethylene group in an amount of 40 mol% or more, preferably 50
It is desirable that the content is at least mol%. The structure other than the oxyethylene group may be arbitrary, but a polyoxypropylene group is preferable. Further, the oxyethylene group-containing compound (B) is preferably an alcohol having one or more hydroxyl groups, preferably has a hydroxyl group at the molecular end, and more preferably has 2 or more functional groups. Is desirable.

When it has a hydroxyl group, the hydroxyl value is preferably 20 mgKOH / g or more and 500 mgKOH / g or less, more preferably 30 mgKOH / g or more and 250 mgKOH / g or less, and particularly preferably 40 mgKOH / g or more and 200 mgKOH / g or less. The oxyethylene is 40 mol% or more, more preferably a random or block addition polymerization at a ratio of 50 mol% or more, the primary hydroxyl value is preferably 20% or more 80% or less,
More preferably, the polyol is 40% or more and 80% or less.

By using the oxyethylene group-containing compound (B) having a hydroxyl value, an oxyethylene group content and a primary hydroxyl group ratio, it is possible to obtain a flexible polyurethane foam having a small air flow rate and a reduced number of closed cell. In particular, when the hydroxyl value and the primary hydroxyl value are within the above ranges, it is possible to obtain a flexible polyurethane foam having a small air permeability and improved vibration transmission.

The oxyethylene group-containing compound (B) is used in an amount of 0.5 to 20 parts by mass, preferably 1 to 10 parts by mass, per 100 parts by mass of the polyol (A). It is desirable to use an amount. [Foaming agent] As the foaming agent used in the present invention, chlorofluorocarbons, hydroxychlorofluorocarbons (HCFC-134a, etc.) and hydrocarbons (cyclopentane) developed for the purpose of protecting the global environment are used as physical foaming agents. Etc.), carbon dioxide gas, liquefied carbon dioxide gas, and other foaming agents can be used alone or in combination with water as a foaming auxiliary agent.

Of these, carbon dioxide gas and liquefied carbon dioxide gas are preferable, from the viewpoint of the load on the global environment and the fact that the density of the flexible polyurethane mold foam can be largely changed by changing the addition amount in a small amount. Liquefied carbon dioxide gas is more preferable. Such a physical foaming agent is preferably used in an amount of 0.1 to 4.0 parts by mass, more preferably 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the polyol (A). desirable.
If the amount of the foaming agent is less than 0.1 parts by mass, it may be difficult to stabilize the foaming, and if the amount of the foaming agent is more than 4.0 parts by mass, the foaming may not be effectively performed.

In the case of the cold cure mold foam method, water can be preferably used as the foaming agent, and the amount of water usually used is preferably 1.8 to 5 with respect to 100 parts by mass of the polyol (A). The amount is preferably 0.0 parts by mass, more preferably 2.0 to 4.0 parts by mass. If the amount of water as the foaming agent is less than 1.8 parts by mass, foaming may not be stable, and the amount of the foaming agent is 5.0.
If the amount is more than the amount by mass, foaming may not be effectively performed.

[Silicone Foam Stabilizer] As the silicone foam stabilizer used in the present invention, a commonly used organosilicon surfactant can be used. For example, Toray
SRX-274C made by Dow Corning Silicone,
SF-2969, SF-2961, SF-2962, Y
-10515 (above, trade name) and L-5309, L-3601, L-5307, L-36 manufactured by Nippon Unicar Co., Ltd.
00, L-5366 (above, product name), Air Products
And Chemicals' DC5164, DC5043, DC516
9, DC2583, DC2585 (above, brand name), B8719, B8724, B8727, B8715, B87 made by Goldschmidt
26, B4113 (above, trade name) and the like can be preferably used.

Of these, SF is more preferable.
-2961, SF-2962, L-5309, L-53
66, DC5164, DC5043, DC5169, B8719, B872
4, it is desirable to use a highly active catalyst such as B8727. The amount of the silicone foam stabilizer used is polyol (A) 1
It is desirable that the amount is 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass, and more preferably 1.5 to 5 parts by mass with respect to 00 parts by mass.

[ Polyisocyanate] The polyisocyanate to be reacted with the polyol such as the polyoxyalkylene polyether polyol according to the present invention is not particularly limited, but conventionally known toluylene diisocyanate (2,4-
The isomer ratio of the body and the 2,6-body is not particularly limited, but 2,4-isomer
A body / 2,6-body ratio of 80/20 is preferably used. ) Or a mixture of toluylene diisocyanate and polymethylene polyphenyl polyisocyanate (for example, Cosmonate M-200 manufactured by Mitsui Takeda Chemical Co., Ltd.) is preferably used.

A mixture of polyisocyanate which is a composition of polymethylene polyphenyl polyisocyanate or its urethane modified product and tolylene diisocyanate can also be preferably used. When manufacturing flexible polyurethane foam by the cold cure mold foam method,
Toluylene diisocyanate alone or a mixture of toluylene diisocyanate and polymethylene polyphenyl polyisocyanate can be preferably used.

In the cold cure mold foam method, when the polyisocyanate is a mixed system of toluylene diisocyanate and another polyisocyanate, the toluylene diisocyanate is preferably 50 to 100% by mass, more preferably 60 to 90% by mass. It is desirable that the content is particularly preferably 65 to 85% by mass.

When the content of toluylene diisocyanate is within the above range, it is preferable from the viewpoint of the balance between durability and mechanical strength of the foam. The total number of isocyanate groups in such a polyisocyanate is an amino group such as a hydroxyl group or a cross-linking agent of polyoxyalkylene polyether polyol,
The NCO index is the value divided by the total number of active hydrogen that reacts with isocyanate groups such as water. That is, when the number of active hydrogens that react with the isocyanate group and the isocyanate group in the polyisocyanate are stoichiometrically equal,
The NCO index will be 1.0. In the present invention, the NCO index is preferably in the range of 0.70 to 1.30, more preferably 0.80 to 1.20.

[Catalyst ] In the present invention, a catalyst can be added in the production of the flexible polyurethane foam.
As the catalyst, a conventionally known catalyst can be used, and there is no particular limitation. For example, triethylenediamine, bis- (2
-Dimethylaminoethyl ether) and the like can be preferably used.

These catalysts can be used alone or in combination of two or more kinds. The amount of the catalyst used is 0.1 to 100 parts by mass of the polyol (A).
It is preferably 10 parts by mass. [Other Additives] In the present invention, other additives such as a cross-linking agent can be used within a range that does not impair the object of the present invention.

(Crosslinking Agent) In the method for producing a flexible polyurethane foam according to the present invention, it is preferable to use a crosslinking agent. When a crosslinking agent is used, a compound having a hydroxyl value of 200 to 1800 mgKOH / g is preferably used as the crosslinking agent. As such a cross-linking agent,
Examples thereof include aliphatic polyhydric alcohols such as glycerin; alkanolamines such as diethanolamine and triethanolamine.

The hydroxyl value is 200 to 1800 mg KO
A polyoxyalkylene polyether polyol having H / g can also be used as a crosslinking agent, and a conventionally known crosslinking agent can also be used. When such a crosslinking agent is used, it is preferable to use an amount of 0.5 to 10 parts by mass based on 100 parts by mass of the total amount of the polyoxyalkylene polyether polyol and / or the polymer polyol.

[Method for producing flexible polyurethane foam]
The method for producing a flexible polyurethane foam according to the present invention,
Using the polyoxyalkylene polyether polyol or the polymer polyol or the like, a known cold cure mold foam method may be used and is not particularly limited, but usually a resin premix and a polyisocyanate are used in a high-pressure foaming machine, a low-pressure foaming machine, or the like. The method of mixing using is preferred.

The resin premix is a mixture of the above polyoxyalkylene polyether polyol or the above polymer polyol, and if necessary, a foaming agent, a crosslinking agent, a foam stabilizer and a catalyst. In addition, flame retardants, pigments, ultraviolet absorbers, antioxidants and the like can be added as auxiliary agents, if necessary.

For example, the polyol, the foaming agent, the cross-linking agent, the foam stabilizer, the catalyst, and other additives according to the present invention are mixed in advance to form a resin premix, and then the resin premixed polyisocyanate is mixed with a predetermined amount. It is possible to obtain a target product having a certain shape by mixing the components in a ratio, injecting them into a mold, reacting, foaming and curing. Curing time is usually 30 seconds ~
30 minutes, the mold temperature is from room temperature to about 80 ° C, and the curing temperature is preferably from room temperature to about 150 ° C.
80 to 1 after curing within a range that does not impair the objects and effects of the present invention
You may heat a hardened | cured material in the range of 80 degreeC.

The resin premix is usually mixed with the polyisocyanate in a high pressure or low pressure foamer,
When a compound having hydrolyzability such as an organotin catalyst is used as a catalyst, it is preferable to separate the water component and the organotin catalyst component from each other in order to avoid contact with water and mix them with a mixing head of a foaming machine. . In the case of a soft polyurethane foam molded by cold cure, it has closed cells at the time of demolding, and the foamability remains. If a large number of these independent bubbles remain, it may lead to cracks during the demolding or crushing and residual crushing.

When a large amount of a highly active foam stabilizer was used in an attempt to reduce the air flow rate, a large amount of closed cells remained at the time of demolding, the 50% compression resistance value after demolding was large, and crushing cracks, Crushing remains. For this reason, when a low-activity foam stabilizer is used in an attempt to reduce the air flow rate, there are few remaining independent bubbles at the time of demolding, the 50% compression resistance value after demolding becomes small, and crushing cracks do not occur. However, the ventilation amount becomes large, and it may not be possible to obtain a flexible polyurethane foam having the desired physical properties.

Therefore, in the present invention, by using 0.5 to 10 parts by mass of the oxyethylene group-containing compound (B),
The air permeability of flexible polyurethane foam is 5cc / cm ² / sec to 45cc / cm ² / sec, and the 50% compression resistance value at the time of demolding is 1
200 N / 314 cm ² or less, it is possible spectrum measured by FT-IR to produce a flexible polyurethane foam having a peak in 1660 cm ^-1 in the range beyond the 1645 cm ^-1.

[Application] The flexible polyurethane foam according to the present invention is suitable for a seat cushion of a vehicle such as an automobile because it has appropriate impact resilience, vibration absorption and durability and reduced vibration transmission. . Further, according to the method for producing a flexible polyurethane foam according to the present invention, it is possible to produce a flexible polyurethane foam having the above-mentioned excellent properties while improving productivity.

The total density, foam hardness, wet heat compression set, elongation, hydroxyl value, impact resilience according to the present invention,
The total degree of unsaturation, the air flow rate, and the vibration test are measured by the following methods. Total density / core density : Measurement was carried out by the method described in JIS K-6400. Refers to the apparent density according to JIS standards. In the present invention, the total density was measured using a rectangular parallelepiped foam sample with an epidermal skin. The core density was measured by removing the skin from the foam sample and preparing a rectangular parallelepiped foam sample. Hardness of foam (abbreviated as "25% ILD" in the table of Examples): Measurement was carried out by the A method described in JIS K-6400. The foam used had a thickness of 94 mm to 100 mm. Impact resilience : Measured by the method described in JIS K-6400. Wet heat compression set (abbreviated as "WS" in the tables of Examples): Measurement was carried out by the method described in JIS K-6400. At the time of measurement, the core portion of the molded flexible polyurethane foam was cut out and used in a size of 50 × 50 × 25 mm. Compress the test piece to a thickness of 50%, sandwich it between parallel flat plates, and
It was left for 22 hours under the condition of relative humidity of 95%. Thirty minutes after the test piece was taken out, its thickness was measured and compared with the value before the test to measure the strain rate. Elongation : Measured according to the method described in JIS K-6400. Hydroxyl value (OHv) : Measured by the method described in JIS K-1557. Total degree of unsaturation : Measurement was carried out by the method described in JIS K-1557. Head-to-tail coupling selectivity : JEOL 400
MHz, ¹³ C-nuclear magnetic resonance (NMR) apparatus was used, deuterated chloroform was used as a solvent, ¹³ C-NMR spectrum of polyoxyalkylene polyol was measured, and head-to-tail (Head-to-Tail) binding was performed. Signal of the methyl group of the oxypropylene segment (16.9 to 17.4 ppm) and the signal of the methyl group of the oxypropylene segment of the head-to-head (17.7 to 18.5 pp)
The head-to-tail binding selectivity was calculated from the ratio of m). In addition, attribution of each signal is macromolecules (Macromolecules), 19.1337-1343 (1986), F.
FC Schiling, Ay Tonel (A.
E.Tonelli) was used as the standard. Aeration rate : Measurement was carried out by the A method described in JIS K-6400. Vibration test : Measurement was carried out by the method described in JASO-B407. The total vertical amplitude was 5 mm, the load was 50 kgf, and a 400 × 400 × 100 mm foam was used as a test sample.

The 50% compression resistance value after demolding the foam was measured by the following method. After the flexible polyurethane foam was cured, the flexible foam taken out of the mold was placed in a hardness measuring instrument. 30 seconds after demolding, using a disk with a diameter of 20 cm, 250 mm / min.
The flexible foam obtained at the speed of was pressed. The drag value at the time of 50% compression was read.

The measuring device is an autograph manufactured by Shimadzu Corporation.
AG-500B was used.

[0075]

Industrial Applicability According to the present invention, since the elastic polyurethane has appropriate impact resilience, durability, low density, and excellent vibration absorption, the vibration transmission rate is low, and the soft polyurethane has high productivity. The form is obtained.

[0076]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Parts and% in the examples represent parts by mass and% by mass, respectively. The following raw materials were used as the polyol, polymer polyol, polyisocyanate and the like.

<Polyol> (hereinafter, abbreviated as “PPG”)
There are Rukoto) (Polyol A) of the initiator functionality 3, a hydroxyl value 34m
gKOH / g, terminal oxyethylene group content is 14.5 wt%,
Total unsaturation 0.025 meq / g, head-to-tail bond selectivity
96.9% polyoxyalkylene polyol. (Polyol B) Number of functional groups of initiator 2, hydroxyl value 56 mg
KOH / g, terminal oxyethylene group content 14.5wt%, total unsaturation 0.034meq / g, head-to-tail bond selectivity 9
7.2% polyoxyalkylene polyol. (Polyol C) Number of functional groups of initiator 3, hydroxyl value 28m
gKOH / g, terminal oxyethylene group content is 14.5 wt%,
Total unsaturation 0.018 meq / g, head-to-tail bond selectivity
96.3% polyoxyalkylene polyol.

<Polymer Polyol> (Hereinafter, “POP”
A shorthand is to) (polymer polyol D) in the polyether polyol A having a hydroxyl value of 34 mg KOH / g and, acrylonitrile, and styrene by graft polymerization, hydroxyl value 28 mg KOH / g, the vinyl polymer content 20 wt% polymer polyol (Polymer polyol D) was obtained.

<Oxyethylene Group-Containing Compound> As the oxyethylene group-containing compound (B), the following polyoxyalkylene polyol was synthesized. (Compound B-1) 1 mol of glycerin to potassium hydroxide
After adding 0.37 mol and dehydration under reduced pressure at 100 ° C for 6 hours, propylene oxide was addition-polymerized at a reaction temperature of 115 ° C and a reaction pressure of 4.8 kg / cm ² , and then propylene oxide and ethylene oxide were randomly added at a reaction temperature of 105 ° C. Thus, a polyoxyalkylene polyol having a hydroxyl value of 52 mgKOH / g and a molecular weight of 3000 was obtained. The oxyethylene group content was 73 mol% and the primary hydroxyl group conversion rate was 45%.

<Polyisocyanate> As the polyisocyanate, the following were used. Cosmonate TM-20 (manufactured by Mitsui Takeda Chemical Co.); 80 parts of a mixture of 2,4-toluylene diisocyanate and 2,6-toluylene diisocyanate in an 80:20 mass ratio and 20 parts of polymethylene polyphenyl polyisocyanate blend.

<Other Raw Materials> In addition to the above-mentioned polyoxyalkylene polyol, polymer polyol, polyisocyanate, and oxyethylene group-containing compound, the following raw materials were used. (Catalyst-1) Minico L-1020; Amine catalyst (Triethylenediamine 3
3% diethylene glycol solution) (Active Material Chemical Co., Ltd.) (Catalyst-2) Minico TMDA; amine catalyst (Active Material Chemical Co., Ltd.). (Crosslinking agent-1) KL-210; a crosslinking agent having a hydroxyl value of 830 mgKOH / g (manufactured by Mitsui Takeda Chemicals, Inc.). (Foam stabilizer-1) L-5309: Silicone foam stabilizer (manufactured by Nippon Unicar Co., Ltd.). (Foam stabilizer-2) SF-2962; Silicone foam stabilizer (manufactured by Toray Dow Corning Silicone Co., Ltd.). (Foam stabilizer-3) L-3601; Silicone foam stabilizer (manufactured by Nippon Unicar Co., Ltd.).

<Production of Polyurethane Foam>

[0083]

Example 1 A resin solution was prepared by mixing the following components. PPG-1 Polyol A / 20 parts PPG-2 Polyol B / 10 parts POP-1 Polymer polyol D / 70 parts Crosslinking agent-1 1 part Water 2.5 parts Catalyst-1 0.4 parts Catalyst-2 0.1 parts Foam stabilizer Foaming agent-1 / 1.5 parts Compound B-1 1.5 parts Polyisocyanate was mixed with the above resin solution in an equivalent amount in the range of NCO index 0.90 to 1.10, and immediately adjusted to 65 ° C in advance. It was poured into a mold of 400 × 400 × 100 mm, and the lid was closed to foam. 6 in a 100 ° C hot air oven
After heat-curing for a minute, the flexible foam was taken out of the mold.

The resin solution and the isocyanate were mixed using a high-pressure foaming machine. The raw material temperature was set to 25 ° C. as the tank temperature, and the discharge was performed at a discharge pressure of 10 to 15 N / cm ² and a discharge rate of 20 kg / min. The high-pressure foaming machine used was manufactured by Polyurethane Engineering Co., Ltd., and the mixing head was 3B type. Table 1 shows the physical properties of the obtained flexible foam.

[0085]

Examples 2 to 4 PPG-1, PPG-2, POP-in Example 1
A flexible foam was obtained in the same manner as in Example 1, except that 1, the type of compound B-1, the crosslinking agent-1, the water, the type of foam stabilizer-1 and the number of parts used were changed according to Table 1. Table 1 shows the physical properties of the obtained flexible foam.

[0086]

[Comparative Examples 1-2] In Example 1, PPG-1, PPG-2, PO
A flexible foam was obtained in the same manner as in Example 1, except that the types and the number of parts of P-1, compound B-1, crosslinking agent-1, water, and foam stabilizer-1 were changed according to Table 2. Table 2 shows the physical properties of the obtained flexible foam.

[0087]

[Table 1]

[0088]

[Table 2]

<Comparison between Example and Comparative Example> The flexible foams of Examples 1 to 4 had good "drag value at 50% compression immediately after demolding" and good air permeability in all NCO index ranges. It showed good impact resilience, good wet heat compression set, good elongation and low resonance magnification. On the other hand, the flexible foam of Comparative Example 1 does not use the compound B-1 and has 50% immediately after demolding.
The% drag value was outside the range of the present invention. In addition, Comparative Example 2
In the flexible foam of No. 2, although the “drag value at 50% compression immediately after demolding” is within the range of the present invention, the ventilation amount is outside the range of the present invention.

Continued front page    (72) Inventor Hiroyuki Utsumi             580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Takeda             Within Mical Co., Ltd. (72) Inventor Kazuhiko Okubo             580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Takeda             Within Mical Co., Ltd. F term (reference) 4J034 BA08 CA01 CA03 DA01 DG02                       DG03 DG04 HA01 HA02 HA06                       HA07 HC12 KA01 KD12 MA24                       NA01 NA05 QA02 QA05 QB14                       QB15 RA12

Claims (4)

[Claims] 1. A method for producing a flexible polyurethane foam by contacting at least a polyol (A), an oxyethylene group-containing compound (B), a foaming agent, a silicone foam stabilizer, and a polyisocyanate. The polyol (A) is a compound different from the oxyethylene group-containing compound (B), and the oxyethylene group-containing compound (B) has 40 constituent components obtained by random polymerization or block polymerization of oxyethylene. It is contained in a proportion of more than mol% and has a molecular weight of 30.
It is in the range of 0 to 30,000, and the polyol (A) is 100.
It is used in a ratio of 0.5 parts by mass or more and 20 parts by mass or less with respect to parts by mass, and the obtained flexible polyurethane foam has an air permeability of 5 cc / c.
m ² / sec or more 45 cc / cm and a ² / sec or less, the spectrum measured by FT-IR has a peak in the range of 1660 cm ^-1 or less beyond 1645 cm ^-1, 50% immediately after the flexible polyurethane foam demoulding A method for producing a flexible polyurethane foam characterized in that a resistance value at compression is 1300 N / 314 cm ² or less (however, the resistance value at 50% compression immediately after demolding the flexible polyurethane foam means that the flexible polyurethane foam is 30 seconds after the mold, 25 using a disk with a diameter of 20 cm
It is a resistance value when a flexible polyurethane foam is compressed to 50% of its thickness at a speed of 0 mm / min.). 2. The oxyethylene group-containing compound (B)
Has one or more hydroxyl groups and has a hydroxyl value of 20 mgKOH / g
The method for producing a flexible polyurethane foam according to claim 1, wherein the alcohol is in the range of 500 mgKOH / g or less and the primary hydroxyl value is 20% or more and 80% or less. 3. The polyisocyanate comprises toluylene diisocyanate in an amount of 50 to 1 in all polyisocyanates.
3. The method for producing a flexible polyurethane foam according to claim 1, wherein the polyisocyanate is contained in an amount of 00% by weight. 4. A ventilation rate of 5 cc / cm ² / sec or more and 45 cc / cm ² / s
ec or less and the spectrum measured by FT-IR is 1645c
A flexible polyurethane foam having a peak in a range of more than m ^-1 and less than or equal to 1660 cm ^-1 , having a resistance value of 1300 N / at 50% compression immediately after demolding the flexible polyurethane foam.
Flexible polyurethane foam characterized by having a size of 314 cm ² or less (however, the resistance value at the time of 50% compression immediately after demolding the foam means that the foam has a diameter of 20 seconds from the demolding time of 30 seconds.
(It is a resistance value when a flexible polyurethane foam is compressed to 50% of its thickness at a speed of 250 mm / min. using a disc of cm).