WO2011125952A1

WO2011125952A1 - Flexible polyurethane foam for hot-press molding, production method therefor, hot-press molded article, and production method therefor

Info

Publication number: WO2011125952A1
Application number: PCT/JP2011/058458
Authority: WO
Inventors: 孝之佐々木; 賀来　大輔
Original assignee: 旭硝子株式会社
Priority date: 2010-04-02
Filing date: 2011-04-01
Publication date: 2011-10-13
Also published as: TW201202287A; JP2013127011A

Abstract

Disclosed is a flexible polyurethane foam with which hot-press molding can be successfully performed that has sufficient firmness and excellent processing workability during cutting. The flexible polyurethane foam for hot-press molding is produced by reacting a polyol mixture (X) and a polyisocyanate compound in the presence of a catalyst for urethanization, a foaming agent, and a foam stabilizer. The polyol mixture (X) includes: a polyoxyalkylene polyol (A) in which the average number of hydroxyl groups is 2 to 3, the hydroxyl value is 5 to 90 mg KOH/g, and the oxyethylene group content is 0 to 30 mass%; a polyoxyalkylene polyol (B) in which the average number of hydroxyl groups is 2 to 3 and the hydroxyl value is 100 to 250 mg KOH/g; and a polyoxyalkylene mono-ol (D) in which the hydroxyl value is 5 to 200 mg KOH/g. The amount of the polyisocyanate compound used is 90 or higher on the isocyanate index.

Description

SOFT POLYURETHANE FOAM FOR HOT PRESS MOLDING AND ITS MANUFACTURING METHOD, AND HOT PRESS MOLDED PRODUCT AND ITS MANUFACTURING METHOD

The present invention relates to a method for producing a flexible polyurethane foam for hot press molding, a soft polyurethane foam for hot press molding obtained by the production method, a method for producing a hot press molded product using the flexible polyurethane foam for hot press molding, and The present invention relates to a hot press molded product obtained by the production method.

Conventionally, a flexible polyurethane foam having a low impact resilience, that is, a low resilience, has been widely used as, for example, an impact absorbing material, a soundproofing material, and a vibration absorbing material for automobiles and electronic devices.
In addition, a flexible polyurethane foam is molded into a desired shape by a hot press molding method.
In the hot press molding method, generally, a flexible polyurethane foam is cut into an appropriate size and shape in advance, and is compressed under heating to obtain a molded product having a shape corresponding to a sheet shape or a mold.

In Patent Document 1, as a method for producing a flexible polyurethane foam suitable for molding by a hot press molding method, a polyoxypropylene polyol (A) having an average number of hydroxyl groups of 2 to 3 and a hydroxyl value of 10 to 90 mgKOH / g, an average A polyol composition containing a polyether polyol (B) having a hydroxyl number of 2 to 3 and a hydroxyl value of 100 to 250 mgKOH / g, and a polyether monool (D) having a hydroxyl value of 5 to 200 mgKOH / g, and a polyisocyanate A method of reacting a compound with an isocyanate index of less than 90 is described.
In Patent Document 2, hot press molding is performed using a blended composition of a known flexible polyurethane foam obtained by mixing and reacting a flexible polyurethane foam raw material comprising a polyol, a polyisocyanate, a foam stabilizer, a foaming agent, a catalyst, and the like. A method is described, and it is described that two or more kinds of polyols having different molecular weights are used as the polyol.

International Publication No. 2009/041535 Pamphlet JP 2009-179720 A

According to the knowledge of the present inventors, the flexible polyurethane foam obtained by the production method of Patent Document 1 is crushed because the hardness of the flexible polyurethane foam is insufficient when cutting prior to the hot press step. It tends to be difficult to cut, for example, foam adheres to a vertical cutting machine used at the time of cutting. For this reason, it is necessary to make the rotational speed of the vertical cutting machine for cutting the flexible polyurethane foam much lower than the normal rotational speed, so that the productivity becomes worse and the workability becomes worse. Further, it has been shown that when the hardness is increased by increasing the isocyanate index (isocyanate index) to 90 or more in order to improve productivity, the molding by the hot press molding method becomes worse.
According to the knowledge of the present inventors, the impact-absorbing flexible polyurethane foam obtained in Patent Document 2 does not necessarily have sufficient moldability by the hot press molding method only by using two or more types of polyols having different molecular weights as polyols. It can not be said.

The present invention has been made in view of the above circumstances, and has a sufficient hardness, good workability at the time of cutting, and a flexible polyurethane foam that can be well molded by a hot press molding method. It is an object of the present invention to provide a production method thereof, a hot press molded article using the flexible polyurethane foam, and a production method thereof.

The present invention is the following [1] to [14].
[1] In the method for producing a flexible polyurethane foam for hot press molding by reacting the polyol mixture (X) with a polyisocyanate compound in the presence of a urethanization catalyst, a foaming agent and a foam stabilizer, the polyol mixture ( X) contains the following polyol (A), the following polyol (B), and the following monool (D), and the amount of the polyisocyanate compound used is 90 or more in terms of isocyanate index. Method.
Polyol (A): a polyoxyalkylene polyol having an average number of hydroxyl groups of 2 to 3, a hydroxyl value of 5 to 90 mgKOH / g, and an oxyethylene group content of 0 to 30% by mass,
Polyol (B): a polyoxyalkylene polyol having an average number of hydroxyl groups of 2 to 3 and a hydroxyl value of 100 to 250 mgKOH / g,
Monool (D): A polyoxyalkylene monool having a hydroxyl value of 5 to 200 mgKOH / g.

[2] Hot press-molding soft polyurethane according to [1], wherein the proportion of the polyol (A) is 5 to 50% by mass in 100% by mass of the total of the polyol (A) and the polyol (B) Form manufacturing method.
[3] In [1] or [2], a total ratio of the polyol (A) and the polyol (B) is 70 to 99% by mass in 100% by mass of the polyol mixture (X). The manufacturing method of the polyurethane foam for hot press molding of description.
[4] The ratio of the monool (D) is 1 to 30 parts by mass with respect to 100 parts by mass of the total of the polyol (A) and the polyol (B). Any flexible polyurethane foam for hot press molding.
[5] The method for producing a flexible polyurethane foam for hot press molding according to any one of [1] to [4], wherein the polyol mixture (X) further contains the following polyol (C).
Polyol (C): Polyoxyalkylene polyol having an average number of hydroxyl groups of 2 to 6, a hydroxyl value of 10 to 60 mgKOH / g, and an oxyethylene group content of 50% by mass or more.

[6] The method for producing a polyurethane foam for hot press molding according to [5], wherein a proportion of the polyol (C) is 0.1 to 10% by mass in 100% by mass of the polyol mixture (X). .
[7] The polyol mixture (X) comprises 10 to 30% by mass of the polyol (A), 50 to 80% by mass of the polyol (B), 0 to 8% by mass of the polyol (C), and the mono The method for producing a polyurethane foam for hot press molding according to [5] or [6], comprising 1 to 24% by mass of all (D).
[8] The method for producing a flexible polyurethane foam for hot press molding according to any one of [1] to [7], wherein the 25% hardness (ILD) of the flexible polyurethane foam is 40 N / 314 cm ² or more.

[9] The method for producing a flexible polyurethane foam for hot press molding according to any one of [1] to [8], wherein the urethanization catalyst contains dioctyltins.
[10] Any one of [1] to [9], wherein the amount of the urethanization catalyst used is 0.01 to 3.0 parts by mass with respect to 100 parts by mass of the entire polyol mixture (X). A method for producing a flexible polyurethane foam for hot press molding.
[11] The method for producing a flexible polyurethane foam for hot press molding according to any one of [1] to [10], wherein the foaming agent comprises only water.

[12] A flexible polyurethane foam for hot press molding obtained by the production method of any one of [1] to [11].
[13] A step of producing a flexible polyurethane foam for hot press molding by the production method of any one of [1] to [11], a step of cutting the obtained flexible polyurethane foam for hot press molding, and the cut hot press A method for producing a hot-press molded article, comprising a step of molding a flexible polyurethane foam for molding by a hot press molding method.
[14] A hot press-molded product obtained by the production method of [13].
In the present specification, “˜” is used to mean that the numerical values described before and after the value are included as the lower limit value and the upper limit value unless otherwise specified.

According to the present invention, a flexible polyurethane foam having sufficient hardness, good workability at the time of cutting, and good molding by hot pressing can be obtained.
Moreover, according to this invention, the hot press molded product of a desired shape can be manufactured efficiently.

In the present specification, the hydroxyl value is a value measured by a method according to JIS K1557-1.
The average number of hydroxyl groups of a polyol means the average value of the number of active hydrogens of the initiator used for manufacture of this polyol.
The total unsaturation of the polyol is a value measured according to JIS K1557 (2007 edition).
The “polyol system liquid” is a liquid to be reacted with the polyisocyanate compound, and is a liquid containing a compounding agent as required, such as a foaming agent, a foam stabilizer, a catalyst, and a flame retardant, in addition to the polyol.
The “foaming stock solution composition” is a liquid obtained by mixing a polyol system liquid, a polyisocyanate compound, and optionally the remaining components.
The isocyanate index is 100 times the value obtained by dividing the equivalent of the isocyanate group of the polyisocyanate compound in the foaming stock composition by the total equivalent of all active hydrogens of all active hydrogen-containing compounds present in the foaming stock composition. It is a value represented by The active hydrogen-containing compound is a compound having a hydrogen atom that can react with the polyisocyanate compound, and examples thereof include a polyol mixture (X) and water that can be used as a blowing agent.
The value of 25% hardness (ILD) is a value measured by a measuring method based on JIS K6400 (1997 edition). Specifically, after the flexible polyurethane foam to be measured is cured in a room controlled at 23 ° C. and 50% relative humidity for 24 hours or more, the length is 300 mm, the width is 300 mm, and the thickness is 50 mm. It is a value measured by the A method. Immediately after measuring the 25% hardness (ILD) by compressing and holding for 25 seconds, the 50% hardness (ILD) was further compressed to 50% with respect to the original thickness of the flexible polyurethane foam, and the 25% hardness ( ILD) is measured under the same conditions. The 65% hardness (ILD) is also compressed to 65% of the original thickness of the flexible polyurethane foam and measured under the same conditions as 25% hardness (ILD).

The method for producing a flexible polyurethane foam for hot press molding according to the present invention (hereinafter sometimes simply referred to as “soft polyurethane foam” or “soft foam”) comprises urethanizing a polyol mixture (X) and a polyisocyanate compound. The reaction is carried out in the presence of a catalyst, a blowing agent and a foam stabilizer.
<Polyol mixture (X)>
The polyol mixture (X) in the present invention contains a polyol (A), a polyol (B), and a monool (D). Further, it preferably contains a polyol (C). In some cases, polyols other than polyols (A) to (C) (hereinafter referred to as polyol (E)) and monools other than monool (D) may be included.

[Polyol (A)]
The polyol (A) in the present invention is a polyoxyalkylene polyol having an average number of hydroxyl groups of 2 to 3, a hydroxyl value of 5 to 90 mgKOH / g, and an oxyethylene group content of 0 to 30% by mass. This polyoxyalkylene polyol is obtained by ring-opening addition polymerization of alkylene oxide with an initiator in the presence of a polymerization catalyst.
A polyol (A) may use only 1 type, or may use 2 or more types together.

Examples of the polymerization catalyst used in the production of the polyol (A) include alkali metal compound catalysts (sodium catalyst, potassium catalyst, cesium catalyst, etc.), cationic polymerization catalyst, composite metal cyanide complex catalyst, phosphazene compound catalyst, and the like. It is done. From the point that the catalyst can be obtained at a low cost, an alkali metal compound catalyst and a double metal cyanide complex catalyst are preferable from the viewpoint that a low by-product polyol is obtained.

Examples of the sodium-based catalyst or potassium-based catalyst include sodium metal, potassium metal, sodium alkoxide or potassium alkoxide (sodium methoxide, sodium ethoxide, sodium propoxide, potassium methoxide, potassium ethoxide, potassium propoxide, etc.), water. Examples include sodium oxide, potassium hydroxide, sodium carbonate, potassium carbonate and the like.
Examples of the cesium catalyst include cesium metal, cesium alkoxide (cesium methoxide, cesium ethoxide, cesium propoxide, etc.), cesium hydroxide, cesium carbonate, and the like.

Examples of the cationic polymerization catalyst include MoO ₂ (diketonate) Cl, MoO ₂ (diketonate) OSO ₂ CF ₃ , trifluoromethanesulfonic acid, boron trifluoride, boron trifluoride coordination compound (boron trifluoride diethyl etherate, three Boron fluoride dibutyl etherate, boron trifluoride dioxanate, boron trifluoride acetate anhydrate or boron trifluoride triethylamine complex)), or an aromatic hydrocarbon group containing fluorine element or fluorine element Aluminum or boron compounds having at least one aromatic hydrocarbon oxy group are preferred.
Examples of the aromatic hydrocarbon group containing fluorine element include pentafluorophenyl, tetrafluorophenyl, trifluorophenyl, 3,5-bis (trifluoromethyl) trifluorophenyl, and 3,5-bis (trifluoromethyl). And phenyl, β-perfluoronaphthyl, 2,2 ′, 2 ″ -perfluorobiphenyl, and the like.
The aromatic hydrocarbon oxy group containing the fluorine element is preferably a hydrocarbon oxy group in which an oxygen element is bonded to the aromatic hydrocarbon group containing the fluorine element.

The double metal cyanide complex catalyst (hereinafter also referred to as “DMC catalyst”) has an organic ligand. Organic ligands include tert-butyl alcohol, n-butyl alcohol, iso-butyl alcohol, tert-pentyl alcohol, iso-pentyl alcohol, N, N-dimethylacetamide, ethylene glycol mono-tert-butyl ether, ethylene glycol dimethyl ether ( And diethylene glycol dimethyl ether (also referred to as diglyme), triethylene glycol dimethyl ether (also referred to as triglyme), iso-propyl alcohol, and dioxane. The dioxane may be 1,4-dioxane or 1,3-dioxane, but 1,4-dioxane is preferred. One type of organic ligand may be used, or two or more types may be used in combination.
Among these, it is preferable to have tert-butyl alcohol as the organic ligand. Therefore, it is preferable to use a DMC catalyst having tert-butyl alcohol as at least a part of the organic ligand. Such DMC catalysts are highly active and can produce polyols with low total unsaturation.

The polyol (A) in the present invention is preferably a polyoxyalkylene polyol obtained by ring-opening addition polymerization of alkylene oxide with an initiator in the presence of a DMC catalyst. By using a DMC catalyst, a polyol (A) having a low total unsaturation can be obtained.
The total unsaturation degree of the polyol (A) is preferably 0.02 meq / g or less, more preferably 0.015 meq / g or less. The durability which was excellent in it being 0.02 meq / g or less can be obtained. More preferably, it is 0.010 meq / g or less.

As an initiator used for the production of the polyol (A), a compound having 2 or 3 active hydrogens (a hydrogen atom of a hydroxyl group or an amino group that can react with an alkylene oxide) in the molecule is used alone, Or use together. As the initiator, hydroxyl group-containing compounds such as polyhydric alcohols and polyhydric phenols are preferable. A small amount of a compound having 4 or more active hydrogens can also be used. Specific examples of the compound having 2 active hydrogens include dihydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, and dipropylene glycol. Specific examples of the compound having 3 active hydrogens include trihydric alcohols such as glycerin and trimethylolpropane. Further, it is preferable to use a high hydroxyl group polyoxyalkylene polyol obtained by subjecting these compounds to ring-opening addition polymerization of alkylene oxide, preferably propylene oxide. Specifically, a polyoxyalkylene polyol (preferably a polyoxypropylene polyol) having 2 or 3 hydroxyl groups and a molecular weight per hydroxyl group of about 200 to 500, that is, a hydroxyl value of 110 to 285 mgKOH / g. It is preferable to use it.

Examples of the alkylene oxide used in the production of the polyol (A) include ethylene oxide, propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane and the like. Among these, only propylene oxide or a combination of propylene oxide and ethylene oxide is preferable, and only propylene oxide is particularly preferable. That is, as the polyol (A), polyoxypropylene polyol obtained by ring-opening addition polymerization of only propylene oxide as an initiator is preferable. It is preferable to use only propylene oxide because the durability of the resulting flexible polyurethane foam during humidification is improved.
The oxyethylene group content in the polyol (A) is preferably 30% by mass or less, and particularly preferably 15% by mass or less. The lower limit is 0% by mass. It is preferable for the oxyethylene group content to be 30% by mass or less because durability during humidification is improved.

When propylene oxide and ethylene oxide are used in combination, any polymerization method of block polymerization and random polymerization may be used. Furthermore, it can also manufacture combining both block polymerization and random polymerization. In the case of block polymerization, the order of ring-opening addition polymerization is preferably such that propylene oxide and ethylene oxide are added in this order, or ethylene oxide is added first, and propylene oxide and ethylene oxide are added in this order. By ring-opening addition polymerization in this order, many of the hydroxyl groups of the polyoxyalkylene polyol (A) become primary hydroxyl groups, and the reactivity between the polyol (A) and the polyisocyanate compound increases. As a result, the moldability of the resulting flexible polyurethane foam tends to be favorable, which is preferable. The terminal is preferably ethylene oxide.

The average number of hydroxyl groups of the polyol (A) in the present invention is 2 to 3. By setting the average number of hydroxyl groups to 2 to 3, the resulting flexible polyurethane foam easily develops thermoplastic properties, so that hot press molding becomes easy. In addition, it is possible to easily remove the mold without coming into close contact when the pressurizing plate is released from the flexible polyurethane foam after hot press molding is completed in a specified time. As the polyol (A), polyoxyalkylene diol having 2 hydroxyl groups is used in an amount of 50 to 100% by mass out of 100% by mass of the polyol (A). Is preferable in that it becomes favorable. In particular, the polyol (A) is preferably a polyoxyalkylene diol having 2 hydroxyl groups.

The hydroxyl value of the polyol (A) is 5 to 90 mgKOH / g, preferably 5 to 60 mgKOH / g, and more preferably 5 to 40 mgKOH / g. When the polyol (A) is not a polymer-dispersed polyol described later, the hydroxyl value is preferably 5 to 12 mgKOH / g in order to improve the molding by the hot press molding method. By setting the hydroxyl value to 5 mgKOH / g or more, collapse or the like can be suppressed, and a flexible foam can be stably produced. In addition, when the hydroxyl value is 90 mgKOH / g or less, even when the isocyanate index is 90 or more, the flexibility of the resulting flexible foam is not impaired, and the workability when cutting with a vertical cutting machine or the like for hot press molding and Hot press molding becomes easy, and improvement in productivity is expected.

The polyol (A) in the present invention may be a polymer-dispersed polyol. The polyol (A) being a polymer-dispersed polyol means a dispersion system in which polymer fine particles (dispersoid) are stably dispersed using the polyol (A) as a base polyol (dispersion medium).
Examples of the polymer of the polymer fine particles include addition polymerization polymers and condensation polymerization polymers. The addition polymerization type polymer is obtained, for example, by homopolymerizing or copolymerizing monomers such as acrylonitrile, styrene, methacrylic acid ester and acrylic acid ester. Examples of the polycondensation polymer include polyester, polyurea, polyurethane, polymethylol melamine and the like. By allowing the polymer fine particles to be present in the polyol, the hydroxyl value of the polyol can be kept low, the hardness of the flexible polyurethane foam can be increased, and the workability when cutting with a vertical cutter for hot press molding, It is effective in improving mechanical properties such as tensile strength of a flexible foam and a molded product obtained by hot press molding the foam.
The content ratio of the polymer fine particles in the polymer-dispersed polyol is not particularly limited. The polymer fine particles present in 100 parts by mass of the polyol mixture (X) are preferably 1 part by mass or more, more preferably 5 parts by mass or more, from the viewpoint that the effect of containing the polymer fine particles is sufficiently obtained. The upper limit is preferably 40 parts by mass or less from the viewpoint of maintaining the moldability of the flexible polyurethane foam and suppressing the viscosity of the polyol mixture (X) from becoming too high.
The various properties (hydroxyl value, total unsaturation, etc.) of the polymer-dispersed polyol as a polyol are considered for the base polyol excluding the polymer fine particles.

[Polyol (B)]
The polyol (B) in the present invention is a polyoxyalkylene polyol having an average number of hydroxyl groups of 2 to 3 and a hydroxyl value of 100 to 250 mgKOH / g. This polyoxyalkylene polyol can be obtained by ring-opening addition polymerization of an alkylene oxide in an initiator in the presence of a polymerization catalyst in the same manner as the polyol (A).
A polyol (B) may use only 1 type or may use 2 or more types together.

As the polymerization catalyst used for the production of the polyol (B), a phosphazene compound catalyst, a Lewis acid compound or an alkali metal compound catalyst, and a double metal cyanide complex catalyst are preferable, and among these, an alkali metal compound catalyst is particularly preferable. Preferred examples of the alkali metal compound catalyst include potassium compounds such as potassium hydroxide and potassium methoxide, alkali metal compounds such as cesium compounds such as cesium metal, cesium hydroxide, cesium carbonate, and cesium methoxide, or alkali metal hydroxides. It is done.

As the initiator used for producing the polyol (B), a compound having 2 or 3 active hydrogen atoms in the molecule is used alone or in combination. A small amount of a compound having 4 or more active hydrogens can also be used. Specific examples of the compound having 2 or 3 active hydrogens include polyhydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, dipropylene glycol, glycerin and trimethylolpropane; bisphenol A and the like And polyamines such as monoethanolamine, diethanolamine, triethanolamine, and piperazine. Of these, polyhydric alcohols are particularly preferred. Further, it is preferable to use a high hydroxyl group polyoxyalkylene polyol obtained by subjecting these compounds to ring-opening addition polymerization of alkylene oxide, preferably propylene oxide.

Examples of the alkylene oxide used for the production of the polyol (B) include ethylene oxide, propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane and the like. Among these, only propylene oxide or a combination of propylene oxide and ethylene oxide is preferable, and only propylene oxide is particularly preferable.
The polyol (B) is preferably a polyol having a low oxyethylene group content, and the oxyethylene group content in the polyol (B) is preferably 0 to 20% by mass, more preferably 0 to 10% by mass. In particular, a polyoxypropylene polyol having only an oxypropylene group as an oxyalkylene group is preferred. When such a polyol having a low oxyethylene group content is used, durability of the obtained flexible polyurethane foam and a molded product obtained by hot press molding the flexible polyurethane foam is improved.

The average number of hydroxyl groups of the polyol (B) in the present invention is 2 to 3. By setting the average number of hydroxyl groups to 2 to 3, the hardness of the obtained flexible polyurethane foam and the molded product obtained by hot press molding the flexible polyurethane foam becomes appropriate, and the feel of the surface of the molded product is also improved. Moreover, it is excellent also in physical properties, such as elongation and tensile strength, of a flexible polyurethane foam and its hot press-molded product.
When two or more polyols (B) are used in combination, the average number of hydroxyl groups after mixing them is preferably 2 to 2.8. When the average number of hydroxyl groups is within the above range, a flexible polyurethane foam having good processability when cutting with a vertical cutter or the like and the surface feel of a hot-press molded product is obtained.

The polyol (B) is preferably used in combination with a polyoxyalkylene diol having an average number of hydroxyl groups of 2 and a polyoxyalkylene triol having an average number of hydroxyl groups of 3. The proportion of the polyoxyalkylene diol contained in 100% by mass of the entire polyol (B) is preferably 35% by mass or more, and more preferably 40% by mass or more. The upper limit is 90% by mass.

The hydroxyl value of the polyol (B) in the present invention is 100 to 250 mgKOH / g. By setting the hydroxyl value to 100 mgKOH / g or more, collapse or the like can be suppressed, and a flexible polyurethane foam can be stably produced. Moreover, by making a hydroxyl value into 250 mgKOH / g or less, the softness | flexibility of the flexible polyurethane foam manufactured can be impaired, and a resilience elastic modulus can be made low. Moreover, the flexible polyurethane foam excellent in workability at the time of cut | disconnecting with a vertical cutter etc. can be obtained. The hydroxyl value of the polyol (B) is more preferably 100 to 200 mgKOH / g.

The polyol (B) in the present invention may be a polymer-dispersed polyol. Examples of the polymer of the polymer fine particles include those described in the section of the polyol (A).

[Polyol (C)]
The polyol (C) in the present invention is a polyoxyalkylene polyol having an average number of hydroxyl groups of 2 to 6, a hydroxyl value of 10 to 60 mgKOH / g, and an oxyethylene group content of 50% by mass or more.
A polyol (C) may use only 1 type, or may use 2 or more types together.

The polyol (C) is obtained by subjecting an alkylene oxide to ring-opening addition polymerization in the presence of a polymerization catalyst in the same manner as the polyol (A) and polyol (B). The polyol (C) may have a structure in which ethylene oxide and propylene oxide are randomly polymerized, or may have a structure in which ethylene oxide is subjected to ring-opening addition polymerization as a block immediately after a terminal or an initiator. Further, it may be polyethylene glycol obtained by multimerization. When the polyol (C) is used, a foam breaking effect is recognized, and the addition of the polyol (C) is effective in improving air permeability.

As the polymerization catalyst used for the production of the polyol (C), the same one as the above-described polyol (B) can be used. In particular, among the polymerization catalysts, an alkali metal compound catalyst is particularly preferable.
As the initiator used for producing the polyol (C), a compound having 2 to 6 active hydrogen atoms in the molecule is used alone, or two or more kinds are used in combination. Specific examples of the number of active hydrogens of 2 to 6 include ring-opening polymerization of diglycerin, pentaerythritol, sorbitol, etc., and alkylene oxides to these compounds in addition to the initiators used for the production of polyol (B). And a high hydroxyl group polyether polyol obtained by the above process. Among these, polyhydric alcohols, or high hydroxyl group polyether polyols obtained by ring-opening polymerization of alkylene oxide, preferably propylene oxide, to polyhydric alcohols are preferable.

Examples of the alkylene oxide used for producing the polyol (C) include ethylene oxide, propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane and the like. Moreover, the oxyethylene content in a polyol (C) is 50 mass% or more, and it is preferable to use ethylene oxide alone or a combination of propylene oxide and ethylene oxide.
By setting the oxyethylene group content in the polyol (C) to 50% by mass or more, high breathability can be secured when the polyol (C) is added.
In particular, the polyol (C) is preferably a polyol obtained by ring-opening addition polymerization of a mixture of propylene oxide and ethylene oxide. In this case, the oxyethylene content in the polyol (C) is preferably 50 to 95% by mass, more preferably 60 to 90% by mass.

The average number of hydroxyl groups of the polyol (C) is 2-6. When the average number of hydroxyl groups is 2 to 6, it is easy to obtain a flexible polyurethane foam excellent in air permeability. The average number of hydroxyl groups is preferably 2-4.
The hydroxyl value of the polyol (C) is 10 to 60 mgKOH / g. When the hydroxyl value is from 10 to 60 mgKOH / g, ethylene oxide in the polyol falls within an appropriate range, so that the feel of a molded product obtained by hot press molding the obtained flexible polyurethane foam is improved. The hydroxyl value is preferably 15 to 50 mgKOH / g.

[Monoall (D)]
The monool (D) in the present invention is a polyoxyalkylene monool having a hydroxyl value of 5 to 200 mgKOH / g. This polyoxyalkylene monool uses an initiator having 1 active hydrogen, and, like the polyol (A) or polyol (B), this initiator opens an alkylene oxide in the presence of a polymerization catalyst. Obtained by addition polymerization.
Monool (D) may use only 1 type, or may use 2 or more types together.

As the polymerization catalyst used in the production of monool (D), a DMC catalyst, a phosphazene compound catalyst, a Lewis acid compound or an alkali metal compound catalyst is preferable, and among these, a composite metal cyanide complex catalyst is particularly preferable. As the double metal cyanide complex catalyst, the above double metal cyanide complex catalyst can be used.

The initiator used for the production of monool (D) is a compound having only one active hydrogen atom. Specific examples thereof include monohydric alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, tert-butyl alcohol; monohydric phenols such as phenol and nonylphenol; dimethylamine, diethylamine and the like. Secondary amines etc. are mentioned. Further, similarly to the high hydroxyl group polyoxyalkylene polyol for producing the polyol (A) and the like, the high hydroxyl group polyoxyalkylene monool having a hydroxyl value higher than that of the target monool (D). Can also be used as an initiator.

Examples of the alkylene oxide used for the production of the monool (D) include ethylene oxide, propylene oxide, 1,2-epoxybutane, and 2,3-epoxybutane. Among these, only propylene oxide or a combination of propylene oxide and ethylene oxide is preferable, and only propylene oxide is particularly preferable. That is, the monool (D) is preferably a polyoxypropylene monool obtained by subjecting only propylene oxide to ring-opening addition polymerization to an initiator. It is preferable to use only propylene oxide because the durability of the resulting flexible polyurethane foam during humidification is improved. Moreover, the tactile sensation of a molded product obtained by hot press molding a flexible polyurethane foam is improved. For example, a molded product that has been hot press-molded into a sheet shape is preferable because it provides a tactile feel like a silk fabric.
The average number of hydroxyl groups of monool (D) in the present invention is 1. When the hydroxyl value of monool (D) is 10 to 200 mgKOH / g, the workability in hot press molding of a flexible polyurethane foam is improved. The hydroxyl value is preferably 10 to 120 mgKOH / g.

In addition, although the polyol mixture in this invention may contain monools other than monool (D) (for example, the polyoxypropylene monool whose hydroxyl value exceeds 200 mgKOH / g), normally monool (D). Other monools are not included. Even if the polyol mixture in the present invention contains a monool other than the monool (D), the proportion is preferably 5% by mass or less, more preferably 2% by mass or less, out of 100% by mass of the polyol mixture. .

[Polyol (E)]
The polyol (E) in the present invention is a polyol that does not fall under any of the polyols (A), (B), and (C). For example, a polyol having a higher hydroxyl value than the polyol (B), the polyol (A), and Examples thereof include polyols having an average number of hydroxyl groups larger than that of polyol (B) and higher oxyethylene content than polyol (C), and high molecular weight polyols other than polyoxyalkylene polyols.

The polyol (E) is preferably a polyol having an average number of hydroxyl groups of 2 to 6 and a hydroxyl value of 300 to 1,830 mgKOH / g. More preferred is a polyol having an average number of hydroxyl groups of 2 to 4 and a hydroxyl value of 300 to 600 mgKOH / g. As this polyol, polyhydric alcohols, amines having 2 to 6 hydroxyl groups, and polyoxyalkylene polyols are preferable. Such a polyol having a high hydroxyl value acts as a crosslinking agent, and mechanical properties such as hardness are improved. Particularly when a low density (light weight) flexible polyurethane foam is to be produced using a large amount of a foaming agent, the foaming stability is good.

Examples of polyhydric alcohols that can be used as the polyol (E) include ethylene glycol, propylene glycol, 1,4-butanediol, dipropylene glycol, glycerin, diglycerin, and pentaerythritol. Examples of amines having 2 to 6 hydroxyl groups include diethanolamine and triethanolamine. Examples of the polyoxyalkylene polyol include polyoxyalkylene polyols obtained by subjecting an alkylene oxide to ring-opening addition polymerization to an initiator, like the polyol (B). As an initiator used for manufacture of polyol (E) which is a polyoxyalkylene polyol, the initiator used for manufacture of the polyhydric alcohols which may be used as polyol (E), or polyol (B) can be illustrated.

Examples of the alkylene oxide used for producing the polyoxyalkylene polyol as the polyol (E) include ethylene oxide, propylene oxide, 1,2-epoxybutane, and 2,3-epoxybutane. Among these, only propylene oxide or a combination of propylene oxide and ethylene oxide is preferable, and only propylene oxide is particularly preferable. That is, the polyoxyalkylene polyol as the polyol (E) is preferably a polyoxypropylene polyol obtained by ring-opening addition polymerization of only propylene oxide as an initiator. As the polyol (E), among the above, polyoxyalkylene polyol is preferable, and polyoxypropylene polyol polyol is particularly preferable. It is preferable to use only propylene oxide because the durability of the resulting flexible polyurethane foam during humidification is improved. A polyol (E) may use only 1 type, or may use 2 or more types together.

The polyol (E) in the present invention may be a polyester polyol or a polycarbonate polyol, which is not limited to the above average number of hydroxyl groups or hydroxyl value. These polyols preferably have an average number of hydroxyl groups of 2 to 3, and a hydroxyl value of 20 to 300 mgKOH / g.

[Formulation of polyol mixture (X)]
In the polyol mixture (X), the proportion of the polyol (A) is preferably 5 to 50% by mass and more preferably 10 to 40% by mass in 100% by mass of the total of the polyol (A) and the polyol (B). . By making the ratio of the polyol (A) in the polyol mixture (X) within the above range, the workability when cutting with a vertical cutting machine or the like is easy, and at the same time, the workability in hot press molding is good. A polyurethane foam is obtained.
The polymer fine particles in the polymer-dispersed polyol are not included in the polyol content.

Further, in 100% by mass of the polyol mixture (X), the total proportion of the polyol (A) and the polyol (B) is preferably 70% by mass or more, more preferably 75% by mass or more, and particularly preferably 90% by mass or more. preferable. The upper limit is 99% by mass. By making the total ratio of the polyol (A) and the polyol (B) in the polyol mixture (X) within the above range, the workability when cutting with a vertical cutting machine or the like is easy, and at the same time, hot press A flexible polyurethane foam having good workability in molding can be obtained.

The proportion of monool (D) is preferably 1 to 30 parts by weight, more preferably 1 to 25 parts by weight, based on 100 parts by weight of the total of polyol (A) and polyol (B). It is particularly preferably 1 to 10 parts by mass. By setting the proportion of monool (D) within the above range, a flexible polyurethane foam having excellent low resilience, excellent durability, and good breathability can be obtained.

In the case where the polyol mixture (X) contains the polyol (C), the proportion of the polyol (C) is preferably 0.1 to 10% by mass, and preferably 1 to 8% by mass, out of 100% by mass of the polyol mixture (X). % Is more preferable. By using the polyol (C) and setting the ratio of the polyol (C) within the above range, the feel of a molded product obtained by hot press molding the resulting flexible polyurethane foam is improved.

In addition, the polyol mixture (X) is less required to contain the polyol (E), but when the polyol (E) is used, the proportion of the polyol (E) in 100% by mass of the polyol mixture (X) is 10 % By mass or less is preferable, 5% by mass or less is more preferable, and 2% by mass or less is particularly preferable. It is preferable to contain 0.1% by mass or more from the viewpoint that the effect of containing the polyol (E) is sufficiently obtained.

In the present invention, specific examples of a suitable composition of the polyol mixture (X) (100% by mass) include 10 to 30% by mass of the polyol (A), 50 to 80% by mass of the polyol (B), C) is 0 to 8% by mass, monool (D) is 1 to 24% by mass, and polyol (E) is 0 to 5% by mass.

<Polyisocyanate compound>
The polyisocyanate compound used in the present invention is not particularly limited, and is a polyisocyanate having two or more isocyanate groups, such as aromatic, alicyclic, and aliphatic groups; a mixture of two or more of the above polyisocyanates; And modified polyisocyanates obtained by modifying.

Specific examples of the polyisocyanate compound include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (common name: crude MDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hexamethylene. And diisocyanate (HMDI). Specific examples of the modified polyisocyanate include prepolymer-modified products, nurate-modified products, urea-modified products, and carbodiimide-modified products of the above polyisocyanates. Among these, TDI, MDI, crude MDI, or modified products thereof are preferable. Further, among these, use of TDI, crude MDI, or a modified product thereof (especially a prepolymer modified product) is preferable in terms of improving foaming stability and improving durability. In particular, it is preferable to use a polyisocyanate compound having a relatively low reactivity among TDI, crude MDI, or a modified product thereof because air permeability is improved. Specifically, a TDI mixture in which the proportion of 2,6-TDI is 20% by mass and the proportion of 2,4-TDI is 80% by mass is preferable. Even if the ratio of 2,6-TDI is 20% by mass or more, it can be used as required.

The amount of the polyisocyanate compound used is such that the ratio of the total active hydrogen-containing compound and the polyisocyanate compound in the foaming stock solution composition is 90 or more in terms of isocyanate index. By setting the isocyanate index to 90 or more, sufficient hardness of the flexible polyurethane foam can be obtained, and processing workability at the time of cutting becomes good. The isocyanate index is preferably 92 or more, more preferably 95 or more. The upper limit of the isocyanate index is preferably less than 105, more preferably 103 or less, from the viewpoint of workability of hot press molding of a flexible polyurethane foam.

<Urethane catalyst>
As the urethanization catalyst for reacting the polyol mixture (X) with the polyisocyanate compound, a known catalyst can be appropriately used as a catalyst for promoting the urethanization reaction.
For example, an amine compound, an organometallic compound, a carboxylic acid metal salt, etc. are mentioned. 1 type may be used independently and 2 or more types may be combined.
Examples of the amine compound include tertiary amines such as triethylenediamine, bis (2-dimethylaminoethyl) ether, N, N, N ′, N′-tetramethylhexamethylenediamine.
Examples of organometallic compounds include dibutyltin oxides such as dibutyltin oxide, dibutyltin dilaurate, dibutyltin, and dibutyltin diacetate, dioctyltins such as dioctyltin oxide, dioctyltin dilaurate, and dioctyltin diacetate, stannous octoate, tin neodecanoate And bismuth octylate.
Examples of the carboxylic acid metal salt include potassium acetate and potassium 2-ethylhexanoate.

The total amount of the urethanization catalyst is preferably 0.001 to 5.0 parts by mass, more preferably 0.01 to 3.0 parts by mass, with respect to 100 parts by mass of the polyol mixture (X). preferable. When the amount is 5.0 parts by mass or less, the foaming reaction can be easily controlled. When the amount is 3.0 parts by mass or less, when producing a flexible polyurethane foam, the rise time of the reaction liquid when the polyol mixture and the polyisocyanate compound react with each other can be sufficiently secured, so that the yield is improved. Moreover, since sufficient cure of a flexible polyurethane foam can be ensured, the processability at the time of cut | disconnecting with a vertical cutting machine etc. is excellent, and preferable. Also when hot-press-molding the cut flexible polyurethane foam, since the foam does not adhere to the press pressure plate, workability and processing time are shortened, which is preferable. The amount of 0.001 part by mass or more is preferable because the curing of the foam is good.

In particular, the urethanization catalyst preferably contains an organometallic compound. When an organometallic compound and a tertiary amine are used in combination, the compatibility of the foaming agent and the polyisocyanate compound is improved, and small homogeneous bubbles are generated during foaming. More preferable.
As the organometallic compound, dioctyltins are preferred in that sufficient cream time can be secured in the production process of the flexible polyurethane foam. That is, the urethanization catalyst preferably contains dioctyltins.
The amount used when dioctyltins are used is preferably 0.01 to 3.0 parts by weight, more preferably 0.03 to 2.0 parts by weight, with respect to 100 parts by weight of the polyol mixture (X). 0.05 to 1.0 part by mass is more preferable, and 0.07 to 0.5 part by mass is most preferable. When the amount is 3.0 parts by mass or less, shrinkage of the foam is suppressed, and when the amount is 0.01 parts by mass or more, settling of the foam is suppressed, and a foam having a good appearance can be manufactured.

As the tertiary amines, triethylenediamine is preferred from the viewpoint of easy control of foaming behavior and economy. The amount of tertiary amines used is preferably 0.01 to 3.0 parts by weight, more preferably 0.05 to 2.0 parts by weight with respect to 100 parts by weight of the polyol mixture (X). The amount is more preferably 0.1 to 1.0 part by weight, and most preferably 0.2 to 0.5 part by weight. When the amount is 3.0 parts by mass or less, the foaming reaction can be easily controlled, and when the amount is 0.01 parts by mass or more, the curability is favorable.

<Foam stabilizer>
Examples of the foam stabilizer include silicone foam stabilizers and fluorine foam stabilizers. Of these, silicone-based foam stabilizers are preferred. Of the silicone foam stabilizers, silicone foam stabilizers based on polyoxyalkylene / dimethylpolysiloxane copolymers are preferred. The foam stabilizer may be a polyoxyalkylene / dimethylpolysiloxane copolymer alone or a mixture containing other combined components. Examples of other combined components include polyalkylmethylsiloxane, glycols, polyoxyalkylene compounds and the like. As the foam stabilizer, a foam stabilizer mixture containing a polyoxyalkylene / dimethylpolysiloxane copolymer, a polyalkylmethylsiloxane and a polyoxyalkylene compound is particularly preferred from the viewpoint of excellent foam stability.

Examples of the foam stabilizer mixture include trade names of Toray Dow Corning: SZ-1127, L-580, L-582, L-520, SZ-1919, L-5740S, L-5740M, SZ-1111. , SZ-1127, SZ-1162, SZ-1105, SZ-1328, SZ-1325, SZ-1330, SZ-1306, SZ-1327, SZ-1336, SZ-1339, L-3601, SZ-1302, SH -192, SF-2909, SH-194, SH-190, SRX-280A, SRX-298, SF-2908, SF-2904, SRX-294A, SF-2965, SF-2962, SF-2961, SRX-274C SF-2964, SF-2969, PRX-607, SZ-1711, SZ-1666, SZ- 627, SZ-1710, L-5420, L-5421, SZ-1669, SZ-1649, SZ-1654, SZ-1642, SZ-1720, SH-193; F-114, F- manufactured by Shin-Etsu Chemical Co., Ltd. 121, F-122, F-348, F-341, F-502, F-506, F-607, F-606, etc .; Y-10366, L-5309, TFA-4200, TFA manufactured by GE Toshiba Silicone -4202 etc .; Gold Schmidt B-8110, B-8017, B-4113, B-8727LF, B-8715LF, B-8404, B-8462 etc. Two or more types of foam stabilizers may be used in combination, or a foam stabilizer other than the specific foam stabilizer may be used in combination.

The amount of the foam stabilizer used is preferably 0.01 to 2 parts by mass and more preferably 1 to 2 parts by mass with respect to 100 parts by mass of the polyol mixture (X). When the content is 0.01 parts by mass or more, a flexible polyurethane foam excellent in foaming stability can be produced. When the amount is 2 parts by mass or less, a flexible polyurethane foam having sufficient air permeability can be obtained.

<Foaming agent>
As the foaming agent, known foaming agents such as fluorinated hydrocarbons can be used, and at least one selected from water and inert gas is preferable. Specific examples of the inert gas include air, nitrogen, carbon dioxide gas, and the like. Among these, water is more preferable in consideration of the environment, and it is most preferable to use only water as a foaming agent.
When water is used, the amount of the blowing agent is preferably 10 parts by mass or less, more preferably 0.1 to 4.0 parts by mass with respect to 100 parts by mass of the polyol mixture (X).
When producing a low-density flexible polyurethane foam, it is preferable to use 0.5 to 5.0 parts by mass of water with respect to 100 parts by mass of the polyol mixture (X).

<Other auxiliaries>
When the flexible polyurethane foam is produced in the present invention, desired additives can be used in addition to the urethanization catalyst, the foaming agent and the foam stabilizer described above. Additives include fillers such as potassium carbonate and barium sulfate; surfactants such as emulsifiers; anti-aging agents such as antioxidants and ultraviolet absorbers; flame retardants, plasticizers, colorants, anti-fungal agents, and foam breaking Agents, dispersants, discoloration inhibitors and the like.

<Foaming method>
The method for producing the flexible polyurethane foam may be a method in which the foamed stock solution composition is injected into a closed mold and foam-molded (mold method), or a method in which the foamed stock solution composition is foamed in an open system (slab method). The slab method is preferred. Specifically, it can be performed by a known method such as a one-shot method, a semi-prepolymer method, or a prepolymer method. For production of the flexible polyurethane foam, a commonly used production apparatus can be used.

<Soft polyurethane foam>
In the flexible polyurethane foam obtained in the present invention, the polyisocyanate compound is used in an amount of 90 or more in terms of the isocyanate index, so that the hardness of the flexible polyurethane foam is increased, and the workability at the time of cutting performed prior to hot press molding is performed. Becomes better. In addition, while the flexible polyurethane foam has a sufficient hardness, molding by the hot press molding method can be performed satisfactorily. The reason is that the polyol (A) has a molecular structure with an average number of hydroxyl groups of 2 to 3 and a hydroxyl value of 5 to 90 mgKOH / g, and is therefore presumed to be superior in developing thermoplastic properties. . That is, hot press molding can be performed at a relatively low temperature.

In this specification, 25% hardness (ILD), 50% hardness (ILD), and 65% hardness (ILD) are used as an index of hardness. As these values are larger, the hardness is higher.
When the 25% hardness (ILD) is 40 N / 314 cm ² or more in the flexible polyurethane foam for hot press molding, the workability when cutting with a vertical cutting machine or the like is improved, and 50 N / 314 cm ² or more is more preferable. The upper limit of the 25% hardness (ILD) is preferably 95/314 cm ² or less in view of workability of hot press molding, and more preferably 92/314 cm ² or less.
Practically, the 50% hardness (ILD) is preferably 60 N / 314 cm ² or more, and more preferably 70 N / 314 cm ² or more.
The 65% hardness (ILD) is preferably 80 N / 314 cm ² or more, and more preferably 90 N / 314 cm ² or more.

In this specification, as an index of durability, compression residual strain and wet heat compression residual strain at a compression rate of 50% are used. The smaller these values, the better the durability.
In practical use, the 50% compression residual strain is preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less. The 50% wet heat compression residual strain is preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less.

The core rebound resilience of the flexible polyurethane foam for hot press molding obtained in the present invention is preferably 20% or less, more preferably 18% or less, further preferably 15% or less, and most preferably 12% or less. By setting the core rebound resilience to 20% or less, sufficient low resilience is exhibited. Usually, the lower limit is 0%.

Core density of the thermal press-molding the flexible polyurethane foam obtained by the present invention (heat press before molding) is preferably 10 ~ 110kg / ^{m 3,} more preferably from ^{10 ~ 80kg / m 3, 20} ~ 50kg / m 3 and more preferable. When the core density is 10 kg / m ³ or more, the workability of hot press molding is good, and when it is 110 kg / m ³ or less, the feel of the hot press-molded product is excellent, for example, hot press molding into a sheet shape. The smoothness like silk fabric is obtained with the molded product.

<Method of manufacturing a hot press molded product>
The method for producing a hot press-molded article of the present invention includes a step of producing a flexible polyurethane foam for hot press molding by the production method of the present invention, a step of cutting the obtained flexible polyurethane foam for hot press molding, It has the process of shape | molding the flexible polyurethane foam for press molding by hot press molding.
The forming by cutting and hot press forming can be performed by appropriately using a known method. The hot press molding temperature is usually 150 to 200 ° C. Since the flexible polyurethane foam for hot press molding of the present invention has high thermoplasticity, that is, high crystallinity, it can be hot press molded even at a relatively low temperature, for example, 150 to 170 ° C. When hot press molding can be performed at a low temperature, the flexible foam is not loaded, and this is preferable in terms of suppressing deterioration. The molding time by hot press molding is usually 5 seconds to 1 hour, preferably 5 seconds to 30 minutes from the viewpoint of more industrial.
Good molding by the hot press molding method means that the thickness of a molded product that has been hot press molded to a desired thickness can be kept within a certain range. For example, when the thickness of the molded product obtained by hot pressing is within 10% of the set value, the hot press molding is considered good.

<Hot press molded product>
The method for producing a hot press molded product of the present invention can be applied to various hot press molded products obtained by molding a flexible polyurethane foam by a hot press molding method. The shape of the hot press molded product is not limited, but for example, a sheet shape having a thickness of about 2 to 50 mm is preferable.
Specific examples of heat-pressed products include clothing insoles such as insoles for shoes, bras and shoulder pads, disposable diapers, medical supplies, sanitary products, sanitary products such as cosmetic puffs, and sound absorbing materials under the floor. Can be mentioned. In particular, a bra pad or a puff for cosmetics is preferable from the viewpoint of excellent hardness and an insole for shoes (insole) and excellent touch feeling.

Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.
<Raw material>
Polyol A1: Polyoxypropylene polyol obtained in the following Production Example 1.
Polyol A2: polyoxypropylene polyol obtained in Production Example 2 below.
Polyol A3: polyoxypropylene polyol obtained in Production Example 3 below.
Polyol A4: a polymer-dispersed polyol obtained in Production Example 4 below.

Polyol B1: Obtained by ring-opening addition polymerization of propylene oxide (hereinafter also referred to as “PO”) using potassium hydroxide catalyst and dipropylene glycol as an initiator, the average number of hydroxyl groups is 2, and the hydroxyl value is 160 mgKOH. / G polyoxypropylene polyol.
Polyol B2: Polyoxypropylene polyol having an average number of hydroxyl groups of 3 and a hydroxyl value of 168 mgKOH / g, obtained by ring-opening addition polymerization of PO using glycerol as an initiator using a potassium hydroxide catalyst.

Polyol C1: An average number of hydroxyl groups of 3 obtained by ring-opening addition polymerization of a mixture of PO and ethylene oxide (hereinafter also referred to as “EO”) using potassium hydroxide catalyst and glycerin as an initiator by random polymerization. Polyoxypropylene oxyethylene polyol having a hydroxyl value of 48 mg KOH / g and an oxyethylene group content of 80% by mass.
Monool D1: obtained by ring-opening addition polymerization of PO using zinc hexacyanocobaltate-tert-butyl alcohol complex catalyst using n-butyl alcohol as an initiator, and having an average hydroxyl number of 1 and a hydroxyl value of 16. 7 mg KOH / g polyoxypropylene monool.

Polyols A1 to A4, polyols B1 to B2, polyol C1 and monool D1 have octadecyl-3- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] as an antioxidant. 1,500 ppm was added to each polyol or monool (trade name: IRGANOX 1076, manufactured by BASF Japan).

-Foaming agent: water.
-Foam stabilizer a: Silicone foam stabilizer (manufactured by Toray Dow Corning, trade name: SRX-298).
-Foam stabilizer b: Silicone foam stabilizer (manufactured by Toray Dow Corning, trade name: SZ-1327).
Urethane catalyst a: Diethylene glycol solution of triethylenediamine (manufactured by Tosoh Corporation, trade name: TEDA-L33).
Urethane catalyst b: Dioctyltin dilaurate (manufactured by Nitto Kasei Co., Ltd., trade name: Neostan U-810).
Polyisocyanate compound a: TDI-80 (2,4-TDI / 2,6-TDI = 80/20 mass% mixture), isocyanate group content 48.3 mass% (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate T-80).

[Production Example 1: Production of polyol (A1)]
In the presence of a potassium hydroxide catalyst, PO was subjected to ring-opening addition polymerization using dipropylene glycol as an initiator until the molecular weight reached 1,000, and then purified with magnesium silicate to produce an initiator (a1). Subsequently, in the presence of a zinc hexacyanocobaltate-tert-butyl alcohol complex catalyst, which is a DMC catalyst, PO is subjected to ring-opening addition polymerization to the initiator (a1) to obtain a polyhydroxy having an average hydroxyl number of 2 and a hydroxyl value of 11 mgKOH / g. Oxypropylene polyol (A1) was obtained. The total degree of unsaturation was 0.007 meq / g.

[Production Example 2: Production of polyol (A2)]
A polyoxypropylene polyol (A2) having an average number of functional groups of 2 and a hydroxyl value of 7.5 mgKOH / g produced by the same method as that for the polyol (A1) was obtained. The total degree of unsaturation was 0.008 meq / g.

[Production Example 3: Production of polyol (A3)]
A polyoxypropylene polyol (A3) having an average number of functional groups of 2 and a hydroxyl value of 14.0 mgKOH / g produced in the same manner as in the polyol (A1) was obtained. The total degree of unsaturation was 0.006 meq / g.

[Production Example 4: Production of polyol (A4)]
A polyol serving as a base of the polyol (A4) was produced as follows. In the presence of zinc hexacyanocobaltate-tert-butyl alcohol complex catalyst, which is a DMC catalyst, using glycerol as an initiator, PO and EO are opened by random polymerization at a ratio of PO: EO of 93: 7 (mass ratio). Cycloaddition polymerization was performed to obtain a polyoxypropylene / polyoxyethylene polyol having an average number of hydroxyl groups of 3, a hydroxyl value of 56.0 mgKOH / g, and a total unsaturation of 0.007 meq / g. In this polyol, as a monomer having an ethylenically unsaturated double bond, styrene and acrylonitrile were copolymerized at 70:30 (mass ratio) to obtain a polymer-dispersed polyol. The overall polymer-dispersed polyol obtained had a hydroxyl value of 32.0 mgKOH / g and a content of polymer fine particles of 43% by mass.

[Examples 1 to 20, 22, 24]
Flexible polyurethane foams having the formulations shown in Tables 1 to 3 were produced and their physical properties were evaluated. The evaluation results are shown in Tables 1 to 3. Examples 7, 14, 19, 22, and 24 are comparative examples.
That is, among the raw materials shown in Tables 1 to 3, all raw materials other than the polyisocyanate compound were mixed to prepare a polyol system liquid having a liquid temperature of 23 ° C. ± 1 ° C. A polyisocyanate compound was prepared at a liquid temperature of 23 ° C. ± 1 ° C.
A predetermined amount of a polyisocyanate compound was added to the polyol system liquid, and mixed for 5 seconds with a mixer (3,000 revolutions per minute) to obtain a foaming stock solution composition. Immediately after mixing, this was poured into a wooden box having an open top and foamed at room temperature (23 ° C.) to obtain a flexible polyurethane foam (slab foam). The wooden box used had a size of 600 mm in length, 600 mm in width, and 400 mm in height, with a vinyl sheet on the inner surface.
The obtained flexible polyurethane foam was taken out of the wooden box, left in a room at room temperature (23 ° C.) and a humidity of 50% for 24 hours, and then evaluated by the following method.

<Evaluation method>
[Core density, core rebound resilience]
The core density and core rebound resilience were measured by a method based on JIS K6400 (1997 edition). Except for the skin part from the center part of the foam, what was cut into a size of 250 mm in length and width and 50 mm in height was used for the measurement.

[Other physical properties]
25% hardness (ILD), 50% hardness (ILD), 65% hardness (ILD), breathability, tensile strength, elongation, tear strength, hysteresis loss rate, 50% compression residual strain and 50% wet heat compression residual The strain was measured by a method based on JIS K6400 (1997 edition).
The air permeability was measured by a method based on method B of JIS K6400 (1997 edition).

[Hot press test]
Samples were prepared by cutting the flexible polyurethane foams obtained in Examples 1 to 20, 22, and 24 into a size of 50 mm in length, 125 mm in width, and 25 mm in thickness, excluding the skin portion from the center. For cutting the foam, a vertical cutting machine (manufactured by Sakura Kikai Kogyo Co., Ltd., device name: manual type SK2-2A type), a cutting knife used is a band knife (width 16 mm, thickness 0.5 mm, length 5,130 mm) It was used. The rotational speed of the vertical cutter was adjusted by an inverter. As the workability, the workability when cut at normal temperature (23 ° C.) was evaluated according to the following criteria.
Note that the flexible foams obtained in Examples 7, 14, 19, and 24 were uncut at room temperature. In addition, the flexible foam obtained in Example 22 could be cut at 500 revolutions per minute at room temperature, but could not be cut uniformly. In order to measure various physical properties, the flexible foams obtained in Examples 7, 14, 19, 22, and 24 were placed in a low-temperature incubator at 5 ° C. (manufactured by Espec Corp., apparatus name: Platinums K series PL-3KT) for 1 hour. It was left to stand and removed immediately after removal.
Next, the cut sample was subjected to hot press molding using a hot press molding machine (manufactured by Iwaki Kogyo Co., Ltd., apparatus name: hydraulic molding machine) as a target shape with a sheet shape having a length of 50 mm, a width of 125 mm, and a thickness of 5 mm. . The hot press conditions were a temperature of 160 ° C., a pressure of 20 MPa, and 120 seconds.
The obtained hot press-molded product was left in a room temperature (23 ° C.) and a humidity of 50% for 1 hour, and then the thickness was measured. The value of the thickness at the thickest part is shown in the table as the maximum thickness d after pressing. Show.
The hot press formability was evaluated according to the following criteria.

(Processing workability)
(Excellent): Cutting is possible at a rotational speed of a vertical cutter of 1,500 revolutions per minute.
○ (good): The vertical cutter cannot be cut at 1,500 revolutions per minute, but can be cut at 1,000 revolutions.
Δ (possible): Although the rotational speed of the vertical cutting machine cannot be cut at 1,000 rotations per minute, it can be cut at 500 rotations.
X (impossible): In a vertical cutting machine, cutting is impossible due to the high viscosity of the flexible polyurethane foam.
In addition, since the flexible foam can be cut faster as the rotational speed of the vertical cutting machine is larger, the workability is better.
(Hot press formability)
○ (good): The maximum thickness d after hot pressing is 4.5 mm or more and less than 5.5 mm.
Δ (possible): The maximum thickness d after hot pressing is 4.0 mm or more and less than 4.5 mm, or 5.5 mm or more and less than 6.0 mm.
X (impossible): The maximum thickness d after hot pressing is less than 4.0 mm, or 6.0 mm or more.
In addition, hot press moldability is so bad that the maximum thickness after hot press is large.

[Examples 21, 23]
About the flexible foam obtained in each of Examples 20 and 22, a hot press test was performed by changing the hot press conditions. Example 23 is a comparative example using the flexible foam obtained in Example 22. That is, cutting, hot press molding, and evaluation were performed in the same manner as in Examples 20 and 22, except that the hot press conditions were a temperature of 200 ° C., a pressure of 20 MPa, and 120 seconds. The evaluation results are shown in Table 3.

As shown in the results of Tables 1 to 3, each of the flexible polyurethane foams obtained in Examples 1 to 6, Examples 8 to 13, and Examples 15 to 18, 20, and 21 according to the present invention has a 25% hardness. (ILD) was 40 N / 314 cm ² or more, the workability was good, and hot press molding was also possible. Moreover, although it was low density, air permeability, mechanical characteristics (tensile strength, elongation, tear strength, hysteresis loss rate), and durability were also good.
In particular, Examples 1, 2, 4 to 6, 8 to 9, 11 to 13, 17, and 20 to 21 had a 25% hardness (ILD) of 50 N / 314 cm ² or more and excellent workability.
In Example 20, the workability is good when the 25% hardness (ILD) is 50 N / 314 cm ² or more. Hot press molding is also possible. In Example 20, hot press molding was performed at 160 ° C., but in Example 21, hot press molding was performed at 200 ° C., so that the maximum thickness d after hot pressing approached 5 mm, and the hot press moldability was improved. When Example 20 and Example 21 are compared with Example 2, the difference is the average hydroxyl value of the polyol (A) in the polyol mixture (X). In Example 2, the average hydroxyl value of the polyol (A) is smaller than those in Examples 20 and 21. That is, in Example 2, the polyol (A1) having a large molecular weight was used, and the hot press moldability at a low temperature (160 ° C.) was good even with an isocyanate index of 100. It is more preferable that hot press molding at a low temperature is possible because a load is not applied to the flexible foam.

On the other hand, Examples 7, 14, and 19, which are comparative examples, had an isocyanate index of less than 90, and therefore had a low 25% hardness (ILD) and poor workability.
Examples 22 to 24 are examples in which the polyol mixture (X) does not contain the monool (D). In Example 22, hot press molding was performed at 160 ° C., but it was hard and had poor hot press moldability. In Example 23, hot press molding was performed at 200 ° C., but the hot press moldability was also poor. In Example 24, the isocyanate index was less than 90, and when the polyol mixture (X) did not contain the monool (D), it was confirmed that the workability and the hot press moldability were poor.

According to the present invention, it is possible to obtain a flexible polyurethane foam having sufficient hardness, good workability at the time of cutting, and capable of being well molded by hot press, and various hot presses. Useful for molded products.
The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2010-086124 filed on April 2, 2010 are incorporated herein by reference. .

Claims

In the method for producing a flexible polyurethane foam for hot press molding by reacting a polyol mixture (X) with a polyisocyanate compound in the presence of a urethanization catalyst, a foaming agent and a foam stabilizer, the polyol mixture (X) comprises: A flexible polyurethane foam for hot press molding comprising the following polyol (A), the following polyol (B) and the following monool (D), wherein the polyisocyanate compound is used in an amount of 90 or more in terms of isocyanate index: Production method.
Polyol (A): a polyoxyalkylene polyol having an average number of hydroxyl groups of 2 to 3, a hydroxyl value of 5 to 90 mgKOH / g, and an oxyethylene group content of 0 to 30% by mass,
Polyol (B): a polyoxyalkylene polyol having an average number of hydroxyl groups of 2 to 3 and a hydroxyl value of 100 to 250 mgKOH / g,
Monool (D): A polyoxyalkylene monool having a hydroxyl value of 5 to 200 mgKOH / g.
The flexible polyurethane foam for hot press molding according to claim 1, wherein the proportion of the polyol (A) is 5 to 50% by mass in 100% by mass of the total of the polyol (A) and the polyol (B). Manufacturing method.
The hot press molding according to claim 1 or 2, wherein a total ratio of the polyol (A) and the polyol (B) is 70 to 99% by mass in 100% by mass of the polyol mixture (X). For producing polyurethane foam for use.
The proportion of the monool (D) is 1 to 30 parts by mass with respect to 100 parts by mass of the total of the polyol (A) and the polyol (B). The manufacturing method of the flexible polyurethane foam for hot press molding of description.
The method for producing a flexible polyurethane foam for hot press molding according to any one of claims 1 to 4, wherein the polyol mixture (X) further contains the following polyol (C).
Polyol (C): Polyoxyalkylene polyol having an average number of hydroxyl groups of 2 to 6, a hydroxyl value of 10 to 60 mgKOH / g, and an oxyethylene group content of 50% by mass or more.
The method for producing a polyurethane foam for hot press molding according to claim 5, wherein a proportion of the polyol (C) is 0.1 to 10% by mass in 100% by mass of the polyol mixture (X).
The polyol mixture (X) comprises 10 to 30% by mass of the polyol (A), 50 to 80% by mass of the polyol (B), 0 to 8% by mass of the polyol (C), and the monool (D The process for producing a polyurethane foam for hot press molding according to claim 5 or 6, comprising 1 to 24% by mass).
The method for producing a flexible polyurethane foam for hot press molding according to any one of claims 1 to 7, wherein the 25% hardness (ILD) of the flexible polyurethane foam is 40 N / 314 cm 2 or more.
The method for producing a flexible polyurethane foam for hot press molding according to any one of claims 1 to 8, wherein the urethanization catalyst contains dioctyltins.
The heat according to any one of claims 1 to 9, wherein an amount of the urethanization catalyst used is 0.01 to 3.0 parts by mass with respect to 100 parts by mass of the whole polyol mixture (X). A method for producing a flexible polyurethane foam for press molding.
The method for producing a flexible polyurethane foam for hot press molding according to any one of claims 1 to 10, wherein the foaming agent comprises only water.
A flexible polyurethane foam for hot press molding obtained by the production method according to any one of claims 1 to 11.
A step of producing a flexible polyurethane foam for hot press molding by the production method according to any one of claims 1 to 11, a step of cutting the obtained flexible polyurethane foam for hot press molding, and the hot press molding cut A method for producing a hot press-formed product, comprising a step of forming a flexible polyurethane foam for use in a hot press forming method.
A hot press-molded product obtained by the production method according to claim 13.