JP2000230030A - Highly durable flexible polyurethane foam and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a flexible polyurethane foam which exhibits an excellent durabilty and small hardness change and thickness change by reacting a polyisocyanate with water and a polyol component which contains a polyoxyalkylene polyol produced by using a catalyst containing cesium hydroxide or rubidium hydroxide. SOLUTION: A flexible polyurethane foam with a density of 25-34 kg/m3, a hardness change in repeated compression test of 25% or lower, and a wet-heat compression set of 25% or lower is produced by reacting a polyisocyanate with water and a polyol component in the presence of a catalyt. The polyol component comprises a polyol (A) containing a polyoxyalkylene polyol which is prepared by reacting an alkylene oxide compound in the presence of a catalyst containing cesium hydroxide or rubidium hydroxide and/or a polymer polyol (B) prepared by dispersing polymer particles which are formed by the radical polymerization of an unsaturated compound in a polyol containing the polyoxyalkylene polyol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a flexible polyurethane foam and a method for producing the same. More specifically, it relates to a flexible polyurethane foam widely used in vehicle interior materials, furniture cushion materials, bedding, miscellaneous goods, etc., having improved durability represented by wet heat compression set, and a polyol obtained by using a specific catalyst in the production thereof. , A specific isocyanate, or a combination of specific isocyanates, or a combination thereof, and a method for producing a flexible polyurethane foam.

[0002]

2. Description of the Related Art A flexible polyurethane foam (hereinafter abbreviated as a flexible foam) has a cushioning property.
It is widely used in cushioning materials for vehicles, backrest materials, furniture, bedding, sundries and the like. This flexible foam is a polyol, a polymer polyol in which polymer particles are dispersed in a polyol obtained by radical polymerization of acrylonitrile or styrene in the polyol, water as a foaming agent, a silicone-based surfactant, an amine or a tin compound, etc. And an aromatic polyisocyanate with a catalyst, a crosslinking agent or the like, if necessary, a flame retardant, a pigment or the like. Water as a foaming agent functions as a foaming agent by a reaction in which aromatic polyisocyanate and water react with each other, and the desorbed carbon dioxide gas becomes a foaming gas, and at the same time, generates an aromatic polyurea. Due to the Montreal Treaty aimed at protecting the global environment, CFC-11 can no longer be used, and the amount of water used in the formulation is increasing in proportion to the foaming effect of this foaming aid.

(Needs in recent years) Further, in recent years, there has been a strong demand for cost reduction, and there has been a demand for lowering the density for weight reduction, and for vehicles, there has been a demand for lowering the density for weight reduction in accordance with fuel efficiency regulations. I have. In order to meet such a demand for lowering the density, water as a foaming agent tends to further increase. Increasing water increases the amount of generated carbon dioxide,
Although effective to reduce the density of the flexible foam, the aromatic polyurea generated is compression set of the flexible foam,
And the durability is deteriorated. Further, the reduction in the density of the foam itself causes deterioration of such distortion characteristics and durability characteristics. The shape stability of such a flexible foam causes various problems. For example, the thickness of the bed cushion decreases with use, and the thickness and hardness of the vehicle cushion change with use. In particular, in the case of vehicle cushions, the cushion thickness and hardness at the time of initial design decrease due to long hours of vehicle operation, the driver's fixed position falls, the visibility is narrowed, safety is impaired, and sitting comfort and riding comfort deteriorate. I do. These problems are durability problems of the flexible foam, and can be evaluated by a change in hardness in a repeated compression test and a permanent set under wet heat compression. As a specific technique for improving the compression strain property of the flexible foam, and the durability property, there is a method of increasing the amount of a cross-linking agent used in the formulation, and the like. In such a method, the elongation and tear strength of the flexible foam are reduced. Issues such as the expectation of further improvement in mechanical properties remain, and flexible foams that can achieve weight reduction and have excellent physical properties in evaluating the change in hardness in wet heat compression set and repeated compression tests are provided. Was desired.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a low-density flexible foam excellent in durability, especially a hardness change rate in a repeated compression test and a thickness change property in a wet heat compression set, and a method for producing the same. Is to provide. It is an object of the present invention to provide a resin premix excellent in moldability and the like in a flexible foam production process, and a method for producing a high-performance flexible foam economically excellent.

[0005]

As a result of various studies, the present inventors have found a flexible foam having excellent durability even at a low density, and have completed the present invention. Further, in the production of a flexible foam, the polyol and / or polymer polyol used contains a polyoxyalkylene polyol synthesized using a catalyst for producing a polyoxyalkylene polyol containing at least one of cesium hydroxide or rubidium hydroxide. It has been found that the use of such a material makes it possible to efficiently produce a flexible foam having excellent durability, and has completed the present invention. That is, the present invention provides the following (1) to (6). (1) a polymer polyol in which polymer particles obtained by radically polymerizing a compound having an unsaturated bond in a polyol containing at least a polyoxyalkylene polyol and / or a polyol containing at least a polyoxyalkylene polyol, and
25 total density from water, catalyst and polyisocyanate
kg / m ³ or more and 34 kg / m ³ or less, and wet heat compression set is 25%
In the production of the following flexible polyurethane foam, wherein the polyoxyalkylene polyol is synthesized using a catalyst for producing a polyoxyalkylene polyol containing at least one of cesium hydroxide or rubidium hydroxide, Of producing a flexible polyurethane foam. (2) a polymer polyol in which polymer particles obtained by radical polymerization of a compound having an unsaturated bond in a polyol containing at least a polyoxyalkylene polyol and / or a polyol containing at least a polyoxyalkylene polyol, and
25 total density from water, catalyst and polyisocyanate
kg / m ³ or more 34 kg / m ³ or less, and the hardness change rate is 25% or less in the repeated compression test, in the production of flexible polyurethane foams wet heat compression set is less than 25%, the polyoxyalkylene polyol is cesium hydroxide Or a method for producing a flexible polyurethane foam, which is synthesized using a catalyst for producing a polyoxyalkylene polyol containing at least one of rubidium hydroxide. (3) The viscosity of a resin premix containing at least a polyol and / or a polymer polyol and water, a catalyst, a crosslinking agent, and a foam stabilizer is 2500 mPa · s or less.
The method for producing a flexible polyurethane foam according to any one of (1) and (2). (4) The method for producing a flexible polyurethane foam according to any one of (1) to (3), wherein the polyisocyanate is toluylene diisocyanate. (5) The polyisocyanate is toluylene diisocyanate and polymethylene polyphenyl polyisocyanate (general formula 1)

[0006]

[Formula 2] (N = 0 or an integer of 1 or more). A process for producing a flexible polyurethane foam according to any one of (1) to (3), wherein the mixture is a 98: 2 to 50:50 (weight ratio) mixture.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Flexible polyurethane foam] The flexible polyurethane foam according to the present invention is produced using a polyoxyalkylene polyol produced using a specific polyoxyalkylene polyol production catalyst as an essential component, and has a total density of 25 kg.
/ m ³ or more and 34 kg / m ³ or less, and the wet heat compression set is 25% or less, preferably, the total density is 25 kg / m ³ or more and 32 kg / m ³ or less, and the wet heat compression set is 25% or less 10 % Or more. Further, the rate of change in hardness of the flexible polyurethane foam of the present invention in a repeated compression test is preferably 25% or less, more preferably 24% or less and 10% or more,
Most preferably, it is 22% or less and 12% or more.

The flexible polyurethane foam is produced by reacting a polyisocyanate compound, a foaming agent and a catalyst with any of the following compounds (a) to (e).
In the present production, a foam stabilizer, a crosslinking agent, and other additives may be used alone or in combination of two or more as necessary. At this time, a foam stabilizer, a cross-linking agent, and other additives described below (a) to (e), even if previously added to either or both of the polyisocyanate, a polyisocyanate compound, a foaming agent, a catalyst and the following (a) ) To (e) may be added in a mixer or a reactor for mixing the compounds. (a) Polyoxyalkylene polyols alone and mixtures thereof. (b) a mixture of a polyoxyalkylene polyol and another polyol (c) a polymer polyol prepared from a polyoxyalkylene polyol alone or a mixture of a plurality of polyols (d) a mixture of a polyoxyalkylene polyol and another polyol alone or a mixture of a plurality of polyols Mixture of polymer polyols (e) (a) and (c), (a) and (d), (b) and (C), and (b) and (d). Description of the production of the flexible polyurethane foam according to the present invention In the above, "parts" means "parts by weight" unless otherwise specified, and based on 100 parts by weight of the polyol or when a polyoxyalkylene polyol or another polyol (including a polymer polyol or the like) is used in combination, the polyoxyalkylene polyol is used. , Other polyoxyalkylene polyol and other polyol based on 100 parts by weight in total.

[Polyol] In producing the flexible urethane foam of the present invention, a polyol having at least a polyoxyalkylene polyol and / or a compound having an unsaturated bond in the polyol containing at least the polyoxyalkylene polyol is subjected to radical polymerization. A polymer polyol in which polymer fine particles are dispersed is essential, but other polyols can also be used in combination. Such a polyol will be described together with a polyoxyalkylene polyol. The polyol to be reacted with the polyisocyanate compound includes, for example, dihydric alcohols (such as ethylene glycol and propylene glycol), trihydric alcohols (such as glycerin and trimethylolpropane), and tetrahydric alcohols (such as pentaerythritol and diglycerin). ), Polyoxyalkylene polyols and polyester polyols. The hydroxyl value of the polyol used in combination with the polyoxyalkylene polyol is 15 mgKOH / g or more and 45 mgKOH / g.
The following are preferable, and those with 20 mgKOH / g or more and 35 mgKOH / g or less are more preferable. Further, the content of ethylene oxide in the alkylene oxide as a polyol is 20% by weight or more,
A polyol with a hydroxyl value of 15 mgKOH / g or more and 100 mgKOH / g or less
0.5 to 30 parts can be used.

(Polyoxyalkylene polyol) The polyoxyalkylene polyol refers to an oligomer or a polymer obtained by ring-opening polymerization of an alkylene oxide, and starts an active hydrogen compound in the presence of a catalyst for producing a polyoxyalkylene polyol. It is obtained by ring-opening polymerization of an alkylene oxide as an agent. These may be used alone or in combination. Sometimes referred to as polyoxyalkylene polyether polyol. In producing the polyoxyalkylene polyol, the initiator and the alkylene oxide may be used alone or in combination. When producing the polyoxyalkylene polyol, a catalyst for producing a polyoxyalkylene polyol containing at least either cesium hydroxide or rubidium hydroxide is used. These polyoxyalkylene polyol-producing catalysts containing at least either cesium hydroxide or rubidium hydroxide may be used alone or in combination of two or more. It goes without saying that a catalyst having a nitrogen-phosphorus double bond such as a phosphazenium compound may be used in combination, as long as the object of the present application is not violated. In particular, when a catalyst for producing a polyoxyalkylene polyol containing at least either cesium hydroxide or rubidium hydroxide is used, the molecular weight of the polyoxyalkylene polyol is increased and by-products are produced as compared with the case where potassium hydroxide or the like is used as a catalyst. A monool having an unsaturated group at one end of a molecule can be suppressed, and a polyoxyalkylene polyol having an extremely low monol content can be produced. Since the monol has a low molecular weight as compared with the polyoxyalkylene polyol produced by the main reaction, the molecular weight distribution of the polyoxyalkylene polyol may be significantly widened and the average number of functional groups may be reduced. For this reason, the monool content in the polyoxyalkylene polyol is preferably lower. Monool content in the polyoxyalkylene polyol is usually represented by the total degree of unsaturation,
The lower this value, the lower the monool content.
Polyoxyalkylene polyol according to the present invention,
(1) hydroxyl value 15 mgKOH / g or more, 25 mgKOH / g or less, total unsaturation 0.060 meq / g or less, (2) hydroxyl value exceeding 25 mgKOH / g and 35 mgKOH / g or less, total unsaturation 0.050 meq / g g or less, or (3) a hydroxyl value exceeding 35 mgKOH / g and not more than 45 mgKOH / g and having a total degree of unsaturation of not more than 0.040 meq / g is suitably used. Preferably, (1) a hydroxyl value of 15 mgKOH / g or more, 25 mgKOH / g or less, and a total degree of unsaturation of 0.040 meq / g or less,
(2) hydroxyl value exceeding 25 mgKOH / g and 35 mgKOH / g or less, total unsaturation degree 0.030 meq / g or less, or (3) hydroxyl value 35 mgK
Over OH / g, below 45mgKOH / g, total unsaturation 0.020meq / g
Any of the following is preferably used. More preferably, (1) a hydroxyl value of 15 mgKOH / g or more and 25 mgKOH / g or less, a total degree of unsaturation of 0.025 meq / g or less, and (2) a hydroxyl value of 25 mgKOH / g
/ g, 35mgKOH / g or less, total unsaturation degree 0.020meq / g or less, or (3) hydroxyl value exceeding 35mgKOH / g, 45mgKOH / g
In the following, any one having a total degree of unsaturation of 0.015 meq / g or less is suitably used. Needless to say, these polyoxyalkylene polyols may be used alone or in combination of two or more.

When a catalyst for producing a polyoxyalkylene polyol containing at least either cesium hydroxide or rubidium hydroxide is used, such a polyoxyalkylene polyol having a low or substantially no monol content can be obtained. When used in the production of a flexible polyurethane foam using the polyoxyalkylene polyol, the obtained flexible foam can easily obtain a flexible foam excellent in physical properties such as hysteresis, extensibility, and curing properties. preferable. It goes without saying that such a monol or a polyoxyalkylene polyol containing a monol may be used without departing from the gist of the present invention. Further, when a polyoxyalkylene polyol is synthesized by ring-opening polymerization of propylene oxide, a sequence in which a methyl group in a side chain is polymerized in a direction on an adjacent carbon and a sequence on a carbon sandwiching a methylene group are included. Possible (head-to-tail coupling). head
-A high toe-tail bond ratio is preferred because the stability of the foamed foam is improved. Specifically, a polyol having a head-to-tail bond selectivity of 96% or more is preferable.

(Catalyst for producing polyoxyalkylene polyol) In producing a polyoxyalkylene polyol, a catalyst for producing a polyoxyalkylene containing at least one of cesium hydroxide and rubidium hydroxide is used.

(Alkylene oxide compound) As the alkylene oxide compound used for producing the polyalkyleneoxy polyol of the present invention, ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-
Butylene oxide, styrene oxide, cyclohexene oxide, epichlorohydrin, epibromohydrin,
Epoxy compounds such as 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 preferred, and ethylene oxide and propylene oxide are more preferred. These may be used in combination of two or more. When used in combination, a method of simultaneously using a plurality of alkylene oxide compounds, a method of sequentially using a plurality of alkylene oxide compounds, or a method of repeatedly repeating the steps can be employed. When used in combination, it is particularly preferable that the ratio of ethylene oxide in the alkylene oxide is 5 to 30% by weight.

[Polymer Polyol] In the present invention, a polymer-dispersed polyol (hereinafter sometimes referred to as a polymer polyol) refers to a compound having an unsaturated bond such as acrylonitrile or styrene and a radical initiator such as azobisbutyronitrile. A vinyl polymer particle (hereinafter simply referred to as polymer) containing a partially grafted product obtained by dispersion polymerization in a polyol containing at least the polyoxyalkylene polyol produced using a specific polyoxyalkylene production catalyst. (Sometimes referred to as fine particles). The polyol used here may be any as long as it contains the polyoxyalkylene polyol, but it is more preferable that the polyoxyalkylene polyol be the main component. In the polymer-dispersed polyol used in the present invention, the proportion of the polymer fine particles in the polyoxyalkylene polyol is usually
It is 2 to 50% by weight, preferably 10 to 40% by weight.

(Compound Having an Unsaturated Bond) The compound having an unsaturated bond is a compound having an unsaturated bond in the molecule, for example, acrylonitrile, styrene and the like. These can be used alone or in combination of two or more, and it is preferable to use a mixture of two or more. In addition, a dispersion stabilizer, a chain transfer agent and the like may be used in combination.

[Urethane Foam Foaming Aid] The auxiliary agent used for urethane foaming includes a cross-linking agent, a foam stabilizer, a catalyst for producing polyurethane foam, a foaming agent, etc., each of which can be added as needed. It goes without saying that other additives and the like may be used in combination.

(Cross-linking agent) The cross-linking agent may not be particularly used, but when used, a compound having a hydroxyl value of 200 to 1800 mgKOH / g is used. For example, aliphatic polyhydric alcohols such as glycerin, and alkanolamines such as diethanolamine and triethanolamine are used. In addition to a polyoxyalkylene polyol having a hydroxyl value of 200 to 1800 mgKOH / g, a conventionally known crosslinking agent can be used in an optional amount of 0.5 to 10 parts.

(Foam stabilizer) As the foam stabilizer, a commonly used organosilicon surfactant can be used. The amount used is 0.2 to 3 parts, for example, manufactured by Dow Corning Toray Silicone Co., Ltd.
SRX-274C, SF-2969, SF-2961, SF-2962 and Nippon Unicar's L-5309, L-3601, L-5307, L-3600, etc. can be used.

(Catalyst used in the production of flexible polyurethane foam) As the catalyst used in the production of the flexible polyurethane foam, conventionally known catalysts can be used, and there is no particular limitation, but the amount used is 0.005 to 10 parts. Is preferred. Examples of the catalyst include aliphatic amines such as triethylenediamine, bis (n, n-dimethylaminoethyl ether) and morpholine, and organotin compounds such as tin octoate and dibutyltin dilaurate. These catalysts may be used alone or in combination.

(Blowing agent) Water is used as a blowing agent by reacting with polyisocyanate to generate carbon dioxide gas. The amount usually used is preferably 2 to 7 parts, more preferably 2.5 to 6 parts. As long as the gist of the present invention is not impaired, chlorofluorocarbons, hydroxychlorofluorocarbons (such as HCFC-134a), hydrocarbons (such as cyclopentane), and other blowing agents developed for the purpose of protecting the global environment Can be used alone or in combination with water as a foaming aid.

(Resin premix) A mixture of these polyols or polymer polyols or a mixture of a polymer polyol and a polyol, and if necessary, a crosslinking agent, a surfactant, water and a catalyst is called a resin premix. Further, a flame retardant, a pigment, an ultraviolet absorber, an antioxidant and the like can be added to the resin premix as necessary.

(Polyisocyanate) The polyisocyanate to be reacted with the resin premix is not particularly limited, but the conventionally known toluylene diisocyanate (2,4-form or
Isomer ratio such as 2,6-isomer is not particularly limited, 2,4-isomer /
Those having a 2,6-body ratio of 80/20 are preferably used. )
And tolylene diisocyanate and polymethylene polyphenyl polyisocyanate represented by the general formula (1) (for example, Cosmonate M-200 manufactured by Mitsui Chemicals, Inc. In the formula, the isomer of the n = 0 component is 2,4 '-Body, 4,4'-body, the ratio of 2,2'-body is not particularly limited, but usually 2,2'-body is a trace amount, 2,4'-body is
Less than 10%. Further, the ratio of the component where n = 0 in the formula is not particularly limited, but those having less than 50% of the polymer diphenylmethane diisocyanate are usually used. )
Is preferably used. When the polyisocyanate is a mixture of toluylene diisocyanate and polymethylene polyphenyl polyisocyanate, the mixing ratio of 98: 2 to 50:50 by weight is particularly suitable for the production of flexible polyurethane foam.

The polyisocyanate can be preferably used even if it is a composition of polymethylene polyphenyl polyisocyanate. A mixture of polyisocyanate which is a composition of polymethylene polyphenyl polyisocyanate or a urethane modified product thereof and toluylene diisocyanate can also be preferably used. When the amount of organic polyisocyanate containing isocyanate groups stoichiometrically equal to the total amount of functional groups that react with isocyanate groups such as hydroxyl groups and amino groups in the resin premix is used for the production of flexible polyurethane foam When the NCO index is defined as 1.00, the NCO index in the present invention is 0.70 to 1.40.
It is preferable to carry out.

(Method for producing flexible polyurethane foam)
Although the method for producing the flexible polyurethane foam of the present invention is not particularly limited, a method of mixing the resin premix and the polyisocyanate using a high-pressure foaming machine or a low-pressure foaming machine is usually employed. In the case of a low-pressure foaming machine, more than two kinds of components can be mixed, so that they can be divided and mixed into a polyol type, an aqueous type, an organotin catalyst type, a flame retardant type, an isocyanate type and the like. The mixed liquid is discharged from the mixing head of the foaming machine, and is foamed and cured as it is to form a flexible polyurethane foam foam and cut out an object therefrom, or the mixed liquid is discharged into a mold, foamed, filled, and cured to be constant. Shaped objects can also be obtained. Curing time is usually
The mold temperature is from room temperature to about 80 ° C., and the curing temperature is from room temperature to 180 ° C., to produce a flexible polyurethane foam for 30 seconds to 30 minutes.

(Regarding the foaming form of flexible polyurethane foam) The resin premix is usually used by being mixed with an isocyanate in a high-pressure foaming machine or a low-pressure foaming machine, and a hydrolyzable compound such as an organotin catalyst is used as a catalyst. When used, it is preferable to separate the water component and the organotin catalyst component from each other in order to avoid contact with water, and to mix them with a mixing head of a foaming machine. The viscosity of the resin premix used is 2500 from the viewpoint of mixability in a foaming machine and foam moldability.
mPa · s or less is preferable.

(Measurement method) Total density: Measurement was carried out according to the method described in JIS K-6400.
Refers to the apparent density in the JIS standard. In this patent, measurement was performed using a rectangular foam sample having a skin skin. Foam hardness: Measurement was performed by the method described in Method A of JIS K-6400. Foam thicknesses of 94 mm to 100 mm were used. Wet heat compression set: Measured by the method described in JIS K-6400. At the time of measurement, a 50 × 50 × 25 mm cutout was used for the core portion of the molded flexible foam. Compress the specimen to 50% thickness, sandwich it between parallel flat plates, 50 ° C, 95% relative humidity
Was left for 22 hours. Thirty minutes after the test piece was taken out, its thickness was measured, compared with the value before the test, and the strain rate was measured. Hardness change rate in repeated compression test: Measured by the method described in JIS K-6400. A 100 x 100 x 50 mm cutout was used for the core portion of the molded flexible foam during the measurement. The test piece was sandwiched between parallel plane plates, and was repeatedly compressed at room temperature at a rate of 60 times per minute and 50% of its thickness continuously for 80,000 times. Thirty minutes after the test piece was taken out, its hardness was measured, compared with the value before the test, and the rate of change in hardness was measured. Elongation: Measured by the method described in JIS K-6400. Hydroxyl value: Measured according to the method described in JIS K-1557. Total unsaturation: Measured according to the method described in JIS K-1557. Head-to-tail coupling selectivity: 400 MHz, manufactured by JEOL Ltd.
Using a C ¹³ -nuclear magnetic resonance (NMR) device, deuterated chloroform is used as a solvent, and a C ¹³ -NMR spectrum of this polyoxyalkylene polyol is taken, and oxypropylene having a head-to-tail bond is obtained. Selectivity of head-to-tail coupling based on the ratio of the segment methyl group signal (16.9 to 17.4 ppm) and the head-to-head bond oxypropylene segment methyl group signal (17.7 to 18.5 ppm) I asked. The assignment of each signal is based on Macromolecule
s), 19.1337-1343 (1986), F., S., Schering (F.
C. Schiling), A, Y, and Tonell (AETonelli).

[0027]

EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. Parts and% in the examples represent parts by weight and% by weight, respectively. (Synthesis of polyoxyalkylene polyol) (Synthesis example of polyoxyalkylene polyol-2) Polyoxyalkylene polyol H: 0.23 mol of cesium hydroxide was added to 1 mol of glycerin, and propylene oxide was reacted after dehydration under reduced pressure at 100 ° C for 6 hours. Addition polymerization was carried out at a temperature of 80 ° C. and a maximum reaction pressure of 3.5 kg / cm ² , followed by addition polymerization of ethylene oxide at a reaction temperature of 100 ° C. to obtain a polyoxyalkylene polyol having a hydroxyl value of 28 mgKOH / g. Terminal oxyethylene group content is 15wt%, total unsaturation 0.016meq / g, head-
The to-tail binding selectivity was 97.1%. Hereinafter, polyoxyalkylene polyols I to K were synthesized in the same manner except that the active hydrogen compound as an initiator and the hydroxyl value of the obtained polyol were as shown in Table 1. Table 3 shows the structures and analysis values of the polyoxyalkylene polyols HK.
Hereinafter, polyoxyalkylene polyols B to D were synthesized in the same manner except that the active hydrogen compound as an initiator and the hydroxyl value of the obtained polyol were as shown in Table 1. table 1
Shows the structures and analytical values of polyoxyalkylene polyols A to D. In the table, the number of hydroxyl groups 3 is glycerin, and the number of hydroxyl groups 4
Used pentaerythritol as the active hydrogen compound.

[0028]

【table 1】

(Synthesis Example 2 of Polyoxyalkylene Polyol) Polyoxyalkylene polyol E: 0.37 mol of potassium hydroxide was added to 1 mol of glycerin, and the mixture was added at 100 ° C. for 6 hours.
After dehydration under reduced pressure, propylene oxide is subjected to addition polymerization at a reaction temperature of 115 ° C. and a reaction pressure of 5.0 kg / cm ² , and then ethylene oxide is subjected to addition polymerization at a reaction temperature of 115 ° C. to obtain a hydroxyl value of 28 mg KOH / g.
Was obtained. The terminal oxyethylene group content was 15 wt%, the total degree of unsaturation was 0.065 meq / g, and the selectivity for head-to-tail bond was 96.2%. Hereinafter, polyoxyalkylene polyols F and G were obtained in the same manner except that the active hydrogen compound as an initiator and the hydroxyl value of the obtained polyol were as shown in Table 2. Table 2 shows the structures and analysis values of the polyoxyalkylene polyols EG.

[0030]

[Table 2]

(Synthesis Example-1 of Polymer Polyol) Polymer polyol a: A polymer polyol having a hydroxyl value of 28 mgKOH / g obtained by graft-polymerizing acrylonitrile and styrene in polyether polyol B having a hydroxyl value of 34 mgKOH / g. 20wt% vinyl polymer content.

(Synthesis Example 2 of Polymer Polyol) Polymer polyol b: a polymer polyol having a hydroxyl value of 28 mgKOH / g obtained by graft-polymerizing acrylonitrile and styrene in polyether polyol F having a hydroxyl value of 34 mgKOH / g. 20wt% vinyl polymer content.

(Production of flexible polyurethane foam) As polyisocyanate, the following raw materials were used. (Polyisocyanate-1) Cosmonate TM-20; 2,4-toluylene diisocyanate and 2,6-toluylene diisocyanate manufactured by Mitsui Chemicals, Inc.
A mixture of 80 parts by weight of the mixture in a 0:20 weight ratio and 20 parts by weight of polymethylene polyphenyl polyisocyanate. In addition to the above-mentioned polyoxyalkylene polyol, polymer polyol and isocyanate, the following raw materials were used. (Communication agent-1) Polyol having an EO content of 70% by weight and a hydroxyl value of 52 mgKOH / g (Catalyst-1) Minico L-1020; an amine catalyst (33% diethylene glycol solution of triethylenediamine in Active Materials Chemical Co.). (Catalyst-2) Minico TMDA; amine catalyst manufactured by Active Materials Chemical Co., Ltd. (Crosslinking agent-1) KL-210; manufactured by Mitsui Chemicals, Inc., hydroxyl value 830 mgK
OH / g crosslinker. (Foam stabilizer-1) L-5309: a silicone foam stabilizer manufactured by Nippon Unicar Co., Ltd. The density in the examples and comparative examples indicates the total density (overall density).

Example 1 A resin solution was prepared by mixing the following seven components. Polyoxyalkylene polyol A 70 parts Polymer polyol a 30 parts Communication material-1 1.0 part Crosslinking agent-1 2.0 parts Water 5.0 parts Catalyst-1 0.4 parts Catalyst-2 0.1 parts Foam stabilizer-1 1.5 parts

The above resin solution 1 using polyoxyalkylene polyol A as the polyoxyalkylene polyol and polymer polyol a as the polymer polyol.
10.1 part was mixed with 63.4 parts of isocyanate-1 and immediately poured into a mold of internal dimensions 400 × 400 × 70 mm adjusted to 65 ° C. in advance,
Close the lid and let it foam. After heating and curing in a hot air oven at 100 ° C. for 7 minutes, the flexible foam is removed from the mold. Table 3 shows the physical properties of the obtained flexible foam. In this example, the equivalent ratio (NCO / H) between the isocyanate and the active hydrogen in the resin solution is 1.05.

(Examples 2 to 7) Same as Example 1 except that polyoxyalkylene polyol A in Example 1 was changed to polyoxyalkylene polyols A to D, and the apparent density was controlled according to Table 3. The method was performed. Table 3 shows the physical properties of the obtained flexible foam.

[0037]

[Table 3]

Comparative Examples 8 to 13 Except that the polyoxyalkylene polyol A in Example 1 was changed to polyoxyalkylene polyols EG and the polymer polyol a was changed to polymer polyol b, and the density was controlled according to Table 4. Is
This was performed in the same manner as in Example-1. The equivalent ratio (NCO / H) between the isocyanate and the active hydrogen in the resin solution was 1.05. Table 4 shows the physical properties of the obtained flexible foam.

[0039]

[Table 4]

The foams of Examples-1 to 7 show good wet heat compression strain and change in hardness in a repeated compression test. On the other hand, it can be seen that the foams of Comparative Examples -8 to 13 were inferior in foam physical properties because the polyol used was out of the range of the present invention. Further, the foams of Examples 1 to 6 are more preferable because they have a lower resin premix viscosity and show better mixing properties and liquid elongation than those of Example 7.

The following raw materials were used as isocyanates. (Isocyanate-2) Cosmonate T-80; 2,4-toluylene diisocyanate and 2,6-toluylene diisocyanate 80: 2 manufactured by Mitsui Chemicals, Inc.
0 weight ratio mixture

Examples 14 to 18 In Example 1, polyoxyalkylene polyol A was replaced with polyoxyalkylene polyols BD, and isocyanate-1 was used as isocyanate.
-2, and the same procedure as in Example 1 was carried out except that the density was controlled according to Table 5. The equivalent ratio (NCO / H) between the isocyanate and the active hydrogen in the resin solution was 1.05. Table 5 shows the physical properties of the obtained flexible foam.

[0043]

[Table 5]

(Comparative Examples 18 to 21) In Example 1, polyoxyalkylene polyol A was replaced with polyoxyalkylene polyols F and G, polymer polyol a was replaced with polymer polyol b, and isocyanate-1 was replaced with isocyanate-2. Example 1 except that the density was changed and the density was controlled according to Table 6.
The same procedure was used. The equivalent ratio (NCO / H) between the isocyanate and the active hydrogen in the resin solution was 1.05. Table 6 shows the physical properties of the obtained flexible foam.

[0045]

[Table 6]

The foams of Examples -14 to 18 show good wet heat compression strain and change in hardness in a repeated compression test. On the other hand, it can be seen that the polyols used in Comparative Examples -19 to 22 are out of the range of the present invention, and the physical properties of the foam are inferior. Further, the forms of Examples -14 to 17 are the same as those of Example -18.
It is more preferable because the resin premix has a lower viscosity and shows better mixability and liquid elongation as compared to

[0047]

The flexible polyurethane foam according to the present invention exhibits using polyols synthesized by a catalyst containing at least one cesium hydroxide or rubidium hydroxide, the total density of 25 kg / m ³ or more 34 kg / m ³ Below, and
The wet heat compression set is 25% or less. The hardness change rate in the repeated compression test can be 25% or less. This results in a foam that is lightweight and has excellent physical properties such as distortion characteristics, and is an excellent cushion for beds and vehicles. In addition, the viscosity of the resin premix is 2500
mPa · s or less, facilitating the handling of polyurethane at the time of production, and enabling production with an inexpensive apparatus. In addition, this makes it possible to easily produce a flexible foam having excellent resistance to wet heat compression set and a change in hardness in a repeated compression test.

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Claims (5)

[Claims] 1. A polymer polyol in which polymer particles obtained by radical polymerization of a compound having an unsaturated bond in a polyol containing at least a polyoxyalkylene polyol and / or a polyol containing at least a polyoxyalkylene polyol, and water, catalyst and the total density obtained from polyisocyanate 25 kg / m ³ or more 34 kg / m ³ or less, and a wet heat compression set
In the production of a flexible polyurethane foam of 25% or less, the polyoxyalkylene polyol is synthesized using a catalyst for producing a polyoxyalkylene polyol containing at least one of cesium hydroxide or rubidium hydroxide. A method for producing a flexible polyurethane foam, which is a feature of the present invention. 2. A polymer polyol in which polymer particles obtained by radically polymerizing a compound having an unsaturated bond in a polyol containing at least a polyoxyalkylene polyol and / or a polyol containing at least a polyoxyalkylene polyol, and Flexible polyurethane foam whose total density obtained from water, catalyst and polyisocyanate is 25 kg / m ³ or more and 34 kg / m ³ or less, the hardness change rate in a repeated compression test is 25% or less, and the wet heat compression set is 25% or less Production of a flexible polyurethane foam, wherein the polyoxyalkylene polyol is synthesized using a polyoxyalkylene polyol production catalyst containing at least one of cesium hydroxide and rubidium hydroxide. Method. 3. The flexible polyurethane according to claim 1, wherein the viscosity of the resin premix containing at least a polyol and / or a polymer polyol, water and a catalyst is 2500 mPa · s or less. Form manufacturing method. 4. The method for producing a flexible polyurethane foam according to claim 1, wherein the polyisocyanate is toluylene diisocyanate. 5. The polyisocyanate is toluylene diisocyanate and polymethylene polyphenyl polyisocyanate (general formula 1). 4. The method for producing a flexible polyurethane foam according to claim 1, wherein the mixture is a mixture of (n = 0 or an integer of 1 or more) of 98: 2 to 50:50 (weight ratio).