WO2003059980A1 - Process for producing flexible polyurethane foam - Google Patents

Abstract

A process for producing a flexible polyurethane foam free from fogging and excellent in curability and durability. The process for producing a flexible polyurethane foam comprises reacting a polyol compound with a polyisocyanate compound in the presence of a catalyst for urethane formation and a blowing agent, and is characterized in that the urethane formation catalyst is an amine compound catalyst having a hydroxy group in the molecule and that the polyol compound is a polyol (1) having a hydroxy value of 5 to 56 mg-KOH/g and comprising an oxyalkylene random chain (1A) formed by the random ring-opening addition polymerization of ethylene oxide and a C3 or higher alkylene oxide with the aid of a composite metal cyanide complex catalyst and a terminal oxyethylene block chain (1B) formed by the ring-opening addition polymerization of ethylene oxide with the aid of an alkali metal catalyst.

Description

 Specification

 Manufacturing method of flexible polyurethane foam

 The present invention relates to a method for producing a flexible polyurethane foam, and more particularly to a method for producing a flexible polyurethane foam having no fogging problem, and having excellent curing properties and durability. Background art

 2. Description of the Related Art Flexible polyurethane foam (hereinafter referred to as flexible foam) is generally used mainly for automobile seat cushions, seat backs, furniture and the like due to its excellent elastic touch.

 Conventionally, it has been essential to add a certain amount or more of an amine catalyst as a reaction catalyst between a polyol and a polyisocyanate in the production of a flexible foam. However, when a flexible foam using this amine-based catalyst is used in an automobile, gases or the like originating from the amine-based catalyst are generated due to the indoor environment or other causes, and the surface of the automotive glass becomes cloudy or is damaged on the instrument panel. The problem of whitening of the polycarbonate used and yellowing of polyvinyl chloride (fogging problem) has come to the fore. For the purpose of preventing fogging, hydroxylated products (hereinafter, referred to as reactive amine catalysts) have been used so that a part of the structure of the amine catalyst reacts with the isocyanate compound. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-181363) describes an invention using a reactive amine catalyst.

However, the reactive amine catalyst reacts with the isocyanate during the reaction, so that the catalytic activity in the latter half of the reaction is low and the curing is insufficient, so that the demolding property (curing property) is insufficient and the flexible foam When the mold is removed from the mold, the skin of the flexible foam is peeled or torn, resulting in mold contamination, and at the same time, the obtained product tends to have a poor appearance. In particular, recently, there has been a demand for demolding of molded articles in a short period of time, so the amount of reactive amine-based catalyst added has increased, and an amine-based catalyst regenerated by thermal decomposition has been required. Fogging has also become a problem.

 In addition, since this reactive amine catalyst often has one hydroxyl group in the molecule, it is a monol from the viewpoint of reaction with isocyanate, and the crosslink density decreases as the amount of monool increases. Therefore, strength and durability (especially wet heat compression set) tend to decrease.

 On the other hand, various studies have been made in order to improve the characteristics of flexible foams. For example, in order to improve the riding comfort performance of seat cushions for automobiles and the like, improvements in rebound resilience, vibration characteristics, durability, and the like are targeted. It has been. In addition, in recent years, with the change in taste for ride comfort performance of users, a soft form having low rebound resilience has been required. Regarding the vibration characteristics, it is said that it is effective to improve the ride comfort by increasing the attenuation in the sensitive frequency range (for example, 4 to 8 Hz or 6 to 2 OHz). I have. In order to improve these properties, it is considered effective to produce a sheet cushion using a polyoxyalkylene polyol having a higher molecular weight.

 Generally, polyoxyalkylene polyols used as raw materials for flexible foams are prepared by using a sodium-based catalyst such as sodium hydroxide, or a potassium-based catalyst such as potassium hydroxide, and using a polyhydric alcohol or the like as an initiator and propylene. It is produced by ring-opening addition polymerization of an alkylene oxide such as an oxide. In this production method, a polyoxyalkylene monool having an unsaturated bond (unsaturated monool) is produced as a by-product, and the amount of the unsaturated monool produced is a decrease in the hydroxyl value of the polyoxyalkylene polyol. (Increase in molecular weight).

In the production of polyoxyalkylene polyols having a hydroxyl value of about 56 mg KOH / g, which are widely used as raw materials for flexible foams, the amount of unsaturated monools produced does not pose a major problem, but the molecular weight In the case of a polyol having a high and low hydroxyl value, the production amount of the unsaturated monol is a problem. In other words, the use of a polyoxyalkylene polyol having a relatively high molecular weight with the aim of improving ride comfort and the production of a soft foam using a reactive amine-based catalyst in order to eliminate the above-mentioned fogging phenomena will lead to strength and durability. However, there was a problem that the softness of the film was deteriorated, so that a good soft foam for an automobile seat cushion could not be obtained. It has been known that a complex metal cyanide complex catalyst is used as a catalyst for producing a high-molecular-weight polyoxyalkylene polyol in order to suppress the generation of this unsaturated monol and improve strength and durability. I have. For example, Patent Document 2 (Japanese Patent Application Laid-Open No. 2000-5177347) discloses an invention for producing a flexible foam using a polyoxyalkylene polyol produced using a double metal cyanide complex catalyst. Has been described.

 Therefore, the present inventors have studied to solve the above-mentioned problem of fogging and to obtain a flexible foam having good strength and durability by using a polyol having a low content of unsaturated monomer. As a result, the present inventors have found that the combination of polyoxyalkylene polyol having a high reactivity and a specific structure and a reactive amine catalyst can significantly reduce the problem of fogging and the problem of strength and durability. It was found that it could be solved at the standard. Disclosure of the invention

 That is, the gist of the present invention is to provide a method for producing a flexible polyurethane foam by reacting a polyol compound and a polyisocyanate compound in the presence of a urethanizing catalyst and a blowing agent, wherein a hydroxyl group in the molecule is used as the urethanizing catalyst. Oxyalkylenes formed by random ring-opening addition polymerization of ethylene oxide and alkylene oxides having 3 or more carbon atoms using a double metal cyanide complex catalyst as a polyol compound using an amine catalyst It has a random chain (1A) and a terminal oxyethylene block chain (1B) formed by ring-opening addition polymerization of ethylene oxide using an alkali metal catalyst, and has a hydroxyl value of A method for producing a flexible polyurethane foam, characterized by using a polyol (1) having 5 to 56 mg KOH.

In the present invention, by combining a specific urethane-forming catalyst and a specific polyol, a fogging problem can be solved, and a flexible foam having good strength and durability can be obtained. In other words, by solving the fogging problem using a specific urethane-forming catalyst and combining it with a highly reactive specific polyol, the reaction rate is maintained in the latter half of the soft foam production, and the strength and durability are good. Flexible foam can get. BEST MODE FOR CARRYING OUT THE INVENTION

 [Structure of polyol (1)]

 In the present invention, the following polyol (1) is used as the polyol compound. The polyol (1) is a polyoxyalkylene polyol produced by subjecting an initiator to ring-opening addition polymerization in the presence of a ring-opening addition polymerization catalyst. The polyol (1) has a random oxyalkylene chain (1A) and a terminal oxyethylene block chain (1B). That is, the polyol (1) has an initiator residue (1S), an oxyalkylene random chain (1A), and a terminal oxyethylene block chain (1B) in a molecule.

 In addition, an oxyalkylene block chain formed by ring-opening addition polymerization of one type of alkylene oxide having 3 or more carbon atoms between the initiator residue (1 S) and the oxyalkylene random chain (1A). 1 P), and a ring-opening addition polymerization of one alkylene oxide having 3 or more carbon atoms between the oxyalkylene random chain (1 A) and the terminal oxyethylene block chain (1B). It may have a formed oxyalkylene block chain (1Q). In particular, it is preferable to have an oxyalkylene block chain (1P). That is, the polyol (1) has an initiator residue (1S), an oxyalkylene block chain (1P), an oxyalkylene random chain (1A), and a terminal oxyethylene block chain in the molecule. (1B) is preferred.

[Initiator residue (1 S)]

 As the polyol initiator in the present invention, active hydrogen compounds such as polyhydric alcohols, polyamines, and condensation compounds can be used. In addition, the initiator residue (1S) refers to a portion derived from the initiator in the polyol (1) in the present invention. The proportion of the initiator residue (1S) is preferably 25% by mass or less, more preferably 2 to 20% by mass, based on the whole polyol (1).

Specific examples of the initiator include ethylene glycol, propylene glycol, 1,4-butanediol, glycerin, trimethylolpropane, and pentaerythritol. Polyol, diglycerin, meso-erythryl] ^ yl, methyldaricoside, darcos, sorbitol, polyhydric alcohols such as sucrose; ethylenediamine, dimethylenamine, triethylenediamine, diaminodiphenylmethane, hexamethylenediamine And active hydrogen compounds having active hydrogen such as amines such as propylene diamine and the like; phenol resins, condensation resins such as nopolak resins and the like. Two or more of these active hydrogen compounds may be used in combination. Among these active hydrogen compounds, polyhydric alcohols are preferred. Among them, polyhydric alcohols having 3 or more valences are preferable because the hardness of a soft form using a polyol produced using the polyhydric alcohol as a starting material is easily developed.

 Further, a compound obtained by ring-opening addition polymerization of an alkylene oxide such as propylene oxide in a small amount may be used as the initiator. As the alkylene oxide to be subjected to the ring-opening addition polymerization in a small amount, propylene oxide is preferable, and the hydroxyl value of the compound thus obtained is preferably 6 OmgKOHZg or more. That is, a compound having a hydroxyl value of 60 mgK〇H / g or more obtained by subjecting propylene oxide to ring-opening addition polymerization of a polyhydric alcohol having a valency of 3 or more is most preferred as the initiator.

 [Oxyalkylene random chain (1A)]

 The polyol (1) in the present invention has an oxyalkylene random chain (1A) formed using a double metal cyanide complex catalyst. Here, the oxyalkylene random chain is a structure obtained by supplying ethylenoxide and an alkylene oxide having 3 or more carbon atoms into the reaction system at a predetermined ratio, and performing random ring-opening addition polymerization. The proportion of the oxyalkylene random chain (1A) is preferably from 5 to 90% by mass, more preferably from 10 to 80% by mass, based on the whole polyol (1).

The content of the oxyethylene group in the oxyalkylene random chain (1A) of the polyol (1) in the present invention is preferably from 3 to 35% by mass, more preferably from 5 to 30% by mass, based on the oxyalkylene random chain (1A). More preferred. That is, the ratio of ethylene oxide and alkylene oxide having 3 or more carbon atoms supplied into the reaction system is preferably 3Z97 to 35-65 by mass ratio (ethylene oxide Z alkylene oxide having 3 or more carbon atoms). 5 / 95-30Z70 is more preferred. Beyond this range Also, the case where the number of oxyethylene groups in the chain (1A) is small or large is not preferable because the flexible foam may have high closed-cell properties and deteriorate moldability.

 [Terminal oxyethylene block chain (1 B)]

 The polyol (1) in the present invention has a terminal oxyethylene block chain (1B) produced using an alkali catalyst at the molecular terminal. That is, as a final step of the ring-opening addition polymerization of alkylene oxide in the production of polyol (1), ethylene oxide is subjected to ring-opening addition polymerization using an alkali metal catalyst. Here, the alkylene oxide ring-opening addition polymerization catalyst converts a double metal cyanide complex catalyst into an alkali metal catalyst. The content of the terminal oxyethylene block chain (1B) is preferably 3 to 40% by mass, more preferably 5 to 30% by mass, based on the whole polyol (1). If the terminal oxyethylene block chain (1B) exceeds 4% by mass, shrinkage tends to occur even after crushing treatment, which is not preferable. Further, when the terminal oxyethylene block chain (1B) is less than 3% by mass, collapse of the foam is apt to occur during production of the flexible foam, which is not preferable because the production becomes difficult. The presence of a predetermined amount of the terminal oxyethylene block chain (1B) can increase the reactivity of the polyol (1).

 [Oxyalkylene block chain (1P), (1Q)]

 The polyol (1) in the present invention preferably has an oxyalkylene block chain (1P) and Z or (1Q) formed using a double metal cyanide complex catalyst. However, the oxyalkylene block chain (1P) is a compound having 3 carbon atoms between the initiator residue (1S) and the oxyalkylene random chain (1A) using a double metal cyanide complex catalyst. The structure is obtained by subjecting one of the above alkylene oxides to ring-opening addition polymerization. Further, an oxyalkylene block chain (1Q) is an alkylene oxide chain having 3 or less carbon atoms using a double metal cyanide complex catalyst.

Chains (1

Oxides are preferred. In this case, the oxyalkylene block chain is Block chain. The total ratio of the oxyalkylene block chains (1P) and (1Q) is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, and more preferably 20 to 30% by mass based on the whole polyol (1). % Is particularly preferred. Among these, it is particularly preferable that the ratio of the oxyalkylene block chain (1P) is 20 to 30% by mass with respect to the entire vorylol (1) because the hardness of the flexible foam can be controlled to be high. If the total ratio of the oxyalkylene block chains (1P) and (1Q) is more than 50% by mass, the foamability of the flexible foam will increase, and the moldability tends to deteriorate. Also, since the curing property is deteriorated, the hardness tends to hardly develop, which is not preferable.

 [Composite metal cyanide complex catalyst]

 'Examples of the double metal cyanide complex catalyst used in the present invention include compounds described in JP-B-46-27250. In particular, a complex containing zinc hexocyanobaltate as a main component is preferable, and a complex in which ether and Z or an alcohol is coordinated is preferable. By using the composite metal succinate complex catalyst, the amount of unsaturated monol by-produced during the production of the polyol can be suppressed, and the durability of the flexible foam using the obtained polyol as a raw material is improved. As this double metal cyanide complex catalyst, a complex in which t-tert-butyl alcohol is coordinated is preferable because the amount of unsaturated monool by-produced is small.

 The ether that forms a complex with the double metal cyanide is not particularly limited, but a compound represented by the formula (1) (hereinafter, referred to as compound (X)) is preferable.

R ¹ -C (CH ₃ ) _2- (OR ² ) _n -OH (1)

However, in the formula (1), R ¹ represents a methyl group or an ethyl group, and R ² represents a group in which one or more hydrogen atoms of an ethylene group or an ethylene group are replaced with a methyl group or an ethyl group. , N represents an integer of 1 to 3. As R ² , a group selected from an ethylene group, a propylene group, an ethylethylene group, a 1,2-dimethylethylene group, and a 1,1-dimethylethylene group is particularly preferable.

 Examples of the compound (X) include the compounds described in WO00Z02951, and specifically, the following compounds are preferred.

When n is 1, ethylene glycol mono-tert-butyl ether, propylene Lenglycol mono-tert-butyl ether, ethylene glycol mono-tert-pentyl ether, propylene glycol mono-tert-pentyl ether. When n is 2, diethylene glycol mono-tert-butyl ether, diethylene glycol mono-tert-pentyl ether. When n is 3, triethylene glycol mono-tert-butyl ether and triethylene glycol mono-tert-pentyl ether.

Further, as the compound (X), a compound in which n is 1 is more preferable, and a compound in which R ¹ is a methyl group is further preferable. Further, as the compound (X), two or more compounds can be used in combination.

 When compound (X) is used in combination with another compound as an organic ligand, compounds that can be used in combination are tert-butyl alcohol, 1-butanol, 2-butanol, tert-pentyl alcohol, isopentyl alcohol, One or more selected from N, N-dimethylacetamide, glyme (ethylene dalicol dimethyl ether), diglyme (diethylene glycol dimethyl ether), triglyme (triethylene dalicol dimethyl ether), 2-propanol and dioxane Is preferable. The dioxane may be 1,4-dioxane or 1,3-dioxane, and 1,4-dioxane is preferred. As the compound to be used in combination, tert-butyl alcohol, tert-pentyl alcohol or glyme is preferred, and tert-butyl alcohol is most preferred.

 [Alkali metal catalyst]

 Examples of the alkali metal catalyst include a sodium catalyst, a potassium catalyst, and a cesium catalyst. Examples of the sodium-based catalyst include sodium metal, sodium alkoxide such as sodium methoxide, sodium hydroxide, and sodium carbonate. The same applies to potassium catalysts and cesium catalysts.

In the production of the polyol (1) used in the present invention, the method of converting the catalyst from the double metal cyanide complex catalyst to the alkali metal catalyst includes: A metal catalyst may be added to the reaction system. Alternatively, the alkali metal catalyst may be added to the reaction system as it is without active deactivation treatment. In the former case, the active deactivation treatment is treatment by adding water, acid or alkali, adsorbent And the like. In the latter case, the addition of the alkali metal catalyst deactivates the double metal cyanide complex catalyst.

 [Alkylene oxide]

 Examples of the alkylene oxide having 3 or more carbon atoms include the above-described propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, epichlorohydrin, styrene oxide, and the like. Propylene oxide is used. It is preferable.

 [Properties of polyol (1)]

 The hydroxyl value of the polyol (1) used in the present invention is from 5 to 56 mgK〇HZg, more preferably from 10 to 42 mgKOHZg, particularly preferably from 10 to 34 mgKOHZg. If the hydroxyl value is larger than 56 mgKOHZg (low molecular weight), the elasticity of the obtained flexible foam tends to be insufficient, which is not preferable. On the other hand, when the hydroxyl value is less than 5 mgKOHZg, the hardness of the obtained flexible foam is not sufficiently high, which is not preferable.

 The number of hydroxyl groups of the polyol (1) used in the present invention is preferably 2 to 8, more preferably 2.7 to 7, and still more preferably 2.8 to 5.2. If the number of hydroxyl groups is less than 2, the obtained flexible foam tends to be soft, and the durability tends to deteriorate. When the number of hydroxyl groups exceeds 8, the obtained flexible foam becomes hard, and mechanical properties such as elongation tend to deteriorate, which is not preferable.

The degree of unsaturation of the polyol (1) used in the present invention is preferably not more than 0.04 me qZg, more preferably not more than 0.03 me qZg, further preferably not more than 0.025 me qZg, and more preferably not more than 0.02 me qZg. The following are particularly preferred. If the degree of unsaturation is greater than 0.04 meq / g, that is, if there is a large amount of unsaturated monol, the durability and ride comfort of the obtained soft foam are likely to deteriorate, which is not preferable. Here, as an index of the durability of the flexible foam, there are dry heat compression set and wet heat compression set. As the degree of unsaturation increases, the value of the compression set increases, and durability tends to deteriorate. As an index of the ride comfort performance of flexible foam, Movement number. As the resonance frequency decreases, there is a correlation that the transmissibility of 6 Hz that a person feels uncomfortable decreases, which is suitable as an index.

 Further, the primary hydroxylation ratio of the terminal hydroxyl group, which is the ratio of the primary hydroxyl group among the terminal hydroxyl groups of the polyol, derived from the terminal oxyethylene block (1B) portion of the molecular terminal of the polyol (1) used in the present invention. Is preferably 60 mol% or more, more preferably 80 to 95 mol%.

 [Polymer-dispersed polyol]

 The polyol (1) used in the present invention may include a polymer-dispersed polyol. The polymer-dispersed polyol is a dispersion in which polymer fine particles (dispersoid) are stably dispersed in a base polyol (dispersion medium), and the polymer may be an addition-polymerized polymer or a condensation-polymerized polymer. .

 The polymer fine particles in the polymer-dispersed polyol include acrylonitrile, styrene, methyl acrylate, acrylate, and other addition-polymerized polymers such as vinyl polymers and copolymers, or polyester, polyurea, polyurethane, and melamine resins. And the like.

 The presence of the polymer fine particles in the polyol suppresses the hydroxyl value of the polyol to a low value, and is effective in improving physical properties such as hardness and air permeability of the flexible foam. The content of the fine polymer particles in the polymer-dispersed polyol is preferably 50% by mass or less, more preferably 3 to 40% by mass. When the mass of the polyol is used for the calculation, the mass of the polymer particles is not included. '

 [Other polyols]

In the present invention, a flexible foam is produced by reacting the above-mentioned polyol (1) and a polyisocyanate compound in the presence of an amine-based urethanization catalyst having a hydroxyl group in a molecule and a foaming agent. Other polyols may be used in combination as long as the durability and ride comfort performance of the flexible foam are not impaired. Such other polyols include a polyoxyalkylene polyol obtained by ring-opening addition polymerization of an alkylene oxide to an initiator such as a polyhydric alcohol using an alkali metal catalyst, and a polymer using this polyol as a base polyol. Dispersed polyols and the like can be used. The proportion of the other polyol is preferably 40% by mass or less based on the whole polyol compound. [Polyisocyanate compound]

 The polyisocyanate compound used in the present invention is not particularly limited, but is preferably an aromatic, alicyclic, or aliphatic polyisocyanate having two or more isocyanate groups, a mixture of two or more thereof, and Modified polysocyanates obtained by modifying them can be mentioned. Specific examples include tolylene diisocyanate (TD I), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (commonly known as MD I), Polyisocyanates such as xylylene diisocyanate (XD I), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HMD I), and their prepolymer-modified, nurate-modified, and urea derivatives Modified form, carbodiimide modified form and the like. Of these, TD I, MD I, solid MD I, and variants thereof are preferred.

 The amount of polyisocyanate used is usually represented by the isocyanate index (a value represented by 100 times the number of isocyanate groups with respect to the total number of active hydrogens in the polyol, crosslinking agent, etc.). The nate index is preferably from 80 to 120, more preferably from 85 to 110.

 [Blowing agent]

 In the present invention, it is necessary to use at least one foaming agent selected from water and an inert gas. Examples of the inert gas include air, nitrogen, carbon dioxide, and the like, and among them, water is preferably used. The amount of these foaming agents is not particularly limited. When only water is used as the foaming agent, the amount is preferably up to 10 parts by mass with respect to 100 parts by mass of the polyol. More preferably, it is used in an amount of from 8 to 8 parts by mass.

 [Urethanation catalyst]

An amine catalyst having a hydroxyl group in the molecule is used as a urethanizing catalyst when reacting a polyol compound and a polyisocyanate compound. Here, as the specific amine catalyst, an amine compound having only a tertiary amino group as an amino group is preferable. That is, an amine compound having no primary amino group (one NH ₂ ) or secondary amino group (one NRH) (where R is a monovalent organic group) is preferred. New Also, the amine compound preferably has only one hydroxyl group in the molecule. If it has two or more, the activity as a urethanization catalyst tends to decrease, which is not preferable. This is because when there are multiple active hydrogen atoms in the molecule, the reaction with the isocyanate compound takes precedence, and the active site having catalytic activity is fixed in the resin at an early stage of the resination reaction. It is considered that it is difficult to function effectively as a catalyst. The specific amine catalyst preferably has a molecular weight of 300 or less, more preferably 200 or less.

Specific examples of the amine catalyst, N, N-dimethylethanolamine § Min _{[H OCH 2 CH 2 N (} CH 3) 2], N- methyl-N- (dimethyl § amino propyl) § amino ethanol [(CH ₃ ) ₂ NCH ₂ CH ₂ CH ₂ N (CH ₃ ) CH ₂ CH ₂ OH], dimethylaminoethoxyethanol C (CH ₃ ) ₂ NCH ₂ CH ₂ 〇CH ₂ CH ₂ OH], trimethylaminoethylethanolamine [(CH ₃ ) ₂ NCH ₂ CH ₂ N (CH ₃ ) CH ₂ CH ₂ 〇H], N-methyl-N,-(2-hydroxyethyl) -piperazine, dimethylhexanolamine [(CH ₃ ) ₂ N (CH ₂ ) ₆ OH] and the like.

 The amount of the specific amine-based catalyst to be used is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 1 part by mass, per 100 parts by mass of the polyol compound.用 い る By using an amine catalyst having a hydroxyl group in the molecule as the retanning catalyst, the amine catalyst is bonded to the polyurethane resin and the amount of free amine is greatly reduced, so that the fogging problem is less likely to occur.

 The specific amine catalyst and other conventionally known catalysts may be used in combination as the perylene catalyst. Conventionally known catalysts include, for example, tertiary amines such as triethylenediamine, bis (2-dimethylaminoethyl) ether, N, N ,,,, N, tetramethylhexamethylenediamine; Carboxylic acid metal salts such as potassium 1,2-ethylhexanoate; and organic metal compounds such as dibutyltin dilaurate. However, it is preferable not to use a catalyst other than these specific amine catalysts.

 [Foam stabilizer]

Further, a foam stabilizer for forming good air bubbles may be used. As a foam stabilizer There is no particular limitation, and examples thereof include a silicone-based foam stabilizer and a fluorine-based foam stabilizer, but a silicone-based foam stabilizer is preferred.

 [Crosslinking agent]

 In the present invention, a crosslinking agent can also be used. As the crosslinking agent, a compound having two or more active hydrogen-containing groups selected from a hydroxyl group, a primary amino group and a secondary amino group is preferable. Further, the hydroxyl value of the crosslinking agent is preferably 10 OmgKOHZg or more, more preferably 150 mgK / H / g or more, and further preferably 200 mgK〇H / g or more. The number of active hydrogen-containing groups is preferably from 2 to 8.

 Specific examples include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, pen Even erythritol, diglycerin, dextroth, sorby! ^, Sucrose, monoethanolamine, diethanolamine, triethanolamine, bisphenol A, ethylenediamine, 3,5-diethyl-2,4 (or 2 , 6)-diaminotoluene (DETDA), 2-chloro-P-phenylenediamine (CPA), 3,5-bis (methylthio)-1, 2, 4

(Or 2,6) diaminotoluene, 1-trifluoromethyl_3,5-diaminobenzene, 1-trifluoromethyl-4-chloro-1,3,5-diaminobenzene, 2,4 (Or 2,6) —toluenediamine, bis (3,5-dimethyl-4-aminophenyl) methane, 4,4, diaminodiphenylmethane, m-xylylenediamine, 1,4-diaminohexane, 1,3— Examples include compounds such as bis (aminomethyl) cyclohexane and isophoronediamine, and compounds obtained by adding a relatively small amount of alkylenoxide to these compounds. Two or more crosslinking agents may be used in combination.

 [Other additives] '―

In the production of the flexible foam of the present invention, in addition to the above, surfactants such as emulsifiers; anti-aging agents such as antioxidants and ultraviolet absorbers; fillers such as calcium carbonate and barium sulfate; flame retardants, plasticizers, coloring Various known additives and auxiliaries such as agents and antifungal agents can be used as necessary. Flexible foam is a reactive mixture obtained by mixing these Can be produced by molding by the following molding method.

 [Method for producing flexible foam]

 As a method for molding the flexible foam according to the present invention, a method (molding method) of injecting a reactive mixture into a closed mold and performing foam molding is preferable. In particular, a method of directly injecting the reactive mixture into a mold using a low-pressure foaming machine or a high-pressure foaming machine (that is, a reaction injection molding method) is preferable. The flexible foam of the present invention can be produced by either the cold cure method or the hot cure method, but the cold cure method is preferred.

 As a use of the flexible foam produced by the production method according to the present invention, an automobile seat cushion or an automobile seat back is suitable.

(Example)

 Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. The numerical values in the prescription columns in Examples and Comparative Examples represent parts by mass. (Production example of polyol A1)

Starting from a compound having a hydroxyl value of 16 S mgZg obtained by adding propylene oxide to glycerin, zinc hexacyanocobaltate ethylene glycol mono-tert-butyl was added in the presence of 100 g of the initiator. Propylene oxide was reacted at about 120 ° C. using an ether complex catalyst, and then 283 33 g of a mixture of ethylene oxide and propylene oxide containing ethylene oxide at 11.6% by mass was added. The reaction was carried out at about 120 ° C. Next, potassium hydroxide was added to the reaction system to convert the catalyst into a hydration-powered rim. (In the following production examples, as in this production example, the active deactivation treatment of the complex metal cyanide complex catalyst was not performed. The production was completed by reacting 1977 g of ethylene oxide at about 120 ° C. with the use of the hydroxide catalyst. After the completion of the reaction, an adsorbent (synthetic magnesium gayate) treatment was performed to obtain a polyol A1. The ratio of the oxypropylene block chain directly linked to the initiator to the entire polyol A1 was 23% by mass, and the ratio of the oxyalkylene random chain was 43% by mass. The ratio of the amount of oxyethylene in the oxyalkylene random chain was 11.6% by mass, and the terminal oxyethylene block in the entire polyol A1 was 11.6% by mass. The proportion of chains was 17%. The hydroxyl value of the polyol A1 was 27.3 mgKOH / g, the degree of unsaturation was 0.00 OS Sme qZg, and the primary hydroxyl group termination ratio was 87 mol%.

 (Production example of Polyol A2)

 Using a compound having a hydroxyl value of 168 mg Zg obtained by adding propylene oxide to glycerin as an initiator, 1497 g of propylene oxide using a zinc hexacyanocobalt tert-butyl alcohol complex catalyst in the presence of 1000 g of the initiator Was reacted at about 120 ° C., and then 2800 g of a mixture of ethylene oxide and propylene oxide containing 11.6% by mass of ethylene oxide was reacted at about 12 O :. Next, a hydroxylating lime was added to the reaction system to convert the catalyst into a hydroxylating lime. Using this potassium hydroxide catalyst, 1087 g of ethylene oxide was reacted at about 120 ° C. to complete the production. After the completion of the reaction, an adsorbent (synthetic magnesium silicate) treatment was performed to obtain polyol A2.

 The ratio of the oxypropylene block chain directly linked to the initiator to the entire polyol A2 was 23% by mass, and the ratio of the oxyalkylene random chain was 43% by mass. The ratio of the amount of oxyethylene in the oxyalkylene random chain was 11.6% by mass, and the ratio of the terminal oxyethylene block chain in the entire polyol A2 was 17%. The hydroxyl value of the polyol A2 was 27.OmgKOH g, the degree of unsaturation was 0.000 Tme qZg, and the primary hydroxylation ratio of terminal hydroxyl groups was 89% by mole.

 (Production example of Polyol B)

 In the presence of 1000 g of glycerin as an initiator, 4358 g of propylene oxide is reacted at about 120 ° C. using a potassium hydroxide catalyst, and then 1097 g of ethylene oxide is added at about 120 ° C. using a potassium hydroxide catalyst. After the reaction, the mixture was treated with an adsorbent (synthetic magnesium silicate) to obtain polyol B.

The proportion of the oxypropylene block chain directly linked to the initiator in the whole polyol B was 83% by mass, and the proportion of the oxyethylene block chain in the whole polyol B was 17% by mass. The hydroxyl value of polyol B is 28 mgKOH / g, the degree of unsaturation is 0.06 meqZg, and the primary hydroxyl group terminal degree is 87 mol. %Met.

 (Production example of polyol C)

 Polyol B was used as a base polyol, and acrylonitrile Z-styrene copolymer microparticles were dispersed therein in an amount of 20% by mass and Polyol B in an amount of 80% by mass to obtain Polyol C.

 (Examples 1-6)

 A mixture of a polyol, a urethane-forming catalyst, a foaming agent, and a foam stabilizer in the formulation shown in Table 1 and a polyisocyanate compound were each adjusted to a liquid temperature of 25 ± 1, and the mixture was added to the mixture. The isocyanate compound was added so that the isocyanate index became 100, and the mixture was stirred and mixed with a high-speed mixer for 5 seconds, and immediately heated to 65 ° C and immediately placed in an aluminum mold having a height of 40 Omm and a height of 10 Omm. Injected and sealed. After curing for 6 minutes, the flexible foam was taken out of the mold and allowed to stand for 24 hours or more before measuring various physical properties. The results are shown in Table 1. Examples 1 to 3 are working examples and examples 4 to 7 are comparative examples.

Cure property was used as an index for evaluation of moldability. The softness of the obtained flexible foam was evaluated by compressing the foam with a finger 30 seconds after demolding and evaluating the degree of deformation recovery in three steps (〇: completely recovered, △: incomplete) Recovers, X: hardly recovers). The specifications used for measuring the physical properties of the flexible foam are shown below. Core density (unit: kgZm ³ ), 25% hardness (I LD) (unit: NZ 314m ² ), core rebound resilience (unit:%), tear strength (unit: NZcm), tensile strength (unit: kPa) ), Elongation (unit:%), dry heat compression set (unit:%), wet heat compression set (unit:%) conform to JIS K6400. The resonance frequency (unit: Hz) and the resonance transmissibility (vibration transmissibility at resonance frequency (unit: none) are as follows: JASO B407-87 (excitation amplitude: ± 2.5 mm, excitation plate: Tekken type, load) : Method according to 490 N).

 The fogging property was measured by the mass method and the haze test (light transmission method) according to the following.

Mass method: Place the sample (size = 5 OmmX 5 Om mX l Omm) dried in a desiccator for 24 hours in a clean glass bottle with a diameter of 47 mm, and place it on the top with a glass plate. Seal the, 110 ^D heated C in 3 hours, and the amount of volatile components obtained from the mass of the glass plate before and after the test the weight of the substance adhering to the glass play Bok set at the mouth of the container (mg).

Light transmission method: A sample (size = 50mmX5OmmX10mm) dried in a desiccator for 24 hours is placed in a clean glass bottle with a diameter of 47mm and a total light transmittance of 0.4% or less, and the upper part is sealed with a glass plate. The glass plate was heated at 80 ° C for 20 hours, and the reduction rate (%) of the total light transmittance of the glass plate before and after the test was measured.

 (table 1)

 The catalyst, foam stabilizer, cross-linking agent, and salt compound used in Table 1 are as follows.

Catalyst 1: A solution of triethylenediamine in dipropylene glycol (Tosoichi Co., Ltd. Product name TEDA L 33).

Catalyst 2: a solution of bis [(2-dimethylamino) ethyl] ether in dipropylene glycol (Toyo Corporation, trade name Toy0cat ET).

Catalyst 3: Trimethylaminoethylethanolamine (trade name Dabco T, manufactured by Air Products).

Catalyst 4: Dimethylhexanolamine (Kaolyzer I No. 25, manufactured by Kao Corporation)

) o

Foam stabilizer: Silicon foam stabilizer (manufactured by Nippon Tunicer, trade name 5309).

Crosslinking agent 1: 900 g of propylene oxide and then 400 g of ethylene oxide are reacted using potassium hydroxide catalyst in the presence of 180 g of sorbitol as an initiator, and after the reaction, adsorbent treatment and filtration are performed. Polyol with a hydroxyl value of 45 OmgKOHZg.

Crosslinking agent 2: diethanolamine.

Isocyanate: TD I-80 (2,4-I TD I / 2, 6-TD 1 = 80Z20 mass% mixture) Zcrew MD 1 = 80/20 mass% mixture, isocyanate group content 44.8 mass% (Japan Made by Polyurethane Industry, trade name Coronate C-1 1021).

 In Example 4, a polyol obtained by ring-opening addition polymerization with a conventional hydroxylating realm catalyst and a polysocyanate compound were urethanized with a non-reactive amine catalyst, and the amine catalyst was volatilized. Poor fogging properties. In addition, the polyol has a relatively high degree of unsaturation and a large permanent set under wet heat compression, indicating poor durability.

 In Examples 5 and 6, the reaction type amine-based catalyst is used, so that it has excellent low fogging properties. However, since a polyol obtained by ring-opening addition polymerization with a conventional potassium hydroxide catalyst is used, the degree of unsaturation of the polyol is relatively high, and the catalytic activity in the latter half of the reaction is low, resulting in poor curing. Since it is sufficient, the mold releasability (curing property) is insufficient, the hardness is low by 25%, the wet heat compression set is large, and the durability is poor.

Example 7 uses a polyol using a double metal cyanide complex catalyst, Although it has excellent wet heat compression set and 25% hardness, it is inferior in low fogging property due to volatilization of amine catalyst because it is urethanized with non-reactive amine catalyst.

 On the other hand, in Examples 1 to 3 (Examples), since a reactive amine-based catalyst is used, excellent low fogging properties are obtained. In addition, the use of a polyol produced using a complex metal cyanide complex catalyst has the drawbacks of lowering the catalytic activity, insufficient curing, and poor durability at the latter stage of the reaction when using a reactive amine catalyst. As a result, a flexible foam excellent in curability and durability can be obtained even when a reactive amine catalyst is used. Industrial applicability

 According to the method for producing a flexible polyurethane foam of the present invention, a flexible foam having excellent low fogging properties can be obtained by using a reactive amine catalyst. Moreover, even when a reactive amine catalyst is used, a flexible foam having excellent curability and excellent durability can be obtained while suppressing the disadvantages of insufficient curing and poor durability.

Claims

The scope of the claims  1. A method for producing a flexible polyurethane foam by reacting a polyol compound and a polyisocyanate compound in the presence of a urethanization catalyst and a foaming agent, wherein the amine catalyst having a hydroxyl group in the molecule is used as the ureation catalyst. An oxyalkylene random chain (1A) formed by random ring-opening addition polymerization of ethylene oxide and an alkylene oxide having 3 or more carbon atoms using a double metal cyanide complex catalyst as a polyol compound; And a polyol (1) having a terminal oxyethylene block chain (1 B) formed by ring-opening addition polymerization of ethylene oxide using an alkali metal catalyst and having a hydroxyl value of 5 to 56 mg KOHZg. Method for producing flexible polyurethane foam characterized by using 2. In the formation of the oxyalkylene random chain (1A), the ratio of the ethylene oxide which has been subjected to the ring-opening addition polymerization to the alkylene oxide having 3 or more carbon atoms is represented by mass ratio. The method for producing a flexible polyurethane foam according to claim 1, wherein the ratio is 3/97 to 35/65.  3. The polyol (1) is a mixture of an alkylene oxide having 3 or more carbon atoms between an initiator residue (1 S) and an oxyalkylene random chain (1A) using a double metal cyanide complex catalyst. The method for producing a flexible polyurethane foam according to claim 1 or 2, having an oxyalkylene block chain (1P) formed by ring-opening addition polymerization of a seed.  4. The method for producing a flexible polyurethane foam according to claim 1, wherein the degree of unsaturation of the polyol (1) is 0.04 me QZg or less.  5. The method for producing a flexible polyurethane foam according to claim 1, wherein the polyol compound comprises a polymer-dispersed polyol.  6. The flexible polyurethane foam according to any one of claims 1 to 5, wherein the urethane-forming catalyst is an amine catalyst having only a tertiary amino group as an amino group and having only one hydroxyl group in a molecule. Production method. ' 7. The method for producing a flexible polyurethane foam according to any one of claims 1 to 6, wherein the flexible polyurethane foam is produced by foam molding in a sealed mold. 8. The method for producing a flexible polyurethane foam according to any one of claims 1 to 7, wherein the application of the flexible polyurethane foam is an automobile seat cushion or an automobile seat back.