JP7219135B2 - Expandable polyurethane composition and polyurethane foam - Google Patents

Description

The present invention relates to expandable polyurethane compositions and polyurethane foams, and more particularly to expandable polyurethane compositions and polyurethane foams comprising the expandable polyurethane compositions.

Polyurethane foams are obtained by reacting a polyisocyanate component and a polyol component in the presence of a catalyst and a blowing agent, and are used in a wide variety of fields.

As a polyurethane foam, for example, a low-resilience urethane foam obtained by reacting a urethane foam composition containing a polyol (a), a polyisocyanate (b), a catalyst (c), and a blowing agent (d) has been proposed. More specifically, 40 parts by mass of a polyoxyalkylene polyol having an average functional group number of about 3 and a hydroxyl value of 34 mgKOH/g and 60 parts by mass of a polyoxyalkylene polyol having an average functional group number of about 3 and a hydroxyl value of 210 mgKOH/g A low-resilience polyurethane foam with a density of about 60 kg/m ³ obtained by reacting and foaming parts by weight of toluene diisocyanate with 36.2 parts by weight of toluene diisocyanate in the presence of 1.5 parts by weight of water has been proposed. (See, for example, Patent Document 1 (Example 4).).

JP-A-11-286566

On the other hand, polyurethane foams are required to have an excellent tactile feel (moist feeling) depending on the application.

In order for a polyurethane foam to have an excellent tactile feel (moist feeling), it is required that the polyurethane foam have an appropriate thickness, a relatively high density, and a small cell diameter.

However, in the polyurethane foam described in Patent Document 1, since the polyisocyanate component is tolylene diisocyanate, which is highly reactive, the cream time during foaming is relatively short. There is a problem that it becomes difficult and the cell diameter becomes large.

In addition, since the content of water as a foaming agent is relatively high, a large number of air bubbles are generated in the polyurethane foam, resulting in a low density.

In response to these, for example, it is considered to increase the density of polyurethane foam and reduce the cell diameter by a method that does not use water as a foaming agent (for example, mechanical froth foaming method). Such a method results in a thin polyurethane foam.

The present invention provides an expandable polyurethane composition from which a polyurethane foam having excellent tactile sensation can be obtained, and a polyurethane foam comprising the expandable polyurethane foam.

The present invention [1] is a foamable polyurethane composition comprising a polyisocyanate component, a polyol component, and a foaming agent containing water, wherein the polyisocyanate component comprises bis(isocyanatomethyl)cyclohexane, The polyol component includes a first polyol having an average functionality of 1.5 to 4.5 and a hydroxyl value of 20 to 70 mgKOH/g, and a second polyol having an average functionality of 1.5 to 4.5 and a hydroxyl value of 140 to 300 mgKOH/g. and a polyol, and the water content is 0.6 parts by mass or more and 1.0 parts by mass or less with respect to 100 parts by mass of the polyol component.

The present invention [2] is the foaming property according to [1] above, wherein the polyisocyanate component contains 1,3-bis(isocyanatomethyl)cyclohexane and 1,4-bis(isocyanatomethyl)cyclohexane. It contains a polyurethane composition.

The present invention [3] comprises the foamable polyurethane composition according to [1] or [2] above, wherein the polyisocyanate component and the polyol component are reacted and foamed in the presence of the foaming agent. Contains polyurethane foam.

The present invention [4] includes a polyurethane foam having a density of 100 kg/m ³ or more and 200 kg/m ³ or less and an average cell diameter of 200 μm or more and 350 μm or less.

The present invention [5] includes the polyurethane foam according to [4] above, which has a thickness of 30 mm or more.

In the foamable polyurethane composition of the present invention, since the polyisocyanate component contains bis(isocyanatomethyl)cyclohexane, the reactivity is lower than that of tolylene diisocyanate, and the cream time during foaming is relatively long. It is easy to remove air bubbles from the polyurethane resin, and the cell diameter can be reduced.

In addition, since the foamable polyurethane composition of the present invention has a relatively low water content, it is possible to reduce the amount of air bubbles in the polyurethane foam and increase the density of the polyurethane foam.

Furthermore, in the foamable polyurethane composition of the present invention, the polyurethane resin is foamed (chemically foamed) with water, so that a thicker polyurethane foam can be obtained than by a mechanical froth foaming method or the like.

Therefore, the polyurethane foam of the present invention has an appropriate thickness, a relatively high density, and a small cell diameter (cell diameter).

As a result, according to the polyurethane foam of the present invention, excellent tactile sensation can be obtained.

The polyurethane foam of the present invention is a reaction product (foam) of a foamable polyurethane composition containing a polyisocyanate component, a polyol component and a blowing agent.

More specifically, polyurethane foam is obtained by reacting and foaming a polyisocyanate component and a polyol component in the presence of a foaming agent (and optionally a catalyst (described later)).

The polyisocyanate component contains bis(isocyanatomethyl)cyclohexane as an essential component.

Bis(isocyanatomethyl)cyclohexane includes 1,2-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, and these can be used alone or in combination of two or more.

Moreover, bis(isocyanatomethyl)cyclohexane can also be prepared as a modified form within a range that does not impair the excellent effects of the present invention.

Modified forms of bis(isocyanatomethyl)cyclohexane include, for example, bis(isocyanatomethyl)cyclohexane oligomers (dimers (e.g., uretdione modified forms), trimers (e.g., isocyanurate modified forms, iminooxadiazinedione modified product, etc.), biuret modified product (e.g., biuret modified product produced by the reaction of bis (isocyanatomethyl) cyclohexane and water), allophanate modified product (e.g., bis (isocyanatomethyl) cyclohexane and monovalent Allophanate modified products produced by reaction with alcohols or dihydric alcohols, etc.), polyol modified products (for example, polyol modified products (adducts) produced by reaction of bis(isocyanatomethyl)cyclohexane and trihydric or higher alcohols, etc. ), modified oxadiazinetrione (e.g., oxadiazinetrione produced by reaction of bis(isocyanatomethyl)cyclohexane and carbon dioxide), modified carbodiimide (e.g., decarboxylation of bis(isocyanatomethyl)cyclohexane carbodiimide-modified products produced by condensation reaction, etc.).

Bis(isocyanatomethyl)cyclohexane is preferably 1,3-bis(isocyanatomethyl)cyclohexane from the viewpoint of reducing the cell diameter of the polyurethane foam, and from the viewpoint of increasing the density of the polyurethane foam, 1,4-bis(isocyanatomethyl)cyclohexane is preferred.

From the viewpoint of balancing the cell diameter and density of the polyurethane foam, the combination of 1,3-bis(isocyanatomethyl)cyclohexane and 1,4-bis(isocyanatomethyl)cyclohexane is more preferred.

In other words, the polyisocyanate component includes 1,3-bis(isocyanatomethyl)cyclohexane and 1,4-bis(isocyanatomethyl)cyclohexane.

If the polyisocyanate component contains 1,3-bis(isocyanatomethyl)cyclohexane and 1,4-bis(isocyanatomethyl)cyclohexane, a polyurethane foam having a small cell diameter and a high density can be obtained. It is possible to improve the tactile sensation.

The combined ratio of 1,3-bis(isocyanatomethyl)cyclohexane and 1,4-bis(isocyanatomethyl)cyclohexane is 100 parts by mass of the total amount of 1,3-bis(isocyanatomethyl) Cyclohexane is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 40 parts by mass or more, for example 90 parts by mass or less, preferably 80 parts by mass parts or less, more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less. Further, 1,4-bis(isocyanatomethyl)cyclohexane is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 40 parts by mass or more, For example, it is 90 parts by mass or less, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less.

In addition, the polyisocyanate component can contain other polyisocyanate as an optional component within a range that does not impair the excellent effects of the present invention.

Other polyisocyanates are polyisocyanates excluding bis(isocyanatomethyl)cyclohexane, such as aliphatic polyisocyanates (excluding bis(isocyanatomethyl)cyclohexane), aromatic polyisocyanates, araliphatic polyisocyanates, etc. can be included as an optional ingredient.

Examples of aliphatic polyisocyanates include ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), octamethylene diisocyanate, nonamethylene diisocyanate, and 2,2'-dimethylpentane diisocyanate. , 2,2,4-trimethylhexane diisocyanate, decamethylene diisocyanate, butene diisocyanate, 1,3-butadiene-1,4-diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 1,6,11-undecamethylene triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,8-diisocyanato-4-isocyanatomethyloctane, 2,5,7-trimethyl-1,8-diisocyanato-5-isocyanatomethyloctane, bis( isocyanatoethyl) carbonate, bis(isocyanatoethyl) ether, 1,4-butylene glycol dipropyl ether-ω,ω'-diisocyanate, lysine isocyanatomethyl ester, lysine triisocyanate, 2-isocyanatoethyl-2,6 - chain aliphatic diisocyanates such as diisocyanatohexanoate, 2-isocyanatopropyl-2,6-diisocyanatohexanoate, bis(4-isocyanato-n-butylidene)pentaerythritol, 2,6-diisocyanatomethylcaproate etc.

Aliphatic polyisocyanates also include alicyclic polyisocyanates (excluding bis(isocyanatomethyl)cyclohexane).

Alicyclic polyisocyanates (excluding bis(isocyanatomethyl)cyclohexane) include, for example, isophorone diisocyanate (IPDI), trans, trans-, trans, cis- and cis, cis-dicyclohexylmethane diisocyanate and mixtures thereof (hydrogenated MDI), 1,3- or 1,4-cyclohexane diisocyanate and mixtures thereof, 1,3- or 1,4-bis(isocyanatoethyl) cyclohexane, methylcyclohexane diisocyanate, 2,2′-dimethyldicyclohexyl methane diisocyanate, dimer acid diisocyanate, 2,5-diisocyanatomethylbicyclo[2,2,1]-heptane, its isomer 2,6-diisocyanatomethylbicyclo[2,2,1]-heptane ( NBDI), 2-isocyanatomethyl 2-(3-isocyanatopropyl)-5-isocyanatomethylbicyclo-[2,2,1]-heptane, 2-isocyanatomethyl-2-(3-isocyanatopropyl) -6-isocyanatomethylbicyclo-[2,2,1]-heptane, 2-isocyanatomethyl 3-(3-isocyanatopropyl)-5-(2-isocyanatoethyl)-bicyclo-[2,2, 1]-heptane, 2-isocyanatomethyl 3-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)-bicyclo-[2,2,1]-heptane, 2-isocyanatomethyl 2-( 3-isocyanatopropyl)-5-(2-isocyanatoethyl)-bicyclo-[2,2,1]-heptane, 2-isocyanatomethyl 2-(3-isocyanatopropyl)-6-(2-isocyanate Natoethyl)-bicyclo-[2,2,1]-heptane and other alicyclic diisocyanates.

Aromatic polyisocyanates include, for example, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, and isomer mixtures of these tolylene diisocyanates (TDI), 4,4′-diphenylmethane diisocyanate, 2,4 '-diphenylmethane diisocyanate and 2,2'-diphenylmethane diisocyanate, and any isomer mixture (MDI) of these diphenylmethane diisocyanates, aromatic diisocyanates such as toluidine diisocyanate (TODI), paraphenylene diisocyanate, naphthalene diisocyanate (NDI), etc. mentioned.

Examples of araliphatic polyisocyanates include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof (XDI), 1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof (TMXDI), etc. and araliphatic diisocyanates.

These and other polyisocyanates can be used alone or in combination of two or more.

In addition, other polyisocyanates can be prepared as modified products as long as they do not impair the excellent effects of the present invention.

Examples of other modified polyisocyanates include polymers of other polyisocyanates (dimers, trimers, etc.), biuret modified products, allophanate modified products, polyol modified products, oxadiazinetrione modified products, carbodiimide modified products, etc. mentioned.

When other polyisocyanate is contained, the content is, for example, 50% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less, relative to the total amount of the polyisocyanate component.

As polyisocyanate component, preferably bis(isocyanatomethyl)cyclohexane is used alone. More preferably, the polyisocyanate component consists of bis(isocyanatomethyl)cyclohexane, more preferably 1,3-bis(isocyanatomethyl)cyclohexane and 1,4-bis(isocyanatomethyl)cyclohexane. .

A polyol component is a component containing a compound having two or more hydroxyl groups in the molecule. More specifically, the polyol component includes a first polyol having an average functionality of 1.5 to 4.5 and a hydroxyl value of 20 to 70 mgKOH/g, and an average functionality of 1.5 to 4.5 and a hydroxyl value of 140 to 300 mgKOH. / g of the second polyol, preferably consisting of the first polyol and the second polyol.

Examples of the first polyol include macropolyols such as polyoxyalkylene polyols, vinyl polymer-containing polyoxyalkylene polyols, polyester polyols, and polyoxyalkylene polyester block copolymer polyols.

Polyoxyalkylene polyols can be obtained, for example, by subjecting alkylene oxides to addition polymerization using water, alcohols, amines, ammonia, or the like as initiators.

Examples of alcohols as initiators include monohydric alcohols such as methanol and ethanol, dihydric alcohols such as ethylene glycol and propylene glycol, trihydric alcohols such as glycerin and trimethylolpropane, and pentaerythritol. monohydric or polyhydric alcohols such as tetrahydric alcohols such as, for example, hexahydric alcohols such as sorbitol, and octahydric alcohols such as sucrose.

Amines as initiators include, for example, monovalent amines such as dimethylamine and diethylamine; divalent amines such as methylamine and ethylamine; trivalent amines such as monoethanolamine, diethanolamine and triethanolamine; Examples include tetravalent amines such as ethylenediamine, and monovalent or polyvalent amines such as pentavalent amines such as diethylenetriamine.

These initiators can be used alone or in combination of two or more.

Examples of alkylene oxide include ethylene oxide, propylene oxide (1,2-propylene oxide), 1,3-propylene oxide (1,3-trimethylene oxide), 1,2-butylene oxide and 1,3-butylene oxide. , 1,4-butylene oxide and 2,3-butylene oxide.

These alkylene oxides can be used alone or in combination of two or more.

When an alkylene oxide is used in combination, either addition form of block polymerization or random polymerization can be appropriately selected.

Preferred alkylene oxides include ethylene oxide and 1,2-propylene oxide.

The alkylene oxide used for producing the polyoxyalkylene polyol corresponds to the oxyalkylene group in the polyoxyalkylene polyol. For example, polyoxyalkylene polyols obtained using ethylene oxide contain oxyethylene groups as oxyalkylene groups. Moreover, the polyoxyalkylene polyol obtained using propylene oxide contains an oxypropylene group as the oxyalkylene group.

The vinyl polymer-containing polyoxyalkylene polyol is obtained by polymerizing a vinyl monomer (e.g., acrylonitrile, styrene, etc.) in the presence of radicals in the above-exemplified polyoxyalkylene polyols to stably disperse the vinyl polymer. mentioned.

The content of the vinyl polymer is, for example, 15 to 45 parts by mass with respect to 100 parts by mass as the total amount of the polyoxyalkylene polyol and the vinyl polymer.

Polyester polyols include, for example, polycondensates obtained by reacting the above polyhydric alcohols (preferably dihydric to hexahydric alcohols) and polybasic acids under known conditions.

Examples of polybasic acids include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, and 3-methyl-3-ethylglutaric acid. , azelaic acid, saturated aliphatic dicarboxylic acids (C11-13) such as sebacic acid, unsaturated aliphatic dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, toluene Dicarboxylic acids, aromatic dicarboxylic acids such as naphthalene dicarboxylic acid, alicyclic dicarboxylic acids such as hexahydrophthalic acid, other carboxylic acids such as dimer acid, hydrogenated dimer acid, het acid, and their carboxylic acids Acid anhydrides derived from acids such as oxalic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, 2-alkyl (C12-C18) succinic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, and also includes acid halides derived from these carboxylic acids, such as oxalic acid dichloride, adipic acid dichloride, sebacic acid dichloride, and the like. These polybasic acids can be used alone or in combination of two or more.

Examples of polyoxyalkylene polyester block copolymer polyols include polyols obtained by blocking polyester chains in polyoxyalkylene polyols, as described in JP-B-48-10078.

A polyoxyalkylene polyester block copolymer polyol can be obtained, for example, by reacting a polyoxyalkylene polyol with a polycarboxylic anhydride and an alkylene oxide.

These first polyols can be used alone or in combination of two or more.

The first polyol preferably includes a polyoxyalkylene polyol.

When the first polyol is a polyoxyalkylene polyol, the alkylene oxide preferably includes ethylene oxide and 1,2-propylene oxide, more preferably 1,2-propylene oxide.

That is, in the first polyol, preferably the oxyalkylene group in the polyoxyalkylene polyol consists of an oxypropylene group.

That is, the first polyol is preferably polyoxypropylene polyol.

The average number of functional groups (average number of hydroxyl groups) of the first polyol is 1.5 or more, preferably 2.0 or more, more preferably 2.5 or more, and 4.5 or less, preferably 4.0 or less. , more preferably 3.5 or less.

The hydroxyl value of the first polyol is 20 mgKOH/g or more, preferably 25 mgKOH/g or more, more preferably 30 mgKOH/g or more, and 70 mgKOH/g or less, preferably 65 mgKOH/g or less, more preferably 60 mgKOH/g. / g or less.

The number average molecular weight (standard polystyrene equivalent molecular weight by GPC measurement) of the first polyol is, for example, 1200 or more, preferably 3600 or more, more preferably 4200 or more, for example, 13000 or less, preferably 10000 or less, or more. Preferably, it is 7000 or less.

Examples of the second polyol include macropolyols such as the above polyoxyalkylene polyols, the above vinyl polymer-containing polyoxyalkylene polyols, the above polyester polyols, and the above polyoxyalkylene polyester block copolymer polyols.

These second polyols can be used alone or in combination of two or more.

The second polyol preferably includes a polyoxyalkylene polyol.

When the second polyol is a polyoxyalkylene polyol, the alkylene oxide preferably includes ethylene oxide and 1,2-propylene oxide, more preferably a combination of ethylene oxide and 1,2-propylene oxide. be done.

That is, in the second polyol, the oxyalkylene group in the polyoxyalkylene polyol preferably has both an oxyethylene group and an oxypropylene group.

That is, the second polyol is preferably a polyoxyethylene/polyoxypropylene (block/random) copolymer. More preferred is a polyoxyethylene/polyoxypropylene (block/random) copolymer having an oxyethylene group at the molecular end. In other words, the second polyol preferably includes a polyoxypropylene polyol having an oxyethylene group at the molecular end.

The ratio of the oxyethylene group and the oxypropylene group is, with respect to the total amount thereof, the oxyethylene group is, for example, 10% by mass or more, preferably 20% by mass or more, for example, 50% by mass or less, preferably , 40% by mass or less. Also, the oxypropylene group is, for example, 50% by mass or more, preferably 60% by mass or more, and is, for example, 90% by mass or less, preferably 80% by mass or less.

The average number of functional groups (average number of hydroxyl groups) of the second polyol is 1.5 or more, preferably 2.0 or more, more preferably 2.5 or more, and 4.5 or less, preferably 4.0 or less. , more preferably 3.5 or less.

The hydroxyl value of the second polyol is 140 mgKOH/g or more, preferably 160 mgKOH/g or more, more preferably 200 mgKOH/g or more, and 300 mgKOH/g or less, preferably 280 mgKOH/g or less, more preferably 270 mgKOH/g. / g or less.

The number average molecular weight (standard polystyrene equivalent molecular weight by GPC measurement) of the second polyol is, for example, 280 or more, preferably 450 or more, more preferably 600 or more, for example, 1800 or less, preferably 1000 or less, or more. Preferably, it is 850 or less.

By using the first polyol and the second polyol together as the polyol component, it is possible to obtain a polyurethane foam having a relatively high density and a small cell diameter (cell diameter), and excellent tactile sensation. can be obtained.

The ratio of the first polyol and the second polyol used in combination is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 25 parts by mass with respect to 100 parts by mass of the total amount of the first polyol. For example, it is 80 parts by mass or less, preferably 60 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 35 parts by mass or less. Further, the second polyol is, for example, 20 parts by mass or more, preferably 40 parts by mass or more, more preferably 60 parts by mass or more, still more preferably 65 parts by mass or more, for example 90 parts by mass or less, preferably is 80 parts by mass or less, more preferably 75 parts by mass or less.

If the combined ratio of the first polyol and the second polyol is within the above range, a polyurethane foam having a relatively high density and a small cell diameter (cell diameter) can be obtained, and excellent tactile sensation can be obtained. can.

A foaming agent contains water as a main component.

In addition, as a blowing agent, physical blowing agents (e.g., halogenated hydrocarbons (e.g., methylene chloride, etc.), hydrocarbons (e.g., cyclopentane, etc.), carbon dioxide gas, liquefied carbon dioxide gas, etc.) and can be used together in an appropriate ratio.

The content of water is, for example, 50 parts by mass or more, preferably 80 parts by mass or more, more preferably 95 parts by mass or more, and most preferably 100 parts by mass with respect to the total amount of the foaming agent.

That is, the blowing agent preferably consists of water.

In addition, the content of water is 0.6 parts by mass or more, preferably 0.65 parts by mass or more, more preferably 0.70 parts by mass or more with respect to 100 parts by mass of the polyol component, and 1.0 Part by mass or less, preferably 0.95 part by mass or less, more preferably 0.90 part by mass or less.

If the water content is below the above lower limit, the density of the polyurethane foam becomes excessively high, resulting in poor tactile sensation.

On the other hand, if the content of water exceeds the above upper limit, the density of the polyurethane foam becomes excessively low and the average cell diameter also becomes large, resulting in poor tactile sensation.

On the other hand, when the content of water is within the above range, an appropriate density and average cell diameter can be obtained, and excellent tactile sensation can be obtained.

Moreover, the foamable polyurethane composition can further contain a catalyst, if desired.

Examples of the catalyst include known urethanization catalysts such as amines and organometallic compounds.

Examples of amines include tertiary amines such as triethylamine, triethylenediamine, bis-(2-dimethylaminoethyl)ether and N-methylmorpholine; quaternary ammonium salts such as tetraethylhydroxyammonium; imidazole; and imidazoles such as 2-ethyl-4-methylimidazole. These amines can be used alone or in combination of two or more.

In addition, these amines are commercially available. 31 (manufactured by Kao Corporation), Kaorizer No. 120 (manufactured by Kao Corporation), Kaorizer No. 12 (manufactured by Kao Corporation), Kaorizer No. 25 (manufactured by Kao Corporation), DABCO 33LV (33 mass% diethylene glycol solution of triethylenediamine, manufactured by EVONIK), Niax A-1 (manufactured by Momentive Performance Materials Japan LLC (hereinafter referred to as "manufactured by Momentive") )), TOYOCAT-NCE (manufactured by Tosoh Corporation), and the like.

Examples of organometallic compounds include tin acetate, tin octoate, tin oleate, tin laurate, dibutyltin diacetate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dimercaptide, dibutyltin maleate, dibutyltin dineodecano. organotin compounds such as ate, dioctyltin dimercaptide, dioctyltin dilaurate, dibutyltin dichloride; organolead compounds such as lead octanoate and lead naphthenate; organonickel compounds such as nickel naphthenate; organic cobalt compounds such as, for example, copper octenoate and other organic copper compounds, and organic bismuth compounds such as bismuth octylate and bismuth neodecanoate. These organometallic compounds can be used alone or in combination of two or more.

In addition, these organometallic compounds can be obtained as commercial products. Fomrez UL-28 (organotin compound, manufactured by Momentive), Stanoct (organotin compound, manufactured by Mitsubishi Chemical Corporation), and the like.

These catalysts (amines and organometallic compounds) can be used alone or in combination of two or more. Preferably, amines and organometallic compounds are used in combination.

The blending ratio of the catalyst (converted to 100% active ingredient amount) is, for example, 0.1 parts by mass or more, preferably 0.3 parts by mass or more, more preferably 1.0 parts by mass with respect to 100 parts by mass of the polyol component. parts or more, and for example, 5 parts by mass or less, preferably 3 parts by mass or less.

If the blending ratio of the catalyst is within the above range, the non-yellowing property of the obtained polyurethane foam can be improved.

Further, when amines and organometallic compounds are used together as a catalyst, the ratio of the blending ratio of amines and organometallic compounds (mixing ratio of amines / blending ratio of organometallic compounds, converted to 100% active ingredient amount ) is, for example, 0.1 or more, preferably 0.5 or more, and is, for example, 5 or less, preferably 2 or less.

In order to produce the polyurethane foam of the present invention, first, the above polyol component and the above foaming agent (and, if necessary, the above catalyst) are blended in the above blending ratio to form a premix (resin premix). ) is prepared.

Moreover, in the preparation of the premix, additives such as foam stabilizers and stabilizers can be blended, if necessary.

Preferably, a premix is prepared from the polyol component described above, the catalyst described above, the blowing agent, foam stabilizer and stabilizer described above.

The foam stabilizer is not particularly limited, and includes known foam stabilizers such as silicone foam stabilizers. These foam stabilizers can be used alone or in combination of two or more.

The blending ratio of the foam stabilizer is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and for example, 5 parts by mass or less, preferably 2 parts by mass, with respect to 100 parts by mass of the polyol component. It is below the department.

Stabilizers include, for example, antioxidants, ultraviolet absorbers, heat stabilizers, light stabilizers, and the like, preferably antioxidants and light stabilizers.

Antioxidants include, for example, hindered phenol antioxidants (e.g., 4-methyl-2,6-di-tert-butylphenol (BHT), triethylene glycol-bis[3-(3-t-butyl- 5-methyl-4-hydroxyphenyl)propionate], pentaerythritol tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], etc.), other antioxidants (e.g., bis(2 ,4-di-t-butylphenyl)pentaerythritol diphosphite, tridecyl phosphite, tris(2-ethylhexyl)phosphite and other phosphorous antioxidants such as 2,5-thiophenediylbis(5-t- butyl-1,3-benzoxazole) excluding hindered phenol antioxidants such as thiophene antioxidants).

These antioxidants can be used alone or in combination of two or more.

Examples of the ultraviolet absorber include benzophenone-based, benzotriazole-based, triazine-based, and cyanoacrylate-based ultraviolet absorbers.

These ultraviolet absorbers can be used alone or in combination of two or more.

Examples of heat stabilizers include compounds containing sulfonamide groups.

The compound containing a sulfonamide group includes, for example, aromatic sulfonamides, aliphatic sulfonamides and the like, preferably o-toluenesulfonamide.

These heat stabilizers can be used alone or in combination of two or more.

Examples of light stabilizers include hindered amine light stabilizers, blend light stabilizers, and the like, preferably hindered amine light stabilizers. Hindered amine-based light stabilizers include, for example, Adekastab LA62, Adekastab LA67 (manufactured by Adeka Argas Chemicals, trade names), Tinuvin 765, Tinuvin 144, Tinuvin 770, Tinuvin 622 (manufactured by BASF Japan, products name), etc.

These light stabilizers can be used alone or in combination of two or more.

The blending ratio of the stabilizer is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass, with respect to 100 parts by mass of the polyol component. It is below.

In addition to the above additives, the premix may further include, if necessary, for example, a cross-linking agent, a communication agent, a pigment (coloring pigment), a dye, a curing accelerator, a matting agent, an adhesion-imparting agent, a silane cup. Other known additives such as a ring agent can be blended in an appropriate proportion within a range that does not impair the excellent effects of the present invention.

In addition, other known additives such as chain extenders, antifoaming agents, plasticizers, antiblocking agents, release agents, lubricants, fillers, hydrolysis inhibitors, etc. can be used to achieve the excellent effects of the present invention. It can also be blended in an appropriate ratio within a range that does not impair the.

Then, the premix obtained in this way and the polyisocyanate component are mixed and reacted, and foamed by a known foaming method such as a slab method, a mold method, a spray method, etc., to obtain the present invention. Obtain a polyurethane foam.

The reaction conditions (for example, reaction temperature, etc.) between the premix and the polyisocyanate component are appropriately set according to the purpose and application.

The blending ratio of the polyisocyanate component is, for example, an isocyanate index (ratio of isocyanate groups to the total amount of 100 of active hydrogen groups such as hydroxyl groups and water as a blowing agent in the polyol component) of, for example, 60 or more, preferably 70 or more, for example, 500 or less, preferably 130 or less, more preferably 100 or less.

As a result, a polyurethane foam is obtained as a reaction product (foam) of the polyisocyanate component and the polyol component.

The polyurethane foam obtained in this manner is a flexible polyurethane foam and is made of the foamable polyurethane composition described above, and therefore has excellent tactile sensation.

That is, in the foamable polyurethane composition described above, since the polyisocyanate component contains bis(isocyanatomethyl)cyclohexane, the reactivity is lower than that of tolylene diisocyanate, and the cream time during foaming is relatively long. , the bubbles can be easily detached from the polyurethane resin, and the cell diameter can be reduced.

In addition, since the foamable polyurethane composition has a relatively low water content, it is possible to reduce the amount of air bubbles in the polyurethane foam and increase the density of the polyurethane foam.

Furthermore, in the foamable polyurethane composition, the polyurethane resin is foamed (chemically foamed) with water, so that a thicker polyurethane foam can be obtained than by a mechanical froth foaming method or the like.

Therefore, the above polyurethane foam has an appropriate thickness, a relatively high density, and a small cell diameter (cell diameter).

More specifically, the thickness of the polyurethane foam is, for example, 20 mm or more, preferably 25 mm or more, more preferably 30 mm or more, and usually 1000 mm or less.

Further, the density of the polyurethane foam (measured according to the examples described later) is, for example, 100 kg/m ³ or more, preferably 110 kg/m ³ or more, more preferably 120 kg/m ³ or more, and still more preferably It is 130 kg/m ³ or more, for example, 200 kg/m ³ or less, preferably 190 kg/m ³ or less, more preferably 180 kg/m ³ or less, still more preferably 170 kg/m ³ or less.

Further, the cell diameter of the polyurethane foam (measured according to the examples described later) is, for example, 200 μm or more, preferably 210 μm or more, more preferably 220 μm or more, still more preferably 230 μm or more, and particularly preferably 240 μm. For example, it is 350 μm or less, preferably 330 μm or less, more preferably 300 μm or less, even more preferably 280 μm or less, and particularly preferably 260 μm or less.

As described above, the polyurethane foam has an appropriate thickness, a relatively high density, and a small cell diameter (cell diameter). Therefore, according to the above polyurethane foam, excellent tactile sensation can be obtained.

The above-described polyurethane foam, which has excellent tactile sensation, can be widely used in various industrial fields (for example, in the fields of automobiles, furniture, bedding, electronic materials, medical care, clothing, sanitary materials, etc.).

Applications of polyurethane foam include, for example, pressure-resistant dispersing materials, shape-retaining materials, sound-absorbing materials, impact-absorbing materials, vibration-absorbing materials, and elastic materials such as optical materials.

More specifically, polyurethane foam is used for seat sheets, headrests, bedding such as pillows and mattresses, sofas, cushion materials for nursing care, leisure sheets, supporters, shape retention agents for wigs, filters, covers for microphones, and earphones. Covers, headphone covers, cushion floor materials, cosmetic puffs, medical materials, coating rolls, OA rolls, electronic components (e.g., electronic tablets, smartphones, etc.), polishing pads, sanitary products, diapers, robot exterior materials Available.

In particular, polyurethane foams are suitable for cosmetic puffs because they have an excellent feel to the touch.

Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited by the following examples. "Parts" and "%" are based on mass unless otherwise specified. In addition, specific numerical values such as the mixing ratio (content ratio), physical property values, and parameters used in the following description are the corresponding mixing ratios ( content ratio), physical properties, parameters, etc. be able to.

Examples 1-9 and Comparative Examples 1-13
Among the components (raw materials) shown in Tables 1 and 2, each component other than the polyisocyanate component and the catalyst was weighed, blended, stirred and mixed to be uniform, and the catalyst was added. Stir for 5 seconds.

The polyisocyanate components shown in Tables 1 and 2 were added to the resulting mixture (premix) so that the isocyanate indexes shown in Tables 1 and 2 were obtained. 170 mm x 170 mm wide x 200 mm high) and foamed. A polyurethane foam was thus obtained.

The amount of raw material was adjusted so that the height of the polyurethane foam after standing still for one day was 150 mm.

Evaluation The polyurethane foam was allowed to stand at room temperature for 1 day.

After that, the polyurethane foam was cut to obtain a test piece for tactile evaluation of 50 mm long×50 mm wide×30 mm thick. The tactile sensation was evaluated using the obtained test pieces. In Comparative Example 1, a polyurethane foam having a thickness of 30 mm or more was not obtained, and thus a test piece for tactile evaluation having the above thickness was not obtained.

Also, the density and cell diameter were measured by preparing a test piece according to the description method of each standard.

<Density (unit: kg/m ³ )>
The density of the polyurethane foam was measured according to JIS K7222 (2005).

<Average cell diameter>
The average cell diameter of the polyurethane foam was measured according to the method described in "Plastic Foam Handbook" P35-37.

That is, the polyurethane foam was cut and the cut cross section was observed with an optical microscope. Then, the average cell diameter R of the entire foam was calculated by the following formula, where r is the average diameter of the circular holes observed in the two-dimensional plane.

R=r/0.785
<Tactile sensation>
The polyurethane foam was pressed or stroked with a finger, and the overall tactile sensation was evaluated on a scale of 5 according to the following criteria.

5: Moist feeling is very high and touch feeling is very good.

4: Moist feeling is high and tactile feeling is good.

3: Moist feeling is normal and tactile feeling is normal.

2: Low moist feeling and poor tactile sensation.

1: Very low moist feeling and very poor tactile sensation.

The details of the abbreviations used in the table are shown below.
Polyol A: polyoxyalkylene polyol, average functionality about 3, hydroxyl value 34 mgKOH/g, oxypropylene content in oxyalkylene portion 100% by mass
Polyol B: polyoxyalkylene polyol, average functionality about 3, hydroxyl value 210 mgKOH/g, oxypropylene content in oxyalkylene portion 70% by mass, oxyethylene content 30% by mass
Polyol C: polyoxyalkylene polyol, average functionality about 3, hydroxyl value 18 mgKOH/g, oxypropylene content in oxyalkylene portion 100% by mass
Polyol D: polyoxyalkylene polyol, average functionality about 3, hydroxyl value 75 mgKOH/g, oxypropylene content in oxyalkylene portion 100% by mass
Polyol E: polyoxyalkylene polyol, average functionality about 3, hydroxyl value 100 mgKOH/g, oxypropylene content in oxyalkylene portion 70% by mass, oxyethylene content 30% by mass
Polyol F: polyoxyalkylene polyol, average functionality about 3, hydroxyl value 320 mgKOH/g, oxypropylene content in oxyalkylene portion 70% by mass, oxyethylene content 30% by mass
Foam stabilizer: silicone foam stabilizer (Shin-Etsu Chemical Co., Ltd., F-242T)
Catalyst A: urethanization catalyst, DABCO 33LV (33 mass% diethylene glycol solution of triethylenediamine) solid content equivalent, manufactured by EVONIK Catalyst B: urethanization catalyst, dibutyltin dilaurate (organometallic catalyst, DBTDL)
Polyisocyanate A: 1,4-bis (isocyanatomethyl) cyclohexane polyisocyanate B: 1,3-bis (isocyanatomethyl) cyclohexane polyisocyanate C: toluene diisocyanate polyisocyanate D: isophorone diisocyanate

Claims (5)

A foamable polyurethane composition comprising a polyisocyanate component, a polyol component, and a water-containing blowing agent,
The polyisocyanate component comprises bis(isocyanatomethyl)cyclohexane,
The polyol component includes a first polyol having an average functionality of 1.5 to 4.5 and a hydroxyl value of 20 to 70 mgKOH/g, and a second polyol having an average functionality of 1.5 to 4.5 and a hydroxyl value of 140 to 300 mgKOH/g. and a polyol;
A foamable polyurethane composition, wherein the water content is 0.6 parts by mass or more and 1.0 parts by mass or less with respect to 100 parts by mass of the polyol component. A foamable polyurethane composition according to claim 1, characterized in that said polyisocyanate component comprises 1,3-bis(isocyanatomethyl)cyclohexane and 1,4-bis(isocyanatomethyl)cyclohexane. . Made of the foamable polyurethane composition according to claim 1 or 2,
A polyurethane foam obtained by reacting and foaming the polyisocyanate component and the polyol component in the presence of the foaming agent. Density is 100 kg/m ³ or more and 200 kg/m ³ or less, and
A polyurethane foam having an average cell diameter of 200 µm or more and 350 µm or less. 5. The polyurethane foam according to claim 4, having a thickness of 30 mm or more.