Polyol mixture for polyurethane foam production

Abstract

To provide a polyol mixture which facilitates adjustment of the average number of functional groups for polyurethane foam production and exhibits enhanced storage stability.SOLUTION: A polyol mixture for polyurethane foam production comprises a polyhydric alcohol A defined below. The polyhydric alcohol A is an adduct formed by addition of 1 mol of an alkylene oxide to at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polyol mixture for producing polyurethane foam. More specifically, it relates to heat insulating materials and dew condensation preventing materials for building materials, refrigerated warehouses, bathtubs, pipes, etc., lightweight core materials filled inside building components such as eaves and window sashes to maintain the product shape, cushioning materials and buffering materials for protecting articles such as automobiles and furniture from impacts, sealing materials for filling gaps, polyol mixtures suitably used for producing polyurethane foam that can be suitably used as sound absorbing materials and vibration damping materials, etc., and a method for producing polyurethane foam using the polyol mixture.

Background Art

[0002] Polyurethane foam is easy to design in terms of hardness and specific gravity. Since low-hardness foam is rich in deformability and has good cushioning properties, it is suitably used for cushions, buffering materials, sealing materials, sound absorbing materials, filters, etc. On the other hand, high-hardness foam has good heat insulating properties and is therefore used as a heat insulating material for building materials, refrigerated warehouses, bathtubs, pipes, etc.

[0003] In the formulation design of a polyol mixture for producing polyurethane foam, the design of the average functionality number is important from the viewpoint of achieving both control of desired urethane physical properties, such as compression set, compression strength, solvent resistance, etc., and moldability, such as filling property and design reproducibility. Here, as an agent for improving the average functionality number, that is, as a crosslinking agent, glycerin shows an excellent effect. By using this, physical properties such as compression set, compression strength, and solvent resistance can be improved with a small amount of addition. On the other hand, it has been said that the addition of glycerin as a crosslinking agent has problems such as a decrease in moldability such as filling property and design reproducibility, and furthermore, an increase in the closed cell property. Using polyglycerin as a crosslinking agent has been proposed (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the polyol mixture, which is a precursor of polyurethane, contains glycerin or a derivative of glycerin, the quality may deteriorate during long-term storage.

[0006] The present invention relates to providing a polyol mixture that facilitates adjustment of the average functionality number for the production of polyurethane foam and has enhanced storage stability.

Means for Solving the Problems

[0007] The present invention relates to the following [1] to [3]. [1] A polyol mixture for producing a polyurethane foam containing the following polyhydric alcohol A. Polyhydric alcohol A: An alkylene oxide adduct of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol [2] A polyol mixture for producing a polyurethane foam containing an alkylene oxide adduct of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol, wherein the average number of moles of alkylene oxide added to the alkylene oxide adduct of the polyhydric alcohol is 1 to 4. [3] A method for producing a polyurethane foam having a step of reacting the polyol mixture for producing a polyurethane foam according to [1] or [2] with an isocyanate component.

Advantages of the Invention

[0008] According to the present invention, the storage stability of the polyol mixture for producing a polyurethane foam can be enhanced.

Embodiments for Carrying Out the Invention

[0009] The polyol mixture for producing a polyurethane foam of the present invention contains an alkylene oxide 1-mole adduct of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. Hereinafter, in this specification, the alkylene oxide 1-mole adduct of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol is also referred to as "polyhydric alcohol A", and the polyol mixture for producing a polyurethane foam containing the polyhydric alcohol A is also simply referred to as "the polyol mixture of the present invention".

[0010] Although the mechanism of the expression of the effects of the present invention is not clear, it is presumed as follows. The polyol compound for producing a polyurethane foam contains a polymer-type polyol. However, when a compound having three or more hydroxyl groups is used to improve the physical properties of the polyurethane foam, if the compound having three or more hydroxyl groups has a low molecular weight, the effect of improving the physical properties is high, but since the hydroxyl equivalent is large, it becomes more hydrophilic. Therefore, when the polymer-type polyol has high hydrophobicity, the compatibility with them decreases. However, the polyhydric alcohol A having 1 mole of added alkylene oxide contained in the polyol mixture of the present invention can relax the entanglement of the hydroxyl groups, which are polar groups, and lower the hydrophilicity while having a low molecular weight. Therefore, it is considered that the compatible state of the mixture can be maintained and the storage stability can be enhanced. However, the present invention should not be construed as being limited to these mechanisms. In this specification, the polyol compound means all compounds having a plurality of hydroxyl groups in the molecule.

[0011] In the present invention, the alkylene oxide added to the polyhydric alcohol A is preferably at least one selected from ethylene oxide, propylene oxide, trimethylene oxide, and tetramethylene oxide. Among these, ethylene oxide and / or propylene oxide are more preferable, and ethylene oxide is even more preferable. Among these, in the present invention, the ratio of ethylene oxide in the alkylene oxide added to the polyhydric alcohol A is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, and even more preferably substantially 100 mol%. In the present invention, the ratio of ethylene oxide in the alkylene oxide of the polyhydric alcohol A being substantially 100 mol% means that the presence of alkylene oxide components other than ethylene oxide present as impurities in ethylene oxide is allowed in the form of being added to the polyhydric alcohol A.

[0012] From the viewpoint of ensuring the storage stability of the polyol mixture of the present invention, the polyhydric alcohol A contained in the polyol mixture of the present invention is preferably an adduct of 1 mol of alkylene oxide of glycerin, and more preferably an adduct of 1 mol of ethylene oxide of glycerin.

[0013] In the present invention, from the viewpoint of ensuring the storage stability of the polyol mixture of the present invention, the content of the polyhydric alcohol A in the polyol mixture of the present invention is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and from the same viewpoint, it is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, still more preferably 8% by mass or less, still more preferably 5% by mass or less, and still more preferably 3% by mass or less.

[0014] In the present invention, the polyhydric alcohol A can be obtained by any known method, but it is preferably obtained by a method of subjecting at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol to ring-opening addition of an alkylene oxide in the presence of a potassium hydroxide (KOH) catalyst.

[0015] The polyol mixture of the present invention preferably further contains a polyol compound P having a number average molecular weight of 400 or more and 20,000 or less.

[0016] In the present invention, the polyol compound P is preferably at least one selected from polyether polyols, polyester polyols, and polyether ester polyols having a number average molecular weight of 400 or more and 20,000 or less. That is, in the present invention, the polyol compound P may be one kind or a combination of two or more kinds.

[0017] In the present invention, the polyether polyol preferably has a structural unit derived from a compound having two or more hydroxyl groups in one molecule and a structural unit of a structure in which an alkylene oxide is ring-opening addition polymerized to the hydroxyl groups of the compound having two or more hydroxyl groups in one molecule. As the compound having two or more hydroxyl groups in one molecule constituting the polyether polyol in the present invention, glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol are preferably mentioned. The alkylene oxide that undergoes ring-opening addition polymerization to the hydroxyl groups of the compound having two or more hydroxyl groups in one molecule is preferably at least one selected from ethylene oxide, propylene oxide, trimethylene oxide, and tetramethylene oxide. Among these, one or more selected from propylene oxide adducts and block adducts of propylene oxide and ethylene oxide are more preferable.

[0018] In the present invention, the polyol compound P preferably further contains an adduct of propylene oxide and / or a block adduct of propylene oxide and ethylene oxide of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol.

[0019] In the present invention, the content ratio of the adduct of propylene oxide and / or the block adduct of propylene oxide and ethylene oxide of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol in the polyol compound P is preferably 50% by mass or more, more preferably 80% by mass or more, still more preferably 95% by mass or more, and even more preferably 100% by mass.

[0020] In the present invention, the polyether polyol may have a structural unit in which an alkylene oxide is subjected to ring-opening addition polymerization to an active hydrogen group of a compound having two or more amino groups in one molecule. Suitable examples of the compound having two or more amino groups in one molecule include alkylene diamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, and neopentyldiamine, and aromatic amines such as tolylenediamine, xylylenediamine, diphenylmethanediamine, and Mannich condensates. The alkylene oxide that undergoes ring-opening addition polymerization to the active hydrogen group of the compound having two or more amino groups in one molecule is the same as the preferred alkylene oxide that undergoes ring-opening addition polymerization to the hydroxyl group of the compound having two or more hydroxyl groups in one molecule.

[0021] In the present invention, the polyester polyol is a polyol having a polyester structural unit, and examples thereof include aromatic polyester polyols and aliphatic polyester polyols. Specific examples of the aromatic polyester polyol preferably include condensates of aromatic dicarboxylic acids such as o-phthalic acid (phthalic acid), m-phthalic acid (isophthalic acid), p-phthalic acid (terephthalic acid), naphthalenedicarboxylic acid and glycols. Specific examples of the aliphatic polyester polyol preferably include condensates of aliphatic carboxylic acids such as malonic acid, succinic acid, adipic acid and glycols.

[0022] In the present invention, the polyether ester polyol is obtained by reacting the polyether polyol with a polybasic acid to effect polyesterification, that is, it is a polyol having both polyether and polyester segments in one molecule.

[0023] In the present invention, the hydroxyl value of the polyol compound P is preferably 15 mgKOH / g or more, more preferably 20 mgKOH / g or more, still more preferably 22 mgKOH / g or more, and preferably 500 mgKOH / g or less, more preferably 450 mgKOH / g or less, still more preferably 400 mgKOH / g or less. In the present invention, the number of hydroxyl groups in the molecule of the polyol compound P is preferably 2 or more and 4 or less, more preferably 3 or more and 4 or less. In the present invention, the molecular weight of the polyol compound P is preferably 400 or more, more preferably 500 or more, still more preferably 600 or more, from the viewpoint of ensuring the storage stability of the polyol mixture of the present invention, and preferably 20,000 or less, more preferably 15,000 or less, still more preferably 12,000 or less, even more preferably 8,000 or less, from the same viewpoint. In the present invention, the hydroxyl value of the polyol compound P is the value determined based on JIS K1557, and the molecular weight of the polyol compound P means the number average molecular weight in terms of polystyrene measured by a GPC measuring device. When using a commercially available product, the hydroxyl value and molecular weight described in the catalog may also be used.

[0024] When the polyol mixture of the present invention contains a polyol compound P, the content of the polyol compound P in the polyol mixture of the present invention is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 65% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 88% by mass or less.

[0025] The polyol mixture of the present invention may contain at least one alkylene oxide adduct of a polyhydric alcohol (hereinafter also referred to as "polyhydric alcohol B") having 2 moles of alkylene oxide and an adduct of 3 moles thereof (hereinafter also referred to as "polyhydric alcohol C") selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. One or more selected from ethylene oxide, propylene oxide, trimethylene oxide, and tetramethylene oxide are preferably used as the alkylene oxide added to one or more selected from polyhydric alcohol B and polyhydric alcohol C in the present invention. Among these, one or more selected from ethylene oxide and propylene oxide are more preferable, and ethylene oxide is still more preferable. When the polyol mixture of the present invention contains one or more selected from polyhydric alcohol B and polyhydric alcohol C, the type of the structural unit of the alkylene oxide of the alkylene oxide adduct of one or more selected from polyhydric alcohol B and polyhydric alcohol C is preferably the same as the type of the structural unit of the alkylene oxide of polyhydric alcohol A. The ratio of ethylene oxide in the alkylene oxide added to one or more selected from polyhydric alcohol B and polyhydric alcohol C in the present invention is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably substantially 100 mol%.

[0026] The polyhydric alcohol B that the polyol mixture of the present invention may contain is preferably an alkylene oxide adduct of glycerin having 2 moles of alkylene oxide, and more preferably an ethylene oxide adduct of glycerin having 2 moles of ethylene oxide, from the viewpoint of ensuring the storage stability of the polyol mixture of the present invention.

[0027] The polyhydric alcohol C that the polyol mixture of the present invention may contain is preferably an alkylene oxide adduct of glycerin with 3 moles of alkylene oxide from the viewpoint of ensuring the storage stability of the polyol mixture of the present invention, and more preferably an ethylene oxide adduct of glycerin with 3 moles of ethylene oxide.

[0028] In an embodiment where the polyol mixture of the present invention contains one or more selected from polyhydric alcohol B and polyhydric alcohol C, a polyhydric alcohol A mixture containing polyhydric alcohol A and one or more selected from polyhydric alcohol B and polyhydric alcohol C (hereinafter, also simply referred to as "polyhydric alcohol A mixture") can be blended. As the polyhydric alcohol A mixture, a polyhydric alcohol A mixture in which the average number of moles of alkylene oxide added is 1 to 4 can be used as an alkylene oxide adduct of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. It is more preferable that the average number of moles of alkylene oxide added is 1 to 3, and it is even more preferable that the average number of moles of alkylene oxide added is 1 to 2. That is, the present invention also provides a polyol mixture for producing a polyurethane foam, which contains an alkylene oxide adduct of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol, and the average number of moles of alkylene oxide added to the alkylene oxide adduct is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 to 2. In the aspect where the polyol mixture of the present invention contains one or more selected from polyhydric alcohol B and polyhydric alcohol C, the ratio of polyhydric alcohol A to the total of polyhydric alcohol A, polyhydric alcohol B, and polyhydric alcohol C in the polyol mixture of the present invention is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 40% by mass or more, even more preferably 50% by mass or more, from the viewpoint of enhancing the storage stability of the polyol mixture of the present invention, and preferably 80% by mass or less, more preferably 70% by mass or less, still more preferably 60% by mass or less, from the same viewpoint and the viewpoint of reaction controllability in the production of polyurethane foam.

[0029] The polyol mixture of the present invention preferably contains at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol (hereinafter this polyhydric alcohol is also referred to as "polyhydric alcohol X"). In the present disclosure, polyhydric alcohol X is preferably used in combination with polyhydric alcohol A in order to enhance the storage stability of the polyol mixture and to achieve the retention of physical properties and low density of the polyurethane foam. The content of polyhydric alcohol X in the polyol mixture of the present invention is preferably 0.01 part or more, more preferably 0.1 part or more, still more preferably 1 part or more, per 100 parts by mass of the polyol mixture, from the viewpoint of enhancing the storage stability of the polyol mixture of the present invention. And from the same viewpoint and the viewpoint of reaction controllability in the production of polyurethane foam, it is preferably 3 parts by mass or less, more preferably 2.5 parts by mass or less, still more preferably 2 parts by mass or less.

[0030] The polyhydric alcohol X that the polyol mixture of the present invention may contain is more preferably one selected from glycerin and trimethylolpropane, and still more preferably glycerin. When the polyol mixture of the present invention contains one or more selected from polyhydric alcohol B and polyhydric alcohol C and further contains polyhydric alcohol X, the ratio of polyhydric alcohol X to the total of polyhydric alcohol A, polyhydric alcohol B, polyhydric alcohol C, and polyhydric alcohol X in the polyol mixture of the present invention is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 5% by mass or more, even more preferably 10% by mass or more, from the viewpoint of enhancing the storage stability of the polyol mixture of the present invention, and preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less, from the same viewpoint and the viewpoint of reaction controllability in the production of polyurethane foam.

[0031] When the polyol mixture of the present invention contains one or more selected from polyhydric alcohol B and polyhydric alcohol C and further contains polyhydric alcohol X, the ratio of polyhydric alcohol A to the total of polyhydric alcohol A, polyhydric alcohol B, polyhydric alcohol C, and polyhydric alcohol X in the polyol mixture of the present invention is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, from the viewpoint of enhancing the storage stability of the polyol mixture of the present invention, and preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less, from the same viewpoint and the viewpoint of reaction controllability in the production of polyurethane foam.

[0032] The polyol mixture of the present invention preferably contains water. In the present disclosure, water is used as a foaming agent. From the viewpoint of maintaining the physical properties of the polyurethane foam and reducing the density, the amount of water is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, still more preferably 1 part by mass or more, and preferably 30 parts by mass or less, more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less, based on 100 parts by mass of the polyol mixture. Within the range that does not inhibit the object of the present invention, together with water, an inert gas such as carbon dioxide or nitrogen, a hydrocarbon having a boiling point of 5°C or lower, a hydrochlorofluorocarbon, a hydrofluorocarbon, etc. may be used. However, considering the environmental aspects, etc., the polyol mixture of the present invention preferably does not contain an inert gas such as carbon dioxide or nitrogen, a hydrocarbon having a boiling point of 5°C or lower, a hydrochlorofluorocarbon, or a hydrofluorocarbon. However, containing the above substances in an amount of 1% by mass or less based on the total mass of the polyol mixture does not interfere with the implementation of the present invention as impurities that cannot be avoided.

[0033] As a preferred embodiment of the polyol mixture of the present invention, there is exemplified a polyol mixture containing a polyhydric alcohol A, a polyol compound P which is an adduct of propylene oxide and / or a block adduct of propylene oxide and ethylene oxide of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol having a number average molecular weight of 400 or more and 20,000 or less, and water. And the polyol mixture of the present invention more preferably contains a polyhydric alcohol A, a polyol compound P which is an adduct of propylene oxide and / or a block adduct of propylene oxide and ethylene oxide of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol having a number average molecular weight of 400 or more and 20,000 or less, water, and one or more selected from a polyhydric alcohol B and a polyhydric alcohol C. Even more preferably, it consists of a polyhydric alcohol A, a polyol compound P which is an adduct of propylene oxide and / or a block adduct of propylene oxide and ethylene oxide of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol having a number average molecular weight of 400 or more and 20,000 or less, water, one or more selected from a polyhydric alcohol B and a polyhydric alcohol C, and a polyhydric alcohol X.

[0034] In the polyol mixture of the present invention, when the polyol mixture of the present invention contains water, the content of the polyhydric alcohol A with respect to 100 parts by mass of the contained water is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, from the viewpoint of enhancing the storage stability of the polyol mixture of the present invention. And from the same viewpoint, it is preferably 2,000 parts by mass or less, more preferably 1,000 parts by mass or less, still more preferably 500 parts by mass or less, even more preferably 200 parts by mass or less, even more preferably 100 parts by mass or less, even more preferably 50 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less.

[0035] From the viewpoint of enhancing the reactivity with the isocyanate component, the polyol mixture of the present invention preferably contains an amine compound A.

[0036] Examples of the amine compound A include a compound represented by the formula (I): (CH3)2N(CH2CH2O) n -H (I) (wherein n represents a number from 1 to 4), a compound represented by the formula (II): (CH3)2NCH2CH2N(CH3)X (II) (wherein X represents a CH2CHYOH group, a CH2CH2N(CH3)2 group, or a CH2CH2N(CH3)CH2CHYOH group, and Y represents a hydrogen atom or a methyl group), a compound represented by the formula (III): (CH3)2NCH2CH2OCH2CH2N(CH2)Z (III) (wherein Z represents a methyl group or a CH2CHYOH group, and Y is the same as above), 1,4-diazabicyclo[2.2.2]octane, 2-methyl-1,4-diazabicyclo[2.2.2]octane, N-methylmorpholine, N-ethylmorpholine, N-(dimethylaminoethyl)morpholine, dimorpholinodiethyl ether, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N'-tetramethyl-1,6-hexanediamine, N,N'-dimethylpiperazine, N,N',N'-trimethylaminopropylpiperazine, tris(3-dimethylaminopropyl)amine, bis(3-dimethylaminopropyl)amine, N,N-dimethylcyclohexylamine, N,N-dimethylbenzylamine, 1,8-diazabicyclo[5.4.0]undecene-7, N,N',N''-tris(3-dimethylaminopropyl)hexahydro-s-triazine, 6-dimethylamino-1-hexanol, 5-dimethylamino-3-methyl-1-pentanol, isopropanolamine, N-(3-dimethylaminopropyl)-N-methylaminoethanol, N,N-dimethyl-N,N’-bis(2-hydroxypropyl)-1,3-propanediamine, N, N-bis(3-dimethylaminopropyl)isopropanolamine, 1-methylimidazole, 1-isobutyl-2-methylimidazole, 1,2-dimethylimidazole and other tertiary amine compounds. These can be used alone or in admixture of two or more thereof.

[0037] In the present invention, the amine compound A includes a compound represented by formula (I), a compound represented by formula (II), and a compound represented by formula (III) from the viewpoint of enhancing the reactivity between the isocyanate component and water. These can be used alone or in combination of two or more thereof.

[0038] Among the compound represented by formula (I), the compound represented by formula (II), and the compound represented by formula (III), 2-(2-dimethylaminoethoxy)ethanol, 2-[2-(2-dimethylaminoethoxy)ethoxy]ethanol, N-(2-dimethylaminoethyl)-N-methylethanolamine, N,N,N',N''-tetramethyl-N''-isopropanol-diethylenetriamine, N,N,N',N'',N''-pentamethyldiethylenetriamine, bis(2-dimethylaminoethyl)ether, and N-(2-(2-dimethylaminoethoxy)ethyl)-N-methylethanolamine are preferable. These can be used alone or in combination of two or more thereof.

[0039] From the viewpoints of reactivity and compatibility, the amount of the amine compound A in the polyol mixture of the present invention is preferably 0.5 part by mass or more, more preferably 1 part by mass or more, still more preferably 1.5 part by mass or more, with respect to 100 parts by mass of the polyol mixture of the present invention, and from the same viewpoints, preferably 15 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 5 parts by mass or less.

[0040] The polyol mixture may optionally contain known additives such as, for example, urethanization catalysts, foam stabilizers, flame retardants, antioxidants, crosslinking agents, etc. described in the Polyurethane Handbook (edited by Keiji Iwata, Nikkan Kogyo Shimbun). The crosslinking agent that may optionally be contained in the present invention means a compound having three or more functional groups capable of reacting with an isocyanate group in a molecule other than polyhydric alcohol A, polyhydric alcohol B, polyhydric alcohol C, polyhydric alcohol X, and the polyol compound P.

[0041] From the viewpoints of enhancing the storage stability of the polyol mixture of the present invention and obtaining a high-quality polyurethane foam, the hydroxyl value of the polyol mixture of the present invention is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, still more preferably 15 mgKOH / g or more, even more preferably 20 mgKOH / g or more, and from the same viewpoints, it is preferably 800 mgKOH / g or less, more preferably 650 mgKOH / g or less, still more preferably 600 mgKOH / g or less. The hydroxyl value of the polyol mixture of the present invention can be measured by the method described in JIS K1557.

[0042] Although the hydroxyl value of the polyol mixture of the present invention varies depending on the type of polyurethane foam to be obtained, from the viewpoints of enhancing the storage stability of the polyol mixture of the present invention and obtaining a high-quality rigid polyurethane foam, it is preferably 20 mgKOH / g or more, more preferably 50 mgKOH / g or more, still more preferably 100 mgKOH / g or more, even more preferably 200 mgKOH / g or more, and from the same viewpoints, it is preferably 800 mgKOH / g or less, more preferably 650 mgKOH / g or less, still more preferably 600 mgKOH / g or less.

[0043] Also, from the viewpoints of enhancing the storage stability of the polyol mixture of the present invention and obtaining high-quality semi-rigid and flexible polyurethane foams, it is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, still more preferably 15 mgKOH / g or more, even more preferably 20 mgKOH / g or more, and from the same viewpoints, it is preferably 800 mgKOH / g or less, more preferably 600 mgKOH / g or less, still more preferably 400 mgKOH / g or less, even more preferably 200 mgKOH / g or less.

[0044] The polyol mixture of the present invention can be prepared by mixing the above components.

[0045] The polyol mixture of the present invention preferably has a step of mixing a polyhydric alcohol A and a polyol compound P. That is, this specification discloses a method for producing a polyol mixture for producing a polyurethane foam (hereinafter also referred to as "the method for producing the polyol mixture of the present invention") having a step of mixing a polyhydric alcohol A and a polyol compound P. In the method for producing the polyol mixture of the present invention, the polyhydric alcohol A is preferably contained together with one or more selected from the aforementioned polyhydric alcohols B and C to have an embodiment of a polyhydric alcohol A mixture 1, and more preferably contains one or more selected from the polyhydric alcohols B and C and a polyhydric alcohol X to have an embodiment of a polyhydric alcohol A mixture 2. That is, the method for producing the polyol mixture of the present invention more preferably has a step of mixing the polyhydric alcohol A mixture 1 and the polyol compound P, still more preferably has a step of mixing the polyhydric alcohol A mixture 2 and the polyol compound P, and even more preferably has a step of mixing the polyhydric alcohol A mixture 2, the polyol compound P, and water. The method for producing the polyol of the present invention produces an alkylene oxide adduct of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol having an average number of moles of alkylene oxide added of 1 to 4, so that in addition to the polyhydric alcohol A, a polyhydric alcohol A mixture containing the polyhydric alcohol B and / or the polyhydric alcohol C can be obtained, and it can also be made to contain the polyhydric alcohol X. In the method for producing the polyol mixture of the present invention, commercially available products can also be used for the polyhydric alcohol A mixtures 1 and 2. Preferred examples of commercially available products of the polyhydric alcohol A mixtures 1 and 2 include Braunon GL-3 (ethylene oxide adduct of glycerin manufactured by Aoki Yushi Co., Ltd.: average number of moles of ethylene oxide added = 3), and preferred examples of commercially available products of alkylene oxide adducts of trimethylolpropane include Braunon TMP-1 and Braunon TMP-3 (ethylene oxide adducts of trimethylolpropane manufactured by Aoki Yushi Co., Ltd.: average number of moles of ethylene oxide added = 1 and 3).

[0046] The polyol mixture of the present invention can maintain a uniform phase even when stored, so the reaction with the isocyanate compound proceeds efficiently, enabling the formation of a good polyurethane foam, and can be suitably used for any of rigid polyurethane foams, semi-rigid polyurethane foams, and flexible polyurethane foams.

[0047] The method for producing a polyurethane foam of the present invention includes a step of reacting the polyol mixture of the present invention with an isocyanate component.

[0048] Examples of the isocyanate component include aromatic polyisocyanates such as polymethylene polyphenylene polyisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and naphthylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate and lysine diisocyanate; alicyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, and isophorone diisocyanate; and polyisocyanate modified products containing one or more of urethane bonds, carbodiimide bonds, uretoimine bonds, allophanate bonds, urea bonds, biuret bonds, and isocyanurate bonds. These isocyanate components may be used alone or in combination of two or more. Among the isocyanate components, from the viewpoints of imparting strength to the polyurethane foam and improving heat resistance, one or more selected from tolylene diisocyanate, diphenylmethane diisocyanate, and polymethylene polyphenylene polyisocyanate are preferable.

[0049] In the method for producing a polyurethane foam of the present invention, it is desirable to adjust the ratio of the polyol mixture of the present invention to the isocyanate component so that the isocyanate index is 20 to 300, preferably 30 to 200, and more preferably 40 to 150.

[0050] In the method for producing the polyurethane foam of the present invention, the reaction between the polyol mixture of the present invention and the isocyanate component can be carried out, for example, by mixing and stirring the polyol mixture of the present invention and the isocyanate component with a molding machine and injecting them into a mold for reaction, or by spraying with a spray machine, colliding and mixing for reaction. More specifically, for example, it can be obtained by adjusting the temperature of the polyol mixture of the present invention and the isocyanate component to 40°C ± 5°C and then reacting them.

[0051] The density of the polyurethane foam of the present invention is not particularly limited, but from the viewpoint of maintaining physical properties, 8 kg / m 3 or more is preferable, 9 kg / m 3 or more is more preferable, and from the viewpoints of weight reduction and reduction of waste amount, 100 kg / m 3 or less is preferable, 50 kg / m 3 or less is more preferable, and 35 kg / m 3 or less is even more preferable.

[0052] According to the method for producing the polyurethane foam of the present invention, homogeneous mixing and high reactivity between the polyol mixture of the present invention and the isocyanate component are realized, the generation of voids is suppressed, the homogenization and stabilization of cells are achieved, and a polyurethane foam excellent in workability can be obtained quickly.

[0053] The obtained polyurethane foam can be suitably used, for example, as heat insulating materials for building materials, cold storage warehouses, bathtubs, pipes, etc., dew condensation prevention materials for detached houses, condominiums, industrial pipes, etc., lightweight core materials filled inside building components such as eaves and window sashes to maintain the product shape, cushioning materials and shock absorbing materials for protecting articles such as automobiles and furniture from impact, sealing materials for filling gaps, sound absorbing materials and vibration damping materials. It can be suitably used for on-site construction type heat insulating materials and dew condensation prevention materials by the spray method, and for manufacturing building materials such as panels and boards on the factory line.

Examples

[0054] Production Example 1 (Production of polyhydric alcohol A mixture a) Charge 230.3 g of glycerin (reagent manufactured by Fujifilm Wako Pure Chemical Corporation) and 1.4 g of potassium hydroxide (reagent manufactured by Fujifilm Wako Pure Chemical Corporation) into a 2-liter autoclave, and heat the mixture to 130°C at a stirring speed of approximately 600 rpm. Then, perform dehydration at 130°C and 1.3 kPa for 30 minutes. After that, heat the mixture to 155°C, and react 110.1 g of ethylene oxide (hereinafter also referred to as EO) (equivalent to 1 mol of EO per 1 mol of glycerin in the autoclave) with the above reaction mixture. The distribution of the number of moles of EO added is as follows: unreacted glycerin (EO = 0 mol): 36.1%, EO = 1 mol: 37.0%, EO = 2 mol: 19.1%, EO = 3 mol: 6.1%, EO = 4 mol: 1.4%, EO = 5 mol: 0.3% (the % is based on weight, the same hereinafter), that is, obtain a polyhydric alcohol A mixture a containing 37.0% of polyhydric alcohol A. The reaction conditions at this time are a temperature of 155°C and a pressure of 0.1 to 0.3 MPa (gauge pressure). The average number of moles of EO added to the glycerin EO adduct in the polyhydric alcohol A mixture a in this production example, that is, the average number of moles of EO added calculated assuming that unreacted glycerin is not an EO adduct, is 1.6.

[0055] Production Example 2 (Production of polyhydric alcohol A mixture b) In Production Example 1, except that 330.5 g of EO (equivalent to 3 mol of EO per 1 mol of glycerin in the autoclave) is reacted with glycerin, in the same manner, the distribution of the number of moles of EO added is as follows: unreacted glycerin (EO = 0 mol): 2.9%, EO = 1 mol: 11.3%, EO = 2 mol: 22.4%, EO = 3 mol: 26.1%, EO = 4 mol: 19.7%, EO = 5 mol: 10.7%, EO = 6 mol: 4.6%, EO = 7 mol: 1.7%, EO = 8 mol: 0.5%, EO = 9 mol: 0.1%, that is, obtain a polyhydric alcohol A mixture b containing 11.3% of polyhydric alcohol A. Incidentally, the average number of moles of EO added to the glycerin EO adduct in the polyhydric alcohol A mixture b in this production example, that is, the average number of moles of EO added calculated assuming that unreacted glycerin is not an EO adduct, is 3.2.

[0056] Production Example 3 (Production of polyhydric alcohol mixture c) In Production Example 1, in the same manner except that 661.0 g of EO to be reacted with glycerin is used (equivalent to 6 moles of EO per 1 mole of glycerin in the autoclave), the distribution of the number of moles of the EO distribution is as follows: unreacted glycerin (EO = 0 mole): 0%, EO = 1 mole: 0%, EO = 2 moles: 0%, EO = 3 moles: 2.8%, EO = 4 moles: 6.1%, EO = 5 moles: 24.5%, EO = 6 moles: 26.7%, EO = 7 moles: 20.9%, EO = 8 moles: 12.1%, EO = 9 moles: 5.2%, EO = 10 moles = 1.7%. That is, a polyhydric alcohol mixture c containing no polyhydric alcohol A is obtained. The average number of added moles of EO of the glycerin EO adduct in the polyhydric alcohol mixture c of this production example, that is, the average number of added moles of EO calculated assuming that unreacted glycerin is not an EO adduct, is 6.2.

[0057] Preparation and Evaluation of Storage Stability of Polyol Mixture Example 1 1 g of the polyhydric alcohol A mixture a obtained in Production Example 1 as a polyhydric alcohol A mixture containing polyhydric alcohol A, as the polyol compound P, Excenol 3030 [trade name, polyether polyol, PO adduct of glycerin, manufactured by AGC Inc., number average molecular weight 3,000, average functionality 3, hydroxyl value 56 mg KOH / g] 25 g, and 5 g of water were put into a glass container and sealed. After strongly shaking the container by hand, it was left at 22°C for 24 hours, and the appearance was observed according to the following criteria to evaluate the storage stability. The results are shown in Table 1. (Criteria) ×: Completely separated into two phases ○: Almost uniform (partially slightly non-uniform part) ◎: Uniform

[0058] Example 2, Comparative Examples 1 and 2 A polyol mixture was prepared in the same manner as in Example 1 except that the composition shown in Table 1 was used instead of the polyhydric alcohol A mixture a obtained in Production Example 1, and the storage stability was evaluated. The results are shown in Table 1.

[0059]

Table 1

[0060] From the obtained results, according to the present invention, a polyol mixture with good storage stability for producing polyurethane foam can be obtained.

Industrial Applicability

[0061] The polyol mixture of the present invention can be suitably used for various polyurethane foams.

Claims

1. A polyol mixture for producing a polyurethane foam, containing the following polyhydric alcohol A. Polyhydric alcohol A: An adduct of 1 mol of alkylene oxide of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol.

2. The polyol mixture for producing a polyurethane foam according to Claim 1, wherein the alkylene oxide added to the polyhydric alcohol A is ethylene oxide and / or propylene oxide.

3. The polyol mixture for producing a polyurethane foam according to Claim 1 or 2, wherein the ratio of ethylene oxide in the alkylene oxide added to the polyhydric alcohol A is 50 mol% or more.

4. A polyol mixture for producing a polyurethane foam, containing an adduct of alkylene oxide of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol, and having an average number of moles of alkylene oxide added to the adduct of alkylene oxide of the polyhydric alcohol of 1 to 4.

5. The polyol mixture for producing a polyurethane foam according to any one of Claims 1 to 4, further containing a polyol compound P having a number average molecular weight of 400 or more and 20,000 or less.

6. The polyol mixture for producing a polyurethane foam according to Claim 5, wherein the polyol compound P contains an adduct of propylene oxide of at least one polyhydric alcohol selected from glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol and / or a block adduct of propylene oxide and ethylene oxide.

7. The polyol mixture for producing a polyurethane foam according to any one of Claims 1 to 6, further containing water.

8. The polyol mixture for producing a polyurethane foam according to any one of Claims 1 to 7, having a hydroxyl value of 5 mg KOH / g or more and 800 mg KOH / g or less.

9. A method for producing a polyurethane foam, comprising a step of reacting the polyol mixture for producing a polyurethane foam according to any one of Claims 1 to 8 with an isocyanate component.

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