JP2002030129A - Slightly foamed polyurethane elastomer and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slightly foamed polyurethane elastomer which realizes the shortening of demolding time and an improvement in mechanical properties as compared with conventional articles as well as improvements in surface properties and coatability, and its manufacturing method. SOLUTION: The slightly foamed polyurethane elastomer is characterized in that (1) it has an overall density (D) in the range from 100 to 900 kg/m3 and (2) the overall density (D) and the compression set (CS2 in %) satisfy the relation of the formula: CS2<=0.00008*D2-0.091*D+42, while the overall density (D) and the diameter (X in μm) of cells observed on the skin surface satisfy the relation of the formula: X<=120e-0.0015D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microfoamed polyurethane elastomer and a method for producing a microfoamed polyurethane elastomer. Specifically, the present invention
The present invention relates to a microfoamed polyurethane elastomer suitably used for shoe soles, and a method for producing the same.

[0002]

2. Description of the Related Art Microfoamed polyurethane elastomers are characterized by having fine and uniformly dispersed cells in a molded article, having a molding density lower than that of a solid type polyurethane elastomer and higher than a flexible polyurethane foam. . Generally, microfoamed polyurethane elastomers are used in fields such as shoe soles, gaskets, sealing materials, and vibration-proofing materials, and their importance is still at a high level.

A typical microfoamed polyurethane elastomer is formed by reacting a resin premix obtained by mixing a polyol component with auxiliaries such as a chain extender, a catalyst, a foam stabilizer and a foaming agent, and an isocyanate component. . It is known to use polyester polyols, polyoxyalkylene polyols and the like as the polyol component. However, microfoamed polyurethane elastomers using polyester polyols are excellent in physical properties such as tensile strength, elongation and tear strength, but have a problem of poor hydrolysis resistance. For this reason, various additives for the purpose of delaying the hydrolysis have been studied and polyester polyols have been studied.
Attempts have been made to study the chemical structure of such compounds. For example, a method is known in which a compound having three active hydrogens is contained in an amount of 0.001 to 0.007 mol in 1000 g of the obtained polyurethane resin to generate a small amount of a branched structure, thereby improving hydrolysis resistance. However, further improvement in hydrolysis resistance is desired.

On the other hand, it is known that the use of polyoxypropylene polyol, which is a polyoxyalkylene polyol, improves the hydrolysis resistance of polyurethane. However, in general, polyoxypropylene polyols are poor in reactivity and cause problems such as prolonged demolding time, reduced green strength and final strength. To solve this problem, a method of increasing the number of catalysts is conceivable, but at the same time, a problem such as deterioration of workability and moldability due to shortening of cream time or gel time occurs.

[0005] In applications where the hydrolysis resistance of the polyoxyalkylene polyols is sufficiently high and applicable, there is a need to develop polyoxyalkylene polyols that exhibit higher physical properties due to the problems caused by the method for producing the polyols. Was desired. As a general industrial production method of a polyoxyalkylene polyol, a method of addition-polymerizing an alkylene oxide to an active hydrogen compound in the presence of a potassium hydroxide (hereinafter abbreviated as KOH) catalyst is known. However, when a general-purpose propylene oxide is added and polymerized as an alkylene oxide using a KOH catalyst, for example, a monool having an unsaturated group at one end of a molecular chain may be by-produced as the molecular weight of the polyoxypropylene polyol increases. Are known.

[0006] Usually, the monool content corresponds to the total degree of unsaturation of the polyoxypropylene polyol. Since the monol has a lower molecular weight than the polyoxypropylene polyol produced by the main reaction, the molecular weight distribution of the polyoxypropylene polyol is greatly widened and the average number of functional groups is reduced. Further, it is also known that the monol inhibits the formation of a polymer network in the urethanization reaction with the polyisocyanate compound, and as a result, lowers the mechanical strength of polyurethane as a reaction product.

Hitherto, in the synthesis of polyoxyalkylene polyol, attempts have been made to suppress the amount of by-product monol while improving the productivity. For example, US Pat. No. 3,829,505, US Pat.
No. 0 discloses a double metal cyanide complex (Double Met) as a catalyst for propylene oxide addition polymerization.
al Cyanide Complex; DMC
A method using a catalyst has been proposed.
Describes that it exhibits excellent performance as a polymerization catalyst for propylene oxide.

Further, US Pat. No. 5,728,745 discloses that
A microporous elastomer is disclosed that uses a polyoxyalkylene polyol synthesized using an improved DMC as a catalyst, and shows a very large increase in green strength and a shortened removal time without lowering the final physical properties of the elastomer. . In addition, examples of Japanese Patent Publication No. 3-47202 include DMC.
It is described that a shoe sole made of a polyurethane resin produced by using a polyoxyalkylene polyol using a catalyst has extremely high wet heat resistance.

However, in the case of addition polymerization of ethylene oxide as an alkylene oxide using DMC as a catalyst, the DMC is first deactivated by reacting with an oxygen-containing gas, an oxidizing agent such as peroxide or sulfuric acid. It is necessary to separate a catalyst residue from a polyoxyalkylene polyol, and to additionally polymerize ethylene oxide using an alkali metal hydroxide such as KOH or an alkali metal alkoxide as a catalyst (US Pat. No. 5,235,114). In addition, the present inventors synthesized a polyoxyalkylene polyol using DMC as a catalyst, and then produced a microfoamed polyurethane elastomer using the polyol. As a result, the demolding time and the compression A microfoamed polyurethane elastomer having durability characteristics such as distortion and a cell shape in a specific range could not be obtained.

A phosphazene compound has been proposed as a catalyst for producing a polyoxyalkylene polyol which is not included in the above (EP 0 763 555, Macromolecule Rapid Communication (Macromol. Rad.)).
pid Commun.) Vol. 17 pp. 143-148 1996
Year and Macromolecular Symposium (Macromo
l. Symp.) 107 331-340 1996
Year). When these phosphazene compounds are used as a catalyst for producing a polyoxyalkylene polyol, there are advantages that the by-product rate of monool is small and the productivity of polyoxyalkylene polyol is dramatically improved.

[0011]

An object of the present invention is to provide a microfoamed polyurethane elastomer which has solved the above-mentioned problems in the prior art, and a method for producing the same. That is, an object of the present invention is to provide a microfoamed polyurethane elastomer which has a short demolding time, shows a remarkable decrease in compression set, has excellent mechanical properties, and has excellent appearance and coatability, and a method for producing the same. That is.

[0012]

The present inventors have developed a microcellular polyurethane elastomer (microcellu) having excellent properties.
lar polyurethane elastomer) and an efficient method for producing finely-foamed polyurethane elastomer,
Excellent mechanical strength if it has a specific range of the total density (D) and the compression set (CS2) and the cell diameter of the skin surface satisfy the specific relation for this total density (D) Has been found to be a microfoamed polyurethane elastomer having Furthermore, hydroxyl value (OHV), total unsaturation,
By using a polyoxyalkylene polyol having a head-to-tail (HT) selectivity in a specific range,
The present inventors have found that a microfoamed polyurethane elastomer having excellent properties can be obtained, and that the demolding time can be shortened to improve the production efficiency, thereby completing the present invention. Furthermore, by using a specific amount of a polyoxyalkylene polyol having a specific range of W ₂₀ / W _{80 as} an index of the molecular weight distribution, a demolding time is short, and a microfoamed polyurethane elastomer having excellent mechanical properties is obtained. The inventors have found that the present invention can be obtained, and have completed the present invention.

That is, the present invention which solves the above-mentioned problems,
The following (1) to (21) are provided. (1) (a) Total density (D) is 100 kg / m ³ or more, 900 k
g / m ³ or less, and (b) the total density (D) and the compression set (CS2: unit%) are given by the following formula (1): CS2 ≦ 0.00008 * D ² −0.091 * D + 42 ... (Equation 1) is satisfied, and the total density (D) and the average cell diameter (X: unit μm) observed on the skin surface are expressed by the following equation (2).

[0014]

(Equation 4)

A microfoamed polyurethane elastomer characterized by satisfying the following relationship: (2) The microfoamed polyurethane elastomer according to (1), wherein the total density is in the range of 200 kg / m ³ or more and 700 kg / m ³ or less. (3) The microfoamed polyurethane elastomer according to (1), wherein the average diameter of the cells inside the microfoamed polyurethane elastomer is 1 μm or more and 200 μm or less. (4) The total density and compression set are given by the following equation (3): CS2 ≦ 0.00008 * D ² −0.091 * D + 40 The microfoamed polyurethane elastomer according to any one of (1) to (3), which satisfies the relationship of (Equation 3). (5) The average diameter (X: unit μm) of the cell observed on the skin surface is represented by the following equation (4).

[0016]

(Equation 5)

(1) to (4) are satisfied.
The microfoamed polyurethane elastomer according to any one of (3). (6) hydroxyl value 2 to 200 mgKOH / g, total unsaturation 0.001 to 0.07 meq. / G, a head-to-tail bond selectivity of polyoxyalkylene polyol by propylene oxide addition polymerization obtained by reacting a polyol containing 50% by mass or more of polyoxyalkylene polyol having 95% by mol or more with a polyisocyanate compound. The total density (D) is 100 kg / m ³ or more,
Fine foamed polyurethane elastomer in the range of 900 kg / m ³ or less. (7) The microfoamed polyurethane elastomer according to (6), wherein the polyoxyalkylene polyol is produced using a compound having a P = N bond as a catalyst. (8) a microfoamed polyurethane elastomer obtained by reacting a polyol with a polyisocyanate compound,
The polyol has a hydroxyl value of 2 to 200 mgKOH /
g, total degree of unsaturation 0.001 to 0.07 meq. / G,
Head-to-tail bond selectivity of polyoxyalkylene polyol by propylene oxide addition polymerization 9
(1) The microfoamed polyurethane elastomer according to (1), which contains 50% by mass or more of a polyoxyalkylene polyol of 5% by mol or more. (9) The microfoamed polyurethane elastomer according to (8), wherein the polyoxyalkylene polyol is produced using a compound having a P = N bond as a catalyst. (10) The polyol contains 0.5 to 50% by mass of a polymer-dispersed polyol containing 1 to 50% by mass of polymer fine particles obtained by polymerizing an ethylenically unsaturated group-containing monomer (8) ). (11) The polymer-dispersed polyol has a hydroxyl value of 2 to 2.
200 mgKOH / g, total unsaturation 0.001-0.
07meq. / G, polymer-dispersed polyol obtained by polymerizing an ethylenically unsaturated group-containing monomer in a polyoxyalkylene polyol having a head-to-tail bond selectivity of 95 mol% or more by propylene oxide addition polymerization The microfoamed polyurethane elastomer according to (10), which is characterized in that: (12) The microfoamed polyurethane elastomer according to (10), wherein the polymer-dispersed polyol contains the polymer fine particles in a range of 10 to 45% by mass. (13) The ethylenically unsaturated group-containing monomer is one or more monomers selected from the group consisting of acrylonitrile, styrene, acrylamide and methyl methacrylate according to any one of (10) to (12). Fine foamed polyurethane elastomer. (14) The microfoamed polyurethane elastomer according to any one of (10) to (13), which contains at least 30% by mass of styrene as an ethylenically unsaturated group-containing monomer. (15) The microfoamed polyurethane elastomer according to any one of (1) to (14), which is obtained by reacting a polyol with an isocyanate-terminated prepolymer obtained from an aromatic polyester polyol and polyisocyanate. . (16) A shoe sole obtained by using the microfoamed polyurethane elastomer according to any one of (1) to (15). (17) hydroxyl value 2 to 200 mgKOH / g, total unsaturation 0.001 to 0.07 meq. / G, 50% by mass of a polyoxyalkylene polyol having a head-to-tail bond selectivity of 95 mol% or more of a polyoxyalkylene polyol by propylene oxide addition polymerization.
By reacting the polyol and the polyisocyanate compound contained above, (a) the total density (D) is in the range of 100 kg / m ³ or more and 900 kg / m ³ or less, and (b) the total density (D) is The permanent set (CS2: unit%) satisfies the following formula (1): CS2 ≦ 0.00008 * D ² −0.091 * D + 42 (Formula 1), and is observed on the total density (D) and the skin surface. The average diameter (X: unit μm) of the cell is expressed by the following equation (2).

[0018]

(Equation 6)

A process for producing a microfoamed polyurethane elastomer, characterized by producing a microfoamed polyurethane elastomer satisfying the above relationship. (18) When the polyoxyalkylene polyol is P = N
(17) The method for producing a microfoamed polyurethane elastomer according to (17), which is produced using a compound having a bond as a catalyst. (19) A microfoamed polyurethane elastomer obtained by reacting a polyol with a polyisocyanate compound, wherein the polymer-dispersed polyol contains 1 to 50% by mass of polymer fine particles obtained by polymerizing an ethylenically unsaturated group-containing monomer. (17) The method for producing a microfoamed polyurethane elastomer according to (17), which comprises 0.5 to 50% by mass. (20) A microfoamed polyurethane elastomer obtained by reacting a polyol with a polyisocyanate compound, wherein the polyisocyanate compound is an isocyanate-terminated prepolymer obtained from an aromatic polyester polyol and a polyisocyanate.
7) The method for producing a microfoamed polyurethane elastomer according to any one of the items (19) to (19). (21) The method according to (20), wherein the polyisocyanate compound contains at least 20% by mass of an isocyanate-terminated prepolymer obtained from an aromatic polyester polyol and a polyisocyanate.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. ≪Microcellular polyurethane elastom≫Microcellular polyurethane elastom
er) has a total density of 100 to 900 kg / m ³ , preferably 200 to 800 kg / cm ³ , more preferably 20
It is 0 to 700 kg / cm ³ . The total density means the density including the surface layer of the microfoamed polyurethane elastomer. When the total density is 100 kg / m ³ or more, the mechanical strength is improved and the mechanical properties after molding are excellent. The mechanical strength of the microfoamed polyurethane elastomer of the present invention depends on its total density, but its hardness (Asker C)
5-95, tensile strength (TB) 0.5-20 MPa, maximum elongation (EB) 100-700%, tear strength (TR) 0.
5 to 50 kN / m, compression set (CS2) 3 to 35%
Range.

The CS2 of the present invention is used especially in the field of shoe soles.
Product quality in micro-foamed polyurethane elastomer
It is an important physical property that influences. The value of CS2 is low
Means polyurethane foam even in repeated use
Small dimensional change of elastomer, long-lasting elasticity
That can be maintained over time. As a measurement method,
 According to the method described in K-6262, a sheet having a diameter of 29
mm circular test piece was collected at a test temperature of 50 ± 1 ° C.
The test time is 6 hours and the compression rate of the test piece is 50%
The permanent set was measured. Compression measured in this way
The permanent set value was “CS2”. CS2 of the present invention
The following equation (1): CS2 ≦ 0.00008 * D^Two-0.091 * D + 42 (Formula 1), preferably CS3 ≦ 0.00008 * D^Two-0.091 * D + 40  (Equation 3), more preferably the following equation (5): CS2 ≦ 0.00008 * D^Two-0.091 * D + 38  (Equation 5), particularly preferably the following equation (6): CS2 ≦ 35 * e^{-0.0025 * D} It is desirable to satisfy the relationship of (Equation 6). In CS2 within this range,
Fine foamed polyurethane elastomer with sufficient mechanical strength
Is obtained.

An important physical property for use in shoe soles is surface properties. Of course, the surface properties have a significant effect on the painted surface after the coating process performed in the post-processing, and, of course, greatly affect the product quality when the product is not coated. It is preferable that the surface before coating has gloss and no flow marks or pinholes, and that the surface after coating has gloss and has no color unevenness.

The present inventors have found that the surface properties depend on the size of the cells present on the skin surface. The skin surface in the present invention refers to a surface of a sheet (finely foamed polyurethane elastomer) formed by a mold (die), which has been in contact with the mold. For example, a mold made of aluminum having an inner size of 12.5 × 150.0 × 250.0 mm is used. For the surface (150.0 × 250.0 mm) in contact with the bottom surface of the above-described mold, 20 mm was taken from the edges in the vertical and horizontal directions.
The diameter of the cell was observed with a micro camera at a total of five points in the corners and the central part of the sheet, and then the average diameter of each cell was determined by an image processing / analyzing device. Average diameter X of the cell.

In the microfoamed polyurethane elastomer of the present invention, the cell diameter (X: unit μm) observed on the skin surface is preferably represented by the following formula (2).

[0025]

(Equation 7)

More preferably, the relationship of the following equation (4) is satisfied.

[0027]

(Equation 8)

More preferably, the following equation (7) is satisfied.

[0029]

(Equation 9)

It is desirable to satisfy the following. By controlling the average diameter of the cells observed on the skin surface within this range, the skin layer can be substantially thickened. Furthermore, the present inventors have found that by increasing the thickness of the skin layer, mechanical properties such as tensile strength are improved. In the microfoamed polyurethane elastomer of the present invention, the average diameter of the cells inside the foam is preferably 1 μm to 200 μm, more preferably 1 μm to 150 μm, more preferably 1 μm to 100 μm, and most preferably 5 μm to 100 μm. It is desirable that: The average diameter of the cells inside the microfoamed polyurethane elastomer in the present invention is, for example, an internal dimension of 12.5 × 15.
A central part of a sheet (finely foamed polyurethane elastomer) made of a 0.0 × 250.0 mm aluminum mold is cut out in a size of 3 cm in length and 1 cm in width, and a portion obtained by removing 4 mm each in the thickness direction from the skin surface in the vertical direction. The cell diameter was observed with a micro camera on four surfaces in the cross-sectional direction (the surface perpendicular to the skin surface), and the average diameter of the cells was determined by an image processing / analyzing device.

The average diameter of the cell is not more than 200 μm, especially 1
By setting the thickness to 00 μm or less, it is possible to suppress the cell diameter from being coarsened, and it is possible to obtain a finely-foamed polyurethane elastomer having a good touch and improved mechanical properties. ≫Production of micro-foamed polyurethane elastomer≫ The micro-foamed polyurethane elastomer of the present invention having the above-mentioned properties is mainly composed of a polyoxyalkylene polyol having a specific structure in the presence of a foaming agent, a catalyst, and a foam stabilizer. And a polyisocyanate compound. First, each component will be described in detail.

{Polyol} The polyol used in the present invention has a hydroxyl value (OHV) of 2 to 200 mgKOH /
g, the total degree of unsaturation is 0.001 to 0.07 m
eq. / G, in which the head-to-tail (HT) bond selectivity of the polyoxyalkylene polyol by propylene oxide addition polymerization is not less than 95 mol% and is not less than 50% by mass. It is assumed that.

<Polyoxyalkylene polyol> The OHV of the polyoxyalkylene polyol is in the range of 2 to 200 mgKOH / g, preferably 9 to 120 mgKOH / g, from the viewpoint of the mechanical properties and removability of the microfoamed polyurethane elastomer. , More preferably 10-1
00 mg KOH / g, more preferably 20 to 8
0 mgKOH / g. Particularly preferably, 20 to 60
mg KOH / g.

In order to improve the mechanical strength of the micro-foamed polyurethane elastomer and to exhibit the property of early development, the total degree of unsaturation of the polyoxyalkylene polyol should be 0.07 meq.
/ G or less, preferably 0.05 meq. / G or less, more preferably 0.04 meq. / G or less, more preferably 0.03 meq. / G or less.

The total degree of unsaturation is 0.07 meq. / G or less greatly improves the mechanical strength of the microfoamed polyurethane elastomer. The lower limit of the total degree of unsaturation according to the present invention is not particularly limited, but is 0.001 meq. / G. The head-to-tail (HT) bond selectivity resulting from the oxirane ring cleavage mode in propylene oxide addition polymerization is 95 mol% or more, preferably 96 mol% or more, and more preferably 97 mol% or more. It is. When the HT bond selectivity is 95 mol% or more, the viscosity of the polyoxyalkylene polyol can be kept in a suitable range, and the compatibility with an auxiliary agent such as a foam stabilizer can be improved. In addition, it is possible to suppress an increase in the average diameter of the cells of the micro-foamed polyurethane elastomer, deterioration of moldability, and the like.

Further, the polyoxyalkylene polyol used in the present invention has a peak height of 100% in a GPC (gel permeation chromatography) elution curve, and the peak height is 20% of the peak height. peak height of the peak width W _20, when the peak width at 80% peak height is defined as W _80, a value obtained by dividing the W ₂₀ with _{W 80, W 20 / W 80} , i.e. GPC elution curve 20
% And a peak width ratio of 80% are preferably 1.5 or more and less than 3.0.

Factors that widen the molecular weight distribution of the polyoxyalkylene polyol include formation of monool by side reaction of propylene oxide and by-product of high molecular weight components. The molecular weight of the monol (corresponding to the total degree of unsaturation defined in the present invention) is smaller than the molecular weight of the polyoxyalkylene polyol obtained in the main reaction, and the retention time of the peak is later than that of the main reaction component in the GPC elution curve. . When the monool is present in a certain amount or less, the total degree of unsaturation can be kept low, and the mechanical strength of the microfoamed polyurethane elastomer can be significantly improved.

Accordingly, the polyoxyalkylene polyol containing a high molecular weight component has a higher viscosity than that of a polyoxyalkylene polyol having a low molecular weight component, and a catalyst, a foam stabilizer, a foaming aid and the like are used. At the same time as the viscosity of the mixed resin premix increases, the viscosity of the isocyanate-terminated prepolymer obtained by the reaction with the polyisocyanate also increases. The moldability is deteriorated and the cell diameter becomes coarse.

It is preferable that the polyoxyalkylene polyol of the present invention contains propylene oxide as a main monomer and uses ethylene oxide in combination. By introducing ethylene oxide to the end of a polyoxyalkylene polyol having propylene oxide as a main chain, a sufficient reaction rate can be exhibited, and a sufficient high molecular weight of the microfoamed polyurethane elastomer can be achieved. . The use amount of ethylene oxide in the polyoxyalkylene polyol according to the present invention is preferably 30% by mass or less, more preferably 5 to 30% by mass, and most preferably 10 to 25% by mass. Further, the terminal primary hydroxyl group conversion rate of the polyoxyalkylene polyol is at least 50%.
Mole percent is preferred, and more preferably at least 70 mole percent.
Mol%, more preferably at least 75 mol%, most preferably at least 80 mol%.

Further, in the present invention, the polyoxyalkylene polyol is preferably produced using a compound having a P = N bond as a catalyst. More preferably, the compound having a P = N bond is at least one compound selected from the group consisting of a phosphazenium compound, a phosphazene compound, and a phosphine oxide compound, and particularly preferably a phosphazenium compound. In the polyoxyalkylene polyol obtained using the phosphazenium compound, the hydroxyl value is in the range of 2 to 200 mgKOH / g, and the total degree of unsaturation is 0.001 to 0.07 meq. / G and the head-to-tail bond selectivity of the polyoxyalkylene polyol by propylene oxide addition polymerization is preferably 95 mol% or more. The polyoxyalkylene polyol is preferably produced using a phosphazenium compound, but may be used in combination with an alkali metal hydroxide such as cesium hydroxide (CsOH) as long as the effects of the present invention are not impaired. The catalyst for producing the polyoxyalkylene polyol will be described later in detail.

In the production of the microfoamed polyurethane elastomer of the present invention, a polyol having a structure other than the above polyoxyalkylene polyol may be used in combination. The polyoxyalkylene polyol according to the invention is at least 50% by weight of the polyol, preferably at least 70% by weight, more preferably at least 80% by weight.
It is. The polyol that can be used in addition to the polyoxyalkylene polyol will be described later in detail.

In particular, when used for shoe soles, the number average molecular weight of the polyoxyalkylene polyol is preferably from 1,000 to 12,000, and more preferably a polyoxyalkylene polyol having a number average molecular weight of from 2,000 to 8,000 with an ethylene oxide terminal-terminated. <Production method of polyoxyalkylene polyol> The polyoxyalkylene polyol of the present invention is also referred to as polyoxyalkylene polyether polyol, and is obtained by ring-opening polymerization of an alkylene oxide using an active hydrogen compound as an initiator in the presence of a catalyst. Oligomer or polymer. The initiator and the alkylene oxide may be used alone or in combination.

<Catalyst for Producing Polyoxyalkylene Polyol> As the catalyst for producing polyoxyalkylene polyol according to the present invention, a compound containing a P = N bond in the molecule is particularly preferable. Examples of such a compound include at least one compound selected from a phosphazenium compound, a phosphazene compound, and a phosphine oxide compound.

As the phosphazenium compound, for example, as described in JP-A-11-106500, the chemical formula (1)

[0045]

Embedded image

A salt of a phosphazenium cation and an inorganic anion represented by the following general formula (2):

[0047]

Embedded image

The phosphazenium compound represented by the following formula can be exemplified as a suitable compound. Here, in the chemical formulas (1) and (2), a, b, c, and d are integers of 0 to 3, which are not all 0 at the same time. R is the same or different hydrocarbon group having 1 to 10 carbon atoms, and two Rs on the same nitrogen atom may combine to form a ring structure. In Formula (1) r is a number from a by phosphazenium cation an integer of 1 to 3, T ^r represents an inorganic anion having a valence of r, the formula of (2) Q ^- hydroxy anion, alkoxy anion , An aryloxy anion or a carboxy anion. Specifically, for example, tetrakis [tris (dimethylamino) phosphoranylideneamino] phosphonium hydroxide, tetrakis [tris (dimethylamino) phosphoranylideneamino] phosphonium methoxide, tetrakis [tris (dimethyl) Amino) phosphoranylideneamino] phosphonium ethoxide, tetrakis [tri (pyrrolidin-1-yl) phosphoranylideneamino] phosphonium te
rt-butoxide and the like.

As the phosphazene compound, for example, E
A compound described in P-765555, and 1-tert.
-Butyl-2,2,2-tris (dimethylamino) phosphazene, 1- (1,1,3,3-tetramethylbutyl) -2,2,2-tris (dimethylamino) phosphazene, 1-ethyl-2 , 2,4,4,4-pentakis (dimethylamino) -2λ ⁵ , 4λ ⁵ -catenadi (phosphazene), 1-tert-butyl-4,4,4-tris (dimethylamino) -2,2-bis [ Tris (dimethylamino) phosphoranylideneamino] -2λ ⁵ , 4λ
⁵ -Catenadi (phosphazene), 1- (1,1,3,3
-Tetramethylbutyl) -4,4,4-tris (dimethylamino) -2,2-bis [tris (dimethylamino)
Phosphoranylideneamino Rani isopropylidene amino] -2λ ^5, 4λ ⁵ - Katenaji (phosphazene), 1-tert-butyl-2,2,
2-tri (1-pyrrolidinyl) phosphazene, or 7
-Ethyl-5,11-dimethyl-1,5,7,11-tetraaza-6λ ⁵ -phosphaspiro [5,5] undeca-1 (6) -ene.

The phosphine oxide compound is, for example, a compound described in Japanese Patent Application No. 11-296610.
And tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide, tris [tris (diethylamino) phosphoranylideneamino] phosphine oxide and the like. Among the compounds having a P = N bond, a compound selected from a phosphazenium compound and a phosphine compound is preferable. Particularly preferred are phosphazenium compounds.

<Initiator> Examples of the active hydrogen compound used as an initiator in the production of the polyoxyalkylene polyol include an active hydrogen compound having an active hydrogen atom on an oxygen atom and an active hydrogen compound having an active hydrogen atom on a nitrogen atom. Is mentioned. Among the active hydrogen compounds exemplified below, ethylene glycol, propylene glycol,
Dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose and the like are particularly preferred.

(1) Active hydrogen compound having an active hydrogen atom on an oxygen atom Among the active hydrogen compounds in the method of the present invention, the active hydrogen compound having an active hydrogen atom on an oxygen atom includes water,
Examples include polycarboxylic acids having a carboxyl group, carbamic acid, polyhydric alcohols having a hydroxyl group, saccharides or derivatives thereof, and aromatic compounds having a hydroxyl group.

Examples of the polycarboxylic acid having a carboxyl group include malonic acid, succinic acid, maleic acid, fumaric acid, adipic acid, itaconic acid, butanetetracarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid and trimellitic acid. Acid or pyromellitic acid. Examples of carbamic acid include N, N-diethylcarbamic acid, N-
Carboxypyrrolidone, N-carboxyaniline or N,
N'-dicarboxy-2,4-toluenediamine and the like.

Examples of the polyhydric alcohol having a hydroxyl group include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,6-hexane. Examples thereof include diol, 1,4-cyclohexanediol, trimethylolpropane, glycerin, diglycerin, pentaerythritol and dipentaerythritol.

Examples of the saccharide or a derivative thereof include glucose, sorbitol, dextrose, fructose and sucrose. Examples of the aromatic compound having a hydroxyl group include 2-naphthol, 2,6-dihydroxynaphthalene, bisphenol A, bisphenol F, hydroquinone, resorcinol, bis (hydroxyethyl) terephthalate, and the like.

(2) Active hydrogen compound having an active hydrogen atom on a nitrogen atom Among the active hydrogen compounds in the method of the present invention, the active hydrogen compound having an active hydrogen atom on a nitrogen atom includes aliphatic or aromatic compounds. Group amines and the like. Examples of the aliphatic or aromatic amine include normal-propylamine, isopropylamine, normal-butylamine, isobutylamine, sec-butylamine, tert-butylamine, cyclohexylamine, benzylamine,
β-phenylethylamine, aniline, o-toluidine, m
-Toluidine or p-toluidine.

Examples of the polyvalent amine include ethylenediamine, di (2-aminoethyl) amine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, tri (2-aminoethyl) amine, N, N′-dimethylethylenediamine, N, N'-diethylethylenediamine or di (2-methylaminoethyl) amine is exemplified. <Alkylene oxide> The alkylene oxide used in the production of the polyoxyalkylene polyol of the present invention preferably contains propylene oxide as a main component, more preferably another alkylene oxide compound containing at least 50% by mass of propylene oxide. Is a mixture of By using such an amount of propylene oxide, the content of oxypropylene groups in the polyoxyalkylene polyol is reduced by at least 50% by mass.
Can be controlled. When the content of the oxypropylene group in the polyoxyalkylene polyol is 50% by mass or more, a low-viscosity polyoxyalkylene polyol is obtained, so that a resin premix having good liquid flowability is obtained.
Alkylene oxide compounds that can be used in combination with propylene oxide include ethylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide, cyclohexene oxide, epichlorohydrin, epibromohydrin, methyl glycidyl ether, allyl glycidyl Epoxy compounds such as ether and phenyl glycidyl ether are exemplified.

It is particularly preferable to use ethylene oxide in combination. <Other polyols> In the production of the microfoamed polyurethane elastomer of the present invention, a polyol having a structure other than the above polyoxyalkylene polyol can be used in combination within a range not to impair the effects of the present invention. Examples of such other polyols include polyhydric alcohols such as divalent to hexavalent, polyester polyols (including general-purpose polyester polyols, aromatic polyester polyols, and polycaprolactone polyols), polycarbonate polyols, and polymer-dispersed polyols. Can be exemplified.

(Polyhydric alcohol) Examples of the polyhydric alcohol include dihydric alcohols such as 1,3-propanediol, 1,4-butanediol, ethylene glycol, diethylene glycol, triethylene glycol,
Propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, pentanediol, hexanediol, cyclohexanediol, neopentyl glycol, and the like; glycerin, trimethylolethane, and trimethylolpropane as trihydric alcohols; and pentaerythritol as a tetrahydric alcohol, Examples of hexahydric alcohols such as diglycerin include sorbitol.

(General-purpose polyester polyol) Examples of the general-purpose polyester polyol include a polyester polyol obtained by polycondensing a dicarboxylic acid and a polyhydric alcohol. Examples of the dicarboxylic acid used for the polyester polyol include adipic acid, succinic acid, azelaic acid, suberic acid, and ricinoleic acid. Polyhydric alcohols include ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, pentanediol, cyclohexanediol,
Examples thereof include polyoxyalkylene polyol, polytetramethylene ether glycol, glycerin, trimethylolpropane, trimethylolethane, and pentaerythritol.

(Polycaprolactone polyol) The polycaprolactone polyol is a polyol obtained from ε-caprolactone and a polyhydric alcohol, and usually has a number average molecular weight of 500 to 4000 and a hydroxyl value of 30.
It is about 240 mgKOH / g. As the polyhydric alcohol, the polyhydric alcohol used for the above-mentioned general-purpose polyester polyol can be used.

(Polycarbonate Polyol) Polycarbonate polyols include polyhydric alcohols such as 1,4-butanediol and 1,6-hexanediol.
It is a linear aliphatic or alicyclic polyol obtained by a condensation reaction of dimethyl carbonate, diethyl carbonate or the like, and is, for example, one represented by the following general formula (3).

[0063]

Embedded image

(Wherein R ¹ and R ² represent an aliphatic alkylene group or an alicyclic alkylene group and may be the same or different). Usually, the hydroxyl value is about 60 to 200 mgKOH / g. (Aromatic polyester polyol) Transesterification reaction of synthetic resin such as polyethylene terephthalate with polyhydric alcohol, or o-phthalic acid, m-phthalic acid, p-
It is produced by polycondensation of an aromatic carboxylic acid such as phthalic acid and a polyhydric alcohol. As the polyhydric alcohol used here, in addition to the above-mentioned polyhydric alcohols, polyoxyalkylene polyol, polytetramethylene ether glycol and the like are preferably used. These can be used alone or as a mixture containing two or more. As the aromatic ester polyol, a hydroxyl value of 10
~ 150 mgKOH / g, more preferably 1
5-100 mgKOH / g. The acid value is preferably 0.7 mg KOH / g or less, more preferably 0.5 mg KOH / g or less. By using the aromatic polyester polyol as the polyol of the isocyanate-terminated prepolymer, a microfoamed polyurethane elastomer having more excellent mechanical properties can be obtained.

(Polymer-dispersed polyol) The polymer-dispersed polyol is obtained by converting an ethylenically unsaturated group-containing monomer having an unsaturated bond such as acrylonitrile or styrene using a radical initiator such as azobisisobutyronitrile.
A dispersion of vinyl polymer particles (sometimes simply referred to as polymer fine particles) containing a partial graft obtained by dispersion polymerization in a polyol. By using the polymer-dispersed polyol, an effect of sufficiently increasing the hardness of the microfoamed polyurethane elastomer can be obtained.

The polyol used here is, for example,
Any of polyols such as polyester polyols and polyoxyalkylene polyols having an average number of functional groups of 2 to 6 may be used, but it is more preferable to use the polyoxyalkylene polyol according to the present invention having the above-mentioned predetermined characteristics. The average particle size of the polymer obtained by this dispersion polymerization is 0.
1 to 10 μm is preferred.

In order to sufficiently develop the mechanical strength of the microfoamed polyurethane elastomer, the hydroxyl value of the polymer-dispersed polyol is preferably 5 to 99 mgKOH / g,
~ 59 mgKOH / g is particularly preferred. In the polymer-dispersed polyol according to the present invention, the proportion of the polymer fine particles in the polyoxyalkylene polyol is 1 to
It is preferably 50% by mass, more preferably 10 to 45% by mass. The monomer containing an ethylenically unsaturated group is preferably at least one monomer containing an ethylenically unsaturated group selected from the group consisting of acrylonitrile, styrene, acrylamide and methyl methacrylate. By using an ethylenically unsaturated group-containing monomer selected from these groups in a polymer-dispersed polyol, a microfoamed polyurethane elastomer having more excellent mechanical properties can be obtained. In particular, a polymer-dispersed polyol containing at least 30% by mass of styrene is preferred, and particularly preferred is 4%.
It is at least 0% by mass, most preferably at least 50% by mass.
When acrylonitrile-styrene copolymer-based polymer fine particles are used for the polymer-dispersed polyol, the whiteness of the microfoamed polyurethane elastomer is affected by the styrene content. By controlling the styrene content, a microfoamed polyurethane elastomer having a white appearance that can be preferably used for a white shoe sole is obtained.

{Polyisocyanate Compound} As the polyisocyanate compound used for producing the microfoamed polyurethane elastomer according to the present invention, any polyisocyanate compound can be used as long as it is used for producing polyurethane. Examples of the polyisocyanate include tolylene diisocyanate (including various mixtures of isomers),
Diphenylmethane diisocyanate (including various mixtures of isomers), 3,3′-dimethyl-4,4′-biphenylene diisocyanate, norbornane diisocyanate,
1,4-phenylene diisocyanate, tetramethyl xylylene diisocyanate, naphthalene diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, hydrogenated xylene diisocyanate,
1,4-cyclohexyl diisocyanate, 1-methyl-2,4-diisocyanatocyclohexane, 2,4
Diisocyanates such as 4-trimethyl-1,6-diisocyanate-hexane; and triisocyanates such as 4,4 ', 4 "-triphenylmethane triisocyanate and tris (4-phenyl isocyanate) thiophosphate. .

Further, polyisocyanates such as urethane-modified products, isocyanurate-modified products, carbodiimide-modified products, and burette-modified products of these polyisocyanates;
Furthermore, crude tolylene diisocyanate, polymethylene
Polyfunctional isocyanates such as polyphenyl isocyanate can be used. Among these, the isocyanate-terminated prepolymer which is obtained by reacting the above-exemplified polyisocyanate and the carbodiimide-modified polyisocyanate with a polyol to form a urethane-modified isocyanate is particularly preferable.

Further, the ratio of isocyanate groups in the isocyanate-terminated prepolymer molecule, that is, the percentage of isocyanate groups in the molecular weight (the content of isocyanate groups in the isocyanate-terminated prepolymer) is from 0.3 to 30.
% By mass, preferably 1 to 30% by mass, more preferably 4 to 25% by mass, and most preferably 5 to 25% by mass.

The polyol used for obtaining the isocyanate group-terminated prepolymer is not particularly limited, and various polyols such as polyoxyalkylene polyol, polyester polyol, polybutadiene polyol, and polycarbonate polyol may be used alone or in combination. You may mix. Particularly preferred is an urethane-modified isocyanate-terminated prepolymer obtained by reacting an aromatic polyester polyol or the polyoxyalkylene polyol according to the present invention with a polyisocyanate.

In particular, when the aromatic polyester polyol is used as the polyol of the isocyanate group-terminated prepolymer, the isocyanate-terminated prepolymer obtained from the aromatic polyester polyol and the polyisocyanate is at least 20% by mass, preferably at least 30% by mass. More preferably, when the content is 40% by mass or more, high reactivity is obtained, and a microfoamed polyurethane elastomer having excellent mechanical strength is obtained.

{Blowing Agent} Water, cyclopentane, trichloromethane, trichloromonofluoromethane, 1,1,2-trichlorotrifluoromethane, and the like are used as the blowing agent in the production of the microfoamed polyurethane elastomer of the present invention.
1,1-dichloro-2,2,2-trifluoroethane,
1,1-Dichloro-1-monofluoroethane and the like can be used alone or in a mixture at an arbitrary ratio. Among them, it is particularly preferable to use water alone.

{Catalyst} As the catalyst, various known catalysts can be used. For example, triethylamine, tripropylamine, tributylamine, morpholine, N-methylmorpholine, N-ethylmorpholine, dimethylcyclohexylamine, 1,4-diazabicyclo- (2,2,2) -octane (hereinafter, referred to as “octane”) , TEDA), TEDA salt, N, N, N ', N'-tetramethylhexamethylenediamine, N, N, N', N'-tetramethylpropylenediamine, N, N, N ', N',
N "-pentamethyldiethylenetriamine, trimethylaminoethylpiperazine, N, N-dimethylcyclohexylamine, N, N-dimethylbenzylamine, N-methylmorpholine, N-ethylmorpholine, bis (dimethylaminoalkyl) piperazine, N, N, N ', N'-
Tetramethylethylenediamine, N, N-diethylbenzylamine, bis (N, N-diethylaminoethyl) adipate, N, N, N ′, N′-tetramethyl-1,3
Amines such as -butanediamine, N, N-dimethyl-β-phenylethylamine, 1,2-dimethylimidazole, 2-methylimidazole, tin octylate, tin oleate, tin laurate, dibutyltin diacetate, dibutyl Organic tin compounds such as tin dilaurate, lead octylate,
An organic lead compound such as lead naphthenate is used. These catalysts are used alone or as a mixture, preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the polyol.

{Chain extender} The chain extender has a molecular weight of 4
A polyol having a low molecular weight of 00 or less is preferably used. For example, propylene glycol, dipropylene glycol, ethylene glycol, diethylene glycol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, 1,6-hexanediol, glycerin, bishydroxyethoxybenzene,
Bishydroxyethyl terephthalate, diethoxyresorcin and the like. Two or more chain extenders may be used in combination. Preferably, they are ethylene glycol and 1,4-butanediol. The chain extender is preferably 3 to 60 parts by mass, more preferably 3 to 50 parts by mass, per 100 parts by mass of the polyol.

{Foam stabilizer} The foam stabilizer is not particularly limited as long as it is a general foam stabilizer used in the production of polyurethane foam, and conventionally known organosilicon surfactants can be used. The amount used is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the polyol. More preferably, 0.
It is 2 to 5 parts by mass. As a foam stabilizer, for example, Toray
Product name: SRX-2, manufactured by Dow Corning Silicone
74C, SF-2969, SF-2961, SF-29
62 or manufactured by Nippon Unicar, trade name: L-530
9, L-5302, L-3601, L-5307, L-
3600 etc. can be used.

{Other Additives} Other additives include a yellowing inhibitor, an ultraviolet absorber, an antioxidant, a flame retardant,
Coloring agents and the like.製造 Production method of microfoamed polyurethane elastomer 微 The microfoamed polyurethane elastomer of the present invention is a polyol containing the polyoxyalkylene polyol according to the present invention, a chain extender, water used as a foaming agent, a catalyst, and a foam stabilizer in advance. Mixed liquid (hereinafter referred to as resin premix)
And a polyisocyanate compound with stirring. Usually, the NCO index at this time is preferably in the range of 0.8 to 1.3, more preferably 0.9 to 1.3.
1.2. The NCO index is the ratio of the number of moles of active hydrogen in all active hydrogen compounds (polyol, water as a chain extender and a blowing agent) to the number of moles of isocyanate groups in a polyisocyanate compound.

The stirring and mixing is usually carried out at a temperature in the range of 20 to 60 ° C. using a low-pressure or high-pressure circulating foaming machine, although it depends on the size of the microfoamed polyurethane elastomer. For example, when an open mold is used in a low-pressure foaming machine, a mixture of the resin premix and the polyisocyanate compound is injected into a mold (die). Quickly close the lid of the open mold with a clamp and cure in a hot air drying oven at 70 ° C. for 5 to 20 minutes. After that, take out the micro-foamed polyurethane elastomer from the mold,
Measure the physical properties. In the case of performing after-curing, for example, after-curing is usually performed at 70 ° C. for 24 hours, or at 70 ° C. for 2 hours.

In order to produce a microfoamed polyurethane elastomer satisfying the above characteristics of the present invention, water used as a foaming aid is usually added to 100 parts by mass of polyol.
0.1 to 5 parts by mass, 0.1 to 20 parts by mass of a foam stabilizer, 0.1 to 10 parts by mass of a urethanization catalyst, and 3 to 3 parts of a chain extender.
60 parts by mass (all the amounts are based on 100 parts by mass of the polyol) are used.

{Applications of Microfoamed Polyurethane Elastomer} The microfoamed polyurethane elastomer of the present invention is excellent in mechanical properties such as tensile strength, 100% modulus, maximum elongation, tear strength, and compression set, and is demolded. Since the time is short, the productivity is excellent. A shoe sole obtained from the microfoamed polyurethane elastomer having such properties is excellent in comfort and durability. Further, since the cell diameter existing on the skin surface is within a specific range, the skin property and the coatability are excellent. Therefore, the microfoamed polyurethane elastomer of the present invention is suitable for applications such as shoe soles, gaskets for electric parts and the like, gaskets for industrial parts and the like, sheet mats, foot wipe mats, static damping materials, silent materials, and shock absorbing materials. It is a material that can be used.

[0081]

EFFECTS OF THE INVENTION A microfoamed polyurethane elastomer which is excellent in mechanical properties such as tensile strength, 100% modulus, maximum elongation, tear strength and compression set, and excellent in surface properties and coatability and suitable for shoe soles is obtained. Can be Because of excellent mechanical properties, it is possible to obtain a low-density finely-foamed polyurethane elastomer with equivalent mechanical properties, and it is possible to reduce the weight in various applications.

In particular, a finely foamed polyurethane elastomer can be obtained while maintaining excellent mechanical properties even when the demolding time is shortened. Shoe soles and the like obtained from such a microfoamed polyurethane elastomer were excellent in comfort, durability and surface properties.

[0083]

EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. Parts and% in Examples are parts by mass and% by mass, respectively. << Measurement Method >> First, the method of measuring the characteristic values measured in the following Examples and Comparative Examples is as follows. <Analytical Method of Polyoxyalkylene Polyol> (1) Hydroxyl Value (OHV, unit: mgKOH / g), Total Unsaturation (C = C, unit: meq./g) Measured by the method described in JIS K-1557. . still,
The number of hydroxyl groups of the polyoxyalkylene polyol is the number of hydroxyl groups of the active hydrogen compound used as the initiator.

(2) Head-to-tail (HT) bond selectivity (unit: mol%) 400 MHz, ¹³ C-nuclear magnetic resonance (NMR) manufactured by JEOL Ltd.
Using a device, deuterated chloroform was used as a solvent, and the ¹³ C-NMR spectrum of the polyoxyalkylene polyol was measured. Head-t-tail
The signal (16.9 to 17.4 ppm) of the methyl group of the oxypropylene segment of the o-Tail bond and the signal (1) of the methyl group of the oxypropylene segment of the head-to-head bond
7.7 to 18.5 ppm). The assignment of each signal is described in Macromolecules, 19.13.
37-1343 (1986); C. schilin
g. E. FIG. The values described in the report of Tonelli were referred to.

(3) W ₂₀ / W ₈₀ (index value of molecular weight distribution of polyoxyalkylene polyol, unit: dimensionless) In a gel permeation chromatogram (GPC) elution curve of polyoxyalkylene polyol, maximum peak height when defined as 100% of, by dividing the peak width at 20% of its peak height W _20, when the peak width at 80% peak height is defined as W _80, the W ₂₀ with W ₈₀ Value. The measurement conditions of GPC are shown below. -Measurement and analysis device: LC-6A system manufactured by Shimadzu Corporation-Detector: RID-6A differential refractometer manufactured by Shimadzu Corporation-Separation column: Shodex GPC manufactured by Showa Denko KK
KF series (KF-801, 802, 802.5, 8
・ Eluent; tetrahydrofuran for liquid chromatogram ・ Liquid flow rate: 0.8 ml / min ・ Column temperature: 40 ° C. (4) Terminal oxyethylene group content of polyoxyalkylene polyol (unit: mass%) The polyoxyalkylene polyol was dissolved in deuterated chloroform, and the oxyethylene group content was measured by ¹ H-NMR.

(5) Primary OH conversion rate at terminal (unit: mol)
%) Polyoxyalkylene polyol was dissolved in deuterated chloroform, and the terminal primary OH conversion was measured by ¹³ C-NMR. <Method of evaluating physical properties of microfoamed polyurethane elastomer> A microfoamed polyurethane elastomer collected from a sheet made of an aluminum mold having an inner size of 12.5 x 150.0 x 250.0 mm using a punch of a predetermined size. Is a sample for physical property evaluation.

(6) Average diameter of cells observed on the skin surface (unit: μm) The skin surface has an inner size of 12.5 × 150.0 × 250.
It refers to the surface of a sheet (finely foamed polyurethane elastomer) made of a 0 mm aluminum mold that was in contact with the mold. The surface in contact with the bottom surface of the mold (15)
0.0 × 250.0 mm), a micro camera (manufactured by Shimadzu Corp.)
The cell diameter is observed by MICROCDC SCOPE / CCD-F2). Next, the average diameter of each cell is determined by the image processing analyzer. The average value of these five locations was defined as the average diameter of the cell observed on the skin surface.

(7) Average diameter of cells inside microfine polyurethane elastomer (unit: μm) Sheet (microfine polyurethane elastomer) made with an aluminum mold having an inner size of 12.5 × 150.0 × 250.0 mm The center part is cut out in a size of 3 cm in length and 1 cm in width, and a portion obtained by removing 4 mm each in the thickness direction from the skin surface in the vertical direction is a micro camera (manufactured by Shimadzu Corporation) for four cross-sectional directions (perpendicular to the skin surface). MI
The cell diameter is observed with a CRO CCD SCOPE / CCD-F2), and the average cell diameter is determined by an image processing / analyzing device.

(8) Total density (unit: kg / m ³ ) Calculated by dividing the weight of the sheet taken out of the mold by the inner volume of the mold. (9) Hardness (unit: none) According to the method described in JIS K-6301, AskerC
Measure with a hardness tester.

(10) Tensile strength (T _B , unit: MP
a), 100% modulus (M ₁₀₀ , unit: MPa),
And maximum elongation (E _B , unit:%) According to the method described in JIS K-6251, a dumbbell-shaped 1
A sample is collected and measured using a model. (11) Tear strength (T _R, Unit: kN / m) by the method of JIS K-6252, wherein samples were taken using an angle type without cut, measured.

(12) Compression set (unit:%) A circular test piece having a diameter of 29 mm is sampled from a sheet and measured according to the method described in JIS K-6262. The test temperature was 55 ± 1 ° C., and the test time was 24 hours. The compression ratio of the test piece is 25%. The compression set value thus measured was defined as “CS”.

A circular test piece having a diameter of 29 mm was sampled from the sheet by the method described in K-6262, and the test temperature was 50 ± 1 ° C., the test time was 6 hours, and the compression ratio of the test piece was 50%. The compression set was measured. The compression set value measured in this manner was designated as “CS2”. (13) Viscosity of resin premix (unit: mPa · s)
/ 25 ° C) using a B-type viscometer (manufactured by Toki Sangyo Co., Ltd.)
The viscosity of the resin premix having the composition shown in Tables 5 and 6 is measured by the method described in -1557. The measurement temperature is 25 ° C.

(14) Demolding time of microfoamed polyurethane elastomer (unit: sec.) Time from injection of a mixed solution of resin premix and polyisocyanate compound into mold until demolding becomes possible (demolding time) Is measured. The term "removable" refers to a state in which the sheet of the microfoamed urethane elastomer is completely cured, and the sheet is not partially peeled off or the sheet is not dropped when the sheet is removed from the mold.

(15) Surface Properties of Microfoamed Polyurethane Elastomer The microfoamed polyurethane elastomer was released from the mold, and the surface properties were visually determined. The surface properties were determined comprehensively based on gloss, presence or absence of flow marks, and presence or absence of pinholes. ：: good, △: average ×: poor (16) Coatability of microfoamed polyurethane elastomer After demolding and storing at room temperature for 1 day, use a black paint (made by Asahipen: lacquer spray) to finely foam polyurethane elastomer. Spray on the surface of. After drying at room temperature for one day, the presence or absence of gloss, uneven color, etc. on the painted surface is visually determined. ：: good △: slightly poor gloss or uneven color
×: no luster and color unevenness {Raw materials} Next, the raw materials used in Examples and Comparative Examples will be described.

<Polyoxyalkylene polyol>

[0096]

Synthesis Example 1 First, the synthesis of the polyoxyalkylene polyol used in the examples will be described. Polyoxyalkylene polyol A For 1 mol of glycerin, tetrakis [tris (dimethylamino) phosphoranylideneamino] phosphonium hydroxide {[(Me ₂ N) ₃ P = N] ₄ P ⁺ OH ⁻ (ie, P5OH). After adding 01 mol and dehydrating under reduced pressure at 100 ° C. for 6 hours, propylene oxide was subjected to addition polymerization at a reaction temperature of 80 ° C. and a maximum pressure of 0.372 MPaG (3.8 kg / cm ² G: G means a gauge pressure). Ethylene oxide is subjected to addition polymerization at a reaction temperature of 100 ° C to give a hydroxyl value of 28.
A mgKOH / g polyoxyalkylene polyol was obtained.

The terminal oxyethylene group content was 15% by mass. The total degree of unsaturation is 0.014 meq. / G. Head-to-tail bond selectivity of 96.8 mol%
Met. Hereinafter, the polyoxyalkylene polyols B, C, and D were prepared in the same manner as the polyoxyalkylene polyol A, except that the hydroxyl value and the number of hydroxyl groups were changed to the values shown in Table 1 for the polyoxyalkylene polyols of the examples. Was manufactured. In addition, propylene oxide was used as a main monomer, and ethylene oxide was used in such an amount that the content of terminal oxyethylene groups in the polyoxyalkylene polyol became 15% by mass. When producing the polyoxyalkylene polyols E and F, the amount used was such that the content of terminal oxyethylene groups became 20% by mass. When producing a polyoxyalkylene polyol having 2 hydroxyl groups, dipropylene glycol was used as an active hydrogen compound, and when producing a polyoxyalkylene polyol having 3 hydroxyl groups, glycerin was used. The obtained polyoxyalkylene polyols A, B, C, D,
Table 1 shows the analysis results of E and F.

[0098]

[Table 1]

[0099]

Synthesis Example 2 Next, the synthesis of a polyoxyalkylene polyol used as a comparative example will be described. Polyoxyalkylene polyol G Potassium hydroxide (hereinafter referred to as KO)
H)), and after dehydration under reduced pressure at 100 ° C. for 6 hours, propylene oxide was reacted at 115 ° C.
Maximum pressure 0.490 MPaG (5.0 kg / cm ² G)
And then ethylene oxide is reacted at a reaction temperature of 1
Addition polymerization was performed at 15 ° C. to obtain a polyoxyalkylene polyol having a hydroxyl value of 28 mgKOH / g. The terminal oxyethylene group content was 15% by mass. Total unsaturation is 0.0
85 meq. / G. Further, the head-to-tail bond selectivity of the polyoxyalkylene polyol was measured in the same manner as in Synthesis Example 1. The head-to-tail bond selectivity was 96.3 mol%.

Hereinafter, a polyoxyalkylene polyol H was produced in the same manner as in the polyoxyalkylene polyol G, except that the hydroxyl value was set to 28 mgKOH / g and the number of hydroxyl groups was set to 2 for the polyoxyalkylene polyol of the comparative example. . In addition, propylene oxide was used as a main monomer, and ethylene oxide was used in such an amount that the content of terminal oxyethylene groups in the polyoxyalkylene polyol became 15% by mass. When producing a polyoxyalkylene polyol having 2 hydroxyl groups, dipropylene glycol was used as an active hydrogen compound.
Table 2 shows the analysis results of the obtained polyoxyalkylene polyols G and H.

[0101]

[Table 2]

[0102]

Synthesis Example 3 The synthesis of another polyoxyalkylene polyol used as a comparative example will be described. A zinc / cobalt cyanide compound and zinc chloride were added to 100 parts by mass of polyoxyalkylene polyol I MN1000 (polyoxypropylene polyol manufactured by Mitsui Chemicals, Inc .: OHV 168 mgKOH / g),
0.05 parts by mass of a so-called double metal cyanation complex (DMC) catalyst composed of water and dimethoxyethanol was added, and propylene oxide was added at a reaction temperature of 90 ° C and a maximum pressure of 0.3.
Addition polymerization at 92 MPaG (4.0 kg / cm ² G),
A polyoxypropylene polyol having a hydroxyl value of 33 mgKOH / g was obtained. Next, the DMC is extracted with aqueous ammonia, and the polyoxypropylene polyol is purified by washing with water. Then, potassium hydroxide (KOH) is added so as to be 0.26 parts by mass with respect to 100 parts by mass of the polyoxypropylene polyol. Dehydration under reduced pressure was performed at 100 ° C. for 6 hours.

Then, ethylene oxide was subjected to addition polymerization at 100 ° C. to obtain a polyoxyalkylene polyol having a hydroxyl value of 28 mgKOH / g. The terminal oxyethylene group content was 15% by mass. The total unsaturation is 0.010m
eq. / G. Further, the head-to-tail bond selectivity of the polyoxyalkylene polyol was measured in the same manner as in Production Example 1. The head-to-tail bond selectivity was 85.4 mol%.

Hereinafter, the polyoxyalkylene polyol G of Comparative Example was changed except that the hydroxyl value and the number of hydroxyl groups were changed to the values shown in Table 3.
Polyoxyalkylene polyols J, K, L, M, and N were produced in the same manner as in the above. In addition, propylene oxide was used as a main monomer, and ethylene oxide was used in such an amount that the content of terminal oxyethylene groups in the polyoxyalkylene polyol became 15% by mass. In producing the polyoxyalkylene polyols M and L, the amount used was such that the content of the terminal oxyethylene group was 20% by mass. When producing a polyoxyalkylene polyol having 2 hydroxyl groups, as an active hydrogen compound,
Polyoxypropylene polyol obtained by addition polymerization of propylene oxide to dipropylene glycol (Diol-
700, manufactured by Mitsui Chemicals, Inc., to produce a polyoxyalkylene polyol having 3 hydroxyl groups, polyoxypropylene polyol obtained by addition polymerization of glycerin and propylene oxide (MN1000, manufactured by Mitsui Chemicals, Inc.)
Was used. Table 3 shows the analysis results of the obtained polyoxyalkylene polyols I, J, K, L, M, and N.

[0105]

[Table 3]

<Polymer-dispersed polyol> Hereinafter, the polymer-dispersed polyol according to the present invention will be described with reference to examples, but the present invention is not limited to these examples. The raw materials, abbreviations, and analytical methods used in the examples are described below. (Polyoxyalkylene polyol) A, I; (Hereinafter, the polyoxyalkylene polyol used in the synthesis of the polymer-dispersed polyol is based on PPG.
Abbreviated). (Ethylenically unsaturated monomer-1); acrylonitrile (hereinafter abbreviated as AN). (Ethylenically unsaturated monomer-2); styrene (hereinafter abbreviated as St).
(Chain transfer agent); triethylamine (hereinafter abbreviated as TEA). (Radical initiator); azobisisobutyronitrile (hereinafter abbreviated as AIBN).

(17) Hydroxyl value (abbreviated as OHV; unit: mgKOH / g) of the polymer-dispersed polyol;
Viscosity (abbreviated as η; unit: mPa · s / 25 ° C.) Determined by the method described in JIS K-1557. (18) Polymer concentration (unit: mass%) Methanol is added to the polymer-dispersed polyol, dispersed well, and then centrifuged to determine the weight of the methanol-insoluble component. However, a polymer-dispersed polyol using acrylonitrile (AN) alone as the ethylenically unsaturated monomer is determined from the nitrogen content by elemental analysis.

The base PPG was charged into a 1-liter autoclave equipped with a thermometer, a stirrer, and a liquid feeder to a full state,
The temperature was raised to 120 ° C. while stirring. Subsequently, a mixed solution of 58.5 parts by mass of PPG PPG, 12.45 parts by mass of AN, 29.05 parts by mass of St, 0.55 parts by mass of V-59, 2.76 parts by mass of IPA, and 0.28 parts by mass of TEA was continuously added in advance. And a polymer-dispersed polyol was continuously obtained from the outlet. At this time, the reaction pressure was 0.444 M
PaG (3.5 kgf / cm2G), retention time was 50 minutes. After reaching a steady state, the resulting reaction solution is
The mixture was heated under reduced pressure at 0 ° C. and 2.66 kPa (20 mmHgabs.) For 3 hours to obtain an unreacted ethylenically unsaturated monomer,
The decomposition products of the polymerization initiator, the chain transfer agent and the like were removed to obtain polymer-dispersed polyols O and P. Table 4 shows the results.

[0109]

[Table 4]

<Polyisocyanate Compound> Isocyanate-terminated prepolymer Q In a nitrogen atmosphere, cosmonate PH was placed in a separable flask.
676 parts by mass of 4,4-diphenylmethane diisocyanate (manufactured by Mitsui Chemicals, Inc.) and 324 parts by mass of Diol-1000 (polyoxypropylene diol of 112 mgKOH / g OHV, manufactured by Mitsui Chemicals, Inc.) were weighed and 80
An isocyanate-terminated prepolymer having an isocyanate group content of 20% by mass, which was reacted at a temperature of 2 ° C. for 2 hours.

Isocyanate-terminated prepolymer R In a four-necked flask, 100 parts of terephthalic acid and 125 parts of tripropylene glycol were charged, and a stirring rod, a dehydrating tube,
A nitrogen gas inlet tube and a thermometer were attached. Next, nitrogen gas was introduced into the flask, and water generated was distilled off while paying attention to bumping, and the temperature was raised to 200 ° C. The acid value of the reactant is 20
At the point of time below, 0.045 parts of tetraisopropyl titanate was added as a titanium-based catalyst, and then the pressure was gradually reduced, and water was further distilled off at 1.33 kPa. By continuing the reaction until the acid value of the obtained reaction solution became 1 mgKOH / g or less, aromatic polyester polyol S was obtained. After returning to normal pressure, the reaction mixture was cooled to 80 ° C., and 3.4 parts by mass of distilled water was added thereto.
After deactivating the titanium-based catalyst by continuing heating for a period of time, water was distilled off under reduced pressure. The obtained aromatic polyester polyol S had an acid value of 0.3 mgKOH / g and a hydroxyl value of 113.1 mgKOH / g.

An isocyanate-terminated prepolymer R was obtained in the same manner as in the isocyanate-terminated prepolymer Q, except that the aromatic polyester polyol S obtained by the above synthesis was used as the polyol to be used as the isocyanate modifier. <Catalyst>MINICO; Amine catalyst (triethylenediamine) manufactured by Active Materials Chemical Co., Ltd. <Chain extender> Ethylene glycol; Wako Pure Chemical Industries, Ltd. <Foam stabilizer>SF-2962; Toray Dow Corning Silicone ) Silicone foam stabilizer <Blowing agent> Ion-exchanged water (hereinafter referred to as water) << Examples and Comparative Examples >> Hereinafter, Examples will be described.

Tables 5 and 6 show the blending of polyoxyalkylene polyol, a chain extender, water as a foaming agent, a foam stabilizer and a catalyst (hereinafter, this blend is referred to as a resin premix). The values other than the molar ratios in Tables 5 and 6 are shown in parts by mass. Formulations using the polyoxyalkylene polyols A to F and the polymer-dispersed polyol O according to the present invention are shown in Examples 1 to 5 in Table 5. As a comparative example, a composition using polyoxyalkylene polyols G and H polymerized by a KOH catalyst is shown in Comparative Example 1 in Table 6. The formulations using the polyoxyalkylene polyols I to N polymerized by the DMC catalyst and the polymer-dispersed polyol P are shown in Comparative Examples 2 to 6 in Table 6.

[0114]

Example 1 In a stainless steel container, 372 parts by mass of polyoxyalkylene polyol A, 563 parts by mass of polyoxyalkylene polyol C, 45 parts by mass of a chain extender, 5 parts of water
5 parts by mass of the catalyst, 10 parts by mass of the foam stabilizer, and 5 parts by mass
00r. p. m. Under the conditions described above, the resin premix was prepared by stirring and mixing for 5 minutes. Next, the polyisocyanate compound is adjusted such that the ratio of the number of moles of active hydrogen in the resin premix to the number of moles of isocyanate groups in the polyisocyanate compound (isocyanate index, hereinafter referred to as NCO / OH) becomes 1.0. Was weighed and added to the resin premix. At this time, the resin premix and the polyisocyanate compound were adjusted to 40 ° C. in advance. Using a homomixer, 1500 r. p. m. Immediately after stirring and mixing at a rotation speed of 3 seconds, the mixture was poured into an aluminum mold having an inner size of 12.5 × 150.0 × 250.0 mm, which was previously adjusted to 40 ° C., and the lid was closed. The mold was placed in an oven adjusted to 40 ° C. The demolding time and after demolding, physical properties of the microfoamed polyurethane elastomer were measured.

Table 7 shows the viscosity of the resin premix, Table 8 shows the demolding time, and Table 9 shows the physical properties of the microfoamed polyurethane elastomer.

[0116]

Example 2 A microfoamed polyurethane elastomer was obtained in the same manner as in Example 1, except that polyoxyalkylene polyols B and D were used instead of polyoxyalkylene polyols A and C. Table 5 shows the formulation, Table 8 shows the demolding time, and Table 9 shows the physical properties. In Table 5, units other than NCO / OH are parts by mass.

[0117]

Example 3 A microfoamed polyurethane elastomer was obtained in the same manner as in Example 1 except that polyoxyalkylene polyols E and F were used instead of polyoxyalkylene polyols A and C. Table 5 shows the formulation, Table 8 shows the demolding time, and Table 9 shows the physical properties.

[0118]

Example 4 A microfoamed polyurethane elastomer was obtained in the same manner as in Example 1, except that polyoxyalkylene polyol C and polymer-dispersed polyol O were used instead of polyoxyalkylene polyols A and C. still,
Table 5 shows the formulation, Table 8 shows the demolding time, and Table 9 shows the physical properties.

[0119]

Example 5 Example 3 except that isocyanate-terminated prepolymer R was used as the polyisocyanate compound.
A microfoamed polyurethane elastomer was obtained in the same manner as described above. Table 5 shows the formulation and Table 8 shows the demolding time.
Shows the physical properties.

[0120]

[Table 5]

[0121]

Comparative Example 1 Finely foamed urethane was prepared in the same manner as in Example 1 except that polyoxyalkylene polyols G and H produced using a KOH catalyst were used instead of polyoxyalkylene polyols A and C. An elastomer was obtained. Table 6 shows the formulation examples, Table 7 shows the viscosity of the resin premix, Table 8 shows the demolding time, and Table 1
0 shows the physical properties of the microfoamed polyurethane elastomer. In Table 6, units other than NCO / OH are parts by mass.

[0122]

Comparative Example 2 Fine foaming was carried out in the same manner as in Example 1 except that polyoxyalkylene polyols I and K produced using a DMC catalyst were used instead of polyoxyalkylene polyols A and C. A urethane elastomer was obtained. Table 6 shows the formulation examples, Table 7 shows the viscosity of the resin premix, Table 8 shows the demolding time,
Table 10 shows the physical properties of the microfoamed polyurethane elastomer.

[0123]

Comparative Example 3 A microfoamed urethane elastomer was obtained in the same manner as in Example 1 except that polyoxyalkylene polyol J and polyoxyalkylene polyol L produced using a DMC catalyst were used. Table 6 shows the formulation examples, Table 8 shows the demolding time, and Table 10 shows the physical properties of the microfoamed polyurethane elastomer.

[0124]

Comparative Example 4 A microfoamed urethane elastomer was obtained in the same manner as in Example 1 except that polyoxyalkylene polyol M and polyoxyalkylene polyol N produced using a DMC catalyst were used. Table 6 shows the formulation examples, Table 8 shows the demolding time, and Table 10 shows the physical properties of the microfoamed polyurethane elastomer.

[0125]

Comparative Example 5 Polyoxyalkylene polyol K produced using DMC catalyst and polymer-dispersed polyol P
Except for using the same procedure, a microfoamed urethane elastomer was obtained in the same manner as in Example 1. Table 6 shows formulation examples, and Table 8
Table 10 shows the demolding time, and Table 10 shows the physical properties of the microfoamed polyurethane elastomer.

[0126]

[Table 6]

[0127]

[Table 7]

[0128]

[Table 8]

[0129]

[Table 9]

[0130]

[Table 10]

In all of Examples 1 to 5 and Comparative Examples 1 to 5, the total density was 510 (kg / m ³ ). In this case, the compression set (CS2) and the total The values of the equations in the relational expression with the density (D) are as follows. 0.00008 * D ² -0.091 * D + 42 = 16.4 0.00008 * D ² -0.091 * D + 40 = 14.4 0.00008 * D ² -0.091 * D + 38 = 12.4 The present invention Are as follows in the relational expression between the cell diameter (X) and the total density (D).

[0132]

(Equation 10)

When the total density of the microfoamed polyurethane elastomer was changed by adjusting the amount of injection into the mold as in the formulations shown in Tables 5 and 6 (Examples 1, 2 and Comparative Examples 1 to 3) The mechanical properties of are shown below.

[0134]

[Table 11]

Example 6 having a total density of 350 (kg / m ³ )
7, In all of Comparative Examples 6 to 8, the values of the mathematical expressions in the relational expression between the cell diameter (X) and the total density (D) according to the present invention are as follows. 0.00008 * D ² -0.091 * D + 42 = 20.0 0.00008 * D ² -0.091 * D + 40 = 18.0 0.00008 * D ² -0.091 * D + 38 = 16.0 The present invention Are as follows in the relational expression between the cell diameter (X) and the total density (D).

[0136]

[Equation 11]

To explain the results, as shown in Table 8,
Examples 1 to 5 of the present invention include Comparative Example 1 using a polyoxyalkylene polyol polymerized using a conventional KOH catalyst and Comparative Examples 2 to 5 using a polyoxyalkylene polyol polymerized using a DMC catalyst. In contrast, it showed a significant reduction in demold time. Shortening of the demolding time can greatly contribute to improvement in productivity.

Further, as shown in Tables 9 and 10, Examples 1 to 5 using the polyoxyalkylene polyol according to the present invention showed comparative examples using the polyoxyalkylene polyol polymerized using the conventional KOH catalyst. Example 1 and DMC
Compared to Comparative Examples 2 to 5 using a polyoxyalkylene polyol polymerized by using a catalyst, remarkable increases in physical properties such as tensile strength, 100% modulus, maximum elongation, and tear strength,
Moreover, it shows a remarkable decrease in compression set and is excellent in mechanical properties. In the combined system of the polymer-dispersed polyol (Example 4) and when the aromatic polyester polyol is used as the isocyanate-terminated prepolymer modifier (Example 5), the mechanical properties are improved, and the surface property and coating property are improved. Are better.

Further, as shown in Table 11, even in the case of a microfoamed polyurethane elastomer having a low total density, Example 6,
And 7 were compared with Comparative Examples 6 to 8, and the tensile strength was 100%.
Modulus, maximum elongation, remarkable increase in physical properties of tear strength, and remarkable decrease in compression set showed improvement in mechanical properties. The cell diameter (X) on the skin surface of the microfoamed polyurethane elastomer achieves the compression set (CS2) specified in the present application within a range satisfying the range specified in the present application. This is an important factor in obtaining a microfoamed polyurethane elastomer that exhibits not only certain surface properties but also excellent mechanical properties.

By using a polyoxyalkylene polyol having a hydroxyl value (OHV), a total degree of unsaturation, and a head-to-tail (HT) selectivity in a specific range, the tensile strength,
00% modulus, maximum elongation, remarkable increase in physical properties such as tear strength and remarkable decrease in compression set, easily produce microfoamed polyurethane elastomer with excellent mechanical properties and excellent surface properties and coatability It becomes possible.

Continued on the front page (72) Inventor Kaoru Ueno 580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals, Inc. (72) Inventor Satoshi Yamazaki 580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals, Inc. ) Inventor Goro Kuwamura 580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals Co., Ltd. (72) Inventor Daisuke Nishiguchi 580-32 Nagaura, Sodegaura-shi, Chiba F-term in Mitsui Chemicals Co., Ltd. 4F050 AA01 AA06 BA01 HA56 HA73 4J034 BA03 DB03 DC50 DQ12 DQ15 DQ16 DQ18 HA01 HA02 HC01 HC03 HC11 HC12 HC13 HC15 QC01 QC02 RA03

Claims (21)

[Claims] (1) The total density (D) is 100 kg / m ³ or more,
Within the range of 900 kg / m ³ or less, (2) Total density (D)
And compression set (CS2: unit%) are given by the following equation (1): CS2 ≦ 0.00008 * D ² −0.091 * D + 42 .. (Equation 1) is satisfied, and the total density (D) and the average cell diameter (X: unit μm) observed on the skin surface are expressed by the following equation (2). A microfoamed polyurethane elastomer characterized by satisfying the following relationship: 2. The micro-foamed polyurethane elastomer according to claim 1, wherein the total density is in the range of 200 kg / m ³ or more and 700 kg / m ³ or less. 3. The microfoamed polyurethane elastomer according to claim 1, wherein the average diameter of the cells inside the microfoamed polyurethane elastomer is 1 μm or more and 200 μm or less. 4. The total density and compression set are given by the following equation (3): CS2 ≦ 0.00008 * D ² −0.091 * D + 40 The microfoamed polyurethane elastomer according to claim 1 or 2, wherein the following relationship is satisfied. 5. The average diameter of cells (X: unit μm) observed on the skin surface is expressed by the following formula (4). The microfoamed polyurethane elastomer according to any one of claims 1 to 3, wherein the following relationship is satisfied. 6. A hydroxyl value of 2 to 200 mg KOH / g and a total unsaturation of 0.001 to 0.07 meq. / G, a head-to-tail bond selectivity of polyoxyalkylene polyol by propylene oxide addition polymerization obtained by reacting a polyol containing 50% by mass or more of polyoxyalkylene polyol having 95% by mol or more with a polyisocyanate compound. The total density (D) is 100 kg / m ³
The fine foamed polyurethane elastomer in the range of 900 kg / m ³ or less. 7. The method according to claim 1, wherein the polyoxyalkylene polyol is P
The microfoamed polyurethane elastomer according to claim 6, wherein the polyurethane foam is produced using a compound having a = N bond as a catalyst. 8. A microfoamed polyurethane elastomer obtained by reacting a polyol with a polyisocyanate compound, wherein the polyol has a hydroxyl value of 2 to 200 mg KO.
H / g, total unsaturation 0.001 to 0.07 meq. /
g, containing at least 50% by mass of a polyoxyalkylene polyol having a head-to-tail bond selectivity of 95 mol% or more of the polyoxyalkylene polyol by propylene oxide addition polymerization.
The microfoamed polyurethane elastomer according to the above. 9. The method according to claim 8, wherein the polyoxyalkylene polyol is P
The microfoamed polyurethane elastomer according to claim 8, which is produced using a compound having a = N bond as a catalyst. 10. The polymer according to claim 1, wherein said polyol is obtained by polymerizing an ethylenically unsaturated group-containing monomer.
0.5 to 50% by mass of a polymer-dispersed polyol
The microfoamed polyurethane elastomer according to claim 8, which contains 50% by mass. 11. The polymer-dispersed polyol has a hydroxyl value of 2 to 200 mg KOH / g and a total unsaturation of 0.001.
~ 0.07 meq. / G, polymer-dispersed polyol obtained by polymerizing an ethylenically unsaturated group-containing monomer in a polyoxyalkylene polyol having a head-to-tail bond selectivity of 95 mol% or more by propylene oxide addition polymerization The microfoamed polyurethane elastomer according to claim 10, wherein: 12. The microfoamed polyurethane elastomer according to claim 10, wherein the polymer-dispersed polyol contains the polymer fine particles in a range of 10 to 45% by mass. 13. The method according to claim 10, wherein the ethylenically unsaturated group-containing monomer is at least one monomer selected from the group consisting of acrylonitrile, styrene, acrylamide and methyl methacrylate. Fine foamed polyurethane elastomer. 14. The microfoamed polyurethane elastomer according to claim 10, which contains at least 30% by mass of styrene as an ethylenically unsaturated group-containing monomer. 15. The microfoamed polyurethane elastomer according to any one of claims 1 to 14, which is obtained by reacting a polyol with an isocyanate-terminated prepolymer obtained from an aromatic polyester polyol and a polyisocyanate. . 16. A shoe sole obtained by using the microfoamed polyurethane elastomer according to any one of claims 1 to 15. 17. A hydroxyl value of 2 to 200 mg KOH / g,
Total unsaturation 0.001 to 0.07 meq. / G, a polyoxyalkylene polyol having a head-to-tail bond selectivity of 95 mol% or more of a polyoxyalkylene polyol obtained by addition polymerization of propylene oxide.
By reacting a polyol and a polyisocyanate compound containing not less than 100% by mass, (1) the total density (D) is 100 kg / m
³ or more, there is the 900 kg / m ³ within the following ranges, (2) compression set and the total density (D) (CS2: unit%) is the following formula (1) CS2 ≦ 0.00008 * D 2 -0.091 * D
+42 satisfies the relationship of (Equation 1), and the total density (D)
And the average diameter of cells observed on the skin surface (X: unit μ)
m) is given by the following equation (2). A method for producing a microfoamed polyurethane elastomer, characterized by producing a microfoamed polyurethane elastomer satisfying the following relationship: 18. The method according to claim 17, wherein the polyoxyalkylene polyol is produced using a compound having a P = N bond as a catalyst. 19. A micro-foamed polyurethane elastomer obtained by reacting a polyol with a polyisocyanate compound, wherein the polymer dispersion contains 1 to 50% by mass of polymer fine particles obtained by polymerizing an ethylenically unsaturated group-containing monomer. The method for producing a microfoamed polyurethane elastomer according to claim 17, comprising 0.5 to 50% by mass of a polyol. 20. A microfoamed polyurethane elastomer obtained by reacting a polyol with a polyisocyanate compound, wherein the polyisocyanate compound is an isocyanate-terminated prepolymer obtained from an aromatic polyester polyol and a polyisocyanate. A method for producing the microfoamed polyurethane elastomer according to any one of claims 17 to 19. 21. The polyisocyanate compound according to claim 1, wherein the isocyanate-terminated prepolymer obtained from the aromatic polyester polyol and the polyisocyanate is at least 2%.
The method for producing a microfoamed polyurethane elastomer according to claim 20, wherein the content is 0 mass%.