KR100797425B1 - Polyurethane foam, production methods thereof and use of same - Google Patents

Abstract

The present invention relates to polyurethane foams used to make shaped articles, such as for example, various types of shoe soles. More specifically, the present invention relates to low density polyurethane foams having suitable mechanical properties for shoe soles, especially sports shoe soles. The foams of the invention are obtained by the reaction of polyester polyols containing inorganic fillers with diisocyanate prepolymers in suspension. In addition, the density of the foam of this invention is about 0.2 g / cm <3>.

Polyurethane, Foam, Shoe Sole, Midsole

Description

Polyurethane foam, preparation method thereof and use thereof {POLYURETHANE FOAM, PRODUCTION METHODS THEREOF AND USE OF SAME}

The present invention relates to polyurethane foams, in particular polyurethane foams used in the production of soles for shaped articles, such as various types of shoes.

More specifically, the present invention relates to low density polyurethane foams exhibiting suitable properties for shoe sole applications, even more specifically for sport shoe soles or especially for women's padded shoe soles.

Polyurethane foams are used in many applications and can be classified into two types, rigid foams and flexible foams. The field of the present invention relates to flexible polyurethane foams.

One important application of such flexible foams is the manufacture of soles of footwear, in particular sports shoes and padded women's shoes. More specifically, polyurethane foams are for the production of a portion of a shoe sole known as a midsole.

In this application, the sole should exhibit good compressive strain, hardness and high tear strength, but also give the user a comfortable fit.

Suitable polyurethane foams have already been proposed for this application.

However, in order to obtain adequate physical property levels, the polyurethane foam must exhibit a density of at least about 0.35 g / cm 3, which makes it impossible to produce soles having a weight equivalent to that obtained using vinyl acetate copolymer (EVA). Do.

In order to obtain an article having a weight equivalent to that obtained using EVA while maintaining the physical level of the polyurethane foam, which is not obtainable using an outsole made of EVA, an article consisting of a novel polyurethane foam having a very low density is used. There is a problem with this.

One of the objectives of the present invention is to provide suitable physical properties for applications which are particularly low in density and particularly preferred for the production of midsoles in comparison with the polyurethane foams of the prior art, in order to be able to produce articles with low weight and excellent physical properties. A novel polyurethane foam is proposed.

To this end, one of the objectives of the present invention is a flexible polyurethane foam obtained by the reaction of a polyesterdiol and a diisocyanate compound, having a density of less than 0.3 g / cm 3, an ASCHER C hardness of 45 or more, and a permanent compression rate ( compression set) is 12% or less.

Advantageously the foam of the invention has a tensile stress of at least 18 kg / cm 2 at break.

According to a preferred feature, the present invention has a tear strength of at least 2.5 kg / cm, advantageously at most 1.0% of shrinkage during molding.

These features and properties are measured by the methods described in the following standards:

Density, also known as apparent density, is determined by ASTM standard D 3574 (A) (foamed plastics and rubber-measurement of the apparent density corresponding to ISO standard 845).

Hardness is measured by NBR standard 14455 (Ascher C) (foamed material, sole material and shoe parts according to DIN standard 53543) using a hardness meter Ascher C.

Tear strength of the foam is measured according to ASTM standard D 3574 (F).

Tensile stress at break is measured according to ASTM standard D 412.

Elongation at break is measured according to ASTM standard D 412 (C).

Shrinkage during molding is measured by standard SATRA ™ 70 (thermal shrinkage of foamed soil).

Permanent compression rate is measured by ASTM standard D 395 (B) (flexible foamed polymer material corresponding to ISO standard 1856).

According to a preferred feature of the invention, the density of the foam is between 0.1 g / cm 3 and 0.25 g / cm 3, advantageously between 0.15 g / cm 3 and 0.23 g / cm 3.

According to a preferred feature of the invention, the polyurethane foam comprises dispersed inorganic filler particles and the weight concentration of such filler is from 0.6 to 8%, preferably from 0.6 to 5% by weight of the foam.

The polyurethane foams of the present invention are obtained by the reaction of a compound comprising two or more isocyanate functional groups and a polyesterdiol compound. Advantageously, isocyanate compounds are usually prepolymers comprising isocyanate terminated functional groups. The molar ratio of isocyanate and hydroxyl functional groups is 1.0 to 1.5, advantageously 1.2 to 1.5.

For example, isocyanate compounds suitable for the present invention include aromatic, saturated or unsaturated cyclic compounds, aliphatic compounds and the like. Isocyanate compounds commonly used in the preparation of foams, in particular polyurethane foams, are prepolymers obtained by the reaction of two molecules of diisocyanate with a polyetherpolyol or polyesterpolyol. In such cases, these compounds are commonly referred to as isocyanate prepolymers.

Examples of diisocyanates which are particularly suitable for the preparation of isocyanate prepolymers are aromatic isocyanates such as toluene diisocyanate, xylylene diisocyanate, polymethylene polyphenylene diisocyanate, saturated cyclic isocyanates such as hydrogenated methylene diphenyl diisocyanate, Hydrogenated toluene diisocyanates and isophorone diisocyanates, aliphatic diisocyanates such as hexamethylene diisocyanate and lysine diisocyanate.

Preferred isocyanate prepolymers commonly used are those comprising flexible segments formed by polyoxyalkylene glycols that react with methylenediphenyl diisocyanate. In particular, such compounds are advantageous for the production of low density foams, in particular the foams of the invention.

Polyester diols suitable for the present invention are generally obtained by the reaction of dicarboxylic acids comprising 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms and at least one diol.

Examples of dicarboxylic acids include aliphatic divalent acids such as adipic acid, succinic acid, glutaric acid, suberic acid, azelaic acid, sebacic acid, aromatic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthenic acid. These divalent acids may be used alone or in combination.

According to a preferred embodiment according to the invention, the divalent acid used is a divalent acid comprising at least 6 carbon atoms, such as adipic acid, and at least one divalent acid comprising up to 5 carbon atoms, advantageously Glutaric acid, in particular adipic acid, succinic acid, glutaric acid.

According to a preferred embodiment of the invention, the divalent acid used in the formation of the polyesterdiol advantageously comprises adipic acid, succinic acid and glutaric acid, and adipic by oxidation of cyclohexanol and / or cyclohexanone It consists of a mixture of divalent acids and adipic acid mixtures known as AGS, obtained as by-products in the production of acids.

It is also possible to use derivatives of these divalent acids, such as diesters containing 1 to 4 carbon atoms for residues from alcohols, anhydrides of acids, acid chlorides.

As diols suitable for the present invention, glycols containing 2 to 10 carbon atoms, preferably 2 to 6 carbon atoms, such as ethylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 2,2-dimethyl-1,3-propanediol, 1,3-propanediol, dipropylene glycol, trimethylpropanol, bisphenol, 1,1,3-trimethyl -Triethylenediol and the like.

Furthermore, polymerization reaction products of the diols and esters of the aforementioned divalent acids, in particular those containing 4 to 6 carbon atoms, hydroxycarboxylic acids such as hydroxycaproic acid, lactones such as caprolactone Particularly preferred polyesterdiols for the present invention are poly (ethanediol adipate), poly (1,4-butanediol adipate), poly (1,6-hexanediol-neopentyl glycol adipate), poly (1,6-hexanediol adipate), poly (1,4-butanediol adipate), polycaprolactone and the like. Advantageously, said polyester diols having a number average molecular weight of 5,000 to 8,000 are preferred.

According to a preferred feature of the invention, the polyurethane foam comprises dispersed inorganic filler particles.

As inorganic filler particles suitable for the present invention, for example, fillers having a size of less than 60 μm, preferably less than 20 and even more advantageously less than 10 μm are mentioned.

Therefore, as a suitable filler for this invention, an aluminosilicate powder, a silica powder, a titanium oxide powder, a talc powder, a kaolin powder, a calcium carbonate powder, etc. are mentioned, for example.

According to a preferred embodiment of the invention, silica, more particularly silica obtained by precipitation, is the preferred filler.

Another object of the present invention is a method of preparing a polyurethane foam comprising dispersed inorganic filler particles, wherein the inorganic filler particles are predispersed in polyesterdiol, and the polyurethane foam is present in the amount necessary to obtain the desired density. Obtained by the reaction of a mixture of a composition formed by the suspension of filler particles in polyesterdiol with a diisocyanate compound in the presence of a foaming agent, a catalyst.

Advantageously, chain extenders and surfactants can be added to the reaction medium of foam formation.

According to a preferred feature of the invention, the suspension of the inorganic filler particles in the polyesterdiol can be obtained by addition of the particles in the esterification medium of the polyesterdiol or in the reaction medium at the start of the condensation polymerization step.

The inorganic fillers may also be added directly in the medium, in the form of premixes with diols, or in the form of premixes with at least a portion of the divalent acid, in accordance with a preferred embodiment of the invention.

In addition, by performing this method, excellent dispersion and suspension of the inorganic filler particles in the polyesterdiol can be obtained, and excellent dispersion in the polyurethane foam obtained by such dispersion is obtained.

According to a preferred feature of the invention, the weight concentration of the inorganic filler in the premix with divalent acid is 2% to 20%, preferably 2% to 12%. The concentration of the inorganic filler in the polyesterdiol is 1 to 18% by weight, preferably 1 to 10% by weight.

In addition, a stable dispersion can be obtained by the process of the invention, in particular by the addition of an inorganic filler in the form of a mixture of divalent acids. Using the process of the invention it is possible to produce dispersions comprising polyesterpolyols and to store them before use in the preparation of polyurethane foams.

In a preferred embodiment of the invention, the mixture of filler and divalent acid can be obtained by mixing inorganic filler particles and divalent acid powder or granules at room temperature, for example, from room temperature to 120 ° C.

It is also possible to coat a portion of the divalent acid and inorganic filler particles. This coating is obtained by heating the mixture at a temperature above the melting or softening point of the divalent acid.

In this embodiment, the inorganic filler particles preferably comprise divalent acids having less than 5 carbon atoms, such as glutaric acid, or divalent compounds containing less than 5 carbon atoms, such as a mixture of divalent acids called AGS. It is coated using a divalent acid containing acid.

It is also possible to add to this mixture or polyesterdiol other additives commonly used in the formulation of polyurethane foams.

The process described above is particularly advantageous for the production of the polyurethane foams of the invention, in particular for obtaining the mechanical and working property levels for use in low density foams.

In particular, in order to use reinforcing inorganic fillers distributed in a uniform manner in the foam, it is important to obtain a compromise of physical properties in polyurethane foams having a density of less than 0.3 g / cm 3, in particular less than 0.25 g / cm 3. .

In addition, by using a mixture of divalent acids comprising a divalent acid having less than 5 carbon atoms as a mixture with a divalent acid having more than 5 carbon atoms, certain mechanical properties, such as foaming, of the polyurethane foam It can improve elongation, hardness and tear strength at break of water. This effect is particularly interesting and important to compensate for the reduction in elongation at break produced by the addition of inorganic fillers. It has been found that the elongation at break increases for a certain range of inorganic filler concentrations (high concentrations) in the presence of polyesterdiols obtained from mixtures of divalent acids as described above.

According to a preferred embodiment of the invention, the inorganic filler is one obtained by amorphous silica, in particular by sedimentation. Such silica is advantageously in the form of aggregate particles of less than 50 μm in size or diameter.

Precipitated silica is preferred because it may be in the form of aggregate particles forming granules having a size of at least 50 μm or greater than 150 μm. Such agglomerates are readily degraded under the action of agitation or shear forces, in particular to provide particles having a size of less than a few microns, for example less than 5 μm, upon mixing of divalent acids or polyols.

Such agglomerates may be present in the form of spheres or pellets substantially obtained, for example by atomization, as described in EP 0 018 866. Such silicas are sold under the trade name Microperle. Such silicas, which exhibit good flow properties, dispersibility and high impregnation capacity, are described in European Patents 966 207, 984 773, 520 862 and International Patent Applications W095 / 09187 and W095 / 09128.

Other types of silica, such as those described in French patent application 01 16881, which are partially hydrolyzed or fumed silica by calcination or surface treatment, may be suitable for the present invention.

Examples of silicas used as solid inorganic substrates are merely presented as preferred embodiments and by way of illustration. It is also possible to use other silicas obtained by other methods having porosity and dispersibility suitable for carrying out the present invention.

The content of the inorganic filler mixed with the suspension or divalent acid in the polyesterdiol is selected as a function of the concentration of the desired inorganic filler in the polyurethane foam.

According to another object of the present invention, a polyesterdiol comprising an inorganic filler is obtained by a production method comprising two steps, a first esterification step and a second condensation polymerization step. The esterification step is carried out by mixing a dihydric acid with a diol such as ethylene glycol and diethylene glycol in a molar ratio of diol / 2 divalent acid of 1.2 to 1.5.

The reaction temperature in the first stage is gradually increased during the course of the reaction. For example, the start of the reaction is carried out at a temperature of 160 ° C. so as to be a temperature of 220 ° C. at the end of the reaction.

According to the invention, it is advantageous to add the divalent acid mixed with an inorganic filler.

The second condensation polymerization step is carried out by adding a catalyst such as t-butyl titanate (TBT) at a weight concentration of 0.001% to 0.010% by weight of the divalent acid. The temperature of the polymerization reaction is 200 ° C. at a pressure of 10 to 20 mbar.

The obtained polyesterdiol has an acid index (I _A ) representing the mg value of KOH required to neutralize 1 g of polyol, and a hydroxyl index corresponding to the number of mg mg of potassium per gram of polyol converting hydroxyl functional groups to alcoholates. _OH ).

Polyesterdiol is also characterized by its viscosity and its molecular weight.

Advantageously, additives which interfere with or limit the hydrolysis of ester functional groups include polyesterdiols such as carbodiimide such as cyanamide; Hydrogen cyanamide; Carbodiimide; Cyanogenamide; Amidocyanogen is added to the polyesterdiol. It may also be advantageous to add UV stabilizing additives such as hindered amines, antioxidants, fire retardants and the like to the polyesterdiols.

The polyurethane of the present invention can be obtained by a common general method. Thus, the polyesterdiols of the present invention are chain extenders, surfactants, such as those sold under the trade names Rhodorsil SP3301 and SP3300 in the presence of Rhodia in the presence of foaming or pore-forming agents and catalysts and And a diisocyanate compound.

As the foaming agent, water, hydrocarbons, chlorofluorocarbons, hydrogenated fluorocarbons, carbon dioxide gas can be used alone or in combination. Water is preferred as the foam former or pore former.

Suitable catalysts for the present invention include tertiary amines such as 1,4-diazabicyclo- (2,2,2) -octane, 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; triethylamine; tributylamine; bis (dimethylaminoalkyl) piperazine; N, N, N ', N'-tetramethylethylenediamine; N, N-diethylbenzylamine, bis (N, N-diethylaminoalkyl) adipate; N, N, N ', N'-tetramethyl-1,3-butanediamine; N, N-dimethyl-β-phenylethyldiamine, 1,2-dimethylimidazole 2-methylimidazole, etc. Other catalysts, such as organometallic compounds, such as dibutyl tin dilaurate, tin oleate, cobalt naphthenate, and lead naphthenate, can be used.

Other additives such as pigments, colorants, antioxidants may also be added.

The mixture may be injected into a mold to form a polyurethane foam and to obtain an article having a predetermined mold such as, for example, a sole.

By controlling the content of the foaming agent, for example water, foaming with varying densities of, for example, 0.1 to 0.3 g / cm 3, advantageously 0.1 to 0.25 g / cm 3, even more advantageously 0.15 to 0.23 g / cm 3 You can get water.

The present invention can yield low density polyurethane foam, for example on the order of 0.2 g / cm 3, and thus has properties and fits suitable for applications such as soles of shoes. This property is particularly suitable for the production of midsoles for sports shoes, women's shoes or other types of shoes.

The composition according to the invention has high rebound properties and tear strength, as well as the hardness to which intermediate soles for shoes, in particular sports shoes, can be formed.

Recoil property is evaluated by measuring the resilience to recoil or impact, measured by the recoil height of the ball falling on the surface of the foam. This property is expressed as a percentage of the rebound height relative to the drop height.

This sole can improve the fit of the shoe, having a sole weight corresponding to the sole made of EVA.

In addition, the sole obtained using the composition of the present invention has an improved lifespan, as the resistance to aging and fatigue of the polyurethane foam against the sole made of EVA limits the deterioration of the sole.

These advantages and properties will be apparent from the following examples which are presented by way of example only.

Comparative Example 1

Tests of the execution of polyurethane foams were carried out from polyols commercially available from the Dow Chemical Company under the trade name VORALAST GF422 and from diisocyanate prepolymers of VORALAST GS 749. The polyurethane foams were obtained by mixing the products of the weight content shown in Table I below.

product Normal Density Foam (g) Analysis 1 Low Density Foam (g) Analysis 1a Polyol 100 100 Chain extender (MEG) 14 8.17 Foaming Agent (Water) 0.1 0.64 catalyst 1.2 1.57 Surfactants 0.2 0.47 Isocyanate Prepolymer 129.3 124.0 NCO / OH molar ratio 1,128 1,124

The physical properties of the foam measured by the aforementioned nominal method are shown in Table II below.

analysis Apparent density (g / cm3) Hardness (Ascher C) Tensile Stress at Break (㎏ / ㎠) Elongation at Break (%) Tear strength (kg / cm) One 0.35 64 24.6 284 6.4 1a 0.20 31 13 289 5.1

This test shows that the hardness is greatly reduced as an effect on the mechanical properties of the density reduction of the polyurethane foam when the compounds used to form such foams are identical.

Example 2

Polyurethane foams were obtained using the following procedure and polyesterdiol prepared using the prepolymer of Example 1 as the diisocyanate prepolymer as polyol.

In the first step, adipic acid mixed with 6% silica was added to a mixture of ethylene glycol (MEG) and diethylene glycol (DEG) comprising 70% by weight of MEG. The molar ratio of alcohol and divalent acid is 1.2 to 1.5.

The reaction was carried out by heating the mixture at 160 ° C for 1 hour, and then gradually increasing the temperature by 15 ° C to 215 ° C. This reaction was carried out under an inert atmosphere, for example under nitrogen.

The resulting esterified product was condensed in the second step after addition of tetrabutyl titanate (TBT) at a concentration of 0.003% by weight relative to the content of the divalent acid added.

The polymerization reaction was carried out at 200 ° C. under reduced pressure of 15-18 mbar.

The resulting polyesterpolyols are characterized by OH index (I _OH ), acid index (I _A ) and viscosity. The mixture of adipic acid / silica is obtained by mixing silica powder and adipic acid granules sold under the trade name TIXOSIL 365 by Rhodia.

Two analyzes were performed using different concentrations of silica in adipic acid.

Example 2A: 6% by weight silica in adipic acid / silica mixture

Example 2B 9 wt% silica in adipic acid / silica mixture

The properties of the obtained polyester polyols are as follows:

Example  2A

▶ ADOH / SiO ₂ (mass ratio): 94/06

MEG / DEG (molar ratio): 70/30

I _OH : 58.5 mg of KOH / g polyol

▶ I _A : 1.0 mg KOH / g polyol

Viscosity: 8,000 mPas at 35 ° C

Example 2B

ADOH / SiO ₂ (mass ratio): 91/09

MEG / DEG (molar ratio): 70/30

I _OH : 51.7 mg KOH / g polyol

▶ I _A : 0.90 mg KOH / g polyol

Viscosity: 11,070 mPas at 35 ° C

The polyurethane foams were obtained by carrying out the compounds and contents shown in Table III below.

product Content (g) Polyol 100 Chain Extender (Ethylene Glycol) 8.83 water 1.23 catalyst 2.6 Surfactants 1.3 Isocyanate Prepolymer 167 NCO / OH molar ratio 1.414

The physical properties of the obtained foam are as follows:

Example 2A

Density: 0.21 ± 0.01 g / cm3

Hardness (Ascher C): 49 ± 1

▶ Tensile Stress at Break: 26.6 ± 1.1 ㎏ / ㎠

Elongation at break: 280 ± 8%

▶ Tear propagation stress at break: 2.34 ± 0.17 ㎏ / ㎝

Tear Strength: 9.9 ± 0.5 ㎏ / ㎝

▶ permanent compression rate: 3.8 ± 0.4%

Example 2B

Density: 0.20 ± 0.01 g / cm3

Hardness (Ascher C): 52 ± 1

▶ Tensile Stress at Break: 24.23 ± 1.60 ㎏ / ㎠

Elongation at break: 218 ± 11%

Tear Propagation Resistance: 2.54 ± 0.14 ㎏ / ㎝

Tear Strength: 9.50 ± 0.40 ㎏ / ㎝

▶ permanent compression rate: 3.0 ± 0.5%

Example 3

Example 3a using adipic acid and 6 wt% silica on the one hand, adipic acid on the other hand, a divalent acid mixture of 6 wt% trade name AGS and an acid / silica mixture of 6 wt% silica, respectively And Example 3b.

The properties of the obtained polyesterdiol are as follows:

Example 3A

▶ ADOH / SiO ₂ (mass ratio): 94/06

MEG / DEG (molar ratio): 70/30

I _OH : 57.7 mg KOH / g polyol

▶ I _A : 0.78 mg KOH / g polyol

Viscosity: 7,440 mPas at 35 ° C

Example 3B

▶ ADOH / SiO ₂ / AGS (mass ratio): 88/06/06

MEG / DEG (molar ratio): 70/30

I _OH : 54.7 mg KOH / g polyol

I _A : 0.70 mg KOH / g polyol

Viscosity: 8,040 mPas at 35 ° C

Polyurethane foams obtained by the values given in Table III have the following physical properties:

Example 3A

Density: 0.20 ± 0.01 g / cm3

Hardness (Ascher C): 46 ± 3

▶ Tensile Stress at Break: 24.00 ± 3.30 ㎏ / ㎠

▶ Elongation at break: 252 ± 29%

Tear Propagation Resistance: 2.63 ± 0.30 ㎏ / ㎝

Tear Strength: 10.5 ± 0.7 ㎏ / ㎝

▶ permanent compression rate: 3.3 ± 0.6%

Example 3B

Density: 0.20 ± 0.01 g / cm3

Hardness (Ascher C): 48 ± 3

▶ Tensile Stress at Break: 24.10 ± 2.30 ㎏ / ㎠

Elongation at break: 280 ± 23%

Tear Propagation Resistance: 2.9 ± 0.26 ㎏ / ㎝

Tear Strength: 10.2 ± 0.8 ㎏ / ㎝

▶ permanent compression rate: 4.9 ± 0.4%

Example 4

Examples 4a and 4b were obtained using adipic acid, a mixture of divalent acids of 6 wt% trade name AGS and an acid / silica mixture comprising 6 wt% silica, respectively. The mixture used in Example 4a is obtained by mechanical mixing of various components. The mixture used for the practice of Example 4b is obtained by coating the inorganic filler by mixing divalent acid AGS and physical mixing with adipic acid.

The properties of the obtained polyester polyols are as follows:

Example 4A

▶ ADOH / SiO ₂ / AGS (mass ratio): 88/06/06

MEG / DEG (molar ratio): 70/30

I _OH : 54.7 mg KOH / g polyol

I _A : 0.70 mg KOH / g polyol

Viscosity: 8,040 mPas at 35 ° C

Example 4B

▶ ADOH / SiO ₂ / AGS (mass ratio): 88/06/06

MEG / DEG (molar ratio): 70/30

I _OH : 51.8 mg KOH / g polyol

I _A : 0.70 mg KOH / g polyol

Viscosity: 10,850 mPas at 35 ° C

Polyurethane foams obtained by the values given in Table III have the following physical properties:

Example 4A

Density: 0.20 ± 0.01 g / cm3

Hardness (Ascher C): 48 ± 3

▶ Tensile Stress at Break: 24.10 ± 2.30 ㎏ / ㎠

Elongation at break: 280 ± 23%

Tear Propagation Resistance: 2.9 ± 0.26 ㎏ / ㎝

Tear Strength: 10.2 ± 0.8 ㎏ / ㎝

▶ permanent compression rate: 4.9 ± 0.4%

Example 4B

Density: 0.20 ± 0.01 g / cm3

Hardness (Ascher C): 52 ± 2

▶ Tensile Stress at Break: 23.00 ± 1.70 ㎏ / ㎠

Elongation at break: 293 ± 23%

Tear Propagation Resistance: 2.83 ± 0.34 ㎏ / ㎝

Tear Strength: 10.1 ± 0.7 ㎏ / ㎝

▶ permanent compression rate: 5.6 ± 0.8%

Claims (24)

Permanent compression rate measured according to ASTM standard D 3574 (A) is less than 0.3 g / cm 3, hardness measured by NBR standard 14455 (Ascher C) of 45 or more, and measured according to ASTM standard D 395 (B). (compression set) flexible obtained by the reaction of polyesterpolyol and diisocyanate, characterized in that the inorganic filler particles are 12% or less and are dispersed at a weight concentration of 0.8% to 8% relative to the total weight of the foam. Sex Polyurethane Foam. The foam according to claim 1, wherein the foam has a density of 0.1 g / cm 3 to 0.25 / cm 3. Foam according to claim 1 or 2, characterized in that the tear strength measured by ASTM standard D 3574 (F) is at least 2.5 kg / cm. The foam according to claim 1 or 2, wherein the tensile stress at break as measured according to ASTM Standard D 412 is 18 kg / cm 2 or more. Foam according to claim 1 or 2, characterized in that the elongation at break measured by ASTM Standard D 412 (C) is at least 250%. The foam according to claim 1 or 2, characterized in that the shrinkage in molding as measured by standard SATRA TM 70 is 1.0% or less. delete The foam of claim 1 wherein the average size of the inorganic filler particles is less than 60 μm. 9. The foam according to claim 8, wherein the average size of the particles is less than 20 mu m. The foam according to claim 1, wherein the inorganic filler is selected from the group consisting of alumina-silicate, silica, titanium oxide, talc, calcium carbonate, mica and kaolin. 11. The foam of claim 10 wherein the inorganic filler is precipitated silica. 3. The reaction according to claim 1, wherein the polyester polyol is a mixture of divalent acids comprising at least one divalent acid comprising at most 5 carbon atoms and at least one adipic acid or a reaction of divalent acids with diols. Foam obtained by 13. The foam of claim 12 wherein the divalent acid comprising less than 5 carbon atoms is glutaric acid. In an extrusion reaction process for supplying a diisocyanate compound, a composition formed by suspension of an inorganic filler, a catalyst, and a foaming agent in a polyesterdiol, wherein the foaming agent is present in an amount necessary to obtain a predetermined density. The manufacturing method of the polyurethane foam of Claim 1 or 2 which is performed. The composition of claim 14 wherein the composition formed by suspension of the inorganic filler in polyesterdiol is obtained by reaction of the diol compound with at least one divalent acid in an esterification step followed by condensation polymerization up to a predetermined degree of polymerization, wherein The addition acid is adipic acid and the inorganic filler is dispersed or fed in the reaction medium before the esterification step or at the start of the polymerization step. 16. The process of claim 15, wherein the divalent acid is a mixture of divalent acid and adipic acid comprising up to 5 carbon atoms. The method of claim 15 wherein the divalent acid is a mixture of adipic acid, succinic acid and glutaric acid. The method of claim 15 wherein the divalent acid is a mixture of adipic acid and AGS. delete 15. The process of claim 14, wherein the inorganic filler is added to the esterification medium as a mixture with at least a portion of the divalent acid. A method of using the polyurethane foam of claim 1 for the production of shaped articles. A process for using the polyurethane foam according to claim 1 for the production of midsoles of shoes. Middle sole of a shoe obtained by molding the polyurethane foam according to claim 1. A shoe comprising at least a portion of a sole made of the polyurethane foam of claim 1.