JP2003128767A - Polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyesterpolyol which hardly solidifies on the stop of a molding machine due to low temperature, on the circulation stop or circulation speed reduction of the polyol component, on the cooling of cooling water in the agitating section of the molding machine, or the like, when molded articles such as soles are manufactured, has excellent extrusion precision stability, and gives polyurethane foams having good mechanical strengths. SOLUTION: This polyesterpolyol is prepared by polycondesing (A) an acid component comprising one phthalic acid component selected from phthalic anhydride and o-phthalic acid and an aliphatic polybasic acid with (B) a polyhydric alcohol component containing diethylene glycol. The polyester polyol composition is prepared by mixing the above polyesterpolyol with a polyesterpolyol produced by reacting an aliphatic polybasic acid with a polyhydric alcohol in a weight ratio of 80/20 to 98/2. The polyurethane foam is prepared by reacting a polyol component comprising the above polyester polyol composition, a chain extender, a foaming agent and a urethanization catalyst with an isocyanate component. And the method for producing the polyurethane foam.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to polyurethane foam. More specifically, the present invention relates to a polyurethane foam that can be preferably used as shoe soles, a method for producing the same, and a polyester polyol and a polyester polyol composition used as a raw material for the polyurethane foam.

[0002]

2. Description of the Related Art A phthalic acid-modified polyester polyol is used as a raw material for urethane shoes because it is excellent in mechanical strength (Japanese Patent Laid-Open No. 11-166041).
In the examples of this publication, ethylene glycol or 1,4-butanediol is used as a polyhydric alcohol that is a raw material for a phthalic acid-modified polyester polyol, and a phthalic acid-modified polyester polyol that is liquid at 40 ° C. A polyol component has been proposed which comprises a polyester polyol mixture of a modified polyester polyol and another polyester polyol, a chain extender, a foaming agent and a foam stabilizer.

However, the freezing point of the polyol component is 23.
Since it is above ℃, and the polyol component itself solidifies at low temperatures (about 10 ℃) such as in winter, it is necessary to raise the set temperature of the oven or lengthen the heating time in order to dissolve it. Further, in order to prevent solidification in the foam molding machine, it is necessary to dispose heating equipment in the pipe, but heating by such heating equipment is not preferable from the viewpoint of energy consumption and productivity.

Further, when this polyol component is used, even when the molding machine is stopped unexpectedly or the circulation of the polyol component is stopped even outside the winter season (about 20 ° C.), the circulation speed is lowered between the productions. When the agitating section of the molding machine is cooled with cold water to prevent the temperature of the agitating section of the molding machine from rising due to continuous injection operation, the polyol component is partially solidified in the pipe of the molding machine and at the outlet of the polyol component. However, there is a drawback that the circulation pressure and the discharge pressure become high and the discharge accuracy becomes unstable.

[0005]

DISCLOSURE OF THE INVENTION According to the present invention, when a molded product such as a shoe sole is manufactured, the molding machine is inadvertently stopped when the temperature is lowered, and the circulation of the polyol component is stopped, the circulation is performed between the production. When the speed is reduced, or even when the stirring section of the molding machine is cooled with cold water in order to prevent the temperature from rising due to continuous injection operation, it is difficult to solidify and the stability of discharge accuracy is excellent, It is an object of the present invention to provide a polyester polyol having a phthalic acid component as an acid component, which has good mechanical strength.

Another object of the present invention is to provide a polyurethane foam having a good surface condition and having sufficient mechanical strength such as tensile strength and flexibility.

[0007]

The summary of the present invention is as follows.
(1) (A) an acid component containing at least one phthalic acid component selected from phthalic anhydride and o-phthalic acid and an aliphatic polybasic acid; and (B) a polyhydric acid containing diethylene glycol. Polyester polyol (hereinafter referred to as polyester polyol A) which is polycondensed with alcohol, exhibits a liquid state at 20 ° C., and has a viscosity at 40 ° C. of 6000 mPa · s or less, (2) Polyester polyol A
And a polyester polyol (hereinafter referred to as polyester polyol B) obtained by reacting an aliphatic polybasic acid and a polyhydric alcohol with a weight ratio (polyester polyol A / polyester polyol B) of 80/20 to 98/2. A polyester polyol composition obtained by mixing so that
(3) Polyurethane foam obtained by reacting a polyol component comprising the polyester polyol composition, a chain extender, a foaming agent and a urethane-forming catalyst with an isocyanate component, and (4) the polyester polyol composition, a chain extender, The present invention relates to a method for producing a polyurethane foam in which a polyol component composed of a foaming agent and a urethanization catalyst is reacted with an isocyanate component.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Polyester polyol A is
It is obtained by polycondensing (A) a phthalic acid component, an acid component containing an aliphatic polybasic acid, and (B) a polyhydric alcohol.

As the phthalic acid component, phthalic anhydride and o
-Phthalic acid is used, and these may be used alone or in combination.

Examples of the aliphatic polybasic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonamethylenedicarboxylic acid, decamethylenedicarboxylic acid,
Undecamethylenedicarboxylic acid, dodecamethylenedicarboxylic acid, tridecamethylenedicarboxylic acid, tetradecamethylenedicarboxylic acid, pentadecamethylenedicarboxylic acid, hexadecamethylenedicarboxylic acid, heptadecamethylenedicarboxylic acid, octadecamethylenedicarboxylic acid,
Nonadecamethylenedicarboxylic acid, icosamethylenedicarboxylic acid, henicosamethylenedicarboxylic acid, docosamethylenedicarboxylic acid, tetracosamethylenedicarboxylic acid,
Examples thereof include saturated aliphatic dicarboxylic acids having 2 to 30 carbon atoms such as octacosamethylene dicarboxylic acid and dotriacontamethylene dicarboxylic acid, and these can be used alone or in admixture of two or more.

Among the aliphatic polybasic acids, adipic acid is
Adipic acid is preferable from the viewpoints of excellent hydrolysis resistance, high tensile strength, high safety, and low cost.

The value of the molar ratio of the phthalic acid component and the aliphatic polybasic acid (phthalic acid component / aliphatic polybasic acid) is preferably 0.05 or more, more preferably 0.1 or more from the viewpoint of maintaining mechanical strength. Is. Further, the value of the molar ratio is, from the viewpoint of maintaining mechanical strength, the viscosity of the polyester polyol at a molding temperature of about 40 ° C. is 6000 mPa · s or less, which facilitates injection and injection during molding. In addition, from the viewpoint of improving the finish of the surface of the obtained molded product, it is preferably 0.25 or less, more preferably 0.2 or less. Considering these, the range of the value of the molar ratio is preferably 0.05 to 0.25, more preferably 0.1 to 0.
It is 2.

The acid component contains a phthalic acid component and an aliphatic polybasic acid. The term "containing" as used herein means that the acid component is composed of a phthalic acid component and an aliphatic polybasic acid, and that the acid component other than the phthalic acid component and the aliphatic polybasic acid is contained in the acid component ( Hereinafter, other acid components) may be contained in an amount within the range that does not impair the object of the present invention. Among these aspects, the acid component is
It is particularly preferable that it is composed of a phthalic acid component and an aliphatic polybasic acid.

The amount of the other acid component in the acid component cannot be unconditionally determined because it varies depending on its type and the like, but it is usually preferably 10% by weight or less, more preferably 5% by weight or less.

As the polyhydric alcohol, diethylene glycol is preferable from the viewpoint of suppressing the crystallinity with the acid component constituting the polyester polyol A and lowering the freezing point of the polyester polyol A. As will be described later, diethylene glycol is contained so that the polyester polyol A becomes liquid at 20 ° C. and the viscosity at 40 ° C. becomes 6000 mPa · s or less.

The content of diethylene glycol in the polyhydric alcohol is preferably 20 mol% or more, more preferably 30 mol% or more, from the viewpoint of freezing point and viscosity.
From the viewpoint of maintaining physical properties, 60 mol% or less, more preferably 40 mol% or less
It is not more than mol%. Considering these, the content of diethylene glycol is preferably 20 to 60 mol%, more preferably 30 to 40 mol%.

Examples of polyhydric alcohols other than diethylene glycol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-propanediol, 1,4-butanediol, 1,5-pentanediol and neopentyl. Glycol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol and the like are mentioned, and these may be used alone or in combination of two kinds. The above can be mixed and used. Among these polyhydric alcohols, ethylene glycol and 1,4-butanediol are preferable, and ethylene glycol is more preferable, from the viewpoint that the resulting polyurethane foam exhibits sufficient mechanical properties. The amount of such polyhydric alcohol is the balance of diethylene glycol, that is, preferably 40 to 80 mol%, more preferably 60 to 70 mol%.

The polyester polyol A is obtained by polycondensing an acid component and a polyhydric alcohol.

The proportion of the acid component and the polyhydric alcohol is stoichiometrically, since the reaction between the acid component and the polyhydric alcohol is a polycondensation reaction and both ends of the polyester polyol are necessarily hydroxyl groups. The equivalent ratio [COOH / OH] between the COOH group of the acid component and the OH group of the polyhydric alcohol is preferably slightly smaller than 1, specifically 0.85 to 0.93.

As a method for polycondensing the acid component and the polyhydric alcohol, for example, Guente Oerter (Guente)
r Oertel) "Polyurethane Handbook" edited by Hansar Co., 2nd edition (1994), p.65 to 72, and the like. However, the present invention is not limited thereto. .

As the polyester polyol A, one which is liquid at 20 ° C. and has a viscosity at 40 ° C. of 6000 mPa · s or less is used.

Here, “liquid at 20 ° C.” means a flat plate (20 ° C.).
1 drop of polyester polyol on 20 ° C
After being left for 1 hour at 0 ° C., the flat plate is erected in the vertical direction and liquid dripping is recognized. Polyester polyol A
Is required to be liquid at 20 ° C. because it is possible to prevent the coagulation of the polyol component in the pipe of the molding machine at low temperatures in winter and to shorten the time required to dissolve the polyol component. Considering this point, the polyester polyol A is preferably liquid at 20 ° C.

The viscosity of the polyester polyol A at 40 ° C. should be 6000 mPa · s or less.
This is to stabilize the discharge rate of the polyurethane foam molding machine and to obtain a surface having a good appearance with no defects in the molded foam. Considering this point, the viscosity of polyester polyol A at 40 ° C. is 6000 mPa · s or less,
It is preferably 00 mPa · s or less, more preferably 3000 mPa · s or less.

The viscosity referred to here is 1 of that of a rotational viscometer.
Type B (Brookfield) viscometer (rotor
No. 3, rotation speed 30 rpm).

Considering the viscosity and melting point of the polyester polyol A, the number average molecular weight of the polyester polyol A is preferably 500 to 3000, more preferably 500 to 2000, and particularly preferably 1000 to 2000.

The polyester polyol A can be preferably used as a polyol component of polyurethane foam. As described above, when the polyester polyol A is used as the polyol component when producing the polyurethane foam, the surface state of the polyurethane foam becomes good.

The polyester polyol composition obtained by mixing the polyester polyol A and the polyester polyol B can be suitably used as a polyol component in the production of polyurethane foam. This polyester polyol composition uses a polyester polyol B modified with a trifunctional polyhydric alcohol such as trimethylol propane or glycerin, so that the demolding time at the time of molding (the mixing of the polyol component and the isocyanate component into the molding die) There is an advantage that it is possible to adjust the time required from the start of injecting the mixture to the time when the molded product is taken out from the molding die.

The polyester polyol B is obtained by reacting an aliphatic polyhydrochloric acid with a polyhydric alcohol.

The polyol component may contain other polyester polyols. Examples of other polyester polyols include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, methylpentanediol, 1,6-hexanediol, trimethylolpropane, glycerin and pentaerythritol. Polycondensation of one or more polyhydric alcohols such as diglycerin, dextrose and sorbitol with one or more dibasic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid and dimer acid The obtained polyester polyol, polypropylene glycol, polyether polyol such as polyoxytetramethylene glycol, polycaprolactone polyol, polycarbonate polyol and the like can be mentioned, and these can be used alone or in combination of two or more kinds. That.

The reaction conditions and the like between the aliphatic polyhydrochloric acid and the polyhydric alcohol may be the same as the reaction conditions for producing the polyester polyol A described above.

The ratio of polyester polyol A to polyester polyol B is polyester polyol A / polyester polyol B from the viewpoint of demolding time at the time of molding which affects the productivity of polyurethane foam and maintenance of mechanical strength of the molded product. (Weight ratio) is 80 / 20-98 / 2,
It is desirable to adjust it so that it is preferably 87/13 to 96/4.

According to the method for producing a polyurethane foam of the present invention, a polyurethane foam is obtained by reacting a polyol component comprising a polyester polyol composition, a chain extender, a foaming agent and a urethanization catalyst with an isocyanate component. You can

The amount of the polyester polyol composition in the polyol component is preferably 80 to 98% by weight, and more preferably from the viewpoint of maintaining a liquid state and viscosity of the polyol component and producing a polyurethane foam excellent in mechanical strength. It is 85 to 95% by weight, more preferably 87 to 93% by weight.

The chain extender has a low molecular weight of 2 in the molecule.
A compound having one or more active hydrogens can be used. Typical examples of chain extenders include ethylene glycol,
Polyhydric alcohols such as diethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, methylpentanediol, 1,6-hexanediol, trimethylolpropane, glycerin, pentaerythritol, diglycerin, dextrose and sorbitol And aliphatic polyvalent amines such as ethylenediamine and hexamethylenediamine, aromatic polyvalent amines, alkanolamines such as diethanolamine, triethanolamine and diisopropanolamine. These may be used alone or in combination of two or more.

The amount of chain extender in the polyol component is
From the viewpoint of maintaining mechanical strength and obtaining a good appearance surface, preferably 2 to 15% by weight, more preferably 3 to 12% by weight,
More preferably, it is 5 to 10% by weight.

Examples of the foaming agent include water and fluorocarbons, which may be used alone or in combination with 2
A mixture of two or more species can be used.

The amount of the foaming agent in the polyol component is preferably 0.05 to 1.0% by weight, more preferably 0.2 to 0.9% by weight, further preferably 0.3 to 0.8% by weight, from the viewpoint of obtaining a good appearance surface.

Examples of the urethanization catalyst include tertiary amines such as triethylenediamine, N, N, N ', N'-tetramethylhexamethylenediamine, and 1,2-dimethylimidazole, tin (II) octoate, Examples thereof include tin compounds such as dibutyltin dilaurate, and these can be used alone or in admixture of two or more.

The amount of the urethanization catalyst in the polyol component cannot be unconditionally determined because it depends on the type of catalyst, but it is preferable from the viewpoint of obtaining a polyurethane foam which does not impair the productivity and has a good surface condition. Is 0.03 to 0.5% by weight, more preferably 0.2 to 0.5
%, More preferably 0.25 to 0.45% by weight.

If necessary, the polyol component may contain
For example, a foam stabilizer, a stabilizer, a pigment or the like may be added in an appropriate amount.

As described above, since the polyester polyol composition is used as the polyol component, it is liquid at room temperature and can be injected even at low pressure.
By reacting with the isocyanate component described below,
Polyurethane foam can be manufactured.

Representative examples of the isocyanate component include isocyanate prepolymers and the like.

The isocyanate prepolymer can be obtained by reacting an isocyanate monomer and a polyol in the presence of an excess of the isocyanate monomer by stirring and reacting by a conventional method.

Specific examples of the isocyanate monomer include tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, polymethylene polyphenyl diisocyanate, 3,3'-Dimethyl-4,4'-biphenylene diisocyanate, 3,3'-Dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-Dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene Examples thereof include isocyanate compounds such as diisocyanate, and modified products thereof, such as carbodiimide modified products. These can be used alone or in combination of two or more.

Among the isocyanate monomers, 4,4'-
Diphenylmethane diisocyanate used alone or 4,4 '
The combined use of diphenylmethane diisocyanate and its carbodiimide modified product is preferable from the viewpoint of maintaining mechanical strength.

Examples of the polyol used in producing the isocyanate prepolymer include polyester polyol A and, for example, ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, methylpentanediol. , 1,6-hexanediol, trimethylolpropane,
One or more polyhydric alcohols such as glycerin, pentaerythritol, diglycerin, dextrose, sorbitol, and oxalic acid, malonic acid, succinic acid, adipic acid,
Polyester polyol, polypropylene glycol, polyoxytetramethylene glycol, etc. obtained by polycondensation with one or more dibasic acids such as sebacic acid, phthalic anhydride, o-phthalic acid, isophthalic acid, terephthalic acid, dimer acid, etc. Examples of the polyether polyol, polycaprolactone polyol, polycarbonate polyol, and the like can be used alone or in admixture of two or more.

When preparing the isocyanate prepolymer, additives may be added if necessary.

The NCO% of the isocyanate prepolymer is
In order not to make the viscosity of the foamer difficult to mold in a low-pressure foamer, it is preferably 15% or more, more preferably 17% or more. In order to avoid this, it is preferably 25% or less, more preferably 23% or less, still more preferably 22% or less. From these facts, the range of NCO% of the isocyanate prepolymer is preferably 15 to 25%, more preferably 17 to 23%.

When reacting the polyol component and the isocyanate component, it is preferable to adjust the ratio of the two so that the isocyanate index is 95 to 105.

A polyurethane foam can be produced by mixing and stirring a polyol component and an isocyanate component with a molding machine, injecting them into a mold and foaming them. More specifically, for example, using a tank or the like, after adjusting the temperature of each of the polyol component and the isocyanate component to about 40 ° C., an automatic mixing injection type foaming machine,
A polyurethane foam can be molded by reacting using a foaming machine such as an automatic mixing injection foaming machine.

The urethane shoe sole can be molded by mixing the isocyanate component and the polyol component and injecting them into a mold whose temperature is usually adjusted to about 40 to 70 ° C.

Molded density of [0052] thus obtained polyurethane foam is preferably 0.3 to 1.0 g / cm ^3, more preferably from .35 to .7 g / cm ^3, more preferably 0.45~0.65g / cm
^{Is 3} .

[0053]

EXAMPLES In the following, "parts" means "parts by weight".

Preparation Examples 1 to 6 Adipic acid 100 parts, phthalic acid component and glycol in the amounts shown in Table 1 were charged in a four-necked flask, and then a stirring rod, a dehydration tube, a nitrogen gas introduction tube and a thermometer were added. Attached to the flask.

Next, nitrogen gas was introduced into the flask, the water generated was distilled off, and the temperature was raised to 230.degree. After confirming that the inside of the flask became transparent, the pressure was gradually reduced, and water was further distilled off.

The reaction was continued until the acid value of the reaction solution became 1 KOHmg / g or less to obtain polyester polyols a to f.

As the physical properties of the obtained polyester polyols a to f, acid value, hydroxyl value, number average molecular weight, viscosity at 40 ° C., freezing point and properties at 20 ° C. were examined. The results are shown in Table 1.

The acid value is JIS K 0070 and the hydroxyl value is J
IS K 0070, viscosity at 40 ° C is JIS Z 8803 [B type (Brookfield) viscometer (rotor No.3, rotation speed
30 rpm) was used], and the freezing point was measured based on JIS K 0065. The number average molecular weight was calculated from the hydroxyl value. Also, 20
The properties at ° C were examined according to the following evaluation methods.

[Properties at 20 ° C.] One drop of polyester polyol was dropped on a flat plate (held at 20 ° C.)
After standing for 1 hour in the above, the flat plate was erected in the vertical direction, and when liquid sagging was observed, it was evaluated as "liquid", and when liquid sagging was not observed, it was evaluated as "solid".

[0060]

[Table 1]

Preparation Example 7 A polymer obtained by polymerizing 31.2 parts of ethylene glycol, 31.2 parts of 1,4-butanediol and 100 parts of adipic acid and having a number average molecular weight of about 1300 and a viscosity at 40 ° C. of 1700 mPa · s.
And a polyester polyol g which is liquid at 20 ° C.
Prepared.

Preparation Example 8 64 parts of diethylene glycol, trimethylolpropane 5.
Obtained by polymerizing 4 parts and 85 parts of adipic acid, the number average molecular weight is about 1600, and the viscosity at 40 ° C is 5500 mPa
and a polyester polyol h which is liquid and has a liquidity at 20 ° C. was prepared.

Examples 1 to 3 and Comparative Examples 1 to 3 Polyester polyol compositions were prepared so that the compositions shown in Table 2 were obtained.
Parts, 8 parts of ethylene glycol as a chain extender, 0.52 parts of water as a foaming agent, 0.34 parts of triethylenediamine as a urethanization catalyst and silicone as a foam stabilizer [Toray Dow Corning Silicone Co., Ltd., product number: SH-193]. 0.5 part and 1.0 part of the black pigment were mixed with stirring at 50 ° C. to obtain a polyol component.

Next, the obtained polyol component and an isocyanate prepolymer (manufactured by Kao Corporation, trade name: Ediform B-2709, NCO%: 18.5%, freezing point: 15 ° C.) are automatically mixed and injection-foamed. Machine (manufactured by Polyurethane Engineering Co., type: MU-203S, model number: 6-018), the polyol component / isocyanate prepolymer (weight ratio) is 102/10
0 (isocyanate index: 100 to 103) was charged, foamed under the following molding conditions, and 100 mm x 300 m
An m × 10 mm polyurethane foam sheet was prepared.

[Molding conditions] Mixing temperature: Both the temperatures of the isocyanate prepolymer and the polyol component are adjusted to 35 to 45 ° C.

[0066]

[0067]   Mold: Mold temperature 45-55 ℃             Release agent Silicone and wax

[0068]

In producing the polyurethane foam sheet, the dischargeability from the injection foaming machine and the foaming machine circulation line (line length: about 8 m, pipe diameter: about 10 mm, circulation flow rate:
The abnormality at 20 g / sec) was investigated. Cooling water of 15 ° C was circulated in the place where the polyol component and the isocyanate component of the foaming machine were mixed with stirring so that the temperature rise of the stirring unit due to continuous injection was suppressed.

Next, as the physical properties of the obtained polyurethane foam sheet, molding density, hardness, tensile strength (tensile strength), elongation at break, tear strength, flexibility and surface condition of the molded article were measured according to the following methods. . The results are shown in Table 2.
Shown in.

[Physical Properties of Sheet] (a) Calculation was carried out by measuring the mass of a polyurethane foam sheet having a molding density of 100 mm × 300 mm × 10 mm (thickness) and dividing the mass by a volume of 300 cm ³ .

(B) Hardness (Asker C) The hardness was measured according to the standard SRIS 0101 of the Japan Rubber Association.

(C) Tensile strength According to the method described in JIS K 6251, the test piece was dumbbell-shaped 2
It was measured using a No. type.

(D) Breaking elongation According to the method described in JIS K 6251, the test piece was dumbbell-shaped 2
It was measured using a No. type.

(E) Tear strength According to the method described in JIS K 6252, the test piece was measured using a notched angle type.

(F) A flexible Sempo flexer was used. Make a 2 mm notch in the bent part of the test piece and
It was repeatedly bent and the crack growth of the notch portion after 50,000 times was observed. The case where the crack growth was 1 mm or less was judged to be acceptable.

(G) Surface Condition of Molded Product A condition in which the entire surface was uniform, had gloss, and had almost no defects in bubbles was considered good.

[0078]

[Table 2]

From the results shown in Table 2, it is understood that good molded products can be obtained in Examples 1 to 3.

On the other hand, in Comparative Example 1, molding is possible,
Roughness was observed on the surface of the molded product, probably because the viscosity of the polyol component was high, and the appearance was poor. In addition, Comparative Examples 2-3
Then, the circulation pressure and discharge pressure of the polyol component change greatly,
The molded body itself could not be obtained. Then, when the discharge port of the polyol component and the inside of the circulation pipe were examined, a solid substance of the polyol component was observed. From this, this solid matter narrowed the inner diameter of the pipe and blocked the discharge port,
It was confirmed that molding could not be performed because the circulation pressure and the discharge pressure changed greatly.

[0081]

According to the present invention, when a molded product such as a shoe sole is manufactured, the molding machine is inadvertently stopped when the temperature is lowered,
Even when the circulation of the polyol component is stopped, when the circulation speed is reduced between production, or when the stirring section of the molding machine is cooled with cold water in order to prevent the temperature from rising due to continuous injection operation. It is possible to obtain a polyester polyol which is hard to coagulate and is excellent in stability of discharge accuracy.

Further, according to the present invention, a polyurethane foam having a good surface condition and having sufficient mechanical strength such as tensile strength and flexibility can be obtained.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Kitagawa             1334 Minato Minato, Wakayama Kao Corporation             Within F term (reference) 4J029 AA03 AB01 AD00 AD01 AE17                       BA01 BA03 BA04 BA05 BA08                       BA09 BA10 BF09 CA01 CA02                       CA03 CA04 CA05 CA06 CB04A                 4J034 BA08 CA03 CA04 CA05 CB03                       CB04 CE01 DA01 DB03 DB04                       DF01 DF14 DF15 DF16 DF20                       DF22 HA01 HA06 HA07 HB06                       HB17 HC02 HC03 HC12 HC13                       HC22 HC46 HC52 HC63 HC64                       HC65 HC66 HC67 HC71 HC73                       JA42 KA01 KC17 KD12 LA08                       NA02 NA03 QB00 RA03

Claims (5)

[Claims] 1. An acid component comprising (A) one or more phthalic acid components selected from phthalic anhydride and o-phthalic acid and an aliphatic polybasic acid, and (B) diethylene glycol. Polycondensation with polyhydric alcohol, 20 ℃
Polyester polyol that is liquid at 40 ° C and has a viscosity of 6000 mPa · s or less at 40 ° C. 2. The value of the molar ratio of the phthalic acid component and the aliphatic polybasic acid (phthalic acid component / aliphatic polybasic acid) is 0.1 to 0.25.
The polyester polyol according to claim 1, which is 3. The polyester polyol according to claim 1 or 2 and the polyester polyol obtained by reacting an aliphatic polybasic acid with a polyhydric alcohol in a weight ratio of 80/20.
A polyester polyol composition obtained by mixing so as to be about 98/2. 4. A polyurethane foam obtained by reacting a polyol component comprising the polyester polyol composition according to claim 3, a chain extender, a foaming agent and a urethanization catalyst with an isocyanate component. 5. A method for producing a polyurethane foam, which comprises reacting a polyol component comprising the polyester polyol composition according to claim 3, a chain extender, a foaming agent and a urethanization catalyst with an isocyanate component.