JPS6338066B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel polyurethane resin composition, and particularly to a polyurethane resin composition that has a high heat distortion temperature and excellent friction and abrasion resistance. Rigid polyurethane is broadly divided into non-foamed molded products and foamed molded products. Non-foamed molded products and low-foamed molded products are used as engineering resins in various equipment parts and automobile parts, and are widely used as resins useful for an extremely wide range of applications. has been done. Conventional rigid polyurethanes are mixtures of one or more polyfunctional aliphatic or aromatic polyol monomers, polyoxyalkylene polyols, especially polyoxypropylene polyols, or functional aliphatic or aromatic polyester polyols. and a polyisocyanate component consisting of one or more aliphatic or aromatic polyisocyanates or polyisothiocyanates are cured and molded in the presence of a catalyst, a blowing agent, etc. However, these polyurethane molded products generally have poor heat resistance, and when heat distortion temperature (measured according to ASTM D-648) is used as a measure to evaluate heat resistance, conventional polyurethane molded products have a temperature of 70 to 90 at most. ℃ is the limit, and it was difficult to exceed 90℃ with practical strength. On the other hand, heat resistance can be improved by introducing isocyanurate groups obtained by trimerization of isocyanate, but at the same time, the resulting molded product becomes extremely brittle and cannot be put into practical use. Also, as an engineering resin, P (load
The PV value, which is the product of Kg/cm ² ) and V (velocity m/min), is
It is said that a value of 800 or more is preferable for a sliding member. However, the current rigid polyurethane made of polyol and polyisocyanate has a PV value of 400 or less, and has the disadvantage that it can only be used under conditions of low speed and low load. Generally, molybdenum disulfide and graphite are used to improve friction and wear resistance, but these compounds have no significant effect on hard polyurethane, but rather improve heat distortion temperature, tensile strength, and bending strength. and reduce impact resistance. In order to improve friction and abrasion resistance, we tried adding various silicone resins, fluorine oligomers, titanium coupling agents, silane coupling agents, encapsulated oil, etc., but none of them had foam-containing, impact resistance, It was found that properties such as tensile strength and bending strength deteriorated. Furthermore, fiber reinforcement had only a negative effect. The object of the present invention is to have high thermal stability and
Our objective is to provide a polyurethane resin composition with excellent friction and abrasion resistance, and in particular, it has a high heat distortion temperature of at least 90°C, which could not be achieved with conventional hard polyurethane, and has practical strength, especially impact resistance. An object of the present invention is to provide a novel polyurethane resin composition having the following properties. Another object of the present invention is to provide a heat-resistant, friction-resistant, and abrasion-resistant polyurethane resin composition that can be used at low speeds and high loads, high speeds and reduced loads, and high speeds and high loads. The present invention relates to a polyurethane obtained by the reaction of a polyol component having at least a difunctional hydroxyl group and an at least difunctional polyisocyanate component, the polyurethane comprising 2,2-bis{4-(2-hydroxypropoxy) as the polyol component. 2,2-bis(4- phenyl}propane as one component)
50 to 80 parts by weight of a propylene oxide adduct of (hydroxyphenyl)propane, 10 to 40 parts by weight of an aromatic amine-based polyoxyalkylene polyol with a hydroxyl value of 200 to 700, and 10 to 40 parts by weight of a polyol with a hydroxyl value of 50 to 1830. A heat-resistant, friction-resistant, and abrasion-resistant polyurethane obtained by using a mixed polyol consisting of a polyol and/or a polyisocyanate component, characterized in that an aliphatic or aromatic oil component is added to the polyol component and/or polyisocyanate component. It relates to a resin composition. The polyurethane resin composition of the present invention can be used in various fields, but is particularly useful as various industrial parts that require heat resistance, friction resistance, and wear resistance, such as sliding material parts and other coatings. be. In the present invention, 2,2-bis(4-hydroxyphenyl)propane (2,2-bis{4-(2-hydroxypropoxy)phenyl}propane) having the following structure as one component of the polyol component is used in the present invention. (hereinafter referred to as bisphenol A)
By using a propylene oxide (hereinafter referred to as PO) adduct, we succeeded in obtaining a rigid polyurethane with excellent heat resistance. That is, in the present invention, since the PO adduct of bisphenol A was used as one component of the polyol component, the polyurethane obtained by reacting with polyisocyanate has a high concentration of aromatic rings in the molecular chain and has a rigid molecular structure, so it has a high glass content. Has a transition point. Therefore, it exhibits excellent thermal stability and a high heat distortion temperature (hereinafter referred to as HDT). The bisphenol A-PO adduct of the present invention can be obtained by reacting 1 mole of bisphenol A with 2 moles or more of PO using a known method. That is, the above adduct is bisphenol A
2,2-bis{4-(2-
Hydroxypropoxy) phenyl}propane 1
Contained as an ingredient, its content is usually about 40% by weight
The content is preferably about 80% by weight or more. Other components include bisphenol A, an adduct containing 3 moles or more of PO per 1 mole, usually about 60%
It may contain up to % by weight, preferably up to about 20% by weight. In addition, bisphenol A having one or two primary terminal hydroxyl groups as other components.
The adduct of 2 moles or 3 moles or more of PO is produced as a by-product during the addition reaction, and can be contained in the polyol component in any proportion. However, the amount of unreacted phenolic hydroxyl groups, such as bisphenol A and PO, 1 molar adducts of bisphenol A, must be 1% by weight or less. In addition, if the adduct of 2 moles of PO per 1 mole of bisphenol A is less than 40% by weight, the concentration of the skeleton of bisphenol A, which is a polyol component, decreases, resulting in a decrease in the heat resistance of the resulting polyurethane. . Furthermore, in the present invention, the polyol has at least a difunctional hydroxyl value of 200 as a polyol component.
-700, preferably 300-500 aromatic amine-based polyoxyalkylene polyol and hydroxyl value 50
~1830 is used in conjunction with a normal polyol. The above-mentioned at least bifunctional hydroxyl value 200~
Aromatic amine-based polyoxyalkylene polyols having a molecular weight of 700, preferably 300 to 500, can be prepared using known methods such as aromatic monoamines such as aniline or 2,4
- and 2,6-tolylene diamine (TDA) and so-called crude TDA, 4,4'-diaminodiphenylmethane and polymethylene polyphenylene polyamines obtained by condensation of aniline and formalin, ortho- or meta- or para-phenylene diamines. , a free primary compound obtained by adding one or more alkylene oxides such as propylene oxide and ethylene oxide to one or more aromatic diamines and aromatic polyamines such as meta- or para-xylylene diamine. Or it is a polyol in which substantially no secondary amine remains. The above-mentioned aromatic amine-based polyol lowers the viscosity of the polyol with the PO adduct of bisphenol A, and at the same time, the aromatic amino group has an affinity with the aromatic group of the PO adduct of bisphenol A, making it compatible. Improve. In order to further improve processability, the following aliphatic glycols and the like can be used as co-initiators in addition to aromatic amines at the stage of synthesis. For example, polyfunctional aliphatic glycols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, glucose, sorbitol, sucrose, aliphatic amines and aliphatic acids such as ethanolamine, diethanolamine, triethanolamine, ethylenediamine, etc. Examples include alkanolamines, and these co-initiators are preferably used in an equimolar or less amount relative to the aromatic amine. Specific examples of common polyols having a hydroxyl value of 50 to 1830 include the following polyols. (a) An aromatic polyol having a hydroxyl value of 50 to 850 and having at least difunctional hydroxyl groups. (a) Hydroquinone, pyrogallol, 4,4'-
Polyol with a hydroxyl value of 250 to 600 obtained by adding an alkylene oxide such as propylene oxide or ethylene oxide to a monocyclic or polycyclic aromatic compound having at least two hydroxyl groups such as isopropylidene diphenol (b) Phthalic acid, isophthalic acid acid, terephthalic acid,
Polyols with a hydroxyl value of 300 to 500 obtained by adding alkylene oxides such as propylene oxide and ethylene oxide to aromatic polybasic acids such as trimellitic acid (c) Metaxylene glycol, paraxylene glycol (d) Phthalic acid, isophthalic acid, The acid component is aromatic dicarboxylic acid such as terephthalic acid or its anhydride or its lower alcohol ester, and/or aliphatic dicarboxylic acid such as adipic acid or succinic acid, and ethylene glycol, 1,4-butylene glycol, or trimethylol. Aliphatic polyols such as propane, 1,4-cyclohexanediol, 1,
4-Cyclohexane dimethanol, β, β,
β',β'-tetramethyl-2,4,8,10-tetraoxaspiro(5,5)-undecane-
A polyester polyol with a hydroxyl value of 50 to 450 whose polyol component is an alicyclic polyol such as 3,9-diethanol or the polyols listed in (a), (b), and (c) above. Use of these aromatic polyols in (a) in combination. In this case, it is preferable that the amount does not exceed 40% by weight based on the total polyol, and that the average hydroxyl value is 200 to 500. (b) Polyfunctional aliphatic glycol with a hydroxyl value of 800 to 1830. Examples include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, and triethanolamine, which can be used in combination in an amount of 10% by weight or less based on the total polyol. (c) A polyfunctional aliphatic polyol with a hydroxyl value of 300 to 800. For example, sucrose, sorbitol, glucose, pentaerythritol, trimethylolpropane, glycerin, ethylenediamine,
A polyol in which one or more alkylene oxides such as propylene oxide and ethylene oxide are added to one or more of diethanolamine, water, etc., and 40% of the total polyol.
It is preferable to use them together in a range of not more than % by weight. The polyols listed above are particularly preferred, and polyols other than these having a hydroxyl value of 50 to 1830 can be used. In the present invention, a mixed polyol consisting of 50 to 80 parts by weight of the PO adduct of bisphenol A, 10 to 40 parts by weight of an aromatic amine-based polyoxyalkylene polyol, and 10 to 40 parts by weight of a conventional polyol is used. When the average hydroxyl value of the mixed polyol component is set to 200 to 700, preferably 300 to 500, the impact strength of the polyurethane obtained is surprisingly contrary to expectations, and the high HDT is almost reduced. It was found that a synergistic effect of increasing the That is, the impact strength of the polyurethane using the above three types of polyol components in combination is superior to the impact strength of each polyurethane when the above three types of polyol components are used alone. The reason for this has not yet been fully elucidated, but considering that with conventional hard polyurethanes, impact strength tends to decrease when HDT is increased, and it is extremely difficult to increase both HDT and impact strength. The above effects of the present invention are surprising. In the present invention, the compatibility between the PO adduct of bisphenol A and ordinary polyol is not good. This problem was solved by adding aromatic amine-based polyols to improve compatibility.
Furthermore, it has been found that by using an aromatic amine-based polyol in combination, not only high HDT and impact strength can be obtained, but also processability, moldability, etc. can be effectively improved. The improvement in processability referred to here refers to the reduction in the viscosity of the polyol liquid due to the introduction of the aromatic amine-based polyol, and the improvement in so-called compatibility in which the polyol liquid and the polyisocyanate liquid mix well even at room temperature. Further, since the chemical reaction proceeds due to the moderate autocatalytic action of the aromatic tertiary amine, no catalyst is intentionally required. Therefore, since there is no need to add a catalyst to the polyol liquid, the polyol liquid has excellent storage stability. Furthermore, improvement in moldability includes increasing the strength of the polyurethane molded product upon demolding due to the introduction of a primary network using at least a difunctional aromatic amine-based polyol. These polyols have a moisture content of 0.05% or less, preferably
It is necessary to keep it below 0.02%. Also, the polyisocyanates should be sufficiently degassed in advance. If these are neglected, unnecessary foaming will occur during the curing reaction. However, this is of course not the case when obtaining a foam. The polyisocyanate component of the present invention includes at least two types of polyisocyanate components in the field of polyurethane production.
Known functional aliphatic, cycloaliphatic and aromatic polyisocyanates can be used, among which aromatic polyisocyanates are particularly preferred. For example, 4,4'-diphenylmethane diisocyanate (MDI) and carbodiimide-modified MDI (e.g. Nippon Polyurethane Co., Ltd. MTL), polymethylene polyphenyl isocyanate (PAPI), polymeric polyisocyanate (e.g. Sumitomo Bayer Urethane 44V), 2,4- and 2,6-tolylene diisocyanate (TDI), orthotoluidine diisocyanate (TODI), naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI)
etc. are preferably used. The polyol component and polyisocyanate component are
The reaction can be carried out either by a one-shot method or a prepolymer method. The reaction between polyol and polyisocyanate preferably has an isocyanate index of 100 to 180, particularly preferably 105 to 180.
It is appropriate to carry out the test within the range of 160; outside this range, heat resistance decreases regardless of whether the isocyanate index becomes smaller or larger. Although the cause of this is not clear, it is presumed that it is due to a decrease in the substantial molecular weight of the polymer. In order to lower the coefficient of friction, the isocyanate index is preferably 100 to 115. In the present invention, in order to improve the friction and abrasion resistance of polyurethane, the above polyol components and/or
Alternatively, an aliphatic or aromatic oil component is added to the polyisocyanate component. Aliphatic oils also include alicyclic oils. Examples of the above aliphatic oil include JIS
Preferably, lubricating bone oils defined in the above are used, and specific examples include turbine oil, gear oil, machine oil, bearing oil, refrigerating machine oil, and lubricating oil for internal combustion engines. In addition, as the aromatic oil, for example, petroleum-based softeners called extender oils or process oils are used, and various softeners such as paraffin-based process oils, naphthenic process oils, and aromatic process oils are used. can be used. In the present invention, the above aliphatic oil or aromatic oil may be used alone or as a mixture, and its ISOVG
[Viscosity grade, cSt (mm ² /s), 40℃] is 68 to 1000
is preferable, and 100 to 680 is particularly preferable. In this range, a bleed phenomenon in which the oil oozes out onto the surface of the polyurethane occurs, and this bleed phenomenon produces a grease effect and improves friction and abrasion resistance. In the present invention, the amount of the oil component added is preferably 1 to 15 parts by weight, particularly preferably 2 to 10 parts by weight, per 100 parts by weight of polyurethane. In this range, the tensile strength, bending strength,
Friction resistance and abrasion resistance can be improved without reducing impact strength or the like. By adding oil components in this way,
The polyurethane of the present invention can be provided with superior friction and wear resistance to polyacetal resin, monomer-cast nylon resin, and high-density polyethylene resin. However, bleeding of oil components onto the surface may adversely affect the appearance of the product and impair its commercial value. In order to solve this drawback, aliphatic oil and solid lubricants such as molybdenum disulfide, graphite, and carbon were added to urethane resin after kneading, but even if the aliphatic oil and solid lubricant were in the same amount, the urethane resin with aliphatic oil Bleeding to the surface could not be prevented. As a result of further intensive research, it was found that in the present invention, it is more preferable to use an oil component and an inorganic compound powder capable of retaining the oil component in combination. Inorganic compounds used here include, for example, metal hydroxides such as calcium hydroxide, zinc hydroxide, and aluminum hydroxide, metal sulfates such as barium sulfate and sodium sulfate, metal sulfites such as sodium sulfite, and sodium chloride. , and metal halides such as potassium chloride. If the particle size of the inorganic compound powder is large, wetting by the oil component will be insufficient, and it will become scattered within the polyurethane resin, causing a local decrease in physical properties and secondary heating, which will have an adverse effect on the resin surface, so the particle size should be 50μ or less. is preferred. Further, in the present invention, the mixing ratio of the oil component and the inorganic compound powder is preferably 2 to 6/1 by weight, and more preferably 3 to 5/1. When kneading the oil component and the inorganic compound powder, it is preferable to knead equal amounts of both in a normal weight ratio using a ball mill or the like, and then dilute with a desired amount of the oil component before use. Adding an oil component and an inorganic compound powder as an oil carrier to a polyurethane resin does not lower the heat distortion temperature, but slightly lowers the impact strength, tensile strength, and bending strength. Therefore, as a result of further intensive research to improve impact strength, tensile strength, and bending strength and to solve the oil bleed phenomenon, the present invention solves the above problems by using a polymer polyol together with an oil component. It became possible to solve the problem. In the present invention, the polymer polyol is a polyether polyol graft-polymerized with a monomer having a vinyl group, and preferably has a hydroxyl value in the range of about 56 to 200. As a specific example, representative examples of commercially available products include POP31/28, 32/30, 34/45, 36/28, 40/ manufactured by Mitsui Nisso.
45 etc. can be mentioned. The amount of polymer polyol added is preferably 2 to 30 parts by weight per 100 parts by weight of the polyol component, and the most desirable range is 6 parts by weight.
~20 parts by weight. In addition, polymer polyols are
It is preferable to add it to the polyol component and/or polyisocyanate component in a well-mixed state with the oil component. Incidentally, it is also possible to suppress the bleeding phenomenon of the oil component to the surface by using a mixture of the oil component, the polymer polyol, and the inorganic compound powder serving as the oil carrier. Although a catalyst is not particularly required for producing the polyurethane of the present invention, known catalysts such as tertiary amines such as triethylene diamine and organometallic compounds such as dibutyltin dilaurate can also be used. However, isocyanate trimerization catalysts that produce isocyanurate rings are not preferred. In addition, in order to further improve the physical properties, the inorganic filler is mixed in advance with the polyol or polyisocyanate using a combination of synthetic resin powder such as fluororesin or polyamide resin and metal soap. It is also possible to use agent-containing polyurethane. Examples of inorganic fillers include graphite, silicon carbide, aluminum oxide, and molybdenum disulfide, which are effective in improving hardness, molding shrinkage, friction coefficient, wear resistance, and the like. Further, in the present invention, water,
It is also possible to form a foam by using a halogenated hydrocarbon such as trifluorotrichloroethane or an organic blowing agent such as azobisisobutyronitrile. In the present invention, the curing reaction can be carried out, for example, as follows. First, the liquid temperature of the compound is set to room temperature to 120℃, and the temperature of the mold to be cast is set to 50 to 120℃.
Cast as a mold, harden and remove from the mold. The cured molded product of the present invention has a higher HDT than conventional polyurethane molded products as it is, but it also has a HDT of 140 to 180℃
By performing heat treatment at a temperature of , the impact strength characteristics can be improved. The heat treatment can be performed in an inert gas atmosphere such as air or nitrogen. The present invention will be explained below with reference to reference examples and examples. Reference example 1 Propylene oxide adduct of bisphenol A [manufactured by Toho Chiba Chemical Co., Ltd., "BISOL-2P" (approx. 93% of 2 mole adduct of PO as determined by gas chromatographic analysis,
Contains about 7% of the 3 molar adduct of PO. OH value 316)]
Heat 600g to 100℃ and dehydrate it under reduced pressure to determine the moisture content.
55g of polyol obtained at 0.015%, 2,4-
300 g of TDA-based polyol (GR-30, manufactured by Takeda Pharmaceutical Co., Ltd.) with an OH value of 400 obtained by addition reaction of 5.6 moles of propylene oxide and 2.6 moles of ethylene oxide to 1 mole of tolylene diamine (TDA).
is heated to 100℃ and dehydrated under reduced pressure to obtain a moisture content of 0.015%.
and sucrose-based polyol (“LV450LA” manufactured by Mitsui Nisso, OH
100 g of a mixed polyol consisting of 15 g of a polyol obtained by heating 250 g of polyol at 100°C and dehydrating it under reduced pressure to a moisture content of 0.015%, and a carbodiimide-modified MDI (Japan Polyurethane Co., Ltd., "Millionate MTL”NCO content 28.8
%) was stirred in a beaker for 40 seconds with a propeller type stirrer and then defoamed in a vacuum desiccator for 1 minute. This mixture was immediately heated to 90℃.
The mixture was poured into a prefabricated glass mold of 130 mm x 130 mm x 6 mm, and reacted for 30 minutes in a constant temperature air bath at 100° C., and then the cured product was taken out from the mold. No bubbles were observed during this period. Next, heat treatment was performed for 2 hours in an air constant temperature bath at 160°C to obtain a non-foamed, tough polyurethane. The heat distortion temperature of the obtained polyurethane was determined by ASTM,
The flexural modulus is determined by D648 under a load of 18.6 kg/cm ² by ASTM, the Izot impact value by D790 is determined by ASTM, and the notched condition is determined by D256.
The friction coefficient was measured using a friction tester manufactured by Toyo Baldwin Co., Ltd. under dry conditions at 20 m/min and 5 to 60 kg/cm ² . Heat deformation temperature 128℃ Bending elastic modulus 25600Kg/ ^cm 2Izotsu impact value 3.6Kg・cm/cm Friction coefficient μ=0.400 PV value 200 Reference example 2 Reference example 1 "BISOL-2P" (OH value 316) 700g
is heated to 100℃ and dehydrated under reduced pressure to reduce the moisture content to 0.015.
% polyol (55 g), 400 g of TDA-based polyol "GR-30" heated to 100°C and dehydrated under reduced pressure to a moisture content of 0.015%, and 6-functional polyol (Mitsui Nisso "HS-700A"). ", OH
100g of mixed polyol consisting of 15g of polyol heated to 100°C and dehydrated under reduced pressure to a moisture content of 0.015%, and carbodiimide-modified MDI
(Millionate MTL), NCO content 28.8%)
Heat 1300g to 80℃ and dehydrate it under reduced pressure to determine the moisture content.
99 g of the isocyanate compound adjusted to 0.015% was taken, and both were stirred in a beaker for 40 seconds with a propeller type stirrer, and then defoamed in a vacuum desiccator for 1 minute. This mixed solution was immediately poured into a prefabricated glass mold with inner dimensions of 130 mm x 130 mm x 6 mm heated to 90°C, and after reacting for 30 minutes in an air constant temperature bath at 100°C, the cured product was taken out from the mold. During this time, no bubbles were observed. Next, heat treatment was performed for 2 hours in an air constant temperature bath at 160°C to obtain a non-foamed, tough polyurethane. Heat deformation temperature 127℃ Flexural modulus 24800Kg/cm ² Izot impact value 3.4Kg・cm/cm Friction coefficient μ=0.380 PV value 250 Example 1 and Reference Examples 3 to 6 Na ₂ SO ₃ (60g) and lubricating oil in a mortar (Manufactured by Maruzen Oil,
Add 60g of "150B" (ISOVG530) and mix well. Next, in a beaker, 10g of the above lubricating oil (Example 1), 4g of the above kneading oil, 8g of lubricating oil (Reference example 3), the above kneading oil
8g and 12g of lubricating oil (Reference Example 4), 14.6g of the above kneading oil and 14.7g of lubricating oil (Reference Example 5), 29g of the above kneading oil and lubricating oil
Add 14.5g (Reference Example 6) and stir well, and add the polyol component prepared in Reference Example 1 and the modified
Add MDI in the proportions shown in Table 1,
A rigid polyurethane was obtained by the same operation as in Reference Example 1. In the table, (Note 1) indicates the content of oil components in the urethane resin, and (Note 2) indicates that some oil oozes out on the surface. Examples 2 to 4 and Reference Examples 7 to 8 Polymer polyol (manufactured by Mitsui Nisso, “POP40/
45'', OH value 110) was heated to 100°C and dehydrated under reduced pressure to bring the moisture content to 0.015%. Next, put the polymer polyol and lubricating oil in the proportions shown in Table 2 in a beaker (8.8g for Reference Example 7, 13.5g for Reference Example 8).
lubricating oil) was added and kneaded well. Further reference example 7
In 8 and 8, NaCl (15 g) and lubricating oil (150B) 15 g were added to the mortar and kneaded oil well.
4.4g (Reference Example 7) and 9g (Reference Example 8) were blended in a beaker and kneaded well. Further reference example 2 to the above formulation
The polyol component prepared above and modified MDI were added in the proportions shown in Table 2, and a hard polyurethane was obtained in the same manner as in Reference Example 2.

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Claims (1)

[Scope of Claims] 1. A polyurethane obtained by the reaction of a polyol component having at least difunctional hydroxyl groups and an at least difunctional polyisocyanate component, the polyurethane comprising 2,2-bis{4 as the polyol component.
50 to 80 parts by weight of a propylene oxide adduct of 2,2-bis(4-hydroxyphenyl)propane containing propane as one component, aromatic amine base with a hydroxyl value of 200 to 700 10~ of polyoxyalkylene polyol
40 parts by weight and a polyol with a hydroxyl value of 50 to 1830 10 to
A polyurethane obtained using a mixed polyol consisting of 40 parts by weight, characterized by the addition of an aliphatic or aromatic oil component to the polyol component and/or polyisocyanate component. Abradable polyurethane composition. 2 A polyurethane obtained by the reaction of a polyol component having at least a difunctional hydroxyl group and an at least difunctional polyisocyanate component, wherein the polyol component is 2,2-bis{4
50 to 80 parts by weight of a propylene oxide adduct of 2,2-bis(4-hydroxyphenyl)propane containing propane as one component, aromatic amine base with a hydroxyl value of 200 to 700 10~ of polyoxyalkylene polyol
40 parts by weight and a polyol with a hydroxyl value of 50 to 1830 10 to
A polyurethane obtained by blending 2 to 30 parts by weight of a polymer polyol obtained by graft polymerizing a monomer having a vinyl group to a polyether polyol to 100 parts by weight of a mixed polyol consisting of 40 parts by weight. A heat-resistant, friction-resistant, and wear-resistant polyurethane composition characterized in that an aliphatic or aromatic oil component is added to the polyol component and/or polyisocyanate component.