JPS60163913A - Heat-, friction- and abrasion-resistant polyurethane - Google Patents

Abstract

PURPOSE:To polyurethane excellent in heat stability and friction and abrasion resistances, obtained by reacting a specified polyol containing an liphatic or aromatic oil component with a polyisocyanate. CONSTITUTION:A polyol mixture of a water content <=0.05% is obtained by mixing 50-80pts.wt. 2,2-bis(4-hydroxyphenyl)-propane/propylene oxide adduct containing 60wt% or above 2,2-bis{4-(2-hydroxypropyl)phenyl}propane with 10- 40pts.wt. aromatic amine-based polyoxyalkylenepolyol of an OH value of 200- 700 and 10-40pts.wt. polyol of an OH value of 50-1830. This polyol mixture is reacted with an at least difunctional polyisocyanate in an amount to provide an isocyanate index of 100-115, an oil in an amount of 1-15pts.wt. per 100pts.wt. polyurethane resin to be formed and an inorganic compound powder in an amount of 1/2-1/6pt.wt. per pt.wt. oil.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new polyurethane, and particularly to a polyurethane 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 contain one or more polyfunctional aliphatic or aromatic polyol monomers, polyoxyalkylene polyols, especially polyoxypropylene polyols, or polyfunctional aliphatic or aromatic polyester polyols. A polyol component consisting of a mixture and a polyisocyanate component consisting of a mixture of one or more aliphatic or aromatic polyisocyanates or polyinthiocyanates are cured and molded in the presence of a catalyst, a blowing agent, etc.

However, these polyurethane molded products have poor heat resistance as a single shell, and when heat distortion temperature (measured according to ΔSTM D-648) is taken as a measure for evaluating heat resistance, conventional polyurethane molded products have a heat resistance of at most 70 The limit is ~90°C, and it was difficult to exceed 90°C with practical strength. On the other hand, heat resistance can be improved by introducing isocyanurate groups obtained by trimerization of incyanate, but at the same time, the resulting molded product becomes extremely brittle, resulting in a drawback that it cannot be put to practical use.

Also, as an engineering resin, P (load kg/cm
PV value, which is the product of 2) and V (velocity m/m1n), is 800.
It is said that the above is preferable for the 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 abrasion resistance, but these compounds have no noticeable effect on hard polyurethane, but rather improve heat distortion temperature, tensile strength, and bending strength. Decreases hardness and 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, friction resistance,
Our goal is to provide polyurethane with excellent wear resistance.
In particular, the object of the present invention is to provide a new polyurethane that has a high heat distortion temperature of at least 90° C. (1) and has practical strength, especially impact resistance, which has not been achieved with conventional rigid polyurethanes.

Furthermore, the object of the present invention is to provide heat resistance and friction resistance that can be used at low speeds and high loads, high speeds and low loads, and high speeds and high loads. The purpose is to provide a wear-resistant polyurethane.

The present invention relates to a polyurethane obtained by the reaction of a polyol component having at least difunctional hydroxyl groups and an at least difunctional polyisocyanate component, wherein the polyol component is 2,2-bis(4-(2-hydroxypropoxy)). 2,2- containing phenyl)propane as one component
50 to 80 parts by weight of propylene oxide adduct of bis(4-hydroxyphenyl)propane, hydroxyl value 200 to
A mixed polyol consisting of 10 to 40 parts by weight of an aromatic amine-based polyoxyalkylene polyol of No. 700 and 10 to 40 parts by weight of a polyol having a hydroxyl value of 50 to 1,830 is used, and the polyol component and/or polyisocyanate component is aliphatic or This invention relates to a heat-resistant, friction-resistant, and abrasion-resistant polyurethane characterized by the addition of an aromatic oil component.

The polyurethane of the present invention can be used in various fields, and is particularly useful as various industrial parts that require heat resistance, friction resistance, and abrasion resistance, such as sliding material parts and ground coverings thereof.

In the present invention, 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as histopropane) containing 2,2-bis14-(2-hydroxypropoxy)phenyl)propane having the following structure as one component of the polyol component. 7e7
By using a propylene oxide (hereinafter referred to as PO) adduct of Polyurethane A (hereinafter referred to as PO), a rigid polyurethane with excellent heat resistance was successfully obtained.

That is, in the present invention, since the PO adduct of bis-7-el-7-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. Therefore, it has a high glass transition point. Therefore, it has excellent thermal stability and the heat distortion temperature (
(hereinafter referred to as +1DT).

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 contains 1 mole of 2,2-bis(4-(2-hydroxypropoxy)phenyl)propane in which 1 mole of PO is added to each of the 7-ethyl hydroxyl groups per 1 mole of bisphenol A. The content is usually about 40% by weight or more, preferably about 80% by weight or more. As other components, an adduct having 3 or more moles of P(') per mole of bisphenol A may be contained, usually at most about 60% by weight, preferably at most about 20% by weight. In addition, other components include one or two primary terminal hydroxyl groups.
The adduct of 2 moles or 3 moles or more of bis7el/-A and PO is produced as a by-product during the addition reaction, and can be contained in the polyol component in any proportion. However, for example, bis7, which has an unreacted 7-ether hydroxyl group,
The content of E7-el A and bisphenol A, Po, 1 molar adducts, etc. must be 1% by weight or less.

Note that if the adduct containing 2 mol of PO per 1 mol of bisphenol A is less than 40% by weight, the concentration of the skeleton of bis7-el A, which is a polyol component, will decrease, resulting in a decrease in the polyurethane obtained. The heat resistance of is reduced.

Furthermore, in the present invention, as a polyol component, an aromatic amine-based polyoxyalkylene polyol having at least a difunctional hydroxyl value of 200 to 700, preferably 300 to 500, and a normal polyol having a hydroxyl value of 50 to 1,830 are used in combination with the above polyol.

the above-mentioned at least bifunctional hydroxyl value 200 to 700,
Preferably, the aromatic amine-based polyoxyalkylene polyol of 300 to 500 is prepared by known methods such as aromatic monoamines such as aniline or 2,4- and 2,6-tolylene diamine (Tll^) and so-called crude TDA, 4
．． One or more aromatic diamines and aromatic polyamines such as 4'-diami7diphenylmethane and polymethylene polyphenylene polyamine obtained by condensation of aniline and formalin, ortho-, meta- or para-phenylene diamine, meta- or para-xylylene diamine, etc. It is a polyol obtained by adding one or more alkylene oxides such as , propylene oxide, ethylene oxide, etc., and substantially no free primary or secondary amine remains.

The aromatic amine-based polyol described above lowers the viscosity of the PO adduct of bisphenol A and the polyol, and at the same time,
The aromatic amine 7 group has affinity with the aromatic group of the PO adduct of bis 7 el 7-el A and improves compatibility. 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, and sucrose, and fats such as ethylamine, jetanolamine, triethanolamine, and ethylenediamine. Examples include group amines and aliphatic alkanolamines, and these co-initiators are preferably used in an equimolar or less amount relative to the aromatic amines.

As a normal polyol with a hydroxyl value of 50 to 1830,
Specifically, the following polyols can be mentioned.

(a) An aromatic polyol having a hydroxyl value of 50 to 850 and having at least difunctional hydroxyl groups.

(a) Hydroxyl group obtained by adding a fullylene oxide such as propylene oxide or ethylene oxide to a monocyclic or polycyclic aromatic compound having at least two hydroxyl groups such as hydroquinone, pyrogallol, and 4,4'-impropylidene diphenol. Polyols with a valence of 250 to 600 (ro) Hepthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and other aromatic polybasic acids, propylene oxide,
Polyol with a hydroxyl value of 300 to 500 obtained by adding alkylene oxide such as ethylene oxide (c) metaxylylene glycol, paraxylylene glycol (d) 7 Aromatic dicarboxylic acids such as talic acid, isophthalic acid, and terephthalic acid or their anhydrides or its lower alcohol ester, and/or aliphatic dicarboxylic acids such as adipic acid and succinic acid as the acid component, mD group polyols such as ethylene glycol, 1,4-phthylene glycol, and trimethylolpropane, and 1,4 -cyclohexanediol, 1,4-cyclohexane dimetatool, β, β, β゛, β゛-tetramethyl-2,4,8,
10-tetraoxaspiro(5,5)-undecane-3
, 9-jethanol, or the above (
A polyester polyester with a hydroxyl value of 50 to 450 containing the polyols of (a), (b), and (c) as polyol components. When using these aromatic polyols of (a) together, make sure that the polyols do not exceed 40 polyols per total polyol. The average hydroxyl value is preferably 200 to 500.

(b) Polyfunctional aliphatic glycol having a hydroxyl value of 800 to 1,830.

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.

(e) A polyfunctional aliphatic polyol having a hydroxyl value of 300 to 800.

For example, one or more alkylene oxides such as propylene oxide and ethylene oxide are added to one or more of sucrose, sorbitol, glucose, pentaerythritol, trimethylolpropane, glycerin, ethylenediamine, jetanolamine, water, etc. It is preferable to use the same polyol at a frequency of 40 times or less per total polyol.

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, the PO adduct of bisphenol A is
80 parts by weight, 10 to 40 parts by weight of aromatic amine-based polyoxyalkylene polyol and 10 parts by weight of normal polyol.
A mixed polyol consisting of ~40 parts by weight is used. And the average hydroxyl value of the above mixed polyol component is 200~
7001, preferably from 300 to 500, the impact strength of the polyurethane obtained was surprisingly contrary to expectations, and it was found that a synergistic effect of increasing the impact strength without almost reducing the high IDT was obtained. 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.

Although the reason for this has not yet been fully elucidated, the impact strength of conventional rigid polyurethanes tends to decrease as IIDT increases, and it is difficult to increase both IDT and impact strength. Considering this, the above effects of the present invention are surprising.

In the present invention, the compatibility between the PO adduct of bisphenol A and ordinary polyols is not good. This problem was solved by adding aromatic amine-based polyols to improve compatibility.

Moreover, by using an aromatic amine-based polyol in combination, not only high IIDT and impact strength can be obtained, but also
It has also been found that processability, moldability, etc. can also 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 storage stability of the polyol liquid can be improved. 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 bifunctional aromatic amine-based polyol.

These polyols need to have a moisture content of 0.05% or less, preferably 0.02% or less prior to the reaction with isocyanates. 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.

As the polyisocyanate component of the present invention, various at least difunctional aliphatic, alicyclic, and aromatic polyisocyanates known in the field of polyurethane production can be used, but aromatic polyisocyanates are particularly preferably used. Ru. For example, 4,4'-diphenylmethane diisocyanate (MDI) and carposiimide-modified MDI
(e.g. Nippon Polyurethane Co., Ltd. NTI), polymethylene polyphenylated 15-lysocyanate (PAPI), polymeric polyisocyanate (e.g. Bayer Urethane 44), 2
．． 4- and 2,6-) lylene diisocyanate (TD
r), ortho-toluidine diisocyanate (TO old),
Naphthylene diisocyanate (NDI), xylylene diisocyanate (MDI), etc. are preferably used.

The polyol component and the polyisocyanate component can be reacted by a one-shot method or a prepolymer method. The reaction between polyol and polyisocyanate preferably has an isocyanate index of 100 to 18.
0, particularly preferably in the range of 105 to 160; outside this range, heat resistance decreases regardless of whether the isocyanate index becomes small or large. 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 incyanate index is preferably 100 to 115.
- Delicious.

In the present invention, an aliphatic or aromatic oil component is added to the polyol component and/or polyisocyanate component in order to improve the friction and abrasion resistance of polyurethane. Fat oil release also includes alicyclic oil release. The above-mentioned fatty oil is preferably a lubricating oil specified by JIS, and specific examples include turbine oil, gear oil, machine oil, bearing oil, refrigeration machine oil, and lubricating oil for internal combustion engines. Further, as the aromatic oil, for example, a petroleum-based softener called extengu oil or process oil is used.
Various softeners such as paraffinic process oil, naphthenic process oil, and aromatic process oil can be used.

In the present invention, the above fatty oil or aromatic oil is used alone or as a mixture, and its l5OV [viscosity grade, cSt (+llll12/S), 40°C] is 68
-1000 is preferable, and 100-680 is particularly preferable. In this range n+, a bleed phenomenon occurs in which the oil oozes out onto the surface of the polyurethane, and this bleed phenomenon produces a grease effect and improves friction resistance and abrasion resistance.

In the present invention, the amount of the oil component added is 1
It is preferably 1 to 15 parts by weight, and 2 to 1 parts by weight per 00 parts by weight.
Particularly preferred is 0 parts by weight. Within this range, friction resistance and abrasion resistance can be improved without reducing the tensile strength, bending strength, impact strength, etc. of the polyurethane obtained.

By adding the oil component in this manner, the polyurethane of the present invention can be provided with superior friction and abrasion 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 problem, fat-free oil and solid lubricants such as molybdenum disulfide, graphite, and carbon were added to the urethane resin after mixing, but even if the fat-free oil and solid lubricant were used in the same amount, the fat-free urethane resin Bleed to the surface could not be prevented.

Therefore, as a result of further intensive research, it was found that in the present invention 1, it is more preferable to use an oil component and an inorganic compound powder having the ability to retain 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 sulfuric acid; and metal sulfites such as sodium sulfite. One or more types of salts, metal halides such as sodium chloride, potassium chloride, etc. can be used. If the particle size of the inorganic compound powder is large, wetting by the oil component will be insufficient and it will become scattered in the polyurethane resin, resulting in a local decrease in physical properties and a negative effect on the resin surface during secondary heating. It is preferably 50μ or less.

Further, in the present invention, the mixing ratio of the oil component and the inorganic compound powder 19- is preferably 2 to 6/1 by weight, more preferably 3 to 6/1.
A range of 5/1 is more preferred. When mixing 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 polyurethane resin does not lower the heat distortion temperature, but
Impact strength, tensile strength and bending strength are slightly reduced.

Therefore, we improved impact strength, tensile strength and bending strength,
As a result of further intensive research in order to solve the oil bleed phenomenon, it has become possible to solve the above problems by using a polymer polyol together with the oil component in the present invention.

In the present invention, the polymer polyol is a polyether polyol graft-polymerized with MOAR 7- having a vinyl group, and preferably has a hydroxyl value in the range of about 56 to 200. Specific Examples and 20- For example, a representative example of a commercially available product is PO manufactured by Mitsui Nichikou.
P 31/213.32/30.34/45.36/2
8.40745 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 to 30 parts by weight.
It is 20 parts by weight. Further, the polymer polyol is preferably added to the polyol component and/or the polyisocyanate Y 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, incyanate 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.

Inorganic fillers include graphite, silicon carbide, aluminum oxide, molybdenum disulfide, etc.
Effective in improving mold shrinkage, friction coefficient, wear resistance, etc. In the present invention, it is also possible to form a foam by using water, 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, adjust the liquid temperature of the compound to room temperature.
Set the temperature to 120℃ and the temperature of the casting mold to 50~+20"
As C, cast, harden and demold. The cured molded product of the present invention has a higher I than the conventional polyurethane molded product even as it is.
Although it has IDT, properties such as impact strength can be improved by further performing heat treatment at a temperature of 140 to 180°C. 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 Industries, II) ISQL-21'J (approx. 93% of 2 molar adduct of PO by gas chromatographic analysis, PO
Contains about 7% of the 3 molar adduct of O8 value 316) ) 6
00g was heated to 100℃ and dehydrated under reduced pressure to reduce the moisture content to 0.
．． 015% polyol 55g12.4-
) TD octahedral polyol (manufactured by Takeda Pharmaceutical Co., Ltd. [G R-30J) 300
g is heated to 100°C and dehydrated under reduced pressure to give a moisture content of 0.01.
30 g of the polyol obtained at 5% and a sucrose-based polyol (Mitsui Nisso J1.V 450L)
8", OT (value 450) 250 g to 100"CF
:: Heating and dehydration under reduced pressure to reduce the moisture content to O, O], 5%
100 g of a mixed polyol consisting of 15 g of the polyol obtained by
99 g of MTLJ (NCO content 28.8%) was stirred in a beaker for 40 seconds with a propeller stirrer and then defoamed in a vacuum desiccator for 1 minute. Immediately heat this mixture to 90"C. Inside size: 1.30mm x 1.30mm.
Pour into a 6 mm x 6 mm prefabricated glass mold, 1
After reacting for 30 minutes in an air constant temperature bath at 00°C, the cured product was taken out from the mold. No bubbles were observed during this time. Next, heat treatment was performed for 2 hours in an air constant temperature bath at 160'C to obtain a non-foamed, tough, rigid polyurethane.

The heat distortion temperature of the obtained polyurethane was determined by ASTM1, D6.
The flexural modulus was determined by ASTM under the load of 18.6 kg/cm2 by 48, the Izod impact value was determined by ASTM by D790, and the friction coefficient was determined by D256 under the condition of 7 points by ASTM. Measurement was carried out using a friction tester under the conditions of dry condition, 20 n+/min, and 5 to 60 kg/cm2.

Heat deformation temperature 128°C Flexural modulus 25600kg/cm2 Izot impact value 3.6kg-cm/cm Friction coefficient
μ=0.400 pv value 200 Reference example 2 Reference example 1 NoJBIsOL-2PJ (O8 value 316) 7
00Fi was heated to 100°C and dehydrated under reduced pressure to give a moisture content of 0.015%, and 400g of TD octahedral polyol rGR-30J was heated to 1.00°C and dehydrated under reduced pressure to give a moisture content of 0.015%. 30g of polyol with 0.015% and hexafunctional polyol (Mitsui Nisso Seikuchi Is
-700^'', OH value 460) 300g at 1.00℃
100 g of a mixed polyol consisting of polyol 158 heated to and dehydrated under reduced pressure to a moisture content of 0.015%, and carposiimide-modified MDI (Millionate M T L
), NCO content 28.8%) 1300, was heated to 80°C and dehydrated under reduced pressure to give a moisture content of 0.015%. The mixture was stirred using a mold stirrer and then defoamed in a vacuum desiccator for 1 minute. Immediately pour this mixture into
Inner dimensions heated to 0°C: 1.30mm x 1301 x 6 +
The cured product was poured into a type glass mold by assembling the om, and reacted for 30 minutes in an air constant temperature bath at 100°C, and then the cured product was taken out from the mold. No bubbles were observed during this time. Next, heat treatment was performed for 2 hours in an air constant temperature bath at 160° C. to obtain a non-foamed, tough, rigid polyurethane.

Heat deformation temperature 127℃ Flexural modulus 24800kg/Cm2 Izot impact value 3.4kg-Cm/Cm Friction coefficient
μ=0.380 PV value 250 Examples 1 to 5 In a mortar, NaNa2S03 (60) and lubricating oil (Maruzen Sekiyu Co., Ltd.,
60 g of 530) was added to 1150 Town 1, TSOV and kneaded well.

Next, in a beaker, 10 g of the above lubricating oil (Example 1), 4 g of the above mixing oil and 8 g of lubricating oil (Example 2), 8 g of the above kneading oil and 1.2 Fi of lubricating oil (Example 3), 14. 6
g, lubricating oil 14.7 g <Example 4), and the above kneading oil 29 g
Add 14.5 g of lubricating oil and stir well, add the polyol component prepared in Reference Example 1 and modified MDI in the proportions shown in Table 1, and perform the same operation as in Reference Example 1. A hard polyurethane was obtained. In the table (Note 1)
indicates the content of oil components in the urethane resin, and (Note 2) indicates that some oil oozes from the surface.

Examples 6-10 Polymer polyol (Mitsui Nisso, rPOP 40/4
5j, OH value 110) 150g was heated to 1.00°C and dehydrated under reduced pressure to make the moisture content 0.015%. Next, polymer polyol and lubricating oil (8.8 g of lubricating oil in Example 7 and 13.5 g of lubricating oil in Example 8) were added to the beaker in the proportions shown in Table 27-2, and the mixture was thoroughly kneaded. Furthermore, in Examples 7 and 8, NaCI (15 g) and lubricating oil (150B) were placed in the mortar.
4.4 g of kneading oil (Example 7) and 9 g (Example 8) of which 5 g was added and well kneaded were added to a beaker and kneaded well. The polyol component prepared in Reference Example 2 and modified MDI were further added to the above mixture in the proportions shown in Table 2, and the same procedure as in Reference Example 2 was carried out to obtain a hard polyurethane.

28- Table 2 Patent applicant: Toyo Rubber Industries, Ltd. Agent: Patent attorney Enso Iwao 31-

Claims (3)

[Claims] (1) 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 contains 2,2-bis14-(2-hydroxypropoxy)phenyl ) 50 to 80 parts by weight of a propylene oxide adduct of 2,2-bis(4-hydroxyphenyl)propane containing propane as one component, hydroxyl value 200 to 7
A mixed polyol consisting of 10 to 40 parts by weight of an aromatic amine-based polyoxyalkylene polyol of No. 00 and 10 to 40 parts by weight of a polyol having a hydroxyl value of 50 to 1,830 is used, and the polyol component and/or polyisocyanate component is aliphatic or A heat-resistant, friction-resistant, and abrasion-resistant polyurethane characterized by the addition of an aromatic oil component. (2) Use 1 to 15 parts by weight of the oil component per 100 parts by weight of the polyurethane resin, and further use the inorganic compound powder in such a range that the weight ratio of the oil component to the inorganic compound powder is 2 to 6/1. Polyurethane according to claim 1. (3) 2 to 30 parts by weight of a polymer polyol is further disposed with respect to 100 parts by weight of the polyol component.
The polyurethane according to item 1 or 2.