JPS60190410A - Abrasion-resistant polyurethane - Google Patents

Abstract

PURPOSE:An abrasion-resistant polyurethane that is obtained by allowing a specific polyalkylene polyol based on aromatic amine and a polyisocyanate component to react in the presence of an aliphatic or aromatic oil component. CONSTITUTION:The objective polyurethane is obtained by allowing (A) a polyol consisting of a polyalkylene polyol based on an aromatic amine of 200-700 hydroxyl values, bearing 2 or more functional hydroxyls on the average and (B) a 2 or more functional isocyanate compound to react with each other in the presence of (C) an aliphatic or aromatic oil component. Further, it is preferred to use (D) an inorganic powder in such an amount as the weight ratio of C/D is 2- 6/1.

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 classified into non-foamed molded products and foamed molded products, and the non-foamed molded products and low-foamed molded products are used as engineering resins in various equipment parts, automobile parts, etc.

Conventional rigid polyurethanes are mixtures of 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 an aliphatic or aromatic polyisocyanate or a polyisothiocyanate, or a polyisocyanate component consisting of a mixture thereof 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 ΔSTM D-648) is taken as a measure for evaluating heat resistance, conventional polyurethane molded products have a temperature of 70 to 90 at most. °C
is the limit, and it was difficult to exceed 90°C with practical strength. On the other hand, the introduction of incyanurate groups obtained by trimerization of isocyanate improves heat resistance.
However, 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 kg/cm
The pv value, which is the product of 2) and V (velocity m/l6in), is 80.
It is said that a value of 0 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.
It 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 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, it is an object of the present invention to provide a new polyurethane that has a high heat distortion temperature of at least 90° C., which could not be achieved with conventional rigid polyurethanes, and has practical strength, especially impact resistance.

3- Another object of the present invention is to provide a polyurethane with friction and wear resistance that can be used at low speeds and high loads, high speeds and low 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, wherein the polyol component is an aromatic amine-based polyoxyalkylene having a hydroxyl value of 200 to 700. The present invention relates to a friction-resistant and abrasion-resistant polyurethane characterized by using a polyol and adding an aliphatic or aromatic oil component to the polyol component and/or polyisocyanate 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.

Polyols generally used for soft 7 ohms and hard 7 ohms have excellent compatibility with incyanate, but poor compatibility with lubricating oils and aliphatic oils.

It has been found that the use of aromatic amine-based polyols in the present invention not only provides good compatibility with lubricating oils and provides high HDT and impact strength, but also effectively improves moldability.

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. In addition, the improvement in moldability includes the fact that the strength of the polyurethane molded product upon demolding becomes poor due to the introduction of a primary network using at least a bifunctional aromatic amine-based polyol.

the above-mentioned at least bifunctional hydroxyl value 200 to 700,
Preferably 300 to 500 aromatic amine-based polyoxyalkylene polyols are prepared by known methods such as aromatic monoamines such as aniline or 2,4- and 2,6-tolylene diamines (TDA) and so-called crude TDA, 4
．． Aromatic diamines and aromatic polyamines such as 4'-diami7nophenylmethane and polymethylene polyphenylene polyamines obtained by condensation of aniline and formalin, ortho-, meta-, or para-phenylene diamines, meta- or para-xylylene diamines, and 1'I4 or aromatic polyamines. It is a polyol obtained by adding one or more alkylene oxides such as propylene oxide and ethylene oxide to the polyol, and substantially no free primary or secondary amine remains.

The polyurethane made of the above-mentioned aromatic amine-based polyol and polyisocyanate has a high IIDT, but has poor friction resistance and abrasion resistance. As a result of intensive efforts to improve friction and wear resistance, it has been found that friction and wear resistance can be improved by adding lubricating oils such as fatty oils and aromatic oils.

In the present invention, this oil component causes a bleed phenomenon in which it oozes out onto the surface of the polyurethane, and this bleed phenomenon produces a grease effect and improves friction resistance and abrasion resistance. However, since the migration of oil components to the surface can have a negative effect on the appearance of the product and reduce its commercial value, we conducted research to suppress the migration of oil components.

First, fat oil and a solid lubricant such as molybdenum disulfide, graphite, carbon, etc. were mixed together and then added to the urethane resin, but even if the fat oil and solid lubricant were in the same amount, the fat oil would migrate to the urethane resin surface. could not be prevented.

Therefore, as a result of further intensive research, it has become possible to solve the above problems by using in combination an oil component and an inorganic compound powder having the ability to retain the oil component in the present invention.

In the present invention, alicyclic oils are also included as fatty oils. The above-mentioned fat release oil is preferably a lubricating oil specified by JIS, and specific examples thereof include turf oil, gear oil, machine oil, bearing oil, refrigeration machine oil, and lubricating oil for internal combustion engines. In addition, as the aromatic oil, for example, a petroleum-based softener called extengu oil or process oil is used, and various softeners such as paraffin-based process oil, naphthenic process oil, aromatic process oil, etc. are used. can do.

In the present invention, the above fatty oil or aromatic oil is used alone or as a mixture, and its l5OVG [viscosity grade, cst (mm2/s), 40'C] is 68-100
0 is preferred, and 100 to 680 are particularly preferred. In this range, a migration phenomenon occurs in which the oil oozes onto the surface of the polyurethane, and this migration phenomenon produces a grease effect and improves the friction and wear resistance.

In the present invention, the amount of the oil component added is 10% polyurethane.
It is preferably 1 to 20 parts by weight, and 2 to 15 parts by weight relative to 0 parts by weight.
Parts by weight are particularly preferred. Within this range, it is possible to improve the friction resistance and abrasion resistance without reducing the tensile strength, bending strength, impact strength, etc. of the polyurethane obtained.

Inorganic compounds used in the present invention include, for example, metal hydroxides such as calcium hydroxide, zinc hydroxide, and aluminum hydroxide, metal sulfates such as barium sulfate and sodium sulfate, and metal sulfites such as sulfite). , sodium chloride, potassium chloride, and other metal halides. If the particle size of the inorganic compound powder is large, it will not be sufficiently wetted by the oil component, and will be scattered in the polyurethane resin, causing local physical property deterioration and secondary heating, which will have an adverse effect on the resin surface. The following are 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. Kneading the oil component and inorganic compound powder is
It is preferable to knead equal amounts of both in a normal weight ratio using a ball mill or the like, and dilute with a desired amount of oil component before use. By adding the oil component and inorganic compound powder in this manner, the polyurethane of the present invention can exhibit superior friction and wear resistance to polyacecool resin, monomer cast nylon resin, and high-density polyethylene resin. .

However, the addition of inorganic compounds is less desirable for physical properties. Therefore, as a result of further intensive research, it has become possible to solve the above problems by using a polymer polyol together with an oil component and/or an inorganic compound powder in the present invention.

In the present invention, the polymer polyol is obtained by graft-polymerizing a polyether polyol with a moamer having a vinyl group, and preferably has a hydroxyl value in the range of about 56 to 200. As a specific example, a representative example of a commercially available product is 1101131/28.32/30 manufactured by Mitsui Nisso.
．． Examples include 34/45.36/28.40/45. The amount of polymer polyol added is preferably in the range of 2 to 30 parts by weight per 100 parts by weight of the polyol component. Further, it is preferable that the polymer polyol is added to the polyol component and/or the polyisocyanate component in a state mixed 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.

These polyols must 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 poly-11-incyanate is particularly preferred. used 6 e.g. 4.4
゛-nophenylmethane diisocyanate (formerly N) and carposiimide-modified MDI (for example, Ippon Polyurethane Co., Ltd. M
T1. ), polymethylene polyphenylisocyanate)
(PAPI), polymeric polyisocyanates (e.g. Sumitomo Bayer Urethane 44V), 2.4- and 2.6-
-lylene diisocyanate ('rot), orthotoluidine diisocyanate (TODI), natylene diisocyanate (NDI), xylylene diisocyanate-4 (XDI), and the like 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 a polyol and a polyisocyanate is preferably performed in an isocyanate index of 100 to 180.
It is particularly preferable to carry out the process within the range of 105 to 160. Outside this range, heat resistance decreases regardless of whether the incyanate index becomes small or large. Although the reason for this is not clear, it is presumed that the substantial molecular weight of the polymer is reduced. In order to lower the coefficient of friction, the incyanate index is preferably 100 to 115.

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 physical properties, fluororesin,
It is also possible to obtain an inorganic filler-containing polyurethane by using a synthetic resin powder such as a polyamide resin together with a metal soap and mixing the inorganic filler with the polyol or polyisocyanate in advance. 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, the present invention can also be made into a foam by using water, a halogenated hydrocarbon such as MJ fluorotrichloroethane, 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°C, and the temperature of the casting mold is set to 50 to 120'C, and the mixture is cast, cured, and demolded. Although the cured molded product of the present invention has higher IIDT than conventional polyurethane molded products, properties such as impact strength can be improved by heat treatment at a temperature of 140 to 180"C. The heat treatment can be carried out in an inert gas atmosphere such as air or nitrogen.

The present invention will be explained below with reference to reference examples and examples.

Example I TD octahedral polyol [manufactured by Take IB Pharmaceutical Industry Co., Ltd. [GR-30]
1. A sample having a hydroxyl value of 4,001,540 g was taken, heated to 100°C, and dehydrated under vacuum for about 30 minutes. Water content is 0.
It was 0.015%. Also, tolylene diisocyanate]
1"DI, NC0%48.8%] Take 350g and 8
It was heated to 0° C. and dehydrated under vacuum for about 30 minutes. Moisture content was 0.02%.

Next, 100 g of TD eight-body polyol was placed in a beaker, TDI (65 g) was added to the beaker, and lubricating oil [Maruzen Oil Co., Ltd., "RO-320-l, 15OVt',
320] was added and stirred for 20 seconds using a propeller-type stirrer, and then defoamed in a vacuum desiccator for 1 minute.
8 This mixture was immediately heated to 90°C with an inner dimension of 130Io.
mX1.30 mX: (2-ply assembly type of to+n)
After pouring into a lath mold and reacting for 30 minutes in an air constant temperature drying oven at 100°C, the cured product was taken out from the mold.

Next, heat treatment was performed for 2 hours in a constant temperature air drying oven at 140° C. to obtain a non-foamed and tough polyurethane.

Examples 2 to 4 15-Ba504 (20 g) was placed in a mortar and lubricating oil 1.0-0-320 (20 g) was added thereto and kneaded to obtain a kneading oil.

Then, put the kneading oil and lubricating oil in Example 2 in a beaker.
Example 3 Example 4 Kneading oil (Fi) 6.6 11,0 18,2 lubricating oil (
B) 5 11,0 16,5 Add as above (2. Mix well, add dehydrated GR-30 (100 g
) and TDI (65FI) in the same manner as in Example 1 to obtain a non-foamed, tough polyurethane.

The heat distortion temperature of the obtained polyurethane is ^STM, Ba4
8 is the flexural modulus under a load of 18.6 kHz/ca+2, ^STM, l'') 790 is the Izot impact value ^STN, and D256 is the friction coefficient under the notched condition, manufactured by Toyo Baldwin Co., Ltd. Dry condition, 20m/1n, 5-60kg/cm" using a friction tester.
Measured under the following conditions.

Reference example] =16- GR-30 (100g) and Til prepared in Example 1
1 (65 g) was placed in a beaker and the same procedure as in Example 1 was carried out to obtain non-foamed polyurethane.

The results of Examples 1 to 4 and Reference Example 1 are shown in Table 1.

Example 5 T0 eight base polyol [1”GR-30J, hydroxyl value 4
001540g was taken, heated to 100°C, and dehydrated under vacuum for about 30 minutes. Moisture content was 0.016%. In addition, Polymeric MDI [manufactured by Bayer Urethane,
1-44V20J, NC0% 31.1%] 560 g was heated to 80° C. and dehydrated under vacuum for about 30 minutes.

The moisture content was 0.018%.

The above GR-30 (100 g) was placed in a beaker, 44 V-20 (101 g) was added thereto, and lubricating oil [Maruzen Oil Co., Ltd., [RO-260J, 15OVG 2] was added.
601]-0g was added and the same procedure as in Example 1 was carried out to obtain a non-foamed and tough polyurethane.

Examples 6 to 8 Lubricating oil [Maruzen Oil Co., Ltd., j 1.50 B J, 15OV
G 5: 10175g and Polymer Polyol 1 manufactured by Mitsui Nisso, "POII 40/45J, hydroxyl value 110175.
The mixture was kneaded, heated to 70°C, and dehydrated under vacuum. Next, the GR-30 (100,) prepared in Example 5 was placed in a beaker, a predetermined amount of 44V-20 was added to the beaker, a lubricating oil/polymer polyol mixture was added, and polyurethane was prepared in the same manner as in Example 1. I got it.

Reference Example 2 GR-30 (100EI) and 4 prepared in Example 5
4V-20 (101 g) was placed in a beaker and carried out in the same manner as in Example 5 to obtain polyurethane.

The results of Examples 5 to 8 and Reference Example 2 are shown in Table 2.

Example 9 TDA-based polyol [[GR-30,1, hydroxyl value 4
001540g was heated and dehydrated under reduced pressure. The moisture content was 0.015%. Also, carposiimide modified N
DII Nippon Polyurethane Co., Ltd., [Millionate MT
1. J, NGO content 28.8%] 570 g was heated and dehydrated under reduced pressure. The moisture content was 0.015%.

2. Take G R-30 (100g) in a beaker and add its J: HT 1. (109g) Add all Sarani lubricating oil [[RO-2601, 2601 to 15OV]
Polyurethane was obtained in the same manner as in Example 1 by adding 10.5 g.

Examples 10-12 Place Na2SO3 (15g) in a mortar, and add lubricating oil [rRO-260J, 15OVG 260) on top of it, total 15
8 and knead well to make a mixed wire mixture. On the other hand, 100 g of polymer polyol ([P OP 40/45 J, hydroxyl value 1101] was heated to 100° C. and dehydrated under reduced pressure. Then, it was added to a beaker as shown below and stirred well.

=19-Example 10 Example 1] Example 12 Na2SO-" Lubricating oil 5.2 8.4 9.8 Kneaded product (g) Lubricating oil (g) 8.4 +9.3 30.1 Polymer bottle 8 16 24 Riolu (g) GR-30 and MTl prepared in Example 9 were added thereto to obtain polyurethane in the same manner as in Examples 2 to 4.

Reference Example 3 GR-30 (100g) prepared in Example 9 and MTI
.

(109 g) was placed in a beaker and carried out in the same manner as in Example 9 to obtain polyurethane.

The results of Examples 9 to 12 and Reference Example 3 are shown in Table 3.

20- Table 1 Table 2 Table 3 (that's all) Patent applicant: Toyo Rubber Industries, Ltd. Agent: Patent attorney Iwao Tamura

Claims (3)

[Claims] (1) A polyurethane obtained by the reaction of a polyol component having at least 62 functional hydroxyl groups and an at least difunctional polyisocyanate component, wherein the polyol component is an aromatic amine-based polyoxylic acid having a hydroxyl value of 200 to 700. A friction-resistant and wear-resistant polyurethane characterized by using an alkylene polyol and adding an aliphatic or aromatic oil component to the polyol component and/or polyisocyanate component. (2) The oil component is used in an amount of 1 to 20 parts by weight per 100 parts by weight of the polyurethane resin, and the inorganic compound powder is further used in a range in which the weight ratio of the oil component to the inorganic compound powder is 2 to 671. A polyurethane according to Range 1. (3) Claims v&
The polyurethane according to item 1 or 2.