JP2520343B2 - Transmission belt - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission belt made of urethane elastomer which has excellent wear resistance and has a long life in a high temperature environment.

[0002]

2. Description of the Related Art Transmission belts made of urethane elastomer have been conventionally used for various purposes. However, when they are driven at a high load and a high speed in a high temperature environment, the belts are cut due to wear and fatigue and their life is short.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in a conventional transmission belt made of urethane elastomer, and is excellent in wear resistance and high in a high temperature environment. It is an object of the present invention to provide a transmission belt which has a long life without being cut even when it is driven at a high speed under load.

[0004]

The power transmission belt according to the present invention is characterized in that it is made of a urethane elastomer in which a polyolefin powder is dispersed. Such a power transmission belt according to the present invention can be preferably obtained by injecting a urethane prepolymer having a terminal isocyanate group, in which a polyolefin powder is dispersed, together with a chain extender into a predetermined mold, and curing by heating. Urethane prepolymers having terminal isocyanate groups can generally be obtained by reacting a polyol with an excess of polyisocyanate.

In the present invention, the polyisocyanate for preparing the urethane prepolymer is not particularly limited, but for example, diphenylmethane diisocyanate, tolylene diisocyanate, toluidine diisocyanate, xylidine diisocyanate, naphthalene. Diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, p-phenylene diisocyanate and the like are preferably used.

The polyol is also not particularly limited, and various polyester polyols, polyether polyols, lactone polyols, etc. are appropriately used.
Examples of such polyester polyols include polybasic acids such as aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid, suberic acid, brassic acid, and succinic acid, and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid. 2 to 2 carbon atoms such as ethylene glycol, propylene glycol, butylene glycol, pentane glycol, hexane glycol and neopentyl glycol
Polyester polyols having a polyalkylene glycol such as aliphatic glycol, diethylene glycol or dipropylene glycol of 6 as a polyol component are preferably used.

Specifically, for example, polyethylene adipate polyol, polybutylene adipate polyol,
Adipate-based polyols such as polyethylene polypropylene adipate polyol and terephthalic acid-based polyester polyols are preferably used. As the polyether polyol, for example, polyoxyethylene polyol, polyoxypropylene polyol, polyoxytetramethylene polyol and the like are preferably used.

Other than the above, for example, polycarbonate polyol, polybutadiene polyol, polyventadiene polyol, castor oil-based polyol and the like can be used. The power transmission belt according to the present invention can be preferably obtained by the method using the above-mentioned prepolymer, but can be obtained by various methods other than this prepolymer method.

For example, the polyolefin powder may be mixed and dispersed in the polyol, the polyisocyanate and the chain extender may be added to the mixture, and the mixture may be poured into a predetermined mold and cured by heating. Alternatively, the polyolefin powder may be mixed and dispersed in a mixture of a polyol, a polyisocyanate and a chain extender, and the mixture may be poured into a predetermined mold and cured by heating. As yet another method, a mixture of a chain extender and a polyolefin powder is prepared, this is mixed with a polyol and a polyisocyanate, and the mixture thus obtained is poured into a predetermined mold and cured by heating. Good. In this method, as the polyisocyanate and the polyol, those mentioned above can be used.

In the present invention, as the polyolefin powder, for example, polyethylene or polypropylene powder is preferably used. Particularly, in the present invention, the average molecular weight is 5000 or more, the melting point or softening point is 50 to 250 ° C.,
It is preferably in the range of 80 to 200 ° C. and has a particle size of 500.
A polyolefin powder having a particle size of less than or equal to μm, preferably less than or equal to 100 μm is preferably used. The amount thereof, per 100 parts by weight of the resulting urethane elastomer, 1 0
It is in the range of 30 parts by weight.

Aliphatic or aromatic diols, aliphatic or aromatic diamines and the like are preferably used as the chain extender. Examples of the aliphatic diol include ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol and the like. Examples of aromatic diols include (p-hydroxyethoxy) benzene, hydroxyethyl terephthalate, hydroxyethyl ester of bisphenol A, and bis (p-hydroxyethoxyphenyl) sulfone.

On the other hand, examples of the aliphatic diamine include ethylenediamine, hexamethylenediamine, isophoronediamine and the like. As an aromatic diamine,
For example, 4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane and the like can be mentioned. When heating and curing the urethane prepolymer,
The chain extender is a chemical equivalent ratio of the active hydroxyl group of the chain extender and the isocyanate group of the urethane prepolymer,
That is, the hydroxyl group / isocyanate group equivalent ratio is 0.9 to 1.4,
It is preferably used in the range of 0.95 to 1.1.

The transmission belt according to the invention is preferably
The tensile body is buried. Steel cords, polyester fiber cords, aromatic amide fiber cords and the like are preferably used as the tensile body, but the tensile body is not limited to these. Further, when producing the power transmission belt, a plasticizer such as dioctyl phthalate and dioctyl adipate, a pigment, a catalyst, an antioxidant and the like may be added, if necessary.

The heat curing temperature for obtaining the urethane elastomer is usually room temperature to 200 ° C., preferably 50 to 1
50 ° C. For example, in the case of the above-mentioned prepolymer method, a urethane prepolymer in which a polyolefin powder is dispersed is injected into a mold in which a tension body is inserted in advance together with a chain extender, and the temperature is from room temperature to 200 ° C, preferably 50 to 150 ° C.
By heat-curing at the temperature of 1 and then further post-curing, a transmission belt having a tensile body embedded therein can be obtained.

[0015]

The power transmission belt according to the present invention is made of urethane elastomer in which polyolefin powder is dispersed,
Since the polyolefin powder reduces the friction coefficient of the transmission belt made of urethane elastomer, enhances the lubricity, and improves the wear resistance, it has a long life even under high temperature and high load operation at high speed.

[0016]

The present invention will be described below with reference to examples.
The present invention is not limited to these examples. Example 1 An adhesive-treated aromatic polyamide (Kevlar manufactured by Dyupon) cord was placed in a cylindrical mold (inner mold) having an inner diameter of 100 mm.
After spirally winding with a 5 mm pitch, this mold was inserted into a cylindrical mold (outer mold) and preheated to 80 ° C.

Next, a prepolymer from polyoxytetramethylene glycol (average molecular weight 2000) and 2,4-tolylene diisocyanate (isocyanate group content 3.
6 parts by weight) (100 parts by weight) and 15 parts by weight of polyethylene powder (PRIMAX UH-1250 manufactured by Air Products Co., melting point 147 ° C.) were added, and mixed and dispersed at 80 ° C. 3,3'-dichloro-4,4 'melted in this mixture
11 parts by weight of diaminodiphenylmethane were added, mixed and degassed.

The above degassed mixture was poured into a preheated mold and heat-cured at 100 ° C. for 30 minutes. After this,
It was degassed, heated in an oven at a temperature of 100 ° C. for 10 hours, and post-cured to obtain a flat belt having a thickness of 1.2 mm and having a Kevlar cord as a tensile body inside. This flat belt is hung between a metal drive pulley with a diameter of 20 mm and a metal driven pulley with a diameter of 20 mm, a tension of 10 kg is applied to the driven pulley side at a temperature of 100 ° C, and the drive pulley is rotated at 2500 rpm. When the damage time was measured as an evaluation index of the wear resistance of the belt under high temperature,
It took 135 hours. Example 2 In the same manner as in Example 1 except that 30 parts by weight of polyethylene powder was used, a flat belt having a thickness of 1.2 mm and having a Kevlar cord as a tensile member inside was obtained.

With respect to this flat belt, the damage time was measured as an index of the abrasion resistance of the belt at high temperature in the same manner as in Example 1, and it was 146 hours. Comparative Example 1 In the same manner as in Example 1 except that polyethylene powder was not mixed with the prepolymer, a flat belt having a thickness of 1.2 mm and having a Kevlar cord as a tensile body inside was obtained. .

With respect to this flat belt, the damage time was measured as an index for evaluating the abrasion resistance of the belt at a high temperature in the same manner as in Example 1, and it was 40 hours. The above results show that the power transmission belt according to the present invention has a long life even when driven at a high load under a high temperature environment at a high load.

Claims (3)

(57) [Claims] 1. A urethane prepolymer or polyisocyanate
Heat cure anate and polyol with chain extender
The transmission belt made of urethane elastomer
Te, transmission belt, characterized by comprising per 100 parts by weight of a urethane elastomer, a urethane elastomer containing dispersed polyolefin powder 10-30 parts by weight. 2. The transmission belt according to claim 1, wherein the polyolefin is polyethylene or polypropylene. 3. The transmission belt according to claim 1, wherein a tensile body is embedded.