DE1926964A1 - Method of making a nylon belt - Google Patents

Description

THE GOODYEAR TIHE AND RUBBER COMPAHY, Akron, Ohio, 44316, USA Method of making a nylon belt

The invention relates to polyurethane elastomer compositions and their method of production. The invention particularly relates to discloses a process for the production of molded articles from polyurethane which have a surface coating made from a polyamide.

Polyurethane elastomers have found common use and have excellent physical properties, however, where polyurethane elastomers are used in the manufacture of Belts such as drive belts, keel belts or transmission belts have shown excessive surface abrasion.

One of the tasks underlying the invention is to create a polyurethane-elastomer composite that has improved abrasion resistance and also has a lower coefficient of friction.

According to the invention, a polyamide coating is applied to the polyurethane elastomer provided «This is achieved by the Mold covered with a coating of a polyamide and then the polyurethane reaction mixture on the coated with polyamide Mold surface is poured, and you can play the implementation allows a deformed polyurethane elastomer to be formed, which has a polyamide coating connected to it *

The invention is hereinafter referred to by way of example explained on the accompanying drawing;

909881/094 2

Fig. 1 is a cross-sectional view through a. Xeirienenform 2, a polyamide coating 3 having been applied to the hot mold i3t. The polyamide coating can be applied in the form of an aqueous dispersion or as a solvent solution. In general, it is found to be preferred that polyamide be in the form of a solvent dispersion in a suitable solution, medium, such as a mixture of isopropyl alcohol and ethyl alcohol use fcu. The polyamide cover can be brushed on, sprayed, Dipping or other suitable means, however, spraying or brushing is generally preferred. The coating made of polyamide is usually a thickness of 0.025-0.25 mm with the preferred range being 0.05 to 0.150 mm. -

After the nylon coating is applied and the i / water or solvent has been removed, a suitable polyurethane reaction mixture poured into the cavity of the mold and allowed to set to form a belt with a polyamide coating.

Optionally, the belt can be fabric or wire reinforcement 5 included, which will be placed inside the mold after a part of the polyurethane reaction mixture poured into the same has been or before the reaction mixture has been poured. It is usually convenient to have the finished belt at temperatures of about 38-150 ° C for several hours, i.e. to cure about 0.25 to 20 hours so as to be more effective the mold to use, but of course you can also use the polyurethane reaction mixture cure at room temperature by letting it stand for a long enough time.

The polyamides useful according to the invention are the condensation products of an organic diamine and an organic one Dicarboxylic acid or its anhydride. The kind of organic Diamines and organic dicarboxylic acids are well known and these are those normally used to manufacture a so-called shape type nylon or barrier type nylon in use coming connections, as well as those how to make them of textiles are used.

909881/0942 - ~ 3 -

The polyamide or Ilylone need not be a pure condensation product of an organic diamine and a dicarboxylic acid, albeit essentially true, and suitable additive means are obvious to those skilled in the art. A suitable composition corresponding additives are given below:. "

HyIon plastic 100 parts by weight

Tributylamine 7 parts by weight

LX-1117 "10 parts by weight

Maleic anhydride 4 parts by weight

Sufficient amount of low molecular weight alcohol (ethyl and Isopropyl alcohols are preferred) in water (3: 1) to form a solution with 10? Nylon content.

The nylon plastic of the above composition is manufactured by the Belding-Corticelli-CoEipany of New York and is designated by that company as Type 3-1-8. It is a terpolymer of hexamethylene adipamide, hexamethylene sebacic acid and Capro Iac tarn in a weight ratio of 60/20/20, which is ethoxylated and then treated with alkali. The tributylamine of the specified composition catalyzes the esterification of the halic acid anhydride with the hydroxymethyl groups on the nylon with crosslinking of the same. The LX-1117 is a plasticizer also manufactured by the Belding-Corticelli Company. The alcohol is a cheap solvent. It may be aqueous and other low-boiling organic solvent or non-aqueous "solvent be employed. The term" low boiling "means a solvent is to be understood that sufficiently rapidly evaporated under production conditions _s so that an economic application is possible.

Other soluble nylon products can also be used. Satisfactory are those under the designation duPont Type 6A and $ B and Type 8 are known. The networkable ones Nylon products (e.g. methoxylated and alkylene oxide treated nylon products) that react with polyurethane precursors, can also be used.

909881 / & 942

ORIGINAL

- If -

The polyurethane reaction mixture suitable according to the invention can either by the prepolymer or the so-called oneshort process getting produced. In general, the prepolymer process is preferred and the subject matter becomes specific regarding the use of the prepolymer process.

The prepolymer is preferably by means of reacting a degassed ,, active hydrogen atoms containing product with a Molecular weight from about 700 to about 7,000 with the preferred range being from about 1,000 to about 3,500 with an organic Polyisocyanate, preferably a difunctional polyisocyanate manufactured. Usually about 1 mole of the active hydrogen-containing product is used with an excess of an organic Brought polyisocyanates to react, the preferred molar ratios being from about 1.5 to about 2.5, if also in some cases as little as 1.1 moles can be applied.

The prepolymer is then preferably reacted with a suitable crosslinking agent, such as a monomeric glycol or an organic diamine or an alcohol amine. The proportions of the crosslinking agent will normally be selected so that a slight excess of the isocyanate with the total of active hydrogen atoms present is present ₄ wherein an amount of from about 0.1 to about 0.9 'of the crosslinker per mole of the excess organic polyisocyanate is selected. With regard to the specific nature of the products containing active hydrogen atoms, these are any of the well-known polyether diols, the hydrocarbon ^{diols and the polyesters ---. "-:} diols. Corresponding examples of this can be found in British Patent 1,015,125.

Examples of organic polyisocyanates can be found in the US patent 2,937,151, also hydrogenated methylenediphenyl isocyanate.

With regard to the type of crosslinker, it is any the well-known monomeric glycols such as those having from 2 to 10 carbon atoms, as well as those generally known organic diamines which react either quickly or slowly, as indicated by the hot methylene chloride test is determined, see U.S. Patent 2,620,516.

909881/0942 " ⁵ "'

The invention is illustrated below with the aid of a number of exemplary embodiments with all parts being explained on a weight basis understand, unless otherwise noted.

example 1

A suitable for the casting of polyurethane belts steel .form is cleaned by means of inflation with shot and heated to .120 ⁰ C. The cavity of the steel mold is then spray coated with a mixture of 3/5 parts granular nylon type 809, 12.5 parts denatured alcohol and 29.5 parts n-propyl alcohol. Once the alcohol solvent has evaporated, a polyurethane is poured into the mold by pouring a polyurethane reaction mixture made by reacting a polyurethane prepolymer with a crosslinker. The polyether prepolymer is converted by means of ^! made of 500 parts Polytetramethylenätherglykol having a molecular weight of 990 and 175 parts of toluene diisocyanate, said polyether is gassed for 1 hour at 120 ⁰ C nnter a pressure of 20 mm Hg prior to the addition of the toluene diisocyanate. The toluene diisocyanate can be reacted with the glycol for 1/2 hour at 120 ^° C. with stirring and under a pressure of 20 mm Hg. This prepolymer is then mixed with 100 parts of methylenebis-o-chloroaniline containing 5 parts of phenyl-βnaphthylamine as an antioxidant to form a polyurethane reaction mixture which is poured into the mold to form a belt. The cast polyurethane is allowed to then in the form of stand 16 stood at 120 ⁰ C. The cast V-belt is then removed from the mold and its coefficient of friction against smooth steel is determined. The same is found for Oj32, while a polyurethane belt made without a nylon coating has a coefficient of friction of 0.66.

Example 2

Another belt is made using the steel mold, which is coated with nylon according to the procedure of Example 1. The casting compound consists of a polyurethane reaction mixture, the 700 parts of polyethylene glycol azelate with one Molecular weight of about 2000, 150 parts of diphenylmethane diisocyanate and 50 parts of methylenebis-o ^ chloroaniline contains. This Pre-polymer reaction mixture is poured into the steel mold, and

909881/094 2 '■ " ⁶ "

it is allowed to react with a new coating to form a finished object. The coefficient of friction is at this Cured polyurethane with a nylon coating was determined and found to be 0.39, while the polyurethane without a nylon coating has a coefficient of friction of 0.60.

Instead of the polyethers described in the examples above For example, the prepolymer can be easily prepared using a mixed ethylene propylene adipate having a molecular weight of about 2000 or any of the other well known polyesters to make those in these examples described belt. Furthermore, the hydrocarbon polyols, those by polymerizing a conjugated diene such as isoprene and butadiene as such or with a copolymer such as styrene and hydrolyzing the polymer to form the hydrocarbon glycol are obtained to produce the Polyurethane reaction mixture applied according to Examples 1 and 2 are used to obtain the inventive Belt.

The coefficient of friction is determined using the so-called moving sled stationary plane method according to ASTM method 894-63.

909881/0942

Claims (3)

Claims 1.) Belt, characterized in that the same essentially. borrowed from a polyurethane elastomer core and a Polyamide cover, which is bound to this on the free surface, consists of * 2. Belt according to claim 1, characterized in that the polyamide coating has a thickness of about 0.025 to 0.25 mm, 3. A method for producing a belt, characterized in that that a mold covered with a polyamide and then In contact with this polyamide, a polyurethane reaction mixture is deformed and cured and joined together Polyurethane with polyamide. 90 9881/094 OBlGlHAL INSPECTED Empty soap