Elastomer modified textile material and method of producing same

A method for producing an elastomer modified textile material which comprises coating a textile substrate with at least 1 weight percent of an amine substituted elastomer, curing the resulting elastomer coated substrate, and thereafter recovering the elastomer modified material. The elastomer modified material possesses improved adhesion properties for subsequent laminating of a second substrate thereto.

This invention relates to an elastomer modified material. In one aspect it 
relates to an elastomer modified textile material having improved adhesion 
properties. In yet another aspect it relates to an improved method for 
producing elastomer modified textile materials. 
Rubber coated fabrics have found use in industrial applications where their 
characteristic odor and color limitations are not objectionable. Such 
fabrics are frequently used in the manufacture of products requiring very 
low temperature flexibility, such as balloon bags, diaphragms, gaskets, 
conveyor belts, tire cords, inflatable life rafts, pontoons and the like. 
Various methods have heretofore been employed in producing rubber coated 
fabrics, such as application of the rubber or latex constituents as an 
organic solvent dispersion or by the so-called hot-roll calendering 
technique. The choice of coating technique has generally been dictated by 
the manufacturer or the end use for which the rubber coated fabric is 
intended. 
Problems have, however, been encountered in that many of the rubber coated 
fabrics have lacked sufficient adhesion properties for lamination of 
another or different substrated to the rubber coated fabric. The 
insufficient adhesion properties of the rubber coated fabrics have often 
resulted in separation of the laminated products. Problems of separation 
have especially been severe when using a polyester or polyester containing 
textile material as the initial fabric substrate onto which the rubber or 
elastomer is coated. Because of the availability of such polyester or 
polyester containing fabrics, and the properties which such fabrics impart 
to a rubber or elastomer coated laminated product, new and improved 
elastomer coated textile materials, and processes for producing same have 
long been sought. 
Therefore, an object of the present invention is to provide elastomer 
coated textile materials having improved adhesion properties. 
Another object of the invention is to provide an improved method for 
producing elastomer coated textile materials. 
These and other objects, advantages and features of the present invention 
will be apparent to those skilled in the art from a reading of this 
disclosure. 
Broadly, the present invention relates to elastomer modified textile 
materials having improved adhesion properties and to methods for producing 
same. More specifically, the elastomer modified textile materials are 
produced by coating a textile substrate with at least about 1 weight 
percent of an amine substituted elastomer, curing the resulting elastomer 
coated substrate and thereafter recovering an elastomer modified textile 
material having improved adhesion properties. 
In a more specific aspect, a polyester or polyester containing textile 
material is coated with from about 1 to about 50 weight percent based on 
the weight of the textile material of an amine substituted elastomer. 
Thereafter, the resulting amine coated polyester or polyester containing 
textile material is cured for an effective period of time at a temperature 
in the range of from about 75.degree. to about 480.degree. F. The 
elastomer modified textile material so produced possesses improved 
adhesion properties which, when laminated to a second textile material or 
a different elastomer, results in a laminated product having improved 
resistance to separation. 
The textile material employed as the textile substrate to produce the 
elastomer modified textile materials of the present invention can be any 
suitable textile material containing natural and/or synthetic fibers. 
Examples of suitable textile materials are those containing fibers of 
polyester, nylon, acetate, Kevlar, wool, cotton, linen, silk, acrylic, and 
mixtures or blends of such synthetic and natural fibers. Especially 
desirable results can be obtained employing the method of the present 
invention to produce an elastomer modified textile material having 
improved adhesion properties when a polyester or polyester containing 
textile material is employed as the textile substrate. 
Once the textile material to be used as the textile substrate has been 
selected the material is coated with an effective amount of an amine 
substituted elastomer to insure that at least one side or surface portion 
of the textile material is substantially coated with the elastomeric 
constituent. The amount of amine substituted elastomer employed can vary 
widely, but will generally be in an amount of at least about 1 weight 
percent, based on the weight of the textile substrate. Desirable results 
can be obtained when the amine substituted elastomer is employed in an 
amount of from about 1 to about 50 weight percent, preferably from about 5 
to about 20 weight percent. 
The term "amine substituted elastomer" as used herein is to be understood 
to include terminal or non-terminal amine substituted elastomers and 
mixtures thereof. The term "elastomer" is to be further understood to 
include those compounds having the properties of natural, reclaimed, 
vulcanized or synthetic rubber, e.g. compounds which stretch under 
tension, have a high tensile strength, retract rapidly and recover their 
original dimensions. Typical of such elastomers are natural rubber, 
homopolymers, such as polychlorobutadiene, polybutadiene and polyisoprene, 
copolymers, such as styrene-butadiene rubber, butyl rubber, nitrile 
rubber, ethylenepropylene copolymers, and polyacrylic compounds, and 
polycondensation products such as polyurethanes, silicone rubber and the 
like. 
The average molecular weight of the elastomers which can be aminated to 
produce the amine substituted elastomers for use in the present invention 
can vary widely. Generally such elastomers will have an average molecular 
weight in the range of from about 100 to about 500,000. Especially 
desirable results can be obtained when the elastomer has an average 
molecular weight of from about 300 to about 10,000. 
The amine moieties substituted onto the elastomer backbone can be primary 
amines, secondary amines or tertiary amines. Typical of such amine 
moieties are --NH.sub.2, --NHR and --NRR.sub.1 wherein R and R.sub.1 are 
alkyl, aryl, alicyclic, substituted alkyl, substituted aryl and 
substituted alicyclic groups. Especially desirable results can be obtained 
when the amine moieties are NH.sub.2. 
The degree of amine substitution on the elastomer backbone can vary widely. 
However, it is generally desirable that the amine substituted elastomer 
have an average of at least two amine moieties. 
The amine substituted elastomer can be applied to the textile material 
substrate by any suitable manner. For example, if the particular amine 
substituted elastomer is in a liquid state such can be applied by spraying 
or dipping of the substrate into a bath containing the liquid elastomer. 
Thereafter, the elastomer coated substrate is passed under a knife blade 
of between nip rollers to insure a substantially uniform elastomer 
coating. If the amine substituted elastomer is in a solid or particulate 
state the elastomer can be applied to the textile material substrate by 
the hot roll calendering technique, or, when in a particulate form, as a 
liquid admixture or dispersion. When applying the amine substituted 
elastomer to the textile substrate as a liquid admixture any suitable 
liquid can be employed which is substantially inert to the elastomer, e.g. 
does not readily react with the elastomer. Typical of such carrier liquids 
are water, toluene and chlorinated hydrocarbon solvents such as 
chloroform, carbon tetrachloride, tetrachloroethylene, methylene chloride 
and the like. 
The amount of amine substituted elastomer present in the liquid admixture 
or dispersion can vary widely. However, sufficient elastomer must be 
present to provide a deposition, based on the dry weight of the elastomer, 
of at least 1 weight percent of the elastomer. Desirably, the amount of 
amine substituted elastomer present in the admixture will be that required 
to provide from about 1 to about 50 weight percent of the elastomer on the 
textile substrate, preferably from about 5 to about 20 weight percent. 
When applying the amine substituted elastomer to the substrate as a liquid 
admixture or dispersion, it is desirable to thereafter remove the carrier 
liquid from the elastomer and, when applicable, the textile substrate to 
improve the bonding of the amine substituted elastomer to the textile 
substrate. The removal of the liquid carrier can be accomplished by drying 
the amine substituted coated textile material for an effective period of 
time to remove substantially all of the carrier liquid. Any suitable means 
well known in the art can be employed. For example, the coated textile 
substrate can be heated to drive off the carrier liquid and produce a 
substantially dry material. In such case, however, care must be exercised 
to insure that the heating of the coated textile material is maintained 
below the curing temperature of the amine substituted elastomer to prevent 
entrappment of solvent therein. 
The elastomer modified material so produced can then be bonded to a second 
elastomer or a second textile substrate. The particular choice of the 
second elastomer or textile substrate will be dependent, to a large 
extent, on the end use of the resulting laminated product. Any suitable 
elastomer can be employed as the second elastomer, such as natural rubber, 
reclaimed rubber, vulcanized rubber or synthetic rubber. Typical of such 
synthetic rubber are homopolymers, such as polychlorobutadiene, 
polybutadiene and polyisoprene, copolymers, such as styrene-butadiene 
rubber, butyl rubber, nitrile rubber and polyacrylates, and 
polycondensation products, such as polyurethanes, silicone rubber and 
polysulfide rubber. Any suitable textile material, such as those 
containing fibers of polyester, nylon, acetate, Kevlar, wool, cotton, 
linen, silk, acrylic and mixtures or blends of such synthetic and natural 
fibers. Desirably the second textile material will be a polyester or a 
polyester containing textile material. 
Once the desired second elastomer or second textile substrate has been 
selected, the selected second component, preferably in sheet form, is 
contacted with the surface portion of the elastomer modified material 
containing the amine substituted elastomer. Thereafter, the resulting 
laminated product is subjected to an additional curing step to securely 
bond the second component to the elastomer modified material through the 
amine substituted elastomer. 
The curing conditions employed to bond the second substrate component to 
the elastomer modified material can vary widely, such depending to a large 
measure on the composition of the second substrate component. Generally, 
however, such additional curing is effected by maintaining the resulting 
laminated product at a temperature in the range of from about 75.degree. 
F. to about 480.degree. F. for a period of time of from about 5 seconds to 
about 20 minutes. Further, the resulting laminated product may be 
subjected to pressure during the curing step. When employing pressure, 
such will generally be in the range of from about 5 psi to about 500 psi. 
It is to be understood that many variations can be made in the method and 
products of the present invention without departing from the spirit 
thereof. For example, it is to be understood that a resulting laminated 
product having improved adhesion and thus improved resistance to 
separation of the substrates or layers of the laminated product by coating 
at least one surface of two substrates with an amine substituted 
elastomer, curing the amine substituted elastomer coated substrates and 
thereafter forming a resulting laminated product from the two amine 
substituted elastomer coated substrates. The resulting laminated product, 
which is formed so as to allow the amine substituted elastomer coated 
portion of one substrate to be in contact with the amine substituted 
elastomer coated portion of the second substrate is then cured and a 
resulting laminated product is recovered. Many other variations will be 
apparent from a reading of the disclosure.

In order to illustrate further the details of the method of the invention, 
and the product produced thereby, the following specific example is given. 
The example is presented primarily for the purpose of illustration and any 
enumerations or details contained therein are not to be interpreted as a 
limitation on the invention except as indicated in the appended claims. 
All weight referred to in the example are parts by weight unless otherwise 
indicated. 
EXAMPLE 
An experiment was conducted to determine the effectiveness of a 
polybutadiene nitrile amine terminated rubber having an average of from 
about 2.3 --NH.sub.2 groups per molecule (an amine substituted elastomer) 
as a bonding agent for polyester fabric and a compounded styrene-butadiene 
test rubber. A second experiment was also conducted using a polybutadiene 
nitrile rubber (non-amine substituted elastomer) as a bonding agent for 
polyester fabric and the compounded styrene-butadiene test rubber. 
In each experiment the bonding agents were liquid rubber components having 
approximately the same average molecular weights, e.g. about 3600. The 
bonding agents were applied to substantially identical polyester fabrics 
so as to provide about 2.5 weight percent of the polybutadiene nitrile 
amine terminated rubber on one of the polyester fabric substrates and 
about 2.4 weight percent of the polybutadiene nitrile rubber on another 
polyester fabric substrate. Thereafter, each of the elastomer coated 
substrates was cured for 5 minutes at a temperature of 425.degree. F. 
Laminates were then formed using the elastomer modified polyester 
substrates and a compounded styrene-butadiene test rubber. The laminates, 
which were substantially identical except for the variation in bonding 
agent, were put in a press and cured at 300.degree. F. for 30 minutes at 
100 psi. 
The resulting laminated products, after cooling, were cut into one (1) inch 
wide strips and thereafter the strips were subjected to a standard peel 
test. The peel test revealed that the laminate containing the 
polybutadiene nitrile rubber (non-amine substituted) bonding agent had an 
adhesion factor of 4.5 pounds; whereas, the laminate containing the 
polybutadiene nitrile amine terminated rubber bonding agent had an 
adhesion factor of 11.1 pounds. 
Since the higher the adhesion factor the better the bond created between 
the segments of the laminate, the above example clearly indicates the 
improved adhesion properties obtained when employing an amine substituted 
elastomer as a bonding agent.