The invention relates to a process wherein A a heat curable froth or foamable mixture of polyurethane reaction components is applied to the back of a fabric, B the coated fabric is heated to form a gelled, tack-free and storable foam-backed fabric and C the fabric is shaped and cured using a hot molding process. The polyurethane formulation contains a hydroxy functional ester of an acrylic or alkyl acrylic acid and a free radical initiator.

BACKGROUND OF THE INVENTION 
This invention is an outgrowth of the development of molded polyurethane 
foam-backed fabrics (and, particularly carpets) which are sufficiently 
stiff upon demolding to retain their shape and yet are not so stiff that 
they crack when bent. The process for making such foamed-backed fabrics 
involves the application of a heat curable froth or foamable mixture of 
polyurethane reaction components to the back of a fabric. The polyurethane 
is then cured, normally under heat, to a tack-free, gelled state. The 
fabric is then cut into sized pieces and molded to the desired shape. 
The general drawback to this process is the difficulty in formulation a 
system which can undergo the above mentioned steps in an industrial 
setting. Until now, it has not been possible to produce a tack-free, 
gelled foam backing which could be stored for long periods of time, be cut 
into a desired sized piece when needed, and molded in a reasonably short 
period of time into a molded part which will retain its shape while at the 
same time not being so stiff that it will crack if bent. 
The general method of applying foam to a fabric substrate and subsequently 
molding the laminate into a desired shape is known e.g. U.S. Pat. Nos. 
3,175,936; 3,046,177; 3,440,307; 3,772,224; 3,849,156 and 3,175,936. None 
of these methods, however, permits the foam-backed fabric to be stored for 
prolonged periods and then be hot molded at a much later time into 
excellent contoured laminates. 
In U.S. Pat. No. 3,860,537, a foam which is storable in a roll is produced 
and is capable of being molded at a later time. The method requires the 
use of a significant quantity of an ethylenically unsaturated polyester 
together with an ethylenically unsaturated monomer copolymerizable with 
the polyester. The shortcoming of the process is that the curing/molding 
step requires molding times of 30-35 minutes (note Examples 1 and 10) 
which is an economically unacceptably long time. The patent also fails to 
suggest applying the foamable reaction mixture to the back of a fabric, or 
in fact to any substrate. 
The present invention utilizes a hydroxy functional acrylate and a free 
radical initiator as a means of overcoming the lengthy mold time. The use 
of hydroxy functional acrylates is not new to the polyurethane art. For 
example, there are the polymer polyols e.g. U.S. pat. Nos. 3,383,351; 
3,652,639; 3,523,093 and 3,576,706. There are a number of coating 
applications described in U.S. Pat. Nos. 3,975,457; 3,919,351; 3,989,609. 
There are also patents such as U.S. Pat. No. 3,954,584 directed to a photo 
polymerizable vinyl urethane composition and U.S. Pat. No. 4,052,282 
directed to a photocurable bandage. However, as far as Applicant is aware, 
there is no prior art directed to the specific application of producing a 
curable and moldable polyurethane foam which has been applied to a fabric 
substrate. 
DESCRIPTION OF THE INVENTION 
The present invention provides a process for preparing molded polyurethane 
foam-backed fabric where the polyurethane reaction mixture can be applied 
to the fabric without significant reaction so that it can be easily 
handled. The fabric is then heated to form a gelled and tack-free foam 
laminate which can be stored for long periods of time prior to shaping and 
molding. In addition, the foam-backed fabric can be molded in very short 
cycle times of as little as 30 seconds to 1 minute and form a fabric with 
good shape retention. 
The invention relates to a process for preparing a molded, polyurethane 
foam-backed fabric comprising the steps of: 
(A) applying a foamable mixture or froth of polyurethane reaction 
components to the back of a fabric, said reaction components comprising 
(1) a polyisocyanate; 
(2) an organic compound containing at least two hydrogen atoms capable of 
reacting with isocyanate groups, having a molecular weight of between 400 
and 16,000 and containing essentially no ethylenically unsaturated groups; 
(3) hydroxy containing esters of acrylic or alkyl acrylic acids and 
preferably hydroxy acrylates of the formula: 
##STR1## 
wherein R.sub.1 is an x+y valent, optionally branched, C.sub.1 -C.sub.18 
alkylene, arylene or aralkylene group; 
R.sub.2 is H or a C.sub.1 -C.sub.18 alkyl group 
x and y are integers which may be the same or different and represent 1-8, 
with the proviso that x+y does not exceed 8; 
(4) a free radical initiator; 
(5) a heat activated catalyst for the reaction between components (1) and 
(2); 
(6) a blowing agent, or inert gas for frothing; 
(7) a surface active agent for foam stability; 
(B) heating the coated fabric for from 15 seconds to 10 minutes at about 
80.degree.-250.degree. F. to allow the polyurethane reaction to proceed to 
produce a gelled, tack-free polyurethane foam, and 
(C) shaping and curing the resultant foam-backed fabric by a hot molding 
process. 
The preferred hydroxy acrylates are those of the above mentioned formula in 
which R.sub.1 is C.sub.1 -C.sub.4 alkylene and R.sub.2 is H or --CH.sub.3, 
and x and y each equal 1. The most preferred materials are 2-hydroxy ethyl 
acrylate and 2-hydroxy propyl acrylate. 
The hot molding process of step (C) can include placing the foam-backed 
fabric in a heated mold where at least the polyurethane side is subjected 
to temperatures of from 200.degree. to 350.degree. F. and a pressure of 
from 0.1 to 20 psi for anywhere from 15 seconds to 5 minutes. 
Alternatively, the foam-backed fabric can itself be heated to a 
temperature of from 200.degree. to 350.degree. F. and then shaped in an 
unheated mold under the same pressure and time conditions. The heating of 
the foam-backed fabric is preferably done while the fabric is laid out 
flat and can be accomplished by any of the methods commonly used in the 
art, such as forced hot air, infrared radiation, microwave radiation and 
the like. 
The ability to store the fabric prior to shaping and molding and yet form a 
molded fabric with excellent properties is thought to be particularly due 
to the use of the hydroxy functional acrylate and free radical initiator 
which is primarily activated only at the molding temperature. 
Suitable hydroxyl group containing esters include 2-hydroxyethyl acrylate, 
2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl 
methacrylate, 4-hydroxybutyl acrylate, hydroxyoctyl methacrylate and the 
like and mixtures thereof. 
Also suitable are partially acrylated polyols such as pentaerythritol mono, 
di- and tri-acrylate, trimethylol propane diacrylate, mannitol acrylates, 
sucrose acrylates and the like. It would, of course, also be possible to 
alkoxylate a polyol to produce a polyether polyol and then to partially 
acrylate the polyether polyol with acrylic acid or an alkylacrylic acid. 
Various other hydroxy functional acrylates used in the present process and 
their methods of preparation are known. In general a diol or polyol is 
reacted with acrylic, methacrylic or other alkyl acrylic acids in amounts 
sufficient to form a compound containing at least one hydroxyl group, and 
at least one acrylate, methacrylate or alkyl acrylate group. Thus, any 
compound containing at least one hydroxyl group and at least one acrylate 
or alkyl substituted acrylate group would be effective. The acrylate can 
be used in amounts ranging from 0.5 to 50, preferably from 5 to 20 and 
most preferably from 8 to 15 parts by weight per 100 parts by weight of 
component (2). 
Suitable free radical initiators include those well known to initiate the 
polymerization of carbon-carbon double bonds and preferably which have a 
half-life of less than 1 minute at the molding temperatures. Such 
initiators include, for example, the peroxides, persulfates, perborates, 
percarbonates, azo compounds, etc., including hydrogen peroxide, dibenzoyl 
peroxide, acetyl peroxide, benzoyl hydroperoxide, t-butyl hydroperoxide, 
di-t-butyl peroxide, lauroyl peroxide, butyryl peroxide, 
diisopropylbenzene hydroperoxide, cumene, hydroperoxide, paramenthane 
hydroperoxide, diacetyl peroxide, di-.alpha.-cumyl peroxide, dipropyl 
peroxide, diisopropyl peroxide, isopropyl-t-butyl peroxide, butyl-t-butyl 
peroxide, dilauroyl peroxide, difuroyl peroxide, ditriphenylmethyl 
peroxide, bis(p-methoxybenzoyl)peroxide, p-monomethoxybenzoyl peroxide, 
rubrene peroxide, ascaridol, t-butyl peroxybenzoate, diethyl 
peroxyterephthalate, propyl hydroperoxide, isopropyl hydroperoxide, 
n-butyl hydroperoxide, t-butyl hydroperoxide, cyclohexyl hydroperoxide, 
trans-Decalin hydroperoxide, .alpha.-methylbenzyl hydroperoxide, 
.alpha.-methyl-.alpha.-ethyl benzyl hydroperoxide. Tetralin hydroperoxide, 
triphenylmethyl hydroperoxide,diphenylmethyl hydroperoxide, 
.alpha.,.alpha.-azo-2-methyl butyronitrile, .alpha.,.alpha.-2-methyl 
heptonitrile, 1,1'-azo-1-cyclohexane carbonitrile, dimethyl 
.alpha.,.alpha.'-azoisobutyrate, 4,4'-azo-4-cyanopentanoic acid, 
azobis-(isobutyronitrile), persuccinic acid, diisopropyl peroxy 
dicarbonate, and the like; a mixture initiators may also be used. 
Azobis(isobutyronitrile) dissolved in a minimum amount of a suitable 
solvent is the preferred initiator. 
It is preferred to use from 0.01 to 1 part of initiator per 100 parts by 
weight of component (2), most preferably from 0.05 to 0.5 part. 
In addition to the hydroxy functional acrylate used in the present process, 
it is possible to use in addition thereto other hydroxy functional 
compounds containing ethylenically unsaturated groups. From 0 to 50 parts 
by weight per 100 parts of component 2 and, preferably from 8 to 15 parts 
can be used. Examples of such compounds include hydroxy terminated 
butadiene homopolymers, hydroxy-terminated butadiene-styrene copolymers 
and hydroxy terminated butadiene-acrylonitrile copolymers available from 
ARCO, trimethylol propane di-2-propenyl ether, and the like. These 
compounds are not in themselves sufficiently active to provide molded 
fabrics which are sufficiently stiff to retain their shapes. They also 
tend to be too insoluble in the polyol blend to be storage stable for any 
prolonged period of time. 
While the process for making the polyurethane backed fabrics can generally 
utilize any known formulation for making polyurethane foams, certain 
preferred general formulations have been found to be most advantageous in 
optimizing the backed fabric properties. In general, in addition to the 
polyisocyanate, compounds containing active hydrogen atoms, silicone 
surfactant, heat activated catalyst and blowing agent or inert gas for 
frothing, it is useful to include a chain extender and substantial amounts 
of an inorganic filler. 
As is known in the art, compounds useful in preparing polyurethane foams 
include organic compounds with at least two hydrogen atoms capable of 
reacting with isocyanates and having molecular weights of from about 400 
to 16,000. The active hydrogen containing compounds used in the present 
invention should contain essentially no ethylenically unsaturated groups. 
As is recognized in the art, most polyether polyols will contain very small 
amounts of terminal unsaturated groups. By "essentially no ethylenically 
unsaturated groups" is meant that component (2) does not contain so many 
ethylenically unsaturated groups that they begin to take a significant 
part in the free radical polymerization during step (C) with the 
carbon-carbon double bonds of the acrylate. Apart from compounds 
containing amino groups, thiol groups or carboxyl groups, compounds of 
this type which are preferred are polyhydroxyl compounds. Particularly 
preferred compounds are those containing 2 to 8 hydroxyl groups, and 
expecially those with molecular weights of from 800 to 10,000 (most 
preferably 1,000 to 6,000). Examples include, polyesters, polyethers, 
polythioethers, polyacetals, polycarbonates and polyesteramides containing 
at least 2 and generally 2 to 8 and preferably 2 to 4 hydroxyl groups, of 
the type known per se for the production of homogeneous and cellular 
polyurethanes. 
Examples of suitable polyesters containing hydroxyl groups include reaction 
products of polyhydric, preferably dihydric, and, optionally, trihydric 
alcohols with polyvalent, preferably divalent carboxylic acids. Instead of 
the free polycarboxylic acids the corresponding polycarboxylic acid 
anhydrides or esters with lower alcohols or mixtures thereof may also be 
used for the production of the polyesters. The polycarboxylic acids may be 
aliphatic, cycloaliphatic, aromatic and/or heterocyclic, and may 
optionally be substituted, for example, by halogen atoms. Examples of 
these polycarboxylic acids are succinic acid, adipic acid, suberic acid, 
azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic 
acid, phthalic acid anhydride, hexahydrophthalic acid anhydride, glutaric 
acid anhydride. Examples of suitable polyhydric alcohols include ethylene 
glycol, 1,2- and 1,3-propylene glycol, 1,4- and 2,3-butylene glycol, 
1,6-hexane diol, 1,8-octane diol, neopentyl glycol, cyclohexane dimethanol 
(1,4-bis-hydroxymethyl-cyclohexane), 2-methyl 1,3-propane diol, glycerol, 
trimethylol-propane, 1,2,6-hexane triol, 1,2,4-butane triol, 
trimethylolethane, pentaerythritol, quinitol, mannitol, sorbitol, methyl 
glycoside, diethylene glycol, triethylene glycol, tetraethylene glycol, 
polyethylene glycols, dipropylene glycol, polypropylene glycols, 
dibutylene glycol and polybutylene glycols. The polyesters may contain 
terminal carboxyl groups. Polyesters glycols of lactones, for example, 
.epsilon.-caprolactone, or hydroxycarboxylic acids, for example, 
.OMEGA.-hydroxycaproic acid, may also be used. 
Polyethers containing at least two and usually two to eight, and preferably 
two to three hydroxyl groups suitable for use in accordance with the 
invention, include those obtained by the polymerization of epoxides, such 
as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, 
styrene oxide or epichlorohydrin, for example, in the presence of 
BF.sub.3, or by the chemical addition of these epoxides to starting 
components with reactive hydrogen atoms, such as water, ethylene glycol, 
1,2- or 1,3-propylene glycol, trimethylolpropane, 
4,4'-dihydroxydiphenylpropane, aniline, ammonia, ethanolamine and ethylene 
diamine, tolylene diamine 4,4'-diaminodiphenyl methane, and the like. In 
many cases, it is preferred to use polyethers of the type which contain 
primary OH-groups (e.g., either by tipping the polyol with ethylene oxide 
or by using a polyether containing as much as 90% by weight of primary OH 
groups or based on all the OH-groups present in the polyether). 
Among the polythio-ethers usable are included the condensation products of 
thiodiglycol with itself and/or with other glycols, dicarboxylic acids, 
formaldehyde, aminocarboxylic acids or aminoalcohols. Depending on the 
cocomponents, these products are polythio-mixed ethers, polythio-ether 
esters or polythio-ether ester amides. 
Suitable polyacetals include those compounds which may be obtained from 
glycols, such as diethylene glycol, triethylene glycol, and hexane diol, 
and formaldehyde. Polyacetals suitable for the purposes of the invention 
may also be obtained by polymerizing cyclic acetals. 
Suitable polycarbonates containing hydroxyl groups include those obtainable 
by reacting diols, such as 1,3-propane diol, 1,4-butane diol and/or 
1,6-hexane diol, diethylene glycol, triethylene glycol and tetraethylene 
glycol, with diarylcarbonates, such as diphenylcarbonate or phosgene. 
Examples of polyester amides and polyamides include the predominantly 
linear condensates obtained from polyvalent saturated carboxylic acids or 
their anhydrides and polyhydric, saturated amino alcohols, diamines, 
polyamines and mixtures thereof. 
Polyhydroxyl compounds already containing urethane or urea groups and 
modified natural polyols, such as castor oil, carbohydrates and starch, 
may also be used. The addition products of alkylene oxides with 
phenol-formaldehyde resins or even with urea-formaldehyde resins may also 
be used in accordance with the invention. 
Further examples of suitable active hydrogen containing compounds are known 
and can be found, e.g., in High Polymers, Vol. XVI, "Polyurethanes, 
Chemistry and Technology" by Saunders-Frisch, Interscience Publishers, New 
York, London Vol. I, 1962, pages 32 to 42, and Vol. II, 1964, pages 5 to 6 
and 198 and 199, and in Kunststoff-Handbuch, Vol. VII, Vieweg-Hochtlen, 
Carl-Hanser-Verlag Munich, 1966, pages 45 to 71. 
The most preferred high molecular weight compounds containing active 
hydrogen groups are polyethers with a high primary hydroxyl content. They 
include compounds having a molecular weight of from about 400 to 10,000, 
and preferably from 2,000 to 6,000, and having hydroxyl numbers of from 
about 15 to 100, and preferably from 28 to 56. 
Polyesters are generally not preferred because of their hydrolytic 
instability. 
It is preferred but not necessary that a chain extender be used in the 
resin formulation. Such extenders include compounds having molecular 
weights of from 32 to about 400 which contain at least two hydrogen atoms 
capable of reacting with isocyanates. These include compounds containing 
hydroxyl groups and/or amino groups and/or thiol groups and/or carboxyl 
groups, and preferably compounds containing hydroxyl groups and/or amino 
groups. They generally contain from 2 to 8 hydrogen atoms capable of 
reacting with isocyanates, and preferably contain 2 or 3 such hydrogen 
atoms. The following are mentioned as examples of such compounds: ethylene 
glycol; propylene glycol--(1,2) and --(1,3); butylene glycol --(1,4), 
--(1,3) and --(2,3); pentanediol-(1,5); hexanediol-(1,6); 
octanediol-(1,8); neopentylglycol; 1,4-bis-hydroxymethylcyclohexane; 
2-methyl-1,3-propanediol; glycerol; trimethylolpropane; 
hexanetriol-(1,2,6); trimethylolethane; pentaerythritol; quinitol; 
mannitol and sorbitol; diethylene glycol; triethylene glycol; 
tetraethylene glycol; polyethylene glycols having a molecular weight of up 
to 400; dipropylene glycol, polypropylene glycols having a molecular 
weight of up to 400; dibutylene glycol; polybutylene glycols having a 
molecular weight of up to 400; 4,4'-dihydroxy diphenylpropane; 
di(hydroxyethyl)hydroquinone; ethanolamine; diethanolamine; 
triethanolamine; 3-aminopropanol; ethylenediamine-1,3-diaminopropane; 
1-mercapto-3-aminopropane; 4-hydroxyphthalic acid or 4-aminophthalic acid; 
succinic acid, adipic acid; hydrazine; N,N'-dimethylhydrazine, 
4,4'-diaminodiphenylmethane, tolylene diamine and diethyl tolylene 
diamine. Mixtures of these various compounds may also be used. 
These extenders may generally be used in, amounts varying from about 0.5 to 
about 30 parts by weight, preferably 5 to 15, based on the total amount of 
above-mentioned higher molecular weight active hydrogen containing 
compound (2). 
The isocyanates suitable for the process according to the invention include 
essentially any organic polyisocyanate such as aliphatic, cycloaliphatic, 
araliphatic, aromatic and heterocyclic polyisocyanates of the type known 
and described, for example, by W. Siefken in Justus Liebigs Annalen der 
Chemie, 562, pages 75 to 136. Specific examples include ethylene 
diisocyanate; 1,4-tetramethylene diisocyanate; 1,6-hexamethylene 
diisocyanate; 1,12-dodecane diisocyanate; cyclobutane-1,3-diisocyanate; 
cyclohexane-1,3- and 1,4-diisocyanate, and mixtures of these isomers; 
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (German 
Auslegeschrift No. 1,202,785); 2,4- and 2,6-hexahydrotolylene 
diisocyanate, and mixtures of these isomers; hexahydro-1,3- and/or 
1,4-phenylene diisocyanate; perhydro-2,4' and/or -4,4'-diphenylmethane 
diisocyanate; 1,3- and 1,4-phenylene diisocyanate; 2,4- and 2,6-tolylene 
diisocyanate, and mixtures of these isomers; diphenylmethane 2,4'-and/or 
-4,4'-diisocyanate; naphthylene-1,5-diisocyanate; 
triphenylmethane-4,4',4"-triisocyanate; polyphenylpolymethylene 
polyisocyanates of the type obtained by condensing aniline with 
formaldehyde, followed by phosgenation and described, for example, in the 
British Pat. Nos. 874,430 and 848,671; perchlorinated arylpolyisocyanates 
of the types described, for example, in German Auslegeschrift No. 
1,157,601; polyisocyanates containing carbodiimide groups of the type 
described in German Pat. No. 1,092,007; diisocyanates of the type 
described in U.S. Pat. No. 3,492,330; polyisocyanates containing 
allophanate groups of the type described, for example, in British Patent 
994,890, Belgian Pat. No. 761,626 and published Dutch Patent Application 
No. 7,102,524; polyisocyanates containing isocyanurate groups of the type 
described, for example, in German Pat. Nos. 1,022,789; 1,222,067 and 
1,027,394 and German Offenlegungsschriften Nos. 1,929,034 and 2,004,048; 
polyisocyanates containing urethane groups of the type described, for 
example, in Belgian Pat. No. 752,261 or U.S. Pat. No. 3,394,164; 
polyisocyanates containing acylated urea groups as disclosed in German 
Pat. No. 1,230,778; polyisocyanates containing biuret groups of the type 
described, for example, in British Pat. No. 956,474 and 1,072,956, U.S. 
Pat. No. 3,567,763 and German Pat. No. 1,231,688; and reaction products of 
the aforementioned isocyanates with acetals as described in German Pat. 
No. 1,072,385. It is also possible to use the distillation residues 
containing isocyanate groups accumulating in the commercial production of 
isocyanates, optionally dissolved in one or more of the aforementioned 
polyisocyanates. It is also possible to use mixtures of the aforementioned 
polyisocyanates. 
In general, it is preferred to use the readily available polyisocyanate 
such as 2,4- and 2,6-tolylene diisocyanate and mixtures of these isomers 
("TDI"). Particularly preferred are polyphenyl polymethylene 
polyisocyanates, of the type obtained by aniline-formaldehyde condensation 
and subsequent phosgenation ("crude MDI") in various isomeric 
distributions. The functionality of the crude MDI may vary from 2.0 to 4.0 
but is preferably from 2.5 to 3.0. The volatility of tolylene diisocyanate 
generally deters its advantageous use under many circumstances. 
Also suitable are polyisocyanates containing carbodiimide groups, urethane 
groups, allophanate groups, isocyanurate groups, urea groups or biuret 
groups ("modified polyisocyanates"). 
Isocyanate terminated prepolymers may also be used in the process of the 
invention. Such prepolymers are made by reacting a stoichiometric excess 
of a polyisocyanate with an active hydrogen containing compound. Blocked 
isocyanates which may be formed by adding a monofunctional organic 
compound such as phenol to a polyisocyanate may also be used. 
In general, it is preferred that the foam index (eq. of NCO/ eq. of active 
hydrogens) be in the range from about 100 to about 200, and preferably 
from 125 to 150. 
A particularly advantageous embodiment of the invention is the pre-reacting 
of at least part of the polyisocyanate used as component (1) with the 
hydroxy functional acrylate, component (3). Acrylates are known irritants 
to a number of susceptible people. Thus, by this method, the acrylate need 
only be handled once and need not be contained as a volatile component in 
the resin blend system which is often transported from the manufacturer to 
the processor as a blend. This prepolymer can be prepared by reacting all 
or part of the polyisocyanate with the hydroxy acrylate under typical 
conditions known for the preparation of NCO-terminated prepolymers with 
other hydroxy functional compounds. 
It is preferred to prepare a froth of the reaction components rather than 
using blowing techniques normally used to make foams i.e. with the use of 
water and/or Freon. Froths are normally prepared by dispersing an inert 
gas throughout the reaction mixture to form a heat curable froth. With the 
use of heat activated catalysts, the froth is basically structurally and 
chemically stable and workable at ambient conditions. Frothing techniques 
are well known and are described, for example, in U.S. Pat. Nos. 
3,108,976; 3,849,156 and 3,772,224. Sufficient air or inert gas is 
included to produce foams of desired density. The density of the froth is 
essentially the same as the foam product. 
Readily volatile organic substances may be also used as blowing agents in 
the production of the polyurethane foams. Suitable organic blowing agents 
include halogen-substituted alkanes, such as methylene chloride, 
chloroform, ethylidene chloride, vinylidene chloride, 
monofluorotrichloromethane, chlorodifluoromethane, and 
dichlorodifluoromethane; butane; hexane; heptane; or diethylether. A 
blowing effect, may also be obtained by adding compounds which decompose 
spontaneously at temperatures above room temperature, giving off gases 
such as nitrogen. Further examples of blowing agents and details of the 
use of blowing agents may be found in Kunststoff-Handbuch Vol. VII, 
published by Vieweg and Hoechtlen, Carl-Hanser-Verlag, Munich 1966, for 
example, on pages 108 and 109, 453 to 455 and 507 to 510. These blowing 
agents may be used in amounts from 0 to 10 parts by weight per 100 parts 
of components (2), (3), (4), (5) and (7). 
When using the amidine heat activated catalysts discussed below, it is 
preferred to use a carboxylic acid (preferably aliphatic and optionally 
halogen substituted) with from 1-30 carbon atoms and which may be mono or 
difunctional. They may be used exclusively or in addition to the above 
mentioned blowing agents. Particularly preferred among this group are 
oleic acid, lauric acid, trichloroacetic acid, cyanoacetic acid, phthalic 
acid, adipic acid, propionic acid, butyric acid, fumaric, isophthalic, 
terephthalate, ricinoleic, stearic, cyclohexanecarboxylic acid, 
.omega.-hydroxy caproic acid and polyesters of dicarboxylic acids and 
glycols which have a high acid number. These acids may be used in amounts 
varying from 0 to about 5 parts by weight per 100 parts of Components (2), 
(3), (4), (5) and (7) preferably from 0.01 to 2 parts by weight. It is 
also preferred to use in addition thereto from 0 to about 1 part by weight 
of water, most preferably from 0 to 0.1 part by weight. 
Any of the many catalysts known in and/or used polyurethane chemistry may 
be used, including organo-tin compounds; tertiary amines; tertiary amines 
containing hydrogen atoms which can react with isocyanate groups; 
silamines with carbon-silicon bonds; nitrogen containing bases; alkali 
metal hydroxides, phenolates or alcoholates; hexahydrotriazines and the 
like. However, it is preferred to use a heat activated catalyst e.g. 
bicyclic and monocyclic amidine catalysts; nickel acetylacetonate or Union 
Carbide's LC 5613; catalysts produced by Witco (particularly UL 29); and 
Dabco WT and the like. Amidine catalysts are preferred. In fact, in order 
to allow for a reasonable working time in which the reaction mixture will 
remain stable and workable while it is being spread on the fabric, it is 
best only to use a heat activated catalyst. 
Cyclic amidines usable as catalysts or accelerators in the instant 
invention are known and are described in U.S. Pat. No. 3,814,707. They are 
generally used in quantities of from about 0.001 to about 10 percent by 
weight, preferably from about 0.1 to about 5, and most preferably from 
about 0.3 to about 1 percent by weight (based on all the components). 
Suitable bicyclic amidines include compounds of the following general 
formula: 
##STR2## 
wherein m=2 or 3 and n=3, 4 or 5. 
Suitable monocyclic amidines include compounds of the following general 
formula: 
##STR3## 
in which R represents an aliphatic, cycloaliphatic, araliphatic or 
aromatic group with 1 to 15 carbon atoms which may be branched and/or may 
contain hetero atoms. Examples of R include methyl, cyclohexyl, 
2-ethylhexyl, benzyl, cyclohexylmethyl, ethoxy, or a group of the 
following formula: 
##STR4## 
2,3-Dimethyl-3,4,5,6-tetrahydropyrimidine and 
1,5-diazabicyclo[5.4.0]undec-5-ene are preferred catalysts according to 
the invention. 
According to the invention, surface-active additives (emulsifiers and foam 
stabilizers) may also be used. Examples of emulsifiers include the sodium 
salts of castor oil sulphonates or of fatty acids or salts of fatty acids 
with amines, such as diethylamine/oleic acid or diethanol-amine/stearic 
acid. Alkali or ammonium salts of sulphonic acids, such as those of 
dodecyl-benzene sulphonic acid or dinaphthylmethane disulphonic acid, or 
even of fatty acids, such as ricinoleic acid, or of polymeric fatty acids, 
may also be used as surface-active additives. 
Suitable foam stabilizers include water-soluble polyether siloxanes. These 
compounds are generally of such structure that a copolymer of ethylene 
oxide and propylene oxide is attached to a polydimethylsiloxane radical. 
Foam stabilizers of this type are described, for example, in U.S. Pat. No. 
3,201,372, Column 3, line 60 to Column 4, line 3. From 0.1 to 10 parts by 
weight of a stabilizer per 100 parts of Component (2) are generally used. 
It is particularly useful to use anywhere from 0 to about 500 parts by 
weight and preferably from 300 to 500 parts by weight per 100 parts of 
Component (2) of an inorganic filler in finely divided form, (e.g. with a 
particle size from 0.3 to 80 .mu.m). Suitable inorganic fillers include 
e.g. barium sulphate (baryta) calcium carbonate (chalk), alumina 
trihydrate, kieselguhr and clays (e.g. kaolin), silica talc, quarts, 
ground shale, fly ash microspheres and the like. The use of a filler is 
not only advantageous for improving the general backing properties but 
also significantly enables the fabric to comply with burn tests, such as 
the Motor Vehicle Safety Standard 302, without the use of fire retardants, 
and improves the economics of the process. In general, the filler must be 
mixed, mechanically or otherwise, with the other resin blend components in 
a separate operation. Barium sulphates, calcium carbonate and alumina 
trihydrate are preferred. 
According to the invention, it is also possible to use reaction retarders 
such as hydrochloric acid or organic acid halides; cell regulators such as 
paraffins or fatty alcohols or dimethyl polysiloxanes; pigments or dyes; 
flameproofing agents such as trischloroethylphosphate or ammonium 
phosphate and polyphosphate; stabilizers against the effects of ageing and 
weather; plasticizers; substances with fungistatic and bacteriostatic 
effects. 
It has also been found advantageous to use an antioxidant in amounts 
varying from 0 to 0.5 part by weight per 100 parts of Components (2), (3), 
(4), (5) and (7). Examples include 2,6-di-t-butyl-4-methylphenol (BHT), 
hydroquinone, 4-t-butylcatechol, resorcinol, and 4-methoxyphenol (MEHQ). 
Further examples of the surface-active additives and foam stabilizers 
optionally used in accordance with the invention, and of cell regulators, 
reaction retarders, stabilizers, flameproofing agents, plasticizers, dyes, 
fillers, substances with fungistatic and bacteriostatic effects, and 
details on the way in which these additives are to be used and how they 
work, are known and may be found, i.e., in Kunststoff-Handbuch, Vol. VI, 
published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich, 1966, pages 
103 to 113. 
It is also preferred in some instances, to use dehydrating or water-binding 
agents in the process of the instant invention. The presently preferred 
agents are the alkali metal alumino-silicates (so-called molecular sieves) 
such as those known under the trade name "Zeolite" and described e.g. in 
U.S. Pat. No. 3,326,844. The oxides of calcium and barium may also be 
used. The dehydrating agents are generally used in a quantity sufficient 
to ensure that the maximum quantity of mositure which can be carried in 
with the fillers will be from about 1 to about 10% by weight, based on the 
polyurethane. It is preferred to use a Zeolite paste, particularly a 
sodium aluminum silicate as a 50% suspension in castor oil. 
According to the instant invention, the reactants may be reacted together 
in a known manner by the one-step, prepolymer, semi-prepolymer or frothing 
process, often using mechanical devices such as those described in U.S. 
Pat. No. 2,764,565 are used. Details concerning suitable processing 
apparatus may be found, e.g., in Kunststoff-Handbuch, Volume VI, published 
by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich, 1966, pages 121 to 
205. 
Essentially any fabric may be used in the instant invention. They may be 
woven, non-woven, knitted, spun bonded, or felted, and made of natural or 
synthetic fibers and/or filaments. It is preferred, however, to use carpet 
type materials. The type of carpeting which is generally contemplated by 
the present invention includes any conventional carpet backing material 
(e.g., jute or polypropylene) and the fibers can be mechanically anchored 
to the first backing by any conventional means (e.g., by sewing, tufting 
or needle punching). The fibers can be composed of any conventional 
carpeting material (e.g., cotton, rayon, wool, nylon, acrylonitrile 
polymers, vinyl halide polymers, etc.). The fibers can be in any suitable 
form (e.g., in the form of pile yarns threaded through the first backing 
having cut or looped pile faces on the front side of the first backing). 
The froth can be applied to the first backing by any suitable procedure 
(e.g., knife coating). The backing can have any desired thickness (e.g., 
from 1/16 to 178 inch). 
The reactive mass may either flow onto a suitable conveyor belt in front of 
a doctor knife and the fabric allowed to run thereon (reverse coating), or 
the mixture may be applied directly to the fabric in front of a doctor 
knife. 
Any number of known pieces of equipment may be used to carry out the 
invention, e.g., low pressure mixheads with solvent flushes, conveyor 
means, heated molds, ovens and the like. 
The polyurethane foam layer which results from the present process is 
generally between about 1 and about 25 mm thick and has a closed surface 
skin. The foam density will vary anywhere from 10 to 100, preferably 20 to 
60 and most preferably from 30 to 50 lbs./ft.sup.3. 
The time, temperature, pressure and formulation parameters are all 
interdependent and the various choices will depend on the particular 
properties to be engineered. The following examples serve to explain the 
process of the invention. All parts and percentages are by weight unless 
otherwise indicated. In the examples, the following materials were used: 
Polyol A is an ethylene oxide tripped polypropylene glycol with a molecular 
weight of 4800 and an OH number of 35. 
Polyol B is a modified version of Polyol A with a Mw of 6000 and an OH 
number of 28. 
DEG is diethylene glycol. 
L6202 and 
L 5612 are Union Carbide polysiloxane surfactants. 
The catalyst is 
##STR5## 
HEA is 2-hydroxyethyl acrylate. HPA is 2-hydroxypropyl acrylate. 
AIBN is azobis (isobutyronitrile). 
Zeolith T Paste is a sodium-aluminum silicate type paste used as a 
dessicant. 
CS-15 is a hydroxy terminated polybutadiene-styrene copolymer available 
from ARCO. 
R45HT is a hydroxy terminated polybutadiene homopolymer available from 
ARCO. 
Polyisocyanates A and B are polymethylene polyphenyl polyisocyanates with 
NCO contents of 31.5% and functionalities averaging from 2.6 to 2.7. 
Polyisocyanate C is a polymethylene polyphenyl polyisocyanate with 
carbodiimide and uretonimine modification with a 30% NCO content and a 
functionality of about 2. 
Polyisocyanate D is a liquid modified diphenyl methane diisocyanate with an 
NCO content of 22.6%.

EXAMPLES 
The following method was followed in preparing the foam-backed carpets from 
the formulations mentioned in the Table below. All of the components 
except the filler and isocyanate were pre-blended. The filler (e.g., 
barium sulfate) was then mixed with the liquid resin blend via a feed 
hopper and static mixer. The polyisocyanate was then blended with the 
resin/filler in a mixhead. The effluent from the mixhead ran through a 
pipe into which an air nozzle is placed for injecting air into the 
mixture. The air-reactive component mix was then homogenized in a froth 
producing mixer. 
The froth was dispensed onto the carpet via a reciprocating applicator and 
was evenly spread over the carpet by a doctor knife. The carpet was then 
placed in a heated oven for curing for about 4 minutes at an oven 
temperature of about 110.degree. C. 
At this point, the polyurethane backing was fully foamed and was in a 
tack-free gelled state. It could be stored in rolls for substantial 
periods of time. When a piece of moldable carpet is needed, the proper 
sized piece was cut off from the roll. In the present case, the piece was 
placed in a heated mold, under pressure, for the period of time indicated 
and then removed. 
__________________________________________________________________________ 
POLY- 
POLY- 
Di- ISO ISO 
POLY- Cumyl CYA- 
CYA- 
OL Oleic 
Acetic Cat- Perox- Barium 
NATE 
NATE 
A CS15 
R45HT 
DEG Acid 
Acid 
L6202 
alyst 
HEA HPA 
ide AIBN 
Sulfate 
A B Index 
__________________________________________________________________________ 
1 90 -- 10 -- -- .25 1.0 0.3 
10 -- -- 0.1 320 -- 21 110 
2 90 -- 10 -- -- .25 1.0 0.3 
-- 10 -- 0.1 320 -- 20 110 
3 95 -- -- 7 1.0 -- 1.0 0.3 
3 -- -- 0.1 320 -- 29 110 
4 95 -- -- 7 1.0 -- 1.0 0.3 
5 -- -- 0.1 320 -- 32 110 
5 95 -- -- 7 1.0 -- 1.0 0.3 
10 -- -- 0.1 320 -- 38 110 
6 95 -- -- 7 1.0 -- 1.0 0.3 
-- 10 -- 0.1 320 -- 36 110 
7 90 10 -- -- -- .25 1.0 0.3 
10 -- 0.1 -- 320 -- 21 110 
8 85 15 -- -- -- .25 1.0 0.3 
10 -- -- 0.1 320 -- 25 130 
9 85 15 -- -- -- .25 1.0 0.3 
10 -- -- 0.1 320 25 -- 130 
__________________________________________________________________________ 
In Examples 1-6, the carpet was post shaped in a mold heated to 320.degree. 
F. and pressed at 0.5 psi for approximately one minute. The carpets had 
been stored for three weeks following the initial spreading of the 
polyurethane reaction mixture onto the back of the carpet. 
Each finished product had good to excellent moldability, stiffness and yet 
were flexible enough not to crack when flexed. They also had very good 
mold definition (i.e., the final foam surface duplicated the inside of the 
mold). 
In Examples 7-9, the carpets had been stored for five weeks and were 
similarly molded but at a mold temperature of 280.degree. F. Comparable 
results to the carpets of Examples 1-6 were obtained. 
The use of only 3 or 5 parts of hydroxy ethyl acrylate in Examples 1 and 3 
or 5 parts of hydroxy propyl acrylate in Examples 2 and 6 resulted in 
products with poorer moldability which were too soft to retain their 
molded shape. 
Experiments similar to Examples 3-6 using polyisocyanate C at a 110 index 
also did not mold well. This is presumably due to the isocyanate's lower 
functionality. 
Experiments similar to Examples 2 and 3 using 3, 5 and 10 parts of 
trimethylol propane di-2-propenyl ether 
##STR6## 
also resulted in foams without good shape retention. Apparently, only 
those compounds with carbon-carbon double bonds which are activated by a 
proximate carbonyl group (e.g. acrylates, methacrylates etc.) are 
effective. 
EXAMPLE 10 
The following formulation has been found to be particularly useful in 
preparing excellent molded fabrics by the same general method outlined in 
the above examples 
______________________________________ 
Polyol B 88 
DEG 12 
HEA 10 
L5612 4.0 
AIBN .3 
Catalyst .45 
Oleic Acid 1.0 
BaSO.sub.4 320 
Polyisocyanate D 100 
(Index = 150) 
______________________________________ 
EXAMPLE 11 
To 660 parts by weight of a polymethane polyphenyl polyisocyanate (85% 
dinuclear polymeric isocyanate, 15% wt. and higher nuclear and 10% of the 
dinuclear being 2,4' isomer) were added 125 parts by weight 2-hydroxyethyl 
acrylate at 40.degree. C. over 10 minutes. The reaction mixture exothermed 
to 90.degree. C. The batch was cooled to 80.degree. C. and held at that 
temperature for one hour. The reaction product had an NCO content of 
21.9%. This prepolymer can be effectively used as the isocyanate component 
(1) in the process of the present invention in the absence of additional 
hydroxy acrylate to form excellent molded foam-backed fabrics. 
The foam-backed carpets in Examples 1-11 can survive the following physical 
testing conditions without suffering cracking. 
(1) Heat ageing for 14 days at 70.degree. C.; 
(2) Cold ageing for 14 days at -30.degree. C.; 
(3) humid ageing for 72 hours at 35.degree. C. and 100% relative humidity.