Thermoplastic compositions of multi-block copolyester elastomer and chlorosulfonated polyethylene

A thermoplastic composition comprising about 10-80 parts by weight total polymers of a multi-block copolyester elastomer having a melting point of from about 100.degree.-200.degree. C. and about 20-90 parts by weight total polymers of a crosslinked chlorosulfonated polyethylene elastomer dispersed in said copolyester elastomer, said chlorosulfonated polyethylene elastomer being crosslinked to an extent such that not more than about 45% by weight of said elastomer is extractable with toluene at 25.degree.0 C.

BACKGROUND OF THE INVENTION 
Copolyester elastomers are thermoplastic polymers which are easily 
processed but they lack the important physical characteristic of good 
compression set resistance found in vulcanized thermoset elastomers. 
Further, copolyester elastomers exhibit high permanent set values and a 
draw plateau when elongated. 
There has been a need in the industry to develop a thermoplastic 
composition having improved compression set resistance so that the 
dimensions of an article of manufacture, for example, the thickness of 
seals, will be restored after pressure that has been applied is released. 
Also, multi-block copolyester elastomers are deficient in resistance to 
permanent set. It is important for the material to return to substantially 
its original form after deformation by extension. For some uses, for 
example, gaskets and seals, multi-block copolyester elastomers are harder 
than desirable and either cannot be used or they are limited in their uses 
for such applications. Multi-block copolyester elastomers are not 
especially scuff resistant and there is a need to improve this 
characteristic. Also, there is a need for elastomeric thermoplastic 
compositions which do not have the draw plateau that is observed for 
multi-block copolyester elastomers. 
Although multi-block copolyester elastomers are not normally compounded 
with fillers and extenders, the thermoplastic elastomeric compositions of 
the present invention can accept substantial amounts of processing oils 
and/or fillers while still retaining good physical properties. The 
incorporation of fillers and/or extenders in the thermoplastic 
compositions of the present invention is beneficial because it lessens the 
cost of the polymers, makes processing easier and improves properties such 
as tear strength. The thermoplastic compositions of the present invention 
have good compression set resistance, improved resistance to permanent set 
relative to copolyester elastomers, they are scuff resistant and softer 
than copolyester elastomers. Further, the compositions show good 
resistance to oil swell and they can be readily processed by conventional 
means used for thermoplastic compositions. 
SUMMARY OF THE INVENTION 
This invention is directed to a thermoplastic composition comprising about 
10-80 parts by weight total polymers of a multi-block copolyester 
elastomer having a melting point of from about 100.degree.-200.degree. C. 
and about 20-90 parts by weight total polymers of a crosslinked 
chlorosulfonated polyethylene elastomer dispersed in said copolyester 
elastomer, said chlorosulfonated polyethylene elastomer being crosslinked 
to an extent such that not more than about 45% by weight, preferably 35% 
by weight, of said elastomer is extractable with toluene at 25.degree. C. 
Preferably, the thermoplastic composition comprises a multi-block 
copolyester elastomer that consists essentially of (A) repeating high 
melting point blocks comprising repeating short chain ester units having 
the formula: 
##STR1## 
wherein D is a divalent radical remaining after removal of hydroxyl groups 
from a low molecular weight diol having a molecular weight not greater 
than 250 and R is a divalent radical remaining after the removal of 
carboxyl groups from a dicarboxylic acid having a molecular weight not 
greater than 300, D and R being selected so that a polymer which consists 
essentially of short-chain ester units having a number average molecular 
weight of at least 5000 has a melting point above 100.degree. C., (B) 
repeating low melting point blocks which are derived from compounds 
containing two hydroxyl or carboxyl groups or mixtures thereof and has a 
number average molecular weight of 400-4000 and a melting point not 
greater than 100.degree. C., preferably not greater than 75.degree. C., 
and (C) an amount of difunctional radicals sufficient to join repeating 
blocks of (A) and (B) to form a multi-block copolyester elastomer, the 
weight ratio of (A) to (B) being from about 1:4 to 1:0.1, preferably 1:2 
to 1:0.5. 
The chlorosulfonated polyethylene usually contains from about 15-50% by 
weight chlorine and about 0.1-4% by weight sulfur as sulfonyl chloride 
groups. 
The thermoplastic elastomer compositions can be prepared by mixing and 
shearing uncured chlorosulfonated polyethylene with a molten multi-block 
copolyester elastomer, preferably in a high shear mixer, and carrying out 
curing of the chlorosulfonated polyethylene simultaneously with the mixing 
operation. Alternatively, the chlorosulfonated polyethylene can be cured 
alone, then finely divided into a powder, and the powder mixed with the 
molten multi-block copolyester elastomer while shearing. In order for the 
compositions to process well as thermoplastics the crosslinked 
chlorosulfonated polyethylene elastomer component must be dispersed in the 
multi-block copolyester elastomer during mixing. 
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
The thermoplastic multi-block copolyester elastomers used as a component in 
this invention consist essentially of repeating blocks of repeating short 
chain ester units, as described above, which have high melting points 
(above 100.degree. C.) and repeating low melting point blocks (not greater 
than 100.degree. C., preferably below 75.degree. C.) which are derived 
from difunctional compounds having a number average molecular weight of 
about 400-4000. The low melting point and high melting point blocks are 
joined together by difunctional radicals which, for example, can be 
derived by reaction of the high or low melting point blocks with diols, 
dicarboxylic acids, diepoxides, bis(acyl lactams) and diisocyanates. The 
high melting point blocks crystallize at useful service temperatures to 
provide physical crosslinks in the multi-block elastomer while the low 
melting point blocks provide elastomer characteristics. At processing 
temperatures, generally of the order of about 100.degree.-220.degree. C., 
preferably 140.degree.-190.degree. C., the high melting point blocks melt 
and the polymer is molten. 
Multi-block copolyester elastomers of the type described herein which have 
high melting points, e.g. above about 200.degree. C., do not blend readily 
with chlorosulfonated polyethylene elastomers at safe processing 
temperatures for the chlorosulfonated polyethylene elastomers. Therefore, 
the multi-block copolyester elastomers used in this invention have melting 
points no more than about 200.degree. C. If the multi-block copolyester 
elastomers have melting points below about 100.degree. C., the resulting 
composition of copolyester elastomer and chlorosulfonated polyethylene 
elastomer will have a limited useful temperature range. Preferably, the 
melting point of the multi-block copolyester elastomers used as a 
component of the blend is from about 130.degree. C.-180.degree. C. 
The high melting point blocks which comprise repeating short chain ester 
units of the formula 
##STR2## 
derived from one or more low molecular weight diols, HODOH, having a 
molecular weight not greater than 250 and one or more dicarboxylic acids, 
HOOCRCOOH, having a molecular weight of not greater than 300. 
The term "low molecular weight diols" as used herein should be construed to 
include equivalent ester-forming derivatives, provided, however, that the 
molecular weight requirement pertains to the diol only and not to its 
derivatives. 
Aliphatic or cycloaliphatic diols with 2-15 carbon atoms are preferred, 
such as ethylene, propylene, tetramethylene, pentamethylene, 
2,2-dimethyltrimethylene, hexamethylene, and decamethylene glycols, 
dihydroxy cyclohexane and cyclohexane dimethanol. Unsaturated diols such 
as butene-2-diol-1,4 can also be used, particularly in minor amounts in 
admixture with a saturated diol. 
The term "dicarboxylic acids" as used herein, includes equivalents of 
dicarboxylic acids having two functional carboxyl groups which perform 
substantially like dicarboxylic acids in reaction with glycols and diols 
in forming multi-block copolyester elastomers. These equivalents include 
esters and ester-forming derivatives, such as acid anhydrides. The 
molecular weight requirement pertains to the acid and not to its 
equivalent ester or ester-forming derivative. 
Among the aromatic dicarboxylic acids for preparing the copolyester 
elastomers that are used, those with 8-16 carbon atoms are preferred, 
particularly the phenylene dicarboxylic acids, i.e., phthalic, 
terephthalic and isophthalic acids and their dimethyl esters. 
The diol and dicarboxylic acid must be chosen to provide a melting point of 
at least 100.degree. C. for a polymer having a number average molecular 
weight of at least 5000 and which is derived exclusively from short chain 
ester units. Preferred high melting point blocks are derived from ethylene 
glycol, 1,4-butanediol or hexanediol by reaction with terephthalic acid 
alone or in admixture with up to about 30% by weight isophthalic acid or 
phthalic acid or mixtures thereof. Polymers based solely or principally on 
1,4-butanediol are especially preferred. 
The low melting point blocks in said multi-block copolyester elastomers can 
be provided by a variety of difunctional compounds having number average 
molecular weights of 400-4000 which contain hydroxyl groups or carboxyl 
groups or mixtures thereof. Suitable compounds for forming low melting 
point blocks include poly(alkylene oxide) glycols, low melting point 
polyester glycols and hydrocarbon glycols or diacids. 
Representative poly(alkylene oxide) glycols have a carbon-to-oxygen atomic 
ratio of about 2.0-4.3 and a number average molecular weight of about 
400-4000 and include poly(ethylene oxide) glycol, poly(1,2- and 
1,3-propylene oxide) glycol, poly(tetramethylene oxide) glycol, random or 
block copolymers of ethylene oxide and 1,2-propylene oxide, and random or 
block copolymers of tetrahydrofuran with minor amounts of a second monomer 
such as ethylene oxide. Preferred poly(alkylene oxide) glycols include 
poly(tetramethylene oxide) glycol having a number average molecular weight 
of 600-2000, especially 800-1200, and ethylene oxide-capped poly(propylene 
oxide) glycol having a number average molecular weight of 1500-2800 and an 
ethylene oxide content of 15-35% by weight. 
The required low melting point blocks (i.e., not greater than about 
100.degree. C., and, preferably, below about 75.degree. C.) from polyester 
glycols are either polylactones or the reaction products of low molecular 
weight diols (i.e., less than about 250) and aliphatic dicarboxylic acids. 
Representative low melting point polyester glycols are obtained by 
reaction of diols such as ethylene glycol, 1,4-butanediol, pentanediol, 
hexanediol, 2,2-dimethyl-1,3-propanediol and mixtures of ethylene glycol 
and propylene glycol with diacids such as adipic acid, glutaric acid, 
pimelic acid, suberic acid and isosebacic acid. Polylactone glycols 
derived from unsubstituted and substituted caprolactone or butyrolactone 
are also useful as low melting point polyester glycols. Preferred 
polyester glycols include polycaprolactone glycol and poly(tetramethylene 
adipate) glycol having number average molecular weights of 800-2500. 
Representative hydrocarbon glycols or diacid derivatives which can be used 
to provide low melting point blocks include polybutadiene or polyisoprene 
glycols and saturated hydrogenation products of these materials. 
Dicarboxylic acids formed by oxidation of polyisobutylene/diene copolymers 
are also useful materials. Dimer acid, particularly the more highly 
refined grades, is a useful hydrocarbon diacid which can be used alone or 
in combination with other low melting point compounds such as the 
poly(alkylene oxide) glycols to provide low melting point blocks. 
As previously indicated, multi-block copolyester elastomers used as a 
component of the thermoplastic compositions of the present invention must 
have melting points which are not above about 200.degree. C. Since 
copolyester elastomers based exclusively on butylene terephthalate units 
or exclusively on ethylene terephthalate units for the high melting point 
blocks will often melt above 200.degree. C., it may be necessary to 
introduce minor amounts of a second diol or diacid to lower the polymer 
melting point. The general relationship between monomer mole fraction and 
polymer melting point is discussed by Flory, Principles of Polymer 
Chemistry, page 570, Cornell University Press, 1953. Flory has suggested 
that the copolymer melting point (T.sub.m) depends upon homopolymer's 
melting point (T.sub.m .degree.), the homopolymer mole fraction (N.sub.A), 
homopolymer heat of fusion (.DELTA.H.mu.) and the gas constant (R) by the 
following expression: 
EQU 1/T.sub.m -1/T.sub.m .degree.=-(R/.DELTA.H.mu.)1.sub.n N.sub.A 
This equation has been found to be reasonably valid for the class of 
multi-block copolyester elastomers employed in the compositions of this 
invention. For multi-block copolyester elastomers in which the major short 
chain ester units are 1,4-butylene terephthalate units, T.sub.m 
.degree.=234.degree. C. and .DELTA.H.mu.=12.1 cal./g. To prepare 
copolyester elastomers having melting points no more than about 
200.degree. C., it can be calculated that the mole fraction of 
1,4-butylene terephthalate units must be less than about 82.5%. The 
calculated value is supported by the observed melting points of a number 
of copolyester elastomers based on 1,4-butylene terephthalate units. 
Similar calculations can be made for other short chain units if the 
homopolymer melting point and heat of fusion are known. 
The multi-block copolyester elastomers described herein can be made by 
procedures known in the art. Elastomers in which the low melting point 
blocks are provided by poly(alkylene oxide) glycols or hydrocarbon glycols 
or diacids are readily made by ester interchange reactions followed by 
polycondensation. Different procedures are required when the low melting 
point block is provided by a polyester glycol because ester exchange can 
take place with the high melting point ester blocks which ultimately 
destroys the blockiness of the polymer. 
A typical procedure for preparing elastomers by ester interchange involves 
heating a dicarboxylic acid or its methyl ester with a poly(alkylene 
oxide) glycol or hydrocarbon glycol or diacid or mixtures thereof and a 
molar excess of low molecular weight diol in the presence of a catalyst at 
about 150.degree.-260.degree. C. and a pressure of 0.05 to 0.5 MPa, 
usually ambient pressure, while distilling off water formed by 
esterification and/or methanol formed by ester interchange. The glycol or 
the diacid that provides the low melting point blocks is incorporated into 
the polymer through difunctional radicals provided by the dicarboxylic 
acid in the case of the glycols, or by the low molecular weight diols in 
the case of the diacids. The particular amount of difunctional radicals 
incorporated into the polymer to join the high and low melting point 
blocks will vary and depends on the molecular weights and the ratio of the 
high and low melting point blocks and the functional groups on the blocks. 
However, in all cases the difunctional radicals constitute a minor amount 
of the total weight of the polymer. 
Depending on temperature, catalyst, glycol excess and equipment, this 
reaction can be completed within a few minutes, e.g., about two minutes, 
to a few hours, e.g., about two hours. This procedure results in the 
preparation of a low molecular weight prepolymer which can be carried to a 
high molecular weight multi-block elastomer by distillation of the excess 
of short-chain diol. This second process stage is known as 
"polycondensation". 
Additional ester interchange occurs during this polycondensation which 
serves to increase the molecular weight of the polymer. Best results are 
usually obtained if this final distillation or polycondensation is run at 
less than about 670 Pa, preferably less than about 250 Pa, and about 
200.degree.-280.degree. C., preferably about 220.degree.-260.degree. C., 
for less than about two hours, e.g., about 0.5 to 1.5 hours. It is 
customary to employ a catalyst while carrying out ester interchange 
reactions. While a wide variety of catalysts can be employed, organic 
titanates such as tetrabutyl titanate used alone or in combination with 
magnesium or calcium acetates are preferred. The catalyst should be 
present in an amount of about 0.005 to 2.0 percent by weight based on 
total reactants. 
Both batch and continuous methods can be used for any stage of polymer 
preparation. Polycondensation of prepolymer can also be accomplished in 
the solid phase by heating divided solid prepolymer in a vacuum or in a 
stream of inert gas to remove liberated low molecular weight diol. 
Several procedures have been used to prepare multi-block copolyester 
elastomers wherein the low melting point blocks are polyesters as well as 
the high melting point blocks. One procedure involves carrying out a 
limited ester interchange reaction in the presence of an exchange catalyst 
between two high molecular weight polymers such as poly(butylene 
terephthalate) and poly(butylene adipate). Ester exchange at first causes 
the introduction of blocks of one polyester into the other polyester chain 
and vice versa. When the desired multi-block polymer structure is formed 
the catalyst is deactivated to prevent further interchange which 
ultimately would lead to a random copolyester without any blockiness. This 
procedure is described in detail in U.S. Pat. No. 4,031,165 to Saiki et 
al. Other useful procedures involve coupling of preformed blocks of high 
and low melting point polyester glycols. Coupling can be accomplished by 
reaction of a mixture of the blocks with a diisocyanate, as described in 
European Pat. No. 0013461 to Huntjens et al. Coupling can also be 
accomplished by heating the mixed blocks in the presence of terephthaloyl 
or isophthaloyl bis-caprolactam addition compounds. The caprolactam 
addition compounds react readily with the terminal hydroxyl groups of the 
polyester blocks joining the blocks. This coupling method is described in 
Japanese Pat. No. 700740 (Japanese Patent Publication No. 73/4115). 
Another procedure of use when the low melting blocks are to be provided by 
polycaprolactone involves reacting a preformed high melting point block 
terminated with hydroxyl groups with epsilon-caprolactone in the presence 
of a catalyst such as dibutyl tin dilaurate. The caprolactone polymerizes 
on the hydroxyl groups of the high melting point ester block which groups 
serve as initiators. The resulting product is a relatively low molecular 
weight triblock polymer having the high melting point block in the middle 
with low melting point polycaprolactone blocks on each end. The triblock 
polymer is hydroxyl terminated and may be joined to give a finished 
product by reaction with a diepoxide such as diethylene glycol diglycidyl 
ether, (see, for example, Japanese Patent Publication No. 83/162654). 
The chlorosulfonated polyethylene elastomers used to prepare the 
compositions of the present invention contain from about 15-50% by weight 
chlorine, usually 20-45% by weight. If sufficient chlorine atoms are not 
substituted on the backbone carbon atoms of the polyethylene, the 
crystallinity of the polymer is not sufficiently interrupted and its 
elastomeric properties are poor. If more than about 50% by weight chlorine 
atoms are substituted on the backbone carbon atoms, the polymer becomes 
stiff. 
The chlorosulfonated polyethylene contains from about 0.1-4% by weight, 
usually 0.6-2% by weight, sulfur as sulfonyl chloride groups. 
The thermoplastic multi-block copolyester elastomers in amounts of about 
10-80 parts by weight total polymers are blended with about 20-90 parts by 
weight total polymers of chlorosulfonated polyethylene, preferably, 20-60 
parts copolyester by weight total polymers are blended with about 40-80 
parts chlorosulfonated polyethylene by weight total polymers. 
The mixing of the thermoplastic multi-block copolyester elastomers with the 
chlorosulfonated polyethylene elastomers is accomplished by any one of a 
number of conventional techniques, for example, in a Banbury mixer, 
two-roll mill or extruder. This mixing is done at a temperature high 
enough to soften the polymers for adequate mixing, but not so high as to 
degrade the chlorosulfonated polyethylene. Generally, mixing is done at a 
temperature range from about 100.degree.-220.degree. C., preferably 
140.degree.-190.degree. C. Mixing is carried out for a time sufficient to 
allow for crosslinking of the chlorosulfonated polyethylene and for 
shearing and dispersing the chlorosulfonated polyethylene substantially 
uniformly throughout the copolyester. Adequacy of mixing can be determined 
by observing the processability of the compositions by means of a piston 
rheometer. If the degree of mixing is inadequate as indicated by poor 
extrudability at processing temperatures, additional mixing at the 
original mixing temperature or at lower temperatures can be employed to 
further comminute and disperse the crosslinked chlorosulfonated 
polyethylene in the multi-block copolyester elastomer in order to obtain 
satisfactory thermoplastic processability. 
An important aspect of the process for making the thermoplastic composition 
is crosslinking the chlorosulfonated polyethylene elastomer component of 
the composition. Crosslinking is carried out using any one or more of the 
well known crosslinking system for chlorosulfonated polyethylenes. Typical 
crosslinking systems consist of an acid acceptor and a vulcanizing agent 
or accelerator. Representative acid acceptors include organic lead bases, 
epoxies, and metal oxides such as litharge, magnesia, and calcium oxide or 
hydroxide. Representative vulcanizing agents include bismaleimides, 
peroxides, sulfur, and sulfur-bearing accelerators such as 
dipentamethylene thiuram hexasulfide. If desired, various conventional 
activators may be added to enhance the crosslinking rate. The crosslinking 
of the chlorosulfonated polyethylene can be carried out before or 
concurrently with mixing the elastomer with the multi-block copolyester. 
If the chlorosulfonated polyethylene is crosslinked prior to mixing, it is 
necessary to pulverize or powder the cured elastomer before mixing. In 
this instance no cure is involved during mixing. The high shear mixers 
mentioned above can be conveniently used to mix the elastomer powder with 
the copolyester elastomer. Representative crosslinking systems for the 
chlorosulfonated polyethylene include: 
N,N'-meta-phenylenedimaleimide plus butyraldehyde-aniline condensation 
product plus calcium oxide; N,N'-meta-phenylenedimaleimide plus 40% 
dicumyl peroxide on calcium carbonate; magnesium oxide plus 
pentaerythritol plus dipentamethylene thiuram hexasulfide; epoxy resins 
(e.g., Epon 828) plus pentaerythritol plus dipentamethylene thiuram 
hexasulfide plus 2,2'-dibenzothiazyl disulfide; fumed litharge plus 
dipentamethylene thiuram hexasulfide plus 2,2'-dibenzothiazyl disulfide. 
The term crosslinked refers to a degree of crosslinking such that the 
chlorosulfonated polyethylene elastomers when mixed with the multi-block 
copolyester elastomers yield a thermoplastic elastomeric composition in 
which not more than 45% by weight of the chlorosulfonated polyethylene 
elastomer is extractable with toluene at 25.degree. C., the balance, i.e, 
at least about 55% by weight of the chlorosulfonated polyethylene is 
gelled to the point of insolubility. To quantify the degree of 
crosslinking the amount of insoluble, and hence crosslinked polymer is 
determined by leaching a sample of the polymer, after crosslinking, in 
toluene at 25.degree. C. for 48 hours, isolating the insoluble portion and 
weighing the dried residue, making suitable corrections based upon 
knowledge of the composition. For example, the weight of components 
soluble in toluene such as extenders and processing oils are subtracted 
from the initial weight; and components insoluble in toluene, such as 
pigments, fillers, etc. are subtracted from both the initial and final 
weight. Small amounts of the order of 3-4 percent by weight of the 
multi-block copolyester elastomer are soluble in toluene at 25.degree. C. 
and such amounts should be taken into consideration when determining the 
degree of crosslinking of the chlorosulfonated polyethylene elastomer. The 
insoluble polymer recovered is reported as percent by weight gel content. 
For purposes of the subject invention, the chlorosulfonated polyethylene 
elastomer component of the compositions need to be crosslinked so that not 
more than 45% by weight of the elastomer is extractable with toluene at 
25.degree. C., preferably not more than 35% by weight. Thus the 
chlorosulfonated polyethylenes have a gel content of at least 55 percent 
by weight, preferably at least 65 percent by weight. The conditions under 
which this crosslinking is carried out, i.e., type and quantity of 
crosslinking agent, crosslinking time and temperature, to arrive at a 
polymer having a gel content within this operable range, can be determined 
empirically and is well known in the art of making chlorosulfonated 
polyethylene elastomers. When chemical crosslinking agents are utilized, 
e.g., peroxides, it is preferable that they be substantially totally 
consumed during the crosslinking step. 
Although not essential components of the composition of this invention, 
preferably, especially from a cost standpoint, various amounts of any 
number of conventional fillers or compounding ingredients normally used 
with elastomers may be admixed with the compositions of this invention. 
Examples of such ingredients include extending oils and fillers, such as 
various carbon blacks, clays, silica, alumina, calcium carbonate; 
pigments, such as titanium dioxide; antioxidants; antidegradants; 
tackifiers; processing aids such as lubricants and waxes; and plasticizers 
such as dialkylphthalates; trialkylmellitates and polyester oligomers. It 
is preferable to add processing oils and fillers to the thermoplastic 
composition to improve its processing characteristics and the amounts used 
depend, at least in part, upon the quantities of other ingredients in the 
composition and the properties desired from the composition. 
The compositions of the subject invention are melt processible using 
conventional plastic processing equipment. Articles molded from the 
thermoplastic elastomeric compositions of the present invention exhibit 
properties generally only associated with vulcanized rubber. For example, 
these compositions have resistance to compression set values of about 20 
to 65 percent (at 70.degree. C.); and elongation at break values of 150 to 
700 percent. Various uses for the thermoplastic elastomer compositions 
include wire coverings, seals and gaskets, automotive parts, sheet liners 
and packaging films. They can be used to coat fabric, industrial belts and 
various hard surfaces by extrusion coating, for example, on substrates 
made from polyester, polyamide, polyimide or metal fibre or fabric 
reinforcement. They find utility in adhesive and sealant applications, as 
well as for modification of other polymer systems. 
Further, thermoplastic elastomeric compositions within the scope of this 
invention can be fabricated into tubing for laboratory, medical and 
industrial uses. Such tubing could also be used as the inner tube of 
reinforced hoses, wherein the extruded tube is overlaid with wire or 
textile cords, applied as a spiral, knit or braid. Optionally, a polymeric 
covering may be applied (extruded or spiral wound calendered sheet) over 
the reinforced tubing to provide protection from the working environment 
and mechanical abuse. Compositions within the scope of this invention can 
be used as the protective covering of reinforced tubes of similar or 
different composition.

The following examples, in which parts are by weight, unless otherwise 
indicated, are illustrative of the present invention and show advantages 
resulting therefrom. 
EXAMPLES 
General Procedures for Preparing Thermoplastic Compositions 
The polymers to be mixed were charged to a preheated Brabender Plastograph 
laboratory-size mixer equipped with cam-type blades. Mixer speed was 
maintained at about 90 rpm during the mixing procedure. After mixing the 
two polymers together for six minutes, crosslinking agents were added and 
mixing was continued for the times noted in the Examples. The temperature 
of the polymer mixture often rose above the preheat temperature of the 
Plastograph during mixing. The resulting polymer compositions were removed 
from the Plastograph, allowed to cool, and then individually blended for 
about three minutes on a two-roll rubber mill at the temperatures noted. 
The polymer compositions were then remixed in the preheated Plastograph at 
about 90 rpm for the times noted in the Examples. 
______________________________________ 
Polymer Test Methods 
Test specimens were cut from slabs 
Test methods used were: 
______________________________________ 
compression molded at 200.degree. C. 
ASTM D412, die C 
tensile strength at break 
at 8.5 mm/s 
elongation at break at 8.5 mm/s 
ASTM D412, die C 
permanent set 5 min. after break 
ASTM D412, die C 
compression set after 22 hrs/70.degree. C. 
ASTM D395 
method B 
volume swell in ASTM #3 oil 
ASTM D471 
tear strength at 21 mm/s 
ASTM D1938 
______________________________________ 
Stress-strain measurements were run on test specimens approximately 1 mm in 
thickness. Specimens used in the tear-strength test were cut from about 
0.8 mm thick slabs and were 37 by 75 mm rectangles slit lengthwise to 
their center. Specimens for oil-swell tests were cut from 1.9 mm thick 
slabs which were remolded from previously molded slabs in order to 
demonstrate the remoldability of the blends. Compression sets were 
measured using 13 mm diameter discs died out of about 2 mm thick slabs and 
piled up to a thickness of about 13 mm. 
The amounts of toluene-extractable materials in the compositions were 
determined by immersion for 48 hr in 500 ml of toluene at 25.degree. C. of 
1.7 g samples pressed to a thickness of about 0.2 mm. The percent of 
toluene-soluble chlorosulfonated polyethylene in the blends was calculated 
from the initial and final dry-sample weights after correcting for the 
small amount of material (3-4% by wt) extractable by toluene from the 
multi-block copolyester elastomer component of the compositions as 
determined by toluene extraction of nonblended copolyester elastomer. 
Polymers Employed 
Characteristics of five different chlorosulfonated polyethylene elastomers 
used as components in the blend illustrating the invention are listed 
below: 
______________________________________ 
Chloro- 
sulfonated 
Weight % of 
Polyethylene 
Chlo- Sul- Specific 
Mooney Viscosity 
(CSPE) rine fur Gravity 
ML 1 + 4 at 100.degree. C. 
______________________________________ 
CSPE A 29 1.4 1.14 28 
CSPE B 43 1.1 1.27 30 
CSPE C 35 1.0 1.18 56 
CSPE D 36 1.0 1.20 97 
CSPE E 43 1.0 1.26 78 
______________________________________ 
The multi-block copolyester elastomers used as components in the blend 
illustrating the invention are listed below: 
______________________________________ 
Melt Index 
Multi-Block 
Shore D Specific at 190.degree. C., 
Melting 
Copolyesters 
Hardness Gravity g/10 min 
Point, .degree.C. 
______________________________________ 
Copolyester A 
40 1.17 5 168 
Copolyester B 
40 1.18 5 173 
______________________________________ 
Copolyester A is prepared by reacting a mixture of 40.2 parts dimethyl 
terephthalate, 11.7 parts dimethyl isophthalate, 44.9 parts 
poly(tetramethylene oxide) glycol having a number average molecule weight 
of about 1000, and 20 parts of butanediol in the presence of 0.1 part 
tetrabutyl titanate catalyst. The reaction conditions are substantially 
identical to those disclosed in Example 1 of U.S. Pat. No. 3,652,014. 
Copolyester B is prepared by reacting a mixture of 39.4 parts dimethyl 
terephthalate, 11.4 parts dimethyl isophthalate, 42.7 parts of ethylene 
oxide-capped poly(propylene oxide) glycol having a number average 
molecular weight of about 2160 and an ethylene oxide content of 26% by 
weight and 22 parts of butanediol in the presence of 0.2 parts tetrabutyl 
titanate catalyst. The reaction conditions are substantially identical to 
those disclosed in Example 1 of U.S. Pat. No. 3,651,014. 
EXAMPLE 1 
Before blending, the CSPE and the copolyester elastomers were dried for 2 
hours at 120.degree. C. under reduced pressure with a nitrogen atmosphere. 
A series of compositions containing varying amounts of the multi-block 
Copolyester A and Chlorosulfonated polyethylene elastomer C were prepared. 
Conventional crosslinking agents were added during mixing to effect 
crosslinking of the chlorosulfonated polyethylene. 
The compositions were prepared by mixing the polymers together for 6 
minutes in a Brabender Plastograph preheated to 160.degree. C., adding 4 
parts per 100 parts of blended polymers (phr) of calcium oxide and mixing 
for 1 minute, adding 3 parts phr of the crosslinking agent, 
N,N'-meta-phenylenedimaleimide ("HVA-2"), and mixing for 1 minute, adding 
2 parts phr of butyraldehyde-aniline condensation product ("Vanox AT") 
which is an initiator for crosslinking, and mixing for 6 minutes. The 
compositions were then mixed for about 3 minutes on a 2-roll rubber mill 
heated to about 160.degree. C. and finally for an additional 2 minutes in 
the Plastograph preheated to 160.degree. C. 
A second series of blends of Copolyester A and Chlorosulfonated 
polyethylene C were prepared containing the same ratios of the two 
polymers as the first series and made under the same conditions but 
without crosslinking agent and initiator. This second series was prepared 
by mixing the polymers together for 14 minutes in the Brabender 
Plastograph preheated to 160.degree. C. followed by mixing for about 3 
minutes on a hot two-roll rubber mill and then for an additional 2 minutes 
in the Plastograph preheated to 160.degree. C. The total mixing time, 
temperature, and speed were substantially the same for the two series of 
blends. 
The polymer proportions and the properties of the two series of 
compositions are listed in Table I. Those compositions identified as 1C-8C 
were prepared using crosslinking agents and are illustrative of the 
invention. Those blends identified as 1N-8N were prepared without added 
crosslinking agents and are included only for comparison purposes. 
TABLE I 
__________________________________________________________________________ 
Permanent Set at 
Com- % Volume Solubility in Toluene 
of 
Chloro- 
Copoly- Break Elon- 
pression 
Swell Tensile Chloro- 
sulfonated 
ester Tensile 
Percentage of 
gation 
Set ASTM #3 
Strength sulfonated 
Com- 
Poly- Elastomer 
Strength 
Elongation 
At Resist- 
Oil At Break Poly- 
posi- 
ethylene 
A At Break 
at Break Break 
ance 7 days 
At 100.degree. C. 
Composi- 
ethylene 
tion 
(wt %) 
(wt %) 
(MPa) 
(%) (%) (%) 100.degree. C. 
(MPa) tion (wt 
(Wt 
__________________________________________________________________________ 
%) 
1C 20 80 27 30 600 61 32 6.3 5.0 14 
1N 20 80 21 38 905 67 41 3.9 17 71 
2C 30 70 24 29 510 59 35 5.3 5.6 13 
2N 30 70 13 36 700 70 56 3.0 26 77 
3C 40 60 22 26 445 63 42 4.9 5.9 11 
3N 40 60 9.0 36 690 72 fused 1.6 41 98 
4C 50 50 20 21 370 56 47 3.9 5.8 
9.4 
4N 50 50 7.9 38 840 79 fused 1.0 51 99 
5C 60 40 21 16 325 51 51 2.9 6.0 8.8 
5N 60 40 4.6 38 1070 
99+ fused 0.4 63 103 
6C 70 30 14 10 255 37 59 2.1 7.7 11 
6N 70 30 4.0 -- 1560 
100+ 
melted 
0.3 dispersed 
-- 
7C 80 20 13 7.1 225 32 69 2.1 9.1 12 
7N 80 20 2.3 -- 1530 
100+ 
melted 
.about.0 
dispersed 
-- 
8C 90 10 6.0 3.5 200 22 96 1.0 12 14 
8N 90 10 1.6 -- 1450 
100+ 
melted 
.about.0 
dispersed 
-- 
__________________________________________________________________________ 
It can be seen from the results obtained and recorded in Table I above, the 
compositions of this invention excel in tensile strength at break at both 
room temperature and at 100.degree. C., in resistance to compression set, 
and in resistance to oil swell. Both series of compositions were 
remoldable demonstrating their thermoplastic character even though there 
is a substantial amount of crosslinked chlorosulfonated polyethylene 
elastomer in the compositions of the present invention. In the oil swell 
test compositions 3N-8N containing 40% or more of chlorosulfonated 
polyethylene elastomer which had not been crosslinked absorbed so much oil 
that they either softened to the point where the samples fused together or 
at 70% or more chlorosulfonated polyethylene elastomer they melted or 
disintegrated. Toluene extraction of compositions 1C-8C demonstrated that 
more than 65% of the chlorosulfonated polyethylene elastomer component of 
the compositions was not extractable by toluene due to being crosslinked. 
Blends 6N-8N containing 70% or more chlorosulfonated polyethylene 
elastomer which had not been crosslinked disintegrated into small 
particles when immersed in toluene at room temperature for 48 hrs. 
Compositions 1C-8C are lower in permanent set at break on an absolute basis 
and as a percentage of elongation at break than the 35% permanent set at 
break as a percentage of elongation at break value for multi-block 
Copolyester elastomer A. 
EXAMPLE 2 
Before mixing, the polymers were dried for 2 hours at 120.degree. C. under 
reduced pressure with a nitrogen atmosphere. A variety of chlorosulfonated 
polyethylene elastomers, as indicated in Table 2, were mixed with 
multi-block copolyester elastomers in the ratio 60 parts (wt) of 
chlorosulfonated polyethylene to 40 parts (wt) of multi-block copolyester 
elastomer. Compositions 9C-13C contain in addition to two polymers a 
crosslinking system for the chlorosulfonated polyethylene elastomer 
consisting of 2 parts per 100 parts of blended polymers of calcium oxide, 
1.6 parts of the crosslinking agent N,N'-meta-phenylenedimaleimide, and 
0.9 parts of the initiator and antioxidant butyraldehyde-aniline 
condensation product. 
Compositions 9C-12C were prepared by mixing the polymers together for 6 
minutes in a Brabender Plastograph preheated to 160.degree. C., adding the 
calcium oxide and mixing for 1 minute, adding the 
N,N'-meta-phenylenedimaleimide and the butyraldehyde-aniline condensation 
product and mixing for 3 minutes past the time of maximum composition 
viscosity as measured by the torque to the Plastograph rotors. The 
compositions were then mixed for about 3 minutes on a two-roll rubber mill 
heated to about 165.degree.-170.degree. C. and finally for an additional 2 
minutes in the Plastograph preheated to 160.degree. C. Composition 13C was 
prepared in the same manner except the Plastograph and the rubber mill 
were preheated to 170.degree. C. and the crosslinking system consisted of 
2.4 parts of calcium oxide, 2 parts of the crosslinking agent 
N,N'-meta-phenylenedimaleimide, and 1.1 parts of the initiator and 
antioxidant butyraldehyde-aniline condensation product per 100 parts of 
the mixed polymers. Blends 9N-13N were prepared in the same manner as 
blends 1N-8N of Example 1 except for blend 13N the Plastograph was 
preheated to 170.degree. C. and the rubber mill to 150.degree.-170.degree. 
C. Blends 9N-13N contain no crosslinking agents. 
The proportions of polymers and the properties of the two series of 
compositions are listed in Table 2. The compositions identified as 9C-13C 
prepared using added crosslinking agents are illustrative of the 
invention. These compositions excel in tensile strength at break at room 
temperature and at 100.degree. C., in resistance to compression set, and 
in resistance to oil swell. Toluene extraction of compositions 9C-13C 
demonstrated that more than 65% of the chlorosulfonated polyethylene 
elastomer component of the blends was not extractable by toluene due to 
being crosslinked. Those blends identified as 9N-13N are Comparative 
Examples prepared without crosslinking agents. 
In preparing the compositions of the present invention it is important that 
crosslinking of the chlorosulfonated polyethylene elastomer takes place 
while the compositions are subjected to mixing and shearing so that the 
chlorosulfonated polyethylene elastomer component is dispersed in the 
copolyester elastomer component. Alternatively the chlorosulfonated 
polyethylene can be crosslinked, ground into small particles, and then 
mixed with the copolyester elastomer component. The crosslinking agents 
employed in compositions 9C-12C were added to compositions 9N-12N on a 
rubber mill held at room temperature so that crosslinking would not occur. 
Blends 9N-12N with the added crosslinking agents were then compression 
molded for 15 minutes at 160.degree. C. to crosslink the chlorosulfonated 
polyethylene elastomer component of the blends while forming 75 mil slabs 
free of apparent defects. The resulting slabs were cut up and remolded for 
3 minutes at 200.degree. C. They formed 75 mil slabs which contained many 
voids and flaws. Compositions such as those, described hereinabove, in 
which crosslinking of the chlorosulfonated polyethylene elastomer occurred 
in the absence of mixing and shearing are not thermoplastic, as 
demonstrated by their lack of remoldability as evidenced by the many flaws 
in the remolded slabs. Compositions 1C-13C which are illustrative of the 
invention can be remolded into void free slabs thus demonstrating their 
thermoplastic character. 
TABLE 2 
__________________________________________________________________________ 
% Volume 
Swell Tensile 
Chlorosul- Copoly- 
Tensile ASTM #3 
Strength 
Solubility in Toluene of 
Com- 
fonated 
ester Strength 
Elongation 
Compression 
Oil At Break Chlorosulfonated 
posi- 
Polyethylene 
Elastomer 
At Break 
At Break 
Set Resist- 
7 days 
At 100.degree. C. 
Composi- 
Polyethylene 
tion 
(CSPE) A or B 
(MPa) 
(%) ance (%) 
100.degree. C. 
(MPa) tion (wt 
(wt 
__________________________________________________________________________ 
%) 
9C CSPE A A 11 285 42 76 2.8 5.6 7.5 
9N CSPE A A 0.9 200 100+ 301 0.1 60 98 
10C CSPE B A 15 300 58 36 2.0 9.9 15 
10N CSPE B A 11 940 95+ 56 0.6 54 87 
11C CSPE D A 19 415 44 52 2.8 5.6 7.5 
11N CSPE D A 4.3 1300 88 102 0.5 59 96 
12C CSPE E A 14 325 57 36 1.8 11 16 
12N CSPE E A 12 950 96+ 68 0.5 60 98 
13C CSPE C B 18 370 42 51 3.1 8.1 11 
13N CSPE C B 5.5 850 82 134 1.2 61 99 
__________________________________________________________________________ 
EXAMPLE 3 
Before mixing, both polymers were dried for 2 hours at 120.degree. C. under 
reduced pressure with a nitrogen atmosphere. Compositions of a multi-block 
copolyester elastomer (Copolyester A) with Chlorosulfonated polyethylene 
elastomer C were prepared using a variety of different crosslinking 
systems for the chlorosulfonated polyethylene. All of the compositions 
were prepared using a Brabender Plastograph preheated to 160.degree. C. 
and a rubber mill heated to 130.degree.-180.degree. C. Composition 14C was 
prepared by mixing the polymers together in the Plastograph for 6 minutes, 
adding N,N'-meta-phenylenedimaleimide and mixing for 1 minute, adding 
dicumyl peroxide and mixing for 3 minutes past the time of maximum torque 
on the rotors of the Plastograph, followed by about 3 minutes mixing on 
the rubber mill and a final 2 minutes of mixing in the Plastograph. Blend 
14N was mixed for 6 minutes in the Plastograph, about 3 minutes on the 
rubber mill and a final 2 minutes in the Plastograph. Compositions 15C-17C 
were prepared by mixing the polymers together in the Plastograph for 6 
minutes, adding the crosslinking agents and mixing for 3 minutes past the 
time of maximum torque on the rotors of the Plastograph, followed by about 
3 minutes mixing on the rubber mill and a final 2 minutes of mixing in the 
Plastograph. Blend 5N was prepared as described in Example 1. Blends 5N 
and 14N contain no crosslinking agents and are present only for comparison 
purposes. 
TABLE 3 
__________________________________________________________________________ 
14C 14N 15C 16C 17C 6N 
__________________________________________________________________________ 
Composition Components (parts by weight) 
Copolyester A 50 50 40 40 40 40 
Chlorosulfonated Polyethylene C 
50 50 60 60 60 60 
N,N'--meta-phenylenedimaleimide 
1 
40% dicumyl peroxide on calcium 
1 
carbonate ("DiCup" 40C) 
magnesium oxide ("Maglite" D) 
2.9 
fumed litharge 21 
epoxy resin ("Epon" 828) 10 
pentaerythritol (PER 200) 2.1 
1 
dipentamethylene thiuram hexasulfide 
1.4 
0.3 
1.4 
("Tetrone" A) 
2,2'-dibenzothiazyl disulfide (MBTS) 
0.1 
0.3 
Composition Properties 
tensile strength at break (MPa) 
13 9.5 
18 19 13 4.6 
elongation at break (%) 
465 860 465 510 185 1070 
compression set (%) 64 79 62 52 56 99+ 
% volume swell ASTM #3 oil, 
56 120 61 55 57 fused 
7 days/100.degree. C. 
tensile strength at break at 100.degree. C. 
1.9 
0.6 
3.0 
1.7 
2.0 
0.4 
solubility in toluene of 
composition (wt %) 14 51 7.7 
16 5.8 
63 
chlorosulfonated polyethylene (wt %) 
25 98 12 28 9.6 
103 
__________________________________________________________________________ 
It can be seen from the results obtained and recorded in Table 3 above that 
the compositions prepared using crosslinking agents while mixing, 
compositions 14C-17C, excel in tensile strength at break at both room 
temperature and at 100.degree. C., in resistance to compression set, and 
in resistance to oil swell. Compositions 14C-17C are remoldable thus 
demonstrating their thermoplastic character. Toluene extraction of blends 
14C-17C demonstrated that more than 65% (wt) of the chlorosulfonated 
polyethylene elastomer in the compositions is crosslinked and thus not 
extractable by toluene. 
EXAMPLE 4 
Chlorosulfonated polyethylene elastomer C was mixed on a rubber mill at 
about room temperature with curatives in the ratio 100 parts of 
chlorosulfonated polyethylene to 4 parts of calcium hydroxide, 3 parts of 
the crosslinking agent, N,N'-meta-phenylenedimaleimide, and 2 parts of 
butyraldehyde-aniline condensation product. The resulting stock was cured 
for 30 minutes at 160.degree. C. as compression-molded slabs. The 
crosslinked slabs were ground to a powder in a Bantam Micropulverizer at 
low temperatures. The resulting crosslinked and powdered Chlorosulfonated 
polyethylene C was mixed with Copolyester C in the following manner: the 
polymers were mixed for 10 minutes at 160.degree. C. at 90 rpm under 
nitrogen in a small Haake mixer equipped with cam rotor blades, the 
composition was mixed on a rubber mill at about 160.degree. C. for a few 
minutes and then remixed in the Haake mixer for two minutes under the 
original conditions. The polymer proportions and the properties of the 
composition are shown in Table 4. The composition of Table 4 which is 
illustrative of the present invention excels in tensile strength at break 
at room temperature and at 10.degree. C., in resistance to compression 
set, and in resistance to oil swell. 
TABLE 4 
______________________________________ 
Composition Components (parts by weight) 
Copolyester A 40 
crosslinked and powdered 
Chlorosulfonated Polyethylene C 
60 
Composition Properties 
tensile strength at break (MPa) 
15 
elongation at break (%) 515 
compression set (%) 59 
% volume swell ASTM #3 oil, 
59 
7 days/100.degree. C. 
tensile strength at break at 100.degree. C. 
2.2 
solubility in toluene of 
composition (wt %) 11 
chlorosulfonated polyethylene (wt %) 
15 
______________________________________ 
EXAMPLE 5 
Before blending, the polymers were dried for 2 hours at 120.degree. C. 
under reduced pressure with a nitrogen atmosphere. A series of 
compositions were prepared with multi-block Copolyester A and 
Chlorosulfonated polyethylene elastomer C. The compositions contained 
equal amounts of each polymer and varying amounts of filler and oil. The 
filler was carbon black and the oil was Sundex 790 aromatic oil ASTM 
D2226. 
The component proportions and properties of the compositions are listed in 
Table 5. The compositions were prepared by mixing the polymers together 
for 6 minutes in the Plastograph preheated to 160.degree. C., adding 
filler and oil, or nothing, as called for in the composition recipe in 
Table 5, and mixing for 2 minutes, adding calcium oxide and mixing for 1 
minute, add N,N'-meta-phenylenedimaleimide and mixing for 1 minute, adding 
butyraldehyde-aniline condensation product ("Vanox" AT) and mixing for 3 
minutes past the time of maximum torque (maximum torque was attained in 
less than 2 minutes). The compositions were then mixed for about 3 minutes 
on a 2-roll rubber mill heated to about 160.degree. C. and finally for an 
additional 2 minutes in the Plastograph preheated to 160.degree. C. The 
excellent properties of all four compositions listed in Table 5 
demonstrate that the invention can be carried out either in the presence 
or in the absence of filler and oil additives. 
TABLE 5 
______________________________________ 
19C 20C 21C 22C 
______________________________________ 
Composition Components 
Copolyester A 50 50 50 50 
Chlorosulfonated Poly- 
50 50 50 50 
ethylene C 
carbon black ASTM N744 22.5 27.5 
55 
aromatic oil, ASTM D2226, 15 30 
type 102 
calcium oxide 2 2 2 2 
N,N'--meta-phenylenedi- 
1.57 1.5 1.5 1.5 
maleimide 
butyraldehyde-aniline 
1 1 1 1 
condensation product 
Composition Properties 
tensile strength at break (MPa) 
17 21 15 14 
elongation at break (%) 
380 310 340 230 
compression set (%) 
54 53 52 40 
tensile strength at break 
2.5 3.9 2.2 2.5 
at 100.degree. C. 
tear strength, pli 
4.9 8.2 11 7.2 
______________________________________