CA1098239A - Compositions containing hydrogenated block copolymers and engineering thermoplastic resins - Google Patents

Abstract

A B S T R A C T

In a composition containing a partially hydrogenated block copolymer, a polyurethane and at least one dissimilar engineering thermoplastic resin at least two of the polymers form at least partial continuous interlocked networks with each other.

Description

The invent:ion relates to a cornposition containing a partially hydrogenated block copolymer comprising at least two terminal polymer blocks A Or a monoalkenyl arene having an avera~e molecular weight of f'rom 5,000 to 125,000 and at least one lnterrnediate polymer block B of a conjugated' diene having an average molecular weight of from 10,000 to 3005000, in which the terminal polymer blocks A const1tute ~rom 8 to 55~ by weight Or the blocl: copolymer and no more than 25% Or the arene double bonds Or the polymer blocks and at least 80% of the aliphatic double bonds Or the polymer blocks B have been reduced by hydrogenation.
Engineering thermoplastic resins are a group of polymers that possess a balance of properties comprising strength, stiffness, impact resistance~ and long term dimensional stability that make them useful as structural materials.
Engineering thermoplastic resins are especially attractive as replacements for metals because of the reduction in weight that can often be achieved as, f'or example, in automotive applications.
For a particular application~ a single thermoplastic resin may not offer the combination of prope~ties desired and, therefore, means to correct this deficiency are of interest. One particularly appealing route is through blending together two or more polymers (which individually have the properties sought) to give a material with the desired combination of properties. This approach has been :

3~1 successful in limited cases~ SllCh as in the :improveTnent of impact resistance for thermoplastic resins, e.g., polystyrene, polypropylene and poly(vinyl chloride), using special blending procedures or additives for this purpose. However, in general, blending of thermoplastic resins has not been a successrul route to enable one to combine into a single material the desirable individual characteristics Or two or more polymers. Instead, It h;ls often been found that such blending results ln combinir-g the worst features of each with the result being a material Or such poor properties as not to be of any ;~ practical or commercial value. The reasons for this failure are rather well understood and stem in part fr~m the fact that thermodynamics teaches that most combinations Or polymer pairs are not misc1ble, although a number of notable exceptions are known. More importan-tly, most polymers adhere poorly to one another. As a result, the , :
interraces between component domains (a result of their mmisclbility~ represent areas Or severe weakness in blends ~and, therefore, provide natural flaws and cracks wh1ch reæult in facile mechanical failure. Bècause Or this, most polymer pairs are said to be "incompatible". In some instances the term compatlbility is used synonymously ~ `
with miscibility, however, cumpatlbility is used here in a more general way that describes the ability to combine two polymers togrther for beneficial results and may or may not connote miscibility.

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One method which may be used to circumvent this problern in polymer blends is to "compatibilize" the two polymers by blending in a third component, orten referred to as a "compatibili~ing agent", that possesses a du~L
solubility nature for the two polymers to be blended.
Examples of this third component are obtained in b]ock or graft copolymers. As a result Or this characteristic, this agent locates at the interface between components ~ and greatly improves interphase adhesion and thererore increases stability to gross phase separation.
The invention covers a means to stabilize multi-polymer blends that is independent of the prior art ~; compatibilizing process and is not restricted to the necessity for restrictive dual solubility characteristics.
The materials used for this purpose are special block co polymers capable Or thermally reversible self-cross-linkingO
Their action in the present invention is not that visualized by the usual compatibilizing concept as evidenced by the general ability of these materials to perrorm similarly for a wide range Or blend components which do not conform to the solubility requirements of the previous concept.
Now7 the inventlon provides a composition containing a partially hydrogenated block copolymer comprising at least two terrninal polymer blocks A Or a monoalkenyl arene ~5 having an average molecular weight Or from 5,000 to 125~000, and at least one intermediate polymer block B Or a con-3~

jugated diene having an average molecular weight of from 107000 to 300,000, in which the terminal polymer blocks A constitute from 8 to 55% by weight of the block copolymer and no more than 25% of the a~ene double bonds of the polymer blocks A and at least 80% of the aliphatic double bonds of the polymer blocks B have been reduced by hydrogenation, which composition is characterized in that the composition comprises:
(a) ~ to 40 parts by weight of the partially hydrogenated block copolymer;
(b) a thermoplastlc polyurethane having a generally crystalline structure and a melting point over 120C;
(c) 5 to 48 parts by weight of at least one dissimilar engineering thermoplastic resin being selected from the group consisting of polyamides, polyolefins, thermoplastic polyesters, poly(aryl ethers), poly(aryl sulphones), polycarbonates, acetal resins, halogenated thermoplastics, and nitrile resins, in which the weight ratio of the thermoplastic polyurethane to the dissimilar engineering thermoplastic resin is greater than l:l so as to form a polyblend wherein at least two of the polymers form at least partial continuous mter- .
locked networks with each other. :~
In another aspect, the invention provides a process for the preparation of a composition as defined above, charac~erized in that (a) 4 to 40 parts by weight of a partially hydrogenated block copolymer comprising at leas~ two terminal polymer blocks A of a monoalkenyl arene having an average molecular weight of from 5,000 to 125,000, and at least one intermediate polymer block B of a conjugated diene having an average mole~
cular weight of from 10,000 to 300,000, in which ~he terminal polymer blocks :~.
A constitute from 8 to 55% by weight of the block copolymer and no more than 25% of the arene double bonds of the polymer blocXs A and at least 80% of the aliphatic double bonds o~ the polymer blocks B have been reduced by hydrogenation, are mixed at a processing temperature Tp of between 150C and 400 C with ~ r (b) a thermoplastic polyurethane having a generally crystalline structure and a melting point of over 120C, and 3~9 (c) 5 to ~8 parts by weight of at least one dissimilar engineering thermoplastic resin being selected from the group consisting of polyamides, polyolefins, thermoplastic polyesters, poly(aryl ethers), poly(aryl sulphones), polycarbonates, acetal resins, halogenated thermoplastics and nitrile resins, in which the weight ratio of the thermoplastic polyurethane to the dissimilar engineering thermoplastic resin is greater than 1:1 so as to form a polyblend wherein at least two of the polymers form at least partial continuous inter-locked networks with each other.
The block copolymer of the invention effectively acts as a mechanical or structural stabilizer which interlocks - 5a -the various polymer structure ne~works and prevents the consequent separation O.r the polymers during processing and their subsequent use. As defined more ~ully herein-after, the resulting structure Or the polyblend (short ~5 for "polymer blend") is that Or at least two partial continuous interlocking networks. q'his interlocked structure results in a dimensionally stable polyblend that will not delaminate upon extrusion and subsequent use.
To produce stable blends it is necessary that at ~ -least two of the polymers have at least partial con~inuous networks whlch lnterlock with each other. Preferably, the block copolymer and at least one other polymer have partial ~ ~ continuous interlocking networlc structures. In an ideal ;~ 15~ situation all of the polymers would have complete con-::: .: :
~ tinuous networks which interlock with each other. A ~
, partial continuous network means that a portion Or the ; polymer has a continuous network phase structure while , ~ ~ the other portion has a disp'erse phase structure. Prefer-! ~ 20 ` ~ ably, a major proportion (greater than 50% by weight) of the partial continuous network is continuous. As can be readily seen, a large variety o~ blend structures is possible since the structure Or the polymer in the blend may be completely continuous, completely disperse, or partially continuous and partially disperse. Further yet, the disperse phase of' one polymer may be dispersed in a -7~

second polymer and not ;n a third polymer. To illustrate some of the structures, the following lists the various combinations of polymer structures possible where all structures are complete as opposed to partial structures.
Three polymers (A, B and C) are i.nvolved. The subscript "c" signifies a continuous structure while the subscript "d" signifies a disperse structure. Thus, the desi.gnation ''AcB'' means that polymer A is continuous with polymer B, and the designation "BdC" means that polymer B is disperse 10 ~ ln polymer C, etc.
AcB AcC BcC
AdB AcC BcC
AcB AcC BdC
BdA Ac~ BcC
15~ BdC AcB AcC
CdA AcB AcC
C B AcB AcC
Through practice of the invention, it is possible to ~ \
\

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~-7a~

improve one type of physical property of the composite blend while not causing a signif'icant deterioration in another physical property. In the past this has not always been possible. F'or example, in the past it was expected that by adding an amorphous rubber such as an ethylene-propylene rubber to a thermoplastic polymer to improve impact strength, one would necessarily obtain a composite blend having a signif'ican-tly reduced heat distortion temperature (HDT). This results f'rom the fact that the amorphous rubber forms discrete particles in the composite and the rubber, almost by definition, has an exceedingly low HDT, around room temperature.
However, in the present invention it is possible in some cases to significantly improve impact strength while not detracting from the heat distortion temper- ~
ature. In fact,when the relative increase in Izod impact -strength is measured against the relative decrease in ~ ' HDT, the value o~ the ratio is of'ten much higher than one would expect. For example, in blends containing a thermoplastic polyurethane, block copolymer, and other engineering thermoplastics such as polycarbonates, this ratio is about 3, whereas one would typically expect positive values of less than 1.
_ .
.

It is partlcularly fiurprising that even just small amounts Or the block copolymer are sufricient to stabilize the structure of the polymer blend over very wide relative concentrations. For example, as little as four parts by 5 weight of the block copolymer is sufficlent to stabilize a blend of 5 to 90 parts by weightpolyureth~ewith 90 to 5 parts by weight of a dissim.ilar engineering thermoplastic.
In addition, it is also surprising that the block co-polymers are useful in stabilizlng polymers of such a wide variety and chemical make-up. As exp.lained more fully hereinafter9 the block copolymers have this ability to ~
stabilize a wide variety of polymer over a wide range of concentrations since they are oxidat:ively stable, possess essentially an infinite viscosity at zero shear stress, and retain network or domain structure in the melt.
Another significant aspect of the invention is that : ~ the ease of processing and foY-mi.ng the various polyblends is greatly improved by employing the block copolymers as stabilizers.
~:~ 20 The block copolymers employed in the compo.sition according to the invention may have a variety of geometrical structure, since the invention doe~ not depend on any specific geometrical structure, but rather upon the chemical constitution of each of the polymer blocks. Thus~
the block copolymers may be linear~ radial or branched.
Methods for the preparation of such polymers are known in the art. The structure of the polymers :is de-termined by ; their methods of polymerization. For example, linear polymers result by sequential introduction Or the desired monomers into the reaction vessel when using such initiators as lithium-alkyls or dilithio-stilbene~
~ or by coupling a two-segment block copolymer with a ~i~
- di.functional coupling agent. Branched structures,on the other hand, may be obtained by the use of suitable coupling agents having a runct:ionality with respect to ~
the precursor polymers Or three or more. Coupling may be ~ -effected with rnultifunctional coupling agents, such as dlhaloalkanes or -alkenes and divinyl benzene as well as certain polar compounds, such as sil.icon halides, siloxane, or esters Or monohydric alcohols with carboxylic acids.
The presence 0r any coupling residues in the polymer may be ignored for an adequate description of the polymers forming a part of the compositions of this invent:ion.
.
~ Likewise, in the generic sense, the specific structures : . , .
also may be ignored. The invention applies especially 20 ~ to the use of selectively hydrogenated polymers having the configuration before hydrogenation of the following typical species:
polystyrene~polybutadi.ene-polystyrene (SBS) polystyrene-polyisoprene-po].ystyrene (SIS) poly(alpha methylstyrene)polybutadiene-poly(alpha-methylstyrene) and poly(alpha-methylstyrene)poly;.soprene-poly(alpha-methylstyrene~.
Both polymer blocks A and B may be either homopolymer or random copolymer ~locks as long as each polymer block predomlnates in at least one class of the monomers charac-: :~ terizing the polymer blocks. The polymer block A may ; comprise homopolymers of' a monoalkenyl arene and co-polymers of a monoalkenyl arene with a conjugate~d diene as long as the polymer blocks A indi.vidual:ly predornirlate ~10 in monoalkenyl arene units. The term "monoalkenyl arene"
; w.ill be taken to include especially styrene and its ~: : analogues and homologues including alpha-methylstyrene and .ring-substituted styrenes, particularly ring-methyl-ated styrenes. The preferred monoalkenyl arenes are styrene and alpha-methylstyrene, and styrene is particularly preferred. The polymer blocks B may comprise -~
; : homopolymers Or a conjugated diene~ such as butadiene or isoprene~ and copolymers of a conjugated diene wîth a ~, ;, , :
monoalkenyl arene as long as~the polymer blocks B pre- :
~20 ~ dominate in conjugated diene units. When the monomer employed is butadiene~ i.t is preferred that between 35 and 55 mol. per cent of the condensed butadiene units in the butadiene polymer block have 1,2-configuration. Thus, when such a block is hydrogenated, the resulting product is, or resembles~ a regular copolymer block of ethylene and butene-1 (~B). If the conjugated diene employed is --ll--isoprene, the resulting hydrogenated product ls or : :
resembles a regular copolymer block o~` ethylene and propylene (EP).
Hydrogenation of the precursor block copolymers is preferably effected by use of a catalyst comprising the ~ :
reaction products of an aluminium alkY.l compound with nickel or cobalt carboxylates or alkoxides under such conditions as t,o substantially completely hydrogenate ~ :
: at least 80% Or the aliphati.c double bonds, while hydrogenating no more -than 25% of the alkenyl arene aromatic double bonds. Prererred block copolymers are those where at least 99% of the allphatic double bonds are hydrogenated while less than 5% of the aromatic double;bonds are hydrogenated.
15~ ~ The average molecular weights of the individual ~.
blocks may vary within certaln limits. The block co poly~er present in the composition according to the :~
invention has at least two terminal polymer blocks A of ~. ~ . ,:
a monoalkenyl arene having a~:number average molecular ~:20: :~ weight of from 5,000 to 125,000, preferably from 7,00:0 ~ to 60,000, and at least one intermediate polymer block B
~ . of~a conjugated diene having a number average molecular~
weight of from 10000 to 300,000, preferably from 30,000 to 150~000. These molecular weights are mo,st accurately determined by tritium counting methods or osmotic pressure measurements.

-12 ~ 2~

The proportion o.f the polymer blocks A of the mono-alkenyl arene should be between 8 and 55~0 by weight of the block copolymer, preferably between 10 and 30% by weight.
Polyurethanes, otherwise known as isocyanate resins, are employed in the composition according to the invention as long as they are thermoplastic as opposed to thermo setting. For example, polyurethanesformed from toluene di-isocyanate (TDI) or diphenyl methane 4,4-di-isocyanate (MDI) and a wide range of po]yols, such as, polyoxyethylene glycol, polyoxypropylene glycol, hydroxy-terminated poly- ~.
esters, polyoxyethylene-oxypropylene glycols are sultable.
These thermoplastic polyurethanes are available under D~ ~ ~~
the trade r~ame Q-THANE'Y and under the trade ~a~e PELLETHANE ~
CPR. ~ - .
:
: The term "dissimilar engineeri.ng thermoplastic resin" ~.
refers to engineering thermoplastic resins different from ~;
those encompassed by the polyurethanes present in the com~
~ ..
positions according to the invention.
~::20 ~ The term ~engineering thermoplastic resin" encompasses the various polymers found in the classes listed in Table A
below and thereafter define.d in the specification.
TABLE A
1. Polyolefins : 25 2. Thermoplastic polyesters . Poly(aryl ethers) and poly(aryl sulphones) `:~

-13~ 2 ~
~ ., 4. Polycarbonates 5~ Acetal resins 6. Polyarnides 7. Halogenated thermoplastics ~ -8. Nitrile resins Preferably these engineering thermoplastic resins have glass transition temperatures or apparent crystalline melting points (defined as that temperature at which the modulus, at low stress, shows a catastrophic drop) of over 120C, preferably between 150C and 350C, and are capable of forming a continuous network structure through a thermally reversible cross-linking mechanism.
Such thermally reversible cross-linking mechanisms in~
~ ; clude crystallites, polar aggregations, ionic aggregations, `~ 15;~ lamellae, or hydrogen bonding. In a specific embodiment~
where the viscosity of the block copolymer or blended;
block copolymer composition at processing temperature Tp and a~sh~r rate of 100 s 1 i.s n, the ratio of the~
ity of the engineering thermoplastic resins, or 20 ~ blend of engineering thermoplastic resin with viscosity modifiers to n may be~between 0.2 and 4.0, preferably~O.8 and 1.2. As~used in the specification and claims, the visoosity 0f the block copolymer, polyurethane and the thermoplastic engineering resin is the "melt viscosity"
obtained by employing a piston-driven caplllary melt ~
rheometer at constant shear rate and at some consistent : :: : :
,:

- 1 L~ %3~

temperature above melting, say 260 C. The upper limit (350C) on apparent crystalline melting point or glass transition temperature is set so that the resin may be processed in low to medium shear rate equipment at com-mercial temperature levels of 350C or less.
The engineering thermoplastic resin includes also blends of various engineering thermoplastic resins and blends with additional viscosity modifying resins.
These various classes of engineering thermoplastics are defined below.
The polyolefins, if present in the compositions ac-cording to the invention are crystalline or crystallizabIe.
They may be homopolymers or copolymers and may be derived from an alpha-olefin or 1-olefin having 2 to 5 carbon 15~ atoms. Examples of particular useful polyolefins include low density polyethylene, high-density polyethylene, iso-tactic polypropylene, poly(1-butene), poly(4-methyl-1-pentene), and copolymers of 4-methyl-1-pentene with ` ~ linear or branched alpha-olefins. A crystalline or crystallizable structure is important in order for the polymer to be capable of forming a continuous structure with the other polymers in the polymer blend according to the invention. The number average molecular weight o~
the polyolefins may be above 10,000, preferably above 5' In addition, the apparent crystalline melting point may be above 100C, preferably between 100C and ~ 3 ~ .
' 250C, and more preferably between 140C and 250C.
The preparation of these various polyolefins are well :
known. See generally "Olefin Polymers", Volume 14, Kirk-Othmer Encyclopedia of Chemical Technology, ; 5 pages 217-335 (1967).
When a high-density polyethylene is employed, it has an approximate crystallinity of over 75% and a density in , ,:
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:,, ~ ~ \ : ~ :

: , ~ : : , ~ ~, ~ .

~ 2 ~16-kilograms per litre (kg/l) o~ between 0.94 and 1.0 while ; when a low density polyethylene is employed, it has an approximate crystallinity of over 35% and a density Or between 0.90 kg/l and 0.94 kg/l. The composition ac-5 cording to the invention may contaln a polyethylene hav;~ng a number average molecular weight o~ 50,000 to 5009000.
When a polypropylene is employed~ it is the so-called isotactic polypropylene as opposed to atactic polypropylene. The number average molecular weight Or the ~10 polypropylene er(lployed ~y ~ ~n excess o~ 100,000. r~ e r~oly~
propylene may be prepared using methods Or the prior ; art. Depending on the speciflc catalyst and polymer~
izat~ion conditions employed, the polymer produced may ~ -~; contain atactic as well as isotactic~ syndiotactic or ~ ~
::
so-called stereo-block molecules. These may be separated by selective solvent extraction to yield products of :
low atactic content that crystallize more completely. `
The preferred commercial polypropylenes are generally ;~; prepared us~ing a solid~ crystalline, hydrocarbon-in~
Z0~ soluble catalyst made from a titanium trichloride com- ~ ~n position and an aluminium alkyl compound, e.g., tri~
ethyl aluminium or diethyl aluminium chloride. If desired, the polypropylene employed is a copolymer ~ containing minor ~1 to 20 per cent by weight) amounts Or ethylene or another alpha~olefin as comonomer.

The poly(1-butene) preferably has an lsotactic structure.
The catalysts used in preparing the poly(1-butene) are preferably organo-metallic compounds commonly rererred to as Ziegler-Natta catalysts. A typical catalyst is the interacted product resulting from mixing equimolar quan-tities of titanium tetrachloride and triethylaluminium.
The manufacturing process is normally carried out in an inert diluent such as hexane. Manufacturing operations, in all phases of polymer formation, are conducted in such a manner as to ~uarantee rigorous exclusion of water even in trace amounts.

.i . . .
One very suitable po1yolefin is poly(4-methyl-1-penterle).
Poly(4-methyl-1-pentene? has an apparent crystalline melt-ing point of between 240 and 250C and a relative density of between 0.80 and 0.85. Monomeric 4-methyl-1-pentene is commerc;ally manufactured by the alkali~metal catalyzed dimerization o~ propylene. The homopolymerization o~
4-methyl-1-pentene with Ziegler-Natta catalysts is ~escribed in the Kirk-Othmer Enclopedi~a of Chemical Technology, Supplement volume, pages 789-792 (second edition, 1971~.
However, the isotactic homopolymer Or 4-methyl-1-perltene has certain technical defects, such as brittleness and inadequate transparency. Therefore, commercially available poly(4-methy].-1-perlterle) is actually a copolymer with minor proportions of other alpha-olefins, together with the addition of suitable oxidation and melt stabilizer -18- ~ 2 3 systems. These copolymers are described in the Kirk~
Othmer Encyclopedia of Chemical Technology, Supplement volume, pages 792 907 (second edition, 1971), and are available under the trade namo TPX ~ resin. Typical alpha-olefins are l;near alpha-olefins having from 4 to 18 carbon atoms. Suitable resins are copolymers of 4-methyl-1-pentene with from 0.5 to 30% by weight of a linear alpha-olefin.
If desired, the polyolefin is a mixture of various polyolefins. However, the much preferred polyolefin is isotactic polypropylene.
The thermoplastic polyesters, if present in the com~
positions according to the invention, have a generally crystalline structure, a melting point over 120C, and 15 ~ ~ are thermoplastic as opposed to thermosetting. `~
~: ~ :
\` ~: .

' ~ : .

Q ~ 3~

One partlcularly user`ul. group Or po:Lyesters are tho (~
therrnoplastic polyesters prepared by condensing a di-carboxylic acid or the :I.ower a:lkyl ester, acid hali.de, or anhydride derivati.ves thereof with a glycol, accordi.ng to methods well known in the art.
Among the aromatic and aliphatic dicarboxylic ac.lds suitable .for preparing polyesters are oxal.ic acid, malonic acid, succinic acid~ glutaric a.cid, adipi.c acidj suberic acid, azelaic acid, sebacic ac:id, terephthalic acid, iso-phthalic acid, p-carboxyphenoacetic aci.d, p,p'~icarboxydi.phenyl, p,p'-dicarboxydiphenyl~ulE~lone, p-cal~boxyph~-~noxyac(:,~tic Cl(~ i.ti~
p-carboxyphenoxypropionic acid, p-carboxyphenoxybutyri.c acid~
p-carboxyphenoxyvaleric acid, p-carboxyphenoxyhexanoic acid, p,p'-dicarboxydiphenylmethane, p,p-di.carboxydiphenylpropane, p~p'-dicarboxydiphenyloctane, 3-alkyl.-4-(~-carboxyethoxy)-:~ benzoic acid~ 2,6-naphthalene dicarboxylic acid, and 2,7-naphthalene dicarboxylic acid. Mixtures of dlcarboxylic acids can also be employed. Terephthalic acid is particularly preferred. ~ .
The glycol~ suitable ror preparing the polyesters include straight-chain alkylene gIycols of 2 to 12 carbon atoms~ such as ethylene glycol, 1~3-propylene glycol, 1,6-hexylene glycol~ 1,10-decamethylene glycol, and 1,12-dodecarnethylene glycol.. Aromatic glycols can be substitu~ed in whole or in part. Suitable aromatic dihydroxy compounds include p-xylylene glycol1 pyrocatechol, resorcinol, 3~) hydroquinone, or alkyl-substituted derivatives of these compounds. Another suitable glycol is 1,4-cyclohexane dimethanol. Much preferred glycols are ~e straight-chain - -alkylene glycols having 2 to 4 carbon atoms.
A prererred group of polyesters are poly(ethylene terephthalate), poly(propylene terephthalate), and poly-(butylene terephthalate). A much preferred polyester is poly(butylene terephthalate). Poly(buty]ene terephthalate), ~ a crystalline copo]ymer, may be fornled by the polycondensati()n of 1,4~butanediol and dimethyl terephthalatc or terepht;ha]:ic ~-~
acid, and has the generalized Iormula:

o~l~o~

n where n varies from 70 to 140. The average molecular wei~ht of the poly(butylene terephthalate) preferably varies ~rom 20~000 to 25,000.
Commercially avallable poly(butylene terephthalate) ls available under the trade ~=e VALOX ~ thermoplastic polyester. Other commercial polymers include CELANEX ~, TENITE ~ and VITIJFF ~ .
Other useful polyes~ers include the cellulosic esters.
The thermoplastic cellulosic esters employed herein are widely used as mouldirlg, coating and film-rorming materia:Ls ~

~38;~

and are well known. These materials include the solid thermoplastic rorms Or cellulose nitrate, cellulose acetate (e.g., cellulose diacetate, celluLose tri-acetate), cellulose butyrate, cellulose acetate butyrate, ~ -cellulose propionate, cellu]ose tridecanoate, carboxy-methyl cellulose, ethyl cellulose, hydroxyethyl cellulose and acetylated hydroxyethyl cellulose as described on pages 25-28 of Modern Plastics Encyclopedia, 1971-72, and references liste~ therein.
10Another useful polyester is a polypivalolactone. Poly-pivalolactone is a linear polymer having recurring ester structural units mainly of the formula:
; CH2 C(CH3)2 ~ C(O)O
~ ~ i.e., units derived rrom pivalolactone. Preferably, the poly-, ~15 ester is a pivalolactone homopolymer. Also included, however, are the copolymers of pivalolactone with no more tharl 50 Illol.%, preferably not ~ore than 10 mol.% of another beta-propio-lactone, such as beta-propiolactone, alpha,alpha-diethyl-beta-propiolactone and alpha-methyl-alpha-ethyl-beta-propio-lactone. The term "heta-propiolactones" rerers to beta-propiolactone (2-oxetanone) and to derivatives thereof which carry no substituents at the beta-carbon atom of the lactone ring. Prererred beta-propiolactones are those containing a tertiary or quaternary carbon atom in the alpha-position relative to the carbonyl group. Especially preferred are the alpha,alpha dialkyl-beta-propiolactones wherein each Or the alkyl groups independently has from one to four carbon atoms.

-2~

Examples Or useful monomers are:
alpha-ethy1-alpha-methyl-beta-propiolactone, alpha-methyl-alpha-isopropyl-beta-propiolactone, alpha-ethyl-alpha-n-butyl-beta-propiolactorle, : :
al.pha-chloromethyl-alpha-methyl-beta-propiolactone, alpha,alpha-bis(chloromethyl)-beta-propiolactone, and alpha,alpha-dimethyl-beta-propiolactone (pivalolactone). :~
These polypivalolactones have an average molecular welght in excess of 20,000 and a melting point ln excess of 120C.
;lO Another userul polyester is a polycaprolactone.
~ Preferred poly(~-caprolactones) are substantially linear ~ polymers in which the repeating unit is:
~_ O
t - -C~i2- -C~l2 CH2 C.~l2 C}2 ~ , ~ - _ ~ These polymers have similar properties to the polyplvalo-lactones and may be prepared by a similar polymerization ; mechanism.
Various polyaryl polyethers are also useful as engineer~
ing thermoplastic resins. The poly(aryl polyethers) which may be present in the composition according to the invention include the linear thermoplastic polymers composed of re-curring units having the formula:

-(O - G -0 - G'~

wherein Gisthe residuum of a dihydric phenol selected from :~
the group consisting of:

3~

.,' .
and ' wherein R represents a bond between aromatic carbon atoms, :~ - O - , - S - ~ - S -S-,or a divalent hydrc~carbon radical having ~rom 1 to i8 carbon atoms inc~lusive, and G' is the 5~ residuum of a dibromo or di-iodobenzenoid compound selected ~rom the group consisting O r:

IV

and 93 V ~ ~ ~

wherein R' represents a bond between aromatic carbon atoms, O - , - S- -g - S - S - ,or a divalent hydrocarbon ~lO radical having from 1 to 18 carbon atoms inclusive, with the provisions that when R i5 - O - , R' iS other than O - ; when R' is O - ~ R is other than O --;
when G is II~ G' is V, and when G' is IV, a is III.

`~

23~

-2~-Polyarylene polyethers of' this type exhibit excellent physic.ll properties as well as excellent therrnal ox:idative and chemical stabillty. Cornmercial poly(ary:l polyethers) are L~ available under the trade *~me ARYLON T ~ Polyary] ethers, having a melt temperature Or between 280C and ~10C.
Another group Or userul engineering thermoplastic resins include aromatic poly(sulphones) comprising re-peating units of the rormula:

n which Ar is a bivalent aromatic radical and may vary from unit to unit in the polymer chai.n (so as to rorm co-polymers Or various kinds). Thermoplastic poly(sulphones) generally have at least some units Or the structure:

~z~9 ~ :

~: 2 in which Z i5 oxygen or sulphur or the residue of an aromatic diol, such as a 4,4'-bisphenol. One example Or such a poly(sulphone) has repeating units Or the formula:
~,3 o <~s02~

~9~323~

: -25-.
another has repeatlng units Or the formula:

~ ~ S ~ 2 - -and others have repeating units of the formula: -~ ~3 C3cl,3~
or copolymerized units in vario~s proportions of the~
formula:
: .
~ S2 : : 5 ~ and ~ ~ 52--The thermoplastic poly(sulphpnes) may also have repeating :
units having the formula: ~
~3 ~3 .
Poly(ether sulphones) having repeating units Or the following structure:

' 3239 ~

o~ So2~-and poly(ether sulpholles) having repeatirl~ units Or the following ~tructure:
_ `2~ C-3 ~ ~_ _ - _ Cli3 . n : are also use~ul as engineering thermoplastic resins.

- The polycarbonates which may be preserlt in the com-~5 positions acGording to the invention are of the general formulae~
~: O ;

Ar-- A--Ar-- O-- C-- 0~
~: ; n ~ :
and - ::
. ~ .
Ar- O- C - 03 n wherein Ar represents a phenylene or an alkyl, alkoxy, halogen or nitro-substituted phenylene group; A represents~
a carbon-to-carbon bond or an alkylidene~ cycloalkylldene, alkylene, cycloalkylene, azo~ :imino, sulphur, oxy~en, sulphoxide or sulphone ~roup, and n is at least two.

%3~

The preparation of the polycarbonate~; is well known.
A preferred method Or preparatiorl is ba~ed on the reaction carried out by dir3solving the dihydroxy cornponent in a base, such as pyridine and bubbling phosgene into the stirred solution at the desired rate. Tertlary amines may be used to catalyze the reaction as well as to act as acid acceptors throughout the reaction. Since the reaction is normally exothermic, the rate of phosgene addition can be used to control the reaction tcmperature. The reactions generally utilize equlmolar amounts o~ pho~gerle and di~
hydroxy reactants, however, the molar ra~io~; can be varied dependent upon the reaction condltions.
In the farmulae I and II mentioned, Ar and A are, preferably, p-phenylene and isopropylidene, respectively.
~15 This polycarbonate ls prepared by reacting para~para'-lsb~
propylidenediphenol with phosgene and is sold under the trade mark LEXAN ~ and under the trade mark M~RLON Q
This commercial polycarbonate has a molecular weight Or ~ around 18,0QO, and a melt temperature of over 230C.
j~ 20 ~ ~Other polycarbonates may be prepared by reacting other dihydroxy compounds, or mixtures of dihydroxy compounds,`
with phosgene. The dihydroxy compounds may include aliphatic dihydroxy compounds although ~`or best high temperature properties aromatic rings are essential. The dihydroxy compounds may include within the structure diurethane linkages. Also, part Or the structure may be replaced by siloxane linkage.

3~3 -2~
-The acetal resins wh;ch may be present in the com-positions according to th~ invention include the high molecular weight polyaceta] homopolymers made by polymer-izing formaldehyde or trioxane. These po~yacetal homo-~ o,~5 polymers are conlmercia1ly availab:Le under the trade r~e DELRIN ~. A related polyether-type resin is available under the trade ~a~ PENTON V and has the structure:

CH2Cl i ~ _ _o - CH2----C--C112 _ , ~ ' C~12Cl ` n , The acetal resin prepared from formaldehyde has a high molecular weight and a structure typlfied by the fol:lowin~:
, .

H O ~ 2----C~12--O) H--,: x lO ~ where terminal groups are derived from controlled amounts Or water and the x denotes a large (preferably 1500) number of ~ormaldehyde units linked in head to-tail fashion. To in-crease khermal and chemical resistance~ terminal groups - are typically converted to esters or ethers.
Also included in the term polyacetal resins are the polyacetal copolyrners. These copolymers include block co-polymers of formaldehyde with rnonomers or prepolymers of other rnaterials capable of providing active hydrogens, ~8;23~

such as al~ylene glycol. , polyth:i.c)]s, v;nyl acetate-acrylic acid copolymers 3 or reduced ~utadi.ene/acry~.c)nitri1e polyTners .
Celanese has commcrcially available a copo].ymer o~
~ormaldehyde and cthylenc oxidc und~r the tradc name CL.L,~ON~
that is userul i.n thc ~lcnds o~ th( prcsent i.r~vent.i.c)n. 'I'llæse copolymérs typically have a structure comprising recurrin~r ; units having the formula:

wherein each R1 and T~2 ls selected rrom thc ~;roup consist;.nlr IO Of hydrogen~ lower alkyl and lower halogen substituted .; ` alkyl radicals and whereirl n is an inte~c-~r 1`rorn zero to three and whereln n is zero in ~rom 85% to 99.9% Or the rccurr-;ng -units.
Formaldehyde and trioxane can be copolymerized with 15i other aldehydes, cyclic ethers, vinyl compounds, ketcneæ, cyclic carbonates, epoxides, isocyanates and ethers. These compounds include ethylene oxideg 1,3-dioxolane, 1,3-dioxane, 1,3~dioxepene, epichlorohydrin, propylene oxide, isobutylene oxide, and styrene oxide.

- ~30~ ~ 3~

By polyamide is meant a condensation prod~ct which contains recurring aromatic and/or aliphatic amide groups as integral parts of the main polymer chain3 such products being known generically as "nylons". A polyamide may be ob-tained by polymerizing a mono-aminomonocarboxylic acid or an internal lactam thereof having at least two carbon atoms between the amino and carboxylic acid groups; or by polymerizing substantially equimolar proportions of a diamine which contains at least two carbon atoms between ~ the amino groups and a dicarboxylic acid; or by polymer-izing a mono-aminocarboxylic acid or an internal lactam thereof as defined above together wlth substantially equi-molar proportions of a diamine and a dicarboxylic acid.
~ he dicarboxylic acid may be used in the form of a ; 15~ functional derivative thereof, for example an ester.
The term "substantially equimolecular proportions"~
; (of the diamine and of the dicarboxylic acid) is used to cover both strict equimolecular proportions and the slight depart ~ therefrom which are involved in conventional .

' ~ , : ., ~

' ~ . .

techniques for stabilizing the viscoslty Or the resultant polyamides.
As examples Or the said mono-aminomonocarboxylic acids or lactams thereor there may be mentioned those compounds 5 containing from 2 to 16 carbon atoms between the amino and carboxylic acid groups, said carbon atoms forming a ring with the - CO.NH group in the case Or a lactam. As particular examples Or aminocarboxylic acids and lactarns there may be mentloned ~-aminocaproic acid, butyrolactam, lO~ pivalolactam, caprolactam~ capryl-lactam, enan-tholactam, undecanolactam, dodecanolactam and 3 and 4-amino benzoic acids.
Examples Or the said diamines are diamines o~ the general rormula }I2N(CH2)nNH2~ wherein n is an integer Or 15~ from 2 to 16, such as trimethylenediamine, tetramethylene-diamine, pentamethylenediamine, octamethylenediamine~
decamethylerIediamine~ dodecarnethylenediamine, hexadeca-~ ~ , methylenediamine, and especially hexamethylenediamine.

C-alkylated diamines, e.g., 2,2-dimethylpentamethylene- ~ ~`

- diamine and 2~2,4-and 2,4,4-trimethylhexamethylenediamine are further examples. Other diamines which may be mentioned .
a8 examples are aromatic diaminesg e-g., p-phenylene-diamine, 4,4'-diaminodiphenyl sulphone, 4,4'-diaminodi-phenyl ether and 4,lI'-diaminodiphenyl sulphone, 4,4'-di-aminodiphenyl ether and 4~4'-diaminodiphenylmethane; and cycloaliphatic diamines, for example diaminodicyclohexyl-methane.

The said dicarboxylic a.cids may be aromatic~ for ; example isophthalic and terephthalic acids. Pre~erred dicarboxylic acids are of the formula HOOC.Y.COOH, wherein Y represents a divalent aliphatic radical containing at least 2 carbon atoms, and examples of such acids are sebacic acid, octadecanedioic acid, suberic acid, azelaic acid, undecanedioic acid, glutaric-acid, pimelic acid, and especia]ly adipic a.cid. Oxalic acid is also a preferred acid.
Speci.rically the followin~ polyamides may be :in-corporated in the thermop~.astlc polymer blends Or the .
nventlon:
polyhexamethylene adipamide (nylon 6:6) polypyrrolidone (nylon Ij) polycaprolactam (nylon 6) polyheptolactam (nylon 7) polycapryllactam (nylon 8) polynonanolactam (nylon 9) . ~.. . .
polyundecanolactam (ny:lon 11)~

polydodecanolactam (nylon 12) polyhexamethylene azelaiamide (nylon 6:9) polyhexamethylene sebacamide (nylon 6~10) polyhexamethylene isophtIIalamide (nylon 6:iP) polymetaxylylene~ipamide (nylon MXD:6) : 25 polyamide of hexamethylene diamine and n-dodecanedioic acid (nylon 6:12) polyamide of' dodecamethylenediam;ne and n-dodecanediolc acid (nylon 12:12).
Nylon copolymers may also be used, ror example co- :
polymers Or the following: : .
hexamethylene ad;~amide/caprolactam (nylon 6:6/6) hexamethylene adipami.de/hexamethylene-;.sophthala.mi.de (nylon 6:6/6ip) hexamethylene adipamide/hexamethylene-terephthalam:i.de (nylon 6:6/6T) trimethy],hexamethylene oxamide/hexamethylene oxam.ide (nylon trirnethyl-6: 2/G: 2) ~ : hexamethylene adipamide/hexamethylene-azelaiamide .~ ~ . (nylon 6:6/6:9) hexamethylene adipamide/hexamethylene-azela.iamide/ ':
~:15 ~ caprolactam (nylon 6:6/6:9/6).
Also useful is nylon 6:3. This polyamide is the product Or the dimethyl ester Or terephthalic acid and a rnixture O:r : :
isomeric trimethyl hexamethylenediamine.
~: Pre~erred nylons include nylon 6,6/6, 11~ 12, 6/3 ~20 and 6/12.
The number average molecular weights o~ the polyamides ~:
: may be above 10,000.

3~

Another group of useful engi.neering therrnoplastics in-clude those halogenated thermoplastics having an essentially crystal].ine structure and a melt point in excess of 120C.
These halogenated thermoplastics include homopolymers and copolymers derived from tetrafl.uoroethylene, chl.orotrifluoro-ethylene, bromotrifluoroethylene, vinylidene fluoride, and vinylidene chloride.
Polytetrafluoroethylene (PTFE) is the name given to fully rluorinated polymers of the basic chemical formula ~ C~12 - - CF2 ~ - which contain 76% by weight fluorine.
Th-se polymers are highly crystal.line and have a crystalline 3~

melting point of over 300 C. Comrnercial. Prl'FE; is avai.lable ~, ~f~ r~ ~Or~
~: under the trade ~a~ TLI?LON ~ and under the trade ~e FL~ON ~ . Polychlorotri.fluoroethy:Lene (~CrJ'I~'E) and poly-bromotrifluoroethylene (PBT~E) are also ava.ilable in high molecular wei.~hts and can be ernployecl in the r,res(r-l~ in-vention.
Especially preferred halogenated polymers are horno-polyrners and copolym(?rs Or vinylidene rlllor:ide. Poly-(vinyli.dene fluor:i.dc) homopolymers are the partially fluori.nated pol.ymers Or the chem:i.(.al rorrnula -~--Cl-12 C1~2 : These polymers are tough linear polymers w;th a cry-;talline melting point at 170 C. Comrnercial homopolymer i.s avail.able under the trade ~u~ KYNAr~ ~ The term "poly(v;nylideno `
rluoride)" as used herein ref`ers not only to ~he normally solid homopolymers Or vinylidene fluoride, but also to the ~: normally solid copolymers Or vinylidene f]uoride contalnin~
at least 50 mol.% o~ polymerized vinylidene fluoride units, ~
preferably at least 70 mol.% vinylidene fluoride and more ~ :
preferably at least 90 molO%. Suitable comonomers are halogenated olefins containing up to ll carbon atoms, f'or example, sym. dichlorodi~luoroethylene, vinyl ~luoride, vinyl chloride, vinylidene chloride, perf.l.uoropropene~per-f'luorobutadiene, chlorotrirluoroethylene, trichloroethylene and tetrafluoroethylene.
Another useful group of halogenated thermoplastics lnclude homopolymers and copolymers derived from vinylidene chloride. Crystalline vinylidene chloride copolymers are ~ 2 -~6-; especially preferred. ~'he normally crysta:l.l.;ne vinyliderle chloride copolymers that are useful in the present in-vention are those containing at least 70% by we.ight O.r vinylidene chloride together wi.th 30% or less of a co-polymerizable monoethylenic monomer. Exemplary of` such monomers are vinyl chlor;de, vinyl acetate, vinyl propionate, acrylonitrile, alkyl and aralky] acrylates hav`ing alkyl and aralky]. groups of up to about 8 carbor atoms, acrylic aci.d, acrylamide, vinyl alky] ethera, vinyl alkyl ketones, acrolci.n~ al]yl ethers and others, butadie~ne and chloropropene. i5nown ~I!rrlclry (.~orrl~)o it:ior~ . :
also.may be employed adva.ntageously. Representativ(? of`
such polymers are those composed of at least 70% by weight of vinylidene chloride w:ith the remain(ler made UE) Or~ for ~ 15 exarnple, acrolein and vinyl chloride, acrylic acid and acrylonitrile, alkyl acrylates and alkyl methacrylates, acrylonitrile and:butadiene, acrylonitrile and ita.conic acid, acrylonitrile and vinyl acetate, vinyl propionate or vinyl chloride, allyl esters or ethers and vinyl : 20 chloride, butadiene and vinyl acetate, vinyl propionate, or vinyl chloride and vinyl ethers and vinyl chloride~
Quaternary polymers of similar monomeric composition will also be known. Partlcularly useful for the purposes ~

the present invention are copolymers Or frorn 70 to 95% by weight vinylidene chloride with the balance being vinyl chlori.de. Such copolymers may contain conventional. amounts and types of plasticizers, stabilizers, nuc:Leators and extrusion aids. Further~ blends o~ two or more of such normally crystalline vinylidene chloride polymers may be used as well as blends cornprising such normally crystalline polymers :in combination with other polymeric modifiers, e.g., the copolymers of ethylene-vinyl acetate, styrene-maleic anhydride, styrene-acrylonitrile and poly-ethylene.
~ The nitrile resins userul as engineering thermoplastic resin are those thermoplastic materlals having an alpha,beta-olefinically unsaturated mononitrile content Or 50% by weight or greater. These nitrile resins rnay be homopolymers, copolymers, grarts Or copolymers onto a rubbery substrate, or blends of homopolymers and/or copo:Lymers.
The alpha,beta-olefinically unsaturated mononitriles encompassed herein have the structure CH2 ~ C CN
R
where R is hydrogen, an alkyl group having from 1 to 4 carbon atoms, or a halogen. Such compounds include acrylo-nitrile, alpha-bromoacrylonitrile, alpha-fluoroacrylo-20 ~ nitrile, methacrylonitrile and ethacrylonitrile 4 The mostpreferred olefinically unsaturated nitriles are acrylo-nitrile and methacrylonîtrile and mixtures thereof.
These nitrile resins may be divided into several classes on t,he basi Or complexity. The simplest molecular structure is a random copolymer, predomlnantly acrylonitrile or methacrylonitrile. The most common example is a styrene-acrylonitrile copolymer. Block copolymers of acrylonitrile, in which long segments o~ polyacrylonitrile alternate with segments Or polystyrene, or of` polymethyl methacrylate, are also known.
Simultaneous polymerization of more than two co-monomers produces an interpolymer, or in the case Or three components, a terpolymer~ A large number of co~
monomers are known. ~hese include alpha-olefins o~from 2 to 8 carbon atoms, e.g.~ ethylene, propylene~ iso-butylene, butene-1, pentene 1, and their halogen and aliphatic substituted derlvatives as represented by vinyl chloride and vinylidene chloride; monovinylidene aromatic 15~ hydrocarbon monomers o~ the general formula:

- - H2C ~ C \

wherein~R1 is hydrogen, chlorine or methyl and R2 i9 an aromatic radical of 6 to 10 carbon atoms which may also contain substituents, such as halogen and alkyl groups attached to the aromatic nucleus~ e.g., styrene9 alpha-methyl styrene, vinyl toluene, alpha chlorostyrene, ortho-chlorostyrene~ para-chlorostyrene 3 meta-chlorostyrene, ortho-methyl styrene, para methyl styrene, ethyl styrene, 3~

isopropyl styrene, d:ichlorostyrene and vinyl naphthalene.
Especially preferr~cl comonomers are isobutylene and styrene.
Another group Or comonomers are vinyl ~ster monomers Or the general formula:

3C C, C=O

wherein R3 i5 selected from the group comprising hydrogen, alkyl groups of from 1 to 10 carbon atoms, aryl grOllp5 of from 6 to 10 carbon atoms including the carbon atoms in ring-substituted alkyl substituents; e.g., vinyl formate, vinyl acetate~ vinyl propionate and vinyl benzoate.
Similar to the foregoing and also use~ul are the vinyl ether monomers of the general formula:

2C-C~I- - R4 wherein R4 is an alkyl group of from 1 to 8 carbon atoms~
; an aryl group of from 6 to 10 carbons, or a monovalent aliphatic radical of from 2 to 10 carbon atoms, which aliphatic radical may be hydrocarbon or oxygen-containing, .
e.g., an aliphatic radical with ether linkages, and may al~o contain other substituents, such as halogen and carbonyl. Examples o~ these mono~eric vinyl ethers include vinyl methyl ether, vinyl ethyl ether, vinyl n~butyl ether, vinyl 2-chloroethyl ether~ vinyl phenyl ether, vinyl iso-~ 0--butyl ether, viny.l cycloh~xyl ether, p-buty:L cycloil~xyl ether, vinyl ether or p-chlorophelly~ ~lycol.
Other comonomers are those cornonomers which contcL;.n a mono- or dinitrile :runction. Examples Or these include methylene glutaronitri.]e, (2,4-dicyarlobuterle-1), virlyl-idene cyanide, crotonitri:l.e, rumarotlinitri..le, rnclleo~i-nitrile.
Other comonomers include the esters of` oler:inically unsaturated carboxylic acids,l~rererably the lower a:l.ky].
esters Or alpha,beta-olef`:inically unsaturated carboxylic acids and more preferred the este~rs hav:ing the structure: :

, ~ ~ C~2--C CO(:)R2 ~1 wherein R1 is hydrogen, an alkyl group having from 1 to 4 carbon atoms, or a halogen and R2 is an al.kyl group havinp;
. : from 1 to 2 ca.rbon atoms. Compounds of this type include ~15 methyl aorylate, ethyl acrylate, methyl methacrylate~
ethyl methacrylate and methyl alpha-chloro acrylate. Most preferred are methyl acryla-te, ethyl acrylate, methyl metha-. crylate and ethyl methacrylate.
Another class of nitrile resins are the grart co- .
polymers wh.ich have a polymeric backbone on which branches :
o~ another pol.ymeric chain are attached or grafted.
Generally the backbone is preformed in a separate reaction.
Polyacrylonitrile may be grarted with chains Or styrene~ -vinyl acetate, or met;l~yl methacry~ate, ror example. The backbone may consist Or one, two, thrc?e, or more com-ponents, and the grarted branc~es rnay be composed Or one, two~ three or more comonomers.
The most pronlising product; are the nitrile co-polymers that are partia:Lly grafted on a prerormed rubbery substrate. This substrate contemplates the use Or a synthetic or natural rubber cornponent such as poly-butadiene, isoprene, neoprene, nitrile rubbers, natural rubbers, acrylonitr1le-butadiene copo]yrners, ethylene-~; propylene copolymers, and c})lorinated rubbers which are used to strengthen or toughen the polymer. Th;s rubbery cornponent may be incorporated into the nitrile containing polymer by any Or the methods which are well known to those skilled in the art, e.g., direct polymerization Or monomers> gra~ting the acry].onitrile monomer mixture onto the rubber backbone or physical admixtures Or the rubbery component. Especially preferred are polymer blends derived by mixing a graft copolymer of the acrylonitrile and co-monomer on the rubber backbone with another copolymer of acrylonitrile and the same comonomer. The acryloni-trile-based thermoplastics are frequently polymer blends Or a grafted polymer and an ungrafted homopolymer.
Cornmercial examples Or nitrile resins include BAREX
21Q resin~ an acrylonitrile-based high nitrile resin con-taining over 65% nitrile, and LOPAC ~ resin containing 3~

over 70% ni-trile, three-rourths of it derived from metha-crylonitrile.
In order to better match the viscosity c,haracter;stics of the thermoplastic engineering resin, the polyurethane and the block copolymer, it is sometimes userul to first blend the dissimilar thermoplastic engineering resin with a viscosity modirier before blending the resulting mixture with thepolyurethaneand block copolymer. Suitable viscosity modifiers have a relatively high viscosity, a melt temper-ature of over 230 C, and possess a viscosity that is notvery sensitivo to changos in temperature. ~xarTIpl(~s o~` suL~-able viscosity modifiers include poly(2,6-dimethyl-1,4-I phenylene)oxide and blends Or poly(2,6-dimethyl 1,4-phenyl-ene)oxide with polystyrene.
The poly(phenylene oxides) included as possible viscosity modifiers may be presented by the ~ollowing formula:
:
~o}

wherein R1 is a monovalent substituent selected from the group consisting of hydrogen, hydrocarbon radicals rree Or a tertiary alpha-carbon atom, halohydrocarbon radicals ~ 3 ~
-~13-having at least two carbon atoms between the halogen atom and phenol nucleus and being free of a tertiary alpha-carbon atom, hydrocarbonoxy radicals free o~
aliphatic, tertiary alpha-carbon atoms~ and halohydro-carbonoxy radicals having at least two carbon atomsbetween the halogen atom and phenol nucleus and being free of an aliphatic~ tertiary alpha-carbon atom; R'l is the same as Rl and may additionally be a halogen; m is an integer equal to at least 50, e.g., from 50 to 800 and preferably 150 to 300. Included among these preferred polymers are polymers having a molecular weight in the range o~ between 6,ooo and 100,000, preferably 40,000.
, Preferably~ the poly(phenylene oxide) is poly(2,6-di-methyl-1,4-phenylene)oxide.
Commercially, the poly(phenylene oxide) is available as a b]end with styrene resin. These blends typically comprise between 25 and 50% by weight polystyrene units, ~B~ and are available under the ~ -- -trade ~a~e NORYL thermoplastic resin. The preferred molecular weight when employing a poly(phenylene oxide)~
polystyrene blend is between lO,000 and 50,000, preferably around 30,000.
The amount of VlSCOSity modifier employed depends primarily upon the difference between the viscosities of the block copolymer and the engineering thermoplastic resin at the temperature Tp. The amounts may range from 0 to lO0 r _ 1I L~ _ parts by weight viscosity modlrier per lO0 parts by weight engineering thermoplastic re.sin, preferably from lO to 50 parts by weight per lO0 parts of engineering thermoplastic resin.
There are at least two methods (other than the absence Or delamination) by which the presence of an interlocking network can be shown. In one method~ an interlocking net-work is shown when moulded or extruded objects made from the blends of this lnvention are placed in a refluxing solvent that quantitatively dissolves away the block co~
polymer and other soluble components, and the remaining polymer structure (comprisirlg the thermoplastic engineer-ing resin and ~l~ur~hane3 still has the shape and con-tinuity of the moulded or extruded ob,ject and is intact structurally without any crumbling or delamination, and the re~luxing solvent carries no insoluble particulate matter. If these criteria are ful~/illed, then both the unextracted and extracted phase~ ~e interlocking and continuous. The unextracted phase must be continuous because it is geometrically and mechanically intact.
The extracted phase must have been continuous before extraction~ since quantitative extraction of a dispersed phase ~rom an insoluble matrix is highly unlikely.
Finally, interlocking networks must be present in order to have simultaneous continuous phases. Also, confirmation of the continuity Or the unextracted phase may be 5~ ;23~ ~

confirmed by microscopic examination. In the present blends containing more than two components, the inter-locking nature and continuity of each separate p~lase may be established by selective extraction.
In the second method, a mechani.cal property such as tensile modulus is measured and compared with that expected from an assumed system where each continuous iso-tropically distributed phase contributes a fraction of the mechanical response, proportional to its compositional fraction by volume. Correspondence of the two values -~
indicates presence of the interlocking network~ whereas~
if the interlocking network is not present~ the measured value is different than that of the predicted value.
An important aspect of the present invention is that ' 15 the relative proportions of the various polymers in the blend can be varied over a wide range. The relative proportions of the polymers are presented below ln parts by welght (the total blend comprising 100 parts):
Parts by Preferred ;~ weight parts by ~ weight :
20Dissimilar engineering thermoplastic resin , 5 to 48 10 to 35 Block copolymer 4 to 40 8 to 20 The polyurethane is present in an amount greater than the amount o~ the dissimilar engineering thermo--~l6~

plastic, i.e., the we;ght ratio of polyurethane to dissimilar engineering thermop~astic is greater than 1:1. Accordingly, the amount of polyurethane may vary from 30 parts by ~eight to 91 parts by weight, preferably from 48 to 70 parts by weight. Note that the minimum amount of block copolymer necessary to achieve these blends may vary with the particular engineering thermo-plastic.
The dissimilar engineering thermoplastic resin, polyurethane and the block copolymer may be blended in any manner that produces the interlocking network. ~or example, the resin~ polyurethane and block copolymer may be dissolved in a solvent common ~or all and coagulated by admixing in a solvent in which none o~ the polymers are soluble. fiut, a particularly use~ul procedure is to intimately mix the polymers in the form of granules and/or powder in a high shear mixer. "Intirnately mixing" means to mix the polymers with sufficient mechanical shear and ~:
thermal energy to ensure that inter:Locking of the various ~~~
\~

::

_1~7_ -networks is achieved. Intimate mixing is typically achieved by employing high shear extrusion compounding machines, such as twin screw compounding extruders and ~ ~
thermoplastic extruders having at least a 20:1 L/D ratio ~ -and a compression ratio Or ~ or 4:l.
The mixing or processing temperature (Tp) is selected in accordance with the particular polymers to be blended.
For example, when melt blending the polymers instead of solution blending, it will be necessary to select a processing temperature above the melting point Or the highest melting point polymer. In addition, as explained more fully hereinafter, the processing temperature may also be chosen so as to permit the isoviscous mixing the polymers. The mixing or processing temperature may be between 150 C and 400C, preferably between 230C and ~!
00C.
Another parameter that is important in melt blending to ensure the formation Or interlocking networks is matching the viscosities of the block copolymer,polyur~haneand the 20 ; dissimilar engineering thermoplastic resin (isoviscous mixing) at the temperature and shear stress of the mixing process. The hetter the interdispersion of the engineering resin and ~lyurethaneinthe block copolymer network, the better the chance for formation Or co-continuous inter locking networks on subsequent cooling. Therefore, it has been ~ound that when the block copolymer has a viscosity ~823~

n poise at temperature Tp and shear rate of 100 s 1, it is preferred that the engineering thermoplastic resin and/or the ~lyuretha~ nave such a viscosity at the temper-ature ~p and a shear rate o~ 100 s that the ratio Or the viscosity of the block copolymer divided by the viscosity of the engineering thermoplastic and/or polyurethane be between 0.2 and 4.0, preferably between o.8 and 1.2.
Accordingly, as used herein, isoviscous mixing means that the viscosity of the block copolymer divided by the viscosity of the other polymer or polymer blend at the temperature ~p and a shear rate of 100 s 1 is between 0.2 and 4Ø It should also be noted that within an extruder, there isawide distribution of shear rates.
Therefore, isoviscous mixing can occur even though the 15~ viscosity curves of two polymers dif~er at some of the shear rates.
In some cases~ the order of mixing the polymers is critical. Accordingly~ one may choose to mix the block copolymer with the ~lyurethaneor other polymer first, and then mix the resulting blend with the dissimilar engineer-- ing thermoplastic, or one may sirnply mix all the polymers at the same time. There are many variants on the order of mixing that can be employed, resulting in the multi-component blends o~ the present invention. It is also clear that the order of mixing can be employed in order to better match the relative viscosities of the various polyrner~.

_L19-The block copolymer or block copolymer blend may be selected to essentially match the viscosit~ of the engineering thermoplastic resin and/or polyurethane.
Optionally, the block copolymer may be mixed with a rubber compounding oil or supplemental resin as described hereinafter to change the viscosity charac-teristics of the block copolymer.
The particular physical properties of the block copolymers are important in forming co continuous inter-10 ~ locking networks. Specifically, the most preferred blockcopolymers when unblended do not melt in the ordinary sense with increasing temperature, since the viscosity ~; of these polymers is highly non-Newtonian and tends to increase without limit as zero shear stress is approached.
Further~ the viscosity of these block copolymers is also relatively insensitive to temperature. This rheological behaviour and inherent thermal stability of the ~lock co-polymer ehhances its ability to retaln its network (domain) structure in the melt so that when the various 20 ~ blends are made,interlocking and continuous networks are formed.
- The viscosity behaviour of the engineering thermoplastic resins, an(l~lyur~hanes on the other hand, is more sensitive to temperature than that of the block copolymers. Ac cordingly, it is often possible to select a processing temperature Tp at which the v;scosities of the block ~ 2 copolymer and dissimilar engineering resin and/or poly-urethc~eI~all within the required range necessary to form interlocking networks. Optionally, a viscosity modifier~
as hereinabove describedg may first be blended with the engineering thermoplastic resin or ~lyur~hane to achieve the necessary viscosity matching.
The ~end of partially hydrogenated block copolymer, ~lyureth~Y~ and dissimilar engineering thermoplastic resin may be compounded with an extending oil ordinarily used in the processing of rubber and plastics. Especially preferred are the types Or oil that are compatible with ~the elastomeric polymer blocks of the block copolymer.
While oils of hi~her aromatics content; are satisfactory, those petroleum-based white oils having low volatility and less tharl 50% aromatics content as determined by the clay `
gel method (tentative ASTM method D 2007) are particularly preferred. The oils pre~erably have an initial boiling poînt above 260C.
The amount of oil employed may vary from O to 100 phr 20 ~ (phr = parts by weight per hundred partæ by weight of block copolymer), preferably from 5 to 30 phrO
The blend Or partially hydrogenated block copolymer, ~lyuretha-e ~nd dissimilar engineering thermoplastic res;n may be further compounded with a resin. The additional res;n may be a flow promoting resin such as an alpha-methylstyrene resin and an end-block plast;cizing resin.

~ ~ 8 23 Suitable end-block plasticizing resins include coumarone-indene resins, vinyl toluene-alpha-methylstyrene co-polymers, polyindene resins and low molecular weight polystyrene resins.
The amount of additional resin may vary from 0 to 100 phr, preferably from 5 to 25 phr.
Further the composition may contain o-ther polymers, fillers, reinforcements, anti-oxidants, stabllizers, fire retardants~ anti-blocking agents and other rubber and plastic compounding ingredients.
Examples of fillers that can be employed are mentioned in the 1971-1972 Modern Plastics ~ncyclopedia, pages 2ll0-247.
Reinforcements are also useful in the present polymer ~ -.
blends. A reinforcement may be defined as the material that ~; 15~ is added to a resinous matrix to improve the strength of ~ ~ :
the polymer. Most Or these reinforcing materials are in-organic or organic products Or high molecular weight.
Examples of reinforcements are glass fibres, asbestos 9 ~ ~ boron ~ibres 9 carbon and graphite fibres, whiskers, quartz and silica fibres, ceramlc fibres, metal fibres, natural ; organic ~ibres 9 and synthetic organic fibres. Especially preferred are reinforced polymer blends containing 2 to 80 per cent by weight of glass fibres~ based on the total ~ -weight of the resulting reinrorced blend.
The polymer blends of the invention can be employed as meta] rep~acements and in those areas where high perforrnance is necessary.

-~2 ~ 3~

In the illustrative Examples and the comparative Example given below various polymer blends were prepared by mixing the polymers in a 3.125 cm Sterling Extruder having a Kenics nozzle. The extruder has a 24:1 L/D
ratio and a 3.8:1 compression ratio screw.
The various materials employed i.n the blends are listed below:
l) Block copolymer - a selectively hydrogenated block copolymer according to the invention having a structure S-EB-S.
B 2) Oil - TIJF`FLO 6056 rubber extending oi].
3) Nylon 6 - PLASKON ~ 8207 polyamide.

4) Nylon 6-12 - ZYTEL ~ 158 polyamide. ~ .

5) Polypropylene - an essentially isotactic poly-propylene having a melt flow index of 5 (230C/2.16 kg).

6) Poly(butylene terephthalate) ("PBT") - VQLOX ~ 310 resin.

7) Polycarbonate - MERLON ~ M-40 polycarbonate.

8~ Poly(ether sulphone) - 200 P.

9) Polyurethane - PELLETHANE ~ CPR having an apparent crystalline melting point of 165C.

10) Polyacetal - DELRIN ~ 500.

11) Poly(acrylonitrile-co-styrene) - BAREX ~ 210.

12) Fluoropo].ymer - TEFZEL ~ 200 poly(vinylidene fluoride) copolymer.

,~ ~,~ o ~ ,~

-53~

In all blends contairlirlg an oil component, the block copolymer and oil were premixed prior to the addition of the other polymers.
Illustrative Example I
Various polymer blends were prepared according to the invention. A blend of two block copolymers of a higher and lower molecular weight was employed in some polymer blends in order to better match the viscosity with the polyurethane and/or other dissimilar engineering thermo-plastic resin. Comparative blends not containing a block copolymer were also prepared. However, these blends were not easily mixed. For example, blend 114 comprising just a polyurethane and Nylon 6 suffered from surging and a ~ ~ grainy appearance. In contrast, in each blend containing a block copolymer, the polymer blend was easily mixed, and the extrudate was homogeneous in appearance. Further~
in each blend containing a block copolymer~ the re-sulting polyblend had the desired continuous, inter-locking networks as established by the criteria herein-above described.
The compositions and test results are presented below in Tables 1 and 2. The compositions are listed in percent by weight.

~5~-- 5 ~

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O
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N C~ 1~Lf 'r'I m m ~ m m m Z ~; Z Z Z

o o o o o o ~1 0 0 0 0 0 0 ~ ~ ~ ~ o~Lr :
o ~ i~
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Q, O Q~ O ~ ~:
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Claims (30)

C L A I M S

1. A composition containing a partially hydrogenated block copolymer comprising at least two terminal polymer blocks A of a monoalkenyl arene having an average molecular weight of from 5,000 to 125,000, and at least one intermediate polymer block B of a conjugated diene having an average molecular weight of from 10,000 to 300,000, in which the terminal polymer blocks A con-stitute from 8 to 55% by weight of the block copolymer and no more than 25% of the arene double bonds of the polymer blocks A and at least 80% of the aliphatic double bonds of the polymer blocks B have been reduced by hydrogenation, characterized in that the composition comprises:
(a) 4 to 40 parts by weight of the partially hydrogen-ated block copolymer, (b) a thermoplastic polyurethane having a generally crystalline structure and a melting point over 120°C, (c) 5 to 48 parts by weight of at least one dissimilar engineering thermoplastic resin being selected from the group consisting of polyamides, poly-olefins, thermoplastic polyesters, poly(aryl ethers), poly(aryl sulphones), polycarbonates, acetal resins, halogenated thermoplastics, and nitrile resins, in which the weight ratio of the thermoplastic polyurethane to the dissimilar engineering thermoplastic resin is greater than 1:1 so as to form a polyblend wherein at least two of the polymers form at least partial continuous inter-locked networks with each other.

2. A composition as claimed in claim 1, in which the polymer blocks A
have a number average molecular weight of from 7,000 to 60,000 and the polymer blocks B have a number average molecular weight of from 30,000 to 150,000.

3. A composition as claimed in claim 1 or 2, in which the terminal polymer blocks A constitute from 10 to 30% by weight of the block copolymer.

4. A composition as claimed in claim 1, in which less than 5% of the arene double bonds of the polymer blocks A and at least 99% of the aliphatic double bonds of the polymer blocks B have been reduced by hydrogenation.

5. A composition as claimed in claim 1, in which the dissimilar engineering thermoplastic resin has an apparent crystalline melting point in excess of 120°C.

6. A composition as claimed in claim 5, in which the dissimilar engineering thermoplastic resin has an apparent crystalline melting point of between 150°C and 350°C.

7. A composition as claimed in claim 1, in which the dissimilar engineering thermoplastic resin is a thermoplastic polyester having a melting point in excess of 120°C.

8. A composition as claimed in claim 1, in which the dissimilar engineering thermoplastic resin is poly(ethylene terephthalate), poly(propylene terephthalate) or poly(butylene terephthalate).

9. A composition as claimed in claim 8, in which the dissimilar engineering thermoplastic resin is poly(butylene terephthalate) having an average molecular weight in the range of from 20,000 to 25,000.

10. A composition as claimed in claim 1, in which the engineering thermoplastic resin is a polycarbonate having the general formula:

I
or II

wherein Ar represents a phenylene or an alkyl, alkoxy, halogen or nitro-substituted phenylene group, A represents a carbon-to-carbon bond or an alkylidene, cycloalkylidene, alkylene, cycloalkylene, azo, imino, sulphur, oxygen sulphoxide or sulphone group, and n is at least two.

11. A composition as claimed in claim 1, in which the dissimilar engineering thermoplastic resin is a polyamide having a number average molecular weight in excess of 10,000.

12. A composition as claimed in claim 1, in which the engineering thermoplastic resin is a nitrile resin having an alpha,beta-olefinically unsaturated mononitrile content of greater than 50% by weight.

13. A composition as claimed in claim 12, in which the alpha,beta-olefinically unsaturated mononitrile has the general formula:

wherein R represents hydrogen, an alkyl group having from 1 to 4 carbon atoms or a halogen.

14. A composition as claimed in claim 1, in which the composition contains the block copolymer and the dissimilar thermoplastic resin in an amount of from 8 to 20 parts by weight and from 10 to 35 parts by weight, respectively,

15. A composition as claimed in claim 1, in which the composition contains an extending oil in an amount of from 0 to 100 phr.

16. A composition as claimed in claim 15, in which the composition contains an extending oil in an amount of from 5 to 30 phr.

17. A composition as claimed in claim 1, in which the composition contains a flow-promoting resin as additional resin in an amount of from 0 to 100 phr.

18. A composition as claimed in claim 17, in which the composition contains a flow-promoting resin as additional resin in an amount of from 5 to 25 phr.

19. A composition as claimed in claim 17 or 18, in which the composition contains an additional resin selected from the group consisting of an alpha-methylstyrene resin, coumarone-indene resins, vinyl toluene-alpha-methyl-styrene copolymers, polyindene resins and low molecular weight polystyrene resins.

20. A process for the preparation of a composition as claimed in claim 1, characterized in that (a) 4 to 40 parts by weight of a partially hydrogenated block copolymer comprising at least two terminal polymer blocks A of a monoalkenyl arene having an average molecular weight of from 5,000 to 125,000, and at least one intermediate polymer block B of a conjugated diene having an average molecular weight of from 10,000 to 300,000, in which the terminal polymer blocks A constitute from 8 to 55% by weight of the block copolymer and no more than 25% of the arene double bonds of the polymer blocks A and at least 80% of the aliphatic double bonds of the polymer blocks B have been reduced by hydrogenation, are mixed at a processing temperature Tp of between 150°C
and 400°C with (b) a thermoplastic polyurethane having a generally crystalline structure and a melting point of over 120°C, and (c) 5 to 48 parts by weight of at least one dissimilar engineering thermoplastic resin being selected from the group consisting of polyamides, polyolefins, thermoplastic polyesters, poly(aryl ethers), poly(aryl sulphones), polycarbonates, acetal resins, halogenated thermoplastics and nitrile resins, in which the weight ratio of the thermoplastic polyurethane to the dissimilar engineering thermoplastic resin is greater than 1:1 so as to form a polyblend wherein at least two of the polymers form at least partial continuous inter-locked networks with each other.

21. A process as claimed in claim 20, characterized in that the polymers are mixed at a processing temperature Tp of between 230°C and 300°C.

22. A process as claimed in claim 20 or 21, characterized in that the polymers are dissolved in a solvent common for all and coagulated by admixing in a solvent in which none of the polymers are soluble.

23. A process as claimed in claim 20 or 21, characterized in that the polymers are mixed as granules and/or powder in a device which provides shear.

24. A process as claimed in claim 20, characterized in that the ratio of the viscosity of the block copolymer divided by the viscosity of the poly-urethane, the dissimilar engineering thermoplastic resin or the mixture of the polyurethane and the dissimilar engineering thermoplastic resin is between 0.2 and 4.0 at the processing temperature Tp and a shear rate of 100s-1.

25. A process as claimed in claim 24, characterized in that the viscosity ratio of the viscosity of the block,copolymer divided by the viscosity of the polyurethane, the dissimilar engineering thermoplastic resin or the mixture of the polyurethane and the dissimilar engineering thermoplastic resin is between 0.8 and 1.2 at the processing temperature Tp and a shear rate of 100 s-1.

26. A process as claimed in claim 20, characterized in that the dissimilar thermoplastic resin is first blended with a viscosity modifier before blending with the polyurethane and the block copolymer.

27. A process as claimed in claim 20, characterized in that as viscosity modifier poly-(2,6-dimethyl-1,4-phenylene)oxide, or a blend of poly-(2,6-dimethyl-1,4-phenylene)oxide with polystyrene is used.

28. A process as claimed in claim 26 or 27, characterized in that the viscosity modifier is used in an amount of from 0 to 100 parts by weight per 100 parts by weight of engineering thermoplastic resin.

29. A process as claimed in claim 28, characterized in that the viscosity modifier is used in an amount of from 10 to 50 parts by weight per 100 parts by weight of engineering thermoplastic resin.

30. A process as claimed in claim 20, characterized in that the block copolymer and the dissimilar engineering thermoplastic resin are used in an amount of from 8 to 20 parts by weight and from 10 to 35 parts by weight, respectively.