CA1270979A - Polyetherimide-polyamide blends - Google Patents

Abstract

POLYETHERIMIDE-POLYAMIDE BLENDS
ABSTRACT OF THE DISCLOSURE
Disclosed are blends comprising from about 40 to 80 wt. % of a polyetherimide and the remainder one or more polyamides. The blends generally have a tensile strength which is greater than the tensile strength of polyetherimide-polyamide blends which do not contain from about 40 to 80% polyetherimide, while still retaining a good combination of other physical properties such as heat distortion characteristics and impact strength. In addition, the blends of the invention may have a flexural strength which is greater than that of other polyether-imidepolyamide blends which do not contain from about 40 to 80% polyetherimide. The blends of the present invention find use in automobile and aviation applications for decorative and protective purposes and in high temperature electrical insulation applications.

Description

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POLYETHERI~IDE-POLYAMIDE BLENDS
-The invention relates to a particular class of polyetherimide-polyamide blends where the blend contains from 40 to 80 wt. % polytheri~ide~;~- .Among other things, such blends have a hi~her tensile strength than those associated wit~ polyetherimide-polyamides blends contain-ing less t~an ~0% polyetherimide and some.blends containing more than 80% polyethermide.
The blends o~ the invention include a polyetherimide o~ the formula:

o_z_O~

O o whexe a represents a whole number in excess af 1~ e.g., 10 to 10,000 or more, the group.-O-A = is selected from:

' ~ ~

.,. ~.

:~ .; . .: , , :. : .. , '';,, ','. ;

~L2~37~
` 8CU-3456 S _~ ~

" _ I

R' being hydrogen, lower alkyl or lower alXoxy, prefer~bly the polyetherimide includes the latter -O-A group 1~ where R' is hydrogen such that the polyether~mide lS
of the formula: .

O. -~o - o ..
n t f \ -- -- O ~ / N R t ~5 " a O O

and the divalent bonds of tbe -O-Z-O-radical are in the 3,3';3,4';4,3' or the 4,4' position;
and Z is a member of the class consisting of (11 ~ .

.

. .: . , ::
~ ,, . ,. ~ ,. ~ , . -,- : . .. , -. ~: .. ..

' '` ''~ . ' '. ' "" ' ' ,. ' '; . ' ` ' ' ' " " ' '' ' '~' ~.'. ''.' .1 ,. ' , , `.

~7~?~7~

.

- ~/3 ~`
~If~ ~

l~ ~ ~ C(C~3)~

and (2~ divalent organic radicals of -the general formula:

` {O} tX) ~0}

.
where X is a member selected from the class consisting o~ divalent radicals of the formulas, O O
CyH2y C - , S - - O - and - S -o where q is O or 1, y is a whole number from 1 to 5, and R is a divalent organic radical selected from the class consisting of (11 aromatic hydrocarbon radicals having from 6-20 carbon atoms and halogenated derivatives thereof, (2~ alkylene ra~icals and cycloalkylene radicals having from 2-20 carbon atoms, C(2 8~ alkylene terminated polydiorganosiloxane, and (31 divalent radicals included ,. ~

-. -:

.~ . . . .

, . . .

.. . .

.:.. ,, .,.:.. . ~: ., .

'' ' :: , ~7~

~ 4 by the formula ~ ~ Q - ~ .

where Q is a member selected from the class conslsting of O O

- O - - C ~ - S ~ - S - and - C~H2 where X is a whole number from 1 to 5 inclusive. Par-ticularly preferred polyetherimides for the purposes of the present invention include those where - O - A- and 15 ~ r~Spectively are: CH3 - O ~ and CO } ~ -7~) and R is selected from:

--~'CH2 ~ (~ (~

The polyetherimides where R is metaphenylene are most . . . . . ................ ~ ... ~ .

: . ; .:., .

~Z7~

preferred.
As mentioned previously, the hlends of the invention also include a polyamide. Polyamides are well known in the art and the term embraces those semi-crystalline and amorphous resins having a molecular weight of at least 5000 commonly referred to as nylons. Polyamides generally have a repeating structual units represented by the general formula;

1~ ~ O H

t N ~ or t C - R3~ C - N - R - N

1~
where R2, R3r and R4, which may be the same or different, each represents an alkylene group having from 4 to 11 carbon atoms, and n is an integer of 30 to 500 or more.
Suitable examples of alkylene groups containing 4 to 11 ~o carbon atoms for R2, R3, and R4 include a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, decamethylene group, an undecamethylene group, and the like.
~5 Specif~cally, the following polyamides may be incorporated in the blends of the invention:
polyhexamethylene adipamide (nylon 6;6) polypyrrolidone (nylon 4) polycaprolactam (nylon 6) polyheptolactam (nylon 7) polycapryllactam (nylon 81 polynonanolactam ~nylon 9 polyundecanolactam (nylon 11 polydodecanolactam (nylon 12 polyhexamethylene azelaiamide (nylon 6:9~
polyhexamethylene sebacamide (nylon 6010) :: ~ - , ; : :, : :- :, - , ::: .

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8CU-3~56 polyhexamethylene isophthalamide (nylon 6:ip) polymetaxylylene adipamide (nylon MXD:6) polyamide ~ hexamethylenedediamine and n-dodecanedioic acid (nylon 6:12~
polyamide of dodecamethylenediamine and n-dodecanedioic acid (nylon 12:12) Nylon copolymers may also be used as the polyamide component of the blends of this invention. For example, suitable copolymers include the following:
hexamethylene adipamide/caprolactam (nylon 6:6/6) hexamethylene adipamide/hexamethylene-isophthalamide ~nylon 6:6~6ip~
hexamethylene adipamide/hexamethylene-terephthalamide (nylon 6:6/6T~
trimethylhexamethylene oxamide/hexamethylene oxamide (nylon trimethyl-6:2/6:2~
hexamethylene adipamide/hexamethylene-azelaiamide ~nylon 6:6/6:9) hexamethylene adipamide/hexamethylene-azelaiamide/
caprolactam (nylon 6:6/6:9/6) Also useful is nylon 6:3 produced by Dynamit Nobel.
This polyamide is the product of the dimethyl ester of terephthalic acid and a mixture of isomeric trimethyl hexamethylenediamine. Preferred nylons for the blends of the invention include 6,6/6; 11,/6/3 and 6/12.
In addition, specific polyamides are described in U.S. Patent Nos~2,071,.250; 2,071,251; 2,130,523;
,130,948; 2,241,322; 2,312,966; 2,512,606 to Bolton dated June 27, 19.50 and 3,393,210 to Speck dated July 16, 1968.
The polyetherimides can be obtained by any of the methods well known to those skilled in the art including the reaction of ~ny ar~matic bis (ether anhydrides) of the formula : ~`

. .. ,: ...................... .

D7~

. O
/C\[~ - Z

where 2 is as defined hereinbefore with an organic diamine of the formula where R is as defined hereinbefore.
Aromatic bis(ether anhydride)s of the above formula include, for example, 2,2-bisl4-(2,3-dicarboxyphenoxy~phenyl]-propane dianhydride; 4,4'-bis(2, 3-dicarboxyphenoxy~diphenyl ether dianhydride; 1,3-bis(2, dicarboxyphenoxy~diphenyl sulfide dianhydride; 1,4-bi 5( 2, 3-dicarboxyphenoxy~benzene dianhydride; 4,4'-bis(2,3-dicarboxyphenoxy~benzophenone dianhydride; 4,4'-bis (~,3-dicarboxyphenoxyldiphenyl sulfone dianhydride;

2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride;
4,4'-bis(3,4-dicarboxyphenoxy~diphenyl ether dianhydride;
~,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride;
1,3-bis(3,4-dicarboxyphenoxy)benzene-dianhydrlde;
1,4-bis(3,4-~iaarboxyphenoxy)benzene~dianhydride;~
~5 ~,4`-bis(3,4-dicarboxypheno-xy)benzophenone dianhydride;
4-(2,3-dicarboxyphenoxy~-4'(3,4-dicarboxyphenoxy)diphenyl 2,2-propane dianhydride; etc., and mixtures of such dianhydrides.
In addition, aromatic bis(ether anhydride)s also included by the above formula are shown by Koton, M~M.;
Florinski, F.S.; Bessonov, M.I.; Rudakov, A.P. (Institue of Heteroorganic compounds, Academy of Sciences, U.S.S.R.), U.S.S.R. 257,010, Nov. 11, 1969, Appl. May 3, 1967. In ~ddition, dianhydride~ are shown by M.M. Koton, F.S.
35 Florinski, Zh Org. Khin, 4(5~, 774 (1968).

.

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Organic diamines of the above formula include, for example, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylmethane, benzidine, 4,4'-diaminodiphenyl sulfide, 5 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3'-dirnenthylbenzidine !

3,3'-dimethoxybenzidine, 2,4-bis,P -amino-t-butyl)toluene, bis~p- ~ -amino-t-butylphenyl) ether, bis (p-7~- methyl-o-aminopentyl)benzene, 1,3-diamino-4-isopropylbenzene, 1,2-bis~3-aminopropoxy~ethane, m-xylylenediamine, p-xylylened~amine, 2,4-diaminotoluene, 2,6-diaminotoluene, bis(4-aminocyclohexyl)methane, 3-methylheptamethylene-diamine, 4,4-dimethylheptamethylenediamine, 15 2,11-dodecanediamine, 2,2-dimethylopropylenediamine, octamethylenediaminer 3-methoxyhexamethylenediamine, 2,5-dimethylhexamethylenediamine, ~,5-dimethylheptamethylenediamine, 3-methylheptamethylenediamine, 20 5-methylnonamethylenedediamine, 1,4-cyclohexanediamine, 1,12-octadecanediamine, bis(3-aminopropyl~sulfide, N-methyl-bis~3-aminopropyl)amine, hexamethylenediame, lleptamethylenediamine, nonamethylenediamine, decamethylenediamine, bis(3-aminopropyl) tetramethyldisiloxane, bis (4-aminobutyl~
tetramethyldisiloxane, and the like.
In general, the reactions can be advantageoulsy carried out employing well-known solvents, e.g., o~dichlorobenzene, m-cresol/dianhydrides and the diamines, 30 at temperatures of from about 100 to about 250C. Altern-atively, the polyetherimides can be prepared by melt poly-merization of any of the above dianhydrides with any of the above diamine compounds while heating the mixture of the ingredients at elevated temperatures with 35 cc~ncurrent intermixing. Generally, melt polymerization temperatures between about 200 to 400C. and preferably ., : , . ~ : , . . . ;
. . " :. , - : . :, ~ .- . :. : :
~"~

~7q:~7~3 g 230 to 300C. can be employed. The conditions of the reaction and the properties of ingredients can be varied widely depending on the desired molecular weight, intrinsic viscosity, and solvent resistance. In general, equimolar amounts of diamine and dianhydride are employed for high molecular weight polyetherimides, however, in certain in-~tances, a slight molar excess (about 1 to 5 mol percent) of diamine can be employed resulting in the production of polyetherimides having terminal amine groups. Generally, useful polyetherimides ha~e an intrinsic viscosity greater than 0.2 deciliters per gram, preferably 0.35 to 0.60, or 0.7 deciliters per gram or even higher when measured in m-cresol at 25C.
Included among the many methods of making the poly-etherimides are those disclosed in U.S. Patent Nos.Heath et al, 3,847,867 dated November 12,1974, Williams 3,8~7,869 dated November 12, 1974, Takehoshi et al, 3,850,885 dated Noyember 26, 1974, White 3,852,242 dated December 3, 1974 and 3,855,178 dated December 17, 1974.
These disclosures teach general and specific methods for preparin~ polye`therimides suitable for the blends of this invention.
Polyamides may be obtained by polymerizing a monoaminomonocarboxylic acid or an internal lactam thereof ~avin~ at least t~o carbon atoms between the amino and carboxylic acid groups; or by polymerizing substantially equimolar proportions of a diamine which contains at least t~o carbon atoms between the amino groups and a dicar-boxylic acid; or by polymerizing a monoaminocarboxylic acid or an internal lactam thereof as defined above together with substantially equimolecular proportions of a diamine and a dicarboxylic acid. The dicarboxylic acid may be used in the from of a functional derivative thereof, for example, an ester.
The term "substantially equimolecular proportions"
(o~ the diamine and of the dicarboxylic acid) is used to . .

7 ~ ~ 7 ~

comprehend both strict equimolecular proportions and the slight departures therefrom which are in~olved in conventional techniques for stabilizing the ~iscosity of the resultant polyamides.
As examples of the monoaminomonocarboxylic acids or lactams thereof, there may be mentioned those compounds containing from 2 to 16 carbon atoms between the amino an~ carboxylic acid groups, the carbon atoms forming a rill~ with the -CO-NH- group in the case of a lactam. As particular examples of aminocarboxylic acids and lactams there may be mentioned ~ -aminocaproic acid, butyrolactam, pivalolactam, caprolactam, capryl-lactam, enantholactam, undecanolactam, dodecanolactam and 3- and 4-amino benzoic acids.
Examples of suitable diamines are diamines of the ~ene~al formula H2N(CH2~nNH2 wherein n is an integer of from ~ to 16, such as trimethylenediamine, tetramethyl-enediamine, pentamethylenediamine, octamethylenediamine, decamethylenediamine, dodecamethylenediamine, hexade-camethylenediamine, and especially hexamethylenediamine.
C-alkylated diamines, e.g., 2,2-dimethylpentamethylene-diamine and 2,2,4-and~2,4,4-trimethylhexamethylenediamine ~re further examples. Other diamines which may be mentioned ~s examples are aromatic diamines, e.g., p-phenylenediamine, ~,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether and 4,4'-diaminodiphenylmethane; and cycloaliphatic diamines, for example, diaminodicyclohexylmethane.
The dicarboxylic acids may be aromatic, for example, 3~ isophthalic and terephthalic acids. Preferred dicar-boxylic acids are of the formula HOOC-Y-COOH wherein Y
presents a divalent aliphatic radical containing at least two carbon atoms, and examples of such acids are sebacic acid, octadecanedioic acid, suberic acid, azelaic acid, undecanedioic acid, glutaric acid, pimelic acid, and especially adipic acid. Oxalic acid is also a preferred 8CU-3~56 acid.
As was mentioned previously, the blends of the present invention comprise from about 40 to 80 wt. % preferably from 40 to 60 wt. % of a polyetherimide and the remainder one or more polyamides. Such blends generally have a tensile strength which is greater than the tensile strength of polyetherimide-polyamide blends which do not contain from 40 to 8Q% polyetherimide, while still retaining a good combination of other physical properties such as heat distortion characteristics and impact strength. In addition, the blends of the invention may have a flexural strength which is greater than that of polyetherimide-polyamide blends outside the scope of the invention.
Consequently, by controlling the proportions of the poly-etherimide and po-lycarbonate relative to each other within the above range, it was surprisingly found that blends having properties which are improved over those of blends outside the range as well as over the polyetherimide or polyamide components alone can be achieved. Thus, the i~o blends of the invention provide materials which have certain properties approaching those of the polyetherimide component ~l~ne while contalning a significant proportion of the generally presently less expensive polyamide relative to the polyetherimide. Furthermore, blends within the composition range of the present invention have an appearance which suggests that the blends are of one phase and there fore compatible.
The unlque characteristics of the blends of the pre-sent invention are illustrated ln the drawings in which;
Figure 1 is a plot of unnotched impact strength versus polyetherimide content for blends of a polyetherimide and a polyamide, Figure 2 is a plot of heat distortion temperature versus polyetherimide content for blends of a polyetherimide and a polyamide, Figure 3 is a plot of ultimate flexural strength versus ~ ,~

,, ",, ' ' ,. :,, , ! ~ `
': , 7~97~

polyetherimide content for blends of a polyetherlmide and a polyamide, Figure 4 is a plot of flexural modulus versus poly-etherimide concentration for blends of a polyetherimide and a polyamide, and Figure 5 is a plot of tensile strength versus poly-etherimide concentration for blends of a polyetherimide ~nd a polyamide.
It is contemplated that the polyetherimide-polyamide blends of the present invention may also include other additives materials such as fillers, stabilizers, plastici-zers, fle~ibilizers, surfactant agents, pigments, dyes, reinforcements, flame retardants and diluents in conven-tional amounts. It is also contemplatea that the blends of the in~ention may include two or more polyetherimides with one or more polyamides or two or more polyamides in combination w~th one or more polyetherimides.
Methods for forming polyetherimide-polyamide blends may vary considerably. Prior art blending techniques ~o are generally satisfactory. A preferred method comprises blending the polymers and additives such as reinforcements in power, granular or ~ilamentous form, extruding the blend/ and chopping the extrudate into pellets suitable for moldin~ by means con~entionally used to mold normally solid thermoplastic compositions.
The particular polyetherimide-polyamide blends of the present invention have application in a wide variety of physical shapes and forms, including the use as films, molding compounds, coatings, etc. When used as films or when made into molded products, these blends, including laminated products prepared therefrom, not only possess good physical properties at room temperature but they train their strength and excellent response to workloading at elevated tempexatures for long periods of time. Films ~ormed from the blends of this invention may be used in application where films have been used previously. ThUs~the ,. , ..

- , ., .. , . : :. :

blends of the present invention can be used in automobile and aviation applications for decorative and protective purposes, and as high temperature electrical insulation for motor slot liners/ transformers, dielectric capacitors, cable and coil wrappings (form wound coil insulation for motors~, and for containers and container linings. ~he blends can also be used in laminated structures where films or solutions of the blend are applied to ~arious heat-resistant or other type of materials such as asbestos, mica, ~lass fiber and the like, the sheets super-imposed one upon the other, and thereafter subjecting the sheets to elevated temperatures and pressures to effect flow and cure of the resinous binder to yield cohesive laminated strcutures. Films made from the subject poly-l~ etherimide-polyamide blends can also serve in printed circuit applications.
Alternatively, solutions of the blends herein des-cribed can be coated on electrical conductors such as copper, aluminum, and the like and thereafter the coated conductor can be heated at elevated temperatures to remove the solvent and to form a continuous coating of the re-sinous composition thereof. If desired, an additional overcoat may be applied to such insulated conductors includin~ the use of polymeric coatings, such as poly-amides, polyesters, silicones, polyvinylformal resins, epo~y resins, polyimides, polytetrafluorethylene, etc.
The use of the blends of the present invention as overcoats on other types of insulation is not precluded.
Other applications which are contemplated for these blends include their use as binders for asbestos fibers, carbon iberst and other fibrous materials in making brake linings. In addition, molding compositions and molded articles may be formed from the polymeric blends of the in~ention such as by incorporating such fillers as asbestos, glass fibers, tàlc, ~uartz, powder, finely divided carbon, silica, and the like into the blends prior to molding.

, ~ .. . : :

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- 14 ~

~naped articles may be formed under heat, or under heat and pressure, in accordance with practices well-known in the art.
The following examples illustrate specific poly-etherimide-polyamide blends in accordance with the pre-sent invention. It should be understood that the examples are given for the purpose of illustration and do not limit the invention. In the examples, all parts alld percentages are by weight unless otherwise specified.
1~
Example I
A series of polyetherimide-nylon 6:6 blends, some according to the inYention and some outside the invention, were prepared, the hlends molded into test specimens and the specimens tested for various physical properties.
1~ The polyetherimide of the blends was prepared from the reaction product of essentially equimolar amounts of 2,2-bis~4-(3,~-dicarboxy phenoxy~phenyl] propane dianhy-dride and m-phenylene diamine produced at elevated temperature of about 250 to about 300C. and under a nitrogen atmosphere. The polymer was extruded at about 300C. to form a strand and mechanically chopped into pellets. A test specimen of the polyetherimide was injection molded from the pellets at a temperature of about 685-700F. The physical properties of the poly-etherimide are set forth in the first line of the following Table I.
The polyamide used in preparing the blends was a general purpose nylon 6:6 sold under the tradename Vydyne 21X by Monsanto Chemical Co. This polyamide alone has the properties set forth at the bottom of Table I.
About ~0 parts of the above polyetherimide were mixed with about lQ parts of the polyamide. The mixture of the7rt~wo ; polymers was then extruded in a Werner & Pfleiderer extruder havin~ a temperature profile varying from about 226 to , , . : , , : - ., , ~2~7~?~7~

326C and a die temperature of about 316C. The resulting extrudate was comminuted into pellets and the pellets - injection molded into test specimens in a sattenfield ~
molding machine at a temperature of about 265C to 321C.
The impact strength of these specimens were measured according to the unnotched and notched Izod impact test and the results are set forth in the following Table I.
The heat distoration temperature, flexural properties, tensile properties and appearance of the blend were also determined and are given in Table I.
The above procedure for preparing the blend was then repeated to produce test specimens of three additional blends having varying amounts of polyetherimide relative to the polyamide. The results of the unnotched and notched Izod impact test, as well as the heat distortion temperature, flexural properties, tensile properties and ~ppearance for thes lends are also detailed in Table I.

~ .., - 1 6 ~ 7 ~ 8CU 3 4 5 6 a) ~ I ~ s o o ~ a) o ~:
V o X o a) ~ o ~ o ~ >1~ rl v a) ~ s~ ~ o o t~
s~
E~ O O ~ O ~ O
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~o '~ a o I
S~ ~ O
Q) H ~ Q~ D ~1 1 . , ,. . . (~
O ~P. ~1 0 0~1 0 .-1 P -- _ , U~
d~ ~ ~ O Ln O O O
\O ~ ~ O
.
O
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~ ~ ou~ n . ~h li5 ~,~o ~ I II I I S.C
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~ ~. S a X o ~ ~ ~
I . . .
r~ ~ .P. ~,~ ~1 o O
U~

^
r~ mo .~ ~X ~~D ~ ~ ~ ~r o o o o o ~ H O ~ D ~1 ~ ~S ~ S
H :~~ ~ r~ Ei . _ H 1-1 H H
(~
o~ ~ ~ o ~r o o o o ~
P. ~!) ~ ODr~ ~ J ~ ~ ~ ~
CO ~ Ir~ ~
_ S ~ h h 'h h S
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N (~1 0 r~ r-l O O O r~l r~
H A Z _ _ .
~ o o o o n ~ d~ 'I ~ ~ ~ O
z~8 , .

,, - ~ ,,; . . . .
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In Figures 1-5, some of the data from Table I is plotted versus relative concentration of the components of the blends in solid lines. From Figure 1, a plot of the unnotched Izod impact strength versus polyetherimide concentration, it can be observed that small amounts of nylon result in significantly lower unnotched impact strength values. However, af~er this initial drop, the impact values remain relatively constant to the 50:50 ~lend level before another small decrease is observed.
The notched Izod impact strength values are somewhat similar to the unnotched values. The notched impact strength of the blends decreased from pure polyetherimide to the 70% polyetherimide blend level and then remains ~airly constant regardless of the blend ratio. From Figure 2, it is apparent that the heat distortion tem-perature values decrease only slightly from 100% poly-etherimide to 70% concentrations of polyetherimide, but beyond this point the heat distortion temperature drops a~out 30C. to 140C. where it remains generally constant oyer the rema~nder of the blend compositions tested.
The flexural properties are plotted in Figures 3 an ~. The flexural strength decreases very rapidly from the 100~ polyetherimide to 90% blend level and then increases slightly to a maximum occurring at about a 50:50 blend ratio as is shown in Figure 3. In Figure ~, the flexural modulus can be seen to decrease as nylon is initially added, then level out, and decrease again as the ccncen-tration of polyetherimide in the blends if reduced below about 50%.
From Figure 5, the plot shows that the tensile failure strength decreases substantially at the 10% nylon blend level from the pure polyetherimide level but then the strength`increases to a maximum at about the 50:50 blend level`where it is only about 6% lower than the tensile failure strength of the polyetherimide. The substantial lowering o~ thè tensile strength`in the 90% polyetherimide . ~

.

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: :::: :: :. :~ :

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blend may be due to the presence of a two phase system.
From the above discussion, it can be observed that several of the measured properties of the blends reach a maximum relative to other blends of the total con-centration range at the 50:50 blend level of polyetherimideto polyamide. Consequently, the concentration range about the 50:5Q blend level, i.e., from about 40 to about 60~ polyetherimide is presently preferred for the ~lends of the invention.
Example II
The basic procedure of Example I was repreated using a nylon 12 sold under the tradename L-2101 by Huls instead of nylon 6:6. This polyamide along has the properties set forth at the bottom of Table II. In addition, the extruder temperature profile varied from about 320 to 32~C for the blends containing 10 and 30% polyetherimide and from about 315 to 332C for the remainder of the blends.
The die temperature used in preparing all the blends was about 321.C.
As in Example I, test specimens of each blend were tested for notched and unnotched Izod impact strength as ~ell as for heat distortion temperature, flexural proper-ties and tensile properties. These results and the visual appearance of the various blends are set forth in Table II.

.. . . ... . .. ... . .. ... . . . .... . .. . . .
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7~

The data from Table II is also plotted in dotted lines in Figures 1 throu~h 5 versus relative concentra-tions of the components of the blends. From Figure 1, a plot of unnotched impact strength values versus polyetherimide concentration, it is evident that the unnotched impact decrease from pure polyetherimide (~6.5 ft-lb/inl to the blend containing 70% polyetherimide ~ontent where the values start to increase and finally exhibit maximum at approximately 30% polyetherimide.
In a similar manner, the notched Izod impact strength values of the blends decrease very rapidly between 90%
and 5Q% polyetherimide content and then remain fairly constant as the concentration of nylon increases further.
The heat distort~on temperature values, plotted in Figure 2, decrease rapidly from pure polyetherimide to the 50:50 blend level. Below 50% polyetherimide the heat distortion temperature values decrease only slightly as more nylon is included in the blends. This data suggest a phase inversion occurs around a 50:50 blend composition of the two components.
The flexural strength, plotted in Figure 3, exhibits behavior similar to the unnotched Izod values where the values decreases as the polyetherimide concentration is lo~red to the ~0% level and then increase to a maximum ~5 at approximately a 50:50 blend ratio. The flexural modulus does not exhibit this same behavior but at the 5Q:50 blend ratio the curve does change slope as is shown in Figure 4.
The curve formed by the tensile failure strength in Figure 5 is very similar to both the flexural strength and Izod curves. A maximum in the tensile failure strength is found at about a 30% polyetheri~ide com-position while the tensile failure elongation reaches its hightest value at 3I%. No tensile yield points are e~hibited by any o~ these blends.
It is cont`emplated that substitution of other poly-:, ~ - .

~27~97~

etherimides and/or other polyamides for the polyetherimides and/or polyamides in the blends of the above examples may result in the formulation of polymer blends having similar characteristics.
While the present invention has been described with reference to particular embodiments thereof, it will be ~mderstood that numerous modifications may be made by those skilled in the art withour actually departing from the spirit and scope of the invention as defined in the appended claims.

Claims (23)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A composition comprising a blend of (a) a polyetherimide and (b) a polyamide wherein the polyetherimide comprises about 40% to about 70%
of the blend by weight wherein the polyetherimide has the formula where a represents a whole number in excess of 1, the group selected from:
R1 being hydrogen, lower alkyl or lower alkoxy, Z is a member of the class consisting of (1)
1. Claim 1 continued:
   and (2) divalent organic radicals of the general formula:
   where X is a member selected from the class consisting of divalent radicals of the formulas, -CyH2y-, ?, , -O- and -S-where q is 0 or 1, y is a whole number from 1 to 5, and R is a divalent organic radical selected from the class consisting of (1) aromatic hydrocarbon radicals having from 6-20 carbon atoms and halogenated derivaties thereof, (2) alkylene radicals and cycloalkylene radicals having from 2-20 carbon atoms, and C(2-8) alkylene terminated polydiorganosiloxane, and (3) divalent radicals included by the formula where Q is a member selected from the class consisting of - O- , ? , , -S- and -CxH2x where x is a whole number from 1 to 5 inclusive.
2. 2. A composition in accordance with claim 1 wherein the polyetherimide comprises from about 40% to about 60% of the blend by weight.
3. 3. A composition in accordance with claim 2 wherein the polyetherimide is of the formula:
   and the divalent bonds of the -O-Z-O- radical being in the 3,3'; 3,4'; 4,3' or the 4,4' position.
4. 4. A composition in accordance with claim 1 wherein the polyetherimide is of the formula:
   and the divalent bonds of the -O-Z-O- radical being in the 3,3'; 3,4'; 4,3' or the 4,4' position.
5. 5. A composition in accordance with claim 3 wherein Z is:
   and R is selected from:
   .
6. 6. A composition in accordance with claim 4 wherein Z is:
   and R is selected from:
   .
7. 7. A composition in accordance with claim 5 wherein the polyetherimide is of the formula:
   .
8. 8. A composition in accordance with claim 6 wherein the polyetherimide is of the formula:
   
   .
9. 9. A composition in accordance with claim 1 wherein the polyamide has repeating structural units of the formula:
   wherein R2, R3 and R4, which may be the same or different, each represents an alkylene group having from 4 to 11 carbon atoms, and n is an integer of 30 to 500 or more.
10. 10. A composition in accordance with claim 2 wherein the polyamide has repeating structural units of the formula:
    wherein R2, R3 and R4, which may be the same or different, each represents an alkylene group having from 4 to 11 carbon atoms, and n is an integer of 30 to 500 or more.
11. 11. A composition in accordance with claim 3 wherein the polyamide has repeating structural units of the formula:
    
    wherein R2, R3 and R4, which may be the same or different, each represents an alkylene group having from 4 to 11 carbon atoms, and n is an integer of 30 to 500 or more.
12. 12. A composition in accordance with claim 4 wherein the polyamide has repeating structural units of the formula:
    wherein R2, R3 and R4, which may be the same or different, each represents an alkylene group having from 4 to 11 carbon atoms, and n is an integer of 30 to 500 or more.
13. 13. A composition in accordance with claim 5 wherein the polyamide has repeating structural units of the formula:
    wherein R2, R3 and R4, which may be the same or different, each represents an alkylene group having from 4 to 11 carbon atoms, and n is an integer of 30 to 500 or more.
14. 14. A composition in accordance with claim 6 wherein the polyamide has repeating structural units of the formula:
    wherein R2, R3 and R4, which may be the same or different, each represents an alkylene group having from 4 to 11 carbon atoms, and n is an integer of 30 to 500 or more.
15. 15. A composition in accordance with claim 7 wherein the polyamide has repeating structural units of the formula:
    wherein R2, R3 and R4, which may be the same or different, each represents an alkylene group having from 4 to 11 carbon atoms, and n is an integer of 30 to 500 or more.
16. 16. A composition in accordance with claim 8 wherein the polyamide has repeating structural units of the formula:
    wherein R2, R3 and R4, which may be the same or different, each represents an alkylene group having from 4 to 11 carbon atoms, and n is an integer of 30 to 500 or more.
17. 17. A composition in accordance with claim 9, 10 or 11 wherein the polyamide is nylon 66.
18. 18. A composition in accordance with claim 12,13 or 14 wherein the polyamide is nylon 66.
19. 19. A composition in accordance with claim 15 or 16 wherein the polyamide is nylon 66.
20. 20. A composition in accordance with claim 1 wherein the polyamide is nylon 66.
21. 21. A composition in accordance with claim 9, 10 or 11 wherein the polyamide is nylon 12.
22. 22. A composition in accordance with claim 12, 13 or 14 wherein the polyamide is nylon 12.
23. 23. A composition in accordance with claim 15 or 16 wherein the polyamide is nylon 12.