Graft polymer of acrylic ester rubber and polyolefin

13 Pages·2013·1.33 MB·English

Unl.t ed States Patent [191 [11] Patent Number: 4,654,402
Patel [45] Date of Patent: Mar. 31, 1987
[54] GRAFI' POLYMER OF ACRYLIC ESTER’ 3,972,961 8/ 1976 Hammer et a1. .................. .. 525/2 21
RUBBER AND POLYOLEFIN 4,129,608 12/1978 Murayama et a1. . 260/836
. 4,211,691 7/1980 Fitzgerald et al .. 525/221
[75] Inventor: Ramnn Patel, Akron, 01110 4,278,572 7/1981 Coran .... .. 260/3
. _ . 4,299,931 11/1981 Coran et a1 525/95
[73] Ass‘gnem Mum” C‘m‘P‘mY’ St- L°“‘s’ Mo' 4,366,289 12/1982 Keskkula ct al .... .. 525/78
[21] APP]_ No‘; 773,763 4,528,329 7/1985 Inoue et a1. ......................... .. 525/78
[22] Filed: Sep. 9, 1985 FOREIGN PATENT DOCUMENTS
_ 429752 6/ 1970 Australia .
Related U.S. Applleation Data 1283213 7/ 1972 United Kingdom .
[62] ‘lggisslgreof Ser. No. 674,240, Nov. 27, 1984, Pat. No. Primary Examiner_carman J. Seccuro
’ ’ Attorney, Agent, or Firm-Gordon B. Seward
[51] Int. C1.4 .................... .. C08L 23/26; C08L 23/36;
COSG 81/02 [57] ABSTRACT
[52] US’ Cl‘ """ "5&3;'gig?gzjggggf;521%2“; Compatibilized polymer blends are described compris
[ss] Field of Search ....... .f ...... .. 525/194 221’ 931 74 mg a blend °f def-m P°1Ym°" cmss'linkabk Wyn"
’ ’ 525/“; ester copolymer rubber, and a compatibilizing amount
_ of a graft copolymer comprising acrylic ester copoly
[56] References Cited mer compatibilizing segments and ole?n polymer com
patibilizing segments.
U.S. PATENT DOCUMENTS
3,236,914 2/1966 Murdock et a1. .. 260/857
3,966,672 6/1976 Gaylord ................ .. 525/197 6 Claims, No Drawings
4,654,402
1 2
ing molecular segments are chemically linked to one
GRAFI‘ POLYMER OF ACRYLIC ESTER RUBBER another. The term, as used herein, encompasses block
AND POLYOLEFIN copolymers as well. Examples of ole?n compatibilizing
segments are polybutadiene, polyisoprene, and po
This is a division of application Ser. No. 674,240, ?led
lyalkenamer segments, as well as segments of the ole?n
Nov. 27, 1984, now U.S. Pat. No. 4,555,546.
polymers themselves and any other segments compati
This application relates to improved polymer blends
ble with the ole?n polymer. Examples of acrylic co
of ole?n polymer and cross-linkable acrylic ester co
polymer rubber compatibilizing ‘segments are segments
polymer rubber, and in particular, blends of enhanced
of epichlorohydrin polymer, nitrile polymer, urethane
compatibility due to the presence of a graft copolymer
polymer, vinyl chloride polymer, polyamide, poly
comprising acrylic ester copolymer rubber compatibil
amine, acrylic polymer, and polyester, as well as seg
izing segments and ole?n polymer compatibilizing seg
ments of acrylic ester copolymer rubber itself and any
ments. . other segments compatible with the acrylic ester co
BACKGROUND OF THE INVENTION polymer rubber. Compatibilizing segments have chemi- .
Compatibilized blends of ole?n polymer and nitrile cal or physical af?nity for ole?n polymer or acrylic
rubber are known, U.S. Pat. No. 4,299,931. Although ester copolymer rubber. The compatibilizing graft co
these blends exhibit useful properties, they are not suit polymer has af?nity for both the ole?n polymer and the
able for applications involving low and high tempera 20 acrylic ester copolymer rubber and its presence im
ture exposures. Ole?n polymers and acrylic ester co proves the compatibility between ole?n polymer and
polymer rubber are not very compatible with each acrylic ester copolymer rubber. Examples of satisfac
other. Their lack of compatibility prevents the develop tory graft copolymers are described in U.S. Pat. No.
ment of optimum properties in blends of these materials, 4,299,931, Column 3, which disclosure is incorporated
Thus, if the compatibility of the blend components can by reference. A thermoplastic graft copolymer of
be increased, improved blends may be obtained which acrylic ester copolymer rubber and ole?n polymer is
can be used where they are subjected to low and high preferred for preparing the improved compatibilized
temperature environments. blends of the invention. This graft copolymer may be
SUMMARY OF THE INVENTION 30 prepared by causing a reaction to form a bond between
the ole?n polymer and acrylic ester copolymer rubber.
It has now been discovered that an improved compo
Preferably, only one bond is formed for each ole?n
sition comprising a blend of about l-99 parts by weight
polymer molecule and acrylic ester copolymer rubber
of an ole?n polymer which is an amorphous or crystal
molecule. Graft copolymers containing more than one
line essentially saturated homopolymer or copolymer of 35
bond per molecule are satisfactory; but it is preferred
C2-C3 alpha monoole?ns, about 99-1 parts by weight of
that prior to vulcanization the number of bonds is not so
cured acrylic ester copolymer rubber and at least 0.1
high that the resulting graft copolymer is in the form of
weight percent of a graft copolymer which has at least
a network molecular structure and is no longer thermo
one ole?n polymer compatibilizing segment derived
plastic. However, during vulcanization of the rubber
from an ole?n polymer which is an amorphous or crys
the graft copolymer {may become extensively cross
talline essentially saturated homopolymer or copolymer
of C2-C3 alpha monoole?ns, or from polybutadiene, linked.
One embodiment of the invention relates to an espe
polyisoprene or a polyalkenamer, and at least one
cially effective class of graft copolymers comprising
acrylic ester copolymer rubber compatibilizing segment 45
segments of ole?n polymer and acrylic ester copolymer
derived from a polymer selected from epichlorohydrin
rubber, said graft copolymer being prepared from an
polymers, nitrile rubber, urethane polymers, vinyl chlo- .
ride polymers, polyamides, polyamines, polyesters and ole?n polymer containing one or more graft forming
functional groups. More preferred graft copolymers are
cross-linkable acrylic ester compolymer rubbers.
prepared from ole?n polymer and acrylic ester copoly
A preferred composition comprises a blend of about
mer rubber each of which contains graft forming func
10-90 vparts by weight of ole?n polymer; and corre
sponding, about 90-10 parts by weight of acrylic ester tional groups. Examples of satisfactory functional
groups are carboxy-, halo- (preferably, chloro- or‘
copolymer rubber, and 05-25 parts by weight of a
compatibilizing graft polymer. A more preferred com bromo-), amino-, isocyanate groups, groups derived
from methylol phenolic material, hydroxy groups,
position comprises a thermoplastic blend of about 20-60
parts by weight of polypropylene, about 80-40 parts by epoxy groups and sulfonyl, sulfonic acid or salt groups.
weight of cured acrylic ester copolymer rubber and Functional ole?n polymer and acrylic ester copolymer
0.5-25 parts by weight of a compatibilizing graft poly rubber may be prepared by known techniques and some
mer in which the rubber is dynamically vulcanized by of these materials are commonly available. For exam
masticating the blend under vulcanization conditions. It ple, functional groups may be provided during poly
is believed that when the blend is dynamically vulca merization/ by copolymerizing an ole?n and a monomer
nized that the cured rubber is in the form of small parti coontaining functional groups, for example, an unsatu
cles dispersed throughout the polypropylene. rated carboxylic acid. Alternatively, functional groups
65
The term “graft copolymer” means a material in may be introduced by direct reaction with the polymer
which ole?n polymer compatibilizing molecular seg by known grafting reactions. The functional groups
ments and acrylic ester copolymer rubber compatibiliz may react directly to form a graft copolymer between
4,654,402
3 4
the ole?n polymer and acrylic ester copolymer rubber. very small amount of free radical generator which form
If the functional groups are such that they will not react transient “molecules” of functionalized ole?n polymer
with each other, it will be necessary to provide another in which the functional groups are unpaired electrons of
reactant, herein referred to as a grafting agent, in order the so-formed polymeric free radical. The polymeric
to form a graft copolymer. For example, when the func free radical (functionalized ole?n polymer) then attacks
tional group of the polyole?n is carboxy and the acrylic the acrylic ester copolymer rubber molecules to form
ester copolymer rubber also contains carboxy groups a the compatibilizing graft copolymer molecules which
polyfunctional reactant such as a polyamine, preferably contain molecular segments of both acrylic ester co
a diamine, may react with the earboxy groups to form a polymer rubber and ole?n polymer. A reduction in
graft copolymer. If the functionalities on the polyole?n either the molecular weight or concentration of acrylic
and the acrylic ester copolymer rubber are hydroxy and ester copolymer rubber suppresses the formation of
amino, a polyisocyanate grafting agent will be effective rubber gel. Also, low molecular weight rubber mole
to form a graft copolymer. Graft copolymers which are cules are mobile and can diffuse rapidly to the ole?n
derived from methylolphenolic modi?ed ole?n poly polymer free radical sites for graft copolymer forma
mer or maleic modi?ed ole?n polymer, carboxy-con tion; the resulting compatibilizing graft copolymer mol
taining acrylic ester copolymer rubber, and a diamino ecules can also diffuse more rapidly to the ole?n polym
grafting agent are especially preferred. er-acrylic ester copolymer rubber interface to exert
To insure that reaction occurs between functionaliz 20 their compatibilizing effect.
ing agent and ole?n polymer, it is frequently advisable, - Any graft copolymer of ole?n polymer and acrylic
and sometimes essential, that the ole?n polymer be ester copolymer rubber is suitable for preparing com
functionalized in the absence of rubber, before admix patibilized blends of the invention. Examples of suitable
ture with rubber in a later portion of the procedure. graft copolymers, methods for preparing them, and the
However, an ole?n polymer can be functionalized in 25 types of linkages visualized between, for example, poly=
the presence of acrylic ester copolymer rubber by the propylene (PP) and acrylic ester copolymer rubber
action of a highly active curative such as an azide. Here, containing carboxy groups (AAR) are shown as fol
molecules of ole?n polymer are functionalized by a‘ lows:
GRAFT COPOLYMER SYNTHESIS
Treat a molten mixture of
PP and MR with a small amount
of radical source such as an
azide, azo compound, peroxide
or radiation source. For
example, Silane sulfonyl
azide (Hercules ®
coupling agent S3076).
Halogenated polypropylene and
AAR were melt mixed and treated
with a grafting agent containing
amino functional groups. In
general Rl and R can be a
CH; alkyl, aryl group (phenyl)
or hydrogen. R is a hydrocarbon
radical of 2-20 carbon atoms, for
example, alkylene, cycloalkylene,
arylene or combinations of them.
Preferred radicals are radicals
of 6-20 carbon atoms. If 4,4
methylene di-aniline (MDA)
HZN CH2 NH; were used,
R1, R2 are H and Ris
First treat molten PP with
maleic acid or anhydride (in
the presence of peroxide) then
melt mix with AAR and a grafting
agent with —NH2 functional
groups. R being the same as in
2. For example, if 4,4'-methylene
bis(cyclohexylamine) were used,
4,654,402
-continued
GRAFT COPOLYMER SYNTHESIS
Ris
First molten PP is treated with
OH a dimethylol phenolic derivative
(with a catalyst). The modi?ed
PP is then melt mixed with AAR.
I I
Dimethylol phenolic modi?ed PP
OH is melt mixed with MR and a
grafting agent containing
amino groups.
Iii-CH2
Maleic acid/anhydride modi?ed
PP and AAR are treated with a
grafting agent containing —OH
functional groups above melt
temperature of PP. R3 may
be di-, tri-, or tetra
alkylene, cycloalkylene or
arylene. Preferably, R3 is
the same as R above.
ll
o-m-oc-FEJ
i?
o-m-oc-hTJ
Maleic acid/anhydride modi?ed
PP and AAR are melt mixed and
treated with an epoxide wherein
R4 is a substituted ethylene
radical where the substituent
is the residue of the epoxide
molecule.
Maleic acid/anhydride modi?ed
PP and AAR are melt mixed
and treated with a di
isocyanate, wherein R has the
same meaning as before. For
example, if tolylene 2,4
diisocyanate were used, R is
4,654,402
7
-continued
GRAFI' COPOLYMER SYNTHESIS
CH3
The properties of the rubber-plastic blends and their
vulcanizates are improved by the presence of an appro
priate compatibilizing graft copolymer". The compatibil period of about l—20 minutes, and 0.1 to 20 weight
percent methylol phenolic material, in the presence of
izing graft copolymer can be formed by the direct inter
an activator (catalyst) which promotes reaction be
action of the functional groups present on the individual
tween methylol phenolic material and the ole?n poly
components, i.e., the ole?n polymer and the acrylic
mer. An example of a satisfactory activator is a Lewis
ester copolymer rubber, or by an interaction of these
acid. Another suitably functionalized ole?n polymer
individual components with another bi- or multifunc
may be prepared by causing an unsaturated carboxylic
tional compound (grafting agent). The direct interac
20 acid such as acrylic or methacrylic acid, maleic acid,
tion of functional groups occurs when the functional
anhydride, or ester, or N-substituted maleamic acid, to
group on each component is different, but is capable of
react in the presence of a free radical generator with
reacting with the functional group present on the other
ole?n polymer, by known processes. For example, see
component. If, for example, an acid or anhydride group
US. Pat. No. 2,973,344. The resulting functionalized
is present on one component, then any other component 25
ole?n polymer is then caused to react with functional
with an
ized acrylic ester copolymer rubber.
Ole?n polymers suitable for functionalization to give
r-OH, —T'7 —NHR, —CH2OH, or —NCO group graft copolymer precursors comprise amorphous or
O 30 crystalline essentially saturated homopolymers or co
polymers of C2-C3 alpha monoole?ns. Thermoplastic
can interact to form a compatibilizing graft copolymer. crystalline ole?n polymers are especially preferred. An
If both the components have similar groups, such as an important subgroup of ole?n polymers comprises high
acid group, then a di- or poly-functional grafting agent molecular weight solid products from the polymeriza
such as a diol or polyol, for example, pentaerythritol, a tion of one or more monoolefms by either high pressure
diamine, for example, methylene dianiline, an epoxide, or low pressure processes. Examples of such polymers
di- or polyisocyanate, etc., can be used to react with are the isotactic or syndiotactic monoolefm polymers,
both the functionalized ole?n polymer and acrylic ester representative members of which are commercially
copolymer rubber. When dissimilar groups which do available. Satisfactory ole?ns include ethylene, propy
40
"not react with one another, such as'an —-OH on one lene, 1=butene, 1=pentene, l-hexene, 2~methyl~l-pro
component and a halogen or —NHR are present on the pene, 3~methyl-l-pentene, 4-methyl-=l-pentene, 5=meth
other component, then the bridging component should yl-l-hexene, and mixtures thereof. Commercially avail
be such that its functional groups should interact with able thermoplastic polyole?n resins, such as polyethyl
both the components. To prepare the compatibilizing ene, polybutene-l, and polypropylene, or mixtures
graft copolymer in another way, one can mix the appro thereof, may be advantageously used in the practice of
priate components together and treat the mixture with a the invention with polypropylene being preferred. Also
radical source such as a peroxide, radiation, or a his azo suitable for the practice of the invention are copolymers
compound. The compatibilizing graft copolymer may of two or more ole?ns with copolymers of ethylene and
be pre-formed and then added to the blend or it may be propylene being preferred.
formed in situ. Any methylol phenolic material which will form a
Generally, the amount of graft forming functional graft with ole?n polymer may be used in the practice of
groups does not exceed 10 weight percent of the olefin the invention. Suitable methylol phenolic material may
polymer or acrylic ester copolymer rubber. It can, how be prepared by condensation of unsubstituted phenol, a
ever, be considerably lower with amounts of about 1 C1—C1() aJkyl-p-substituted phenol, or halogen substi
percent or less being enough to cause sufficient graft tuted phenol with an aldehyde, preferably, formalde
copolymer formation to enhance the compatibility of a hyde in an alkaline medium, or by condensation of phe»
blend of ole?n polymer and acrylic ester copolymer nol dialcohols. Methylol phenolic material includes
rubber. polymeric phenols containing up to 10 benzene rings
The compatabilizing graft copolymer can be formed but preferred materials contain no more than three ben
from compatibilizing segments provided they are func zene rings. Especially preferred are methylol phenolic
tionalized so as to mutually interact to form a link there materials derived from dimethylol phenol substituted
between. 65 with C5~C1Q alkyl groups preferably tertiary alkyl
A suitable functionalized ole?n polymer may be con groups in the para position. Examples of satisfactory
veniently prepared by masticating ole?n polymer, pref dimethylol phenolic materials are described in US. Pat.
erably at a temperature above its melting point, for a Nos. 2,972,600; 3,093,613; 3,287,440; 3,709,840; and
4,654,402
10
3,211,804, Column 5, lines 3-67, the disclosures of depend upon the types of ole?n polymer and acrylic
which are incorporated herein by reference. Haloge ester copolymer rubber and upon the type and amount
nated, for example brominated, methylol phenolic ma of graft copolymer. Typically, mixing times of about
terials are also suitable. These halogenated materials 0.5-30 minutes are satisfactory. If the polymer blend is
release, at elevated temperatures, hydrogen halide, obviously non-homogeneous, additional mixing is re
which in the presence of a metal oxide such as zinc quired. When the blend components are thoroughly
oxide, serves as an acidic activator. Suitable methylol mixed, improved properties are obtained.
phenolic materials are commercially available; for ex The copatibilized blends of the invention are further
ample, they may be purchased under the trade names of 0 improved by cross-linking, or curing acrylic ester c0
SP-l045, SP-l055, SP-1056, CRJ 352, and certain Aro polymer rubber by conventional techniques. Cross-link
fene resins. ing agents (curatives) are incorporated into the blends
Any activator (catalyst) which promotes the graft
and the blends are heated to effect cure. The character
formation between ole?n polymer and methylol pheno istics of the blends containing cured acrylic ester co
lic materials is suitable for the practice of the invention. polymer rubber depend upon the relative proportions of
Preferred activators are Lewis acids which include the ole?n polymer and acrylic ester copolymer rubber and "
acid-acting metal halides such as boron tri?oride, stan whether the compositions are statically or dynamically
nous chloride, zinc chloride, titanium tri- or tetrachlo cured. Static curing can give thermosetcompositions
ride, aluminum chloride, ferric chloride, ferric bromide,
when the blend contains more than 30 parts by weight
zinc bromide, aluminum bromide or complexes thereof.
of cured acrylic ester copolymer rubber per 100 parts
Suitable Lewis acids are described in U.S. Pat. No. by weight of total polymer; whereas, dynamic curing
4,121,026, Columns 5-6, the disclosure of which is
can give thermoplastic compositions even when the
incorporated herein by reference.
blend contains 80 or more parts by weight of cured
Suitable acrylic ester copolymer rubbers comprise 25
acrylic ester copolymer rubber per 100 parts by weight
rubbery, cross-linkable acrylic ester copolymers. The
of total polymer. Generally, compositions comprising
rubbers of the invention are copolymers of one or more
about 50 parts or more of cured acrylic ester copolymer
C1-C4 alkyl acrylate or methyacrylate ester with one or
rubber per 100 parts by weight of ole?n polymer are
more C2-C8 alpha ole?ns or dissimilar C1-C4 alkyl acry
elastomeric. The effect of the relative proportions on
late or methacrylate ester, and are cross-linkable by
blend composition characteristics cannot be de?ned
virtue of having reactive groups such as carboxy, hy
with precision because the limits vary depending upon a
droxy, epoxy, halo, amino, isocyanates, sulfonyl or sul
number factors, such as, the kind of ole?n polymer and
fonate groups. These rubbers may be prepared by copo
acrylic ester copolymer rubber, the presence of ?llers,
lymerizing an alkyl ester of an unsaturated carboxy acid
plasticizers and other ingredients, and the extent the
with another such ester or with an alpha ole?n and a
rubber is cured. When preparing graft copolymer in
third monomer containing any of the reactive groups
situ, it is not necessary that the grafting agent and the
referred to above. Or, a cross-linkable acrylic ester
rubber curative are the same material, however, often it
rubber can be prepared by the process of U.S. Pat. No.
is convenient and sometimes preferred that they are the
4,415,710, the disclosure of which is-hereby incorpo
same. Generally, the graft copolymer forms prior to or
rated by reference. Preferred rubbers include acrylic
simultaneous with curing (cross-linking) the rubber. Of
acid-acrylic ester-alpha-olefm terpolymers which are’
essentially non-crystalline and have glass transition tem course, it is understood that the properties of the com
positions of the invention may be modi?ed by the addi
peratures (T g) below room temperature. The rubber 45
may be prepared by partial hydrolysis of a polyacrylate tion of ingredients which are conventional in the com
pounding of ole?n polymer, acrylic ester copolymer
rubber to obtain the required acid groups. Polyacrylate
rubber, and blends thereof. For additional information
rubbers suitable for this preparation are described in
concerning compounding and dynamic vulcanization,
Rubber World Blue Book, 1975 Edition, pages 399-400.
Suitable acidic copolymer rubbers are preferably pre refer to U.S. Pat. No. 4,104,210, issued Aug. 1, 1978.
pared by polymerization of alkyl acrylate, acrylic acid Compositions prepared by dynamic vulcanization com
prising a blend of about 20-60 parts by weight of ole?n
or methacrylic acid and an alpha ole?n of 2-8 carbon
polymer, preferably polypropylene, and correspond
atoms. A preferred rubber is a polymer of ethylene,
ingly, about 80-40 parts by weight of cured acrylic ester
C1-C4 alkyl acrylate and acrylic acid. A more preferred
copolymer rubber in the form of small particles (prefer
acrylic acid rubber is a polymer comprising at least 50
mole percent of ethylene, about 0.5 to 10 mole percent ably 50 microns or less) dispersed throughout the ole?n
acrylic acid and about 10 to 49.5 mole percent of alkyl polymer, in which the blend has been compatibilized,
acrylate. before or after vulcanization, with a graft copolymer
comprising ole?n polymer compatibilizing segments
The improved blends of the invention may be pre
pared by mixing ole?n polymer, acrylic ester copoly and .acrylic ester copolymer rubber compatibilizing
mer rubber, and graft copolymer, preferably above the segments are especially preferred. Elastomer composi
melting point of the ole?n polymer by use of conven tions generally contain no more than 55 parts of poly
tional masticating equipment, for example, a rubber propylene per 100 parts of the composition.
mill, Brabender Mixer, Banbury Mixer, or twin screw Improved blend compositions of the invention can be
continuous mixer. Mixing times should be suf?cient to used. to form a variety of molded, extruded, or calen
obtain homogeneous blends. Satisfactory mixing times dered articles. The properties of the blend depend upon
4,654,402
11 12
the proportions of the components in the blend with a from the solution upon cooling. The unreacted 4,4’
wide range of properties being available simply by methylene bis(cyclohexylamine) and any by-products
varying the proportions of the blend components. are removed by washing with acetone. The product,
The stress-strain properties of the composition are amine-modi?ed polypropylene, is designated DA
determined in accordance with ASTM test procedure mod-PP.
D-638. True stress at break (T SB) is the tensile strength A graft copolymer is prepared by melt mixing at 190‘
at break multiplied by the extension ratio also at break, C. for 4-5 minutes in a Brabender mixer, 40 parts of
extension ratio being the length of a tensile test speci DA- mod-PP and 60 parts of acidic acrylic ester co
men at break divided by the original, unstressed length polymer rubber, Vamac G (described in greater detail
of the test specimen. Alternatively, extension ratio is below). The product designated Graft Copolymer-l is a
1.00 plus l/ 100 of the percent ultimate elongation. graft copolymer comprising polypropylene compatibil
izing segments and acidic acrylic ester copolymer rub
DESCRIPTION OF THE PREFERRED
EMBODIMENTS ber compatibilizing segments.
15
Modi?ed (Functionalized) Ole?n Polymers Compatibilized-Polymer-Compositions
Polypropylene having maleic acid groups grafted compatibilized polymer compositions are prepared
thereto is prepared by feeding a blend of 100 parts of by melt mixing ole?n polymer, acrylic ester copolymer
polypropylene (Profax @ 6723), 2.5 parts of maleic acid rubber and a graft copolymer (compatibilizing agent).
20
and 2 parts of an organic peroxide, 2,5-dirnethyl-2,5 Usually, the graft copolymer is made in situ by melt
bis(t-butylperoxy)hexane (40% active on clay), Luper mixing a functionalized ole?n polymer and acrylic ester
co ® 101X to a Reedco twin-screw mixing extruder at copolymer rubber with a difunctional grafting agent.
200° C. with a feed rate of 200 g/min. All parts are by Since usually the grafting agent is also a curative for the
weight in this and the following examples. The product, 25 rubber, it is convenient to use enough grafting agent
maleic acid modi?ed polypropylene, is designated MA (rubber curative) to form the graft copolymer and to
cross-link the rubber. Preferably, the rubber is dynami
I PP-l.
Polyethylene, having maleic acid groups grafted cally vulcanized, i.e., the mass of molten ole?n polymer
thereto, is prepared by masticating 100 parts of high and rubber are masticated until the rubber is cured.
30
density polyethylene (Marlex ® EHM 6006), 2.5 parts Materials used to illustrate the invention are as fol
of maleic acid and 0.05 parts of 2,5-dimethyl-2,5-bis(t lows: acidic acrylic ester copolymer rubber (AAR) in
butylperoxy)hexane (90% active), Lupersol ® 101 at 80 the tables) is purchased under the tradename Vamac,
rpm in a Brabender mixer. The batch size is 50-55 grams believed to be a terpolymer of about 73 mole percent of
and cam type rotors are used. The polyethylene and 35 ethylene, about 26 mole percent of methyl acrylate and
maleic acid are ?rst melt mixed at 150° C. and then the about one mole percent of a carboxylic acid. Vamac G
peroxide ‘is added and mixing is continued for about 5 is the neat terpolymer. Vamac 123 is a masterbatch of
minutes at l60°—165° C. The mass is then removed and 100 parts of rubber and 23 parts of fumed silica, stabiliz
cooled in a press. The product, maleic acid modi?ed ers and processing aids which, for convenience, are
polyethylene is designated MA-PE-l. shown separately in the tables and designated S,S, PA.
The same procedure is followed except low density An amine antioxidant, Naugard 445, is designated in the
polyethylene (Dowlex @ 2476) and 0.1 part of peroxide tables as N445. Polypropylene (PP) is Profax ® 6723.
are used. The product, maleic acid modi?ed polyethyl Low density polyethylene (LDPE) is Dowlex ® 2476,
ene is designated MA-PE-Z. 45 high density polyethylene (HDPE) is Marlex ® EHM
Polypropylene having methylol phenolic groups 6006. 4,4'-methylene dianiline, is designated‘ MDA.
grafted thereto is prepared by masticating 100 parts 4,4’-methylene bis(cyclohexylamine) is designated
polypropylene (Profax 6723) and 2 parts of dimethylol MCA. Hexamethylenediamine carbamate is DIAK-l.
p-octylphenol (SP-1045) at 80 rpm and 190° C. in a 4,4’-methylene bis(cyclohexylamine)carbamate is
Brabender until a molten homogeneous mixture is ob 50 DIAK-4. MDA, MCA, DIAK-l and DIAK-4 act both
tained. 0.2 parts of SIlCl2.2H2O are added and mixing is as grafting agents and rubber curatives. All 'parts are by
continued for 3 minutes. The mass is then removed and weight in the tables.
cooled in a press. The product is designated Ph.Mod. Compositions of the invention comprising improved
PP. 55 compatibilized blends are illustrated in Tables l-8.
Polypropylene having amino groups grafted thereto Table 1 illustrates compositions prepared from pre-pre
is prepared by ?rst preparing a maleic acid modi?ed pared graft copolymer compatibilizing agent and from
polypropylene and then reacting it with excess diamine. graft copolymer compatibilizing agent prepared in situ.
To a Brabender mixer at 180° C. and 100 rpm, there are The acidic acrylic ester copolymer rubber (AAR) is
charged 100 parts of polypropylene (Profax 6801) and Vamac G. The DA modi?ed-PP] and Graft Copolym
2.5 parts of maleic acid. After the mass is molten and er-l are as described above. Compositions of Stocks 1,
mixed, there is added 0.15 parts of organic peroxide, 3, and 5 are prepared by melt mixing at 100 rpm at 190°
Lupersol 101, and mixing is continued for ?ve minutes. C. for ?ve minutes in a Brabender mixer. The stocks are
Five parts of 4,4'-methylene bis(cyclohexylamine) is removed, then returned to the mixer and remixed for
65
then added and mixing is continued for ?ve minutes at one additional minute. Compositions 2, 4 and 6-9 were
190° C. The mass is removed, cooled, crushed and then dynamically vulcanized by masticating in the presence
dissolved in boiling xylene. The product precipitates of curatives. After melt mixing the AAR and PP for
4,654,402
13 14
two minutes, the stabilizer and curatives are added. The tions are nearly the same as the controls since the graft
MDA is added before the MCA or DIAK-4 is added. copolymer contains 60% AAR and 40% polypropyl
Mixing (at 190° C. and 100 rpm) is continued for 3 min ene.
TABLE 1
1 2 3 4 5 6 7 8 9
AAR 6O 60 54 54 60 60 6O 6O 60
PP 40 40 36 36 36 36 40 40 40
DA-Mod. PP-l - - - - 4 4 - _ -
Graft Copolymer-l — -— 10 10 — - — 6 6
MDA - 0.9 - 0.9 - 0.9 1.2 1.2 1.2
MCA - 0.6 - 0.6 - 0.6 - - -
DIAK-4 - — - - - - 0.3 0.3 0.3
N-445 1.2 1 2 1 2 1.2 1.2 1.2 1.2 1.2 1.2
ProErties
Ts, MP8 3.8 9.2 2.8 18.6 4.3 20.6 11.4 18.6 189
Mm. MPa - _ - 14.8 - 15.7 10.1 12.6 12.3
UE, % 80 160 120 390 150 450 440 470 470
Ten. Set, % Broke 46 81 43 81 39 56 41 45
TABLE 2
1 2 3 4 5
(a) (b) (a) (b) (a) (b) (a) (b) (a) (b)
AAR 10 10 20 20 30 30 40 40 50 50
PP 90 85.5 80 72 70 63 60 54 50 45
MA-PP-l - 4.5 -— 8 -— 7 — 6 — 5
MDA 0.15 0.15 0.3 0.3 0.45 0.45 0.6 0.6 0.75 0.75
MCB 0.1 0.1 0.2 0.2 0.3 0.3 0.4 0.4 0.5 0.5
N 445 0.2 0.2 0.4 0.4 0.6 0.6 0.8 0.8 1.0 1.0
2%
TS, MPa 21.4 34.6 17.4 37.2 14.4 38.6 13.2 26.9 11.1 25.8
M100, MPa 19.8 21.3 — 22.5 — 23.5 — 16.0 — 16.3
U.E., % 380 490 220 520 135 540 150 550 185 525
Tension Set, % Broke Necked Broke Neeked Broke 59 67 54 56 48
TSB, MP8 103 204 56 231 34 247 33 175 32 162
6 7 8 9
(a) (b) (a) (b) (a) (b) (a) (b)
AAR 60 6O 70 70 80 80 90 90
PP 40 36 30 27 20 18 10 9
MA-PP - 4 - 3 - 2 _ 1
MDA 0.9 0.9 1.05 1.05 0.36 0.36 0.41 0.41
MCBA 0.6 0.6 0.7 0.7 0.24 0.24 0.27 0.27
Stabilizer 1.2 1.2 1.4 1.4 1.6 1.6 1.8 1.8
£19m.
TS, MPa 9.2 25.1 9.2 17.1 4.9 8.4 3.3 4.5
M300, MPa -— 13.7 — 12.3 3.8 5.2 1.4 1.5
U.E.. % 190 515 275 420 630 640 780 1150
Tension Set, % 43 37 29 25 41 47 13 17
TSB, MPa 27 155 35 89 36 62 29 56
utes after maximum consistency is reached. In Stocks 3, TABLE 3
4 and 8, the Graft Copolymer-l is added before the 1 2 3 4 5 6
curatives. In Stock 9, the Graft Copolymer-l is added 50
. . . . . . AAR 60 60 60 60 60 60
after vulcanization is complete as indicated by maxi- S’S’ PA m; m; 13$ 1“ 13.8 133
mum consistency of the Brabender mixer. The stocks PP 36 36 36 36 36 36
are removed, then returned to the mixer and re-mixed gas“ I; 4 0‘; 0‘; 0‘; 1;
for one additional minute. All compositions are com- 55 DIAKJ '_ 11 0:9 '_ ' '
pression molded at 210° C. Tensile properties of speci- DIAK-4 —— — —- 0.9 0.6 0.3
Propgrties
mens are evaluated on a T-500 Tensometer at a speed of TS MP 24 4 21 7 17 1 19 o 20 2 2o 8
20 i. nches (50.8 cm) per mi.n ute. Stocks 1, 2 and.3' are M30,0 , MaP 3 I“. 19.2 16.5 _. l7'. 7 17.9
controls of unvulcanized and vulcanized compositions, UE, % 430 350 330 270 380 370
respectively, of a blend of acidic acrylic ester copoly- 6'0 Tm Se" % 37 3° 33 3° 33 33
. TSB, MP3 129 98 74 70 97 98
mer rubber and unmodified polypropylene. The data #3 ASTM on, 27 29 23 24 24 23
shows that tensile properties are improved by vulcani- (70 h, _100‘’ 0) wt. % swell
zation. Stock 3 shows that the addition of a graft 00- 5182:" Agggé
polymer has little effect in the absence of curatives 65 TS MP3 213 195 214 1&1 190 220
while Stock 4 shows that tensile properties are about UE, % 350 260 180 170 230 210
double when the rubber is cured in the presence of the TSB, MPa 129 98 74 70 97 98
graft copolymer. It should be noted that the composi
4,654,402
15 16
TABLE4
1 2 3 4 5 6 7 8 9 10 11
AAR 50 50 50 50 50 50 50 75 75 25 25
S,S+PA 11.5 11.5 11.5 11.5 11.5 11.5 11.517.2517.25 5.75 5.75
PP 50 49.5 47.5 45 40 30 -— 25 22.5 75 67.5
MA-PP-1 —- 0.5 2.5 5 10 20 50 -— 2.5 -— 7.5
MDA 1.5 1.5 1.5 1.5 1.5 1.5 1.5 2.25 2.25 0.75 0.75
DIAK-4 0.25 0.25 0.25 0.25 025 0.25 0.25 0.38 0.38 0.13 0.13
mime-s .
TS, MPa 11.6 15.5 25.0 28.7 24.5 23.7 16.7 8.17184 18.3 27.1
M300,MPa -— — 18.1 18.3 17.9 17.9 14.4 7.6 7.9 -- 18.3
U.E.,% 97 290 410 445 405 415 230 120 295 63 460
Tension Set, % broke 45 42 40 39 41 46 18 17 broke 62
TSB,MPa 23 60 128 156 124 122 55 18 73 30 152
TABLE 5
1 2 3 4 5 6 7 8 9 10
AAR 60 60 60 60 60 60 60 60 60 60
S,S+PA 13.8 13.8 13.8 13.8 13.8 13.8 13.8 13.813.8 13.8
HDPE 40 36 32 28 2O — - - — —
LDPE — -- -— — —— 40 36 32 28 20
MA-PE-l — 4 8 12 20 —- — -— —— —
MA-PE-Z - — -— — — — 4 8 12 20
Ban-iii
TS,MPa 12.3 16.8 18.5 19.6 17.4 12.6 15.4 15915.9 16.8
MgooMPa — 14.5 14.8 13.1 14.8 — 14.1 12812.6 13.3
U.E.,% 210 360 380 440 360 280 340 360 380 370
Ten. Set, % 38 34 35 39 37 25 24 27 27 29
TSB,MPa 38 77 89 106 80 48 68 73 76 79
TABLE 6 3° TABLE 6-continued
1 2 3 4 5 1 2 3 4 5
AAR 60 60 60 60 60 TS, MP3 4.8 5.9 10.7 22.1 17.2
S, S, PA 13.8 13.8 13.8 13.8 13.8 M100, MP3 4.9 5.9 10.0 10.1 10.0
PP 40 -- 40 — 2O UE, % 190 175 140 405 355
Ph.-Mod.-PP - 40.9 - 40.9 20.4 35 Ten. Set,% so broke 34 34 34
MDA — — 1.8 1.8 1.8 TSB, MP1! 14 16 26 112 78
Progerties
TABLE 7
1 2 3 4 5 6 7 8 9 10 11 12
AAR 60 60 6O 60 6O 60 6O 6O 60‘ 6O 60 60
S,S,PA 13.8 13.8 13.8 13.8 13.8 13.8 13.8 13.8 13.8 13.8 13.8 13.8
PP 40 36 40 36 40 36 4O 36 40 36 40 36
CH’? - 4 - -- - - - - - - - -
MA-PP'I - - - 4 - 4 - 4 - 4 - 4
MDA 1.8 1.8 - - _ - _ — - - - -
Silane A-1100 -— — 1.8 1.8 -— -- -— -— -— — —- —
Silane A-187 -— — — 1.8 1.8 -— — —- —- —
Pentaerthyritol — - — — - — 1.8 1.8 — — — —
Epoxide,Epon 828 —- —- —— -- —- —- — -— 2.4 2.4 —— -—
Tolylcne 2,4- -— — — — — — — — -— —- 2.4 2.4
diisocyanam
Progerties
TS, MPa 10.7 22.6 9.5 14.5 9.2 11.0 9.6 21.4 9.9 13.2 11.4 23.5
M30Q,MP8 — 12.3 — 14.5 —— -— — 18.2 -—- 13.2 -— 16.3
UE,% 140 510 110 300 60 .270 80 350 160 300 190 420
Ten. Set, % 34 38 broke 47 broke 50 broke 32 52 41 40 40
T53, MP8 26 138 20 58 15 41 17 96 26 53 33 122
TABLE 8
1 2 3 4 5 6 7 8 9
Plasticizer none M-17 79TM B-16 429 diundecyl 148 711 97
phthalate
Properties
TS, MPA 27.3 20.6 18.9 19.8 20.8 19.5 20.0 21.6 19.2
M300, MP8 20.5 16.1 17.2 16.2 17.8 17.2 16.2 18.7 17.2.
UE, % 430 430 340 410 370 360 390 370 350
Shore D Hardness 44 38 37 38 38 36 39 38 37
Ten. Set, % 35 32 27 30 31 26 34 27 24
#3 ASTM 011, 38 29 28 30 34 27 30 28 28
4,654,402
17 18
TABLE 8-continued
1 2 3 4 5 6
wt. % Swell
Stock 6 illustrates the preparation of a graft copolymer
in situ by the reaction of modi?ed PP, AAR and graft
ing agent (curative). The curative, MDA, serves both as
a grafting agent to form a graft copolymer comprising amount of graft copolymer has been formed. Stock 7
polypropylene compatibilizing segments and rubber shows that all of the polypropylene can be replaced by
compatibilizing segments and as a rubber curative. The modi?ed polypropylene, but that lower tensile proper
data shows that blends containing graft copolymer pre ties result. Stocks 9 and 11 illustrate compositions with
pared in situ exhibit superior properties. The data of different rubber/polypropylene ratios. ,
Stocks 8 and 9 show that improved compatibilized Compositions of the invention comprising polyethyl
blends are obtained when the graft copolymer is added 15 ene and the effect of the amount of functionalized poly
either before or after dynamic vulcanization. ethylene are illustrated in Table 5. The compositions are
The effect of the relative proportions of polypropyl prepared and tested by the procedures of Table 1. The
ene and acidic acrylic ester copolymer rubber is illus amounts of curatives and stabilizer for all compositions
trated in Table 2. The acidic ester copolymer rubber, are 1.2 parts of MDA, 0.3 parts of DIAK-4 and 1.2 parts
20
polypropylene, stabilizer and curatives are the same as of N-445. The data indicate that larger quantities of
in Table l. A maleic acid functionalized polypropylene functionalized polyethylene are required for optimum
is used as an intermediate for the in situ formation of a properties (as compared to PP compositions) and that
graft copolymer compatibilizer. The proportions of high density polyethylene compositions exhibit better
rubber and polypropylene are varied from 10-90 and 25 tensile properties than corresponding compositions con
90-10 parts by weight, respectively, in steps of 10 parts taining low density polyethylene.
by weight. For each composition, there is a control (a) Compositions of the invention in which the graft
comprising unmodi?ed polypropylene. In compositions copolymer compatibilizing agents are made in situ from
of the invention (b), 10 percent of the polypropylene is methylol phenolic modi?ed polypropylene are illus
replaced by maleic acid modi?ed polypropylene. The trated in Table 6. The compositions are prepared and
compositions are melt mixed and dynamically vulca tested by the procedures of Table 1. Stock 1 is a control
nized by the procedure of Table 1. Specimens are com with unmodi?ed polypropylene and no curative. Stock
pression molded at 220° C. Tensile properties are deter 2 is a composition corresponding to Stock 1 except the
polypropylene is replaced with phenolic modi?ed poly
mined as in Table 1, except for Stocks 1-3 which were 35
pulled at 2 inches (5.08 cm) per minute. The data show propylene. Stock 3 is a composition corresponding to
that each composition containing maleic acid modi?ed Stock 1, but is dynamically vulcanized. Stock 4 is a
polypropylene (in situ graft copolymer formed) exhibit composition corresponding to Stock 2, but a graft co
substantially improved tensile strength and ultimate polymer is formed in situ and the composition is dynam
elongation. The data show that the true stress at break ically vulcanized. The true stress at break of Stock 4
is two or more times greater when the graft copolymer indicates that this composition is 4 or more times better
is present. than the controls. Stock 5 illustrates a composition com
A study of curatives is shown in Table 3. The acidic prising a 50/50 mixture of unmodi?ed polypropylene
acrylic ester copolymer rubber is Vamac 123 which is a 45 and phenolic modi?ed polypropylene.
masterbatch containing 13.8 part silica, stabilizers Compositions of the invention comprising graft co
processing aids (S,S,PA). The compositions arepre polymers made in situ from various grafting agents
pared and tested by the procedures of Table l. The data (curatives) are illustrated in Table 7. The compositions
show that excellent compositions are obtained with are prepared and tested by the procedures of Table l.
each of the curative systems. The data indicate that The odd numbered stocks are controls and the even
MDA is superior, especially upon aging. numbered stocks are illustrative of compatibilized
The effect of the amount of functionalized polypro blends ofv the invention. Stock 2 contains chlorinated
pylene on blend properties is shown in Table 4. The polypropylene, 26% Cl, m.p. 100° C., Polycoat CP26P.
rubber is Vamac 123. The curative level is held constant 55 Stocks 3 and 4 contain as grafting agent/curative gam
with 3 parts of MDA and 0.5 DIAK-4 for 100 parts of ma-aminopropyltriethyloxysilane, Silane ® A-llOO.
rubber. The compositions are prepared and tested by Stocks 5 and 6 contain as grafting agent/curative gam
the procedures of Table l. The amount of maleic acid ma-glycidoxypropyltrimethoxysilane, Silane® A-l87.
modi?ed polypropylene is varied from replacing one Stocks 9 and 10 contain as grafting agent/curative a
percent of the unmodi?ed polypropylene to replacing it bisphenol-A/epichlorohydrin-based epoxy curing resin,
completely. The data of Stock 2 indicates that improved Epson 828. The data show that superior compositions
compositions are obtained by replacing one percent of are obtained by the presence of a graft copolymer pre
the unmodi?ed polypropylene with MA-modi?ed poly pared in situ from a functionalized polypropylene. The
propylene. The data of Stock 4 indicates that replacing ‘ data also show that compositions comprising chlori
65
ten percent of the polypropylene with MA-modi?ed nated polypropylene (Stock 2), pentaerthyritol (Stock
polypropylene results in compositions exhibiting opti 8) and tolylene 2,4-diisocyanate (Stock 12) exhibit ex
mum properties. This suggests that the optimum traordinarily good tensile properties.