Note: Descriptions are shown in the official language in which they were submitted.
202~121
'..
A PROCESS FOR THE PRODUCTION OF RUBBERS
This invention relates to a process for the production
of a rubber containing 5 to 60 and preferably 5 to 40
phenolic OH groups, characterized in that rubbers contain-
lng 3 to 250 and preferably 3 to 10 double bonds per 1,000
S carbon atoms in the rubber are reacted in bulk with phen-
018, optionally in the presence of a catalyst, for 1 minute
to 30 ~inutes at temperatures of 50 to 150-C and preferably
at temperatures of 70 to 130-C. The reaction product is --
cooled and granulated in the usual way.
The invention also relates to the rubbers obtainable
by the process according to the invention. ~ ~
' ' ';.`; ., , ,:
prior Art ~ -
,. . , .. .. -
lS Hydrocarbon polymers bearing hydroxyphenyl-terminated
hydrocarbon chains in the end position or as grafted-on
side chains are known from JA 63/268 703. They are pro-
duced, ~or example, from hydrogenated polybutadiene con-
taining alcoholic OH groups and methyl salicylate in the
presence of p-toluenesulfonic acid. However, the terminal
bydroxyphenyl groups may also be introduced during the
synthesis of the hydrocarbon chains by anionic polymeriza-
tion of dienes with incorporation of p-hydroxystyrene of
which the hydroxy group is temporarily masked.
JA 52/009 098 (only available as an abstract) de-
scribes reaction products of rubbers with phenols in the
`~ presence of Friedel-Crafts catalysts which are reacted to
polyp~enylene oxides by oxidative coupling.
Hydrocarbon resin~polyphenylene ether comb polymers
are known from DE-OS 3 509 093 and from EP-A O 195 199.
These comb polymers are produced by reaction of
hydrocarbon resins, i.e. rubbers, with phenols in the
presence of an acid (see page 8 of DE-OS 3 509 093).
Le A 26 793
~. 2 ~ ~ 4 ~ 2 ~
; ,.-
It can be seen from Example 1 of DE-OS 3 509 093 that
the reaction takes place in solution.
However, acid-catalyzed reactions such as these in
solution have the disadvantage that the phenols are poly-
alkylated in the ring by the unsaturated groups of the
hydrocarbon resins.
$o avoid this, special phenol s which can only be
alkylated once on account of their particular substitution
are used in accordance with DE-OS 3 509 093 and ~P-A O 195
199 (cf. the phenols (IV) on page 8 and in claim 1 of DE-
OS 3 509 093)-
Corresponding reaction products of hydrocarbon resins
with phenols are known from EP-A O 236 554. In this case,
too, the reaction i6 only described in solution. It was ~ -
again found (cf. the "Makromol. Chem. 24, 205 ç~ ~ç~
~1972), more particularly page 212, cited on page 3 of EP-
A-O 236 554) that polyalkylation occurs and leads to -
crosslinking of the products. It has now surprisingly been
found that ~ven polyalkylatable pbenols, i.e. phenols
unsubstituted in at least two ortho and/or para positions,
can be attached to rubbers without crosslinking.
S~uitable phenols for the process according to the
invention are, preferably, phenols corre~ponding to formula
(I)
R2~__~RI
~)H (I) ;;
R3
in which
R" R2 and R3, independently of one another, may be the same
or different and represent H, Cll2 alkyl, cyclohexyl,
phenyl, C~.l2 alkoxy, C~ alkyl phenyl, phen-Cl.6-alkyl,
fluorine or chlorine. In addition, Rl and Rz may form a
cycloaliphatic or aromat~c, fused 6-membered ring.
Other preferred phenols for the proces6 according to
.
Le A 26 793 2 ;
202412t
.. . .
the invention are phenols corresponding to formula (II)
~ R 1
Y¦ ~ H~
l ~3 m
in which R~ to R~ are as defined for formula (I), m - 1 or
2 and Y i8 a raaical-reactive group
In the context of the invention, the radical-reactive
group Y 1~ preferably an alkenyl group, an HS group, an
alkylmercaptan ~roup or a poly~ulflde bridge containing in
particular 2 to 8 S atoms
Suitable phenols corresponding to formula (I) are, for
example, phenol chlorophenola, such as 2-chlorophenol, 3~
ohlorophenol, 4-chlorophenolf 2,5-dichlorophenol alkyl-
ph-nols, ~uch as technical cresol, 2-methylphenol, 3-
~othylph-nol, 4-methylph-nol, 2,3-dimethylphenol, 3,4-
dim thylphenol, 3,5-di~ethylphenol, 2,5-dimethylphenol, ;
ao ; 2,3,S-trimethylphenol, 2-ethylphenol, 2-isopropylphenol, 3-
ethyl-S-methylph-nol, 2-soc -butylphenol, 2-tert -butyl-
phenol~ 4-t-rt -butylph-nol, 2-lsopropyl-S-methylphenol, 3- ~ ~
lsopropyl-5-methylphenol~4-tert~-pentylphenol~4-~ 3~3- ; ~ ;-
tetramethylbutyl)-phenol, nonylphenol, dodecylphenol 4-
25 ~ cyolohexylphenol, 2-oyclohexylphenol,; 2-phenylphenol, 4- ;;;
phenylphenol, 3-phenylphenol; 5,6,7,8-tetrahydro-1-naph-
thol, 1,1,3,3-tetramethyl-5-indanol, l-naphthol, l-anthrol;
benzylphenol; 3-methoxyphenol, 2-methoxyphenol, 2-ethoxy-
' iphenol, 2-isopropoxyphenol and 4-methoxyphenol
; ~ 30Suitable phenolsi corresponding to formula (II) are, `;i -
for example, 4-moraaptouhenol, 4-methylmercaptophenol; bis- - i~ ;
;~ (4-hydroxyphonyl)-dlsulfido, bl~i-(4-hydroxyphenylj-trisul- ;; i
fide, bisi-~4-hydroxy-3-methylphenyl)-disulfide, 4-vinyl- ` i
phonol, 2-methyl-4-vinylphonol, 3-methyl-4-vinylphenol, 4- ` ;
;~ ~3Sisoproponylphenol, 2-methyl-4-i~opropenylphenol and 4-(1-
Le A 26 793 3
, .:. .,;~ . .. .
' "i'~,.,','-'' :.,"
: ` 20~2~
'
- .
buten-2-yl)-phenol.
Preferred phenols corresponding to formulae (I) and
(II) are phenol, 2-methylphenol, 3-methylphenol, 4-methyl-
phenol, naphthol, 4-isopropenylphenol and bis-(4-hydroxy-
phenyl)-disulfide. ~ ;
Phenol is particularly preferred.
Catalysts suitable for the reaction with the phenols
corresponding to formula (I) are protonic acids, such as
for example sulfuric acid, phosphoric acid, phosphorous
acid, hydrogen halides, perchloric acid or strong organic
acids, such as alkyl or aryl sulfonic acid, such as me-
thanesulfonic acid, 2-chloroethanesulfonic acid, trifluoro- -
methanesulfonic acid, perfluorobutane-1-sulfonic acid,
benzenesulfonic acid~, toluenesulfonic acid, naphthalenesul-
lS fonic acid, 1,3-benzenedisulfonic acid and benzylsulfonic
acld; formic acid, acetic acid, trichloroacetic acid or
~ewis acids, ouch as for example boron trifluoride, alumin-
ium chloride, zinc chloride, iron(III) chloride, tin
tetrachloride, titanium(IV) chloride or mixtures of the
catalysts mentioned.
Catalysts suitable for the reaction with the phenols
corresponding to formula (II) are azo compounds, such as
for example azo-bis-isobutyronitrile, 2,2'-azo-bis-(2,4-
dimethylvaleronitrile),(l-phenylethyl)-azodiphenylmethane,
dimethyl-2,2'-azo-bis-isobutyrate, l,l'-azo-bis-(l-cyclo-
hexanecarbonitrile),2,2'-azo-bis-(2,4,4-trimethylpentane),
2,2'-azo-bis-(2-methylpropane), or organic peroxides, such
as for example diacyl peroxides, such as dilauroyl per~
oxide, diacetyl peroxide, dibenzoyl peroxide; peroxydicar-
bonates, such as diacetyl peroxydicarbonate; alkyl per-
esters, such as tert.-butyl per-2-ethyl hexanoate, tert.-
butyl perisononanoate, tert.-butyl perbenzoate; dialkyl
peroxides, such as dicumyl peroxide, di-tert.-butyl per-
oxide, di-(tert.-butylperoxyisopropyl)-benzene; alkyl
hydroperoxides, such as cumenehydroperoxide, tert.-butyl
Le A 26 793 4
~- 2~%~21
:
.
bydroperoxide or perketals and ketone peroxides, such as
2,2-bis-(tert.-butylperoxy)-butane and methylethyl ketone
peroxide.
Preferred catalysts for phenols corresponding to
formula (I) are alkyl and aryl sulfonic acids, methanesul-
fonic acid being particularly preferred.
The quantity of catalyst used depends on the type and
quantity of phenol, the reactivity of the rubber used and
the desired phenol content of the end product and is from
0 to 0.2 mol and preferably from 0.05 to 0.1 mol per mol
phenol. There is no need for the catalyst if the phenol
used ha~ suffiaient acid strength. The reaction with the
reactive phenols is generally carried out in the absence of
catalysts by thermal activation of the reactive substit-
uent~.
a large number of rubbers may be provided with hydrox-
yphenyl groups by the described process.
Natural or ~ynthetic rubbers having an Mn of greater
than 40,000 and preferably in the range from 40,000 to
200,000, or mixtures thereof, may be used for the process
aocord~ng to the invent~on. Homopolymers of a diene,
copolymers o~ at least two con~ugated dienes, copolymers of
at least one con~ugated diene and at least one other
olefinic monomer, polymers obtained by ring-opening poly-
merization of a cycloolefin, copolymers of a cyclic, uncon-
~ugated diene and at least one other olefinic monomer,
polymers obtained by partial hydrogenation of the above-
mentioned polymers, or mixtures thereof, may be used. More
particularly, suitable rubbers are natural rubber, syn-
thetic rubbers, such as polybutadiene, styrene/butadiene
rubbers, acrylonitrile/butadiene rubbers, partly hydrogen-
ated acrylonitrile/butadiene rubbers, polychloroprene,
isoprene/isobutylene rubbers, halogenated copolymers of
isoprene and isobutylene, ethylene/propylene/diene rubber~
propylene oxide/allyl glycidyl ether copolymers, polyocten-
, .~ .:
Le A 26 793
~ ~ ~`'~
202~.t21 ; ~:
' : , : '
: -
ylene and polynonbornene.
It is preferred to use polymers in the form of a
terpolymer of 20 to 60% by weight propene, 40 to 80% by
weight ethene and 1.5 to 13% by weight of a C~ 2~ diene,
5preferably a 5-alkylidene-2-norbornene, in which the
al~cylidene group contains 2 to 5 carbon atoms, having a
molecular weight Mn of greater than 40,000.
Copolymers of 55 to 85S by weight butadiene and 15 to ;
45% by weight acrylonitrile, in which 90 to 999~ of the
10double bonds present have been saturated by hydrogenation,
are also preferred. Within this group, copolymers of 55 to
70% by weight butadiene and 30 to 45% by weight acrylo-
nitrile, in which 93 to 97% of the double bonds present
have been saturated by hydrogenation, are particularly
lSpr-f-rred.
Particularly suitable rubbers according to the inven- ~;
tion are rubbers having Mooney viscosities of at least 30
and pr-fe,rably 30 to 150 (as measured in accordance with
DIN 53 523 (Part 1-3); ASTM-D 1646-74 at 100-C) in addition
20to the required Mn of at least 40,000 and preferably 40,000
to 200,000.
F~r the process according to the invention, the ratio
of phenols to rubbers ahould be gauged in such a way that
1 to 5 phenolic OH is used in the reaction mixture for
25every phenolic OH group in the reaction product.
The process according to the invention is carried out
in the absence of a solvent by intensive mixing of the
components. Mixing is carried out in a mixing unit of the -
kind typically used in the processing of rubber or plas-
30tics, including for example reaction screws, extruders or
knoaders. The reaction time is between 1 and 30 minutes.
After the reaction, excess phenol, if any, may be removed
in a vacuum stage, by stripping with steam or by extraction
with a solvent.
35The mixing temperature is between 50 and 150-C and
Le A 26 793 6 -
r~ 202~1:121
I
preferably between 70 and 130-C. The reaction product i8
cooled and may then be granulated or compacted in known
manner.
The following substances known EÇL se may be used as
S additional additives during or after the reaction according
to the invention: stabilizers, such as antiagers, anti-
fatigue agents and anti-ozonants, plasticizers, fillers,
pigments, factices, release agents or powdering agents and
the vulcanization auxiliaries typically used in the rubber
industry.
The rubbers obtainable by the process according to the -~
invention may be vulcanized to moldings of any kind by
standard methods of vulcanization.
The moldings obtained, for example in the form of
lS s-als, may be industrially used in the same way as normal
rubber articles. ~
However, the rubbers obtainable in accordance with the ~ -
lnv-ntion may al-o be used without preliminary vulcaniza-
tion as a mixing component in other rubbers, for example to
improve their tackiness. - ;; v
, ,; , :: .
' ~ ,;,.; ",:,.. ' ;'.,. ;:,
~3xamDle-s " ,': ' " i,
:,.~ '`: ' :"
Exam~le 1
; 25
~ In a twin-screw extruder equipped in its end zone with i ~`
;~ a vacuum evaporation unit to remove the excess phenol, an
EPDM resin (copolymer consisting of 50% by weight ethylene, ~ -
41% by weight propylene and 9% by weight 5-ethylidene- -
bicyclo-(2.2.1)-hept-2-ene, Mooney viscosity ML (1+4) at ~1
;~ ~ lOO'C - gO, Mn approx. 95,000) i5 mixed with 9% by weight ~ -
of a mixture o~ phenol and methanesulfonic acid (99:1) at
a cylinder temperature of 90-C. The exit temperature is -~
approx. 120'C and the average residence time to the vacuum `~
stage approx. 12 minutes. The issuing strand is passed ; ;~
- - ,-: . " ,
Le A 26 793 7 : ~
~ 2024121
through a water bath, air-dried and then granulated with
addition of 1% by weight talcum. According to IR measure-
ments, the bound phenol content is 2.8 to 3.2% by weight.
The free-flowing granules dissolve without gel formation
and can be sheeted out.
EX~1Ç 2
An EPDM resin (copolymer consisting of 68% by weight
ethylene, 27% by weight propylene and 5% by weight 5-
ethylidenebicyclo-(2.2.1)-hept-2-ene, Mooney viscosity ML
(114) at lOO-C - 85, Mn approx. so,ooO) is treated as in
Example 1. In~tead of talcum, however, bisphenol A poly-
¢arbonate powder i8 used for powdering. According to IR
measuremQnts, the bound phenol content is 1.9 to 2.5% by
woight. The product dissolves without gel formation and
can be sheeted out.
~' '.
Example 2 is repeated without the addition of powder-
lng agents. The granules remain free-flowinq through rapid
cooling to approx. 20-C.
ExamDle 4
10% by weight bisphenol A polycarbonate powder is
added to the EPDM resin of Example 1 during introduction
into the screws. The granules obtained remain free-flowing
without powdering.
~xample 5
800 g of the EPDM resin of Example 1 are masticated in
a 1.3 liter Pomini kne~der at a ~acket temperature of 60~C
and at a rotational speed of 40 l/minute. After 1 minute,
72 g phenol, 7.2 g methanesulfonic acid and another 100 g
EPDM resin are added and mixed for another 8 minutes. The
melt temperature rises to 90 - lOO'C. The product i9
Le A 26 793 8
~ 20241~
. ....
ejected into a water bath. After removal of the excess
phenol by extraction with toluene/methanol, the bound
phenol content is 3.2% by weight, as determined by IR
6pectroscopy. The product dissolves without gel formation
S and ean be sheeted out.
Exam, D~6
A total of 900 g of an HNBR resin (copolymer of 43% by
weight aerylonitrile and 57% by weight butadiene, Nooney
viseosity ML (1+4) at lOO-C - 75, Nn approx. 70,000,
r-dueed by hydrogenation to 4~ of the original double bond
eontent) are treated as in Example 4. The bound phenol
eontent is 3.8~ by weight, a- determined by IR spectro~
~eopy. The produet di~-olves without gel formation and ean
lS b- ~heeted out.
`.:,: " '
ExamDle 7
2.12 g b1--(4-hydroxyphenyl)-di-ulfide are added to,
and mixed for 10 minutes with, 45 g of the EPDM resin of
Exampl- 1 in a 70 ml kn-ader at a ~aeket temperature of
120-C and at a rotational speed of S0 l/min. The erude
produot i~ xtraeted with tolu-ne/ethanol: the ¢ontent of
phenolie group- i- 2.8% by weight, as determined by IR-
speetroseopy.
ExamDle 8
2.3 g isopropenyl phenol are added to, and mixed for
0 minutes with, 45 g of the EPDM resin of Examplell inla
'`` 70 ml kneader at a jacket temperature of 120-C and at a
rotational speed of S0 l/min. The crude product is ex-
traeted with toluene/ethanol; the content of phenolic
group- ls 1.7% by weight, a- determined by IR-spectroscopy.
Le A 26 793 9
