Note: Descriptions are shown in the official language in which they were submitted.
The present lnventiQn relates to rnolded bodîes o~
elastomeric macro~molecular material with a direct binding
mixture serving for produoing a bonding connection with
metals or other rigid m~terials during polymerization or
vulcani~a~ion of lthe macro~fnoleel1les.
In the production of molded bodies of rubber or
synthetic material of all types s~rith metallic re~nforcing
inserts or layers, for exarnple oiE conv~yor belts wî~h
longîtudinally ex'cending embedded steel wire c~bles7 it has
10 been known for a long tîme aI~d .is common practice to use
so-called "direct-bindîng'l mixtures fox producing the
necessary adhering binding of the rein~orcing ~lements to
the elastomeric material during the vulc~ization or psly-
m~rizati-~n accomp~:nying ~he fînal shaping. The durabîlity
of ~he coxmection îs ~he decisîve factor :~r the service~
ability or function value of the finished molded bodi~s;
thîs durability is determ~ned essentially by two parameters~
n~mel~, orl the one hand, the quality o ~che îni~cial bondîng
attainable wi h the ~rea'cment process arld~ on ~he o~her
20 harld ~ by the aging behavior of ~he connection , i . e ., ~he
gradual abatement or subsiding of khe honding orces. ~ile
the initial bonding primarily depends upon the par.i~ular
utiliæed base polymer, still other effects exîst ~ich in"
fluen-~ each other or superimpose upon each other for the
aging ~ehavior. Asîde from the actual connectîon itself "
the polymer îs al~o subjected to the influence of aging, and
-- 1 ~
~` ' !
. ; '
as a cons~quence thereof9 the binding half in he boundary
layer nex~ to ~he me~al ls at~acked in time.
The difficulties in producing a highly loadable or
stressable and durable binding connection are still further
incrcased by the fact that the initial bonding and aging
behavinr for pol~ners of dif~erent types c~n be of entirely
differen~ importanceO Th~s, or example, for the so-called
all-purpose-rubhers, lik~ natural ~nd styrene~b~tadieDe
r~bber, the deterioration of the connec~ion by aging is in
the foreground, while, in contrast, for example for nitrile~
butadiene rubber or for other sp~cial ~ubbers, o~ the other
hand, a satisfactory ini~ial bonding c~n be at~ained ~nly
wqth difficulties.
Accordingly, the object o the present invention is to
attain a consider~bly irnproved bonding for both phases, in~
dependently of the characteristic of the base polymer~ This
objec~- of the present invention goes :Ear beyond the possi~
bilities ofered by ~he kno~ gal~anizing (~inc pla~ing~,
brass plating, or bronzing of the metallic parts with other
; 20 surface treatmentsO
By one aspect of thi~ inv~ntion, there is provided a
molded body, of ~n elastomeric material, whi~h comprises a
direct binding mixture containing halogen or hydrogen halide
releasing materials for pro~ucing a bonding connection of
elastomeric mat:erial with metallic or other rigid materials
during polymeri.zation or vulc~ni~ation of the elastomeric
~ 2 -
, ~
material; saîd binding mîxture conkaining at least ~e .su~
st~nc~ which liberates material selected from the group con~
- sisting o~ halogeDs and hydrogen halides as halogen sources
for such elast~meric material including all purpose rubbers,
like natural and poly~utadiene, styrene-butadiene9 poly~
chloroprene, nitrile rubber, and nitrile-butad:iene rubber.
Improvements in the initi~1 bondi~g by frqm 10% to
20% are thus possiblet while simul~aneously the lo.sses in
strength of the general purpose rubbers d~e to aging can be
10 practically completely suppressed7 and in pa~t ran be re-
versed into the opposite in comparison to the ini~.ial bonding.
Liqu~d chloriDated paraffins, especially with a chlor-
ine proportion of approximately 70V/o~ bromina~.ed phenol
resins, and chlorinated polyethylenes, poss~y also in com~
bination with each other~ as well as chlorinat~d rubber, have
proven themselves suitable ~s halogen sources. Undesired
overrea~tions are expediently precluded by the addition of
magnesium oxide or other s~abilizing substances. The scope
of the prese~t i~vention also includes the further addition
to the binding mixture o halogen in a proportional ratio
ranging be~ween 0.7/0 to 15~/o~ preferably rom 2% to 7%O
The teaching o the present invention is clarified
still ~urther by the following listing of several mix~.ure
examples and of th~ test results at~ained ~herewi~h~ In
all GaSes~ direct binding mixtures are involYed on differen~
rubber bases, on the one hand wi~h ~he ad~ition of halogen
~ 3 -
~6J~
( Column a), ~3nd on the other hand without the addition of
halogen (Col~ b)o Galv~nized steel ~ire cables o:f 4 rnm
diameter were vulcanized into the mixtures produced in a
conventional manner in an internal mixer, and thereafter,
respectively a~tler an aging period of 22S minutes at a
temperature of 1~5G, the tearing or pull~out values were
determined according to DIN 22 1'31 (German Industrial Norm
or Standard 22 131).
- 3a -
}~q~j
:
ture on Natural R b_ Base a b
Shee~s RSS 1 34.4 34.4
Polybut~diene 18.90 18.G0
Magnesium Oxide 205 2.5
Carbon black N660 13.1 1.301
Silicon dioxide 1300 13.0
Hydrocarbon resln 1.2 1~2
Softener 5~0 6.4
Liquid chlorinated paraffin (70~/0 chlorine~ 1.4
Phenolic aging protection mea~s 0.5 0~5
Zinc oxide 4.0 4.0
Lead monoxide 1~0 1~0
Stearic acid 1.0 1.0
Resorcinol 1.5 1.5
~examethylenete~ramine 0~8 0.8
Benzothiazole-2-sulfenmorpholine 0.~ 0.6
Sulfur 2.0 2 0
. ~
100.~ 1~0.0
- Vulcanlza~ion 35 min. a~ 150'C
Specific welght 1.20 1.19
Strength N~mm 15.5 lS~7
Breaking tension % (elongation a~ break) 564 ~70
Shore A ~ardnless 62 62
Tear~ or pull-out values N~mm
fresh 79.5 79.5
aged 94.00 73 00
- 4 -
Mixture on ~ nitri.le ru~ber base a
Nltrile R~bber (28~/o ACN) 45.0 45.0
Phenolic aging protect;on means 0.3 0.3
Stearic acid 0~7 0.7
Silicon dioxide 15.S 15~5
Carbon bl~ck N339 .13dO 13.0
Softener 4~0 4.0
Hydrocarb4n resin 5~0 8,0
2inc oxide 5.~ 5.0
Resorcinol 1~5 1~5
Cobalt c~mplex in oil (16% Co) 2,0 2~0
Hex~methylenetetramine 2.0 2.0
Tetramethylthiuram disulfide (thiramj 1.5 1.5
Benzothiazole~2-sulfe~norpholine 1.0 1.0
sulfur 005 0~5
Liquid chlorinated paraff~n (70% chlorine~ 3.0
___._
100~ 0 10~. 0
Vulcanization 20 min. at 150C
Specific weight 1027 1.25
Strength N~mm19.5 18.2
Breaki~g ten~ion % (elonga~ion at braak) 637 745
Shore A Hardness 67 64
Tear- or pull-out values Njmm 6003 43~7
_ 5 ~
a b
Polychloroprene (Mercaptan~type 50iO 50~0
Magnesium oxide 2.5 2,5
Carbon black N339 14.0 17.0
Stearic acid loO 1,0
Softener - 7.0
Aminic aging protection means 1.0 1.0
Zinc oxid~ 7.75 7.75
Chalk fli~t lO.0 10~0
Cobalt c~mplex in oil (16% Co) 2.5 2.5
Tetramet~yl~h~uram disulfide Sthiram) 005 0.5
Diortho-tol~yl-Gu~idine 0.2$ 0.25
Sulfur 0.5 005
Liquid chlorinated paraffin ~70% chlorine) lO.0
. 0
Vulcanization 40 min~ at 160C
Specific weight 1~52 1047
Stre~gth N~mm 17~7 17.9
Breaking tension % (elongation ~ break) 428 409
Shore A hardness 68 70
Tear~ or pull-out values N/mm 10207 90~0
qj
The present inventioII is, of course, in no wa,v re-
st~icted to the 5p~3cif ic disclosure of the speci:Eication
and examples9but also encompasses any modi~ications within
the scope of ~he apper~ed claims,,
