DESCRIPTION
VINYL·CIS-POLYBUTADIENE RUBBER BUTADIENE RUBBER
COMPOSITION USING THE SAME
Technical Field
The present invention relates to a novel vinyl-cispolybutadiene
rubber produced by concurrently allowing 1,2-
1 polybutadiene of a high melting point of 170°C or more and
polyisoprene or polybutadiene of a lOW melting point to
exist and be dispersed in tbe -trix of cis-polybutadiene
u
In the -.Jecnlar chain of polybutadiene, a binding
portion generated by 1,4 polymerization (1,4 structure) and
a binding portion generated by 1,2 polymerization (1,2
structure) concurrently exist as so-called microstructure.
The 1,4 structure is divided in two types of structures,
namely cis structure and trans structure. Alternatively,
the 1,2 structure takes a structure with vinyl group as a
side chain.
A method for producing vinyl-cis-polybutadiene
rubber composition in the related art has been carried out
in inert organic solvents such as aromatic hydrocarbons
-z--
such as benzene, toluene and xylene and ha1ogenated
bydrocarbons thereof for example chlorobenzene.
sol vents such as aromatic hydrocarbons and ha1ogenated
hydrocarbons are used, however, the resu1ting
polymerization solution has such a high viscosity that the
agitation, heat transmission and transfer thereof are
troub1esome, which requires excessive energy for the
recovery of such so1vent. Additionally, so1vents such as
; 1 aromatic hydrocarbons and ha1ogenated hydrocarbons are very
; )
"-·
hazardous for envi~t, due to the toxicity and
carci nogene sis.
of ci.s-1,4
Al~ (provided that R is an al.ky1 group with one to 6
carbon atoms, phenyl group or cyc1oa11ty1 group; X is a
ha1ogen e1ement; and n is a numerical figure of 1.5 to 2)
in the inert organic so1vent, and a step of syndiotactic
1,2 polymerization (abbreviated as "1,2 polymerization"
hereinafter) of 1, 3-butadiene in the presence of a
syndiotactic 1,2 polymerization cata1yst obtained from a
soluble cobalt c()!I!\:'Ound, an organic aluminum compound
represented by the general formul.a Al~ (provided that R is
an a11tyl group with one to 6 carbon atoms, pheny1 group or
cyc.1oa1kyl group) and carbon disulfide, with addition or no
addition of 1,3-butadiene and/or the solvent to the
resulting polymerization system is known (see "for exa.,.;>le
JP-B-49-17666 (patent reference 1) and JP-B-49-17667
(patent reference 2)).
~tionally, for exa.,.;>le, JP-B-62-171 (patent
reference 3), JP-B-63-36324 (patent reference 4), JP-B-2-
37927 (patent reference 5) , JP-B-2-38081 (patent reference
( ') 6), and JP-B-3-63566 (patent reference 7) describe methods
including a step of producing vinyl· cis-polybutadiene
rubber c•"""'oosit:i:oD by cis-1,4 pol.~ization of 1,3-
bota-di- iA t:he pn~n K"e m:- atln -ce of carbon cti"''ll.fida.
u
1.3 buta« rec::yc:l.e 1.3 b;ala«er containing 1,2-
polybutadiene and a polymer substance with a melting point
~ than that of the 1,2-pol.ybotadiene-and with at least
ODe -blEated doWI.le t.c.d per ~ aat:Uag 11D:it, wlaeno the
1 ,2-pol.-yt>ut adi- and the pcdy.er su~~e•a- are ~
at physi.cal.1y and/or dr ieally adsodled states iD the cispol.
ybot:arti- z:ot.t.er illS the -ttix c .. -t of the
vinyl.·cis--polybotadi- u•.t.er.
0
2. 'lbe vinyl· cis-polybutadiene rubber described in 1.
above, where the 1,2-polybutadiene and the polymer
substance are dispersed in short crystal fiber and/or
particle in the cis-polybutadiene rubber as the matrix
c:oaponent of the vinyl· cis-polybutadiene rubber.
3. The vinyl·cis-polybutadiene rubber described in 1.
or 2. above, where the 1,2-polybutadiene is 1,2-
polybutadiene of a melting point of 170°C or more and the
polymer substance is at least one selected from
polyisopr~, crystallizable polybutadiene of a mel.ting
n
point of 150"C or less, liquid polybutadiene and
derivatives thereof.
4. The vinyl·cis-polybutadiene rutiber described in any
of 1. through 3. above, where the unsaturated polymer
substance is contained within a range of 0. 01 to 50 t by
mass to the total of the crystal fiber of the 1, 2-
polybutadiene and cis-polybutadiene rubber.
5. The vinyl·cis-polybutadiene rubber described in any
of 1. through 4. , where the viscosity of the cispolybutadiene
rubber as the matrix caaponent in toluene
solutiooat 25"C is wit:b:in a r.mge of 10 to 150.
6. '!he Yi.Jiy1·c:ia-pol.~a-li- utber desc::ri.bed iA aay
of 1. Uaroogh 5., ~ ("'] of t:be cis-po1ybubM!i- u•..._.
as t:be -tri.x c•,.. ~t is wit:b:in a range of 1.0 to 5.0.
7. '!he riay1·cis-po1ybuta-ti- rutot.er desc::ri.bed iA aay
of 1. through 6., where t:be c:ooteot of the 1,4-c:is
structure of the cis-polybutadiene rubber as the matrix
cc~onent is within a range of 80 !II by mass or more.
8. The vinyl· cis-polybutadiene rubber described in any
of 1. through 7. above, where the Mooney viscosity of the
cis-polybutadiene rubber as the matrix component of the
vinyl·cis-polybutadiene rubber is within a range of 10 to
so.
9. The vinyl· cis-polybutadiene rubber described in any
of 1. through 8., where the polymer substance is a matter
insoluble in boiling n-hexane.
10. The vinyl·cis-polybutadiene rubber described in any
of 1. through 9., where tbe 1,2-polybutadiene is dispersed
in short crystal fiber in tbe cis-polybutadiene rnbber as
the matrix ~t of tbe vinyl·cis-polybutadiene rubber
and tbe pol~ substance is dispersed in particle therein,
and where tbe short crystal fiber of the 1,2-polybutadiene
is dispersed in the particle of the pol~r substance.
11. The vinyl· cis-polybutadiene rubber described in 1Q
() above, where the short crystal fiber of the 1,2-
polybutadiene is never contained in the particle of the
poly.er subs.-..- but is also dispersed in the cispol.
ytlut3'di- u•"-r - tbe -ai.x • ·-. ~ •nt, aDd 1lheEe tbe
0
l.ength of tbe abort c:zyatal. fiber di.spll:£secl in the -t:zix
al.oag -jor axis· is witllin a range of 0.2 to 1,000 .- aDd
the l.ength of t:be abort c:zyatal. fiber of the 1,2-
polybutadiene dispereed in the particle of the pol.~
substance along major axis is within a range of 0.01 to 0.5
pm.
12. A butadiene prepared by
compounding the vinyl· cis-polybutadiene rubber described in
1. or 2. above at 10 to 300 parts by wei.ght per 100 parts
by wei.ght of a rubber selected from natural rubber,
polyisoprene rubber, styrene-butadiene copolymer rubber, or
a blend rubber of at least two types thereof.
13. A butadiene rubber composition for tire, where the
vinyl·cis-polybutadiene rubber described in 1. through 11.
above, and/or the butadi- rubber c•~oosition described in
12 above is used.
14. A method for producing vinyl· cis-polybotadiene
rubber by a step of the cis-1,4 polymerization of 1,3-
butadiene using a cis-1,4 poly.erization catalyst in a
hydrocarbon-series solvent, a step of the 1,2
polymerization of 1,3-butadiene in the concurrent presence
of a 1,2 polymerization catalyst in the resulting
() polymerization mixture to generate 1,2-polybotadiene of a
~ting point of 170"C or -.>re, and a step of the
se:paratioo aDd recovery of- viDyl,cis-pol:ybut:adiene :rubber
9"'*r..t:ed faa t:be rRBIII.tiJI9 po.}.'J ri zatioa ~. t:be
-t:hocl iDc:l'IICting a step o€ adting a pol.~ sabetaw? wit:b
at l.east c.. -blEated domble hoDd per r-. aati.JI9 ~t to
u
t:be palducl:iOD syst
15- '!be -'tbod for
r>Wber as described
prodlring viny1· cis-polybat:adiene
in 14. above, where the polymer
substance is at 1east one se1ected from polyisoprene,
crysta11izab1e po1ybutadiene of a me).ting point of 0°C to
150°C, 1iquid polybutadiene, and derivatives thereof.
16. The method for producing vinyl·cis-po1ybotadiene
rubber as described in 14 . or 15. above, --where the amount
of the po1ymer substance to be added to the production
system is within a range of 0.01 to 50 \ by mass to the
Viny1·cis-po1ybotadiene r>Jbber to be obtained.
17. The method for producing vinyl· cis-po1ybotadiene
()
rubber as described in any of 14. through 16. above, where
the step of adding the pol.~ substance to the production
system is carried out in the polymerization mixture at an
appropriate time point fro. the step of the cis-1,4
pol~ization step to the step of the separation and
recovery of the vinyl· cis-polybutadiene rubber generated
fran the polymerization mixture obtained after the
CCliJPletion of the 1,2 polymerization.
18. '!'he -thod for producing vinyl·cis-polybutadiene
rubber as described in any of 14. through 17. above, where
the hychor:a"-'-series sol:vent is a bydrocarboo-serisol.-
t wi.th a sol.vbiJit:y papall:•-et:tnerr of 9.0 or l.eea.
19. A butadi- :n* .. 4r
c•-.=-•..ting tlle riay-1-c:ia-pol.)tl:lutadi- rnN>er Clbbi.-.l by·
the pnKtucticD -u.od de 1 • i.._, iA aiiiY of 1C. t:bEough 18.
above at 10 t:o 300 parts by _.s per 100 parts by -.a of a
rubber sel.ected fran natural. rubber, polyisoprene rubber,
styrene-butadiene copolymer rubber or a blend rubber of at
least two types thereof.
20. A butadiene rubber comp-.:>sition for tire, where the
vinyl· cis-polybutadiene rubber obtained by the production
method described in any of 14. through 18. above and/or the
butadiene rubber c:omposi tion described in 12, 13 or 19
above is used.
In a the vinyl·cis-
-lo()
u
polybutadi.ene rubber of the invention (abbreviated as "'VCR,.
~nafter) is a novel VCR where the 1,2-polybutadiene is
1,2-polybutadiene of a ._lting point of 170°C or more,
where the polymer substance of a .-lting point lower than
that of the 1,2-polybutadiene and with at least one
unsaturated double bond per repeating unit (sometimes
abbreviated as "'unsaturated polymer substance• hereinafter)
is at least one selected froiD polyisoprene, crystallizable
polybutadiene of a .-lting point less than 170°C, liquid
polybutadiene and derivatives thereof, and where the 1,2-
pol.ybubtctiene of a -.1tiDg point of 170"C or .ore and the
-tuEa~ po:l~ Sllbio' a- are JC888Dt CaKMU:eDtl.y i.a
t:be -trix of c:is-po1ybwbtcti- r•.t.er and aze diapereed
therei.A.
o.iDg to t:be CIODCUEniDt presaroce of 1,2-
polybutadi.ene of a high .-J.ting point exerting vary strong
interaction be~ polymers as a very excellent
reinforcing camponent and such unsaturated polymer
substance with a relatively low .-lting point such as
polyisoprene, consequently, the VCR in accordance with the
· invention has remarkably improved dispersibility of the
1,2-polybutadiene of a high melting point in the cispolybutadiene
rubber as the matrix component due to the
compatible effect of the concurrently present unsaturated
polymer substance, ~with the VCR in the related art,
so that the content of the 1 ,2-polybutadiene of a high
-II()
0
~ting point as an exceU.ent reinforcing caaponent can be
raised.
The characteristics of the VCR in accordance with
the invention as described above enable great iq>~t
of various physico ..._ical properties strongly demanded in
the production of tire articles and in other uses. When
the VCR of the invention is used in a butadiene rubber
cc-.;osi tion for tire, in particular, the composition has
such a small die swell ratio (as the ratio of the diameter
of the c• ""'"ounded 111atarial to die orifice diameter cluring
ext:rusi.on) doriDg tin. prodoction, so that the c• -.<>ai tion
8!ll8rts peat ex:h:c.i.CID JIIRICIU?bilit:y ;mel q>erabi)it;y_
Jlddi.ti1'!ft2Uy, the YDJraniza!! pEOdDct oL the « •-."D«it:i.oD
exerts e-11ent meak-zesi.stant ~. ilbEas:i.on
zesi....._, s)jcting fricti- r..:i.~Jta- ;mel the l.ib -i•Jy
required for side tE ad of tire and the like. Beca- the
flex-craclt-growth resistance thereof is very great and the
rigidity thereof is high, further, the amount of
reinforcing materials such as carbon and silica to be used
can be reduced, enabling low fuel consUDption owing to the
weight decrease of tire. '!'bus, tire using the VCR of the
invention as a raw material for side treads and the like
exerts excellent running stability and high-speed
durability and additionally enables low fuel consumption.
Brief Description of the Drawings
()
(J
Fig.l is one scbanatic view of a dispersion
bodiment of the unsaturated pol~ substance in relation
to the crysW fiber of the 1,2-polybQtadiene of a me1ting
point of 170°C or more.
Fig. 2 is another schelllatic vi- of a dispersion
.., b>diment of the unsaturated pol~ substance in relation
to the crystal fiber of the 1,2-polybutadiene of a me1ting
point of 170"C or more.
Fig. 3 is a. still other schematic view of a
dispersion ""Pt-odiment of the unsaturated pol~ substance
in relation to the crystal fiber of _the 1,2-polybutadiof
a -.1t:iag point of 170"C or--
F.i9-• u aa additiCJ!'A1 ••cciiiMI-tic view of a
i.D relation to the CAY•~ fiber of the 1,2--pol~ta.tiof
a .al.t:iag point of 17o-'C or--
Fig. 5 is an electron aicxograph depicting the
microstructure of the vinyl·cis-polybutadiene rubber
obtained in Conparativa Exaupte 1.
Fig. 6 is an electron micxograph depicting the
microstructure of the vinyl·cis-polybutadiene rubber
obtained in Exanple 1.
Fig.7 is an electron micrograph depicting the
microstructure of the vinyl·cis-polybutadiene rubber
obtained in Exanple 3.
Fig. 8 is an electron microgzaph depicting the
-l3-
n
0
microstructure of the vinyl·cis-polybutadiene rubber
obtained in Ex:mq:>le 4.
In the figures, symbol "'1" expresses matrix; "'2",
the crystal fiber of the 1,2-polybutadiene of a melting
point of 170°C or more; "'3", the microparticle of
unsaturated polymer substance.
Best Mode for carrying out the Invention
The VCR of the invention generally has the following
constitution. Specifically, the VCR generally contains (1)
one to 50 parts by JII!UIS of 1,2-po1ybutadiene of a mel.tin9
point of 170'"C or ~; (2) 100 parts by -- of cispo1ybut:
adi- rnt.t.er and (3) - 1ID8atllrated po1~
sab&t-aw- at 0.01 to 50 t by ....... of the tot:a1 of (1) aDd
(2). Addi.tiCli!Q1ly, the 1,2-po1ybut;rti- of a ~tiDg
point of 170'"C or ~:re as the «'1'CIDM'It (1) genera11y f~
a crystal fiber with the mean length of the mono-dispersed
fiber crystal along short axis being 0.2 pm or less and an
aspect ratio being 10 or less, which is in a short fiber
fonn with the mean number of the mono-dispersed fiber
crystal being 10 or more.
The crystal fiber of the 1,2-polybutadiene as the
component (1) is in a short fiber fonn of the mean length
of the mono-dispersed fiber crystal along short axis being
0.2 pm or less, preferably 0.1 pm or less; with an aspect
ratio of 10 or less, preferably 8 or less; and with the
-lit-.
m o.....tJer of the mono-dispersed fiber crystal being 10 or
1110re, preferab1y 15 or .ore, and additiona11y of a me1ting
point of 170°C or 1110re, preferab1y 190 to 22.0°~.
The cis-po1ybutadiene rnN!er as the compommt (2)
preferab1y bas the fo11owing characteristics. In other
wol:ds, the cis-po1ybutadiene rubber as the component (2)
bas a Mooney viscosity CML.... 100°C abbreviated as "ML,.
hereinafter) of preferab1y 10 to 50, 1110re preferab1y 10 to
40. In such manner, effective1y, the operability during
CXllllpOUDding is ~roved, whi1e the dispersion of the
(1)_ in the o-.<>nent (2) is ~roved.
C2) baa p:efer.abl.y the followiag cbaract•riatics. ID other
woa:da, the 'ri.scoeity t:bealof in to1- IIOl.uti.-ao
c.-HpoiMt/~ ~ted - •or-cpl" beEeilaf~) i•
prefer.abl.y 10 to 150, - p:eferably 10 to 100; and ('q]
(intrinsic viscosity) is 1.0 to 5.0, preferably 1.0 to 4.0.
Additiona11y, the content ratio of the 1,4-cis structure is
() 80 % by mass or more, preferably 90 % by mass or more.
Additiona11y, the cis-po1ybutadiene rubber as the o:••1onent
(2) substantia11y never contains gel matters. Herein, the
phrase "substantia11y never containing ge1 matters• means
that to1uene-inso1ub1e matters are at 0.5 % by mass or 1ess.
The end and/or main chain of the po1ybutadiene
rubber obtained by the · cis-1,4 po1ymerization may be
modified. As such modifier, organic si1icone COIIIpOUilds
-15"-
()
containing at least amino group and a1koxy group, organic
silicooe ~ containing a1koxy group, unsaturated
carbo11¥1ic acid .or derivatives thereof, ha1ogen-series ·
ccapounds, and ~ with hetero-three 1118111bered-rings
may be used. The aJDOUnt of such IIIOdifier to be used is
0.01 to 150 BADl per lOOg of the g~ted polybutadiene
(polybutadiene rubber) • When the amount of the IIIOdifier to
be used is less, the JDOdi.fication effect is hardly exerted.
When the amount thereof to be used is too IIIUCh, the
JDOdi.fier still unreactive is likely to remain in
polybutadi-. :rt requires laborious works to eli.Jainate
the .od:ifier, 11111ptreferably. BeEeiD, t:lae .__IIY 'Vi-ity
a-tried. PEeferably, the woctified pol.ybuhdi- ClbtaiDed by
the -thod has a Moooey visooeity UU...-, lOO"C) within a
range of 20 to 80 and has a weight average mol.ecular weight
() of 200,000 to :1,000,000 by gel ~tion -thod, where
80 t by mass or more of the repeating unit has cis-1,4
structure. Addi. tiona11y, the content of the vinyl
structure in the microstructure is preferably 15 t by mass
or less.
Herein, the toluene-insoluble matters express gel
matters attached on a -ta1 net after filtration, by
00111pletely dissolving 10 g of a sample rubber and 400 m1 of
toluene in an E.rl~ flask at RT (25°C) and filtering
the resulting solution, using a filtration device arranged
with the metal net of 200 mesh. 'l'be ratio expresses a
val.ue -.asured by drying the net attached with the ge1 in
vaCUUID to measure the attached amount thereof to ca1cul.ate
the percentage to the sample rubber.
Additionally, ["] (intrinsic viscosity) is a val.ue
detexmined according to the following formula, by placing
() 0.1 9 of a sample rubber and 100 ml of toluene in an
Erlenmeyer flask, CXliiiPletely dissolving the sample rubber
at 30"C, subsequently plaMng the sol.ution of 10 ml in a
u
coo~ at 30"C, aDd -•-1111•dic~~"99 tJ. chcJp 0.. ··('Q oL tJ.
sol.uti.oD.
'¥P- 't/T.- 1
('te: ckop ~ oL to1- al-)
"sp/c - [") + k' [")~
("sp: specific viscosity; k':Buqgins constant
(0.37); C: sample concentration (g/ml))
The ratio between the 1,2-polybutadiene crysta1
fiber as the coap>nent (1) and the cis-polybutadiene as the
c• cpponent (2) is one to 50 parts by mass, preferably one to __
30 parts by mass of the 1,2-polybutadiene crystal fiber as
the component (1) to 100 parts by mass of the cispolybutadiene
as the c• cpponent (2) . Within the range, the
following drawbacks can be avoided: when the amount of the
-l7-
1,2-polyotadiene crysta1 fiber is so large to ex• ;ad 50
parts by IBilSS, the short fiber crysta1 of the 1,2-
polybutadiene crysta1 fiber in the cis-polybutadiene rubber
is likely to be large, causing poor dispersibility thereof;
when the aJDOunt of the 1,2-polyutadiene crystal fiber is
small less than one part by mass, the reinforcibility with
the short fiber crysta1 is deteriorated. Thus, problems
bard1 y occur, such that the characteristic elastic modul us,
{') flex-crack-growth resistance, and oxidation degradation are
exerted with difficulty and the processability is
deteriorated. 'lbexefore, the range is preferable. Fllrtber,
the :ratio of the --blratecl pol.y.er sabetaN? as the
••-. -t (3) :is 0.01 b> 50 ~ by-, ))Eeferably 0.01 b>
30 ~ by - of VCR, as deecri.bed abc ua. 'l'ba range is
preferable becan- the deterioration of the dispersibilit:y
due b> the aggzegatioo of the 1,2--pol..ybgtadi- crystal
fiber as the ~t (1) can be suppressed, and an
~- }
associated deterioration of the various physico-chaDi.cal
properties of VCR can be suppressed.
Further, the ratio of the 1, 2-polybutadiene of a
melting point of 170°C or more as the cull(-onent (1) and the
unsaturated polymer substance as the component (3) is 0.02
to 100 parts by mass, preferably 0. 05 to 80 parts by mass
of the c•:•ll(-onent (3) per 100 parts by mass of the C" "t'Qnent
(1) . Addi. tionally, the total amount of tHe components (1)'
and (3) is 1. 01 to 100 parts by mass, preferably 1. 03 to 90
-f8-
,---,
; 1
\ .
0
parts by -s per 100 parts by mass of the cispol.
ybotadiene rubber as the '"••oonent (2).
The -t:bod for producing VCR in accordance with the
invention is described bel.ow in detail.
For the VCR production in accordance with the
invention, generally, 1,3-butadiene is pol~rized, using a
hydrocarbon-series solvent. The hydrocarbon-series solvent
is preferably a hydrocarbon-series solvent with a
solubil.i ty (abbreviated as "'SP val.ue,.
hereinafter) of 9.0 or less and is more preferably a
bydroca.rl:lon-seri.es so1-t with a solubil.ity paraaeter of
8.4 or ~-
solllbiliq ~t:er oL 9.0 or 1- i.mcl:adae for • tle
D-lae'lrime lSP Yal.ue: 7 .2), D pea~ (SP Yal.ue: 7 .0), a~
(SP val.ue: 7.5), cyclobe..._ CSP val.-: 8.1) ;mel nbutane
(SP val.ue: 6.6). Among them, for e.........,le,
cycl.ohexane is preferable.
The SP val.ues of these solvents are known in
references such as Rnbber Industry Manual. (Gomu Kogyo
Binran) (the 4th edition, Nippon Rubber Association
Foundation (Nippon Gomu Kyokai) , issued on January 20, 1994,
page 721).
By using a sol.vent with an SP val.ue smaller than 9.0,
preferably, the dispersion of the short fiber crystal of
the 1,2-polybutadiene crystal fiber in the cis()
polybutadiene :rullber is at a state expected in accordance
with the invention, so that exce11ent die ~1
characteristic, high tensile stress, tensile strength and
high flex-crack-growth perfonaance can be preferably
exerted.
First, 1,3-butadiene and the solvent are mixed
together, to adjust the concentration of water in the
resulting solution. Water is within a range of preferab1y
0.1 to 1.0 mole, particularly preferably 0.2 to 1.0 mole
per one mole of an organic a1uai.nlml ch1oride used as the
cis-1,4 pol~zation cata1yst in the solution. 'fhe range
is pr:eferable '-cav-a svffici-t cata1yt:i.c acti.Y.i.t:y can be
Clbt:ai..t to pEOride a ~ cootaat and _._,.Jar
~t oL ci.s-1,4 atzoetua:e and b8c-•• gal. occn• ,_
dnri"'9 po1~tioD can be ~ud, to PE••-t gal.
aderiDD ODto po1y.eri.zatioD tanka· or tbe like, so t:hat
continuous pol~zation U.. can be prolonged. As the
method for adjusting water concentration, known methods are
() app1icable. A method of addition and dispersion through
porous filters (JP-A-4-85304) is effective.
To the solution obtained by adjusting water
concentration is added an organic aluminum ch1oride as one
of cis-1,4 polymerization cata1ysts. As such organic
aluminlDD chloride, a coqx>und represented by the genera1
fonau1a A1R..X3-.. is preferab1y used. Specific e:uunples
thereof preferably include diethyla1umin1DD monoch1oride,
-20-
dietbylal:~inga monobrc>mide, diisobutyla1uainlml
1110noch1oride, dicyclobexy1a1uain\JIIl monocb1oride,
diphenylaluainlJID monocJ\16ride, and diethy~uainlliD
sesquichloride. 'lhe amount of such organic a1uainlliD
chloride to be used is preferably 0.1 JDDOl or more, 0.5 to
50 aaol per one mole of the total amount of 1 , 3-butadi.ene.
Then, a soluble cobalt ~ as another one of
the cis-1,4 polymerization catalysts is added to a mixture
( l solution to which the organic aluainlliD chloride is
preli.JIIi.narily added, for the cis-1,4 poly.erization of 1,3-
botadi.ene. SUch solubl.e cobalt c• ""''oound incl.udes tl.osol:
uble iD IJojdl:_..._. s~ sol.-b or liqnid 1,3-
butadi- to be 1ISed or -ifonaly dispersible- daeEe:i.D,
for •m Jl.e a>balt p-d:i.ke~ cxaphm, such as cnt:-Jt (:1:1)
acety~toDate aDd a>balt (:Ill) acety~~t:e. cnt:-Jt Itketo
acid -ter CCllllpl.ex, such as a>balt acetoacetic acid
ethyl -ter ccaplex, cobalt salts of organic carboxylic
0
acids with 6 or more carbon atoms, such as cobalt octoate,
cobalt naphthenate and cobalt benzoate, and halogenated
cobalt complexes such as cobalt chloride pyri.dine ccq:>lex
and cobalt chloride ethyl alcohol ccaplex. i'he amount of
such soluble cobalt ccapound to be used is preferably 0.001
mmol or more, more preferably 0.005 mmol or more per one
mole of 1, 3-butadiene. i'he molar ratio (Al/Co) of an
organic aluminUID chloride to such soluble cobalt cc..-q:oound
is 10 or more, particularly 50 or more. Still additionally,
-21-
()
organic carboxylate salts of nickel., organic ~lex salts
of nickel., organic lithi-.- CClllpOUDds, organic carboxylate
salts of neodymi.lml and organic caaplex salts of neodyai.uaa
may also be used other than the soluble cobalt cc'lll);ound.
The teaperature for the cis-1,4 polymerization is
generally within a range· of a tenperature above 0°C to
100°C, preferably 10 to 100"C, 11110re preferably 20 to 100"C.
Polymerization time (mean retention time) is preferably
within a range of 10 lllinutes to 2 hours. The cis-1,4
polymerization is preferably done so that the polymer
concentration after the cis-1,4 poly.erization .ay be 5 to
26 • by--- As U.. poip rizaticiD bmk, ODe taDk or blo
or - tank• ia CDD:}119aticiD aze ueed. 'll..o pcd~ticiD
is carried oat wbil.e U.. 80l.'DticD is wiyed together under
agitation ia tM pcd.,..nzation taDk Cpo:l~tion
...,aratua). As U.. pcdy.erization taDk for - in
·polymerization, a pol~zation tank equipped with an
agitation unit for highly viscous solution, for example the
() apparatus described in JP-B-40-2645, can be used.
For the VCR production in accordance with the
invention, known 11110lecular weight adjusters, for ex:urple
non-conjugated dienes such as cyclooctadiene, allene and
methylallene (1,2-butadiene) or ~-olefins such as ethylene,
propylene and butene-1 can be used during the cis-1,4
polymerization. So as to further suppress gel generation
during polymerization, known gelation-preventing agents can
-1'1--
be used. Jlddi.tiona11y, the content of the cis-1,4
structure in the pol.~rized product is generally 80 % by
mass or DIOre, preferabl.y 90 % by mass or more, with MLI.O to
SO, preferabl.y 10 to 40 and with substantiall.y no content
of gel. matters.
1,3-Butadiene is 1,2 pol.y.aerized to produce VCR, by
a.ddi ng an organic altDDinua caip01lDd represented by the
general. foEIIIUl.a AlRa and carbon sulfide, and the soluble
() cobalt caip01lDd if necessary as the 1,2 pol.ymerization
catalyst, to the cis-1,4 polymerization mixture thus
obtai-.-t. '!'ben, the ~ting -1,3-bntadiene .ay be added
to t:he pol.]! i:zatioa m •• •••- ot::beEwi.aa, tbe 11:aaal.ting
1,3 ba+adi-· .ay' ~ be ••Je.ot to the pol.~ti.OD
mxt:aEe bat 'DDE8i11Ctive 1,3 lla•wti- -r be ~.. 'l'he
OJI:9aldc alwwii- <''1-' :DPt•n ~ by the ~
fo~a Al.Ra pll:efell:ab1y i.Dcl.udas ~:lal.wwii.-,
trietbyl.allWi mw, triisobutylalUIDinua, tri (n-bexyl) aluminum
u and tripbenyl.altDDinum. The organic aluminum c~und is at
0.1 nmol or DIOre, particul.arl.y O.S to SO nmol. or DIOre per
one DIOl.e of 1,3-butadiene. Without specific l.imitation,
carbon disul.fide preferabl.y never contains DIOisture. '!'he
concentration of ~ disul.fide is 20 nmol./L or l.ess,
particul.arl.y preferabl.y 0.01 to 10 nmol./L. As an
al.ternative of carbon disul.fide, known isothiocyanate
phenyl. and xanthogenic acid caapounds may be used.
'!'he teq:>erature for the 1,2 pol.ymerization is
genera1ly within a range of 0 to l00°C, preferably 10 to
lOOOC, 1110re preferably 20 to 100°C. The yield of 1,2-
polybutadiene -can be raised during 1,,2 polym. eriza.t ion, by
adding one to SO parts by mass, preferably one to 20 parts
by mass ·of 1, 3-butadiene per 100 parts by mass of the cis-
1,4 pol~ization mixture to the poly.erization system for
1, 2 polymerization. 'fbe polymerization time (mean
retention time) is preferably within a range of 10 minutes
() to 2 hours. 'fbe 1,2 pol~ization is preferably .carried
out so that the polymer concentration after the 1,2
()
poly.erization JD.gbt be 9 to 29 • by mass. As the
agi.t:at:i.oD i.D the po1~tiOD t:aDk (pol.~t:i.oD
apparatus)_ As the pol~zat:i.oD taDk for - in the 1,2
pol~ization, a polymerization taDk equipped with an
agitation unit for highly viscous solution, for example the
apparatus described in JP-B-40-2645, can be used, becauthe
viscosity" of the pol~ization solution is increased
during the 1,2 polymerization and the polymer apts to be
attached.
For the VCR production in accordance with the
invention, the process of producing VCR by the cis-1,4
polymerization and subsequent 1,2 polymerization as
described above includes a step of adding a polymer
subs~ of a low ~tiDg point and with at least one
unsaturated double bond per repeating unit to the VCR
production system. When the unsaturated polymer substance
is added after VCR production, for example during
c• "'ounding, the advantage of the invention cannot be
obtained. The addition of such unsaturated polymer
substance to a production system is prefQrably done into
the polymerization mixture at an appropriate time point
() frcm the cis-1,4 polymerization to the 1,2 polymerization,
more preferably at the time of the 1,2 polymerization.
0
'lbe UDSaturated po1y.er subs..._ preferably is at
~t oae selected frcla po1yi~~oDpt-, m:ystaUizaNe
polyisop~ (cis-1,4-polyisop~ at a content of the cis
structure of 90 \ by mass or more, etc.), liquid
polyisoprene, and trans-polyisoprene.
The crystallizable polybutadiene of a me1ting point
less than is preferably a crystallizable
polybutadiene of a melting point of 0°C to l50°C, which
includes for example l, 2-polybutadiene and transpolybutadiene
with low me1ting points.
The liquid polybutadiene includes for example
polybutadiene with a very low molecular -ight and with an
intrinsic viscosity ['II = 1 or less.
The polymeric ccapound containing oxygen bond is
preferably caiiPOunds with ether group, epoxy group,
carboxyl group, ester group, hydroxyl group and carbonyl
group. Specific ccmpounds thereof incl.ude for e.-.raq:>le
phenol resin, nylon resin, polyurethane, polyethylene
glycol, epoxylated polybutadi.ene, polyester, epoxylated.
styrene/butadiene copol~r, polyaryl ether, and allyl
() ether copolymer. By ·adding such polymeric coq:>ound
containing oxygen bond to a polymerization system, the
interface affinity--CbaDgea between ci.s-polybutadiene as the
-t:rix (+ ~ ,......t oL t:be Yi.Dy~ -ci.s-polybuJbber as t:he matrix cciPI(">nent can be
prominently i.Jiproved owing to t:he compatible effect of t:he
unsaturated polymer substance in t:he resulting VCR, as
() described above, so t:hat t:he characteristics of t:he
0
resulting VCR are so excellent.
'!be an ount of t:be unsaturated pol.y.er substance to
be :w•te.!! is within a range oL pntferably 0_01 to 50 ~ by
-, - ~erably 0_01 to 30 ~ by - to t:be ~
IU.Pntee to 3 hours, .oxa prefar.abl.y 10 JU.pgtee to 30
minutes after addition. In case of a polymeric CC1IIIP01JilCl
containing oxygen bond, herein, t:he amount thereof to be
added is wi t:hin a range of preferably 0. 01 to 20 % by mass,
more preferably 0. 01 to 10 % by mass to t:he obtained
vinyl·cis-polybutadiene rubber. 'fhe met:hod for addition in
that case is wit:h no specific limitation. During t:he cis
1,4 polymerization or 1,2 polymerization to produce
vinyl·cis polybutadiene rubber, and/or at t:he termination
of t:he polymerization of vinyl· cis polybutadiene rubber,
t:he addition can satisfactorily be done. 'fhe addition at
-2:.1-
the time of 1,2 pol-y~~~erization is preferable. After
addition, preferably, agitation is done for 10 minutes to 3
hours. Preferably, agitation time is 10 minutes to 30
minutes.
In addition to the unsaturated polymer substance, an
organic CXliiiP01JDCl containing oxygen bond is preferably added.
The organic compound containing oxygen bond preferably
includes for example c~unds with ether group, epoxy
( ) group, carboxyl group, ester group, hydroxyl group and
carbonyl gxoup, which includes for e.........,.le acid anhydride,
a1iphatic alcobol, arc.atic alcobol, aliphaticu
etlMI:r·-t:i.c at:her,. aliphatic c:a•tCIIlly:li.c ac::i.cl·-tic
C'at1t ~;aylic acid·-buabld cad>oxylic ac::i.cl,. or aliphatic
caxbocoryla~ ester--tic caxboacyla~ esl:er·DDSatarat.d
0
_o.u. •na·t ~ t:o be a-•lwl is
within a range of patf&Eab1y 0.01 t:o 20 • by -· _,xe
preferably 0.01 to 10 • by aass to the obtained vinyl·cispolybutadiene
rubber. The method for addition in that case
is with no specific limitation. During the cis 1,4
polymerization or 1,2 polymerization to produce vinyl·cis
polybutadiene rubber, and/or at the temdnation of the
polymerization of vinyl·cis polybutadiane rubber, thaaddition
may satisfactorily be dona. The addition at the
time of 1,2 polymerization is prefexable. After addition,
preferably, agitation is done for 10 minutes to 3 houxs.
Preferably, agitation time is 10 minutes to 30 minutes.
-'2.8-
After tbe poly.erization reaches a predetermined
poly.erization ratio, known antioxidants are added
according to general. methods. TypicaL examples of such
antioxidants include ~1-series 2, 6-di -t-butyl-p-cresol
(BIIT), phosphorous-series trinonylphenyl phosphite (TNP),
su1fur-series 4,6-bis(octylthiomethyl)-o-cresol, and
dilauryl-3,3'-thiodiprcipionate (TPL). The antioxidants may
be used singly or in combination of two or more thereof.
The antioxidants are added to 0. 001 to 5 parts by mass per
100 parts by mass of VCR. Subsequently, a polymerizationterwinating_
agent is added to the poly.erization systaa to
t-enwinate the pol~zati.oD. '!be -t:laocl t:beEefor i..Dcl.lldae
for e• ple ~ _...,cis per -· sacb as a dKd of
_ fu",tiD9 a po:L~tioo lllixblre after terainati.oD of t:lle
po:L~tioo to a po:l~tion tenwinati.Dg taDk, aDd
cbargi.ng a large i :"'llllt of a polar sol._t sacb as alcobol.
such as methanol and ethanol and water in the
polymerization mixture or introducing inorganic acids such
(J as hydrochloric acid and su1furic acid, organic ac1ds such
as acetic acid and benzoic acid, and hydrogen chloride gas
to the polymerization mixture. Then, the generated VCR is
separated -and recovered, rinsed and dried according to
general methods, to obtain the intended VCR.
The VCR of the invention thus obtained generally is
at a ratio of the individual. COIJI>Onents, namely the ratio
of 1,2-polybutadiene of a melting point of 170°C or more,
-~9-
cis-polybutadiene rubbo>..r and the unsaturated polyaer
substance as described above, where 80 % by mass of the
microstructure of· cis-polybutadiene rubber is ci.s-1,4-
polybutadiene and the raaai.ning thereof is trans-1,4-
polybutadiene and vinyl-1,2-polybutadiene. file cispolybutadiene
and the unsaturated polymer substance are
singly (namely, at unreactive states) soluble in boiling nhexane,
and the 1,2-polybutadiene of a melting point of
('} 170"C or more and the unsaturated polymer substance
pbysically/a-ically adsorbed are insoluble in boiling nhexane
(abbreviated as •a.I,. berei..nafter). 'l'he 1,2-
pol.~am- o€ a -.l.tiDg poi.Dt o€ no-cor- generally
'baa a .alotiDg po.i.Dt o€ 1'7VC b> 220'"C, aDd is a C1j'ata1
f:iber ba abort f:iber-~ ab ··- Jldd:i.tioaal.1y, t:be
Adcli tiona1ly, the VCR of the invention is c~oosed
of the 1,2-polybutadiene of a melting point of 170°C or
(j more and the unsaturated polymer substance dispersed
uniformly in the matrix of cis-polybutadiene rubber.
In the VCR of the invention, generally, the 1,2-
polybutadiene of a melting point of 170"C or more is
dispersed in crystal fiber as described above.
Additionally, the unsaturated polymer substance can be
dispersed in various modes in association with the crystal
fiber of the 1,2-polybutadiene of a melting point of 170"C
-,30-
or 1110re. As s~tica11y shown in Fig. 1, the various
JDOdes inc1ude for eo: ple a JDOde of the crysta1 fiber ""2"'
of the 1,2-polybutadiene of a me1ting point of 170"C or
_,re and the lllicropart.icl.e "3'" of the unsaturated pol~
substance separate1y dispersed in the matrix "1"'; a JDOde of
the lllicroparti.cl.e "3"' of the unsaturated polymer substance
dispersed in a form being attached to the crysta1 fiber "2"'
of the 1,2-polybutadiene in the matrix •1,. as scme.atically
r 1 shown in Fig.2; a JDOde of the crysta1 fiber "2,. of the 1,2-
, '
polybutadiene dispersed in a fora being attached to the
m~cle "3"' of the unsaturated poJ.y.er---SUbetance in
tbe -tr.ix •1• as s~Mc:ctlt-atti:i"ccc:a:allll:Jy s~ i.D fig.3; iUid a _...
pol.ybvt adi- i.D a state t:llealof i.Dcludecl iUid di BJleES 1 tl i.D
i.D the -trix •1,. as ssccc"tl-atti:i".cc:a~Uy Aolm i.D F.ig.4. A _...
in CCIIIbination of two or .ore of the dispersion modes shown
in Figs. 1 through 4 may be possible. In Figs.1 through 4,
() "1" expresses matrix; "2"', the crysta1 fiber of the 1,2-
polybutadiene of a melting point of 170"C or _,re; and "3,.,
the lllicroparticl.e of the unsaturated polymer substance.
By the method for producing VCR of the invention,
the 1,3-butadiene and the hydrocarbon-sari- solvent
substantially never containing carbon sulfide are recovered
by separating and removing carbon disulfide from a mother
solution of the polymerization lllixture containing the
-.31-
unreactive 1,3-botadiene, the hydrocarbon-series solvent
and carllon disulfide r ining after the separation and
recovery of the generated vt:K, generally by distillation to
separate 1, 3-botadiene and the hydrocarbon-series sol vent
or by adsorption and separation process of carbon disulfide
or by separation process of carbon disulfide adclucts.
Additionally, the 1,3-botadiene and the hydrocarbon-series
solvent substantially never containing carbon sulfide are
( ') recovered by recovering the three ~ts from a mother
solution of the polya&rization mixture by distillation, and
separating and reiM>'Ving carbon disulfide fna the
distillate by t:be aw""':•pticla a..t s IJaratioD or t:be
aaparatioD p:oc••• of eawtw- m-lfi.da aw•h"C~B- '!he rarban
Bit'ima hiua greatiy biuowed nei- ~- -growth resist .....
arouud 30 on an index basis. (i.Dcrea-sed-- such va1ue r~... s-e-n-tsexce11ency)
and exerts an effect of suppressing flex crack.
Additiona11y, the ~1ity of gases such as oxygen as a
thermo-resistant property demanded toward run flat tire and
the 1ike is 1owered by around 5 (1ower such va1ue
represents exce11ancy) on an index1)asis, o-...u:ed with the
VCR obtained by methods of the re1ated art, exerting an
effect on the suppr-sion of heat invo1ved in oxidative
deterioration.
For the exertion of the various physico chemi ca1
-3Jt--
properties, preferabl.y, the 1,2-po1ybutadiene crysta1 fiber
dispersed in VCR is partia11y dispersed in a mono-dispersed
foxm 9Et mi.crofine crysta1 in the matrix of cispo1ybutadiene
rubber (abbreviated as "BR,. hereinafter) and
concurrently present with a 1arge 1,2-po1ybutadiene crysta1
fiber wit:h an aggzegated sb;:uct;QJ:a In other words 1 the
mono-dispersed 1 1 2-po1ybutadiene crysta1 fiber in the BR
matrix is preferab1y in a short fiber of the mean 1ength of
() the mono-dispersed fiber crysta1 a1ong short axis bei.ng 0.2
"'• ,
(J
pm or 1ess, an aspect ratio of 10 or 1ess, the mean number
of the .ono--dispersed fiber crysta1 being 10 or BIOre and a
.al.tiDg poi.at of 170"& or .oEe. ID add:itiOD to t:be 1,2-
J!Cl')blttadi- cx:yst:al. flller of a ~ting point of 1~ or
.oze, prefeJ:abl.y, the -t:uzated pol.y.er sube..._ is
dispersed iD the l!lt _t:z::ix_
substance preferabl.y has high affiDi.ty with the 1,2-
po1ybutadiene crysta1 fiber in the BR matrix, and is
dispersed therein at a state of physica1 and chemica1
adsorption in the vicinity of the crysta1 fiber (dispersion
modes of Figs. 2 to 4) . As described above 1 the concurrent
dispersion of the 1 1 2-po1ybutadiene crysta1 fiber of a
me1ting point of 170"C or more and the unsaturated po1~
substance in the BR matrix makes the various properties
exce11ent, preferab1y.
A rubber coq>osi tion prepared by compounding and
""•t;'Ounding the VCR of the invention in other synthetic
-315"-
rubber or natural rubber is now described in detai1. ftle
rubber c•..-osition is suitab1y ~ with 10 to 300
parts, preferab1y 50 to 200 parts by mass of the VCR per
100 parts by mass of natural rubber, synthetic rubber or a
b1end rubber at an appropriate ratio thereof. ftle
synthetic r>•bber preferab1y inc1udes for ~1e
po1yisoprene rubber and styrene-butadiene c:opo1yner rubber_
Addi.tiona11y, a butadiene rubber ·~sition for tire can
~~~ preferab1y be produced, using the VCR and/or a butadiene
'
'!be nti>er c<"'' oei tion of tbe iDV8Dtion can be
b a led with •>-.w.o-- rli"9 ageat:a for ECIIrt:i..De use i.D. ...... ._r
industries, such as ygJ cani zing agents, Yal.canizationaccelerators,
antioxidants, fi11ers, process oi1, zinc
oxide and stearic acid.
() As the vu1canizinq agents, known vu1canizing agents
for examp1e su1fur, organic peroxides, resin vu1canizing
agents, and meta1 oxides such as magnesium oxide can be
used.
As the valcanization-accel erators, known
va1canization-acce1erators for examp1e a1dehydes, aDDOnias,
amines, guanidines, tbioureas, thiazo1es, tbiurams, dithiocarbamates
and xanthates can be used.
-~-
'lbe antioxidants inc1ude for exaaple amine· ketone
series, imidazole series, amine series, phenol series,
su1fur series and phosphorous series.
'lbe fillers include for exanple inorganic fillers
such as silicic anhydride, CiUcium carbonate, magnesiwa
carbonate, talc, iron sulfide, iron oxide, bentonite, zinc
oxide, diatcaaceous earth, china clay, clay, alumina,
titaniUIII oxide, silica, and carbon black, and organic
() fillers such as regenerated rubber and powdery rubber.
(J
As the process oil, any of aromatic series,
napb~ series and paraffill- series .ay be used.
c:leiJcri.W ~fically .,.,c-.
Ew: (>1& 1
A solution of 1.6 kg of 1,3-butadi- dissolved in.
18 kg of dehydrated cyclohexane was placed in a 30-L
stainless steel-made reaction tank with an agitator after
the inside was substituted with nitrogen gas, into which 4
umol of cobalt octoate, 84 DIIIOl of diethylaluminUJD chloride
and 70 DIIIOl of 1,5-cyclooct:adi.ene were mixed, for agitation
at 25°C for 30 minutes for cis pol~ization. The
resulting polyaer had ML of 33 and T-cp of 59, and a
microstructure of 1,2 structure at 0.9 ' by mass, trans-1,4
structure at 0.9 ' by mass and cis-1,4 structure at 98.2 '
-~-
by .ass. After the cis polyaerization, an unsaturated
polymer substance ~rising polyisoprene (IR) (HL = 87;
cis-1,4· structure at 98 \ by -mass) was added to the
resulting polyaerization solution to 5 \ by mass (as the
percentage to the resulting vinyl·cis-polybutadiene rubber),
for agitation at 25°C for one hour. J)gnpdiately thereafter,
90 .->1 of triethylalUIIIi.nua and 50 DDOl of carbon disulfide
-re added to the polymerization solution, for agitation at
() 25°C for another 60 minutes, for 1,2 polymerization. After
\ '
the ~letion of the polymerization, the resulting
pol.,_rization solution 1laS added to 18 liters of -tbanol
SUbsequently, the vinyl·cis-polybutadiene rubber was
treated in boiling n-hexane, to separate insoluble matters
() and soluble matters, which ~ then dried. The polymer as
a matter soluble in boiling n-hexane had ML of 31, T-cp of
57, and a T-cp/ML relation of about 1. 8, where the micro
structure was composed of 1.0 \ by mass of vinyl-1,2
structure, 0.9 \ by mass of trans-1,4 structure and 98.1 by mass of cis-1,4 structure. Additionally, the mass
average molecular ~ght on a polystyrene basis was 42 x
104
, with (1\J of 1.7. The number of the mono-dispe:.:;sed
fiber cxystal of 0.2 pa or less a1onq short axis as
contained in the vinyl·cis-polybutadi- rubber was 100 or
1110re per 400 ,.,l, while the aspect ratio was 10 or less and
the .al.ting point was 202°C.
':rhe VCR rubber thus obtained was subjected to
physico-chelncal asses-t after the VCR rubber was
COIIIPOUDded as shown below and in Table 1.
r·. AssesSIIIQJlt itals and conditions for carrying out the
' '
c}
assessment
Kiln=ding -tbod
paw-e-..... [~ ( ... t--mng)
rna-Mag ~rabls: Ba • wy wiyer of 1-, liters)
Rotation ......,_r: 77 :qa
start t~ture: 90"c
Kneading procedures:
Time 0: charging VCR/NR (natural rubber)
Time 0: charging filler
Time 3 min: raising ram for cleaning (15 seconds)
Time 5 min: c:luq>.
'lhe d>iilii4d matter was continuously wound with a 10-
inch roll for one minute, for round passing three ti=es and
subsequent sheet extrusion. After the cca1p0und was cooled
for 2 hours or longer, the caapound was subjected to
-3'1-
secondary co•'IOOUDdi.ng according to the following procedures.
[Secondary CCliii\)OUJKiing]
After the ce~~~pletion of the primacy" cc:Jq>OUnding,
secondary oonpound.ing was done according to the following
procedures.
Kneading apparatus: 10-inch roll
Roll teaptrature: 40 to 50°C
Rotation interval: 2 -
(j Kneading procedures:
(J
(1) Time 0: winding m*"ioect -tter and charging sulfur and
vulcanization accelerator
(2) ti-. 2 ai.a: cuU iDg
(3) fi-. 3 ai.a: sJ.et exl:L-iCID ut8r ~ SCLapiDg aDd
1:~ passiDg
~ period for ~canizatiCID
MeasuriDg apparatus: .lSil CUJ:elas~ter type 2F
Measuring ~ture: 150°C
Measuring time period: vulcanization ti.llie periods of t,.. x
2andt,..x3
Vulcanization conditions
Vulcanizing apparatus: press vulcanization
Vulcanizing tMq:>erature: 150°C
[Assessment of physico-chemical properties of raw rnbber]
The microstructure was analyzed by infrared
absorption spectrometry. Based on the absorption intensity
ratio at 740 cm-1 for cis, 967 cm-1 for trans and 910 cm-1
-'tOfor
vinyl., the ai.crost:ruct:ure was cal.cul.ated.
'lbe Mooney viscosity CML:t+4) was measured according
to JYS K6300.
'lbe viscosity in tol.uene sol.ution (Tcp) was measured
at 25"C, by dissol.ving 2.28 g of pol.ymer in 50 ml. of
tol.uene and using the standard sol.ution for cal.ibrating
vis~ter (JYS Z8809) as the standard sol.ution and canon
Fenske visa.eter No. 400.
() ~00 : tensil.e stress va1ue when a sampl.e of vul.canized
rubber exerted an extension ratio of 1.00 lll, as measured
-r_: tensile sl1eogt:b at break oL a • rle of YUlcani.,..t
rut.-_, as rDEed according a. .liS lt5301
'!be -.J:t:ing poiAt oL tbe 1,2-J)01ybat:acti- czystal.
endotberwi c COL- with differential. scanning cal.oriaet:er
(DSC).
[Physico-chemical. properti- of CXlqiOUIKied material.)
(J Die s-1.1.
Measuring apparatus: apparatus for measuring processabil.ity
as manufactured by Monsanto (MPT)
Die shape: circl.e
L/D: 1., 1.0 (D = 1..5 mm)
Measuring teq:>erature: l.OO"C
Shear val.ocity: 1.00 sec-1
[Physico-chemical. properties of vul.canized product)
< I .
Hardness, rebound resilience and tensile strength
'
were measured according to measuring 111ethods defined by
Jl:S-K-6301.
The tan6 of dynamic visoo-elastici ty was measured
under conditions of a taaperature of 70°C, a frequency of
10 Hz and a dynamic strain of 2 t 1 using RSA2 IDilufac:tured
by Pecvetrics Far East LTD.
•
Exothermic property and PS (permanent strain) were
measured under conditions of a strain of 0.175 inch, a load
of 55 ponds, 1000C and 25 Jainut.es with Goodrich f1exrnater
according to AS'lM D623.
~ c "+'-•eel pp-•IDI-•=•t: .train - -.-1 by
22 11oara wi.t:ll a c 1 1 ••ic- ..t bast:er rra .,.... •• •• ...S by
0395.
As the flex-crac:k-gEOM:h resistaace. a W'M--r of· flexing a
s~l e until the Cra.ct. of the s 11 e reac:bed a length of 15
- or - with a flexing -chine .anufactured by tteshima
Seisaltusho Co., Ltd. according to AS'lM 0813 was -.ured.
'1'he gas pe• aaNlity was -.urad aoooJ:di.ng to the
~~~easuring 111etbod defined by .n:s K7126.
'1'he tan6 of the dynam.c Visoo-elastici ty was
measured under conditions of a t perature of 700c. a
frequency of 10 Hz and a dynam.c strain of 2 t using RSA2
-nufac:bJred by Rhec.etrics Far East LM.
-If«.-
)
Table 1
RIJbber ' cbe•i cals
CaapouJided aJM>Unt
60/40
BAF carbon 50
Primary Process oil 10
coup>UDdi.ng Zinc oxide No. 1 5
Stearic acid 2
Antio'lidant AS 1
Secondary
Vul.canization-accelarator cz 1 campounding
SU1fur 1.5
'l'ota1 170.5
() E~le 2
()
Vinyl·cis-polybutadi- r11bher was obtained in the
-blEated po1y.er s .... t • IF (addit:i-~ to be iM\Ipd as
..,_. iD TaW• 2.
Sylltlsris aad. '"*1 - rtiag - "'- iD t:he -
-nner as in E• (•le 1 exc.pt for DO addition of
unsaturated pol:v-r substance (additive), or except for the
addition of unsaturated polymer substance not during
polymerization but during ccq>oundi.ng after VCR rubber
synthesis (the amount of unsaturated pol.ymer substance to
be added was 10 % by mass of VCR).
Tabl.e 2 shows the raw rubber data of vinyl.· cispolybutadiene
rubber ~sitions. In the tabl.e, the
number of mono-dispersed fiber crysta1 was the number per
4 00 J1111.2 as an index while such crystal of a l.ength of 0 . 2 Jl
or l.ess al.ong short axis was defined as mono-dispersed SPB
( )
()
fiber crystal.
'fbe aaicrostructure of bigbl.y mel. ting SPB in
~tive Exa~~~ple 1 was at 98.8 \ by mass of vinyl-1,2
structure, 0.6 \ by Dass of trans-1,4 structure, 0.6 \ by
mass of cis-1 ,4 structure and a ratio (A/B) between (A)
matrix BR as a matter soluble in boiling n-hexane and (B)
higbl.y melting SPB as a ~aatter insoluble in boiling nhexane
was 88/12. In Camparative Exaaple 1, additiona1ly,
l)sp/c of the polymer insoluble in boiling n-hexane was 1.5.
(l)sp/c: expressing the JDagnitude of the JDOlecular weight of
1,2-polybutadi- crystal fiber; -.urad at a t pcrablre
of 13S"'c; illllld u. sol.-t 1llleCl - ~chlonltoee-).
:Ill the t-abJ·e, Ill :nopus-b lJl2200 (pol.yi.II!Dplf-
am:Vac• ,.. eo:1 by .JSit) ; 1,2-PB ~t:s 118820 (1,2-
po.lybabcti- _nuf ........... b.lr .:JSit).
Table 2
Polymer
auk~·
atanoe
Type
<-lt:i.nv
po:l.nt)
IIX&~~~Ple 1
I:R
I
~
IIXIUIIple 2 1,2-n (510°C)
comparat:
Lv. - :&x.-le 1
comparat:
Lv. I:R
IIIX&~~~Ple 2
!
Polymer
,·_aul:
latanoe
T:ime tor
ac:I4:L t:Lon
(uaount
acicieci :Ln
wt t)
At the
t:ime ot
polymer:!.-
zat:l.on
1101
At the
t:ime ot
polymer:!.-
aat:l.on
(101
-
At the
t:ime ot
OOIIIpOunciiA!
i (10)
Mono• .u..,. •••
eel ...
Polymer:!.• ,~.
aat:Lon •¥Y•Q:I.
aolv.nt n\IIUQ
(ap <•¥Y•t•:l.•
value) i400 ua11·
cyolo•
hexane tOO ••
(8 .1) ....
cyGlo•
bezane 10
(8 .1)
cyolo•
bezane • (8 .1)
cyolo•
hexane • (8 .1)
Mono• cU.•· ,..• .•.e ci
Aqte•t
l'at:Lo
to o:r
:~. ...
!
to o:r
lea•
10 o:r
... e
1.0. .o.:r
.....
-'
Mono·
dit·
peraeci ...
lbape
Part:i.-
ole
r~r
and
p&J:t:i.-
ole
r:~.~:~er
r~r
C¥Y&tal C¥Y&tal
t~r t:LI:Ier
di&~~~eter ci:l.ueter
alonv -:lor alonv
ax:l.a ~jor ax:i.a
H.I In -tr:i.x In polyma:&-
(wtt) (j.llll) aul:latanoe
( j.llll)
22.4 0.2 to 0.5 0.1 0:&'
lea•
0.1 0:&' 22.3 0.5 to 1
1•••
12.1 1 or more None
12.3 1 or more · 0.5 or
mon
Emnples 3 tbroogb 12 and Cc-parative Examples 3 through 5
Vinyl·cis-polybotadiene rubber was obtained in the
s- JllallDer".as in Example 1, except for the addition of
polymer substances and solvents shown in Table 3.
In the table, IR represents IR2200 (polyisoprene
manufactured by JSR) ; liquid PB is Biker CTBN 1300 x 8
(liquid polybotadiene with a JDOlecular weight of 3,500 as
manufactured by Obe Industries, Ltd.); epoxylated PB
C) represents Epolead PB3600 (epoxylated polybotadiene with a
viscosity of 33 pascal seconds at 45°C as JllaJlufactured by
Dai.ce1 On i cal :Indostries, Ltd.) ; aryl et:her pol.~ is
HaEyaria N!IS-oe51 IY;iiiClCeit:y oL 400 stok8e at ~ -
tao:: I medJ by )10F ~ti.oD).
()
Table 3
SJ1B
~ror Po~y.eri
'Iype additiOD zation aryata~
Aspect
C.Uti.J>g (-.t -~-t (SP liUIIIber
poiDt) added iD val.-)
ratio
wt t) i4oC.- ~J)
At _ Cyc1obe•ene 100 or ~0 or
h""'P~e 3 Ill po~y.er1-
(5) (8 .1) ... J:e l.ess
At B•-.le 4 cyclobezape 10 or Liqoid PB !7:.~~;, (8 .1) 29
~--
At
()
•xaaple 5 Epoxy- po1peri.- cycJobex- 100 or
7
lated PB zatiOD (8.1) ... J:e
(0.5)
At
~obexa-/
lb I ... 6 Epoxy- po1peri.- :t...-= 60 or
7
lateclPB zatiOD 80/20 (8.3) ... J:e
10.5,
~ c,cl II I • ·-., .. it ~- = 30 DE , ........ , aat:i- ml• - (8..5)
(8.5)
~ • . .... pol'JI yi
qnJ t
16 • zatiOD (1)
(8.1) .. J
• .... , ~ a· a lat.d .. 20 1.8 m CJ-2) .. .... ..,_,. ~ polp eri- cynlM-·-- 29 9
10 lateclPB ... ~~ (5) (8.1)
At
0 •xample Bpoxylatecl
poly.eri- Cyc1o'bexane/
100 or 10 or
zatiOD n-bezane ~ 11 PB (0.5) 50/50 (7 .7) ... J:e 1-•
Allyl At
•xample ~obexane/
ether
poly.eri- n-bex•ne = 20 or 8or
12
ccpo1y.er
zatiOD
50/50 (7. 7) ... J:e 1-•
(0.5)
ec.p..ra- -~ tiva - - 8 11
3 80/20 (8.3)
Ceeparacyclob•
xativa
- - 4 13
4
(8.1)
Ceeparativa
- - 2 12
5 50/50 (7 .7)
Data of pxoducts c~ with viny1.cis-po1ybutadiene
rubber c•~itioos aDd vul.canized products thereof are
shown bel.ow. In exaap1es 8 through 12 and comparative
exawp1es 4 and 5, herein VCJt/liR=100/0, representing that l!IR
(uatura1 rubber) was DOt added during the primary
Sma11er iDdices of Die swe11 (100 sec"1
), gas
perileab:i1ity, exotbena:ic property, PS, compressed peraanent
strain and tomi show better exce11ency.
Larger iDdices of hardness, M100, TB, BB, TR,
abrasion, f1ex-craclt-growth resistance and
resi1ience show better exce11ency.
-4-BRanborn
rebound
Table 4
1ibr (•1e Examp1 ••-"''pll Rxamp11 Comparative~ C01111parative
1 2 e 3 e 4 Bx-:mp1e 1 Kxa"'P1e 2
Pbysico-Ch•lica1 p.:operties of c0111p0•mded :material (index)
Die swe11 L/D=1 I L/D-1 I L/D-1 I L/D=1 I L/D=1 I L/1>=1
100·sec-~ 70 72 76 I 85 I 100 I 99
Physico Ch-ica1 p.:operties of vu1cani~ed product (index)
Hardness 106 107 104 106 100 100
Ml.OO 140 139 138 136 100 101
TB 107 107 104 107 100 100
BB 102 100 101 100 100 100
TR 103 103 104 103 100 101
Ran born
abrasion
(slip 112 109 108 100 100 99
ratio : () 2 0!11)
F1excrackgrowth
135 130 136 131 100 104
Reaiabmce
Gaa
P" nbi]i 95 95 95 95 100 100
ty of~
Gaa
PTLF abili 93 9:2 93 9:2 100 100
ty of~
Re:bomkt
105 104 105 103 100 101
Reallieace
Exothermic
87 88 88 89 100 96
properties
PS 82 83 83 84 100 96
(_) Compressed
penaanent 89 88 88 89 100 98
strain
Tanli 86 85 83 84 100 98
-'t4-
Tab1e 5
l!tlr=- 1•1e 5 I Kx .,•1e 6 Kx~ 1e 7 I Comparative
--Dip E::lramop1e 3
Physico Che.ica1 properties of cOIIIpOUDded -teria1 (i.ndex)
Die swe11 L/D = 1 I L/D = 1 L/D = 1 I L/D = 1
100 sec-• 77 I 78 80 I 100
Physico-Cbem:ica1 properties of vu1canized product (index)
HardDess 104 104 104 100
111.00 141 140 140 100
TB 107 107 106 100
BB 102 102 102 100
TR 103 103 102 100
Ranborn
abrasion
112 112 109 100
(s1ip ratio
: 20 %)
P1ex.-craekgrowth
143 139 139 100
Resistance
Gas
peril ability 95 95 95 100
of~
Gas
per11 abi1i.ty 93 93 93 100
of Oa
~ 105 105 104 100
reaili......,..
Jtxotberafc
properties 88 89 91 95
PS 82 81 83 94
Ccmpressed
permanent 88 89 89 96
() strai.n
tanl) 86 87 86 93
-St>-
Table 6
I Ex-aaple 8 I Ex 1•le 9 Exa-.;•1e 10
C01111parative
Elt'"llllple 4
Physico Cbemi cal properties of
cOIIIpOUDded -terial (iDdex)
Die swell I L/D = 1 I L/D = 1 .L/D = 1 L/D = 1
100 sec-~ I 73 I 71 75 100
Pbysico-Chemi cal properties of vulcanized product (index)
Hardness 107 107 . 106 100
11100 138 139 140 100
TB 107 107 107 100
BB 102 100 100 100
TR 104 103 103 100
RaDborD
abrasion
105 106 106 100
(slip ratio
( } ' 20 %)
Flex-crackgrowth
135 -129 132 100
resi.s~e
Gas
P*ZT? ability 95 95 M 100
of' lf:2
Gas
pe' nMHty 93 92 M 100
of'~
Rt+a-rJ
103 1M 105 100
resilience
Exotberaic
properties 90 91 89 100
PS 82 83 82 100
Compressed
(} permanent 86 87 87 100
strain
ta!W 86 83 84 100
Tabl.e 7
b 1•l.e 11 bft'lll•l.e 12
C01111parative
b~mpl.e 5
Pbysico-cbemica1 properties of coapounded material. (index)
Die swel.1 L/D = 1 L/D = 1 L/D = 1
100 sec-~ . 70 73 100
Pbysico-ch-.ica1 properties of vul.canized product (index)
Hardness 107 107 100
111.00 141 138 100
TB 109 107 100
BB 101 102 100
TR 104 104 100
Ranborn abrasion
(slip ratio : 20 109 111 100
'II)
Fl.ex-crackgrowth
133 135 100
Resistance
Gas per.eabil.ity
95 95 100
of· 1J:t
Gas pemz nbil.it;r
of~
!)3 !)3 100
... [41 " 108 107 1.00 :nei-l :iMPee
~c 86 86 100
palpeXti-
PS 7!) 78 1.00
O:wp.c-Becl 85 87 100
pe'"""RWDt strain
tan6 80 78 100
Figs. 5 through 8 are electron micrographs depicting the microsh uctures of
vinyl cis-polybutadiene mbber actually obtained. Fig.S is the micrograph of
Comparative Example l,where 1,2-polybutadiene of a melting point of l70°C
or more is a whisker-like crystal to form aggregation in the matrix. Fig.6 is the
micrograph of Example 3; Fig.7 is the micrograph of Example 2; and Fig.8 is
the micrograph of Example 4, where the aggregation formed by whisker-like
crystals in the individual figures is small compared with Fig.S, indicating
better dispersion.

We claim
1. A butadiene rubber composition prepared by compounding a
a. 10 to 300 parts by weight of vinyl cispolybutadiene
rubber comprising:
i. cis polybutadiene rubber;
ii. 1,2 polybutadiene in an amount of 1 to so parts
by mass based on 100 parts by mass of cispolybutadiene
rubber; and
iii. a polymer substance having a melting point lower
than that of the 1,2 polybutadiene and having at
least one unsaturated double bond per repeat
unit, in an amount of 0.01 to SO% by mass based
on a total of the cis-polybutadiene rubber and
1,2 -polybutadiene
wherein the 1, 2-polybutadiene and the polymer
substance are dispersed at physically, chemically
or physicochemical adsorbed states in the cispolybutadiene
rubber as the matrix component of
the vinyl cis-polybutadiene rubber, and
b. 100 parts by weight of a rubber selected from
natural rubber, polyisoprene
butadiene copolymer rubber, or a
least two types thereof.
rubber, styreneblend
rubber of at
2. A butadiene rubber composition for tire, where a vinyl
cis-polybutadiene rubber, a butadiene rubber composition
as claimed in claim 1 , or a mixture thereof is used,
wherein the vinyl cis-polybutadiene rubber comprises:
i. cis polybutadiene rubber;
53
ii. 1,2 polybutadiene in an amount of 1 to 50 parts by
mass based on 100 parts by mass of cis-polybutadiene
rubber; and
iii. a polymer substance having a melting point lower
than that of the 1, 2 polybutadiene and having at
least one unsaturated double bond per repeat unit,
in an amount of 0.01 to 50% by mass based on a total
of the cis-polybutadiene rubber and 1,2
polybutadiene
wherein the 1, 2-polybutadiene and the polymer substance
are dispersed at physically, chemically or
physicochemical adsorbed states in the cis-polybutadiene
rubber as the matrix component of the vinyl cispolybutadiene
rubber.
3. A butadiene rubber composition prepared by compounding a
vinyl cis-polybutadiene rubber obtained by a production
method at 10 to 300 parts by mass per 100 parts by mass
of a rubber selected from natural rubber,
rubber, styrene-butadiene copolymer rubber
rubber of at least two types thereof,
poly isoprene
or a blend
wherein the production method comprises a step of cis-
1,4 polymerization of 1,3-butadiene using a cis-1,4
polymerization catalyst in a hydrocarbon-series solvent,
a step of 1, 2 polymerization of 1, 3-butadiene in the
concurrent presence of a 1, 2 polymerization catalyst in
the resulting polymerization mixture to generate 1,2-
polybutadiene of a melting point of 170°C or more, and a
step of the separation and recovery of vinyl·cispolybutadiene
rubber generated from the resulting
polymerization mixture, the method including a step of
54
adding a polymer substance with at least one unsaturated
double bond per repeating unit to the production system
of vinyl·cis-polybutadiene rubber.
4. The butadiene rubber composition for tire as claimed in
claim 3, where the polymer substance is at least one
selected from polyisoprene, crystallizable polybutadiene
of a melting point of 0°C to 150°C, liquid polybutadiene,
and derivatives thereof.
5. The butadiene rubber composition for tire as claimed in
claim 3, where the amount of the polymer substance to be
added to the production system is within a range of 0.01
to 50 % by mass to the vinyl·cis-polybutadiene rubber to
be obtained.
6. The butadiene rubber composition for tire as claimed in
claim 3, where the step of adding the polymer substance
to the production system is carried out in the
polymerization mixture at an appropriate time point from
the step of the cis-1,4 polymerization step to the step
of the separation and recovery of the vinyl· cispolybutadiene
rubber generated from the polymerization
mixture obtained after the completion of the 1, 2
polymerization.
7. The butadiene rubber composition for tire as claimed in
claim 3, where the hydrocarbon-series solvent is a
hydrocarbon-series solvent with a solubility parameter of
9.0 or less.
55
8. A butadiene rubber composition for tire, where a
butadiene rubber composition as claimed in claim 1 or 3
is used.
9. A butadiene rubber composition for tire, where a
butadiene rubber composition as claimed in claim 2 is
used.
10. A butadiene rubber composition for tire, where a vinyl
cis-polybutadiene rubber "obtained by a production method
and a butadiene rubber composition as claimed in claim 1
or 3 is used,
wherein the viriyl cis-polybutadiene rubber is obtained
by a production method comprising a step of cis-1,4
polymerization of 1,3-butadiene using a cis-1,4
polymerization catalyst in a hydrocarbon-series solvent,
a step of 1, 2 polymerization of 1, 3-butadiene in the
concurrent presence of a 1, 2 polymerization catalyst in
the resulting polymerization mixture to generate 1,2-
polybutadiene of a melting point of 170°C or more, and a
step of the separation and recovery of vinyl·cispolybutadiene
rubber generated from the resulting
polymerization mixture, the method including a step of
adding a polymer substance with at least one unsaturated
double bond per repeating unit to the production system
of vinyl·cis-polybutadiene rubber.
11. The butadiene rubber composition for tire as claimed in
claim 10, where the polymer substance is at least one
selected from polyisoprene, crystallizable polybutadiene
56
of a melting point of 0°C to 150°C, liquid polybutadiene,
and derivatives thereof.
12. The butadiene rubber composition for tire as claimed in
claim 10, where the amount of the polymer substance to be
added to the production system is within a range of 0.01
to 50 % by mass to the vinyl·cis-polybutadiene rubber to
be obtained.
13. The butadiene rubber composition for tire as claimed in
claim 10, where the step of adding the polymer substance
to the production system is carried out in the
polymerization mixture at an appropriate time point from
the step of the cis-1,4 polymerization step to the step
of the separation and recovery of the vinyl·cispolybutadiene
rubber generated from the polymerization
mixture obtained after the completion of the 1, 2
polymerization.
14. The butadiene rubber composition for tire as claimed in
claim 10, where the hydrocarbon-series solvent is a
hydrocarbon-series solvent with a solubility parameter of
9.0 or less.
15. A butadiene rubber composition for tire, where a vinyl
cis-polybutadiene rubber obtained by a production method
and a butadiene rubber composition as claimed in claim 2
is used,
wherein the vinyl cis-polybutadiene rubber is obtained
by a production method comprising a step of cis-1,4
polymerization of 1,3-butadiene using a cis-1,4
57
polymerization catalyst in a hydrocarbon-series solvent,
a step of 1,2 polymerization of 1,3-butadiene in the
concurrent presence of a 1, 2 polymerization catalyst in
the resulting polymerization mixture to generate 1,2-
polybutadiene of a melting point of 170°C or more, and a
step of the separation and recovery of vinyl·cispolybutadiene
rubber generated from the resulting
polymerization mixture, the method including a step of
adding a polymer substance with at least one unsaturated
double bond per repeating unit to the production system
of vinyl·cis-polybutadiene rubber.
16. The butadiene rubber composition for tire as claimed in
claim 15, where the polymer substance is at least one
selected from polyisoprene, crystallizable polybutadiene
of a melting point of 0°C to 150°C, liquid polybutadiene,
and derivatives thereof.
17. The butadiene rubber composition for tire as claimed in
claim 15, where the amount of the polymer substance to be
added to the production system is within a range of 0.01
to SO % by mass to the vinyl·cis-polybutadiene rubber to
be obtained.
18. The butadiene rubber composition for tire as claimed in
claim 15, where the step of adding the polymer substance
to the production system is carried out in the
polymerization mixture at an appropriate time point from
the step of the cis-1,4 polymerization step to the step
of the separation and recovery of the vinyl· cispolybutadiene
rubber generated from the polymerization
58
mixture obtained after the completion of the 1, 2
polymerization.
19. The butadiene rubber composition for tire as claimed in
claim 15, where the hydrocarbon-series solvent is a
hydrocarbon-series solvent with a solubility parameter of
9.0 or less.