AU463528B2 - Carbon black products - Google Patents

Description

36,524/71 This invention relates to a novel class of carbon

black products which have high surface area and which

are virtually non-porous. ileretofore, it has been

acknowledged by those skilled in the art of porosity measurement that a significant degree of porosity is

always present in carbon black pigents having a

critical high surface area. In particular, it has been

believed that all carbon black pigments exhibit a

significant degree of porosity at a BET total surface

area of at least -ob-t 140 m2/g.

It has now been found, however, that there may be

prepared a novel class of carbon black pigments having

total surface areas of at least aleg.t 160 m 2/g which,

indeed, are essentially non-porous. The non.-porosity

of the carbon black pigments is defined, for purposes

of this invention, as the ratio of area to BET

total surface area wherein the value for the ratio is

at least 0.9. Furthermore, this invention relates to

the use of the novel class of carbon black products

in the preparation of new and useful natural and synthetic rubber compositions having improved physical properties.

Normally, there have been widely employed as

fillers and reinforcing pigments in the compounding and

preparation of rubber compositions various conventional

carbon blacks known heretofore. Ordinarily, the conven-

tional carbon blacks are effective in the preparation

of rubber vulcanizates having improved reinforcement

properties such as tensile strength or elongation. The

improve~cnt in properties exhibited by an elastomeric article or rubber stock filled with a carbon black will.

4 63. 2e

36,524/71 depend to a great extent upon the type of elastomer utilized and the particular carbon black incorporated therein. 1.owever, the developmnent of' suitab'le car:boni blacks for use aiith several of the more recently developed synthetic rubbers has proven difficult as a result of the increased inertness and reduced reactivity thereof. Typically, the newer synthetic rubbers are commercially desirable for use as general purpose or heavy duty rubber stocks because of the low amount of unsaturation contained therein. Although some improvements have been achieved, for example, by aftertreating carbon blacks, it has now been made possible by using the carbon black products of the present invention to provide finished products having still further improved tensile, hardness, modulus and abrasion-resistant qualities. Accordingly, it is a primary object of this invention to provide a novel class of carbon black products. It is a further object of this invention to provide a suitable carbon black reinforcing additive for natural and synthetic rubbers which provides the desired physical properties to the resultant composition. Other objects and advantage3 of the present invent ion will be apparent to those skilled in the art from the following detailed description and claims. In accordance with this invention, it has been found that the above and still further-objects are achieved by the preparation of novel carbon black products which have a total surface area of at least ee 524 fle 160 i 2/g and are aly non-porous, have a value for the ratio of curve area to total BET it is erre5d iat surf .ce area of at least 0.0. have a total surface the novel carbon black products Further, when incorporating area of at least 170 m 2/g. into a natural or the novel carbon black products of the carbon black product synthetic rubber, amounts 10 to a 250 parts byweight can ranging from W 100 parts by iieight of generally be used for each a significant degree of rubber in order to impart is, however, preferred to reinforcement thereto. It L 20 to abea-t 100 parts use amounts varying from per 100 parts by weight of by weight of carbon black is the utilization rubber and especially preferred 80 parts of carbon black of from ab±u' 40 to about per 100 parts of rubber. novel carbon blacks The rubbers for which the as reinforcing agents of this invention are effective synthetic rubbers. Among include natural rubber and with the present invention the rubbers suitable for use derivatives such as chlor- are natural rubber and its from aboU± 10 to a-oil inated rubber; copolymers of and from sabou 90 to abeu- percent by weight of styrene such as a copolymer percent by weight of butadiene parts butadiene, a copolymer of 19 parts styrene and 81 butadiene, a of 23.5 parts styrene and 76.5 parts and 70 parts butadiene, copolymer of 30 parts styrene and 57 parts butadiene a copolymer of 43 parts styrene styrene and 50 parts and a copolymer of 50 parts of conjugated dienes butadiene; polymers and copolymers

4635.28

36,524/7 such as polybutadiene, polyisoprene polychloroprene,

-ad t li:e and copolymers of such conjugated dienes

.;ith an ethylenic rou:-containini uornoi-er copolymer-

izable therewith such as styrene, rethyl styrene,

chlorostyrene, acrylonitrile, 2-vinylpyridine,

2-vinylpyridine, 5-ethyl-2-vinylpyridine, 2-methyl-

alkyl-substituted acrylates such as

methyl methacrylate, ethyl acrylate, etiylmethacrylate,

ethyl vinyl ketone, methyl isopropenyl ketone, methyl

vinyl ether, alphamethylene carboxylic acids and the

esters and amides thereof such as acrylic acid and

dialkylacrylic acid amide; also suitable for use herein

are copolymers of ethylene and other high alpha olefins

such as propylene, butene-1 and pentene-1; particularly wherein preferred are the ethylene-propylene copolymers the ethylene content ranges from 20 to 90 percent by

weight and also the ethylene-propylene polymers which additionally contain a third monomer such as dicylopent-

adiene, 1,4-hexadiene and methylene norbornene.

The novel class of carbon blacks are readily pre-

pared by contacting a carbon black-producing feedstock with a stream of hot combustion gases flowing at an

average linear velocity of at least 100 feet per second. of The process for preparing the novel carbon blacks

the present invention will be described in greater detail hereinafter.

In the preparation of the hot combustion gases present employed in producing the carbon blacks of the invention there are reacted in any conventional combustion

chamber a liquid or gaseous fuel and an oxygen-containing

4635.28

36,524/71 oxident stream. Exemplary oxidant streams include air,

oxygen, mixtures of air and oxygen, nitrogen and

o._yen, Land other L.ix;heE of oxygen with common gases.

It is preferred, however, that the oxidant streari to

be used in the present invention comprise an amount

greater than aeut 50, molar concentration of oxygen.

Arnong the fuels suitable for use in reacting with

an oxidant stream in a combustion chamber to generate

hot combustion gases there are included any of the

readily combustible gas, vapor or liquid streams such

as hydrogen, carbon monoxide, methane, acetylene,

alcoholsl terosene and the lil. It is generally pre-

ferred, nowever, to utilize fuels having a high content of carbon-containing components and, in particular,

hydrocarbons. For example, streams rich in methane such

as natural gas and modified or enriched natural gas

are excellent fuels as well as other streams containing

high amounts of hydrocarbons such as various petroleum

gases and liquids and refinery by-products including

ethane through pentane fractionsk fuel oilsean& the.-

il In general, the heavier and more viscous tars

and residual type oils should preferably be used with

the more concentrated or relatively pure oxygen-

containing oxidant streams.

The novel carbon blacks of the present invention

are prepared by reacting the aforementioned combustion reaction products with any of a wide variety of hydro-

carbon feedstocks which are, readily volatilizable under

the conditions of the reaction. Suitable for use in

the present invention as hydrocarbon feedstocks are

4635.28

36,524/7f unsaturated hydrocarbons ouch as acetylene, olefins

such as ethylene, propylene, butylene, aromatics

such as benzene, toluene aad xylenc, sateratea hydro-

carbons such as methane, natural gas, ethane and propane and volatilized hydrocarbons such as kerosenes, naph-

thalenes, terpenes, ethylene tars/ aromatic cycle

stocks, and tho li-A.

Accordingly, the above-described novel class of carbon blacks are prepared by reacting a carbon black-

yielding hydrocarbon feedstock with hot gaseous products of an initial combustion reaction which are

flowing at a high linear velocity in a suitable reaction

zone. The hot combustion gases are readily generated

by contacting the desired oxidant stream with a

combustible fuel in any type of conventionally known burner designed to produce a stream of hot combustion

gases flowing at a high linear velocity. In a preferred

embodiment of the present invention, a combustible

fuel is contacted with an oxidant stream containing

at least 50 molar concentration of oxygen in a suitable

burner under a pressure ranging up to about 120 psig with the most preferred combustion pressure varying

from al-Iut 5 to about 75 psig. Under these conditions,

there is produced a stream of gaseous combustion

products possessing sufficient energy to convert a

carbon black-yielding hydrocarbon feedstock to the

desired carbon black products. The resultant combustion

gases emanating from the combustion zone may attain 0 temperatures up to and greater than 500 to 6000 F,

with the most preferable temperatures for the present

36,524 /71 0 The hot combustion process being at least &becut 3000 F. gases are -propelled in an upstream direction at a hig-h linear velocity %xhichmay be effectuated by passihg the comboustion Egases through any suitable passage or inlet which may be tapered or restricted such as a conventional venturi throat. Into the resultant

stream of hot combustion gases traveling at a high velocity there is then introduced a suitable carbon black-yielding hydrocarbon feedstock thus insuring a high rate of mixing and shearing of the hot combustion gases and the hydrocarbon feedstock so as to rapidly and completely decompose and convert the feedstock to the novel carbon blacks in high yields. The manner

in which the carbon black-yielding hydrocarbon feed- stock is introduced into the hot combustion gases traveling upstream at a high linear velocity may be varied considerably. For example, the hydrocarbon feedstock may be introduced into the hot combustion gases through an opening in the reaction chamber which causes the entry to be in a direction perpendicular to the longitudinal axis of the flow of combustion gases. Alternately, the hydrocarbon feedstock may be introduced through a suitable probe type device into the reaction zone in a direction paralleling that of the flow of the combustion gases. It is preferred,

however, that the hydrocarbon feedstock be injected substantially. transversely from the periphery of the stream of hot combustion gases in the form of a single or a plurality of small, cohe rent jets which penetrate into the interior regions of the stream of combustion

36.524/71 gases. It is to be understood, of course, that in

practicing the present process the hydrocrabon feed-

atock ay be int--oduced into the reaction zone as a

liquid or liquid spray by means of a conventional

atomizer or spray nozzle as well as in the form of a gas or vapor. Following the period of reaction in the reaction zone, the effluent gases containing

the novel carbon black products suspended therein are

passed downstream to any conventional cooling and

separating means whereby the novel carbon blacks are

recovered. The separation of the carbon black from the gas stream is readily.accomplished by conventional means such as a precipitator, cyclone separator and

bag filter. The amounts of oxidant gas, fuel and

carbon black-yielding hydrocarbon feedstock may be

readily determined to obtain the desired carbon blacks

having controlled physical properties. Moreover, although the residence time for each instance depends

upon the particular reaction conditions and the

particular carbon black desired, the residence time of

the present process may vary from about I to about

100 milliseconds, or even shorter periods of time.

The following testing procedures are used in the determination and evaluation of the physical properties

and efficiency of the novel carbon blacks of the

present invention.

DBP Absorotion In accordance with the procedure set forth in ASTh D-2414-65T, absorption characteristics

of pelleted carbon blacks are determined. In brief, the test procedure entails adding dibutyl phthalate (DBP)

4 6352

36.524/71 from to a pelleted carbon black until a transition agglomerate a free-flowing powder to a semi-plastic

eeiuskit in a aiarp ji* einv

Sotal S-rface Area The total surface area of

the carbon blacks is measured in accordance vwith the isotherms. wxell-known BET technique utilizing nitrogen is completely The BET (Brunauer-Emmet-Teller) method Journal of described in an article appearing in the 309 (1938). the Aerican Chemical Society, vol. 60 page by BET Surface areas obtained in the usual manner area as well technique include the external surface by the as the internal surface area contributed

presence of pores. Area Surface area of carbon black measured is referred to in accordance with a "t curve method"

herein as area. The "t curve method" for evaluating comparative procedure microporosity of carbon black is a by lMikhail, and is fully described in an article of a Complete Brunauer and Bodor entitled "Investigations of Colloid and Pore Structure Analysis" in the Journal The Interface Science, Vol. 26, pages 45-53 (1968). with technique taught in this article is followed utilized is the exception that the "master t curve" extracted with one for which Sterling FT carbon black

benzene serves as the non-porous, solid standard

more advantageous to employ adsorbent inasmuch as it is when evaluating a carbon black as the master adsorbent

carbon blacks. The carbon black selected as the

standard, Sterling FT, is manufactured and sold by having by Cabot Corporation and is characterized

4 635.28

36.5247 area of 13 a lrigrometer scale value of 107, a-surface particle square meters per gram, an electron micrograph abs.orptionl diameter of 180 ailliiciX;ra and an oil carbon black. value of 35 lbs.. of oil per 100 lbs. of area values The difference, if any, between the surface BET technique and obtained on a carbon black sample by a measure of by means of the "t curve method" provides. black. the extent of porosity in the carbon by The invention will be more readily understood which describe the reference to the following examples compounds. detailed preparation of representative of this invention There are, of course, many other forms in the art, which will become obvious to one skilled and it will once the invention has been fully disclosed, examp les are given accordingly be recognized that these and are not to for the purpose of illustration only, this invention be construed as limiting the scope of in any way. Example I a suitable in this example, there is employed for supplying reaction apparatus provided with means a fuel the combustion gas-producing reactants, streams or and an oxidant stream, either as separate and also as precombusted gaseous reaction products, hydrocarbon means for supplying the carbon black-yielding feedstock to the apparatus. The apparatus may be such as metal and constructed of any suitable material insulation or either provided with a refractory a recirculating surrounded by means for cooling with Additionally, the lioquid which is preferably water.

36.5 24/71 reaction apparatus is equipped with temperature and

pressure recording means, means for quenching the

coixbon bl ck--oriAng re ctic., such as spray ozolzlez,

Leans for coolingL the resultant carbon blac: product

and means for separating and recovering the carbon

black from other undesired by-products. Accordingly,

in carrying out the present process for preparing

this class of novel active carbon blacks, the following

procedure- is enployed. In order to obtain the desired

flame, there are charged into a combustion zone of

the apparatus through one or more inlets oxygen at a

rate of 2000 SCFH and natural gas at a rate of 625

SCUH thereby generating a stream of combustion gases

flowing in a dowmnstream direction at a high linear

velocity. In one preferred embodiment of the present

invention, however, the rapidly flowing stream of

combustion gases may be passed through a constricted

or tapered portion of the apparatus having a fixed

cross section or throat such as a conventional venturi

throat in order to increase the linear velocity of the

stream of combustion gases. There is then introduced

into the resultant stream of hot combustion products a

carbon black--yielding hydrocarbon feedstock through one

or more passages or inlets located peripherally to

the stream of combustion gases at a rate of 15.6 gallons

per hour. The hydrocarbon feedstock employed is Sunray

DX which is a fuel having a carbon content of 91.1% by

weight, a hydrogen content of 7.9 by weight, a sulfur

content of I.3k, by weight, a hydrogen to carbon ratio

of 1.04, a B.LY.C.I. Correlation Index of 133, a specific

4635 28

36524/71 gravity in accordance with ASTI D-287 of 1.09, an API gravity in accordance with AST: D-287 of -2.6,

srU viccosit:.- (A"-Ti 0-68) it 130°' of 350; an. SSU viscosity (ASTM D-88) at 210 0 P of 58 and an

asphaltenes content of 5.7 percent. Potassium chloride is added in an amount of 10 grars per 100 gallons of feedstock. The reacticn conditions used in this instance are such as to provide a residence time of 6

milliseconds and an overall combustion of 30.0 percent.

The carbon black-forming reaction is then quenched with water in a separate zone downstream of the reaction zone and the resultant carbon black-containing gases

are subjected to the conventional steps of cooling,

separation and recovery of the carbon black product.

The carbon black product thus obtained is characterized by having a BET total surface area of 187 m2 a "t"

area of 170 m 2 a value for the ratio of area to BET area of 0.91; a igrometer scale reading of which value represents the relative amount of light

reflected compared to a standard black dispersion in oil; a tinting strength of 286 which value represents

the relative covering power of a carbon black when

incorporated in a one part in thirty parts ratio with

a standard zinc oxide dispersion in a standard oil and

compared to a series of standard reference blacks tested

under similar conditions; an extract value of 0.03%O by

weight which is the amount of matter removed from the

carbon black by refluxing a sample of the black in ten times its weight of benzene for a 12 to 22 hour period;

and a DBP value of 130.

S4635,28

36.524 1 xample 2

A suitable reaction apparatus as described in

Exauie I is cii:--ged .'ith oxr^.i at eavatu- of 2000

SCFH and natural gas at a rate of 625 Ci in order to

produce a suitable flame for carrying out the reaction.

To the dovwnstream-flowing combustion gases which have

been passed through a constricted or tapered portion

of the apparatus there is then fed a hydrocarbon

feedstock at a rate of 16.2 gallons per hour. The

feedstock employed herein is Sunray DX as described

hereinbefore. In this run, 6.5 grams of potassium

chloride are added for each 100 gallons of feedstock

employed and the reaction conditions are maintained in a manner such as to provide a residence time of

2.6 milliseconds and an overall combustion of 29.3

percent. At the conclusion of the reaction there is

produced a novel carbon black having a BET total surface 2 2 area of 173 m a area of 164 m a value for

the non-porosity ratio area to BET area of 0.95,

a 1igrometer scale reading of 81, an extract value of

0.OLfo, a DPT of 176 and a tinting strength of 265. Example 3

Following the procedure of Example 1 there are

charged to a combustion zone a stream of oxygen at a

rate of 3000 SCFH and a stream of natural gas at a

rate of 540 SCFH to produce the desired flame. Into

the gaseous products of the combustion reaction there

is then fed as the hydrocarbon feedstock Sunray DX at

a rate of 25.8 gallons per hour and the reaction con-

ditions are maintained so as to provide a residence

4 635.28

36,524 time of 4 milliseconds and produce /71 an overall combustion of 30.2 percent. As an additive, potassium chloride is added in an b..c-unt U2 grals: oar 'CO -llonr3 of feedstock utilized. The resultant reaction product co r-*rises a carbon black having a BET total surface area of 170 m21g, a area of 162 m a value for the ratio of area to BET area of 0.95, a Yigrometer scale reading of 80, a DBP of 145, a tinting strength of 255, and an extract value of 0.03 percent.

Examnle In accordance with the procedure of Example I, oxygen at a rate of 2000 SCY.1 and natural gas at a rate of 360 SCFIj are fed into the combustion zone of the reaction apparatus. To the resultant downstream flow of hot combustion gases there is charged Sunray DX hydrocarbon feedstock at a rate of 17.3 gallons per hour. Prior to adding the feedstock, potassium chloride is added to the stream of hot combustion gases in amounts of 7.3 grams per 100 gallons of feedstock used. The reaction is carried out over a residence time of 6 milliseconds and at an overall combustion of 30.8 percent. There is obtained a carbon black product having a BET total surface area of 160 m 2 a area of 154 m 2 a value for the ratio of area to BET area of 0.96, a iFigrometer scale reading of 81.5, a DBP of 142, a tinting strength of 254, and an extract value of 0.03 percent. The rubber compositions of this invention are readily prepared by conventional mechanical methods.

36 524 /71 For example, the rubber and the carbon black reinforcing on a conventional agent are intimately admixed together mixirS iin machirle or tI type normally u-e fsr or a Danbury rubber or plastics such as a roll mill The mixer in order to insure efficient dispersion. to standard rubber compositions are compounded according rubber and industry formulations for both a natural The resulting synthetic rubber-containing formulation. for vulcanizates to be tested are cured at 293°F for 50 minutes minutes when natural rubber is used and rubber in when a synthetic rubber, styrene-butadiene the perform- this instance, is employed. In evaluating invention, ance of the novel carbon blacks of the present wherein the the following formulations are utilized

quantities are specified in parts by weight. Natural Synthetic Synthetic

Rubber Rubber Rubber

Recipe Recipe No. 1 Recipe No. 2 Ingredient 100 (Iatural 100 (styrene- 89.38 (styrene- Polymer Rubber) butadiene) butadiene)

(cis-4 poly- butadiene)

5 3 3 Zinc Oxide 2.5 1.75 1.75 Sulfur 3 1.5 2 Stearic Acid

Flexamine I 8 Softener l:Mix 1.25 1.4 Santocure (CBS)

Altax (1:BTS) 0.6 25.62 Sundex 790 (continued)

4635.28

36.5 24/11 Natural Synthetic Synthetic

Rubber Rubber Rubber

Ingredient Recipe No_. NRe.i Rcpe o.

ingstay 100 2

Sunproof Improved

Carbon Black 50 50

l7ith regard to the foregoing formulations, the

Softener Mix comprises equal portions of naphthenic

oil sold under the trade designation Circosol 42XH by

Sun Oil Company and a saturated polymeric petroleum

hydrocarbon sold under the trade name Paraplex by

C. P. Hall Company. Altax (LBTS) is the trade name

of R. T. Vanderbilt Company for mercaptobenzothiazyl

disulfide accelerator. Plexamine is the trade desig-

nation of an anti-oxidant sold by U.S. Rubber Company.

Santocure (CBS) is the trade designation for N-cyclohexyl-

2-benzothiazole-sulfenamide, a curing agent for rubber

systems. Sundex 790 is the trade name for a plasticizer

sold by Sun Oil Company. Sunproof Improved is the

trade name for an antiozonant sold by Uniroyal Chemical

Company. Wingstay 100 is the trade name for a stabilizer comprising mixed diaryl-p-phenylene diamines sold by Goodyear Tire and Rubber Company.

In the following examples there is demonstrated

the advantageous and unexpected results achieved by

the use of the carbon black products described herein-

above as additives in rubber formulations. It will,

of course, be apparent that the examples, while being

4 635. 2R

36.524/71 not be illustrative of the present invention, should

construed as limiting or restrictive in any way. E~fn~l

of Cne hundred parts by weight of a copolymer 3 parts 23.5 parts styrene and 76.5 parts butadiene, of softener by weight of zinc oxide, 8 parts by weight parts by :nix, 1.75 parts by weight of sulfur, 1.0 of Santocure weight of Flexamine, 1.25 parts by weight black (CBS) and 50 parts by weight of the carbon on a roll product described in Example 1 are mixed

mill to a homogeneous blend. The resulting compound minutes. is then cured at 293°F for a period of 60 properties Testing of the blend for conventional rubber a tensile reveals a value for elongation of 549',

strength of 4100 a 300 modulus of 1695 p.s.i., angle abrasion a Shore A hardness of 70, and an Akron

index of 168. Example 6 23.5 parts 100 parts by weight of a copolyrmer of parts by weight styrene and 76.5 parts butadiene, 5 sulfur, 1.5 parts of zinc oxide, 2 parts by weight of weight of by weight of stearic acid, 2 parts by parts by weight mercaptobenzothiazyl disulfide, and 50 on a roll of the carbon black of Example 4 are mixed

mill to a homogeneous blend. A determination of of 23." properties of the vulcanizate gives a value of 4125 for extrusion shrinkage, a tensile strength

a 300L modulus of 2030 an elongation

of 50, and a Shore A hardness of

4635 28

3x 524 /71 In this example there is utilized for rubber

evaluation purposes 8 second synthetic rubber recipe.

In particular, there are mized on a Banbury mixer at

150 rpm to a homTogeneous blend 89.38 parts by weight of a copolymer of 23.5 parts styrene and 76.5 parts

butadiene, 35 parts by ,:reight of cis-4 polybutadiene

rubber, 25.62 parts by weight of Sundex 790 which is

the trade name for a plasticizer sold by Sun Oil

Company, 3 parts by weight of zinc oxide, 2.5 parts name by weight of Sunproof Improved which is the trade for an antiozonant sold by Uniroyal Chemical Company,

2 parts by weight of iingstay 100 which is the trade name for a stabilizer comprising mixed diaryl-p-

phenylene diamines sold by Goodyear Tire and Rubber

Company, 2 parts by weight of stearic acid, 1.75 parts

by weight of sulfur, 1 .4 parts by weight of Santocure

(CBS) and 75 parts by weight of the carbon black

prepared as shown in Example 1. The carbon black of

Example 1 is characterized by having a BT total

surface area of 187 m2/g and a value for the ratio

of area to BET area of 0.91. The results obtained 0 on this vulcanizate cured at 293 for 30 minutes 0 show a value for Looney viscosity YL-4' at 212 F of

56, an extrusion shrinkage of 37.6, a tensile strength of

2820 a 300o modulus of 870 an elongation

of 63Q0, a Shore A. hardness of 57, and an Akron angle

abrasion volume index of 191. Furthermore, using the

Goodrich Flexometer wherein the oven is maintained 0 .175 inch, the at a temperature of 212 F, the stroke is

4 635,28

36524 171 load is 143 p.s.i. and the period of time is 20 minutes,

it is determined that the static compression is 27. S,

the dynamic compression is 9.4g, and the permanent set

is 16.0 percent. Exajorle 8

In accordance with the procedure of Example 7

and using, in lieu of the carbon black employed therein, as parts by weight of the carbon black prepared is described in Example 3, a cured rubber vulcanizate

prepared. The carbon black employed herein is charact- m2/g erized by having a BET total surface area of 170

and a value for the ratio of area to total surface

area of 0.95. The results obtained on this vulcanizate

give a value for Mooney viscosity ML-4' at 212°F of 59,

a tooney Scorch T5/TIO of 17.1/18.4, an extrusion

shrinkage of 34.-7, a tensile strength of 2800 p.s.i.,

a 300' modulus of 990 an elongation of 590?,

a Shore hardness of 59 and an Akron angle abrasion

volume index of 291. Determinations performed on the 31.1?6, Goodrich Flexometer show a static compression of

a dynamic compression of and a permanent set of

11.7 percent. Example 9

A cured rubber vulcanizate is produced according the carbon to Example 7 with the exception that, for of carbon black utilized therein, 75 parts by weight 4 is employed black manufactured as described in Example a BET herein. The carbon black of Example 4 possesses for the ratio total surface area of 160 m2/g and a value

of area to BET total surface area of 0.96.

4635.28

36,524 /71 1'easurements on this vulcanizate reveal a Yooney

of i:L-4' at 212°F of 60, an extrusion shrinkage viscosity

stlength of 2370 a 300, of 3 4 .L a tensile an elongation of 570;, a Shore modulus of 1090

hardness of 60 and, utilizing the Goodrich Flexometer,

static compression of 31.6,c a dynamic compression of a

and a permanent set of 11.4 percent. It will become readily apparent from the foregoing

carbon black products results that the novel group of and synthetic rubber disclosed herein impart to natural properties and there- compositions extremely desirable of reinforcing carbon fore constitute a valuable group

rubber systems. For example, when compared blacks for blacks, it is noted to conventional, commercial carbon at least compar- that the present non-porous blacks are blacks in properties able to the standard conventional

such as abrasion resistance, modulus and/or extrusion

it is found that while these shrinkage. Additionally,

other desirable performance properties are achieved,

characteristics of the compositions of the present

incorporation of the carbon invention are achieved by the

the compositions of this invention. blacks in have been found Numerous chemical curing systems of the carbon black useful in promoting the interaction of synthetic rubber in reinforcement and the natural

the present invention. Exemplary of the practicing disulfide chemical curing agents are mercaptobenzothiazyl and (1BTS), N-cyclohexyl-2-benzothiazole-sulfenamide (TMTD). Furthermore, for tetramethylthiuramdisulfide

it may be desirable to compound the many purposes,

36,524/7, rubber compositions of the present invention with

other conventional rubber additives. Illustrative of

such additives are other reinforcing aLcnts such'as

titanium dioxide, silicon dioxide, zinc oxide, calcium

carbonate, clays, calcium silicate, zinc sulfide,

hydrous alumina and calcined magnesia; thermoplastic

resins such as polyvirnyl chloride and epoxy. resins

as comnounding substances; vulcanizing agents; vulcan-

ization accelerators; accelerator activators, sulfur

curatives; antioxidants; decelerators; heat stabilizers;

plasticizers, softeners or extender oils such as

mineral oil, resins, fats, waxes, petroleum distillates,

vegetable oils, linseed oil and soybean oil,

butyl cellosolve pelargonate, di-n-hexyl adipate,

trioctyl phosphate, chlorinated hydrocarbons, ether,

ketones, terpenes, gum turpentine, rosin, pine tar,

coal tar products including alkyl naphthalenes and

polynuclear aromatics and liquid polymers of conjugated

dienes. and th likoe It will be apparent that com-

positions containing such other additives are within

the scope of this invention. Moreover, it is further

apparent from the foregoing data that the use in rubber

of the present carbon black products having very high

surface areas and which are virtually non-porous

result in reinforced rubber compositions having extremely

desirable physical properties.

22 4635,26

36.524 71 The words "BANBURY", "ALTAX", CALLOSOLVE",

"STERLING" and "SUNRAY" referred to herein are

acknowledged as being Registered Trade Marks.

Applicant is aware of his copending Appli-

cation 39758/72 which claims a carbon black product

having, inter alia, a value of at least 317 for the

relationship of tint 0.6 (DaD wherein Da is

apparent diameter. Having regard to possible overlap

of the claims of Application 39758/72 and the present

application Applicant makes no claim to carbon black

products having the value of at least 317 for the

relationship [tint 0.6 (Da)

Subject to the foregoing disclaimer the

claims defining the invention are as follows

463528

36,5 24 f71

by having a 1. A carbon black product characterized 160 m"/g and a total sul'face area of at least ab- specific surface value for the ratio of non-porous carbon black of at area to total surface area of the least 0.9. in Claim I 2. A carbon black nroduct as defined

wherein the total surface area is at least 170 m 2/g. a rubber 3. A composition of matter comprising of natural and selected from the group consisting product selected synthetic rubbers and a carbon black blacks character- from the group consisting of carbon area of at least about ized by having a total surface of non-porous specific 160 m /g and a value for the ratio 2

of the carbon black surface area to total surface area black product is of at least 0.9, wherein the carbon 10 to ae~e 250 parts present in amounts of from abea-t of rubber. by weight per 100 parts by weight Claim 3 wherein the 4. A composition as defined in

rubber is natural rubber. Claim 3 wherein the A composition as defined in rubber is synthetic rubber. A composition as defined in Claim 3 wherein the 6. surface area of at carbon black product has a total least 170 m2/A. Claim 3 wherein the 7. A composition as defined in amounts of from carbon black product is present in per 100 parts -etv-t 20 to .abQ4 100 parts by weight by weight of rubber. 8. A process for preparing a rubber composition

4 6328 -2 4-

Claims (1)

1. 36.524 71 having improved properties which comprises mixing a

   rubber selected from the group consisting of natural

   and synthetic rubbers with a cbrbon block product

   selected from the group consisting of carbon blacks

   characterized by having a total surface area of at 2 the ratio of least about 160 m /g and a value for

   non-porous specific surface area to total surface

   area of the carbon black of at least 0.9, said carbon

   black product being present in amounts of from aeou--

   to about 250 parts by weight per 2-30 pts by

   weight-peF 100 parts by weight of rubber, and vulcan-

   izing the mixture.

   9. A process as defined in Claim 8 wherein the

   carbon black product is present in amounts of from

   abeo-4 20 to abhwt 100 parts by weight per 100 parts

   by weight of rubber.

   A process as defined in Claim 8 wherein the

   carbon black product is present in amounts of from

   abot 4 0 to ab;et 80 parts by weight per 100 parts by

   weight of rubber.

   4635 28

   36.524171, in Claim -1 substantially 11.0 A process as defined one of the w~ith reference to any as herein described Examples. produced by a process 12. Carbon black Whenever

   as defined in any preceding claim-

   DATED: 30 June, 1975

   FITZPATRICK PHILLIPS ORMONDE- AND Attorneys for

   CABOT CORPORATION

   4 635.28