Патент USA US3042642код для вставки
Unite States Patent (‘Y "ice 3,042,633 Patented July 3, 1962 '5 2 3,042,633 gives ?ocs of reduced size. After the latex has been co agulated to a ?ne ?occulate, an aldehyde resin is incor porated in the aqueous medium of the slurry of the rubber 3. RUBBER rovvnnn Woodrow W. White, ()xford, Conn, assignor to United States Rubber Company, New York, N.Y., a corpora tion of New Jersey N0 Drawing. Fiied Apr. 29, 1957, Ser. No. 653,745 12 Claims. (‘-Cl. 260-3) ?ocs and the resin is precipitated therein to form a water insoluble coating on the ?ocs. The ?ocs may then be de watered as by ?ltering, and dried as in conventional rub ber practice. The aldehyde resin may be phenol-aldehyde, resorcinol-aldehyde, urea-aldehyde, melamine-aldehyde or aniline-aldehyde resin in which the aldehyde is formalde This invention relates to improvements in rubber pow der for incorporation in the bituminous binder used in 10 hyde or acetaldehyde. An aqueous solution of the re atant other than the aldehyde may be added to the aque building roads, and for other purposes. ous slurry of the rubber ?occulate followed by an aqueous In conventional road building practice, hot bituminous solution of the aldehyde or an aqueous solution of a mix~ binder (asphalt or road tar) is mixed with the aggregate ture of the two may be added to the aqueous slurry. The at a pug mill, generally in amount from 3 to 15% on the weight of the aggregate, and the mix is then transported 15 molar ratio of reactant other than aldehyde to aldehyde is generally from about 1:0.75 to 1:2.0. The mixture of to the paving site, or the dry aggregate is ?rst laid on the the resin reactants in aqueous acid medium of the slurry road and the hot bituminous binder is then sprayed on of the rubber ?uocculate is agitated for a short time, e.g. the aggregate. In these operations the binder is at a tem from 1/2 to 3 hours at temperature from 50° C. to 100° C. perature of 250° F. to 400° F. (generally 250° F. to 350° F.). 20 for formation of the water-soluble resin after which the pH is raised’ to 8 or above by the addition of dilute alkali. Rubber powders prepared directly from natural and As the pH is raised, the resin which has been ‘formed in the acid phase is precipitated and deposited on the surface of the rubber ?ocs giving a product which is non-tacky synthetic rubber latices have been incorporated in the hot bituminous binder used with the mineral aggregate in forming paving compositions, generally in amounts to give 1 to 15 parts of rubber per 100 parts of bituminous binder. 25 because the ‘particles are coated with a brittle non-tacky resin. The resulting particles aredewatered as by ?lter ing, and dried, giving a ?ne free-?owing powder. The However, such rubber p wders do not flow easily and have a tendency to sinter in storage and thus make di?i amount of resin may be from 2 to 30% of the ?nal coated cult their handling and measuring and their gradual addi particles with the preferred level being 10 to 16%. The tion to the hot melt of bituminous material.. One method of attempting to overcome this di?iculty has been to’vul 30 dried resin coated rubber particles may be in the range from 10 to 200 mesh, and generally will be in the range y canize the latex before producing the rubber powder. An from 30 to 100 mesh. The amount of the thus prepared other method has been to coprecipitate the rubber in the resin coated rubber powder that is mixed with the hot latex with an equal amount or more of ground inert bituminous binder is that which gives from 1 to 15 parts mineral ?ller. These methods introduce other disadvan tages. The vulcanization reduces the compatibility of the 35 of rubber per 100 parts of the asphalt or road tar binder, whether added as such in the pug mill with the hot ag rubber with the bituminous binder. The large amount gregate and the binder, or mixed with the hot binder be of ?ller increases the extraneous material which is shipped fore introduction into the pug mill, or mixed with the hot about and has a tendency to settle out when added to bulk binder before spraying on the rolled hot aggregate. As quantities of the bituminous binder. By the present invention, there is provided an improved 40 above described, the temperature of the binder in these operations is from 250° F.‘ to 400° F. (generally 250° to rubber powder which is free-?owing and non~sintering 350° F.). under storage conditions and which is readily and uni The latex may be a natural or synthetic rubber latex. formly dissolved or dispersed in hot bituminous material. According to the present invention, the individual par ticles of rubber powder prepared directly from latex are coated with an aldehyde resin which imparts the free The synthetic'rubbcr latex may be a so-called butadiene polymer synthetic rubber latex, i.e. an aqueous emulsion ?owing properties to the crumbs, and permits ready dis ple, butadiene-1,3, 2-methylbutadiene-l,3 (isoprene), 2 solution of the rubber in the bituminous material. Such resin coated powder may be mixed with the hot bitumi nous binder for the aggregate in road building generally in amount from 1 to 15 parts of rubber per 100 parts of bituminous binder. Mixtures of bituminous material and the resin coated powder in amount up to 25 parts of rub ber per 100 parts of bituminous material may be used as expansion joint ?llers in road construction, and as lami nating adhesives in making paper to paper and paper to metal foil laminates. The rubber powders with the resin coating on the individual rubber particles may be used chlorobutadiene-1,3 (chloroprene), 2,3-dimethylbutadi directly in molding and extrusion processes to'give ?nished ' rubber articles. . polymerizate of one or ‘more butadienes-l,3, for exam cue-1,3, piperylene, or a mixture of one or more such butadienes-lfa" with one or, more other polymerizable compounds which are capable of forming rubbery co-' polymers with_butadienes-1,3, for example, up to 70% by weight of such mixture of one or more compounds which contain a CH2=C< group where at least one of the disconnected valences is, attached to an electro-. negative group, that is, a group which substantially in creases the electrical dissyrnmetry or polar‘ character of the molecule; Examples of compounds which contain a CH2=C< group and are copolymerizable with butadi-- ' 60 cue-1,3 hydrocarbons are aryl ole?nes, suchv as styrene,» which may be unvulcanized or vulcanized or which may vinyl toluene, alpha methyl styrene, chlorostyrene, di chlorostyrene, vinyl naphthalene; the alpha methylene contain vulcanizing ingredients, softeners, extenders or ?llers, emulsi?ed or dispersed therein,_is ?occulated in the carboxylic acids and their esters, nitriles and amides, such as acrylic acid, methyl acrylate, methyl .methacrylate; In carrying out the present invention, the rubber latex conventional manner to form ready ?lte'rable ?ocs. For ex acrylonitrile, ,methacrylonitrile, methacrylamide; methyl ample, the latex may be creamed by addition of a solution ~ vinyl ether; methyl vinyl ~ketone; vinylidene ._chloride; of a monovalent salt, such as sodium chloride, and then > vinyl pyridines; alkyl vinyl pyridines. ‘Common com ?occulated with dilute acid, such as sulfuric, hydrochloric I ' mercial synthetic rubber ‘latices ‘arelaticesof GR-S (co or acetic acid, or by dilute solutions of multivalent salts. polymer of a major proportion ‘of butadiene and a minor of strong acids, such as calcium chloride or aluminum sul 70 proportion of styrene), Paracril (copolymer of a major fate. The addition of up to 20 parts of sodium lignate proportion of butadiene and a minor proportion .of per l00 parts of rubber of the latex before ?occulation acrylonitrile); and neoprene (polymerized chloro-Z-butae 4 . diene—1‘,'3). Such latices may be compounded with sof in admixture with previously flocculated rubber latex ' teners, extenders and ?llers by adding emulsions or dis - particles onto said'?occulated rubber latex particles, said persions of the same to the latex before ?occulation. .For example, asphalt and tar softeners and extender oils .such asheavy petroleum fractions may be added to the "latex as emulsions generally in amount up to'one-half rubber being selected from the group consisting of natural rubber and synthetic rubber emulsion polymerizates of material selected from the’ group consisting of butadienes 71,3,and mixtures of butadienes-1,3 with compounds which the weight of the rubber. Similarly inert ?llers, such as. contain a CH2=C< group and are copolymerizable with ‘silica maybe formed in situ'in the latex, or inert ?llers .such as‘ silica and carbon black may be, added to the butadienes-1,3. ' . t ' 2. A free flowing dried resin coated rubber powder the latex as dispersions generally in amount up to one-half 10 particles of which are 1010 200 mesh size and are coated 'of the weight of the rubber. ' ' with aniline-formaldehyde resin, said resin being precip r The following'illustrates the invention. 7 All parts and ’ percentages referred to herein are by weight. . itated from asoluble state in an aqueous acid medium in admixture with previously ?occulated rubber latex 144. pounds (40 pounds dry'weight) of a latex of a particles onto said?oeculated rubber latex particles, said copolymer of 175 ' parts of butadiene and 125 parts of. 15 rubber being selected from ‘the group consisting of natu styrene were stabilized to'oxidation by the addition of ral rubber and synthetic rubber "emulsion polymerizates 1189, pounds (0.6 pounds dry Weight)’ of? an aqueous ' , ‘of material selected from the group consistingof butadi emulsion of condensed diphenylamine acetone reaction . , enes-1,3 and mixtures of.butadiezies-LS,withcompounds A solution of sodium lignate which had been ' preparediby dissolvingf0.82 pounds of sodium hydroxide which containa CH2=C<jgroup and are copolyrneriza-' ' product. 20' ble in;l0 pounds'of water and'dissolving 2.07 pounds of with butadiene's-Lél.l ' l ' " Y - 3. A free ?owing :dried. resin coated rubber powder the particles of which aIe'lO to 200 mesh size and are coated with‘ resin selected from the group consisting of .lignin (Indulin A) in the‘ solution was then‘ added. This ''mixture was creamed .with'320 pounds (24 pounds dry phenol-aldehyde, resorcinol-aldehyde, urea-aldehyde, mel . . weight) or a sodium chloride solution which was ad justed to 'a pH of’ 10' with sodium hydroxide. iFloccula-r 25 amine aldehyde and aniline-aldehyde, resins in which the tion was then accomplished under. vigorous‘ agitation, by aldehyde is selected from the group consisting of formal- ' the addition of sui?cient sulfuric acidltetraethylene pentai . dehyde and acetaldehyde, said resin being in amount mine solution (2 pounds sulfuric acid and 0.4 pounds of from'2 to 30% by weight of the coated particles and tetraethylene pentamine "to obtain smooth ?occulation being‘ precipitated‘ from a solublei'state in an aqueous per 38-pounds of water) to reduce the pH to 2. The ?oci acid medium in'admixture with previously ?occulated fculat‘e was" in very ?ne particles. "A solution containing rubber latex particles onto said'?occulated rubber latex 3.3‘porin‘ds of aniline dissolved in l.9,pounds'of sulfuric particles, said rubber being selected from the group con ' . acid and 74.8 pounds of water was then added followed ' sisting of natural rubber and synthetic rubber emulsion bythe addition of l0v pounds (.4. pounds dry'weight') of 1 ' polymerizates of material's'elected from'the group con 7 210% formaldehyde. The mixture was then held under 35 sisting of butadienes-_l,3 and mixtures of butadienes-1,3 agitation at 140-150” for one hour, ‘after which the‘ .with‘ compounds which contain a'CH2'=C< group and pH was raised to 8 using a solution of sodium hydroxide. are copolymerizable ‘with butadienes-l?q The resin deposited on the‘ rubber ?ocs. The ?ne ?oc '4. A' free ?owing dried resin coated rubber powder culate was then ?ltered onto cheese cloth and dried over: the particles of which are '10 to 2007me7sh’size and are nightfat 170° F. 1 After drying the'iproduct wasfin the form of porous ‘chunks which disintegrated’into very ?ne coated with 'aniline-formaldehydefresin, said resin being in amount from'2lt'o' 30%‘ by weight of the coated parti free-?owing powderiof about 40 rnesh'unde'rv mild grind ing ‘conditions. i ' ' ‘ eles and‘being'precipitated from a soluble state in an 7 :aqueous acid'medium in ‘admixture with previously ?oc ' ‘ ree pants of'the fzhusv prepared‘. resin coated‘rubber . . powder Were added to 97. parts of asphalt heated: to about 45 culated rubber latex particles onto said‘?oc'cul-ated rub ber latex particles‘, said rubber being selected from the 350° in‘ a closed container equipped with an agitator. ‘ group consisting vof natural’ rubber and synthetic rubber I The asphalt had a penetration value at 77°F. of 110-120 . emulsion polymerizatesjof'nlaterial selected from the (A‘.S.T;M.~ D5-52).' The rubber was completely dis f group consisting‘ of butadienes-l? rand of buta . 7 ' persed in‘thew asphaltfgiving a smooth mix in three hours; ' dienes'-l,3 :with‘. compounds which contain a .CH2—_~,C< 'Such blend is useful as a binder “for the aggregate pin. 50 group . and are copolymer‘iizable with _butadie_nes-l,3. ' road construction. V 5.._The method of making free ?owing resin coated rubber powder of particles‘of 10 to 200 mesh sizefrom . latexi which comprises ?rst ?occulating'the latex and l a " 'l‘wenty'p'aritsof the above resin coated rubber powder ‘were vadded'to $0'Iparts of asphalt at 3275*‘ F.‘ in an in 7te'rnal mixer of. the'Werner‘andjP?eidereritype; The ' asphalt had a penetration value at 77° F. of about 200 55 (A.S.T.M. D5,-5.2).’ The rubber was completely dis pensed‘in the asphalt. giving a smooth mix in four hours. V of ‘phenol-aldehyde, resorcinol-aldehyde, urea-aldehyde, . melaminegaldehyde and aniline-aldehyde resins in which the ‘aldehyde I is selected from” the group consisting of Such blend useful for ?lling expansion joints in paving’ ' formaldehydeqandr vacetaldehyde .on wthe-Wet 1109s to coat " ‘construction’ by. pouring in "melted; conditionrbetwee‘n thei'same, dewatering the coated rubber does of the ?oc r 7 adjacent paving sections. " ‘ 60 culatedrlatex, and drying’, said 7 rubber being’ selected, from thegroupiconsistinggof natural. rubbervand synthetic Ingviewq of ‘thegmany changes and modi?cations that , .may be made without departing from the principles un-1 . ‘derlying the inventionkreference should be made to'the , rubber, emulsion polymerizates 'ofmaterial selected from the group consisting of ibutadienes-l? and mixtures of ~appended‘claims 'for anunderstanding?of the scope of . the protection 'a?orded ‘the invention. . ‘ , Having thus described my invention-,what Iclaim ; fdesire-to'protect'wby Letters Patent is: Y ' then depositing resin selected: from the group consisting ' ~ 'butadienesjl? with ‘compounds which contain a andq ' " >';1.'Afree-?owing dried resinjcoated rubber. powder " . a group andiare copolymerizable" with butadienes-l?. _6'. 'The'gmethodf of making ifr‘ee i?owing resin coated ' the'particles'of Whichare 10'to 200 mesh size and are rubber powder ofparticles of £10m 2001mesh'size from‘ coated resin selected from; thepgrou‘p consisting of 70 latex which'tcomprises ‘?rst; ?occulating the latex and’ then phenol; aldehyde, resoreinol-v- aldehyde, ’ urea - aldehyde, depositing ranilinerfolfhqliildehyde ‘resin on the .wet does to 1, ainelamine-alde'hyde and‘aniline-ialdehyde resins in which ' coat the same, dewatering ,the'pcoated rubber ?oes of the ' the aldehyde is'_ selected from the'groupiconsistingrof ' , ?occulated latex,>and drying, saidJubber. being selected formaldehyde andvacetaldehyde, saidresin being preeip» from ,the'group consisting of natural rubber and synthetic itated from ajsoluble state in' an aqueous acid medium 75 rubber emulsion polymerizates iofwmaterial selected from 3,042,833 the group consisting of butadienes-1,3 and mixtures of butadienes-1,3 with compounds which contain a CH2=C< group and are copolymerizable with butadienes-1,3. 7. The method of making free ?owing resin coated rubber powder of particles of 10 to 200 mesh size from latex which comprises ?rst ?occulating the latex and then depositing resin selected from the group consisting of phenol-aldehyde, resorcinal-aldehyde, urea-aldehyde, mel 9. A composition comprising a blend of bituminous material and a vfree ?owing resin coated rubber powder as de?ned in claim 3, the rubber content of the blend being from 1 to 25 parts per 100 parts of the bituminous material. 10. A composition comprising a blend of bituminous material and a free ?owing resin coated rubber powder as de?ned in claim 4, the rubber content of the blend being from 1 to 25 parts per 100 parts of the bituminous amine aldehyde and aniline-aldehyde resins in which the aldehyde is selected from the group consisting of formal 10 material. 11. The method of uniformly dispersing rubber in dehyde and acetaldehyde on the Wet rubber ?ocs of the bituminous material which comprises mixing with hot ?occulated latex to coat the same, dewatering the coated bituminous material a free ?owing resin coated rubber ?ocs, and drying, said resin being precipitated from a powder prepared according to the method of claim 5. soluble state in an aqueous acid medium in admixture 12. The method of uniformly dispersing rubber in with the ?occulated rubber latex particles onto said ?oc 15 bituminous material which comprises mixing with hot culated rubber latex particles, said rubber being selected bituminous material a free ?owing resin coated rubber from the group consisting of natural rubber and synthetic powder prepared according to the method of claim 6. rubber emulsion polymerizates of material selected from the group consisting of butadienes-1,3 and mixtures of References Cited in the ?le of this patent butadienes-1,3 with compounds which contain a CH2=C< 20 group and are copolymerizable With butadienes-l,3. 8. The method of making free ?owing resin coated rubber powder of particles of 10 to 200 mesh size from latex which comprises ?rst ?occulating the latex and then depositing aniline-formaldehyde resin on the Wet rubber ?ocs of the ?occulated latex to coat the same, dewater UNITED STATES PATENTS 2,277,941 2,314,181 2,610,158 2,700,655 Almy _______________ __ Mar. 31, Winterkorn __________ __ Mar. 16, Hall ________________ __ Sept. 9, Endres et a1 ___________ __ Jan. 25, 1942 1943 1952 1955 ing the coated ?ocs, and drying, said resin being precip 2,845,397 Mills _____________ __‘..__ July 29, 1958 itated from a soluble state in an aqueous acid medium 2,857,351 Carrol ______________ __ Oct. 21, 1958 in admixture with the ?occulated rubber latex particles FOREIGN PATENTS onto said ?occulated rubber latex particles, said rubber 30 381,587 Great Britain __________ _._ Oct. 7, 1932 being selected from the group consisting of natural rub bet‘ and synthetic rubber emulsion polymerizates of ma OTHER REFERENCES terial selected from the group consisting of butadienes-1,3 Clinebell et al.: “A Survey on the Use of Rubber in and mixtures of butadienes-1,3 with compounds which Bituminous Pavements,” Rubber Age, volume 70, pub. , contain a CH2=C< group and ‘are copolymerizable with October 1951, page 70. butadienes-l,3.