US4161464A — Devulcanized rubber composition and process for p…

Claim 1

Independent Claim 108 words

A process for devulcanization of scrap rubber comprising, (a) comminuting said scrap rubber to obtain vulcanizate particles small enough to be adequately devulcanized within a predetermined period of time, and, (b) contacting said vulcanizate particles with (i) an organic solvent having dissolved therein a predetermined concentration of an onium salt of an element, selected from the group consisting of nitrogen, phosphorus, and sulfur, and (ii) an aqueous solution containing a sufficient concentration of OH - ions to selectively disrupt enough polysulfide crosslinks to produce devulcanized rubber particles which contain less than about one-half the crosslink density of said scrap rubber from which said devulcanized rubber particles are derived.

Claim 2

Dependent Claim 108 words

A process for devulcanization of scrap rubber comprising, (a) comminuting said scrap rubber to obtain vulcanizate particles small enough to be adequately devulcanized within a predetermined period of time, and, (b) contacting said vulcanizate particles with (i) an organic solvent having dissolved therein a predetermined concentration of an onium salt of an element, selected from the group consisting of nitrogen, phosphorus, and sulfur, and (ii) an aqueous solution containing a sufficient concentration of OH - ions to selectively disrupt enough polysulfide crosslinks to produce devulcanized rubber particles which contain less than about one-half the crosslink density of said scrap rubber from which said devulcanized rubber particles are derived.

Claim 3

Dependent Claim 23 words

The process of claim 1 wherein said vulcanizate particles are in the size range from about 6 to about 325 U.S. Standard mesh.

Claim 4

Dependent Claim 23 words

The process of claim 2 wherein said organic solvent is an effective swelling agent for said rubber and is essentially immiscible with water.

Claim 5

Dependent Claim 71 words

The process of claim 3 wherein said onium salt has the formula R.sub.n Y.sup.+ X.sup.- wherein Y is selected from the group consisting of N, P and S; n is an integer which is 3 or 4; when Y=N or P, n=4; when Y=S, n=3, and R represnets either identical or different monovalent hydrocarbon radicals the total number of carbon atoms in which commulatively range from about 13 to about 57.

Claim 6

Dependent Claim 59 words

The process of claim 4 wherein contacting said vulcanizate particles with said organic solvent and said aqueous solution is effected at a relatively low temperature in the range from about 20° C. to about 150° C., at which temperature said polysulfide bonds are severed at a faster rate than the rate at which destruction of said onium salt occurs.

Claim 7

Dependent Claim 32 words

The process of claim 4 wherein R 1 -R 4 is each selected from the group consisting of alkyl, alkenyl, aryl, alkaryl, aralkyl cycloalkyl, and each substituted with suitable heteroatom-containing functional groups.

Claim 8

Dependent Claim 68 words

The process of claim 4 wherein Y is selected from N and P, n=4, and, said monovalent hydrocarbon radicals are R 1 , R 2 , R 3 , and R 4 , wherein R 1 =CH 3 ; R 2 , R 3 and R 4 is each alkyl; and X=Cl, and said OH - ions selectively disrupt at least about 50 percent of said polysulfide crosslinks.

Claim 9

Dependent Claim 63 words

The process of claim 4 wherein Y is S, n=3, and said monovalent hydrocarbon radicals are R 1 , R 2 , and R 3 wherein R 1 =lower alkyl having from 1 to about 5 carbon atoms; R 2 and R 3 is each alkyl; X=Cl; and said OH 31 ions selectively disrupt at least about 50 percent of said polysulfide crosslinks.

Claim 10

Dependent Claim 21 words

The process of claim 4 wherein said organic solvent is selected from the group consisting of aromatic and paraffinic hydrocarbon solvents.

Claim 11

Dependent Claim 44 words

The process of claim 4 wherein said onium salt is present in an effective amount less than about 0.3 mole per kg of said scrap rubber, which amount is sufficient to effect the desired disruption of polysulfide bonds and yield said devulcanized rubber particles.

Claim 12

Dependent Claim 26 words

The process of claim 6 wherein Y=N, and R 2 , R 3 , R 4 each has from about 5 to about 12 carbon atoms.

Claim 13

Dependent Claim 22 words

The process of claim 5 including in addition, contacting said vulcanizate particles and devulcanized rubber particles with an organo chloride alkylating agent.

Claim 14

Dependent Claim 42 words

The process of claim 6 wherein said organo chloride alkylating agent is represented by R'--CH 2 Cl, where R' is selected from H, an alkyl, aralkyl and alkenyl moiety which does not contain H on a saturated carbon atom beta to Cl.

Claim 15

Dependent Claim 35 words

The process of claim 6 wherein said alkylating agent is selected from the group consisting of benzyl chloride, a lower alkyl chloride, and a lower alkenyl chloride having from 1 to about 6 carbon atoms.

Claim 16

Dependent Claim 68 words

A finely divided devulcanized rubber composition derived from scrap vulcanized rubber, said devulcanized rubber comprising polymeric sulfide derived from scission of polysulfides, said polysulfides being present in said devulcanized rubber in an amount less than 50 percent of the sulfur to sulfur bonds originally present in said scrap rubber, said polymeric sulfide being present in devulcanized rubber particles having a size smaller than about 6 U.S. Standard mesh.

Claim 17

Dependent Claim 68 words

A finely divided devulcanized rubber composition derived from scrap vulcanized rubber, said devulcanized rubber comprising polymeric sulfide derived from scission of polysulfides, said polysulfides being present in said devulcanized rubber in an amount less than 50 percent of the sulfur to sulfur bonds originally present in said scrap rubber, said polymeric sulfide being present in devulcanized rubber particles having a size smaller than about 6 U.S. Standard mesh.

Claim 18

Dependent Claim 38 words

The composition of claim 15 wherein said devulcanized rubber particles are further characterized by the presence of a trace quantity, less than about 1.6×10 -5 mol/gm rubber hydrocarbon of polysulfide crosslinks originally present in said scrap vulcanized rubber.

Claim 19

Dependent Claim 79 words

A devulcanized rubber composition produced by (a) comminuting vulcanized scrap rubber to vulcanizate particles smaller than about 6 U.S. standard mesh, and, (b) contacting said vulcanizate particles with (i) an organic solvent having dissolved therein a predetermined concentration of an onium salt of an element, selected from the group consisting of nitrogen, phosphorus, and sulfur, and (ii) an aqueous solution containing a sufficient concentration of OH - ions to selectively disrupt enough polysulfide crosslinks to produce devulcanized rubber particles.

Claim 20

Dependent Claim 79 words

A devulcanized rubber composition produced by (a) comminuting vulcanized scrap rubber to vulcanizate particles smaller than about 6 U.S. standard mesh, and, (b) contacting said vulcanizate particles with (i) an organic solvent having dissolved therein a predetermined concentration of an onium salt of an element, selected from the group consisting of nitrogen, phosphorus, and sulfur, and (ii) an aqueous solution containing a sufficient concentration of OH - ions to selectively disrupt enough polysulfide crosslinks to produce devulcanized rubber particles.

Claim 21

Dependent Claim 73 words

A devulcanized rubber particle derived from a scrap rubber particle smaller than about 6 U.S. Standard mesh, said devulcanized rubber particle including a small quantity of polymeric sulfide represented by R p --S--CH 3 wherein R p is a rubber polymer radical, and said sulfide is derived from the scission of polysulfide crosslinks in scrap rubber molecules R p --S n --R p , wherein n is equal to or greater than 2.

Claim 22

Dependent Claim 73 words

A devulcanized rubber particle derived from a scrap rubber particle smaller than about 6 U.S. Standard mesh, said devulcanized rubber particle including a small quantity of polymeric sulfide represented by R p --S--CH 3 wherein R p is a rubber polymer radical, and said sulfide is derived from the scission of polysulfide crosslinks in scrap rubber molecules R p --S n --R p , wherein n is equal to or greater than 2.

Claim 23

Dependent Claim 26 words

The devulcanized rubber particle of claim 18 wherein said polymeric sulfide is generated in an amount of about 1.5 mole per mole of polysulfide crosslinks broken.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1982-07-16	1983-01-15	1983-07-17	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1986-07-16	1987-01-15	1987-07-17	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1990-07-16	1991-01-15	1991-07-17	$7700.00	Window Closed / Lapsed

Devulcanized rubber composition and process for preparing same

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