US4180449A — Bonded asbestos diaphragms and mats

Claim 1

Independent Claim 24 words

A porous, fibrous asbestos-containing mat characterized by having the asbestos fibers bonded to one another by the pyrolysis products of a hydrolyzed organic titanate.

Claim 2

Dependent Claim 24 words

A porous, fibrous asbestos-containing mat characterized by having the asbestos fibers bonded to one another by the pyrolysis products of a hydrolyzed organic titanate.

Claim 3

Dependent Claim 24 words

The mat of claim 1 wherein at least some of the asbestos fibers are chrysotile and the organic titanate is an ortho alkyl titanate.

Claim 4

Dependent Claim 49 words

The mat of claim 2 wherein the ortho alkyl titanate is a tetra alkyl titanate in which the alkyl group contains from 2 to 5 carbon atoms and is present in an amount such that said pyrolysis products constitute from 0.5 to 3% by weight of the asbestos fibers.

Claim 5

Dependent Claim 17 words

The mat of claim 1 wherein said mat is a diaphragm for use in an electrolytic cell.

Claim 6

Dependent Claim 74 words

A porous asbestos-containing diaphragm composed at least in part of fibrous chrysotile and intended for use in an electrolytic cell for the production of chlorine and caustic, said diaphragm being characterized by having the asbestos fibers bonded to one another by the pyrolysis products of a hydrolyzed ortho alkyl titanate, said pyrolysis products being present in an amount such as to provide from 0.5 to 3.0% by weight of titanium expressed as titanium dioxide.

Claim 7

Dependent Claim 74 words

A porous asbestos-containing diaphragm composed at least in part of fibrous chrysotile and intended for use in an electrolytic cell for the production of chlorine and caustic, said diaphragm being characterized by having the asbestos fibers bonded to one another by the pyrolysis products of a hydrolyzed ortho alkyl titanate, said pyrolysis products being present in an amount such as to provide from 0.5 to 3.0% by weight of titanium expressed as titanium dioxide.

Claim 8

Dependent Claim 21 words

The diaphragm of claim 5 wherein the alkyl group of the ortho alkyl titanate contains from 2 to 5 carbon atoms.

Claim 9

Dependent Claim 20 words

The diaphragm of claim 6 wherein the weight of titanium present expressed as titanium dioxide is between 1% and 2%.

Claim 10

Dependent Claim 15 words

The diaphragm of claim 7 wherein the ortho alkyl titanate is a tetra alkyl titanate.

Claim 11

Dependent Claim 12 words

The diaphragm of claim 8 wherein the tetraalkyl titanate is tetraisopropyl titanate.

Claim 12

Dependent Claim 12 words

The diaphragm of claim 8 wherein the tetraalkyl titanate is tetrabutyl titanate.

Claim 13

Dependent Claim 72 words

In a porous diaphragm composed essentially of asbestos fibers, at least some of which are chrysotile and which is deposited from an aqueous slurry upon a porous metal cathode member for use in an electrolytic cell, the improvement which comprises impregnating the diaphragm with a solution containing an organic titanate, drying the impregnated diaphragm in the presence of a hydrolyzing agent to hydrolyze the titanate in situ, and pyrolyzing the hydrolyzed titanate.

Claim 14

Dependent Claim 72 words

In a porous diaphragm composed essentially of asbestos fibers, at least some of which are chrysotile and which is deposited from an aqueous slurry upon a porous metal cathode member for use in an electrolytic cell, the improvement which comprises impregnating the diaphragm with a solution containing an organic titanate, drying the impregnated diaphragm in the presence of a hydrolyzing agent to hydrolyze the titanate in situ, and pyrolyzing the hydrolyzed titanate.

Claim 15

Dependent Claim 23 words

The diaphragm of claim 11 in which the electrolytic cell produces caustic and halogen and the organic titanate is an ortho alkyl titanate.

Claim 16

Dependent Claim 29 words

The diaphragm of claim 12 in which the ortho alkyl titanate is a tetra alkyl titanate in which the alkyl groups each contain from 2 to 5 carbon atoms.

Claim 17

Dependent Claim 39 words

The diaphragm of claim 13 in which solution contains from 2% to 15% by weight of tetra alkyl titanate and the balance is essentially a solvent that does not hydrolyze the titanate and which readily wets the asbestos fibers.

Claim 18

Dependent Claim 14 words

The diaphragm of claim 14 in which the tetra alkyl titanate is tetraisopropyl titanate.

Claim 19

Dependent Claim 25 words

The diaphragm of claim 15 in which the tetraisopropyl titanate is present in the solution in amounts between about 4% to about 10% by weight.

Claim 20

Dependent Claim 32 words

The diaphragm of claim 15 in which the solution contains sufficient hydrochloric acid to redissolve any hydrolyzed titanate formed during the preparation of the solution and in which the solvent is isopropanol.

Claim 21

Dependent Claim 52 words

In an electrolytic cell for producing chlorine and caustic and containing an anode, a cathode and a porous asbestos diaphragm positioned between the anode and the cathode, the improvement which comprises impregnating the diaphragm with a solution containing an ortho alkyl titanate, hydrolyzing the titanate in situ, and pyrolyzing the hydrolyzed titanate.

Claim 22

Dependent Claim 52 words

In an electrolytic cell for producing chlorine and caustic and containing an anode, a cathode and a porous asbestos diaphragm positioned between the anode and the cathode, the improvement which comprises impregnating the diaphragm with a solution containing an ortho alkyl titanate, hydrolyzing the titanate in situ, and pyrolyzing the hydrolyzed titanate.

Claim 23

Dependent Claim 40 words

The electrolytic cell of claim 18 wherein at least some of the asbestos in the diaphragm is fibrous chrysotile and the ortho alkyl titanate is a tetra alkyl titanate wherein the alkyl group contains from 2 to 5 carbon atoms.

Claim 24

Dependent Claim 27 words

The electrolytic cell of claim 19 wherein the solution contains sufficient titanate to provide from 1 to 2% titanium in the hydrolyzed titanate calculated as titanium dioxide.

Claim 25

Independent Claim 28 words

A method of treating a fibrous asbestos-containing mat which comprises bonding the asbestos fibers to one another by pyrolyzing in situ in the mat a hydrolyzed organic titanate.

Claim 26

Independent Claim 28 words

A method of treating a fibrous asbestos-containing mat which comprises bonding the asbestos fibers to one another by pyrolyzing in situ in the mat a hydrolyzed organic titanate.

Claim 27

Dependent Claim 26 words

The method of claim 21 wherein the mat is a diaphragm for use in an electrolytic cell and the organic titanate is an ortho alkyl titanate.

Claim 28

Dependent Claim 40 words

The method of claim 22 wherein the electrolytic cell is one for the production of chlorine and caustic and the ortho alkyl titanate is a tetra alkyl titanate in which each alkyl group contains from 2 to 5 carbon atoms.

Claim 29

Dependent Claim 68 words

In a method of making a porous, fibrous asbestos-containing diaphragm for use in an electrolytic cell in which the asbestos fibers are deposited from an aqueous slurry onto a porous metal cathode, the improvement which comprises impregnating the diaphragm with a solution containing a solvent and an organic titanate, drying the impregnated diaphragm in the presence of a hydrolyzing agent for the titanate, and pyrolyzing the hydrolyzed titanate.

Claim 30

Dependent Claim 68 words

In a method of making a porous, fibrous asbestos-containing diaphragm for use in an electrolytic cell in which the asbestos fibers are deposited from an aqueous slurry onto a porous metal cathode, the improvement which comprises impregnating the diaphragm with a solution containing a solvent and an organic titanate, drying the impregnated diaphragm in the presence of a hydrolyzing agent for the titanate, and pyrolyzing the hydrolyzed titanate.

Claim 31

Dependent Claim 39 words

The method of claim 24 in wich at least some of the asbestos fibers are chrysotile and the organic titanate is an ortho alkyl titanate in which each of the alkyl groups contain from 2 to 5 carbon atoms.

Claim 32

Dependent Claim 33 words

The method of claim 25 wherein the solution contains sufficient ortho alkyl titanate such that, upon pyrolysis from 0.5 to 3% by weight of titanium expressed as titanium dioxide remains in the diaphragm.

Claim 33

Dependent Claim 30 words

The method of claim 25 wherein the ortho alkyl titanate is a tetra alkyl titanate and the solution contains from 4% to 10% by weight of the tetra alkyl titanate.

Claim 34

Dependent Claim 40 words

The method of claim 27 wherein the solution contains sufficient hydrochloric acid to redissolve any hydrolyzed titanate that may form during preparation of the solution, and solvent is an alcohol containing the same alkyl group as the tetra alkyl titanate.

Claim 35

Dependent Claim 13 words

The method of claim 27 wherein the tetra alkyl titanate is tetraisopropyl titanate.

Claim 36

Dependent Claim 23 words

The method of claim 29 wherein the tetraisopropyl titanate constitutes 4% to 5% by weight of the solution and the solvent is isopropanol.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1982-12-24	1983-06-25	1983-12-25	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1986-12-24	1987-06-25	1987-12-25	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1990-12-24	1991-06-25	1991-12-25	$7700.00	Window Closed / Lapsed

Bonded asbestos diaphragms and mats

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