US4228058A — Flame retardant latexes

Claim 1

Independent Claim 148 words

A flame retardant latex base consisting essentially of a blend of two separately polymerized aqueous latexes each of which has a polymer content of at least about 35% by weight which in the first latex is a copolymer of which about 70 to 92% by weight is derived from vinylidene chloride with the balance being polar monomers which are predominantly lower alkyl esters of acrylic acids and in the second latex is a copolymer derived primarily from butadiene and styrene in weight proportions of between about 1 part butadiene to 9 parts styrene and about 2 parts butadiene to 1 part styrene, the proportion of said first latex comprising at least about 20% but not over about 90% by weight of said blend and sufficient to provide a vinylidene chloride content equivalent to between about 20 and 80% by weight of the total polymer content in said blend.

Claim 2

Dependent Claim 148 words

A flame retardant latex base consisting essentially of a blend of two separately polymerized aqueous latexes each of which has a polymer content of at least about 35% by weight which in the first latex is a copolymer of which about 70 to 92% by weight is derived from vinylidene chloride with the balance being polar monomers which are predominantly lower alkyl esters of acrylic acids and in the second latex is a copolymer derived primarily from butadiene and styrene in weight proportions of between about 1 part butadiene to 9 parts styrene and about 2 parts butadiene to 1 part styrene, the proportion of said first latex comprising at least about 20% but not over about 90% by weight of said blend and sufficient to provide a vinylidene chloride content equivalent to between about 20 and 80% by weight of the total polymer content in said blend.

Claim 3

Dependent Claim 57 words

A flame retardant latex base as described in claim 1, wherein from about 80 to about 90% by weight of the polymer content of the first latex is derived from vinylidene chloride and the weight proportion of butadiene to styrene in the polymer content of said second latex is between 1 to 3 and 3 to 2.

Claim 4

Dependent Claim 37 words

A flame retardant latex base as described in claim 1, wherein at least about 98% by weight of the polymer content of said first latex is derived from vinylidene chloride plus lower alkyl esters of acrylic acids.

Claim 5

Dependent Claim 31 words

A flame retardant latex base as described in claim 1, wherein at least about 95% by weight of the polymer content of said second latex is derived from butadiene and styrene.

Claim 6

Dependent Claim 44 words

A flame retardant latex base as described in claim 4, wherein up to about 5% by weight of the polymer content of said second latex represents low molecular functional monomers chosen from the group consisting of unsaturated aliphatic acids, amides and N-substituted amide derivatives.

Claim 7

Dependent Claim 41 words

A flame retardant latex base as described in claim 1, wherein the polymer content of the first latex is between about 35 and 50% by weight and the polymer content of second latex is between about 35 and 55% by weight.

Claim 8

Independent Claim 172 words

A method of preparing flame retardant latex bases comprising copolymerizing at temperatures predominantly between about 35° and about 65° C. vinylidene chloride and polar monomers which are predominantly lower alkyl esters of acrylic acids in an acidic aqueous emulsion with a redox-type, water soluble catalyst system comprising a free-radical generating initiator and an effective and compatible sulfoxy reducing agent promotor under conditions yielding a stable aqueous latex containing at least about 35% by weight of a resinous copolymer of which about 70 to 92% by weight represents vinylidene chloride, adjusting the pH of said latex to between about 4 and about 9 and blending same with at least about one ninth but not over about four times its weight of a stable aqueous latex having a pH of between about 5 and about 10 and containing at least about 35% by weight of a copolymer derived primarily from styrene and butadiene in weight proportions of between about 1 part butadiene to 9 parts styrene and 2 parts butadiene to 1 part styrene.

Claim 9

Independent Claim 172 words

A method of preparing flame retardant latex bases comprising copolymerizing at temperatures predominantly between about 35° and about 65° C. vinylidene chloride and polar monomers which are predominantly lower alkyl esters of acrylic acids in an acidic aqueous emulsion with a redox-type, water soluble catalyst system comprising a free-radical generating initiator and an effective and compatible sulfoxy reducing agent promotor under conditions yielding a stable aqueous latex containing at least about 35% by weight of a resinous copolymer of which about 70 to 92% by weight represents vinylidene chloride, adjusting the pH of said latex to between about 4 and about 9 and blending same with at least about one ninth but not over about four times its weight of a stable aqueous latex having a pH of between about 5 and about 10 and containing at least about 35% by weight of a copolymer derived primarily from styrene and butadiene in weight proportions of between about 1 part butadiene to 9 parts styrene and 2 parts butadiene to 1 part styrene.

Claim 10

Dependent Claim 43 words

A method of preparing flame retardant latex bases as described in claim 7, wherein the pH to which the vinylidene chloride copolymer latex is adjusted is on the same side of 7 as that of the styrene-butadiene latex with which it is blended.

Claim 11

Dependent Claim 17 words

A method as described in claim 8, wherein the pH's of both latexes are substantially above 7.

Claim 12

Dependent Claim 59 words

A method of preparing flame retardant latex bases as described in claim 7, wherein vinylidene chloride represents about 80 to about 90% by weight of said resinous copolymer and styrene and butadiene together represent at least 95% by weight of the other copolymer, with styrene alone representing at least 30% and butadiene alone at least 10% by weight thereof.

Claim 13

Dependent Claim 20 words

A method as described in claim 10, wherein butadiene alone represents at least 25% by weight of said other copolymer.

Claim 14

Dependent Claim 47 words

A method of preparing flame retardant latex bases as described in claim 7, wherein the temperatures at which said vinylidene chloride and lower alkyl acrylate monomers are copolymerized are predominantly between about 40° and 60° C. and the free-radical generating initiator is a water soluble peroxy compound.

Claim 15

Dependent Claim 47 words

A method of preparing flame retardant latex bases as described in claim 7, wherein the copolymerization of the vinylidene chloride and lower alkyl acrylate monomers is carried substantially to completion as shown by a residual content of vinylidene chloride of less than about 1000 ppm by weight.

Claim 16

Independent Claim 267 words

A method of preparing flame retardant latex bases comprising: (a) copolymerizing at temperatures predominantly between about 35° and about 65° C. vinylidene chloride and lower alkyl acrylate monomers in an acidic aqueous emulsion with a water-soluble, redox catalyst system essentially free of multivalent metals and comprising a peroxysulfuric free-radical generating initiator and a sulfoxy reducing agent promoter under conditions yielding a stable aqueous latex containing at least about 35% of a resinous copolymer of which about 70 to 92% by weight represents vinylidene chloride, (b) copolymerizing in an aqueous emulsion at a pH of between about 4 and 10, in the presence of a water soluble free-radical initiator and at temperatures predominantly between about 50° and about 85° C. a monomer mixture at least 95% by weight of which is composed of styrene and butadiene in weight proportions of between about 1 part butadiene to 9 parts styrene and about 2 parts butadiene to 1 part styrene under conditions yielding a stable aqueous latex containing at least 35% by weight of polymeric solids, (c) subjecting the latex from step (b) to vacuum stripping to remove most of the unreacted residual monomer content therefrom, (d) adjusting the pH of the latex from step (a) to a value in the range between about 4 and about 9 which value is within approximately 1 pH unit of the pH of said latex from steps (b) and (c), and (e) blending together the two latexes thus prepared in proportions such that between about 20 and about 80% of the total polymer content of the resultant blend is derived from vinylidene chloride.

Claim 17

Independent Claim 267 words

A method of preparing flame retardant latex bases comprising: (a) copolymerizing at temperatures predominantly between about 35° and about 65° C. vinylidene chloride and lower alkyl acrylate monomers in an acidic aqueous emulsion with a water-soluble, redox catalyst system essentially free of multivalent metals and comprising a peroxysulfuric free-radical generating initiator and a sulfoxy reducing agent promoter under conditions yielding a stable aqueous latex containing at least about 35% of a resinous copolymer of which about 70 to 92% by weight represents vinylidene chloride, (b) copolymerizing in an aqueous emulsion at a pH of between about 4 and 10, in the presence of a water soluble free-radical initiator and at temperatures predominantly between about 50° and about 85° C. a monomer mixture at least 95% by weight of which is composed of styrene and butadiene in weight proportions of between about 1 part butadiene to 9 parts styrene and about 2 parts butadiene to 1 part styrene under conditions yielding a stable aqueous latex containing at least 35% by weight of polymeric solids, (c) subjecting the latex from step (b) to vacuum stripping to remove most of the unreacted residual monomer content therefrom, (d) adjusting the pH of the latex from step (a) to a value in the range between about 4 and about 9 which value is within approximately 1 pH unit of the pH of said latex from steps (b) and (c), and (e) blending together the two latexes thus prepared in proportions such that between about 20 and about 80% of the total polymer content of the resultant blend is derived from vinylidene chloride.

Claim 18

Dependent Claim 45 words

A method of preparing flame retardant latex bases as described in claim 14, wherein the pH to which the latex from step (a) is adjusted in step (d) is on the same side of 7 as that of the latex from steps (b) and (c).

Claim 19

Dependent Claim 46 words

A method of preparing flame retardant latex bases as described in claim 14, wherein the mixture of monomers copolymerized in step (b) includes up to about 5% by weight of low molecular functional monomers chosen from the group consisting of unsaturated acids, amides and N-substituted amides.

Claim 20

Dependent Claim 40 words

A method of preparing flame retardant latex bases as described in claim 16, wherein said low molecular functional monomers include at least one unsaturated aliphatic carboxylic acid and said step (b) is carried out at a pH substantially below 7.

Claim 21

Dependent Claim 33 words

A method of preparing flame retardant latex bases as described in claim 14, wherein a minor proportion of a compatible seed latex is included initially in the aqueous emulsion of said step (b).

Claim 22

Dependent Claim 57 words

A method of preparing flame retardant latex bases as described in claim 14, wherein substantially complete conversion of monomers is attained in step (a) in a residence time of less than about 6 hours and at least about 95% conversion of monomers is attained in step (b) in a residence time of less than about 12 hours.

Claim 23

Dependent Claim 29 words

A method as described in claim 19, wherein the same type of acid-stable, anionic surfactant is used to maintain a stable emulsion in both of steps (a) and (b).

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1983-10-14	1984-04-14	1984-10-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1987-10-14	1988-04-14	1988-10-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1991-10-14	1992-04-14	1992-10-14	$7700.00	Window Closed / Lapsed

Flame retardant latexes

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