US5080994A — Processes for the preparation of particles

Claim 1

Independent Claim 108 words

A process for the preparation of polymer particles with an average diameter of from about 0.1 micron to about 40 microns, consisting essentially of (1) mixing at least one monomer with a free radical polymerization initiator, and an initiator capable of being activated with light, which monomer is dispersed in an aqueous phase containing a surfactant; (2) subjecting the aforementioned mixture of (1) to light irradiation for an effective period of time to accomplish stabilization of the mixture, while initiating photopolymerization of the monomer; and (3) subsequently heating the aqueous phase thereby completing polymerization of the monomer wherein the aforementioned dispersion is accomplished with a homogenizer or fluidizer.

Claim 2

Dependent Claim 108 words

A process for the preparation of polymer particles with an average diameter of from about 0.1 micron to about 40 microns, consisting essentially of (1) mixing at least one monomer with a free radical polymerization initiator, and an initiator capable of being activated with light, which monomer is dispersed in an aqueous phase containing a surfactant; (2) subjecting the aforementioned mixture of (1) to light irradiation for an effective period of time to accomplish stabilization of the mixture, while initiating photopolymerization of the monomer; and (3) subsequently heating the aqueous phase thereby completing polymerization of the monomer wherein the aforementioned dispersion is accomplished with a homogenizer or fluidizer.

Claim 3

Dependent Claim 15 words

A process in accordance with claim 1 wherein ultraviolet light or visible light is selected.

Claim 4

Dependent Claim 25 words

A process in accordance with claim 1 wherein heating to complete polymerization is accomplished at a temperature of from about 45° to about 100° C.

Claim 5

Dependent Claim 19 words

A process in accordance with claim 1 wherein there is mixed with the core monomer an inert filler resin.

Claim 6

Dependent Claim 14 words

A process in accordance with claim 1 wherein a mixture of monomers is selected.

Claim 7

Dependent Claim 18 words

A process in accordance with claim 5 wherein the mixture contains from 2 monomers to about 20 monomers.

Claim 8

Dependent Claim 36 words

A process in accordance with claim 6 wherein the inert filler resin which is present in an amount of from about 1 to 10 percent is comprised of a homopolymer or copolymer obtained from vinyl monomers.

Claim 9

Dependent Claim 18 words

A process in accordance with claim 1 wherein the polymerized product obtained is subjected to washing and drying.

Claim 10

Dependent Claim 17 words

A process in accordance with claim 1 wherein the polymeric product particles are substantially free of aggregation.

Claim 11

Dependent Claim 26 words

A process in accordance with claim 1 wherein heating and irradiation polymerization is accomplished at a temperature of from about 25° C. to about 60° C.

Claim 12

Dependent Claim 15 words

A process in accordance with claim 1 wherein the homogenizer is a high shear mixer.

Claim 13

Dependent Claim 15 words

A process in accordance with claim 1 wherein the fluidizer is a micro-fluidizer a microfluidizer.

Claim 14

Dependent Claim 46 words

A process in accordance with claim 1 wherein the monomer is selected from the group consisting of styrene and its derivatives, monocarboxylic acids and the derivatives thereof; dicarboxylic acids and the derivatives thereof; vinyl ketones; vinyl naphthalene; unsaturated mono-olefins; vinylidene halides; N-vinyl compounds; and mixtures thereof.

Claim 15

Dependent Claim 83 words

A process in accordance with claim 1 wherein the monomer is selected from the group consisting of α-methyl-styrene, p-chlorostyrene, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methacrylic acids, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile and acrylamide; maleic acid, monobutyl maleate, dibutyl maleate; vinyl chloride, vinyl acetate and vinyl benzoate; vinylidene chloride; 1,4 butanediol diacrylate; trimethylolpropane triacrylate; unsaturated pentaerythritol vinyl derivatives with one or more double bonds; triethyleneglycol diacrylate; triethyleneglycol dimethacrylate; and N-vinyl pyrrole.

Claim 16

Dependent Claim 32 words

A process in accordance with claim 1 wherein the monomer is a vinyl monomer selected from the group consisting of an acrylate, a methacrylate, a polyester/styrene copolymer and unsaturated diallyl phthalate polymers.

Claim 17

Dependent Claim 34 words

A process in accordance with claim 1 wherein there is selected a monomer or copolymer selected from the group consisting of poly(methyl methacrylate), poly(methyl methacrylate-hydroxy-ethyl acrylate), poly(methyl methacrylate-acrylated glycidyl methacrylate), and poly(methyl methacrylate-methacrylic acid).

Claim 18

Dependent Claim 24 words

A process in accordance with claim 1 wherein the polymerization initiator is selected from the group consisting of organic soluble azo compounds and peroxides.

Claim 19

Dependent Claim 27 words

A process in accordance with claim 17 wherein the free radical polymerization initiator is benzoyl peroxide, lauroyl peroxide, 1-1-(t-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-di-(t-butylperoxy)valerate, dicumyl peroxide, 2,2'azodimethylvaleronitrile, 2,2'azoisobutyronitrile, azobiscyclohexanenitrile, and 2-methylbutyronitrile.

Claim 20

Dependent Claim 22 words

A process in accordance with claim 1 wherein the initiator is comprised of compounds comprised of an ionic dye and its counterion.

Claim 21

Dependent Claim 32 words

A process in accordance with claim 19 wherein cationic dyes selected from the group consisting of methylene blue, safranine O, malachite green, cyanine dyes and rhodamine dyes, and mixtures thereof are utilized.

Claim 22

Dependent Claim 20 words

A process in accordance with claim 19 wherein the counterion for the ionic dye is tetraphenylbutylborate, trianzylbutylborate, or mixtures thereof.

Claim 23

Dependent Claim 14 words

A process in accordance with claim 1 wherein there are selected as initiators propiophenones.

Claim 24

Dependent Claim 48 words

A process in accordance with claim 1 wherein the initiators are selected from the group consisting of mixtures of benzophenone derivatives and organic tertiary aliphatic amines, esters of p-dimethylaminobezoic acids, 4,4'-bisdialylamino benzophenones, polymeric ethers of primary or secondary alcohols, glycols, primary or secondary aliphatic alcohols, and mixtures thereof.

Claim 25

Dependent Claim 22 words

A process in accordance with claim 1 wherein the initiator is comprised of a mixture of benzophenone and an aromatic (Michler's) ketone.

Claim 26

Dependent Claim 28 words

A process in accordance with claim 1 wherein the stabilization of the mixture is accomplished with a medium pressure mercury lamp with a maximum output at 365 nanometers.

Claim 27

Dependent Claim 14 words

A process in accordance with claim 1 wherein the reaction mixture contains a photosensitizer.

Claim 28

Dependent Claim 85 words

A process for the preparation of polymer particles consisting essentially of (1) mixing at least one monomer with a free radical polymerization initiator, and an initiator capable of being activated with light, which monomer mixture is dispersed in an aqueous phase containing a surfactant; (2) subjecting the aforementioned mixture of (1) to light irradiation for an effective period of time to accomplish stabilization of the mixture, while initiating photopolymerization of the monomer; and (3) subsequently heating the aqueous phase thereby completing polymerization of the monomer.

Claim 29

Dependent Claim 85 words

A process for the preparation of polymer particles consisting essentially of (1) mixing at least one monomer with a free radical polymerization initiator, and an initiator capable of being activated with light, which monomer mixture is dispersed in an aqueous phase containing a surfactant; (2) subjecting the aforementioned mixture of (1) to light irradiation for an effective period of time to accomplish stabilization of the mixture, while initiating photopolymerization of the monomer; and (3) subsequently heating the aqueous phase thereby completing polymerization of the monomer.

Claim 30

Dependent Claim 91 words

A process for the preparation of polymer particles with an average diameter from about 0.1 to about 40 microns, consisting essentially of (1) dispersing a monomer, a free radical initiator, an ultraviolet light sensitizer and/or photoinitiator in an aqueous phase containing a surfactant, which dispersion is formed by a homogenizer; irradiating the resulting suspension for an effective period of time to accomplish stabilization of the mixture while initiating photopolymerization of the monomer mixture, subsequently heating the aqueous phase thereby completing polymerization of the monomer and thereafter washing the resulting polymer particles.

Claim 31

Dependent Claim 91 words

A process for the preparation of polymer particles with an average diameter from about 0.1 to about 40 microns, consisting essentially of (1) dispersing a monomer, a free radical initiator, an ultraviolet light sensitizer and/or photoinitiator in an aqueous phase containing a surfactant, which dispersion is formed by a homogenizer; irradiating the resulting suspension for an effective period of time to accomplish stabilization of the mixture while initiating photopolymerization of the monomer mixture, subsequently heating the aqueous phase thereby completing polymerization of the monomer and thereafter washing the resulting polymer particles.

Claim 32

Dependent Claim 15 words

A process in accordance with claim 28 wherein ultraviolet light or visible light is selected.

Claim 33

Dependent Claim 25 words

A process in accordance with claim 28 wherein heating to complete polymerization is accomplished at a temperature of from about 45° to about 100° C.

Claim 34

Dependent Claim 35 words

A process in accordance with claim 28 wherein heating and irradiation polymerization is accomplished at a temperature of from about 25° to about 60° C., and wherein dispersion is accomplished with a high shear mixture.

Claim 35

Dependent Claim 25 words

A process in accordance with claim 28 wherein irradiating is accomplished for a period of time of from about 1 minute to about 7 hours.

Claim 36

Dependent Claim 25 words

A process in accordance with claim 28 wherein irradiating is accomplished for a period of time of from about 30 minutes to about 6 hours.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1995-01-13	1995-07-15	1996-01-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1999-01-13	1999-07-15	2000-01-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2003-01-13	2003-07-15	2004-01-14	$7700.00	Window Closed / Lapsed

Processes for the preparation of particles

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