US4358388A
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Magnetic polymer latex and preparation process
Assignee: Prolabo SA
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Filing: 1981-04-16
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Granted: 1982-11-09
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Expires: 2001-04-16
Abstract
Abstract Magnetic-polymer latex having a concentration of less than 65% by weight of hydrophobic vinyl aromatic polymer particles. The polymer particles have diameters from 0.03 to 5 microns and also have dispersed therein a magnetically-charged material in an amount of from 0.5 to 50% by weight with respect to the polymer portion of the polymer particles. A process for preparing magnetic-polymer latices. Magnetically charged particles are dispersed in an organic phase comprising an organically soluble initiator and an organic monomeric component selected from the group consisting of a single vinyl aromatic monomer and a combination of a single vinyl aromatic monomer and a copolymerizing monomer. The dispersion so obtained is mixed with an aqueous solution containing an emulsifying agent and the mixture is homogenized. Polymerization is then effected to form a magnetic-polymer latex containing hydrophobic vinyl aromatic polymer particle. More organic monomer component may be added immediately prior to or during polymerization. Alternatively, the magnetically-charged material may be dispersed into an organic phase comprising an organically soluble initiator and a water-soluble organic compound. An organic monomeric component is added to the aqueous-organic phase mixture after homogenization and prior to or during polymerization, which is effected to form a magnetic-polymer latex containing hydrophobic polymer particles. The magnetic-polymer latices obtained are useful in paints, magnetic tapes, recordings, and biological applications.
Inventors
- 👤 Jean-Claude Daniel
- 👤 Jean-Luc Schuppiser
- 👤 Marc Tricot, deceased
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:37
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54313; G01N33/54326; G01N33/5434; C; C08; C08F; C08F12/00; C08F12/02; C08F2/00; C08F2/44; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7023; G01N2446/00; G01N2446/20; G01N2446/40; G01N2446/60; G01N2446/64
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
57 words
A magnetic-polymer latex comprising: (a) less than 65% by weight of hydrophobic vinyl aromatic polymer particles having a mean diameter between 0.03 and 5 microns; and (b) a magnetically-charged material in an amount from 0.5 to 50% by weight with respect to the polymer portion of said particles, said magnetically-charged material being dispersed within said polymer particles.
Claim 2
Dependent Claim
57 words
A magnetic-polymer latex comprising: (a) less than 65% by weight of hydrophobic vinyl aromatic polymer particles having a mean diameter between 0.03 and 5 microns; and (b) a magnetically-charged material in an amount from 0.5 to 50% by weight with respect to the polymer portion of said particles, said magnetically-charged material being dispersed within said polymer particles.
Claim 3
Dependent Claim
54 words
The latex of claim 1, wherein said hydrophobic vinyl aromatic polymer is selected from the group consisting of: (a) a water-insoluble vinyl aromatic homopolymer; (b) a copolymer consisting of water-insoluble vinyl aromatic monomers; and (c) a copolymer consisting of at least one water-insoluble vinyl aromatic monomer and at least one other water-insoluble copolymerizing monomer.
Claim 4
Dependent Claim
116 words
The latex of claim 2, wherein (1) said water-insoluble vinyl aromatic monomer homopolymer (a) consists of a monomer selected from the group consisting of styrene, alpha-methylstyrene, ethylstyrene, tert-butyl styrene and vinyl toluene; (2) said copolymer (b) consists of water-insoluble vinyl aromatic monomers selected from the group consisting of styrene, alpha-methylstyrene, ethylstyrene, tert-butyl styrene and vinyltoluene; and (3) said copolymer (c) consists of (i) at least one water-insoluble vinyl aromatic monomer selected from the group consisting of styrene, alphamethyl styrene, ethylstyrene, tert-butyl styrene and vinyl toluene and (ii) at least one other water-insoluble copolymerizing monomer selected from the group consisting of a diene compound, an alkyl acrylate, an alkyl methacylate, an ester of ethylenic acid and alkyl.
Claim 5
Dependent Claim
118 words
A process for preparing the magnetic-polymer latex of claim 1 comprising the steps of: (a) dispersing a magnetically-charged material into an organic phase comprising an organically-soluble initiator and an organic monomeric component selected from the group consisting of a single vinyl aromatic monomer and a combination of a single vinyl aromatic monomer and a copolymerizing monomer; (b) preparing an aqueous solution comprising water and at least one emulsifier; (c) mixing said organic phase containing said dispersed magnetically-charged material with said prepared aqueous solution; (d) homogenizing said mixture of said organic phase containing said dispersed magnetically-charged material and said prepared aqueous solution; and (e) polymerizing said homogenized mixture to obtain a magnetic-polymer latex containing hydrophobic vinyl aromatic polymer particles.
Claim 6
Dependent Claim
18 words
The process of claim 4 wherein said organic phase in step (a) further includes a water-insoluble organic compound.
Claim 7
Dependent Claim
40 words
The process of claim 5 further including the step of adding to said homogenized mixture more of said organic monomeric compound immediately prior to or during or prior to and during the polymerization of said homogenized mixture in step (e).
Claim 8
Dependent Claim
40 words
The process of claim 4 further including the step of adding to said homogenized mixture more of said organic monomeric component immediately prior to or during or prior to and during the polymerization of said organic phase in step (e).
Claim 9
Dependent Claim
26 words
The process of claim 4, wherein said vinyl aromatic monomer is a water-insoluble monomer selected from the group consisting of styrene, alpha-methylstyrene, ethylstyrene, tert-butylstyrene and vinyltoluene.
Claim 10
Dependent Claim
40 words
The process of claim 4, wherein said copolymerizing monomer is a water-insoluble monomer selected from the group consisting of styrene, alpha-methylstyrene, ethylstyrene, tert-butyl styrene, vinyltoluene, a diene compound, an alkyl acrylate, an alkylmethacrylate, an ester of ethylenic acid and alkyl.
Claim 11
Dependent Claim
30 words
The process of claim 4, further including in said organic phase a crosslinking monomer in an amount between 0 and 5% by weight with respect to the organic monomeric component.
Claim 12
Dependent Claim
30 words
The process of claim 10 further including in said organic phase a chain-limiting agent in an amount between 0 and 5% by weight with respect to the organic monomeric component.
Claim 13
Dependent Claim
30 words
The process of claim 4 further including in said organic phase a chain-limiting agent in an amount between 0 and 5% by weight with respect to the organic monomeric component.
Claim 14
Dependent Claim
36 words
The process of claim 4 where said magnetically charged material is selected from the group consisting of a metal, a metal alloy, iron oxide, chromium dioxide, and iron oxide combined or mixed with other metal oxides.
Claim 15
Dependent Claim
17 words
The process of claim 4, wherein the size of the magnetically-charged material is less than 1 micron.
Claim 16
Dependent Claim
27 words
The process of claim 4, wherein the amount of said magnetically-charged material dispersed is between 0.5 and 50% by weight with respect to said organic monomeric component.
Claim 17
Dependent Claim
32 words
The process of claim 4, wherein said organic phase is liquid and homogeneous prior to the steps (c) and (d) of mixing and homogenizing said organic phase and said prepared aqueous solution.
Claim 18
Dependent Claim
136 words
A process for preparing the magnetic-polymer latex of claim 1 comprising the steps of: (a) dispersing a magnetically-charged material into an organic phase comprising an organically-soluble initiator and a water-insoluble organic compound; (b) preparing an aqueous solution comprising water and at least one emulsifier; (c) mixing said organic phase containing said dispersed magnetically-charged material with said prepared aqueous solution; (d) homogenizing said mixture of said organic phase containing said dispersed magnetically-charged material and said prepared aqueous solution; (e) adding to said homogenized mixture an organic monomeric component selected from the group consisting of a single vinyl aromatic monomer and a combination of a single vinyl aromatic monomer and a copolymerizing monomer; and (f) polymerizing said homogenized mixture, after said addition of said organic monomeric component, to obtain a magnetic-polymer latex containing hydrophobic vinyl aromatic polymer particles.
Claim 19
Dependent Claim
26 words
The process of claim 17 further including the step of adding more of said organic monomeric component during the step (f) of polymerizing said organic phase.
Claim 20
Dependent Claim
24 words
The process of claim 17, wherein the step (e) of adding organic monomeric component and the step (f) of polymerizing are carried out simultaneously.
Claim 21
Dependent Claim
93 words
The process of claim 5 or 17, wherein said water-insoluble organic compound is selected from the group consisting of a C 10-30 saturated aliphatic hydrocarbon, a halogenated C 10-30 saturated aliphatic hydrocarbon, a C 10-30 unsaturated aliphatic hydrocarbon, a halogenated C 10-30 unsaturated aliphatic hydrocarbon, a C 10-30 aliciclic hydrocarbon, a halogenated C 10-30 alicylic hydrocarbon, a C 10-30 aromatic hydrocarbon, a halogenated C 10-30 aromatic hydrocarbon, a saturated C 10-30 aliphatic alcohol, an unsaturated C 10-30 aliphatic alcohol, a ester of mineral acid or C 1-20 organic acid and C 1-20 alcohol.
Claim 22
Dependent Claim
14 words
The process of claim 20, wherein said esters have at least 10 carbon atoms.
Claim 23
Dependent Claim
24 words
The process of claim 17 wherein said water-insoluble organic compound represents up to 50% by weight of the organic phase containing the magnetically-charged material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-08 | 1986-05-10 | 1986-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-08 | 1990-05-10 | 1990-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-08 | 1994-05-10 | 1994-11-09 | $7700.00 | Window Closed / Lapsed |