Patent US2688460A successfully refreshed from Google Patents.
Patent EP0080225A1 successfully refreshed from Google Patents.
EP0080225A1
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Method for the preparation of stable aqueous dispersions of polymer beads and the use of these dispersions in photographic elements
Assignee: Agfa Gevaert NV
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Filing: 1982-11-10
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Granted: —
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Expires: 2002-11-10
Abstract
Abstract Method for the preparation of stable aqueous dispersions of finely divided solid spherical polymer beads having an average particle size between about 0.5 and about 5 µm and having a glass transition temperature of at least 40°C by dissolving in an aqueous solvent mixture at least one α,β-ethylenically unsaturated monomercapable of forming a polymer that is soluble in the monomer(s) present in said aqueous solvent mixture but which is insoluble in said aqueous solvent mixture, a free radical-forming polymerization initiator, and a graft-polymerizable polymer containing hydrophilic groups, heating the solution to a temperature from 50°C to the reflux temperature thereof with stirring so as to form said polymer beads. The polymer beads can be used in an antifriction surface layer, an antihalation surface layer, an antistatic surface layer, or in a protective surface layer of a photographic element or in a top layer of a drafting film containing a photosensitive layer.
Inventors
- 👤 Daniel Maurice Timmerman
- 👤 Jan Jozef Priem
- 👤 Jan Henri Janssens
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 23:55
CPC Classifications
C; C08; C08F; C08F257/00; C08F257/02; C08F267/00; C08F267/02; G; G03; G03C; G03C1/00; G03C1/76; G03C1/825; G03C1/85; G03C1/89; G03C1/95; Y; Y10; Y10S; Y10S430/00; Y10S430/132; Y10S430/151; Y10S430/162
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
216 words
Method for the preparation of stable aqueous dispersions of finely divided solid spherical polymer beads having an average particle size between about 0.5 and about 5 µm and having a glass transition temperature of at least 40°C, comprising the steps of : A) dissolving in an aqueous solvent mixture of water and at least one water-miscible polar organic solvent : 1) at least one d,B-ethylenically unsaturated monomer capable of forming a polymer that is soluble in the monomer(s) present in said aqueous solvent mixture but which is insoluble in said aqueous solvent mixture, 2) a free radical-forming polymerization initiator that is soluble in the aqueous solvent mixture, and 3) a graft-polymerizable polymer containing hydrophilic groups, and capable of forming a graft polymer that remains soluble in said aqueous solvent mixture, the weight ratio of said graft-polymerizable polymer to said monomer(s) being in the range from 1.5 : 100 to 8 : 100 and the weight ratio of polymerization initiator to monomer(s) from 0.1 : 100 to 5 : 100, and B) heating the solution obtained to a temperature from 50°C to the reflux temperature thereof with continuous stirring to initiate by polymerization the simultaneous massive formation of homopolymer or copolymer from said monomer and precipitation thereof, and the formation of a small proportion of graft polymer.
Claim 2
Dependent Claim
216 words
Method for the preparation of stable aqueous dispersions of finely divided solid spherical polymer beads having an average particle size between about 0.5 and about 5 µm and having a glass transition temperature of at least 40°C, comprising the steps of : A) dissolving in an aqueous solvent mixture of water and at least one water-miscible polar organic solvent : 1) at least one d,B-ethylenically unsaturated monomer capable of forming a polymer that is soluble in the monomer(s) present in said aqueous solvent mixture but which is insoluble in said aqueous solvent mixture, 2) a free radical-forming polymerization initiator that is soluble in the aqueous solvent mixture, and 3) a graft-polymerizable polymer containing hydrophilic groups, and capable of forming a graft polymer that remains soluble in said aqueous solvent mixture, the weight ratio of said graft-polymerizable polymer to said monomer(s) being in the range from 1.5 : 100 to 8 : 100 and the weight ratio of polymerization initiator to monomer(s) from 0.1 : 100 to 5 : 100, and B) heating the solution obtained to a temperature from 50°C to the reflux temperature thereof with continuous stirring to initiate by polymerization the simultaneous massive formation of homopolymer or copolymer from said monomer and precipitation thereof, and the formation of a small proportion of graft polymer.
Claim 3
Dependent Claim
18 words
A method according to claim 1, characterized in that said α,β-ethylenically unsaturated monomer is methyl methacrylate or styrene.
Claim 4
Independent Claim
21 words
A method according to any of claims 1 and 2, characterized in that said graft-polymerizable polymer is co(styrene/maleic acid monosodium salt)(50/50).
Claim 5
Independent Claim
22 words
A method according to any of claims 1 to 3, characterized in that said water-soluble free radical-forming polymerization initiator is potassium persulphate.
Claim 6
Dependent Claim
31 words
A method according to claim 4, characterized in that the amount of potassium persulphate initiator is chosen in the range from 10x10 -3 to 40x10 -3 mol per litre of solution.
Claim 7
Independent Claim
20 words
A method according to any of claims 1 to 5, characterized in that said water-miscible polar organic solvent is ethanol.
Claim 8
Independent Claim
45 words
A method according to any of claims 1 to 6, characterized in that methyl methacrylate is used as α,β-ethylenically unsaturated monomer, co(styrene/maleic acid monosodium salt) as graft-polymerizable polymer, potassium persulphate as initiator, and equal volumes of water and ethanol are used as aqueous solvent mixture.
Claim 9
Independent Claim
24 words
A method according to any of claims 1 to 7, characterized in that the weight ratio of said polymer to said monomer(s) is 5:100.
Claim 10
Dependent Claim
50 words
Photographic element comprising a support and at least one silver halide emulsion layer characterized in that said element comprises finely divided solid spherical polymer beads obtained by the method according to any of claims 1 to 8 in a layer of the said photographic element and/or in the support thereof.
Claim 11
Dependent Claim
24 words
Photographic element according to claim 9, characterized in that said polymer beads are present in an antihalation layer comprising an antihalation dye or pigment.
Claim 12
Dependent Claim
17 words
Photographic element according to claim 10, characterized in that said antihalation dye or pigment is carbon black.
Claim 13
Dependent Claim
18 words
Photographic element according to claim 9, characterized in that said beads are present in a polyethylene terephthalate support.
Claim 14
Dependent Claim
22 words
Polymer film comprising finely divided solid spherical polymer beads obtained by the method according to any of the claims 1 to 8.
Claim 15
Dependent Claim
16 words
Polymer film according to claim 13, characterized in that said film is a polyethylene terephthalate film.
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