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US4499175A Expired / Lapsed US ⏱️ 0.0 years remaining

Photopolymerizable materials for use in producing screen printing stencils

Assignee: Sericol Ltd
•
Filing: 1982-09-22
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Granted: 1985-02-12
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Expires: 2002-09-22
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Abstract

Abstract Aqueous compositions useful in making stencils for screen printing comprise a solution of an unsaturated prepolymer dispersed in an aqueous solution of a colloid, and a photo-initiator. Such compositions may be coated on suitable support sheets to produce photosensitive sheets useful for making stencils for screen printing by the direct, indirect, or direct/indirect methods.

Inventors

  • 👤 John R. Curtis
  • 👤 John D. Renwick

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 21:41
CPC Classifications
C; C08; C08F; C08F290/00; C08F290/02; C08F290/06; C08F2/00; C08F2/46; C08F2/48; G; G03; G03F; G03F7/00; G03F7/12; Y; Y10; Y10S; Y10S430/00; Y10S430/1053; Y10S430/1055; Y10S430/114; Y10S430/12; Y10S430/122; Y10S430/123

Claims Analysis

Total Claims: 25
Claim 1
Independent Claim 165 words
In a method for producing a stencil for screen printing by forming a layer of an aqueous photopolymerizable composition, drying the said layer, irradiating the dried layer with actinic light in image-wise manner to form an insolubilzed image in the said layer and developing the said insolubilized image by washing out unirradiated portions of the said layer, the said layer being formed directly on the printing screen or on a support sheet and then transferred to the printing screen before or after the said development, the improvement which consists in forming the said layer from an aqueous photopolymerizable composition in the form of a dispersion, in an aqueous solution of a colloid, of a solution of a prepolymer containing terminal ethylenic unsaturation joined to the residue of an aromatic polyester, epoxy or urethane prepolymer via ester, amide or urethane linkages, the said composition containing also a photoinitiator, whereby the insolubilized image may be developed by washing out unirradiated portions of the said layer with water.
Claim 2
Dependent Claim 165 words
In a method for producing a stencil for screen printing by forming a layer of an aqueous photopolymerizable composition, drying the said layer, irradiating the dried layer with actinic light in image-wise manner to form an insolubilzed image in the said layer and developing the said insolubilized image by washing out unirradiated portions of the said layer, the said layer being formed directly on the printing screen or on a support sheet and then transferred to the printing screen before or after the said development, the improvement which consists in forming the said layer from an aqueous photopolymerizable composition in the form of a dispersion, in an aqueous solution of a colloid, of a solution of a prepolymer containing terminal ethylenic unsaturation joined to the residue of an aromatic polyester, epoxy or urethane prepolymer via ester, amide or urethane linkages, the said composition containing also a photoinitiator, whereby the insolubilized image may be developed by washing out unirradiated portions of the said layer with water.
Claim 3
Dependent Claim 34 words
A method according to claim 1 in which the prepolymer is an aromatic urethane prepolymer or aromatic polyester resin having hydroxy groups esterified by an ethylenically unsaturated acid of 3 to 5 carbon atoms.
Claim 4
Dependent Claim 32 words
A method according to claim 1 in which the prepolymer is an aromatic epoxy resin having hydroxy and/or epoxy groups esterified by an ethylenically unsaturated acid of 3 to 5 carbon atoms.
Claim 5
Dependent Claim 21 words
A method according to claim 1 in which the proportion of prepolymer is 5 to 35% by weight of the composition.
Claim 6
Dependent Claim 42 words
A composition according to claim 1 in which the prepolymer is dissolved in an ester of the formula: R--O--(CH.sub.2 CH.sub.2 O).sub.n CO--R.sup.1 where R is methyl or ethyl, n is 1 or 2 and R 1 is methyl, ethyl, isopropyl or n-propyl.
Claim 7
Dependent Claim 18 words
A method according to claim 1 in which the prepolymer is dissolved in a photopolymerisable ethylenically unsaturated solvent.
Claim 8
Dependent Claim 30 words
A method according to claim 6 in which the solvent is hexanediol diacrylate, N-vinyl-pyrrolidone, polyethylene glycol (200) diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, or trimethylolpropane triacrylate.
Claim 9
Dependent Claim 22 words
A method according to claim 6 in which the solvent for the prepolymer constitutes 2 to 15% by weight of the composition.
Claim 10
Dependent Claim 18 words
A method according to claim 1 in which the photo-initiator is a thioxanthone or benzophenone derivative, or 1,1-dimethoxy-acetophenone.
Claim 11
Dependent Claim 22 words
A method according to claim 9 in which the proportion of the photo-initiator is 0.5 to 5% by weight of the composition.
Claim 12
Dependent Claim 38 words
A method according to claim 1 in which the water in the aqueous solution of the colloid is 30 to 80% by weight of the composition and the colloid is 3 to 12% by weight of the composition.
Claim 13
Dependent Claim 24 words
A method according to claim 13 in which the accelerator is an ethylenically unsaturated monomer containing a tertiary nitrogen atom or a tertiary amino-alcohol.
Claim 14
Dependent Claim 18 words
A method according to claim 1 in which the said composition contains an organic nitrogen base as accelerator.
Claim 15
Dependent Claim 23 words
A method according to claim 1 in which the said composition also contains a non-photopolymerisable aminoplast, alkyd, epoxy, blocked isocyanate, or polyurethane resin.
Claim 16
Dependent Claim 16 words
A method according to claim 1 in which the said composition also contains a water-soluble surfactant.
Claim 17
Dependent Claim 18 words
A method according to claim 1 in which the said composition also contains a plasticiser, filler and/or colourant.
Claim 18
Dependent Claim 18 words
A method according to claim 1 in which the said composition also contains a thioindigoid or indigoid dyestuff.
Claim 19
Dependent Claim 22 words
A method according to claim 13 in which the proportion of the accelerator is 1.5 to 3% by weight of the composition.
Claim 20
Dependent Claim 14 words
A method according to claim 15 in which the surfactant is a polyoxyethylenated alkyl-phenol.
Claim 21
Independent Claim 131 words
A method of producing a stencil for screen printing which comprises: (a) coating a transparent and flexible support sheet with an aqueous photopolymerizable composition in the form of a dispersion, in an aqueous solution of a colloid, of a solution of a prepolymer containing terminal ethylenic unsaturation joined to the residue of an aromatic polyester, epoxy or urethane prepolymer via ester, amide or urethane linkages, the said composition comprising also a photoinitiator; (b) drying the said coating; (c) irradiating the coated sheet with actinic light in image-wise manner to form an insolubilized image in the said coating; (d) developing the insolubilized image in the irradiated coating by washing out unirradiated portions of the said coating with water; and (e) transferring the insolubilized image from the support sheet to a printing screen.
Claim 22
Independent Claim 131 words
A method of producing a stencil for screen printing which comprises: (a) coating a transparent and flexible support sheet with an aqueous photopolymerizable composition in the form of a dispersion, in an aqueous solution of a colloid, of a solution of a prepolymer containing terminal ethylenic unsaturation joined to the residue of an aromatic polyester, epoxy or urethane prepolymer via ester, amide or urethane linkages, the said composition comprising also a photoinitiator; (b) drying the said coating; (c) irradiating the coated sheet with actinic light in image-wise manner to form an insolubilized image in the said coating; (d) developing the insolubilized image in the irradiated coating by washing out unirradiated portions of the said coating with water; and (e) transferring the insolubilized image from the support sheet to a printing screen.
Claim 23
Dependent Claim 61 words
A screen for screen printing coated with an aqueous photopolymerisable composition in the form of a dispersion, in an aqueous solution of a colloid, of a solution of a prepolymer containing terminal ethylenic unsaturation joined to the residue of an aromatic polyester, epoxy or urethane prepolymer via ester, amide or urethane linkages, the said composition containing also a photo-initiator, and dried.
Claim 24
Dependent Claim 61 words
A screen for screen printing coated with an aqueous photopolymerisable composition in the form of a dispersion, in an aqueous solution of a colloid, of a solution of a prepolymer containing terminal ethylenic unsaturation joined to the residue of an aromatic polyester, epoxy or urethane prepolymer via ester, amide or urethane linkages, the said composition containing also a photo-initiator, and dried.
Claim 25
Dependent Claim 29 words
A method of producing a stencil for screen printing which comprises irradiating a coated screen as claimed in claim 21 with actinic light, and then developing the insolubilised image.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-02-12 1988-08-13 1989-02-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-02-12 1992-08-13 1993-02-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-02-12 1996-08-13 1997-02-12 $7700.00 Window Closed / Lapsed

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