US4064294A
Expired / Lapsed
US
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In-situ production of microcapsules on a substrate
Assignee: PPG Industries Inc
•
Filing: 1975-06-02
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Granted: 1977-12-20
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Expires: 1995-06-02
Abstract
Abstract Microcapsules are produced in-situ in a film or during the manufacturing process of a water-based coating composition from which the film is formed. A principal process involves the in-situ production of void-containing microcapsules in a film formed from a water-based coating. This principal process involves as a first step the preparation of a polymer composition which may be a homogeneous solution containing a water-immiscible organic polymer, a water-immiscible solvent for the polymer, and a water-immiscible lower volatility non-solvent which is miscible with the solvent; or an emulsion containing as the continuous phase a water-immiscible organic polymer dissolved in a water-immiscible solvent for the polymer and, as the discontinuous phase, droplets of a lower volatility non-solvent dispersed in the continuous phase. This polymer composition is then emulsified under agitation and in the presence of a surfactant into a water-based coating composition. The water-based coating composition containing this emulsified polymer composition is then applied to a substrate and the solvent is evaporated from the polymer composition to produce microcapsules containing discrete droplets of the non-solvent. Subsequent drying of the water-based coating and evaporation of the non-solvent from the microcapsules produces a film having incorporated therein structured, closed-cell, void-containing microcapsules with the voids serving to provide opacity and gloss control to the film. In an alternative to the principal process, microcapsules containing the non-solvent are produced in-situ in the water-based coating composition prior to forming a film therefrom.
Inventors
- 👤 Simon Babil
- 👤 James A. Claar
- 👤 Rodger G. Temple
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:18
CPC Classifications
C; C09; C09D; C09D5/00; C09D5/02; C09D7/00; C09D7/40; C09D7/42; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985; Y10T428/2987; Y10T428/2989
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
182 words
A method of preparing void-containing microcapsules in-situ in a film which comprises the steps of: A. preparing a polymer composition selected from the group consisting of: 1. a homogenous solution containing a water-immiscible organic polymer, a water immiscible solvent for the polymer and a water-immiscible lower volatility non-solvent which is miscible with the solvent, and 2. an emulsion containing as the continuous phase a water-immiscible organic polymer dissolved in a water immiscible solvent for the polymer and as the discontinuous phase droplets of a lower volatility non-solvent dispersed in the continuous phase; B. emulsifying said polymer composition into a water-based polymer coating composition under agitation and in the presence of a surfactant; C. applying the water-based polymer coating composition containing said emulsified polymer composition to a substrate; D. evaporating the polymer solvent from the emulsified polymer composition to produce in-situ in said applied coating composition microcapsules having entrapped therein discrete droplets of the lower volatility non-solvent; and E. drying said coating composition to evaporate the lower volatility non-solvent from the microcapsules thereby producing a film having incorporated therein sructured, closed-celled, void-containing microcapsules.
Claim 2
Independent Claim
182 words
A method of preparing void-containing microcapsules in-situ in a film which comprises the steps of: A. preparing a polymer composition selected from the group consisting of: 1. a homogenous solution containing a water-immiscible organic polymer, a water immiscible solvent for the polymer and a water-immiscible lower volatility non-solvent which is miscible with the solvent, and 2. an emulsion containing as the continuous phase a water-immiscible organic polymer dissolved in a water immiscible solvent for the polymer and as the discontinuous phase droplets of a lower volatility non-solvent dispersed in the continuous phase; B. emulsifying said polymer composition into a water-based polymer coating composition under agitation and in the presence of a surfactant; C. applying the water-based polymer coating composition containing said emulsified polymer composition to a substrate; D. evaporating the polymer solvent from the emulsified polymer composition to produce in-situ in said applied coating composition microcapsules having entrapped therein discrete droplets of the lower volatility non-solvent; and E. drying said coating composition to evaporate the lower volatility non-solvent from the microcapsules thereby producing a film having incorporated therein sructured, closed-celled, void-containing microcapsules.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein the polymer composition contains a polymer selected from the group consisting of thermoplastic and thermosetting resins.
Claim 4
Dependent Claim
31 words
The method of claim 2 wherein the thermoplastic resin is selected from the group consisting of an alkyl acrylate or methacrylate, polystyrene, copolymers of styrene and vinyl monomers, polyolefins, and polycarbonates.
Claim 5
Dependent Claim
11 words
The method of claim 3 wherein the thermoplastic resin is polystyrene.
Claim 6
Dependent Claim
36 words
The method of claim 2 wherein the thermosetting resin is selected from the group consisting of interpolymers of hydroxyesters of ethylenically-unsaturated acids with at least one other polymerizable, ethylenically-unsaturated monomer, alkyd resins, and carboxylic acid-amide interpolymers.
Claim 7
Dependent Claim
21 words
The method of claim 2 wherein the thermosetting resin is a copolymer of an alkyl methacrylate and an aziridinyl alkyl methacrylate.
Claim 8
Dependent Claim
15 words
The method of claim 1 wherein the solution consists of polystyrene, methylene chloride and n-heptane.
Claim 9
Dependent Claim
31 words
The method of claim 1 wherein the emulsion contains as the continuous phase polystyrene dissolved in methylene chloride and as the discontinuous phase droplets of water dispersed in the continuous phase.
Claim 10
Dependent Claim
19 words
The method of claim 1 wherein the solution has a non-solvent to solvent weight ratio of 1:1 to 1:100.
Claim 11
Dependent Claim
19 words
The method of claim 1 wherein the solution has a non-solvent to solvent weight ratio of 1:1 to 1:20.
Claim 12
Dependent Claim
19 words
The method of claim 1 wherein the emulsion has a non-solvent to solvent weight ratio of 1:1 to 1:100.
Claim 13
Dependent Claim
21 words
The method of claim 1 wherein the surfactant is selected from the group consisting of anionic, non-ionic, cationic and amphoteric surfactants.
Claim 14
Dependent Claim
20 words
The method of claim 1 wherein the surfactant is a sodium salt of a sulfate ester of an alkylphenoxy poly(ethyleneoxy)ethanol.
Claim 15
Dependent Claim
11 words
The method of claim 1 wherein the surfactant is potassium oleate.
Claim 16
Dependent Claim
27 words
The method of claim 1 wherein the water-based coating composition comprises an aqueous polymer latex, an aqueous polymer emulsion, a water-soluble polymer or an aqueous polymer dispersion.
Claim 17
Dependent Claim
15 words
The method of claim 1 wherein the water-based coating composition comprises an acrylic polymer latex.
Claim 18
Dependent Claim
23 words
The method of claim 16 wherein the acrylic polymer is derived from a monomer mixture containing methyl methacrylate, butyl methacrylate, and methacrylic acid.
Claim 19
Dependent Claim
12 words
The method of claim 1 wherein the solvent is evaporated by air-drying.
Claim 20
Dependent Claim
12 words
The method of claim 1 wherein the solvent is evaporated by heating.
Claim 21
Dependent Claim
16 words
The method of claim 1 wherein the water-based coating composition is dried by air-drying or baking.
Claim 22
Dependent Claim
16 words
The method of claim 1 wherein the polymer composition has pigment incorporated in the polymer solvent.
Claim 23
Dependent Claim
15 words
The method of claim 1 wherein the polymer composition has pigment incorporated in the non-solvent.
Claim 24
Independent Claim
175 words
A method of preparing in-situ in a film microcapsules having encapsulated therein non-solvents which serve a secondary function and remain encapsulated until the performance of the secondary function is desired, said method comprising the steps of: A. preparing a polymer composition selected from the group consisting of: 1. a homogeneous solution containing a water-immiscible organic polymer, or water immiscible solvent for the polymer and a water-immiscible lower volatility non-solvent which is miscible with the solvent, and 2. an emulsion containing as the continuous phase a water-immiscible organic polymer dissolved in a water immiscible solvent for the polymer and as the discontinuous phase droplets of a lower volatility non-solvent dispersed in the continuous phase; B. emulsifying said polymer composition into a water-based polymer coating composition under agitation and in the presence of a surfactant; C. applying said water-based polymer coating composition containing said emulsified polymer composition to a substrate; and D. evaporating the polymer solvent from the polymer composition to produce in-situ a film formed from the water-based coating composition microcapsules having entrapped therein the non-solvent.
Claim 25
Independent Claim
175 words
A method of preparing in-situ in a film microcapsules having encapsulated therein non-solvents which serve a secondary function and remain encapsulated until the performance of the secondary function is desired, said method comprising the steps of: A. preparing a polymer composition selected from the group consisting of: 1. a homogeneous solution containing a water-immiscible organic polymer, or water immiscible solvent for the polymer and a water-immiscible lower volatility non-solvent which is miscible with the solvent, and 2. an emulsion containing as the continuous phase a water-immiscible organic polymer dissolved in a water immiscible solvent for the polymer and as the discontinuous phase droplets of a lower volatility non-solvent dispersed in the continuous phase; B. emulsifying said polymer composition into a water-based polymer coating composition under agitation and in the presence of a surfactant; C. applying said water-based polymer coating composition containing said emulsified polymer composition to a substrate; and D. evaporating the polymer solvent from the polymer composition to produce in-situ a film formed from the water-based coating composition microcapsules having entrapped therein the non-solvent.
Claim 26
Dependent Claim
23 words
The method of claim 23 wherein the non-solvent is selected from the group consisting of medicaments, minerals, biocides, perfumes, fertilizers, and chemical reactants.
Claim 27
Dependent Claim
22 words
The method of claim 23 wherein the polymer composition contains a polymer selected from the group consisting of thermoplastic and thermosetting resins.
Claim 28
Dependent Claim
31 words
The method of claim 25 wherein the thermoplastic resin is selected from the group consisting of an alkyl acrylate or methacrylate, polystyrene, copolymers of styrene and vinyl monomers, polyolefins, and polycarbonates.
Claim 29
Dependent Claim
11 words
The method of claim 26 wherein the thermoplastic resin is polystyrene.
Claim 30
Dependent Claim
36 words
The method of claim 25 wherein the thermosetting resin is selected from the group consisting of interpolymers of hydroxyesters of ethylenically-unsaturated acids with at least one other polymerizable, ethylenically-unsaturated monomer, alkyd resins, and carboxylic acid-amide interpolymers.
Claim 31
Dependent Claim
21 words
The method of claim 25 wherein the thermosetting resin is a copolymer of an alkyl methacrylate and an aziridinyl alkyl methacrylate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-19 | 1981-06-20 | 1981-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-19 | 1985-06-20 | 1985-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-19 | 1989-06-20 | 1989-12-20 | $7700.00 | Window Closed / Lapsed |