IPC분류정보
| 국가/구분 |
United States(US) Patent
등록
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| 국제특허분류(IPC7판) |
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| 출원번호 |
US-0692464
(1985-01-18)
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발명자
/ 주소 |
- Gajria, Chandrasen
- Ozari, Yehuda
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| 출원인 / 주소 |
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| 대리인 / 주소 |
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| 인용정보 |
피인용 횟수 :
39 인용 특허 :
5 |
초록
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Disclosed are carboxylic acid containing polymeric microgel particles which are prepared by polymerizing in aqueous emulsion a monomer mixture containing about 10-50% by weight of polymerizable carboxylic acid monomers, up to 5% of a difunctional crosslinking monomer and one or more carboxyl-free re
Disclosed are carboxylic acid containing polymeric microgel particles which are prepared by polymerizing in aqueous emulsion a monomer mixture containing about 10-50% by weight of polymerizable carboxylic acid monomers, up to 5% of a difunctional crosslinking monomer and one or more carboxyl-free relatively water insoluble polymerizable vinyl monomers. The resulting microgel particles are water-swellable and may be employed as stabilizers for use in the preparation of aqueous dispersions of film-forming resins containing smaller amounts of organic solvents than conventional aqueous dispersions of this type. Such dispersions are useful as coating compositions, yielding coatings having less water sensitivity and improved adhesion as compared with coatings obtained from conventional aqueous dispersions of film-forming resins.
대표청구항
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1. A process for preparing a stable aqueous dispersion of water-dispersible organic film-forming resin, comprising the steps of: a. dissolving at least one water-dispersible organic film-forming resin in a water-miscible organic solvent to form a solution of said resin, wherein the film-forming r
1. A process for preparing a stable aqueous dispersion of water-dispersible organic film-forming resin, comprising the steps of: a. dissolving at least one water-dispersible organic film-forming resin in a water-miscible organic solvent to form a solution of said resin, wherein the film-forming resin is selected from the group consisting of heat-curable, thermosetting epoxy resins, phenolic resins, alkyd resins, polyester resins, aminoplast resins and mixtures thereof and wherein the organic solvent has a boiling of about 150° F. to about 500° F.; b. separately preparing a stabilizer for said film-forming resin comprising water-swellable, crosslinked microgel particles having a stability in aqueous media of at least about one week when an aqueous dispersion of said microgel particles of about 20% solids content is maintained at 140° F. by polymerizing in an aqueous emulsion a monomer mixture comprising: (i) a major amount of at least one polymerizable carboxylic acid group-free polymerizable vinyl monomer selected from the group consisting of polymerizable vinyl aromatic monomers, methacrylate ester monomers, nitrile monomers, vinyl halide monomers, mixtures thereof, and mixtures thereof with minor amounts of vinyl ester monomers and alkyl acrylate monomers, (ii) from about 10 to 50%, based on the total monomer weight, of at least one polymerizable vinyl monomer selected from the group consisting of α,62 -ethylenically unsaturated carboxylic acid monomers and mixtures thereof, said carboxylic acid monomers being substantially non-gelling when copolymerized with said acid group-free monomers in an aqueous emulsion, and (iii) from a small amount sufficient to crosslink the microgel particle up to about 5%, based on the total monomer weight, of a difunctional crosslinking monomer having at least two polymerizable double bonds; c. adding and admixing together from about 10 to about 50% by weight, based on the total solids weight of the dispersion, of the microgel particles of step (b) to the solution of said film-forming resin; d. at least partially neutralizing the admixture with ammonia or a volatile organic amine in an amount sufficient to provide a pH of about 2 to about 10 to said aqueous dispersion; and e. dispersing the admixture into an aqueous medium to provide a stable aqueous resin dispersion having a total solids content of from about 15 to about 40 weight percent. 2. The process of claim 1, wherein said film-forming resin is present in an amount of from about 50 to about 90% by weight, based on the total solids weight of the dispersion, said water-miscible organic solvent comprises less than about 20% by weight, based on the total weight of the dispersion, and said microgel particles comprise from about 10 to about 50% by weight, based on the total solids weight of said aqueous resin dispersion. 3. The process of claim 1, further comprising the step of adding an aminoplast resin to said aqueous resin dispersion after step(e). 4. The process of claim 2, wherein said aqueous resin dispersion has a solids content of from about 20 to about 30% by weight, and said water-miscible organic solvent is present in an amount just sufficient to dissolve said film-forming resin. 5. The process of claim 2, wherein said microgel particles have a stability in aqueous media of at least about four weeks when an aqueous dispersion of said microgel particles of about 20% solids content is maintained at 140° F. 6. A process for preparing a stable aqueous dispersion of at least one water-dispersible, heat curable thermosetting organic film-forming resin suitable for use as a protective coating composition, comprising the steps of: a. preparing a solution of at least one water-dispersible, thermosetting film-forming resin selected from the group consisting of epoxy resins comprising a glycidyl polyether of a polyhydric phenol or hydrogenated phenol containing an average of more than one epoxide group per molecule and having an epoxy equivalent weight in the range between about 150 and 8000, phenolic resole resins, and mixtures thereof, in a water-miscible organic solvent having a boiling point of about 150° F. to about 500° F., said organic solvent forming less than about 20% by weight of the total dispersion; b. separately preparing a stabilizer for said film-forming resin comprising water-swellable, crosslinked microgel particles having a stability in aqueous media of at least about four weeks when an aqueous dispersion of said microgel particles of about 20% solids content is maintained at 140° F. by polymerizing in an aqueous emulsion a monomer mixture comprising: (i) from about 10-50%, based on the total monomer weight, of methacrylic acid, (ii) from a small amount sufficient to cross-link the microgel particle up to about 5%, based on the total monomer weight, of divinylbenzene, (iii) from about 0 to about 50%, based on the total monomer weight, of methyl methacrylate, (iv) from about 0 to about 10%, based on the total monomer weight, of ethyl acrylate, vinyl acetate and mixtures thereof, and (v) from about 10 to about 90%, based on the total monomer weight, of styrene; c. adding and admixing together from about 10 to about 50% by weight, based on the total solids weight of the dispersion, of the microgel particles of step (b) to the solution of said film-forming resin; d. at least partially neutralizing the admixture with ammonia or a volatile organic amine in an amount sufficient to provide a pH of about 2 to about 10 to said aqueous dispersion; e. dispersing the admixture into an aqueous medium to provide a stable aqueous resin dispersion having a total solids content of from about 15 to about 40 weight percent; and f. adding from about 0 to about 10% by weight, based on the total solids weight of the dispersion, of an aminoplast resin to said aqueous resin dispersion. 7. The process of claim 6, wherein said monomer mixture comprises methacrylic acid, styrene, vinyl acetate and divinylbenzene. 8. The process of claim 6, wherein said monomer mixture comprises methacrylic acid, styrene. ethyl acrylate and divinylbenzene. 9. The process of claim 6, wherein said monomer mixture comprises methacrylic acid, styrene, ethyl acrylate, methyl methacrylate and divinylbenzene.
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