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| Resin denture base molding apparatus |
| In view of the aforementioned problems, it is an object of the present invention to provide an ... |
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| Dental material |
| OF PREFERRED EMBODIMENTS The foregoing object is achieved by impregnating communicating holes of a ... |
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| Dental mouthpiece and method of making same |
| OF PREFERRED EMBODIMENTS Referring to FIG. 1, there is seen an arch-shaped mouthpiece substrate 10.... |
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| Method for manufacturing a dental prosthesis |
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| Nozzle contact device of an injection machine |
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| Process for providing a decorative transfer in a molded product |
| In a first aspect, the present invention pertains to a decorative transfer including a backing and ... |
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| Means for centrifugally casting a plastic tubular member |
| Referring now in more detail and by reference characters to the drawings which illustrate a ... |
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| Methods for emplacing and maintaining transmission lines |
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| Hose reinforced with discontinuous fibers oriented in the radial direction |
| Referring to FIG. 1, hose 1 with a section removed illustrates a hose having fibers 2 oriented in ... |
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Microcapsules based on gelatin and polysaccharides and process for obtaining same
| Details |
Inventors: David, Jacky; Lefrancois, Claudine; Ridoux, Claude;
Assignee: Societe Anonyme: Mero Rousselot Satia (Paris, FR)
Primary Examiner: Lovering; Richard D.
Assistant Examiner: Covert; John M.
Attorney, Agent or Firm: Foley & Lardner
This invention relates to microcapsules based on gelatin and anionic polysaccharides of low molecular weight which may contain solid or liquid matters, prepared by coacervation. The aqueous polysaccharide solutions which may be used present a low viscosity, the value of which is a function of the nature of the polysaccharide; for a concentration of 15 g/l, it is, at 75.degree. C., generally between 1 and 20 mPa.s. These polysaccharides are depolymerization products of natural products:alginates, carragheenans, pectins and pectates, carboxymethylcelluloses, carboxymethylguars and carboxymethyl starches. The microcapsules may be isolated and dried. |
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DETAILED DESCRIPTION What is claimed is: 1.
A process for preparing microcapsules containing an encapsulated substance comprising a hydrophobic liquid or a water-insoluble solid, comprising the steps of: (a) emulsifying a hydrophobic liquid or suspending a water-insoluble solid in a gelatin solution, (b) adding a low molecular weight hydrosoluble anionic polysaccharide to the gelatin solution, wherein said polysaccharide is a chemically depolymerized polysaccharide selected from the group consisting of alginates, carragheenans, pectins, and pectates, carboxymethylcelluloses, carboxymethyl guars and carboxymethyl starches and the viscosity of a 15 g/l aqueous solution of said polysaccharide measured at 75.
degree.
C.
with a rotating Brookfield viscometer of type LVT equipped with a mobile UL at a speed of rotation of 6 rounds/minute is between about 1 and 20 mPa.
s, and (c) encapsulating the hydrophobic liquid or water-insoluble solid within microcapsules by complex coacervation of the gelatin and polysaccharide, with pH adjustment to the extent necessary, isolating the microcapsules, and drying the microcapsules after they are isolated.
2.
The process of claim 1, wherein the gelatin solution contains from 2.
5 to 150 g of gelatin per kg.
of solution.
3.
The process of claim 1, wherein the gelatin solution contains from 2.
5 to 150 g of gelatin per kg of solution.
4.
The process of claim 3, wherein the coacervation mixture comprises 1/5 to 1/4 by weight of alginate with respect to the gelatin.
5.
The process of claim 1, wherein the polysaccharide is a carragheenan having a viscosity between 1 and 10 mPa.
s.
6.
The process of claim 5, wherein the coacervation mixture comprises from 1/6 to 1/10 by weight of kappa carragheenan with respect to the gelatin.
7.
The process of claim 5, wherein the coacervation mixture comprises from 1/9 to 1/14 by weight of lambda carragheenan with respect to the gelatin.
8.
The process of claim 5, wherein the coacervation mixture comprises from 1/10 to 1/16 by weight of iota carragheenan with respect to the weight of gelatin
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Nonmetallic Processes 
