Mixed starch esters and the use thereof
AssigneeThe Sherwin-Williams Company
InventorsStephen Edward Rudolph, Raymond Charles Glowaky
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Abstract
This invention is directed to mixed esters of starch and to the method of preparing and the use of said starch esters which are derived from (a) low molecular weight hydrolyzed starch having a plurality of anhydroglucose units and (b) at least about 0.5 mole of acylating agent per anhydroglucose unit consisting of mono- and polycarboxylic acid anhydrides and acyl halides. These anionic esters of starch with average molecular weights ranging up to 100,000 are characterized as having a high degree of substitution, i.e. ranging up to 3.0 wherein at least about 0.1 of the total degree of substitution consist of ester groups having pendant carboxyl radicals derived from anhydrides of polycarboxylic acids.
Claims43
Mixed esters of starch characterized as having an average molecular weight ranging up to about 100,000 and an average degree of substitution ranging from about 0.5 to 3.0 wherein at least about 0.1 of the total degree of substitution consists of ester groups having pendant carboxyl groups;
- said esters of starch derived from
- a. low molecular weight hydrolyzed starch and the derivatives thereof having a plurality of anhydroglucose units and
- b. at least about 0.5 mole of acylating agent for each anhydroglucose unit of the hydrolyzed starch and the derivatives thereof;
- said acylating agent consisting of (i) from about 0.1 to 2.9 moles of at least one anhydride of a polycarboxylic acid and (ii) from about 0.1 to 2.9 moles of at least one agent selected from the class consisting of anhydrides of monocarboxylic acids and the acyl halides of monocarboxylic acids.
Mixed esters of starch characterized as having an average molecular weight ranging up to about 100,000 and an average degree of substitution ranging from about 1.0 to 3.0 wherein at least about 0.1 of the total degree of substitution consists of ester groups having pendant carboxyl groups;
- said esters of starch derived from
- a. low molecular weight hydrolyzed starch and the derivatives thereof having a dextrose equivalent value ranging up to about 40 and a plurality of anhydroglucose units and
- b. at least about 1.0 mole of acylating agent for each anhydroglucose unit of hydrolyzed starch and the derivatives thereof;
- said acylating agent consisting of (i) from about 0.3 to 2.3 mole of at least one anhydride of a polycarboxylic acid and (ii) from about 0.7 to 2.7 moles of at least one agent selected from the class consisting of anhydrides of monocarboxylic acids and acyl halides of monocarboxylic acids.
A process for preparing mixed esters of starch characterized as having an average molecular weight ranging up to about 100,000 and an average degree of substitution ranging from about 0.5 to 3.0, wherein at least about 0.1 of the total degree of substitution consists of ester groups having pendant carboxyl groups;
- which comprises reacting in an organic medium substantially free of water at temperatures ranging up to about 150.degree. C;
- a. low molecular weight hydrolyzed starch and the derivatives thereof having a plurality of anhydroglucose units and
- b. at least about 0.5 mole of acylating agent for each anhydroglucose unit of the hydrolyzed starch and the derivatives thereof;
- said acylating agent consisting of (i) from about 0.1 to 2.9 moles of at least one anhydride of a polycarboxylic acid and (ii) from about 0.1 to 2.9 of at least one agent selected from the class consisting of the anhydrides of monocarboxylic acids and the acyl halides of monocarboxylic acids.
Dependencies are inferred from the claim text.