Polysaccharide-based thermoplastic material, process for preparing the same and method of use thereof

• US 6,362,330 B1
• Filed: 11/01/1999
• Issued: 03/26/2002
• Est. Priority Date: 04/05/1997
• Status: Expired due to Fees

• Current Assignee: Dow Wolff Cellulosics GMBH
• Original Assignee: Wolff Walsrode AG (Dow, Inc.)
• Inventors: Dijkstra, Dirk Jacques, Weber, Gunter, Simon, Joachim, Müller, Hanns-Peter
• Primary Examiner(s): Fonda, Kathleen Kalher
• Assistant Examiner(s): Maier, Leigh C.
• Application Number:
  US09/402,066
• Time in Patent Office: 876 Days
• Field of Search: 536/30, 536/32, 536/37, 536/38, 536/56, 536/66, 536/124, 525/54.2, 428/508, 428/532
• US Class Current: 536/30
• CPC Class Codes: C08B 13/00 Preparation of cellulose ether-esters
• CPC Class Codes: C08B 15/06 containing nitrogen , e.g. carbamates
• CPC Class Codes: C08B 31/00 Preparation of derivatives of starch derivatives of amylose C08B33/00; derivatives of amylopectin C08B35/00
• CPC Class Codes: Y10T 428/31884 Regenerated or modified cellulose
• CPC Class Codes: Y10T 428/31971 Of carbohydrate

Abstract

The present invention relates to novel thermoplastic materials based on polysaccharide ethers which are simultaneously substituted by carboxylic acid ester groups and carbamate groups, together with mixtures of such derivatives with low molecular weight aliphatic urea derivatives.

Claims

1. A thermoplastic polysaccharide-ether/carbamate/ester derivative of the general structure,

wherein R is H or a substituent having a structure selected from,

2. A thermoplastic molding composition comprising the polysaccharide-ether/carbamate/ester derivative of claim 1, and at least one conventional additive selected from the group consisting of plasticizers, impact resistance modifiers, flame retardants, anti-oxidants, UV protectors, nucleating agents and fillers.

3. A mixture comprising:

X) the thermoplastic polysaccharide-ether/carbamate/ester derivative of claim 1; and

Y) a low molecular weight, unbranched or branched, symmetrical or asymmetrical, aliphatic dialkyl urea derivative having chain lengths of from 1 to 20 carbon atoms,

wherein the molar ratio of X to Y is represented by the formula,

4. The thermoplastic polysaccharide-ether/carbamate/ester derivative of claim 1 wherein said thermoplastic polysaccharide-ether/carbamate/ester derivative is formed from the reaction of a) isocyanates or blocked isocyanates, and b) activated carboxylic acid derivatives with c) said polysaccharide ether, the thermoplastic polysaccharide-ether/carbamate/ester derivative having an overall degree of substitution (based on the anhydroglucose unit) of DS=0.3 to 3.0.

5. The thermoplastic polysaccharide-ether/carbamate/ester derivative of claim 4 having an overall degree of substitution of DS=0.6 to 2.8.

6. The thermoplastic polysaccharide-ether/carbamate/ester derivative of claim 1 wherein said polysaccharide ether is a cellulose ether having an average degree of substitution (MS) of 0.1 to 5, and said thermoplastic polysaccharide-ether/carbamate/ester derivative is a cellulose-ether/carbamate/ester derivative.

7. A method of producing a composition comprising the thermoplastic polysaccharide-ether/carbamate/ester derivative of claim 1 and a low molecular weight urea derivative, said method comprising,

(a) providing a first mixture comprising said polysaccharide ether, a catalyst, a solvent and water, said polysaccharide ether being insoluble in said solvent,

(b) forming a second mixture of a polysaccharide-ether/carbamate intermediate, said low molecular weight urea derivative and said solvent by adding an isocyanate to said first mixture, said polysaccharide-ether/carbamate intermediate and said low molecular weight urea derivative being soluble in said solvent,

(c) adding an activated carboxylic acid derivative to said second mixture, thereby forming said composition comprising the polysaccharide-ether/carbamate/ester derivative of claim 1 and said low molecular weight urea derivative, and

(d) optionally isolating said composition comprising the polysaccharide-ether/carbamate/ester derivative of claim 1 and said low molecular weight urea derivative.