Nonionic cellulose ethers

Claim 2

NONIONIC CELLULOSE ETHERS HAVING ATTACHED TO THE CELLULOSE MOLECULE HYDROXETHYL GROUPS IN A MOLECULAR SUBSTITUTION WITHIN THE RANGE FROM ABOUT 0.1 TO ABOUT 2.5, HYDROXYALKYL GROUPS SELECTED FROM THE GROUP CONSISTING OF HYDROXYPROPYL AND HYDROXYBUTYL IN A MOLECULAR SUBSTITUTION WITHIN THE RANGE FROM ABOUT 0.1 TO ABOUT 4, AND ALKYL GROUPS HAVING FROM 2 TO 4 CARBON ATOMS IN A DEGREE OF SUBSTITUTION WITHIN THE RANGE FROM ABOUT 0.05 TO ABOUT 1.5.

Claim 3

Nonionic cellulose ethers according to claim 1, in which the molecular substitution of the hydroxyethyl groups is within the range from about 0.2 to about 1, the molecular substitution of the hydroxyalkyl groups is within the range from about 0.5 to about 2.5, and the degree of substitution of the alkyl groups is within the range from about 0.1 to about 1.

Claim 4

Nonionic cellulose ethers according to claim 1, in which the molecular and degree of substitution of the ether substituents are taken within the stated ranges so as to render the cellulose ether water-soluble.

Claim 5

Nonionic cellulose ethers according to claim 1, in which the molecular and degree of substitution of the ether substituents are taken within the stated ranges so as to render the cellulose ether organic solvent-soluble.

Claim 6

Nonionic cellulose ethers according to claim 1, having hydroxyethyl, hydroxypropyl, and ethyl substitutents.

Claim 7

Nonionic cellulose ethers according to claim 1, having hydroxyethyl, hydroxybutyl, and ethyl substitutents.

Claim 8

Nonionic cellulose ethers according to claim 1, having hydroxyethyl, hydroxypropyl, hydroxybutyl and ethyl substituents.

Claim 9

A process for preparing nonionic cellulose ethers having as ether substituents hydroxyethyl groups, hydroxyalkyl groups selected from the group consisting of hydroxypropyl and hydroxybutyl groups, and alkyl groups having from two to four carbon atoms, which comprises reacting alkali cellulose mercerized with aqueous alkali hydroxide solution with ethylene oxide, an alkylene oxide selected from the group consisting of propylene oxide and butylene oxide, and an alkyl halide having from two to four carbon atoms, in an organic reaction medium and recovering the resulting cellulose ether from The reaction medium.

Claim 10

A process for preparing nonionic cellulose ethers having as ether substituents hydroxyethyl groups, hydroxyalkyl groups selected from the group consisting of hydroxypropyl and hydroxybutyl groups, and alkyl groups having from two to four carbon atoms, which comprises reacting alkali cellulose mercerized with aqueous alkali hydroxide solution with ethylene oxide, an alkylene oxide selected from the group consisting of propylene oxide and butylene oxide, and an alkyl halide having from two to four carbon atoms, in an organic reaction medium and recovering the resulting cellulose ether from The reaction medium.

Claim 11

A process according to claim 8, which includes washing the resulting cellulose ether, neutralizing remaining alkali hydroxide, and drying the cellulose ether to a solids content of above 90%.

Claim 12

A process according to claim 8, in which the organic reaction medium comprises an alkyl halide having from two to four carbon atoms.

Claim 13

A process according to claim 8, in which the alkoxylation is carried out at a temperature within the range from about 50* to about 75*C.

Claim 14

A process according to claim 8, in which the alkylation is carried out with alkyl halide serving also as reaction medium in an amount within the range from about 0.2 to about 5 parts per part of cellulose at a temperature within the range from about 70* to about 120*C.

Claim 15

A process according to claim 8, in which the alkoxylation is carried out in two steps, ethylene oxide being charged in the first step and propylene oxide and/or butylene oxide being charged together with any additional ethylene oxide in the steps which follow.

Claim 16

A process according to claim 8, in which the cellulose ether reaction product is neutralized and then washed in at least two washing steps, the cellulose ether being brought to a solids content of at least 60% in the first washing step and to at least 90% in the later washing step.