DE1470825A1 - Process for the production of micro-cellulose crystallite aggregates - Google Patents

Description

Dr E Wetzel «οονοπ ·« «!. -19 September 1968

LJt m L · .. »» OlAUI Hetnereplatz3 Telephone 0911 / 204081-83

- ^. . . r- T * _ Tel * 08/22327 Telegram Patweto!

Dipl.-Ing. E. Tergau U 7 O 8 2 5 ° --- »■ - ** ·. ^ - 3ββ «ο

Stadteparkaiee Nuremberg 63835

Patent attorneys ^potitch * ^{eiiiioni0 Nürnb # rg 111β1}

- Always enter under the sign blue -

25/33

70 825.9 "

PMC Corporation, Philadelphia, Pa / USA

Process for the production of micro-cellulose crystallite aggregates

The invention relates to a method for obtaining fiber-free micro-cellulose crystallite aggregates in powder form from cellulose crystallite aggregates. For the sake of simplicity, the following Execution the words cellulose crystallite aggregate duroh CKA and micro-cellulose crystallite aggregates by MCKA abbreviated.

The production of fiber-free CKA and MCKA can be assumed to be known (French patent specification 1 194 486 and the references cited herein). The basis for obtaining the CKA is the treatment of native or regenerated Cellulose duroh acid hydrolysis under conditions which lead to a substantially uniform average degree of polymerization. The fibrous, amorphous components dissolved out. The cellulose obtained in this way is in the form of CKA, which can be washed in water Medium to be freed from the acid. To get MCKA, the CKA are comminuted with or without prior drying in an aqueous medium (cf. also DAS 1 123 460 according to application A 28 768),

909813/1371

(Art. ) S ι ^<Λ ζ $$ ^ Λ'ν * "^ ^ll V.-f'i {'#! / ^! FÜS' ^ul ' ¹ ''* ⁴ " ^J '

U70Q25

Han can now increase the solids content in the aqueous medium and transfer the dispersion into a gel. With increasing pesticide content, a paste-like mass is obtained and Finally, a mass that feels dry, but not dry in the real sense, since it still has something else Contains a certain proportion of the dispersant.

The invention is concerned with the task of MCKA in a To obtain form in which they not only appear dry, but are actually a dry powder. The need after such a dry powder exists in particular for use in the food and beverage industry as Bulking agent, as cellulose is not absorbed by the human body and, as a result, does not make you fat. It has namely shown that the only dry appearing MCKA is difficult to integrate sufficiently homogeneously into the mass of the food or Stimulants can be introduced, so that, as I said, the task arose, the MCKA as an actually dry powder to obtain. One could have started from dried CKA and mechanically crushed it. But one such micro-grinding equipment is expensive; the grinding process would take a relatively long time. The invention therefore takes a different approach, namely, the comminution process, as before, in an aqueous one Medium to be laid, but then subsequently to separate the MCKA formed in this way duroh freeze-drying from the aqueous medium. So the desired dry powder is divided into two

909813/13 7 1

U70R25

Steps gained, in a first step in which the CKA are comminuted in the aqueous medium to MCKA, and a second step in which these MCKA are separated from the aqueous medium in powder form by freeze-drying.

It has been shown that in this way with little grinding and expenditure of time a powder with a very low bulk density, about 0.157 g / ocm, which is soft and is porous and creates a pleasant mouthfeel. However, the field of food and genetics is not the only one Application area of the powder. There are a number of other cases when there is a need for a dry powder of MCKA. This powder is a new and valuable product in cellulose technology.

909813/13 7

Claims (1)

U70825 Claim Process for the production of fiber-free micro-cellulose crystallite aggregates in powder form from cellulose crystallite aggregates which are obtained by acid hydrolysis of cellulose under conditions which lead to an essentially uniform degree of polymerization which, after hydrolysis, is washed out by the acid are freed and then comminuted derafct in an aqueous medium, that at least 1% of the crystallite aggregates having a particle size of less than 1 μ, characterized in that the thus formed micro-cellulose crystallite aggregates by (known per se). Freeze drying can be separated as a powder from the aqueous medium. 909813/137