JP3132882B2 - Thixotropic carboxymethylcellulose sodium composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Object of the invention]

The present invention relates to a low viscosity sodium carboxymethyl cellulose (hereinafter abbreviated as "CMC") composition having a high thixotropic property (thixotropic).

[0002]

2. Description of the Related Art (1) Background of the Invention An aqueous solution of CMC is characterized by having thixotropic properties (thixotropic), but this property becomes less noticeable as the viscosity decreases. However, for example, when CMC is used as a food additive for enhancing the gel strength of jelly, high viscosity CMC having high thixotropy is not preferable from the viewpoint of texture. You.

(2) Problems in the prior art In view of the above demands, thixotropy has been examined from both aspects of the invention in the carboxymethylation reaction of cellulose and the selection of additives. There are problems such as a rise and a decrease in production efficiency, and the latter inevitably causes problems such as the influence of additives. In particular, in the case of a low-viscosity CMC in which the viscosity of a 2% aqueous solution is about 10 to 50 mPa · s, thixotropic property is increased even when the concentration is increased to about 10,000 mpa · s, as compared with a low viscosity product of about 100 mpa · s. Has never been possible before.

[0004]

Accordingly, the present invention provides a 2% liquid having a viscosity of 10 to 50 mpa · s without increasing the cost.
It is an object of the present invention to provide a means for effectively increasing the thixotropic properties of CMC having a low viscosity.

[0005]

[Means for Solving the Problems]

(1) Concept However, as a result of research, the present inventor has found that, by adding a high-viscosity CMC within a certain quantitative range to a low-viscosity CMC, the viscosity does not simply become the average value of the two, and the characteristics of the low-viscosity CMC With great thixotropy while maintaining
It has been found that the C composition can be obtained.

(2) Outline Based on the above findings, the present invention provides a 2% aqueous solution having a viscosity of 10%.
80-95% by weight of low-viscosity sodium carboxymethylcellulose having a viscosity of ~ 50mpa · s
The gist of the present invention is a thixotropic sodium carboxymethylcellulose composition, which is a mixture of 5 to 20% by weight (total amount: 100% by weight) of sodium carboxymethylcellulose having a high viscosity of 10,000 mpa · s.

(3) Evaluation method for thixotropy (a) Instrument used: BH type viscometer manufactured by Tokyo Keiki (b) Measurement method: (a) Adjusting the concentration according to the intrinsic viscosity of sample CMC to 1000
Prepare a CMC aqueous solution of 0 ± 500 mpa · s, stir well, wrap and leave in a 25 ° C. thermostat overnight. (b) Remove from the thermostat and stir well with a glass rod. (c) Using a BH type viscometer and rotor No. 5, each sample was measured for its viscosity at 2 rpm and 20 rpm using a BH-type viscometer. .pm
It is made thixotropic by the quotient of the viscosity at the time. The smaller this value, the greater the thixotropic property.

[0008] Thixotropy = viscosity (20 rpm)
Viscosity (2 rpm)

(4) Compounding ratio The compounding ratio (weight ratio) of high viscosity CMC (H) to low viscosity CMC (L) is L: H = 95: 5 as described in the above item (2).
Suitably, it is in the range of ~ 80: 20. High viscosity CM
When the content of C (H) is less than 5% by weight, the effect of increasing the thixotropic property is poor. Conversely, when the content of CMC (H) exceeds 20% by weight, the whole becomes high in viscosity and can be said to be low viscosity CMC. (The viscosity at a 2% concentration of low viscosity CMC is generally 100 mpa · s or less).

[0010]

As shown in the following Examples, even when high-viscosity CMC is mixed at a ratio of 20% by weight or less with respect to the whole composition, the thixotropy is estimated from the average value, though the viscosity does not increase so much. It will improve above. The reason for this is not clear, but under dynamic conditions, high viscosity CMC is contained in low viscosity CMC particles.
Molecules enter and show the behavior of low viscosity CMC as a whole, but under static conditions, a network of denser polymer CMC becomes entangled with a network of low viscosity CMC molecules, forming a strong gel state overall It is supposed to do.

[0011]

The embodiments of the present invention will be described below with reference to examples. However, the exemplification is merely for explanation, and does not mean limitation or limitation of the inventive idea.

Example 1 The viscosity and thixotropy (PVI value) of 2% aqueous solutions of various CMC samples were determined. Table 1 below shows the replacement degree of each sample.
Shown in

[0013]

[Table 1]

Examples 2 to 4, 5 to 7 and 8 to 10 and Comparative Examples 1 to 3 Each of the aqueous solutions obtained by mixing the respective samples shown in Table 1 above in various ratios was used.
% Solution (25 ° C.) and thixotropy. The results are shown in Table 2 below. Examples 2 to 4 and 5 to 5
The reason why Samples B, E and H were adopted in Examples 7 and 8 to 10 was to make the viscosity of the test liquid as uniform as possible.

[0015]

[Table 2]

As shown in the above table, the thixotropic properties of compositions containing 5% or more of high-viscosity CMC are remarkably improved as compared with those of a single composition. The composition of Example 8 containing only 5% of a high-viscosity CMC having a substitution degree of 2.10 has a thixotropic coefficient of 25%.
It shows a remarkable effect of improving.

Example 11 A camphor ointment was prepared as a trial according to the following formulation, and the degree of sagging was evaluated. The tested CMCs are those of Examples 3, 8 to 10 and Comparative Examples 1 and 3.

[0018]

[Results] As shown in Table 3 below.

[Table 3]

As shown in the above table, the CMC composition of the present invention is not only excellent in gelling property itself, but also gives a smooth feel peculiar to a low-viscosity product when applied with a finger. Since it has the property of giving consistency, it has excellent performance as a base material for ointments.

[0021]

As described above, according to the present invention, by mixing a relatively small amount of a high-viscosity CMC with a low-viscosity CMC, a CMC aqueous solution having a large thixotropic property can be obtained without increasing the overall viscosity. Obtainable. This improves the water retention, gel forming ability and viscosity of the formulation. Therefore, the composition of the present invention is for general industrial use,
It has promising uses as a paste for foods, medicines, cosmetics, a gelling agent, a thickener, a shape retention agent, a water retention material, and the like.

Claims (1)

(57) [Claims] 1. A low-viscosity sodium carboxymethylcellulose having a viscosity of 10 to 50 mpa · s and a high viscosity carboxymethylcellulose having a viscosity of 1000 to 10,000 mpa · s. Sodium 5-20
A thixotropic sodium carboxymethylcellulose composition which is a mixture of 100% by weight (100% by weight in total).