JP2001172395A - Method for producing polymer solution - Google Patents

Abstract

(57) Abstract: A solvent is stirred by a stirrer, air bubbles are entrained in the solvent to form a gas-liquid dispersion, and a polymer powder is charged into the gas-liquid dispersion to swell. Dissolve [Effect] In a general-purpose stirring tank, it is possible to prevent lumps of the polymer by a simple method and efficiently swell and dissolve the polymer efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a uniform polymer solution in a short time by swelling and dissolving a polymer blended in cosmetics, detergents and the like without producing lumps.

[0002]

2. Description of the Related Art Generally, when a polymer compounded in a composition such as a cosmetic or a detergent is brought into contact with a solvent, it forms undissolved substances such as lumps and cages and takes a long time to swell and dissolve. In order to solve this, various methods have been proposed. For example, 30 ° C. or less with a high-speed
A method in which a water-soluble polymer is put into water within 0 seconds, and the temperature is raised immediately (Japanese Patent Laid-Open No. 8-283418). Put the solvent in a tank with a constant temperature jacket and put the temperature at 30-39 ° C
Then, the mixture is stirred so that the stirring Reynolds number becomes 2.0 × 10 ⁵ or more, the polymer powder is charged, and after the dispersion, the temperature is raised to 40 ° C. at a rate of 1 ° C./min or more. ~ 60 ° C
(JP-A-11-209476).
A method of mixing a powder inhibitor (such as cellulose) having an affinity for a solvent with a polymer powder (JP-A-11-197476).
Publication). These methods require special stirrers, strict temperature control, and the need to add a third substance. Therefore, a simple method using a general-purpose stirring tank has been desired.

[0003]

Accordingly, an object of the present invention is to provide a method for preventing lumping of a polymer by a simple method and efficiently swelling and dissolving the polymer uniformly in a general-purpose stirring tank. With the goal.

[0004]

Means for Solving the Problems and Embodiments of the Invention As a result of intensive studies, the present inventors have found that bubbles in a solvent can suppress aggregation of polymer powder particles and prevent lumping. The present invention has been completed. That is, the present invention uses a stirring tank to swell and dissolve polymer powder in a solvent to produce a polymer solution.When the polymer solution is produced, the solvent is stirred by a stirrer, bubbles are entrained in the solvent, and gas-liquid This is a method for producing a polymer solution by forming a dispersion, adding polymer powder to the gas-liquid dispersion, and swelling and dissolving the polymer powder.

Hereinafter, the present invention will be described in more detail.
In addition,% indication of the blending amount described below means mass%. In the method for producing a polymer solution according to the present invention, first, as a first step, one part or all of a solvent necessary for producing a polymer solution is charged into a stirring tank, and the mixture is stirred to introduce air bubbles into the solvent and evaporate. Forming a liquid dispersion;

In the present invention, as the stirring tank, a general-purpose stirring tank such as a paddle, a propeller, a turbine, and a pulsator can be used. As shown in FIG. 1, for example, the stirring state in which air bubbles are entrapped in the solvent is a ratio Z between the depth (L) of the vortex generated by stirring and the height (H) of the stationary liquid surface when stirring is stopped. = L / H x 100 (%) is 5
It is preferable to stir in a state of 0% or more, particularly 50 to 85%.

Next, as a second step, the above-mentioned energy
The polymer powder is charged into the liquid dispersion and swelled and dissolved. It is preferable that the polymer powder is charged at a speed lower than the speed at which the powder charged on the liquid surface is wound into the liquid. A gas-liquid dispersion of the first step is prepared by using one part of the total amount of the solvent necessary for the production of the polymer solution, and the polymer powder is added thereto.
After the dispersion, the remaining solvent may be added. When the polymer powder is entrained in the gas-liquid dispersion and uniformly dispersed and starts to swell and dissolve, the viscosity of the dispersion gradually increases, so that the depth of the vortex gradually decreases, and thus the No air bubbles get caught in the air. In such a state, bubbles in the dispersion liquid gradually escape, and almost no bubbles remain in the liquid by the time the swelling and dissolution of the polymer is completed. When the viscosity of the polymer solution increases rapidly, bubbles may not be removed. The present invention is particularly preferably applied to a polymer-solvent system in which bubbles in a solvent escape during the swelling and dissolution of the polymer.

The solvent used in the present invention includes water, alcohols, polyhydric alcohols, oils (oils, fats, fatty acids, hydrocarbons, esters, etc.) or mixtures thereof, or surfactants, polymers, Those in which other components such as a preservative, an antibacterial agent, a dispersion stabilizer (such as sodium pyrophosphate), and a pH adjuster are dissolved can also be used as appropriate. Particularly preferred is an aqueous solvent.

The polymer powder used in the present invention includes:
Preferably, the powder has a bulk density of 1.0 g / cm ³ or less.
Examples of the polymer include, but are not particularly limited to, for example, cellulose derivatives such as carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, hydroxypropylmethylcellulose, and hydroxyethylcellulose; natural polymers such as xanthan gum and guar gum; carboxyvinyl polymer; polyacrylic acid; Synthetic polymers such as (meth) acrylic acid-based copolymers are exemplified. In particular,
Swelling and dissolution of cellulose derivatives, xanthan gum, carboxyvinyl polymer and the like have a remarkable effect, and it is preferable to apply the present invention to these.

[0010]

According to the method for producing a polymer solution of the present invention, it is possible to prevent lumping of a polymer by a simple method in a general-purpose stirring tank and efficiently swell and dissolve the polymer efficiently. it can.

Examples and Comparative Examples Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[0012]

Example 1 A 500-ml glass container was charged with 250 g of water, and a stirrer equipped with three propeller blades having a diameter of 38 mm was installed at the center of the container and stirred at 800 rpm. At this time, the ratio Z of the vortex depth to the static liquid level was 60%, and the internal solution was in a state in which bubbles were involved. The polymer powder A shown in Table 1 was added to this bubble dispersion liquid.
When 1.25 g was charged in 10 seconds, it was uniformly dispersed in the liquid without lumping. Add 250g of water,
When the stirring was continued, all of the added polymer powder was swollen and dissolved in 20 minutes, and a polymer solution without bubbles could be obtained.

[0013]

Example 2 The procedure was performed in the same manner as in Example 1 except that the stirring device was installed at an intermediate position between the vessel wall and the center. The Z of the gas-liquid dispersion is 65%, the polymer powder is uniformly dispersed in the liquid without lumping, and the added polymer powder swells and dissolves in 25 minutes, and is a polymer without bubbles. A solution could be obtained.

[0014]

Example 3 2000 g of water was put into a 5 liter glass container, and a stirrer equipped with four 38 mm-diameter paddles was installed at the center of the container and stirred at 1200 rpm. The Z of the gas-liquid dispersion was 60%. When 20 g of the polymer powder C shown in Table 1 was added to the bubble dispersion in 20 seconds, the dispersion was uniformly dispersed in the liquid without lumping. . When 2000 g of water was further added and stirring was continued, the polymer powder added was swollen and dissolved in 20 minutes.
A polymer solution without bubbles could be obtained.

[0015]

Example 4 2000 g of water was put into a 5 liter glass container, and a stirrer equipped with four 38 mm-diameter paddles was installed at the center of the container and stirred at 2300 rpm. The Z of the gas-liquid dispersion was 80%. When 40 g of the polymer powder A shown in Table 1 was added to this bubble dispersion in 20 seconds, they were uniformly dispersed in the liquid without lumping. . Further, 2000 g of water was added, and the number of rotations was set to 1000 rpm.
m and continued stirring. At this time, Z was 30%, and the polymer powder was all swollen and dissolved in 20 minutes, so that a polymer solution without bubbles could be obtained.

[0016]

Example 5 3500 g of water was put into a 15-liter glass container, and stirred at 350 rpm by a stirrer equipped with a pulsator having a diameter of 100 mm. Z of the gas-liquid dispersion was 80%, and 70 g of the polymer powder B shown in Table 1 was added to this bubble dispersion in 20 seconds. The dispersion was uniformly dispersed in the liquid without lumping. . Further, 3000 g of a 1/1 (weight ratio) mixed solution of water and ethanol was added, and stirring was continued. As a result, all the polymer powder was swollen and dissolved in 20 minutes, and a polymer solution without bubbles could be obtained. .

[0017]

Comparative Example 1 2000 g of water was put into a 5-liter glass container, and a stirrer equipped with four paddles having a diameter of 38 mm and attached to the center of the container was stirred at 600 rpm. The Z of the dispersion was 30%, and the polymer powder C shown in Table 1 was gradually added to the dispersion. It took a minute.
In addition, despite the very small amount of about 13 times less than 20 g of the powder that could be dissolved in Example 3, the powder entrapped in the liquid was lumped and swelled and dissolved for 60 minutes. Cost.

[0018]

Comparative Example 2 2000 g of water was put into a 5-liter glass container, and a stirrer equipped with four paddles having a diameter of 38 mm and attached to the center of the container was stirred at 500 rpm. The dispersion had a Z of 30%. To this dispersion, 40 g of the polymer powder A shown in Table 1 was gradually added. Compared with Example 4, it took 10 minutes to entangle the powder. Cost me. Moreover, the powder entrained in the liquid is lumpy, and even if the rotation speed is increased to 2300 rpm, the powder is swelled and dissolved by 6 times.
It took 0 minutes.

[0019]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a diagram showing a stirring state of the present invention.

Claims (1)

[Claims] When a polymer solution is produced by swelling and dissolving a polymer powder in a solvent using a stirring tank, the solvent is stirred by a stirrer, air bubbles are entrained in the solvent, and gas-liquid dispersion is performed. A method for producing a polymer solution, comprising forming a liquid, charging a polymer powder into the gas-liquid dispersion, and swelling and dissolving.