JPH05247435A - Aqueous dispersion viscosity modifier composition - Google Patents

Abstract

PURPOSE:To provide a viscosity modifier in the form of an aq. dispersion which manifests a thickening action for a short time and minimizes the amt. of variation of viscosity with time. CONSTITUTION:The title compsn. comprises a liquid A contg. a synthetic clay mineral such as Laponite RD mixed with and dispersed in water, a liquid B of an org. thickener such as a polyol thickener, and an aq. solution C of a salt such as magnesium chloride. The synthetic clay mineral is homogeneous in composition, great in thickening effect and stable in quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-dispersed viscosity modifier composition, and more specifically, to the viscosity adjustment of a water-based suspension of agricultural chemicals such as water-based paints, water-based liquid detergents, water-based flowables or cosmetics The present invention relates to a water dispersion viscosity modifier composition containing a synthetic clay mineral, which is used as an agent.

[0002]

BACKGROUND OF THE INVENTION Bentonite, which is a typical substance of an inorganic thickener, has a property of swelling several times when water is added, and has conventionally been used for drilling mud. It is used in many industrial fields such as and sand-type binders for casting. This bentonite is composed of montmorillonite and beidellite-based smectite group minerals as constituent minerals. In addition to the aforementioned montmorillonite and beidellite, nontronite, saponite, hectorite,
It is well known that minerals such as sauconite are contained.

All of these smectite group clay minerals have swelling properties and are used in various industrial fields because of their large thickening effect in their aqueous dispersions.

Generally, among these clay minerals, naturally occurring clay minerals are often produced in a mixed form of various minerals or contain various metals as impurities, and variations in coloring and thickening effects occur. There is a problem in terms of quality.

[0005] In order to improve the problems of these natural products, some purification of naturally occurring clay minerals has been carried out, but the above problems have not been completely solved.

On the other hand, in order to solve these problems of natural products, various kinds of clay minerals have been synthesized, which are colorless or white as compared with natural products, have a uniform composition and few impurities, and are aqueous dispersions. The demand field is expanding due to the fact that the thickening effect when prepared as described above is large and the quality is stable at the same time.

The use of these synthetic clay minerals is for the purpose of thickening suspensions in water such as aqueous paints, liquid detergents, agricultural chemicals or cosmetics, which have been difficult to use with conventional natural products, or preventing sedimentation. It has started to be used as a viscosity modifier for the purpose.

[0008] In these fields of application, it is generally about 100 centipoise to tens of thousands centipoise, and especially 500 to
There is a demand for a thickener that gives stable viscosity characteristics in a viscosity range of about 3000 centipoise.

Organic thickeners have also been used in these fields, but they have not been able to give completely stable viscosity characteristics, and are satisfactory because they have different viscosity characteristics from inorganic thickeners. It hasn't arrived yet.

Clay minerals are generally characterized in that they have a high thickening effect in a low shear region when prepared in an aqueous dispersion. Particularly, synthetic clay minerals have finer basic particles than natural products. Since the BET specific surface area is high, the thickening performance is also high. For example, when adjusting to the same viscosity, it has an advantage that a small amount is used, but it has a demerit that it takes a long time to develop the thickening effect. It was

That is, when these synthetic clay minerals are used alone, they have such a thickening property that they are completely gelled even in an aqueous dispersion containing 2 to 3% by weight. The time until the effect is exerted, for example, in a simple system consisting only of water and synthetic clay minerals, a thickening action gradually appears and the viscosity rises, and it takes 1-2 weeks until the performance is completely exerted.
If it is long, it may take as long as one month. Further, the amount of change in viscosity over time during this period may be very large.

When used in various industrial fields, it is desired that the time until the onset of viscosity increase is short, and the stability of the viscosity over time is such that the amount of change is within about ± 10% of the average viscosity value. What is adjusted is desired. Therefore, there has been a strong demand for shortening the time until the thickening of the aqueous dispersion of these synthetic clay minerals occurs and reducing the change in viscosity over time.

[0013]

[Means for Solving the Problems] The present inventors have earnestly conducted research on a formulation for shortening the development of thickening and reducing the change in viscosity over time of an aqueous dispersion containing a synthetic clay mineral. As a result, they have found that by adding an organic thickener and a salt to an aqueous dispersion of synthetic clay mineral, it is possible to shorten the expression of thickening and reduce the change in viscosity over time, and completed the present invention.

That is, the present invention comprises a water-dispersed viscosity modifier composition characterized by containing water, a thickened synthetic clay mineral, an organic thickener and a salt (hereinafter referred to as the present composition).
Is provided.

The synthetic clay mineral used in the composition of the present invention may be a synthetic product having a thickening effect. For example, as described above, montmorillonite, beidellite, nontronite, saponite, hectorite or sauconite. Compounds such as smectite group clay minerals can be used. These synthetic clay minerals may be used alone or as a mixture of two or more, and the ratio in the case of mixing can be freely selected.

The organic thickener used in the composition of the present invention is not particularly limited, and various natural, synthetic or semi-synthetic water-soluble polymer compounds which are usually used as thickeners are used. can do. Examples of organic thickeners that can be used include various gums such as guar gum, locust bean gum, quince seed gum, tara gum, tragacanth gum, karaya gum, xanthan gum (xanthan gum), welan gum, rhamzan gum, carrageenan, and arabic gum. , Sodium alginate, ammonium alginate, alginic acid derivatives such as propylene glycol alginate, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methacrylate, polyethylene oxide, polyacrylic acid, sodium polyacrylate, polyacrylamide, etc. , Natural products such as dextrin, pectin, gelatin, casein, glue, albumin, water-soluble polymer compounds, methylcellulose, carboxymethyi Cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, cellulose derivatives such as hydroxypropyl cellulose, sodium carboxymethyl starch, can be exemplified such as starch derivatives such as hydroxyethyl starch. These organic thickeners are
For example, Agrisol (commercial product of Kao), Kelzan, Jaguar, Emcogum (commercial product of Sansan Co., Ltd.), Rhodpole (commercial product of Rhone-Poulin), Gohsenol (commercial product of Nippon Synthetic Chemical Co., Ltd.), Rheozic (Nippon Pure). Commercially available products such as Yakuhin Co., Ltd., Carbopol (B. F. Goodrich Co., Ltd. product) and Natrosol (Nissho Iwai Co., Ltd. product) can be used. These organic thickeners may be used alone or in combination of two or more, and the ratio in the case of mixing can be freely selected.

The salt used in the composition of the present invention is not particularly limited, and various inorganic or organic acids such as alkali metal, alkaline earth metal, aluminum, manganese, iron,
Various 1 to 3 valent metal salts such as copper and zinc and ammonium salts can be used. Salts that can be used include
Examples thereof include sodium chloride, potassium chloride, magnesium chloride, calcium chloride, aluminum chloride, ammonium chloride, sodium sulfate, magnesium sulfate, ammonium sulfate, ammonium nitrate, potassium bromide, sodium acetate, ammonium acetate and the like. These salts may be used alone or in combination of two or more, and the ratio in the case of mixing can be freely selected. The composition of the present invention is a water dispersion viscosity modifier composition containing water, a synthetic clay mineral, an organic thickener and a salt. Among these constituents, a water dispersion of only two components, a synthetic clay mineral and a salt, is carried out. In the liquid compounding system, it is possible to accelerate the onset of thickening of the synthetic clay mineral by adding salt to some extent, but it is not possible to obtain stability of viscosity with time. Further, in an aqueous dispersion liquid compounding system containing only two components, a synthetic clay mineral and an organic thickener, it takes a long time to develop thickening, and similarly, a satisfactory result cannot be obtained. Satisfactory results can be obtained only in the case of an aqueous dispersion compounding system in which the synthetic clay mineral which is the composition of the present invention, an organic thickener and a salt are simultaneously used.

The amount of each component used in the composition of the present invention can be appropriately selected depending on the intended system and the target viscosity to be achieved. In general, the amount of the synthetic clay mineral used in the composition of the present invention is preferably about 3 wt% or less based on the whole system. The amount of the organic thickener used in the composition of the present invention is generally 0.
It is preferably in the range of about 1 to 10 times, and the amount of salt used varies depending on the type of salt, but is generally 50 to 5000 ppm (wt / wt%) as the concentration in the total dispersion.
It is preferable to prepare in the range of

[0019]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples. Example 1 ² g of commercially available synthetic clay mineral Laponite RD (synthetic hectorite having a BET specific surface area of 380 m ² / g; manufactured by Nihon Silica Kogyo Co., Ltd.) was weighed and mixed with 98 g of distilled water (auto homomixer). , Made by Tokushu Kika Kogyo, 40mmφ
Dissolver blade, 1000 rpm, dispersion for 10 minutes)
Then, it was used as a premix dispersion liquid (liquid A) of 2% synthetic clay mineral. Aglycol (polyol-based thickener; product of Kao Corporation, nonvolatile content: 15 wt%), which is a commercially available organic thickener, was used as the liquid B in a liquid state. A 0.2 wt% aqueous solution of magnesium chloride was prepared in advance and used as the C liquid. When preparing each liquid, the total amount is 15
Weigh a balance amount of distilled water calculated to be 0 g,
In the following order, 60 g of solution A, 30 g of solution B, and 22.5 g of solution C were weighed out. For stirring, use the auto homomixer described above, and
Dispersed at 200 rpm for 5 minutes. During this period, all temperatures were adjusted to room temperature.

The viscosity of the prepared synthetic clay mineral aqueous dispersion was measured as shown below, after the passage of time, using a BL type viscometer, rotor No. Two
Was used and the viscosity was read after 4 minutes at 30 rpm.

Initial viscosity value (aged for 20 minutes): A, B, and C preparations were aged in a water bath at 20 ° C. for 20 minutes,
Measure viscosity.

1-day time-dependent viscosity value;
After aging for 1 day in a constant temperature bath at 0 ° C, and after aging for 2 hours in a water bath at 20 ° C, the viscosity was measured.

Similarly, after aging at 40 ° C., the temperature was cooled to 20 ° C., and the 7-day aging viscosity value and the 28-day aging viscosity value were measured.

The results are shown in Table 1. Examples 2 to 7 As the synthetic clay mineral, the laponite used in Example 1 or Smecton SA (BET) which is a commercially available synthetic clay mineral.
A synthetic montmorillonite having a specific surface area of 184 m ² / g; a product of Kunimine Industry Co., Ltd. was premixed in the same manner as in Example 1 and used as a solution A.

As an organic thickener, xanthan gum (trade name: Kelzan; product of Sansan Co., Ltd.) or HEC (trade name: Natrosol HR-250; Nissho Iwai product) is used as an aqueous dispersion (concentration of Kerzan is 0.5 wt. %, Natrozole was adjusted to a concentration of 1 wt%) and was used as solution B.

As salt, sodium chloride (2 wt%),
Calcium chloride (1 wt%), sodium sulfate (0.5
wt%) or sodium acetate (2 wt%) aqueous solution was prepared and used as C liquid.

Various formulations of these liquids A to C were prepared and used in Example 1.
In the same manner as above, the viscosity with time was measured after mixing and stirring. The results are shown in Table 1.
It was shown to.

Comparative Examples 1 to 5 Liquids in which the premix liquids A, B and C used in Examples 1 to 7 were mixed in different formulations were prepared and the viscosity with time was measured in the same manner as in Example 1. The results are shown in Table 1.

[0029]

[Table 1]

[0030]

By using the composition of the present invention, it is possible to fully utilize the high thickening effect of synthetic clay minerals, and to develop the thickening within a short time. It is possible to maintain an extremely stable state in which the viscosity does not change with time.

Therefore, it can be used as an extremely excellent viscosity modifier in the case of increasing viscosity or preventing sedimentation in various industrial fields, and is highly practical.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kenji Zuki 8-8, Sakane-cho, Shinnanyo-shi, Yamaguchi Prefecture

Claims (2)

[Claims] 1. A water dispersion viscosity modifier composition comprising water, a thickening synthetic clay mineral, an organic thickening agent and a salt. 2. The water-dispersed viscosity modifier composition according to claim 1, wherein the thickened synthetic clay mineral is a smectite group mineral.