JPS62285902A - Production of hydroxyalkylated xanthan gum - Google Patents

Abstract

PURPOSE:To produce difficult-to-putrefy hydroxyalkylated xanthan gum at a low cost in good yield, by adding an alkali metal hydroxide and an organic medium to a xanthan gum powder and reacting the resulting mixture with an alkylene oxide. CONSTITUTION:100pts.wt. crushed or finely ground xanthan gum powder is homogeneously mixed with 2-20pts.wt. alkali metal hydroxide (e.g., NaOH), 3-30pts.wt. organic solvent (e.g., methanol) and 0-10pts.wt. (at most 30% of water to obtain a mixture. 5-90pts.wt. lower alkylene oxide (e.g., ethylene oxide) is added to this mixture and reacted at 40-100 deg.C until the pressure in the system decreases to a constant value (3-12hr), and the obtained mixture is neutralized with an acid, dried and ground.

Description

DETAILED DESCRIPTION OF THE INVENTION & DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing hydroxyalkylated xanthan gum.

Xanthanoga L is a pure cultured microorganism, Xanthomas campestris.
Pestris) is a high-molecular polysaccharide that accumulates outside the bacterial cell during the fermentation process, and its constituent monosaccharides are glucose, manonose, and glucuroa M (2:I:1). When dissolved in water, xanthan gum exhibits a highly pseudoplastic-like viscosity, so it is widely used in the food and industrial fields. , there are some uses to which it cannot be applied.

In order to improve this drawback, it is known to hydroxyalkylate the hydroxyl groups in the constituent molecules of beef soup/rib/gum.
Examples of the manufacturing method include the methods disclosed in US Pat.

The method of U.S. Patent No. 3,349,077 involves adding a large amount of residual solvent and water and carrying out the reaction in a slurry.
(I) Recovering the solvent and water after the reaction is time-consuming; (2+X the amount of solvent and water added is large; and the large amount of added water causes the Kisa/Tangaf to become viscous; therefore, large equipment is required. It has drawbacks such as high cost from (31(11,(21)).

The method of JP-A No. 00-252001 includes the above-mentioned (1),
(Although the disadvantages of 2+ have been overcome, the reaction is carried out under an inert gas such as argon, so it still has the disadvantage of high costs.

The present inventors conducted intensive research to produce hydroxyalkylated xanthan gum at low cost while maintaining the proportion, and as a result, they arrived at the present invention.

The present invention relates to a method for producing hydroxyalkylated xanthan gum, which is characterized in that a YT n medium which may contain an alkali metal hydroxide and a small amount of water is added to bovine santhanum gum powder, and an alkylefluoride is reacted therewith.

For xanthan gum powder, coarsely crushed kisa/kungum,
Use pulverized or finely ground material.

As the alkali metal hydroxide, sodium hydroxide, potassium hydroxide, etc. are suitable;
0 parts by weight, 2 to 20 parts by weight, preferably 4 to 1
O parts by weight are used. If the amount is less than 2 parts by weight, the reaction will not proceed sufficiently, and if it is more than 20 mff, the xanthan gum will gelatinize, making it impossible to obtain a good reaction product, which is not preferable.

Water is used to uniformly dissolve the alkali metal hydroxide, but originally 100ff of tan gum in Kisa/tan gum
0 to 10ffifik parts, preferably 2 to 5 parts by weight per part of lt ffi, and 30 parts by weight of the organic solvent.
If it is more than 1 part per 1 meter, the xanthan gum will gelatinize and the reaction will not proceed uniformly, which is not preferable. If the amount exceeds 30% of the weight of the organic solvent, the xanthan gum will dissolve in the solvent system, making it impossible to proceed the reaction uniformly, which is not preferable.

In order to produce a homogeneous alkali metal salt of xanthan gum, the battering machine solvent used is one that is compatible with water that dissolves the alkali metal hydroxide. Alcohols such as methanol, ethanol, and impropatol are preferred, but ketos/groups such as acetone and methyl ethyl keto 7, and furanos such as tetrahydrofuran and dioxa 7 can also be used. The amount used is 3 parts for 1 ooff m part of xanthan gum.
~30 parts by weight, preferably 6 to 15 parts by weight. If it is less than 3 parts by weight, the above objective cannot be achieved, and if it is more than 30 parts by weight, the recovery work becomes complicated.

Examples of alkylene oxide include ethylene oxide,
A lower alkylene oxide such as propylene oxide or butylene oxide is used. The amount used can be arbitrarily changed depending on the degree of hydroxyalkylation, but
5 to 90 parts by weight per 100 parts by weight of Kisa/Ri7 gum,
Preferably it is 30 to 60 parts by weight.

In this reaction, an alkali metal hydroxide dissolved in an organic solvent that may contain a small amount of water is added to xanthan gum powder, mixed and stirred to make it homogeneous, and an alkylene oxide is added thereto, and the mixture is added to the The reaction is carried out at 100° C. (preferably 60 to 80° C.). It is completed when the pressure in the system decreases and becomes constant, but usually 3 to 1
It takes 2 hours. After the reaction is completed, the product is neutralized with an acid such as sulfuric acid, acetic acid, or hydrochloric acid, dried to remove added Tadatsuki r8 soot and water, and pulverized to obtain a product. Incidentally, the product may be purified by a conventional method, and then neutralized, dried, and pulverized.

In the production method of the present invention, since the amount of solvent and water used is small, a small and simple reaction apparatus can be used. Furthermore, there is no need to replace the gas with an inert gas such as argon, and it can be manufactured at low cost, which has high practical value.

The hydroxyalkylated xanthan gum produced according to the present invention is used in industrial applications such as paint, paper manufacturing, petroleum, civil engineering and construction, coal slurry, and explosives.

EXAMPLES In order to explain the present invention in more detail, Examples are given below, but the present invention is of course not limited to these.

In the following examples, the degree of substitution of hydroquine propylation (d
egree orsubstition;hereinafter referred to as D
S) stands for American Standards.
or Te5t ~1ethodD -2307-7
Measured according to 2.

Example 1 Production of wI agent of the present invention 200 g of xanthan gum (Keltrol ■, manufactured by Kelco), 8 g of sodium hydroxide, 12 g of methanol, and 4 g of water are added to a closed reaction vessel equipped with a stirrer, and the mixture is stirred in a chamber for about 1 hour. . Add 80g of propylene oxide to it,
After reacting at 70 to 75°C for 4 hours, the mixture was cooled to room temperature, neutralized with concentrated sulfuric acid, dried, and ground to obtain 225 g of hydroxypropylated xanthan gum powder. Hydroxypropylation DS was 0.05.

When the main island is added with water, it becomes gelatinous, producing a transparent and viscous paste liquid. The viscosity of its 1.0% aqueous solution is 1440 c
(Using a 13L Brufuku Field Viscometer manufactured by Tokyo Keiki Seisakusho at 25°C and 30 rpm.Measurements are made under the same conditions below.) No growth of signs was observed in this paste solution even after one month. .

Example 2 Production of a sizing agent according to the present invention Xanthan gum (Kelzan ■,
Add 200g of Kelco ¥B), 16g of sodium hydroxide, 2↓g of methanol, and 8g of water, and mix at room temperature for about 1 hour. After reacting for 1 hour at °C,
After cooling to room temperature, neutralize with +5 sulfuric acid.

Dry and grind to obtain 259 g of hydroxypropylated xanthan gum powder. Hydroxypropylation DS is 0.15
Met.

Honjima gelatinizes easily when water is added, producing a transparent and viscous paste liquid. The viscosity of the 1.0% water + 8 liquid is IO + 2cp
It is s. With this glue solution, no reproduction was observed even after one month.

Example 3 Thickening agent of the present invention! 200 g of xanthan gum (Keltrol ■, Kelco 5D) and 12 g of sodium hydroxide in a closed reaction pot with an i2 stirrer
, 18 g of methanol and 6 g of water are added, and the mixture is stirred for about 1 hour at room temperature. There Probile/Oxide 1
After adding 20 g of the mixture and reacting at 70 to 75° C. for 5 hours, it was cooled to room temperature, neutralized with Ω sulfuric acid, dried, and ground to obtain 265 g of hydroxypropylated xanthan gum powder. Hydroquine propylation DS was 0.23.

Honjima gelatinizes easily when water is added, producing a transparent and viscous paste liquid. Viscosity of its 1.0% aqueous solution i; t723cl
) There is a ste. With this glue solution, no song reproduction was observed even after one month.

Claims (1)

[Claims] (1) A method for producing hydroxyalkylated xanthan gum, which comprises adding an alkali metal hydroxide and an organic medium that may contain a small amount of water to xanthan gum powder, and reacting the alkylene oxide.