JPS6011921B2 - Method for producing cationically modified starch derivatives - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing cationically modified starch derivatives by cationizing starch or its derivatives.

Cation-modified polymer substances have become widely used in recent years as flocculants, tenner retention agents in the paper industry, antistatic agents for fibers and woven fabrics, and compounding agents for cosmetics, shampoos, etc. Applications in fields such as , rinse, and treatment are attracting attention.

When using cation-modified polymeric substances as compounding agents in cosmetics, shampoos, conditioners, treatments, etc., in addition to their remarkable effects, they must also be highly safe for the human body and have a good feel when used. etc. are required. Cation-modified cellulose is known to be used as a material that satisfies this requirement, but cation-modified polymeric materials based on starch are also highly safe for the human body, have good adsorption properties on hair and skin, and are easy to use. Since it has good texture, water retention, etc., it can be said to be an extremely suitable substance as the above-mentioned compounding agent. Conventional methods for producing cationically modified starch derivatives include a method in which starch or starch derivatives are reacted with a halogenated alkylamine salt in the presence of an alkali catalyst (Taruko No. 36-18246, Tokusekki No. 48-16). 5) and the method of reacting with betaine hydrazide hydrochloride (Japanese Patent Publication No. 14959/1982), but the products obtained by these methods have a positive group for glucose residues in starch. The degree of substitution is low, and the nitrogen content in the product is 1% by weight.
The drawback was that you could only get the following:

Therefore, in order to increase the degree of substitution, the use of quaternary ammonium salts containing a glycidyl group or halohydrin group as a cationizing agent was proposed (1971).
-25875 Publication, Mochiseki Publication No. 47-1961, Special Publication No. 48-93684, JP-A-51112106
No. 2), it has become possible to obtain products with a considerably high degree of substitution (nitrogen content of about several percent). However, even with these methods, the effective utilization rate of the cationizing agent is 50%.
~60%, which is not only less economical, but also requires a large amount of cleaning agent to clean the unreacted cationizing agent.
Moreover, there is a risk of causing pollution due to its disposal. In addition, the aqueous solutions of the products obtained by these methods have a drawback that the transparency is not very high. The present inventors have conducted extensive research to develop a method for producing cationically modified starch derivatives that overcomes the drawbacks of the above-mentioned conventional methods. In the reaction, it was discovered that the effective utilization rate of the cationizing agent was significantly increased, and the transparency of the aqueous solution of the reaction product was also significantly improved, and based on this knowledge, the present invention was completed.

That is, the present invention provides a method for producing a cationically modified starch derivative by reacting starch or its alkylene oxide derivative with a glycidyl trialkylammonium salt, in which the starch or its alkylene oxide derivative is previously treated with an inorganic alkali. The present invention provides a method for producing a cationically modified starch derivative characterized by the following.

As the raw material starch of the present invention, all kinds of naturally occurring starches can be used, including those that can be easily obtained such as kanshiyo, barley, starch, corn, wheat, rice, tapioca, etc. can.

Further, if necessary, these commercially available products may be purified and used, or soluble starch hydrolyzed with an inorganic or organic acid (acid-treated starch) may be used. As the alkylene oxide derivative of starch, 3 is preferably an ethylene oxide or propylene oxide derivative.

The number of moles of alkylene oxide added is preferably 0.1 to 3 moles, preferably 0.1 to 2 moles, per rice bran water glucose unit.
3. The starch of the present invention or its alkylene oxide derivative can be used as a mixture if necessary. In the method of the present invention, it is first necessary to disperse starch or its alkylene oxide derivative in a solvent and to perform pretreatment by adding 4 inorganic alkalis.

This pretreatment is carried out at 40-80°C, preferably 40-60qo
It will be held in If the temperature is lower than 40q○, starch will not be activated sufficiently, and if it exceeds 80℃, starch will undergo gelatinization in a broad sense, or the glucoside bonds of starch will cleave, resulting in an extremely low degree of polymerization. I don't like it because it is. The appropriate processing time is 1 to 3 hours.
If this treatment time is too short, activation will not proceed; if it is too long, the degree of polymerization will decrease. The inorganic alkali used for this pretreatment is sodium hydroxide, potassium hydroxide, lithium hydroxide, etc., and starch or its alkylene oxide derivatives are
Add 0.05 to equimole per anhydroglucose unit of the body.

However, when the pretreatment solution is directly transferred to the next cationization reaction, it is preferable to add an inorganic alkali in the range of 0.05 to 0.4 mol. These inorganic alkalis are added to the solvent as they are or as an aqueous solution. The solvent is
2 to 1 parts by weight, preferably 4 to 7 parts by weight, are used per 1 part by weight of the starch or its alkylene oxide derivative. This solvent is preferably a mixed solvent of an alcohol having 2 to 4 carbon atoms and water, with a mixing ratio of 1:1 to 4:1 by weight. If the amount of water is less than this range, the contact between the starch and the alkali will be insufficient, and if it is too much, the starch will swell and form a highly viscous slurry, making it difficult to handle and preventing cationization during the subsequent cationization reaction. This causes the problem of poor diffusion of the agent. Note that this mixing of water has the effect of suppressing the reaction between a solvent such as alcohol and a cationizing agent during the cationization reaction when the reaction solution is directly transferred to the cationization reaction. In the method of the present invention, pretreated starch or its alkylene oxide derivative is subjected to a cationization reaction as follows, and as a result, a desired cationically modified starch derivative can be obtained.

Examples of the cationizing agent include glycidyl-type or halohydrin-type alkylammonium salts. cosmetics,
When used as an additive for shampoos, conditioners, etc., it is preferable that the amount of by-product salts mixed in the cation-modified starch derivative be as small as possible, so a glycidyl-type trialkylammonium salt represented by the following formula is preferred. (
In the formula, R represents a lower alkyl group having 1 to 3 carbon atoms, which may be the same or different, and X represents chlorine, bromine or iodine.

) When using a halohydrin type, for example, 3-halogeno 2-hydroxypropyl trialkylammonium salt, as a cationizing agent, a large amount of alkaline catalyst is required for the reaction because it involves a dehydrochloric acid reaction, and a large amount of created salt is used. As a result, this by-product salt must be removed when used in cosmetics, shampoos, etc.
This is not preferred because it requires a large amount of cleaning solvent. The amount of the cationizing agent to be used is appropriately determined depending on the application so as to obtain the desired nitrogen content.

Generally, a nitrogen content of 1.0 to 4.5% by weight satisfies all uses, and in this case the amount of cationizing agent used is 100 parts by weight of starch or its alkylene oxide derivative.
15-12a parts by weight, molar ratio of starch anhydrous gluco-
The amount is 0.16 to 1.3 times the mole per s unit. As a dispersion medium for the cationization reaction, inert organic solvents such as inpropyl alcohol, sec-butyl alcohol, tertiary-butyl alcohol, ethanol, etc. can be used for the glycidyl trialkylammonium salt; Secondary butyl alcohol, tertiary butyl alcohol and especially inpropyl alcohol are preferred.

These dispersed particles are used as a mixed solvent with water, for example, a mixture of 50 to 8 parts by weight of the above-mentioned organic solvent and 50 to 2 parts by weight of water. In the presence of water, starch undergoes Q conversion in a broad sense when heated or treated with an alkali. However, in a mixed solvent having the above ratio, swelling of starch is suppressed during the reaction between starch and glycidyl trialkylammonium salt, and workability is greatly improved. The amount of reaction dispersed soot must be such that it can physically stir the raw material starch, and is usually 2 to 1 part by weight, preferably 4 to 1 part by weight, per 1 part by weight of starch or its alkylene oxide derivative. 7 parts by weight are used.

If the amount of the dispersant exceeds 1 part by weight, the alkali concentration and glycidyl trialkylammonium salt concentration described below will be diluted, which is economically disadvantageous. This cationization reaction is usually carried out in the presence of an alkali catalyst.

As the alkali catalyst, inorganic alkalis such as sodium hydroxide, potassium hydroxide, and lithium hydroxide, and organic bases such as triethylamine are used. When using an organic base, it is preferable to completely remove the inorganic alkali in the pretreatment before carrying out the reaction. This alkaline catalyst needs to be present in a sufficient amount to activate the reaction sites, ie, hydroxyl groups, of starch or its alkylene oxide derivative; for example, in the case of sodium hydroxide, starch 0 or its alkylene oxide derivative 100 1.23 to 24.67 parts by weight, molar ratio 0.0
5-1.0 mol (per anhydroglucose unit), preferably 1.23-9.80 parts by weight, molar ratio 0.05-0.
4 times the molar amount (per anhydroglucose unit) is present.

If the amount of the catalyst is less than 0.03 sonic moles in terms of mortar ratio, the effect will be small, and if it is more than equimolar, a large amount of salt will be produced during neutralization, which is not preferable. The reaction temperature is 30 to 80°C, preferably 40 to 60°C, and the reaction time varies depending on the temperature, but 1 to 5 hours is appropriate. 0 The reaction solution obtained in this way is neutralized with acid, the reaction product is separated and purified,
It is made into a product after drying under reduced pressure.

In this case, as a neutralizing agent, hydrochloric acid, sulfuric acid, acetic acid, oxalic acid, etc. are used.

Neutralization is usually carried out by adding a neutralizing agent equivalent to 1 to 4 times the amount of catalyst used, diluted with a reaction dispersion medium or methanol 2 to 5 times the weight of the starch or its alkylene oxide derivative used. This can be done by adding. The temperature at this time is usually 20 to 50 qo, and the treatment time is 3 females to 1 hour. Separation and purification of the reaction product is carried out after neutralization with a concentration of 5 to 1M of the starch used or its alkylene oxide derivative.
According to the method of the present invention, reprecipitation is carried out using a sonic weight of methanol, and the product obtained as a precipitate is filtered and washed two to three times with the same amount of methanol. The effective utilization rate of the cationizing agent is dramatically increased, and not only is it highly economical, but cleaning is also simple, and pollution problems associated with cleaning can be avoided.

Further, according to the method of the present invention, by-product salts are less produced, and the transparency of the obtained aqueous solution of the cation-modified starch derivative is significantly improved. Furthermore, a cationically modified starch derivative with a high degree of substitution of enteric groups can be obtained, and the cationically modified starch derivative obtained by the method of the present invention can be used as a compounding agent applied in fields such as cosmetics, shampoos, conditioners, and treatments. It is suitable as Next, the present invention will be explained in more detail based on examples.

Example 1 30% of barley starch was dispersed in 150% by weight aqueous inpropyl alcohol solution, and 9.92% by weight of 15% by weight aqueous sodium hydroxide solution (0.2 times mole of starch: per anhydroglucose unit) , hereinafter the same) is added with Z,
The alkali-free treatment was performed at 40 pm while stirring for 2 hours.

Thereafter, this dispersion was added to 8.4% of the active ingredient (vs. 0% of starch).
．． Add an aqueous solution of glycidyltrimethylammonium chloride (hereinafter abbreviated as GTA) of 3 times the mole and raise the temperature to 50
The reaction was carried out at qo for 8 hours with stirring. After the reaction is complete, add 4.2 hours of concentrated hydrochloric acid (1.1 times the mole of the sodium hydroxide charged) to a 50% by weight aqueous solution of inpropyl alcohol.
It was diluted at 0 pm and used for neutralization. After neutralizing for 1 hour at room temperature,
The reaction solution was poured into 300 methanol to precipitate the reaction product, which was filtered. The resulting precipitate was washed in methanol for 300 min. After repeating such washing and purification three times, the reaction product was dried under reduced pressure. The cationically modified starch thus obtained had a nitrogen content of 1.7% by weight.

From this nitrogen content, the degree of substitution of the quaternary nitrogen group bonded to one unit of anhydroglucose in starch is 0.255, and ~G
The reaction rate of TA was extremely high at 85%. Comparative Example 1 Barley starch 309 was dispersed in a 5% by weight aqueous solution of inpropyl alcohol, and 9.9% by weight of a 15% by weight aqueous sodium hydroxide solution (0.2 times the mole of starch) was added. Immediately add an aqueous GTA solution containing 8.4 ml of active ingredient (0.3 times the mole of starch) and raise the temperature to 50 q.
The reaction mixture was stirred at o for 8 hours.

After the reaction was completed, a reaction product was obtained by neutralization, precipitation, filtration, washing and purification, and drying under the same conditions as in Example 1 above. The cationically modified starch thus obtained has a nitrogen content of 1
．． It was 4% by weight of the box. Based on this nitrogen content, the degree of substitution of the quaternary nitrogen group bonded to one unit of anhydroglucose in starch was 0.196, and the conversion rate of GTA was 65%. Example 2 30 parts of barley and barley starch were dispersed in 150 parts of a 5% by weight aqueous solution of inpropyl alcohol, and 9.9 parts of a 15% by weight aqueous sodium hydroxide solution (0.2 times the mole of starch) was added. The alkali treatment was performed while stirring at .40oo for 2 hours.

Thereafter, this dispersion was added to the active ingredient 8.49 (vs. starch 0).
．． A GTA aqueous solution of *Sound mole) was added, the temperature was raised, and the mixture was stirred at 50° C. for 3 hours to react. After the reaction is complete, add concentrated hydrochloric acid 4.
2 mols (1.1 times the mole of the sodium hydroxide used) to 15
It was neutralized with 09-5 diluted with an aqueous solution of inpropyl alcohol at 5% by weight. After neutralizing for 1 hour at room temperature, the reaction solution was poured into methanol for 300 minutes to precipitate the reaction product,
This was filtered out. The resulting precipitate was washed in methanol for 300 min. After repeating such washing and purification three times, the reaction product was dried under reduced pressure. The cationically modified starch thus obtained has a nitrogen content of 1. The chlorine content was 4.42% by weight. Based on this nitrogen content, the degree of substitution of the quaternary nitrogen group bonded to one unit of anhydroglucose in starch was 0.248, and the conversion rate of GTA was extremely high at 83%. Further, as can be seen from comparison with Comparative Example 1, according to the method of the present invention, the reaction time for cation modification can be significantly shortened.

Examples 3 to 6 Under the pretreatment conditions, the amount of GTA added, and the cationization reaction conditions shown in Table 1, the same method as in Example 1 was used to find out, and cationic modified products were obtained from Japanese cabbage starch and wheat starch.

The nitrogen content, degree of substitution of quaternary nitrogen groups, and effective utilization rate of GTA of the product thus obtained are also shown in Table 1. Table 1 *Comparative examples 2 to 5 (per mole of starch) (per anhydroglucose unit)
The cationization reaction conditions and the amount of GTA added shown in Table 2 were used, and the starch and wheat starch were cationically modified.

The nitrogen content, degree of substitution of quaternary nitrogen groups and effective utilization of GTA of the product thus obtained are also shown in Table 2. Table 2 (vs. starch times mole per anhydroglucose unit) As can be seen by comparing Comparative Examples 2 to 5 and Examples 3 to 6 above, the method of the present invention that performs pretreatment can produce The nitrogen content of the product and the degree of substitution of quaternary nitrogen groups are higher, and GT
The effective utilization rate of A is very good.

Example 7 Aqueous solution of 30 parts of soluble starch and 7 parts by weight of ethanol
50% by weight of aqueous sodium hydroxide solution (0.1 times the molar amount of soluble starch) was added, and alkali treatment was performed while stirring at 4 ml for 1 hour.

Thereafter, an aqueous GTA solution containing 20.8 molar amounts of the active ingredient (0.74 times the molar amount of soluble starch) was added to this dispersion, the temperature was raised, and the mixture was stirred at 60° C. for 6 hours to react. After the reaction was completed, the mixture was neutralized with 1.9 μm of concentrated hydrochloric acid (equivalent to the sodium hydroxide used) diluted with 150 μm of a 7% by weight aqueous ethanol solution, and washed by stirring at room temperature for 1 hour. After neutralization and washing, the reaction solution was filtered to obtain a reaction product. The obtained product was purified by washing with a 7% by weight aqueous ethanol solution for 300 minutes and dried under reduced pressure. The nitrogen content of the cationically modified soluble starch thus obtained is 2.64
% by weight.

The degree of substitution of the quaternary nitrogen group is 0.428, and CT
The reaction rate of A is 58%. This reaction rate was 5 to 10% higher than that without pretreatment, and the reaction time was also shortened by about 1 hour. In addition, JISK OI02-1974
Transparency of 1% by weight aqueous solutions of the reaction products of Examples 1 to 6 and the present example and 1% by weight aqueous solutions of the reaction products of Comparative Examples 1 to 5 was examined using the transparency measurement method.

Claims (1)

[Scope of Claims] 1. A method for producing a cationically modified starch derivative by reacting starch or its alkylene oxide derivative with a glycidyl trialkylammonium salt, which comprises treating the starch or its alkylene oxide derivative with an inorganic alkali in advance. A method for producing a cationically modified starch derivative, characterized by: 2. The method according to claim 1, wherein the treatment time with an inorganic alkali is 1 to 3 hours. 3. The method according to claim 1 or 2, wherein the treatment with an inorganic alkali is carried out at 40 to 80°C.