JPH01193301A - Production of modified starch - Google Patents

Abstract

PURPOSE:To obtain the title starch useful as an adhesive with water and oil resistances, binder, filler for polymers, etc., by reaction of starch with an organosilane in the presence of a specific compound as the catalyst. CONSTITUTION:The objective modified starch can be obtained by reaction of (A) starch (e.g., wheat starch, potato starch, rice starch) with (B) an organosilane of the formula (X is amino, H, CH3 Cl, CHCl2, SH, of formula II or III; R is 1-6C alkyl; n is 10-20; m is 0-2) (e.g., decyltrimethoxysilane) in the presence of, as the catalyst, a compound selected from alkali aluminates (e.g., 0.005-10wt.% based on the starch, of sodium aluminate), alkali hydroxides (e.g., 0.005-4wt.% of potassium hydroxide), tin compounds (e.g., 0.005-10wt.% of stannous chloride), zinc compounds (e.g., 0.005-10wt.% of zinc chloride). Al compounds (e.g., 0.005-10wt.% of aluminum chloride) and Ti compounds (e.g., 0.005-10wt.% of TiCl4).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing modified starch using organosilane, and this modified starch can be used as an adhesive or binder having water resistance and oil resistance.

It can also be used as a sizing agent, coating agent, etc.

It can also be used as a filler for polymers.

(Prior art) As a method of using organosilane, reacting an alkyl alkyl having 1 to 3 carbon atoms or an alkyl alkoxy silane containing a functional group or an organic functional alkoxy silane is disclosed in JP-A-59-179501, Japanese Unexamined Patent Publication 1987-
It is disclosed in Japanese Patent No. 207902.

(Problems to be Solved by the Invention) The modified starch obtained by the above method has a problem that sufficient water resistance cannot be obtained because the number of carbon atoms in the alkyl chain or functional group bonded to the silicon atom is small. Currently, there is no modified starch that has strong properties and is easy to manufacture and use.

(Means for Solving the Problems) As a result of intensive research to solve the above problems, we found that starch was treated with long-chain alkyl groups using an alkali aluminate, an alkali hydroxide, a tin compound, a zinc compound, an aluminum compound, or a titanium compound as a catalyst. It has been found that a modified starch obtained by reacting with an organosilane having a high water resistance has strong water resistance.

The method for producing modified starch of the present invention involves dissolving or suspending organosilane in water and/or an organic solvent to form a hydrolyzate thereof, adding starch thereto, and then adding alkali aluminate, hydroxide, etc. Add alkali, tin compound, zinc compound, aluminum compound or titanium compound,
Carry out the reaction with sufficient stirring. However, these catalysts may be added before adding the WQ powder. The reaction temperature may be room temperature, but it is more advantageous to heat the reaction to a temperature below the gelatinization temperature of starch (generally about 40°C).

When the reaction is carried out in a wet manner as described above, after the reaction, the modified starch of the present invention can be obtained by washing with water, dehydration, and drying by a known method.

However, when alkali hydroxide is used as a catalyst,
It is advisable to neutralize with an appropriate acid before carrying out the following operations.

In addition, starch is heated to form a paste, which is then mixed with organosilane, alkali aluminate, alkali hydroxide, etc.
It is also possible to add and react a tin compound, zinc compound, aluminum compound or titanium compound. The reaction temperature after gelatinizing the starch may be lower than the gelatinizing temperature of the starch.

The modified starch of the present invention obtained by the gelatinization reaction as described above can be used as it is, or can be dried by drum drying or the like and powdered.

Alternatively, by mixing organosilane and an alkali aluminate, alkali hydroxide, tin compound, zinc compound, aluminum compound or titanium compound with starch at a moisture content of 2 to 50% using an appropriate mixing or kneading device. It also becomes possible to work at temperatures higher than the gelatinization temperature of starch in a short time.

In the method for producing modified starch of the present invention, the reaction is basically carried out in an aqueous medium, but an organic solvent may be added if necessary.
The organic solvent that can be used in the present invention is desirably one that dissolves the organosilane and has good compatibility with water.6 For example, methyl alcohol, ethyl alcohol,
Alcohols such as propyl alcohol, isopropyl alcohol, butyl alcohol, 2-butyl alcohol, t-butyl alcohol, ethylene glycol, propylene glycol, and glycerin; ketones such as acetone and methyl ethyl ketone; amides such as formamide and dimethylformamide; tetrahydrofuran; Ethers such as dioxane and diethyl ether; dimethyl sulfoxide, acetonitrile and the like.

Alkali aluminates are used as 5-15% aqueous solutions or as solids, sodium aluminate being preferably used. The amount added is 0.005 to 1 per starch.
It is 0%.

Alkali hydroxides are used as aqueous solutions (10% or less) or as solids, with sodium hydroxide and potassium hydroxide being advantageously used. Addition amount is 0.005%~4
%. However, if the alkali concentration is high and the starch gelatinizes, it is advisable to dissolve an appropriate amount of sodium sulfate in advance.

The tin compound is used as a 5-10% aqueous solution or a stock solution, and the amount added is 0.005-10% based on the starch. For example, chlorides such as stannous chloride and stannic chloride, stannous acetate, dibutyltin dilaurate, dibutyltin dioctoate, stannous octoate, and stannous naphthenate.
Tin, stannous isobutyrate, stannous linoleate, stannous stearate, stannous penzoleate, stannous naphthoate, stannous laurate, stannous 0-timate, β
- stannous benzoylpropionate, stannous crotonate, stannous trobate, stannous P-bromobenzoate,
Stannous palmitoleate.

Included are tin salts of carboxylic acids, such as stannous cinnamate and stannous phenylacetic acid.

The zinc compound is used as a 5-10% aqueous solution or a stock solution, and the amount added is 0.005-10% based on the starch. For example, zinc chloride, zinc bromide.

Zinc iodide, zinc thiocyanide, zinc ammonium chloride, zinc nitrate, zinc sulfate, zinc ammonium sulfate, zinc hydrogen phosphate, zinc dihydrogen phosphate, zinc formate, zinc acetate, zinc lactate, zinc phenolsulfonate, zinc salicylate,
Examples include ethylenediaminetetraacetic acid zinc complex salt and nitrilotriacetic acid zinc complex salt.

The aluminum compound is used as a 55-10% aqueous solution or a stock solution, and the amount added is 0°005-10% based on the starch.
For example, aluminum chloride, aluminum bromide, aluminum iodide, aluminum thiocyanide, sodium aluminum chloride, aluminum nitrate, aluminum sulfate.

Examples include aluminum ammonium chloride, aluminum ammonium sulfate, aluminum potassium sulfate, aluminum formate, aluminum phenolsulfonate, aluminum acetate, ethylenediaminetetraacetate aluminum complex, and nitrilotriacetate aluminum complex.

The titanium compound is used as a 5-10% aqueous solution or a stock solution, and the amount added is 0.005-10% based on the starch. Titanium tetrachloride, titanium trichloride, titanium sulfate, titanium sulfate, tetra-i-propoxytitanium, tetra-n-butoxytitanium, tetrakis(2-ethylhexoxy)titanium, di-propoxy bis(acetylacetonate) ) titanium, di-n-butoxy bis(triethanolamineto) titanium, dihydroxy bis(lactato) titanium, and the like.

Starch raw materials that can be used to produce the modified starch of the present invention include, for example, wheat starch, potato starch, corn starch, sweet potato starch, tapioca starch, sago starch, rice starch,
Unprocessed starch or wheat flour such as waxy corn starch, high amylose content corn starch, tapioca powder,
Cornflower.

Also included are starch-containing materials such as rice flour, and those subjected to etherification, esterification, crosslinking, oxidation, acid treatment, etc.

In the present invention, organosilane that can be used as a modifier is represented by the following general formula.

X-(CH,)n-8i-(OR)z-m(CH□)m [In the formula, X is an amino group, Hl-CH,, C1, -CH=
CH2, OQ CH.

R is an alkyl group having 1 to 6 carbon atoms, n is an integer of 10 to 20, and 1m is O, 1, or 2. ]For example, decyltrimethoxysilane, decylmethyldimethoxysilane, undecyltrimethoxysilane,
Dodecyltrimethoxysilane, tridecyltrimethoxysilane, tetradecyltrimethoxysilane, pentadecyltrimethoxysilane, hexadecyltrimethoxysilane, heptadecyltrimethoxysilane, octadecyltrimethoxysilane, nonadecyltrimethoxysilane, eicosyltrimethoxy Alkylsilane such as silane, butylenetrimethoxysilane, butylenemethyldimethoxysilane, γ-chlordecyltrimethoxysilane, γ-chlordecylmethyldimethoxysilane, γ-mercaptodecyltrimethoxysilane, γ-mercaptodecylmethyldimethoxysilane, γ- Aminodecyltrimethoxysilane.

Examples include organic functional silanes such as γ-aminodecylmethyldimethoxysilane, γ-aminodecyltriethoxysilane, γ-aminodecylmethyljethoxysilane, γ-glycidyloxydecyltrimethoxysilane, and γ-methacryloxydecyltrimethoxysilane. .

The amount added is 0.01 to 10% based on starch.

(Function) The modified starch of the present invention exhibits hydrophobicity even when treated with a small amount of organosilane. When the modified starch of the present invention is coated or impregnated on paper or board, the surface becomes silicon and long chain. Because it is covered with alkyl groups, it exhibits water resistance. Additionally, as a secondary effect, the strength of the paper is improved.

Although the modified starch paste of the present invention may have a higher viscosity than its raw material starch, it does not have a disadvantageous effect on the dispersion of pigments, etc.

(Examples and Effects of the Invention) (Example 1) 1.62 g of octadecyltrimethoxysilane (LSX-6817 manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed with water:methanol=
The mixture was stirred and mixed into 260 g of a 1:1 mixed solvent. After 15 minutes, 200 g of potato starch was stirred and mixed. 4.1 g of sodium aluminate was made into an approximately 10% aqueous solution and mixed with stirring. This mixture was reacted at 40°C for 4 hours. Thereafter, the starch was filtered off, washed and dried.

The silicon content of the starch obtained by this method is 0°051%
Approximately 80% of the silicon provided by starch was fixed by starch.

A wet test of the modified starch was carried out by adding a small amount of starch to deionized water present in a beaker.

In this case, the total starch content remained suspended in water for at least 24 hours.

When a filter paper (Toyo Roshi Nn2) was dipped in a size solution with a concentration of 2% and then dried, the filter paper showed hydrophobicity.

However, when I drew a line on the same treated filter paper with an oil-based pen (Shunga Kagaku Magic Ink 4500), the ink was not repelled and the line could be drawn with the thickness of the pen tip.

Measuring the viscosity of a glue solution with a concentration of 5% is 7900 cps.
(30°C), and a significant increase in viscosity was observed compared to the raw material potato starch.

(Example 2) 1.62 g of octadecyltrimethoxysilane was stirred and mixed in 260 g of a mixed solvent of water:ethanol=1:1. After 15 minutes, 200 g of corn starch was stirred and mixed. 0.8 g of sodium hydroxide was added as an approximately 10% aqueous solution. This mixture was reacted at 40°C for 4 hours.

After neutralizing to pH 6-8 with dilute hydrochloric acid, starch was filtered off, washed, and dried.

Results similar to those in Example 1 were obtained in the wet test.

The filter paper that was dried after soaking in a size solution with a concentration of 2% was also used in Example 1.
As in the case of , it showed hydrophobicity.

(Example 3) 1.62 g of octadecyltrimethoxysilane was stirred and mixed in 260 g of a mixed solvent of water:acetone=1=1.

After 15 minutes, 200 g of tapioca starch was stirred and mixed. 2.2 g of stannic chloride was added as an approximately 10% aqueous solution.

The mixture was reacted for 4 hours at 40"C. Thereafter, the starch was filtered off, washed and dried.

Results similar to those in Example 1 were obtained in the wet test.

The filter paper that was dried after soaking in a size solution with a concentration of 2% was also used in Example 1.
As in the case of , it showed hydrophobicity.

(Example 4) Octadecylmethyldimethoxysilane (LSX-681
6 (manufactured by Shin-Etsu Chemical Co., Ltd.) was stirred and mixed in 260 g of a mixed solvent of water:methanol=1:1. 15
After a few minutes, 200 g of oxidized starch was stirred and mixed. 1.6 g of aluminum acetate was added as an approximately 10% aqueous solution. This mixture was reacted at 40°C for 4 hours. Thereafter, the starch was filtered off, washed and dried.

Results similar to those in Example 1 were obtained in the wet test.

The filter paper that was dried after soaking in a size solution with a concentration of 2% was also used in Example 1.
As in the case of , it showed hydrophobicity.

(Example 5) 1.55 g of octadecylmethylcytoxysilane in water:
The mixture was stirred and mixed into 260 g of a mixed solvent of methanol=1:1. After 15 minutes, 200 g of wheat starch was stirred and mixed. 1.4 g of zinc chloride was added as an approximately 10% aqueous solution. This mixture was reacted at 40°C for 4 hours. Thereafter, the starch was filtered off, washed and dried.

Results similar to those in Example 1 were obtained in the wet test.

The filter paper dried after being immersed in a size solution having a concentration of 2% also exhibited hydrophobicity as in Example 1.

(Example 6) 1.75 g of γ-aminooctadecyltrimethoxysilane
was stirred and mixed in 260 g of a mixed solvent of water:methanol (1:1). After 15 minutes, 200 g of hydroxypropyl etherified starch was stirred and mixed. Jimmy propoxy bis(acetylacetonato) titanium 50% aqueous solution 1.04
g was diluted to about 10% and added. This mixture was heated at 40°C.
The mixture was allowed to react for 4 hours. Thereafter, the starch was filtered off, washed and dried.

Results similar to those in Example 1 were obtained in the wet test.

The filter paper that was dried after soaking in a size solution with a concentration of 2% was also used in Example 1.
As in the case of , it showed hydrophobicity.

(Example 7) Potato starch log is dispersed in 480 g of water and heated at 85° C. or higher for 10 minutes to form a uniform paste.

Octadecyltrimethoxysilane o, o s g in water:
Added to 10 mQ of mixed solvent of methanol = 1 = 1
The mixture was stirred and mixed for a minute and then added to the above paste solution, followed by stirring and mixing. Add 0.5 g of sodium aluminate as a 10% aqueous solution, stir at 60°C or higher for 2 hours to react,
A silane-modified starch paste solution was obtained.

The filter paper dried after being soaked in the above-mentioned size solution also showed hydrophobicity as in Example 1.

Further, when the above paste was dried in a drum dryer and made into powder, a wetness test was conducted, and the same results as in Example 1 were obtained.

(Example 8) Put 800 g of potato starch into a kneader, and add 6.5 g of octadecyltrimethoxysilane in water:methanol=1=1
The mixture was added to 30 mQ of the mixed solvent and stirred and mixed for 15 minutes, followed by dropwise mixing. 3.4.1g of sodium aluminate
It was dissolved in 0 mQ water and mixed. This mixture was reacted at 70°C for 2 hours. Then, cool it down and put it in water.
It was filtered, washed and dried.

Results similar to those in Example 1 were obtained in the wet test.

The filter paper that was dried after soaking in a size solution with a concentration of 2% was also used in Example 1.
As in the case of , it showed hydrophobicity.

(Comparative Example 1) 1.62 g of octadecyltrimethoxysilane was mixed with 200 g of potato starch. When a wet test was performed on this mixture, the starch immediately began to settle.

Also, after soaking the filter paper in this 2% concentration glue solution.

Even when dried, the filter paper did not exhibit hydrophobicity.

Claims (4)

[Claims] (1) A method for producing modified starch, which comprises reacting starch with an organosilane represented by the following formula using an alkali aluminate, an alkali hydroxide, a tin compound, a zinc compound, an aluminum compound or a titanium compound as a catalyst. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, X is an amino group, H, -CH_3, Cl, -CH=
CH_2, -SH, ▲Mathematical formulas, chemical formulas, tables, etc. are available▼
or ▲There are numerical formulas, chemical formulas, tables, etc.▼ It is a group represented by: where R is an alkyl group having 1 to 6 carbon atoms, n is an integer of 10 to 20, and m is 0, 1, or 2. ] (2) Organosilane is dissolved or suspended in water and/or an organic solvent while forming its hydrolyzate, starch is added to this solution or suspension, and then alkali aluminate and alkali hydroxide are added. , tin compounds, zinc compounds,
Claim 1: Adding an aluminum compound or a titanium compound and stirring the resulting suspension at a temperature of up to 45°C.
) method described. (3) Starch and water are heated to form a size liquid, and organosilane and an alkali aluminate, an alkali hydroxide, a tin compound, a zinc compound, an aluminum compound, or a titanium compound are added to the size liquid. the method of. (4) A claim in which organosilane and an alkali aluminate, alkali hydroxide, tin compound, zinc compound, aluminum compound, or titanium compound are mixed with starch at a moisture content of 2 to 50% using a mixing or kneading device ( 1) The method described.