JPS5831082B2 - Method for producing carboxymethylated starch for printing paste - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for economically and stably producing carboxymethylated starch having excellent quality and performance as a sizing agent for printing textile materials.

Conventionally, starch and modified starch have been widely used in large quantities as a sizing agent for printing textile materials.

This is because by applying starch and modified starch to printing pastes, it is possible to economically obtain high-quality printed products with good sharpness and high color value.

In particular, modified starch has come into widespread use in recent years because it can be easily gelatinized even with cold water.

Processed starches include methyl etherified starch, hydroxyethylated starch, carboxymethylated starch, etc. Among them, carboxymethylated starch has excellent printing properties when used as a thickening agent for printing, and its production is comparatively It is often used because it is easy to use.

Various studies have been conducted for a long time regarding methods for producing carboxymethylated starch.

For example, US Patent No. 2523709 (1950), Swiss Patent No. 276408 (1951), British Patent No. 6859
No. 59 (1953).

These are all methods of producing carboxymethylated starch by heating and mixing starch, caustic alkali, monochloroacetic acid, sodium monochloroacetate, etc. in water or an organic solvent, and the carboxymethylated starch obtained by this method is suitable for textile printing. When applied as a glue, the viscosity is too low to be of practical use.

Attempts have also been made to crosslink carboxymethylated starch using a crosslinking agent as a method of increasing the viscosity of a sizing agent.

For example, Special Publication No. 308092, Special Publication No. 30-8738,
In JP-A No. 5,089,684, a crosslinking reaction is carried out simultaneously with carboxymethylation in water or an organic solvent using formalin dimethylol urea, epichlorohydrin, etc. as a crosslinking agent.

In this case, the following problems exist.

That is, reactions using solvents have the problem of danger and high cost due to the use of solvents.

In addition, in the one-step reaction in an aqueous solvent, when the resulting carboxymethylated starch is applied to a printing paste, dyeing spots caused by particles generated by the heterogeneous reaction of the crosslinking agent, and hue differences due to viscosity variations, etc. This is problematic and not a practical method.

In a practical method using water as a solvent, we
They have discovered a method for stably producing crosslinked carboxymethylated starch that has a viscosity suitable for use as a sizing agent and has excellent quality and performance.

In the method of the present invention, starch is dispersed in 1 to 3 times the amount of water, and crosslinking is performed using a crosslinking agent at a temperature ranging from room temperature to 60°C in the presence of an alkali catalyst, and then in the presence of an excess of alkali. characterized by carrying out carboxymethylation with sodium monochloroacetate or monochloroacetic acid,
This is a method for producing carboxymethylated starch for textile printing through a two-step reaction in an aqueous solvent.

In the production method of the present invention, starch (water content of about 12
%) in 1 to 3 times the amount of water, and 0.5 to 1.0 parts by weight of caustic alkali is added to 100 parts by weight of starch.

Further, add 0.005 mol of crosslinking agent to 1 mol of starch (1 unit of glucose) and heat at room temperature to 60 ml.
The crosslinking reaction is carried out with stirring at a temperature in the range of °C.

The crosslinking time is preferably 4 to 20 hours, and the crosslinking is preferably carried out until the crosslinking agent is completely consumed.

The crosslinking reaction generally proceeds with a low viscosity, but if the amount of alkaline catalyst or reaction temperature is higher than specified, the viscosity will increase and there is a high possibility that the homogeneity of the reaction system will be lost (and the product Care must be taken as this may cause the generation of particles.

The amount of crosslinking agent used within the above range is sufficiently effective.

If the amount of crosslinking agent is 0.001 mol or less per 1 mol of starch, the viscosity will be low when the product is applied to printing paste.
．． If more than 0.005 moles are used, the printing paste tends to have poor fluidity and poor water-holding properties.

Once the crosslinking reaction is completed, the next step is to proceed to the carboxymethylation reaction.

0.4 to 1 mole of starch (1 unit of glucose)
Add 0.8 mol of sodium monochloroacetate or monochloroacetic acid to the aqueous dispersion of cross-linked starch, and after mixing and homogenizing, add 0.8 mol of sodium monochloroacetate or monochloroacetic acid to a 1-20% excess of sodium monochloroacetate (11-120% excess of monochloroacetic acid). ) Add a highly concentrated aqueous solution of sodium hydroxide and heat at 60-100°C for 2-6 hours.
Perform a time reaction.

At this time, the reaction rate of sodium monochloroacetate progresses to 80% or more.

At the beginning of the carboxymethylation reaction, the viscosity increases rapidly and becomes a paste, but the viscosity tends to decrease over time.

This phenomenon is caused by deterioration of the product due to alkali or heat.

The method for producing carboxymethylated starch of the present invention involves a two-stage reaction in an aqueous solvent as described above, and only this method can easily prevent particle formation and viscosity variation.

The starch used in the present invention may be any commercially available starch.

Examples include corn starch, potato starch, tapioca starch, and wheat starch.

Crosslinking agents include formaldehyde, acetaldehyde, dimethylol urea, methylol acrylamide, methylene bisacrylamide, cyclotrimethylene trisacrylamide (TAF), dibromobutane, dibromopropane, dibromobutane α-chlorcrycerol, epichlorohydrin, ethylene glycol ciflicidil Examples include ether, glycerin diglycidyl ether, polyethylene glycol diglycidyl ether, and the like.

Among these, preferred are compounds that are soluble in water and are alkaline and stable.

When using a water-insoluble crosslinking agent, care must be taken because the crosslinking reaction will be non-uniform.

Sodium hydroxide or potassium hydroxide is effective as a catalyst for the crosslinking reaction.

In the production of carboxymethylated starch according to the present invention, since the viscosity is low during the crosslinking reaction, a reaction vessel with a special structure is not necessary, and a conventional reaction vessel may be used.

However, in the carboxymethylation step, the viscosity increases significantly, so a reaction vessel for high viscosity is required.

Generally, a kneader type reaction vessel for high viscosity is suitable.

The product produced by the method of the present invention has a solid content of 25 to 60% and can be diluted and used as a sizing agent.

Alternatively, it can be dried by a known method (drum dryer, etc.) to form a flaky paste, which can be used by dissolving it in water.

The carboxymethylated starch produced by the method of the present invention has good stability, with no significant difference in base viscosity or colored paste viscosity, whether undried or dried.

Furthermore, there is no significant difference in viscosity even when the paste is made by manual stirring or mechanical stirring.

De-sizing properties, which are a drawback of starch-based sizing agents, are also improved, and dilution resistance is also good.

As described above, by the method of the present invention, it is possible to economically and stably produce carboxymethylated starch with excellent printing suitability.

The invention will now be explained in more detail by way of examples.

In addition, "parts" and "%" in the examples indicate "weight output" and "weight %", respectively.

Example 1 1.2 parts of caustic soda was placed in a 500TLl flask,
Add 250 parts of warm water to dissolve.

The temperature inside the flask was 55℃, and the corn starch was 182℃.
Add part.

This is followed by 1 with isopropanol of epichlorohydrin.
Add 2.8 parts of a 0% solution and carry out a crosslinking reaction at 55° C. for 2.5 hours.

The crosslinking reaction system was in a dispersed state throughout.

The crosslinking reaction product was transferred to a table kneader with an IJ footer, 62.6 parts of sodium monochloroacetate was added thereto, and 94.8 parts of a 22% aqueous solution of caustic soda was gradually added, and the temperature was raised.
Carboxymethylation is carried out for 3 hours at 0°C.

After the reaction, it was dried using a double drum dryer to form flakes.

The degree of carboxymethylation of the product was 0.38.

When a 10% aqueous solution (glue) was prepared from the product, it exhibited a good pasty appearance.

Example 2 A crosslinking reaction was carried out in the same manner as in Example 1 using 0.3 part of methylenebisacrylamide as a crosslinking agent, and subsequent carboxymethylation and drying were also carried out in the same manner as in Example 1.

The degree of carboxymethylation of the product was 0.38.

The product showed good pastiness when a 10% paste was prepared.

Example 3 Polyethylene glycol (molecular weight approximately 400
) A crosslinking reaction was carried out in the same manner as in Example 1 using 1.4 parts of diglycidyl ether, and subsequent carboxymethylation and drying were also carried out in the same manner as in Example 1.

The degree of carboxymethylation of the product was 0.38.

The product showed good pastiness when a 10% paste was prepared.

Example 4 A crosslinking reaction was carried out in the same manner as in Example 1, using potato starch as the starch and epichlorohydrin as the crosslinking agent.
Perform carboxymethylation and drying.

The degree of carboxymethylation of the product was 0.38.

The product showed good pastiness when a 10% paste was prepared.

Example 5 Crosslinking, carboxymethylation, and drying are carried out in the same manner as in Example 1, using tapioca starch as the starch and epichlorohydrin as the crosslinking agent.

The degree of carboxymethylation of the product was 0.38.

The product showed good pastiness when a 10% paste was prepared.

Example 6 1.2 parts of caustic soda is placed in a 1-liter flask, and 350 parts of warm water is added to dissolve it.

The temperature inside the flask was set at 40°C, and corn starch 18
Add 2 parts.

Add 3.7 parts of a 10% solution of epichlorohydrin in propatool, and carry out a crosslinking reaction at 40° C. for 7 hours.

The crosslinking reaction system was in a dispersed state throughout. Transfer the cross-linking reaction product to a 1 liter tabletop Nigu and add 87.5 g of sodium monochloroacetate.
Add 7 parts and further add 28.3% caustic soda aqueous solution 1046
carboxymethylation was carried out at 80° C. for 4 hours.

The reaction product was dried and flaked using a double drum dryer.

The degree of carboxymethylation of the product was 0.53.

The product showed good pastiness when a 10% paste was prepared.

Example 7 1.3 parts of caustic soda is placed in a 500ml flask, and 267 parts of warm water is added to dissolve it.

Set the internal temperature to 50°C and add 200 parts of corn starch.

30.2 parts of a 10% solution of epichlorohydrin in isopropanol is added, and a crosslinking reaction is carried out at 50° C. for 3.5 hours.

The crosslinking reaction product was transferred to a 5-liter tabletop Niguu, 52.2 parts of monochloroacetic acid was added thereto, and further 126.4 parts of a 35% aqueous sodium hydroxide solution was added, and carboxymethylation was carried out at 90° C. for 3 hours.

The reaction product was dried and flaked using a double drum dryer.

The degree of carboxymethylation of the product was 0.36.

The product showed good pastiness when a 10% paste was prepared.

Comparative Example 1 182 parts of corn starch and 250 parts of water were placed in a 1 liter tabletop niegu, and 62 parts of sodium monochloroacetate was added to it.
Add 6 parts of epichlorohydrin, mix and add 0.93 parts of epichlorohydrin.
Add part.

96 parts of a 23% aqueous solution of caustic soda was gradually added, and the temperature was raised to 80° C. for 4 hours to carry out crosslinking reaction and carboxymethylation.

The reaction product was dried into flakes using a double drum dryer.

The degree of carboxymethylation of the product was 0.37.

When a 10 part glue was prepared using the product, non-uniform particles were observed.

Comparative Example 2 A crosslinking reaction, carboxine methylation, and drying were carried out in the same manner as in Comparative Example 1 using 0.3 part of methylenebisacrylamide as a crosslinking agent.

The product had a degree of carboxymethylation of 0.36.

Non-uniform particles were observed when preparing a 10 part paste of the product.

Comparative Example 3 Polyethylene glycol (molecular weight 400) as a crosslinking agent
Using 1.4 parts of diglycidyl ether, a crosslinking reaction, carboxymethylation, and further drying were carried out in the same manner as in Comparative Example 1.

The degree of carboxymethylation of the product was 0.37.

Non-uniform particles were observed when the product was used to prepare a 10 part glue.

Comparative Example 4 8 parts of caustic soda was placed in a 200ml flask, and 21 parts of water was added.
Dissolve in 8 parts.

Add 87.2 rrLl of methanol and bring to 60°C.

To this were added 72.8 parts of corn starch and 25 parts of sodium monochloroacetate with stirring, and further added 4 parts of a 1% solution of epichlorohydrin in methanol, and the mixture was reacted at 60° C. for 3 hours.

After the reaction, filter under reduced pressure and dry.

The product obtained was in powder form.

The degree of carboxymethylation of the product was 0.39.

A 10-part paste was prepared using the product and exhibited good pastiness.

Test Example (I) Preparation of base paste and viscosity measurement Take flaky carboxymethylated starch in a table kneader, add warm water to make a 10% solution, and stir for 30 minutes to prepare base paste.

After the prepared original glue was allowed to stand for 12 hours or more, the viscosity at 2 Orpm was measured using a BH type viscometer (manufactured by Tokyo Keiki Co., Ltd.) using a No. 7 rotor, and this was determined as the original glue viscosity.

(n) Preparation of colored paste and viscosity measurement Prepare colored paste by thoroughly stirring the chemicals in the above ratio by hand.

After this colored paste was allowed to stand for 12 hours or more, the viscosity at 12 rpm was measured using a BM type viscometer (manufactured by Tokyo Keiki Co., Ltd.) using a No. 4 rotor, and this was determined as the colored paste viscosity.

100% mechanically stable colored paste using a homomixer (manufactured by Tokushu Kika Kogyo)
After stirring at 0.00 rpm for 5 minutes, the viscosity was measured in the same manner as the viscosity measurement method for colored paste, and the mechanical stability was quantified using the following formula.

The smaller the number, the better the mechanical stability.

□□□ Polyester knit with colored glue on the printing surface (date 92.5? / m
) using an autoscreen printing machine (manufactured by Showa Kikai) and dried at 130°C for 1 minute.

For color development, use an HT steamer (manufactured by Showa Kikai) at 170°C.
for 7 minutes, and then soaped in the usual manner.

After drying, the uniformity of the printed surface is visually judged.

(7) Color development The reflectance of the test cloth printed in section (5) at a wavelength of 640 mμ is measured using a colorimeter (Kolmorgen KC8-18), and the K/S value is calculated.

Relative values of each are calculated by setting NI/S of the printed fabric using hand-stirred colored paste of commercial product B as 100.

The larger the value, the better the color development.

■ Pour the paste from which particle amount is to be measured into a 120-mesh sieve, wash thoroughly with running water, and drain away the amount that has passed through the sieve.

The remaining residue was transferred to a beaker using methanol and IG
Filter through the glass filter from Step 4.

Dry the filter at 105°C for 1 hour and weigh the amount of particles.

The amount of particles is expressed as a percentage of the sizing agent.

(2) Results As is clear from Table 1, no insoluble particles are observed in the carboxymethylated starch paste obtained by the method of the present invention, and therefore a printed fabric with a uniform printed surface can be obtained.

When a strong shearing force is applied to a glue obtained by a solvent method or a commercially available glue, the viscosity decreases and the color development property also decreases significantly.

The paste obtained by the method of the present invention has good mechanical stability, stable viscosity, and good color development.

Claims (1)

[Claims] 1 Starch is dispersed in 1 to 3 times the amount of water, and crosslinked using a crosslinking agent at a temperature ranging from room temperature to 60°C in the presence of an alkali catalyst, followed by sodium monochloroacetate in the presence of an excess of alkali. Or, a method for producing carboxymethylated starch for printing paste, which comprises carrying out carboxymethylation with monochloroacetic acid.