JPS6343902A - Production of modified starch - Google Patents

Abstract

PURPOSE:To obtain easily and cheaply a modified starch readily soluble in cold water, by adding a suitable amount of boric acid (salt) or a (bi)carbonate to starch, heating the mixture at an elevated pressure under controlled conditions of pH and water content, releasing the mixture into the air to expand the starch grains and grinding it. CONSTITUTION:Starch is mixed with a suitable amount of at least one member (e.g., borax or sodium carbonate) selected from among boric acid (salt) and (bi)carbonate, and if necessary, mixed with other acids. The obtained mixture is fed to a continuous high-pressure heating apparatus having integrated means for agitation, transfer, heating and water supply (e.g., a twin-screw extruder). This mixture is heated to a temperature >=100 deg.C under controlled conditions including a pH of 3-7 and a water content of 10-30%, and the mixture under an elevated pressure is released into the air to fully expand the starch grains. This mixture is ground into particles of a suitable size to obtain the purpose modified starch readily soluble in cold water.

Description

[Detailed description of the invention] l-1 Riju 1 Direct senior 1 (Technical field) The present invention relates to a method for producing processed starch that is readily soluble in cold water.

(Prior art) Pregelatinized starch has been used for various purposes, but
When using this as a laundry starch, it is not easily soluble in cold water and requires heating and dissolution. Furthermore, it has not been used because of its drawbacks such as poor dispersion in cold water.

Technical discussions regarding starch for laundry glue in the laundry industry include:
Almost none. The reason for this is that, in addition to the type of starch used for washing, it is believed that the finishing technique and skill level of the washing far exceeds the quality of the starch used for laundry glue, and has a great influence on the quality of the finished washing. This is because it was

For many years, rice starch has been used as a raw material for industrial and household laundry starch. Although rice starch is expensive, it has a good reputation for its ability to penetrate into fabrics, its flexibility and glossy finish. The main reason for this is that rice starch has extremely small particles. Recently, research into starch for laundry glue has been underway to simplify the process, improve the finish, and even address drainage problems.For example, if cornstarch glue is used.

The finished product has a hard texture, while wheat starch paste can be used to create a soft texture. If you use a mixture of them, you will get a texture that combines the advantages of both.

However, all of these require the starch granules to be gelatinized by heating before use. The quality of the glue varies considerably depending on the conditions for preparing the glue, such as heating, and the glue preparation requires skill. For this reason, modified starches with low gelatinization temperatures, soluble starches, dextrins, and the like are sometimes used as laundry glues.

The purpose of laundry starching is to allow starch molecules to penetrate between the thin fibers and form a thin film of starch on the fibers, which provides the first effect = (1) to the fibers. Add appropriate hardness, texture and elasticity.

(2) Add luster and slip to the fibers to improve comfort.

(3) Iron clothes well to help retain their shape.

(4) Dirt is prevented from penetrating directly into the fibers during wear, and when the garment is first washed, the glue attached to the fibers is washed away and dirt is easily removed.

Gluing that meets the above purpose includes natural products such as the starch glue and french described above, and carboxymethyl cellulose,
There are synthetic products such as polyvinyl alcohol. 1 of them
Starch glue is relatively often used because it is inexpensive and the glue comes off easily after the first wash.

Starches commonly used as laundry starch are corn starch and wheat starch. However, the production of wheat starch has drastically decreased due to raw material issues and the difficulty of treating wastewater during production, and currently only corn starch is used as starch for laundry glue.

An example of a method of using corn starch as a laundry starch is as follows: In the laundry industry, it is said to be ``3 years of starvation'', and starvation is considered to be extremely difficult.

(1) Cook Moto-nori (5% Moto-nori) Cook a certain concentration of Moto-nori in advance, and dilute it appropriately depending on the garment to be glued to make a starch solution. An example of how to cook it is to put water into a 101 graduated bucket at the 7th minute mark, add 500 g of cornstarch, and stir well.
Turn on the steam, and when the temperature reaches 80-85°C, turn off the steam and add water or hot water to bring the total volume to 101.

(2) Gluing is carried out in the case of 50 shirts (10 kilograms). Hot water 51 is added to starch 51 and the mixture is placed in a washer for gluing.

As mentioned above, starch cannot be used as laundry glue unless it is heated to form a glue.

On the other hand, gelatinized starch that is soluble in cold water can omit the heat gelatinization process and is easy to use.

Various methods have been developed to produce cold water soluble starch. One method is to pass starch containing water between heated rolls to gelatinize the starch.

After drying, the starch is crushed to obtain dried pregelatinized starch. Another method is to partially hydrolyze starch with an acid or an enzyme at the same time as heating and solidifying it, and then drying it by passing it between heated rolls and pulverizing it to obtain dry pregelatinized starch. Yet another method is to oxidize starch with an oxidizing agent, then gelatinize it, pass it between heated rolls, dry it, and crush it. Yet another method is to add 7-15% borax to starch.

This is a method (US Patent No. 2,819.980) to obtain dry pregelatinized starch by passing it between hot rolls, drying and pulverizing it.

When cold water soluble starches produced by these methods are used as laundry starches, the following problems arise: (1) Production costs are high.

(2) Does not disperse quickly in water.

(3) Leaves are likely to form.

(4) It is not completely soluble in water, and a considerable amount of deposits remain at the bottom of the container when the size solution is stored.

Many businesses in the laundry industry operate on a relatively small scale.

Complete mechanization and automation cannot be expected. Therefore, it is necessary to save labor as much as possible in all processes. Problems (2) and (3) above can be solved by sufficient stirring without the need for heating. The problem with (4) above is that
The pregelatinized starch used must be completely soluble in cold water without forming deposits.

Since this is not possible with conventional pregelatinized starch, it has not yet been solved. The deposits that occur cause uneven gluing.

(Problems to be Solved by the Invention) The present invention is intended to solve the above-mentioned conventional problems, and its first purpose is to provide a powdered starch that is easily soluble in cold water for laundry starch and has the following properties: The object of the present invention is to provide a manufacturing method: (1) It does not require heating, is readily soluble in cold water, and has instant properties.

(2) Even if the raw materials are added all at once during dissolution in cold water, no leftover powder will be produced, even if the material is stirred for one instant. It also has excellent monodispersibility.

(3) No deposits should be formed when dissolved in cold water and left to stand.

(4) The laundry starch must meet the following four conditions.

Namely.

b) Add appropriate hardness, texture and elasticity to the fibers.

TI) Adds luster and slip to the fibers, making them more comfortable to wear.

C) Help with ironing and shaping of clothing. and.

2) Prevents dirt from penetrating directly into the fibers during wear, and when washed for the first time, the glue applied to the fibers is washed away, and dirt from the fibers is also easily removed.

(Means for Solving the Problems) The present inventors have successfully developed a starch for use in laundry starch that is easily soluble in cold water and has excellent performance that has never existed before. The method for producing soluble laundry starch is as follows:
Appropriate amount of boric acid and chloride in starch.

One or more selected from bicarbonates and carbonates are mixed, and if necessary, other acids are added,
The pH of the resulting mixture is 3-7. It has integrated stirring, transfer, heating, and water supply equipment under conditions of 10 to 30% moisture. In continuous high pressure, pressurization, and heating equipment,
Both were heated to 100°C or higher, and the mixture under pressure was released into the atmosphere to sufficiently expand the starch granules.

It is characterized by grinding into suitable particles, thereby achieving the purpose.

The starches used are corn starch, waxy corn starch, potato starch, sweet potato starch, and wheat starch.

Any industrially produced starch such as davio castarch may be used. Furthermore, starches 6 that are chemically modified from various natural starches, such as mildly hydrolyzed starches such as acid-treated starches, oxidized starches, various starch esters, and various starch esters are also included in the definition of starch herein. Practically speaking, corn starch is preferred because it is produced in the largest quantity and has a stable price. The substance added to starch is boric acid, and the boric acid salt is borax bicarbonate, which is soda bicarbonate.

Soda carbonate is suitable as the carbonate. As other acids, inorganic acids such as sulfuric acid and phosphoric acid and various organic acids can be used. If the substances to be added are finely ground, they can be homogeneously mixed with the starch as is, and these can be added to the starch at a rate of 1/1 minute.

If its particle size is large, it is finely ground in a grinder and then mixed homogeneously with starch. It is preferable to homogeneously mix it with the starch flour and then crush it with a crusher because this increases the uniformity of the mixture.

In addition, if the amount used is small or if the product is S-shaped, it can be added as a suitable solution from the water supply device of the pressurizing and heating device and mixed in the device before being heated.

In this case, the amount of each additive used varies depending on the nature of the additive.

For example, when using boric acid and bicarbonate of soda.

Boric acid 3-10%, bicarbonate of soda 0.1-0.5%.

When using boric acid and borax, boric acid 3-10%, borax 0.1%
~1.5%. 1 when neither boric acid nor borate is used
Soda bicarbonate or soda carbonate is used at 0.1-0.5%. Further, as described below, an appropriate amount of acids is added as necessary to adjust the pH. 12% as total amount of additives
The following is good.

In this way, one can be selected and used from these depending on the purpose of use of the product according to the present invention.

The next important thing is the pH of the mixture obtained by mixing these additives with starch. Take some of the mixture.

Suspend in twice the amount of water and measure the pH. Its pH
should be in the range 3 to 7, preferably in the pH range 4.5 to 6.5, after mixing the additives.
If it deviates from the above-mentioned range, the starch for laundry paste will not have the performance as the object of the present invention. especially.

Dispersibility when dissolving in cold water is poor and particles tend to form. Even if dissolved with strong stirring, deposits are formed when left to stand, resulting in uneven gluing. p) If l becomes too high beyond the above range, especially 8 or more, apply continuous high pressure or pressurization using a two-wheel extruder, etc.

During the heat treatment, the two colors (brown-brown and black) are intense, making it unusable as a laundry paste.

The starch mixed with additives is then subjected to heat and pressure treatment using a twin-screw extruder, etc., but it is important for the present invention that the moisture content during this treatment is within the range of 10 to 30% by weight. is an element. There are no particular restrictions on the method of adjusting moisture.

When the water content exceeds 30% by weight, the swelling effect described below disappears, and the solubility of the finished product in cold water deteriorates. A more preferable water content is in the range of 10% to 20% by weight.

The two-shaft extruder used for heat and pressure treatment of additive-mixed starch is used in the plastics industry.

It may be one that is widely used in the food industry and does not need to be of any special standard. A two-axis extruder.

In the present invention, although a co-rotating type is used, the present invention is not particularly limited to a different-direction rotating type. It is preferable that the pressure at the tip can be increased to at least 100 kg/c+jG and up to 200 kg/aJG. This extruder treatment ensures that the feedstock material is sufficiently and moderately packed to achieve sufficient starch particle expansion, and that fine needle-like crystal-like substances are observed when the product is crushed and examined under a microscope. When microbubbles appear when the starch is dissolved in cold water, the starch for laundry glue that best meets the purpose of the present invention can be obtained. When glass-like lumps are observed when the crushed pieces of the product are examined under a microscope, the object of the present invention will not be achieved9. The present invention was completed by researching the combination of mixing treatment of chemicals such as acids and starch, heating/pressure/swelling treatment of mixed starch using a twin-screw extruder, and pulverization of the puffed starch. The starch for laundry paste that is easily soluble in cold water obtained by the method of the present invention has superior performance and reduced production costs as compared to products produced by conventional production methods, and is extremely useful industrially.

Note that the cold water easily soluble starch obtained by the present invention has the following features.

■When added to cold water, it does not turn into powder, but forms a sufficiently uniform dispersion, is stable for a long time, and produces almost no deposits.

(2) The viscosity of this dispersion is about 1/10 lower than that of pregelatinized starch produced by conventional roll heating and drying methods, and the viscosity of this dispersion does not change even when heated.

■The adhesive strength is also strong, and by making the solution at an appropriate concentration,
Of course, it can also be used as an adhesive.

■The process is simple, there is no drying process, and the production cost is low. Therefore, it can be said that the 2-layer method can be used not only as a laundry thickener but also for other conventional pregelatinized starches or modified starches, and is a new method for producing modified starches.

The manufacturing process of pregelatinized starch using the conventional roll heating method and the manufacturing process of cold water easily soluble starch according to the present invention are as follows.

(Left below) In the conventional method, the R starch slurry can be used directly as a raw material, but in the method of the present invention, starch that has been dried must be used.

However, the conventional method requires a drying step after the heat gelatinization treatment.

Comparing an example of the drying costs of these two methods, drying after heating and gelatinization using a conventional hot roller etc.

The drying cost (airflow drying) for preparing dried starch according to the present invention is about 6 yen per kg, whereas it costs about 25 yen per kg of the product.

This drying cost is approximately 2% of the price of raw starch.
7-28% and 6-7%.

There are no major differences in other operating costs (electricity costs, etc.) between the two processes. Therefore, the manufacturing cost is considerably lower than that of the conventional method.

The product produced by the method of the present invention has the advantage that it is easily soluble in cold water compared to the conventional method, but has the disadvantage that the inn preparation has a high dust generation property. It has been found that this drawback can be easily prevented by spray-mixing 0.5 to 2% of oils, and that it does not have any negative effect on the easily cold water-soluble bidispersibility. Preferably, liquid paraffin is mixed by spraying in a powder mixer. Depending on the intended use of the product, one edible oil may be used.

J Koutun - Example - ↓ 2 kg of cornstarch (manufactured by Sanwa Starch Industries Co., Ltd.) and boric acid (IJ, S, Borax & CheIl, C
orp, powder form) 500g,! 25 g of borax (A-Fine, manufactured by US Corporation) was added thereto, and the mixture was passed through a pulverizer (Model AP-1, manufactured by Hoiyo Micron Ryōryō) to obtain a homogeneous mixture. An additional 8 kg of cornstarch was added and mixed well.

The pl () of this additive-mixed starch was 5.7. This pi () was measured by adding twice the amount of water to this additive-mixed starch and measuring the pH of the suspension water obtained. .

As shown in the table, the pH after treatment had increased to 7.0. This water content was 12.5%. This additive-mixed starch was then subjected to a twin-screw extruder (model 11i1-45-15 manufactured by Kowa Kogyo Co., Ltd.). The screw pattern of this extruder was a pair of fly-cut reverse screws and a kneading disk attached to the tip of a normal screw. There was one opening, and its diameter was 5 mm. Raw materials were supplied at a rate of 500 g per minute, water was supplied only at the start of operation, and no water was added thereafter. The rotation of the screw was 290 revolutions per minute. The temperature conditions for Extrap and -der are 30℃ near the screw supply port and 8℃ in the middle part.
0”c.

The temperature at the tip was 160°C, and the temperature at the goo was 125°C.

The pressure at the tip was 15 kg/efflG. The expanded starch discharged in the form of strands from the goo is produced by a single rotating blade (6
It was hot-cut at a speed of 1,700 revolutions (1,700 rpm), and immediately transported by air to a fluidized bed cooling device where it was cooled to room temperature. This was crushed and passed through a 20-mesh sieve, and the resulting crushed product was used as a sample for the following starch suitability test for laundry paste. The particle size distribution of this sample was as follows: 20 mesh to 60 mesh was 35.6% of the total weight, and 60 mesh to 150 mesh was 3967% by weight.
The amount of through was 24.7% by weight. The apparent specific gravity was approximately 0.15. The suitability test of cold water soluble starch for laundry glue was carried out in the following manner.

a. Viscosity i) Viscosity when cold: 1.Pour 450ra 1 of pure water at 30°C into a 500m6 stainless steel beaker.

2. Collect 25g (anhydrous equivalent) of the sample using a top balance, pour it into a beaker little by little and dissolve while stirring well, and further dilute with water to make a total amount of 500g.

3. After this, stir at room temperature for 30 minutes. Stirring is 550
rpa+ to 600 rpm.

4. Measure with a type B viscosity needle at 30°C.

ii) The liquid after heating viscosity 1 and cold viscosity measurement is heated to 90° C. while stirring well in a hot water pot with vigorous boiling.

2. When the temperature reaches 90°C, add pure water to bring the content to 500g, and cool while stirring in running water.

3. Measure with a B-type viscometer at 30°C.

If the heated viscosity is higher than the cold viscosity, there are starch granules remaining in the product that are insufficiently swollen, and these are
It is thought that it has changed to exhibit viscosity, so when it is dissolved in cold water and used, this will cause an uneven state after gluing or ironing.

b. Amount of deposits 1. Collect 4g (actual) sample using a top balance.

2. Pour water into a 100 mA beaker and dissolve the sample while stirring well.

3.Pour the dissolved solution into a 200m6 measuring cylinder and add water to make the total volume 200ml.

4. Leave at room temperature for 3 hours, and after 3 hours, read the volume (mA') of the deposit.

The formation of this deposit means the presence of non-uniform particles of starch in the liquid, which is not desirable as a starch for laundry glue.

C1 The apparent specific gravity is 200mj in a plastic graduated cylinder with a specific gravity of 1.20On+6! Pour the contents gently until it reaches 100 degrees, measure the weight of the contents, and calculate the rough appearance and specific gravity.

2. Measure the volume when tapping the graduated cylinder sufficiently, and calculate the apparent density and specific gravity from that value.

If the apparent specific gravity is extremely high, solubility is often poor.

d, pH Collect 3g of the sample on an anhydrous basis, and
Pour the mixture into a 100 ml beaker containing +1 pure water little by little while stirring, then measure the total amount using a PH meter.

Determine an appropriate pH range depending on the intended use of the product.

e. For gluing, take 4g of the test sample (washing starch suitability test) in terms of dryness, dissolve it in water at 30°C, and make a total of 200m of water.
Make 1 liter of 2% starch solution. Dip a bleached cloth soaked in water (squeeze) thoroughly into this starch solution, shake off the excess starch solution, and then dry. Iron the half-dry state and check the condition and glossiness of the glue with the naked eye. Alternatively, use a magnifying glass or even a drop of iodine solution and observe under a microscope.

Comparison ■ Pressurization was carried out in the same manner as in Example 1 except that only cornstarch was used and boric acid and borax were not used.

It is heat treated. The properties of starch for laundry paste obtained through the above tests are compared with conventionally produced Al°2 Acorn Starch (manufactured by Sanwa Starch Industries Co., Ltd.) and comparative examples, as shown in the following table.

(Left below) When conventional pregelatinized cornstarch is dissolved in water and examined under a microscope, sections of swollen starch granules of 0.1 to 0.2 mm are observed, and it is not completely suspended. Therefore.

When dissolved in water at 30°C and measured, the viscosity was 280 cp, but when dissolved in hot water at 90°C and then cooled to 30°C, the viscosity was measured to be 820 C[). As much as 40% of the glue dissolved in cold water was deposited when left standing. This conventional pregelatinized cornstarch is not completely gelatinized.

This shows that there is still room for melting and thickening due to heat.

On the other hand, when the modified starch produced in Example 1 was dissolved in water and examined under a microscope, its original shape completely collapsed at a rate of 150 mm.
No shape is allowed. The viscosity when cold and when heated is 62. Furthermore, no deposits are generated. This shows that it is almost completely gelatinized. Moreover, the viscosity is extremely lower than that of conventional pregelatinized cornstarch. This means that the starch molecules are subjected to large mechanical shearing due to the heating, pressurizing, and swelling treatment performed by the twin-screw extruder.

In other words, the starch molecules are fragmented and become smaller. This word is advantageous in terms of permeability of laundry starch into fibers, and is thought to be the reason why it adheres uniformly.

Furthermore, the three most important features of the processed starch of the present invention are:

It has excellent dispersibility without turning into powder when dissolved in cold water, and dissolves easily. In the case of conventional pregelatinized cornstarch and comparative examples, the sample was added in very small amounts at a time of 7 while stirring the water quite vigorously during dissolution.

Leaves will form. - After that, the powder will remain as it is.

It will not dissolve with slight stirring.

n1? In place of the cornstarch in Example 1, 6 potato flour was used. Same as starch obtained in Example 1.

A starch for laundry paste, which was easily soluble in cold water and had good suitability as a laundry paste, was obtained.

Wheat starch was used instead of cornstarch in Example 1. As with the starch obtained in Example 1, a starch for laundry paste that was easily soluble in cold water and had good suitability as a laundry paste was obtained.

500 g of boric acid and 15 g of bicarbonate of soda were thoroughly mixed with 10 kg of corn starch. The pH at this time was 6.0. Moisture was 12.8%. Regarding this product, processed starch was prepared in the same manner as in Example 1.

As with the starch of Example 1, a starch for laundry paste, which had good suitability as a laundry paste and was easily soluble in cold water, was obtained.

Big storm Mix 10kg of cornstarch and 200g of borax thoroughly.

Further, 500 l of 10% sulfuric acid was mixed well and then sprayed. The pH at this time was 5.5. Moisture is 13.2%
Met. The following is all about this thing, Example 1
Starch was prepared in the same manner. Like the starch of Example 1, all the laundry starch properties were good.

A starch for laundry paste which is easily soluble in cold water was obtained.

10 kg of Yudan corn starch and 3 parts of bicarbonate of soda as a food additive
0 g and 20 g of citric acid, which is also a food additive, were thoroughly mixed through a pulverizer. The pi at this time is 6. l,
Moisture was 12.7%. Regarding this product, starch was prepared in the same manner as in Example 1.

The modified starch according to this example has an effective suitability as a low-viscosity thickening agent that is easily soluble in cold water, and is good as a thickening agent for food products.

1. 10 g of the cold water easily soluble modified starch obtained in Example 4 was thoroughly mixed and stirred, and 100 g of liquid paraffin heated to about 60° C. was spray-mixed.

Unlike the starches produced in Examples 1 to 6, which generate some dust, this modified starch hardly generates dust, and is convenient in use. At the same time, the effectiveness of the processed starches of Examples 1 to 6 according to the present invention was not impaired in any way.

While vigorously mixing and stirring 10 kg of the cold water easily soluble modified starch obtained in Example 6, add 100 kg of corn salad oil.
g Spray mixed.

While the starch produced in Example 6 has a slight dust-generating property, this modified starch has almost no dust-generating property and is convenient in use.

At the same time, the effectiveness of the processed starch of Example 6 according to the present invention is not impaired in any way.

(Effects of the Invention) According to the method of the present invention, as described above, the mixing treatment of additives such as boric acid, borax, carbonates, bicarbonates, and other acids with raw starch, the pH of the additive-mixed starch, and the water content After strictly regulating the process, a skillful combination of continuous high pressure, pressurization, heating, and swelling treatment using a two-screw extri-kneader, etc., and pulverization of the starch puffed material are used.

■ A starch with excellent dispersibility that easily dissolves in cold water without forming a lump by simple stirring; ■ A starch that does not form deposits even if left standing after being dissolved in cold water; and ■ A starch that has an appropriate hardness on the fiber It provides texture, elasticity, shine, and slippage, making it comfortable to wear.

It is possible to obtain a starch that improves iron shaping and helps shape retention, and also allows stains on fibers to be easily removed by washing. By selecting a combination of the various conditions described above, the production method of the present invention can produce a processed starch that is easily soluble in cold water and has characteristics that can be applied to a variety of uses. Moreover, the manufacturing process is significantly simpler and easier than conventional methods, and the manufacturing cost is also significantly lower than conventional methods.

that's all

Claims (1)

[Claims] 1. Mix an appropriate amount of one or more selected from boric acid, borates, bicarbonates, and carbonates with starch, and further add other acids as necessary; pH of the resulting mixture
is 3 to 7 and the moisture content is 10 to 30%, stirring,
The starch granules are heated to at least 100°C in a continuous high-pressure, pressurized, and heated device that has integrated transfer, heating, and water supply devices, and the mixture under pressure is released into the atmosphere. A method for producing a processed starch that is readily soluble in cold water, which comprises sufficiently expanding the starch and then pulverizing it into suitable particles. 2. The manufacturing method according to claim 1, wherein the borate is borax, the bicarbonate is sodium bicarbonate, and the carbonate is soda carbonate. 3. The total amount of the additives is 0 per 100 parts by weight of starch.
．． The manufacturing method according to claim 1, wherein the amount is 1 to 30 parts by weight. 4. The manufacturing method according to claim 1, wherein a two-shaft extruder is used as the continuous high pressure, pressurization, and heating device. 5. Processed starch that is easily soluble in cold water by spray-mixing 0.5 to 3% of oil to the powdered starch that is easily soluble in cold water produced by the method described in claims 1 to 4. Production method.