JPS6339708B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel acid-treated clay composition that is particularly suitable as a fabric softener. Normally, when clothes are washed, they stiffen due to deterioration of fibers and shrinkage of woven structures, so it is recommended to soften clothes by adding cationic surfactants in the final rinse step after washing. It is being said. However, cationic surfactants have the disadvantage that when they are adsorbed in large amounts to clothing, they make the fiber surface hydrophobic and reduce water absorption. Addition (Japanese Unexamined Patent Publication No. 49-85102,
JP-A-49-132104) and the combination of a specific clay and a specific cationic surfactant (JP-A-50-3, JP-A-50-4) have been proposed. ing. By the way, the clay mixed in the above cleaning agent is
All of these are smectite-type clays, or bentonites, whose main component is clay minerals belonging to the montmorillonite group such as montmorillonite, saponite, hectorite, and nontronite, but these minerals contain iron ions in their crystal lattices and on the particle surfaces. Or, the presence of iron oxides causes problems such as coloring of clothing during softening treatment. In particular, when bentonite is used in detergents, the clay minerals of the montmorillonite group, which is the main component of bentonite, quickly adsorb to clothing in water, so dirt attached to clothing is not completely removed. Then, a thin film of clay minerals will cover it. In order for the clay minerals adsorbed in this way to exert a softening effect, they must be retained on the fiber surface throughout the washing, rinsing, dehydration, and drying processes, so it is natural that Unremoved stains also remain on the clothes, resulting in a decrease in cleaning effectiveness, and with the addition of coloration from bentonite itself, the clothes become increasingly yellow. In order to prevent undesirable coloring and deterioration of cleaning effectiveness due to the iron content in bentonite,
Bentonite is boiled in a mineral acid such as concentrated sulfuric acid,
Attempts have been made to remove iron, but if the processing conditions are made too strict to completely remove iron, the softening effect is lost as the structure of the clay mineral is destroyed, making it difficult to control the conditions. However, since a large amount of acid must be used, the equipment must be large-scale, which is a disadvantage, and it cannot be said to be a satisfactory method for practical use. The present inventors have overcome these drawbacks of conventional bentonite, and have developed a fabric softener that can be used as a fabric softener without coloring the fabric, and that can be blended into detergents. As a result of intensive research to develop clay that does not reduce its cleaning power, it was surprisingly possible to achieve this goal by adding citric acid to clay that had been treated with hydrochloric acid in a semi-moist state. Based on this finding, we have accomplished the present invention. That is, the present invention provides an acid-treated clay composition in which 1 to 10 parts by weight of citric acid is blended with 100 parts by weight of clay whose main component is a clay mineral belonging to the montmorillonite group that has been treated with hydrochloric acid in a semi-moist state. It is something to do. The clay minerals belonging to the montmorillonite group used in the present invention include montmorillonite, saponite, hectorite, sauconite, and nontronite, all of which have the property of swelling significantly when placed in water. This is because these clay minerals form a layered structure in which three lattices (SiO ₂ lattice/Al ₂ O ₃ lattice/SiO ₂ lattice) overlap, and these three
This is because water molecules enter between one lattice unit and the adjacent lattice unit, expanding the interlayer space, and eventually 1~
It becomes a thin film-like particle with a thickness of about 10 nm and is dispersed in water. In the present invention, it is necessary to use a clay whose main component is a clay mineral belonging to the montmorillonite group, which has been treated with hydrochloric acid in a semi-moist state. Here, the semi-moist state means a state in which liquid is added little by little to the powder and stopped before it becomes a paste, that is, a state in which the powder becomes a "collection of wet powder". In common terms, this refers to a dry or crumbly state, or in academic terms, it refers to the Pendular range or Funicular-1 range (published by Maruzen Co., Ltd., "Powder Theory and Application", page 500).
This corresponds to The semi-moist state when treating with hydrochloric acid in the present invention may be prepared, for example, by adding hydrochloric acid little by little to dry clay and stirring, or by achieving a semi-moist state using water and then adding hydrogen chloride. It may be blown into a state containing hydrochloric acid. The amount of hydrochloric acid or hydrogen chloride used at this time varies depending on the iron content in the raw clay and the strength of its adhesion to clay minerals, but it is usually 100 parts by weight of clay converted to the amount of hydrogen chloride. The amount ranges from 10 to 50 parts by weight. In addition, when using hydrochloric acid, it is necessary to determine the concentration of hydrochloric acid in consideration of the desired amount of hydrogen chloride and the amount of water required to obtain a semi-humid state. Next, hydrochloric acid treatment can be performed by heating in a semi-humid state in the presence of hydrochloric acid. This heating time varies depending on other conditions, but is usually in the range of several hours to several tens of hours. It is possible to remove iron to a certain extent simply by keeping it at room temperature in a closed container without heating, but it takes a long time, several days or more, and the excess hydrochloric acid must be removed by volatilization. is not carried out, so it is not preferred in practice. The treatment of clay in the present invention requires the use of hydrochloric acid. It is possible to remove iron using mineral acids other than hydrochloric acid, such as sulfuric acid or nitric acid, but it is difficult to control the conditions so that the clay mineral structure is not destroyed due to excessive treatment, and unreacted acid This method has the disadvantage that troublesome operations must be performed to remove it, making it impractical. When using hydrochloric acid, even if an excessive amount is used to increase the reaction rate, it evaporates as hydrogen chloride during heat treatment, so there is no need to pay attention to condition control, and unreacted hydrochloric acid can be easily removed. can do. In the clay treated with hydrochloric acid in this way,
Iron oxide adhering to the surface of the clay mineral particles and iron ions between the layers or within the crystal lattice of the clay mineral are desorbed and solubilized. By the way, this solubilized iron only shows a pale yellow color under acidic conditions.
Under neutral or alkaline conditions, such as in washing and rinsing liquids, iron ions once made water-soluble become iron hydroxide, rapidly oxidized and begin to turn brown, and are adsorbed onto clothing. It may cause yellowing or reduce the cleaning power of detergent. Therefore, the clay treated with hydrochloric acid is not suitable as it is to be incorporated into a detergent or to be added to washing water as a softening agent during rinsing. In the present invention, by adding citric acid to the clay treated with hydrochloric acid, it is possible to soften clothes without reducing detergency or discoloring clothes even under neutral or alkaline conditions. It can be carried out. This citric acid may be added at the time of hydrochloric acid treatment, or may be added after the hydrochloric acid treatment is completed. The blending amount of citric acid varies slightly depending on the amount of iron in the raw clay, the amount of solubilized iron ions, etc., but it is 1 to 10 parts by weight per 100 parts by weight of clay.
Preferably it is within the range of 2 to 6 parts by weight. Methods of adding citric acid include dissolving it in hydrochloric acid and adding until it becomes semi-moist, making the clay semi-moist with a citric acid solution and then blowing in hydrogen chloride, and spraying the citric acid solution after treating it with hydrochloric acid. Any method can be used. Among these methods, the method of adding citric acid dissolved in hydrochloric acid is advantageous in terms of ease of operation, and the method of adding it after the acid treatment is advantageous in terms of effectiveness. In the hydrochloric acid-treated clay obtained in this way, most of the added hydrochloric acid has been volatilized by heating, but some of it is adsorbed to the clay and remains, or remains as an acidic salt, so it is not acidic. show. Therefore, if stored as is, it will not only corrode the container, but also generate a pungent odor of hydrogen chloride.
Alternatively, when blended into detergents, it brings about the undesirable effect of losing the effect of fragrances. In order to improve these drawbacks, it is preferable to prepare the desired composition and then neutralize it by adding a water-soluble basic substance. As such a basic substance, an aqueous solution of sodium hydroxide, sodium carbonate, etc. is preferable. When using the composition of the present invention as a softening agent, it is desirable to form it into granules for handling reasons, although this has nothing to do with the softening effect. In this way, even if it is blended into a cleaning agent, it can be avoided that the entire product becomes colored and the product value decreases. In addition to the composition of the present invention, granulating agents, perfumes, anti-caking agents, dyes, pigments, etc. can also be added to this softener. Examples of granules include binders such as ethylene glycol and carboxymethyl cellulose, and apparent density regulators to prevent uneven distribution of softeners when they are blended into detergents. After the composition of the present invention is used in a detergent, it can be treated with a conventional fabric softener containing a cationic surfactant as a main component in the rinsing step. In this way, the effect can be significantly enhanced compared to when a conventional fabric softener is used alone. In order to incorporate the composition of the present invention into a cleaning agent, it is preferable to mold it into granules and mix them as described above, but if desired, it may also be added in powder form to the cleaning agent slurry before spray drying. can. When forming into granules, approximately 50 to 500 μm (passes through a Tyler standard sieve with 270 to 32 mesh openings)
It is preferable to have a particle size of . The detergent to which the composition of the present invention is blended as a fabric softener may be any conventional laundry detergent and is not particularly limited. Examples of surfactants used in this case are:
Alkali metal salt or magnesium salt of linear alkylbenzenesulfonic acid having an alkyl group having 10 to 15 carbon atoms, alkali metal salt or magnesium salt of α-olefin sulfonic acid having 12 to 20 carbon atoms, alkyl sulfuric acid having 10 to 18 carbon atoms Sodium salts of esters, alkali metal salts of α-sulfo fatty acid esters with 12 to 20 carbon atoms, alkali metal salts or magnesium salts of sulfuric esters of ethylene oxide adducts of higher alcohols with 8 to 20 carbon atoms, Sodium paraffin sulfonate, carbon number 12-18
HLB approximately 8 selected from anionic surfactants such as Setsuken, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene sorbitan fatty acid ester.
~18 nonionic surfactants may be mentioned. These surfactants are blended into the cleaning agent in a proportion of 5 to 40% by weight, preferably 10 to 30% by weight.
In the case of nonionic surfactants, since they tend to inhibit the dispersion of the clay composition of the present invention in water, the amount incorporated is preferably about 15% by weight or less. In addition, as the builder used in combination, inorganic and organic builders commonly used in laundry detergents can be used. Examples include sodium or potassium salts of condensed phosphoric acids such as tripolyphosphoric acid, hexametaphosphoric acid, pyrophosphoric acid, sodium or potassium carbonate (soda ash), sodium or potassium silicates, inorganic builders such as synthetic zeolites, or sodium polycarboxylate. Alternatively, organic builders such as potassium, sodium or potassium citrate, sodium nitrilotriacetate (NTA) or potassium, etc. can be mentioned, and these can be used alone or in combination. This builder works to keep the cleaning solution alkaline, preferably in the pH range of about 8 to 11, and also prevents calcium and magnesium ions in the cleaning solution from bonding with the anionic surfactant. Dirt components once separated from the fabric,
In particular, it helps prevent solid particle components from re-depositing on fabrics and improves fabric cleaning performance. In addition, other components commonly used in general detergent compositions can be blended. These include, for example, fabric re-stain inhibitors such as polyethylene glycol (PEG) and carboxymethyl cellulose (CMC), cleaning aids such as sodium sulfate, fluorescent agents,
These include dyes, enzymes, and bleach. Water can also be added. Next, the present invention will be explained in more detail with reference to examples, and the evaluation results shown in each example were performed using the following test method. (1) Cleaning power test method (1) Artificially soiled cloth After drying clay mainly composed of crystalline minerals such as kaolinite and vermiculite as inorganic soils at 200℃ for 30 hours, the average particle size was 1 μm. It was crushed and used. Add 3.5 g of gelatin and 0.25 g of carbon to 950 c.c. water,
After dissolving gelatin at about 40℃, we use a powerful emulsifying and dispersing machine called Polytron (Switzerland).
(manufactured by KINEMATICA) to disperse carbon in water. Next, 14.9g of inorganic dirt was added and dispersed with Polytron, and then 31.35g of oily dirt was added.
was added, emulsified and dispersed using a Polytron to create a stable dirt bath. 10cm x 20cm in this dirt bath
specified cleaning cloth (Japan Oil Chemists Association designated cotton cloth 60
After soaking the soil, the water was squeezed out using two rubber rolls to equalize the amount of dirt attached. After drying this soiled cloth at 105° C. for 30 minutes, both sides of the soiled cloth were rubbed 25 times on each side. This was cut into 5 cm x 5 cm pieces with a reflectance in the range of 42±2% and used as a dirty cloth. The soil composition of the artificially soiled cloth thus obtained is shown in Table 1.

[Table] (2) Sebam cloth Cloth (cotton knitted 5cm x 5cm) with 60mg of oil-based dirt shown in Table 1 attached to each piece. (3) Clean knitted cloth Cotton knitted cloth (same cloth used for sebum cloth) (4) Cleaning method The cleaning device is USTesting's Terg-O-
Using a tometer, put 10 pieces of artificially soiled cloth and 3 pieces of Sebum cloth, then add a clean knitted cloth, adjust the bath ratio to 30 times, and set the bath ratio to 120 rpm.
Wash at 25 °C for 10 min. Use 900 ml of cleaning solution with a detergent concentration of 0.133%, and rinse with 900 ml of detergent concentration.
ml of water for 3 minutes. The water used was 3°DH. (5) Cleaning power evaluation method Cleaning power (%) = (K/S of dirty cloth - K/S of cleaning cloth) / (K/ of dirty cloth
S - K/S of unstained cloth) x 100 K/S = 1 - R/100 ² /2R/100... [Kubelka-Munk equation] R is measured by Carl Zelss's ELREPHO reflectance meter Reflectance (%). The values in the test examples are the average values of 10 test artificial soiled cloths. (2) Softness test method (1) When mixed with detergent ``Commercially available cotton towels were washed in a regular two-tank electric washer using a commercially available heavy-duty laundry detergent, and the washing and drying process was repeated three times. Removes various processing agents that have adhered to towels.'' The washing tank of a two-tank washing machine (washing tank capacity 30, jet type for washing, centrifugal type for dehydration)
Add 30°C tap water (hardness approximately 3°DH), 40g of detergent, and 1kg of the above-treated towel, and wash for 10 minutes. After rinsing twice with the same tap water and centrifuging dehydration, hang it outside to dry. The softness of the towel after drying was evaluated by 10 people using the method described in "Industrial Sensory Testing Handbook" (edited by the Japan Society of Science and Technology Sensory Testing Committee, published by JUSE Publishing Co., Ltd., 1963), pages 300 to 309. Measured according to. According to Sheffe´'s paired comparison method, if there is a difference in softness between a pair of towels washed with two different detergents, the softer one will receive +2 points and the harder towel will receive +2 points. -2 points are given to the towels, if there is a slight difference, +1 points and -1 points are given respectively, and if there is no difference at all, 0 points are given to both. The scores obtained in this way were statistically processed using a computer, and a relative ranking of flexibility was determined. (2) When mixed with a fabric softener A commercially available cotton towel that has been washed, dried, and treated in the same manner as above is soaked in the fabric softener solution for a certain period of time, dehydrated in the same manner, and then hung outdoors. and dry. The test fabrics were thus evaluated in the same manner as described above. (3) Coloring test method Among each group made up of test fabrics of the same type, the one with the deepest redness as determined by naked eye observation is rated 2.0, the palest one is 0.0, and the one in between is 1.0. do. Using these criteria, 10 people scored all the test fabrics in each group by assigning one of the above numerical values, and the sum of the numerical values for each test fabric was averaged to obtain the score. Example 1 35.0 g of concentrated hydrochloric acid in which 5.0 g of citric acid anhydride was dissolved was added to 100 g of bentonite (mainly Na-type montmorillonite) produced in Wyoming, USA.
After stirring well, it was heated. The reactant was taken out, and a 20% aqueous solution of sodium hydroxide was sprayed and mixed to adjust the pH to 6.5. (PH is measured after adding 5% clay to pure water and stirring well.) Add 25℃ tap water to a two-tank electric washing machine (washing tank has a capacity of 30, washing is a jet type, and dehydration is a centrifugal separation type). (Hardness about 3゜DH) and 5g of the above acid-treated clay were added and dispersed well, then 1 cotton towel
Kg was added and stirred for about 5 minutes. The towels were taken out, dehydrated, air-dried, and the softness and yellowing (change in redness) of the towels were measured. For comparison, the same procedure was carried out using raw material bentonite without acid treatment (Comparative Example 1-1), clay treated with acid without adding citric acid (Comparative Example 1-2), and clay The softness and yellowing of the towel were similarly measured in the case where no towel was used (control). The results are shown in Table 2.

[Table] Example 2 30 g of concentrated hydrochloric acid was added to 100 g of bentonite produced in Wyoming, USA (main component is Na-type montmorillonite), mixed well, and reacted by heating. After the reaction is complete, spray 100 ml of 6% anhydrous citric acid aqueous solution onto the clay, stir, and then add sodium hydroxide.
The pH was neutralized to 7.2 by spraying a 20% aqueous solution. moisture
Dry until 10% and add white carbon there.
After adding 20 g of titanium oxide and 1.0 g of titanium oxide and mixing well, the mixture was granulated in a fluidized bed granulator while spraying water, and dried again to have a moisture content of 8%. Of these, the granular clay of 32 mesh passes and 100 mesh passes was used in the same manner as in Example 1 (however, 8 g of clay was used) to measure the softness and yellowing (change in reddish shade) of the towel. For comparison, raw bentonite without acid treatment (Comparative Example 2-1), acid-treated clay without citric acid (Comparative Example 2-2), and acid-treated clay in which raw bentonite was boiling-point treated with concentrated hydrochloric acid (Comparative Example 2-1) Example 2-
3) was similarly granulated with white carbon and titanium oxide, and towels were treated with each. A case of using only water without adding any clay (control) was also conducted. The results are shown in Table 3.

[Table] Example 3 Water was added to 100 g of bentonite produced in Gunma Prefecture, and the mixture was stirred well to make it semi-moist, and then reacted with hydrogen chloride gas while heating in an autoclave.
After the reaction, an aqueous citric acid solution was sprayed onto the clay in an amount equivalent to 3 g of citric acid, and the clay was further neutralized in the same manner as in Example 1. Pour 30 g of tap water into the washing tank of the same washing machine used in Example 1, add 40 g of commercially available heavy laundry detergent and 2.5 g of the above acid-treated clay, disperse, and then add 1 kg of cotton towel. Wash for 10 minutes, rinse once with the same tap water, then dehydrate.
Air dried. For comparison, raw bentonite without acid treatment (Comparative Example 3-1), clay without citric acid (Comparative Example 3-2), and clay made by boiling the same bentonite in concentrated sulfuric acid and washing with water (Comparative Example Towels washed in the same manner using 3-3) and those washed only with a detergent without using clay (control) were prepared, and their softness and yellowing were relatively evaluated. Also, by keeping the same weight ratio of cleaning agent and clay,
The detergency against artificially soiled cloth was also measured using a tergotometer. The results are shown in Table 4.

[Table] Example 4 Two types of bentonite produced in the United States [one mainly composed of Na-type bentonite (A) and one mainly composed of saponite (B)] were treated with acid and citric acid was added using various methods. . 80 g of the treated clay and ±20 g of calcined diatom were mixed and granulated into 16 mesh passes and 48 mesh overs using a dish-type granulator while spraying water. It was dried until the moisture content was 6% to obtain granular clay. A slurry in which various components other than clay were mixed was spray-dried to obtain a granular cleaning agent, and the above-mentioned granular clay was dry-blended to the slurry to obtain the following composition. Component weight% LAS-Na ^* 16 AES-Na ^** 4 Sodium pyrophosphate 15 Sodium silicate (JIS No. 2) 10 Sodium carbonate 6 Sodium sulfate 23 Beef tallow 2 PEG#6000 ^*** 1 Clay 15 Water 8 *Direct Sodium chain alkylbenzene sulfonate (average molecular weight 346) **Sodium alkyl ethoxy sulfate (alkyl group has 12 to 15 carbon atoms, EO = 3) ***Polyethylene glycol with average molecular weight 6000 Using the cleaning agent thus obtained, Cotton towels were washed, and the softness and yellowing of the towels were evaluated relative to each other, and the detergency was measured using a tergotometer.
The results are shown in Table 5. In addition, in the table (control)
In this case, the clay was replaced with the same amount of sodium sulfate.

【table】

Claims (1)

[Claims] 1. An acid-treated clay composition prepared by blending 1 to 10 parts by weight of citric acid to 100 parts by weight of clay, the main component of which is a clay mineral belonging to the montmorillonite group, which has been treated with hydrochloric acid in a semi-moist state.