JPH0437120B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing an acidic detergent containing colloidal silicon dioxide as a thickener. Naturally, the effect of the cleaning agent increases as the contact time between the target surface and the cleaning agent increases. Foaming and thickening by adding soluble thickeners are used as a means to achieve this goal, but acidic detergents themselves have strong chemical reactivity, so foaming agents and thickeners deteriorate over time. It is not always easy to obtain stable preparations using these methods. Therefore, the next possible method is to thicken the slurry by adding colloidal silicon dioxide, which itself is a solid acid and has poor reactivity with acids. This method was not necessarily easy to adopt, as it was accompanied by various other types of defective phenomena, typified by solidification or sedimentation over time. As a result of research using rheological methods, the inventor discovered that by adding an appropriate protective colloid and stirring vigorously, the dilatancy system was converted into a thixotropic system, that is, the phase was inverted. He discovered that this could be done and completed this invention. There are many brands of colloidal silicon dioxide commercially available. The inventor typically uses the trade name "Shilton"
(manufactured by Mizusawa Chemical Industry Co., Ltd.) in the research, but this does not preclude the use of other brand products in the practice of the present invention. In addition, the three types of "Shilton" are "Lp-1", "Lp-1",
"A", "R", the degree of purification is higher in this order,
In addition, the particle size becomes smaller, but the price also increases in this order. For the purpose of the title, high purity is not necessarily required, and there is a tendency that it is easier to prevent liquid syneresis by using a low-grade product. However, as the quality decreases, the amount of occluded gas increases, and the defective phenomenon of causing an increase in the internal pressure of the container after commercialization becomes noticeable. As a countermeasure for this, you can use "Silton" after burning it to dissipate the stored gas, or you can mix "Silton" with an acid aqueous solution and leave it open and wait for the stored gas to dissipate before using it. An effective method is to create However, the latter is more desirable because in the former, partial fusion of the "silton" particles occurs and the properties of the colloid are slightly degraded. In the latter case, the rate of release of the stored gas increases as the concentration of the acid used and the temperature of the mixture increase. In extreme cases, a method can be adopted in which all ingredients are mixed to complete the designed recipe and then subjected to open aging, but this has the disadvantage that it takes a long time to degas to a level that is acceptable for practical use. arise. Rather, use the appropriate amount of acid in the recipe to make an aqueous solution as highly concentrated as possible.
After processing "Shilton" in advance with this,
It is desirable to complete the formulation by adding the remaining ingredients, and conditions such as the acid used, concentration, temperature, etc. can be appropriately selected in consideration of economic factors. The amount of colloidal silicon dioxide necessary to increase the viscosity of the product and extend its residence time on the surface to which it is applied is generally difficult to determine, as it depends on the personal preference of the user. A survey conducted during this invention research process determined that products containing 13% to 28% were more in line with the preferences of general consumers. There is no reason to limit the type of acid to be added. However, of course, it has a great cleaning effect,
Alternatively, it is advantageous to use an inexpensive one, and it is desirable to select from inorganic acids such as hydrochloric acid, phosphoric acid, sulfuric acid, and nitric acid, and organic acids such as formic acid, oxalic acid, and glycolic acid. In addition, citric acid, malic acid, gluconic acid, ethylenediaminetetraacetic acid, etc. may be added to prevent secondary pollution of waste liquid and other secondary reasons. Furthermore, the combined concentration of acids is 2.73 in total for general household use.
There is a legal regulation that the weight must be less than N, but there is no such regulation when it is intended for commercial use.
An appropriate concentration can be selected depending on the purpose of use. A mixture of "Silton" simply mixed with an acid solution essentially exhibits dilatancy, and this property tends to increase as the amount of "Silton" added increases. Dilatancy means that the bonds between suspended particles are loose and the viscosity is low when left still.
This refers to the phenomenon in which the bonds between particles become stronger and harder when stress is applied. Therefore, there are disadvantages in that the liquid syneresis is large when left still, and it also resists stirring when mixing the product. On the other hand, thixotropy is a phenomenon in which the bonds between particles are strong when they are left still, and when stress is applied, these bonds loosen.Contrary to the above case, it is a phenomenon that becomes hard when left still and becomes soft when stress is applied. . Since it is hard when standing still and the bonds between the particles are strong and it is easy to form a network structure, the liquid syneresis property when standing still is naturally low. Both dilatancy and thixotropy
This is a phenomenon unique to colloidal suspensions, and refers to changes in the degree of bonding between colloidal particles due to stress. Furthermore, the degree of bonding between particles is influenced by the degree of charge and other particle surface conditions. Therefore, if individual particles are coated with a monomolecular film of a different substance to change the surface condition, it is natural that these two viscoelastic properties will change. When used for this purpose, these different substances are called protective colloids, and the theoretical optimum amount is enough to cover the surface of the colloidal particles as a monomolecular film. . If it is added in large excess, it is not preferable because it forms multiple layers on top of the suspended particles and inhibits the bonding between the suspended particles. However, in practice, factors such as the quality of the dispersion of the protective colloid and variations in the surface area of suspended particles are added, so it is difficult to specify the amount of the protective colloid in a narrow range, and it is difficult to specify the amount of the protective colloid within a narrow range. It is necessary to have the width of Many of the protective colloids used are polymeric substances because they require film-forming properties, and include proteins, cellulose derivatives, alginic acid, polymeric acids such as vectin, latex, and synthetic polymeric substances. However, since acidic detergents are highly reactive and tend to depolymerize these polymeric substances, it is necessary to select and use a detergent that has as high resistance to the action of this acid as possible. In this invention, high molecular weight polyoxyethylene was used as one of the acid-resistant polymers. Average degree of polymerization 16000, 40000 and
We compared the three brands of 85000, but in terms of usefulness for the purpose of the title, it was difficult to discern any difference in the degree of polymerization among the three types, and it can be used over the entire range of degrees of polymerization of the raw materials contained in these three types. It is judged as a thing. When dispersing these polyoxyethylenes in water, a practical difficulty is the formation of so-called "mamako". That is, when mixed with water, the polyoxyethylene that dissolves quickly forms a film as a concentrated solution on the powder mass, which obstructs subsequent seepage of water, thereby inhibiting dispersion or dissolution.
One way to solve this difficult problem is to pre-disperse polyoxyethylene particles in a medium that does not dissolve them and does not easily mix with water.
A method of mixing this mixture with water is commonly used, and alcohols, surfactants, salts, etc. are used as the medium. In the research for this invention, polyoxyethylene nonyl phenyl ether was selected and used because of its relatively high acid resistance, but this does not limit the use of other media. Furthermore, there is no restriction on the amount of use. When only colloidal silicon dioxide is added to an aqueous acid solution and mixed with stirring, the viscosity increases as the dispersion progresses. After the mixed sample was allowed to stand for a day, an attempt was made to measure the viscosity using an H-type rotational viscometer. As the rotation time of the viscometer increased, the measurement reading increased, indicating that the sample had dilatancy. . When an appropriate amount of the polyoxyethylene mixture previously kneaded with polyoxyethylene nonyl phenyl ether is added to this formulation and the mixture is kneaded again, the viscosity of the mixture increases even more than before the addition of this mixture, but if kneading is continued further, After a certain point, the viscosity decreases rapidly, resulting in a uniform slurry with a beautiful appearance. This final sample was allowed to stand for one day and then measured using an H-type rotational viscometer. As the rotation time increased, the measurement reading decreased, indicating that the sample was thixotropic. That is, by adding a protective colloid and stirring strongly, the silicon dioxide particles are gradually coated with the protective colloid, changing the surface condition, and when this coating progresses to a certain extent, the bonds between the silicon dioxide particles are loosened. It is interpreted as a reversal from dilatancy to thixotropy. A sample that has completed phase inversion in this manner is very stable and shows no signs of reversal to dilatancy over a long period of time. In addition, the degree of syneresis over time is much smaller in those that have become thixotropic, and the quality of the product is dramatically improved. Incidentally, the measured viscosity value of such non-Newtonian fluids varies significantly depending not only on the magnitude of the stress applied during measurement, but also on the magnitude of the total stress history of the sample, so it cannot be determined by measuring only under a single condition. It is not possible to determine the original viscosity of the sample. When using a rotational viscometer, the rotation time and rotation speed of the viscometer will affect the measured value. In researching this invention, we accurately measured the viscosity value, which changes moment by moment due to the rotation of a rotating body, and calculated these logarithms using the empirical rule that the logarithm of the viscosity value is proportional to the elapsed time. By using the viscosity value obtained by extrapolating to time 0 as the kinematic viscosity, we first eliminate the influence of the measurement time, and then we can say that the logarithm of the logarithm of the kinematic viscosity obtained using multiple rotational speeds is proportional to the rotational speed. By calculating the viscosity value corresponding to the rotational speed of 0 using empirical rules, the influence of rotational strength is eliminated, and this calculated value is expressed as the static viscosity to mutually compare the original viscosity between different samples. Examples will be described below. However, to simplify the description, hereinafter polyoxyethylene will be abbreviated as "PEO" and polyoxyethylene nonyl phenyl ether will be abbreviated as "PEO-NP".
In addition, among the test values, the upper layer syneresis rate is the ratio (%) of the length of the upper clear layer that occurs in the sample over time to the total layer length. The values shown here are representative. Furthermore,
The amount of gas generated is determined by accurately weighing 80g of the sample and determining the internal volume.
Pour water into a 100ml glass bottle, seal it with a rubber stopper that passes through a U-shaped tube containing water for water level display, and leave it at room temperature for 24 hours. Measure the water level difference in the U-shaped tube and find out that the water level difference is 0. Calculate the increase in the volume of the sample side space converted to a room temperature of 25°C using the sample side space volume, U-shaped tube internal cross-sectional area, and room temperature at the start and 24 hours later measurement, and divide this by 80. It is shown as a numerical value. That is, from 1 g of sample at 25°C, 24
It is the amount of gas released in time. Example 1 The ingredients shown in Table 1 were added in the order listed in the table while stirring, and after the addition of all ingredients was completed, the mixture was further stirred for 2 hours. However, PEO, PEO-NP and blue 404
The numbers were kneaded in advance and added.

【table】

[Table] Example-2 The components shown in Table 2 were mixed and stirred in the same manner as in Example-1 to prepare a sample. However, each PEO brand used had the following polymerization degree distribution.

【table】

【table】

[Table] In other words, the physical properties of each finished sample are almost the same, and no difference is observed due to the degree of compositeness of PEO. Example 3 As shown in Table 3, the blended concentrations of components other than PEO were made the same, only the blended amount of PEO was changed, and samples were prepared by mixing and stirring in the same manner as in Example 1.

[Table] To avoid complication, Table 3 lists only typical blended concentrations of PEO, but the PEO blended concentration is 0.05%.
At 2.5% to 2.5%, there is no essential difference in the physical property values of each sample, and at 3.0%, there are signs of slight excessive blending. Example 4 As shown in Table 4, samples were prepared by mixing and stirring in the same manner as in Example 1, changing only the concentration of PEO-NP and making the blended concentrations of other components the same.

【table】

[Table] The blending concentration of PEO-NP does not essentially affect the physical properties of each sample, but as the amount increases, the static viscosity tends to decrease and the degree of syneresis in the upper layer tends to increase, so excessive blending is not preferable. Example 5 “Silton” with a moisture content of 9.8% (110°C, 3 hours)
When ``Lp-1'' was placed in an evaporating dish and heated at approximately 500°C until it reached a constant weight, the weight loss on burning was 17.1%. The burnt residue is solidified into a slightly hard lump. Grind this in a mortar and replace the lost amount with water, Table 5
A sample was prepared by mixing and stirring in the same manner as in Example-1 using the following recipe.

【table】

[Table] "Silton" stores a non-negligible amount of gas. Although this gas can be scorched and dissipated, samples prepared using the sintering treatment "Silton" are said to be sufficiently usable, but their physical properties are slightly deteriorated in static viscosity and upper layer syneresis. Example 6 Using the dilution heat of sulfuric acid, "Silton Lp-1"
was treated with a hot sulfuric acid solution in an attempt to expel the occluded gas. As shown in Table 6, "Silton Lp-1" is kneaded with water that has been reduced to the point where it can barely be kneaded and heated, and 95%
% sulfuric acid was injected to further raise the temperature of the mixture, and after kneading for 2 hours, the amount obtained was measured.
Calculate the volatilization loss. Next, while stirring in the order shown in the lower column of the table, other ingredients and supplementary water corresponding to the volatilization loss generated in the pretreatment process were added to complete the formulation, and stirring was continued for an additional 2 hours to prepare samples.

[Table] The method of treating "Silton Lp-1" using a warm sulfuric acid solution is effective as a means of releasing occluded gas, but it is impossible to immediately and completely release it using only this method. Example 7 The pre-treated "Silton" sulfuric acid paste prepared according to Example No. 6A was left open at room temperature, and on the same day,
After 1 day, 2 days, and 3 days, the calculated amount, i.e., 59.0 parts, was collected and mixed with 24.5 parts of water, 11.4 parts of 35% hydrochloric acid, 4.0 parts of oxalic acid dihydrate, and PEO while stirring.
-B 0.1 part, PEO-NP 1.0 part, Blue No. 404
1.104 parts of the mixed solution of 0.004 parts were successively added and kneaded for 2 hours to prepare a sample, and the test values shown in Table 7 were obtained.

【table】

[Table] Since the gas stored in "Silton" is released under acidic conditions, degassing occurs simply by mixing it with acid and leaving it to stand, making it a useful method for release along with heating. However, the diffusion rate was relatively low, and the diffusion was completed after approximately two days under the conditions of Example-7. Example 8 For the purpose of examining whether the type of acid affects physical properties, the components shown in Table 8 were added in the order listed in the table, and 2
The mixture was kneaded for several hours and used as a sample. However, the pre-treatment "Silton" sulfuric acid mixture was treated according to Example No. 6A and then left at room temperature for 7 days, and PEO, PEO-NP, and Blue No. 404 were kneaded beforehand and added. did. In addition, the combined concentration of each acid was distributed so that the total concentration would be approximately 2.8 N/Kg when titrated using bromothymol blue as an indicator.

【table】

[Table] As mentioned above, the slurry-type acidic cleaning agent produced by the method of the present invention has an extremely low syneresis rate, does not separate from water, does not precipitate and solidify, and is tictropic, so it can be easily stirred. This is an extremely effective invention that can provide an acidic cleaning agent that is softened, easy to use, and has a property of quickly returning to its viscosity before stirring after application, and thus has strong adhesion.

Claims (1)

[Claims] 1. In an acidic cleaning agent containing colloidal silicon dioxide as a thickener, the raw silicon dioxide is heated or treated with a highly concentrated acid to remove acidic gases occluded in the silicon dioxide. After air dissipation, a prescribed amount of acids, protective colloids, dispersants, colorants and other property improving agents, as well as water sufficient to complete the formulation, are added and stirred until phase inversion is completed. Static viscosity 2000 or more
Manufacturing method of 30000cps slurry type acidic cleaning agent. 2. The method for producing a slurry-type acidic detergent according to claim 1, wherein the acid content of the product is 1.2 to 12.0 N/Kg. 3 Acids are formic acid, hydrochloric acid, phosphoric acid, sulfuric acid, oxalic acid,
The method for producing a slurry-type acidic cleaning agent according to claim 1, which comprises one or more of nitric acid, glycols, citric acid, and gluconic acid. 4. The method for producing a slurry-type acidic cleaning agent according to claim 1, wherein the amount of colloidal silicon dioxide is 10 to 30% by weight in terms of the weight before the storage gas is released. 5. The method for producing a slurry-type acidic detergent according to claim 1, wherein the protective colloid is polyoxyethylene with a degree of polymerization of 10,000 to 100,000, and its content is 0.01 to 3.0%.