JP3823369B2 - Reaction product of sulfonated amino resin and amino group-containing substance and process for producing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a product obtained by reacting a sulfonated amino resin with an amino group-containing substance and a method for producing the same.
[0002]
[Prior art]
Japanese Patent Application Laid-Open No. 60-259699 has proposed a zeta potential regulator for papermaking which contains a sulfone group-containing melamine-formaldehyde condensate as an active ingredient. In this specification, as the sulfone group-containing melamine-formaldehyde condensate, 1 mol part of a mixture of melamine or melamine and other condensable compounds and 2 to 4 mol parts of formaldehyde or a corresponding molar amount of formaldehyde donating compound , And 0.5 to 2 mole parts of bisulfite and sulfite or a compound that provides a corresponding molar amount of bisulfite or sulfite, with a molar ratio of formaldehyde to bisulfite or sulfite of 4.5: It is described that it is obtained by condensation in 1-2: 1.
[0003]
Many proposals have been made on sulfonated amino resins used as concrete water reducing agents. Japanese Patent Publication No. 52-13991 has a sulfone group by reacting a melamine-urea mixture, formaldehyde and alkali sulfite in an aqueous solution at a molar ratio of 1: 2.7 to 3.2: 0.9 to 1.1. An aqueous solution of a melamine-formaldehyde condensation product has been proposed. JP-B-1-43699 discloses a melamine, formaldehyde, and sulfite that are condensed in an aqueous medium at a molar ratio of 1: 2.2 to 3.2: 0.3 to 1.0. Sulfone group-containing melamine-formaldehyde condensates have been proposed.
[0004]
[Problems to be solved by the invention]
The sulfone group-containing melamine-formaldehyde condensate has a drawback that the yield improving effect is small as a yield improver in the papermaking process and is very effective as a concrete water reducing agent, but it has a poor slump holding power. In addition, this sulfone group-containing melamine-formaldehyde condensate has disadvantages such as the use field and the amount of use being limited because free formalin remains. Furthermore, it is difficult to produce a highly viscous sulfone group-containing melamine-formaldehyde condensate by the method as described in the above patent.
[0005]
There has been no report on a product obtained by reacting a sulfonated amino resin with an amino group-containing substance.
An object of the present invention is to provide a product obtained by reacting a sulfonated amino resin, which is a novel material that can withstand a wide range of uses, and an amino group-containing substance, and a method for producing the same, which eliminates the above-mentioned drawbacks of the prior art.
[0006]
That is, the present invention relates to a yield improver in the production of cellulose fiber or paper mainly composed of this and an inorganic filler, a flocculant in waste liquid treatment, a water reducing agent in the production of hydraulic inorganic members such as cement or gypsum, and the shield method. A product obtained by reacting a sulfonated amino resin with an amino group-containing substance, which can be used in a wide range of industrial fields such as drilling aids and dispersants in paints, a sol thereof, and a method for producing the same It is.
[0007]
The present inventors have found that an amino group-containing substance such as melamine is easily dissolved in a sulfonated amino resin aqueous solution, and as a result of intensive studies, the present invention has been completed.
[0008]
[Means for Solving the Problems]
  The present invention comprises a sulfonated amino resin,Melamine,1: a product obtained by reacting at a weight ratio of 0.05 to 3,A sol in which particles of the product having a primary particle size of 1 to 100 nm are dispersed in a liquid medium.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
As the sulfonated amino resin used in the present invention, a sulfonate-containing melamine-formaldehyde condensate can be preferably used. The sulfonate is an alkali metal salt, and a sodium salt is particularly preferable. As the sulfonate-containing melamine-formaldehyde condensate, those commercially available as an aqueous solution can be used. Any sulfonic acid salt-containing melamine-formaldehyde condensate aqueous solution produced by a known method can be used. For example, JP-B-2-43763 discloses that an amino group-containing substance containing melamine as a main component is 0.9 to 1.1 mol of formaldehyde and 0.3 to 0.4 mol of sulfite with respect to 1 mol of amino group. The reaction mixture is heated at a pH of 10 to 13 and a temperature of 60 to 80 ° C. for 20 to 60 minutes in an aqueous medium, and then amidosulfonic acid and / or sulfuric acid is added to the reaction mixture to adjust the pH to 4 to 6 and a temperature of 40 to 60. A method for producing a high-concentration sulfonate-containing melamine-formaldehyde condensate aqueous solution, which is heated at 50 ° C. for 50 to 300 minutes, immediately adjusted to pH 11.5 to 13.5 and then cooled, was obtained by this method. A sulfonate-containing melamine-formaldehyde condensate aqueous solution can be used in the present invention. In this method, the amino group-containing substance mainly composed of melamine is melamine alone or melamine and an amino-containing compound in a proportion of 20% by weight or less, such as urea, guanamines, dicyandiamide, amine, acid amide, It is a mixture with phenol, resorcin, etc. Formaldehyde is formalin, paraformaldehyde, etc., and sulfite is sodium sulfite, ammonium sulfite, sodium bisulfite, ammonium bisulfite, sodium pyrosulfite, etc. Is to be done. The molecular weight of the sulfonated amino resin is not particularly limited, but is preferably 2000-200000.
[0010]
The amino group-containing substance used in the present invention can be used as melamine alone or as a mixture of melamine and urea, guanamines, dicyandiamide, amine, acid amide, phenol, resorcin and the like. Especially melamine (C_Three H₆ N₆ ) Is preferably used alone. The melamine can be used in the form of a commercially available powder.
[0011]
The method for producing a product obtained by reacting a sulfonated amino resin and an amino group-containing substance of the present invention comprises a sulfonated amino resin aqueous solution and an amino group-containing substance in a solid content weight ratio of 1: 0.05-3. It consists of mixing and heating to a temperature of 50-150 ° C. In the above production method, there are a method in which an aqueous sulfonated amino resin solution and an amino group-containing substance are mixed in advance and then heating, and a method in which an amino group-containing substance is added to a heated aqueous sulfonated amino resin solution. In order to prevent a condensation reaction between amino resins, a method of heating after mixing a sulfonated amino resin aqueous solution and an amino group-containing substance in advance is more preferable. In this reaction, by heating to the above temperature, a dehydration reaction occurs between the methylol group or sulfone group in the sulfonated amino resin and the amino group of the amino group-containing substance, and the condensation reaction proceeds to produce a condensation product. It is obtained. In the above reaction, the condensation reaction proceeds efficiently by adding a mineral acid such as sulfuric acid or hydrochloric acid, an organic acid such as sulfamic acid, formic acid or acetic acid as a catalyst. The catalyst is preferably added so that the pH of the aqueous liquid containing the sulfonated amino resin and the amino group-containing substance is 5 to 10. In general, since sulfonated amino resins contain sulfuric acid and sulfamic acid alkali salts, the pH can be adjusted to 5 to 10 by cation exchange.
[0012]
In the present invention, a solution obtained by further adding a catalyst such as sulfuric acid to a solution composed of an aqueous sulfonated amino resin solution and an amino group-containing substance is heated at a temperature of 50 to 150 ° C. for 5 to 6 hours, and then diluted with water or an alkaline substance. It can be manufactured by stabilization by addition. Moreover, after heating the solution containing a sulfonated amino resin aqueous solution and an amino group-containing substance to a temperature of 50 to 150 ° C., a catalyst such as sulfuric acid is added and heated for 5 to 6 hours, and then diluted with water or alkali. It can be manufactured by stabilization by addition of a substance.
[0013]
In the present invention, the product obtained by reacting the sulfonated amino resin with the amino group-containing substance is 1: 0.05 to 3 in terms of the weight ratio of the sulfonated amino resin and the amino group-containing substance. The weight ratio of the above products can be measured by elemental analysis. When the ratio of the amino group-containing substance to the sulfonated amino resin exceeds 3, an excessive amino group-containing substance precipitates although a product is formed, which is not preferable. On the other hand, if it is less than 0.05, the production amount of the product decreases, which is not preferable. In the production of a product obtained by reacting the sulfonated amino resin of the present invention with an amino group-containing substance, the concentration of the mixture of the sulfonated amino resin aqueous solution and the amino group-containing substance should be 1 to 50% by weight. I can do it. If it is less than 1% by weight, the production efficiency is lowered, which is not preferable. If it exceeds 50% by weight, the viscosity of the resulting liquid becomes too high, which is not preferable. 5 to 20% by weight is particularly preferred.
[0014]
The reaction temperature for obtaining a condensation product from a liquid obtained by mixing an aqueous sulfonated amino resin solution and an amino group-containing substance is preferably 50 to 150 ° C. When the reaction is performed at a temperature equal to or higher than the boiling point of the aqueous medium, it can be performed using an autoclave apparatus. If the reaction temperature is less than 50 ° C., the production of the product is insufficient, which is not preferable. Moreover, although the product can be produced even when the temperature exceeds 150 ° C., it is difficult to control the reaction, which is not preferable. 60-100 degreeC is especially preferable. The reaction time for producing this product varies depending on the reaction temperature, but is 10 minutes to 20 hours. If it is less than 10 minutes, the production of the product is insufficient, the reaction can be completed in 20 hours, and if it is longer, it is not economical.
[0015]
In the present invention, a sulfonated amino resin aqueous solution or an amino group-containing substance is further added to a liquid containing a product obtained by heating a solution obtained by mixing a sulfonated amino resin aqueous solution and an amino group-containing substance at 50 to 150 ° C. It is also possible to heat at 50 to 150 ° C.
The product obtained by reacting the sulfonated amino resin of the present invention with an amino group-containing substance is basically a colloidal substance having a particle property, and the product solution obtained by the present invention is a colloidal solution (sol). It can be said. The primary particle size of the colloidal particles of this product is 1 to 100 nm (nanometers), and the colloidal solution of the product has a transparent colloid color from a transparent one because it exists alone or in an aggregated form. There are things to present. In the present invention, a sol in which particles obtained by reacting a sulfonated amino resin and an amino group-containing substance and having a primary particle diameter of 1 to 100 nm are dispersed in a liquid medium is obtained. The liquid medium is preferably an aqueous medium. Here, the primary particle diameter is not the diameter of the particles in the aggregated form but the diameter of one particle when individually separated, and can be measured by observation with an electron microscope in the present invention. The primary particles aggregate to form an aggregate. The particle size of the aggregate is determined by a dynamic light scattering method, for example, N_Four It can be measured by the device. Moreover, the viscosity of the colloidal solution of this product is 1.5-10000 mPa * S in the 10 weight% liquid of a product, and shows the gelatinization phenomenon resulting from being a colloidal solution.
[0016]
The colloid of the product has a negative charge due to the sulfone group, but has a cation site due to the amino group, so it can basically be said to be amphoteric. The zeta potential is 0 to minus 60 mV.
In the present invention, the pH can be adjusted to 7 to 12 by adding an alkali metal hydroxide, sodium aluminate, sodium silicate, ammonia, amine or the like to the product solution. In addition, since free formaldehyde present in the sulfonated amino resin aqueous solution reacts with the amino group-containing substance to form an amino resin by heating at the time of reaction, free formaldehyde is substantially contained in the resulting product solution. Does not exist.
[0017]
The solution of the product obtained by reacting the sulfonated amino resin of the present invention with an amino group-containing substance can be concentrated by a method such as evaporation or ultrafiltration if necessary. In particular, the ultrafiltration method can simultaneously remove salts such as sodium sulfate in the solution. Further, this solution can be made into a dry powder using a spray dryer, a drum dryer or the like. This dry powder is dispersed again in water to form a colloidal solution (sol) in which the product particles are dispersed in water.
[0018]
In general, a sulfonated amino resin aqueous solution is stabilized with caustic soda. Also in the present invention, the product solution obtained by reacting the sulfonated amino resin with the amino group-containing substance is stabilized with caustic soda, and this solution is exchanged with a cation such as ammonia, amine, calcium, etc. By passing through a column filled with resin, a solution of the above product stabilized with ammonia, amine, calcium, or the like can be obtained. Surfactant such as naphthalene sulfonate, lignin sulfonate, alkylbenzene sulfonate, anionic polymers such as silica sol, bentonite, anionic polyacrylamide, polyvinyl alcohol, hydroxyethyl cellulose, carboxy A water-soluble polymer such as methyl cellulose can be mixed.
[0019]
A sulfonated amino resin generally has an average molecular weight of 2,000 to 200,000, is a polycondensation polymer in two dimensions, is negatively charged by a sulfone group, and is usually obtained as a colorless and transparent polymer aqueous solution. Surprisingly, the amino group-containing substance is dissolved in this sulfonated amino resin aqueous solution by adding a substance having a low solubility in water, such as melamine, to the solubility or higher. Precipitation does not occur. This cannot be explained simply by the fact that an amino group-containing substance having a positive charge is adsorbed on the surface of a sulfonated amino resin having a negative charge. This is a product obtained by depolymerizing a sulfonated amino resin when heated in the presence of an amino group-containing substance, chemically bonding with the amino group-containing substance, and reacting the sulfonated amino resin with the amino group-containing substance. It should be considered that the thing is formed. That is, a methylol group (—CH in the sulfonated amino resin).₂ OH) or sulfone group (-SO_Three H) and an amino group (-NH) of the amino group-containing substance₂ )) And a chemical bond is considered to be formed. When the amino group-containing substance has two or more amino groups, a reaction product of the sulfonated amino resin extending in the three-dimensional direction and the amino group-containing substance is formed. Therefore, this product is basically a colloidal substance having particle properties, and the product solution obtained by the present invention can be called a colloidal solution (sol).
[0020]
The product obtained by reacting the sulfonated amino resin of the present invention with an amino group-containing substance is basically negatively charged, but has amphoteric properties because it contains a sulfone group and an amino group. It is a monodisperse or aggregate of fine colloidal particles having a primary particle diameter of 1 to 100 nm. Therefore, it adsorbs well to both anionic and cationic particles and exhibits excellent dispersibility. It also adsorbs well to cationic polymers and exhibits significant cohesiveness by lowering the zeta potential.
[0021]
A conventional sulfonate-containing melamine-formaldehyde condensate (SMF) is a linear water-soluble polymer and is dissolved in water. On the other hand, the product obtained by reacting the sulfonated amino resin of the present invention with an amino group-containing substance combines a sulfonated amino resin oligomer having a negative site with an amino group-containing substance such as melamine having a positive site. As a result, a micro-aggregate having a colloidal particle size is formed. The product solution obtained by the present invention is a stable colloidal solution (sol), but the above product solution is added to the papermaking process from pulp slurry containing cellulose fiber, inorganic filler, and ionic polymer as components. Since the product has a cation site and an anion site and adsorbs to an ionic component in the pulp slurry due to a large specific surface area, and exhibits remarkable cohesiveness to form a floc, it is excellent as a yield improver. Compared to the conventional sulfonate-containing melamine-formaldehyde condensate dissolved in water, the use of the colloidal product of the present invention facilitates floc formation. It is extremely useful as an additive for papermaking.
[0022]
【Example】
Example 1
Sulfonated amino resin aqueous solution produced by a known method (sodium sulfonate-containing melamine-formaldehyde condensate aqueous solution, specific gravity 1.214 (20), in a 2 liter four-necked flask equipped with a reflux condenser, a stirrer, and a thermometer. ), PH 8.50, viscosity 23.9 mPa · S (measured at 20 ° C.), conductivity 31.00 mS / cm, sulfonated amino resin solid content 32.9% by weight (14.4% by weight as melamine) , Formaldehyde / sulfonic acid molar ratio 3.6, free formaldehyde (measured by titration method) 0.7% by weight, formaldehyde / melamine molar ratio 3.50, average molecular weight 15000, transmittance (L value) 99.8% It is a colorless and transparent liquid. ] 200 g (containing 65.8 g as a sulfonated amino resin) and 690 g of pure water were added, and 3.5 g of 10% sulfuric acid was added with stirring, followed by addition of 39.0 g of melamine (manufactured by Nissan Chemical Industries, Ltd.). did. The total solid content of the resin mixture of the sulfonated amino resin and melamine was 11.2% by weight, the melamine / sulfonated amino resin weight ratio was 0.593, and the pH was 7.50. The mixture was heated and reacted at 98 ° C. for 2 hours, and then cooled to obtain 932.5 g of a product solution obtained by reacting the sulfonated amino resin and melamine. The above mixed solution was completely dissolved by heating at 80 to 90 ° C. to become a transparent solution, and continued to be heated to exhibit a colloidal color.
[0023]
The resulting product solution has a specific gravity of 1.056 (measured at 25 ° C.), pH 8.13, viscosity of 2.4 mPa · S (measured at 25 ° C.), solid content of product 11.2% by weight, melamine / sulfone Weight ratio of fluorinated amino resin 0.593, molar ratio of formaldehyde / sulfonic acid 3.6, molar ratio of formaldehyde / melamine 1.49, average particle diameter by dynamic light scattering method (Coulter N, Coulter N_Four It was 16.1 nm, the zeta potential was minus 10 mV, and it was a transparent solution showing a slightly colloidal color. Particles were observed by electron microscope observation, and the primary particle diameter was 5 to 10 nm. In this solution, no free formaldehyde was detected by the titration method, and the solution was stable for more than 6 months at room temperature.
[0024]
Example 2
120 g of a sulfonated amino resin aqueous solution [sodium sulfonate-containing melamine-formaldehyde condensate aqueous solution] used in Example 1 in a 2 liter four-necked flask equipped with a reflux condenser, a stirrer, and a thermometer (as sulfonated amino resin) 39.5 g.), 615 g of pure water was added, 4.3 g of 10% sulfuric acid was added with stirring, and then 21.4 g of melamine (manufactured by Nissan Chemical Industries, Ltd.) was added. The total solid content of the resin in the mixture of the sulfonated amino resin and melamine was 8.0% by weight, the melamine / sulfonated amino resin weight ratio was 0.542, and the pH was 6.75. The mixture was reacted by heating at 98 ° C. for 2.5 hours. The resulting product solution had a colloidal color. Further, 36 g of a sulfonated amino resin aqueous solution used in Example 1 (containing 11.8 g as a sulfonated amino resin) was added, reacted at 98 ° C. for 3.5 hours, and then 2.6 g of 10% sodium hydroxide aqueous solution was added. After heating at 98 ° C. for 10 minutes, the product was cooled to obtain 920.7 g of a product solution obtained by reacting the sulfonated amino resin and melamine.
[0025]
The resulting product solution had a specific gravity of 1.039 (measured at 25 ° C.), pH 9.62, viscosity 5.2 mPa · S (measured at 25 ° C.), conductivity 13.30 mS / cm, product solid content 7 90% by weight, melamine / sulfonated amino resin weight ratio 0.417, formaldehyde / sulfonic acid molar ratio 3.6, formaldehyde / melamine molar ratio 1.79, average particle size 103 nm by dynamic light scattering method, The zeta potential was minus 12 mV, the transmittance (L value) was 86.7%, free formaldehyde was not detected at all by the titration method, and the solution was a highly transparent solution exhibiting a colloidal color. Particles were observed by electron microscope observation, and the primary particle diameter was 5 to 10 nm (FIG. 1). This solution was stable for more than 6 months at room temperature.
[0026]
Example 3
200 g of a sulfonated amino resin aqueous solution [sodium sulfonate-containing melamine-formaldehyde condensate aqueous solution] used in Example 1 in a 2-liter four-necked flask equipped with a reflux condenser, a stirrer, and a thermometer (as sulfonated amino resin) 65.8 g of pure water), 589 g of pure water was added, 4.0 g of 10% sulfuric acid was added with stirring, and then 39.0 g of melamine (Nissan Chemical Industries, Ltd.) was added. The total solid content of the resin mixture of the sulfonated amino resin and melamine was 12.6% by weight, the melamine / sulfonated amino resin weight ratio was 0.593, and the pH was 7.31. The mixture was heated and reacted at 98 ° C. for 2 hours, after which 2 g of 10% sodium hydroxide and 40 g of a sulfonated amino resin aqueous solution used in Example 1 (containing 13.2 g as a sulfonated amino resin) were added. After further reaction at 98 ° C. for 1.5 hours, cooling was performed to obtain 912 g of a product solution obtained by reacting the sulfonated amino resin and melamine.
[0027]
The resulting product solution had a specific gravity of 1.067 (measured at 25 ° C.), pH 8.79, viscosity of 2.6 mPa · S (measured at 25 ° C.), conductivity of 17.90 mS / cm, product solid content of 12 0.9% by weight, melamine / sulfonated amino resin weight ratio 0.494, formaldehyde / sulfonic acid molar ratio 3.6, formaldehyde / melamine molar ratio 1.64, average particle size by dynamic light scattering method 16. It was 3 nm, the zeta potential was minus 12 mV, and the transmittance (L value) was 96.9%. Free formaldehyde was not detected at all by the titration method, and it was a transparent solution having a slightly colloidal color. Particles were observed by electron microscope observation, and the primary particle diameter was 5 to 10 nm. This solution was stable for more than 6 months at room temperature.
[0028]
Example 4
600 g of a sulfonated amino resin aqueous solution [sodium sulfonate-containing melamine-formaldehyde condensate aqueous solution] used in Example 1 in a 2-liter four-necked flask equipped with a reflux condenser, a stirrer, and a thermometer (as sulfonated amino resin) In addition, after adding 1200 g of pure water with stirring and adding 24 g of 10% sulfuric acid with stirring, 81 g of melamine (manufactured by Nissan Chemical Industries, Ltd.) was added. The total solid content of the resin and melamine in the mixture of the sulfonated amino resin and melamine was 14.6% by weight, the melamine / sulfonated amino resin weight ratio was 0.41, and the pH was 6.83. After heating this mixed liquid and reacting at 92 ° C. for 6 hours, 960 g of pure water was added and then cooled, and further 16 g of 10% by weight NaOH aqueous solution was added to react the sulfonated amino resin and melamine. 2881 g of product solution was obtained. The above mixed solution was completely dissolved by heating at 80 to 90 ° C. to become a transparent solution, and continued to be heated to exhibit a colloidal color.
[0029]
The resulting product solution has a specific gravity of 1.044 (measured at 25 ° C.), a pH of 10.38, a viscosity of 65 mPa · S (measured at 25 ° C.), a solid content of 10.0% by weight, and a melamine / sulfonated amino acid. Resin weight ratio 0.41, formaldehyde / sulfonic acid molar ratio 3.6, formaldehyde / melamine molar ratio 1.81, average particle diameter by dynamic light scattering method (Coulter, Coulter N_FourIt was a transparent solution with a slightly colloidal color at 179 nm and a zeta potential of minus 10 mV. Particles were observed by electron microscope observation, and the primary particle diameter was 5 to 10 nm. In this solution, no free formaldehyde was detected by the titration method, and the solution was stable for more than 6 months at room temperature.
[0030]
Example 5
600 g of a sulfonated amino resin aqueous solution [sodium sulfonate-containing melamine-formaldehyde condensate aqueous solution] used in Example 1 in a 2-liter four-necked flask equipped with a reflux condenser, a stirrer, and a thermometer (as sulfonated amino resin) 19 g), and 1000 g of pure water were added, 24 g of 10% sulfuric acid was added with stirring, and then 69 g of melamine (Nissan Chemical Industry Co., Ltd.) was added. The total solid content of the resin and melamine in the mixture of the sulfonated amino resin and melamine was 15.7% by weight, the melamine / sulfonated amino resin weight ratio was 1.40, and the pH was 6.65. The solution was heated and reacted at 93 ° C. for 7 hours, then 1083 g of pure water heated to 48 ° C. was added and held for 1 hour at 82 ° C., then cooled, and 14 g of 10% NaOH aqueous solution was added at 60 ° C. and cooled. 2790 g of a product solution obtained by reacting a sulfonated amino resin with melamine was obtained. The above mixed solution was completely dissolved by heating at 80 to 90 ° C. to become a transparent solution, and continued to be heated to exhibit a colloidal color.
[0031]
The resulting product solution has a specific gravity of 1.042 (measured at 25 ° C.), pH 9.73, viscosity of 17.8 mPa · S (measured at 25 ° C.), 10.0% by weight of the solid content of the product, melamine / sulfone Amino acid resin weight ratio 1.40, formaldehyde / sulfonic acid molar ratio 3.6, formaldehyde / melamine molar ratio 1.95, average particle diameter by dynamic light scattering method (Coulter N, Coulter N_FourIt was a transparent solution with a slightly colloidal color at 135 nm and a zeta potential of minus 12 mV. Particles were observed by electron microscope observation, and the primary particle diameter was 5 to 10 nm. In this solution, no free formaldehyde was detected by the titration method, and the solution was stable for more than 6 months at room temperature.
[0032]
Example 6
400 g of a sulfonated amino resin aqueous solution [sodium sulfonate-containing melamine-formaldehyde condensate aqueous solution] used in Example 1 in a 2-liter four-necked flask equipped with a reflux condenser, a stirrer, and a thermometer (as sulfonated amino resin) 131.6 g.), 360 g of pure water was added, and 14.0 g of melamine [manufactured by Nissan Chemical Industries, Ltd.] was added with stirring. The total solid content of the resin in the mixed solution of the sulfonated amino resin and melamine was 18.8% by weight, the melamine / sulfonated amino resin weight ratio was 0.106, and the pH was 8.4. This mixture was heated to react at 70 ° C. for 3 hours, cooled, then added with 5 g of 10% sodium hydroxide, stirred at room temperature for 30 minutes, and the product obtained by reacting the sulfonated amino resin and melamine 779 g of solution was obtained.
[0033]
The resulting product solution has a specific gravity of 1.110 (measured at 25 ° C.), a pH of 11.90, a viscosity of 3.0 mPa · S (measured at 25 ° C.), a solid content of 18.7% by weight, melamine / sulfone. This was a colorless and transparent solution having a weight ratio of fluorinated amino resin of 0.106, a molar ratio of formaldehyde / sulfonic acid of 3.6, a molar ratio of formaldehyde / melamine of 2.82, an average particle diameter of 5.8 nm by dynamic light scattering method. It was. Particles were observed by electron microscope observation, and the primary particle diameter was 5 to 10 nm. This solution was stable for more than 6 months at room temperature.
[0034]
Comparative Example 1
140 g of a sulfonated amino resin aqueous solution [sodium sulfonate-containing melamine-formaldehyde condensate aqueous solution] used in Example 1 in a 2 liter four-necked flask equipped with a reflux condenser, a stirrer, and a thermometer (as sulfonated amino resin) 46.1 g.), 700 g of pure water was added, 5.0 g of 10% sulfuric acid was added with stirring, and then 25 g of melamine [Nissan Chemical Industry Co., Ltd.] was added. The total solid content of the resin of the mixed solution of the sulfonated amino resin and melamine was 8.18% by weight, the melamine / sulfonated amino resin weight ratio was 0.542, and the pH was 6.75. The mixture was heated and reacted at 40 ° C. for 12 hours. However, the added melamine did not dissolve, and the mixture remained as a mixed slurry of an aqueous resin solution and melamine.
[0035]
Comparative Example 2
14 g of a sulfonated amino resin aqueous solution [sodium sulfonate-containing melamine-formaldehyde condensate aqueous solution] used in Example 1 in a 2 liter four-necked flask equipped with a reflux condenser, a stirrer and a thermometer (as sulfonated amino resin) 4.6 g), 700 g of pure water, and 50 g of melamine (manufactured by Nissan Chemical Industries, Ltd.) were added. The total solid content of the sulfonated amino resin / melamine resin mixture was 7.15% by weight, the melamine / sulfonated amino resin weight ratio was 10.9, and the pH was 9.60. The mixture was heated and reacted at 98 ° C. for 6 hours and then cooled. Although it became transparent in 2 hours after heating, it remained transparent even after 6 hours of heating, but remained transparent, but due to cooling, a large amount of melamine precipitated and settled, so it separated into two layers and became uniform A complex solution could not be obtained. The upper layer had a colloidal color and product formation was observed, but the melamine / sulfonated amino resin weight ratio was 3.0.
[0036]
【The invention's effect】
The product obtained by reacting the sulfonated amino resin of the present invention with an amino group-containing substance is a cationic starch in a papermaking method in which papermaking is performed from cellulose fiber or a papermaking stock solution containing this and an inorganic filler, followed by dehydration and drying. It can be used as a yield improver by using it together with a cationic polymer such as a cationic polyacrylamide derivative, amphoteric starch, and an amphoteric polyacrylamide derivative. In addition, this product includes refractories, inorganic powders such as pigments, organic powder dispersants such as phenolic resins, anti-dusting agents for various powders such as silica powder, antistatic agents such as paper, fiber, plastics, and films. Can be used. Further, the product can be used as a water reducing agent for concrete or gypsum, a drilling aid for shield method, a grout agent used in combination with silica sol, a waste liquid, a flocculant in drainage purification, a flocculant for forming inorganic fibers, and the like.
[Brief description of the drawings]
FIG. 1 is a transmission electron micrograph showing the particle structure of a colloidal particle of a product obtained by reacting a sulfonated amino resin prepared in Example 2 with an amino group-containing substance, and the magnification is 200,000 times.

Claims (3)

A product obtained by reacting a sulfonated amino resin with melamine in a weight ratio of 1: 0.05 to 3 and particles of the product having a primary particle size of 1 to 100 nm in a liquid medium Dispersed sol. The sol according to claim 1, wherein the sulfonated amino resin is a sulfonate-containing melamine-formaldehyde condensate . Sulfonated amino resin solution, melamine, 1: and be mixed in a solid weight ratio of 0.05 to 3, according to claim 1 or claim 2 comprises heating to a temperature of 50 to 150 ° C. Sol production method.

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