JP2009019079A - Method for producing water-soluble formaldehyde condensation product having reduced residual formaldehyde content - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means to obtain dispersants for various applications, such as a water reducing agent for cement and a dispersant for gypsum by reducing residual formaldehyde in an aqueous solution of a bisphenol type formaldehyde condensation product and/or an aqueous solution of a naphthalenesulfonic acid-formaldehyde condensation product by a simple technique without affecting performances as various dispersants. <P>SOLUTION: A method for producing a formaldehyde condensation product having a reduced formaldehyde content includes adding hydroxylamines to a formaldehyde condensation product comprising specific components, and reacting the hydroxylamines with residual formaldehyde in the condensation product. There are also provided a water reducing agent for cement or a dispersant for gypsum comprising a reaction product obtained by this formaldehyde reducing method. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for reducing formaldehyde in a formaldehyde condensate, and more specifically, a water reducing agent for cement, a dispersant for gypsum, and a bisphenol-based formaldehyde condensate useful as a dispersant for applications such as pigments, ceramics, pigments, dyes, and agricultural chemicals. The present invention relates to a method for reducing formaldehyde remaining in an aqueous solution or a naphthalenesulfonic acid formaldehyde condensate aqueous solution. Moreover, this invention relates to the water reducing agent for cement or the dispersing agent for gypsum containing the reaction material obtained by the said formaldehyde reduction method.

  Bisphenol formaldehyde condensate having a bisphenol skeleton in the molecular structure and naphthalene sulfonic acid formaldehyde condensate having a naphthalene skeleton in the molecular structure include cement water reducing agents, gypsum dispersants, pigments, ceramics, pigments, It is also used as a dispersant for applications such as dyes and agricultural chemicals. On the other hand, in the production process, that is, the condensation reaction with formaldehyde, there is a disadvantage that formaldehyde remains unreacted. Since formaldehyde has a specific odor and is harmful to health, its reduction is required in each field.

  Regarding the reduction of residual formaldehyde, there is no conventional technique for bisphenol-based formaldehyde condensate aqueous solution, but various reduction methods have been proposed for naphthalenesulfonic acid formaldehyde condensate aqueous solution.

  For example, a method of oxidizing formaldehyde with a peroxide such as hydrogen peroxide or sodium hypochlorite to form formic acid is generally known, but the reaction vessel is enlarged to cope with foaming during the reaction. There are complicated problems such as countermeasures and prevention of corrosion of the reaction tank by by-products, and the effect of reducing residual formaldehyde is not sufficient. Moreover, when it treats with a large excess amount of chemical | medical agent in order to reduce a residual formaldehyde, it has the problem that the performance as a dispersing agent will deteriorate, such as a use as a water reducing agent for cement and a dispersing agent for gypsum. Similar problems are expected to occur when these methods are applied to aqueous bisphenol formaldehyde condensate solutions.

  A method of removing formaldehyde contained in the neutralized naphthalenesulfonic acid formalin condensate with a thin film evaporator is described in Patent Document 1 (Japanese Patent Laid-Open No. 5-320120). However, the effect of reducing formaldehyde is insufficient, and it is necessary to introduce a large-scale apparatus, resulting in high cost and complicated operation.

  Patent Document 2 (Japanese Patent Laid-Open No. 4-211046) discloses a method for maintaining a naphthalenesulfonic acid formaldehyde condensation product at a pH higher than 11.5 at a temperature not lower than 80 ° C. immediately after the condensation. . However, the pH of the resulting condensate is very high, which is problematic from the viewpoint of handling when used for general dispersant applications.

  In addition to naphthalenesulfonic acid formaldehyde condensate, as a formaldehyde reducing agent, treatment with ammonia and its salts (for example, ammonium sulfate and ammonium chloride) is also known, but bisphenol formaldehyde condensate aqueous solution and / or naphthalenesulfonic acid The residual formaldehyde reduction effect in the aqueous formaldehyde condensate solution is hardly recognized.

  As described above, various methods for reducing residual formaldehyde in formaldehyde condensate aqueous solutions have been proposed. However, they have a sufficient effect of reducing the amount of residual formaldehyde and are suitable for various applications such as a water reducing agent for cement and a dispersant for gypsum. There is currently no method that does not adversely affect the performance as a dispersant, and development is desired.

  Although the fields are different, a method using hydroxylamines as a method for reducing formaldehyde in a microcapsule has been disclosed (Japanese Patent Laid-Open No. 51-75676 (Patent Document 3), Japanese Patent Laid-Open No. 54-5874). (Patent Document 4), JP-A-55-145524 (Patent Document 5)). However, the effect of reducing residual formaldehyde is not sufficient, and there is a disadvantage that an unpleasant combined odor of ammonia and other decomposed products generated by reaction of hydroxylamines with formaldehyde and decomposition of hydroxylamines remains due to residual formaldehyde. It has been pointed out and there is a problem in industrial implementation (Japanese Patent Laid-Open No. 61-438: Patent Document 6).

JP-A-5-320120 JP-A-4-211046 JP-A-51-75676 JP 54-5874 A JP-A-55-145524 JP-A-61-438

  Therefore, the present invention has been made to solve such problems. The object of the present invention relates to a method for reducing formaldehyde remaining in a bisphenol-based formaldehyde condensate aqueous solution and / or a naphthalenesulfonic acid formaldehyde condensate aqueous solution, and affects the performance as various dispersants by a simple method. The object is to provide a method having a sufficient residual formaldehyde reduction effect. Moreover, it is providing the dispersing agent for various uses, such as the water reducing agent for cement which reduced the residual formaldehyde, and the dispersing agent for gypsum.

  As a result of repeated studies by the present inventors, it was found that residual formaldehyde can be greatly reduced by adding hydroxylamines to an aqueous solution of aldehydes and reacting with formaldehyde remaining in the aqueous solution. . Also, the bisphenol-based formaldehyde condensate aqueous solution and / or naphthalenesulfonic acid formaldehyde condensate aqueous solution obtained by this method has excellent performance as a water reducing agent for cement and a dispersant for gypsum, and is used for applications as these dispersants. It was also confirmed that it was possible to arrive at the present invention.

That is, the present invention provides the following inventions.
[1] Hydroxylamines are added to the condensate of the following components (I), (II) and (IV) and / or the condensate of components (III) and (IV) and remain in the condensate. A method for producing a formaldehyde condensate having a reduced formaldehyde content, comprising a step of reacting with formaldehyde.
(I) Bisphenol compound or salt thereof (II) One or more compounds selected from the following (a) to (d) (a) Aromatic aminosulfonic acid or salt thereof (b) Sulphite (c) Amino acid (d ) Aliphatic sulfonic acid having an amino group in the molecule (III) Naphthalenesulfonic acid or salt thereof (IV) Aldehydes [2] The component (II) is (a) aromatic aminosulfonic acid [1] The manufacturing method of the formaldehyde condensate of description.
[3] The method for producing a formaldehyde condensate according to [1] or [2], wherein the amount of the hydroxylamine added is 1.3 times or more equivalent to the formaldehyde remaining in the condensate.
[4] The method for producing a formaldehyde condensate according to any one of [1] to [3], wherein the hydroxylamine is hydroxylamine sulfate.
[5] Hydroxylamines are added to the condensate of the following components (I), (II) and (IV) and / or the condensate of components (III) and (IV) and remain in the condensate. A method for reducing formaldehyde remaining in an aqueous formaldehyde condensate solution, characterized by reacting with formaldehyde.
(I) Bisphenol compounds or salts thereof (II) One or more compounds selected from the following (a) to (d) (a) Aromatic aminosulfonic acid (b) Sulphite (c) Amino acid (d) In the molecule (III) Naphthalenesulfonic acid (IV) Aldehydes [6] A cement water reducing agent or a gypsum dispersant containing a formaldehyde condensate obtained by the production method according to [1].
[7] Condensate of the following components (I), (II) and (IV) and / or a condensate of components (III) and (IV), wherein the amount of residual formaldehyde in the condensate is 500 ppm or less Aldehyde condensate.
(I) Bisphenol compounds or salts thereof (II) One or more compounds selected from the following (a) to (d) (a) Aromatic aminosulfonic acid (b) Sulphite (c) Amino acid (d) In the molecule Aliphatic sulfonic acid having amino group in (III) Naphthalenesulfonic acid (IV) Aldehydes

  In conventional methods for producing bisphenol-based formaldehyde condensates and naphthalene sulfonic acid formaldehyde condensates, there are problems such as the danger of formaldehyde remaining in the condensate, adverse effects on human bodies, and harmfulness. In the present invention, since the amount of formaldehyde in the condensate can be greatly reduced, a safe formaldehyde condensate can be obtained. Further, the formaldehyde condensate obtained by the present invention is advantageous not only in terms of safety but also in handling because it does not cause an unpleasant complex odor due to ammonia and other decomposition products. In addition, it is advantageous for use in building materials.

  Moreover, this invention can acquire the formaldehyde amount reduction effect simply and reliably only by adding hydroxylamines with respect to a specific formaldehyde condensate. And, when the formaldehyde condensate obtained by the present invention is used as a dispersant, its performance is equivalent or better, so it is useful as a dispersant for various applications such as a water reducing agent for cement and a dispersant for gypsum. .

  The present invention relates to a technique for reducing the formaldehyde content in a condensate by adding hydroxylamines to a bisphenol-based formaldehyde condensate or a naphthalene sulfonic acid formaldehyde condensate in which residual formaldehyde is a problem. It is. According to the present invention, it is possible to greatly reduce the amount of formaldehyde remaining in these condensates, and it is possible to obtain a condensate that is excellent in safety and has an unpleasant complex odor.

  In the present invention, the condensate to be reduced in formaldehyde is a condensate of the following components (I), (II) and (IV), and a condensate with the following components (III) and (IV). The former corresponds to a so-called bisphenol / formaldehyde condensate, and the latter corresponds to a naphthalenesulfonic acid / formaldehyde condensate. These condensates may be mixed and used as a dispersant, but these mixtures are also the subject of the present invention.

（一般式（Ｉ）中、Ｘは下記一般式（ｐ），（ｑ），（ｒ）または Ｏ のいずれかを示す。

（一般式（ｐ），（ｑ）及び（ｒ）のうち、Ｒ_１，Ｒ_２，Ｒ_３は夫々独立して水素またはアルキル基を示す。また、Ｒ_４はアルキル基を示す。） Component (I) is a bisphenol compound or a salt thereof. A bisphenol compound means, for example, a compound having bisphenol, and examples thereof include compounds represented by the following general formula (I).

(In the general formula (I), X represents any one of the following general formulas (p), (q), (r) or O 2.

(In the general formulas (p), (q) and (r), R ₁ , R ₂ and R ₃ each independently represent hydrogen or an alkyl group. R ₄ represents an alkyl group.)

Examples of the compound represented by the following general formula (I) include 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 4,4′-dihydroxydiphenyl sulfone (bisphenol S), and 4,4′-dihydroxy. Diphenylmethane (bisphenol F), 2,2-bis (4-hydroxyphenyl) butane, 4,4′-dihydroxybiphenyl (DHBP), 4,4′-dihydroxydiphenyl ether (DHPE), 4,4′-ethylidene-bisphenol, Mention may be made of 4,4-bis (4-hydroxyphenyl) valeric acid (DPA), 4,4-bis (4-hydroxyphenyl) butyric acid and their isomers or salts thereof. These may be used alone or in combination of two or more. Of these, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) and 4,4′-dihydroxydiphenyl sulfone (bisphenol S) are preferable. Of these, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) is particularly preferable. The chemical structure of 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) is as shown in the following structural formula (I-1), and the chemical structure of 4,4′-dihydroxydiphenylsulfone (bisphenol S) is It is as shown by the following chemical formula (I-2).

  Examples of the salt of the bisphenol compound include a metal salt of the compound represented by the general formula (I).

  As the component (I), one of the above compounds or salts thereof may be used alone, or two or more of them may be used.

  Component (II) is one or more selected from (a) aromatic aminosulfonic acid or a salt thereof, (b) sulfite, (c) amino acid, and (d) an aliphatic sulfonic acid having an amino group in the molecule. It is a compound of this.

（一般式（ＩＩ）中、Ｙは水素またはアルキル基を示す。） (A) Aromatic aminosulfonic acid means a compound having an aromatic ring, an amino group and a sulfonic acid group or a salt thereof, and examples thereof include a compound represented by the general formula (II) or a salt thereof.

(In general formula (II), Y represents hydrogen or an alkyl group.)

芳香族アミノスルホン酸の塩としては、上記一般式（ＩＩ）で表される化合物の金属塩を挙げることができる。 Examples of the compound represented by the general formula (II) include 4-aminobenzenesulfonic acid, 2-amino-5-methylbenzenesulfonic acid, and isomers thereof, and 4-aminobenzenesulfonic acid is preferable. The chemical structure of 4-aminobenzenesulfonic acid is represented by the following structural formula (II-1).

Examples of the salt of aromatic aminosulfonic acid include metal salts of the compound represented by the general formula (II).

  (A) As the aromatic aminosulfonic acid or a salt thereof, one of the above compounds or a salt thereof can be used alone, or two or more of them can be used, and a compound represented by the general formula (II) is preferable, In particular, 4-aminobenzenesulfonic acid is preferable. Among the compounds represented by the general formula (II) or salts thereof, 4-aminobenzenesulfonic acid has an excellent effect of reducing residual formaldehyde, and is a dispersant for various uses such as a water reducing agent for cement and a dispersant for gypsum. It is preferably used because of its high suitability.

  (B) As a sulfite, sodium sulfite, ammonium sulfite, sodium hydrogen sulfite, sodium pyrosulfite, potassium bisulfite, ammonium bisulfite, etc. can be used alone or in combination of two or more. Of these, sodium sulfite is preferred.

  (C) Examples of amino acids include glutamic acid, glycine, iminodiacetic acid, alanine, aspartic acid, serine, aminobutyric acid, glutathione, aminocaproic acid, valine, phenylalanine, methionine, leucine, etc., or a combination of two or more. It can also be used.

  (D) As the aliphatic sulfonic acid having an amino group in the molecule, sulfonated products such as melamine, acetoguanamine and benzoguanamine, sulfamic acid and the like can be used. In addition, the bisphenol formaldehyde condensate used by this invention can also be manufactured following sulfonation of a melamine, an acetoguanamine, and a benzoguanamine.

  As the component (II), compounds selected from the above (a) to (d) may be used alone, or two or more kinds may be used in combination. In particular, it is preferable to use (a) an aromatic aminosulfonic acid or a salt thereof, and it is particularly preferable to use a compound represented by the general formula (II) or a salt thereof.

  Component (III) is naphthalenesulfonic acid or a salt thereof. Naphthalene sulfonic acid may be a metal salt such as sodium salt or calcium salt.

  Component (IV) is an aldehyde. Aldehydes means a compound having an aldehyde group, and examples include formaldehyde polymerization and condensates such as paraformaldehyde and hexamethylenetetramine, acetaldehyde, and the like in addition to formaldehyde. Moreover, these derivatives may be sufficient. As the component (IV), one of the above compounds or a salt thereof may be used alone, or two or more thereof may be used, but it is particularly preferable to use formaldehyde or a derivative thereof.

  The most preferred condensate of component (I), component (II) and component (IV) is 2,2-bis (4-hydroxyphenyl) propane or a salt thereof as component (I), and component (II) 4-aminobenzenesulfonic acid as a component and formaldehyde as a component (IV) are subjected to a condensation reaction.

  The conditions for the condensation reaction of component (I), component (II) and component (IV) are not particularly limited. The blending ratio of each component is not particularly limited, but particularly in the case of a condensate of components (I), (II) and (IV), a compound represented by the general formula (II) or a salt thereof is used as component (II). In the case, the constituent molar ratio of component (I) to component (II) is preferably 0.2 to 1.4: 1.0, more preferably 0.3 to 1.3: 1.0. Can be adjusted.

  Condensates of components (I), (II) and (IV) are obtained by condensing each component by heating in the presence of an alkali under aqueous conditions. Conditions such as reaction temperature, time, and pH are not particularly limited, and can be appropriately determined according to the type and use of the compound. For example, the reaction temperature is 30 to 140 ° C., and the reaction time is about 2 to 50 hours. The condensation reaction is carried out by adding (Component 3) dropwise to a reactor containing components (I) and (II). Component (IV) is preferably added dropwise within 1 to 3 hours, and the reaction concentration Is usually carried out at 20 to 50% by weight.

  As the alkali catalyst used in the condensation reaction, metal hydroxides such as sodium hydroxide, calcium hydroxide, and potassium hydroxide, ammonium hydroxides, and the like can be used. It is preferable to adjust the pH during the condensation reaction to 6 to 14, preferably 7 to 12, using the alkali catalyst.

  In addition, the condensation reaction is performed in the presence of water, but in the present invention, an aqueous solution of the condensate obtained after completion of the condensation reaction can be used as a treatment target. The weight average molecular weight of the condensate of components (I), (II) and (IV) is preferably 10,000 to 50,000. Further, in addition to the condensate, other components such as lignin may be contained.

  On the other hand, the most preferable condensate of component (III) and component (IV) is a condensate obtained by subjecting naphthalenesulfonic acid or a salt thereof as component (III) to formaldehyde as component (IV). It is. Commercial products such as Vanillol HDL-100 (trade name) manufactured by Nippon Paper Chemicals Co., Ltd. used in Examples described later can also be used.

  Conditions for the condensation reaction of component (III) and component (IV) are not particularly limited. That is, there are no particular limitations on the reaction time, temperature, pH, and other conditions during the condensation, and conditions under which the condensation reaction between component (III) and component (IV) proceeds to a high degree can be appropriately determined. In addition, the condensation reaction is performed in the presence of water, but in the present invention, an aqueous solution of the condensate obtained after completion of the condensation reaction can be used as a treatment target. Further, in addition to the condensate, other components such as lignin may be contained. When the condensate of the above components (I), (II) and (IV) and the condensate of the above components (III) and (IV) are mixed and used, their blending ratio is not particularly limited.

  In the present invention, in producing a formaldehyde condensate having a reduced formaldehyde content, the condensate of the above components (I), (II) and (IV) and / or the condensate of components (III) and (IV) are used. And adding a hydroxylamine and reacting with formaldehyde remaining in the condensate. That is, it is sufficient if it includes a step of adding a hydroxylamine to the condensate and causing a predetermined reaction, and only the step may be performed using a commercially available condensate, or the step Before the step, a step for obtaining a condensate by a condensation reaction may be separately provided. About the process for obtaining a condensate, it is as having described in the example about each said condensate.

  In the present invention, hydroxylamines are used. Specific examples of hydroxylamines include hydroxylamine, hydroxyaminoacetic acid, oxyphenylhydroxylamine, o-methylhydroxylamine, o-ethylhydroxylamine, N-methylhydroxylamine, N-ethylhydroxylamine, N-hydroxypropylhydroxyl Amine, phenylhydroxylamine, N-formyl-N-phenylhydroxylamine, tolylhydroxylamine, methoxyphenylhydroxylamine, etc., and usually hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, acetic acid, oxalic acid, citric acid, etc. Used as a salt with acid. Moreover, you may use combining these 1 or 2 or more. Of these, hydroxylamine sulfate, hydroxylamine hydrochloride, and hydroxylamine phosphate are preferable, but hydroxylamine sulfate is most suitable because it is excellent in reducing the amount of residual formaldehyde, does not contain chlorine, and is inexpensive.

  As a form of addition of hydroxylamines, powder may be added, but it is more preferable to add in the form of an aqueous solution from the viewpoint of handling and uniform reaction. The amount of hydroxylamine in the aqueous solution is not particularly limited, but is preferably 50% by weight or less from the viewpoint of safety, and preferably 10 to 30% by weight from the viewpoint of handling.

  The amount of hydroxylamine added is preferably larger than the remaining formaldehyde in the aqueous bisphenol-based formaldehyde condensate solution and / or aqueous naphthalenesulfonic acid formaldehyde condensate solution, and preferably 1.1 times the amount of residual formaldehyde. The above is preferable, and 1.3 times or more is preferable. In particular, if the amount added is less than 1.3 times, the effect of reducing residual formaldehyde may not be sufficiently exhibited. The upper limit is preferably 2.5 times or less. Even if it is added in an amount of 2.5 times or more, no further effect can be obtained, and since hydroxylamines are expensive, the addition cost becomes high.

  In the present invention, the reaction of adding hydroxylamines to the above-mentioned condensate can be performed by adding the hydroxylamines to the condensate (usually an aqueous solution of the condensate) under stirring conditions.

  In the present invention, the pH of the reactant during the reaction (measured value at 20 ° C.) is usually in the range of 3.0 to 9.5, preferably in the range of 3.0 to 9.0, The pH range is more preferably 6.0 to 8.5, and particularly preferably 6.0 to 8.0. In particular, if the pH range is out of 3.0 to 9.0, the amount of residual formaldehyde may not be sufficiently reduced, which is not preferable from the viewpoint of product handling (acidity and alkalinity). The pH of the reaction product during the reaction can be adjusted, for example, by adding an alkaline agent such as NaOH to the condensate in advance before adding hydroxylamines. The pH can be adjusted at any time, and can be appropriately selected before starting the reaction, during the reaction, after the reaction, and the like.

  Moreover, reaction temperature is 20-80 degreeC normally, Preferably it is 30-70 degreeC, More preferably, it can set in the range of 40-60 degreeC. When the temperature is low, it takes too much reaction time to obtain a desired residual aldehyde reduction amount, resulting in poor efficiency and poor productivity. If the temperature is too high, the effect of reducing the amount of residual formaldehyde is not sufficient.

  The reaction time is generally 0.5 to 30 hours, preferably 0.5 to 20 hours. If the reaction time is too short, the effect of reducing the amount of residual formaldehyde is not sufficient, and if the reaction time is too long, the efficiency is low and the productivity is poor. In the present invention, the combination of the reaction temperature and the reaction time is particularly preferably 0.5 to 20 hours at 30 to 70 ° C, particularly 2 to 4 hours at 40 to 60 ° C.

  The formaldehyde condensate produced according to the present invention has a greatly reduced formaldehyde content. The formaldehyde content of the formaldehyde condensate produced by the conventional production method is usually around 800 to 1000 ppm, but it can be reduced by adding hydroxylamine and reacting it according to the present invention. Usually, it can be reduced to 500 ppm or less, preferably to an amount below 200 ppm, more preferably to the detection limit level (0.1 ppm or less). The formaldehyde condensate produced by the addition reaction with hydroxylamine according to the present invention may increase the formaldehyde content again when stored for a long period of time. However, by treating such a condensate as a subject of the present invention again, A condensate having a low formaldehyde content can be obtained.

In addition, the formaldehyde condensate obtained by the present invention retains the same dispersibility as the condensate produced by the conventional production method, so that the amount of residual formaldehyde is drastically reduced. It can be used as a dispersing agent for various uses such as an agent.
That is, the formaldehyde condensate obtained by the present invention has a high water-reducing property with respect to cement compositions such as cement, mortar, concrete, etc., and is less susceptible to deterioration over time during flow, improving workability and workability. It can be used as a water reducing agent for the composition. Moreover, it is excellent in the dispersibility of gypsum and can be used as a dispersant for gypsum. Further, it can be used as a dispersant for dyes, a coal / water slurry, calcium carbonate and the like. When the formaldehyde condensate obtained by the present invention is used as the water reducing agent or dispersant, other additives may be added.

[Action]
The method for reducing residual formaldehyde in the aqueous formaldehyde condensate solution of the present invention can be achieved by adding hydroxylamines to the bisphenol-based formaldehyde condensate aqueous solution and / or the naphthalenesulfonic acid formaldehyde condensate aqueous solution and reacting them. In this reaction, it is considered that formaldehyde and hydroxylamines react to form an oxime compound. For example, when the hydroxylamine is hydroxylamine sulfate as an example, it is considered that the following formula 1 is obtained.
[Formula 1]
2HCHO + (NH ₂ OH) 2H ₂ SO ₄ → 2H ₂ C = NOH + H ₂ SO ₄ + H ₂ O

  In other applications, such as formaldehyde reduction in microcapsules, the effect of reducing residual formaldehyde is not sufficient, and the residue in the reaction of adding hydroxylamines to a bisphenol-based formaldehyde condensate aqueous solution and / or a naphthalenesulfonic acid formaldehyde condensate aqueous solution. The reason why the formaldehyde reduction effect is excellent is unknown, but the compatibility of the bisphenol-based formaldehyde condensate aqueous solution and / or naphthalenesulfonic acid formaldehyde condensate aqueous solution with hydroxylamines is very good. It is conceivable that the reaction efficiency with hydroxylamines is good and other unnecessary side reactions do not occur.

  EXAMPLES Hereinafter, although this invention is explained in full detail according to an Example, this invention is not limited by this.

The weight average molecular weight was measured by GPC method using polyethylene glycol as a standard and a differential refractometer as a detector. The columns and eluents used are shown below.
Column: OH pak KB-806 + KB-802.5 + KB-802.5 (manufactured by Showa Denko KK)
Eluent: 0.05 molar aqueous solution of sodium nitrate and acetonitrile with a volume ratio of 8: 2.

  The amount of residual formaldehyde was quantified using a Wako Pure Chemical Industries Ltd. formaldehyde-test Wako measuring kit for measuring formaldehyde. The same applies to the following embodiments.

Production Example 1 (Production of bisphenols / aminobenzenesulfonic acid / formaldehyde condensate aqueous solution)
To a reactor equipped with a stirrer, a reflux device, a thermometer, and a formaldehyde aqueous solution dropping device, 173.20 g (1 mol) of 4-aminobenzenesulfonic acid and 100.12 g (0.5 of 4,4′-dihydroxydiphenylsulfone) were added. Mol), 48.43 g (1.15 mol) of 95% NaOH, and 736.00 g of water.

  Next, 171.43 g (2 mol) of 35% aqueous formaldehyde solution was added to the solid-liquid suspension at a temperature of 90 ° C. under reflux, and the reaction mixture was stirred for 10 hours under reflux to obtain an aqueous solution of a condensate.

  The weight average molecular weight (Mw) of the obtained condensate was 21,000.

Production Example 2 (Production of bisphenols / aminobenzenesulfonic acid / formaldehyde condensate aqueous solution)
In a reactor equipped with a stirrer, a reflux device, a thermometer, and an aqueous formaldehyde dropping device, 297 parts (1.2 mol) of 2,2-bis (4-hydroxyphenyl) propane and 173 parts of 4-aminobenzenesulfonic acid (1.0 mol), 44 parts (1.1 mol) of sodium hydroxide, and 1575 parts of water were charged.

  Next, 211 parts (2.6 mol) of a 37 wt% formaldehyde aqueous solution at 90 ° C. is dropped into the solid-liquid suspension under reflux, and the ratio of the molecular weight of 20,000 or less at that temperature is 40 wt% or less. The reaction was carried out while analyzing by GPC method. In the reaction of Production Example 2, the time required for the ratio of the molecular weight of 20,000 or less to be 40% by weight or less is 35 hours.

  Moreover, the weight average molecular weight of the obtained condensate aqueous solution and the weight% of molecular weight 20,000 or less were 24,000 and 31 weight%, respectively.

Production Example 3 (Production of bisphenols, sulfites, formaldehyde condensate aqueous solution)
A reactor equipped with a stirrer, a reflux device, a thermometer, and an aqueous formaldehyde dropping device was charged with 228.3 parts (1 mol) of 2,2-bis (4-hydroxyphenyl) propane and 126.3 parts of sodium sulfite (1 Mol), 826 parts of water was charged.

  Next, 243.3 parts of a 37 wt% aqueous formaldehyde solution (formaldehyde 3 mol) was added dropwise to the solid-liquid suspension at a temperature of 90 ° C. over 1 hour, and the mixture was further reacted at that temperature for 14 hours to obtain an aqueous solution of the condensate of the present invention. Got. The weight average molecular weight of the obtained condensate was 29,000. In Tables 1 to 8, the condensate obtained in Production Example 2 is referred to as “bisphenol-based condensate (2)”.

  The condensates obtained in the above Production Examples 1, 2, and 3 are shown in Tables 1 to 8 below, as “bisphenol-based condensate (1)”, “bisphenol-based condensate (2)”, and “bisphenol-based”, respectively. It shall be expressed as “Condensate (3)”.

Example 1
Addition of 10% aqueous solution of hydroxylamine sulfate equivalent to 1.2 times the amount of residual formaldehyde to the aqueous solution of bisphenols, aminobenzenesulfonic acid and formaldehyde condensate obtained in Production Example 1 (residual formaldehyde amount: 900 ppm of the liquid) And reacted at 50 ° C. for 3 hours. Prior to the addition of hydroxylamine sulfate, the pH of the reaction product during the reaction was adjusted to 7.0 (20 ° C.). The amount of formaldehyde remaining in the reaction product was measured and found to be 200 ppm. Moreover, there was no generation of unpleasant odor due to this reaction.

Examples 2-7
The same procedure as in Example 1 was performed except that the amount of hydroxylamine sulfate added was changed to the amount shown in Table 1. The amount of residual formaldehyde of the obtained reaction product is as shown in Table 1. In any of the examples, an excellent effect of reducing formaldehyde is exhibited. Further, in Examples 4 to 7 in which the amount is 1.8 times or more, the detection limit ( 0.1 ppm) or less.

Examples 8-14
In Example 1, it implemented like Example 1 except having replaced each amount of hydroxylamine hydrochloride shown in Table 2 instead of hydroxylamine sulfate. The amount of residual formaldehyde of the obtained reaction product is as shown in Table 2, and the amount of formaldehyde was reduced in all Examples. Especially in Examples 9 to 14 in which the addition amount was 1.3 times or more, an excellent effect of reducing formaldehyde was exhibited, and in Examples 12 to 14 in which the addition amount was 2.0 times or more, the detection limit (0.1 ppm) or less. Met.

Examples 15-21
In Example 1, it implemented like Example 1 except having replaced each amount of hydroxylamine phosphate shown in Table 3 instead of hydroxylamine sulfate. The amount of residual formaldehyde of the obtained reaction product is as shown in Table 3, and the amount of formaldehyde was reduced in all Examples. Especially in Examples 16 to 21 in which the addition amount was 1.3 times or more, an excellent effect of reducing formaldehyde was exhibited, and in Examples 19 to 21 in which the addition amount was 2.0 times or more, the detection limit (0.1 ppm) or less. Met.

Examples 22-26
Example 5 was carried out in the same manner as Example 1 except that the pH was adjusted to the numerical values shown in Table 4. The amount of residual formaldehyde of the obtained reaction product is as shown in Table 4, and the amount of formaldehyde was reduced in all Examples. In particular, in Examples 23 to 25 in which the pH was adjusted between 3 and 9, an excellent effect of reducing formaldehyde was exhibited, and in Examples 23 and 24 at pH 3 to 7, the detection limit (0.1 ppm) or less was obtained.

Examples 27-33
In Example 5, it implemented like Example 1 except having adjusted reaction temperature so that it might become the numerical value shown in Table 5. FIG. The amount of residual formaldehyde of the obtained reaction product is as shown in Table 5, and the amount of formaldehyde was reduced in all examples. In particular, Examples 28 to 32 adjusted to 30 to 70 ° C. exhibited an excellent effect of reducing formaldehyde, and Examples 30 and 31 of 50 to 60 ° C. were below the detection limit (0.1 ppm).

Examples 34-40
The same procedure as in Example 1 was performed except that the reaction time in Example 5 was adjusted to the values shown in Table 6. The amount of residual formaldehyde of the obtained reaction product is as shown in Table 6, and the amount of formaldehyde was reduced in all Examples. Especially in Examples 35 to 40 adjusted to 0.5 hours or more, an excellent effect of reducing formaldehyde was exhibited, and in Examples 36 to 38 for 1 to 10 hours, it was below the detection limit (0.1 ppm).

Example 41
Bisphenol / aminobenzenesulfonic acid / formaldehyde condensate aqueous solution obtained in Production Example 1 (residual formaldehyde amount: 900 ppm to the liquid) and naphthalenesulfonic acid formaldehyde condensate (Nippon Paper Chemical Co., Ltd., trade name: Vaniol HDL-100, Residual formaldehyde amount: 1000 ppm to the liquid) was mixed at a weight ratio of 50:50. To this, a 20% aqueous solution of hydroxylamine sulfate having an equivalent amount of 2.3 times the amount of residual formaldehyde was added and reacted at 50 ° C. for 4 hours. Before the addition of hydroxylamine sulfate, the pH of the reaction product during the reaction was adjusted to 7.5 (20 ° C.) in advance. When the amount of formaldehyde remaining in the obtained reaction product was measured, it was below the detection limit (0.1 ppm) (Table 7). Moreover, there was no generation of unpleasant odor due to this reaction.

Example 42
Naphthalene sulfonic acid formaldehyde condensate (Nippon Paper Chemical Co., Ltd., trade name: vaniol HDL-100, residual formaldehyde amount: 1000 ppm of the liquid), and a 30% aqueous solution of hydroxylamine sulfate equivalent to 1.8 times the amount of residual formaldehyde The mixture was added and reacted at 60 ° C. for 1 hour. Prior to the addition of hydroxylamine sulfate, the pH of the reaction product during the reaction was adjusted to 7.8 (20 ° C.) in advance. When the amount of formaldehyde remaining in the obtained reaction product was measured, it was below the detection limit (0.1 ppm) (Table 7). Moreover, there was no generation of unpleasant odor due to this reaction.

Example 43
Add 20% aqueous solution of hydroxylamine sulfate equivalent to 2.3 times the amount of residual formaldehyde to the aqueous solution of bisphenols, aminobenzenesulfonic acid and formaldehyde condensate obtained in Production Example 2 (residual formaldehyde amount: 800 ppm to the liquid) The reaction was carried out at 45 ° C. for 8 hours. Prior to the addition of hydroxylamine sulfate, the pH of the reaction product during the reaction was adjusted to 6.6 (20 ° C.) in advance. When the amount of formaldehyde remaining in the obtained reaction product was measured, it was below the detection limit (0.1 ppm) (Table 7). Moreover, there was no generation of unpleasant odor due to this reaction.

Example 44
A 20% aqueous solution of hydroxylamine sulfate, 1.8 times equivalent to the amount of residual formaldehyde, was added to the aqueous solution of bisphenols, aminobenzenesulfonic acid and formaldehyde condensate obtained in Production Example 2 (residual formaldehyde content: 800 ppm of the liquid). And reacted at 80 ° C. for 2 hours. Before the addition of hydroxylamine sulfate, the pH of the reaction product during the reaction was adjusted to 8.3 (20 ° C.). The amount of formaldehyde remaining in the reaction product was measured and found to be 90 ppm with respect to the liquid (Table 7). Moreover, there was no generation of unpleasant odor due to this reaction.

Example 45
Add 20% aqueous solution of hydroxylamine sulfate equivalent to 2.3 times the amount of residual formaldehyde to the aqueous solution of bisphenols, aminobenzenesulfonic acid and formaldehyde condensate obtained in Production Example 2 (residual formaldehyde amount: 800 ppm to the liquid) The reaction was carried out at 25 ° C. for 25 hours. Prior to the addition of hydroxylamine sulfate, the pH of the reaction product during the reaction was adjusted to 9.2 (20 ° C.) in advance. The amount of formaldehyde remaining in the reaction product was measured and found to be 120 ppm against the liquid (Table 7). Moreover, there was no generation of unpleasant odor due to this reaction.

Example 46
Add 20% aqueous solution of hydroxylamine hydrochloride equivalent to 2.3 times the amount of residual formaldehyde to the aqueous solution of bisphenols, aminobenzenesulfonic acid and formaldehyde condensate obtained in Production Example 2 (residual formaldehyde content: 800 ppm to the liquid) The reaction was carried out at 25 ° C. for 25 hours. Prior to the addition of hydroxylamine hydrochloride, the pH of the reaction product during the reaction was adjusted to 9.2 (20 ° C.) in advance. The amount of formaldehyde remaining in the reaction product was measured and found to be 160 ppm against the liquid (Table 7). Moreover, there was no generation of unpleasant odor due to this reaction.

Example 47
Add 10% aqueous solution of hydroxylamine sulfate 1.5 times equivalent to the amount of residual formaldehyde to the aqueous solution of bisphenols, aminobenzenesulfonic acid and formaldehyde condensate obtained in Production Example 1 (residual formaldehyde content: 900 ppm to the liquid) And reacted at 75 ° C. for 1 hour. Prior to the addition of hydroxylamine sulfate, the pH of the reaction product during the reaction was adjusted to 7.3 (20 ° C.) in advance. The amount of formaldehyde remaining in the reaction product was measured and found to be 50 ppm against the liquid (Table 7). Moreover, there was no generation of unpleasant odor due to this reaction.

Example 48
To the bisphenol / aminobenzenesulfonic acid / formaldehyde condensate aqueous solution obtained in Production Example 1 (residual formaldehyde content: 900 ppm of the liquid), a 10% aqueous solution of hydroxylamine phosphate equivalent to 1.1 times the residual formaldehyde content was added. The mixture was added and reacted at 80 ° C. for 1 hour. Prior to the addition of hydroxylamine phosphate, the pH of the reaction product during the reaction was adjusted to 9.4 (20 ° C.) in advance. When the amount of residual formaldehyde of the obtained reaction product was measured, it was 240 ppm with respect to the liquid (Table 7). Moreover, there was no generation of unpleasant odor due to this reaction.

Example 49
To the aqueous solution of bisphenols, sulfite and formaldehyde condensate obtained in Production Example 3 (residual formaldehyde amount 920 ppm), a 10% aqueous solution of hydroxylamine phosphate equivalent to 1.2 times the amount of residual formaldehyde was added, The reaction was carried out for 2 hours. Prior to the addition of hydroxylamine phosphate, the pH of the reaction product during the reaction was adjusted to 9.4 (20 ° C.) in advance. When the amount of residual formaldehyde of the obtained reaction product was measured, it was 290 ppm with respect to the liquid (Table 7). Moreover, there was no generation of unpleasant odor due to this reaction.

Comparative Example 1
To the bisphenol / aminobenzenesulfonic acid / formaldehyde condensate aqueous solution obtained in Production Example 1 (residual formaldehyde amount: 900 ppm of the liquid), a 10% aqueous solution of ammonium sulfate equivalent to 2.0 times the residual formaldehyde amount was added, Reaction was performed at 50 degreeC for 3 hours. When the amount of residual formaldehyde of the obtained reaction product was measured, it was 850 ppm, and almost no reduction effect of residual formaldehyde was recognized (Table 8).

Comparative Example 2
The aqueous bisphenols / aminobenzenesulfonic acid / formaldehyde condensate solution obtained in Production Example 1 (residual formaldehyde amount: 900 ppm of the liquid) was adjusted to pH 12. A 2% by weight hydrogen peroxide solution (concentration 30%) was added to the solid content weight in the aqueous condensate solution, and the reaction was carried out at 90 ° C. for 3 hours. When the amount of residual formaldehyde of the obtained reaction product was measured, it was 500 ppm (Table 8).

Comparative Example 3
30 g of sodium hypochlorite solution (effective chlorine 5%) was added to 300 g of the aqueous solution of bisphenols, aminobenzenesulfonic acid and formaldehyde condensate obtained in Production Example 2 (residual formaldehyde amount: 800 ppm of the liquid), and 60 ° C. The reaction was carried out for 3 hours. When the amount of residual formaldehyde of the obtained reaction product was measured, it was 750 ppm, and almost no reduction effect of residual formaldehyde was recognized (Table 8).

Comparative Example 4
The aqueous bisphenol / aminobenzenesulfonic acid / formaldehyde condensate solution obtained in Production Example 2 (residual formaldehyde content: 800 ppm of the liquid) was adjusted to pH 11.7. A 2.5% by weight hydrogen peroxide solution (concentration 30%) was added to the solid content weight in the condensate aqueous solution, and the reaction was performed at 90 ° C. for 3 hours. When the amount of residual formaldehyde of the obtained reaction product was measured, it was 550 ppm (Table 8).

Comparative Example 5
The aqueous bisphenols / aminobenzenesulfonic acid / formaldehyde condensate solution obtained in Production Example 1 (residual formaldehyde content: 900 ppm to the liquid) was used as it was (Table 8).

Comparative Example 6
The aqueous bisphenols / aminobenzenesulfonic acid / formaldehyde condensate solution obtained in Production Example 2 (residual formaldehyde amount: 800 ppm of the liquid) was used as it was (Table 8).

Comparative Example 7
Bisphenol / aminobenzenesulfonic acid / formaldehyde condensate aqueous solution obtained in Production Example 1 (residual formaldehyde amount: 900 ppm to the liquid) and naphthalenesulfonic acid formaldehyde condensate (Nippon Paper Chemical Co., Ltd., trade name: Vaniol HDL-100, Residual formaldehyde amount: 1000 ppm with respect to the liquid) was mixed in the form of 50:50 (Table 8).

Comparative Example 8
Naphthalene sulfonic acid formaldehyde condensate (Nippon Paper Chemical Co., Ltd., trade name: Vanillol HDL-100, amount of residual formaldehyde: 1000 ppm of liquid) was used as it was (Table 8).

[Test example]
Concrete test Consistency (viscosity) of concrete to which the amount of cement water-reducing agent consisting of the reaction product obtained by the formaldehyde reduction method of the present invention shown in the examples is added as shown in Table 10, and the water-reducing agent of the comparative example It is shown in comparison with the consistency of the added concrete.
The formulation is shown in Table 9.

(Footnote in Table 9)
* C cement: Ordinary Portland cement: specific gravity 3.16
W Tap water S Fine aggregate: Hiroshima processed sand Specific gravity 2.59, F.R. M.M. 2.59
G Coarse aggregate: Yamaguchi crushed stone, specific gravity 2.71, F.R. M.M. 6.86

  For concrete, cement, aggregate, and water or water containing a water reducing agent were kneaded for 3 minutes with a 100 liter portable tilting barrel mixer, and the slump immediately after that was measured. The concrete slump and the amount of air were measured according to JIS. That is, the slump measurement is performed according to the slump test of JIS A 1101, and the concrete packed in the cone (upper surface inner diameter 10 cm, lower surface inner diameter 20 cm, height 30 cm) drops from the initial height after the cone is pulled out. Was shown as the slump value. The amount of air was determined by reducing the pressure in the air chamber according to the air amount test method of JIS A 1128.

  The measurement results are as shown in Table 10. The cement water reducing agent comprising the reaction product obtained by the formaldehyde reduction method of the present invention shown in Examples 5, 47, and 48 is equivalent to the slump compared with the water reducing agent before the formaldehyde reduction treatment (Comparative Example 5). It can be seen that there is no influence on the slump by the formaldehyde reduction treatment. The same results were obtained for the relationship between Example 42 and Comparative Example 8, and between Example 41 and Comparative Example 7.

  On the other hand, the water reducing agent for cement composed of the reaction product obtained by the method for reducing formaldehyde shown in Comparative Examples 1 and 2 has a performance due to a decrease in slump as compared with the water reducing agent before the formaldehyde reduction treatment (Comparative Example 5). A decrease is observed.

● Gypsum Dispersibility Test The dispersibility of the gypsum slurry to which the dispersant for gypsum made of the reaction product obtained by the formaldehyde reduction method of the present invention shown in the examples was added, and the dispersibility of the gypsum slurry to which the dispersant of the comparative example was added It showed in comparison with.

  110 g of gypsum (SK: trade name manufactured by Sakai Chemical Industry Co., Ltd.) and 65 g of water (including a gypsum dispersant) are stirred for 15 seconds with a mixer and poured into a hollow cylindrical container having an inner diameter of 50 mm and a height of 50 mm. Then, the diameter (flow value) of the circular spread of the gypsum slurry is measured at two locations and averaged. The amount of dispersant added (in terms of solid content) is 0.1% by weight of gypsum. The larger the flow value, the better the gypsum dispersion performance.

  The results of the gypsum dispersibility test are as shown in Table 11. The gypsum dispersant comprising the reaction product obtained by the formaldehyde reduction method of the present invention shown in Examples 43, 44, 45, and 46 is treated with formaldehyde. Compared with the dispersant before performing (Comparative Example 6), an equivalent flow value is obtained, the flow value is not affected by the formaldehyde reduction treatment, and the performance as a dispersant for gypsum is maintained. Similar results were obtained for the relationship between Example 42 and Comparative Example 8 and for the relationship between Example 41 and Comparative Example 7.

  On the other hand, the gypsum dispersant comprising the reaction product obtained by the formaldehyde reduction method shown in Comparative Examples 3 and 4 is due to a decrease in the flow value compared to the dispersant before the formaldehyde reduction treatment (Comparative Example 6). A decrease in gypsum dispersion performance is observed.

Claims (7)

Hydroxylamines are added to the condensates of the following components (I), (II) and (IV) and / or the condensates of components (III) and (IV) and reacted with formaldehyde remaining in the condensate A process for producing a formaldehyde condensate having a reduced formaldehyde content, comprising the step of:
(I) Bisphenol compound or salt thereof (II) One or more compounds selected from the following (a) to (d) (a) Aromatic aminosulfonic acid or salt thereof (b) Sulphite (c) Amino acid (d ) Aliphatic sulfonic acid having amino group in the molecule (III) Naphthalenesulfonic acid or its salt (IV) Aldehydes   The method for producing a formaldehyde condensate according to claim 1, wherein the component (II) is (a) an aromatic aminosulfonic acid.   The method for producing a formaldehyde condensate according to claim 1 or 2, wherein the amount of the hydroxylamine added is 1.3 times the equivalent of formaldehyde remaining in the condensate.   The method for producing a formaldehyde condensate according to any one of claims 1 to 3, wherein the hydroxylamine is hydroxylamine sulfate. Hydroxylamines are added to the condensates of the following components (I), (II) and (IV) and / or the condensates of components (III) and (IV) and reacted with formaldehyde remaining in the condensate A method for reducing formaldehyde remaining in an aqueous formaldehyde condensate solution, characterized by comprising:
(I) Bisphenol compounds or salts thereof (II) One or more compounds selected from the following (a) to (d) (a) Aromatic aminosulfonic acid (b) Sulphite (c) Amino acid (d) In the molecule Aliphatic sulfonic acid having amino group in (III) Naphthalenesulfonic acid (IV) Aldehydes   A water reducing agent for cement or a dispersing agent for gypsum containing a formaldehyde condensate obtained by the production method according to claim 1. Condensates of the following components (I), (II) and (IV) and / or condensates of components (III) and (IV), wherein the amount of residual formaldehyde in the condensate is 500 ppm or less .
(I) Bisphenol compounds or salts thereof (II) One or more compounds selected from the following (a) to (d) (a) Aromatic aminosulfonic acid (b) Sulphite (c) Amino acid (d) In the molecule Aliphatic sulfonic acid having amino group in (III) Naphthalenesulfonic acid (IV) Aldehydes