JP3062899B2 - Method for stabilizing aqueous sodium formaldehyde sulfoxylate solution - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to sodium formaldehyde sulfoxylate (NaSO ₂ CH ₂ OH · 2H).
₂ O) relates to a method of stabilizing an aqueous solution.

[0002]

2. Description of the Related Art Sodium formaldehyde sulfoxylate is a useful compound used as a catalyst or cocatalyst in redox polymerization and for printing cellulose fibers.

[0003] In use, water is added and used as an aqueous solution. Especially when used as a catalyst or cocatalyst in redox polymerization, sodium formaldehyde sulfoxylate is unstable in an aqueous solution. Dissolved and used. For this reason, a large amount of time and labor is required for the melting operation, and the present situation is that it hinders efficient production activities. Further, when the amount of use is large and the frequency of dissolution is high, there is a concern that the working environment may be deteriorated due to sodium formaldehyde sulfoxylate dust generated during mixing.

Therefore, stabilization of an aqueous sodium formaldehyde sulfoxylate solution using a stabilizer has been studied. Conventionally, as a stabilizer of sodium formaldehyde sulfoxylate aqueous solution, sodium sulfide (Kim. Kim. Teckhnol 26 (1)
0). 1231-4 (Russ) 1983), formaldehyde (Barwnikiki-Srodki Pomo)
cnice 20 (1). 1-12 (Pol) 197
6) and the like are known.

[0005]

However, among the above stabilizers, sodium sulfide may inhibit the activity of the polymerization catalyst when sodium formaldehyde sulfoxylate is used, for example, as a cocatalyst in a redox polymerization reaction. . In addition, formaldehyde has a problem in its toxicity, and its use in the final product is strictly regulated, so its use is not preferred.

[0006] It is an object of the present invention to provide a stabilizer of an aqueous sodium formaldehyde sulfoxylate solution which does not have the above-mentioned disadvantages. The purpose of the present invention is to prevent the formation of formalin, sulfide and the like, and at the same time, to prevent a decrease in alkalinity. Another object of the present invention is to improve the efficiency of the melting operation and improve the working environment.

[0007]

Means for Solving the Problems In view of the above situation, the present inventors have conducted intensive studies and as a result, have found that certain aldehydes, ketones, oximes, amides, and acetals are useful as stabilizers for aqueous sodium formaldehyde sulfoxylate. They have found something and arrived at the present invention.

That is, the gist of the present invention is to prepare an aqueous solution of sodium formaldehyde sulfoxylate from a group of compounds represented by the following general formulas (I) to (V) with respect to 100 parts by weight of solid sodium formaldehyde sulfoxylate. 0.1 to at least one selected
A method for stabilizing an aqueous sodium formaldehyde sulfoxylate solution, characterized by adding 3.0 parts by weight. R ¹ CHO (I) R ² R ³ C = O (II) R ⁴ R ⁵ C = N—OH (III) R ⁶ CONH ₂ (IV) R ⁷ R ⁸ C (OR ⁹ ) ₂ (V) (Formula In the formula, R ^{1 to} R ³ and R ⁹ each represent a C _{1 to} C ₉ linear or branched alkyl group, and R ^{4 to} R ⁸ each represent a hydrogen atom or a C _{1 to} C ₉ linear or Represents a branched alkyl group.)

Specific examples of the stabilizer for the aqueous sodium formaldehyde sulfoxylate solution which can be used in the present invention include aldehydes such as acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, valeraldehyde, isovaleraldehyde, hexanal and heptanal. Acetone, methyl ethyl ketone, 3-pentanone, isopropyl methyl ketone;
Methyl propyl ketone, 3-hexanone, 2-methyl-
3-pentanone, 4-heptanone, 2,4-dimethyl-
Ketones such as 3-pentanone and 2-methyl-3-hexanone; formaldehyde oxime, acetaldehyde oxime, propionaldehyde oxime, butyraldehyde oxime, isobutyraldehyde oxime, valeraldehyde oxime, isovaleraldehyde oxime,
Oximes such as hexanal oxime, heptanal oxime and nonanal oxime; amides such as formamide, acetamide, propionamide, butylamide, isobutylamide, valeramide, isovaleramide, hexaneamide, heptaneamide, nonanamide, etc .; formaldehyde dimethyl acetal, formaldehyde Acetals such as diethyl acetal, acetaldehyde dimethyl acetal, and acetone dimethyl acetal; and mixtures thereof.

[0010] Among them, acetaldehyde, because it can stabilize the storage for a long time by adding a small amount,
Butyraldehyde, isobutyraldehyde, acetone,
Methyl ethyl ketone, 3-hexanone, 2-methyl-3
-Pentanone, acetaldehyde oxime, butyraldehyde oxime, valeraldehyde oxime, nonanal oxime, acetamide, isobutylamide, hexaneamide, formaldehyde dimethyl acetal, formaldehyde diethyl acetal, acetaldehyde dimethyl acetal, and the like are preferably used.

The amount of the stabilizer is 0.1 to 3.0 parts by weight, preferably 0.3 to 2.0 parts by weight, per 100 parts by weight of solid sodium formaldehyde sulfoxylate.
Parts by weight are appropriate. If the amount is less than 0.1 part by weight, the effect of adding the stabilizer is not substantially exhibited, and if the amount exceeds 3.0 parts by weight, the effect corresponding thereto cannot be obtained. As for the method of adding the stabilizer, when preparing the aqueous sodium formaldehyde sulfoxylate solution, it may be added and mixed simultaneously with the solid sodium formaldehyde sulfoxylate, or after preparing the aqueous sodium formaldehyde sulfoxylate solution, add the stabilizer May be.

When prepared as described above, the concentration is from 1 to 6
A 0% by weight aqueous solution of sodium formaldehyde sulfoxylate can be obtained, and when stored at 30 to 40 ° C., can be stably stored for up to 60 days.

[0013]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. (Hereinafter, “parts” indicates “parts by weight”.)

Examples 1 to 16 and Comparative Examples 1 to 3 An aqueous solution of sodium formaldehyde sulfoxylate was prepared with the formulations shown below, and a predetermined amount of a stabilizer shown in Tables 1 to 4 was added. The stability of the aqueous solutions was compared. The aqueous solution is sealed in a glass container and sealed.
After storage at 0 ° C., changes over time were measured for the concentration of sodium formaldehyde sulfoxylate, the presence or absence of sulfide, and the alkalinity. The results are shown in Tables 1 to 4. In addition, the composition example and the analysis method are as follows.

[Formulation Example] Water 700 parts Sodium formaldehyde sulfoxylate 300 parts (NaSO ₂ CH ₂ OH.2H ₂ O) Stabilizer (described in Tables 1 to 4) Predetermined amount (parts)

[Analytical Method] The concentration (% by weight) of the aqueous sodium formaldehyde sulfoxylate solution was determined according to JIS K 1476-198.
0 was determined according to the method described. For the analysis of the presence or absence of sulfide, see JIS K14
The method was carried out according to the method described in No. 76-1980, and a case where a dark color appeared immediately (the presence of sulfide) was evaluated as x, and a case where a dark color did not appear immediately (the absence of sulfide) was evaluated as ○. Alkalinity: A sodium formaldehyde sulfoxylate aqueous solution was sampled in an amount corresponding to about 1 g in terms of solids of sodium formaldehyde sulfoxylate, diluted to 100 ml, and stirred gently with a magnetic stirrer using N / 10 hydrochloric acid. , Neutralization titration. A phenolphthalein solution was used as an indicator. The amount of N / 10 hydrochloric acid required for the neutralization was converted to the weight of NaOH, and expressed as the weight (% by weight) of NaOH per 1 g of sodium formaldehyde sulfoxylate solid.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

[Table 3]

[0020]

[Table 4]

[0021]

When the stabilizer is not used, the concentration and alkalinity of sodium formaldehyde sulfoxylate in the aqueous solution of sodium formaldehyde sulfoxylate gradually decrease with time, and the sulfide increases gradually. However, according to the method of the present invention, sodium formaldehyde sulfoxylate can be stably stored in the form of an aqueous solution for a long period of time, and the labor required for dissolution can be reduced and the working environment can be improved.

Continuation of the front page (56) References JP-A-55-28954 (JP, A) Patent 38776 (JP, C1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 313/00 C07C 315 / 00 C07C 381/00 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] When preparing an aqueous solution of sodium formaldehyde sulfoxylate, solid sodium formaldehyde sulfoxylate (NaSO ₂ CH ₂ OH.
2H ₂ O) to 100 parts by weight, the following general formula (I) ~
At least one selected from the group of compounds represented by (V)
A method for stabilizing an aqueous sodium formaldehyde sulfoxylate solution, comprising adding 0.1 to 3.0 parts by weight of a seed. R ¹ CHO (I) R ² R ³ C = O (II) R ⁴ R ⁵ C = N—OH (III) R ⁶ CONH ₂ (IV) R ⁷ R ⁸ C (OR ⁹ ) ₂ (V) (Formula In the formula, R ^{1 to} R ³ and R ⁹ each represent a C _{1 to} C ₉ linear or branched alkyl group, and R ^{4 to} R ⁸ each represent a hydrogen atom or a C _{1 to} C ₉ linear or Represents a branched alkyl group.)