JP2001031733A - Production of glyoxal resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a glyoxal resin for use in processing a white fiber which is slightly colored. SOLUTION: The process (I) for producing a glyoxal resin comprises, in the presence of an aqueous medium, a step (a) of reacting urea or its derivative with glyoxal in a reaction vessel and subsequently a step (b) of reacting the reaction mixture with formaldehyde, wherein at least in the step (a), an oxidizing agent is permitted to be present and a compressed air or an oxygen gas is introduced into the liquid phase part or the gas phase part in the reaction vessel. Alternatively, a process (II) for producing a glyoxal resin comprises, in the presence of an aqueous medium and an oxidizing agent, reacting urea or its derivative with glyoxal and formaldehyde in a reaction vessel, wherein a compressed air or an oxygen gas is introduced into the phase part or the gas phase part in the reaction vessel. Additionally, the glyoxal resin produced by the process (I) or (II) is reacted with an aliphatic lower alcohol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a glyoxal resin used for, for example, processing fibers, and more particularly, it is useful as a processing agent for white coats or form-stable white cutter shirts. And a method for producing a novel glyoxal resin.

[0002] Glyoxal resin production methods include:
A method of reacting urea or a derivative thereof with glyoxal and then reacting the reaction mixture with formaldehyde, a method of reacting urea or a derivative thereof with glyoxal and formaldehyde, and further reacting the resin obtained by these methods with alcohol. Methods and the like are known.
However, a glyoxal resin for fiber processing using glyoxal as a raw material compound is not suitable for processing white fibers because the resin is colored from yellow to brown.

As a solution to this problem, a method of adding slightly less than 3% of alkali persulfate to a resin component in an aqueous solution is known. However, according to the known method, alkali persulfate in the resin is reduced to form alkali sulfate, and thus a relatively large amount of alkali sulfate remains in the processed fiber. There was a point. Further, when the amount of the alkali persulfate added to the resin is reduced, the resin is also colored.

[0004]

SUMMARY OF THE INVENTION The present inventor has intensively studied a method for producing a glyoxal resin which has little coloring even when the amount of an oxidizing agent such as alkali persulfate added to the resin is reduced. As a result, the present invention has been completed.

[0005]

That is, the present invention provides:
A method for producing a glyoxal resin, comprising: (a) reacting urea or a derivative thereof with glyoxal in a reaction vessel in the presence of an aqueous medium; (b) then reacting the reaction mixture with formaldehyde; At least an oxidizing agent is present in the step (a),
And a method for producing a glyoxal resin, wherein compressed air or oxygen gas is introduced into a liquid phase portion or a gas phase portion in a reaction vessel. (B) Urea or a derivative thereof in the presence of an aqueous medium and an oxidizing agent And a method for producing a glyoxal resin by reacting glyoxal and formaldehyde in a reaction vessel, characterized in that compressed air or oxygen gas is introduced into a liquid phase or a gas phase in the reaction vessel. And (c) reacting an aliphatic lower alcohol with a glyoxal resin obtained by the method described in the above (a) or (b) to provide a resin production method. Hereinafter, the present invention will be described in detail.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As the aqueous medium used in the methods (a) and (b) of the present invention, water or water and water such as methanol, ethanol, n-propanol, i-propanol or n-butanol can be used. Mixtures with alcohols are mentioned, but water is more preferred. The oxidizing agent used in the methods (a) and (b) of the present invention includes, for example, alkali persulfates such as potassium persulfate and sodium persulfate;
Examples thereof include calcium persulfate, magnesium persulfate, ammonium persulfate, and hydrogen peroxide, and more preferred are potassium persulfate, sodium persulfate, and ammonium persulfate. The amount of these oxidants used is
It is preferably 0.1 to the glyoxal resin (solid content).
Less than 4% by weight, more preferably about 0.01-0.2% by weight
It is. The methods (a) and (b) of the present invention are characterized by introducing compressed air or oxygen gas into the liquid phase or gas phase in the reaction vessel.
Since the purpose is to prevent coloring of the glyoxal, the method (a) requires the introduction of compressed air or oxygen gas at least in the step of reacting the urea or its derivative with glyoxal. Similarly, the oxidizing agent must be present at least in the step of reacting urea or a derivative thereof with glyoxal. That is, in the above methods (a) and (b), when glyoxal remains in the reaction system, introduction of compressed air or oxygen gas and the presence of an oxidizing agent are essential.

The urea derivative used in the methods (a) and (b) of the present invention includes, for example, mono-substituted derivatives, di-substituted derivatives, tri-substituted derivatives, tetra-substituted derivatives and urea hydrochloride. Preferred urea derivatives are mono-substituted derivatives, di-substituted derivatives or mixtures thereof, and examples of the substituent include an acetyl group, C1 to C4
Examples include an alkyl group and C1 to C4 alkoxy. Examples of formaldehyde include formalin, paraformaldehyde, polyoxymethylene and the like. The urea or urea derivative, glyoxal and formaldehyde used in the methods (a) and (b) of the present invention are preferably used in a molar ratio of 1: 0.5: The range is from 0.5 to 1: 1.5: 3.

In the above method (a), the reaction between urea or its derivative and glyoxal is carried out under acidic or weak alkaline conditions, and the preferred pH is in the range of 4-8. The reaction temperature is preferably in the range of 30 to 80C, more preferably 40 to 70C. The reaction between the resin solution obtained by the reaction and formaldehyde is carried out under acidic or weak alkaline conditions, and the preferred pH is in the range of 4 to 8. The reaction temperature is preferably in the range of 30 to 80C, more preferably 50 to 70C. In the above method (b), the reaction between urea or a derivative thereof, glyoxal and formaldehyde is carried out under acidic or weak alkaline conditions, and the preferred pH is in the range of 4 to 8.
The reaction temperature is preferably 30 to 80 ° C, more preferably 50 to 70 ° C.
It is in the range of ° C.

The aliphatic lower alcohol used in (c) of the present invention includes, for example, methanol, ethanol,
Examples include n-propanol, i-propanol, n-butanol and the like, and more preferably methanol. In the above method (c), the reaction is preferably performed in a state where the resin concentration is high, and when the solid content concentration in the resin solution obtained in the above (a) and (b) is low, after the concentration, It is preferred to react with alcohol. The above reaction (c) is carried out under acidic conditions, and the preferred pH is 1-5.
Range. The reaction temperature is preferably in the range of 20-70 ° C, more preferably 30-50 ° C. After completion of the reaction, the glyoxal resin solution is neutralized with caustic soda or the like, if necessary, and then the alcohol is distilled off to adjust to a desired solid content concentration.

[0010]

According to the methods (a) to (c) of the present invention,
Glyoxal resin with little coloring can be obtained, the amount of oxidizing agent such as alkali persulfate added can be reduced, and even when glyoxal resin is used for fiber processing,
It has the advantage that the amount of by-products such as alkali metal salts of sulfuric acid and ammonium sulfate is small.

[0011]

The present invention will be described in more detail with reference to the following examples. Parts and% in the examples are parts by weight and% by weight, respectively.
It is.

Example 1-2 In a reaction vessel equipped with a stirrer, 284 parts of 40% glyoxal, urea 1
18 parts and 300 parts of 37% formalin were charged and then the pH was adjusted to 7 using 28% caustic soda. Then, ammonium persulfate was added to the solid content in the glyoxal resin at 0.
At the same time as adding 1% or 0.05%, oxygen gas was introduced into the gas phase in the reaction vessel. Next, the mixture in the reaction vessel is maintained at about 63 to 65 ° C., and the pH is adjusted to 6.
The reaction was performed for 3 hours while adjusting to 8 to 7.2. Thereafter, the reaction mixture was cooled, and water was partially distilled off under reduced pressure at 40 to 55 ° C. Then, 247 parts of methanol were charged, the pH was adjusted to 1.5 to 2 using 71% sulfuric acid, and the pH was further adjusted to 39 to 41 ° C.
Allowed to react for hours. Thereafter, unreacted methanol and water were distilled off under reduced pressure at 40 to 60 ° C. After completion of the concentration, the mixture was diluted with water to obtain a glyoxal resin having a solid content of about 42%. The number of colors of the obtained resin is shown in Table 1 below.

Comparative Example 1-2 A glyoxal resin was obtained in the same manner as in Example 1 except that ammonium persulfate was not added. Also, except for introducing nitrogen gas instead of oxygen gas into the gas phase in the reaction vessel,
A glyoxal resin was obtained in the same manner as in Example 1.

[0014]

[Table 1] Example number Ammonium persulfate amount Introduced gas Color number (APHA) Solids concentration Example 1 0.1% oxygen 20 42% Example 2 0.05% oxygen 40 42% Comparative Example 1 No added oxygen 120 42% Comparative Example 2 0.1% Nitrogen 100 42%

Claims (4)

[Claims] 1. A process for producing a glyoxal resin comprising: (a) reacting urea or a derivative thereof with glyoxal in a reaction vessel in the presence of an aqueous medium; and (b) then reacting the reaction mixture with formaldehyde. A glyoxal resin, characterized in that at least an oxidizing agent is present in the step (a) and compressed air or oxygen gas is introduced into a liquid phase or a gas phase in the reaction vessel. Production method. 2. A method for producing a glyoxal resin by reacting urea or a derivative thereof with glyoxal and formaldehyde in a reaction vessel in the presence of an aqueous medium and an oxidizing agent, comprising the steps of: A method for producing a glyoxal resin, which comprises introducing compressed air or oxygen gas into a gas phase. 3. A method for producing a resin, comprising reacting a glyoxal resin obtained by the method according to claim 1 with an aliphatic lower alcohol. 4. The method according to claim 1, wherein the oxidizing agent is potassium persulfate, sodium persulfate or ammonium persulfate.