阅读说明：本技术 甲基羧甲基瓜尔胶及其制备方法和应用 (Methyl carboxymethyl guar gum and preparation method and application thereof ) 是由 彭树华 陆伟 孙雪莲 李博 邓明宇 陈卫平 何建平 王军民 于 2020-06-15 设计创作，主要内容包括：本发明提供了一种甲基羧甲基瓜尔胶及其制备方法和应用,属于活性印染糊料技术领域。本发明提供了一种甲基羧甲基瓜尔胶,甲基羧甲基瓜尔胶的水溶液具有较高粘度,具有良好的流变性能和高的渗透率,将甲基羧甲基瓜尔胶作为活性印染中的糊料,具有良好的水溶性,易洗脱,过印花网时流变性能良好、不与活性染料和面料发生化学反应,进而不影响织物手感；且甲基具有一定的疏水性,更有利于染料在糊料中的分散,具有更高的脱糊率。(The invention provides methyl carboxymethyl guar gum and a preparation method and application thereof, belonging to the technical field of active printing and dyeing paste. The invention provides the methyl carboxymethyl guar gum, the aqueous solution of the methyl carboxymethyl guar gum has higher viscosity, good rheological property and high permeability, the methyl carboxymethyl guar gum is used as a paste material in active printing and dyeing, the water solubility is good, the washing is easy, the rheological property is good when the methyl carboxymethyl guar gum passes through a printing net, the chemical reaction with active dye and a fabric is avoided, and the fabric hand feeling is not influenced; and the methyl has certain hydrophobicity, is more beneficial to the dispersion of the dye in the paste, and has higher paste removal rate.)

1. The structure of the methyl carboxymethyl guar gum is shown as the formula I:

wherein R is₁～R₉Independently is-CH₃、-CH₃COONa or-H and simultaneously containing-CH₃and-CH₃COONa；

The weight average molecular weight of the methyl carboxymethyl guar gum is 60-200 ten thousand.

2. The methyl carboxymethyl guar gum according to claim 1, wherein the carboxymethyl guar gum has a carboxymethyl degree of substitution of 0.01 to 0.3 and a methyl degree of substitution of 1.2 to 1.5.

3. Process for the preparation of methylcarboxymethyl guar according to claim 1 or 2, characterized by comprising the following steps:

mixing carboxymethyl guar gum, an inorganic alkaline substance and water for an alkalization reaction to obtain an alkalization product;

and mixing the alkalized product with methyl chloride under a vacuum condition to carry out etherification reaction to obtain the methyl carboxymethyl guar gum.

4. The preparation method according to claim 3, wherein the inorganic alkaline substance is sodium hydroxide, and the mass ratio of the sodium hydroxide to the carboxymethyl guar gum is 0.3-0.6: 1.

5. the preparation method according to claim 3, wherein the time of the alkalization reaction is 10 to 20 min.

6. The preparation method according to claim 3, wherein the etherification reaction comprises a first etherification stage and a second etherification stage which are sequentially carried out, wherein the temperature of the first etherification stage is 25-60 ℃ and the time is 1-2 hours, and the temperature of the second etherification stage is 70-80 ℃ and the time is 4-10 hours.

7. The preparation method according to claim 3, wherein the mass ratio of the methyl chloride to the carboxymethyl guar gum is 0.45-0.8: 1.

8. the preparation method according to claim 3, characterized in that the carboxymethyl guar is prepared by a process comprising the following steps:

mixing guar gum, inorganic alkaline substances and an alcohol-water solution, carrying out an alkalization reaction, and then carrying out carboxymethyl etherification on the obtained product and sodium chloroacetate to obtain the carboxymethyl guar gum.

9. The method according to claim 8, wherein the temperature of the carboxymethyl etherification is 25 to 80 ℃ and the time is 50 to 90 min.

10. Use of a methylcarboxymethyl guar according to claim 1 or 2 in the field of reactive printing.

Technical Field

The invention relates to the technical field of active printing and dyeing paste, in particular to methyl carboxymethyl guar gum and a preparation method and application thereof.

Background

The printing paste is an important component of printing paste, does not react in the printing process, mainly plays a role of a transfer medium, and the performance of the printing paste directly influences the quality and the cost of printed products. Currently, with the development of printing and dyeing technology, various synthetic thickeners with excellent performance have been widely used in practical production, but the sodium alginate which is the traditional thickener for printing by the reactive dye still has the most extensive application, however, sodium alginate has the defects of long pulping time, strong fluidity, easy leakage and the like in the using process, researchers can prepare the carboxymethyl guar gum offset printing paste with high substitution degree, excellent water solubility, fluidity and permeability and good net penetrating performance by carrying out carboxymethyl modification on guar gum (the structural formula is shown as a formula II), can partially or completely replace the application of the sodium alginate in printing and dyeing, such as CN102720073B, CN104672341A and CN104130337A, which disclose carboxymethyl guar, carboxymethyl hydroxyethyl guar and carboxymethyl hydroxypropyl guar, respectively, but still have the problems of poor water solubility, flowability and permeability.

Disclosure of Invention

In view of the above, the present invention aims to provide a methyl carboxymethyl guar gum, a preparation method thereof and an application thereof. The methyl carboxymethyl guar gum provided by the invention has good solubility and fluidity and high permeability.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides methyl carboxymethyl guar gum, which has a structure shown in a formula I:

wherein R is₁～R₉Independently is-CH₃、-CH₃COONa or-H and simultaneously containing-CH₃and-CH₃COONa；

The weight average molecular weight of the methyl carboxymethyl guar gum is 60-200 ten thousand.

Preferably, the carboxymethyl degree of substitution in the methyl carboxymethyl guar gum is 0.01-0.3, and the methyl degree of substitution is 1.2-1.5.

The invention also provides a preparation method of the methyl carboxymethyl guar gum in the technical scheme, which comprises the following steps:

mixing carboxymethyl guar gum, an inorganic alkaline substance and water for an alkalization reaction to obtain an alkalization product;

and mixing the alkalized product with methyl chloride under a vacuum condition to carry out etherification reaction to obtain the methyl carboxymethyl guar gum.

Preferably, the inorganic alkaline substance is sodium hydroxide, and the mass ratio of the sodium hydroxide to the carboxymethyl guar gum is 0.3-0.6: 1.

preferably, the time of the alkalization reaction is 10-20 min.

Preferably, the etherification reaction comprises a first etherification stage and a second etherification stage which are sequentially carried out, wherein the temperature of the first etherification stage is 25-60 ℃ and the time is 1-2 hours, and the temperature of the second etherification stage is 70-80 ℃ and the time is 4-10 hours.

Preferably, the mass ratio of the methyl chloride to the carboxymethyl guar gum is 0.45-0.8: 1.

preferably, the carboxymethyl guar is prepared by a process comprising the steps of:

mixing guar gum, inorganic alkaline substances and an alcohol-water solution, carrying out an alkalization reaction, and then carrying out carboxymethyl etherification on the obtained product and sodium chloroacetate to obtain the carboxymethyl guar gum.

Preferably, the temperature of the carboxymethyl etherification is 25-80 ℃ and the time is 50-90 min.

The invention also provides application of the methyl carboxymethyl guar gum in the technical scheme in the field of active printing and dyeing.

The invention provides the methyl carboxymethyl guar gum, the aqueous solution of the methyl carboxymethyl guar gum has higher viscosity, good rheological property and high permeability, the methyl carboxymethyl guar gum is used as a paste material in active printing and dyeing, the water solubility is good, the washing is easy, the rheological property is good when the methyl carboxymethyl guar gum passes through a printing net, the chemical reaction with active dye and a fabric is avoided, and the fabric hand feeling is not influenced; and the methyl has certain hydrophobicity, is more beneficial to the dispersion of the dye in the paste, and has higher paste removal rate.

Furthermore, the invention can also adjust the substitution ratio of carboxymethyl and methyl, and flexibly adjust the water solubility of the methyl carboxymethyl guar gum.

Drawings

Fig. 1 is a nuclear magnetic hydrogen spectrum of the methyl carboxymethyl guar gum prepared by the invention.

Detailed Description

The invention provides methyl carboxymethyl guar gum, which has a structure shown in a formula I:

wherein R is₁～R₉Independently is-CH₃、-CH₃COONa or-H and simultaneously containing-CH₃and-CH₃COONa；

The weight average molecular weight of the methyl carboxymethyl guar gum is 60-200 ten thousand.

In the invention, the carboxymethyl substitution degree of the methyl carboxymethyl guar gum is preferably 0.01-0.3, more preferably 0.16, and the methyl substitution degree is 1.2-1.5.

The invention also provides a preparation method of the methyl carboxymethyl guar gum in the technical scheme, which comprises the following steps:

mixing carboxymethyl guar gum, an inorganic alkaline substance and water for an alkalization reaction to obtain an alkalization product;

and mixing the alkalized product with methyl chloride under a vacuum condition to carry out etherification reaction to obtain the methyl carboxymethyl guar gum.

According to the invention, carboxymethyl guar gum, an inorganic alkaline substance and water are mixed for an alkalization reaction to obtain an alkalization product. In the invention, the inorganic alkaline substance is preferably sodium hydroxide, and the mass ratio of the sodium hydroxide to the carboxymethyl guar gum is preferably 0.3-0.6: 1, the function of the inorganic alkaline substance for alkalization is to activate hydroxyl. According to the invention, preferably, sodium hydroxide and water are mixed to obtain a sodium hydroxide aqueous solution, and then the carboxymethyl guar gum is added. In the invention, the mass fraction of the sodium hydroxide aqueous solution is preferably 27-45%, the water solubility of the carboxymethyl guar gum is obviously improved, and the sodium hydroxide aqueous solution can be used for enabling the molecular chain of the carboxymethyl guar gum to be more stretched.

In the invention, the time of the alkalization reaction is preferably 10-20 min, the temperature of the alkalization reaction is preferably room temperature, and no additional heating or cooling is required.

The source of the carboxymethyl guar gum is not particularly limited in the present invention, and the carboxymethyl guar gum can be prepared by a method well known to those skilled in the art or a commercially available product.

In the present invention, the carboxymethyl guar is preferably prepared by a process comprising the following steps:

mixing guar gum, inorganic alkaline substances and an alcohol-water solution, carrying out an alkalization reaction, and then carrying out carboxymethyl etherification on the obtained product and sodium chloroacetate to obtain the carboxymethyl guar gum. In the present invention, the alkalization reaction can make the guar gum fully swell, make the guar gum molecule chain stretch, and activate the hydroxyl on the guar gum into negative ions.

In the present invention, the inorganic alkaline substance is preferably sodium hydroxide. In the invention, the mass ratio of the guar gum to the sodium hydroxide is preferably 1: 1-1: 2. In the invention, the time of the alkalization reaction is preferably 10-20 min, the temperature of the alkalization reaction is preferably room temperature, and no additional heating or cooling is required.

The invention preferably mixes the inorganic alkaline substance and the alcohol-water solution to obtain the alcohol-water sodium hydroxide solution, and then adds the guar gum. In the present invention, the alcohol-water sodium hydroxide solution preferably has a mass concentration of 10% to 20%. In the present invention, the alcohol in the alcohol-water solution is preferably ethanol, and the alcohol-water solution has a stronger activating ability. In the present invention, the ratio of the alcohol to the water in the alcohol-water solution is not particularly limited, and the guar gum may be dissolved.

In the invention, the temperature of the carboxymethyl etherification is preferably 25-80 ℃, and the time is preferably 50-90 min. In the invention, the total time of the alkalization reaction and the carboxymethyl etherification is preferably 0.1-6 h.

In the invention, the mass ratio of the guar gum to the sodium chloroacetate is preferably 1: 0.1-0.4.

In the present invention, the sodium chloroacetate is preferably added in the form of a sodium chloroacetate solution, in a specific embodiment of the present invention, the mass concentration of the sodium chloroacetate solution is preferably 15%,

after the carboxymethyl etherification is finished, the temperature of the obtained carboxymethyl etherification product is preferably naturally reduced to 25-30 ℃.

In the present invention, the carboxymethyl guar is preferably carried out in an autoclave with a nickel lining.

After an alkalized product is obtained, the alkalized product and methyl chloride are mixed for etherification reaction under the vacuum condition, and the methyl carboxymethyl guar gum is obtained. The invention preferably vacuumizes the autoclave with the lining nickel to realize the vacuum condition.

In the invention, the mass ratio of the methyl chloride to the carboxymethyl guar gum is preferably 0.45-0.8: 1.

in the invention, the etherification reaction preferably comprises a first etherification stage and a second etherification stage which are sequentially carried out, wherein the temperature of the first etherification stage is preferably 25-60 ℃, the time is preferably 1-2 hours, and the temperature of the second etherification stage is preferably 70-80 ℃, and the time is preferably 4-10 hours. In the invention, the heating rate of the temperature from room temperature to the temperature of the first etherification stage is preferably 0.2-8 ℃/min, and the heating rate of the temperature from the temperature of the first etherification stage to the temperature of the second etherification stage is preferably 0.2-10 ℃/min.

In the invention, the total time of the alkalization reaction and the etherification reaction is preferably 5-12 h.

After the etherification reaction is finished, the obtained etherification reaction product is preferably subjected to distillation, hot water washing, precipitation and drying in sequence. In the present invention, the distillation parameters are not particularly limited, and the excess methyl chloride can be removed. The present invention is not particularly limited with respect to the specific operation of the hot water washing, precipitation and drying, and the precipitation preferably uses alcohol or acetone as a precipitant.

The invention also provides application of the methyl carboxymethyl guar gum in the technical scheme in the field of active printing and dyeing.

In order to further illustrate the present invention, the following describes in detail the methylcarboxymethylguar gum provided by the present invention, its preparation and use in connection with the examples, which should not be construed as limiting the scope of the invention.