阅读说明：本技术 2,2,4-三甲基-3羟基戊酸异丁酯的制备方法、真石漆及其制备方法 (Preparation method of isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate, really stone paint and preparation method thereof ) 是由 卢小松 张世元 姜明秋 王永成 张润赟 于 2019-10-31 设计创作，主要内容包括：本发明涉及有机化合物合成及应用技术领域,具体涉及一种2,2,4-三甲基-3羟基戊酸异丁酯的制备方法、真石漆及其制备方法。本发明的2,2,4-三甲基-3羟基戊酸异丁酯的制备方法,包括以下步骤：1)异丁醛在碱性催化剂作用下发生羟醛缩合反应,生成2,2,4-三甲基-3-羟基戊醛；将上述得到的2,2,4-三甲基-3-羟基戊醛与H<Sub>2</Sub>O<Sub>2</Sub>发生氧化反应得到2,2,4-三甲基-3羟基戊酸；2)将步骤1)制得的2,2,4-三甲基-3羟基戊酸和异丁醇在强酸催化剂作用下反应得到2,2,4-三甲基-3羟基戊酸异丁酯。本发明的2,2,4-三甲基-3羟基戊酸异丁酯的制备方法,反应产物单一,无需进行多步分离,操作简单,同时本发明还提供了一种含有上述2,2,4-三甲基-3羟基戊酸异丁酯的真石漆及其制备方法。(The invention relates to the technical field of synthesis and application of organic compounds, in particular to a preparation method of 2,2, 4-trimethyl-3-hydroxy valeric acid isobutyl ester, really stone paint and a preparation method thereof. The preparation method of isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate comprises the following steps: 1) isobutyraldehyde is subjected to aldol condensation reaction under the action of an alkaline catalyst to generate 2,2, 4-trimethyl-3-hydroxypentanal; reacting the obtained 2,2, 4-trimethyl-3-hydroxypentanal with H 2 O 2 Carrying out oxidation reaction to obtain 2,2, 4-trimethyl-3-hydroxyvaleric acid; 2) reacting the 2,2, 4-trimethyl-3-hydroxyvaleric acid prepared in the step 1) with isobutanol under the action of a strong acid catalyst to obtain the compoundIsobutyl 2,2, 4-trimethyl-3-hydroxypentanoate. The preparation method of the isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate has the advantages of single reaction product, no need of multi-step separation and simple operation, and simultaneously provides the real stone paint containing the isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate and the preparation method thereof.)

1. A preparation method of isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate is characterized by comprising the following steps:

1) preparation of 2,2, 4-trimethyl-3-hydroxypentanoic acid

Isobutyraldehyde undergoes aldol condensation reaction under the action of an alkaline catalyst to generate 2,2, 4-trimethyl-3-hydroxypentanal, and the reaction formula is as follows:

reacting the obtained 2,2, 4-trimethyl-3-hydroxypentanal with H₂O₂Oxidation takes place to give 2,2, 4-trimethyl-3-hydroxyvaleric acid, the reaction scheme being:

2) preparation of isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate

Reacting the 2,2, 4-trimethyl-3-hydroxypentanoic acid prepared in the step 1) with isobutanol under the action of a strong acid catalyst to obtain 2,2, 4-trimethyl-3-hydroxypentanoic acid isobutyl ester, wherein the reaction formula is as follows:

2. the method for preparing isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate according to claim 1, wherein in the step 1), the basic catalyst is NaOH, KOH, Ca (OH)₂,BA(OH)₂And LiOH, wherein the mass ratio of the isobutyraldehyde to the basic catalyst is 100: 1-3.

3. The method for preparing isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate according to claim 1, wherein in the step 2), the strong acid catalyst is any one of sulfuric acid, hydrochloric acid and p-toluenesulfonic acid.

4. The method for preparing isobutyl 2,2, 4-trimethyl-3 hydroxypentanoate according to claim 1, wherein in the step 2), the amount of the strong acid catalyst is 0.2 to 0.5% by weight based on the total weight of the isobutyl 2,2, 4-trimethyl-3 hydroxypentanoate and isobutanol, and the mass ratio of the isobutyl 2,2, 4-trimethyl-3 hydroxypentanoate to the isobutanol is 1000: 500-700.

5. The method for preparing isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate according to claim 1, wherein in the step 2), the esterification reaction temperature of isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate and isobutanol is 50 to 145 ℃ and the esterification reaction time is 10 to 30 hours.

6. The method for preparing isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate according to claim 1, wherein in the step 2), 2, 4-trimethyl-3-hydroxypentanoate and isobutanol are mixed, a strong acid catalyst is added, the temperature is raised to 50-60 ℃, the mixture is fully stirred and dissolved to form a mixed solution, the mixed solution is stirred and slowly raised to 70-100 ℃, reflux is started, after 1-3 hours of reflux, the temperature at the bottom of the tower is steadily raised to 140-145 ℃, the temperature at the top of the esterification tower is 120-125 ℃, the acid value of the esterification solution is less than or equal to 4mgKOH/g, the esterification solution is subjected to reduced pressure distillation to remove isobutanol, isobutanol is discharged at the top of the tower under the conditions that the temperature at the bottom of the tower is 130-140 ℃, the temperature at the top of the tower is 120-130 ℃, and the vacuum degree is-0.1-0.08 Mpa, and isobutyl 2, to obtain the crude product of isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate.

7. The method for preparing isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate according to claim 6, wherein alkali liquor is added to the obtained crude isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate for alkali washing neutralization, the addition amount of the alkali liquor is 3-10% of that of the crude isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate, the temperature is 50-80 ℃, the time is 2-8 hours, and then primary oil-water separation is performed; washing the oil phase obtained by primary oil-water separation, adding purified water, wherein the addition amount of water is 5-20% of the oil phase obtained by primary oil-water separation, the temperature is 60-95 ℃, the time is 2-6 hours, and then performing secondary oil-water separation; and (3) sequentially passing the oil phase obtained by secondary oil-water separation through a dehydration tower to finally obtain the isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate.

8. The method for preparing isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate according to claim 7, wherein a bottom temperature in the dehydration column is 95-130 ℃.

9. A stone-like paint containing isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate is characterized by comprising the following components: 100-500 parts of acrylic emulsion, 10-40 parts of water-retaining agent, 1-4 parts of hydroxyethyl modified cellulose, 1-4 parts of preservative, 1-3 parts of pH regulator, 4-10 parts of film-forming additive 2,2, 4-trimethyl-3 isobutyl hydroxypentanoate, 1-3 parts of defoaming agent, 1-3 parts of thickening agent, 700-800 parts of colored sand and 50-100 parts of water, wherein the 2,2, 4-trimethyl-3 isobutyl hydroxypentanoate is prepared by the preparation method of 2,2, 4-trimethyl-3 isobutyl hydroxypentanoate according to any one of claims 1-8.

10. The preparation method of the stone-like paint as claimed in claim 9, wherein the method comprises the steps of adding water into a container, adding the water-retaining agent, the film-forming aid 2,2, 4-trimethyl-3-hydroxy isobutyl valerate, the defoaming agent and the hydroxyethyl cellulose under the condition of stirring speed of 500-600 rpm, slowly adding the pH regulator, gradually increasing the rotation speed to 1200-1500 rpm, dispersing for 10-30 minutes, reducing the stirring speed to 500-600 rpm after dispersion is finished, adding the acrylic emulsion, the thickening agent and the preservative, stirring, adding the colored sand, and uniformly stirring to obtain the stone-like paint.

Technical Field

The invention relates to the technical field of synthesis and application of organic compounds, in particular to a preparation method of 2,2, 4-trimethyl-3-hydroxy isobutyl valerate and a preparation method of really stone paint containing the 2,2, 4-trimethyl-3-hydroxy isobutyl valerate.

Background

The stone-like paint is a coating with decorative effect exactly similar to marble and granite, is mainly prepared from natural stone powder with various colors, is applied to the stone-like effect of the building outer wall, and has the advantages of strong decoration, wide application range, water-based environmental protection, good pollution resistance, long service life and the like. The existing film-forming assistant for the stone-like paint generally adopts dodecyl alcohol ester (2,2, 4-trimethyl-1, 3 pentanediol-monoisobutyrate), so that the prepared stone-like paint has the problems of low drying speed, poor water whitening resistance at low temperature and in the initial stage, large addition amount of the film-forming assistant and the like in the low-temperature state, and therefore a film-forming assistant capable of improving the low-temperature drying speed of the stone-like paint and solving the problems of low temperature and water whitening resistance of the stone-like paint needs to be developed, and the stone-like paint containing the film-forming assistant needs to be developed.

Disclosure of Invention

The invention aims to provide a preparation method of an efficient film-forming aid 2,2, 4-trimethyl-3-hydroxy isobutyl valerate, a real stone paint containing 2,2, 4-trimethyl-3-hydroxy isobutyl valerate and a preparation method of the real stone paint.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a preparation method of isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate comprises the following steps:

1) preparation of 2,2, 4-trimethyl-3-hydroxypentanoic acid

Isobutyraldehyde undergoes aldol condensation reaction under the action of an alkaline catalyst to generate 2,2, 4-trimethyl-3-hydroxypentanal, and the reaction formula is as follows:

reacting the obtained 2,2, 4-trimethyl-3-hydroxypentanal with H₂O₂Oxidation takes place to give 2,2, 4-trimethyl-3-hydroxyvaleric acid, the reaction scheme being:

2) preparation of isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate

Reacting the 2,2, 4-trimethyl-3-hydroxypentanoic acid prepared in the step 1) with isobutanol under the action of a strong acid catalyst to obtain 2,2, 4-trimethyl-3-hydroxypentanoic acid isobutyl ester, wherein the reaction formula is as follows:

in the step 1), the alkaline catalyst is NaOH, KOH, Ca (OH)₂,BA(OH)₂And LiOH, wherein the mass ratio of the isobutyraldehyde to the basic catalyst is 100: 1-3.

In the step 2), the strong acid catalyst is any one of sulfuric acid, hydrochloric acid or p-toluenesulfonic acid.

In the step 2), the amount of the strong acid catalyst is 0.2-0.5% of the total weight of the 2,2, 4-trimethyl-3-hydroxyvaleric acid and isobutanol, and the mass ratio of the 2,2, 4-trimethyl-3-hydroxyvaleric acid to the isobutanol is 1000: 500-700.

In the step 2), the esterification reaction temperature of the 2,2, 4-trimethyl-3-hydroxyvaleric acid and isobutanol is 50-145 ℃, and the esterification reaction time is 10-30 hours.

In the step 2), 2, 4-trimethyl-3 hydroxyvaleric acid and isobutanol are mixed, a strong acid catalyst is added, the temperature is raised to 50-60 ℃, the mixture is fully stirred and dissolved to form a mixed solution, the mixed solution is stirred and slowly raised to 70-100 ℃, reflux is started, after the reflux is carried out for 1-3 hours, the temperature of the tower bottom is stably raised to 140-145 ℃, the temperature of the esterification tower top is 120-125 ℃, the acid value of the esterification liquid is less than or equal to 4mgKOH/g, the esterification liquid is subjected to reduced pressure distillation to remove the isobutanol, under the conditions that the temperature of the tower bottom is 130-140 ℃, the temperature of the tower top is 130-135 ℃, and the vacuum degree is-0.1-0.08 MPa, the isobutanol is discharged from the tower top, the isobutyl 2, 4-trimethyl-3 hydroxyvaleric acid is discharged from the tower bottom.

Adding alkali liquor into the obtained crude isobutyl 2,2, 4-trimethyl-3-hydroxyvalerate to perform alkali washing neutralization, wherein the addition amount of the alkali liquor is 3-10% of that of the crude isobutyl 2,2, 4-trimethyl-3-hydroxyvalerate, the temperature is 50-80 ℃, the time is 2-8 hours, and then performing primary oil-water separation; washing an oil phase obtained by primary oil-water separation, adding purified water, wherein the addition amount of water is 5-20% of the oil phase obtained by primary oil-water separation, namely 5-20% of the crude isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate, the temperature is 60-95 ℃, the time is 2-6 hours, and then performing secondary oil-water separation; and (3) treating an oil phase obtained by secondary oil-water separation, namely the crude product of the isobutyl 2,2, 4-trimethyl-3 hydroxypentanoate in sequence by a dehydration tower to finally obtain the isobutyl 2,2, 4-trimethyl-3 hydroxypentanoate.

The temperature of the middle tower bottom of the dehydration tower is 95-130 ℃; and dehydrating the crude product of the isobutyl 2,2, 4-trimethyl-3 hydroxypentanoate obtained by secondary oil-water separation to obtain isobutyl 2,2, 4-trimethyl-3 hydroxypentanoate.

A stone-like paint containing isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate comprises the following components: 100-500 parts of acrylic emulsion, 10-40 parts of water-retaining agent, 1-4 parts of hydroxyethyl modified cellulose, 1-4 parts of preservative, 1-3 parts of pH regulator, 4-10 parts of film-forming assistant 2,2, 4-trimethyl-3 isobutyl hydroxypentanoate, 1-3 parts of defoaming agent, 1-3 parts of thickening agent, 700-800 parts of colored sand and 50-100 parts of water, wherein the 2,2, 4-trimethyl-3 isobutyl hydroxypentanoate is prepared by the preparation method of the 2,2, 4-trimethyl-3 isobutyl hydroxypentanoate.

The water-retaining agent is any one of ethylene glycol or propylene glycol, the preservative is a kasong preservative, the pH regulator is any one of ammonia water, NaOH or AMP-95 (2-amino-2-methyl-1-propanol), the defoaming agent is any one of a mineral oil-based defoaming agent, an organic silicon defoaming agent or an emulsion type defoaming agent, and the thickening agent is any one of an alkali swelling thickening agent or a polyurethane thickening agent.

A preparation method of the stone-like paint comprises the following steps of adding water into a container, adding a water-retaining agent, a film-forming aid 2,2, 4-trimethyl-3-hydroxy isobutyl valerate, a defoaming agent and hydroxyethyl cellulose under the condition that the stirring speed is 500-600 rpm, slowly adding a pH regulator, gradually increasing the rotating speed to 1200-1500 rpm, dispersing for 10-30 minutes, reducing the stirring speed to 500-600 rpm after dispersion is finished, adding an acrylic emulsion, a thickening agent and a preservative, stirring, adding colored sand, and uniformly stirring to obtain the stone-like paint.

The preparation method of isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate has the beneficial effects that:

the preparation method of the isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate provided by the invention comprises the steps of carrying out aldol condensation reaction on isobutyraldehyde under the action of a basic catalyst to generate 2,2, 4-trimethyl-3-hydroxypentanal, and then carrying out reaction on the 2,2, 4-trimethyl-3-hydroxypentanal and H₂O₂The oxidation reaction is carried out to generate 2,2, 4-trimethyl-3 hydroxypentanoic acid, and the high-purity 2,2, 4-trimethyl-3 hydroxypentanoic acid is obtained through recrystallization, the reaction product is single, multi-step separation is not needed, the production process is simplified, the yield of the 2,2, 4-trimethyl-3 hydroxypentanoic acid is high, reactants and a catalyst are common chemical raw materials, and the production cost is low; and simultaneously, the prepared 2,2, 4-trimethyl-3-hydroxypentanoic acid and isobutanol are subjected to esterification reaction under the action of a strong acid catalyst to generate the isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate, the esterification reaction has few side reactions, high reaction rate and complete esterification, no byproduct is generated, and the high-purity isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate can be prepared.

In the preparation method of the isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate, the esterification reaction is stopped when the acid value of the esterification liquid is less than or equal to 4mgKOH/g, the esterification reaction is complete, and the yield of the generated isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate is higher.

In the preparation method of isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate, the prepared crude isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate is dehydrated so as to remove water in the crude isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate, so that the purity of the prepared isobutyl 2,2, 4-trimethyl-3-hydroxypentanoate is higher.

The real stone paint adopts 2,2, 4-trimethyl-3-hydroxy isobutyl valerate as a film forming auxiliary agent, and the 2,2, 4-trimethyl-3-hydroxy isobutyl valerate has better intermiscibility with acrylic monomers due to the existence of a pentanoate group compared with an alcohol acid ester group in dodecyl alcohol ester (2,2, 4-trimethyl-1, 3-pentanediol monoisobutyrate), so that latex particles in the latex paint have better plasticizing effects, and the 2,2, 4-trimethyl-3-hydroxy isobutyl valerate has higher film forming efficiency and faster volatilization speed in a low-temperature state compared with the dodecyl alcohol ester, so that the paint film of the real stone paint has higher drying speed, better water whitening resistance in the initial stage of the real stone paint and higher drying speed in the low-temperature state, the real stone paint has good water whitening resistance effect at low temperature and initial stage, and has small addition amount.

Detailed Description