阅读说明：本技术 一种增白发泡剂的制备方法 (Preparation method of whitening foaming agent ) 是由 罗李华 于 2019-09-28 设计创作，主要内容包括：本发明公开了一种增白发泡剂的制备方法,包括下列步骤：S11、将碳酸氢钠与复合钙锌稳定剂搅拌混合均匀；S12、进行气流粉碎,得到半成品A；S21、将柠檬酸盐和柠檬酸混合均匀后,进行气流粉碎；S22、完成脂肪酸及其衍生物对柠檬酸盐和柠檬酸的包覆,得到半成品B；S3、所述增白发泡剂的制备：将半成品A和半成品B进行混合,再加入适量尿素及其衍生物和环氧化合物,得到所述增白发泡剂；所述碳酸氢钠与复合钙锌稳定剂的质量比为100：(1～5)。本发明的增白发泡剂的制备方法制得的增白发泡剂,对聚氯乙烯具有优良的发泡效果,发泡速率适中,发泡过程中热量少,可显著改善聚氯乙烯发泡产品的白度、表面光泽度、泡孔细腻度等。(The invention discloses a preparation method of a whitening foaming agent, which comprises the following steps: s11, stirring and mixing the sodium bicarbonate and the composite calcium-zinc stabilizer uniformly; s12, performing jet milling to obtain a semi-finished product A; s21, mixing citrate and citric acid uniformly, and then carrying out jet milling; s22, finishing the coating of the citrate and the citric acid by the fatty acid and the derivatives thereof to obtain a semi-finished product B; s3, preparation of the whitening foaming agent: mixing the semi-finished product A and the semi-finished product B, and adding a proper amount of urea and derivatives thereof and epoxy compounds to obtain the whitening foaming agent; the mass ratio of the sodium bicarbonate to the composite calcium-zinc stabilizer is 100: (1-5). The whitening foaming agent prepared by the preparation method of the whitening foaming agent has an excellent foaming effect on polyvinyl chloride, is moderate in foaming rate and low in heat in the foaming process, and can remarkably improve whiteness, surface gloss, foam fineness and the like of a polyvinyl chloride foamed product.)

1. The preparation method of the whitening foaming agent is characterized by comprising the following steps:

s1, preparing a semi-finished product A:

S11, adding sodium bicarbonate and a composite calcium-zinc stabilizer into a high-speed mixer, and uniformly stirring, wherein the mixing temperature is not more than 80 ℃;

s12, feeding the mixed material obtained in the step S11 into a jet mill, and carrying out jet milling to obtain modified superfine sodium bicarbonate, namely a semi-finished product A;

S2, preparing a semi-finished product B:

s21, uniformly mixing citrate and citric acid, and feeding the mixture into an airflow crusher for airflow crushing to obtain powder with a median particle size of 5-25 um;

S22, adding the powder obtained in the step S21 into a high-speed mixer, and dissolving the fatty acid and the derivative thereof by using a low-boiling-point organic solvent to obtain a fatty acid and derivative solution; then, the solution of the fatty acid and the derivatives thereof is sprayed and added into the mixture of the citrate and the citric acid which is stirred at a high speed, the high-speed stirring is continued, the temperature is raised to 60 ℃, and the high-speed mixer is vacuumized during the period, so that the low-boiling-point organic solvent is volatilized quickly, the coating of the citrate and the citric acid by the fatty acid and the derivatives thereof is completed, and a semi-finished product B is obtained;

s3, preparation of the whitening foaming agent:

Adding the semi-finished product A and the semi-finished product B into a high-speed mixer, mixing, adding a proper amount of urea and derivatives thereof and epoxy compounds into the mixed system, stirring at a high speed, and discharging to obtain the whitening foaming agent;

Wherein, the step S1 and the step S2 have no sequence;

in step S11, the mass ratio of the sodium bicarbonate to the composite calcium-zinc stabilizer is 100: (1-5).

2. The method for preparing whitening foaming agent according to claim 1, wherein in step S11, the sodium bicarbonate is food grade sodium bicarbonate; the dosage of the sodium bicarbonate and the composite calcium-zinc stabilizer is respectively 100 parts and 1-5 parts by weight.

3. The method for preparing whitening foaming agent according to any one of claims 1 or 2, wherein in step S11, the composite calcium-zinc stabilizer is prepared from the following raw materials in parts by weight: 5-10 parts of zinc stearate, 10-20 parts of calcium stearate, 15-30 parts of seiko, 10-50 parts of hydrotalcite, 10-50 parts of zeolite and 0.1-0.5 part of antioxidant 1010.

4. the method for preparing the whitening foaming agent according to any one of claims 1 or 2, wherein in the step S21, the citrate and the citric acid are both industrial anhydrous grades, and the total amount of the citrate and the citric acid is 5-50 parts.

5. the method for preparing a whitening foaming agent according to any one of claims 1 or 2, wherein in steps S12 and S21, the jet milling is carried out under a jet pressure of 0.8 to 1.0MPa, a milling frequency of 15 to 50Hz, and a classification frequency of 30 Hz.

6. the method for preparing whitening foaming agent according to any one of claims 1 or 2, wherein in step S22, the fatty acid and the derivative thereof are both technical grade, and the total amount of the fatty acid and the derivative thereof is 1-5 parts.

7. the method for preparing whitening foaming agent according to any one of claims 1 or 2, wherein the low boiling point organic solvent used in step S22 is one or more of tetrahydrofuran, ethyl acetate, dichloroethane, chloroform and acetonitrile; the total amount of the low-boiling organic solvent is 5-20 parts.

8. The method of preparing a whitening foaming agent according to any one of claims 1 or 2, wherein in step S3, the urea and its derivatives are any one or a mixture of urea ester, diphenylurea, phenylurea, methylurea, dimethylurea, diethylurea, hydroxyurea, hydantoin and its derivatives; the total dosage of the urea and the derivatives thereof is 1-20 parts.

9. the method for preparing a whitening foaming agent according to any one of claims 1 or 2, wherein in step S3, the epoxy compound is an epoxy fatty acid ester with different epoxy values; the total amount of the epoxy compound is 3-15 parts.

10. A whitening foaming agent, which is prepared by the method for preparing a whitening foaming agent according to any one of claims 1 or 2.

Technical Field

The invention relates to the field of foaming agents, in particular to a preparation method of a whitening foaming agent, and more particularly relates to a whitening foaming agent for polyvinyl chloride and a preparation method thereof.

background

polyvinyl chloride (PVC for short) is one of five general purpose plastics in the world, wherein the rigid polyvinyl chloride foamed plastic has the characteristics of low density, geothermal conductivity, high chemical stability and high energy absorption, is widely used as a heat-insulating, noise-reducing and shock-absorbing material, and is particularly suitable for production and processing of bathroom cabinet boards, special boards for building templates, special boards for automobiles and ships, special boards for advertisement engraving and special boards for chemical corrosion prevention.

polyvinyl chloride is a chain high polymer formed by homopolymerization of vinyl chloride monomers, and the decomposition temperature of the polyvinyl chloride is lower than the glass transition temperature of the polyvinyl chloride, so that dehydrochlorination decomposition is easy to occur, the color of a product is changed, the processability of the polyvinyl chloride is influenced, and the mechanical property of the product is reduced. The strength of the melt is improved by introducing the superfine high-residue inorganic foaming agent sodium bicarbonate, the fluidity of the melt is poor, the internal friction heat generation is increased, and meanwhile, the insulation performance and the mechanical performance of the material are greatly influenced by the water generated by the absorption and decomposition of the sodium bicarbonate; the introduction of exothermic AC blowing agents (azodicarbonamide) causes localized overheating of the PVC melt and scorching and yellowing.

The problems are obvious in the conventional foaming agent, so that the production quality of downstream product manufacturers is extremely unstable, the using amount of the stabilizer has to be increased, and the machine is frequently stopped and debugged.

Based on the situation, the invention provides a preparation method of a whitening foaming agent, which can effectively solve the problems.

disclosure of Invention

The invention aims to provide a preparation method of a whitening foaming agent. According to the preparation method of the whitening foaming agent, the raw material composition is selected, the content of each raw material is optimized, and the technological condition parameters of each step are strictly controlled, so that the prepared whitening foaming agent has an excellent foaming effect on polyvinyl chloride, is moderate in foaming speed, has little heat in the foaming process, and can obviously improve the whiteness, the surface gloss, the foam fineness and the like of a polyvinyl chloride foamed product; and the foaming ratio is higher.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

A preparation method of a whitening foaming agent comprises the following steps:

S1, preparing a semi-finished product A:

S11, adding sodium bicarbonate and a composite calcium-zinc stabilizer into a high-speed mixer, and uniformly stirring, wherein the mixing temperature is not more than 80 ℃;

s12, feeding the mixed material obtained in the step S11 into a jet mill, and carrying out jet milling to obtain modified superfine sodium bicarbonate, namely a semi-finished product A;

The co-crushing (airflow crushing) is not simple physical crushing, and relates to a grinding aid which is a composite calcium-zinc stabilizer and is used for sodium bicarbonate, so that the grinding efficiency can be effectively improved, and the sodium bicarbonate can be coated in a modified manner in the co-crushing process.

S2, preparing a semi-finished product B:

S21, uniformly mixing citrate and citric acid, and feeding the mixture into an airflow crusher for airflow crushing to obtain powder with a median particle size of 5-25 um;

s22, adding the powder obtained in the step S21 into a high-speed mixer, and dissolving the fatty acid and the derivative thereof by using a low-boiling-point organic solvent to obtain a fatty acid and derivative solution; then, the solution of the fatty acid and the derivatives thereof is sprayed and added into the mixture of the citrate and the citric acid which is stirred at a high speed, the high-speed stirring is continued, the temperature is raised to 60 ℃, and the high-speed mixer is vacuumized during the period, so that the low-boiling-point organic solvent is volatilized quickly, the coating of the citrate and the citric acid by the fatty acid and the derivatives thereof is completed, and a semi-finished product B is obtained;

S3, preparation of the whitening foaming agent:

adding the semi-finished product A and the semi-finished product B into a high-speed mixer, mixing, adding a proper amount of urea and derivatives thereof and epoxy compounds into the mixed system, stirring at a high speed, and discharging to obtain the whitening foaming agent;

Wherein, the step S1 and the step S2 have no sequence;

in step S11, the mass ratio of the sodium bicarbonate to the composite calcium-zinc stabilizer is 1: (1-5).

according to the preparation method of the whitening foaming agent, the raw material composition is selected, the content of each raw material is optimized, and the technological condition parameters of each step are strictly controlled, so that the prepared whitening foaming agent has an excellent foaming effect on polyvinyl chloride, is moderate in foaming speed, has little heat in the foaming process, and can obviously improve the whiteness, the surface gloss, the foam fineness and the like of a polyvinyl chloride foamed product; and the foaming ratio is higher.

(1) the preparation method of the whitening foaming agent uses co-crushing (airflow crushing) rather than simple physical crushing, relates to a composite calcium-zinc stabilizer serving as a grinding aid of sodium bicarbonate, can effectively improve grinding efficiency, and realizes modified coating of the sodium bicarbonate in the co-crushing process, namely the grinding aid is added in the airflow crushing process to improve the grinding efficiency.

(2) according to the preparation method of the whitening foaming agent, the composite calcium-zinc stabilizer is used for carrying out surface modification on sodium bicarbonate in a grinding stage (carrying out jet milling).

(3) according to the preparation method of the whitening foaming agent, citrate and citric acid are used as a sodium bicarbonate foaming agent.

(4) The preparation method of the whitening foaming agent disclosed by the invention realizes the coating and isolation of fatty acid and derivatives thereof on acidic substances by a solvent method.

(5) The preparation method of the whitening foaming agent of the invention introduces a large amount of urea and derivatives thereof into the sodium bicarbonate foaming agent for the first time.

(6) according to the preparation method of the whitening foaming agent, the epoxy compound is used as the stabilizing agent and the isolating agent, so that the whiteness of a foamed product is improved, the waterproof performance of the foaming agent is improved, the coexistence problem of acid and alkali substances is solved, the dispersion problem of urea and derivatives thereof in polyvinyl chloride is improved, and the dust pollution of the powder foaming agent is reduced.

Preferably, in step S11, the sodium bicarbonate is food grade sodium bicarbonate; the dosage of the sodium bicarbonate and the composite calcium-zinc stabilizer is respectively 100 parts and 1-5 parts by weight.

Preferably, in step S11, the composite calcium zinc stabilizer is prepared from the following raw materials in parts by weight: 5-10 parts of zinc stearate, 10-20 parts of calcium stearate, 15-30 parts of seiko, 10-50 parts of hydrotalcite, 10-50 parts of zeolite and 0.1-0.5 part of antioxidant 1010.

preferably, in step S21, the citrate and citric acid are both industrial anhydrous grades;

more preferably, the total amount of the citrate and the citric acid is 5-50 parts.

preferably, in the steps S12 and S21, the airflow pressure for the airflow pulverization is 0.8-1.0 MPa, the pulverization frequency is 15-50 Hz, and the classification frequency is 30 Hz.

preferably, in step S22, the fatty acids and derivatives thereof are both technical grade;

more preferably, the total amount of the fatty acid and the derivative thereof is 1-5 parts;

Preferably, in step S22, the low-boiling organic solvent is one or more of tetrahydrofuran, ethyl acetate, dichloroethane, chloroform, and acetonitrile;

more preferably, the total amount of the low-boiling organic solvent used is 5 to 20 parts.

preferably, in step S3, the urea and its derivatives are any one or a mixture of urea ester, diphenyl urea, phenyl urea, methyl urea, dimethyl urea, diethyl urea, hydroxyurea, hydantoin and its derivatives;

more preferably, in step S3, the total amount of urea and its derivatives is 1-20 parts;

preferably, the epoxy compound is an epoxy fatty acid ester with different epoxy values;

more preferably, the total amount of the epoxy compound is 3 to 15 parts.

The invention also provides a whitening foaming agent prepared by the preparation method of the whitening foaming agent.

compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the preparation method of the whitening foaming agent uses co-crushing (airflow crushing) rather than simple physical crushing, relates to a composite calcium-zinc stabilizer serving as a grinding aid of sodium bicarbonate, can effectively improve grinding efficiency, and realizes modified coating of the sodium bicarbonate in the co-crushing process, namely the grinding aid is added in the airflow crushing process to improve the grinding efficiency; and is actually verified, belonging to the first time in the foaming agent industry.

(2) According to the preparation method of the whitening foaming agent, the composite stabilizer is used as a modifier and is directly added into a sodium bicarbonate foaming agent system, and the synchronous operation of airflow crushing and coating modification is realized by utilizing a co-crushing method.

(3) According to the preparation method of the whitening foaming agent, the anhydrous citrate and the citric acid are used together, so that the problem of insufficient gas forming amount caused by single use of the citrate is avoided; meanwhile, the severe corrosion to mechanical equipment caused by using pure citric acid is avoided; the synergistic effect of the two is utilized to realize the double effect of foaming and foaming.

(4) According to the preparation method of the whitening foaming agent, the citrate and the citric acid are not used, so that the foam holes of the foaming product are finer, the using amount of the sodium bicarbonate is reduced, and the whiteness of the foaming product is improved to a certain extent.

(5) according to the preparation method of the whitening foaming agent, the urea and the derivatives thereof are introduced into a system, on one hand, the urea and the derivatives thereof can be used as a stabilizer to capture hydrogen chloride generated by the decomposition of polyvinyl chloride, and are complexed with iron elements brought in the processes of airflow crushing and high-speed mixing to form urea iron chelate, so that the polyvinyl chloride discoloration caused by ferrous iron and ferric iron is avoided.

(6) according to the preparation method of the whitening foaming agent, the epoxy compound is introduced into the system, so that on one hand, the whitening foaming agent can play a role of a stabilizer to improve whiteness, on the other hand, acidic substances and alkaline substances can be further isolated, the storage stability is improved, meanwhile, the dispersibility of urea and derivatives thereof in polymers can be greatly improved, and the foaming agent can play a role in preventing water absorption and reducing dust pollution.

(7) according to the preparation method of the whitening foaming agent, the raw material composition is selected, the content of each raw material is optimized, and the technological condition parameters of each step are strictly controlled, so that the prepared whitening foaming agent has an excellent foaming effect on polyvinyl chloride, is moderate in foaming speed, has little heat in the foaming process, and can obviously improve the whiteness, the surface gloss, the foam fineness and the like of a polyvinyl chloride foamed product; and the foaming ratio is higher.

Detailed Description

in order that those skilled in the art will better understand the technical solutions of the present invention, the following description of the preferred embodiments of the present invention is provided in connection with specific examples, which should not be construed as limiting the present patent.

The test methods or test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials, unless otherwise indicated, are conventionally obtained commercially or prepared by conventional methods.