CN112608570B - Polyvinyl chloride auxiliary heat stabilizer and preparation method thereof - Google Patents

Abstract

The invention discloses a polyvinyl chloride auxiliary heat stabilizer and a preparation method thereof, wherein the polyvinyl chloride auxiliary heat stabilizer comprises a component A, a component B and modified hydrotalcite; the polyvinyl chloride auxiliary heat stabilizer is prepared by the following steps: firstly, preparing a component A and a component B; step two, preparing modified hydrotalcite; thirdly, mixing the component A and the component B according to the weight ratio of 1: 1 to obtain a first component, and then mixing the modified hydrotalcite and stearic acid according to a mass ratio of 1: 1-3 to obtain a second component, and mixing the second component and the first component according to the mass ratio of 7-9: 1, the modified hydrotalcite is added into the polyvinyl chloride synthesis process, due to dehydration, hydrogen bonds of lamella disappear, lamella are dissociated, bubbles generated during preparation of a polyvinyl chloride product are reduced, and the prepared component A and component B are matched with the modified hydrotalcite to achieve the effect of auxiliary heat stabilization.

Description

Polyvinyl chloride auxiliary heat stabilizer and preparation method thereof

Technical Field

The invention belongs to the technical field of preparation of plastic additives, and particularly relates to a polyvinyl chloride auxiliary heat stabilizer and a preparation method thereof.

Background

The polyvinyl chloride has excellent corrosion resistance and high mechanical property, and has the advantages of low price, rich resources and mature manufacturing process, so that the product is widely applied to various fields of industrial and agricultural production. However, since polyvinyl chloride contains double bonds, branched structures, initiator residues, etc. in its structure, it is degraded by dehydrochlorination reaction at processing temperature, and discoloration and macromolecular crosslinking also occur. Therefore, polyvinyl chloride processing must use thermal stabilizers. For a long time, the main heat stabilizers used for polyvinyl chloride include lead salts, complex metal soaps, and organotins. The cadmium soap in the lead salt and the metal soap has good thermal stability, but has limited application range due to the toxicity problem; organotins have excellent thermal stability and transparency, but are relatively expensive; most metal soaps are low in price, but the stability does not meet the application requirement.

In order to improve the stabilizing effect of metal soaps, people introduce a variety of auxiliary heat stabilizers into the metal soaps, and the compounds do not contain metals and are characterized in that the heat stabilizing effect is small or the heat stability is not realized at all when the compounds are used alone, but when the compounds are used together with metal or organic tin heat stabilizers, a synergistic effect can be generated between the metal or organic tin heat stabilizers, and further, the heat stabilizing performance of the system is effectively improved.

Disclosure of Invention

In order to overcome the technical problems, the invention provides a polyvinyl chloride auxiliary heat stabilizer and a preparation method thereof.

The technical problems to be solved by the invention are as follows:

currently, organic auxiliary heat stabilizers widely used mainly include phosphites, epoxy compounds, polyols, nitrogen-containing compounds, sulfur-containing compounds, β -diketone compounds, and the like. In the prior art, the auxiliary heat stabilizer has the problems of poor high-temperature performance and influence on the transparency of the polyvinyl chloride material.

The purpose of the invention can be realized by the following technical scheme:

a polyvinyl chloride auxiliary heat stabilizer comprises a component A, a component B and modified hydrotalcite;

the polyvinyl chloride auxiliary heat stabilizer is prepared by the following steps:

firstly, preparing a component A and a component B;

step two, preparing modified hydrotalcite;

thirdly, mixing the component A and the component B according to the weight ratio of 1: 1 to obtain a first component, and then mixing the modified hydrotalcite and stearic acid according to a mass ratio of 1: 1-3 to obtain a second component, and mixing the second component and the first component according to the mass ratio of 7-9: 1, mixing to obtain the polyvinyl chloride auxiliary heat stabilizer.

Further, the preparation of component a comprises the following steps:

step A11, adding xylene, methyl stearate and sodium methoxide into a four-neck flask, setting the temperature at 140 ℃ and the rotating speed at 300r/min, dropwise adding acetophenone while stirring, keeping the temperature and the rotating speed unchanged after the acetophenone is completely added, continuously stirring for 50-60min, cooling the temperature to room temperature after stirring is finished, adding a sulfuric acid solution with the mass fraction of 30%, adjusting the pH value of the reaction solution to 3-4, keeping the rotating speed unchanged, continuously reacting for 60-70min, washing the reaction solution to be neutral by deionized water after the reaction is finished, carrying out reduced pressure concentration on the obtained organic phase to obtain a concentrated solution, adding petroleum ether into the concentrated solution, cooling the temperature to 10 ℃ for crystallization, carrying out reduced pressure suction filtration, and drying the obtained solid to constant weight at 40 ℃ to obtain an intermediate a;

step A12, adding L-aspartic acid and sodium hydroxide into anhydrous methanol under the conditions of setting the temperature to be 25 ℃ and the rotating speed to be 700r/min, stirring for 10min, then adding sodium ethoxide and acetone, setting the temperature to be 50 ℃ and the rotating speed to be 400r/min, stirring for 10min, adding the methanol solution of the intermediate a, keeping the temperature and the rotating speed unchanged, reacting for 2h, after the reaction is finished, distilling the obtained reaction liquid at 60 ℃ under reduced pressure, separating out a solid, then carrying out suction filtration under reduced pressure, washing the obtained solid with anhydrous ether for 3-5 times, and after the washing is finished, carrying out vacuum drying at 40 ℃ to constant weight to obtain the component A.

Further, the molar ratio of methyl stearate to acetophenone in step a11 was 2: 1, the dosage ratio of the dimethylbenzene to the methyl stearate is 10 mL: 1g of a compound; the mol ratio of sodium methoxide to acetophenone is 1.6-2: 1; the molar ratio of L-aspartic acid to sodium hydroxide in step A12 was 1: 2; the ratio of the total dosage of the L-aspartic acid and the sodium hydroxide to the total dosage of the anhydrous methanol is 1 g: 10-20mL, wherein the dosage ratio of the intermediate a, sodium ethoxide and acetone is 1 g: 50 mg: 10mL, wherein the mass ratio of the L-aspartic acid to the intermediate a is 1: 3, the using ratio of the intermediate a to the methanol in the methanol solution of the intermediate a is 1 g: 5 mL.

Further, the preparation of component B comprises the following steps:

step B11, adding xylene, methyl benzoate and sodium methoxide into a four-neck flask, setting the temperature at 110-;

and step B12, adding L-aspartic acid and sodium hydroxide into anhydrous methanol under the conditions of set temperature of 25 ℃ and rotation speed of 700r/min, stirring for 10min, then adding sodium ethoxide and acetone, setting temperature of 50 ℃ and rotation speed of 400r/min, stirring for 10min, adding the methanol solution of the intermediate B, keeping the temperature and the rotation speed unchanged for reaction for 2h, after the reaction is finished, carrying out reduced pressure distillation on the obtained reaction solution at 60 ℃ to separate out a solid, then carrying out reduced pressure suction filtration, washing the obtained solid for 3-5 times by using anhydrous ether, and after the washing is finished, carrying out vacuum drying at 40 ℃ to constant weight to obtain the component B.

Further, the molar ratio of methyl benzoate to acetophenone in step B11 is 4: 1, the dosage ratio of the dimethylbenzene to the methyl benzoate is 10 mL: 1-3g, wherein the molar ratio of sodium methoxide to acetophenone is 1.6: 1; the molar ratio of L-aspartic acid to sodium hydroxide in step B12 was 1: 2; the ratio of the total dosage of the L-aspartic acid and the sodium hydroxide to the total dosage of the anhydrous methanol is 1 g: 10-20mL, wherein the dosage ratio of the intermediate b, sodium ethoxide and acetone is 1 g: 50 mg: 10mL, wherein the mass ratio of the L-aspartic acid to the intermediate a is 1: 1.6-1.8, wherein the dosage ratio of the intermediate b to methanol in the methanol solution of the intermediate b is 1 g: 5 mL.

Further, the modified hydrotalcite is prepared by the following steps:

step S11, preparing solution C: dissolving magnesium nitrate hexahydrate and aluminum nitrate nonahydrate in deionized water, wherein the using amount ratio of the magnesium nitrate hexahydrate to the aluminum nitrate nonahydrate to the deionized water is 13 g: 10 g: 100 mL; preparing a solution D: dissolving sodium hydroxide and sodium carbonate in deionized water, wherein the dosage ratio of the sodium hydroxide to the sodium carbonate to the deionized water is 6 g: 1.6 g: 100 mL;

step S12, adding deionized water and monoalkyl phosphate into a three-neck flask, setting the temperature to be 80 ℃, simultaneously and respectively dropping the solution C and the solution D into the three-neck flask by using a dropping funnel under the protection of nitrogen, controlling the dropping speed of the funnel to be 1 drop/second, adjusting the pH value of the mixed solution in the three-neck flask by using 1mol/L sodium hydroxide solution when the dropping of the solution C and the solution D is about to be finished, reducing the temperature to room temperature, stirring for 1h, then increasing the temperature to 65 ℃, preserving the temperature for 1h, carrying out constant temperature reaction for 14-18h, after the reaction is finished, carrying out suction filtration on the solution, washing a filter cake to be neutral by using the deionized water, and drying the washed filter cake to be constant weight at 80 ℃ to obtain the modified hydrotalcite.

Further, the volume ratio of the solution C to the solution D in step S12 is 1: 1; the dosage ratio of the deionized water to the monoalkyl phosphate ester to the solution C is 25 mL: 1 g: 50 mL.

A preparation method of a polyvinyl chloride auxiliary heat stabilizer comprises the following steps:

firstly, preparing a component A and a component B;

step two, preparing modified hydrotalcite;

thirdly, mixing the component A and the component B according to the weight ratio of 1: 1 to obtain a first component, and then mixing the modified hydrotalcite and stearic acid according to a mass ratio of 1: 1-3 to obtain a second component, and mixing the second component and the first component according to the mass ratio of 7-9: 1, mixing to obtain the polyvinyl chloride auxiliary heat stabilizer.

The invention has the beneficial effects that:

the preparation process of the component A comprises the following steps: acetophenone and methyl stearate are used as raw materials, an intermediate a is prepared under the conditions that sodium methoxide is used as a catalyst and xylene is used as a solvent, the intermediate a is a beta-diketone compound, the intermediate a contains carbonyl, the L-aspartic acid molecule contains amino, and the prepared intermediate a and the L-aspartic acid react under the catalytic action of sodium ethoxide to prepare a component A; the component A contains active methylene of beta-diketone, and can quickly replace allyl chloride in polyvinyl chloride to terminate the zipper type degradation reaction, so that the yellowing reaction caused by degradation is prevented; the preparation process of the component B comprises the following steps: acetophenone and methyl benzoate are used as raw materials, an intermediate B is prepared under the conditions that sodium methoxide is used as a catalyst and xylene is used as a solvent, the intermediate B and the intermediate a are both beta-diketone compounds, the intermediate B contains carbonyl, the L-aspartic acid molecule contains amino, and the prepared intermediate B and the L-aspartic acid react under the catalytic action of sodium ethoxide to prepare a component B; the component B contains active methylene of beta-diketone, and can quickly replace allyl chloride in polyvinyl chloride to terminate the zipper type degradation reaction, so that the yellowing reaction caused by degradation is prevented; the molecules of the component A and the component B contain-C ═ N-characteristic groups generated by the reaction of carbonyl and amino, and the-C ═ N-characteristic groups can be coordinated with metal ions, so that the component A and the component B are firmly adsorbed to the surface of a metal matrix, and the prepared component A and the component B are matched with the modified hydrotalcite to achieve the auxiliary thermal stabilization effect.

The potassium monoalkyl phosphate ester cannot damage the original structural form of the hydrotalcite, has good crystallinity, maintains the mechanical property of the polyvinyl chloride product, the hydrotalcite has a lamellar structure, has an alkaline surface, can react with HCl molecules released in the degradation process of a polyvinyl chloride molecular chain, effectively inhibits the HCl-catalyzed thermal degradation reaction, and then CO existing in the interlayer of the hydrotalcite₂The modified hydrotalcite has an ion exchange effect, can exchange unstable chlorine atoms in a polyvinyl chloride molecular chain to play a thermal stabilization role, and reduces bubbles generated in the preparation of polyvinyl chloride products due to dehydration, disappearance of hydrogen bonds of lamella layers and dissociation of lamella layers in the synthetic process of adding the modified hydrotalcite into polyvinyl chloride.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

A polyvinyl chloride auxiliary heat stabilizer comprises a component A, a component B and modified hydrotalcite;

the polyvinyl chloride auxiliary heat stabilizer is prepared by the following steps:

firstly, preparing a component A and a component B;

step two, preparing modified hydrotalcite;

thirdly, mixing the component A and the component B according to the weight ratio of 1: 1 to obtain a first component, and then mixing the modified hydrotalcite and stearic acid according to a mass ratio of 1: 1 to obtain a second component, and mixing the second component and the first component according to the mass ratio of 7: 1, mixing to obtain the polyvinyl chloride auxiliary heat stabilizer.

Wherein, the preparation of the component A comprises the following steps:

step A11, adding xylene, methyl stearate and sodium methoxide into a four-neck flask, setting the temperature at 140 ℃ and the rotating speed at 300r/min, dropwise adding acetophenone while stirring, keeping the temperature and the rotating speed unchanged after the acetophenone is completely added, continuously stirring for 50min, cooling the temperature to room temperature after stirring is finished, adding a sulfuric acid solution with the mass fraction of 30%, adjusting the pH value of a reaction solution to 3, keeping the rotating speed unchanged, continuously reacting for 60min, washing the reaction solution to be neutral by deionized water after the reaction is finished, carrying out decompression concentration on the obtained organic phase to obtain a concentrated solution, adding petroleum ether into the concentrated solution, cooling the temperature to 10 ℃ for crystallization, carrying out decompression suction filtration, and drying the obtained solid to constant weight at 40 ℃ to obtain an intermediate a;

step A12, adding L-aspartic acid and sodium hydroxide into anhydrous methanol under the conditions of setting the temperature to be 25 ℃ and the rotating speed to be 700r/min, stirring for 10min, then adding sodium ethoxide and acetone, setting the temperature to be 50 ℃ and the rotating speed to be 400r/min, stirring for 10min, adding the methanol solution of the intermediate a, keeping the temperature and the rotating speed unchanged, reacting for 2h, after the reaction is finished, distilling the obtained reaction liquid at 60 ℃ under reduced pressure, separating out a solid, then carrying out suction filtration under reduced pressure, washing the obtained solid with anhydrous ether for 3 times, and after the washing is finished, carrying out vacuum drying at 40 ℃ to constant weight to obtain the component A.

Wherein the molar ratio of methyl stearate to acetophenone in step a11 is 2: 1, the dosage ratio of the dimethylbenzene to the methyl stearate is 10 mL: 1g of a compound; the molar ratio of sodium methoxide to acetophenone was 1.6: 1; the molar ratio of L-aspartic acid to sodium hydroxide in step A12 was 1: 2; the ratio of the total dosage of the L-aspartic acid and the sodium hydroxide to the total dosage of the anhydrous methanol is 1 g: 10mL, wherein the dosage ratio of the intermediate a, sodium ethoxide and acetone is 1 g: 50 mg: 10mL, wherein the mass ratio of the L-aspartic acid to the intermediate a is 1: 3, the using ratio of the intermediate a to the methanol in the methanol solution of the intermediate a is 1 g: 5 mL.

Wherein, the preparation of the component B comprises the following steps:

step B11, adding xylene, methyl benzoate and sodium methoxide into a four-neck flask, setting the temperature to be 110 ℃ and the rotating speed to be 300r/min, dropwise adding acetophenone while stirring, continuously heating to 140 ℃ after dropwise adding, continuously stirring for 5h with the rotating speed kept unchanged, cooling the temperature to room temperature, adding a sulfuric acid solution with the mass fraction of 30%, adjusting the pH value of a reaction solution to be 3, keeping the rotating speed unchanged, continuously reacting for 60min, adjusting the pH value of the reaction solution to be 7 with a sodium carbonate solution with the mass fraction of 10%, separating liquid, carrying out pressure concentration on the obtained organic phase to remove a solvent, and then naturally cooling and crystallizing to obtain an intermediate B;

and step B12, adding L-aspartic acid and sodium hydroxide into anhydrous methanol under the conditions of set temperature of 25 ℃ and rotation speed of 700r/min, stirring for 10min, then adding sodium ethoxide and acetone, setting temperature of 50 ℃ and rotation speed of 400r/min, stirring for 10min, adding the methanol solution of the intermediate B, keeping the temperature and the rotation speed unchanged for reaction for 2h, after the reaction is finished, carrying out reduced pressure distillation on the obtained reaction solution at 60 ℃ to separate out a solid, then carrying out reduced pressure suction filtration, washing the obtained solid for 3 times by using anhydrous ether, and after the washing is finished, carrying out vacuum drying at 40 ℃ to constant weight to obtain the component B.

Wherein the molar ratio of the methyl benzoate to the acetophenone in the step B11 is 4: 1, the dosage ratio of the dimethylbenzene to the methyl benzoate is 10 mL: 1g, the molar ratio of sodium methoxide to acetophenone is 1.6: 1; the molar ratio of L-aspartic acid to sodium hydroxide in step B12 was 1: 2; the ratio of the total dosage of the L-aspartic acid and the sodium hydroxide to the total dosage of the anhydrous methanol is 1 g: 10mL, wherein the dosage ratio of the intermediate b, sodium ethoxide and acetone is 1 g: 50 mg: 10mL, wherein the mass ratio of the L-aspartic acid to the intermediate b is 1: 1.6, the dosage ratio of the intermediate b to the methanol in the methanol solution of the intermediate b is 1 g: 5 mL.

Wherein the modified hydrotalcite is prepared by the following steps:

step S11, preparing solution C: dissolving magnesium nitrate hexahydrate and aluminum nitrate nonahydrate in deionized water, wherein the using amount ratio of the magnesium nitrate hexahydrate to the aluminum nitrate nonahydrate to the deionized water is 13 g: 10 g: 100 mL; preparing a solution D: dissolving sodium hydroxide and sodium carbonate in deionized water, wherein the dosage ratio of the sodium hydroxide to the sodium carbonate to the deionized water is 6 g: 1.6 g: 100 mL;

step S12, adding deionized water and monoalkyl phosphate into a three-neck flask, setting the temperature to be 80 ℃, simultaneously and respectively dropping the solution C and the solution D into the three-neck flask by using a dropping funnel under the protection of nitrogen, controlling the dropping speed of the funnel to be 1 drop/second, adjusting the pH value of a mixed solution in the three-neck flask by using 1mol/L sodium hydroxide solution when the dropping of the solution C and the solution D is about to be finished, reducing the temperature to room temperature, stirring for 1h, then increasing the temperature to 65 ℃, preserving the temperature for 1h, carrying out constant temperature reaction for 14h, after the reaction is finished, carrying out suction filtration on the solution, washing a filter cake to be neutral by using the deionized water, and drying the washed filter cake to be constant weight at 80 ℃ to obtain the modified hydrotalcite.

Wherein the volume ratio of the solution C to the solution D in the step S12 is 1: 1; the dosage ratio of the deionized water to the monoalkyl phosphate ester to the solution C is 25 mL: 1 g: and (mL).

Example 2

A polyvinyl chloride auxiliary heat stabilizer comprises a component A, a component B and modified hydrotalcite;

the polyvinyl chloride auxiliary heat stabilizer is prepared by the following steps:

firstly, preparing a component A and a component B;

step two, preparing modified hydrotalcite;

thirdly, mixing the component A and the component B according to the weight ratio of 1: 1 to obtain a first component, and then mixing the modified hydrotalcite and stearic acid according to a mass ratio of 1: 2, mixing the mixture to obtain a second component, and mixing the second component and the first component according to the mass ratio of 8: 1, mixing to obtain the polyvinyl chloride auxiliary heat stabilizer.

Wherein, the preparation of the component A comprises the following steps:

step A11, adding xylene, methyl stearate and sodium methoxide into a four-neck flask, setting the temperature at 140 ℃ and the rotating speed at 300r/min, dropwise adding acetophenone while stirring, keeping the temperature and the rotating speed unchanged after the acetophenone is completely added, continuously stirring for 55min, cooling the temperature to room temperature after stirring is finished, adding a sulfuric acid solution with the mass fraction of 30%, adjusting the pH value of a reaction solution to 3, keeping the rotating speed unchanged, continuously reacting for 65min, washing the reaction solution to be neutral by deionized water after the reaction is finished, carrying out decompression concentration on the obtained organic phase to obtain a concentrated solution, adding petroleum ether into the concentrated solution, cooling the temperature to 10 ℃ for crystallization, carrying out decompression suction filtration, and drying the obtained solid to constant weight at 40 ℃ to obtain an intermediate a;

step A12, adding L-aspartic acid and sodium hydroxide into anhydrous methanol under the conditions of setting the temperature to be 25 ℃ and the rotating speed to be 700r/min, stirring for 10min, then adding sodium ethoxide and acetone, setting the temperature to be 50 ℃ and the rotating speed to be 400r/min, stirring for 10min, adding the methanol solution of the intermediate a, keeping the temperature and the rotating speed unchanged, reacting for 2h, after the reaction is finished, distilling the obtained reaction liquid at 60 ℃ under reduced pressure, separating out a solid, then carrying out suction filtration under reduced pressure, washing the obtained solid with anhydrous ether for 4 times, and after the washing is finished, carrying out vacuum drying at 40 ℃ to constant weight to obtain the component A.

Wherein the molar ratio of methyl stearate to acetophenone in step a11 is 2: 1, the dosage ratio of the dimethylbenzene to the methyl stearate is 10 mL: 1g of a compound; the molar ratio of sodium methoxide to acetophenone was 1.8: 1; the molar ratio of L-aspartic acid to sodium hydroxide in step A12 was 1: 2; the ratio of the total dosage of the L-aspartic acid and the sodium hydroxide to the total dosage of the anhydrous methanol is 1 g: 15mL, wherein the dosage ratio of the intermediate a, sodium ethoxide and acetone is 1 g: 50 mg: 10mL, wherein the mass ratio of the L-aspartic acid to the intermediate a is 1: 3, the using ratio of the intermediate a to the methanol in the methanol solution of the intermediate a is 1 g: 5 mL.

Wherein, the preparation of the component B comprises the following steps:

step B11, adding xylene, methyl benzoate and sodium methoxide into a four-neck flask, setting the temperature to be 115 ℃ and the rotating speed to be 300r/min, dropwise adding acetophenone while stirring, continuously heating to 145 ℃ after dropwise adding, continuously stirring for 5h with the rotating speed kept unchanged, cooling the temperature to room temperature, adding a sulfuric acid solution with the mass fraction of 30%, adjusting the pH value of a reaction solution to be 3, keeping the rotating speed unchanged, continuously reacting for 65min, adjusting the pH value of the reaction solution to be 7 with a sodium carbonate solution with the mass fraction of 10%, separating liquid, carrying out pressure concentration on the obtained organic phase to remove a solvent, and then naturally cooling and crystallizing to obtain an intermediate B;

and step B12, adding L-aspartic acid and sodium hydroxide into anhydrous methanol under the conditions of set temperature of 25 ℃ and rotation speed of 700r/min, stirring for 10min, then adding sodium ethoxide and acetone, setting temperature of 50 ℃ and rotation speed of 400r/min, stirring for 10min, adding the methanol solution of the intermediate B, keeping the temperature and the rotation speed unchanged for reaction for 2h, after the reaction is finished, carrying out reduced pressure distillation on the obtained reaction solution at 60 ℃ to separate out a solid, then carrying out reduced pressure suction filtration, washing the obtained solid for 4 times by using anhydrous ether, and after the washing is finished, carrying out vacuum drying at 40 ℃ to constant weight to obtain the component B.

Wherein the molar ratio of the methyl benzoate to the acetophenone in the step B11 is 4: 1, the dosage ratio of the dimethylbenzene to the methyl benzoate is 10 mL: 2g, the molar ratio of sodium methoxide to acetophenone is 1.6: 1; the molar ratio of L-aspartic acid to sodium hydroxide in step B12 was 1: 2; the ratio of the total dosage of the L-aspartic acid and the sodium hydroxide to the total dosage of the anhydrous methanol is 1 g: 15mL, and the dosage ratio of the intermediate b, sodium ethoxide and acetone is 1 g: 50 mg: 10mL, wherein the mass ratio of the L-aspartic acid to the intermediate b is 1: 1.7, the dosage ratio of the intermediate b to the methanol in the methanol solution of the intermediate b is 1 g: 5 mL.

Wherein the modified hydrotalcite is prepared by the following steps:

step S11, preparing solution C: dissolving magnesium nitrate hexahydrate and aluminum nitrate nonahydrate in deionized water, wherein the using amount ratio of the magnesium nitrate hexahydrate to the aluminum nitrate nonahydrate to the deionized water is 13 g: 10 g: 100 mL; preparing a solution D: dissolving sodium hydroxide and sodium carbonate in deionized water, wherein the dosage ratio of the sodium hydroxide to the sodium carbonate to the deionized water is 6 g: 1.6 g: 100 mL;

step S12, adding deionized water and monoalkyl phosphate into a three-neck flask, setting the temperature to be 80 ℃, simultaneously and respectively dropping the solution C and the solution D into the three-neck flask by using a dropping funnel under the protection of nitrogen, controlling the dropping speed of the funnel to be 1 drop/second, adjusting the pH value of a mixed solution in the three-neck flask by using 1mol/L sodium hydroxide solution when the dropping of the solution C and the solution D is about to be finished, reducing the temperature to room temperature, stirring for 1h, then increasing the temperature to 65 ℃, preserving the temperature for 1h, carrying out constant temperature reaction for 16h, after the reaction is finished, carrying out suction filtration on the solution, washing a filter cake to be neutral by using the deionized water, and drying the washed filter cake to be constant weight at 80 ℃ to obtain the modified hydrotalcite.

Wherein the volume ratio of the solution C to the solution D in the step S12 is 1: 1; the dosage ratio of the deionized water to the monoalkyl phosphate ester to the solution C is 25 mL: 1 g: 50 mL.

Example 3

A polyvinyl chloride auxiliary heat stabilizer comprises a component A, a component B and modified hydrotalcite;

the polyvinyl chloride auxiliary heat stabilizer is prepared by the following steps:

firstly, preparing a component A and a component B;

step two, preparing modified hydrotalcite;

thirdly, mixing the component A and the component B according to the weight ratio of 1: 1 to obtain a first component, and then mixing the modified hydrotalcite and stearic acid according to a mass ratio of 1: 3, mixing to obtain a second component, and mixing the second component and the first component according to the mass ratio of 9: 1, mixing to obtain the polyvinyl chloride auxiliary heat stabilizer.

Wherein, the preparation of the component A comprises the following steps:

step A11, adding xylene, methyl stearate and sodium methoxide into a four-neck flask, setting the temperature at 140 ℃ and the rotating speed at 300r/min, dropwise adding acetophenone while stirring, keeping the temperature and the rotating speed unchanged after the acetophenone is dropwise added, continuously stirring for 60min, cooling the temperature to room temperature after stirring is finished, adding a sulfuric acid solution with the mass fraction of 30%, adjusting the pH value of a reaction solution to 4, keeping the rotating speed unchanged, continuously reacting for 70min, washing the reaction solution to be neutral by deionized water after the reaction is finished, carrying out decompression concentration on the obtained organic phase to obtain a concentrated solution, adding petroleum ether into the concentrated solution, cooling the temperature to 10 ℃ for crystallization, carrying out decompression suction filtration, and drying the obtained solid to constant weight at 40 ℃ to obtain an intermediate a;

step A12, adding L-aspartic acid and sodium hydroxide into anhydrous methanol under the conditions of setting the temperature to be 25 ℃ and the rotating speed to be 700r/min, stirring for 10min, then adding sodium ethoxide and acetone, setting the temperature to be 50 ℃ and the rotating speed to be 400r/min, stirring for 10min, adding the methanol solution of the intermediate a, keeping the temperature and the rotating speed unchanged, reacting for 2h, after the reaction is finished, distilling the obtained reaction liquid at 60 ℃ under reduced pressure, separating out a solid, then carrying out suction filtration under reduced pressure, washing the obtained solid with anhydrous ether for 5 times, and after the washing is finished, carrying out vacuum drying at 40 ℃ to constant weight to obtain the component A.

Wherein the molar ratio of methyl stearate to acetophenone in step a11 is 2: 1, the dosage ratio of the dimethylbenzene to the methyl stearate is 10 mL: 1g of a compound; the molar ratio of sodium methoxide to acetophenone is 2: 1; the molar ratio of L-aspartic acid to sodium hydroxide in step A12 was 1: 2; the ratio of the total dosage of the L-aspartic acid and the sodium hydroxide to the total dosage of the anhydrous methanol is 1 g: 20mL, wherein the dosage ratio of the intermediate a, sodium ethoxide and acetone is 1 g: 50 mg: 10mL, wherein the mass ratio of the L-aspartic acid to the intermediate a is 1: 3, the using ratio of the intermediate a to the methanol in the methanol solution of the intermediate a is 1 g: 5 mL.

Wherein, the preparation of the component B comprises the following steps:

step B11, adding xylene, methyl benzoate and sodium methoxide into a four-neck flask, setting the temperature to be 120 ℃ and the rotating speed to be 300r/min, dropwise adding acetophenone while stirring, continuously heating to 150 ℃ after dropwise adding, continuously stirring for 5h with the rotating speed kept unchanged, cooling the temperature to room temperature, adding a sulfuric acid solution with the mass fraction of 30%, adjusting the pH value of a reaction solution to be 4, keeping the rotating speed unchanged, continuously reacting for 70min, adjusting the pH value of the reaction solution to be 7 with a sodium carbonate solution with the mass fraction of 10%, separating liquid, carrying out pressure concentration on the obtained organic phase to remove a solvent, and then naturally cooling and crystallizing to obtain an intermediate B;

and step B12, adding L-aspartic acid and sodium hydroxide into anhydrous methanol under the conditions of set temperature of 25 ℃ and rotation speed of 700r/min, stirring for 10min, then adding sodium ethoxide and acetone, setting temperature of 50 ℃ and rotation speed of 400r/min, stirring for 10min, adding the methanol solution of the intermediate B, keeping the temperature and the rotation speed unchanged, reacting for 2h, after the reaction is finished, distilling the obtained reaction solution at 60 ℃ under reduced pressure, separating out a solid, then carrying out suction filtration under reduced pressure, washing the obtained solid with anhydrous ether for 5 times, and after the washing is finished, carrying out vacuum drying at 40 ℃ to constant weight to obtain the component B.

Wherein the molar ratio of the methyl benzoate to the acetophenone in the step B11 is 4: 1, the dosage ratio of the dimethylbenzene to the methyl benzoate is 10 mL: 3g, the molar ratio of sodium methoxide to acetophenone is 1.6: 1; the molar ratio of L-aspartic acid to sodium hydroxide in step B12 was 1: 2; the ratio of the total dosage of the L-aspartic acid and the sodium hydroxide to the total dosage of the anhydrous methanol is 1 g: 20mL, wherein the dosage ratio of the intermediate b, sodium ethoxide and acetone is 1 g: 50 mg: 10mL, wherein the mass ratio of the L-aspartic acid to the intermediate b is 1: 1.8, the dosage ratio of the intermediate b to the methanol in the methanol solution of the intermediate b is 1 g: 5 mL.

Wherein the modified hydrotalcite is prepared by the following steps:

step S11, preparing solution C: dissolving magnesium nitrate hexahydrate and aluminum nitrate nonahydrate in deionized water, wherein the using amount ratio of the magnesium nitrate hexahydrate to the aluminum nitrate nonahydrate to the deionized water is 13 g: 10 g: 100 mL; preparing a solution D: dissolving sodium hydroxide and sodium carbonate in deionized water, wherein the dosage ratio of the sodium hydroxide to the sodium carbonate to the deionized water is 6 g: 1.6 g: 100 mL;

step S12, adding deionized water and monoalkyl phosphate into a three-neck flask, setting the temperature to be 80 ℃, simultaneously and respectively dropping the solution C and the solution D into the three-neck flask by using a dropping funnel under the protection of nitrogen, controlling the dropping speed of the funnel to be 1 drop/second, adjusting the pH value of a mixed solution in the three-neck flask to be 11 by using 1mol/L sodium hydroxide solution when the dropping of the solution C and the solution D is about to be finished, reducing the temperature to room temperature, stirring for 1h, then increasing the temperature to 65 ℃, preserving the temperature for 1h, carrying out constant temperature reaction for 18h, after the reaction is finished, carrying out suction filtration on the solution, washing a filter cake to be neutral by using the deionized water, and drying the washed filter cake to be constant weight at 80 ℃ to obtain the modified hydrotalcite.

Wherein the volume ratio of the solution C to the solution D in the step S12 is 1: 1; the dosage ratio of the deionized water to the monoalkyl phosphate ester to the solution C is 25 mL: 1 g: 50 mL.

Comparative example 1

A common beta-diketone polyvinyl chloride auxiliary heat stabilizer in the market.

The polyvinyl chloride auxiliary heat stabilizers of examples 1-3 and comparative example were tested;

samples of PVC material were prepared according to the following formulation: 100 parts of PVC, 0.5 part of calcium stearate, 2.5 parts of zinc stearate and 0.4 part of auxiliary heat stabilizer. Auxiliary Heat stabilizers were those of inventive examples 1-3 and comparative example 1, respectively, corresponding to samples 1-3 and comparative sample 1, respectively. Set control sample 1: no auxiliary heat stabilizer is added; set control sample 2: the auxiliary heat stabilizer of example 1 was added without adding calcium stearate and zinc stearate. Wherein the initial coloration is yellowness measured according to a Hunter colorimeter, and the light transmittance is measured according to GB/T2410-2008:

TABLE 1

As can be seen from the above Table 1, the auxiliary heat stabilizer prepared by the invention has no obvious effect on improving the thermal stability of PVC when used alone, and can obviously prolong the coloring time and the blackening time of the PVC material when used in combination with the calcium stearate and zinc stearate stabilizers, i.e. obviously improve the thermal stability of the PVC material without affecting the transparency of the material.

The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to limit the invention to the precise embodiments described, and various modifications, additions, and substitutions may be made by those skilled in the art without departing from the scope of the invention or exceeding the scope of the claims.

Claims (6)

1. The polyvinyl chloride auxiliary heat stabilizer is characterized by comprising a component A, a component B and modified hydrotalcite;

the polyvinyl chloride auxiliary heat stabilizer is prepared by the following steps:

firstly, preparing a component A and a component B;

step two, preparing modified hydrotalcite;

thirdly, mixing the component A and the component B according to the weight ratio of 1: 1 to obtain a first component, and then mixing the modified hydrotalcite and stearic acid according to a mass ratio of 1: 1-3 to obtain a second component, and mixing the second component and the first component according to the mass ratio of 7-9: 1 mixing to obtain a polyvinyl chloride auxiliary heat stabilizer;

the component A is prepared by the following steps:

step A11, adding xylene, methyl stearate and sodium methoxide into a four-neck flask, setting the temperature at 140 ℃ and the rotating speed at 300r/min, dropwise adding acetophenone while stirring, keeping the temperature and the rotating speed unchanged after the acetophenone is completely added, continuously stirring for 50-60min, cooling the temperature to room temperature after stirring is finished, adding a sulfuric acid solution with the mass fraction of 30%, adjusting the pH value of the reaction solution to 3-4, keeping the rotating speed unchanged, continuously reacting for 60-70min, washing the reaction solution to be neutral by deionized water after the reaction is finished, carrying out reduced pressure concentration on the obtained organic phase to obtain a concentrated solution, adding petroleum ether into the concentrated solution, cooling the temperature to 10 ℃ for crystallization, carrying out reduced pressure suction filtration, and drying the obtained solid to constant weight at 40 ℃ to obtain an intermediate a;

step A12, adding L-aspartic acid and sodium hydroxide into anhydrous methanol under the conditions of setting the temperature to be 25 ℃ and the rotating speed to be 700r/min, stirring for 10min, then adding sodium ethoxide and acetone, setting the temperature to be 50 ℃ and the rotating speed to be 400r/min, stirring for 10min, adding a methanol solution of an intermediate a, keeping the temperature and the rotating speed unchanged, reacting for 2h, after the reaction is finished, distilling the obtained reaction liquid at 60 ℃ under reduced pressure, separating out a solid, then carrying out suction filtration under reduced pressure, washing the obtained solid with anhydrous ether for 3-5 times, and after the washing is finished, carrying out vacuum drying at 40 ℃ to constant weight to obtain a component A;

the component B is prepared by the following steps:

step B11, adding xylene, methyl benzoate and sodium methoxide into a four-neck flask, setting the temperature at 110-;

and step B12, adding L-aspartic acid and sodium hydroxide into anhydrous methanol under the conditions of set temperature of 25 ℃ and rotation speed of 700r/min, stirring for 10min, then adding sodium ethoxide and acetone, setting temperature of 50 ℃ and rotation speed of 400r/min, stirring for 10min, adding the methanol solution of the intermediate B, keeping the temperature and the rotation speed unchanged for reaction for 2h, after the reaction is finished, carrying out reduced pressure distillation on the obtained reaction solution at 60 ℃ to separate out a solid, then carrying out reduced pressure suction filtration, washing the obtained solid for 3-5 times by using anhydrous ether, and after the washing is finished, carrying out vacuum drying at 40 ℃ to constant weight to obtain the component B.

2. The polyvinyl chloride auxiliary heat stabilizer of claim 1, wherein the molar ratio of methyl stearate to acetophenone in step A11 is 2: 1, the dosage ratio of the dimethylbenzene to the methyl stearate is 10 mL: 1g of a compound; the mol ratio of sodium methoxide to acetophenone is 1.6-2: 1; the molar ratio of L-aspartic acid to sodium hydroxide in step A12 was 1: 2; the ratio of the total dosage of the L-aspartic acid and the sodium hydroxide to the total dosage of the anhydrous methanol is 1 g: 10-20mL, wherein the dosage ratio of the intermediate a, sodium ethoxide and acetone is 1 g: 50 mg: 10mL, wherein the mass ratio of the L-aspartic acid to the intermediate a is 1: 3, the using ratio of the intermediate a to the methanol in the methanol solution of the intermediate a is 1 g: 5 mL.

3. The polyvinyl chloride auxiliary heat stabilizer of claim 1, wherein the molar ratio of methyl benzoate to acetophenone in step B11 is 4: 1, the dosage ratio of the dimethylbenzene to the methyl benzoate is 10 mL: 1-3g, wherein the molar ratio of sodium methoxide to acetophenone is 1.6: 1; the molar ratio of L-aspartic acid to sodium hydroxide in step B12 was 1: 2; the ratio of the total dosage of the L-aspartic acid and the sodium hydroxide to the total dosage of the anhydrous methanol is 1 g: 10-20mL, wherein the dosage ratio of the intermediate b, sodium ethoxide and acetone is 1 g: 50 mg: 10mL, wherein the mass ratio of the L-aspartic acid to the intermediate b is 1: 1.6-1.8, wherein the dosage ratio of the intermediate b to methanol in the methanol solution of the intermediate b is 1 g: 5 mL.

4. The polyvinyl chloride auxiliary heat stabilizer of claim 1, wherein the modified hydrotalcite is prepared by the following steps:

step S11, preparing solution C: dissolving magnesium nitrate hexahydrate and aluminum nitrate nonahydrate in deionized water, wherein the using amount ratio of the magnesium nitrate hexahydrate to the aluminum nitrate nonahydrate to the deionized water is 13 g: 10 g: 100 mL; preparing a solution D: dissolving sodium hydroxide and sodium carbonate in deionized water, wherein the dosage ratio of the sodium hydroxide to the sodium carbonate to the deionized water is 6 g: 1.6 g: 100 mL;

step S12, adding deionized water and monoalkyl phosphate into a three-neck flask, setting the temperature to be 80 ℃, simultaneously and respectively dropping the solution C and the solution D into the three-neck flask by using a dropping funnel under the protection of nitrogen, controlling the dropping speed of the funnel to be 1 drop/second, adjusting the pH value of the mixed solution in the three-neck flask by using 1mol/L sodium hydroxide solution when the dropping of the solution C and the solution D is about to be finished, reducing the temperature to room temperature, stirring for 1h, then increasing the temperature to 65 ℃, preserving the temperature for 1h, carrying out constant temperature reaction for 14-18h, after the reaction is finished, carrying out suction filtration on the solution, washing a filter cake to be neutral by using the deionized water, and drying the washed filter cake to be constant weight at 80 ℃ to obtain the modified hydrotalcite.

5. The polyvinyl chloride auxiliary heat stabilizer of claim 4, wherein the volume ratio of solution C to solution D in step S12 is 1: 1; the dosage ratio of the deionized water to the monoalkyl phosphate ester to the solution C is 25 mL: 1 g: 50 mL.

6. The method for preparing a polyvinyl chloride auxiliary heat stabilizer according to claim 1, which is characterized by comprising the following steps:

firstly, preparing a component A and a component B;

step two, preparing modified hydrotalcite;

thirdly, mixing the component A and the component B according to the weight ratio of 1: 1 to obtain a first component, and then mixing the modified hydrotalcite and stearic acid according to a mass ratio of 1: 1-3 to obtain a second component, and mixing the second component and the first component according to the mass ratio of 7-9: 1, mixing to obtain the polyvinyl chloride auxiliary heat stabilizer.