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RU-2861669-C1 - METHOD FOR PRODUCING ANTIFOULING ADDITIVE BASED ON COPOLYMER OF ALPHA-NAPHTHOL AND FORMALDEHYDE FOR PVC PRODUCTION

RU2861669C1RU 2861669 C1RU2861669 C1RU 2861669C1RU-2861669-C1

Abstract

FIELD: chemical industry. SUBSTANCE: invention relates to the production of antifouling additives in the production of dyes, binders or coatings. A method for producing a solution of a condensation product of α-naphthol and formalin is proposed, comprising the following stages: I) a condensation stage, comprising the following steps: a) boiling water for 6-24 hours in an inert gas atmosphere; b) cooling the water after step a) to a temperature of 50-55°C and adding a 20-25% aqueous sodium hydroxide solution followed by holding for 10-15 minutes; c) adding α-naphthol over 25-30 minutes to the reaction mass after step b) in a molar ratio to sodium hydroxide of 1:2-2.1 followed by holding for 40-45 minutes; d) adding sodium thiosulfate to the reaction mass after step c) in a molar ratio to α-naphthol of 1:20-25 followed by holding for 20-25 minutes; e) metering formalin in a ratio of 2-2.1 mol of formaldehyde per 1 mol of α-naphthol followed by holding for 60-70 minutes and then cooling to 30-35°C; II) a stage of preparing a stabilising solution, comprising the following steps: a) boiling water for 6-24 hours in an inert gas atmosphere; b) cooling the water after step a) to a temperature of 20-25°C and adding sodium hydroxide to obtain a solution with a sodium hydroxide concentration of 0.01-0.02 mol/l followed by holding for 10-25 minutes, and then adding sodium thiosulfate to obtain a solution with a sodium thiosulfate concentration of 0.0048-0.005 mol/l followed by holding for 10-15 minutes; c) adding 0.2-0.6 g of polyvinyl alcohol to the solution after step b) followed by holding for 60-70 minutes; III) mixing the reaction mass obtained in stage Ie and the solution after stage IIc with holding for 15-20 minutes at 20-25°C to form the target solution of the condensation product of α-naphthol and formalin. EFFECT: increasing the efficiency of the method for producing a solution of a polycondensation product of α-naphthol and formalin, providing a high yield of the condensation product, which is carried out in two stages, wherein the resulting solution is used as an antifouling additive for PVC production. 11 cl, 1 dwg, 2 tbl, 2 ex

Inventors

  • EGOROV SERGEJ ANATOLEVICH
  • Ovchinnikova Valeriya Leonidovna
  • Valkovskaya Anna Andreevna

Dates

Publication Date
20260507
Application Date
20250904

Claims (20)

  1. 1. A method for obtaining a solution of the condensation product of α-naphthol and formalin, comprising the following stages:
  2. I) the condensation stage, which includes the following steps:
  3. a) boiling water for 6-24 hours in an inert gas atmosphere;
  4. b) cooling the water to a temperature of 50-55°C after step a) and adding a 20-25% aqueous solution of sodium hydroxide, followed by holding for 10-15 minutes;
  5. c) adding α-naphthol over 25-30 minutes to the reaction mass after step b) in a molar ratio to sodium hydroxide of 1:2-2.1, followed by holding for 40-45 minutes;
  6. d) adding sodium thiosulfate to the reaction mass after step c) in a molar ratio to α-naphthol of 1:20-25, followed by holding for 20-25 minutes;
  7. d) dosing formalin in a ratio of 2-2.1 mol of formaldehyde per 1 mol of α-naphthol, followed by holding for 60-70 minutes and cooling afterward to 30-35°C;
  8. II) the stage of preparation of the stabilizing solution, which includes the following steps:
  9. a) boiling water for 6-24 hours in an inert gas atmosphere;
  10. b) cooling the water to a temperature of 20-25°C after step a) and adding sodium hydroxide to obtain a solution with a sodium hydroxide concentration of 0.01-0.02 mol/l, followed by holding for 10-25 minutes, and then adding sodium thiosulfate to obtain a solution with a sodium thiosulfate concentration of 0.0048-0.005 mol/l, followed by holding for 10-15 minutes;
  11. c) adding 0.2-0.6 g of polyvinyl alcohol to the solution after step b), followed by holding for 60-70 minutes;
  12. III) mixing the reaction mass obtained in stage Id and the solution after stage IIc with a 15-20 minute hold at 20-25°C to form the target solution of the condensation product of α-naphthol and formalin.
  13. 2. The method according to claim 1, wherein the polyvinyl alcohol has a degree of polymerization of 500-2500.
  14. 3. The method according to claim 2, wherein the polyvinyl alcohol has a degree of polymerization of 1500-1600 or 2000-2200.
  15. 4. The method according to claim 1, in which constant mixing is maintained at all stages and steps.
  16. 5. The method according to claim 1, wherein at stage Ia and/or IIa, boiling of water in an inert gas atmosphere is carried out for 6-8 hours.
  17. 6. The method according to claim 1, wherein at stage Ia and/or IIa, water is bubbling with an inert gas.
  18. 7. The method according to claim 1, wherein the inert gas is argon or nitrogen.
  19. 8. The method according to claim 1, wherein stages I and II are carried out in parallel.
  20. 9. The method according to claim 1, wherein the dosing at stage Id is carried out over 10 minutes.

Description

Field of technology The invention relates to the field of organic synthesis, in particular to a method for producing solutions based on α-naphthol, formaldehyde and polyvinyl alcohol, which can be used as an anti-pollution additive in the production of dyes, binders or coatings. State of the art The prior art recognizes the use of polymerization of aqueous suspensions of monomers, such as vinyl chloride, to produce polymers. A problem encountered during this type of polymerization is that some of the polymer material coats the reactor, leading to certain process complications and reduced process efficiency. To address these issues, antifouling compounds are used. These materials are applied to the reactor walls and prevent the formation of a polymer coating. For example, the use of naphthol and formaldehyde condensation products as antifouling additives is known, including for treating equipment surfaces during polymerization reactions [RU 2612673]. It is also known to produce adsorption coatings based on the products of interaction of phenols and aldehydes or coatings that prevent the formation of adhesion or build-up in reactors during the implementation of certain technological processes [WO 1982002555, EP 0052421 B1]. Despite the well-known nature of various approaches to obtaining condensation products of naphthol and formaldehyde, there remains a need to develop new methods with improved efficiency. Disclosure of invention The objective of the present invention is to develop a new and efficient method for obtaining a solution of the condensation product of α-naphthol and formalin. The stated problem is solved by implementing a method for obtaining a solution of the condensation product of α-naphthol and formalin, which includes the following stages: I) the condensation stage, which includes the following steps: a) boiling water for 6-24 hours in an inert gas atmosphere; b) cooling the water to a temperature of 50-55°C after step a) and adding a 20-25% aqueous solution of sodium hydroxide, followed by holding for 10-15 minutes; c) adding α-naphthol over 25-30 minutes to the reaction mass after step b) in a molar ratio to sodium hydroxide of 1:2-2.1, followed by holding for 40-45 minutes; d) adding sodium thiosulfate to the reaction mass after step c) in a molar ratio to α-naphthol of 1:20-25, followed by holding for 20-25 minutes; d) dosing formalin in a ratio of 2-2.1 mol of formalin per 1 mol of α-naphthol, followed by holding for 60-70 minutes and cooling afterwards to 30-35°C; II) the stage of preparation of the stabilizing solution, which includes the following steps: a) boiling water for 6-24 hours in an inert gas atmosphere; b) cooling the water to a temperature of 20-25°C after step a) and adding sodium hydroxide to obtain a solution with a sodium hydroxide concentration of 0.01-0.02 mol/l, followed by holding for 10-25 minutes, and then adding sodium thiosulfate to obtain a solution with a sodium thiosulfate concentration of 0.0048-0.005 mol/l, followed by holding for 10-15 minutes; c) adding 0.2-0.6 g of polyvinyl alcohol to the solution after step b), followed by holding for 60-70 minutes; III) mixing the reaction mass obtained in stage Id and the solution after stage IIc with a 15-20 minute hold at 20-25°C to form the target solution of the condensation product of α-naphthol and formalin. In particular embodiments of the invention, polyvinyl alcohol has a degree of polymerization of 500-2500. In more specific embodiments of the invention, polyvinyl alcohol has a degree of polymerization of 1500-1600 or 2000-2200. In particular embodiments of the invention, constant mixing is maintained at all stages and steps. In particular embodiments of the invention, at stage Ia and/or IIa, boiling of water in an inert gas atmosphere is carried out for 6-8 hours. In particular embodiments of the invention, at stage Ia and/or IIa, water is bubbling with an inert gas. In particular embodiments of the invention, the inert gas is argon or nitrogen. In particular embodiments of the invention, stages I and II are carried out in parallel. In particular embodiments of the invention, dosing at stage Id is carried out over a period of 10 minutes. In particular embodiments of the invention, at stage IIb, the addition of polyvinyl alcohol is carried out in an amount of 0.5-0.55 g. In particular embodiments of the invention, mixing of the reaction mass obtained in stage Id and the solution after stage IIb is carried out in a mass ratio of 1.16-1.21:1. As a result of implementing the invention, the following technical results are achieved: - a new and effective method has been developed for obtaining a solution of the condensation product of α-naphthol and formalin with a high yield of the condensation product, at least 80%, which is carried out in two stages - the main reaction of condensation of α-naphthol with formalin in an alkaline medium with the addition of a stabilizer (sodium thiosulfate) and the preparation