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CN-121991413-A - Modified sulfonate flame retardant suitable for PC and preparation method thereof

CN121991413ACN 121991413 ACN121991413 ACN 121991413ACN-121991413-A

Abstract

The invention discloses a modified sulfonate fire retardant suitable for PC and a preparation method thereof, and forming a layer of polysiloxane or polyborosiloxane shell on the surface of the sulfonate by an in-situ polymerization mode to obtain the modified sulfonate flame retardant with the core-shell structure. The flame retardant has excellent flame retardant efficiency, and can lead Polycarbonate (PC) to reach UL 94V-0 (1.5 mm) under the condition of extremely small addition amount. Meanwhile, the flame retardant has good hydrophobicity, flame retardance is not easily affected by moisture, and the flame retardant has good compatibility with PC and is not easy to migrate and run off. Therefore, the flame retardant can ensure that PC keeps excellent flame retardant performance for a long time, and effectively solves the problem of poor flame retardant durability of the traditional sulfonate flame retardant.

Inventors

  • RAN GUOWEN
  • Yuan Gehui
  • XIE HAISHENG
  • LI TAO
  • ZHANG JINGFAN

Assignees

  • 中蓝晨光化工研究设计院有限公司
  • 中蓝晨光化工有限公司

Dates

Publication Date
20260508
Application Date
20241106

Claims (10)

  1. 1. A modified sulfonate fire retardant suitable for PC is characterized in that the modified sulfonate fire retardant is a substance with a core-shell structure, and a polysiloxane shell shown as (I) is formed on the surface of a sulfonate fire retardant serving as a core body in an in-situ polymerization mode; in the formula (I), a, b, c and d are integers of more than 0, wherein a, b, c, d=1-3:1-3:3-7:1-3, R 1 ,R 2 are respectively selected from one of methyl and ethyl; or as a polyborosiloxane shell as shown in (II) or (III); In the formula (II), a, b, c and d are integers of more than 0, wherein a, b, c, d=1-3:1-3:3-7:1-3, R 1 ,R 2 are respectively selected from one of methyl and ethyl; In the formula (III), a, b, c and d are integers of >0, a is b, c is d=1-3:1-3:3-7:1-3, and R 1 ,R 2 is one of methyl and ethyl respectively.
  2. 2. The method for preparing the modified sulfonate fire retardant for PC according to claim 1, which is characterized by comprising the following steps: (1) Adding the mixture into a three-neck flask according to the proportion of each 100g of sulfonate flame retardant and 50-200ml of solvent, heating to 55-78 ℃ while stirring, and then adding siloxane monomer accounting for 10-60% of the weight of the sulfonate flame retardant for pre-reaction for 20-30min; (2) After the pre-reaction is completed, glacial acetic acid is added into the system as a catalyst, so that the pH value of the reaction system is=3-5, and the reaction is continued for 3-8 hours at the temperature of 60-78 ℃; (3) And heating and distilling to remove the solvent after the reaction is finished, washing the product with deionized water to remove the residual catalyst until the pH value is 6-7, and then placing the product in a vacuum oven at 100-200 ℃ for 3-6 hours to remove the moisture, the residual solvent and the micromolecular byproducts, thereby obtaining the modified sulfonate flame retardant.
  3. 3. The method for preparing the modified sulfonate fire retardant for PC according to claim 1, which is characterized by comprising the following steps: (1) Adding the mixture into a three-neck flask according to the proportion of 50-200ml of solvent and each 100g of sulfonate flame retardant, heating to 55-78 ℃ while stirring, then adding siloxane monomers and boron-containing compounds, and pre-reacting for 20-30min, wherein the total amount of the siloxane monomers and the boron-containing compounds is 10-60% of the weight of the sulfonate flame retardant; (2) After the pre-reaction is completed, glacial acetic acid is added into the system as a catalyst to ensure that the pH value of the reaction system is=3-5, and the reaction is continued for 3-8 hours at the temperature of 60-78 ℃; (3) Heating and distilling to remove the solvent after the reaction is finished, washing the product with deionized water to remove the residual catalyst until the pH value is 6-7, and then placing the product in a vacuum oven at 100-200 ℃ for 3-6 hours to remove the moisture, the residual solvent and the micromolecular byproducts, thus obtaining the modified sulfonate flame retardant.
  4. 4. The method for preparing a modified sulfonate flame retardant for PC according to claim 2 or 3, wherein the sulfonate flame retardant is one of diphenyl sulfone sulfonate and perfluoroalkyl sulfonate.
  5. 5. The method for preparing the modified sulfonate fire retardant for the PC, which is disclosed in claim 2 or 3, is characterized in that the solvent is one of absolute ethyl alcohol, toluene and tetrahydrofuran.
  6. 6. The method for preparing a modified sulfonate flame retardant for PC according to claim 2, wherein the siloxane monomer in the step (1) is composed of diphenyl dimethoxy siloxane, dimethyl dimethoxy silane, phenyl trimethoxy siloxane and methyl trimethoxy silane; or the siloxane monomer in the step (1) is composed of diphenyl dimethoxy siloxane, diethyl diethoxy silane, phenyl trimethoxy siloxane and methyl trimethoxy silane.
  7. 7. The method for preparing a modified sulfonate flame retardant for PC according to claim 2, wherein the siloxane monomer in the step (1) is composed of diphenyl dimethoxy siloxane, dimethyl dimethoxy silane, phenyl trimethoxy siloxane and ethyl trimethoxy silane; Or the siloxane monomer in the step (1) is composed of diphenyl dimethoxy siloxane, diethyl diethoxy silane, phenyl trimethoxy siloxane and ethyl trimethoxy silane.
  8. 8. A method for preparing a modified sulfonate flame retardant for PC, as claimed in claim 3, wherein the siloxane monomer in the step (1) is composed of diphenyldimethoxy siloxane, dimethyldimethoxy silane, phenyltrimethoxy siloxane, or is composed of diphenyldimethoxy siloxane, diethyldiethoxy silane, phenyltrimethoxy siloxane.
  9. 9. The method for preparing a modified sulfonate flame retardant for PC according to claim 2 or 3, wherein the boron-containing compound is one of boric acid and phenylboric acid.
  10. 10. A modified sulfonate fire retardant suitable for PC according to claim 1, wherein 0.3-0.4% of modified sulfonate fire retardant is added into PC according to weight percentage, so that PC reaches UL 94V-0 at a thickness of 1.5 mm.

Description

Modified sulfonate flame retardant suitable for PC and preparation method thereof Technical Field The invention relates to a flame retardant for PC, in particular to a modified sulfonate flame retardant and a preparation method thereof, and belongs to the technical field of flame retardants. Technical Field Polycarbonate (PC) is engineering plastic with excellent comprehensive performance, excellent transparency, heat resistance and impact strength, and has wide application in the fields of electronic and electric appliances, automobile manufacturing, rail transit and the like. Although PC itself has good flame retardant properties, which can reach UL 94V-2 grade, it still cannot meet the flame retardant requirements of V-0 grade in many fields. Thus, PC needs to be modified by further flame retardance to find application in some fields with high flame retardance requirements. Currently, suitable flame retardants for PC include halogen flame retardants, phosphorus flame retardants, silicon flame retardants, sulfonate salt flame retardants, and the like. Among the flame retardants, sulfonate has extremely high flame retardant efficiency on PC, and the flame retardant performance of PC can be remarkably improved by only adding less than 0.5 wt%. The low addition amount ensures that the sulfonate flame retardant hardly affects the transparency, mechanical strength, heat resistance and other key performances of the PC, and is widely applied to flame retardant modification of the PC. However, when the sulfonate flame retardant is used alone, PC can achieve stable UL 94V-0 grade only at a thickness of 3.0mm or more, and V-0 grade is hardly achieved at a thickness of 1.5mm or less, and the flame retardant effect is still to be improved. Therefore, sulfonate flame retardants are generally used in combination with silicone flame retardants and the like to improve the flame retardant properties of PC. As disclosed in patent CN104497536B, a flame retardant PC containing sulfonate and silicone can reach V-0 grade at a thickness of 1.0 mm. In addition, the sulfonate flame retardant is extremely easy to absorb water, and the flame retardant effect is greatly reduced after the water absorption. Meanwhile, the sulfonate flame retardant has poor compatibility with PC, and can gradually migrate and run off. Therefore, PC containing the sulfonate flame retardant cannot maintain the flame retardancy for a long period of time, and is greatly reduced only after several days. Aiming at the problem, some improvements are made in the industry, for example, CN105837825B discloses a polyphosphate polymer with a sulfonate structure, which has good flame retardant effect on PC and is not easy to deliquescence. Patent CN104893272B discloses a microcapsule coated sulfonate flame retardant, which solves the problems that sulfonate is easy to absorb water and is incompatible with PC. However, these improvements have not been very effective in improving the flame retardant efficiency and durability of the sulfonate salt to PC. Therefore, it is still a research topic to modify sulfonate to make it better used in PC. Disclosure of Invention In order to solve the problems of limited flame retardant effect and poor flame retardant durability of PC when the sulfonate flame retardant is singly used in the prior art, the primary purpose of the invention is to provide a modified sulfonate flame retardant with a core-shell structure, namely a polysiloxane or polyborosiloxane shell is formed on the surface of the sulfonate flame retardant in an in-situ polymerization mode. The flame retardant not only contains a sulfonate structure, but also contains silicon or silicon and boron flame retardant elements, and a plurality of flame retardant factors are mutually cooperated, so that the PC can reach V-0 level at the thickness of 1.5mm only by adding 0.3-0.4wt%. Meanwhile, the polysiloxane or the polyborosiloxane shell has excellent hydrophobicity and good compatibility with PC, so that the flame retardance of the PC can be kept for a long time. The invention also aims to provide a preparation method of the modified sulfonate flame retardant. The invention further aims to provide the application of the modified sulfonate flame retardant in PC flame retardant modification. The invention aims at realizing the technical scheme that the modified sulfonate flame retardant suitable for PC is a substance with a core-shell structure, and a polysiloxane shell or a polyborosiloxane shell is formed on the surface of which a core is the sulfonate flame retardant in an in-situ polymerization mode. The polysiloxane shell is shown as (I): in the formula (I), a, b, c and d are integers of >0, wherein a, b, c, d=1-3:1-3:3-7:1-3, and R 1,R2 are respectively selected from one of methyl and ethyl. The polyborosiloxane shell is shown as (II) or (III): In the formula (II), a, b, c and d are integers of >0, a is b, c is d=1-3:1-3:3-7:1-3, and R 1,R2 is one of methyl and ethyl r