WO2022083035A1 - 一种核壳结构ptfe分散树脂的制备方法 - Google Patents

一种核壳结构ptfe分散树脂的制备方法 Download PDF

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WO2022083035A1
WO2022083035A1 PCT/CN2021/076001 CN2021076001W WO2022083035A1 WO 2022083035 A1 WO2022083035 A1 WO 2022083035A1 CN 2021076001 W CN2021076001 W CN 2021076001W WO 2022083035 A1 WO2022083035 A1 WO 2022083035A1
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core
reaction
dispersion resin
stage
ptfe dispersion
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PCT/CN2021/076001
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French (fr)
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陈振华
周黎旸
周晓勇
王树华
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浙江巨化技术中心有限公司
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Priority to US18/031,696 priority Critical patent/US20230383029A1/en
Publication of WO2022083035A1 publication Critical patent/WO2022083035A1/zh

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F14/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen
    • C08F14/18—Monomers containing fluorine
    • C08F14/26—Tetrafluoroethene
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F216/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal or ketal radical
    • C08F216/12—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal or ketal radical by an ether radical
    • C08F216/14—Monomers containing only one unsaturated aliphatic radical
    • C08F216/1408—Monomers containing halogen
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/12—Polymerisation in non-solvents
    • C08F2/16—Aqueous medium
    • C08F2/22—Emulsion polymerisation
    • C08F2/24—Emulsion polymerisation with the aid of emulsifying agents
    • C08F2/26—Emulsion polymerisation with the aid of emulsifying agents anionic
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/38—Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F214/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen
    • C08F214/18—Monomers containing fluorine
    • C08F214/26—Tetrafluoroethene
    • C08F214/262—Tetrafluoroethene with fluorinated vinyl ethers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L27/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers
    • C08L27/02—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment
    • C08L27/12—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
    • C08L27/18—Homopolymers or copolymers or tetrafluoroethene
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2201/00—Properties
    • C08L2201/08—Stabilised against heat, light or radiation or oxydation
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2201/00—Properties
    • C08L2201/54—Aqueous solutions or dispersions
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2203/00—Applications
    • C08L2203/18—Applications used for pipes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2207/00—Properties characterising the ingredient of the composition
    • C08L2207/53—Core-shell polymer

Definitions

  • the invention belongs to the field of polymers, and in particular relates to a preparation method of a core-shell structure PTFE dispersion resin.
  • PTFE commonly known as "Plastic King”
  • Plastic King is the most widely used fluoropolymer. It has excellent chemical stability, corrosion resistance, sealing, high lubrication and non-stick properties, electrical insulation and good anti-aging endurance. It is widely used in national defense, Aerospace, electronics, electrical, chemical, machinery, instruments, meters, construction, textile, metal surface treatment, pharmaceutical, medical, textile, food, metallurgy and other fields.
  • the methods of producing PTFE resin usually include suspension method and dispersion method, and the resin obtained from this is called suspension resin and dispersion resin respectively.
  • the dispersion resin is a polymerization of tetrafluoroethylene (TFE) monomer, which is dispersed into an emulsion state under the action of an emulsifier. Dispersion polymerization involves two distinct stages: the nucleation stage at the beginning of the reaction, in which a certain number of polymerization sites or cores are formed, followed by the growth stage, in which the TFE monomer continues to polymerize on the surface of the already formed core, Little or no new nuclei are formed at this stage as the latex particle size gradually increases as the polymerization proceeds.
  • the preparation of high solid content dispersions generally requires the addition of fluorosurfactants (emulsifiers) to stabilize the dispersions and prevent the aggregation and precipitation of polymer particles.
  • fluorosurfactants emulsifiers
  • the nucleation stage of PTFE dispersion polymerization plays a decisive role in the shape, size and quantity of the primary particles of the resin, and will also directly affect the growth of subsequent particles in the growth stage.
  • Reasonable control of the particle structure in the nucleation stage can greatly improve the performance of the resin, especially the paste extrusion processability of the resin.
  • the selection of emulsifiers is very important.
  • the emulsifiers used in TFE dispersion polymerization are mostly perfluorooctanoic acid and its salts, such as ammonium perfluorooctanoate (perfluorooctanoic acid is hereinafter referred to as PFOA).
  • PFOA perfluorooctanoic acid and its salts, such as ammonium perfluorooctanoate
  • Studies have shown that the perfluoroalkyl chain of PFOA is difficult to degrade, so it will accumulate in the environment and organisms, causing toxic hazards to the environment and humans. Restriction requirements have been placed on PFOA in related products.
  • the environmental problems caused by PFOA can be gradually reduced, but the existence of PFOA cannot be fundamentally eliminated. Therefore, finding an environmentally friendly emulsifier to replace PFOA is the solution to the PFOA problem.
  • the optimal solution has gradually become a research hotspot in recent years.
  • Another method is to introduce heteroatoms into perfluorosurfactant molecules.
  • the emulsifier used for TFE dispersion polymerization needs to be at least partially fluorinated. For example, it is easier to introduce hydrogen, oxygen, nitrogen, etc.
  • Degraded atoms introduce "weak points" into the molecular chain to increase its degradability.
  • Patents US3271341A, US3391099A, etc. use perfluoroether carboxylic acid/salt for dispersion polymerization of PTFE, but the stability of the emulsion is still not ideal, resulting in the production of more aggregates.
  • Patents US 7671112 and US 7776946 use fluorine-containing ether carboxylic acids/salts (such as perfluoro 2,6-dioxa-octanoic acid ammonium) as emulsifiers to carry out dispersion polymerization of TFE, but the solid content of the dispersion obtained by this method is only At around 10 wt%, higher solids polymerization attempts have not been made.
  • fluorine-containing ether carboxylic acids/salts such as perfluoro 2,6-dioxa-octanoic acid ammonium
  • Patent US 7897682B2 adopts perfluorosurfactant (such as perfluoropolyether carboxylic acid/salt) and hydrocarbon surfactant in combination to conduct dispersion polymerization of PTFE to obtain a dispersion liquid with satisfactory solid content and stable emulsion.
  • perfluorosurfactant such as perfluoropolyether carboxylic acid/salt
  • hydrocarbon surfactant in combination to conduct dispersion polymerization of PTFE to obtain a dispersion liquid with satisfactory solid content and stable emulsion.
  • this method is mainly used to develop melt-processable PTFE polymers such as TFE-PPVE (PFA), TFE-HFP (FEP), which are mainly formed by melt processing. Therefore, there is no requirement for the control of the primary particle structure of the dispersion liquid, so the dispersion system is not suitable for the preparation of PTFE dispersion resin, especially for the preparation of high compression ratio PTFE dispersion resin by paste extrusion.
  • Patent US 7705074 uses fluoropolyether acid/salt with a molecular weight of at least about 800g/mol and a short-chain fluorosurfactant with a chain length of not more than 6 atoms (such as short-chain fluoroether salt C2H5OCF(CF3)COONH4) composite use
  • Patent US 7932333 uses a combination of high molecular weight fluoropolyether acid or salt and low molecular weight fluoropolyether acid or salt. Both methods can effectively carry out the dispersion polymerization of TFE, and use fluorosurfactant or low molecular weight fluorine alone. Compared with polyether acid or salt surfactants, this method can greatly reduce the generation of agglomerates, but the solid content of the PTFE emulsion prepared by this method still cannot meet the expectations of industrial production.
  • Patents US 5789508, US 5688884 and US 4380618 use the general formula Rf-C2H4-SO3M (represents perfluorinated aliphatic hydrocarbon group, M represents cation) fluorine-containing aliphatic hydrocarbon sulfonate surfactant, but the terminal ethanesulfonic acid of the emulsifier is used.
  • the H atom on the acid group may cause a chain transfer reaction during the nucleation stage.
  • Patent US 5763552 adopts fluorine-containing alkyl carboxylate (general formula Rf-(CH2)n-R'f-COOM) containing alkylene in the main chain as emulsifier, and the prepared high molecular weight PTFE homopolymer resin shows that this type of emulsifier The chain transfer efficiency is low, and the influence on the molecular weight of the resin is negligible, but the PTFE resin prepared by this method cannot be used for high compression ratio extrusion processing.
  • fluorine-containing alkyl carboxylate generally formula Rf-(CH2)n-R'f-COOM
  • Patent US 2012116017 adds a water-soluble hydrocarbon-containing compound as a nucleation point in the initial stage of polymerization, and adds another hydrocarbon-containing surfactant (such as SDS) in the stable stage of polymerization.
  • SDS hydrocarbon-containing surfactant
  • the object of the present invention is to provide a preparation method of PTFE dispersion resin, which can avoid the use of PFOA surfactant, and has low surfactant consumption and good emulsion stability, and the prepared PTFE dispersion resin has core-shell multilayers structure, low extrusion pressure, good thermal stability and excellent mechanical properties, especially suitable for the preparation of small diameter pipes by paste extrusion with high compression ratio.
  • the present invention adopts the following technical solutions:
  • a preparation method of a core-shell structure PTFE dispersion resin characterized in that: adding fluorine-containing hydrocarbons and fluorine-containing modified monomers as nucleating agents at the nucleation stage in the initial stage of polymerization, and adding a small amount of non-PFOA surfactant, To control the particle core structure, and add the same or different non-PFOA surfactants to stabilize the dispersion during the growth stage.
  • Stage I add high-purity water to the polymerization kettle, add fluorine-containing hydrocarbon nucleating agent, fluorine-containing modified monomer, stabilizer, and a small amount of non-PFOA surfactant in turn, and feed TFE monomer to After a certain pressure, the temperature is raised to the reaction temperature, and after dispersing for a certain period of time under the action of stirring, the initiator is added to start the polymerization reaction. , remove the modified monomer to the greatest extent possible, and complete the reaction in the nucleation stage;
  • Stage II add TFE monomer to a certain pressure to enter the homopolymerization reaction of the growth stage, and add the same or different non-PFOA surfactants at this stage to stabilize the dispersion, and keep the reaction pressure constant by adding TFE ;
  • the PTFE dispersion resin is obtained by post-processing after cooling the dispersion to remove the stabilizer.
  • the nucleation stage of dispersion polymerization is very important to the whole reaction.
  • the addition of nucleating agent in the nucleation stage can induce the nucleation reaction of TFE monomer.
  • the requirement of surfactant can reduce the amount of surfactant, and can well control the particle size and distribution of particles in the nucleation stage.
  • the lipophilic part of the surfactant can effectively bind fluorine-containing hydrocarbons, and the hydrophilic part of the surfactant can ensure that the lipophilic part and the nucleation point are in the aqueous medium It is uniformly dispersed and stable, and fluorocarbons act as lipophilic nucleation sites to induce the nucleation reaction of TFE. Therefore, under the action of fluorine-containing hydrocarbons, the requirement of TFE dispersion polymerization on surfactants is greatly reduced.
  • the nucleating agent is a fluorine-containing olefin, such as CH 3 CClF 2 , CH 3 CCl 2 F, CF 3 CF 2 CCl 2 H, CF 2 ClCF 2 CFHCl and other hydrochlorofluorocarbons; CF 2 ClCFCl 2.
  • Chlorofluoroalkanes such as CF 2 ClCFClCF 2 CF 3 , CF 3 CCFClCFClCF 3 , etc.; perfluorocarbons such as perfluorocyclobutane, perfluorobutane, perfluoropentane, perfluorohexane, etc., among which the ones without chain transfer effect are preferred Perfluoroalkanes.
  • the amount of the nucleating agent is 0.01-2 wt% of the reaction medium, preferably 0.05-1.5 wt%, more preferably 0.1-1 wt%.
  • the non-PFOA surfactants are fluoroether acids or salts, fluoroether sulfonic acids or salts, fluoropolyether carboxylic acids or salts, fluoropolyether sulfonic acids or salts, hydrofluoroalkyl carboxylic acids or salts, hydrofluoric acid or salts Alkyl sulfonic acid or salt, one or mixture of hydrocarbon-containing surfactants.
  • Hydrocarbon-containing as expressed in this application means that the hydrogen atom on the carbon chain in the hydrocarbon surfactant can be substituted with fluorine or chlorine, and preferably a hydrocarbon surfactant with unsubstituted hydrogen, such as sodium dodecyl sulfate. (SDS), sodium octylsulfonate (SOS), sodium dodecylbenzenesulfonate (SDBS), etc.
  • the surfactant is added to the polymerization tank in two times, respectively, in the nucleation stage and the growth stage, and the total amount of the two additions is controlled at 0.05-0.6wt% of the reaction medium, preferably 0.06-0.3wt%, more preferably 0.08-0.15wt%, wherein, the amount added in the nucleation stage is 5-50wt% of the total amount added, preferably 10-35wt%, more preferably 15-25wt%.
  • the modified monomer is a fluorine-containing vinyl monomer, such as PPVE, PEVE, PMVE, CTFE, HFP, VDF, PFBE and the like.
  • the core-modified monomer is perfluoroalkyl vinyl ether, preferably PPVE, and its content is 0.02-0.5wt% of the dispersing resin, preferably 0.03-0.3wt%, more preferably 0.05-0.2wt%;
  • Shell modification monomers are fluorinated olefins, preferably HFP and CTFE, and the content of fluorinated olefins is 0-0.5wt% of the PTFE dispersion resin, preferably 0-0.4wt%, more preferably 0-0.3wt%.
  • stage I the reaction proceeds to 5-20 wt% of the total TFE feeding amount
  • stage II is when the reaction proceeds to 80-95 wt% of the total TFE feeding amount.
  • the core-shell structure PTFE dispersion resin has a three-layer structure of core-shell-shell, wherein the core is modified PTFE with fluoroolefin, the middle shell is a high molecular weight PTFE homopolymer, and the outer shell is a lower molecular weight PTFE Homopolymer or fluoroolefin-modified PTFE.
  • the polymerization initiator is well known in the art, and the present invention is preferably compounded with an initiator system, such as a mixed system of ammonium persulfate and peroxysuccinic acid.
  • an initiator system such as a mixed system of ammonium persulfate and peroxysuccinic acid.
  • the content of the initiator used in the aqueous medium is 50-150 ppm, wherein the mass ratio of ammonium persulfate and peroxysuccinic acid is 0.03-0.1.
  • the stabilizer is paraffin, and the amount is 4-5wt% of the reaction medium
  • the chain transfer agent is hydrogen, low molecular weight alcohols, alkanes, low molecular weight alcohols include methanol, ethanol, alkanes include methane, ethane, propane, preferably methanol.
  • the amount of chain transfer agent used is 0.05-1 wt% of the consumption of TFE.
  • the reaction temperature is 10-100°C, preferably 40-90°C, more preferably 60-80°C.
  • the reaction pressure is 0.5-3Mpa, preferably 0.7-2.5Mpa, more preferably 1.0-2.0Mpa.
  • the solid content of the dispersion is 10-60wt%, preferably 20-55wt%, most preferably 30-50wt%.
  • the present invention has the following beneficial effects:
  • the present invention can avoid the use of PFOA surfactant, and the dosage of surfactant is low, and the emulsion stability is good. , especially suitable for the preparation of small diameter pipes by paste extrusion with high compression ratio.
  • the lipophilic part of the surfactant can effectively bind fluorine-containing hydrocarbons, and the hydrophilic part of the surfactant can ensure that the lipophilic part and the nucleation point are in the aqueous medium It is uniformly dispersed and stable, and fluorocarbons act as lipophilic nucleation sites to induce the nucleation reaction of TFE. Therefore, under the action of fluorine-containing hydrocarbons, the requirement of TFE dispersion polymerization on surfactants is greatly reduced.
  • the obtained emulsified dispersion of TFE copolymer was cooled, the paraffin in the supernatant was removed, and the dispersion was filtered through a filter bag to remove about 3 g of aggregates.
  • the dispersion was diluted with pure water to a concentration of 15% by weight, the temperature was adjusted to 30°C and vigorously stirred to obtain wet micropowder, which was passed through a vibrating sieve, and then dried at 150°C for 20 hours.
  • the obtained emulsified dispersion of the TFE copolymer was cooled, the paraffin in the supernatant was removed, and the dispersion was filtered through a filter bag to remove about 2.5 g of aggregates.
  • the dispersion was diluted with pure water to a concentration of 15% by weight, the temperature was adjusted to 30°C and vigorously stirred to obtain wet micropowder, which was passed through a vibrating sieve, and then dried at 150°C for 20 hours.
  • the obtained emulsified dispersion of TFE copolymer was cooled, the paraffin in the supernatant was removed, and the dispersion was filtered through a filter bag to remove about 4.8 g of agglomerates.
  • the dispersion was diluted with pure water to a concentration of 15% by weight, the temperature was adjusted to 30°C and vigorously stirred to obtain wet micropowder, which was passed through a vibrating sieve, and then dried at 150°C for 20 hours.
  • the obtained emulsified dispersion of TFE copolymer was cooled, the paraffin in the supernatant was removed, and the dispersion was filtered through a filter bag to remove about 1.7 g of aggregates.
  • the dispersion was diluted with pure water to a concentration of 15% by weight, the temperature was adjusted to 30°C and vigorously stirred to obtain wet micropowder, which was passed through a vibrating sieve, and then dried at 150°C for 20 hours.
  • Example 2 Similar to Example 1, the only difference is that no octafluorocyclobutane nucleating agent is added, and the obtained dispersion is filtered through a filter bag to remove about 1524 g of agglomerates.
  • Test method of the present invention is as follows:
  • the structural properties of the resin are mainly determined by the solid content, the unit content of the modified monomer in the copolymer, the average primary particle size, the apparent density, and the standard specific gravity.
  • the processability of the resin is characterized by paste extrusion pressure, tensile strength and elongation at break.
  • the high compression ratio PTFE dispersion resin powder was extruded to obtain a film disk, and the infrared absorbance of the film disk was measured to obtain the content.
  • CTFE chlorotrifluoroethylene
  • PPVE perfluoropropyl vinyl ether
  • HFP hexafluoropropylene
  • the value obtained by dividing the pressing force of the portion in the equilibrium state by the die cross-sectional area was used as the pressure in the later stage of pressing, and the paste extrusion pressure (MPa) was obtained.
  • the tensile sample was stretched at a tensile speed of 200 mm/min at room temperature, and the maximum tensile strength was measured.
  • the elongation at break sample bar is the same as the tensile strength test sample bar.
  • the tensile testing machine is used for testing.
  • the distance between the chucks is adjusted to 40mm, the sample is clamped up and down, and the upper chuck is raised at a speed of 20mm/min.
  • the elongation at break is calculated by the position of the grip at this time.

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
  • Polymerisation Methods In General (AREA)

Abstract

本发明公开了一种核壳结构PTFE分散树脂的制备方法，其特征在于：在聚合初期的成核阶段加入含氟烃类以及含氟改性单体作为成核剂，并加入少量的非PFOA表面活性剂，来调控粒子核结构，并在生长阶段加入同种或不同种非PFOA表面活性剂来稳定分散液。该方法可避免PFOA表面活性剂的使用，而且表面活性剂用量低，乳液稳定性好，由此制备的PTFE分散树脂具有核壳多层结构，挤出压力低、热稳定性好、机械性能优异，尤其适合采用高压缩比糊状挤出制备小口径管。

Description

一种核壳结构PTFE分散树脂的制备方法 技术领域
本发明属于高分子领域，具体涉及一种核壳结构PTFE分散树脂的制备方法。
背景技术
PTFE俗称“塑料王”，是用量最大的含氟聚合物，具有优良的化学稳定性、耐腐蚀性、密封性、高润滑不粘性、电绝缘性和良好的抗老化耐力，广泛应用于国防、航天、电子、电气、化工、机械、仪器、仪表、建筑、纺织、金属表面处理、制药、医疗、纺织、食品、冶金冶炼等领域。
生产PTFE树脂的方法通常有悬浮法和分散法，由此制得的树脂分别称为悬浮树脂和分散树脂。分散树脂是四氟乙烯(TFE)单体，在乳化剂的作用下分散成乳液状态进行的聚合。分散聚合涉及两个不同的阶段：反应初期的成核阶段，该过程形成一定数量的聚合反应位点或核心，随后进入生长阶段，该过程TFE单体在已形成的核表面上继续聚合反应，随着聚合进行乳胶颗粒尺寸逐渐增大，该阶段形成很少或不形成新核。高固含量分散液的制备一般都需要加入含氟表面活性剂(乳化剂)，以稳定分散液，防止聚合物颗粒凝聚析出。在以上过程中PTFE分散聚合成核阶段对树脂的一次粒子的形态、尺寸和数量起决定性作用，也将直接影响后续粒子在生长阶段的生长。合理地控制成核阶段的粒子结构，能够极大地提升树脂的性能，尤其是影响树脂的糊状挤出加工性能，而对于制备高压缩比PTFE分散树脂，合理控制成核时的粒子结构就显得更为重要了。因此乳化剂的选用至关重要，通常情况下，TFE分散聚合采用的乳化剂大都是全氟辛酸及其盐类等，例如全氟辛酸铵(全氟辛酸类物质以下简称PFOA)。研究表明PFOA全氟烷基链很难降解，因此会在环境和生物体中积聚，对环境和人体造成毒性危害，相关产品中已对PFOA提出限制要求。通过减少含氟聚合物生产过程中PFOA的使用和排放，可逐步降低PFOA导致的环境问题，但是无法从根本上消除PFOA的存在，因此寻找替代PFOA的环境友好乳化剂，才是解决PFOA问题 的最佳方案，近年来逐渐成为研究的热点。
一种方法是采用短链(通常碳链少于8个)全氟羧酸类乳化剂。2002年3M开发出全氟丁基磺酸(PFBS，简称C4)，该产品无持久的生物积累性，降解物无危害。杜邦开发出六碳产品(简称C6)，其降解物生物毒性要比PFOA类产品低很多，满足环境限制要求。但以上产品由于碳链短，达到的表面张力不够低，其分散效果远不及PFOA，因此在工业化生产固含量较高的分散液时，往往在聚合过程中出现大量凝聚物。
另一种方法就是在全氟表面活性剂分子中引入杂原子，通过研究表明，为了保证分散效果，用于TFE分散聚合的乳化剂至少需要部分氟化，如采用引入氢、氧、氮等更易降解的原子来向分子链引入“弱点”，以增加其可降解性。
在已公开的文献资料中，采用主链含氧原子的全/含氟醚羧酸或盐作为TFE分散聚合乳化剂有较广泛的研究。专利US3271341A、US3391099A等采用全氟醚羧酸/盐进行PTFE的分散聚合，但乳液稳定性还是不够理想，导致较多的凝聚物的产生。专利US 7671112、US 7776946采用含氟醚类羧酸/盐(如全氟2,6-二氧杂辛酸铵)作为乳化剂进行TFE的分散聚合，但该方法制得的分散液固含量仅为10wt％左右，并未进行更高固含量的聚合尝试。
专利US 7897682B2采用全氟表面活性剂(如全氟聚醚羧酸/盐)和碳氢表面活性剂复合使用进行PTFE的分散聚合，得到固含量满意、乳液稳定的分散液。但该方法虽然避免了PFOA类乳化剂的使用，但该方法主要用于开发可熔融加工PTFE聚合物如TFE-PPVE(PFA)、TFE-HFP(FEP),这类树脂主要通过熔融加工成型，因此其对分散液初级粒子结构的控制并无要求，故该分散体系并不适合应用于PTFE分散树脂的制备，尤其不适合应用于采用糊状挤出成型的高压缩比PTFE分散树脂的制备。
专利US 7705074采用分子量至少约800g/mol的氟聚醚酸/盐和链长不大于6个原子的短链含氟表面活性剂(如短链氟醚酸盐C2H5OCF(CF3)COONH4)复合使用，专利US 7932333则采用高分子量氟聚醚酸或盐和低分子量氟聚醚酸或盐复合使用，两种方法均可有效的进行TFE的分散聚合，和单独使用含氟表面活 性剂或低分子量氟聚醚酸或盐表面活性剂相比，该方法可以大大减少凝聚物的产生，但该方法制备的PTFE乳液固含量仍然达不到工业化生产的期望。
为了增加含氟表面活性剂的可降解性，很多研究者采用部分氟化的含氟羧酸盐或磺酸盐进行TFE的分散聚合。专利US 5789508、US 5688884、US 4380618采用通式为Rf-C2H4-SO3M(表示全氟化脂烃基，M表示阳离子)含氟脂烃基磺酸盐表面活性剂，但该乳化剂的端乙烷磺酸基上的H原子在成核阶段可能会引起链转移反应。专利US 5763552采用主链含亚烷基的含氟烷基羧酸盐(通式为Rf-(CH2)n-R′f-COOM)作为乳化剂，制备的高分子量PTFE均聚树脂表明该类乳化剂链转移效率低，对树脂分子量的影响可忽略不计，但该方法制备的PTFE树脂无法用于高压缩比挤出加工。
也有专利在PTFE粒子的成核阶段加入成核剂诱导TFE的成核反应，再在生长阶段加入非PFOA表面活性剂来保持分散液稳定。专利US 2012116017在聚合初期加入水溶性含烃化合物作为成核点，在聚合稳定期加入另一种含烃表面活性剂(如SDS)。该方法制得的分散体固含量仍有待提高，且该体系的分散稳定性仍然不够理想，导致在较高固含量时有较多的凝聚物生成。
由此可见虽然有关PFOA替代的研究非常多，但相对PFOA乳化剂而言，各种新型替代型分散剂或多或少都存在各种问题，如乳化剂用量多，但乳液仍然存在稳定性差、凝聚物多、固含量不高等问题。
发明内容
本发明的目的是提供一种PTFE分散树脂的制备方法，该方法可避免PFOA表面活性剂的使用，而且表面活性剂用量低，乳液稳定性好，由此制备的PTFE分散树脂具有核壳多层结构，挤出压力低、热稳定性好、机械性能优异，尤其适合采用高压缩比糊状挤出制备小口径管。
由于解决上述技术问题，本发明采用如下技术方案：
一种核壳结构PTFE分散树脂的制备方法，其特征在于：在聚合初期的成核阶段加入含氟烃类以及含氟改性单体作为成核剂，并加入少量的非PFOA表面活 性剂，来调控粒子核结构，并在生长阶段加入同种或不同种非PFOA表面活性剂来稳定分散液。
优选的，具体步骤如下：
(1)I阶段：向聚合釜中加入高纯水，依次加入含氟烃类成核剂、含氟改性单体、稳定剂、少量的非PFOA表面活性剂，置换合格后通入TFE单体至一定压力，升温至反应温度，在搅拌作用下分散一定时间后，加入引发剂开始聚合反应，当反应进行到一定程度时，将聚合釜中的未反应完的单体及改性单体放空置换，尽可能最大程度的除去改性单体，完成成核阶段的反应；
(2)II阶段：加入TFE单体至一定压力进入生长阶段的均聚反应，并在该阶段加入同种或不同种非PFOA表面活性剂来稳定分散液，并通过补加TFE保存反应压力恒定；
(3)III阶段：加入链转移剂或者同时加入改性单体继续反应直至反应结束；
(4)冷却分散液除去稳定剂后后处理得到PTFE分散树脂。
分散聚合成核阶段对整个反应时至关重要的，在成核阶段成核剂的加入可以诱导TFE单体的成核反应，在含氟烃类成核剂的协同分散作用下，可以大大降低对表面活性剂的要求，可以减少表面活性剂的用量，并且可以很好的控制成核阶段粒子的粒径及分布。本发明在含氟烃类和表面活性剂的协同作用下，表面活性剂的亲油部分可以有效的结合含氟烃类，而其亲水部分可以保证亲油部分及成核点在水介质中均匀分散并稳定，而含氟烃类作为亲油性成核点可诱导TFE的成核反应。因此在含氟烃类的作用下，TFE分散聚合对表面活性剂的要求就大大降低。
优选的，成核剂为含氟烯烃类物质，可列举的有CH 3CClF 2、CH 3CCl 2F，CF 3CF 2CCl 2H、CF 2ClCF 2CFHCl等氢氯氟烃；CF 2ClCFCl 2、CF 2ClCFClCF 2CF 3、CF 3CCFClCFClCF 3等氯氟烷烃；全氟环丁烷、全氟丁烷、全氟戊烷、全氟己烷等全氟烃，其中优选无链转移效果的全氟烷烃。
优选的，成核剂用量为反应介质的0.01-2wt％，优选为0.05-1.5wt％，更优 选为0.1-1wt％。
优选的，非PFOA类表面活性剂为氟醚酸或盐、氟醚磺酸或盐、氟聚醚羧酸或盐、氟聚醚磺酸或盐、氢氟烷基羧酸或盐、氢氟烷基磺酸或盐、含烃表面活性剂的一种或混合物。本申请所表达的含烃是指烃类表面活性剂中碳链上的氢原子可为氟或氯取代，而优选氢未取代的烃类表面活性剂，可列举的有十二烷基硫酸钠(SDS)、辛基磺酸钠(SOS)、十二烷基苯磺酸钠(SDBS)等。
优选的，表面活性剂分两次加入到聚合釜，分别在成核阶段和生长阶段加入，两次加入的总量控制在反应介质的0.05-0.6wt％，优选0.06-0.3wt％，更优选0.08-0.15wt％，其中，成核阶段的加入量为加入总量的5-50wt％，，优选10-35wt％，更优选15-25wt％。
优选的，改性单体为含氟乙烯基单体，可列举的有PPVE、PEVE、PMVE、CTFE、HFP、VDF、PFBE等。
优选的，核改性单体为全氟烷基乙烯基醚，优选为PPVE，其含量为分散树脂的0.02-0.5wt％，优选为0.03-0.3wt％，更优选为0.05-0.2wt％；壳层改性单体为氟化烯烃，优选为HFP和CTFE，氟化烯烃的含量为PTFE分散树脂的0-0.5wt％，优选为0-0.4wt％，更优选为0-0.3wt％。
优选的，I阶段为反应进行到TFE总投料量的5-20wt％，II阶段为反应进行到TFE总投料量的80-95wt％。
优选的，核壳结构PTFE分散树脂具有核-壳-壳的三层结构，其中核含氟烯烃的改性的PTFE，中层壳为高分子量PTFE均聚物，外层壳为较低分子量的PTFE均聚物或含氟烯烃改性的PTFE。
优选的，聚合引发剂为本领域公知的，本发明优选复配引发剂体系，例如过硫酸铵和过氧化丁二酸的混合体系。
优选的，引发剂用在水介质中的含量为50-150ppm，其中过硫酸铵和过氧化丁二酸的质量比为0.03-0.1。
优选的，稳定剂为石蜡，用量为反应介质的4-5wt％
优选的，链转移剂为氢气、低分子醇类、烷烃，低分子醇类包括甲醇、乙 醇，烷烃包括甲烷、乙烷、丙烷，优选为甲醇。
优选的，III阶段中，链转移剂的用量为TFE消耗量的0.05-1wt％。
优选的，反应温度为10-100℃，优选为40-90℃，更优选为60-80℃。
优选的，反应压力为0.5-3Mpa，优选0.7-2.5Mpa，更优选为1.0-2.0Mpa。
优选的，分散液的固含量为10-60wt％，优选20-55wt％，最优选为30-50wt％。
由于采用上述技术方案，本发明具有以下有益效果：
本发明可避免PFOA表面活性剂的使用，而且表面活性剂用量低，乳液稳定性好，由此制备的PTFE分散树脂具有核壳多层结构，挤出压力低、热稳定性好、机械性能优异，尤其适合采用高压缩比糊状挤出制备小口径管。本发明在含氟烃类和表面活性剂的协同作用下，表面活性剂的亲油部分可以有效的结合含氟烃类，而其亲水部分可以保证亲油部分及成核点在水介质中均匀分散并稳定，而含氟烃类作为亲油性成核点可诱导TFE的成核反应。因此在含氟烃类的作用下，TFE分散聚合对表面活性剂的要求就大大降低。
具体实施方式
以下结合具体实施例，进一步阐明本发明。
实施例1
向置换合格的1L不锈钢立式反应釜(锚式桨)中，分别加入6.5L的去离子水，30g石蜡，2g SDS，10g八氟环丁烷，8g PPVE，开搅拌至85rpm，反应釜升温至70℃，加入TFE单体至2.0MPa，搅拌分散10min。然后加入20g溶有0.03g过硫酸铵和0.6g过氧化丁二酸的引发剂水溶液开始反应。通过补加TFE单体保持聚合釜压力为2.0MPa。当反应进行到TFE的消耗量为250g时，停止搅拌，将聚合釜内压力泄压至0.05MPa，完成成核阶段的反应。开搅拌，继续通入TFE单体至反应压力2.0Mpa，并同时加入含20ml含有7g SDS的水溶液，通过补加TFE单体保持聚合压力稳定在2.0Mpa，当反应进行到TFE消耗量为2400g时，向聚合釜加入6g PPVE以及1g甲醇继续反应，直至TFE单体的消耗量达到3000g，反应结束，降温停搅拌。将得到的TFE共聚物的乳化分散液冷却，除却上清的 石蜡，分散液经滤袋过滤除去凝聚物约3g。将分散液用纯水稀释到浓度为15重量％，温度调整到30℃剧烈搅拌，得到湿微粉，过振动筛，然后，在150℃下将湿粉末干燥20h。
实施例2
向置换合格的1L不锈钢立式反应釜(锚式桨)中，分别加入6.5L的去离子水，30g石蜡，1.5g SDBS，20g八氟环丁烷，5g PPVE，开搅拌至85rpm，反应釜升温至70℃，加入TFE单体至1.5MPa，搅拌分散10min。然后加入20g溶有0.03g过硫酸铵和0.6g过氧化丁二酸的引发剂水溶液开始反应。通过补加TFE单体保持聚合釜压力为1.8MPa。当反应进行到TFE的消耗量为600g时，停止搅拌，将聚合釜内压力泄压至0.05MPa，完成成核阶段的反应。开搅拌，继续通入TFE单体至反应压力1.8Mpa，并同时加入含20ml含有6.5g SDBS的水溶液，通过补加TFE单体保持聚合压力稳定在1.5Mpa，当反应进行到TFE消耗量为2600g时，向聚合釜加入2g甲醇继续反应，直至TFE单体的消耗量达到3000g，反应结束，降温停搅拌。将得到的TFE共聚物的乳化分散液冷却，除却上清的石蜡，分散液经滤袋过滤除去凝聚物约2.5g。将分散液用纯水稀释到浓度为15重量％，温度调整到30℃剧烈搅拌，得到湿微粉，过振动筛，然后，在150℃下将湿粉末干燥20h。
实施例3
向置换合格的1L不锈钢立式反应釜(锚式桨)中，分别加入6.5L的去离子水，30g石蜡，1g SDS，25g八氟环丁烷，8g PPVE，开搅拌至85rpm，反应釜升温至70℃，加入TFE单体至2.0MPa，搅拌分散10min。然后加入20g溶有0.03g过硫酸铵和0.6g过氧化丁二酸的引发剂水溶液开始反应。通过补加TFE单体保持聚合釜压力为1.5MPa。当反应进行到TFE的消耗量为400g时，停止搅拌，将聚合釜内压力泄压至0.05MPa，完成成核阶段的反应。开搅拌，继续通入TFE单体至反应压力1.5Mpa，并同时加入含20ml含有6g SDS的水溶液，通过补加TFE单体保持聚合压力稳定在1.5Mpa，当反应进行到TFE消耗量为2700g时，向聚合釜加入4g HFP以及1g甲醇继续反应，直至TFE单体的消耗量达到3000g，反 应结束，降温停搅拌。将得到的TFE共聚物的乳化分散液冷却，除却上清的石蜡，分散液经滤袋过滤除去凝聚物约4.8g。将分散液用纯水稀释到浓度为15重量％，温度调整到30℃剧烈搅拌，得到湿微粉，过振动筛，然后，在150℃下将湿粉末干燥20h。
比较例1
向置换合格的1L不锈钢立式反应釜(锚式桨)中，分别加入6.5L的去离子水，30g石蜡，2g PFOA，8g PPVE，开搅拌至85rpm，反应釜升温至70℃，加入TFE单体至2.0MPa，搅拌分散10min。然后加入20g溶有0.03g过硫酸铵和0.6g过氧化丁二酸的引发剂水溶液开始反应。通过补加TFE单体保持聚合釜压力为2.0MPa。当反应进行到TFE的消耗量为250g时，停止搅拌，将聚合釜内压力泄压至0.05MPa，完成成核阶段的反应。开搅拌，继续通入TFE单体至反应压力2.0Mpa，并同时加入含20ml含有7g PFOA的水溶液，通过补加TFE单体保持聚合压力稳定在2.0Mpa，当反应进行到TFE消耗量为2400g时，向聚合釜加入6g PPVE以及1g甲醇继续反应，直至TFE单体的消耗量达到3000g，反应结束，降温停搅拌。将得到的TFE共聚物的乳化分散液冷却，除却上清的石蜡，分散液经滤袋过滤除去凝聚物约1.7g。将分散液用纯水稀释到浓度为15重量％，温度调整到30℃剧烈搅拌，得到湿微粉，过振动筛，然后，在150℃下将湿粉末干燥20h。
比较例2
同实施例1相似，唯一的区别是不加八氟环丁烷成核剂，得到的分散液经滤袋过滤除去凝聚物约1524g。
将上述实施例1-3和对比例1-2得到的PTFE分散液的相关数据见表1，经凝聚后所得树脂的结构及性能测试见表2。
具体测试方法如下：
本发明所述测试方法如下:
树脂的结构性能主要通过固含量、共聚物中改性单体的单元含量、平均一次粒径、表观密度、标准比重。树脂的加工性能通过糊状挤出压力、拉伸强度 以及断裂伸长率来表征。
(1)固含量
在培养皿上取10g的改性PTFE水性分散体，在150℃加热约3小时候进行称量，根据所称得的固体成分的重量，计算出固体成分的重量与改性PTFE水性分散体重量的比例作为聚合物的固含量。
(2)平均一次粒径
采用马尔文激光粒度分析分布仪器检测。
(3)共聚物中改性单体含量
将高压缩比PTFE分散树脂粉末挤压成型，制得薄膜盘，测定薄膜盘的红外吸光度，由此求得含量。如果改性单体时三氟氯乙烯(CTFE)，用957cm -1的吸光度/2360cm -1的吸光度的比值乘以0.58求得。如果改性单体是全氟丙基乙烯基醚(PPVE)，将995cm -1的吸光度/935cm -1的吸光度的比值乘以0.14而求得。如果改性单体时六氟丙烯(HFP)，用982cm -1的吸光度值/935cm -1的吸光度的比值乘以0.3而求得。
(4)标准相对比重(SSG)
称取12.0g树脂，在内径为28.6mm的圆筒型模具内以34.5MPa的压力保持2分钟。再把它放入290℃炉子内以120℃/hr升温，在380℃状态下保持30分钟，然后以60℃/h降温，在294℃下保持24分钟。接着，在23℃的干燥器内保持12小时，然后测定23℃下的成形物与水的比重值，以此为标准比重。在改性单体含量相同的条件下，标准比重的值越小表明分子量越大。
(5)糊状挤出压力
在玻璃瓶中混合226.8g的聚合物粉末和43.2g的烃类润滑剂，室温下(25℃)进行8小时以上的熟化处理。然后，将上述混合物填入内径39.4mm的不锈钢模具中，向插入模具的活塞施加55kg的荷重，保持2分钟。将上述混合物从该模具中取出，装入附于模具(内径40.3mm)的冲模(冲模角20度，模孔直径0.27mm)，以冲头速度20mm/分钟、模温40℃挤出上述混合物，获得带状物。这里，RR是指挤压机模具的截面积(Ac)/模的截面积(Ad)的比值，即换算成RR＝Ac/Ad。将 变成平衡状态的部分的挤压力除以模具截面积而求得的值作为挤压后期的压力，求得糊状挤出压力(MPa)。
(6)拉伸强度
使用万能精密材料试验机，在室温以200mm/min的拉伸速度对拉伸样进行拉伸，测定最大拉伸强度。另外，测定用成型体式如下制得的：将50.00g改性PTFE粉末和10.25g挤出助剂在玻璃瓶中混合，于室温熟化一小时，在压力为2MPa的条件下于室温将所得混合物填充于挤出机的机筒内并保持1min，立刻向插入机筒的柱塞施加5.7MPa的负荷，以20mm/mim的柱塞速度从模孔挤出(RR＝400)原料混合物，进行成型，得到直径0.63mm，长为80mm的圆柱状成型体，对成型体生料进行烧结后得到拉伸样条。
(7)断裂伸长率
断裂伸长率样条同拉伸强度测试样条，使用拉伸试验机进行测试，将夹头间距调整为40mm，上下夹住样品，使上夹头以速度20mm/min进行上升，在样品断裂的时刻停止。通过此时夹头的位置进行计算断裂伸长率。
断裂伸长率＝(断裂时夹头的距离/40mm)×100％
表1
Figure PCTCN2021076001-appb-000001
表2
Figure PCTCN2021076001-appb-000002
Figure PCTCN2021076001-appb-000003
*挤出压力为2000:1
由表1和表2可以看出，采用本发明分散体系制备的PTFE分散树脂，和采用PFOA乳化剂制备的PTFE分散树脂，其分散液及树脂性能都比较接近。
以上仅为本发明的具体实施例，但本发明的技术特征并不局限于此。任何以本发明为基础，为解决基本相同的技术问题，实现基本相同的技术效果，所作出地简单变化、等同替换或者修饰等，皆涵盖于本发明的保护范围之中。

Claims (10)

  1. 一种核壳结构PTFE分散树脂的制备方法，其特征在于：在聚合初期的成核阶段加入含氟烃类以及含氟改性单体作为成核剂，并加入少量的非PFOA表面活性剂，来调控粒子核结构，并在生长阶段加入同种或不同种非PFOA表面活性剂来稳定分散液。
  2. 根据权利要求1所述一种核壳结构PTFE分散树脂的制备方法，其特征在于，包括如下步骤：
    (1)I阶段：向聚合釜中加入高纯水，依次加入含氟烃类成核剂、含氟改性单体、稳定剂、少量的非PFOA表面活性剂，置换合格后通入TFE单体，升温至反应温度，在搅拌作用下分散，加入引发剂开始聚合反应，将聚合釜中的未反应完的单体及改性单体放空置换，除去改性单体，完成成核阶段的反应；
    (2)II阶段：加入TFE单体至一定压力进入生长阶段的均聚反应，并在该阶段加入同种或不同种非PFOA表面活性剂来稳定分散液，并通过补加TFE保存反应压力恒定；
    (3)III阶段：加入链转移剂或者同时加入改性单体继续反应直至反应结束；
    (4)冷却分散液除去稳定剂后后处理得到PTFE分散树脂。
  3. 根据权利要求1所述一种核壳结构PTFE分散树脂的制备方法，其特征在于：所述成核剂为含氟烯烃类物质。
  4. 根据权利要求1所述一种核壳结构PTFE分散树脂的制备方法，其特征在于：所述成核剂用量为反应介质的0.01-2wt％。
  5. 根据权利要求1所述一种核壳结构PTFE分散树脂的制备方法，其特征在于：所述非PFOA类表面活性剂为氟醚酸或盐、氟醚磺酸或盐、氟聚醚羧酸或盐、氟聚醚磺酸或盐、氢氟烷基羧酸或盐、氢氟烷基磺酸或盐、含烃表面活性 剂的一种或混合物。
  6. 根据权利要求5所述一种核壳结构PTFE分散树脂的制备方法，其特征在于：所述表面活性剂分两次加入到聚合釜，分别在成核阶段和生长阶段加入，两次加入的总量控制在反应介质的0.05-0.6wt％，其中，成核阶段的加入量为加入总量的5-50wt％。
  7. 根据权利要求1所述一种核壳结构PTFE分散树脂的制备方法，其特征在于：所述改性单体为含氟乙烯基单体。
  8. 根据权利要求7所述一种核壳结构PTFE分散树脂的制备方法，其特征在于：所述核改性单体为全氟烷基乙烯基醚，其含量为分散树脂的0.02-0.5wt％；壳层改性单体为氟化烯烃，氟化烯烃的含量为PTFE分散树脂的0-0.5wt％。
  9. 根据权利要求1所述一种核壳结构PTFE分散树脂的制备方法，其特征在于：所述I阶段为反应进行到TFE总投料量的5-20wt％，II阶段为反应进行到TFE总投料量的80-95wt％。
  10. 根据权利要求1所述一种核壳结构PTFE分散树脂的制备方法，其特征在于：所述核壳结构PTFE分散树脂具有核-壳-壳的三层结构，其中核含氟烯烃的改性的PTFE，中层壳为高分子量PTFE均聚物，外层壳为较低分子量的PTFE均聚物或含氟烯烃改性的PTFE。
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4038230A (en) * 1970-11-19 1977-07-26 Allied Chemical Corporation Aqueous dispersion of particulate spheroidal polytetrafluoroethylene
CN102264775A (zh) * 2008-12-23 2011-11-30 杜邦公司 使用原位制备的氟化离聚物的分散颗粒通过含水聚合制备含氟聚合物
CN103201301A (zh) * 2010-11-09 2013-07-10 纳幕尔杜邦公司 含氟单体的含水聚合反应中的成核作用
CN109776821A (zh) * 2018-12-18 2019-05-21 浙江巨化技术中心有限公司 一种改性ptfe分散树脂及其制备方法

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2663275C (en) * 2007-08-03 2015-04-28 Charles A. Glew Compositions for compounding, extrusion and melt processing of foamable and cellular fluoropolymers
US20090270573A1 (en) * 2008-04-29 2009-10-29 Christopher John Bish Process for coagulating perfluoroelastomers
US8178592B2 (en) * 2009-05-15 2012-05-15 E.I. Du Pont De Nemours And Company Foamable fluoropolymer composition
US10676555B2 (en) * 2015-02-12 2020-06-09 3M Innovative Properties Company Tetrafluoroethylene copolymers having sulfonyl groups
CN106279491A (zh) * 2015-05-27 2017-01-04 陈英 可熔性聚四氟乙烯的制备方法
CN109563206A (zh) * 2016-08-17 2019-04-02 3M创新有限公司 四氟乙烯和全氟化烯丙基醚共聚物

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4038230A (en) * 1970-11-19 1977-07-26 Allied Chemical Corporation Aqueous dispersion of particulate spheroidal polytetrafluoroethylene
CN102264775A (zh) * 2008-12-23 2011-11-30 杜邦公司 使用原位制备的氟化离聚物的分散颗粒通过含水聚合制备含氟聚合物
CN103201301A (zh) * 2010-11-09 2013-07-10 纳幕尔杜邦公司 含氟单体的含水聚合反应中的成核作用
CN109776821A (zh) * 2018-12-18 2019-05-21 浙江巨化技术中心有限公司 一种改性ptfe分散树脂及其制备方法

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
CHEN MINGHUA, KOU KAICHANG,WANG ZHICHAO,ZHANG DONGNA: "Development on Core-shell Polymers With Polytetrafluoroethylene Core", ENGINEERING PLASTICS APPLICATION, no. 3, 10 March 2010 (2010-03-10), pages 75 - 78, XP055923136 *
ZHANG LUQING, ZHANG YA-BIN,WANG REN-ZHEN,ZHANG SHU-XIANG: "The Studies of Emulsion Polymerization in Fluoropolymer Systhesise", SHANDONG HUAGONG = SHANDONG CHEMICAL INDUSTRY., SHANDONG SHENG HUAGONG XINXI ZHONGXIN, CN, vol. 39, no. 4, 15 April 2010 (2010-04-15), CN , pages 22 - 25, XP055923134, ISSN: 1008-021X, DOI: 10.19319/j.cnki.issn.1008-021x.2010.04.007 *

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