阅读说明：本技术 一种用于塑料管道复合钙锌稳定剂的制备方法 (Preparation method of composite calcium-zinc stabilizer for plastic pipeline ) 是由 刘琴 于 2019-11-17 设计创作，主要内容包括：本发明涉及塑料管道稳定剂技术领域,公开了一种用于塑料管道复合钙锌稳定剂的制备方法。包括以下步骤：1)按重量份称取原料：硬脂酸钙15-30份,硬脂酸锌15-30份,改性蒙脱石10-15份,硬脂酸丁酯润滑剂3-5份,抗氧剂0.5-1份,紫外线吸收剂0.5-1份；2)将硬脂酸钙、硬脂酸钙和硬质酸丁酯加入高速搅拌机中在50-60℃下搅拌均匀,得预混料；3)将改性蒙脱石、抗氧剂和紫外线吸收剂加入预混料中在45-50℃下搅拌均匀,即得。本发明制备的复合钙锌热稳定剂绿色环保,能够显著提高聚氯乙烯管道的耐热性能。(The invention relates to the technical field of plastic pipeline stabilizers, and discloses a preparation method of a composite calcium-zinc stabilizer for a plastic pipeline. The method comprises the following steps: 1) weighing the following raw materials in parts by weight: 15-30 parts of calcium stearate, 15-30 parts of zinc stearate, 10-15 parts of modified montmorillonite, 3-5 parts of butyl stearate lubricant, 0.5-1 part of antioxidant and 0.5-1 part of ultraviolet absorbent; 2) adding calcium stearate, calcium stearate and butyl stearate into a high-speed stirrer, and uniformly stirring at 50-60 ℃ to obtain a premix; 3) adding the modified montmorillonite, antioxidant and ultraviolet absorbent into the premix, and stirring at 45-50 deg.C. The composite calcium-zinc heat stabilizer prepared by the invention is environment-friendly, and can obviously improve the heat resistance of the polyvinyl chloride pipeline.)

1. The preparation method of the composite calcium-zinc stabilizer for the plastic pipeline is characterized by comprising the following steps of:

1) weighing the following raw materials in parts by weight: 15-30 parts of calcium stearate, 15-30 parts of zinc stearate, 10-15 parts of modified montmorillonite, 3-5 parts of butyl stearate lubricant, 0.5-1 part of antioxidant and 0.5-1 part of ultraviolet absorbent;

2) adding calcium stearate, calcium stearate and butyl stearate into a high-speed stirrer, and uniformly stirring at 50-60 ℃ to obtain a premix;

3) adding the modified montmorillonite, antioxidant and ultraviolet absorbent into the premix, and stirring at 45-50 deg.C.

2. The method for preparing the composite calcium zinc stabilizer for plastic pipelines as claimed in claim 1, wherein the stirring speed of the high-speed stirrer in the step 2) is 1000-1200r/min, and the stirring time is 20-40 min.

3. The method for preparing the composite calcium zinc stabilizer for plastic pipelines as claimed in claim 1, wherein the stirring speed of the high-speed stirrer in the step 3) is 800-900r/min, and the stirring time is 1-3 h.

4. The preparation method of the composite calcium-zinc stabilizer for the plastic pipeline as claimed in claim 1, wherein the preparation method of the modified montmorillonite comprises the following steps: adding montmorillonite and sodium tripolyphosphate into deionized water, stirring uniformly to obtain suspension, adding amino quaternary ammonium salt into the suspension, heating in water bath to 50-60 deg.C, stirring for reaction for 2-4h, centrifuging, filtering, washing, and drying in oven to obtain montmorillonite-loaded amino quaternary ammonium salt powder; adding an aminosilane coupling agent into an ethanol water solution, uniformly stirring and dispersing, adjusting the pH value to 5-6, heating in a water bath to 45-55 ℃, stirring and hydrolyzing for 1-2h to obtain a silane coupling agent solution, adding montmorillonite-loaded amino quaternary ammonium salt powder into the silane coupling agent solution, stirring and reacting for 3-5h, centrifuging, filtering, washing, and then transferring into an oven to dry for 2-5h at the temperature of 45-50 ℃ to obtain the modified montmorillonite.

5. The preparation method of the composite calcium zinc stabilizer for the plastic pipeline as claimed in claim 4, wherein the mass ratio of montmorillonite to amino quaternary ammonium salt is 1: 2-3.

6. The preparation method of the composite calcium zinc stabilizer for the plastic pipeline as claimed in claim 4, wherein the mass ratio of the montmorillonite-loaded amino quaternary ammonium salt powder to the aminosilane coupling agent is 1: 1-2.

7. The preparation method of the composite calcium zinc stabilizer for plastic pipes as claimed in claim 4, wherein the preparation method of the amino quaternary ammonium salt comprises the following steps: adding hyperbranched polyethyleneimine into an ethanol water solution, stirring and dissolving to obtain a hyperbranched polyethyleneimine solution, adding epichlorohydrin into the hyperbranched polyethyleneimine solution, heating in a water bath to 45-50 ℃, carrying out condensation reflux reaction for 3-5h under a stirring condition, removing the ethanol water solution through rotary evaporation and concentration, transferring into an oven to dry to obtain an intermediate product, adding the intermediate product and dimethylethanolamine into deionized water, heating in a water bath to 55-60 ℃, carrying out heat preservation reaction for 10-15h, carrying out rotary evaporation and concentration, and transferring into the oven to dry to obtain the amino quaternary ammonium salt.

8. The method as claimed in claim 7, wherein the molecular weight of the hyperbranched polyethyleneimine is 10000-20000 Da.

9. The preparation method of the composite calcium-zinc stabilizer for plastic pipes according to claim 7, wherein the mass ratio of the hyperbranched polyethyleneimine to the epichlorohydrin is 1: 0.1-0.3.

10. The preparation method of the composite calcium-zinc stabilizer for plastic pipes as claimed in claim 7, wherein the mass ratio of the intermediate product to dimethylethanolamine is 1: 0.2-0.4.

Technical Field

The invention relates to the technical field of plastic pipeline stabilizers, in particular to a preparation method of a composite calcium-zinc stabilizer for a plastic pipeline.

Background

The plastic pipe is a product with large consumption in plastic products, polyvinyl chloride (PVC) is used as a general plastic, and has the characteristics of flame retardancy, wear resistance, excellent electrical insulation, high mechanical strength and the like, and the yield of the hard PVC pipe accounts for more than 55% of the yield of the whole plastic pipe. The cable has the advantages of good strength, acid and alkali corrosion resistance, good insulativity, good fluid conveying performance, convenient pipe orifice connection, long service life, convenient secondary processing, sufficient raw material source, low price and the like, and is widely applied to the fields of chemical production, aquaculture, mine ventilation, human and animal water diversion engineering, drainage facilities, cable threading pipes and the like. However, polyvinyl chloride itself has drawbacks and disadvantages such as poor thermal stability, unstable plasticization, easy migration, high melt apparent viscosity in preparing hard products, poor processing flow properties, brittleness of hard products, poor impact resistance, and the like. Among the above drawbacks, thermal stability is a fatal weak point thereof. The chlorine atoms on the branched chains of the polyvinyl chloride are extremely unstable due to the unsaturated bonds, the branching points, the initiator residues and the like in the molecular structure of the polyvinyl chloride, so that the pure PVC resin can be slightly decomposed at 90 ℃, is accelerated to be decomposed at 120 ℃, is accelerated to be decomposed at 140 ℃, can be changed into coke after being heated for a long time at the temperature of more than 140 ℃, and greatly limits the development of high value-added PVC products and the application of the high value-added PVC products in wider fields. Therefore, the improvement of the thermal stability of the PVC plastic pipeline has important value and significance.

Chinese patent publication No. CN102329467 discloses a polyvinyl chloride pipeline and a preparation method thereof, the polyvinyl chloride pipeline comprises the following raw materials by weight: the heat-resistant polyvinyl chloride flame-retardant plastic comprises polyvinyl chloride resin, a heat stabilizer, a processing aid, an impact modifier, a flame-retardant smoke-eliminating modifier, a lubricant, pigment and calcium carbonate. Chinese patent publication No. CN103012998 discloses a chlorinated polyvinyl chloride pipeline, which comprises the following components: chlorinated polyvinyl chloride resin, a heat-resistant modifier NR-188, a calcium-zinc stabilizer, a filler, chlorinated polyethylene, paraffin, stearic acid and a pigment; also, for example, chinese patent publication No. CN110079030 discloses an environment-friendly pollution-free industrial chlorinated polyvinyl chloride pipe, and a preparation method and application thereof, which is prepared from the following raw materials in parts by mass: PVC-C resin, an environment-friendly nontoxic calcium-zinc stabilizer, an external lubricant, an internal lubricant, a processing modification aid, shock resistance, a filler, an antioxidant and a pigment, wherein the used polyvinyl chloride pipe stabilizers are all environment-friendly nontoxic calcium-zinc heat stabilizers, but the improvement of the heat resistance of the calcium-zinc heat stabilizers on polyvinyl chloride is limited.

Disclosure of Invention

The invention provides a preparation method of a composite calcium-zinc stabilizer for a plastic pipeline, aiming at overcoming the problems of the prior art. The composite calcium-zinc heat stabilizer prepared by the invention is environment-friendly, and can obviously improve the heat resistance of the polyvinyl chloride pipeline.

In order to achieve the purpose, the invention adopts the following technical scheme: a preparation method of a composite calcium-zinc stabilizer for plastic pipelines comprises the following steps:

1) weighing the following raw materials in parts by weight: 15-30 parts of calcium stearate, 15-30 parts of zinc stearate, 10-15 parts of modified montmorillonite, 3-5 parts of butyl stearate lubricant, 0.5-1 part of antioxidant and 0.5-1 part of ultraviolet absorbent;

2) adding calcium stearate, calcium stearate and butyl stearate into a high-speed stirrer, and uniformly stirring at 50-60 ℃ to obtain a premix;

3) adding the modified montmorillonite, antioxidant and ultraviolet absorbent into the premix, and stirring at 45-50 deg.C.

The invention uses calcium stearate and zinc stearate as main heat stabilizers and uses modified montmorillonite as an auxiliary heat stabilizer. The action mechanism of the main heat stabilizer in the polyvinyl chloride pipe is as follows: heating the polyvinyl chloride pipe to release HCl from the polyvinyl chloride and generate linear conjugated polyene, wherein the linear conjugated polyene is cyclized to generate non-substituted benzene aromatic hydrocarbon; on the other hand, crosslinking between conjugated polyene chains generates crosslinked polyene, and then cyclization is carried out to generate the substituted aromatic hydrocarbon compound. Therefore, there are two reactions in the thermal degradation of polyvinyl chloride: the first is intramolecular cyclization reaction, and the second is intermolecular crosslinking reaction. The higher the ratio of intramolecular cyclization reaction is, the more aromatic compounds released in the degradation process of the polyvinyl chloride are, and the higher the degradation degree is; conversely, the higher the proportion of intermolecular crosslinking reaction, the less aromatic compounds are released during the degradation of polyvinyl chloride, and the lower the degree of degradation. ZnCl is generated by the main stabilizer of calcium stearate and zinc stearate in the process of PVC pipe heated₂ZnCl formed₂Capable of cross-linking polyvinyl chloride moleculesAnd the aromatic hydrocarbon compound generated by the intramolecular cyclization reaction is inhibited, so that the heat resistance of the PVC pipe is improved. The action mechanism of the auxiliary heat stabilizer is as follows: polyvinyl chloride releases HCl after being heated on a polyvinyl chloride pipe, generated hydrogen chloride further generates catalytic action on thermal degradation of PVC resin, the degradation reaction of polyvinyl chloride is accelerated, the auxiliary stabilizer montmorillonite is a clay mineral with a three-layer sheet structure consisting of silicon-oxygen tetrahedrons, the adsorption performance is extremely strong, montmorillonite can timely adsorb the generated HCl after the polyvinyl chloride pipe is heated and releases HCl, so that the hydrogen chloride is prevented from generating catalysis on the thermal degradation of the PVC resin, and the thermal degradation degree of the polyethylene is reduced. In addition, the antioxidant is added into the PVC pipe stabilizer disclosed by the invention, so that the thermal oxidation resistance of the PVC pipe can be improved, and the ultraviolet absorber is added so that the photooxidation resistance of the PVC pipe can be improved. The compounded polyvinyl chloride pipe stabilizer can obviously improve the heat resistance and the oxidation resistance of polyvinyl chloride pipes.

Preferably, the stirring speed of the high-speed stirrer in the step 2) is 1000-1200r/min, and the stirring time is 20-40 min.

Preferably, the stirring speed of the high-speed stirrer in the step 3) is 800-.

Preferably, the preparation method of the modified montmorillonite comprises the following steps: adding montmorillonite and sodium tripolyphosphate into deionized water, stirring uniformly to obtain suspension, adding amino quaternary ammonium salt into the suspension, heating in water bath to 50-60 deg.C, stirring for reaction for 2-4h, centrifuging, filtering, washing, and drying in oven to obtain montmorillonite-loaded amino quaternary ammonium salt powder; adding an aminosilane coupling agent into an ethanol water solution, uniformly stirring and dispersing, adjusting the pH value to 5-6, heating in a water bath to 45-55 ℃, stirring and hydrolyzing for 1-2h to obtain a silane coupling agent solution, adding montmorillonite-loaded amino quaternary ammonium salt powder into the silane coupling agent solution, stirring and reacting for 3-5h, centrifuging, filtering, washing, and then transferring into an oven to dry for 2-5h at the temperature of 45-50 ℃ to obtain the modified montmorillonite.

The montmorillonite is used as an auxiliary heat stabilizer of the PVC pipe, and the PVC pipe is polymerized after being heatedThe generated HCl can be adsorbed by montmorillonite in time after HCl is released by chloroethylene, so that the catalytic action of HCl on the thermal degradation of PVC resin is avoided. Meanwhile, the first problem of adding montmorillonite is that polyvinyl chloride generates a large amount of HCl due to thermal degradation, the montmorillonite absorbs HCl to quickly reach a saturated state and reach adsorption balance, so that the montmorillonite loses the adsorption property on the HCl, and the montmorillonite is further modified to solve the problem: the montmorillonite unit cell has an excess negative charge, and in order to maintain the charge balance, the montmorillonite layer has adsorbed Na in the same amount⁺、Ca²⁺、K⁺、Mg²⁺Plasma ions, but the adsorption force among the ions is relatively weak, the cations among the layers are easily replaced by the cations with strong acting force, and the invention replaces Na among montmorillonite layers by using polyamino quaternary ammonium salt cation compounds⁺、Ca²⁺、K⁺、Mg²⁺Ions are subjected to plasma hydration, so that the polyamino quaternary ammonium salt is introduced into the interlayer of the montmorillonite, and HCl adsorbed in the interlayer of the montmorillonite is consumed by utilizing the reaction between the amino group on the polyamino quaternary ammonium salt and HCl generated by thermal degradation of the PVC pipe, so that the problem that the HCl is easily adsorbed and saturated by the montmorillonite is solved, and the utilization rate of the montmorillonite is improved. The montmorillonite added in the PVC pipe material has the second problem that the montmorillonite is easy to agglomerate and disperse unevenly in the PVC pipe material, so that the adsorption performance of HCl generated in polyvinyl chloride by the montmorillonite is reduced. On the other hand, the silane coupling agent containing amino is specifically used, and the amino attached to the silane coupling agent can react with HCl, so that HCl generated by PVC thermal degradation is further consumed, and HCl is prevented from further generating a catalytic effect on the PVC resin thermal degradation.

Preferably, the mass ratio of the montmorillonite to the amino quaternary ammonium salt is 1: 2-3.

Preferably, the mass ratio of the montmorillonite-supported amino quaternary ammonium salt powder to the aminosilane coupling agent is 1: 1-2.

Preferably, the preparation method of the amino quaternary ammonium salt comprises the following steps: adding hyperbranched polyethyleneimine into an ethanol water solution, stirring and dissolving to obtain a hyperbranched polyethyleneimine solution, adding epichlorohydrin into the hyperbranched polyethyleneimine solution, heating in a water bath to 45-50 ℃, carrying out condensation reflux reaction for 3-5h under a stirring condition, removing the ethanol water solution through rotary evaporation and concentration, drying in an oven to obtain an intermediate product, adding the intermediate product and dimethylethanolamine into deionized water, heating in a water bath to 55-60 ℃, carrying out heat preservation reaction for 10-15h, carrying out rotary evaporation and concentration, and drying in the oven to obtain the amino quaternary ammonium salt.

The preparation method of the amino quaternary ammonium salt comprises the steps of firstly using partial amino on hyperbranched polyethyleneimine to perform ring-opening reaction with epoxy groups on epichlorohydrin, grafting chlorine groups on epichlorohydrin to hyperbranched polyethyleneimine macromolecules, and then forming coordination covalent bonds by using lone-pair electron pairs on nitrogen atoms on dimethylethanolamine molecules and carbon atoms connected with chlorine on epichlorohydrin molecules, thereby generating the cationic amino quaternary ammonium salt compound. According to the invention, hyperbranched polyethyleneimine is used as a reaction monomer, and on one hand, more amino groups exist in molecules of the hyperbranched polyethyleneimine, so that the generated amino quaternary ammonium salt contains more amino groups, thereby improving the reaction efficiency of the amino quaternary ammonium salt and HCl, and ensuring that HCl generated by thermal degradation of the generated polyvinyl chloride can be completely reacted. On the other hand, the hyperbranched polyethyleneimine has a larger branched molecular space structure, so that the generated amino quaternary ammonium salt has a larger branched space structure, and the amino quaternary ammonium salt is introduced into montmorillonite interlamination and then the interlayer spacing of montmorillonite is improved by using the hyperbranched space structure of the amino quaternary ammonium salt, so that the adsorption performance of the montmorillonite on HCl is improved.

Preferably, the molecular weight of the hyperbranched polyethyleneimine is 10000-20000 Da.

Preferably, the mass ratio of the hyperbranched polyethyleneimine to the epichlorohydrin is 1: 0.1-0.3.

Therefore, the invention has the following beneficial effects: (1) the auxiliary stabilizer montmorillonite is silicon oxide tetraThe clay mineral with a three-layer sheet structure formed by the surface body has extremely strong adsorption performance, and the montmorillonite can adsorb the generated HCl in time after the polyvinyl chloride releases HCl after the polyvinyl chloride pipe is heated, so that the catalysis of hydrogen chloride on the thermal degradation of PVC resin is avoided, and the thermal degradation degree of polyethylene is reduced; (2) replacement of Na between montmorillonite layers by using polyamino quaternary ammonium salt cation compound⁺、Ca²⁺、K⁺、Mg²⁺Ions are subjected to plasma hydration, so that the polyamino quaternary ammonium salt is introduced into the interlayer of the montmorillonite, and meanwhile, HCl adsorbed in the interlayer of the montmorillonite is consumed by utilizing the reaction between amino groups on the polyamino quaternary ammonium salt and HCl generated by thermal degradation of a PVC pipe, so that the problem that HCl is easily adsorbed and saturated by the montmorillonite is solved, and the utilization rate of the montmorillonite is improved; (3) modifying montmorillonite by using an aminosilane coupling agent not only improves the dispersion performance of the montmorillonite in PVC resin, but also consumes HCl generated by PVC thermal degradation; (4) the amino quaternary ammonium salt contains more amino groups, so that the reaction efficiency of the amino quaternary ammonium salt and HCl is improved, and HCl generated by thermal degradation of the generated polyvinyl chloride can be completely reacted.

Detailed Description

The technical solution of the present invention is further illustrated by the following specific examples.

In the present invention, unless otherwise specified, all the raw materials and equipment used are commercially available or commonly used in the art, and the methods in the examples are conventional in the art unless otherwise specified.