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CN-122011479-A - Ultrahigh viscosity foaming regulator for low-density PVC wood-plastic composite material

CN122011479ACN 122011479 ACN122011479 ACN 122011479ACN-122011479-A

Abstract

The invention relates to the technical field of PVC foaming regulators, in particular to an ultrahigh viscosity foaming regulator for a low-density PVC wood-plastic composite material, which comprises, by mass, 40-90 parts of core-shell acrylate copolymer particles, 2-40 parts of layered double metal hydroxide, 0.2-20 parts of inorganic porous carrier with an average pore diameter of 0.3-50nm, 0.05-10 parts of inorganic nano nucleating agent or carbon nano material, 0.1-5 parts of beta-diketone or beta-dicarbonyl compound and 0.1-5 parts of coupling agent. The core layer of the a-component comprises cross-linking units and the shell layer comprises polar or reactive units. According to the invention, a multidimensional cooperative defense closed loop is constructed, the A component is utilized to chemically anchor wood powder to prevent puncture, the C component intercepts water to prevent bumping, the B component and the E component cooperatively absorb acid to prevent degradation, and the D component promotes nucleation. Under the working conditions of high wood powder filling and high water content, micron-sized fine foaming, extremely low density and excellent bending strength can still be realized.

Inventors

  • FENG LINQING

Assignees

  • 山东三润助剂科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260330

Claims (10)

  1. 1. The ultra-high viscosity foaming regulator for the low-density PVC wood-plastic composite material is characterized by comprising the following components in parts by mass, wherein the foaming regulator is a powder composition; 40-90 parts of core-shell acrylate copolymer particles; 2-40 parts of layered double hydroxide; component C comprises 0.2-20 parts of inorganic porous carrier, wherein the average pore diameter of the inorganic porous carrier is 0.3-50nm; 0.05-10 parts of inorganic nano nucleating agent or carbon nano material; 0.1-5 parts of beta-diketone compound or beta-dicarbonyl compound; 0.1-5 parts of coupling agent; The composite particle powder comprises a component A, a component B and a component D, wherein the component A is a core layer of acrylic ester phase containing a crosslinking monomer unit, a shell layer of the component A contains a polar monomer unit or a reactive monomer unit, the component B and the component D are respectively coated or adsorbed on the surface of the component A to form a composite precursor, and the composite precursor and the component C are combined to form the composite particle powder.
  2. 2. The ultra-high viscosity foaming modifier for low-density PVC wood-plastic composite according to claim 1, wherein the A component is formed by at least two-stage emulsion polymerization, the core layer further comprises butyl acrylate units, the shell layer comprises polymethyl acrylate, polymethyl methacrylate or copolymer phase thereof, and the mass ratio of the core layer to the shell layer is 5:95 to 40:60.
  3. 3. The ultra-high viscosity foaming regulator for the low-density PVC wood-plastic composite material according to claim 2, wherein the shell layer of the A component comprises the total mole number of the shell layer monomers A polar monomer unit or a reactive monomer unit selected from at least one of glycidyl methacrylate, maleic anhydride, and maleic half-ester; the polar monomer unit is at least one selected from methacrylic acid, acrylic acid and hydroxyethyl acrylate.
  4. 4. An ultra-high viscosity foam regulator for a low density PVC wood plastic composite according to claim 3, wherein the core layer comprises cross-linking monomer units formed by polymerizing cross-linking monomers or branching monomers selected from at least one of allyl methacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate.
  5. 5. The ultra-high viscosity foam regulator for low-density PVC wood-plastic composite according to claim 4, wherein the component B is at least one selected from the group consisting of magnesium aluminum hydrotalcite, zinc aluminum hydrotalcite, calcium aluminum hydrotalcite and magnesium zinc aluminum hydrotalcite.
  6. 6. The ultra-high viscosity foaming regulator for low-density PVC wood-plastic composite according to claim 5, wherein the component C is at least one selected from the group consisting of 3A molecular sieves, 4A molecular sieves, mesoporous silica, activated alumina, silica gel and zeolite.
  7. 7. The ultra-high viscosity foaming regulator for the low-density PVC wood-plastic composite material according to claim 6, wherein the component D is at least one selected from nano calcium carbonate, nano silicon dioxide, titanium dioxide, montmorillonite, carbon nano tube and graphene.
  8. 8. The ultra-high viscosity foaming regulator for low-density PVC wood-plastic composite according to claim 7, wherein the E component is at least one selected from zinc acetylacetonate, acetylacetone and stearoyl benzoyl methane.
  9. 9. The ultra-high viscosity foam regulator for low density PVC wood plastic composite according to claim 8, wherein the composite particle powder is formed by introducing an aqueous dispersion comprising the B component, the D component, the E component and the F component into the A component latex to be adsorbed on the surfaces of the A component particles to form a composite precursor slurry, and then mixing the composite precursor slurry with the dry powder of the C component and co-spray-drying.
  10. 10. The ultra-high viscosity foaming regulator for the low-density PVC wood-plastic composite material according to claim 9, wherein the bulk density of the composite particle powder is 0.30-0.70 g/cm < 3 >.

Description

Ultrahigh viscosity foaming regulator for low-density PVC wood-plastic composite material Technical Field The invention belongs to the technical field of PVC foaming regulators, and particularly relates to an ultrahigh-viscosity foaming regulator for a low-density PVC wood-plastic composite material. Background To achieve weight reduction and cost optimization, PVC foamed articles need to maintain adequate melt strength and cell stability within the melt plasticizing-foaming window. The disclosed technology generally employs acrylic processing aids/foam regulators to improve melt elasticity and strength and inhibit cell collapse. For example, publication CN105254817a discloses a core-shell ultra-high molecular weight acrylate foam regulator for improving PVC plasticization, melt strength and cell fineness and uniformity. However, when PVC and wood powder/plant fiber form a wood-plastic composite system, the complex physical and chemical coupling damage environment of far ultra-pure PVC foaming is faced, firstly, natural bound water and small molecular volatile matters introduced by the wood powder are easy to flash instantly when the wood powder is extruded out of a die, so that the gas release is extremely unstable, and foam cells are formed, coarse foam cells and pinholes are densely distributed on the surface. Secondly, the high proportion of large-size rigid wood flour filling severely breaks the continuous phase of the melt, and its sharp edges are extremely prone to puncture the weak cell walls during foaming biaxial stretching, resulting in large-area collapse of the foam. Traditional pure linear ultra-high molecular weight acrylic aids often exhibit insufficient tear resistance due to molecular chain slippage in the face of such "mechanical point stress" puncture. Finally, the high filler system generates extremely strong mechanical friction shearing heat in the extruder, so that PVC releases hydrogen chloride at high temperature in an accelerating way and causes 'zip-like' autocatalytic degradation, thereby causing the processing window to be narrowed sharply and even the material to be carbonized and blackened. The prior art has often attempted to address the above problems, respectively, by simply compounding higher molecular weight regulators, adding additional water scavengers or heat stabilizers. However, the increase of the high molecular weight inevitably leads to the extremely easy agglomeration and agglomeration of the powder, and the powder is difficult to disperse and disentangle in a matrix in a short time, while the simple physical compounding is not only easy to generate phase separation in a screw rod, but also can not synchronously resist the multisource simultaneous explosion of 'water bumping, hydrogen chloride degradation and mechanical piercing' on each microscopic cell interface. Therefore, how to realize synchronous coordination of high melt strength, puncture resistance, controlled slow release of water and in-situ acid absorption on a microscopic interface through a multifunctional integrated material structure under the conditions of extremely high wood flour filling and high water content, and realize lower density and higher closed pore rate is a technical bottleneck to be broken through in the field. Disclosure of Invention In order to make up the defects of the prior art, the invention provides the ultrahigh viscosity foaming regulator for the low-density PVC wood-plastic composite material. The invention is mainly used for solving the technical problem of how to lead the PVC wood-plastic composite check material to have lower density and more uniform cells through the foaming regulator under the condition of higher wood powder content in the prior art. According to a first aspect of the invention, an ultra-high viscosity foaming regulator for a low-density PVC wood-plastic composite material is a powder composition and comprises the following components in parts by mass; 40-90 parts of core-shell acrylate copolymer particles; 2-40 parts of layered double hydroxide; component C comprises 0.2-20 parts of inorganic porous carrier, wherein the average pore diameter of the inorganic porous carrier is 0.3-50nm; 0.05-10 parts of inorganic nano nucleating agent or carbon nano material; 0.1-5 parts of beta-diketone compound or beta-dicarbonyl compound; 0.1-5 parts of coupling agent; The composite particle powder comprises a core layer of an A component, a shell layer of the core layer of the B component, a shell layer of the core layer of the D component, a shell layer of the core layer of the A component, a shell layer of the core layer of the B component, and a shell layer of the core layer of the B component. Preferably, the A component is formed by at least two-stage emulsion polymerization, the core layer further comprises butyl acrylate units, the shell layer comprises polymethyl acrylate, polymethyl methacrylate or copolymer phase thereof, and the mass ratio of the core