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CN-121827133-B - PHA-nano rosin synergistic high-barrier water-based coating and preparation and application thereof

CN121827133BCN 121827133 BCN121827133 BCN 121827133BCN-121827133-B

Abstract

The invention discloses a PHA-nano rosin synergistic high-barrier water-based coating and preparation and application thereof, and belongs to the technical fields of bio-based high polymer materials, interface modification and paper-based functional coatings. According to the scheme, nano rosin derivatives and modified lamellar barrier fillers are cooperatively introduced into a polyhydroxyalkanoate matrix, and a stable chemical bonding interlocking network is constructed between an organic phase and an inorganic phase by utilizing an interface crosslinking coupling agent. The micro-penetration filling effect of the nano rosin is deeply cooperated with the labyrinth effect of the high-diameter-thickness-ratio lamellar filler, so that the paper-based material has oil-proof, water-proof and water vapor high-barrier effects. The composition has certain film forming flexibility and adhesive strength after solidification, and can still maintain the physical integrity of the barrier coating under the working conditions of complex machining, indentation and severe folding. The invention has full water-based property and excellent repulping recovery performance, and meets the transformation requirements of the fields of food packaging and the like.

Inventors

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Assignees

  • 都佰城新材料技术（上海）有限公司
  • 博碳(上海)生物材料有限公司
  • 中科联化有限公司
  • 环涂士涂料有限公司
  • 都佰城集团有限公司

Dates

Publication Date
20260508
Application Date
20260316

Claims (10)

  1. 1. A PHA-nano rosin synergistic high-barrier water-based coating composition is characterized by comprising, by dry solid total amount, 45-90 parts of polyhydroxyalkanoate film forming substances, 3-35 parts of nano rosin derivatives, 5-15 parts of lamellar barrier fillers, 0.05-8 parts of interface crosslinking coupling agents, 0-20 parts of toughening plasticizers and 0-10 parts of auxiliary agents, wherein the nano rosin derivatives form a dispersed phase with a volume median particle diameter D 50 of 50-300 nm in an aqueous phase, the lamellar barrier fillers have a diameter-thickness ratio of more than or equal to 20 and are subjected to surface modification treatment, and the interface crosslinking coupling agents comprise one or more epoxy functional silane coupling agents; The polyhydroxyalkanoate film-forming substance exists in the form of polyhydroxyalkanoate aqueous dispersion, the volume median particle diameter D 50 of polyhydroxyalkanoate particles in the polyhydroxyalkanoate aqueous dispersion is less than or equal to 3 mu m, the pH value of the coating composition is 6.5-9.5, the coating composition is coated on at least one side surface of a paper-based substrate and is dried, then heat curing film formation is further carried out, and a barrier coating is obtained, wherein the dry coating weight of the barrier coating is 3g/m < 2 > -30 g/m < 2 >.
  2. 2. The coating composition according to claim 1, wherein the polyhydroxyalkanoate film-forming material is selected from a short-chain polyhydroxyalkanoate selected from one or a combination of two or more of a poly 3-hydroxybutyrate, a poly 3-hydroxybutyrate-co-3-hydroxyvalerate, a poly 3-hydroxybutyrate-co-4-hydroxybutyrate, a medium-long-chain polyhydroxyalkanoate selected from one or a combination of two or more of a poly 3-hydroxyhexanoate, a poly 3-hydroxyheptanoate, a poly 3-hydroxyoctanoate, a poly 3-hydroxynonanoate, a poly 3-hydroxydecanoate, a poly 3-hydroxyundecanoate, a poly 3-hydroxydodecanoate, a poly 3-hydroxytridecanoate, a poly 3-hydroxytetradecanoate, and the aqueous polyhydroxyalkanoate dispersion has a solid content of 5 to 70wt%.
  3. 3. The coating composition according to claim 1, wherein the nano-sized rosin derivative is a rosin-based material selected from the group consisting of rosin acid or a salt or ester thereof, hydrogenated rosin acid or a salt or ester thereof, disproportionated rosin, polymerized rosin, rosin ester, hydrogenated rosin ester, maleated rosin and ester thereof, fumarated rosin and ester thereof, rosin modified phenolic resin, rosin modified terpene resin, rosin-based acrylate polymer or rosin-based methacrylate polymer, wherein the rosin ester comprises one or a combination of two or more of rosin glycerol ester, rosin pentaerythritol ester, rosin trimethylpropane ester, and wherein the rosin-based acrylate polymer or rosin-based methacrylate polymer is obtained by copolymerizing a rosin-based acrylate monomer or rosin-based methacrylate monomer with at least one vinyl monomer selected from the group consisting of acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, styrene, vinyl acetate, acrylonitrile, and KOH/mg of the rosin derivative is 200 mg/mg.
  4. 4. The coating composition according to claim 1, wherein the lamellar barrier filler is selected from one or more of lamellar silicate, lamellar double hydroxide, lamellar oxide and lamellar boron nitride, wherein the lamellar silicate comprises one or more of lamellar kaolin, montmorillonite, vermiculite, mica and talcum, and has a volume median particle diameter D 50 μm or less, the surface modification treatment of the lamellar barrier filler is selected from one or more of silane coupling agent treatment, titanate coupling treatment, zirconate coupling treatment, phosphate coupling treatment, aluminate coupling treatment, fatty acid hydrophobization treatment, wax hydrophobization treatment, cationic surfactant intercalation treatment, nonionic surfactant intercalation treatment and inorganic sol-gel coating treatment, and the silane coupling agent used for the silane coupling agent treatment comprises one or more of epoxy functional silane coupling agent selected from gamma-glycidoxypropyl trimethoxysilane, gamma-glycidoxypropyl triethoxy silane, gamma-methyloxypropyl dimethoxysilane and a combination of two or more of glycidyl dimethoxysilanes.
  5. 5. The coating composition of claim 1, wherein the interfacial crosslinking coupling agent further comprises a crosslinking component selected from one or more of carbodiimides, oxazolines, multifunctional epoxies, aminosilanes, polycarboxylic acids, anhydrides, or combinations thereof, and the total amount of the crosslinking component is in the range of 0.05 to 8 parts of the interfacial crosslinking coupling agent, the toughening plasticizer is a bio-based plasticizer selected from one or more of citric acid esters, succinic acid esters, fatty acid esters, epoxidized vegetable oils, the adjuvant comprises one or more of wetting dispersants, emulsifiers, defoamers, leveling agents, thickeners, anti-settling agents, preservatives, pH modifiers, protective colloids, wherein the emulsifier or protective colloid is selected from one or more of anionic surfactants, nonionic surfactants, amphoteric surfactants, polyvinyl alcohol, and when the polyvinyl alcohol is used as a protective colloid, the additive is 1wt% to 15wt% of the rosin derivative on a dry solids basis.
  6. 6. The coating composition according to claim 1, wherein the final solid content of the coating composition is 30 to 60wt%, the coating composition is dried at 60 to 130 ℃ after coating, and the coating film obtained by further thermally curing at 80 to 160 ℃ for 0.5 to 10min is immersed in deionized water at 23 ℃ for 24 hours at a mass gain rate of 15wt% or less.
  7. 7. The preparation method of the PHA-nano rosin synergistic high-barrier water-based coating composition according to claim 1 is characterized by comprising the following steps of 1, carrying out surface modification and dispersion on a lamellar barrier filler, dispersing the lamellar barrier filler in an aqueous phase to form slurry, adding a surface modifier for shearing and dispersing, and finishing surface modification to obtain modified lamellar filler slurry; Step 2 is rosin nanocrystallization, wherein rosin derivatives are mixed with water phase containing emulsifying agent and/or protective colloid and pre-emulsified, and then high-pressure homogenization, micro-jet, ultrasonic emulsification, membrane emulsification or rotor-stator high-shear emulsification are carried out to prepare rosin nanoemulsion with volume median particle diameter D 50 of 50-300 nm; step 3, aqueous blending, namely adding the rosin nano emulsion obtained in the step2 into the polyhydroxyalkanoate aqueous dispersion for mixing, and then adding the modified lamellar filler slurry obtained in the step 1, the interface crosslinking coupling agent, the toughening plasticizer and the auxiliary agent, and adjusting the solid content and the pH value to obtain a premix coating composition; step 4 is curing, curing the premix coating composition obtained in step 3 at 25 ℃ to 60 ℃ for 0.5 to 6 hours, and obtaining the coating composition.
  8. 8. The method of claim 7, wherein the surface modifier in the step 1 is one or more selected from the group consisting of a silane coupling agent, a titanate coupling agent, a zirconate coupling agent, a phosphate coupling agent and an aluminate coupling agent, the surface modifier is used in an amount of 0.1 to 8wt% of the mass of the lamellar barrier filler, the high-pressure homogenizing pressure in the step 2 is 20 to 120MPa, the homogenizing times are 2 to 8, the rosin nanoemulsion in the step 3 is added dropwise or in a stepwise manner when the polyhydroxyalkanoate aqueous dispersion is added, and the modified lamellar filler slurry obtained in the step 1 is added after the addition and the interfacial crosslinking coupling agent is added at the end, thereby obtaining the coating composition.
  9. 9. The paper-based barrier material prepared by the PHA-nano rosin synergistic high-barrier water-based coating composition according to claim 1, wherein the PHA-nano rosin synergistic high-barrier water-based coating composition is coated on one side surface or a plurality of side surfaces of paper, paperboard, molded pulp substrate or composite paper substrate thereof, and is dried and thermally cured to form a barrier coating, the paper-based barrier material has a water absorption value of 30minCobb of less than or equal to 5g/M2 according to ISO 535:2023, an oil resistance Kit value of more than or equal to 11 according to TAPPI/ANSI T559 cm-22, a water vapor transmission rate of less than or equal to 12 g/(M2 & d) according to ASTM E96/E96M-24a at 23 ℃ and 50% RH, a cross cut adhesion of 0 or 1 according to ISO 2409:2020, an MIT folding number of more than or equal to 250 according to TAPPI/ANSI T511 om-25, and a Kit value of more than or equal to 11 at 180 degrees fold, and a total fluorine content of less than 5mg/kg measured according to T/CNFIA-2024.
  10. 10. The packaging article made of the paper-based barrier material according to claim 9, wherein the packaging article is selected from one or more of food packaging paper, paper cup, paper bowl, paper cutlery box, take-away paper bag, molded pulp cutlery box or tray, and the surface thereof contacting food or daily chemical products comprises the paper-based barrier material.

Description

PHA-nano rosin synergistic high-barrier water-based coating and preparation and application thereof Technical Field The invention belongs to the technical field of bio-based high polymer materials, interface modification and paper-based functional coatings, and particularly relates to a PHA-nano rosin synergistic high-barrier water-based coating and preparation and application thereof. Background There is an increasing demand for paper-based packaging materials to replace traditional plastic composites. In order to meet the packaging requirements of food and daily chemical products, paper-based materials must have excellent oil repellency, water vapor barrier properties, folding endurance, and durable adhesion. Currently, a variety of aqueous barrier coating systems and processes for their preparation have been developed, with bio-based materials being of great interest due to their environmental characteristics. In the field of aqueous coatings of polyhydroxyalkanoates (hereinafter referred to as PHAs), various studies have been made in the prior art. For example, CN120757803a discloses a PHA dispersion emulsion aimed at improving low temperature film forming and storage stability by defining the polymer molecular weight and polydispersity index and incorporating the film forming aid 2, 4-trimethyl-1, 3-pentanediol monoisobutyrate and aliphatic polyisocyanate cross-linking agent. CN119777197a relates to a water paint prepared by breaking wall of PHA fermentation liquor and then mixing with emulsifying agent, thickening agent and the like. WO2020036843A1 discloses aqueous dispersions of biodegradable PHA suitable for use in food contact substrates. In order to further improve the barrier property, CN117884325A proposes to add a hot pressing process after coating to form a film, to reduce the coating amount and improve the compactness. In addition, CN120250392a tried to compound PHA with polyvinyl alcohol (hereinafter, PVA) and prepare a nano-sized paper-based barrier emulsion using a high pressure homogenization process. CN120026524B constructed an aqueous emulsion blend comprising PHA, polybutylene adipate-terephthalate (PBAT) and PVA. US11866606B2 incorporates inorganic fillers with crosslinking components in PHA dispersions to enhance water resistance. In the aspects of functional modification and filler compounding, the application of natural resins and inorganic materials is also common. CN119265999a discloses a heat seal coating composition comprising biomass material, PHA emulsion and rosin or epoxidized vegetable oil, the slurry being prepared mainly by physical blending. CN111138718a utilizes the combination of rosin glyceride emulsion and nanocellulose to improve the water-proof and oil-proof properties. WO2024127356A1 uses rosin-based plant acids to modify PHA. WO2009134538A1 extends the diffusion path by introducing layered inorganic fillers for the barrier mechanism of the inorganic fillers. CN115996838a adopts a structure in which a water-based biodegradable polymer layer and a hydrophilic nanosheet dispersion layer are superimposed. Regarding environmental evaluation, CN120944505A discloses fluorine-free bio-based paper protective coatings and mentions the evaluation of recyclability using the european paper industry consortium laboratory evaluation method. Although the prior art described above has made some progress in film forming, barrier or heat sealing properties, it still faces many challenges in practical applications. First, existing PHA aqueous coating systems focus on improving film formation quality through film forming aids, but when handling high strain conditions such as folding, creasing, etc., the coating is prone to microcracking, forming permeation pathways, leading to substantial attenuation of barrier properties. Secondly, although rosin and its derivatives have excellent hydrophobic and tackifying properties, in aqueous systems, phase separation or interfacial defects are very likely to occur if introduced by conventional emulsification or coarse dispersion alone. Such interface defects tend to cause cracking or peeling of the coating, especially at paper folds, so that the water and oil repellency becomes unstable. Again, while layered inorganic fillers can theoretically promote barrier properties by the labyrinth effect, without effective surface modification and chemical bonding between the organic and inorganic phases, the fillers are prone to clumping and void formation at the interface. Water molecules tend to penetrate along this interfacial void, making it difficult to combine low water absorption values, low water vapor transmission rates, and high fold resistance. In addition, in order to pursue high barrier property, part of the prior art adopts complex processes such as hot pressing, multi-layer compounding and the like, which not only increases equipment investment and energy consumption, but also is unfavorable for large-scale continuous production, and eve