Search

CN-122012003-A - High-strength gas barrier polyurethane adhesive and preparation method thereof

CN122012003ACN 122012003 ACN122012003 ACN 122012003ACN-122012003-A

Abstract

The invention discloses a high-strength gas-barrier polyurethane adhesive and a preparation method thereof, wherein the high-strength gas-barrier polyurethane adhesive comprises a main component A and a curing agent B, the main component A comprises, by weight, 80-85 parts of a solvent A and 15-20 parts of polyurethane resin, and the curing agent B comprises, by weight, 0.75-2.0 parts of lamellar hydrotalcite (LDHs), 2.0-6.0 parts of polyisocyanate and 20.0-50.0 parts of a solvent B. The polyisocyanate modified lamellar LDHs can be uniformly dispersed with the polyurethane matrix, and the prepared polyurethane adhesive has excellent gas barrier property and mechanical property, is used for bonding film materials, and has good bonding property.

Inventors

  • ZHANG JUNYING
  • GUO YINGHAN
  • SHI YALIN
  • CHENG YU

Assignees

  • 北京化工大学
  • 黎明化工研究设计院有限责任公司

Dates

Publication Date
20260512
Application Date
20260129

Claims (10)

  1. 1. A high-strength gas barrier polyurethane adhesive consists of a main agent A component and a curing agent B component, wherein the main agent A component comprises the following components in parts by weight: 80-85% of solvent A 15-20 Parts of polyurethane resin The curing agent B comprises the following components in parts by weight: 0.75 to 2.0 portions of lamellar hydrotalcite (LDHs) Polyisocyanate 2.0 to 6.0 20.0 To 50.0 parts of solvent B.
  2. 2. The high strength gas barrier polyurethane adhesive of claim 1, wherein the polyurethane resin is prepared from a polyester polyol, a diisocyanate, and a small molecule alcohol chain extender.
  3. 3. The high strength gas barrier polyurethane adhesive of claim 1, wherein the polyester polyol is one or more of polyethylene glycol adipate glycol, polybutylene glycol adipate glycol, polyhexamethylene glycol adipate glycol, polybutylene glycol hexanediol adipate glycol, polyethylene glycol hexanediol adipate polyol, and the number average molecular weight of the polyester polyol is preferably 2000-3000.
  4. 4. The high strength gas barrier polyurethane adhesive of claim 1, wherein the diisocyanate is preferably one or more of diphenylmethane diisocyanate (MDI), 4-4' -dicyclohexylmethane diisocyanate (HMDI), isophorone diisocyanate (IPDI), hexamethylene Diisocyanate (HDI), xylylene Diisocyanate (XDI).
  5. 5. The high strength gas barrier polyurethane adhesive of claim 1, wherein the small molecule alcohol chain extender is preferably one or two of 1, 4-butanediol, 1, 6-hexanediol, dipropylene glycol, diethylene glycol, propylene glycol, neopentyl glycol.
  6. 6. The high strength gas barrier polyurethane adhesive of claim 1, wherein the molar ratio of the polyester polyol to the small molecule alcohol chain extender in the polyurethane resin is preferably 1:0.35 to 1:4.6.
  7. 7. The high strength gas barrier polyurethane adhesive of claim 1, wherein the polyurethane resin preferably has a hard segment content of 15% to 35% and an R value of 0.95 to 0.98.
  8. 8. The high-strength gas barrier polyurethane adhesive according to claim 1, wherein the lamellar hydrotalcite is selected from binary hydrotalcite, preferably magnesium aluminum hydrotalcite and zinc aluminum hydrotalcite, or modified hydrotalcite, preferably hydrotalcite prepared by intercalation modification of 3, 5-di-tert-butyl-4-hydroxyphenylpropionic acid (DBHP) organic anion antioxidant, 2, 4-dimethoxybenzoic acid (2, 4-DMBA) and 4,4' -stilbenedicarboxylic acid (SDCA) organic anion ultraviolet absorbent.
  9. 9. The high strength gas barrier polyurethane adhesive of claim 1 wherein the polyisocyanate is a polyisocyanate having a functionality >2, preferably one or more of an adduct of HDI-TMP, HDI trimer, HDI biuret, IPDI trimer, polyphenyl polymethylene diisocyanate, TDI-TMP adduct, XDI-TMP adduct.
  10. 10. A method of preparing the high strength gas barrier polyurethane adhesive of any one of claims 1-9, comprising the steps of: (1) Uniformly mixing polyurethane resin and a solvent A to obtain an adhesive A component; (2) Adding lamellar hydrotalcite (LDHs), polyisocyanate and a solvent B into a reaction device according to a metering ratio, and grinding and dispersing after reflux reaction to obtain a component B of an adhesive curing agent; (3) And mixing and stirring the polyurethane adhesive A component liquid and the curing agent B component uniformly according to the mass ratio, and curing to obtain the polyurethane adhesive.

Description

High-strength gas barrier polyurethane adhesive and preparation method thereof Technical Field The invention belongs to the field of polyurethane adhesive materials, and particularly relates to a high-strength gas barrier polyurethane adhesive and a preparation method thereof. Background Polyurethane (PU) is a polymer material formed by block copolymerization of a flexible soft section and a rigid hard section, has excellent flexibility, wider hardness range, good wear resistance and bonding property due to strong molecular structure adjustability, and is widely applied to the fields of food packaging, hot air balloons, civil airships, aerostats, ship inflation fenders and the like. Particularly, as a barrier type bonding material, PU can effectively realize high-strength bonding among various base materials such as Polyester (PET), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), fabrics and the like, and has the function of blocking air, water vapor, oxygen, helium and other gases, thereby showing wide application prospects in high-end flexible packages, new energy storage and transportation equipment and special protective materials. However, the conventional polyurethane material has poor gas barrier property, and is difficult to meet the severe requirement of high-performance barrier application scenes on low permeability. In order to improve the barrier property, the prior art generally adopts a method of introducing two-dimensional layered nano materials (such as montmorillonite MMT, layered double hydroxide LDHs, graphene and derivatives thereof, hexagonal boron nitride h-BN, molybdenum disulfide MoS 2, transition metal carbon/nitride MXene and the like) into a PU matrix, and effectively prolonging the diffusion path of gas molecules under a lower addition amount by utilizing the path bending effect given by the lamellar structure of the nano materials, thereby obviously improving the gas barrier property of the polyurethane-based composite material. CN114853978A and CN116063650A respectively adopt an in-situ polymerization method to introduce Ti 3C2Tx, MXene and flaky pearl powder into a PU matrix to prepare the gas barrier film material with high weather resistance and good mechanical property, however, the method has the problems of complex preparation flow, poor process stability and unfavorable mass production. CN113831830a and CN119503850a propose to introduce graphene microcapsules or large-sized hydrotalcite into PU, but the obtained material still does not reach an ideal level in terms of gas barrier properties. In addition, CN113337101A discloses a method for preparing a high-barrier TPU film by introducing ionol into a Thermoplastic Polyurethane (TPU) film, coating the ionol on the surface of graphene-hydrotalcite after the ionol reacts with vinyl polysiloxane, so that the ionol is uniformly dispersed, and successfully improving the barrier property of the material, wherein the tensile strength of the obtained film is only about 20 MPa, and the requirement of high-strength application is far not met. In summary, most of the current researches prove that the nano lamellar filler has an effect of improving the barrier property of PU, but the nano lamellar filler still faces a plurality of challenges in realizing high strength, high barrier, good compatibility, process simplicity and the like. Particularly in the aspects of polyurethane matrix structural design, nano filler dispersibility, simplified preparation process and the like, an effective solution is not yet available. Therefore, how to cooperatively improve the mechanical property and the barrier property of the material based on reasonable polyurethane molecular structure design and a composite strategy, solve the problems of dispersion of nano fillers and compatibility with a polyurethane matrix, realize simple and optimized preparation process, and become a technical problem that the preparation of high-performance polyurethane adhesives is needed to overcome currently. Disclosure of Invention Aiming at the technical problems, the invention aims to provide a high-strength gas barrier polyurethane adhesive and a preparation method thereof. In order to solve the technical problems, the first aspect of the invention provides a high-strength gas barrier polyurethane adhesive which consists of a main agent A component and a curing agent B component, The main agent A comprises the following components in parts by weight: 80-85% of solvent A 15-20 Parts of polyurethane resin The curing agent B comprises the following components in parts by weight: 0.75 to 2.0 portions of lamellar hydrotalcite (LDHs) Polyisocyanate 2.0 to 6.0 20.0 To 50.0 parts of solvent B. Preferably, the polyurethane resin is prepared from polyester polyol, diisocyanate and a small molecular alcohol chain extender. The polyester polyol is preferably one or more of polyethylene glycol adipate glycol, polybutylene glycol adipate glycol, polyhexamethylene glycol