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CN-122011995-A - Aviation flame-retardant polyurethane pressure-sensitive adhesive and preparation method thereof

CN122011995ACN 122011995 ACN122011995 ACN 122011995ACN-122011995-A

Abstract

The invention relates to the technical field of adhesives, in particular to an aviation flame-retardant polyurethane pressure-sensitive adhesive and a preparation method thereof, wherein the flame-retardant polyurethane pressure-sensitive adhesive is prepared by modifying cyclophosphazene into a dihydroxy compound, so that the excellent gas-phase dilution flame retardance and ceramic formation charcoal capability of the flame-retardant polyurethane pressure-sensitive adhesive are maintained, the crosslinking and catalysis problems caused by cyclophosphazene multifunctional groups are avoided, a flame-retardant polymer is prepared by copolymerizing the flame-retardant polymer and DOPO-HQ through isocyanate, a flame-retardant structure of 'PZ-isocyanate-DOPO-HQ' is formed, the synergistic effect of PZ and DOPO-HQ is utilized to realize the effect of phosphorus-nitrogen-phosphorus multiple elements Gao Xiaoxie, the flame-retardant polymer can be formed into an interpenetrating network structure with polyurethane prepolymer, the flame-retardant performance of the whole material is obviously improved, the excellent adhesive performance and flexibility are effectively maintained, the prepared halogen-free environment-friendly flame-retardant flame-sensitive adhesive meets the strict requirements of low smoke non-toxicity, high flame retardance and high safety of aviation materials, and is particularly suitable for the scenes such as aircraft interior decoration, floor, wire harness fixing and bonding of composite materials.

Inventors

  • LIAO DONG
  • RAO QIUSHI
  • LI JIAN

Assignees

  • 深圳市航信科技有限公司

Dates

Publication Date
20260512
Application Date
20260224

Claims (10)

  1. 1. The preparation method of the aviation flame-retardant polyurethane pressure-sensitive adhesive is characterized by comprising the following steps: Modifying the cyclophosphazene compound to obtain dihydroxycyclophosphazene diol; Mixing the dihydroxycyclophosphazene glycol with 10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diisocyanate and an organotin catalyst, and carrying out copolymerization reaction to obtain a flame-retardant polymer; mixing the flame-retardant polymer with a polyurethane prepolymer and a curing agent to obtain a curable pressure-sensitive adhesive composition; And coating the curable pressure-sensitive adhesive composition on a substrate, and curing to obtain the aviation flame-retardant polyurethane pressure-sensitive adhesive.
  2. 2. The method for preparing an aviation flame retardant polyurethane pressure sensitive adhesive according to claim 1, wherein the step of modifying a cyclophosphazene compound to obtain a dihydroxycyclophosphazene diol comprises the steps of: mixing hexachlorocyclotriphosphazene with a monofunctional hydroxyl compound, an acid binding agent and an organic solvent, and carrying out partial end-capping reaction to obtain a first product with an active chlorine atom; Mixing the first product with one active chlorine atom with glycerin compound, and performing nucleophilic substitution reaction to obtain the dihydroxycyclophosphazene diol.
  3. 3. The method for preparing aviation flame-retardant polyurethane pressure-sensitive adhesive according to claim 2, wherein the monofunctional hydroxyl compound comprises one or more of methanol, ethanol and butanol, and the molar ratio of hexachlorocyclotriphosphazene to the monofunctional hydroxyl compound is 1:5; And/or the organic solvent comprises one or more of tetrahydrofuran, N-dimethylformamide, diethyl ether, dichloromethane, acetonitrile and N-methylpyrrolidone, and the addition amount of the organic solvent is 0.5-10 times of the mass of the hexachlorocyclotriphosphazene.
  4. 4. The preparation method of the aviation flame-retardant polyurethane pressure-sensitive adhesive according to claim 2, wherein the acid-binding agent is one or more of triethylamine, a derivative of triethylamine, diisopropylethylamine, a derivative of diisopropylethylamine, pyridine and a derivative of pyridine, and the addition amount of the acid-binding agent is 0.1-1% of the mass of hexachlorocyclotriphosphazene.
  5. 5. The method for preparing an aviation flame retardant polyurethane pressure sensitive adhesive according to claim 2, wherein the temperature of the partial end-capping reaction is 0 ℃ to 40 ℃, and the time of the partial end-capping reaction is 1h to 3h; And/or the nucleophilic substitution reaction temperature is 50-75 ℃, and the nucleophilic substitution reaction time is 2-4 h.
  6. 6. The method for preparing aviation flame-retardant polyurethane pressure-sensitive adhesive according to claim 2, wherein the glycerin compound is a C3-C6 saturated polyol containing two or three hydroxyl groups, and the molar ratio of the first product with one active chlorine atom to the glycerin compound is 1:1.
  7. 7. The method for preparing aviation flame-retardant polyurethane pressure-sensitive adhesive according to claim 1, wherein the temperature of the copolymerization reaction is 60-90 ℃, and the time of the copolymerization reaction is 2-5 h.
  8. 8. The preparation method of the aviation flame-retardant polyurethane pressure-sensitive adhesive according to claim 1, wherein the diisocyanate comprises one or more of hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate and isophorone diisocyanate, and the organotin catalyst comprises one of dibutyltin dilaurate and stannous octoate; Preferably, the mass ratio of the 10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, the dihydroxycyclophosphazene glycol, the diisocyanate and the organotin catalyst is 1 (1-3): 0.01-0.5; preferably, the polyurethane prepolymer is prepared by dehydrating and polymerizing polyester polyol or polyether polyol and aromatic or aliphatic diisocyanate; Preferably, the curing agent comprises one or more of hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate trimer, isophorone diisocyanate trimer; Preferably, the addition amount of the curing agent is 1% -15% of the mass of the polyurethane prepolymer.
  9. 9. The method for preparing an aviation flame retardant polyurethane pressure sensitive adhesive according to claim 1, wherein the mass fraction of the flame retardant polymer in the curable pressure sensitive adhesive composition is 5% -15%.
  10. 10. An aviation flame-retardant polyurethane pressure-sensitive adhesive, which is prepared by the preparation method of the aviation flame-retardant polyurethane pressure-sensitive adhesive according to any one of claims 1 to 9.

Description

Aviation flame-retardant polyurethane pressure-sensitive adhesive and preparation method thereof Technical Field The invention relates to the technical field of adhesives, in particular to an aviation flame-retardant polyurethane pressure-sensitive adhesive and a preparation method thereof. Background In the aerospace field, the pressure-sensitive adhesive is widely applied to key parts such as aircraft interior trim bonding, wire harness bundling, sensor fixing, composite material skin splicing and the like. Because the space inside the aircraft is airtight and personnel intensive, and the electronic equipment is highly concentrated, once a fire disaster occurs, the fire spreads rapidly, and the escape window is extremely short, the extremely severe requirement is put forward on the flame retardant property of the material. The existing polyurethane pressure-sensitive adhesive has excellent adhesion, flexibility and ageing resistance, but is a flammable organic polymer material, is extremely easy to burn and release a large amount of toxic smoke under the action of high temperature or electric arc, has serious potential safety hazard, and must be modified by flame retardance to meet aviation materials such as strict flame retardance, low smoke and low toxicity standards. Currently, the usual flame retardant strategies rely mainly on additive flame retardants, such as halogen-based or traditional phosphorus-based. However, halogen flame retardants can generate corrosive gas and highly toxic substances in the combustion process, seriously threaten the safety of passengers and do not meet environmental regulations, while additive phosphorus flame retardants are easy to migrate and separate out, have poor long-term use stability, often need higher additive amount to reach the flame retardant requirement, and seriously affect the adhesive property and the temperature resistance of colloid. Although the compatibility and durability of the partial reactive flame retardant can be effectively improved, the introduction of the single compounds is difficult to realize the synergistic flame retardance of high-efficiency gas phase and condensed phase, the colloid becomes brittle easily due to the structure of the partial flame retardant, the initial adhesion and the peeling strength are reduced, and the balance of flame retardance and adhesive property is difficult to be achieved. Accordingly, the prior art is still in need of improvement and development. Disclosure of Invention In view of the defects of the prior art, the invention aims to provide an aviation flame-retardant polyurethane pressure-sensitive adhesive and a preparation method thereof, and aims to solve the problems that the existing pressure-sensitive adhesive is difficult to realize efficient gas phase and gel phase synergistic flame retardance and the colloid becomes brittle due to the addition of a flame retardant. The technical scheme of the invention is as follows: a preparation method of aviation flame-retardant polyurethane pressure-sensitive adhesive comprises the following steps: Modifying the cyclophosphazene compound to obtain dihydroxycyclophosphazene diol; Mixing the dihydroxycyclophosphazene glycol with 10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diisocyanate and an organotin catalyst, and carrying out copolymerization reaction to obtain a flame-retardant polymer; mixing the flame-retardant polymer with a polyurethane prepolymer and a curing agent to obtain a curable pressure-sensitive adhesive composition; And coating the curable pressure-sensitive adhesive composition on a substrate, and curing to obtain the aviation flame-retardant polyurethane pressure-sensitive adhesive. The preparation method of the aviation flame-retardant polyurethane pressure-sensitive adhesive comprises the steps of modifying a cyclophosphazene compound to obtain dihydroxycyclophosphazene diol, and comprises the following steps: mixing hexachlorocyclotriphosphazene with a monofunctional hydroxyl compound, an acid binding agent and an organic solvent, and carrying out partial end-capping reaction to obtain a first product with an active chlorine atom; Mixing the first product with one active chlorine atom with glycerin compound, and performing nucleophilic substitution reaction to obtain the dihydroxycyclophosphazene diol. The preparation method of the aviation flame-retardant polyurethane pressure-sensitive adhesive comprises the steps that the monofunctional hydroxyl compound comprises one or more of methanol, ethanol and butanol, and the molar ratio of hexachlorocyclotriphosphazene to the monofunctional hydroxyl compound is 1:5. The preparation method of the aviation flame-retardant polyurethane pressure-sensitive adhesive comprises the steps of preparing an aviation flame-retardant polyurethane pressure-sensitive adhesive, wherein the organic solvent comprises one or more of tetrahydrofuran, N-dimethylformamide, diethyl ethe