Polyurethane AB Adhesive Powder Flame Retardant Formulations

Polyurethane AB Adhesive Powder Flame Retardant Formulations
Raws li qhov kev thov rau halogen-dawb nplaim retardant formulations rau polyurethane AB adhesives, ua ke nrog cov yam ntxwv thiab synergistic teebmeem ntawm nplaim retardants xws li txhuas hypophosphite (AHP), txhuas hydroxide (ATH), zinc borate, thiab melamine cyanurate (MCA), cov nram qab no peb compounding schemes yog tsim. Cov formulations no tsis muaj tshuaj chlorine thiab tsom rau optimizing nplaim retardant efficiency, lub cev ua tau zoo compatibility, thiab cov txheej txheem feasibility:

1. High Flame Retardancy Formulation (Rau hluav taws xob potting, roj teeb encapsulation, phiaj UL94 V-0)

Core Flame Retardant Combination:

• Aluminium hypophosphite (AHP): 8-12 phr (waterborne polyurethane-coated hom pom zoo los daws cov teeb meem nag lossis daus)
• Aluminium hydroxide (ATH): 20-25 phr (qib submicron, 0.2-1.0 μm, txhawm rau txhim kho oxygen index thiab char compactness)
• MCA: 5-8 phr (gas-theem mechanism, synergistic nrog AHP hauv theem condensed)
• Zinc borate: 3-5 phr (txhim kho ceramic char tsim thiab inhibits smoldering)

Kev Ua Haujlwm Cia Siab:

• Oxygen Performance index (LOI): ≥32% (PU ntshiab ≈22%);
• UL94 ntsuam xyuas: V-0 (1.6 hli thickness);
• Thermal conductivity: 0.45-0.55 W/m·K (pab los ntawm ATH thiab zinc borate);
• viscosity tswj: 25,000-30,000 cP (kev kho saum npoo yuav tsum tau tiv thaiv sedimentation).

Txheej txheem tseem ceeb:

• AHP yuav tsum tau muab pov tseg ua ntej hauv cov khoom siv polyol (Tshooj A) kom tsis txhob muaj cov tshuaj tiv thaiv ntxov ntxov nrog isocyanate (Tshooj B);
• ATH yuav tsum tau hloov kho nrog tus neeg sawv cev silane coupling (xws li KH-550) txhawm rau txhim kho kev sib txuas ntawm lub ntsej muag.

2. Tus nqi qis General Formulation (Rau kev tsim sealing, rooj tog sib txuas, lub hom phiaj UL94 V-1)

Core Flame Retardant Combination:

• Aluminium hydroxide (ATH): 30-40 phr (tus qauv micron-qib, nqi-zoo, muab tub lim-hom nplaim hluav taws xob);
• Ammonium polyphosphate (APP): 10-15 phr (ua ke nrog MCA rau lub cev tsis muaj zog, hloov cov tshuaj halogenated);
• MCA: 5-7 phr (qhov piv rau APP 1: 2 ~ 1: 3, txhawb nqa foaming thiab oxygen cais);
• Zinc borate: 5 phr (kev haus luam yeeb, kev sib koom ua ke char tsim).

Kev Ua Haujlwm Cia Siab:

• LOI: ≥28%;
• UL94 ntsuas: V-1;
• Tus nqi txo: ~ 30% (piv rau cov qauv hluav taws kub-retardancy);
• Tensile zog tuav: ≥80% (APP yuav tsum tau encapsulation los tiv thaiv hydrolysis).

Txheej txheem tseem ceeb:

• APP yuav tsum yog microencapsulated (piv txwv li, nrog melamine-formaldehyde resin) kom tsis txhob muaj dej nqus thiab tsim npuas;
• Ntxiv 1-2 phr hydrophobic fumed silica (piv txwv li, Aerosil R202) rau kev tiv thaiv.

3. Low-Viscosity Easy-Process Formulation (Rau precision electronics bonding, xav tau siab flowability)

Core Flame Retardant Combination:

• Aluminium hypophosphite (AHP): 5-8 phr (nanosized, D50 ≤1 μm);
• Cov kua organic phosphorus nplaim hluav taws retardant (BDP lwm txoj): 8-10 phr (piv txwv li, halogen-free phosphorus-based DMMP derivatives, tswj viscosity);
• Aluminium hydroxide (ATH): 15 phr (spherical alumina composite, ntsuas thermal conductivity);
• MCA: 3-5 phr.

Kev Ua Haujlwm Cia Siab:

• viscosity ntau: 10,000-15,000 cP (ze rau cov kua nplaim hluav taws xob);
• Nplaim hluav taws xob: UL94 V-0 (ua kom zoo dua los ntawm cov kua phosphorus);
• Thermal conductivity: ≥0.6 W / m·K (tsim los ntawm spherical alumina).

Txheej txheem tseem ceeb:

• AHP thiab spherical alumina yuav tsum tau muab sib xyaw thiab sib cais nyob rau hauv siab shear (≥2000 rpm);
• Ntxiv 4-6 phr molecular sieve desiccant rau Tshooj B kom tiv thaiv AHP noo noo nqus.

4. Muab Cov Ntsiab Lus Qhia & Lwm Cov Kev daws teeb meem

1. Synergistic Mechanisms:

• AHP + MCA:AHP txhawb nqa lub cev qhuav dej thiab charring, thaum MCA tso cov pa roj nitrogen thaum cua sov, tsim ib txheej honeycomb zoo li char txheej.
• ATH + Zinc borate:ATH absorbs cua sov (1967 J / g), thiab zinc borate tsim ib txheej iav borate los npog qhov chaw.

2. Lwm yam nplaim taws retardants:

• Polyphosphazene derivatives:High-efficiency thiab eco-friendly, nrog byproduct HCl siv;
• Epoxy silicone cob (ESR):Thaum ua ke nrog AHP, nws txo tag nrho cov khoom thauj (18% rau V-0) thiab txhim kho cov khoom siv kho tshuab.

3. Txheej Txheem Tswj Kev Nyab Xeeb:

• Sedimentation:Cov tshuaj tiv thaiv kab mob (xws li, polyurea-hloov hom) yuav tsum tau yog tias viscosity <10,000 cP;
• Kev tiv thaiv kab mob:Tsis txhob siv cov nplaim hluav taws kub alkaline ntau dhau (piv txwv li, MCA) txhawm rau tiv thaiv kev cuam tshuam nrog cov tshuaj tiv thaiv isocyanate.

5. Cov lus pom zoo rau kev siv

• Ua ntej ntsuas cov nplaim hluav taws kub-retardancy formulation: coated AHP + submicron ATH (nruab nrab particle loj 0.5 μm) ntawm AHP: ATH: MCA = 10: 20: 5 rau thawj zaug optimization.
• Cov kev ntsuam xyuas tseem ceeb:
  → LOI (GB/T 2406.2) thiab UL94 ntsug hlawv;
  → Bond zog tom qab thermal cycling (-30 ℃ ~ 100 ℃, 200 teev);
  → Nplaim retardant nag lossis daus tom qab ceev kev laus (60 ℃ / 7d).

Nplaim Retardant Formulation Table