Kev Taw Qhia Txog UV absorber

Lub hnub ci muaj ntau lub teeb ultraviolet uas ua rau cov khoom muaj xim puas tsuaj. Nws qhov wavelength yog li 290 ~ 460 nm. Cov teeb ultraviolet no ua rau cov xim molecules lwj thiab ploj mus los ntawm cov tshuaj oxidation-reduction reactions. Kev siv cov khoom nqus ultraviolet tuaj yeem tiv thaiv lossis ua kom tsis muaj zog ntawm kev puas tsuaj ntawm cov teeb ultraviolet rau cov khoom tiv thaiv.

UV absorber yog lub teeb stabilizer uas tuaj yeem nqus tau qhov ultraviolet ntawm lub hnub ci thiab lub teeb fluorescent yam tsis hloov nws tus kheej. Yas thiab lwm yam khoom siv polymer tsim cov tshuaj tiv thaiv auto-oxidation hauv qab lub hnub ci thiab fluorescence vim yog qhov kev ua ntawm ultraviolet rays, uas ua rau muaj kev puas tsuaj thiab kev puas tsuaj ntawm cov polymers, thiab kev puas tsuaj ntawm cov tsos thiab cov khoom siv kho tshuab. Tom qab ntxiv UV absorbers, lub teeb ultraviolet siab no tuaj yeem nqus tau xaiv, hloov nws mus rau hauv lub zog tsis muaj teeb meem thiab tso tawm lossis noj. Vim muaj ntau hom polymers, qhov wavelengths ntawm ultraviolet rays uas ua rau lawv puas tsuaj kuj txawv. Cov UV absorbers sib txawv tuaj yeem nqus tau cov ultraviolet rays ntawm ntau qhov wavelengths. Thaum siv, UV absorbers yuav tsum tau xaiv raws li hom polymer.

Hom ntawm UV absorber

Cov hom UV absorbers feem ntau muaj xws li: benzotriazole (xws liCov khoom nqus UV 327), benzophenone (xws liCov khoom nqus UV 531), triazine (xws liCov khoom nqus UV 1164), thiab cov amine uas cuam tshuam (xws liLub Teeb Ruaj Kho 622).

Benzotriazole UV absorbers tam sim no yog cov khoom siv dav tshaj plaws hauv Suav teb, tab sis cov nyhuv ntawm triazine UV absorbers zoo dua li benzotriazole. Triazine absorbers muaj cov yam ntxwv zoo heev rau kev nqus UV thiab lwm yam zoo. Lawv tuaj yeem siv dav hauv cov polymers, muaj kev ruaj khov zoo heev, kev ua haujlwm zoo, thiab kev tiv taus kua qaub. Hauv kev siv tiag tiag, triazine UV absorbers muaj kev sib koom tes zoo nrog cov tshuaj amine teeb stabilizers. Thaum ob qho no siv ua ke, lawv muaj cov txiaj ntsig zoo dua li thaum siv ib leeg.

Muaj ntau yam khoom nqus UV uas pom ntau

(1)UV-531
Hmoov crystalline daj los yog dawb. Qhov ceev 1.160g/cm³ (25℃). Melting point 48~49℃. Yaj hauv acetone, benzene, ethanol, isopropanol, yaj me ntsis hauv dichloroethane, yaj tsis tau hauv dej. Yaj tau hauv qee cov kuab tshuaj (g/100g, 25℃) yog acetone 74, benzene 72, methanol 2, ethanol (95%) 2.6, n-heptane 40, n-hexane 40.1, dej 0.5. Ua ib qho UV absorber, nws tuaj yeem nqus tau lub teeb ultraviolet nrog lub wavelength ntawm 270~330nm. Nws tuaj yeem siv rau hauv ntau yam yas, tshwj xeeb tshaj yog polyethylene, polypropylene, polystyrene, ABS resin, polycarbonate, polyvinyl chloride. Nws muaj kev sib raug zoo nrog cov resins thiab tsis tshua muaj volatility. Qhov ntau npaum li cas yog 0.1%~1%. Nws muaj qhov zoo synergistic nyhuv thaum siv nrog me me ntawm 4,4-thiobis (6-tert-butyl-p-cresol). Cov khoom no kuj tseem siv tau ua lub teeb stabilizer rau ntau yam coatings.

(2)UV-327
Ua ib qho khoom nqus UV, nws cov yam ntxwv thiab kev siv zoo ib yam li benzotriazole UV-326. Nws tuaj yeem nqus tau cov teeb ci ultraviolet nrog lub wavelength ntawm 270 ~ 380 nm, muaj kev ruaj khov tshuaj zoo thiab tsis tshua muaj volatility. Nws muaj kev sib raug zoo nrog polyolefins. Nws yog tshwj xeeb tshaj yog tsim rau polyethylene thiab polypropylene. Tsis tas li ntawd, nws kuj tuaj yeem siv rau polyvinyl chloride, polymethyl methacrylate, polyoxymethylene, polyurethane, unsaturated polyester, ABS resin, epoxy resin, cellulose resin, thiab lwm yam. Cov khoom no muaj kev tiv thaiv zoo heev rau kev kub sublimation, kev tiv thaiv ntxuav, kev tiv thaiv roj fading thiab kev khaws cia cov khoom siv kho tshuab. Nws muaj cov nyhuv synergistic tseem ceeb thaum siv ua ke nrog cov antioxidants. Nws yog siv los txhim kho qhov ruaj khov thermal oxidation ntawm cov khoom.

(3)UV-9
Hmoov crystalline daj los yog dawb. Qhov ceev 1.324g/cm³. Melting point 62~66℃. Boiling point 150~160℃ (0.67kPa), 220℃ (2.4kPa). Yaj tau hauv feem ntau cov organic solvents xws li acetone, ketone, benzene, methanol, ethyl acetate, methyl ethyl ketone, ethanol, tab sis tsis yaj hauv dej. Qhov yaj tau hauv qee cov solvents (g/100g, 25℃) yog benzene 56.2 solvent, n-hexane 4.3, ethanol (95%) 5.8, carbon tetrachloride 34.5, styrene 51.2, DOP 18.7. Ua ib qho khoom nqus UV, nws tsim nyog rau ntau yam yas xws li polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, unsaturated polyester, ABS resin, cellulose resin, thiab lwm yam. Qhov siab tshaj plaws ntawm qhov nqus tau yog 280 ~ 340 nm, thiab qhov ntau npaum li cas yog 0.1% ~ 1.5%. Nws muaj kev ruaj khov zoo thiab tsis lwj ntawm 200 ℃. Cov khoom no tsis tshua nqus lub teeb pom kev, yog li nws tsim nyog rau cov khoom xim pob tshab. Cov khoom no kuj tseem siv tau rau hauv cov xim pleev xim thiab roj hmab hluavtaws.