Gabatarwa na UV absorber

Hasken rana ya ƙunshi hasken ultraviolet mai yawa wanda ke cutar da abubuwa masu launi. Tsayinsa yana kusan 290 ~ 460nm. Wadannan haskoki na ultraviolet masu cutarwa suna haifar da kwayoyin launi suyi rubewa da dushewa ta hanyar sinadarai-rage halayen. Yin amfani da abubuwan sha na ultraviolet na iya hanawa yadda ya kamata ko raunana lalacewar hasken ultraviolet ga abubuwan da aka karewa.

UV absorber wani haske ne mai daidaitawa wanda zai iya ɗaukar ɓangaren ultraviolet na hasken rana da hasken rana ba tare da canza kansa ba. Filastik da sauran kayan aikin polymer suna samar da halayen auto-oxidation a ƙarƙashin hasken rana da haske saboda aikin haskoki na ultraviolet, wanda ke haifar da lalacewa da lalacewar polymers, da lalacewar bayyanar da kayan aikin injiniya. Bayan ƙara masu ɗaukar UV, wannan hasken ultraviolet mai ƙarfi yana iya ɗaukar shi ta hanyar zaɓi, yana mai da shi makamashi mara lahani kuma a sake shi ko cinye shi. Saboda nau'ikan polymers daban-daban, tsayin raƙuman hasken ultraviolet wanda ke sa su lalacewa shima ya bambanta. Masu ɗaukar UV daban-daban na iya ɗaukar haskoki na ultraviolet na tsawon tsayi daban-daban. Lokacin amfani, yakamata a zaɓi masu ɗaukar UV bisa ga nau'in polymer.

Nau'in UV absorber

Nau'ikan masu ɗaukar UV na yau da kullun sun haɗa da: benzotriazole (kamarUV absorber 327benzophenone (irin suUV absorber 531triazine (kamarUV absorber 1164), da kuma hana amine (kamarHaske Stabilizer 622).

Benzotriazole UV absorbers a halin yanzu mafi yadu amfani iri-iri a kasar Sin, amma aikace-aikace sakamako na triazine UV absorbers ne muhimmanci fiye da na benzotriazole. Triazine absorbers suna da kyawawan kaddarorin sha na UV da sauran fa'idodi. Ana iya amfani da su a ko'ina a cikin polymers, suna da kyakkyawan kwanciyar hankali na thermal, kyakkyawan tsarin aiki, da juriya na acid. A aikace-aikace masu amfani, masu ɗaukar triazine UV suna da tasiri mai kyau na daidaitawa tare da hana amine haske stabilizers. Lokacin da aka yi amfani da su biyu tare, suna da tasiri mafi kyau fiye da lokacin da aka yi amfani da su kadai.

Yawancin abubuwan sha da UV da aka fi gani

(1)UV-531
Hasken rawaya ko fari lu'ulu'u foda. Yawaita 1.160g/cm³ (25 ℃). Matsayin narkewa 48 ~ 49 ℃. Mai narkewa a cikin acetone, benzene, ethanol, isopropanol, dan kadan mai narkewa a cikin dichloroethane, mai narkewa cikin ruwa. Solubility a wasu kaushi (g/100g, 25 ℃) shine acetone 74, benzene 72, methanol 2, ethanol (95%) 2.6, n-heptane 40, n-hexane 40.1, ruwa 0.5. A matsayin mai ɗaukar UV, yana iya ɗaukar hasken ultraviolet da ƙarfi tare da tsawon 270 ~ 330nm. Ana iya amfani dashi a cikin robobi daban-daban, musamman polyethylene, polypropylene, polystyrene, guduro ABS, polycarbonate, polyvinyl chloride. Yana da kyawawa mai kyau tare da resins da ƙananan rashin ƙarfi. Babban sashi shine 0.1% ~ 1%. Yana da sakamako mai kyau na haɗin gwiwa lokacin amfani da ƙaramin adadin 4,4-thiobis (6-tert-butyl-p-cresol). Hakanan za'a iya amfani da wannan samfurin azaman stabilizer mai haske don sutura daban-daban.

(2)UV-327
A matsayin mai ɗaukar UV, halayensa da amfaninsa sun yi kama da na benzotriazole UV-326. Zai iya ɗaukar haskoki na ultraviolet da ƙarfi tare da tsawon tsayin 270 ~ 380nm, yana da kwanciyar hankali mai kyau kuma yana da ƙarancin ƙarfi. Yana da dacewa mai kyau tare da polyolefins. Ya dace musamman don polyethylene da polypropylene. Bugu da kari, shi ma za a iya amfani da polyvinyl chloride, polymethyl methacrylate, polyoxymethylene, polyurethane, unsaturated polyester, ABS guduro, epoxy guduro, cellulose guduro, da dai sauransu Wannan samfurin yana da kyau kwarai juriya ga zafi sublimation, wanka juriya, iskar gas Fading juriya da inji dukiya riƙewa. Yana da tasiri mai mahimmanci lokacin da aka yi amfani da shi a hade tare da antioxidants. Ana amfani da shi don haɓaka kwanciyar hankali na thermal oxidation na samfurin.

(3)UV-9
Hasken rawaya ko fari lu'ulu'u foda. Yawaita 1.324g/cm³. Matsayin narkewa 62 ~ 66 ℃. Matsayin tafasa 150 ~ 160 ℃ (0.67kPa), 220 ℃ (2.4kPa). Mai narkewa a cikin mafi yawan kaushi na halitta kamar acetone, ketone, benzene, methanol, ethyl acetate, methyl ethyl ketone, ethanol, amma insoluble cikin ruwa. Solubility a wasu kaushi (g/100g, 25 ℃) shi ne benzene 56.2, n-hexane 4.3, ethanol (95%) 5.8, carbon tetrachloride 34.5, styrene 51.2, DOP 18.7. A matsayin UV absorber, shi ne dace da wani iri-iri na robobi irin su polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, unsaturated polyester, ABS guduro, cellulose guduro, da dai sauransu Matsakaicin sha raƙuman ruwa iyaka ne 280 ~ 340nm, da kuma general sashi ~ 1.51%. Yana yana da kyau thermal kwanciyar hankali kuma ba ya bazu a 200 ℃. Wannan samfurin da kyar yake ɗaukar hasken da ake iya gani, don haka ya dace da samfurori masu launin haske. Hakanan ana iya amfani da wannan samfurin a cikin fenti da roba na roba.