I. Sharuɗɗa da Ma'anoni

Hasken rana yana ɗauke da babban adadin hasken ultraviolet (UV), tare da tsawon tsayin kusan 290-460 nm, wanda ke da illa ga abubuwa masu launi. Wannan hasken UV mai cutarwa yana sa ƙwayoyin launi su ruɓe kuma su ɓace ta hanyar amsawar sinadarai ta hanyar redox. Amfani da masu sha UV na iya hana ko rage tasirin radiation UV akan abubuwan da aka kare yadda ya kamata.

Mai ɗaukar UV wani abu ne mai daidaita haske wanda ke shan ɓangaren hasken rana na UV da tushen hasken fluorescent ba tare da fuskantar wani canji ba. A ƙarƙashin hasken rana da hasken rana, robobi da sauran polymers suna fuskantar halayen oxidation ta atomatik saboda aikin hasken UV, wanda ke haifar da lalacewa da lalacewa, wanda ke haifar da mummunan kamanni da halayen injiniya. Ƙara masu ɗaukar UV yana ɗaukar wannan hasken UV mai ƙarfi sosai, yana mayar da shi zuwa makamashi mara lahani wanda aka saki ko aka cinye. Tunda polymers daban-daban suna da bambancin tsayin tsayin UV wanda ke haifar da lalacewa, masu ɗaukar UV daban-daban suna shan bambancin tsayin tsayin hasken UV. Saboda haka, ya kamata a zaɓi mai ɗaukar UV da ya dace bisa ga nau'in polymer da aka yi amfani da shi.

II. Rarrabawa da Ayyukan Masu Shakar Ultraviolet

Masu ɗaukar hasken ultraviolet ya kamata su cika waɗannan sharuɗɗan:

① Yana iya shan hasken ultraviolet sosai (musamman hasken ultraviolet mai tsawon tsayi na 290 ~ 400nm); ② Yana da kyakkyawan kwanciyar hankali na zafi kuma ba zai canza ba saboda zafi ko da a lokacin sarrafawa, tare da ƙarancin canjin yanayin zafi; ③ Yana da kyakkyawan kwanciyar hankali na sinadarai kuma ba zai yi mummunan tasiri ga abubuwan da ke cikin samfurin ba; ④ Yana da kyakkyawan daidaituwa kuma ana iya warwatse shi daidai a cikin kayan ba tare da fure ko zubewa ba; ⑤ Mai sha da kansa yana da kyakkyawan kwanciyar hankali na photochemical, baya ruɓewa, kuma baya canza launi; ⑥ Ba shi da launi, ba ya da guba, kuma ba shi da wari; ⑦ Ana iya wanke shi; ⑧ Yana da araha kuma yana samuwa cikin sauƙi.

A halin yanzu, masu shanyewar UV na Benzotriazole sune nau'in da aka fi amfani da shi a China, amma masu shanyewar UV na triazine suna nuna kyakkyawan aiki fiye da benzotriazoles. Masu shanyewar Triazine suna da kyawawan kaddarorin shanyewar UV, tare da wasu fa'idodi, wanda hakan ke sa su zama masu amfani sosai a cikin polymers. Suna nuna kyakkyawan kwanciyar hankali na zafi, kyakkyawan kwanciyar hankali na sarrafawa, da juriya ga acid. A aikace-aikace na zahiri, masu shanyewar UV na triazine suna nuna ƙarfi mai ƙarfi na haɗin gwiwa tare da masu daidaita hasken amine masu hanawa; idan aka yi amfani da su tare, suna samar da sakamako mafi kyau fiye da lokacin da aka yi amfani da su daban-daban.

III. Da dama daga cikin abubuwan shaye-shayen ultraviolet da aka saba amfani da su

(1) Kayayyakin amsawar o-nitroaniline da p-cresol

Yana bayyana a matsayin lu'ulu'u marasa launi ko rawaya mai haske. Yana narkewa a cikin sinadarai da yawa na halitta kamar fetur, benzene, da acetone. Yana da ƙarancin narkewa a cikin ruwa kuma ba ya rugujewa ta hanyar alkalis ko acid mai ƙarfi. Yana iya amsawa da ions na ƙarfe masu nauyi don samar da gishiri. Yana iya shanye hasken ultraviolet tare da tsawon tsayi na 270-280 nm. Wurin narkewarsa shine 130-131℃.

Ana amfani da shi galibi a cikin resins kamar polyester, polyester mai chlorinated, cellulose acetate, polyvinyl chloride, polystyrene, plexiglass, da polyacrylonitrile. Yana nuna kwanciyar hankali mafi kyau a cikin samfuran haske fiye da samfuran launi. Yawan da ake buƙata a cikin samfuran da aka gama shine ≤0.5%.

(2) 2-Hydroxy-4-methoxybenzophenone (UV-9)

Foda mai launin rawaya ko fari. Yawansa 1.324 g/cm³. Matsayin narkewa 62-66℃. Matsayin tafasa 150-160℃ (0.67 kPa), 220℃ (2.4 kPa). Ana narkewa a yawancin sinadaran da ke narkewa a cikin halitta kamar acetone, ketones, benzene, methanol, ethyl acetate, methyl ethyl ketone, da ethanol; ba ya narkewa a cikin ruwa. Narkewa (g/100g, 25℃) a cikin wasu sinadaran da ke narkewa kamar haka: benzene 56.2, n-hexane 4.3, ethanol (95%) 5.8, carbon tetrachloride 34.5, styrene 51.2, DOP 18.7.

A matsayinsa na mai shaƙar UV, ya dace da nau'ikan robobi daban-daban kamar polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, unsaturated polyester, ABS resin, da cellulose resin. Matsakaicin tsawon sha shine 280~340nm, kuma matsakaicin adadin shine 0.1%~1.5%. Yana da kyakkyawan kwanciyar hankali na zafi kuma baya ruɓewa a 200℃. Wannan samfurin baya shan kusan babu haske da ake gani, wanda hakan ya sa ya dace da samfuran masu launin haske da haske. Haka kuma ana iya amfani da shi a cikin fenti da robar roba.

(3) 2-Hydroxy-4-n-octyloxybenzophenone (UV-531)

Foda mai launin rawaya ko fari. Yawansa 1.160 g/cm³ (25℃). Matsayin narkewa 48~49℃. Yana narkewa a cikin acetone, benzene, ethanol, da isopropanol; yana narkewa kaɗan a cikin dichloroethane; ba ya narkewa a cikin ruwa. Narkewa (g/100g, 25℃) a cikin wasu sinadarai shine: acetone 74, benzene 72, methanol 2, ethanol (95%) 2.6, n-heptane 40, n-hexane 40.1, ruwa 0.5.

A matsayinsa na mai shaƙar UV, yana shan hasken ultraviolet sosai tare da tsawon tsayin 270-330 nm. Ana iya amfani da shi a cikin robobi daban-daban, musamman polyethylene, polypropylene, polystyrene, ABS resin, polycarbonate, da polyvinyl chloride. Yana da kyakkyawan jituwa da resins da ƙarancin canjin yanayi. Matsakaicin adadin shine 0.1% zuwa 1%. Yana da kyakkyawan tasirin haɗin gwiwa idan aka yi amfani da shi tare da ƙaramin adadin 4,4-thiobis (6-tert-butyl-p-cresol). Hakanan ana iya amfani da wannan samfurin azaman mai daidaita haske a cikin nau'ikan rufi daban-daban.

(4) 2-(2′-hydroxy-3′,5′-di-tert-phenyl)-5-chlorobenzotriazole (UV-327) wani abu ne mai shaƙar UV wanda ke da irin wannan siffa kuma yana amfani da shi ga benzotriazole UV-326. Yana shan hasken ultraviolet sosai tare da tsawon tsayin 270~380nm, yana da kyakkyawan kwanciyar hankali na sinadarai, kuma yana da ƙarancin canzawa. Yana da kyakkyawan jituwa da polyolefins. Ya dace musamman ga polyethylene da polypropylene. Bugu da ƙari, ana iya amfani da shi a cikin polyvinyl chloride, polymethyl methacrylate, polyoxymethylene, polyurethane, polyester mara cika, resin ABS, resin epoxy, resin cellulose, da sauransu. Wannan samfurin yana da kyakkyawan juriya ga zafi, wankewa, juriya ga bushewar iskar gas, da riƙe kayan injiniya. Yana da tasiri mai mahimmanci idan aka yi amfani da shi tare da antioxidants. Ana amfani da shi don inganta kwanciyar hankali na thermo-oxidative na samfuran.

(5) Resorcinol monobenzoate foda ne mai farin crystalline. Wurin narkewa 132~135℃. Yawan yawa 0.68 g/cm³ (20%). Yana narkewa a cikin acetone da ethanol, yana narkewa kaɗan a cikin benzene, ruwa, n-heptane, da sauransu. A matsayin mai daidaita hasken UV, aikinsa yayi kama da na masu daidaita hasken benzophenone. Ana amfani da shi galibi a cikin polyvinyl chloride, resin cellulose, da polystyrene, yawanci a cikin adadin 1% zuwa 2%.