He tirohanga whānui mō te whakamahinga ongā kaihoko hononga kapia amino
Ko te mahi matua a ngā kapia amino (melamine-formaldehyde, benzomelamine-formaldehyde, me ngā kapia urea-formaldehyde) i roto i ngā paninga thermosetting ko te hono i ngā ngota rauemi hanga kiriata matua ki roto i tētahi hanganga whatunga toru-ahu mā roto i ngā tauhohenga matū. Ka whiwhihia tēnei hanganga whatunga mā te tauhohenga o ngā ngota kapia amino me ngā rōpū mahi i runga i ngā ngota rauemi hanga kiriata, ā, i te wā kotahi mā te polymerization condensation me ētahi atu ngota kapia amino. Ka tere te tauhohenga o ngā kapia amino ki ngā polymer kei roto ngā rōpū hydroxyl tuatahi me te tuarua, ngā rōpū carboxyl, me ngā rōpū amide; nō reira, he mea noa te whakamahi i ngā kapia amino i roto i ngā pūnaha peita i runga i ngā kapia acrylic, polyester, alkyd, epoxy rānei.
Ka whakamahia hoki ngā kapia amino i roto i ngā pūnaha polyurethane hei tāpiri paninga hei whakapai ake i te mahi whānui o ngā paninga mō ētahi tono.
Te kaupapa matua o ngā kapia amino:
Ko te hiranga o ngā kapia amino i roto i ngā wanihi tunu kai he nui atu i tōna nui i roto i ngā paninga. Kei te piki haere te hiranga o te mārama ki te whakamahi i ngā āhuatanga matū o ngā kapia amino i roto i te hoahoa hanganga paninga. Hei tauira,Mena kāore ngā kaihanga paninga i te makona ki ētahi āhuatanga o te kiriata paninga, ka taea e rātou te whakatika mā te whakamahi i ngā tikanga e whai ake nei:
1. Te whakapai ake, te whiriwhiri anō rānei i te kapia hanga-kiriata tonu;
2. Te kōwhiringa o ngā kapia amino (te whakapūtanga methyl etherification, te whakapūtanga butyl rānei, me te kōwhiringa o te taumata o te whakapūtanga, me ētahi atu);
3. Te ōwehenga o te kapia hanga-kiriata ki te kapia amino.
4. Kōwhiringa o te kaiwhakaoho (me tāpiri, me te nui hoki hei tāpiri).
Ko ngā kōrero e whā i runga ake nei, haunga te tuatahi,e pā ana ki ngā kapia amino. Ko ngā āhuatanga o ngā kapia amino e whakawhirinaki ana ki ō rātou rōpū mahi me ō rātou mahiNō reira, he mea nui te mārama ki te hanganga o ngā kapia amino. Heoi, i mua i te mārama ki ngā kapia amino, he mea nui kia mārama ki ngā kapia manaaki e whakamahia ana me ēnei.
E ai ki te kōrero i mua ake nei, ko ngā kapia amino te nuinga o te wāe whakamahia ana me ngā kapia alkyd, ngā kapia acrylic, ngā kapia polyester, me ngā kapia epoxy. Ko ngā kapia alkyd ka hangaia i te nuinga o te wā mai i ngā kapia polyol me ngā kapia polyacid mā te esterification. I te wā e hangaia ana, he nui rawa ngā waipiro; kāore pea ētahi rōpū carboxyl o ngā polyacids e tauhohe katoa, ka hua ake he nui ngā rōpū carboxyl me te hydroxyl kei roto i ngā kapia alkyd. Ko te nui o ngā rōpū carboxyl me te hydroxyl ka tohuhia e te uara waikawa me te uara hydroxyl. Ko te uara waikawa e pā ana ki te maha o ngā mirikaramu o te KOH e hiahiatia ana hei whakakore i te 1 karamu o te kapia totoka mā te titration ki te KOH. Ko te uara hydroxyl e pā ana ki te maha o ngā mirikaramu o te KOH e hiahiatia ana hei whakakore katoa i ngā rōpū OH i roto i te 1 karamu o te kapia totoka mā te titration ki te KOH. Waihoki, kei roto hoki i ngā kapia polyester, ngā kapia acrylic, me ngā kapia amino he nui o ngā rōpū carboxyl me te hydroxyl. Ko te rerekētanga kei roto i ngā rauemi mata e whakamahia ana hei hanga i ngā kapia; hei tauira, ko ngā rōpū carboxyl i roto i ngā kapia acrylic i ahu mai i te waikawa acrylic, ā, ko ngā rōpū hydroxyl i ahu mai i te waikawa hydroxyacrylic. He rerekē anō hoki te nui o ngā rōpū carboxyl me te hydroxyl i roto i ngā amino resins. Ko te uara waikawa, te uara hydroxyl, me te matotoru he tohu nui katoa o ngā resins, e pā tika ana ki tā rātou mahi.
Hei te hoki ki te kaupapa o ngā kapia amino, me titiro tuatahi tātou ki tōna hanganga:
Pikitia 1:
Pikitia 2
E whakaatu ana te Pikitia 1 i tētahi kapia amino kua whakapūmautia ā-wāhanga kei roto ngā rōpū alkoxy, imino, me te hydroxymethyl. Mēnā ka whakaarohia te mowhiti ono-mema i hangaia e ngā ngota waro me te hauota hei angaanga, ka taea te whakaahua i ngā manga, i ngā hanganga rānei i ahu mai i taua mowhiti he toru ngā pane me ngā ringa e ono. Ko te tini o ngā rerekētanga o ngā āhuatanga o ngā kapia amino nā ngā rerekētanga o ēnei "ringa" e ono me ō rātou whakaritenga me ngā huinga uaua.
E whakaatu ana te Pikitia 2 i tētahi hanganga HMMM tino ōrite, arā, he kapia amino kua methylated katoa, me te kotahi anake te rōpū mahi: te rōpū methoxy, he mea tino pai. Nā te mea kāore e taea e te taumata o te etherification te eke ki te 1:6 (te teitei rawa) i roto i te hanga tuturu, ka mau tonu i roto i te kapia amino kua methylated katoa ētahi rōpū imino me te hydroxymethyl.
Me tīmata mā te mārama ki ngā mātāpono o ngā kapia amino kia mōhio ai tātou ki ō rātou āhuatanga:
Ko te taahiraa tuatahi i roto i te hanga i te kapia ko te tauhohe i te melamine ki te formaldehyde i te aroaro o te whakakorikori hei hanga i te polyhydroxymethyl melamine. Ka taea te huri i ngā ngota hauwai hohe katoa i runga i te mowhiti triazine ki ngā rōpū hydroxymethyl, engari i roto i te mooni, e 2 ki te 6 ngā mole o te formaldehyde e tauhohe ana ki runga i te mowhiti triazine. Ko ngā ngota hauwai hohe kāore i tauhohe e toe ana e tohuhia ana e ngā rōpū imino. Ka kite tātou i muri mai, he mahi nui tā ēnei rōpū i roto i te tukanga whakamaroke mā te polymerization whaiaro-whakapūmau.
He tino pūmau te polyhydroxymethyl melamine, ā, he iti noa te wairewa i roto i ngā whakarewa paninga tikanga. Ko te mahi matua a ngā kapia amino he hononga whakawhiti me te whakamaroke i roto i ngā paninga. Hei waihanga i tētahi kaiawhina hononga whakawhiti e tika ana mō ngā paninga, ka whakaeterehia te rōpū hydroxymethyl ki tētahi waipiro mekameka-poto hei whakaiti i tōna tauhohenga me te whakapai ake i tōna hototahi ki ngā rauemi hanga kiriata tikanga me ngā whakarewa aliphatic. Ko te methanol me te butanol e whakamahia whānuitia ana hei waipiro mekameka-poto. Mā te whakahaere i te nui o te methanol, te butanol rānei i tāpirihia me ētahi atu āhuatanga, ka taea te whiwhi kapia amino me ngā nekehanga rerekē o te whakaetere.
Ko ngā pae kua tauhohe ki te formaldehyde (ngā rōpū hydroxymethyl) anake ka taea te whakakī ki ngā waipiro; ko ngā ngota hauwai kāore i tauhohe (ngā rōpū imino) kāore e tauhohe ki ngā waipiro mekameka-poto. Hei tāpiri, e whakaatu ana tēnei tauhohenga ka tauhohe ngā rōpū hydroxymethyl e ono ki ngā waipiro hei hanga hexaalkoxymethyl melamine, ko te tikanga ka taea te whakahaere i te tauhohenga o te kotahi ki te ono ngā rōpū hydroxymethyl ki ngā waipiro. Koinei te take he rerekē ngā momo amino resins.
Te whakapūhui-ā-koe o ngā kapia amino :
Ko te taumaha ngota o ngā kapia amino ka whakatauhia e te nui o te whakapūtanga-ake, tehononga whakawhitii waenga i ngā rōpū mahi (imino, hydroxymethyl, alkoxymethyl) i runga i te mowhiti triazine me ngā ngota melamine. I ngā tono mutunga, ka pā nui te nui o te polymerization hononga-whiti ki te taumaha ngota o te amino resin me te mahi a te kiriata paninga.
Ka taea te tauhohenga whakapūmau-ake o ngā kapia amino mā te ara e whai ake nei:
Pikitia 3:
Ko te tauhohenga i te taha maui ka hanga he piriti methylene, ko te tauhohenga i te taha matau ka hanga he piriti methylene ether. Ko te nui o te hononga i roto i ngā kapia amino ka whakaatuhia i te nuinga o te wā ko te nui o te polymerization (DP): DP = te taumaha ngota / te taumaha o ia mowhiti triazine. Ko ngā kapia amino o mua he polymerizing-whaiaro te nuinga, me te DP > 3.0. Nā ngā whanaketanga hangarau kua taea te whakaiti i te condensation-whaiaro i roto i ngā kapia amino kua oti. I tēnei wā, ko ngā kapia melamine e wātea ana i te hokohoko he iti iho i te 1.1 ngā DP.
Ko te pānga matua o te taumaha ngota ngota o te kapia amino e whakaatahia ana i roto i te matotoru o te paninga. Me whakaranua ngā kapia melamine me te DP > 2.0 ki te whakarewa ki te 50%–80% o ngā totoka kia tutuki ai te matotoru e tika ana. Ko ngā kapia melamine momo-monomer me te DP i waenga i te 1.1 me te 1.5 ka tukuna i roto i te ahua totoka whai hua 100%; he pānga nui ngā whakarewa tāpiri ki ngā VOC o te paninga kua oti. Ka pā hoki te taumaha ngota ngota o ngā kapia amino ki te tauhohenga whakamaroke paninga me ngā āhuatanga kiriata. Ka tae te pūnaha paninga e whakamahi ana i te kapia amino DP-teitei ki te mātotoru hononga kua tohua i roto i te wā poto ake i te pūnaha paninga e whakamahi ana i te kapia amino me te hanganga ōrite engari he DP iti ake. Nō reira, ko ngā paninga kei roto ngā kaihoko hononga DP-teitei e hiahia ana ki te iti ake o te whakakorikori, ki te whakakorikori waikawa ngoikore rānei kia tutuki ai te āhua whakamaroke ōrite. Ko te pānga o te taumaha ngota ngota ki ngā āhuatanga kiriata kei roto i te awhe ngāwari. Ko ngā paninga kua whakamarokehia ki ngā kapia amino DP-teitei he nui ake te ōrau o ngā here amino-amino me te iti ake o ngā here amino-rākī. Ka hangaia e tēnei momo hanganga whatunga whakawhiti he paninga he pakari pai engari ka pakarukaru pea. I ētahi wā ka taea te whakatika mā te whiriwhiri i tētahi kapia peita ngāwari ake. Heoi, ko ngā tono e hiahia ana ki ngā paninga tino ngāwari ka hiahiatia he kapia amino monomeric.
Ka taea e ngā polyester kei roto ngā rōpū carboxyl te tauhohe ki te melamine-formaldehyde hei whakaputa i ngā paninga mata thermosetting whai hua me te whānuitanga o ngā āhuatanga ā-tinana.
He maha ngā kapia melamine-formaldehyde butylated e whai hua ana i te taha hokohoko, nā te rerekētanga o te taumata tīmatanga o te polymerization (taumaha ngota) me te ōwehenga o ngā rōpū alkoxy ki ērā kāore he rōpū hydroxymethyl me ngā hauwai amino. Ka pā ēnei rerekētanga ki te matotoru wai, ki te hototahitanga o te melamine me te polyester, me te tere o te whakamaroke o te enamel. Ko ngā kapia melamine tuku iho, e tauhohe ana ki ngā rōpū hydroxyl taha, ka honoa tuatahi ki ngā ngota polyester. Nā te mea ka whakakorikorihia te tauhohenga hononga-waikawa, i ngā pāmahana whakamaroke i waenga i te 120°C me te 150°C, ka pāngia e ngā waikawa kaha te tauhohenga hononga-waikawa o ngā kapia polyester; heoi, ko ētahi polyester me tāpiri he whakakorikori waikawa ki roto i ngā waikawa ngoikore rawa hei whakamaroke i te pūnaha enamel.
Ko te āhuatanga e whai ake nei: Haunga te tauhohenga honohono o te melamine-polyester, ka pāngia hoki te kapia melamine-formaldehyde butylated e te tauhohenga whakapūmau-ake. Arā, ka pāngia te kapia amino e te hononga-ake hei hanga i te hanganga whatunga melamine. Ka puta tēnei tauhohenga i te wā kotahi me te tauhohenga melamine-polyester, ā, he tauhohenga whakataetae. Ko te take o tēnei tauhohenga, hei tāpiri atu ki ngā rōpū butoxy, kei roto hoki i te kapia melamine-formaldehyde butylated ngā rōpū methyl warowaihā kore utu me te hauwai mai i ngā rōpū imino, ka taea e ēnei katoa te tauhohe tetahi ki tetahi. Kia pāngia te kapia amino e te hononga-ake, ka ngaro ētahi o ana mahi.
Ahakoa he maha ngā wā ka nui ake te mārō me te ātete matū o ngā paninga nā te hononga-whaiaro, ka nui ake te ngaronga o te ngāwari. Hei whakatutuki i te ngāwari e tika ana i roto i ngā wanihi polyester...
Ko te Hexamethoxymethyl melamine (HMMM) he kapia amino monomeric kua hydroxymethylated katoatia, kua methylated katoatia. He rite ki te butylated melamine-formaldehyde, ka pāngia e te tauhohenga hononga-whiti me ngā rōpū hydroxyl o te kapia polyester i te wā e whakamahanahia ana, ka hanga he totoka kore-ngawari. Ko te tikanga, ki te kore he whakakorikori waikawa, e kore te HMMM e pāngia e te hononga-whaiaro ahakoa te roa o te wā, te pikinga rānei o te pāmahana. Heoi, ka pāngia e te HMMM papatipu he tauhohenga hononga-whaiaro i te 150°C i te aroaro o te whakakorikori waikawa kaha. I tetahi atu taha, ahakoa te kore o te waikawa kaha, ka pāngia e ngā kapia butylated melamine me te urea tikanga ngā tauhohenga hononga-whaiaro kaha me te pikinga o te pāmahana.
Te tauhohenga whakamaroke o ngā kapia amino:
I te mea e whakamahia ana ngā kapia amino hei hono i ngā ngota rauemi hanga kiriata matua ki roto i tētahi hanganga whatunga, he mea tino whakamere te tauhohenga whakapūtātanga-tahi o ngā kapia amino me ngā kapia peita. Ko tētahi tauira noa ko te tauhohenga etherification (whakawhiti)o ngā rōpū hydroxyl i runga i ngā kapia peita me ngā rōpū alkoxymethyl i runga i ngā kapia amino.
I raro i ngā āhuatanga o te wera me te waikawa whakakorikori (ko te tikanga he whakamaroke), ka tere te hononga whakawhiti, ka hono i ngā rōpū hydroxyl katoa e wātea ana i runga i te peita. Inaa, i te hanganga o te whatunga polymer, ka heke te rere o ngā tauhohenga, ka waiho ētahi rōpū hydroxyl kāore e tauhohe. I te nuinga o te wā, ina he nui rawa te kapia amino i roto i te paninga ki te ōwehenga pai, ka taea e ngā rōpū alkoxy e toe ana te whai wāhi ki ētahi atu tauhohenga, ka noho kore tauhohenga rānei i roto i te kiriata paninga. E ai ki te kōrero i mua ake nei, ka tere te hononga o ngā kapia amino ki a rātou anō, ka hua ake he pikinga o te taumaha ngota i te wā e hangaia ana. Ka puta anō hoki ēnei tauhohenga i te wā e whakamaroke ana i te paninga. Nō reira, kaua e waiho hei āhuatanga kino, he mea nui te hononga-whakakorikori o ngā kapia amino kia whiwhi ai i tētahi matrix polymer pakari, piri. Ka whai wāhi ngā rōpū mahi e toru o ngā kapia amino ki ngā tauhohenga hononga-whakakorikori, ā, i roto i ngā paninga kapia melamine kua whakakorikoria katoatia e ngā waikawa kaha, kei reira ngā taunakitanga e puta ai ēnei tauhohenga i muri i te whakawhiti ether me te kapia paninga. I te korenga o ngā whakakōkī o waho, ngā whakakōkī waikawa ngoikore rānei, ka puta ake ēnei tauhohenga honohono-ake ki te whānuitanga nui ake i roto i ngā pūnaha kapia melamine me te mahi imino/hydroxymethyl teitei. I ngā take e rua, he mea nui te tauhohenga whakakōkī-ake iti mō te hanganga o tētahi hanganga whatunga pai.
I te wā e whakamarokehia ana ngā paninga honohono kapia amino, ko ētahi atu tauhohenga ka puta ko te tango formaldehyde me te hydrolysis. Ka puta wawe te tango formaldehyde i ngā pāmahana whakamaroke noa, koinei pea te take anake mō te tukunga o te formaldehyde i te wā e whakamarokehia ana ngā kapia amino; ko tētahi atu formaldehyde he formaldehyde kore utu.
Ina honoa ngā kapia amino ki te hanga kiriata me te whakamaroke, ka puta ētahi tauhohenga waikura. I roto i tēnei tukanga, ka hurihia ētahi rōpū alkoxymethyl ki ngā rōpū hydroxymethyl. Ka taea te waikura o ngā kapia melamine he nui te ihirangi imino, hydroxymethyl rānei e ngā kawakore, ā, ka taea hoki te āta haere i te pāmahana rūma. Nā tēnei ka ngāwari ake te hono-whaiaro o ngā kapia amino, ka piki ake te matotoru o te paninga i te wā e rongoatia ana. Hei karo i tēnei, ka taea te whakamahi i ngā kapia melamine kua methylated katoa, i ngā whakarewa-tahi rānei e ātete ana ki te waikura kawakore i roto i ngā paninga wai-hāngai. He ātete ngā kapia melamine kua alkylated katoa ki te waikura kua whakakōkiritia ki te kawakore i roto i ngā pūnaha wai-hāngai. Kāore ngā kapia melamine kua alkylated katoa me te alkylated wāhanga e ātete ana ki te waikura kua whakakōkiritia ki te waikawa i roto i ngā pūnaha wai-hāngai; nō reira, me whakamahi he whakakōkiri waikawa kua āraia i roto i te pūnaha wai-hāngai.
Ki te hiahia koe ki te mōhio atukaihoko hononga whakawhitihua, tēnā whakapā mai ki a mātou.
Wā tuku: Hakihea-19-2025