Ukubuka konke kokusetshenziswa kweama-amino resin crosslinking agents
Indima eyinhloko yama-amino resins (i-melamine-formaldehyde, i-benzomelamine-formaldehyde, kanye nama-urea-formaldehyde resins) ekumbozweni kwe-thermosetting ukuxhumanisa ama-molecule ayinhloko ezinto ezakha ifilimu abe yisakhiwo senethiwekhi esinezinhlangothi ezintathu ngokusebenzisa ukusabela kwamakhemikhali. Lesi sakhiwo senethiwekhi sitholakala ngokusabela kwama-molecule e-amino resin namaqembu asebenzayo kuma-molecule ezinto ezakha ifilimu, kanye ngesikhathi esifanayo ngokusebenzisa i-condensation polymerization namanye ama-molecule e-amino resin. Ama-amino resins asabela kalula nama-polymer aqukethe amaqembu e-hydroxyl ayinhloko nawesibili, amaqembu e-carboxyl, namaqembu e-amide; ngakho-ke, ama-amino resins avame ukusetshenziswa ezinhlelweni zokupenda ezisekelwe kuma-resin e-acrylic, i-polyester, i-alkyd, noma i-epoxy.
Ama-resin e-amino asetshenziswa futhi ezinhlelweni ze-polyurethane njengezengezo zokumboza ukuze kuthuthukiswe ukusebenza okuphelele kokumboza kwezinye izinhlelo zokusebenza.
Isimiso sama-amino resins:
Ukubaluleka kwama-amino resins kuma-varnish okubhaka kudlula kakhulu isilinganiso sawo ekumbozweni. Ukuqonda ukuthi ungawasebenzisa kanjani amakhemikhali ama-amino resins ekwakhiweni kokwakheka kokumbozwa kuya ngokuya kuba kubaluleke kakhulu. Isibonelo,Uma abakhiqizi bokumboza benganelisekile ngezakhiwo ezithile zefilimu yokumboza, bangazilungisa besebenzisa izindlela ezilandelayo:
1. Ukuthuthukiswa noma ukukhethwa kabusha kwe-resin eyakha ifilimu ngokwayo;
2. Ukukhethwa kwama-amino resins (i-methyl etherification noma i-butyl etherification, kanye nokukhethwa kwezinga le-etherification, njll.);
3. Isilinganiso se-resin eyakha ifilimu ne-amino resin.
4. Ukukhetha i-Catalyst (ukuthi kufanele uyifake noma cha, nokuthi kufanele wengeze malini).
Wonke amaphuzu amane angenhla, ngaphandle kwelokuqala,Izimpawu zama-amino resins zincike emaqenjini azo asebenzayo kanye nomsebenzi wawo.Ngakho-ke, ukuqonda isakhiwo sama-amino resins kubalulekile. Kodwa-ke, ngaphambi kokuqonda ama-amino resins, kubalulekile ukuba nokuqonda okuyisisekelo ngama-host resins asetshenziswa kanye nawo.
Njengoba kushiwo ngaphambili, ama-amino resins ngokuyinhlokoisetshenziswa kanye nama-resin e-alkyd, ama-resin e-acrylic, ama-resin e-polyester, nama-resin e-epoxy. Ama-resin e-alkyd akhiqizwa ngokuyinhloko kuma-polyol nama-polyacid resin ngokusebenzisa i-esterification. Ngesikhathi sokwenziwa, ama-alcohols ngokuvamile ayanda; amanye amaqembu e-carboxyl ama-polyacid angase angasabeli ngokuphelele, okuholela kuma-resin e-alkyd aqukethe inani elithile lamaqembu e-carboxyl nama-hydroxyl. Inani lamaqembu e-carboxyl nama-hydroxyl ngokuvamile libonakala ngenani le-acid kanye nenani le-hydroxyl. Inani le-acid libhekisela enanini lama-milligram e-KOH adingekayo ukuze kuncishiswe i-1g ye-resin eqinile ngokuyihlanganisa ne-KOH. Inani le-hydroxyl libhekisela enanini lama-milligram e-KOH adingekayo ukuze kuncishiswe ngokuphelele amaqembu e-OH ku-1g ye-resin eqinile ngokuyihlanganisa ne-KOH. Ngokufanayo, ama-resin e-polyester, ama-resin e-acrylic, nama-resin e-amino nawo aqukethe inani elithile lamaqembu e-carboxyl nama-hydroxyl. Umehluko usezintweni zokusetshenziswa ezisetshenziselwa ukwenziwa kwama-resin; isibonelo, amaqembu e-carboxyl kuma-resin e-acrylic avela ku-acrylic acid, kanti amaqembu e-hydroxyl avela ku-hydroxyacrylic acid. Amanani amaqembu e-carboxyl kanye ne-hydroxyl kuma-amino resins nawo ayahluka. Inani le-asidi, inani le-hydroxyl, kanye ne-viscosity konke kuyizinkomba ezibalulekile zama-resins, okuthinta ngqo ukusebenza kwawo.
Uma sibuyela esihlokweni sama-amino resins, ake siqale sibheke isakhiwo sawo:
Umfanekiso 1:
Umfanekiso 2
Isithombe 1 sibonisa i-amino resin e-alkylated ngokwengxenye equkethe amaqembu e-alkoxy, i-imino, kanye ne-hydroxymethyl. Uma sibheka indandatho enamalungu ayisithupha eyakhiwe ama-athomu e-carbon ne-nitrogen njengohlaka lwamathambo, amagatsha noma izakhiwo ezithathwe kuyo zingachazwa ngokomfanekiso njengezinamakhanda amathathu nezingalo eziyisithupha. Ukwehluka okuningi kwezakhiwo zama-amino resin kubangelwa ngqo umehluko kulezi "zingalo" eziyisithupha kanye nokuhlelwa kwazo okuyinkimbinkimbi kanye nokuhlanganiswa kwazo.
Isithombe 2 sibonisa isakhiwo se-HMMM esilingana kakhulu, okungukuthi, i-amino resin egcwele i-methyl, eneqembu elilodwa elisebenzayo: iqembu le-methoxy, eliyi-idealized. Njengoba izinga le-etherification lingakwazi ukufinyelela ku-1:6 (eliphezulu kakhulu) ekukhiqizweni kwangempela, lokho okubizwa ngokuthi i-amino resin egcwele i-methyl lizohlala liqukethe amanye amaqembu e-imino kanye ne-hydroxymethyl.
Ake siqale ngokuqonda izimiso zama-amino resins ukuze sifunde ngezakhiwo zawo:
Isinyathelo sokuqala sokuhlanganisa i-resin ukusabela i-melamine ne-formaldehyde lapho kukhona i-catalyst ukwakha i-polyhydroxymethyl melamine. Wonke ama-athomu e-hydrogen asebenzayo eringini ye-triazine angaguqulwa abe amaqembu e-hydroxymethyl, kodwa empeleni, ama-moles amabili kuya kwayisithupha e-formaldehyde asabela eringini ye-triazine. Ama-athomu e-hydrogen asebenzayo angaphendulwanga asele amelelwa amaqembu e-imino. Njengoba sizobona kamuva, la maqembu adlala indima ebalulekile enkambisweni yokwelapha ngokusebenzisa i-self-condensation polymerization.
I-Polyhydroxymethyl melamine ayizinzile kakhulu futhi inokuncishiswa okulinganiselwe ezincibilikisini ezivamile zokumboza. Ama-amino resins asebenza ngokuyinhloko njengezinto zokuxhumanisa nokwelapha ezincibilikisini. Ukuze kudalwe i-ejenti efanelekile yokuxhumanisa ezincibilikisini, iqembu le-hydroxymethyl livame ukushiswa nge-short-chain alcohol ukuze kuncishiswe ukusabela kwalo futhi kuthuthukiswe ukuhambisana kwalo nezinto ezivamile zokwakha ifilimu kanye nezincibilikisini ze-aliphatic. I-Methanol ne-butanol zivame ukusetshenziswa njenge-short-chain alcohols. Ngokulawula inani le-methanol noma i-butanol eyengeziwe kanye nezinye izimo, ama-amino resins anamazinga ahlukene e-etherification angatholakala.
Izindawo ezisabelane ne-formaldehyde (amaqembu e-hydroxymethyl) kuphela ezingagcina zimbozwe yi-alcohols; ama-athomu e-hydrogen angasabelanga (amaqembu e-imino) awasabelani ne-short-chain alcohols. Ngaphezu kwalokho, lokhu kusabela kubonisa ukuthi wonke amaqembu ayisithupha e-hydroxymethyl asabela ne-alcohols ukuze akhe i-hexaalkoxymethyl melamine, okusho ukuthi ukusabela kweqembu elilodwa kuya kwayisithupha le-hydroxymethyl nge-alcohols kungalawulwa ngempela. Yingakho sinezinhlobo ezahlukene zama-amino resins.
Ukuzilungisa ngokwakho ama-amino resins :
Isisindo sama-molecule sama-amino resins sinqunywa izinga lokuzinza nomaukuxhumanisaphakathi kwamaqembu asebenzayo (imino, i-hydroxymethyl, i-alkoxymethyl) endandatho ye-triazine kanye nama-molecule e-melamine. Ekusetshenzisweni kokugcina, izinga le-polymerization yokuxhumanisa lithinta kakhulu isisindo sama-molecule se-amino resin kanye nokusebenza kwefilimu yokumboza.
Ukusabela kokuziqinisa kwama-amino resins kungenzeka ngale ndlela elandelayo:
Umfanekiso 3:
Ukusabela ngakwesobunxele kwakha ibhuloho le-methylene, kuyilapho ukusabela ngakwesokudla kwakha ibhuloho le-methylene ether. Izinga lokuhlanganisa ama-amino resins livame ukuvezwa njengezinga le-polymerization (DP): DP = isisindo sama-molecule / isisindo sendandatho ngayinye ye-triazine. Ama-amino resins okuqala ayezibumba ngokwawo, kanti i-DP > 3.0. Intuthuko yezobuchwepheshe yenze kwaba nokwenzeka ukunciphisa ukuzibumba kuma-amino resins aqediwe. Njengamanje, ama-melamine resins atholakala kwezentengiselwano anama-DP aphansi njengo-1.1.
Umthelela oyinhloko wesisindo sama-molecule se-amino resin ubonakala ekuqineni kokumboza. Ama-resin e-Melamine ane-DP > 2.0 kumele axutshwe ne-solvent abe yi-50%–80% ye-solids ukuze kufezwe i-viscosity efanele. Ama-resin e-melamine ohlobo lwe-Monomer ane-DP ephakathi kuka-1.1 no-1.5 avame ukunikezwa ngesimo se-solids esisebenzayo esingu-100%; i-solvent eyengeziwe inomthelela omkhulu kuma-VOC e-coating eqediwe. Isisindo sama-molecule sama-resin e-amino sithinta futhi ukusabela kokwelapha kokumboza kanye nezakhiwo zefilimu. Uhlelo lokumboza olusebenzisa i-amino resin ephezulu ye-DP luzofinyelela ubuningi obucacisiwe bokuxhumanisa ngesikhathi esifushane kunesistimu yokumboza esebenzisa i-amino resin enesakhiwo esifanayo kodwa i-DP ephansi. Ngakho-ke, i-coating equkethe ama-agent okuxhumanisa aphezulu e-DP idinga i-catalyst encane noma i-acid catalyst ebuthakathaka ukuze kufezwe isimo esifanayo sokwelapha. Umphumela wesisindo sama-molecule ezakhiweni zefilimu usezingeni lokuguquguquka kakhulu. I-coating elashwe ngama-amino resin aphezulu e-DP aqukethe iphesenti eliphezulu lama-amino-amino bonds kanye ne-amino-lacquer bonds ezimbalwa. Lolu hlobo lwesakhiwo senethiwekhi yokuxhumanisa lwakha ungqimba olunobulukhuni obuhle kodwa lungase lube buthakathaka. Lokhu ngezinye izikhathi kungakhokhelwa ngokukhetha i-resin yopende eguquguqukayo. Kodwa-ke, izinhlelo zokusebenza ezidinga ungqimba oluguquguqukayo kakhulu ngokuvamile zidinga ama-resin e-monomeric amino.
Ama-polyester aqukethe amaqembu e-carboxyl angasabela ne-melamine-formaldehyde ukuze akhiqize izembozo eziwusizo zokubeka i-thermosetting surface ezinezakhiwo eziningi zomzimba.
Ama-resins amaningi e-melamine-formaldehyde ane-butylated ayasebenza kwezentengiselwano, ikakhulukazi ngenxa yokwehluka kwezinga lokuqala le-polymerization (isisindo sama-molecule) kanye nesilinganiso samaqembu e-alkoxy kulawo angenawo amaqembu e-hydroxymethyl nama-amino hydrogen. Lokhu kwehluka kuthinta i-liquid viscosity, ukuhambisana kwe-melamine ne-polyester, kanye nesivinini sokuqina kwe-enamel. Ama-resins endabuko e-melamine, asabela namaqembu e-side hydroxyl, ikakhulukazi axhumene nama-molecule e-polyester. Njengoba ukusabela kwe-crosslinking kubangelwa yi-acid, emazingeni okushisa aphakathi kuka-120°C no-150°C, ama-asidi aqinile ngokuvamile athinta ukusabela kwe-crosslinking kwama-resins e-polyester; noma kunjalo, amanye ama-polyester adinga i-acid catalysis eyengeziwe kuma-asidi abuthakathaka kakhulu ukuze aphulukise uhlelo lwe-enamel.
Kukhona lesi simo esilandelayo: Ngaphezu kokusabela kokuxhumanisa kwe-melamine-polyester, i-resin ye-melamine-formaldehyde ene-butylated nayo ibhekana nokusabela kokuzimela. Okusho ukuthi, i-amino resin ibhekana nokuzibandakanya kwayo ukwakha isakhiwo senethiwekhi ye-melamine. Lokhu kusabela kwenzeka ngesikhathi esisodwa nokusabela kwe-melamine-polyester futhi kuyisenzo esincintisanayo. Isizathu salokhu kusabela ukuthi, ngaphezu kwamaqembu e-butoxy, i-resin ye-melamine-formaldehyde ene-butylated iphinde ibe namaqembu e-hydrocarbon methyl amahhala kanye ne-hydrogen evela kumaqembu e-imino, wonke angasabelana. Uma i-amino resin ibhekene nokuzibandakanya kwayo, izolahlekelwa eminye yemisebenzi yayo.
Nakuba ukuzihlanganisa ngokwakho kuvame ukwenza uboya bube lukhuni kakhulu futhi bumelane namakhemikhali, kuholela ekulahlekelweni okukhulu kokuqina. Ukuze kutholakale ukuqina okwanele kuma-varnish e-polyester...
I-Hexamethoxymethyl melamine (HMMM) iyi-amino resin egcwele i-hydroxymethyl futhi egcwele i-methylated. Njenge-butylated melamine-formaldehyde, idlula ekusabeleni kokuxhumanisa namaqembu e-hydroxyl e-polyester resin lapho ifudumala, yakha i-solid engathambisi. Empeleni, ngaphandle kwe-asidi catalyst, i-HMMM ngeke idlule ekuxhumaneni kwayo ngisho nangesikhathi eside noma izinga lokushisa elikhuphukile. Kodwa-ke, i-bulk HMMM izodlula ekusabeleni kokuxhumanisa kwayo ku-150°C lapho kukhona i-asidi catalyst enamandla. Ngokuphambene nalokho, ngisho noma kungekho i-asidi enamandla, ama-melamine ajwayelekile ane-butylated kanye ne-urea resin azodlula ekusabeleni kokuxhumanisa kwayo okukhulu ngokushisa okwandayo.
Ukusabela kokwelapha kwama-amino resins:
Njengoba ama-amino resins asetshenziswa ukuxhumanisa ama-molecule ayinhloko akha ifilimu abe yisakhiwo senethiwekhi, ukusabela kokuhlangana kwama-amino resins nama-peint resins kuyathakazelisa kakhulu. Isibonelo esijwayelekile ukusabela kwe-etherification (exchange)amaqembu e-hydroxyl kuma-resin opende kanye namaqembu e-alkoxymethyl kuma-amino resin.
Ngaphansi kwezimo zama-catalyst okushisa kanye ne-asidi (ngokuvamile izimo zokupholisa), ukuxhumanisa kwenzeka ngokushesha, kuxhumanisa wonke amaqembu e-hydroxyl atholakalayo kupende. Eqinisweni, njengoba isakhiwo senethiwekhi ye-polymer sakha, ukuguquguquka kwama-reactants kwehla, okushiya amanye amaqembu e-hydroxyl engasabelanga. Ngokuvamile, lapho kukhona i-amino resin eningi embozweni uma kuqhathaniswa nesilinganiso esifanele, amaqembu asele e-alkoxy angahlanganyela kwezinye izindlela zokusabela noma ahlale engasabelanga efilimu yokugcoba. Njengoba kushiwo ngaphambili, ama-amino resin ayazixhumanisa kalula futhi asabelane, okuholela ekwandeni kwesisindo sama-molecule ngesikhathi sokukhiqizwa. Lokhu kusabela kwenzeka futhi ngesikhathi sokugcoba. Ngakho-ke, kunokuba kube yinto engemihle, izinga elithile lokuzixhumanisa kwama-amino resin libalulekile ukuze kutholakale i-matrix ye-polymer eqinile, ehlanganiswe kahle. Wonke amaqembu amathathu asebenzayo ama-amino resin ahlanganyela ekuzixhumaniseni, futhi ekumbozweni kwe-melamine resin egcwele i-alkylated eqhutshwa ama-acid aqinile, kunobufakazi bokuthi lokhu kusabela kwenzeka ngemva kokushintshana kwe-ether ne-resin yokugcoba. Uma kungekho ama-catalyst angaphandle noma ama-catalyst e-acid abuthakathaka, lokhu kusabela okuzihlanganisayo kwenzeka ngezinga elikhulu nakakhulu ezinhlelweni ze-melamine resin ezine-imino/noma i-hydroxymethyl ephezulu. Kuzo zombili izimo, ukusabela okuncane kokuzihlanganisa kubalulekile ekwakhiweni kwesakhiwo esihle senethiwekhi.
Ngesikhathi sokuqiniswa kwe-amino resin, ezinye izindlela zokwenza izinto ezihambisanayo ukususwa kwe-formaldehyde kanye ne-hydrolysis. Ukususwa kwe-formaldehyde kwenzeka kalula emazingeni okushisa ajwayelekile okuqina, okuwukuphela kwesizathu sokukhishwa kwe-formaldehyde ngesikhathi sokuqiniswa kwe-amino resin; enye i-formaldehyde yi-free formaldehyde.
Uma ama-amino resin ehlangana ukuze akhe amafilimu futhi aphulukise, kwenzeka ukusabela okuthile kwe-hydrolysis. Phakathi nale nqubo, amanye amaqembu e-alkoxymethyl aguqulwa abe amaqembu e-hydroxymethyl. I-hydrolysis yama-melamine resin anokuqukethwe okuphezulu kwe-imino noma i-hydroxymethyl ingashukunyiswa yi-alkalis, futhi ingenzeka kancane kancane ekushiseni kwegumbi. Lokhu kwenza ama-amino resin athambekele kakhulu ekuzihlanganiseni, okuholela ekwandeni kwe-viscosity yengubo ngesikhathi sokugcina. Ukuze kugwenywe lokhu, ama-melamine resin agcwele i-methylated noma ama-co-solvents amelana ne-alkali hydrolysis angasetshenziswa ezimbozweni ezisekelwe emanzini. Ama-melamine resin agcwele i-alkylated amelana ne-alkali-catalyzed hydrolysis ezinhlelweni ezisekelwe emanzini. Ama-melamine resin agcwele i-alkylated kanye ne-alkylated ngokwengxenye awamelani ne-acid-catalyzed hydrolysis ezinhlelweni ezisekelwe emanzini; ngakho-ke, i-catalyst ye-asidi evinjiwe kumele isetshenziswe ohlelweni olusekelwe emanzini.
Uma ufuna ukwazi okwengeziwei-ejenti yokuxhumanisaimikhiqizo, zizwe ukhululekile ukuxhumana nathi.
Isikhathi sokuthunyelwe: Disemba-19-2025