Incamake y'ishyirwa mu bikorwa ryaamino resin crosslinking agents
Uruhare rw'ingenzi rwa resine za amino (melamine-formaldehyde, benzomelamine-formaldehyde, na resine za urea-formaldehyde) mu gusiga thermosetting ni uguhuza molekile z'ingenzi zikora filime mu miterere y'urusobe rw'ibice bitatu binyuze mu mikorere ya shimi. Iyi miterere y'urusobe iboneka binyuze mu mikorere ya molekile za resine za amino hamwe n'amatsinda imikorere kuri molekile zikora filime, kandi icyarimwe binyuze mu gupomeranya polymeri n'izindi molekile za resine za amino. Resine za amino zishobora gukorana na polimeri zirimo amatsinda y'ibanze n'ay'inyongera ya hydroxyl, amatsinda ya karubokisili, n'amatsinda ya amide; bityo, resine za amino zikoreshwa cyane mu buryo bw'irangi bushingiye kuri resine za acrylic, polyester, alkyd, cyangwa epoxy.
Ama-resin amino akoreshwa kandi muri sisitemu ya polyurethane nk'inyongera zo gusiga kugira ngo anonosore imikorere rusange y'udupira ku bikorwa bimwe na bimwe.
Ihame ry'amaresine amine:
Akamaro k'ama-resin amine mu mavarnish yo gutekesha karenze cyane urugero rwayo mu mavuta yo gutekesha. Gusobanukirwa uburyo bwo gukoresha imiterere y'imiti ya amine mu gushushanya imvange y'amavuta biri kugenda birushaho kuba ingenzi. Urugero,Iyo abakora imashini zisiga amarangi batishimiye imiterere imwe n'imwe ya firime isiga amarangi, bashobora kuyakosora bakoresheje uburyo bukurikira:
1. Kunoza cyangwa guhitamo bundi bushya resin ikora filime ubwayo;
2. Guhitamo amino resins (methyl etherification cyangwa butyl etherification, no guhitamo urugero rwa etherification, nibindi);
3. Igipimo cya resine ikora filime na resine amine.
4. Guhitamo Catalyst (niba ari iyo kongeramo cyangwa ntayongeremo, n'ingano yo kongeramo).
Ingingo enye zose zavuzwe haruguru, usibye iya mbere,bifitanye isano na resins za amino. Imiterere ya resins za amino iterwa n'imikorere yazo n'imikorere yazo; bityo rero, gusobanukirwa imiterere ya amino resins ni ingenzi cyane. Ariko, mbere yo gusobanukirwa amino resins, ni ngombwa kugira ubumenyi bw'ibanze ku ma resins akoreshwa hamwe na yo.
Nkuko byavuzwe mbere, amino resins ahanini niikoreshwa hamwe na resins za alkyd, resins za acrylic, resins za polyester, na resins za epoxy. Resine za Alkyd zikorwa ahanini muri polyols na polyacid resins binyuze mu gupima. Mu gihe cyo gukora, alkoholi muri rusange ziba nyinshi cyane; amwe mu matsinda ya carboxyl ya polyacids ashobora kudakora neza, bigatuma alkyd resins zirimo ingano runaka ya carboxyl na hydroxyl. Ingano y'amatsinda ya carboxyl na hydroxyl ubusanzwe igaragazwa n'agaciro ka aside n'agaciro ka hydroxyl. Agaciro ka aside yerekeza ku mubare wa miligarama za KOH zisabwa kugira ngo zihagarike 1g ya resin ikomeye hakoreshejwe titration na KOH. Agaciro ka Hydroxyl yerekeza ku mubare wa miligarama za KOH zisabwa kugira ngo zihagarike burundu amatsinda ya OH muri 1g ya resin ikomeye hakoreshejwe titration na KOH. Mu buryo nk'ubwo, resine za polyester, resine za acrylic, na resine za amino nazo zirimo ingano runaka ya carboxyl na hydroxyl. Itandukaniro riri mu bikoresho fatizo bikoreshwa mu gukora resine; urugero, amatsinda ya carboxyl muri resine za acrylic akomoka kuri aside acrylic, naho amatsinda ya hydroxyl akomoka kuri aside hydroxyacrylic. Ingano ya karubokisili na hydroxyli muri amino resins nayo iratandukanye. Agaciro ka aside, agaciro ka hydroxyli, n'ubukana byose ni ibipimo by'ingenzi bya resins, bigira ingaruka ku mikorere yazo.
Tugarutse ku ngingo ya amino resins, reka tubanze turebe imiterere yazo:
Igishushanyo cya 1:
Igishushanyo cya 2
Ishusho ya 1 igaragaza resine ya amino ifite alkyle irimo amatsinda ya alkoxy, imino, na hydroxymethyl. Iyo dufashe impeta ifite ibice bitandatu igizwe na atome za karuboni na azote nk'agatsinsino, amashami cyangwa imiterere ikomoka kuri yo ishobora gusobanurwa mu buryo bw'ikigereranyo nk'ifite imitwe itatu n'amaboko atandatu. Itandukaniro rinini mu miterere ya resine za amino riterwa neza n'itandukaniro riri muri izi "maboko" esheshatu n'imiterere yazo igoye n'uruvange rwazo.
Ishusho ya 2 igaragaza imiterere ya HMMM ifite imiterere ingana cyane, ni ukuvuga resine ya amino yuzuye methyl, ifite itsinda rimwe gusa rikora: itsinda rya methoxy, rikaba ari idealized. Kubera ko urugero rwa etherification rudashobora kugera kuri 1:6 (hejuru cyane) mu musaruro nyawo, icyo bita resine ya amino yuzuye methyl izahora irimo amatsinda amwe ya imino na hydroxymethyl.
Reka dutangire dusobanukirwa amahame ya amino resins kugira ngo tumenye imiterere yazo:
Intambwe ya mbere mu gukora resin ni ugukora melamine na formaldehyde mu gihe hari catalyst ikora polyhydroxymethyl melamine. Atome zose za hydrogen zikora ku ruziga rwa triazine zishobora guhindurwamo amatsinda ya hydroxymethyl, ariko mu by'ukuri, ni moles 2 kugeza kuri 6 za formaldehyde zigira uruhare ku ruziga rwa triazine. Atome za hydrogen zikora zitarakorwa zigaragazwa n'amatsinda ya imino. Nkuko tuzabibona nyuma, aya matsinda agira uruhare runini mu nzira yo gukaraba binyuze mu kwiyungurura polymer.
Polyhydroxymethyl melamine ntabwo ihamye cyane kandi ifite ubushobozi buke bwo gushonga mu bintu bisanzwe bisiga irangi. Resine za amino zikora cyane cyane nk'ibintu bihuza kandi bikiza mu bisiga irangi. Kugira ngo habeho ikintu gihuza irangi gikwiye, itsinda rya hydroxymethyl rikunze guhindurwamo alcool y'umugozi mugufi kugira ngo igabanye uburyo bwo gukora no kunoza uburyo ikorana n'ibikoresho bisanzwe bitunganya filime n'ibindi bisiga irangi. Methanol na butanol bikunze gukoreshwa nk'ibisiga irangi mugufi. Mu kugenzura ingano ya methanol cyangwa butanol yongewemo n'izindi ndwara, resine za amino zifite urwego rutandukanye rwa etherification zishobora kuboneka.
Ahantu habaye ikibazo cya formaldehyde (amatsinda ya hydroxymethyl) ni ho honyine hashobora gushyirwaho alcool; atome za hydrogen zitarafatwa (amatsinda ya imino) ntizifatwa na alcool zo mu miyoboro migufi. Byongeye kandi, iki kibazo kigaragaza ko amatsinda atandatu yose ya hydroxymethyl akorana na alcool bigatuma hakorwa hexaalkoxymethyl melamine, bivuze ko ingaruka z'amatsinda rimwe kugeza kuri atandatu ya hydroxymethyl hamwe na alcool zishobora kugenzurwa. Niyo mpamvu dufite ubwoko butandukanye bwa amino resins.
Kwihindura polimeri za amine resins :
Uburemere bwa molekile za resine za amino bugenwa n'urugero rwo kwihuza cyangwaguhuzahagati y’amatsinda y’imikorere (imino, hydroxymethyl, alkoxymethyl) ku mpande ya triazine na molekile za melamine. Mu ikoreshwa rya nyuma, urwego rwa polymerization ihuza bigira ingaruka zikomeye ku buremere bwa molekile ya amino resin ndetse n’imikorere ya filime yo gusiga.
Uburyo resins amine zikora ubwazo bushobora kubaho binyuze mu buryo bukurikira:
Igishushanyo cya 3:
Inzira y'ubuhumekero ikora ikiraro cya methylene, mu gihe intera y'iburyo ikora ikiraro cya methylene ether. Ingano y'ihuza ry'ama-resin amino ikunze kugaragazwa nk'urugero rwa polymerization (DP): DP = uburemere bwa molekile / uburemere bwa buri ruziga rwa triazine. Ama-resin amino yo hambere ahanini yishyiraga ubwayo, aho DP > 3.0. Iterambere ry'ikoranabuhanga ryatumye bishoboka kugabanya kwihuza kw'ama-resin amino arangije. Muri iki gihe, ama-resin a melamine agurishwa afite ama-DP ari hasi ya 1.1.
Ingaruka nyamukuru z'uburemere bwa molekile ya amino resin igaragarira mu buryo bwo gusiga. Resine za melamine zifite DP > 2.0 zigomba gukurwamo solvent kugeza kuri 50%–80% by'ibintu bikomeye kugira ngo haboneke uburemere bukwiye. Resine za melamine zo mu bwoko bwa monomer zifite DP hagati ya 1.1 na 1.5 akenshi zitangwa mu buryo bwa 100% by'ibintu bikomeye; ibindi bisuguti bigira ingaruka zikomeye kuri VOCs z'igishishwa cyarangiye. Uburemere bwa molekile bwa resine za amino bugira ingaruka ku buryo bwo gusiga no ku miterere ya firime. Sisitemu yo gusiga ikoresha resine ya amino ifite DP nyinshi izagera ku bucucike bwagenwe bwo gusiga mu gihe gito kurusha sisitemu yo gusiga ikoresha resine ya amino ifite imiterere imwe ariko ifite DP nke. Kubwibyo, ibisuguti birimo ibintu bihuza byinshi bya DP bisaba catalyst nke cyangwa catalyst nkeya kugira ngo bigere ku rwego rumwe rwo gusiga. Ingaruka z'uburemere bwa molekile ku miterere ya firime ziri ahanini mu rwego rwo koroha. Ibisuguti bivuwe na resine za amino zifite DP nyinshi zigizwe n'ijanisha ryinshi ry'imigozi ya amino-amino hamwe n'imigozi mike ya amino-lacquer. Ubu bwoko bw'imiyoboro ihuza imiterere bukora irangi rifite ubukana bwiza ariko rishobora kwangirika. Ibi rimwe na rimwe bishobora kwishyurwa no guhitamo irangi ryoroshye cyane. Ariko, ikoreshwa risaba irangi ryoroshye cyane muri rusange risaba irangi rya monomeric amino resins.
Polyester irimo amatsinda ya karubokisili ishobora gukorana na melamine-formaldehyde kugira ngo ikore irangi ry'ubuso rifite imiterere myinshi ifatika.
Resine nyinshi za melamine-formaldehyde zikomoka kuri butyl zirashobora kugurishwa, ahanini bitewe n'itandukaniro mu rugero rwa mbere rwa polymerization (uburemere bwa molekyuli) n'ikigereranyo cy'amatsinda ya alkoxy n'adafite amatsinda ya hydroxymethyl na amino hydrogens. Izi tandukaniro zigira ingaruka ku bucucike bw'amazi, guhuza kwa melamine na polyester, n'umuvuduko wo gushya kwa enamel. Resine za melamine zisanzwe, zikorana n'amatsinda ya hydroxyl, cyane cyane zihuza na molecule za polyester. Kubera ko reaction crosslinking iba ikoreshwa na aside, ku bushyuhe buri hagati ya 120°C na 150°C, aside zikomeye zikunze kugira ingaruka ku reaction crosslinking ya polyester resins; icyakora, zimwe muri polyester zikenera catalysis y'inyongera ya aside muri aside nke cyane kugira ngo zivure sisitemu ya enamel.
Hari ibi bikurikira: Uretse uburyo melamine-polyester ikora, resin ya melamine-formaldehyde nayo ikora self-condensation reaction. Ni ukuvuga ko amino resin ikora self-connecting kugira ngo ikore imiterere ya melamine. Iyi reaction ibaho icyarimwe na melamine-polyester reaction kandi ni reaction ihanganye. Impamvu y'iyi reaction ni uko, uretse amatsinda ya butoxy, resin ya melamine-formaldehyde ya butylated inarimo amatsinda ya methyl ya hydrocarbon na hydrogen biva mu matsinda ya imino, byose bishobora kugirana imikoranire. Iyo amino resin imaze gukora self-connecting, izatakaza zimwe mu nshingano zayo.
Nubwo kwihuza ubwabyo akenshi biha irangi gukomera no kudakoresha imiti, bituma ritakaza ubushobozi bwo kwiyubaka. Kugira ngo rigere ku busugire buhagije muri varnish za polyester...
Hexamethoxymethyl melamine (HMMM) ni resin amino monomeric yuzuye hydroxymethyl kandi yuzuye methyl. Kimwe na melamine-formaldehyde ya butyl, ihura n'ingaruka zo guhuza hamwe n'amatsinda ya hydroxyl ya polyester resin iyo ishyushye, bigatuma ihinduka ikintu kidakonjesha. Mu by'ukuri, iyo nta catalyst ya aside, HMMM ntabwo izigera yihuza nubwo igihe kirekire cyangwa ubushyuhe bwiyongera. Ariko, HMMM nyinshi izahura n'ingaruka zo guhuza kuri 150°C iyo hari catalyst ya aside ikomeye. Ku rundi ruhande, nubwo nta aside ikomeye ihari, melamine isanzwe ya butyl na urea resin zizahura n'ingaruka zikomeye zo guhuza hamwe n'ubushyuhe bwiyongera.
Uburyo amino resins zivura:
Kubera ko resine za amino zikoreshwa mu guhuza molekile z’ingenzi zikora filime mu miterere y’urusobe rw’amakuru, uburyo resine za amino zikorana n’irangi ni ingenzi cyane. Urugero rusanzwe ni uburyo resine zihinduranya amajwi (etherification) zikoreshwa.y'amatsinda ya hydroxyl kuri resins z'irangi n'amatsinda ya alkoxymethyl kuri resins z'amine.
Mu gihe cy’ubushyuhe n’ibinyabutabire bya aside (ubusanzwe biba mu bihe byo gushya), guhuza bibaho vuba, bihuza amatsinda yose ya hydroxyl aboneka ku irangi. Mu by’ukuri, uko imiterere y’urusobe rwa polymer ikorwa, uburyo ibintu bihindukamo bigabanuka, bigatuma amwe mu matsinda ya hydroxyl adafatwa. Muri rusange, iyo hari amino resin nyinshi mu gipfundikizo ugereranije n’igipimo cyiza, andi matsinda ya alkoxy ashobora kugira uruhare mu bindi bikorwa cyangwa agakomeza kuba adafatwa mu gipfundikizo. Nkuko byavuzwe mbere, amino resin zihita zihuza kandi zigakorana, bigatuma uburemere bwa molekile bwiyongera mu gihe cyo gukora. Ibi bikorwa kandi bibaho mu gihe cyo gushya. Bityo, aho kuba ikintu kibi, urwego runaka rwo guhuza amino resin ni ingenzi kugira ngo haboneke matrix ya polymer ikomeye kandi ifatanye neza. Amatsinda yose atatu y’imikorere ya amino resin agira uruhare mu guhuza, kandi mu gushya kwa melamine resin byakozwe neza bivangwa na aside ikomeye, hari ibimenyetso bigaragaza ko ibi bikorwa bibaho nyuma yo guhinduranya ether na resin yo gushya. Iyo nta catalysts zo hanze cyangwa catalysts zidafite aside nke, izi reactions zo kwihuza zibaho cyane muri sisitemu ya melamine resin ifite imikorere myinshi ya imino/cyangwa hydroxymethyl. Muri ibyo bihe byombi, reaction nto yo kwihuza ni ingenzi cyane kugira ngo habeho imiterere myiza y’urusobe rw’amakuru.
Mu gihe cyo gukaraba amino resin, izindi ngaruka zibaho ni ugukaraba formaldehyde no gukaraba hydrolysis. Gukaraba formaldehyde bibaho byoroshye ku bushyuhe busanzwe bwo gukaraba, ari nayo mpamvu yonyine ituma formaldehyde irekurwa mu gihe cyo gukaraba amino resin; indi formaldehyde ni formaldehyde yigenga.
Iyo amino resins zihujwe zigakora filime zikanakira, habaho ingaruka zimwe na zimwe za hydrolysis. Muri iki gikorwa, amwe mu matsinda ya alkoxymethyl ahindurwamo amatsinda ya hydroxymethyl. Hydrolysis ya melamine resins ifite imino cyangwa hydroxymethyl nyinshi ishobora gukururwa na alkali, ndetse ishobora no kubaho buhoro buhoro mu bushyuhe bw'icyumba. Ibi bituma amino resins zikunze kwihuza, bigatuma ubushyuhe bw'igitambaro bwiyongera mu gihe cyo kubika. Kugira ngo hirindwe ibi, melamine resins yuzuye methyl cyangwa co-solvents zirwanya hydrolysis ya alkali zishobora gukoreshwa mu bipfundikizo bishingiye ku mazi. Melamine resins yuzuye allyd irwanya hydrolysis ya alkali-catalyze muri sisitemu zishingiye ku mazi. Melamine resins yuzuye allyd n'igice cya alkali-catalyze ntabwo irwanya hydrolysis ya aside-catalyze muri sisitemu zishingiye ku mazi; bityo, hagomba gukoreshwa catalyst ya aside ifunze muri sisitemu ishingiye ku mazi.
Niba ushaka kumenya byinshiumukozi uhuzaibicuruzwa, andika ubutumwa bwawe.
Igihe cyo kohereza: Ukuboza 19-2025