Risposta rapida: acquirenti che scelgono additivi per 2K polyurethane clearcoats usually get a better shortlist when they stop treating every clear-finish problem as the same job. CHLUMIAG® 3467 should move first when the clearcoat is still fighting compatibility-sensitive anti-cratering, bagnatura del substrato, or broader formulation instability. CHLUMIFE® 3370 appartiene prima quando l'acquirente ha bisogno di un reactive 2K PU leveling and gloss-hold route for a cleaner clear film. CHLUMIFE® 3307X deserves earlier review when the clearcoat can already form but still needs post-cure scratch resistance, levigatezza della superficiee recoat-aware durability.
That is the commercially useful split. In clearcoats, defects stay visible. A transparent film does not hide crater edges, weak flow-out, or mar damage the way a more forgiving pigmented finish sometimes can. So the first additive decision should match the failure the buyer actually sees.
Why 2K polyurethane clearcoats need a narrower additive screen
Longchang already has adjacent pages for 2K polyurethane primers, Rivestimenti di finitura in poliuretano 2K, and the wider CHLUMICRYL® Additivi per vernici e inchiostri branch. Those pages help buyers understand the broader system.
This page answers a tighter B2B question: which additive route should 2K PU clearcoat buyers screen first when the finish is being judged by crater visibility, DOI and gloss hold, or post-cure scratch performance?
That is a distinct page type. It is not just another broad topcoat article. Clearcoat buyers usually care more about surface cleanliness, transparent-film laydowne how the cured clear layer survives touch and handling after the appearance already looks acceptable.
What 2K PU clearcoat buyers are usually trying to fix
In practical 2K polyurethane clearcoat work, the first bottleneck usually lands in one of these lanes:
- the film is still cratering or wetting unevenly, especially in formulation-sensitive packages where compatibility matters before fine appearance tuning
- the clearcoat reaches the surface but still does not level cleanly enough, so gloss, DOI, or smoothness stay below target
- the cured clear film looks acceptable at first, but the buyer still needs better scratch resistance, abrasion handling, or more confidence around recoating and downstream durability
That is also consistent with general industry framing. Clearcoat programs usually separate wet-stage defect cleanup, visible-film levelinge post-cure durability before they lock the first additive shortlist. The product facts below stay tied to Longchang-supported product pages and current company-controlled comparison content.
Tabella comparativa rapida: quale percorso risolve prima cosa?
| Fattore d'acquisto | CHLUMIAG® 3467 | CHLUMIFE® 3370 | CHLUMIFE® 3307X |
|---|---|---|---|
| Principale ruolo di primo schermo | Compatibility-first anti-cratering, wetting, and broader surface-balance entry | Reactive leveling, gloss, and smooth clear-film refinement in 2K PU systems | Post-cure scratch resistance, abrasion handling, smoothness, and recoat-aware finish support |
| Lingua di sistema supportata da Longchang | UV, solvent, and water-based systems, plus polyurethane resin modification | Two-component polyurethane crosslinking systems, hydroxyl topcoats, UV, solvent, water-based, and baking-finish routes | UV and solvent systems, non-water-based route with solvent pre-dilution guidance |
| Corrispondenza più forte supportata per questa pagina | Formulation-sensitive 2K PU clearcoats where compatibility and crater cleanup matter first | 2K PU clearcoats that need cleaner leveling, gloss hold, and smooth transparent laydown | Clearcoats that already level directionally but still need stronger mar or scratch durability after curing |
| Punti di forza chiave supportati | Leveling, anti-cratering, substrate wetting, anti-sticking and peeling, scratch resistance, abrasion resistance | Leveling, gloss, smoothness, and direct fit for two-component polyurethane crosslinking systems | Abrasion and scratch resistance after film formation, surface smoothness, leveling, and recoatability priority |
| Punto di osservazione importante | Best used as a compatibility-first route, not as a promise that every clear-finish target will be solved by one additive alone | Should be screened when reactive clear-film refinement is the real target, not when the main problem is still crater rescue | Not a water-based route, and Longchang’s handling logic still points to solvent pre-dilution before use |
When CHLUMIAG® 3467 is the better fit
CHLUMIAG® 3467 should move earlier when the 2K PU clearcoat problem still feels formulation-sensitive. Longchang positions it as a modified silicone additive for comprehensive modification of polyurethane coatings, PU leather, and composite coatings. The same supported route includes livellamento, anti-cratere, bagnatura del substrato, antiaderente e sbucciante, resistenza ai graffie resistenza all'abrasione, plus broader notes around low-temperature flexibility, breathabilitye moisture permeability. Longchang also supports it across Sistemi a base di raggi UV, solventi e acqua with a typical Da 0,1% a 1,0% addition range.
That makes 3467 the stronger first route when:
- the clearcoat is still showing crateri or unstable wetting and the buyer does not want to jump too fast into a narrower finish-only additive
- the project needs a benchmark incentrato sulla compatibilità before the team optimizes DOI or scratch performance more aggressively
- the formulator wants a route that can also sit inside polyurethane-resin-modification logic or broader cross-system development
- the commercial risk is more about whether the clearcoat behaves cleanly enough at the surface interface than about the final scratch number alone
In short, 3467 is the earlier route when the buyer still needs a stable entry into the clearcoat surface window.
When CHLUMIFE® 3370 is the better fit
CHLUMIFE® 3370 belongs earlier when the buyer already knows the project is really about reactive 2K polyurethane surface refinement. Longchang supports it as an agente tattile organosilicico e tensioattivo siliconico per sistemi di reticolazione poliuretanica bicomponente e hydroxyl coating systems. The supported performance points include livellamento, lucidoe smoothness, with broader applicability across Sistemi di finitura UV, a solvente, a base d'acqua e a forno. The addition range on current Longchang-supported pages is Da 0,1% a 1,0%.
That makes 3370 the better first route when:
- the 2K PU clearcoat already reaches the surface, but the buyer still wants a cleaner gloss-hold and DOI-style appearance result
- the commercial target is a smoother transparent film rather than a broad compatibility rescue
- the clearcoat line is already clearly inside a sistema di reticolazione poliuretanica bicomponente and the team wants a route directly supported for that lane
- the surface needs to look more refined without jumping immediately to a post-cure durability-first additive
This is why 3370 earns a distinct place on a clearcoat page. It is not just a generic surface additive. It is a reactive clear-film refinement route tied to a specific 2K PU selection story.
Quando CHLUMIFE® 3307X è la soluzione migliore
CHLUMIFE® 3307X deserves earlier review when the clearcoat can already level directionally, but the buyer still needs a stronger answer on resistenza ai graffi dopo la formazione del film. Longchang supports 3307X around resistenza all'abrasione e ai graffi delle pellicole di resina dopo la formazione, while also keeping levigatezza della superficie, livellamentoe riverniciabilità in the supported selection logic. Current company-controlled content also keeps the product inside a UV and solvent route, with a typical Da 0,1% a 1,0% addition range and a practical note that it is usually prepared as a solvent solution before use.
That makes 3307X the stronger first move when:
- the clearcoat appearance is mostly acceptable, but the cured film still marks too easily in handling or service
- the buyer needs a clearer scratch or mar-resistance route instead of re-running another wet-stage leveling trial
- levigatezza della superficie e riverniciabilità still matter together in the final finish decision
- the system is already in a non-water-based 2K PU lane where solvent-side handling is acceptable
3307X is not the first tool for crater rescue. It is the earlier choice when the buyer is already looking at the cured clear film and asking whether the finish can stay commercially acceptable after contact, wiping, or handling.
Come gli acquirenti dovrebbero scegliere prima di richiedere i campioni
1. Decide whether the failure starts before or after the clear film looks acceptable
If the film still shows crater, wetting, or compatibility instability, start earlier with 3467. If the surface reaches the panel but still lacks smooth gloss-hold or DOI-style refinement, 3370 deserves earlier screening. If the clearcoat already looks directionally right but fails after cure, move faster to 3307X.
2. Keep transparent-film watchpoints visible
In 2K PU clearcoats, crater edges, gloss breaks, and mar damage stay visible. That means buyers should not judge the additive shortlist only by whether a panel cures. They should judge whether the transparent film still looks commercially clean after curing.
3. Do not ask one additive to solve crater rescue, final leveling, and post-cure scratch at the same time
Those jobs can influence each other, but they are still different first-screen tasks. Clearcoat development usually gets cleaner faster when the first additive screen matches the stage where the failure actually begins.
4. Keep the system boundary visible
3467 supports broader UV, solvent, and water-based logic plus resin-modification paths. 3370 is directly supported for two-component polyurethane crosslinking systems and hydroxyl topcoats. 3307X sits in a non-water-based UV or solvent route with solvent-side handling guidance. That boundary matters before fine dosage differences matter.
5. Build the first shortlist deliberately
Per molti acquirenti, il primo round più pulito è uno compatibility-first crater route, uno reactive clear-film leveling routee uno percorso di graffio post-polimerizzazione. That usually teaches more than screening three products from the same logic bucket.
Percorso consigliato per Longchange da questa pagina
- Compatibility-first 2K PU route: CHLUMIAG® 3467
- Reactive clear-film leveling route: CHLUMIFE® 3370
- Post-cure scratch route: CHLUMIFE® 3307X
- Panoramica del cluster: CHLUMICRYL® Additivi per vernici e inchiostri
- Related upstream page: How to Choose Surface Additives for 2K Polyurethane Primers
- Related finish page: Come scegliere gli additivi di superficie per le finiture poliuretaniche bicomponenti
- Pagina relativa alla funzione: Come scegliere gli additivi livellanti per rivestimenti e inchiostri
- Pagina correlata sulla durabilità: Come scegliere additivi antigraffio per rivestimenti e inchiostri
FAQ
Which additive should 2K PU clearcoat buyers test first when the film is still cratering?
Usually CHLUMIAG® 3467, because Longchang supports it for anti-cratering, substrate wetting, leveling, and broader polyurethane-coating modification logic.
When should CHLUMIFE® 3370 move ahead of CHLUMIAG® 3467?
3370 should move earlier when the clearcoat already behaves directionally at the surface and the main goal becomes reactive leveling, gloss, and smoother transparent-film refinement inside a 2K polyurethane crosslinking route.
Why would CHLUMIFE® 3307X be chosen before another leveling additive?
Because some clearcoat programs are no longer blocked by wet-stage laydown. They are blocked by post-cure scratch resistance, abrasion handling, and finish durability after the film has already formed.
Uno di questi tre prodotti può sostituire gli altri due?
No. They belong to different first-screen jobs. 3467 is a compatibility-first crater and wetting route, 3370 is a reactive clear-film leveling route, and 3307X is a post-cure scratch and durability route.
Qual è il modo più rapido per ridurre la lista degli additivi?
Define whether the problem starts at the interfaccia superficiale, in the visible clear-film laydown, o nel cured clearcoat durabilityQuesto di solito indica quale percorso merita il primo giro di campionamento.
Need a tighter 2K PU clearcoat shortlist?
If your team is stuck between crater cleanup, gloss-hold leveling, and post-cure scratch performance, do not keep asking one additive to solve all three. Split the problem by stage first. That usually makes the CHLUMICRYL® route easier to validate and move toward inquiry.