快速回答： buyers should not treat CHLUMIAG® 2750, 2760, 2780, and 2505 as four unrelated reactive additives. The current Longchang family page supports one shared reactive route with reactive acrylic functional groups, radiation-curing suitability， 和 crosslinking into the polymer network structure. The first real split is usually this: 2750 should move up first when the project is closer to reverse varnish or a reactive UV route where surface smoothness and tape resistance matter. 2780 should move up first when the buyer is closer to anti-blocking or anti-graffiti handling. 2760 和 2505 are most useful when the buyer has already decided the reactive-family direction is right and now needs a different viscosity window for formulation handling or process fit rather than a different chemistry story.
This page is narrower than the broader anti-blocking additive guide and different from the already-live 2750 vs 2780 comparison. That earlier page helps buyers choose the first reactive direction. This page is the next step for buyers who need to choose the right grade inside the 2750 family.
Why this reactive family needs a dedicated grade-selection page
In many B2B coating and ink projects, the lab first decides on a chemistry direction and only then discovers that the grade window still matters. Longchang’s current public family page already gives enough support for that second-stage decision. The family is positioned for 紫外线系统 和 溶剂体系, not for water-based systems, with a recommended dosage of 0.1% to 3% 和 addition at any stage of production. The same page also gives separate viscosity windows for the four grades:
- 2750: 1000 to 4000 mPa.s
- 2760: 1000 to 8000 mPa.s
- 2780: 5000 to 30000 mPa.s
- 2505: 4000 to 12000 mPa.s
That means buyers can use one page for the first chemistry choice and another page, this one, for the grade-selection and handling-fit choice.
Quick comparison table: when each grade is the better first screen
| 等级 | 最佳首次适应 | 为什么买家会将其列入候选名单 | 主要观察点 |
|---|---|---|---|
| 2750 | Reactive UV work closer to reverse varnish and cured-film surface fixation | Longchang explicitly says 2750 is more suitable for reverse varnish and supports the family with reactive acrylic functionality, surface smoothness, and tape resistance | If the project is really anti-blocking or anti-graffiti-led, 2780 is usually the stronger first direction |
| 2760 | Same-family option when the reactive 2750-type route is directionally right but the process needs a broader mid-range viscosity window | Longchang gives 2760 its own 1000 to 8000 mPa.s viscosity band inside the same reactive UV family | The public page does not give it a separate application story as explicit as 2750 or 2780, so it should be chosen honestly as a same-family process-fit grade |
| 2780 | Reactive UV or solvent-side work closer to anti-blocking and anti-graffiti surface control | Longchang explicitly says 2780 is more commonly used in anti-blocking and anti-graffiti applications | If the buyer really needs reverse-varnish-first logic, 2750 is usually the cleaner first route |
| 2505 | Same-family option when the chemistry direction is already right but a higher viscosity window is a better process match | Longchang gives 2505 its own 4000 to 12000 mPa.s viscosity band inside the same reactive family | Like 2760, its strongest current public role is grade-window selection, not a separate headline application story |
What the whole 2750 family shares before you split grades
Before choosing a grade, it helps to remember what the family already shares on the current Longchang page. The family is positioned with reactive acrylic functional groups and is described as crosslinking into the polymer network structure in radiation-curing systems. Longchang also supports the family with excellent leveling, 表面光滑度， 和 tape resistance. The family is shown as suitable for 紫外线系统 和 溶剂体系, but not for water-based systems. Longchang also says the products can be added at any stage and should be stored sealed, away from high temperature and strong light, with a mix-with-caution note.
That shared base matters because it keeps buyers from over-interpreting the four numbers as four unrelated chemistries. The family decision is usually already made before the grade decision starts.
When 2750 is the better fit
CHLUMIAG® 2750 should move up first when the project is driven by reverse varnish or by the desire to use a more clearly framed reactive UV surface-control route. Longchang’s current public wording says 2750 is more suitable for reverse varnish. That matters because it gives the grade a distinct first-screen job inside a family where several grades otherwise share the same reactive base story.
2750 also makes sense when the buyer wants the family’s reactive-network fixation, surface smoothness, and tape-resistance story but does not need to start from an anti-blocking or anti-graffiti problem. In practical buying terms, 2750 is the grade to move forward first when the question is, “Which family member is most clearly aligned with reverse-varnish-led UV work?”
When 2780 is the better fit
CHLUMIAG® 2780 should move up first when the coating or ink project is closer to anti-blocking or anti-graffiti performance. Longchang’s current public family page explicitly says 2780 is more commonly used in anti-blocking and anti-graffiti applications. That is the strongest current company-supported reason to separate it from 2750.
Commercially, that makes 2780 the more logical first screen when the project brief is not about reverse varnish, but about cleaner surface separation, easier handling after contact, or broader easy-clean style performance inside the reactive family. Buyers should still remember that it remains part of the same UV and solvent reactive family rather than a completely different chemistry lane.
When 2760 is the better fit
CHLUMIAG® 2760 matters when the buyer has already decided that the 2750-family reactive route is directionally correct but needs a different viscosity window for process integration. The current Longchang page gives 2760 a 1000 to 8000 mPa.s viscosity range, which places it above 2750 on the upper end while still staying below the much wider 2780 range.
That does not justify inventing a separate application story. The stronger and safer B2B use of 2760 is as a same-family mid-window option when the reverse-varnish or reactive-surface-control direction is already accepted, but the team wants a different handling window for the formulation or production step.
When 2505 is the better fit
CHLUMIAG® 2505 belongs in the shortlist for the same reason 2760 does, but with a different grade window. Longchang gives 2505 a 4000 to 12000 mPa.s viscosity range, which makes it a practical same-family option when the buyer wants a higher viscosity band than 2750 and a narrower band than the broad upper reach of 2780.
Again, the safer company-supported position is not to invent a new headline application story for 2505. Its current strength is that it gives a buyer another process-fit grade inside a reactive UV family that already matches the broader commercial job.
How buyers should narrow the first sample round
1. Choose the first surface-control job before the grade window
If the project is clearly reverse-varnish-led, start with 2750. If it is clearly anti-blocking or anti-graffiti-led, start with 2780. Only after that should 2760 or 2505 move up as same-family grade-window options.
2. Do not pretend 2760 or 2505 are separate chemistry stories if the public evidence does not support that
The current Longchang page supports distinct application direction most clearly for 2750 and 2780. Use 2760 and 2505 honestly, as grade-window choices inside the family.
3. Keep the system boundary visible
This family is supported for 紫外线 和 solvent systems, not for water-based systems. If the project is really a water-based route, leave this family early and choose a different branch.
4. Treat storage and handling notes as part of the buying decision
Longchang’s sealed-storage, light-avoidance, and mix-with-caution notes are part of realistic grade selection, especially when the buyer is narrowing a reactive family for production rather than only for a small lab comparison.
5. Use the shortest first sample plan that still teaches something
For many buyers, the cleanest first screen is 2750 or 2780 as the directional grade, then 2760 or 2505 only if the lab needs another viscosity-window option inside that same direction.
本页推荐的龙昌路线
- Reactive family product page: CHLUMIAG® 2750 / 2760 / 2780 / 2505
- First-direction comparison page: CHLUMIAG® 2750 vs 2780
- Related anti-blocking page: 如何选择涂料和油墨的防粘连添加剂
- Related release page: How to Choose Release Coating Additives for UV Inks and Overprint Varnishes
- 集群概览： CHLUMICRYL® 涂层和油墨添加剂
常见问题
What is the main difference between CHLUMIAG® 2750 and 2780?
The strongest current public difference is application direction. Longchang says 2750 is more suitable for reverse varnish, while 2780 is more commonly used in anti-blocking and anti-graffiti applications.
When should I choose 2760 instead of 2750?
Choose 2760 when the 2750-family reactive direction is already right but the team wants a broader mid-range viscosity window. Its current public value is process fit inside the same family, not a separate headline application story.
When should I choose 2505 instead of 2780?
Choose 2505 when the reactive family direction is already right and a 4000 to 12000 mPa.s grade window fits the formulation or production plan better. If the real first decision is anti-blocking or anti-graffiti direction, 2780 still moves up first.
Can this family be used in water-based systems?
No. The current Longchang family page shows the 2750, 2760, 2780, and 2505 family as applicable for UV and solvent systems, but not for water-based systems.
Need a tighter grade-selection shortlist?
If your team already knows it wants the reactive CHLUMIAG® 2750 family, stop treating the four grades as if they all solve different chemistry problems. First choose whether the job is reverse-varnish-led or anti-blocking or anti-graffiti-led. Then use 2760 or 2505 as same-family viscosity-window options when the chemistry direction is already correct and the process still needs finer tuning.