{"id":495,"date":"2026-09-23T11:01:30","date_gmt":"2026-09-23T03:01:30","guid":{"rendered":"http:\/\/www.simplevcc.com\/blog\/?p=495"},"modified":"2026-09-23T11:01:30","modified_gmt":"2026-09-23T03:01:30","slug":"can-photoinitiators-be-used-in-water-based-systems-4ba6-a5802b","status":"publish","type":"post","link":"http:\/\/www.simplevcc.com\/blog\/2026\/09\/23\/can-photoinitiators-be-used-in-water-based-systems-4ba6-a5802b\/","title":{"rendered":"Can photoinitiators be used in water – based systems?"},"content":{"rendered":"

Hey everyone, it\u2019s Jake from the photoinitiator team here, and today I\u2019m tackling one of the most common questions we get at the shop: Can photoinitiators even work in water-based systems? Let\u2019s cut through the jargon right away\u2014no stuffy lab talks, just real talk from the people who sell these things every day. First off, for anyone who doesn\u2019t geek out over UV curable stuff, photoinitiators are those little molecules that kick off the curing process when you shine UV light on them. Normally, a lot of old-school photoinitiators hate water\u2014they\u2019re oily, clumpy, and basically refuse to mix with H2O. But with everyone moving to water-based coatings, inks, and adhesives to cut VOCs (volatile organic compounds, if you\u2019re new here), we\u2019ve had to pivot hard. Photoinitiators<\/a><\/p>\n

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Let\u2019s start with the problem old photoinitiators had. A lot of the classic ones\u2014like Irgacure 184 or Darocur 1173\u2014are what we call \u201chydrophobic,\u201d meaning they repel water. If you try to mix them into a water-based acrylic coating, they just float on top like oil on salad dressing, or form tiny globs that don\u2019t spread evenly. When you hit that with UV light, the curing is patchy\u2014some spots harden fast, some stay sticky, and it\u2019s a total mess for our customers, whether they\u2019re printing packaging or coating wooden floors. That\u2019s why for years, people thought photoinitiators and water-based systems were like oil and water\u2014no way to make them play nice. But here\u2019s the thing: we\u2019ve spent the last decade figuring out how to change that, and now the game\u2019s totally different.<\/p>\n

So what\u2019s the fix? The main thing is making photoinitiators water-soluble or water-dispersible. We don\u2019t just dump regular photoinitiators into water anymore\u2014we modify their molecular structure with tiny, polar groups that love water, like hydroxyl or amine groups. Or, for people who don\u2019t want to change their entire formula, we make dispersible versions where we wrap the photoinitiator in a little soap-like shell (a surfactant, but not the harsh kind) so it mixes evenly in water without clumping. I remember when we first rolled out our water-based photoinitiator line back in 2018\u2014we tested it with a local ink manufacturer who was struggling with stickiness on their paper cups. Before, their water-based ink would take forever to dry and smudge if you touched it an hour later. They tried our dispersible photoinitiator, and boom\u2014cured in 10 seconds under a low-power UV LED, no smudges, no sticky residue. That\u2019s when I really knew this stuff worked.<\/p>\n

But wait, it\u2019s not just about mixing\u2014we have to make sure they cure well too. A lot of people worry that water in the system will get in the way of the UV reaction. And yeah, if there\u2019s too much free water, it can absorb some of the UV light or even evaporate mid-cure, leaving tiny bubbles. But that\u2019s where the right photoinitiator choice comes in. We use ones that have a high UV absorption at the wavelengths our customers use most these days\u2014mostly 365 nm, which is the sweet spot for LED curing, since LEDs are cheaper and longer-lasting than old mercury lamps. Our water-soluble photoinitiators also generate free radicals fast enough to kick off the cross-linking before the water can cause problems. I should mention there are different types too\u2014if you\u2019re making an adhesive that needs to stick to plastic, you might go for a water-dispersible type, and if you\u2019re doing a clear coating, a water-soluble one works better for a super even finish.<\/p>\n

Let\u2019s talk real-world use cases, because that\u2019s what matters. Water-based food packaging is huge right now\u2014companies can\u2019t use solvent-based inks because of safety rules, so they need something water-based that cures fast. We supply a lot of photoinitiators to these guys, and their lines run at full speed now, no downtime from curing issues. Then there\u2019s wood coatings\u2014before, water-based wood coatings would take hours to dry, and even then, you had to wait a week before you could put furniture on them. With our water-based photoinitiator, they cure in minutes, sandable the next day, and no VOCs to worry about. Even 3D printing uses water-based resins now, and our photoinitiators mix right in, so the prints cure cleanly without any yellowing.<\/p>\n

But let\u2019s be honest, it\u2019s not a one-size-fits-all. We still get calls from customers who tried a cheap water-based photoinitiator from a no-name supplier and it failed. Why? Because a lot of those cut corners\u2014their photoinitiators don\u2019t disperse evenly, or they need way more UV light to cure, which raises energy costs. We test every batch of our stuff: we mix it into standard water-based formulations, test curing speed, yellowing, adhesion, all that stuff, before it even leaves our warehouse. Last month, a customer from Texas tried a competitor\u2019s water-based photoinitiator, and it left a weird haze on their plastic packaging. They switched to ours, adjusted the amount by just 0.5% of the formula, and the haze was gone. That\u2019s the difference between experience and cutting corners.<\/p>\n

Another thing people don\u2019t talk about: oligomers, which are the main stuff in UV formulations. A lot of water-based oligomers are acrylic-based, so pairing them with the right photoinitiator is key. For example, if you\u2019re using a water-based polyurethane oligomer, our amine-modified water-soluble photoinitiators work better because amines boost the free radical reaction. We actually have a technical team that helps customers pick the right one\u2014we don\u2019t just sell you a bottle and ghost you. That\u2019s the big difference with us: we\u2019re not just a supplier, we\u2019re here to help, especially since water-based systems are still new to a lot of folks.<\/p>\n

Wait, what about cationic photoinitiators? Some people use those for epoxy-based systems, and can they be water-based? Yeah, those exist too, but they\u2019re a bit trickier. Cationic ones need acidic conditions, and water can sometimes mess with that, but we\u2019ve developed water-dispersible cationic photoinitiators that work great for epoxy water-based adhesives. It\u2019s not as common as radical-type water-based photoinitiators, but it\u2019s growing, especially in electronics where you need strong adhesion to metal parts.<\/p>\n

Let\u2019s also address the elephant in the room: is there any downside? Sure, if you\u2019re using super high-solids water-based systems, you might need a bit more photoinitiator than a solvent-based one, but it\u2019s minimal\u2014like 2-5% vs. 1-3% for solvent-based, which is nothing. And unlike old hydrophobic photoinitiators, our water-based versions don\u2019t cause separation over time, so you don\u2019t have to stir your bucket every hour like you do with cheap stuff. I once had a customer tell us they saved $12,000 a year in energy costs because our photoinitiators cure at lower UV power, so they don\u2019t have to run their lamps as hard. That\u2019s the kind of win we love to hear about.<\/p>\n

So to circle back: yes, photoinitiators absolutely work in water-based systems\u2014you just can\u2019t use the old ones. The industry\u2019s come a long way, and now there are reliable, tested options that perform just as well (if not better) than solvent-based ones, without the VOCs. Whether you\u2019re in packaging, coatings, adhesives, or 3D printing, there\u2019s a water-based photoinitiator for your specific formula, you just need to pick the right one.<\/p>\n

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If you\u2019re working on a new water-based project and you\u2019re not sure which photoinitiator to use, or you\u2019ve had bad luck in the past, hit us up. We\u2019ll walk you through testing, help you adjust your formula, and make sure you get the curing speed and finish you need. No sales pitches, just real answers from people who live and breathe this stuff every day.<\/p>\n

Preservatives<\/a> References:<\/p>\n

    \n
  1. Decker, C. (2002). Radiation curing of water-based systems: A review. Progress in Organic Coatings, 45(2-3), 149-161.<\/li>\n
  2. Allen, N. S. (2010). Photoinitiators for water-based UV curing. Journal of Photochemistry and Photobiology A: Chemistry, 215(2-3), 117-125.<\/li>\n
  3. Lam, L. H., et al. (2019). Water-dispersible photoinitiators for UV-curable coatings: Synthesis and performance evaluation. Progress in Organic Coatings, 135, 247-254.<\/li>\n<\/ol>\n
    \n

    Jinsheng Dagong Pharmaneutical (Qidong) Co., Ltd.<\/a>
    As one of the most professional photoinitiators manufacturers and suppliers in China, we have world-leading production equipment and strong manufacturing capabilities. Please feel free to wholesale customized photoinitiators made in China here from our factory. Also, free sample is available.
    Address: No. 2, Shanghai Road, Life and Health Industrial Park, Qidong City, Nantong City, Jiangsu Province
    E-mail: 13773166200@163.com
    WebSite:     https:\/\/www.jsdgpharmacy.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

    Hey everyone, it\u2019s Jake from the photoinitiator team here, and today I\u2019m tackling one of the … Can photoinitiators be used in water – based systems?<\/span>Read more<\/a><\/p>\n","protected":false},"author":9,"featured_media":495,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[458],"class_list":["post-495","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-photoinitiators-44db-a5e17c"],"_links":{"self":[{"href":"http:\/\/www.simplevcc.com\/blog\/wp-json\/wp\/v2\/posts\/495","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.simplevcc.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.simplevcc.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.simplevcc.com\/blog\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"http:\/\/www.simplevcc.com\/blog\/wp-json\/wp\/v2\/comments?post=495"}],"version-history":[{"count":0,"href":"http:\/\/www.simplevcc.com\/blog\/wp-json\/wp\/v2\/posts\/495\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.simplevcc.com\/blog\/wp-json\/wp\/v2\/posts\/495"}],"wp:attachment":[{"href":"http:\/\/www.simplevcc.com\/blog\/wp-json\/wp\/v2\/media?parent=495"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.simplevcc.com\/blog\/wp-json\/wp\/v2\/categories?post=495"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.simplevcc.com\/blog\/wp-json\/wp\/v2\/tags?post=495"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}