{"id":10009,"date":"2026-06-10T00:00:52","date_gmt":"2026-06-10T00:00:52","guid":{"rendered":"https:\/\/longchangchemical.com\/?p=10009"},"modified":"2026-06-10T02:07:59","modified_gmt":"2026-06-10T02:07:59","slug":"cat-440-vs-550-vs-261","status":"publish","type":"post","link":"https:\/\/longchangchemical.com\/fr\/cat-440-vs-550-vs-261\/","title":{"rendered":"CAT-440 contre 550 contre 261 : Comment choisir un photoinitiateur cationique pour les rev\u00eatements de canettes, les adh\u00e9sifs et le durcissement compatible avec les LED"},"content":{"rendered":"<p><strong>R\u00e9ponse rapide :<\/strong> Buyers should not treat <a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-cat-440-cas-60565-88-0\/\">CAT-440<\/a>, <a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-550-cas-591773-92-1\/\">550<\/a>, and <a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-cat-261-cas-32760-80-8\/\">261<\/a> as interchangeable cationic photoinitiators. In Longchang&#8217;s current product positioning, <strong>CAT-440<\/strong> is the more balanced starting point when the buyer needs a broad cationic route across optical materials, can-coating and packaging work, and thicker adhesive or composite jobs. <strong>550<\/strong> moves up when the project is closer to <strong>canned-food coatings, coil coatings, pharmaceutical packaging coatings, white or colored inks, and overprint-varnish routes<\/strong>. <strong>261<\/strong> becomes especially relevant when the project needs a <strong>405 nm-capable route, latent-cure adhesive logic, opaque-substrate bonding, or precision electronics and packaging processing<\/strong>.<\/p>\n<p>That is the useful commercial split. A better shortlist comes from identifying the real curing path first, then matching the photoinitiator to that path.<\/p>\n<h2>Why this comparison matters<\/h2>\n<p>Cationic UV systems are usually chosen for a reason. The buyer is often trying to improve adhesion, reduce shrinkage pressure, keep odor or migration under tighter control, work around pigment or oxygen-related limitations, or fit a more specialized adhesive, coating, packaging, or electronics job.<\/p>\n<ul>\n<li><strong>CAT-440<\/strong> is currently positioned by Longchang as an <strong>iodonium salt cationic photoinitiator<\/strong> with high initiator activity, fast curing speed, good surface drying, no yellowing, no migration, and no odor, plus good absorption at <strong>365 nm and 385 nm when used with a sensitizer<\/strong>.<\/li>\n<li><strong>550<\/strong> is currently positioned as a <strong>cationic photoinitiator with high activity, good surface drying, no yellowing, no migration, and no odor<\/strong>, with some absorption at <strong>365 nm<\/strong> and explicit <strong>LED-curing suitability<\/strong>.<\/li>\n<li><strong>261<\/strong> is currently positioned as a cationic route for <strong>adhesives, coatings, inks, electronics, and packaging materials<\/strong>, with a <strong>latent curing mechanism<\/strong>, suitability for <strong>opaque-substrate bonding<\/strong>, and response to <strong>visible light such as 405 nm LED<\/strong>.<\/li>\n<\/ul>\n<p>If a buyer ignores those differences, the first sample round can mix together products that are solving different commercial problems.<\/p>\n<p>For the broader curing-mechanism context, see <a href=\"https:\/\/longchangchemical.com\/fr\/comparison-of-uv-free-radical-and-cationic-curing\/\">Comparison of UV Free Radical and Cationic Curing<\/a>.<\/p>\n<h2>Quick comparison table: CAT-440 vs 550 vs 261<\/h2>\n<table>\n<thead>\n<tr>\n<th>Produit<\/th>\n<th>Best first fit<\/th>\n<th>Why buyers shortlist it<\/th>\n<th>When it is not the first option<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-cat-440-cas-60565-88-0\/\">CAT-440<\/a><\/td>\n<td>Balanced cationic screening across optical materials, can coatings, packaging inks, wood finishes, composites, and broader coating routes<\/td>\n<td>Longchang positions CAT-440 for optical materials, metal can interior coatings, food and pharmaceutical packaging inks, premium wood finishes, adhesives, composites, and 3D-printing resins, with good 365\/385 nm absorption when sensitized<\/td>\n<td>When the buyer already knows the project is mainly a 405 nm adhesive route or a can-coating and colored-system job where 550 is the more direct first review point<\/td>\n<\/tr>\n<tr>\n<td><a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-550-cas-591773-92-1\/\">550<\/a><\/td>\n<td>Canned-food coatings, coil coatings, pharmaceutical packaging coatings, white or colored printing inks, and overprint varnish<\/td>\n<td>Longchang directly lists those packaging and coating applications and also positions 550 for good surface drying, no yellowing, no migration, no odor, 365 nm absorption, and LED-curing suitability<\/td>\n<td>When the buyer&#8217;s real bottleneck is 405 nm response, latent cure after assembly, or opaque-substrate adhesive processing<\/td>\n<\/tr>\n<tr>\n<td><a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-cat-261-cas-32760-80-8\/\">261<\/a><\/td>\n<td>Adhesives, electronics, packaging materials, photoresists, and LED-leaning precision work where latent cure or opaque-substrate bonding matters<\/td>\n<td>Longchang positions 261 for structural and laminating adhesives, coatings and inks, electronics and packaging materials, and explicitly notes visible-light response around 405 nm plus a latent-cure mechanism<\/td>\n<td>When the project is a more routine broad cationic coating or packaging route that can be screened more simply with CAT-440 or 550 first<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>When CAT-440 is the better fit<\/h2>\n<p>CAT-440 deserves early attention when the buyer needs a broad and balanced cationic starting point instead of a narrow single-application answer.<\/p>\n<ul>\n<li><strong>Its application range is broad on the current company page:<\/strong> Longchang directly lists <strong>photoresist for PCBs, chip encapsulation resin, optical fiber coating, optical lens adhesive<\/strong>, plus <strong>metal can interior coatings<\/strong>, packaging inks, wood finishes, structural adhesives, laminating adhesives, and composite-bonding routes.<\/li>\n<li><strong>Its cure profile is positioned as commercially clean:<\/strong> the page highlights <strong>high initiator activity, fast curing speed, good surface drying, no yellowing, no migration, and no odor<\/strong>.<\/li>\n<li><strong>Its wavelength window matters:<\/strong> Longchang also states that CAT-440 has good absorption at <strong>365 nm and 385 nm when used with a sensitizer<\/strong>.<\/li>\n<li><strong>It is useful when one buyer project spans more than one requirement:<\/strong> for example, packaging plus coating, or optical precision plus stronger chemical resistance expectations.<\/li>\n<\/ul>\n<p>If the technical team still needs to identify whether the real problem is packaging, optical precision, or a heavier adhesive\/composite route, CAT-440 is often the strongest first shortlist item because it keeps more paths open.<\/p>\n<h2>When 550 is the better fit<\/h2>\n<p>550 should move up when the application already points toward packaging and coating routes that need a more direct cationic answer.<\/p>\n<ul>\n<li><strong>Can-coating relevance is direct:<\/strong> Longchang calls canned-food coatings one of the typical applications for 550.<\/li>\n<li><strong>Coil and pharmaceutical-packaging routes are also explicit:<\/strong> those use cases are already listed on the company page.<\/li>\n<li><strong>Colored systems matter here:<\/strong> Longchang specifically says 550 is suitable for <strong>colored systems such as white inks<\/strong> because it resists pigment-shielding deactivation.<\/li>\n<li><strong>LED capability is already part of the positioning:<\/strong> the same page says 550 has some absorption at <strong>365 nm<\/strong> et <strong>can be used for LED curing<\/strong>.<\/li>\n<li><strong>Epoxy-system relevance is also direct:<\/strong> Longchang notes high initiation activity in epoxy resin photopolymerization for high-performance composites or adhesives.<\/li>\n<\/ul>\n<p>If the buyer already knows the project is driven by can coatings, packaging coatings, or pigment-sensitive cationic printing routes, 550 is often the sharper first sample than a more general shortlist.<\/p>\n<p>For a broader guide to the family, see <a href=\"https:\/\/longchangchemical.com\/fr\/photoinitiator-selection-guide\/\">How to Choose a Photoinitiator for UV Curing<\/a>.<\/p>\n<h2>When 261 is the better fit<\/h2>\n<p>261 becomes more important when the buyer&#8217;s real problem is not just cationic curing, but <strong>how and when<\/strong> the cure completes.<\/p>\n<ul>\n<li><strong>405 nm relevance is already explicit:<\/strong> the current company page says 261 responds to visible light such as <strong>405 nm LED<\/strong>.<\/li>\n<li><strong>The latent-cure mechanism changes the process logic:<\/strong> Longchang describes a route where the resin does not fully cure immediately on light exposure, but forms a latent cured gel layer and then completes curing after bonding and appropriate heat.<\/li>\n<li><strong>Opaque-substrate bonding is directly supported:<\/strong> the page says 261 is suitable for bonding opaque substrates and gives structural, assembly, and laminating adhesives as examples.<\/li>\n<li><strong>Electronics and packaging precision work are already part of the use case:<\/strong> Longchang lists <strong>photoresists, electronic component encapsulants, and insulating coatings<\/strong>.<\/li>\n<li><strong>Low-shrinkage, adhesion, and chemical-resistance logic are already positioned on the page:<\/strong> those are part of the coatings and inks explanation for 261.<\/li>\n<\/ul>\n<p>If the production route involves staged assembly, deeper post-exposure completion, visible-light equipment, or electronics-style process control, 261 often deserves to move ahead of a more routine packaging-first route.<\/p>\n<h2>How buyers should choose between CAT-440, 550, and 261<\/h2>\n<h3>1. Start with the actual process, not the chemistry name<\/h3>\n<p>Ask whether the project is mainly a broad cationic coating route, a packaging and can-coating route, or an adhesive and electronics route with more specific process pressure.<\/p>\n<h3>2. Keep wavelength fit visible from the start<\/h3>\n<p>CAT-440 already carries 365\/385 nm-with-sensitizer positioning, 550 carries 365 nm and LED language, and 261 carries visible-light and 405 nm positioning. That changes the shortlist quickly.<\/p>\n<h3>3. Separate packaging logic from latent-cure adhesive logic<\/h3>\n<p>A can coating or white-ink project should not automatically start with the same first candidate as an assembly adhesive or photoresist route.<\/p>\n<h3>4. Keep pigment and substrate difficulty visible<\/h3>\n<p>550 becomes stronger when pigment shielding is part of the problem. 261 becomes stronger when opaque-substrate bonding and staged cure completion matter more. CAT-440 is stronger when the buyer needs a broader balanced screen first.<\/p>\n<h3>5. Keep the first sample round tight<\/h3>\n<p>The better commercial answer usually comes from matching two or three well-framed candidates to the actual process, rather than screening many cationic names without a decision structure.<\/p>\n<h2>Recommended Longchang product and article paths<\/h2>\n<ul>\n<li><strong>Balanced cationic route:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-cat-440-cas-60565-88-0\/\">Photoinitiator CAT-440<\/a><\/li>\n<li><strong>Can coatings and colored packaging route:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-550-cas-591773-92-1\/\">Photoinitiator 550<\/a><\/li>\n<li><strong>405 nm adhesive and electronics route:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-cat-261-cas-32760-80-8\/\">Photoinitiator 261<\/a><\/li>\n<li><strong>Cationic product family:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/product-category\/photoinitiator\/cationic-photoinitiator\/\">Cationic Photoinitiator Products<\/a><\/li>\n<li><strong>Broader curing-mechanism article:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/comparison-of-uv-free-radical-and-cationic-curing\/\">Comparison of UV Free Radical and Cationic Curing<\/a><\/li>\n<li><strong>Broader family guide:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/photoinitiator-selection-guide\/\">How to Choose a Photoinitiator for UV Curing<\/a><\/li>\n<\/ul>\n<h2>FAQ<\/h2>\n<h3>Which cationic photoinitiator is best for can coatings?<\/h3>\n<p>In Longchang&#8217;s current product positioning, 550 deserves very early attention because the company page directly lists canned-food coatings and coil coatings as typical applications. CAT-440 can also be relevant when the project needs a broader balanced screen that includes packaging and metal-can interior coating routes.<\/p>\n<h3>When should I choose 261 instead of 550?<\/h3>\n<p>Choose 261 earlier when the project needs visible-light response around 405 nm, latent cure after assembly, opaque-substrate bonding, or electronics and packaging precision processing. Choose 550 earlier when the project is mainly can coating, packaging coating, or white and colored cationic printing routes.<\/p>\n<h3>Is CAT-440 a better general starting point than 550?<\/h3>\n<p>Often yes, when the buyer still needs a broad cationic screen across optical, packaging, coating, and adhesive routes. If the application is already clearly centered on can coatings, pharmaceutical packaging coatings, or pigment-sensitive packaging routes, 550 can be the sharper first review point.<\/p>\n<h3>Are CAT-440, 550, and 261 interchangeable?<\/h3>\n<p>No. They overlap inside cationic UV curing, but the company-supported application scope and process logic are different enough that buyers should shortlist them by job type, wavelength fit, substrate behavior, and cure path rather than by category label alone.<\/p>\n<h2>Need a tighter shortlist for cationic UV curing?<\/h2>\n<p>If your project is being limited by wavelength fit, pigment shielding, low-shrinkage needs, opaque-substrate bonding, or can-coating process demands, define the bottleneck first and then compare only the most relevant Longchang routes. That usually produces a cleaner sample plan than treating all cationic photoinitiators as equivalent.<\/p>","protected":false},"excerpt":{"rendered":"<p>A practical B2B comparison of CAT-440, 550, and 261 for cationic UV curing, focused on can coatings, packaging, adhesives, optical work, and LED-capable selection logic.<\/p>","protected":false},"author":6,"featured_media":10010,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-10009","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v25.3.1 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>CAT-440 vs 550 vs 261: Cationic Photoinitiator Selection for UV Curing<\/title>\n<meta name=\"description\" content=\"Compare CAT-440, 550, and 261 for cationic UV curing by looking at can coatings, packaging, adhesives, optical applications, 365\/385\/405 nm fit, latent cure logic, and buyer shortlist decisions.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/longchangchemical.com\/fr\/cat-440-vs-550-vs-261\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"CAT-440 vs 550 vs 261: Cationic Photoinitiator Selection for UV Curing\" \/>\n<meta property=\"og:description\" content=\"Compare CAT-440, 550, and 261 for cationic UV curing by looking at can coatings, packaging, adhesives, optical applications, 365\/385\/405 nm fit, latent cure logic, and buyer shortlist decisions.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/longchangchemical.com\/fr\/cat-440-vs-550-vs-261\/\" \/>\n<meta property=\"og:site_name\" content=\"Longchang Chemical\" \/>\n<meta property=\"article:published_time\" content=\"2026-06-10T00:00:52+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-06-10T02:07:59+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/cat-440-vs-550-vs-261-hero.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1024\" \/>\n\t<meta property=\"og:image:height\" content=\"576\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"marketing@longchang Group\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/\"},\"author\":{\"name\":\"marketing@longchang Group\",\"@id\":\"https:\/\/longchangchemical.com\/#\/schema\/person\/03647a4ce07fdc0e453f27a2b96ccce5\"},\"headline\":\"CAT-440 vs 550 vs 261: How to Choose a Cationic Photoinitiator for Can Coatings, Adhesives, and LED-Capable Curing\",\"datePublished\":\"2026-06-10T00:00:52+00:00\",\"dateModified\":\"2026-06-10T02:07:59+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/\"},\"wordCount\":1519,\"publisher\":{\"@id\":\"https:\/\/longchangchemical.com\/#organization\"},\"image\":{\"@id\":\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/cat-440-vs-550-vs-261-hero.jpg\",\"articleSection\":[\"Uncategorized\"],\"inLanguage\":\"fr-FR\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/\",\"url\":\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/\",\"name\":\"CAT-440 vs 550 vs 261: Cationic Photoinitiator Selection for UV Curing\",\"isPartOf\":{\"@id\":\"https:\/\/longchangchemical.com\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/cat-440-vs-550-vs-261-hero.jpg\",\"datePublished\":\"2026-06-10T00:00:52+00:00\",\"dateModified\":\"2026-06-10T02:07:59+00:00\",\"description\":\"Compare CAT-440, 550, and 261 for cationic UV curing by looking at can coatings, packaging, adhesives, optical applications, 365\/385\/405 nm fit, latent cure logic, and buyer shortlist decisions.\",\"breadcrumb\":{\"@id\":\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#breadcrumb\"},\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#primaryimage\",\"url\":\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/cat-440-vs-550-vs-261-hero.jpg\",\"contentUrl\":\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/cat-440-vs-550-vs-261-hero.jpg\",\"width\":1024,\"height\":576},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/longchangchemical.com\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"CAT-440 vs 550 vs 261: How to Choose a Cationic Photoinitiator for Can Coatings, Adhesives, and LED-Capable Curing\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/longchangchemical.com\/#website\",\"url\":\"https:\/\/longchangchemical.com\/\",\"name\":\"Longchang Chemical\",\"description\":\"China chemical manufacturer \uff06 supplier\",\"publisher\":{\"@id\":\"https:\/\/longchangchemical.com\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/longchangchemical.com\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"fr-FR\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/longchangchemical.com\/#organization\",\"name\":\"Longchang Chemical\",\"url\":\"https:\/\/longchangchemical.com\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/longchangchemical.com\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2020\/08\/cropped-longchang-logo.png\",\"contentUrl\":\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2020\/08\/cropped-longchang-logo.png\",\"width\":512,\"height\":512,\"caption\":\"Longchang Chemical\"},\"image\":{\"@id\":\"https:\/\/longchangchemical.com\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/longchangchemical.com\/#\/schema\/person\/03647a4ce07fdc0e453f27a2b96ccce5\",\"name\":\"marketing@longchang Group\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/longchangchemical.com\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/a6a906641262cdfd34e337a3fa18594a?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/a6a906641262cdfd34e337a3fa18594a?s=96&d=mm&r=g\",\"caption\":\"marketing@longchang Group\"},\"url\":\"https:\/\/longchangchemical.com\/fr\/author\/marketinglongchang-group\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"CAT-440 vs 550 vs 261: Cationic Photoinitiator Selection for UV Curing","description":"Compare CAT-440, 550, and 261 for cationic UV curing by looking at can coatings, packaging, adhesives, optical applications, 365\/385\/405 nm fit, latent cure logic, and buyer shortlist decisions.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/longchangchemical.com\/fr\/cat-440-vs-550-vs-261\/","og_locale":"fr_FR","og_type":"article","og_title":"CAT-440 vs 550 vs 261: Cationic Photoinitiator Selection for UV Curing","og_description":"Compare CAT-440, 550, and 261 for cationic UV curing by looking at can coatings, packaging, adhesives, optical applications, 365\/385\/405 nm fit, latent cure logic, and buyer shortlist decisions.","og_url":"https:\/\/longchangchemical.com\/fr\/cat-440-vs-550-vs-261\/","og_site_name":"Longchang Chemical","article_published_time":"2026-06-10T00:00:52+00:00","article_modified_time":"2026-06-10T02:07:59+00:00","og_image":[{"width":1024,"height":576,"url":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/cat-440-vs-550-vs-261-hero.jpg","type":"image\/jpeg"}],"author":"marketing@longchang Group","twitter_card":"summary_large_image","schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#article","isPartOf":{"@id":"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/"},"author":{"name":"marketing@longchang Group","@id":"https:\/\/longchangchemical.com\/#\/schema\/person\/03647a4ce07fdc0e453f27a2b96ccce5"},"headline":"CAT-440 vs 550 vs 261: How to Choose a Cationic Photoinitiator for Can Coatings, Adhesives, and LED-Capable Curing","datePublished":"2026-06-10T00:00:52+00:00","dateModified":"2026-06-10T02:07:59+00:00","mainEntityOfPage":{"@id":"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/"},"wordCount":1519,"publisher":{"@id":"https:\/\/longchangchemical.com\/#organization"},"image":{"@id":"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#primaryimage"},"thumbnailUrl":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/cat-440-vs-550-vs-261-hero.jpg","articleSection":["Uncategorized"],"inLanguage":"fr-FR"},{"@type":"WebPage","@id":"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/","url":"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/","name":"CAT-440 vs 550 vs 261: Cationic Photoinitiator Selection for UV Curing","isPartOf":{"@id":"https:\/\/longchangchemical.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#primaryimage"},"image":{"@id":"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#primaryimage"},"thumbnailUrl":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/cat-440-vs-550-vs-261-hero.jpg","datePublished":"2026-06-10T00:00:52+00:00","dateModified":"2026-06-10T02:07:59+00:00","description":"Compare CAT-440, 550, and 261 for cationic UV curing by looking at can coatings, packaging, adhesives, optical applications, 365\/385\/405 nm fit, latent cure logic, and buyer shortlist decisions.","breadcrumb":{"@id":"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#breadcrumb"},"inLanguage":"fr-FR","potentialAction":[{"@type":"ReadAction","target":["https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/"]}]},{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#primaryimage","url":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/cat-440-vs-550-vs-261-hero.jpg","contentUrl":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/cat-440-vs-550-vs-261-hero.jpg","width":1024,"height":576},{"@type":"BreadcrumbList","@id":"https:\/\/longchangchemical.com\/cat-440-vs-550-vs-261\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/longchangchemical.com\/"},{"@type":"ListItem","position":2,"name":"CAT-440 vs 550 vs 261: How to Choose a Cationic Photoinitiator for Can Coatings, Adhesives, and LED-Capable Curing"}]},{"@type":"WebSite","@id":"https:\/\/longchangchemical.com\/#website","url":"https:\/\/longchangchemical.com\/","name":"Longchang Chemical","description":"Fabricant chinois de produits chimiques \uff06 fournisseur","publisher":{"@id":"https:\/\/longchangchemical.com\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/longchangchemical.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"fr-FR"},{"@type":"Organization","@id":"https:\/\/longchangchemical.com\/#organization","name":"Longchang Chemical","url":"https:\/\/longchangchemical.com\/","logo":{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/longchangchemical.com\/#\/schema\/logo\/image\/","url":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2020\/08\/cropped-longchang-logo.png","contentUrl":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2020\/08\/cropped-longchang-logo.png","width":512,"height":512,"caption":"Longchang Chemical"},"image":{"@id":"https:\/\/longchangchemical.com\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/longchangchemical.com\/#\/schema\/person\/03647a4ce07fdc0e453f27a2b96ccce5","name":"marketing@longchang Group","image":{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/longchangchemical.com\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/a6a906641262cdfd34e337a3fa18594a?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/a6a906641262cdfd34e337a3fa18594a?s=96&d=mm&r=g","caption":"marketing@longchang Group"},"url":"https:\/\/longchangchemical.com\/fr\/author\/marketinglongchang-group\/"}]}},"_links":{"self":[{"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/posts\/10009","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/comments?post=10009"}],"version-history":[{"count":2,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/posts\/10009\/revisions"}],"predecessor-version":[{"id":10012,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/posts\/10009\/revisions\/10012"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/media\/10010"}],"wp:attachment":[{"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/media?parent=10009"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/categories?post=10009"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/tags?post=10009"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}