{"id":10053,"date":"2026-06-12T00:00:17","date_gmt":"2026-06-12T00:00:17","guid":{"rendered":"https:\/\/longchangchemical.com\/?p=10053"},"modified":"2026-06-12T12:05:39","modified_gmt":"2026-06-12T12:05:39","slug":"coil-coatings-photoinitiator","status":"publish","type":"post","link":"https:\/\/longchangchemical.com\/fr\/coil-coatings-photoinitiator\/","title":{"rendered":"Photoinitiator for UV Coil Coatings: How to Choose 551, 550, and CAT-440"},"content":{"rendered":"<p><strong>R\u00e9ponse rapide :<\/strong> Buyers choosing a <strong>photoinitiator for UV coil coatings<\/strong> should usually separate three first-screen situations early: <strong>a direct coil-coating route centered on metal-coil lines and broader long-wave fit<\/strong>, <strong>a packaging-crossover route that still includes coil coatings but also reaches can or pharmaceutical-packaging systems<\/strong>, and <strong>a balanced light-color cationic route when the team wants wider coating and packaging screening before narrowing the final formulation<\/strong>. In Longchang&#8217;s current product positioning, <a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-551-cas-591773-90-9\/\">Photoinitiator 551<\/a> deserves very early attention when the project is directly about <strong>coil coatings, metal coatings, can coatings, and pharmaceutical packaging<\/strong>, and when the team values its stated <strong>365\/385\/395 nm response<\/strong> and LED-curing fit. <a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-550-cas-591773-92-1\/\">Photoinitiator 550<\/a> becomes the stronger first screen when the buyer still wants direct <strong>coil-coating relevance<\/strong> but also needs a broader crossover into <strong>canned-food coatings, pharmaceutical packaging, overprint varnishes, or epoxy-resin photopolymerization<\/strong>. <a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-cat-440-cas-60565-88-0\/\">Photoinitiator CAT-440<\/a> moves up when the formulation team wants a <strong>balanced cationic shortlist<\/strong> that covers <strong>high-performance coatings, packaging inks, metal can interior coatings, and light-colored systems<\/strong>, with sensitizer-assisted <strong>365\/385 nm<\/strong> fit.<\/p>\n<p>That is the practical buying split. UV coil coatings are rarely judged by cure speed alone. Buyers usually care about the real metal-coil application, wavelength fit, surface drying, appearance sensitivity, shrinkage behavior, and whether the first sample plan is built around a narrow commercial decision or a broader cationic screening round.<\/p>\n<h2>Why UV coil coatings need a tighter shortlist<\/h2>\n<p>In many coating plants, the problem is not finding any cationic photoinitiator. The problem is finding the shortest first shortlist that matches the actual line pressure.<\/p>\n<ul>\n<li><strong>Some projects are directly about pre-coated metal coils:<\/strong> the buyer wants a product already positioned for coil coatings instead of a generic coatings answer.<\/li>\n<li><strong>Some projects are packaging-adjacent:<\/strong> the same decision may touch can coatings, pharmaceutical packaging, or low-odor expectations.<\/li>\n<li><strong>Some projects are appearance-sensitive:<\/strong> light-color systems, no-yellowing requirements, and clean surface drying become more important than a broad catalog list.<\/li>\n<li><strong>Some teams still need a wider cationic screen:<\/strong> they may be comparing coatings, inks, and adhesive-adjacent routes before locking the formulation path.<\/li>\n<\/ul>\n<p>That is why a generic \u201cphotoinitiator for coatings\u201d page is usually too loose. A better shortlist starts by identifying whether the real bottleneck is <strong>direct coil-line fit<\/strong>, <strong>packaging crossover<\/strong>, or <strong>balanced light-color cationic screening<\/strong>.<\/p>\n<h2>Quick comparison table: 551 vs 550 vs CAT-440<\/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-551-cas-591773-90-9\/\">551<\/a><\/td>\n<td>Direct coil coatings, metal coatings, can coatings, and pharmaceutical-packaging cationic routes<\/td>\n<td>Longchang directly lists coil coatings in the usage path and also positions 551 for can coatings, metal coatings, pharmaceutical packaging, 365\/385\/395 nm response, LED curing, good surface drying, no yellowing, no migration, and no odor<\/td>\n<td>When the buyer needs broader crossover into packaging varnish, epoxy photopolymerization, or a more balanced light-color cationic screen<\/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>Coil coatings with broader packaging crossover, canned-food coatings, pharmaceutical packaging, printing inks, and epoxy-resin photopolymerization<\/td>\n<td>Longchang directly lists coil coatings, canned-food coatings, pharmaceutical packaging coatings, printing inks and overprint varnishes, plus 365 nm absorption, LED-curing suitability, good surface drying, no yellowing, no migration, and no odor<\/td>\n<td>When the line is clearly a direct coil-coating screen and the buyer wants the sharper long-wave 365\/385\/395 nm route already stated on 551<\/td>\n<\/tr>\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 high-performance coatings, metal can interior coatings, packaging inks, and light-colored systems<\/td>\n<td>Longchang positions CAT-440 for high-performance coatings and inks, metal can interior coatings, plastic coatings, food and pharmaceutical packaging inks, and mostly light-colored systems, with sensitizer-assisted 365\/385 nm absorption, fast curing, and clean surface drying<\/td>\n<td>When the buyer&#8217;s real job is already a narrow direct coil-coating decision and does not need the broader balanced cationic screen<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>When 551 is the better fit<\/h2>\n<p>551 should usually move to the front of the sample plan when the buyer is already in a <strong>direct coil-coating or metal-coating conversation<\/strong>.<\/p>\n<ul>\n<li><strong>Coil-coating relevance is direct:<\/strong> Longchang lists <strong>coil coatings<\/strong> in the usage path instead of only giving general coatings language.<\/li>\n<li><strong>Metal-surface crossover is still strong:<\/strong> the same page also supports <strong>can coatings<\/strong> et <strong>metal coatings<\/strong>.<\/li>\n<li><strong>The wavelength window is broader on the current page:<\/strong> Longchang states that 551 has absorption at <strong>365\/385\/395 nm<\/strong>.<\/li>\n<li><strong>LED fit is already part of the positioning:<\/strong> the company page says 551 can be used for <strong>Durcissement par LED<\/strong>.<\/li>\n<li><strong>Commercial cleanliness is already framed:<\/strong> Longchang highlights <strong>good surface drying, no yellowing, no migration, and no odor<\/strong>.<\/li>\n<\/ul>\n<p>If the line is truly about coated metal coils and the team wants a product page already aligned to that route, 551 is usually the clearest first review point.<\/p>\n<h2>When 550 is the better fit<\/h2>\n<p>550 becomes more attractive when the buyer still needs <strong>coil-coating relevance<\/strong> but the project is broader than one narrow metal-line decision.<\/p>\n<ul>\n<li><strong>Coil coatings are still explicit:<\/strong> Longchang directly lists <strong>coil coatings<\/strong> among the application scenarios.<\/li>\n<li><strong>Packaging crossover is stronger:<\/strong> the page also lists <strong>canned food coatings<\/strong> et <strong>pharmaceutical packaging coatings<\/strong>.<\/li>\n<li><strong>Varnish and ink relevance are already supported:<\/strong> Longchang also points to <strong>printing inks and overprint varnishes<\/strong>, especially in colored systems.<\/li>\n<li><strong>Epoxy-resin photopolymerization is also on the page:<\/strong> that gives 550 wider crossover value than a coil-only discussion.<\/li>\n<li><strong>365 nm and LED fit remain practical:<\/strong> the company page states that 550 has some absorption at <strong>365 nm<\/strong> and can be used for <strong>Durcissement par LED<\/strong>.<\/li>\n<\/ul>\n<p>If the supplier evaluation spans coil coatings plus other packaging or cationic-epoxy routes, 550 often deserves earlier attention than a narrower coil-line-first screen.<\/p>\n<h2>When CAT-440 is the better fit<\/h2>\n<p>CAT-440 becomes more relevant when the buyer is not only trying to solve coil coatings, but also wants a <strong>balanced cationic shortlist<\/strong> for broader coating and packaging work.<\/p>\n<ul>\n<li><strong>Coatings relevance is already direct:<\/strong> Longchang lists <strong>high-performance coatings and inks<\/strong>, including <strong>metal can interior coatings<\/strong> et <strong>plastic coatings<\/strong>.<\/li>\n<li><strong>Packaging-adjacent coverage is broader:<\/strong> the same page supports <strong>food and pharmaceutical packaging inks<\/strong>.<\/li>\n<li><strong>Light-color positioning is clearer:<\/strong> Longchang states that CAT-440 is used mainly in <strong>various cationic light-curing systems, mostly in light-colored systems<\/strong>.<\/li>\n<li><strong>Sensitizer-assisted wavelength fit is useful:<\/strong> the page gives CAT-440 good absorption at <strong>365 nm and 385 nm when used with a sensitizer<\/strong>.<\/li>\n<li><strong>The cure profile is still commercially clean:<\/strong> Longchang highlights <strong>fast curing speed, good surface drying, no yellowing, no migration, and no odor<\/strong>.<\/li>\n<\/ul>\n<p>CAT-440 is not the direct coil-coating specialist in this shortlist. It is stronger when the buyer wants a broader balanced cationic route, especially for light-color or packaging-adjacent screening.<\/p>\n<h2>How buyers should choose a photoinitiator for UV coil coatings<\/h2>\n<h3>1. Start with the real line constraint<\/h3>\n<p>If the job is directly about coil coatings on metal lines, start with 551. If the job includes packaging crossover or broader cationic-epoxy discussion, 550 usually moves up. If the team still needs a wider light-color cationic screen, bring in CAT-440 earlier.<\/p>\n<h3>2. Keep the wavelength window visible from the first sample round<\/h3>\n<p>551 carries direct 365\/385\/395 nm language. 550 carries 365 nm and LED language. CAT-440 carries sensitizer-assisted 365\/385 nm language. That difference should shape the first shortlist before the team adds extra products.<\/p>\n<h3>3. Separate direct coil-line logic from broader packaging logic<\/h3>\n<p>A project centered on pre-coated metal coils is not always screening the same first candidate as a packaging-crossover or light-color cationic project. Keep those decision paths separate.<\/p>\n<h3>4. Keep the first screening round narrow<\/h3>\n<p>For many buyers, one direct coil-line product, one broader packaging-crossover product, and one balanced light-color cationic product is a cleaner first sample plan than comparing many names without a structure.<\/p>\n<h3>5. Use company-supported product paths, not generic assumptions<\/h3>\n<p>These three products overlap as cationic photoinitiators, but Longchang&#8217;s current product pages position them differently enough that buyers should shortlist them by <strong>application path, wavelength fit, and crossover need<\/strong>, not by category label alone.<\/p>\n<h2>Recommended Longchang product and article paths<\/h2>\n<ul>\n<li><strong>Direct coil-line route:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-551-cas-591773-90-9\/\">Photoinitiator 551<\/a><\/li>\n<li><strong>Packaging-crossover route:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/product\/photoinitiator-550-cas-591773-92-1\/\">Photoinitiator 550<\/a><\/li>\n<li><strong>Balanced light-color 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>Adjacent application page:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/can-coatings-photoinitiator\/\">Photoinitiator for UV Can Coatings<\/a><\/li>\n<li><strong>Direct product comparison page:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/550-vs-551\/\">550 vs 551<\/a><\/li>\n<li><strong>Broader cationic comparison page:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/cat-440-vs-550-vs-261\/\">CAT-440 vs 550 vs 261<\/a><\/li>\n<li><strong>Cationic family page:<\/strong> <a href=\"https:\/\/longchangchemical.com\/fr\/product-category\/photoinitiator\/cationic-photoinitiator\/\">Cationic Photoinitiator Products<\/a><\/li>\n<\/ul>\n<h2>FAQ<\/h2>\n<h3>Which photoinitiator is the best starting point for UV coil coatings?<\/h3>\n<p>In Longchang&#8217;s current product positioning, 551 is the clearest first screen when the project is directly about coil coatings and the team wants direct metal-coating relevance plus 365\/385\/395 nm language.<\/p>\n<h3>When should I choose 550 instead of 551 for coil coatings?<\/h3>\n<p>Choose 550 earlier when the project still includes coil coatings but also crosses into canned-food coatings, pharmaceutical packaging, overprint varnishes, or broader epoxy-resin photopolymerization work.<\/p>\n<h3>When does CAT-440 belong in the shortlist?<\/h3>\n<p>CAT-440 belongs in the shortlist when the team wants a broader balanced cationic screen across high-performance coatings, metal can interior coatings, packaging inks, and mostly light-colored systems instead of a narrow direct coil-line decision.<\/p>\n<h3>Are 551, 550, and CAT-440 interchangeable in UV coil coatings?<\/h3>\n<p>No. They overlap in cationic UV curing, but the company-supported application scope and wavelength framing are different enough that buyers should shortlist them by direct coil-line fit, packaging crossover, and light-color screening needs.<\/p>\n<h3>Do all three products fit LED or longer-wave curing discussions?<\/h3>\n<p>551 is positioned with 365\/385\/395 nm response and LED fit, 550 with 365 nm and LED fit, and CAT-440 with sensitizer-assisted 365\/385 nm absorption. That means the line setup and screening goal should shape the shortlist early.<\/p>\n<h2>Need a tighter shortlist for UV coil coatings?<\/h2>\n<p>If your coil-coating project is being limited by wavelength fit, metal-surface line pressure, packaging crossover, or light-color cationic screening, start by defining that bottleneck first. That usually produces a cleaner first sample plan than treating all cationic photoinitiators as interchangeable catalog numbers.<\/p>","protected":false},"excerpt":{"rendered":"<p>A practical B2B guide to choosing a photoinitiator for UV coil coatings by comparing 551, 550, and CAT-440 for metal-coil line fit, 365\/385\/395 nm response, packaging crossover, and light-color cationic screening.<\/p>","protected":false},"author":6,"featured_media":10054,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-10053","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>Photoinitiator for UV Coil Coatings: Selection Guide for 551, 550, and CAT-440<\/title>\n<meta name=\"description\" content=\"Learn how to choose a photoinitiator for UV coil coatings by comparing 551, 550, and CAT-440 for coil-line speed, metal-surface fit, 365\/385\/395 nm response, and broader cationic coating selection.\" \/>\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\/coil-coatings-photoinitiator\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Photoinitiator for UV Coil Coatings: Selection Guide for 551, 550, and CAT-440\" \/>\n<meta property=\"og:description\" content=\"Learn how to choose a photoinitiator for UV coil coatings by comparing 551, 550, and CAT-440 for coil-line speed, metal-surface fit, 365\/385\/395 nm response, and broader cationic coating selection.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/longchangchemical.com\/fr\/coil-coatings-photoinitiator\/\" \/>\n<meta property=\"og:site_name\" content=\"Longchang Chemical\" \/>\n<meta property=\"article:published_time\" content=\"2026-06-12T00:00:17+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-06-12T12:05:39+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/coil-coatings-photoinitiator-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\/coil-coatings-photoinitiator\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/\"},\"author\":{\"name\":\"marketing@longchang Group\",\"@id\":\"https:\/\/longchangchemical.com\/#\/schema\/person\/03647a4ce07fdc0e453f27a2b96ccce5\"},\"headline\":\"Photoinitiator for UV Coil Coatings: How to Choose 551, 550, and CAT-440\",\"datePublished\":\"2026-06-12T00:00:17+00:00\",\"dateModified\":\"2026-06-12T12:05:39+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/\"},\"wordCount\":1523,\"publisher\":{\"@id\":\"https:\/\/longchangchemical.com\/#organization\"},\"image\":{\"@id\":\"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/coil-coatings-photoinitiator-hero.jpg\",\"articleSection\":[\"Uncategorized\"],\"inLanguage\":\"fr-FR\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/\",\"url\":\"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/\",\"name\":\"Photoinitiator for UV Coil Coatings: Selection Guide for 551, 550, and CAT-440\",\"isPartOf\":{\"@id\":\"https:\/\/longchangchemical.com\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/coil-coatings-photoinitiator-hero.jpg\",\"datePublished\":\"2026-06-12T00:00:17+00:00\",\"dateModified\":\"2026-06-12T12:05:39+00:00\",\"description\":\"Learn how to choose a photoinitiator for UV coil coatings by comparing 551, 550, and CAT-440 for coil-line speed, metal-surface fit, 365\/385\/395 nm response, and broader cationic coating selection.\",\"breadcrumb\":{\"@id\":\"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#breadcrumb\"},\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#primaryimage\",\"url\":\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/coil-coatings-photoinitiator-hero.jpg\",\"contentUrl\":\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/coil-coatings-photoinitiator-hero.jpg\",\"width\":1024,\"height\":576},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/longchangchemical.com\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Photoinitiator for UV Coil Coatings: How to Choose 551, 550, and CAT-440\"}]},{\"@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":"Photoinitiator for UV Coil Coatings: Selection Guide for 551, 550, and CAT-440","description":"Learn how to choose a photoinitiator for UV coil coatings by comparing 551, 550, and CAT-440 for coil-line speed, metal-surface fit, 365\/385\/395 nm response, and broader cationic coating selection.","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\/coil-coatings-photoinitiator\/","og_locale":"fr_FR","og_type":"article","og_title":"Photoinitiator for UV Coil Coatings: Selection Guide for 551, 550, and CAT-440","og_description":"Learn how to choose a photoinitiator for UV coil coatings by comparing 551, 550, and CAT-440 for coil-line speed, metal-surface fit, 365\/385\/395 nm response, and broader cationic coating selection.","og_url":"https:\/\/longchangchemical.com\/fr\/coil-coatings-photoinitiator\/","og_site_name":"Longchang Chemical","article_published_time":"2026-06-12T00:00:17+00:00","article_modified_time":"2026-06-12T12:05:39+00:00","og_image":[{"width":1024,"height":576,"url":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/coil-coatings-photoinitiator-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\/coil-coatings-photoinitiator\/#article","isPartOf":{"@id":"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/"},"author":{"name":"marketing@longchang Group","@id":"https:\/\/longchangchemical.com\/#\/schema\/person\/03647a4ce07fdc0e453f27a2b96ccce5"},"headline":"Photoinitiator for UV Coil Coatings: How to Choose 551, 550, and CAT-440","datePublished":"2026-06-12T00:00:17+00:00","dateModified":"2026-06-12T12:05:39+00:00","mainEntityOfPage":{"@id":"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/"},"wordCount":1523,"publisher":{"@id":"https:\/\/longchangchemical.com\/#organization"},"image":{"@id":"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#primaryimage"},"thumbnailUrl":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/coil-coatings-photoinitiator-hero.jpg","articleSection":["Uncategorized"],"inLanguage":"fr-FR"},{"@type":"WebPage","@id":"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/","url":"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/","name":"Photoinitiator for UV Coil Coatings: Selection Guide for 551, 550, and CAT-440","isPartOf":{"@id":"https:\/\/longchangchemical.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#primaryimage"},"image":{"@id":"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#primaryimage"},"thumbnailUrl":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/coil-coatings-photoinitiator-hero.jpg","datePublished":"2026-06-12T00:00:17+00:00","dateModified":"2026-06-12T12:05:39+00:00","description":"Learn how to choose a photoinitiator for UV coil coatings by comparing 551, 550, and CAT-440 for coil-line speed, metal-surface fit, 365\/385\/395 nm response, and broader cationic coating selection.","breadcrumb":{"@id":"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#breadcrumb"},"inLanguage":"fr-FR","potentialAction":[{"@type":"ReadAction","target":["https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/"]}]},{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#primaryimage","url":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/coil-coatings-photoinitiator-hero.jpg","contentUrl":"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/06\/coil-coatings-photoinitiator-hero.jpg","width":1024,"height":576},{"@type":"BreadcrumbList","@id":"https:\/\/longchangchemical.com\/coil-coatings-photoinitiator\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/longchangchemical.com\/"},{"@type":"ListItem","position":2,"name":"Photoinitiator for UV Coil Coatings: How to Choose 551, 550, and CAT-440"}]},{"@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\/10053","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=10053"}],"version-history":[{"count":2,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/posts\/10053\/revisions"}],"predecessor-version":[{"id":10056,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/posts\/10053\/revisions\/10056"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/media\/10054"}],"wp:attachment":[{"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/media?parent=10053"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/categories?post=10053"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/longchangchemical.com\/fr\/wp-json\/wp\/v2\/tags?post=10053"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}