{"id":11360,"date":"2026-08-27T06:56:35","date_gmt":"2026-08-27T06:56:35","guid":{"rendered":"https:\/\/longchangchemical.com\/product\/photoinitiator-pi-991\/"},"modified":"2026-08-27T07:30:56","modified_gmt":"2026-08-27T07:30:56","slug":"photoinitiator-pi-991","status":"publish","type":"product","link":"https:\/\/longchangchemical.com\/hu\/product\/photoinitiator-pi-991\/","title":{"rendered":"CHLUMINIT\u00ae PI-991 \/ OXE-01 Alternative Oxime Ester Photoinitiator for Photoresists"},"content":{"rendered":"<h2 class=\"product_title entry-title\"><strong>PI-991 Oxime Ester Photoinitiator for Photoresists<\/strong><\/h2>\n<p>PI-991 is a free-radical oxime ester photoinitiator for UV curing. The supplied TDS describes it as a low-odor, low-toxicity product with resistance to yellowing. It can be used in combination with other Type I photoinitiators. Users should review the current SDS and applicable regulatory requirements before use.<\/p>\n<h2><strong>Why PI-991 for Photoresist Formulations?<\/strong><\/h2>\n<p>Photoresist formulations based on unsaturated resins and their monomers, including color-filter and black-matrix applications.<\/p>\n<ul>\n<li>Designed to initiate UV curing in formulations based on unsaturated resins and their monomers.<\/li>\n<li>Suitable for photoresist systems, including color-filter and black-matrix applications.<\/li>\n<li>The supplied TDS describes low odor and resistance to yellowing.<\/li>\n<li>Can be evaluated in combination with other Type I photoinitiators.<\/li>\n<\/ul>\n<h2><strong>Product Information and Specifications<\/strong><\/h2>\n<table>\n<tbody>\n<tr>\n<td width=\"245\"><strong>Term\u00e9k neve<\/strong><\/td>\n<td width=\"390\">PI-991<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>Chemical class<\/strong><\/td>\n<td width=\"390\">Oxime ester photoinitiator<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>CAS-sz\u00e1m.<\/strong><\/td>\n<td width=\"390\">Confidential<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>Chemical structure<\/strong><\/td>\n<td width=\"390\">Confidential<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>Megjelen\u00e9s<\/strong><\/td>\n<td width=\"390\">Feh\u00e9r vagy halv\u00e1nys\u00e1rga krist\u00e1lyos por<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>Tisztas\u00e1g (HPLC)<\/strong><\/td>\n<td width=\"390\">\u226598%<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>Olvad\u00e1spont<\/strong><\/td>\n<td width=\"390\">59-62\u00b0C<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>Weight loss on drying<\/strong><\/td>\n<td width=\"390\">\u22640,5%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2><strong>UV-Vis Absorption Data<\/strong><\/h2>\n<p>The supplied TDS includes UV-Vis absorption spectra under the following test conditions:<\/p>\n<table>\n<tbody>\n<tr>\n<td width=\"245\"><strong>Test medium<\/strong><\/td>\n<td width=\"390\">Acetonitrile solution<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>Concentrations shown in the source spectrum<\/strong><\/td>\n<td width=\"390\">0.001%, 0.01% and 0.1%<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>Peak values<\/strong><\/td>\n<td width=\"390\">Not numerically specified in the supplied TDS<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2><strong>Alkalmaz\u00e1sok<\/strong><\/h2>\n<ul>\n<li>Photoresists and UV-curable patterning formulations<\/li>\n<li>Color filters<\/li>\n<li>Black matrices<\/li>\n<li>3D printing materials<\/li>\n<li>UV-h\u0151\u00e1ll\u00f3 bevonatok<\/li>\n<li>UV-curable inks<\/li>\n<\/ul>\n<section id=\"lc-pi991-performance\">\n<h2><strong>PI-991 as an Alternative to Photoinitiator OXE-01<\/strong><\/h2>\n<p><strong>Important clarification:<\/strong> In the supplied technical communication, the shorthand &#039;01&#039; means Photoinitiator OXE-01. PI-991 is positioned as an alternative candidate to OXE-01 for photoresist and high-depth-to-width-ratio dry-film applications.<\/p>\n<div class=\"lc-pi991-performance-chart\">\n<img decoding=\"async\" src=\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/08\/pi-991-performance-comparison.jpg\" alt=\"PI-990 PI-991 sensitized photopolymerization comparison with OXE-01 and TPO at 395 nm\" loading=\"lazy\" \/><\/p>\n<p><em>Provided comparison slide for the PI-990\/PI-991 sensitization platform.<\/em><\/p>\n<\/div>\n<h3><strong>Reported Sensitization Test<\/strong><\/h3>\n<table>\n<tbody>\n<tr>\n<td width=\"245\"><strong>Comparison slide title<\/strong><\/td>\n<td width=\"390\">PI-990\/PI-991<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>Sensitized system shown<\/strong><\/td>\n<td width=\"390\">2% PI-990 + 0.1% sensitizer<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>Reference systems shown<\/strong><\/td>\n<td width=\"390\">2% OXE-01, 2% TPO and 2% PI-990<\/td>\n<\/tr>\n<tr>\n<td width=\"245\"><strong>Polymerization conditions<\/strong><\/td>\n<td width=\"390\">395 nm; TMPTA photopolymerization<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3><strong>Reported Results<\/strong><\/h3>\n<ul>\n<li>Adding the sensitizer clearly accelerated the photopolymerization rate.<\/li>\n<li>The sensitized system showed a clear advantage over OXE-01 and TPO in the presented conversion curve.<\/li>\n<li>The system was identified as suitable for dry-film applications with a high depth-to-width ratio.<\/li>\n<\/ul>\n<h3><strong>Supplier Technical Communication<\/strong><\/h3>\n<ul>\n<li>Only a small amount of sensitizer is needed, and the reported sensitivity is higher than OXE-01.<\/li>\n<li>The reported double-bond conversion is also higher.<\/li>\n<\/ul>\n<p><strong>In these statements, \u201c01\u201d refers specifically to Photoinitiator OXE-01.<\/strong><\/p>\n<div class=\"lc-pi991-communication-screenshot\">\n<img decoding=\"async\" src=\"https:\/\/longchangchemical.com\/wp-content\/uploads\/2026\/08\/pi-991-technical-communication.jpg\" alt=\"Supplier technical communication positioning PI-991 as an alternative to Photoinitiator OXE-01\" loading=\"lazy\" \/><\/p>\n<p><em>Supporting technical communication: higher reported sensitivity than OXE-01 with a small sensitizer addition, OXE-01 alternative positioning, and higher reported double-bond conversion.<\/em><\/p>\n<\/div>\n<p><strong>Data scope:<\/strong> The slide is titled PI-990\/PI-991, but the test formulation and individual curve are specifically labeled PI-990. The chart should therefore be treated as comparative screening data for the PI-990\/PI-991 platform, not as a standalone PI-991 COA or product-specific test report. Confirm PI-991 performance in the customer&#039;s resin, exposure and process conditions before substitution.<\/p>\n<\/section>\n<h2><strong>Formulation Guidance<\/strong><\/h2>\n<p>The supplied TDS does not state a universal addition level. Determine the appropriate concentration and any Type I photoinitiator combination through formulation screening under the intended resin system, film thickness, pigment loading, exposure source and process conditions.<\/p>\n<h2><strong>Storage and Packaging<\/strong><\/h2>\n<p><strong>T\u00e1rol\u00e1s:<\/strong> Keep in a tightly sealed container in a cool, dry, dark and ventilated area. The stated shelf life is 24 months from the date of production under appropriate storage conditions.<\/p>\n<p><strong>Csomagol\u00e1s:<\/strong> 20 kg\/drum; customized packaging may be available according to customer requirements.<\/p>\n<h2><strong>Handling and Documentation<\/strong><\/h2>\n<p>The CAS number and chemical structure are confidential in the supplied TDS and are therefore not disclosed on this page. Request the current TDS, COA and SDS before formulation, handling or production use.<\/p>\n<div class=\"lc-related-products\">\n<h2><strong>Related Photoresist Photoinitiators<\/strong><\/h2>\n<ul>\n<li><a href=\"https:\/\/longchangchemical.com\/hu\/product\/photoinitiator-oxe-01\/\">CHLUMINIT\u00ae OXE-01<\/a><\/li>\n<li><a href=\"https:\/\/longchangchemical.com\/hu\/product\/photoinitiator-oxe-02-cas-478556-66-0\/\">CHLUMINIT\u00ae OXE-02<\/a><\/li>\n<li><a href=\"https:\/\/longchangchemical.com\/hu\/product\/chluminit-oxe-06-for-negative-photoresist\/\">CHLUMINIT\u00ae OXE-06 for Negative Photoresist<\/a><\/li>\n<li><a href=\"https:\/\/longchangchemical.com\/hu\/product-category\/type-i-free-radical-photoinitiator\/\">More Type I free-radical photoinitiators<\/a><\/li>\n<\/ul>\n<\/div>\n<h2><strong>L\u00e9pjen kapcsolatba vel\u00fcnk most!<\/strong><\/h2>\n<p>If you need pricing, a sample, COA, SDS or TDS for photoresist formulation screening, please complete the contact form below. We usually respond within 24 hours. You can also email <a href=\"mailto:info@longchangchemical.com\">info@longchangchemical.com<\/a> during business hours (8:30 am to 6:00 pm UTC+8, Monday to Saturday) or use the website live chat.<\/p>","protected":false},"excerpt":{"rendered":"<p>CHLUMINIT\u00ae PI-991 is an oxime ester photoinitiator positioned as an OXE-01 alternative candidate for photoresists, color filters and black matrices.<\/p>","protected":false},"featured_media":11361,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"product_brand":[],"product_cat":[174,177],"product_tag":[],"class_list":{"0":"post-11360","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-photoinitiator","7":"product_cat-type-i-free-radical-photoinitiator","9":"first","10":"instock","11":"shipping-taxable","12":"product-type-simple"},"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v25.3.1 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>PI-991 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