UV-328 Benzotriazole UV Absorber Supplier

SUNSORB® 328 (UV-328) is a benzotriazole UV absorber used in coatings and plastics. UV-328 is listed under the Stockholm Convention and as a REACH SVHC, so its use is restricted in many markets; check your destination first.

CAS 25973-55-1 · Benzotriazole · UV absorber
Illustration of polymer pellets, molded samples and film
Application illustration — not a photograph of the product

Présentation du produit

UV-328 (2-(2H-benzotriazole-2-yl)-4,6-di-tert-pentylphenol) has been used in automotive coatings, PVC and polyolefins. It is now listed for elimination under the Stockholm Convention (with limited exemptions) and is a REACH SVHC. We supply it only where the destination allows, and help buyers move to alternatives such as 329, 234 ou liquide 384-2 for coatings.

Typical specification. Every shipment is supplied with a batch COA; the limits that apply to your order are confirmed in the quotation and contract.

Key Benefits

Know the restrictions

We check your destination and end use before quoting.

Replacement support

We propose and supply alternatives for restricted markets.

Coatings and plastics

Historically used in coatings, PVC and polyolefins.

Spécifications techniques

Typical specification. Every shipment is supplied with a batch COA; the limits that apply to your order are confirmed in the quotation and contract.

ParameterTypical value
Nom du produitUV Absorber UV-328
MarqueSUNSORB® 328
Numéro CAS.25973-55-1
Nom chimique2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol
Formule moléculaireC22H29N3O
Masse moléculaire351.5
ApparenceLight-yellow powder
Point de fusion80–83 °C
Essai≥99%

Applications by Material

Pick an application to see how 328 is normally used and what to confirm before your trial.

Illustration of polymer film, molded components and masterbatch granules
Polymer and coating application illustration

Regulatory Status

Listed under the Stockholm Convention and REACH. Use depends on country and on specific exemptions.

What to confirm for your application

  • Destination country
  • End use and any exemption claimed
  • Customer specifications
Discuss this application →

Coatings Replacement

For coatings, liquide 384-2 or triazine 400 with a liquid HALS are common replacements.

What to confirm for your application

  • Coating type and binder
  • Target durability
  • Current 328 Chargement en cours
Discuss this application →

Plastics Replacement

For plastics, 329 ou 234 are common replacements depending on processing temperature.

What to confirm for your application

  • Polymer type
  • Température de traitement
  • Weathering test
Discuss this application →

Emballage & Storage

Emballage

25 kg net bags or cartons with a PE inner liner. Palletized; private-label packing on request.

Storage

Keep sealed in a cool, sec, ventilated place away from heat and direct sun. See the SDS for full handling details.

Délai de mise en œuvre & terms

Typically 3–15 business days from order confirmation, depending on quantity. GOUSSET, CIF or DAP to major ports.

Technique & Buying Information

Selecting a UV Absorber

Your requirementWhat usually works
Clear or light-colored polyolefin parts and filmBenzophenone (531) or benzotriazole (326) at low loading
High processing temperature (PC, ANIMAUX, Pennsylvanie)Low-volatility grades: 234, 360 or 1577-type triazines
Thin films and fibersHigher-MW, low-volatility grades so the absorber is not lost in processing
Solvent-borne and waterborne coatingsLiquid benzotriazoles (384-2, 1130) or triazine (400), paired with a HALS
Outdoor service longer than one seasonUV absorber plus a HALS; the absorber filters, the HALS stops radical chains
Exports to the EUCheck REACH status first; some benzotriazoles (327, 328) are restricted
Replacing an existing gradeSend your current TDS or COA; we match on chemistry and the parameters you approve

UV Absorber Comparison

Swipe or scroll horizontally to see all columns →

ProduitChemistryMol. weightPoint de fusion / formBest fitTypical starting level*
SUNSORB® 328Benzotriazole351.580–83 °CRevêtements, PVC (restricted markets)0.1–0,5%
SUNSORB® 329Benzotriazole323.4103–105 °CPC, ANIMAUX, PVC, PMMA0.1–0,5%
SUNSORB® 234Benzotriazole447.6137–141 °CPC, ANIMAUX, PA at high temperature0.1–0,5%
SUNSORB® 384-2Benzotriazole, liquide—LiquideRevêtements1–3% on binder solids
SUNSORB® 400Hydroxyphenyl-triazine, liquide—LiquideAutomotive and industrial coatings1–3% on binder solids

*Starting points for trials, not fixed recommendations. Loading depends on part thickness, pigment, target service life and the HALS used alongside. UV absorbers and HALS work by different mechanisms and are usually combined.

Documents & Qualité

COA — Certificat d'analyse

Issued for every batch shipped, with the test results for that lot.

FT — Fiche technique

Typical properties and specification for evaluation and supplier approval.

SDS — Safety Data Sheet

GHS-format handling, storage and transport information.

Échantillons

Lab samples for evaluation; tell us the test you plan to run so the sample size fits.

Third-party testing

SGS or Intertek testing can be arranged on request.

Regulatory statements

ATTEINDRE, food-contact and other statements are issued per grade and destination; ask before ordering.

UV Absorber UV-328 Buyer Guide

Define the exposure

Indoor light behind glass, outdoor temperate climate and desert or tropical exposure need very different packages. Note the target service life and the weathering test you use (xenon or QUV, heures, ΔE or gloss retention).

Match absorber to process and thickness

A UV absorber works by filtering, so it needs enough path length: thick parts need less, thin films and fibers need more and need a low-volatility grade. Check the absorber survives your processing temperature.

Combine with a HALS

For outdoor use the standard approach is UV absorber plus HALS. Send your current package and pigment system and we suggest a starting combination for the trial.

Check regulations before you buy

Some benzotriazoles are restricted in the EU and other markets. Tell us the destination and end use, and we confirm the REACH and food-contact position of the grade before you order.

Request a Quotation for UV Absorber UV-328

Start with your material, part thickness, quantité et destination. Add your current UV package and we will quote against it.

InformationExample
Polymer / MaterialPP, PE, abdos, composé, mélange maître
ApplicationInjection molding, extrusion, film, fibre
Current additiveGrade or supplier you use today
Required specificationYour TDS, COA or key limits
QuantityTrial order / monthly / annual volume
EmballageStandard 25 kg or specific requirement
DestinationCountry and port
Documents neededCOA, FDS, ATTEINDRE, food-contact statement
Send RFQ by EmailContact SUNCHEM →

Related UV Absorbers & Stabilisateurs

SUNSORB® 329

Benzotriazole UV absorber for PC, ANIMAUX, PVC and PMMA.

View product →

SUNSORB® 234

High-MW benzotriazole for high-temperature engineering plastics.

View product →

SUNSORB® 384-2

Liquid benzotriazole UV absorber for solvent- and waterborne coatings.

View product →

SUNSORB® 400

Hydroxyphenyl-triazine liquid UV absorber for durable automotive and industrial coatings.

View product →

UV Absorber UV-328 FAQ

Is UV-328 banned?

It is listed under the Stockholm Convention for elimination, with limited exemptions, and is a REACH SVHC. Rules differ by country, so tell us your market before ordering.

What replaces UV-328 in coatings?

Liquid benzotriazole 384-2 or hydroxyphenyl-triazine 400, combined with a liquid HALS such as 292, are common replacements.

What replaces UV-328 in plastics?

329 ou 234, depending on polymer and processing temperature. Re-run your weathering test after switching.

Can I get a sample before ordering?

Oui. Tell us the polymer, the test you plan to run and the quantity you need. Samples ship with a COA so you can compare the lot against your current material.

What if a COA does not match our agreed specification?

Send us the agreed specification and the COA showing the difference (parameter, unit and test method). We check it with the production batch record before you accept the material, and replace or re-test where the lot is out of specification.

Discuss Your UV Absorber UV-328 Requirements

Send your application, specification and quantity to request a quotation or supporting documents.

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