Matting Agent for Coatings: Compare Wax Grades Fairly
A lower gloss reading does not automatically identify the better wax. Match the coating system and test conditions, then judge appearance together with the surface properties the application needs.
A matting wax has to deliver the intended finish without making the coating unacceptable in other ways. The lowest gloss reading is not the whole selection decision. First match the binder and coating technology, then compare cured films under equivalent conditions. This guide focuses on wax-based matting; it does not treat every filler, silica or surface modifier as an interchangeable product.
Choose the wax around the finished coating
The MOS coating additives catalogue lists Crayvallac WN-1135 as a PP wax with a matting function. That provides a real product-family enquiry route. It does not establish that every additive in the catalogue, or a similarly named powder, will produce the same finish.
Start with the binder, waterborne or solventborne technology, application method and cure. A clear topcoat may put clarity and feel alongside gloss; an opaque industrial coating may have different appearance and handling requirements. Define which properties must be retained before comparing samples. A shared wax family is not evidence of a drop-in replacement.
Arkema’s surface-modifier guidance selects products around coating technology and the required surface effect. Use that application logic to shortlist a grade, rather than ranking products from a wax name or powder-size number alone. The producer’s guidance is a selection aid, not proof of a result in the buyer’s formulation.
Make gloss results comparable before ranking grades
Specify target gloss together with measurement geometry. “Matt” alone is not a reproducible acceptance criterion, and results at different angles are not interchangeable. Keep the instrument setup and sample identity in the comparison record.
The public scope of ISO 2813 covers gloss measurement at 20°, 60° and 85° for non-textured coatings on plane, opaque substrates. A textured finish or a transparent substrate needs an agreed, appropriate evaluation method and visual reference; do not assume that the same interpretation applies outside that scope. A clear coating is not excluded merely because the coating itself is transparent. This guide does not reproduce the full standard’s procedure.
| Keep comparable | Record | Why it matters |
|---|---|---|
| Measurement | Geometry, instrument setup, conditioning and panel positions | A change in measurement conditions can obscure the grade comparison. |
| Film specimen | Substrate, preparation, application and dry-film thickness | Specimen differences can be mistaken for a wax effect. |
| Cure | Cure schedule and elapsed time before evaluation | Judge panels at the same agreed stage. |
| Formulation | Binder, other additives, exact wax grade and supplied-product dose basis | Equal added mass does not establish equal material function. |
| Incorporation | Addition order, temperature and mixing history | A process change can be mistaken for a chemistry change. |
Retain an unchanged reference formulation and use replicate specimens or representative panel positions appropriate to the method. If film thickness or cure differs, resolve that difference before ranking matting efficiency or cost. A pair of gloss readings does not establish a universal dose-response relationship.
Separate useful matting from a defective film
Lower gloss can be desirable while visible specks, uneven texture, haze or poor levelling make the film unacceptable. Inspect panels under consistent lighting as well as measuring gloss. Then assess the surface properties required by the end use with their own relevant tests: a gloss reading does not prove scratch resistance, slip, recoating behaviour or durability.
| Observation | Next controlled check | Does not prove |
|---|---|---|
| Lower gloss with specks or uneven appearance | Check distribution and incorporation; compare against a control at equivalent film thickness. | An acceptable matt finish. |
| Fresh trial passes but stored material gives a different film | Repeat application and measurement on identified stored material; check separation and mixing history. | A single confirmed cause or a shelf-life limit. |
| Similar gloss but different feel or handling | Use the relevant property test at matched cure and film thickness. | Equal performance in service. |
If the main change is pigment identity, hiding or colour, the functional pigment selection guide addresses a different decision. Keep the pigment package unchanged in the first wax comparison; changing both at once makes the result harder to interpret.
Control incorporation before changing the chemistry
Do not automatically send every wax through the pigment-grinding stage. The current Crayvallac WN-1135 technical data sheet describes addition to the binder premix or after dispersion before final let-down, using low-to-medium shear. That is guidance for the identified producer grade, not a universal procedure for all waxes or MOS products.
Agree a trial with the supplier around the current grade-specific instructions. Keep the reference formula and other additives fixed, compare a small planned dose series on the supplied-product basis, and record addition sequence and processing conditions. Change one planned variable at a time. No general RPM, temperature or dosage limit can be inferred from this comparison.
For fresh-versus-stored checks, retain material identity and use the same incorporation and film-preparation conditions. A changed appearance alone cannot diagnose particle damage, incompatibility or a storage limit. Where thermal values differ between a catalogue and a current data sheet, confirm the method and document revision with the supplier; do not substitute one value as a process limit.
Send a wax enquiry that can be quoted and tested
Send the coating additives team the binder and coating technology, target gloss with measurement angle, reference finish, substrate, dry-film thickness, cure and application method. Include the current additive and incorporation process, properties that must be retained, sample and order quantities, packaging and destination.
Ask for the exact offered grade, current TDS/SDS, agreed specification and batch COA where applicable, together with a sample evaluation plan. Confirm particle-size or thermal test methods when they affect the trial. A catalogue listing or one successful panel does not guarantee current stock, distribution authorisation, regulatory suitability or performance in another formulation.