Lacquers

What leather lacquers are

Leather lacquers in this range are nitrocellulose (NC) systems used as the glossy, protective top on resin-finished leather. They supply gloss, wet and dry rub, flexural endurance and a defined handle after the acrylic or PU season. Dyna Glycols offers VENOLAC LMF, a water-dilutable NC lacquer emulsion, and VENOLAC WS, a solvent NC lacquer that can be let down with water or with NC thinner.

The top coat is what the customer touches and what rub and flex tests hit first. An emulsion lacquer (LMF) is the usual choice for water-borne shops that want to iron at elevated temperature with reduced tack. A solvent lacquer (WS) is chosen for high gloss, silky handle and when solvent dye solutions are part of the season.

How Dyna Glycols manufactures leather lacquers

NC emulsions and solvent lacquers are manufactured to agreed solids, appearance and dilution behaviour. LMF is a white emulsion at about 14% solids, freely dilutable with water. WS is a pale-yellow medium-viscosity liquid at about 26% solids, compatible with solvent dye solutions.

Nitrocellulose products require the handling, storage and transport rules on the SDS: keep away from ignition sources for solvent grades, and protect emulsions from frost.

Typical grades in this range

Choose emulsion versus solvent top first, then dilution ratio for gloss versus fastness.

• VENOLAC LMF — NC lacquer emulsion; water dilutable; gloss, rub, flex; ironing up to about 100 °C
• VENOLAC WS — solvent NC lacquer; dilutable with water or NC thinner / butyl acetate; high gloss, soft handle

Where leather lacquers are used

LMF is sprayed as the top glossy protective coat on resin-finished shoe upper, leather goods and similar articles. Typical practice is 1:1 or 1:0.5 LMF:water depending on gloss and fastness. It reduces tack and allows high-temperature ironing.

WS is used when a silky high gloss and soft handle are required. For water dilution, add 1–2 parts water to 1 part lacquer, stir, rest ten minutes, stir again. For solvent dilution, up to 3 parts NC thinner or butyl acetate. It can carry solvent-based dye solutions for shaded tops.

Neither lacquer replaces the binder film. Poor adhesion is usually a base-coat or preparation issue. Trial the lacquer on the actual VENRES season, not on untreated crust.

How to specify leather lacquers

State water-borne versus solvent shop, required gloss, rub and flex tests, ironing temperature, and whether solvent dyes will be added. Share the current top-coat solids if a match is needed.

For automotive or furniture, list the specific rub and hydrolysis tests. NC tops may need a different stack than a pure PU top; say if NC is mandatory.

Quality, documents and supply

Lots are released against appearance, solids and dilution. SDS and COA follow verification. Gloss and rub must be measured on the customer finish stack after the recommended drying and ironing.

Store LMF frost-free; typical shelf life six months. Store WS as a flammable solvent product per SDS. Mix before use. Do not contaminate water-borne LMF with leftover solvent thinner.

Practical notes on leather lacquers

LMF solids are lower than WS; dilution ratios are not interchangeable millilitre for millilitre. Compare dry film weight, not wet grams, when switching.

Ironing: LMF is positioned to allow ironing up to about 100 °C. Confirm plate temperature on the tannery’s iron or roller; overheating can print or yellow NC.

WS water-dilution still starts as a solvent NC. VOC, flash point and workshop extraction remain the tannery’s responsibility. If the site must be water-only, specify LMF.

Flex and feel: a hard glossy top can harshen a soft garment season. Reduce top solids or plasticise the season rather than changing the acrylic binder first.

Repair and two-tone: WS with solvent dyes is the usual shading top. LMF is the cleaner water-borne protective gloss.

Dyna Glycols samples LMF and WS with the VENRES binders so gloss can be judged on the same crust and pigment.

Ordering and evaluating leather lacquers

Dyna Glycols supports leather lacquers with laboratory samples, current SDS, TDS and COA from the Kandla SEZ manufacturing network. Tell us the intended application, the substrate, the required moles or molecular weight, and any limits on colour, odour, cloud point, hydroxyl value, pH or residual feedstock. A matching catalogue grade of leather lacquers in the Leather Chemicals family can then be confirmed, or a custom batch can be planned on the ethoxylation, esterification or related plant.

When you evaluate leather lacquers, send the competitor grade if one exists, the bath or emulsion conditions, and the tests your receiving laboratory will run. Pack options for leather lacquers typically include drums, IBCs and bulk where the viscosity and melting point of the selected grade allow safe handling from the Leather Chemicals manufacturing line.

A first order of leather lacquers is easier when the purchase specification lists identity tests, not only a local trade name. Hydroxyl value, saponification value, acid value, cloud point, pH, water, colour and appearance are the numbers the Kandla QA laboratory can lock. If your QC uses a different solvent or a different cloud-point electrolyte for leather lacquers, write that method on the order so the COA speaks the same language.

Custom lots of leather lacquers are quoted after the hydrophobe or acid/alcohol pair, the target analytical window, the annual volume and the pack. Pilot batches are available when a catalogue point in the Leather Chemicals range is close but not exact. Once a trial lot is approved, that TDS should be frozen so the tenth delivery of leather lacquers matches the first approved drum.

Storage of leather lacquers should follow the SDS: keep containers closed, protect hygroscopic grades from moisture, and warm high-melt or high-mole grades until uniform before sampling. FIFO rotation protects colour and odour. If a drum of leather lacquers has frozen or separated in transit, homogenise it before charging a batch; do not decant only the liquid layer.

Application advice for leather lacquers is given against the process you describe, not as a universal recipe. Share machine type, temperature, pH, electrolytes, fibre or hide type, and any ban on APEO, formaldehyde or food-contact lists. Dyna Glycols can then sample leather lacquers alone or as a pair with a sister grade from the same Leather Chemicals family so compatibility is checked in one evaluation.