PVP K90 in Adhesives and Coatings

Polyvinylpyrrolidone K90 (PVP K90, CAS 9003-39-8) is a high-molecular-weight, water-soluble polymer used as a film-forming binder and thickener in adhesives and coatings. Its combination of solubility in water and in many polar organic solvents, clear film formation and strong adhesion makes it useful where a single binder has to work across different systems.

Why K90 for adhesives and coatings?

Property	Benefit in adhesives / coatings
High molecular weight (K90)	Strong cohesion, high viscosity, tough films
Film formation	Clear, continuous films on drying
Adhesion	Bonds to paper, film, metal and mineral surfaces
Water + solvent solubility	Works in aqueous and mixed-solvent formulations
Non-ionic, pH-stable	Compatible with a wide range of additives

The high K-value is the point: K90 gives more binding strength and hold than a low-K grade at the same solids, which is why it is chosen for remoistenable adhesives, strong binders and coatings where cohesion matters.

Adhesive applications

Remoistenable adhesives – stamps, labels and envelopes; PVP forms a film that re-wets and sticks.
Water-based and hot-melt adhesives – as binder, tackifier aid or viscosity builder.
Industrial binders – binding pigments, fillers and powders in bonded products.
Barrier / protective films – clear, adhesive films where a soluble binder is wanted.

Coating and ink applications

Function	Role of PVP K90
Pigment dispersion	Wets and stabilises pigments, improving dispersion stability
Film former	Gives a clear, continuous binder film on drying
Rheology / thickening	Raises viscosity of the formulation
Adhesion promoter	Improves bonding of the coating to the substrate

Formulation notes

Solution viscosity – K90 is high-viscosity, so prepare stock solutions at modest solids and add under good agitation to avoid lumps.
Solvent choice – the same grade dissolves in water and in many polar solvents, giving flexibility in formulation.
Moisture sensitivity – PVP films are hygroscopic; where water resistance is required, blend with a more hydrophobic binder or a crosslinker.
Compatibility – non-ionic and pH-stable, so it is compatible with most common additives; check specific combinations by test.

Specification

Parameter	Specification
Appearance	White or yellowish-white hygroscopic powder
K-Value	87.4 – 94.2 (nominal K90)
Vinylpyrrolidone (NVP)	0.1% max
Water	5.0% max
Residue on ignition	0.1% max
Nitrogen content	11.5 – 12.8%
pH	4.0 – 9.0

Technical grade; per-batch COA and SDS available.

Frequently Asked Questions

Why use PVP K90 rather than a lower K grade in adhesives?

K90’s higher molecular weight gives stronger binding, higher viscosity and tougher films – useful where hold and cohesion matter.

Does PVP work in solvent-based coatings?

Yes – PVP dissolves in water and in many polar organic solvents, so it suits aqueous and mixed-solvent systems.

Are PVP films water-resistant?

PVP films are hygroscopic and will soften with moisture; where water resistance is needed, use it in a blend or with a crosslinker.

Is it compatible with pigments and fillers?

Yes – it acts as a dispersant and binder for many pigments and fillers.

Is this technical grade?

Yes; the product is technical grade. Confirm the grade against your end use.