Water-Based PU Resins for Synthetic Leather
Synthetic leather producers replacing solvent-borne PU look for a water-based PU resin for synthetic leather that keeps the flex, grain and adhesion of the finished material across the whole coating stack. chemlinkai supplies polyurethane dispersions for surface and tie coats, synthesized in-house and matched to your base fabric, release system and embossing conditions.
How the system works
A synthetic leather is a multi-layer construction: base fabric, resin-impregnated or foam layer, tie coat, color layer and surface resin. The surface resin delivers the feel and wear behavior; the tie coat holds the stack together through flexing.
We supply PU dispersions for each role in the stack, with polymer parameters tuned to the role. Surface resins are built for dry feel, abrasion and hydrolysis resistance; tie-coat resins for adhesion between layers that flex at different rates. Because the layers are applied wet-on-wet or wet-on-dry depending on your line, we qualify the coating order and drying conditions on your process.
- Surface and tie-coat dispersions from one in-house PU platform
- Polymer parameters matched to your base, release paper and embossing
- Flex, adhesion and aging behavior checked on the finished construction
- Chemistry developed and synthesized in-house for batch control
Why do water-based PU coatings crack or delaminate in use — and what prevents it?
Two failures dominate water-based synthetic leather. The first is surface cracking: if the surface resin is harder than the material demands, the flexing of the finished product opens microcracks that grow into visible grazing. The second is delamination: the tie coat must grip a base that flexes and a surface layer with different stiffness, and any mismatch shows up at the interface after repeated flex or heat aging.
A water-based PU resin for synthetic leather is specified by the whole construction, not by a single film property. We set the hardness and elongation balance of the surface resin against your flex target, and the tie coat against the adhesion test of your finished material. Trial samples are coated on your line or in our lab on your base, then aged and flex-tested before a production recipe is fixed.
Representative system parameters
Guidance ranges across the PU dispersion platform for synthetic leather. Grade-specific values are confirmed per sample and batch TDS.
| Parameter | Representative range | Remark |
|---|---|---|
| Solids content | 30 – 45 % | Depends on grade and application method |
| Viscosity (Brookfield) | 100 – 3000 mPa·s across grades | Matched to coating method |
| pH | 7.0 – 9.0 | Stability window of the dispersion |
| Film hardness | Grade-specific — per TDS | Selected against flex and feel targets |
| Elongation at break | Grade-specific — per TDS | Balanced with hardness for crack resistance |
| Heat resistance | Method-specific — set by trial | Checked against your embossing temperature |
| Storage stability | 6 months sealed, 5 – 35 °C | Avoid freezing; handling guide supplied |
Representative ranges for system selection — typical values — batch TDS on request.
Where the PU resin sits in the synthetic leather stack
The surface resin carries feel and wear, the tie and color layers sit between it and the base, and the whole stack must flex as one material — each interface is a formulation decision.
Two entry points into the PU resin platform
Whether you enter from the chemistry side or the application side, the platform and the qualification path are the same.
Waterborne Resins & Surface Treatment
Resin platforms and treatment systems across synthetic leather, inks, coatings and adhesives — with formulation support.
Synthetic Leather & Footwear Industry
Application-side view: coated fabrics, footwear materials and the test criteria that define acceptance.
Verified data on flex resistance, adhesion and aging of coated constructions is published after customer and company approval. Request current test results via the form.
PU resin for synthetic leather — common questions
Direct answers for coating plants, R&D teams and purchasing managers.
Do you supply both surface resin and tie coat, or only one?
Both, from one PU platform. Supplying the stack together lets us hold the interfaces accountable, but we also supply single layers where you already run the rest of the construction.
Can your resin work with our existing release paper and base fabric?
Release behavior and base anchorage depend on the full system. We qualify against your release paper and base in the trial, including the embossing temperature you run.
What is the difference between your surface and tie-coat grades?
Surface grades are tuned for hardness, feel and wear; tie-coat grades for adhesion between layers and flex endurance. The TDS states the polymer parameters for each role.
What are the terms for a coating trial?
Sample dispersions are supplied under the trial agreement, with the coating plan agreed in advance. Production MOQ, packaging and lead time are confirmed in the commercial proposal.
How is hydrolysis and aging resistance verified?
Aged samples are tested under the conditions your end customer specifies — heat, humidity or flex cycles. Results are published after approval; request current data through the form.
Documentation
Documents are released per grade and application after final verification.
Documents marked “pending” are released after final verification — request the current version through the form and we will send it with the applicable scope.
Request a coating sample for your base material.
Describe your base fabric, release system, embossing conditions and the flex or aging criteria you must meet. We match the PU grades and set up the coating trial.