NNO is the trade name of Dispersant NNO, a sodium naphthalene sulfonate formaldehyde condensate (CAS 9084-06-4). It is mainly a dispersant for dyes and pigments, but the same chemistry also works as a water-reducing agent in cement-based materials. This page explains what “NNO” means and how it is used as a water reducer.
What NNO Means
NNO is a trade designation used in the dye and auxiliary industry for the naphthalene sulfonate formaldehyde condensate dispersant. It is not an abbreviation of a chemical name. The same chemistry is sold for concrete as SNF or PNS, usually under CAS 36290-04-7 and specified for cement fluidity rather than dye dispersion.
How a Water-Reducing Agent Works
A water-reducing agent disperses cement particles so that less mixing water is needed for the same workability. NNO adsorbs on the particles and gives them a negative charge; they repel each other and release trapped water.
NNO or SNF for Concrete?
| Dispersant NNO | SNF concrete grades | |
|---|---|---|
| Specified for | Dye and pigment dispersion | Cement paste fluidity and concrete water reduction |
| Typical CAS on SDS | 9084-06-4 | 36290-04-7 |
| Concrete data on TDS | High-Purity TDS gives a starting range of 0.5–1.2% of cementitious material | Concrete test data (water reduction, strength ratio) on the SNF-5 TDS |
For concrete, SNF grades are usually the more direct choice because their data sheets give concrete test results. See the SNF product page. Low-formaldehyde applications can use the NNO High-Purity grade.
Other Water-Reducing Uses
The High-Purity TDS gives these supplier-recommended starting trial ranges: 2–5% of total dry solids for pigments and dyestuffs, 0.3–0.8% of dry gypsum for wallboard, and 0.5–1.2% of cementitious material for concrete. Confirm by trials.
NNO Grades
| Grade | Content | Dispersing power (vs. standard) | Sodium sulfate | pH | Other limits |
|---|---|---|---|---|---|
| Grade A (GAC-NNO-A) | 95% min | 95% min | 5% max | 7 – 9 (1%) | Ca + Mg 0.4% max; insolubles 0.05% |
| Grade B (GAC-NNO-B) | 92% min | 90% min | 18% max | 7 – 9 (1%) | Ca + Mg 0.4% max; insolubles 0.05% |
| Grade C (GAC-NNO-C, HG/T 2562-2012) | Not listed | Not listed | 22% max | 7 – 9 (1%) | Water 8% max; free formaldehyde 200 ppm max |
| High-Purity (GAC-NNO-HP) | Solids 93% min | Not listed | Sulphate about 3% | 7.0 – 9.0 (2%) | Free naphthalene <5 ppm; free formaldehyde <50 ppm; quinoline <200 ppm |
Frequently Asked Questions
What does NNO mean?
NNO is the trade name of Dispersant NNO, a sodium naphthalene sulfonate formaldehyde condensate dispersant (CAS 9084-06-4).
Is NNO a water-reducing agent?
It can act as one in cement and gypsum, because it disperses the particles. For concrete, SNF grades with concrete test data are usually chosen.
What is a water-reducing agent?
An admixture that disperses cement particles so that less mixing water is needed for the same workability.
