 |
| Synonyms:Zinc bis(dihydrogen phosphate) Zinc phosphate monobasic Phosphoric acid, zinc salt (2:1) Zinc diacid phosphatePigment White 32 Molecular Formula:Zn(H₂PO₄)₂·2H₂O Molecular Weight: 295.39 HS Code: 2835299000 Grade:According to phosphate and zinc content: Superior grade phosphate: 47.5% min, zinc: 20.2% min Grade 1 phosphate: 46% min, zinc: 19.5% Hazard Class:Class9 | |||||||||
13598-37-3
Boss Chemical
13598-37-3
Zinc dihydrogen phosphate (Zn(H₂PO₄)₂, CAS 13598-37-3) is the water-soluble, acidic zinc phosphate salt — the primary zinc source of industrial phosphating chemistry. It is the workhorse salt of zinc phosphating baths that convert steel surfaces into corrosion-resistant, paint-adherent phosphate coatings, and it outperforms manganese dihydrogen phosphate in the anticorrosive treatment of ferrous parts in the electroplating industry. Beyond metal pretreatment, it serves as a non-toxic anticorrosive pigment and coating binder, a glass fining and ceramic coloring auxiliary, a flame retardant for polymers, and a dental impression material.
One salt, four core value propositions:
Metal Phosphating & Electroplating Feedstock (Core Application):
● the key zinc salt of phosphating baths — corrosion protection and paint adhesion for steel, superior to manganese phosphate treatment;
Non-Toxic Anticorrosive Pigment & Coating Binder:
● base of zinc phosphate anticorrosive pigments and alkyd/phenolic/epoxy coating formulations;
Glass & Ceramic Auxiliary:
● fining agent for glass and coloring agent for ceramics;
Polymer Flame Retardancy & Specialty Uses:
● flame retardant for chlorinated rubber and polymer systems, plus dental and analytical applications.
Item | Specification |
Chemical Name | Zinc dihydrogen phosphate (zinc bis(dihydrogen phosphate); monobasic zinc phosphate) |
Synonyms | Zinc diacid phosphate; zinc primary phosphate; phosphoric acid zinc salt (2:1) |
CAS No. | 13598-37-3 |
EC No. (EINECS) | 237-067-2 |
Molecular Formula | Zn(H₂PO₄)₂ (anhydrous); Zn(H₂PO₄)₂·2H₂O (dihydrate) |
Molecular Weight | 259.36 (anhydrous); 295.39 (dihydrate) |
Appearance | White triclinic crystalline solid (also available as 50% aqueous solution) |
Solubility in Acids/Alkali | Soluble in hydrochloric acid and alkali; deliquescent |
Zinc dihydrogen phosphate is the monobasic zinc salt of phosphoric acid, Zn(H₂PO₄)₂ (anhydrous MW 259.36; dihydrate MW 295.39). It is a white, triclinic crystalline solid with exceptional water solubility — the property that makes it the convenient zinc source of phosphating solutions. It is an acidic salt: aqueous solutions are acidic, and on dissolution it hydrolyzes to release phosphate and zinc ions, the active species of phosphating baths. It is deliquescent, dissolves in hydrochloric acid and alkali, has a low melting point and begins to decompose at ≈ 100 °C (boiling/decomposition ≈ 158 °C per LookChem). It is manufactured by reacting phosphoric acid with zinc oxide at 100–120 °C, concentrating at ≈ 130 °C and crystallizing. It is supplied as crystals or as a 50% aqueous solution.
● Phosphating workhorse: the primary zinc salt of industrial zinc phosphating baths.
● Superior ferrous protection: outperforms manganese dihydrogen phosphate in electroplating-industry anticorrosion treatment.
● Very high solubility : fast, uniform bath make-up and replenishment.
● Active species on demand: controlled release of Zn²⁺ and phosphate ions in solution.
● Lead-free anticorrosive value: non-toxic pigment and coating-binder alternative to lead pigments.
● Multi-industry reach: metals, coatings, glass, ceramics, polymers, dental and analytical use.
● Consistent quality: controlled assay, acidity and solubility with COA.
Zinc dihydrogen phosphate is the salt at the heart of zinc phosphating chemistry:
● Phosphating baths: primary zinc salt of zinc-phosphating solutions for steel;
● Anti-rust phosphating of steel parts: converts the surface into a corrosion-resistant, paint-adherent phosphate coating;
● Electroplating-industry anticorrosion: protective treatment of ferrous workpieces — performance superior to manganese dihydrogen phosphate treatment;
● Film-forming and corrosion-inhibiting auxiliary: supports coating formation and passivation in pretreatment lines.
● Zinc phosphate anticorrosive pigment: lead-free rust-inhibiting pigment base;
● Alkyd, phenolic and epoxy coating binders: pigment and binder base of industrial and can coatings;
● Water-borne coatings: soluble phosphate component of water-based anticorrosive systems;
● Primer and rust-inhibitive formulations: metal-protection coatings for construction and industrial use.
● Glass fining agent: clarifying/refining auxiliary in glass melting;
● Ceramic coloring agent: zinc-phosphate based colorant in ceramic bodies and glazes;
● Ceramic and enamel formulations: phosphate fluxing and color contribution;
● Glass and ceramic raw-material blends: consistent zinc phosphate addition.
● Flame retardant for chlorinated rubber: intumescent/phosphorus flame-retardant contribution;
● Polymer flame retardance: phosphorus-based retardancy in synthetic materials and coatings;
● Cable and rubber formulations: flame-retardant filler and synergist roles;
● Consistent particle and assay control for reproducible FR performance.
● Dental impression material: zinc phosphate component of impression and cement-type dental materials;
● Analytical reagent: high-purity grade for laboratory analysis;
● Preservative/anticorrosion applications: corrosion-inhibiting additive use;
● Specialty chemical synthesis: zinc phosphate source for fine-chemical work.
Packaging (customizable):
● 25 kg lined bags or fiber drums with PE liner; 500 kg / 1,000 kg big bags;
● Deliquescent, acidic product — moisture-barrier, corrosion-resistant packaging is standard.
Storage:
● Store in a cool, dry, well-ventilated area; keep containers tightly closed;
● Separate from alkalis and reactive chemicals; protect from moisture to prevent caking and hydrolysis;
● Avoid heating above ≈ 100 °C (decomposition).
● Factory-direct supply: own production and sourcing capability, transparent pricing, no middleman markup;
● Stable quality: strict internal control, every batch tested (assay, acidity, solubility), COA with every shipment; sample orders welcome;
● Application know-how: phosphating, coating and ceramic experience for technical support;
● Export experience: compliant sea/air shipping with complete documentation;
Zinc dihydrogen phosphate is the primary zinc salt of industrial zinc phosphating baths that convert steel surfaces into corrosion-resistant, paint-adherent phosphate coatings; it is used for the anticorrosive treatment of ferrous parts in the electroplating industry (outperforming manganese dihydrogen phosphate); as a non-toxic (lead-free) anticorrosive pigment and binder in alkyd, phenolic and epoxy coatings; as a glass fining agent and ceramic coloring agent; as a flame retardant for chlorinated rubber and polymer systems; and in dental impression materials and analytical reagents.
Phosphating requires a controlled, soluble source of zinc and phosphate ions that forms a crystalline zinc-phosphate conversion layer on the steel surface — the layer that blocks corrosion and anchors paint. Zinc dihydrogen phosphate delivers both ions in the right stoichiometry with exceptionally high water solubility (≈ 1,000 g/L), so bath make-up and replenishment are fast and uniform. The resulting zinc phosphate coating gives corrosion resistance, paint adhesion and cold-forming lubricity in one step, which is why zinc phosphating is the standard pretreatment for automotive, appliance and construction steel.
Zinc dihydrogen phosphate is an acidic, hygroscopic salt: its solutions are corrosive/irritating to eyes, skin and the respiratory tract — wear gloves, eye protection and dust control, and avoid inhaling dust. It hydrolyzes in water (acidic solution, pKa ≈ 4.7) and decomposes on heating from ≈ 100 °C, releasing phosphate/phosphoric-acid vapors — do not overheat. Keep containers sealed and dry (deliquescent). Follow the SDS of the grade and form (solid or 50% solution) supplied, including transport classification, for full handling guidance.
