Dover Chemical Doverphos Phosphite Antioxidants, Flame Retardants and Lubricant Additives

Selection and quotation of Dover Chemical products: Doverphos S-9228 and LGP-12 phosphites, Dovernox antioxidants, DoverGuard flame retardants, Paroil and Doverlube additives.

Doverphos Liquid Phosphites and HiPure TNPP

Doverphos liquid organophosphites act as secondary antioxidants and heat stabilizers for PE, PP, PVC, styrenics and elastomers. Grades differ in phosphorus content, viscosity and alkylphenol profile. HiPure 4 is TNPP with low free nonylphenol, HiPure 4HR adds enhanced hydrolytic stability.

Doverphos 4 (TNPP): 4.3% phosphorus, 6,000 cps
Doverphos 10 triphenyl phosphite: 10.0% phosphorus
Doverphos 6 triisodecyl phosphite: 15 cps
Doverphos 12: 12.0% phosphorus, 487 cps

Solid Phosphites S-9228, 480 and Dovernox Antioxidants

Doverphos S-9228 is a free-flowing pentaerythritol diphosphite powder for polymer processing at elevated temperatures, hydrolytically stable without added triisopropanolamine. Doverphos 480 powder and S-680 flake complete the range. Dovernox 10 and Dovernox 76 are hindered phenolic antioxidants.

S-9228: 7.3% phosphorus, melting point 225 °C min.
Doverphos 480 powder: melting point 185 °C
S-680 flake: 8.0% phosphorus, melting point 55 °C
Dovernox 10: molecular weight 1178

Doverphos LGP-12 Polymeric Phosphite

LGP-12 is a liquid polymeric phosphite without alkylphenol, offered by the manufacturer as an alternative to TNPP in polyolefins. High molecular weight reduces volatility and migration in food packaging. It serves film extrusion, compounding and processing of PCR and PIR recycled polyolefins.

Phosphorus 7.3%, no alkylphenol
Clear to slightly hazy liquid
LLDPE, LDPE, HDPE and PP
FDA food contact and EFSA authorization

DoverClear and DoverCycle Process Aids

DoverClear process aids for polyethylene film and sheet extrusion are PFAS-free and siloxane-free: they eliminate melt fracture and shark skin and reduce gels. DoverCycle is an additive platform for PCR and PIR recycled polyolefins that preserves melt flow stability over repeated thermal histories.

DoverClear: powder or masterbatch
DoverClear: metallocene and Ziegler-Natta PE
DoverCycle: masterbatch or neat blend
Blown film and sheet extrusion

DoverGuard E-35, Hordaflam 70R and Doversperse Flame Retardants

DoverGuard E-35 is a patented chlorinated ester used as a secondary flame retardant plasticizer for PVC, plastisols, cable compounds, coatings and adhesives. Hordaflam 70R is a solid chlorinated alkane for coatings, inks, plastics and foams. Doversperse offers water-based emulsions.

DoverGuard E-35: 35% chlorine, specific gravity 1.16
DoverGuard E-35: pour point below −30 °C
Hordaflam 70R: approx. 70% chlorine
Doversperse: emulsions for water-based coatings

Paroil and Chlorowax Chlorinated EP Additives

Medium, long and very long chain chlorinated alkanes serve as extreme pressure and lubricity additives for metalworking fluids and industrial lubricants. Grades differ in chlorine level and viscosity, the 300 Series adds corrosion inhibitors. Uses: machining, drawing, stamping, forming.

Paroil 10-NR: medium chain, 40% chlorine
Paroil 63-NR: 62% chlorine
Chlorowax 40: 42% chlorine, 29 cSt at 100 °C
Paroil 500: 53% chlorine, 135 cSt at 100 °C

Doverlube and Mayfree Phosphorus Anti-Wear Additives

Phosphate esters, phosphite esters, phosamides and additive packages for metalworking fluids and industrial lubricants give anti-wear, EP and antioxidant action. Doverlube AW 265P is a polymeric phosphite ester for oils, greases and driveline, Mayfree 133 is a phosamide for metal forming.

AW 265P: 6.5% phosphorus, 190 cSt at 40 °C
AW 265P: 0.5–2.0% treat rate as antiwear
Doverlube NCL-2: package for rolling oils
Mayphos 45: phosphate ester for flute grinding

PNP, DNP, DCP and PCP Alkylphenols

Alkylphenols are chemical intermediates for surfactants, antioxidants, resins and lubricant additives. The range covers para-nonylphenol PNP and its ethoxylate intermediate PNPEG, di-nonylphenol DNP, di-cumylphenol DCP and para-cumylphenol PCP. Choice depends on structure and reactivity.

PNP para-nonylphenol: surfactants and antioxidants
PNPEG intermediate: nonionic surfactants
DNP di-nonylphenol: lubricant additives
DCP di-cumylphenol: antioxidants and polymer additives

Choosing a Phosphite by Polymer and Processing Temperature

Doverphos liquid organophosphites are compared by phosphorus content, acid number, viscosity and alkylphenol profile: from Doverphos 49 with 4.9% phosphorus to Doverphos 213 with 13.3%.

Phosphites decompose hydroperoxides formed during melt processing and work together with the Dovernox 10 and Dovernox 76 phenolic antioxidants.

For elevated temperature processing the manufacturer offers solid S-9228: a high melting point and low volatility limit additive loss during extrusion and compounding. Doverphos 480 is a powder melting at 185 °C, S-680 and S-682 are flakes melting at 55–56 °C with 8.0% phosphorus.

Replacing TNPP and Food Packaging

TNPP remains in the range as Doverphos 4 and the high-purity HiPure grades: HiPure 4 with low free nonylphenol, HiPure 4HR and 4HR Plus with triisopropanolamine for enhanced hydrolytic stability.

Where a formulation needs an alkylphenol-free phosphite, the manufacturer offers polymeric LGP-12 with 7.3% phosphorus: its high molecular weight reduces volatility and migration in packaging.

For S-9228 the oxidative and hydrolysis products are included on European food registrations and are considered non-NIAS. Food contact suitability of a specific grade is checked against its TDS and regulatory status.

Metalworking Additives: Chlorine or Phosphorus

Chlorinated alkanes are selected by chain length, chlorine level and viscosity: medium chain (Paroil 10-NR, 40% chlorine) balances EP performance and lubricity, long chain (Chlorowax 40, Paroil 142) builds film strength for drawing, stamping and aluminum machining, very long chain grades serve severe-duty formulations.

Chlorine-free formulations use phosphorus additives: Mayfree phosamides for water-soluble fluids and Doverlube AW polymeric phosphites to combine anti-wear and antioxidant action. In the ASTM D-4172 four ball test Doverlube AW 265P at 1.0% reduces the wear scar from 1.10 to 0.48 mm.

Flame Retardants for PVC and Water-Based Systems

DoverGuard E-35 is added to PVC as a secondary flame retardant plasticizer replacing part of phosphates, phthalates or chlorinated paraffins; the loading level depends on the formulation.

According to the data sheet it is readily biodegradable, not a substance of very high concern and gives lower plastisol viscosity than common phthalate plasticizers.

Recommended storage is 80–100 °F. Solid Hordaflam 70R with approximately 70% chlorine serves coatings, inks, foams, paper and textiles, while Doversperse emulsions suit water-based coatings, adhesives and sealants.

Dover Chemical and model names are trademarks of their respective owners and are used only to identify the equipment for which we source parts. SpareX is not an official dealer, distributor or representative of Dover Chemical and is not affiliated with the trademark owner. Origin, documents and warranty are stated for each item in the quotation.