Scorch retarder

Scorch retarder. Magnesium oxide retards scorch during mill processing of polychloroprene adhesives. 

Retard or prevent chemical reactions (such as cure). See Scorch retardants. 

The standard approach to reducing scorch (e.g. discoloration resulting from oxidation) involves addition of one or more antioxidants. Scorch retardants prevent premature decomposition of peroxides and cross-linking of polymers (pre-vulcanisation). 

Antiscorch agents - Scorch retardants Antisettling agents Antiskinning agents Antistatics... 

TV-Cyclohexylthiophthal i m idc (CTP) functions as an effective retarder of vulcanisation for accelerators in the sulphenamide classes. It produces scorch retardation without effect on compound modulus. It is not effective, however, in other classes of vulcanisation systems, notably those based on thiazoles, thiurams and dithiocarbamates. 

Scorch retarders - [ARSENIC COMPOUNDS] (Vol 3) -magnesium compounds for [MAGNESIUM COMPOUNDS] (Vol 15)... 

Use A scorch retarder in chloraprene and fluorelas-tomers, thickening agents for SMC/BMC acid acceptors in halogenated and chloroprene adhesives. 

Acrylic acid, zinc salt Ageflex ZDA EINECS 238-692-3 2-Propenoic acid, zinc salt Zinc acrylate Zinc dlacrylate. Crosslinker for molded polybutadiene compounds, conductive and protective coatings, coagent for SBR compounds and reactive pigments activator for rubber compounding scorch retarder. Rit-Chem. 

Uses Antioxidant, antiozonant for petroleum-based and synthetic lubricants, rubbers, and plastics (PU) scorch retarder for CR in food-pkg. adhesives in closure-sealing gaskets for food containers antioxidant/stabilizer for food-grade polymers, pressure-sensitive adhesives antioxidant in food-contact rubber articles for... 

Hazardous Decomp. Prods. Heated to decomp., emits very toxic fumes of NOx and SOx Uses Accelerator and vulcanizer for natural and synthetic rubbers sulfur donor for NR and SR scorch retarder staining protector for rubber fungicide in food-pkg. adhesives accelerator for food-contact rubber articles for... 

CAS 13189-00-9 EINECS/ELINCS 236-144-8 Synonyms Methacrylic acid, zinc salt 2-Methylacrylic acid zinc salt 2-Propenoic acid, 2-methyl-, zinc salt ZDMA Zinc dimethacrylate Zinc 2-methyl-2-propenoate Classification Nonaromatic acid salt Empirical CsHio04Zn Properties M.w. 235.54 m.p. 229-232 C Toxicology Irritating to eyes, skin, respiratory system sensitizer TSCA listed Uses Coagent, scorch retarder, crosslinking agent for elastomer processing and cure polymer modifier... 

The same behaviour occurs with the scorch-retarded version of ZDMA and is illustrated in Table 8.1 with EPDM rubber. In this example, a 40% increase in TSj is obtained with Saret 634, the scorch-retarded version of ZDMA, without any significant loss in maximum torque (MHF). MHF is the difference between the minimum torque (Ml) and the maximum torque (M ) obtained for a rubber compound by oscillating disk rheometer (ODR). It is a measure of the crosslink density of a compound and is part of the curing characteristics of a compound. 

The chlorosulphonated PE compound, see Table 8.5, was used with or without (control) Saret 633. Saret 633 is ZDA containing a non-nitroso scorch retarder to provide scorch safety during processing. 

Saret 633 and Saret 634 (Sartomer Company) are the scorch-retarded versions of zinc diacrylate and zinc dimethacrylate, respectively. The Saret metallic coagents are used in rubber compounding to avoid premature curing during mixing. 

These metallic mono—rs are currently offered in the form of diacrylates, dimethacrylates and mono—thacrylate, na—ly SARET-633 Metallic Diacrylate with scorch retarder SR-705 Metallic Diacrylate SR-708 Metallic Dimethacrylate SR-709 Metallic Mono—thacrylate... 

Magnesium oxide can function as an activator, scorch retarder, and cure modifier. As an acid acceptor, magnesium oxide activates amine cure and improves heat resistance of thiuram-thiazole cures. It is effective as a scorch retarder with all cure systems (except amine systems). In carbon black filled compounds, magnesium oxide has a marked effect on scorch safety even at low level (0.25 phr), lengthening the available processability time. In mineral filled compounds, magnesium oxide can function in a role... 

The Fast, Safe Cure System Consists of a Diamine, a Peroxide, a Coagent, an Accelerator and Optionally, a Scorch Retarder. 

An examination is made of the antioxidant and antiozonant effects of Q-Flex QDI, a quinone diimine produced by Flexsys, in sulphur vulcanised unsaturated rubbers. It is also shown that this additive acts as a scorch retarder and viscosity modifier in NR compounds, and that it modifies the viscoelastic properties of NR compounds resulting in reduced rolling resistance of tyre treads. 5 refs. 

The primary function of Vulkalent E (N phenyl N(tri chloromethyl sulphenyl) benzenesulphonamide) is as a scorch retarder in sulphur vulcanisation of unsaturated rubbers. The accelerating affect of this chemical, particularly in mercapto accelerated sulphur vulcanisation where it can replace other, nitrosamine-forming, secondary accelerators, is examined. This accelerating effect is combined with its delaying effect on the onset of cure. 

A study is made of the retarding and accelerating activity of Bayer s Vulkalent E, a sulphonamide derivative, in the vulcanisation of a number of rubber compounds, and of its effects on the mechanical properties of vulcanisates. It is shown that this additive acts as an effective retarder of scorch in several cure systems, and that in most cases it combines the function of scorch retarding at both processing and moulding temperatures with secondary... 

It is explained that acrylic coagents can improve processability and vulcanisation of elastomers used in automotive applications, and that Saret coagents from Sartomer Co. of the USA provide scorch-retarding properties along with improved radiator hose properties for all curing situations. This article describes tests comparing several coagents in ethylene propylene diene monomer radiator hose formulations. Results are presented and discussed. 

A survey is made of applications of melamine derivatives in the rubber industry, with particular reference to their uses as adhesion promoters, accelerators and scorch retarders. 43 refs. (Translation of Kauchuk i Rezina, No.4, 1996, p.45). 

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