Light stabilizers (UV Absorbers), Antioxidants, Effect-Additives for polymers

To ensure that plastics keep their properties for as long as possible, they need physical and/or chemical long term protection, especially against UV radiation. Just as skin can be protected with sun lotion, plastic can be protected by UV absorbers. HALS (hindered amine light stabilizers) slowdown the degradation of polymers by free radicals.
Light Stabilizers absorb the UV radiation and transform the incident energy into harmless heat. The great benefit of organic UV absorbers over substances such as commercially available carbon black or TiO2 is that they neither compromise colour nor transparency nor are easy to disperse in the polymer. This also allows transparent or coloured polymer applications to be protected against UV radiation without problems.
In contrast to the physically active UV absorbers, HALS (Hindered Amine Light Stabilizers) react chemically. HALS achieve their high protection level, because each stabilizer molecule can react many times. Monomeric HALS are subject to migration and provide a good surface protection. Oligomeric HALS do not migrate, they have a good stability against extraction and a low volatility.

UV-Absorber
Chimassorb®, Tinuvin® and Uvinul®
To maintain their qualities over longer time, polymers require physical or chemical protection against UV radiation.
UV absorbers (Light Stabilizers) absorb the UV radiation and transform the incident energy into harmless heat. The great benefit of organic UV absorbers over substances such as commercially available carbon black or TiO2 is that they neither compromise colour nor transparency and are easy to disperse in the polymer. This also allows transparent or coloured polymer applications to be protected against UV radiation without problems.

HALS
Chimassorb®, Tinuvin® and Uvinul®
In contrast to the physically active UV absorbers, HALS (Hindered Amine Light Stabilizers) react chemically. HALS achieve their high protection level, because each stabilizer molecule can react many times. Monomeric HALS are subject to migration. Oligemeric HALS do not migrate, if their structure is matched to the application polymer.

A remarkable property of HALS is their excellent UV protection effect in thin wall applications.
HALS are grouped in 2 types:
Monomeric HALS are migrating and provide a good stabilisation of external surfaces
Oligomeric HALS are less migrating and provide good stability against extraction and a low volatility.


List of products:
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Polymers are melted in the course of various processing steps and are exposed to high temperatures and sheer forces. This leads to a thermo-oxidative degradation. This degradation is also promoted when the end products are used at higher temperatures for longer time. Processing and long term thermal stabilizers slow down the degradation process and contribute to maintain the high performance level of the final products.

Processing stabilizers
Irgafos®, Irganox® B and Irgastab® FS
Phosphites, as processing stabilizers, provide thermal stabilization to the melted polymer during processing and thereby a good control of the viscosity (MFI). They also protect against discoloration. Processing stabilizers and long term thermal stabilizers are often used together in synergistic blends.

Long term thermal stabilizers
Irganox®, Irgastab®, Chimassorb® and Tinuvin®
Phenolic antioxidants are often used as thermal stabilizers. They protect the polymers during processing as well as in use. High molecular weight HALS are also excellent long term thermal stabilizers in a temperature range up to100°C. Thioethers in combination with phenolic antioxidants act as good long-term thermal stabilizers for elevated usage temperatures.


List of products:
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Permanent antistatics
Irgastat® P
Polymers generally have a high resistivity. Antistatic effects are traditionally obtained adding carbon black or migrating surfactants. With carbon black, the disadvantage is that end articles can not have bright colours. With migrating surfactants, the disadvantage is that the antistatic effect is strongly depending on the ambient humidity and not lasting in time.
Irgastat P products provide a permanent antistatic effect and their high efficiency is virtually not depending on ambient humidity. Additionally they can be used to make end articles with bright colours. Irgastat P products are mainly used in Polyolefins and styrenic polymers.

Halogen free flame retardants
Melapur® and Flamestab®
Inflammable polymers can be made resistant to flames by addition of halogen free flame retardants.
Melamin based products of the Melapur range are especially suitable to achieve this effect in polyamide the thermoplastic polyurethanes.
For Polypropylene fibres and thin films, the specialty HALS Flamestab® NOR® 116 brings a good flame retardency effect as well as UV protection.

Optical brighteners
Tinopal ®
Polymers can become yellowish in processing or in use. Optical brighteners improve the whiteness of the end products.

Nucleants
Irgastab®
Accelerated by the nucleants, the crystallisation of polymer melts improves the processing properties of the polymer melt and on the mechanical properties of the end-products.

Clarifiers
Irgaclear®
With clarifiers, only very small crystals are formed during cooling of the polymer melt. The light is less diffracted by smaller crystals which results in a greater transparency.



List of products:
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