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Latest developments in heavy metal-free PVC systems from Akcros
Additives for Polymers
MATERIALS BASF improves conductivity, promises more in FR grades BASF has announced a minor breakthrough in using carbon black as a conductive additive in polyacetal compounds - a notoriously difficult matrix, due to its tendency to degrade while the necessary level of black is added. It is no coincidence that, in polyacetal manufacture, it is in partnership with Degussa, one of the leading manufacturers of carbon black. With the need to improve safety of automotive fuel systems, there is strong demand (especially in the USA) for a conductive grade of polyacetal for moulded components, but conductive additives other than carbon black are costly. A special type of carbon black has been developed, giving good conductive properties but not requiring so much work. The process has been patented and, although applied at present to polyacetal, it could be relevant to other thermoplastics as well. BASF is also moving towards another key target: halogen-free flame-retardant grades of polybutylene terephthalate (PBT). The company has a strong position in flameretardant technology, especially in halogenfree products (and its Ultramid X polyamides, flameproofed with red phosphorus, have become classics, complemented by mineral- and nitrogen-containing compounds to make a Ml range). BASF executives forecast that halogen-free FR grades of PBT (which has been a major challenge) will be on the market in one year. Another significant improvement has been made by blending 20% GF PBT with acrylonitrile-styrene-acrylate copolymer (ASA), giving a major improvement in warpage properties and other advantages. The PBT component contributes good mechanical properties and processability while the ASA, due to its amorphous character, is characterised by extremely low warpage. 2
December 1996
Scanning electron micrographs of the polymer phase show that incorporation of compatibilisers produces a homogeneous dispersion of ASA in the partially crystalline PBT matrix. Warpage, which is normally a problem in crystalline materials, is significantly improved; flow is also improved, giving shorter moulding cycles and density is also reduced compared with a ‘straight’ 20% GF PBT grade, so offering a cost-saving. Contact: BASF AG, 67056 Ludwigshafen, Germany; tel: +49-621600; fax: +49-621 602 0129
Additives were prominent at UK plastics exhibition There was an impressive number of leading additives manufacturers at the recent Interplas exhibition (Birmingham, UK, lo- 14 November). The new developments featured included: --Latest developments
in heavy
metal-free PVC systems from Akcros Latest developments in heavy metal-free solid stabiliser systems for PVC were featured by Akcros Chemicals at Interplas: Interlite additives and Interwax lubricant systems. The Interlite range is predominantly based on calcium-zinc and has been developed to satisfjr environmental concerns, while still meeting high performance requirements for rigid PVC applications in the construction industry. It is also finding increasing markets in medicals, and in wire and cable sheathing. Interwax lubricants are available both as internal and external systems, acting as an interface reducing shear and mechanical work between the melt and the processing equipment, so giving faster cycling and throughput rates. In PVC they also help to optimise the stabiliser systems, allowing processing at lower temperatures. For users still working with original additive 01996 Elsevier Science
Additives for Polymers
December 1996
One-pack stabilisers for window profiles Notched impact strength double-v (0.1 mm) DIN 53753 Vicat VST/B 50 (silicon oil) DIN 53470 Thermal stability (DHC) DIN 53381 Method B
I
Reversion RAL 716/l
I I
unit
Pb-Ba-Cd
Pb
Ca-Zn
(kJ/m2)
45
43
45
eC)
81
82
80
(min)
92
77
42
(W
I
1.5
I
1.6 I I
1.6 I I
Source: Chemson formulations, Akcros offers its Interstab stabiliser/lubricant packages, including leadbased packs which can provide a highly efficient first-stage replacement for cadmiumcontaining systems. A range of liquid stabilisers under the name Lankromark, which includes cadmiumcontaining and cadmium-free formulations as well as barium-zinc and calcium-zinc types, was also featured by the company. The additives can provide, for example, colour stability and clarity relative to a particular processing method or type of equipment. The low-toxic barium-zinc and calcium-zinc grades are used in compounds for children’s toys and are also certified for food-contact applications. The company, formed by Akzo and Harcros, is the largest supplier of PVC additives in Europe, and is now concentrated into three areas: Polymer Additives (including stabilisers, plasticisers and fungicides), Application Chemicals (polysulphides, polyurethanes and metal stearates and surfactants) and Radiation Curing chemicals (for coatings and printing inks). Akcros claims to be unique in being the only additives specialist which will undertake customised pre-blending in its own facilities, so ensuring that all the operations are carried out to the highest standards of quality and consistency. Contact: Akcros Chemicals Ltd, PO Box I, Eccles, Manchester A430 OBH, UK; tel: +44-161 789 7300;fax: +44-16I 788 7886
01996 Elsevier Science
--New range of PVC ‘one-packs’ The new range of Nattosafe one-pack mixed metal stabilisers for PVC was featured by Chemson, with the assurance that they helped to ensure a successful future for PVC into the next millennium (see table above). Based on cadmium/zinc combinations (which have been used for many years in key PVC applications such as mineral water bottles, food packaging and pharmaceuticals), the range can be produced in solid freeflowing dust-free forms, but handled and processed in the same way as traditional lead stabilisers (so not requiring any additional investment in mixing plant). A further advantage is the ability to recycle with other PVC formulations, without the risk of crosscontamination due to incompatibility. Typical properties (for window profile formulations) in comparison with lead/ barium/cadmium and lead-only stabilisers are shown in the table. Contact: Chemson Polymer-Additive Gesellschaft mbH, Gailitz I95, A-9601 Arnoldstein, Austria; tel: + 43-4255 2226; fax: +43-4255 2435 --Better options from ‘sponge’ concentrates Offering a better range of options to users, such as manufacturers of polymers and additives and plastics compounders and processors, Akzo Nobel Fibres has revised its novel Accurel range of additive concentrates. The concentrates use unique 3
MATERIALS BASF improves conductivity, promises more in FR grades BASF has announced a minor breakthrough in using carbon black as a conductive additive in polyacetal compounds - a notoriously difficult matrix, due to its tendency to degrade while the necessary level of black is added. It is no coincidence that, in polyacetal manufacture, it is in partnership with Degussa, one of the leading manufacturers of carbon black. With the need to improve safety of automotive fuel systems, there is strong demand (especially in the USA) for a conductive grade of polyacetal for moulded components, but conductive additives other than carbon black are costly. A special type of carbon black has been developed, giving good conductive properties but not requiring so much work. The process has been patented and, although applied at present to polyacetal, it could be relevant to other thermoplastics as well. BASF is also moving towards another key target: halogen-free flame-retardant grades of polybutylene terephthalate (PBT). The company has a strong position in flameretardant technology, especially in halogenfree products (and its Ultramid X polyamides, flameproofed with red phosphorus, have become classics, complemented by mineral- and nitrogen-containing compounds to make a Ml range). BASF executives forecast that halogen-free FR grades of PBT (which has been a major challenge) will be on the market in one year. Another significant improvement has been made by blending 20% GF PBT with acrylonitrile-styrene-acrylate copolymer (ASA), giving a major improvement in warpage properties and other advantages. The PBT component contributes good mechanical properties and processability while the ASA, due to its amorphous character, is characterised by extremely low warpage. 2
December 1996
Scanning electron micrographs of the polymer phase show that incorporation of compatibilisers produces a homogeneous dispersion of ASA in the partially crystalline PBT matrix. Warpage, which is normally a problem in crystalline materials, is significantly improved; flow is also improved, giving shorter moulding cycles and density is also reduced compared with a ‘straight’ 20% GF PBT grade, so offering a cost-saving. Contact: BASF AG, 67056 Ludwigshafen, Germany; tel: +49-621600; fax: +49-621 602 0129
Additives were prominent at UK plastics exhibition There was an impressive number of leading additives manufacturers at the recent Interplas exhibition (Birmingham, UK, lo- 14 November). The new developments featured included: --Latest developments
in heavy
metal-free PVC systems from Akcros Latest developments in heavy metal-free solid stabiliser systems for PVC were featured by Akcros Chemicals at Interplas: Interlite additives and Interwax lubricant systems. The Interlite range is predominantly based on calcium-zinc and has been developed to satisfjr environmental concerns, while still meeting high performance requirements for rigid PVC applications in the construction industry. It is also finding increasing markets in medicals, and in wire and cable sheathing. Interwax lubricants are available both as internal and external systems, acting as an interface reducing shear and mechanical work between the melt and the processing equipment, so giving faster cycling and throughput rates. In PVC they also help to optimise the stabiliser systems, allowing processing at lower temperatures. For users still working with original additive 01996 Elsevier Science
Additives for Polymers
December 1996
One-pack stabilisers for window profiles Notched impact strength double-v (0.1 mm) DIN 53753 Vicat VST/B 50 (silicon oil) DIN 53470 Thermal stability (DHC) DIN 53381 Method B
I
Reversion RAL 716/l
I I
unit
Pb-Ba-Cd
Pb
Ca-Zn
(kJ/m2)
45
43
45
eC)
81
82
80
(min)
92
77
42
(W
I
1.5
I
1.6 I I
1.6 I I
Source: Chemson formulations, Akcros offers its Interstab stabiliser/lubricant packages, including leadbased packs which can provide a highly efficient first-stage replacement for cadmiumcontaining systems. A range of liquid stabilisers under the name Lankromark, which includes cadmiumcontaining and cadmium-free formulations as well as barium-zinc and calcium-zinc types, was also featured by the company. The additives can provide, for example, colour stability and clarity relative to a particular processing method or type of equipment. The low-toxic barium-zinc and calcium-zinc grades are used in compounds for children’s toys and are also certified for food-contact applications. The company, formed by Akzo and Harcros, is the largest supplier of PVC additives in Europe, and is now concentrated into three areas: Polymer Additives (including stabilisers, plasticisers and fungicides), Application Chemicals (polysulphides, polyurethanes and metal stearates and surfactants) and Radiation Curing chemicals (for coatings and printing inks). Akcros claims to be unique in being the only additives specialist which will undertake customised pre-blending in its own facilities, so ensuring that all the operations are carried out to the highest standards of quality and consistency. Contact: Akcros Chemicals Ltd, PO Box I, Eccles, Manchester A430 OBH, UK; tel: +44-161 789 7300;fax: +44-16I 788 7886
01996 Elsevier Science
--New range of PVC ‘one-packs’ The new range of Nattosafe one-pack mixed metal stabilisers for PVC was featured by Chemson, with the assurance that they helped to ensure a successful future for PVC into the next millennium (see table above). Based on cadmium/zinc combinations (which have been used for many years in key PVC applications such as mineral water bottles, food packaging and pharmaceuticals), the range can be produced in solid freeflowing dust-free forms, but handled and processed in the same way as traditional lead stabilisers (so not requiring any additional investment in mixing plant). A further advantage is the ability to recycle with other PVC formulations, without the risk of crosscontamination due to incompatibility. Typical properties (for window profile formulations) in comparison with lead/ barium/cadmium and lead-only stabilisers are shown in the table. Contact: Chemson Polymer-Additive Gesellschaft mbH, Gailitz I95, A-9601 Arnoldstein, Austria; tel: + 43-4255 2226; fax: +43-4255 2435 --Better options from ‘sponge’ concentrates Offering a better range of options to users, such as manufacturers of polymers and additives and plastics compounders and processors, Akzo Nobel Fibres has revised its novel Accurel range of additive concentrates. The concentrates use unique 3