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New successes promised by new technology
P O W D E R C O AT I N G S A MONTHLY REPORT FROM SID HARRIS DECEMBER 2003
NEW SUCCESSES PROMISED BY NEW TECHNOLOGY
In this issue
TECHNICAL
2-4
Fluoropolymer for powder coating Nanoparticles in powder coatings
INDUSTRY NEWS
4-5
Coating raw material suppliers struggle with costs Monopol acquires facade coatings activities from Vernicolor
MARKETS
5-6
Assessing industrial coatings technologies Surge in production for German powder coatings manufacturers
NEW PRODUCTS
6-7
Spray drying employed in new production process for acrylic powder coating: Dainippon Ink and Chemicals/Liquid Gas
INSTALLATIONS
7-8
Major New MDF powder line in Holland
EVENTS
AN INTERNATIONAL NEWSLETTER MONITORING TECHNICAL AND COMMERCIAL DEVELOPMENTS IN POWDER COATINGS ISSN 1364–5439
8
Most powder producers engaged in architectural finishing have long appreciated the exterior performance of fluoropolymers but the inclusion of thermoplastic PVdF polymers in their production schedules creates problems of cross contamination with adjacent thermosetting powder lines. The abstracted paper by S Mahuda of Asahi Glass offers the attractive alternative of FEVE polymers. These materials have a number of distinct advantages: they can be produced as solid co-polymers for use in powder coatings having a cross-linkable functional group; it is claimed that certain copolymers exhibit excellent storage stability; and there is little or no risk of cross contamination with other conventional powder coating systems. An important factor, however, is the need to incorporate an efficient catalyst in the favoured urethane system, and work is proceeding to improve the performance of the bismuth catalyst. While nanoscience has been explored over the past twenty years there has been little commercial exploitation of nanotechnology. Now it seems that small is a beautiful tool for the coatings industry and nanotechnology is the theme for international conferences describing the endless benefits of applying the nanoparticle to every
conceivable aspect of the materials industry. Several papers have reported that nano sized fillers can significantly improve the surface hardness and scratch resistance of coatings. A most interesting account of the application of nanotechnology to polymers is contained in the abstract of work carried out by Borbely and his co-workers in Hungary, and a US company is already exploring the potential for its use in the coatings industry. Although the polymers that have been developed are extremely small they behave as though they were much smaller than they actually are. The basic concept of core-shell polymers is not new but the technique for manipulating the shell functionality is a novel departure from other polymer applications. The paper describes the use of these nanoparticles in solvent-borne coating systems where solids contents of 75% or greater can be attained at very low viscosities. It goes on to suggest that these nanoparticles could be applied to powder coating formulating offering the prospect of significant reductions in both melting and curing temperatures that could be further reduced by combining with crosslinking agents. Regular readers of my editorials will be aware that I believe powder binders should be tailored by
F O C US controlling the polymerisation process to give a polymer particle having the correct size and shape and, most importantly, a uniform distribution of functional groups. I am convinced that Borbely is correct in expressing his belief that powder coatings have much to gain from nanoparticle polymers. Industry news continues to report the problems faced by the industry over the past few years but the reports are now tempered with the belief that the worst is over, and the major players are seen to be actively supporting growth in the powder coatings industry for it is likely to become the first of the coatings technologies to show genuine recovery. The marketing news is heartening. Bob McElroy of Sherwin-Williams gives an indepth assessment of the competing industrial coatings technologies in the North American market that highlights the advantages and disadvantages of solvent-borne, water-borne and powder coatings. Setting the performance standards for the other technologies is the current role for solvent-borne coatings but the disadvantages are obvious in view of the everincreasing environmental pressures. Water-borne finishes offer some positive advantages over solvent-borne but they do not apply as easily and he considers that their early promise has not been realised. In his review of powder coatings he cites several examples of customers who have converted from liquid to powder with, in some cases, remarkable improvements in productivity and cost savings. Production figures for German powder coatings in the first quarter of 2003 show a 7% increase compared to the same quarter in 2002. A report on the Asian market from a Japanese publication confirms that powder coatings double-digit growth will continue for the foreseeable future. It is good to report the success 2
O N
POWDER
of new powder coating installations and the upgrading of existing plants as improvements are made in application equipment. Two UK based equipment suppliers feature in the section on Installations. The first case history describes the unique equipment supplied by Eurotec to a company in Holland adopting powder coating in a new MDF coating facility. The sophisticated equipment not only meets the precise requirements of the customer but also offers on-line trouble shooting assistance linked directly to the supplier. The second case history details the efforts of Sames UK in up-grading the well-established Italian plant at Otefal, a company renowned for its powder coil coating facility. In this case, the existing 16 electrostatic spray guns were replaced by eight powder coating bell applicators. This new equipment not only improved application efficiency and film aesthetics but also cut powder consumption by 20%. These are classic examples of the achievements that can result from the close co-operation of equipment suppliers, the end user and the powder producer. Sid Harris
TECHNICAL Fluoropolymer for powder coating Fluoropolymer composed of fluoroethylene and alkyl vinyl ether (FEVE) was produced as a liquid coating by Asahi Glass Co, in 1982, under the trade name Lumiflon. Over the years it has become accepted in the coatings industry for its unparalleled durability compared to conventional paint and as an improvement upon PVdF (poly vinylidene fluoride). Environmental pressures have created demands for a fluorocarbon capable of use in powder coatings and studies have been made into the synthesis of FEVE solid co-
C OAT I N G S polymers for incorporation into powder coatings having a crosslinkable functional group. A study of the synthesis, characteristics and applications of solid FEVE co-polymers is the subject of an article by S Mahuda of Asahi Glass. The targets for the solid polymer were defined as: melting point around 90°C, glass transition point (Tg) around 50°C, introduction of a carboxyl or hydroxyl crosslinkable group with a functionality in the range 25-60 mg KOH/gm. Cross-linking was considered to be essential to the formation of a tough film and hydroxyl functionality was chosen for its better shelf life. The FEVE copolymer has an almost perfectly symmetrical structure consisting of repetitive units of fluoroethylene and chlorotrifluoroethylene and the alkyl vinyl ether appendages were chosen for introducing the hydroxyl groups. After the initial assessment, two alkyl vinyl ethers were selected: HBVE (hydroxy butyl vinyl ether) and CHVE (cyclohexyl vinyl ether). A range of various monomer additions to the backbone oligomer was evaluated with regard to Tg, melting point, and polymer hardness. Samples of hydroxylated polymers capable of crosslinking with isocyanate and melamine resins were shown to have excellent storage stability. Polymers containing a carboxyl group for crosslinking with epoxy, TGIC and HAA, exhibited good storage stability, while polymers containing the glycidyl group, capable of reacting with acid and amine curatives, gave poor storage stability characteristics. The hydroxylated resin, Lumiflon LF710F, was chosen as a suitable solid grade polymer for use in powder coatings. It is a light yellow flake with Tg between 50-55°C and hydroxyl value 53 mg KOH/gm. Powder coatings were prepared using the standard methods for production of thermoset grades, namely mixing, extrusion and fine grinding. Melt DECEMBER 2003
NEW SUCCESSES PROMISED BY NEW TECHNOLOGY
In this issue
TECHNICAL
2-4
Fluoropolymer for powder coating Nanoparticles in powder coatings
INDUSTRY NEWS
4-5
Coating raw material suppliers struggle with costs Monopol acquires facade coatings activities from Vernicolor
MARKETS
5-6
Assessing industrial coatings technologies Surge in production for German powder coatings manufacturers
NEW PRODUCTS
6-7
Spray drying employed in new production process for acrylic powder coating: Dainippon Ink and Chemicals/Liquid Gas
INSTALLATIONS
7-8
Major New MDF powder line in Holland
EVENTS
AN INTERNATIONAL NEWSLETTER MONITORING TECHNICAL AND COMMERCIAL DEVELOPMENTS IN POWDER COATINGS ISSN 1364–5439
8
Most powder producers engaged in architectural finishing have long appreciated the exterior performance of fluoropolymers but the inclusion of thermoplastic PVdF polymers in their production schedules creates problems of cross contamination with adjacent thermosetting powder lines. The abstracted paper by S Mahuda of Asahi Glass offers the attractive alternative of FEVE polymers. These materials have a number of distinct advantages: they can be produced as solid co-polymers for use in powder coatings having a cross-linkable functional group; it is claimed that certain copolymers exhibit excellent storage stability; and there is little or no risk of cross contamination with other conventional powder coating systems. An important factor, however, is the need to incorporate an efficient catalyst in the favoured urethane system, and work is proceeding to improve the performance of the bismuth catalyst. While nanoscience has been explored over the past twenty years there has been little commercial exploitation of nanotechnology. Now it seems that small is a beautiful tool for the coatings industry and nanotechnology is the theme for international conferences describing the endless benefits of applying the nanoparticle to every
conceivable aspect of the materials industry. Several papers have reported that nano sized fillers can significantly improve the surface hardness and scratch resistance of coatings. A most interesting account of the application of nanotechnology to polymers is contained in the abstract of work carried out by Borbely and his co-workers in Hungary, and a US company is already exploring the potential for its use in the coatings industry. Although the polymers that have been developed are extremely small they behave as though they were much smaller than they actually are. The basic concept of core-shell polymers is not new but the technique for manipulating the shell functionality is a novel departure from other polymer applications. The paper describes the use of these nanoparticles in solvent-borne coating systems where solids contents of 75% or greater can be attained at very low viscosities. It goes on to suggest that these nanoparticles could be applied to powder coating formulating offering the prospect of significant reductions in both melting and curing temperatures that could be further reduced by combining with crosslinking agents. Regular readers of my editorials will be aware that I believe powder binders should be tailored by
F O C US controlling the polymerisation process to give a polymer particle having the correct size and shape and, most importantly, a uniform distribution of functional groups. I am convinced that Borbely is correct in expressing his belief that powder coatings have much to gain from nanoparticle polymers. Industry news continues to report the problems faced by the industry over the past few years but the reports are now tempered with the belief that the worst is over, and the major players are seen to be actively supporting growth in the powder coatings industry for it is likely to become the first of the coatings technologies to show genuine recovery. The marketing news is heartening. Bob McElroy of Sherwin-Williams gives an indepth assessment of the competing industrial coatings technologies in the North American market that highlights the advantages and disadvantages of solvent-borne, water-borne and powder coatings. Setting the performance standards for the other technologies is the current role for solvent-borne coatings but the disadvantages are obvious in view of the everincreasing environmental pressures. Water-borne finishes offer some positive advantages over solvent-borne but they do not apply as easily and he considers that their early promise has not been realised. In his review of powder coatings he cites several examples of customers who have converted from liquid to powder with, in some cases, remarkable improvements in productivity and cost savings. Production figures for German powder coatings in the first quarter of 2003 show a 7% increase compared to the same quarter in 2002. A report on the Asian market from a Japanese publication confirms that powder coatings double-digit growth will continue for the foreseeable future. It is good to report the success 2
O N
POWDER
of new powder coating installations and the upgrading of existing plants as improvements are made in application equipment. Two UK based equipment suppliers feature in the section on Installations. The first case history describes the unique equipment supplied by Eurotec to a company in Holland adopting powder coating in a new MDF coating facility. The sophisticated equipment not only meets the precise requirements of the customer but also offers on-line trouble shooting assistance linked directly to the supplier. The second case history details the efforts of Sames UK in up-grading the well-established Italian plant at Otefal, a company renowned for its powder coil coating facility. In this case, the existing 16 electrostatic spray guns were replaced by eight powder coating bell applicators. This new equipment not only improved application efficiency and film aesthetics but also cut powder consumption by 20%. These are classic examples of the achievements that can result from the close co-operation of equipment suppliers, the end user and the powder producer. Sid Harris
TECHNICAL Fluoropolymer for powder coating Fluoropolymer composed of fluoroethylene and alkyl vinyl ether (FEVE) was produced as a liquid coating by Asahi Glass Co, in 1982, under the trade name Lumiflon. Over the years it has become accepted in the coatings industry for its unparalleled durability compared to conventional paint and as an improvement upon PVdF (poly vinylidene fluoride). Environmental pressures have created demands for a fluorocarbon capable of use in powder coatings and studies have been made into the synthesis of FEVE solid co-
C OAT I N G S polymers for incorporation into powder coatings having a crosslinkable functional group. A study of the synthesis, characteristics and applications of solid FEVE co-polymers is the subject of an article by S Mahuda of Asahi Glass. The targets for the solid polymer were defined as: melting point around 90°C, glass transition point (Tg) around 50°C, introduction of a carboxyl or hydroxyl crosslinkable group with a functionality in the range 25-60 mg KOH/gm. Cross-linking was considered to be essential to the formation of a tough film and hydroxyl functionality was chosen for its better shelf life. The FEVE copolymer has an almost perfectly symmetrical structure consisting of repetitive units of fluoroethylene and chlorotrifluoroethylene and the alkyl vinyl ether appendages were chosen for introducing the hydroxyl groups. After the initial assessment, two alkyl vinyl ethers were selected: HBVE (hydroxy butyl vinyl ether) and CHVE (cyclohexyl vinyl ether). A range of various monomer additions to the backbone oligomer was evaluated with regard to Tg, melting point, and polymer hardness. Samples of hydroxylated polymers capable of crosslinking with isocyanate and melamine resins were shown to have excellent storage stability. Polymers containing a carboxyl group for crosslinking with epoxy, TGIC and HAA, exhibited good storage stability, while polymers containing the glycidyl group, capable of reacting with acid and amine curatives, gave poor storage stability characteristics. The hydroxylated resin, Lumiflon LF710F, was chosen as a suitable solid grade polymer for use in powder coatings. It is a light yellow flake with Tg between 50-55°C and hydroxyl value 53 mg KOH/gm. Powder coatings were prepared using the standard methods for production of thermoset grades, namely mixing, extrusion and fine grinding. Melt DECEMBER 2003