INDUSTRIAL AND PROTECTIVE COATINGS A SUSTAINABLE APPROACH TO MODERN COATING TECHNOLOGY

Transcription

1 A SUSTAINABLE APPROACH TO MODERN COATING TECHNOLOGY INDUSTRIAL AND PROTECTIVE COATINGS

2 A Sustainable Approach to Modern Coating Technology Patcham FZC is a well-established manufacturer of specialty additives headquartered in the United Arab Emirates. Since its inception, Patcham has steadily grown into a leading supplier of specialty additives for the Paint & Coatings, Ink, PVC and Composite industries. The company s Pat-Add range of coating additives includes wetting & dispersing agents, defoamers, slip & leveling agents, rheology modifiers. Whilst keeping focus on environmental sustainability, the company produces products using green raw materials that are APEO free and have low or no VOC. These products are multi functional and multi compatible, which simplifies the production process, reduces the chance of errors and minimizes inventory thus improving cost effectiveness. Patcham has built a strong manufacturing and R&D infrastructure that enables the rapid transition from concept to products. The company has strategically located technical service laboratories, offices and representatives around the world to provide the most efficient customer service. In addition, a well-developed robust supply chain network enables it to deliver its products and services to customers around the globe with minimal lead-time.

3 Contents Introduction Pat-Add additives for high performance industrial coatings Industrial high performance primers 2K PU and Epoxy primer Industrial high performance topcoat Topcoat based on Alkyd, PU and Epoxy systems Topcoats for high end application Alkyd topcoats Additives for waterborne epoxy systems

4 Introduction An industrial coating is a paint or coating defined by its protective, rather than its aesthetic properties. The most common use of industrial coatings is for corrosion control of steel structures such as offshore platforms, pipelines, OEM machineries, engineering civil structures and other various substrates. The occurrence of corrosion is a universal phenomenon and defined as the deterioration of a material, usually a metal, because of a reaction with its environment. The ingress of water through the coating on a metal surface, can lead to the start of corrosion which if not corrected can weaken the metal structures. The coating (both liquid and final dried film) has to have over all high performance in terms of superior flow, sag resistance, high build, hiding, gloss and above all provide corrosion resistance. Furthermore, various pigments such as zinc phosphate are included in coating formulations in order to further alleviate the chance of corrosion. Due to the high specific gravity of these kind of pigments, very efficient wetting and dispersing agents are required to provide optimal stabilisation and avoid the possibility of settling. It also requires multicompatible additives that can work through systems such as polyurethane, epoxy, alkyds, thermo plastic, thermo setting acrylics, etc. 1

5 Pat-Add additives for industrial coatings Patcham offers a package of additives, that can help to improve the appearance and durability of industrial and protective coating by providing optimum mill base viscosity, efficient grinding, flow, leveling, improved gloss and DOI. Efficient dispersion of the pigmented coatings further enhances the barrier properties, particularly against corrosion. This further boosts the performance of the coating system. Pat-Add additive package for industrial applications includes dispersing agents, anti settling agents, leveling agents and defoamers. These multifunctional and multicompatible additives can be incorporated in Epoxy, PU, alkyds and other solventborne formulations. A selection of Pat-Add additives for Solventborne (SB) systems are illustrated below in Table 1. Table 1: Patcham additives for solventborne industrial applications. Additive for solventborne primers and topcoats Additive Pat-Add DA 1666 Features Uniquely designed multifunctional polymer with multi compatibility with different types of resin systems. Acts as wetting and dispersing agent, anti settling agent, anti sagging agent and anti flocculating agent. Dosage on total formulation (%) Grinding / Letdown Pat-Add DA 707 Pat-Add DA 1808 Pat-Add DA 786 Pat-Add DA 932 Pat-Add LE 1020 Pat-Add AF 62 Amphoteric dispersing agent effective in alkyd paints. Strongly adsorbed onto inorganic and black pigments, contributing steric stabilization against re-flocculation. Efficient dispersing agent for alkyd system and suitable for organic, inorganic and black pigments Water incorporation additive offers excellent gloss retention, stable viscosity, anti-settling and anti-sagging properties High Molar Volume technology polymeric dispersing agent for all kind of carbon blacks, organic pigments and inorganic pigments. Enables high pigment loading for pigment concentrates (PC) and supports stabilization of pigments Polyether modified polysiloxane surface modifier improves flow, leveling, DOI and gloss Silicone free defoamer for both clear and pigmented systems. Suitable for all kinds of SB resin systems Grinding stage Grinding stage Grinding stage (PC) Grinding stage Letdown stage Grinding / Letdown 2

6 Industrial high performance primers The primers are formulated generally with high levels of Zinc dust, Zinc phosphate or other anti-corrosive extenders to enhance the corrosive barrier. One of the draw backs of using high levels of these types of pigments is that these pigments are more prone to settling issues and require an efficient dispersing and stabilizing agent to overcome this problem. Pat-Add DA 1666 is a special additive compatible with all solventborne systems such as PU, Epoxy, Alkyd, TPA, etc. The key features are: Excellent wetting and dispersing agent for fillers, anti-corrosive pigments, inorganic and organic pigments Reduced mill base viscosity and milling time Prevention of flocculation and floatation in pigment blends Acts as a compatibilizer Good anti sagging property and eliminates settling thereby enhancing the stability 2K PU and epoxy primer Table 2: Formulation of 2K PU red oxide primer 2K PU Red oxide zinc phosphate primer Raw materials Weight (%) Part A Pat-Add DA 1666/Reference Red oxide Zinc phosphate CaCO3 Talc Acrylic polyol Xylene Butyl acetate Letdown Acrylic polyol 1% Patcat 3001 (DBTDL ) Butyl acetate Total Part B Aromatic isocyanate Mixing ratio part A:B (weight) :1 Viscosity (cp) Mill base viscosity of 2K PU primer Reference Pat-Add DA 1666 Figure 1: Mill base viscosities of 2K PU red oxide zinc phosphate primer 3

7 Industrial high performance primers Table 3: Viscosity and grinding parameters Properties Reference Pat-Add DA 1666 Mill base viscosity (cp) Paint viscosity (cp) Fineness of grind (µm) Grinding time (hour) Reference Pat-Add DA 1666 Figure 2: Representation of de flocculation in 2K PU red oxide primer with Pat-Add DA 1666 Figure 3: Sag resistance test - 2K PU and alkyd red oxide zinc phosphate primer Reference Pat-Add DA 1666 Figure 4: Pictorial representation of stability of alkyd primer with Pat-Add DA

8 Industrial high performance primers The formulation of 2K PU primer surfacer and epoxy zinc rich primer are given in Tables 4 & 5. Table 4: Formulation of 2K PU surfacer white 2K PU surfacer white Raw materials Weight (%) Part A Pat-Add DA 1666 Silica Titanium dioxide Barytes Talc Acrylic polyol Solvesso 100 MIBK Butyl acetate Pat-Add AF 70 1% Patcat 3001 (DBTDL) Total Part B Aromatic isocyanate Mixing ratio :1 Table 5: Formulation of epoxy zinc rich primer Epoxy zinc rich primer Raw materials Weight (%) Part A Pat-Add DA 1666 Moisture scavenger Epoxy resin (75%) Organoclay thickener Fumed silica Zinc dust Butyl cellosolve Butanol Xylene Total Part B Polyamide 125 (50%) Xylene Total Mixing ratio (w/w) :1 Pat-Add DA 1666 provides excellent stabilization of pigments and extenders that increases the stability of the system. The reference sample showed hard settling whereas DA 1666 did not have any settling. It also enhances the anti sagging property of the primer, wherein the reference sample sags from 100 microns WFT, while there is no sagging observed up to 225 microns WFT. The anti settling and anti sagging properties are evident in Figure 5 and 6 below. Heavy settling Reference Pat-Add DA 1666 WFT in microns 75 µm 100 µm 125 µm 150 µm 175 µm 200 µm 225 µm 250 µm 275 µm 300 µm Reference Pat-Add DA 1666 Sagging limit Figure 5: Stability test for 2K PU surfacer white Figure 6: Sagging test for 2K PU surfacer white 5

9 Industrial high performance primers Table 6: Formulation of epoxy zinc phosphate red oxide primer Pat-Add DA 1666 in Epoxy zinc phosphate primer Raw materials Weight (%) Part A Epoxy resin (75%) Pat-Add DA 1666 Organoclay thickener Red oxide Talc CaCO3 Zinc phosphate Xylene Butyl cellosolve Letdown Epoxy resin (75%) Butyl cellosolve Xylene Part B Polyamide 125 hardener Mixing ratio A:B (w/w) Total :1 As can be seen from the results for sag resistance, adhesion and bend test (Figure 7) from a formulation based on an epoxy zinc phosphate primer (Table 6), the addition of Pat Add-DA 1666 helps to optimise the overall performance of the epoxy zinc phosphate primer. Figure 7: Performance of epoxy red oxide primer 6

10 Industrial high performance topcoat The function of a topcoat in an industrial coating is not only to provide the final barrier to the substrate but also to give an appealing and aesthetic appearance to the substrate. Top coat based on alkyd, PU and epoxy systems Specially designed multicompatible and multifunctional Pat-Add DA 1666 can be used in a formulation for industrial topcoat to provide the required characteristics such as stabilization of the pigments, good flow and improved final appearance such as gloss in a high performance coating. Table 7: Formulation for 2K PU white topcoat 2K PU white topcoat Raw materials Weight (%) Part A Acrylic polyol Organoclay thickener Pat-Add DA 1666/Reference Titanium dioxide PU solvent Letdown Acrylic polyol Pat-Add LE % Patcat 3001 (DBTDL) PU solvent Total Part B Aliphatic isocyanate Mixing ratio A:B (w/w) :28 Pat-Add DA 1666 shows better coloristic values with PU direct grinding systems due to their efficient wetting and dispersing properties and compatibility with the system. Figure 8 shows that white paint made using this additive gives better brightness, low yellow index and good gloss values. Yellow index L* Gloss value Reference Pat-Add DA 1666 Reference Pat-Add DA 1666 Reference Pat-Add DA 1666 Figure 8: L* value, yellow index and gloss value in polyurethane white paint 7

11 Industrial high performance topcoat The same trend of higher brightness, low yellow index and good gloss values are possible with Pat-Add DA 1666 in Alkyd, PU, Epoxy and other solventborne systems. It has the ability to reduce the mill base viscosity and improve the grinding efficiency. Mill base viscosity of Alkyd, PU and Epoxy systems are shown in Table 10. Table 8: Formulation of epoxy white topcoat Table 9: Formulation of 2K PU co-grinding system Epoxy white topcoat Raw materials Weight (%) Part A Epoxy resin (75%) Organoclay thickener Pat-Add DA 1666 Titanium dioxide Epoxy solvent (xylene, butanol) Letdown Epoxy resin (75%) Pat- Add LE 1040 Epoxy solvent (xylene, butanol) Total Part B Polyamide 115 (60% solution) Mixing ratio Part A:B (w/w) :30 2K PU co-grinding system Raw materials Weight (%) Part A - Mill base Acrylic polyol Pat-Add DA 1666 Titanium dioxide Yellow PY 42 PB 15:3 Black oxide Organoclay thickener PU solvent Letdown Acrylic polyol Pat-Add LE 1020 Pat-Add AF 62 1% Patcat 3001 (DBTDL) PU solvent Total Part B Aliphatic isocyanate Mixing ratio (w/w) 100: units Figure 9: Flow behaviour of 2K PU co-grinding system Table 10: Mill base viscosity of alkyd, PU and epoxy white paint Properties Pat-Add DA 1666 Alkyd white PU white Epoxy white Pat-Add Pat-Add Reference Reference Reference DA 1666 DA 1666 Mill base viscosity (cp) Paint viscosity (cp)

12 Industrial high performance topcoat Topcoats for high end application Pat-Add DA 932 is a dispersing agent based on High Molar Volume technology. The higher volume occupied by the dispersant results in a thicker adsorbed layer around the pigments which increases resistance to attractive forces and therefore gives a more stable pigment dispersion. It has wide compatibility with PU, epoxy, TPA, NC and other solventborne systems. High performances can be achieved in co-grinding, direct grinding, resin free and resin minimal pigment concentrates. The key features are: Dense network of anchoring groups stabilize black, organic and inorganic pigments Contributes to optimum mill base viscosity and reduced milling time High jetness and blue under tone for black pigments Provides excellent long term stability of pigment dispersions Superior gloss and transparency Table 11: Formulation of 2K PU black 2K PU black topcoat Raw materials Weight (%) Part A Mill Base Acrylic polyol Organoclay thickener Pat-Add DA Carbon black FW Butyl acetate 3.00 Xylene 3.00 Letdown Acrylic polyol Butyl acetate 3.00 Pat-Add LE 1020 MPA 4.00 Xylene % Patcat 3001 (DBTDL) Total Part B Aliphatic isocyanate Mixing ratio A:B (w/w) 100:33 Particle size (µm) Fineness of grind vs grinding time 30 mins 1 hr 1 hr 30 2 hr 3 hr Reference Grinding time Pat-Add DA 932 Figure 10: Grinding time vs particle size of PU black topcoat As shown in Figure 10, Pat-Add 932 helps in reducing the grinding time of pigments. It also helps in obtaining stable dispersions and enriching the coloristic values. NB: For optimum performance of Pat-Add DA 932 in grinding of pigments, it is advised to grind pigments till the required particle size is achieved in terms of Hegman gauge and color strength. Over grinding may lead to change in coloristic properties 9

13 Industrial high performance topcoat Reference Pat-Add DA 932 L* values Reference Pat-Add DA 932 Figure 11: L* value of 2K PU black topcoat mins 1hr 1hr 30 2hrs 3hrs mins Figure 12: Mc values of 2K PU black topcoat Pat-Add DA 932 shows less L* values and higher Mc values for 2K PU black with FW 200 which indicates higher jetness and bluish under tone of black is obtained. Reference Pat- Add DA 932 Figure 13: Jetness of 2K PU black topcoat Alkyd topcoats Pat-Add DA 1808 shows excellent compatibility with most alkyds including long, medium, short and other modified alkyd systems used on different types of substrates such as plastic, and steel structures. Key benefits that Pat-Add DA 1808 can bring to the formulation includes Optimization of the milling process Provides excellent color development Prevention of floating and flocculation Excellent compatibility with Alkyd resin systems Formulation of Alkyd paint based on Pat-Add DA 1808 is shown in Table 12. It can be seen to bring out and enhances the jetness of carbon black in Alkyd black topcoat (Figure 14). 10

14 Industrial high performance topcoat Table 12: Formulation of alkyd black topcoat Alkyd black topcoat Raw materials Weight (%) Long oil alkyd Pat-Add DA 1808 Carbon black N 330 White spirit Letdown Long oil alkyd Patcom 24 (Combination drier) Patox 1 (MEKO) White spirit Total Alkyd black paint made with Pat-Add DA 1808 shows better jetness as can be seen in Figure 14. A stable black dispersion is achieved and is shown in Figure 15 with lower ΔE values for rubbed and unrubbed areas. Figure 14: Jetness of alkyd black topcoat Rub out test results ΔE values Reference Pat-Add DA 1808 Figure 15: Rubout test of alkyd black topcoat 11

15 Additives for waterborne epoxy systems Waterborne industrial epoxy coatings offer exceptional performance as a barrier to corrosion along with other performance properties, whilst being environmentally friendly. Applicators however come across issues of dewetting of substrate and foam. It is well understood that wetting agents (surfactants) help to increase substrate wetting, flow and to some extent leveling. Surfactant De wetting Foam generation Anti foaming agent Figure 16: Competition cycle of conventional surfactants and defoamers The challenge has always been to find the right wetting agent that does not lead to foam generation and if at all it does, a right defoamer to destroy this foam generated due to the presence of the wetting agent. The selection of a suitable surfactant and defoamer combination becomes critical to formulators. Patcham has developed a package of additives (Table 13), for waterborne epoxy system which can overcome the issues related to these systems. It consists of Dispersing agent with anti settling properties Leveling agent with excellent flow, leveling and substrate wetting Defoamer with excellent balance between defoaming and compatibility with the system 12

16 Additives for waterborne epoxy systems Table 13: Additives for WB epoxy topcoat Additive Pat-Add DA 817 Pat-Add AF 31 Pat-Add LE 1030 Waterborne epoxy system Features Efficient dispersing optimizes the milling process and strong prevention of pigment flocculation, floating and settling issues. Compatible with all WB and SB systems. Easily dispersible and very effective anti foaming agent with optimum compatibility Polyether modified polysiloxane surface modifier provides excellent flow and leveling enhances substrate wetting, avoids pinholes and craters. Dosage on total formulation (%) Grinding stage Grinding / Letdown Letdown stage Table 14: Formulation of waterborne epoxy grey Waterborne epoxy grey Raw materials Weight (%) Part A Mill base Epoxy amine adduct Pat-Add DA 817 Pat-Add AF 31 Barytes Talc Titanium dioxide Iron oxide black Iron oxide yellow Fumed silica Butyl carbitol Butyl cellosolve MPA Water Letdown Epoxy amine adduct Water Pat-Add LE 1030 Total Part B Liquid epoxy resin Mixing ratio A:B (w/w) :1 Pat-Add DA 817 optimizes the viscosity of waterborne epoxy paint whilst the leveling and anti foaming agents provide the synergistic effect to avoid issues of dewetting and foaming. 13

17 Additives for waterborne epoxy systems Pat-Add DA 817 is a unique dispersing agent that also acts as an anti-settling agent. The electrostatic repulsion created by charged polymeric dispersants adsorbed on the surface of the pigments helps to reduce particle aggregation. This in turn reduces the chances of flocculation while continuing to maintain the smaller particle size. Reference Pat-Add DA 817 Figure 17: Stability of WB epoxy primer The stability of waterborne epoxy primer is represented in Figure 17. Epoxy primer has optimum viscosity with no settling whereas, the reference sample shows settling of pigmnets during the stability test. The package of Pat-Add additives have an excellent balance of compatibility and do not show any side effects such as de wetting (Figure 18), craters, fish eyes and intercoat adhesion issues (Figure 19). Reference Pat-Add LE 1030 Figure 18: Substrate wetting of waterborne epoxy primer with Pat-Add LE 1030 Performance properties such as flexibility and adhesion tests showed no intercoat adhesion failure. These findings are illustrated in Table 15 and Figure 19. Table 15: Performance of waterborne epoxy paint Physical properties Dry film thickness Gloss Flexibility by conical mandrel 7mm Adhesion test after 24 hrs (1.5 mm) Adhesion test after 7 days (1.5 mm) 55-60µm 90 units Passes 5B passes 5B passes Figure 19: Adhesion and bending test results of WB epoxy paint 14

18 Notes

19 Notes

20 PATCHAM (FZC) P.O. Box: 7753, Saif Zone, Sharjah, UAE Tel: Fax: PATCHAM INDIA B-52, Pravasi Industrial Estate Vishweshwar Nagar, Off Aarey Road Goregoan (E), Mumbai (India) Tel: india@patchamltd.com PATCHAM EUROPE BV Klavermaten DD Goor Netherlands eu@patchamltd.com PATCHAM USA LLC 10 Commerce Road Fairfield, New Jersey Tel: (201) Fax: (201) info@patchamusa.com The information given in this booklet is intended for technical guidance without obligation. Ver