Smart-Formulation-Journal-2012
2 We love your problems – at first that might seem a strange thing to say. Evonik loves my problems? Do they want me to have problems? Far from it. But problems, challenges and solving them are part of everyday business. So it’s good to have a partner who’s committed to solving your problems and developing forward-looking solutions with commitment and creativity. That’s the core message behind “We love your problems”. For us, every problem is an opportunity to develop great solutions, solutions that are dovetailed to your needs because we’ve developed them together with you. Here are three examples to demonstrate just what we mean. Coatings with Fish Eyes When spraying modern high-solids coatings, there are often problems like blisters, fish eyes and other defects. The biggest challenge was to find an additive that reliably prevents these problems while displaying good compatibility. To solve this problem, we worked closely with a number of our customers. As a result of our working together, two new deaerators for high solids coatings have been developed, TEGO® Airex 990 and TEGO® Airex 991, that can reliably prevent foam / blister formation even in high film thicknesses and give our customers greater freedom in choosing the type and quantity of solvents for their coating. Cans in Danger The inner coating of a food can has a lot to put up with. During forming as part of the manufacturing process, it has to be flexible and yet still retain its high hardness. But that’s only the start. It then has to withstand the high temperatures of the sterilization process and display lasting resistance to aggressive contents such as acetic acid in order to prevent metal particles getting into the food. That’s a lot of work for a coating and, above all, for the binder. The solution: DYNAPOL®. Our polyester resins offer optimum protection, high flexibility in the manufacturing process, a level of temperature resistance that can withstand sterilization at 130 degrees Celsius, and high resistance to aggressive contents. Film Shrinkage Under the Spotlight The absence of a solvent often causes problems in the matting of UV-curable coatings because the necessary film shrinkage does not take place and has to be replaced by other mechanisms. For this reason, we channeled a great deal of passion into conducting an extensive series of painstaking tests to find out how to provide effective matting for UV-curable coatings. The result: Our new matting agent ACEMATT® 3600 which, thanks to its special surface treatment, permits effective matting without solvents and so gives our customers more freedom in formulating matt, UV-curable coatings. Curious about how exactly we went about things in our three examples? This issue deals with these topics in great detail. Happy reading! Contact Dr. Ulrich Küsthardt ulrich.kuesthardt@evonik.com DEGALAN® Resins – Excellent Base for Formulating Intumescent Paints Intumescent paints are functional coatings that expand their volume under heat building a foam. This foam works as heat shield protecting the substrates from direct fire contact and thus delaying the spread of fire. More time for the rescue of people is available and protection against massive damages. Essential for high protection is a uniform foam structure and height. Typically intumescent paints are based on a polymer, a catalyst (e. g. aluminum phosphate), a carbon source (e. g. pentaerythrit) and a foaming agent (e. g. melamine). DEGALAN® resins based on thermoplastic (meth)acrylics are ideal binders for intumescent paints as they simply do not influence the foam development. In fact the DEGALAN® polymers shield the water sensitive paint ingredients, reduce mechanical impacts, promote adhesion on several substrates and give excellent UV-resistance. Thus DEGALAN® resins help in formulating efficient intumescent coatings. Contact Andreas Olschewski andreas.olschewski@evonik.com Smart Formulating Journal | Issue 9 | April 2012
3 Corrosion Protection Systems Environmentally Friendly Solutions with Novel Water-Borne Silane Sol-Gel Formulations and Water-Borne Coatings Aluminium alloys are used extensively in the aerospace, automotive and construction industry because of their low density and high strength to weight ratio. Although some aluminium alloys can exhibit good corrosion resistance when exposed to the environment, the majority of aluminium alloys have to be protected against corrosion. Established surface pre-treatment processes, like chromating and phosphating, are of high economic significance. Due to high toxicity the use of chromium (VI) is no longer approved in the automotive and the electronic industries. Silane based systems are one of the most attractive alternatives since they are environmentally friendly. Silanes were originally developed for adhesion promotion. They can improve the adhesion between inorganic fillers and organic binders in composites. Silanes can be used as primers in formulations for better adhesion of polymers and coatings on inorganic substrates like metals. Figure 1 shows the improved peel strength of a maleic acid grafted polyolefin on an aluminium alloy primed with a silane solution. and pigments can be a problem, especially when the pH of the water-borne sol-gel system (Dynasylan® SIVO 160 has a pH of 4 – 4.5) and e. g. the pH of the polymer dispersion does not match. In the following example Figure 2 shows a diluted Dynasylan® SIVO 160 and a formulated Dynasylan® SIVO 160 solution used for the blank corrosion protection of the aluminium alloy 5005 used for construction applications. An untreated panel is used as control. In Figure 2 it can be seen that after 1000 hours in the neutral salt spray test only the blank aluminium alloy 5005 showed corrosion. The samples treated with the diluted Dynasylan® SIVO 160 solution and the Dynasylan® SIVO 160 formulation showed less corrosion or no corrosion after 1000 hours in the salt spray test. In general, it can be stated for the aluminium alloy 5005: The diluted Dynasylan® SIVO 160 solution and the Dynasylan® SIVO 160 formulation do protect against corrosion. The Dynasylan® SIVO 160 formulation showed the best performance in the corrosion test. Dynasylan® SIVO 160 provides excellent adhesion of the water-borne PUR coating to the aluminium substrate. The combination of Dynasylan® SIVO 160 and the waterborne clear coat results in a protective combination, that is resistant to both moisture and salt corrosion. It should be mentioned that the water-borne coating based on VESTANAT® EP-HP 2033 is displaying an excellent scratch resistance. 200 Hours Humidity Test Control SIVO 160 coating SIVO 160 & coating Medium force in N / 5 cm NSS 1000 Hours corrosion corrosion corrosion no corrosion 84 120 Blank SIVO 160 dilution SIVO 160 formulation Figure 3 Test results of coated aluminium alloy 2024 T3 after 200 hours in the humidity test (100 % RH, 40 °C). Procedure: Cleaning in a mild alkaline solution (60 °C), followed by by dip coating with a Dynasylan® SIVO 160 dilution: 15.0 % (w / w) Dynasylan® SIVO 160, 0.02 % (w / w) wetting agent all in dist. water; Curing at 60 °C for 10 minutes, layer thickness: 100 – 150 nm. Water-borne clear top coat: 19.95 % (w / w). Vestanat® EP-HP 2033, 0.15 % (w / w). BYK 341, 0.1 % (w / w). Reaxis C 333 (catalyst, Reaxis Ínc.), 79.8 % (w / w). dist. water. Coating was applied with a blade and cured at 80 °C for 10 min. Dry film thickness: ~ 5 µm Blank Silane primer Figure 1 Peel strength: Aluminium stripes were primed with amino functional silanes. Primed stripes were bounded with maleic acid anhydride grafted PO at 160 °C. The adhesion was tested in a 180 ° peel test at 20 mm / min. Silanes are more and more used as additives in the field of coatings or even as binders. Especially silane based water-borne sol-gel binders are of interest since they are environmentally friendly, storage stable, defined and offer interesting possibilities in the field of corrosion protection and metal treatment. Dynasylan® SIVO 160 is the latest development of such a silane based water-borne sol-gel system. Water-borne silane systems like Dynasylan® SIVO 160 are fully hydrolyzed, nearly VOCfree and contain reactive silanol groups which are stabilised. Therefore Dynasylan® SIVO 160 is a defined product with constant product quality and performance. The silanol groups can not just react with the metal substrate but also with each other in a condensation reaction. When the condensation reaction takes place, a dense network is formed at the surface of the aluminium substrate. In some cases the pure sol-gel system can form a stable layer and can give a good passive corrosion protection. It is a big advantage that formulations with Dynasylan® SIVO 160 can be used at low curing temperatures. The cured coating layer can protect without top coat against corrosion, whilst simultaneously acting as an adhesion promoter when any subsequent coating is applied. In most cases it is necessary to optimise the anticorrosive properties and the overall performance by formulating water-borne sol-gel systems. Formulating knowhow is helpful but in many cases water-borne sol-gel systems behave differently compared to organic coatings. Compatibility with additives, polymer dispersions, fillers corrosion some corrosion no corrosion Figure 2 Test results of coated aluminium alloy 5005 after 1000 hours neutral salt spray test. Procedure: Cleaning in a mild alkaline solution (60 °C), followed by acid pickling followed by dip coating. Dynasylan® SIVO 160 dilution: 12,5 % (w / w) Dynasylan® SIVO 160, 0,02 % (w / w) wetting agent all in dist. water; Dynasylan®SIVO 160 formulation: 12,5 % (w / w) Dynasylan® SIVO 160, 0,02 % (w / w) wetting agent, 600 ppm Cr(III), all in dist. water. Curing for 10 mins at 80 °C; dry layer thickness: 100 – 200 nm Silane based water-borne sol-gel systems are usually applied as a thin layer in the nm range. In some cases the performance of such a thin layer can be limited. In these cases a top coat should be applied on the sol-gel layer. Since the cured sol-gel layer already protects the metal surface the layer thickness of the top coat can be reduced, depending on the performance that is needed. If a coating with a high corrosion protection performance and vapour barrier is requested, water-borne polyurethane (PUR) coatings can be used together with the sol-gel coatings as a sustainable solution. The additional corrosion protection can be important for corrosive substrates like the aluminium alloy 2024 T3. The excellent performance of such a combination is shown in Figure 3 after 200 hours in the humidity test. The blank sample is discolored by corrosion products. Both, the Dynasylan® SIVO 160 treated plate without clearcoat as well as the aluminium plate coated only with a water-borne PUR clearcoat based on VESTANAT® EP-HP 2033 show corrosion. Perfect results could be obtained with the two layer coating consisting of environmentally friendly Dynasylan® SIVO 160 and a 5 µm layer of the water-borne PUR top coat. The market is looking for alternate corrosion protection systems since chromate is being phased out and other surface pre-treatment processes still use aggressive media and chemicals with a high environmental impact. Novel water-borne silane sol-gel systems like Dynasylan® SIVO 160 are very promising solutions for such applications since they are nearly VOC-free and environmentally friendly. This kind of silane-based binders can be modified and formulated in many ways. It can be combined with environmentally friendly top coats such as the water-borne based on Vestanat® EP-HP 2033. For commercial applications a detailed formulation development and stability testing is required. Contact Dynasylan® Nafta kerstin.weissenbach@evonik.com Contact Vestanat® Nafta corey.king@evonik.com Contact Dynasylan® Europe philipp.albert@evonik.com Contact Vestanat® Europe andre.raukamp@evonik.com Contact Dynasylan® Asia Helmut.Mack@evonik.com Contact Vestanat® Asia qi.fu@evonik.com Smart Formulating Journal | Issue 9 | April 2012
- Page 1: Smart Formulating Journal Issue 9 |
- Page 5 and 6: 5 used standard defoamer formulatio
- Page 7 and 8: 7 TEGO® AddBond - the Multitasking
- Page 9 and 10: 9 Product Overview NANOPOX I Produc
2<br />
We love your problems – at first that might seem a strange<br />
thing to say. Evonik loves my problems? Do they want me<br />
to have problems? Far from it. But problems, challenges and<br />
solving them are part of everyday business. So it’s good to<br />
have a partner who’s committed to solving your problems<br />
and developing forward-looking solutions with commitment<br />
and creativity. That’s the core message behind “We love your<br />
problems”. For us, every problem is an opportunity to develop<br />
great solutions, solutions that are dovetailed to your needs<br />
because we’ve developed them together with you. Here are<br />
three examples to demonstrate just what we mean.<br />
Coatings with Fish Eyes<br />
When spraying modern high-solids coatings, there are<br />
often problems like blisters, fish eyes and other defects.<br />
The biggest challenge was to find an additive that reliably<br />
prevents these problems while displaying good compatibility.<br />
To solve this problem, we worked closely with<br />
a number of our customers. As a result of our working<br />
together, two new deaerators for high solids coatings have<br />
been developed, TEGO® Airex 990 and TEGO® Airex 991,<br />
that can reliably prevent foam / blister formation even in<br />
high film thicknesses and give our customers greater freedom<br />
in choosing the type and quantity of solvents for their<br />
coating.<br />
Cans in Danger<br />
The inner coating of a food can has a lot to put up with.<br />
During forming as part of the manufacturing process, it<br />
has to be flexible and yet still retain its high hardness.<br />
But that’s only the start. It then has to withstand the high<br />
temperatures of the sterilization process and display lasting<br />
resistance to aggressive contents such as acetic acid<br />
in order to prevent metal particles getting into the food.<br />
That’s a lot of work for a coating and, above all, for the<br />
binder. The solution: DYNAPOL®. Our polyester resins<br />
offer optimum protection, high flexibility in the manufacturing<br />
process, a level of temperature resistance that can<br />
withstand sterilization at 130 degrees Celsius, and high<br />
resistance to aggressive contents.<br />
Film Shrinkage Under the Spotlight<br />
The absence of a solvent often causes problems in the<br />
matting of UV-curable coatings because the necessary<br />
film shrinkage does not take place and has to be replaced<br />
by other mechanisms. For this reason, we channeled a<br />
great deal of passion into conducting an extensive series<br />
of painstaking tests to find out how to provide effective<br />
matting for UV-curable coatings.<br />
The result: Our new matting agent ACEMATT® 3600<br />
which, thanks to its special surface treatment, permits<br />
effective matting without solvents and so gives our customers<br />
more freedom in formulating matt, UV-curable<br />
coatings.<br />
Curious about how exactly we went about things in our<br />
three examples? This issue deals with these topics in great<br />
detail. Happy reading!<br />
Contact<br />
Dr. Ulrich Küsthardt<br />
ulrich.kuesthardt@evonik.com<br />
DEGALAN® Resins – Excellent Base for Formulating<br />
Intumescent Paints<br />
Intumescent paints are functional coatings that expand<br />
their volume under heat building a foam. This foam works<br />
as heat shield protecting the substrates from direct fire<br />
contact and thus delaying the spread of fire. More time<br />
for the rescue of people is available and protection against<br />
massive damages. Essential for high protection is a uniform<br />
foam structure and height. Typically intumescent<br />
paints are based on a polymer, a catalyst (e. g. aluminum<br />
phosphate), a carbon source (e. g. pentaerythrit) and a<br />
foaming agent (e. g. melamine). DEGALAN® resins based<br />
on thermoplastic (meth)acrylics are ideal binders for intumescent<br />
paints as they simply do not influence the foam<br />
development.<br />
In fact the DEGALAN® polymers shield the water sensitive<br />
paint ingredients, reduce mechanical impacts, promote<br />
adhesion on several substrates and give excellent<br />
UV-resistance. Thus DEGALAN® resins help in formulating<br />
efficient intumescent coatings.<br />
Contact<br />
Andreas Olschewski<br />
andreas.olschewski@evonik.com<br />
<strong>Smart</strong> Formulating <strong>Journal</strong> | Issue 9 | April <strong>2012</strong>
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