30.01.2016
We hold significant stocks of product in our Adelaide warehouse including consumables, capital equipment and spare parts and have a selected range of demonstration items. Tangent Light Curable Adhesives can be used in a very wide range of industrial applications for the purpose of bonding, sealing, masking, and coating of components and assemblies. Light Curable Adhesives are comprised of three primary components: photoinitiator, monomer, and oligomer. Creativity and technical expertise drive Tangent R&D chemists to develop truly unique light curable adhesive technology.
UV adhesives- multi-purpose adhesives and coating that cure rapidly when exposed to UV light energy, (less than 395nm). LED curable adhesives- adhesives that cure with monochromatic LED systems, with preferred wavelengths of 365nm or 405nm. Please open one of the links below to view pages where our light curable acrylate adhesive products may be found. When you are making DIY printed circuit boards, one of the popular methods requires UV exposure.
This instructable outlines the construction of a double sided UV exposure box using the recent generation of high brightness UV LEDs. LEDs are far more energy efficient than either incandescent or fluorescent lamps offering between 5-10 times more efficiency making them cheaper to run and kinder to the environment.
Whoops, did not immediately notice that the LED banks were set back enough to limit unevenness. Normal compact fluorescent tubes coupled with tracing paper do a very good job with exposing PCB traces.
The resolution (reproduction from transparency to board) should actually be very good with UV LEDs since they generally have very narrow beam width.
Most visible LEDs are slightly less efficient than fluorescents and UV LEDs are much less efficient than fluorescent blacklights.
Black light fluroscents also emit shorter wavelengths mainly 360nm to 380nm which is better for exposing PCBs than the near violet light emitted by most UV LEDs. LEDs do have the advantage of being more robust and if one of them breaks you can still use it.
The fact that fluroscents contain mercury is a non issue because the amount found in a small tube is below the safe daily exposure limit.
Also, adding the insult onto injury, Blacklight fluorescent would just conk out after 2,000 Hours and is easily breakable. The photo etching method needs 60 Watt radiated power at 10 cm target distance, also the wavelength must be 340nm (Near UV) with maximum wavelength 254nm, if you are going to use far UV light tube (190nm for example) the radiation will pass though the film (and though the plastic box) destroying all the photosensitive material, and causing cancer to you! A lot of you are just talking bollocks, I’ve made a UV exposure box using about 100 UV leds from ebay running off 12v, they are about 5 inches from my pcb. Simply print onto transparancy, flip the toner to the board and expose for 30 seconds – works like a charm.
And, another things to consider: Focal points, beam waist, divergence, and transparency of scanner glass (some of them use just plainly a fused Quartz glass for you to put paper on to be copied.
If vacuum UV was a problem then germicidal lamps would emit lots of ozone so will require lots of ventilation to prevent them being a health hazard but this isn’t the case. The worst blacklight tube will have an efficiency of about 15%, the best will be closer to 30% efficient. I’ve never needed to use a fan on a fluorescent enclosure but overheating can be caused by using cheap magnetic ballasts and inadequate ventilation. The same is true for some power LEDs, especially the cheap Chinese variety commonly bought off ebay. It is true LEDs though that last longer than fluorescent tubes but it’s important to note that both get dimmer over time. If you buy cheap LEDs they’ll be very inefficient and much less efficient than a blacklight fluorescent. You can buy a 2ft blacklight fluorescent tube for less than ?3 ($5 US) which will produce as much UV as many hundred UV LEDs. This may be an odd question but its 1AM in the morning and i’m too lazy to google it… what is that green glowing stuff that UV lights excite (in the pic, in the middle of the box)? Typical Use: The thixotropic nature of Loctite 3106 UV Adhesive reduces the migration of liquid product after application to the substrate. Acrylic urethane coatings are used in a variety of applications due to their versatility, durability, appearance and superior weatherability compared to other resin systems.
UV-curable coatings, on the other hand, are one-component (1K) systems that cure by photoinitiated polymerization of the acrylate monomers and oligomers in the formulation (Figure 2). UV-curable formulations typically contain an acrylated oligomer based on a polyether, polyester or epoxy resin. Several companies have recently reported on dual-cure coatings that combine the benefits of UV and 2K urethane systems and overcome some of their limitations (Figure 31). The final coating properties, however, are achieved by the combination of a UV-curing process and a chemical crosslinking process.
We have recently developed a family of acrylic polyols based on allylic alcohols.2 These new acrylic polyols are unique in that they are solvent-free, solid and liquid resins with very low solution viscosities and superior functionality compared to conventional acrylic polyols.
The following paragraphs describe the preparation and properties of new acrylic urethane coatings for weatherable applications.
Results and Discussion1K Acrylic Urethane UV-Cured Coatings Most acrylated oligomers are based on polyether, polyester and epoxy resins. Acrylic polyols, on the other hand, are produced by free-radical polymerization and are usually supplied in solution. Synthesis of Acrylated Urethane-Acrylic Oligomers Initial attempts to prepare acrylic-based prepolymers with HDI (hexamethylene diisocyanate), TDI (toluene diisocyanate) or IPDI (isophorone diisocyanate) led to gelling. The liquid acrylic polyol was first treated with excess IPDI to form an isocyanate pre-polymer, which was then capped with HEA.
The butyl acetate solvent we used to reduce viscosity can be replaced with acrylate monomers such as IBOA (isobornyl acrylate) to produce solvent-free and VOC-free formulations, albeit with much higher viscosity. Acetone is an excellent viscosity reducer for these resins and a good choice for these systems. The same chemistry was used to produce low-viscosity, acrylated urethane-acrylic resins with residual OH functionality.
However, instead of using excess IPDI, the acrylic polyol was first treated with two equivalents of isocyanate in the presence of tin catalyst to reduce the hydroxyl functionality to 3-4 per polymer chain, and then treated with two equivalents hydroxyethylacrylate (HEA). Based on these criteria, we selected IBOA (isobornyl acrylate) and IDEA (isodecyl acrylate) as our mono-functional acrylate monomers and either TMPTA (trimethylolpropane triacrylate), Di-TMPTA or PO6-TMPTA (propoxylated TMPTA) as our multifunctional acrylates. We chose to add solvent to these formulations because we wanted a sprayable system with good sag resistance and minimal shrinkage during UV cure. Furthermore, a sprayable coating system prepared only with acrylate monomer diluents would be much more likely to sag when applied to vertical surfaces.
The choice of photoinitiators was dictated by the UV light source, HALS (hindered amine light stabilizers) and UV-screeners. Film properties were highly dependent on the monomer diluents but were comparable to conventional 2K urethane coatings. In contrast, the formulations containing PO6-TMPTA showed significant gloss loss and failed after approximately 2000 hours of exposure.
UV screeners improved the weatherability of both coatings yet did not interfere with the UV-curing process. 2K, Dual-Cure Coatings Clear coatings were also prepared using the partially acrylated polyol DC60. Because the polyol and isocyanate crosslinker (HDI trimer) react under ambient conditions, they must be mixed shortly before application. Coating hardness was 49 Konig swings immediately after UV cure, and the coatings was tack- and print-free.
2K UV Coatings Without Acrylated Oligomers It is also possible to develop dual-cure coatings using conventional 2K urethane polyol ingredients and acrylate monomers as diluents. The final coating properties and cure speed are controlled by the formulation components, their relative amounts and their order of addition. With liquid acrylic polyols as the base polyol and HDI-trimer as the isocyanate crosslinker, mono-functional acrylates such as IBOA (isobornyl acrylate) do not yield a tack-free state after UV cure, unless the HEA is pre-mixed with the isocyanate, as is illustrated in Figure 12. Replacing a portion of the liquid polyol with a high-Tg polyol was also effective in achieving a tack-free state immediately after UV cure.
Conclusions Low-VOC, sprayable acrylic-urethane clearcoats have been developed for weatherable applications. These coatings have excellent appearance, physical properties and weatherability, suggesting that acrylic-urethane UV-curing clearcoat technology could potentially be applied to automotive OEM and refinish applications, as well as wood and plastic parts. Resin Management Concept is a registered trademark of Lyondell Chemical Company.AcknowledgementsThe authors wish to thank Ann Good, Bob Good, Dave Pangburn and Mark Smithson for expert technical assistance, and Steve Harris for helpful discussions.
Our September issue focuses on sustainable solutions, specialty chemicals, architectural coatings and the latest pigment technology.
SUBMITTEDTom Seung-Tong Cheung, application lab manager at Siltech Corp., indicates the UV-curing cell used to measure mechanical properties as the material is photo cured. One way to alter the fundamental properties of a polymer is to react it with a different polymer generating an AB-type co-polymer or hybrid. PDMS itself has no reactive groups although the polymer can be broken under strong base or acid catalysis and reacted with nucleophilic resin systems.
In this paper, we modify a few coatings systems with reactive silicones and examine the effect on their liquid and cured film properties. The overall design is to use two radiation-cured systems, one acrylate and the other cycloaliphatic epoxy-cured. A nitrogen blanket is used for curing acrylate coating that contains free radical photoinitiator.
In Series B, we extend this success with six silicone acrylate esters that vary by linear vs. Finally in Series C, we run a similar selection of six acrylate ester functional silicones focusing mainly on the linear vs. In this different cure system, we evaluate a series (A) of relatively insoluble epoxy silicones that vary by linear vs.
All tested panels are prepared by drawing down approximately 1 ml of the EPC blends formulation on a 4x6.5" white Leneta paper with wire-wound rod #10. Mar resistance is measured using a Sutherland 2000 Ink Rub Tester - Dry Rub method with the following settings: 500 rubs, 84 rpm stroke speed for all sample sets. The panel to be tested is placed coated side down on the top of a protective paper that sits on a flat steel plate with rubber pad on the bottom. System 1 Series A: Formulations of UV-curable coatings were prepared with epoxy acrylate resin and modified with varying amounts of Silmer® ACR D208 di-functional acrylate ester silicone with a polyethyleneoxide chain for increased solubility. Conclusions System I Series A: This screening study shows this low molecular weight polyethyleneoxide, acrylate ester silicone material is highly compatible with this acrylate resin and reacts into the film completely. System I Series B: Formulations of UV-curable coatings were prepared with epoxy acrylate resin and modified with varying amounts of silicones, all but one of which are modified by polyalkyleneoxides for solubility, and which differ primarily by silicone and polyether chain lengths. Conclusions System I Series B: The LINX400, which has no polyether modification, does not cure completely and leaves unreacted silicone oil on the surface.
All of the test samples modified with 10 percent reactive silicones show better spreading than the control. The peel force, slip and CoF for each of the test samples prepared with 10 percent reactive silicone are significantly improved over the control.


There is no dramatic improvement in mar resistance with 10 percent silicone actives in this series. The uncured material using LINX400 gives the best stain resistance perhaps due to uncured silicone. System I Series C: In this study, formulations of UV curable acrylate coatings are varied with a selection of acrylate ester functional silicones, focusing mainly on absence or presence of a polyalkyleneoxide chain, chain length of silicone and polyether and the linear vs. Conclusions System I Series C: The products with no polyether modification do not cure completely and leave unreacted silicone oil on the surface. All of the test samples modified with 22 percent reactive silicones show better spreading than the control.
All samples prepared with 22 percent reactive silicones give much lower peel force and CoF than the control. System II Series A: Formulations of UV-curable coatings with cycloaliphatic epoxy resin were prepared with 1 percent and 20 percent of a series of relatively insoluble epoxy silicones that vary by linear vs. Conclusions System II Series A: As all of these samples show surface defects and a slightly greasy surface, the materials are not completely compatible and may not have completely cured into the film.
Slip, CoF and peel force of all of the epoxy silicone modified epoxy coatings is significantly lower than the control.
Stain and mar resistance improve significantly when the cycloaliphatic epoxy coating is modified with either linear di-functional or multifunctional epoxy silicones. The impact resistance of epoxy coatings modified with 20 percent epoxy silicone improves significantly, whereas there is no improvement in impact resistance for epoxy coatings modified with the 1 percent epoxy silicones. It is surprising to see that the shear modulus increases as the molecular weight of the linear di-functional epoxy silicone increases in the 20 percent series. System II Series B: In this series we prepared formulations of UV-curable cycloaliphatic epoxy coating resins modified with 1 percent and 20 percent of polyalkyleneoxide modified epoxy silicones that vary by linear vs. Conclusions System II Series B: These epoxy silicone polyethers give smooth coating surfaces indicating they are totally compatible with the epoxy resin system used.
The epoxy coating modified with 20 percent epoxy polyether silicones gives better impact resistance than the control. Stain resistance and mar resistance of silicone polyether modified epoxies is much better than the control for both 1 percent and 20 percent series. The peel release force of epoxy coating is significantly improved, particularly for 20 percent high MW linear di-functional epoxy silicone polyether materials. Epoxy coatings modified with 20 percent epoxy silicone polyether material is more flexible than the control, as indicated by tan delta and impact resistance measurements. The curing rate of linear di-functional silicone polyether is faster than multifunctional polyether.
Stain resistance is seen with most reactive silicones across multiple stains and is increased at higher use levels such as 20 percent over 1 percent. Impact resistance and moduli indicate the increased flexibility of the systems with silicone reacted into the film. In both systems, the incorporation of polyalkyleneoxide into the reactive silicones increases compatibility and degree of curing. The high levels of silicone incorporation tend to make the coating softer and more rubbery. The photoinitiator triggers the curing process when it is exposed to light energy of the appropriate wavelength.
Or, contact Tangent Application Engineering to speak with a trained specialist who can guide you to a product best suited for your application. Fluorescent blacklights are more efficient than visible fluorescent tubes and UV LEDs are much less efficient than visible LEDs.
But if you’re going to use sterilization tube, you’re going to waste several watts here! That’s just bad luck, a typical fluorescent with a properly rated ballast should last for 5000 hours, some last for over 10,000 hours.
The product has shown excellent adhesion to a wide variety of substrates including glass, many plastics and most metals. These applications include automotive clearcoats, industrial maintenance topcoats, general metal, wood furniture and flooring. These oligomers are more difficult to prepare than the acrylic polyols used in 2K urethanes, which contributes to the high cost of UV-curable formulations.
The cured films are usually more flexible and adhere better to the substrate than 100% UV-curable systems, presumably because shrinkage is reduced. These polyols are also designed to be blended together to achieve coating properties for a wide range of applications and technologies, including high solids, UV- and moisture-curable, and powder coatings (Figure 4).
This is because the functionality of these condensation resins can be precisely controlled to 2 or 3 to prevent gelling and keep viscosities low (Figure 5). IPDI was ultimately chosen for the unequal reactivity of the primary and secondary isocyanate groups, which helps control crosslinking and prevents gelling.3 By modifying the process and reagents slightly, we were able to produce gel-free, low-viscosity, low-color acrylated urethane-acrylic oligomers (Table 1).
Excess IPDI is required to prevent gel formation when preparing the isocyanate prepolymer, because the hydroxyl functionality of the acrylic polyol is greater than 5. Under controlled reaction conditions and catalyst concentrations, the acrylic polyols reacted with the primary isocyanate group of IPDI, leaving the secondary isocyanate group intact for subsequent reaction with HEA. It is inexpensive and evaporates quickly, which allows the coating to be sprayed without a lengthy flash-off time.
The residual OH functionality provides a crosslinking site for dark or thermal cure with conventional isocyanates or melamine crosslinkers (Figure 7).
The resulting resin had an average of 2 acrylate and 3.6 hydroxyl groups per polymer chain, making it capable of both UV and chemical crosslinking reactions (Table 2).
Because of the relatively poor solvency of acrylate monomers, we would have had to use large amounts of monomers to reduce the system to spray viscosity, thereby increasing the chance of shrinkage and poor adhesion. We chose acetone as the solvent because of its rapid evaporation rate, excellent solvency, and non-HAP and VOC-exempt status in the U.S. We chose a D-bulb because of its high output in the visible- and near-UV portions of the spectrum and to avoid interference from the HALS and UV screeners. These results illustrate that although the base acrylic urethane resin is weatherable, the choice of acrylate diluents can have a very negative impact on the UV resistance of the coating. Unlike the fully acrylated version, DC60 does not yield a tack-free coating by itself when exposed to UV light.
The NCO-OH reaction continued for another week, during which the coating hardness increased to 120 swings.
This may potentially reduce the cost of dual-cure formulations by eliminating the need for acrylated oligomers.
Since neither the polyol nor the isocyanate crosslinker are involved in the UV-curing reaction, the acrylate monomers, acrylic polyol and isocyanate crosslinker must be carefully selected so that a tack-free state is achieved after UV cure.
This, presumably, generates an acrylated polyisocyanate that can now be involved in the UV-curing process. This approach is preferred over the use of TMPTA because the final coating has better impact resistance and flexibility.
After 5000 hours of exposure, all coatings have retained over 90% of their gloss, even under harsh QUVB conditions (automotive cycle) (Figure 14). One-component, UV-curable coatings were prepared using novel acrylated urethane-acrylic resins. Often defined by their reactive groups, the myriad of resins offer a wide-range of properties. With low surface energy, ultra-low Tg and strong slip, release and flow properties, polydimethylsiloxane (aka PDMS or silicone) can bring profound property changes to these hybrids.
We have chosen UV-cured acrylate and cycloaliphatic epoxy systems as examples, but this concept is valid in heat-cured systems as well. On average, this is a di-functional silicone acrylate ester with polyethyleneoxide chains for increased solubility.
Half the length of the tape is applied on the coated panel at a 45° angle with a wooden applicator.
Rubbings are done using a 4 lb test block that is attached with a 2x4" nylon scrubbing pad. The following stains were used: red lipstick, green permanent marker, black permanent marker, brown crayon, purple crayon, pencil, red ballpoint pen and yellow highlighter.
A steel rod with a 1 cm diameter round steel ball attached at the end of the rod is placed on the back side of the coating surface. The film properties of the acrylate UV coating can be modified by incorporation of more than 60 percent silicone to give very strong release properties. This means the film property tests may not be measuring an inherent change in the film, but rather the surface oil. The best results of the completely cured systems belong to the medium chain length silicones. This may be due to the fact that the coating becomes softer and more rubbery as indicated by storage modulus. In general, there is some improvement in stain resistance, with the exception of LINEL25 and LINPS20. This is perhaps due to the fact that adding a reactive silicone to these systems reduces the viscosity of the resin significantly. The peel force for the samples prepared with linear acrylate ester silicones is significantly lower than those prepared with pendant materials. Multi-functional (pendant) epoxy silicones with higher functionality give lower peel force than those with lower functionality.
Both stain resistance and mar resistance seem to increase as the molecular weight of either polymer architecture is increased.
Multifunctional epoxy silicones seem to give better impact resistance than the linear di-functional silicones. The shear modulus of the high MW linear di-functional epoxy silicone is higher than that of the low molecular weight ones. This is confirmed by gloss reading, where there is no significant change in initial gloss for 1 percent silicone polyether series.
The impact resistance increases as the number of epoxy groups in the silicones increases, but only to the level of the linear, di-functional materials. The 1 percent epoxy silicone polyether sample gives better mar resistance than the corresponding sample in the 20 percent series. The sample with greater number of epoxy groups per silicone polyether molecule results in lower damping factor or lower tan delta. The curing rate of silicone polyether samples increases as the number of epoxy groups in the silicone polyether increases. In fact, the mar resistance properties are often lost at higher loadings, which is believed to be an artifact of the softer films.
Higher use levels are needed here for significant changes, with 1 percent showing little or no effect. Rutnakornpiluk, Modification of epoxy-novolac resis with polysiloxane containing nitrile functional groups, European Polymer Journal, V41, I5, May 2005, P1043.
The monomer component in the formulation primarily impacts the degree of adhesion to any given substrate. Djhamer has provided plans to make a UV LED system that is double sided so that you can expose double sided PDBs without having to flip and repeat half way through the process. It can also be used to make other things such as intricate photo etched parts (a subject for another instructable).


LEDs have a far greater life span than the other types of lamp measured in decades rather than months. While my technique is more or less stable, I sometimes have trouble with toner sticking to tracing paper: there are microscopic gaps, or even smearing. Because, there are way too much free-path collision against lots of molecules in the air while trying to get Extreme UV onto your board, thus attenuate the useful flux of Uv emission. There might be more efficient LED prototypes in the LAB but they’re certainty not ready for the mainstream. I have just bought an Ledengin LZ1-00UA00 Star LED from Farnell here in UK, about ?20, intending to build a light box. The most common coating type is two-component (2K), where an acrylic polyol solution is mixed with a polyisocyanate just before use and applied to the substrate. It is even more difficult to prepare acrylated urethane oligomers based on acrylic polyols because their high functionality often leads to gelling or high viscosities. The UV-curing step is used to obtain tack-free coatings so the parts can be handled, buffed or sanded immediately after UV cure. Also, the dark or thermal cure mechanism provides a means to cure the film in areas not fully exposed to UV light. These coating systems offer instant cure and superior properties compared to conventional UV-curable systems. The resins also contained 20-30% of IPDI diacrylate, which is produced when excess IPDI reacts with hydroxyethylacrylate (HEA). The resulting product is a mixture of acrylated acrylic-urethane oligomer and acrylated IPDI reactive diluent. This unique property of IPDI allows for easy control of the ratio of acrylated urethane-acrylic oligomer to IPDI diacrylate diluent and broader process latitude.
It is important, however to allow the solvent to flash off to prevent the formation of pinholes and solvent popping during the UV cure. This resin can be used in dual-cure coatings diluted with acrylate monomers but does not, by itself, give tack-free coatings after UV cure.
Although not VOC-exempt in Europe, acetone has low ozone-forming potential and should have minimal impact on tropospheric ozone compared to other, more reactive solvents.
We eventually settled on a blend of a BAPO (bis-acyl phosphine oxide) photoinitiator in a liquid µ-hydroxyketone (AHK). Since polyethers are known to have poor UV stability, we attribute this loss of weatherability on the propoxylated TMPTA. This reaction also provides a dark-cure mechanism that is not found in conventional UV-cured systems. Heating the coating to 60 °C for 10 minutes after UV cure accelerated the NCO-OH reaction and hardness development and resulted in a slightly harder final film. The acrylate monomers help reduce the viscosity of the polyol and isocyanate crosslinker and are polymerized with UV light to achieve a solid state.
Some tri-functional TMPTA (timethylolpropane triacrylate) is usually required to build enough molecular weight. Zero-VOC formulations sprayable at 80% solids and above were achieved using acetone and acrylate monomers (Table 5).
Two-component coating systems were developed using a partially acrylated urethane acrylic polyol and conventional 2K urethane components, diluted in acrylate monomers and acetone. In the coatings industry, acrylate, epoxy, urethane and polyester coatings are all quite common and have associated typical properties and expectations. This product is commonly used for screening at Siltech because it has good solubility and good reactivity. A 700 gram weight with a 1.5 cm hole through the middle fitted onto the steel rod drops down freely and vertically along the rod from a distance of 23 cm above the coating surface.
The peel force and impact resistance data show better release and flexibility as more silicone is used as one expects. The highest molecular weight linear di-functional epoxy silicone gives lower peel force than the lower molecular weight ones.
The mar resistance of the 1 percent series is slightly better than the 20 percent series, whereas the latter is better than the former with respect to stain resistance.
The sample prepared with multifunctional epoxy silicone gives lower shear modulus than those with the linear di-functional ones. There is no change in impact resistance and pencil hardness for all 1 percent epoxy silicone polyether samples. This may be due to the fact that the latter is softer than the former or that there is enough slip at 1 percent. In general, the curing rate, hardness and shear modulus of all silicone polyether modified epoxy coatings is lower than the control.
Wang, Toughening of epoxy resins by modification with dispersed acrylate rubber for electronic packaging, J.
Wang, Modification of epoxy resins with polysiloxane thermoplastic polyurethane for electronic encapsulation, Polymer, V37, I13, June 1996, P2733.
Wang, Modification of epoxy resin with siloxane containing phenol aralkyl epoxy resin for electronic encapsulation application, European Polymer Journal, V37, I2, Feb. The oligomer provides most of the post-cure mechanical properties such as hardness, elongation, elasticity, shrinkage, etc.
The trouble is they can be a little pricey for the hobby enthusiast especially if you want the double side type. The frequencies being emitted are also in a tighter band making UV LEDs safer than the traditional UV tubes. Since the transparency is put back-to-back with the resist, lighting angle is not really an issue. Also, it simply get so hot, to some point it would require fan cooling, if left on way too long. The coating then cures by a combination of solvent evaporation and chemical crosslinking to form a durable urethane bond (Figure 1).
This is a significant limitation of 2K urethane coatings since one has to trade productivity for compliance, cost and ease of use. We believe this has contributed to the slow growth of UV-curable coatings in applications where excellent UV stability is required, such as automotive clearcoats.
Another benefit of achieving an instantaneous, tack-free state is that the coating appearance is improved. However, as was the case with conventional UV-curable oligomers, the main polymer backbone is a polyester, not an acrylic resin. These systems may allow UV-cure technologies to be used in the most demanding applications including automotive topcoats.
Consequently, the traditional two-step synthesis shown above typically leads to highly crosslinked, viscous, or even gelled products that are not suitable for coating applications. The final coating hardness is also improved if the solvent is allowed to escape before the coating is UV cured.
Because Europe does not consider acetone VOC-exempt, the VOC content for Europe is around 300 grams per liter.
We again used IBOA as the monofunctional acrylate and TMPTA as the multifunctional acrylate. Adding a hydroxy-functional acrylate monomer (such as HEA) provides a crosslinking mechanism between the UV-generated acrylic resin and the isocyanate crosslinker (Figure 11). However, the impact properties of the final coatings suffer as is expected from the higher crosslink density (Figure 13). Here we examine the silicone at 30 percent and 60 percent of the system so we can see an effect and confirm reactivity.
Kinetic coefficient of friction also is obtained directly from the equipment, representing the ratio of the horizontal component of the force (required to cause the object to slide at a constant velocity) to the vertical component of the object weight (200 grams).
One end of a stainless steel string is attached to the transducer and the other end is fastened onto the remaining half of the tape with a 2" length of standard cellophane tape. The mar resistance rating is determined by visual inspection of surface defects and by the percentage change in gloss reading before and after the rubbing test. All the treated panels were then rinsed with tap water for 1 minute and wiped with an IPA-saturated cotton swab. The impact resistance is estimated by visual inspection of the size and pattern of the damage.
The strongest correlation is between flow and viscosity of the coating rather than surface tension reduction due to the reactive silicone. Without exception, materials without polyether showed signs of incomplete cure or incomplete incorporation of the silicone into the matrix. Small percentages of additives may also be incorporated into the formulations to provide unique features such as fluorescence and color. I suspect that I just have a crappy printer, but who knows, what if there’s some trick to better toner adhesion. Other limitations of UV-curable coatings include the absence of a dark cure mechanism, difficulty in spraying and curing 3D parts, and poor adhesion and flexibility due to shrinkage during the curing process. This is because fewer airborne impurities have time to contact the wet film and cause defects.
After 5,000 hours of UV-A and -B exposure, the base UV120 resin showed good to excellent gloss and color retention (Figure 9). We also used a different adhesion promoter (SR9008 from Sartomer) and added a tin catalyst and amine synergist (triethylenediamine or TEDA) to accelerate the dark cure reaction between the OH groups and the isocyanate crosslinker (Table 4). However, the UV-cure component provides instantaneous hardness development, as illustrated in Figure 10. Record percentage loss of gloss and a subjective rating from 0 to 10, where 10 is the best and indicates no visible effect. The subjective ratings are obtained by visual comparison of stains remaining on the panels for each series and rating them from 1 to 10, where 10 is best and indicates no remaining stain. The subjective ratings are obtained by visual comparison of impact damage on the panels for each series from 1 to 10, where 10 is best and indicates no cracking or breaking of the film. The coating becomes rubbery and very flexible to the hand at these high levels of silicone.
Several properties, such as stain resistance and CoF, were significantly impacted by this free silicone.
During the next 25 years, Ruckle worked in research and development, designing silicone surfactants primarily for the coatings additives market. Nonetheless, we were able to prepare low-viscosity urethane acrylates based on the new liquid acrylic polyols. The slip rating is determined by averaging percent change of CoF with weighting factors against the control in the same series and normalizing to 10 with all the test samples.
If I try it out on the bench before making the box, is the reflected light dangerous, and will the goggles make it safe?
Conversion of the acrylate unsaturation was measured by Raman spectroscopy and was typically 80% after the first pass and above 90% after the 12th. Will there be any problems doing this with UV, like the glass not being transparent, or the ink not opaque?



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Comments Uv curable systems bvba yves

  1. TELEBE_367a2
    The display to the new with automatic sheet feeding harden on exposure.
  2. Tonny_Brillianto
    Cheap to maintain this lamp because most acceptable repair protocol that.