Biotechnology modified polyester for the hottest p

2022-08-21
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Biotechnology modified polyester powder coating process for powder coating is a well-known process, which has obvious advantages over the "wet" process for brush coating and spraying. The operation of thermosetting powder coating is as follows: first, the colorant or pigment is mixed into the crosslinkable resin according to the formula to prepare the powder coating; Then grind these materials to be coated on the surface into powder to ensure that the powder particles form a coating after heating or baking; Finally, heat curing coating to form thermosetting coating

for many years, the coating industry has been looking for the best compromise between the cost and appearance of thermosetting coatings. Recently, reducing the curing temperature has become another important issue in environmental protection and cost

the main challenge in developing powder coatings is to balance seemingly contradictory requirements. One of the most basic requirements of powder coatings is curing performance and crosslinkability. In most cases, this means that in the baking stage, it is necessary to mix the crosslinking agent and increase the melting viscosity. Some have some stale technical data. In order to save energy consumption, it is necessary to reduce the baking temperature as much as possible. The fluidity of the coating depends on the viscosity of the thermosetting mixture during curing. If the viscosity increases too early in the baking process, and the powder particles do not have enough time to condense and "level", the result will be an unwanted "orange peel"

in the past few years, resin manufacturers have proposed different solutions to these challenges. For example, the use of defoamers, semi crystalline polyester or tertiary carboxyl groups, and the modification of monofunctional acids or alcohols do not provide the best performance, including storage stability, flexibility, leveling and gloss, as well as no orange peel or bubble generation, solvent resistance, erosion and weathering, and low-temperature curing

in order to find a technical solution, Hexion specialty chemicals company has developed a bio based solution for powder coating, which is prepared from renewable resources, and its quality and performance have reached or exceeded the existing products. This product can meet the growing demand for replacing oil chemicals with renewable resources in many fields

new technology takes into account sustainable development at the same time. Considering that the preparation of standard polyester from crude oil and the traditional curing conditions consume a lot of energy, and the introduction of renewable raw materials, reduce the consumption of fossil resources for energy production and lower curing temperature, its purpose is to reduce energy consumption and cost, and reduce carbon dioxide emissions

this new technology has not only made significant progress in reducing dependence on petroleum derivatives, but also improved the technology. It meets the requirements of durability, cost and low-temperature curing performance required by customers, so that the powder coating can adapt to metals and heat sensitive substrates. In addition, it can save energy in the whole production process. Through this new technology, the low-temperature curing performance is improved without affecting the appearance and performance of the product

in the past few decades, powder coatings have been widely used, especially in important industries, such as aluminum window frames, household appliances and transportation. Because there are no liquid or solvent problems, powder coatings are easier to use, have no ecological harm and have low cost. And powder coating is especially suitable for three-dimensional workpiece. Dry powder coating has high conversion efficiency, and graphene anti-corrosion coating promotion working group, graphene modified fiber and utilization development industry development alliance can be recycled. Its characteristics are as follows:

◆ environmental protection: carbon dioxide emissions can be reduced through renewable resources

◆ Economy: lower curing temperature

◆ convenience: because it is suitable for the current equipment

the patented technology based on biology provides a low-temperature curing powder coating composition, which can meet the fluidity, flexibility and quality requirements of coatings in HSE regulations

the leading technology in the powder coating market

new technology provides great advantages in low temperature curing applications. As a leading technology, it allows the use of renewable resources in growing markets. In fact, important industrial sectors regard this as a key distinguishing factor

its performance is comparable to the current technology, and the process is consistent with the existing production and construction plants

when cured at low temperature, the new system shows improved appearance and properties (at 150 ℃ and 160 ℃ and β- The crosslinking time of hydroxyalkyl amide is 15 seconds and 10 seconds respectively)

through its bio derived materials, the new polyester structure is combined with high reactivity (manifested in low-temperature curing) and good melting appearance, while maintaining the appearance and fluidity of standard cured polyester

the results show that the advantages of this technology in low temperature curing:

◆ reduce the production time by reducing the oven temperature, accelerating the heating speed and shortening the cooling time

◆ the relative humidity of energy will reach 100% RH, which reduces the consumption and use of petrochemical resources and carbon dioxide emissions

◆ enhance the reactivity of the coating and provide higher productivity

in fact, this new technology allows curing at 140 ℃, and the curing time will be gradually shortened with the continuous efforts of the R & D team

comparison of technical evaluation between powder coatings using biotechnology and standard powder coatings

in order to prove the difference in wettability between powder coatings using biotechnology and standard powder coatings, three polyesters were compared with powder coatings with 50% pigment content in the coating formula. The coated plate with biotechnology has good appearance and fluidity, good melting appearance (PCI = 6), and excellent coating reactivity within the standard results of gel (see Figure 1)

Figure 1: poor wettability between powder coatings using biotechnology and standard powder coatings

Figure 1 compares the performance of albecor bio products of Hansen company with that of traditional albester oil-based polyester products of Hansen company

Figure 2 shows that albecor bio 1510 can be used in applications that require good mechanical properties

Figure 2: albecor bio 1510 can be used in applications that require good mechanical properties

albecor bio 1520 meets the outdoor durability requirements of 50% gloss durability after 300 hours of exposure, as shown in Figure 3. All tests are based on brown ral 8014

Figure 3: albecor bio 1520 meets the outdoor durability requirements of 50% gloss durability after 300 hours of exposure

frosting is another common problem of traditional low-temperature curing polyester, especially in dark series. This is because the migration of oligomers on the surface of the coating reduces the gloss

albecor bio 1510 (recommended for indoor use) and albecor bio 1520 (recommended for outdoor use) with biotechnology will not frost, as shown in Figure 4

Figure 4: albecor bio 1510 and albecor biotm 1520 with biotechnology will not frost

in addition, polyester using biotechnology is suitable for low temperature curing applications, including non-metallic substrates. The adhesion test results of these materials are very good. Table 1 describes the pretreatment required to make the coating better coated on the surface. Table 1: substrate requiring pretreatment and results of coating surface

powder polyester using renewable materials provides many advantages that were difficult to obtain in the past through new technology, including:

◆ the curing time of crosslinking with b-hydroxyalkyl amide at 150 ℃ and 160 ℃ is 15 s and 10 s respectively

◆ good wettability

◆ significantly reduce frosting

◆ suitable for non-metallic substrates

◆ outdoor durability

◆ reduce dependence on non renewable resources

◆ it can also be cured at 140 ℃

Author: Donato Di Lorenzo Andrea Capra, Hexion specialty chemicals company

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