Experiment § Introduction to water-based acrylic
Aqueous
acrylic is a polymer emulsion obtained by acrylic monomers, initiators, and water under the action of an emulsifier, and then heated for emulsification polymerization. Finally, it can be used as an adhesive. This method has the advantages of fast reaction rate, easy control of the reaction, good safety of the emulsion drying process, no solvent pollution, and low price. The emulsifier makes the monomer (oil phase) evenly dispersed in the water (water phase), and the polymer emulsion obtained by polymerization also needs to rely on the emulsifier to be stably stored for a long time without the problem of phase separation. Commonly used emulsifiers can be divided into three types: anionic, cationic, and nonionic. When the emulsifier concentration is high enough, the emulsifier molecules will form micelles, and if the emulsifier concentration is higher, microemulsions will be formed. The droplet size of ordinary emulsions is usually 0.1-10 μm, and the reflection of visible light is remarkable, and it has an opaque, milky appearance. The droplet size of the microemulsion is usually 10nm, which is already a nanoparticle, and the appearance is transparent or translucent. The application of water-based acrylic in adhesives will affect the physical properties of the product by changing the ratio of different monomers, different starting agent concentrations, or different feeding (monomer) speeds. The faster the monomer absorbs the material, the larger the particle size will be. The size of the emulsion particles is also related to the type and dosage of the emulsifier. The more emulsifier, the more particles with small particle sizes will be produced, but the emulsifier should not be too much, too much will cause the instability of the emulsion and phase separation. ※Note: The picture on the left is a successful phase-independent water-based acrylic emulsion. The image on the right is an aqueous acrylic emulsion that failed to phase separation.
─Author: Dr. Zhao-An, Chen Everwide Chemical
Activity § Shore Durometer
The Shore Scleroscope, also known as the Shore Durometer, was invented by Albert F. Shore in the 1920s and is mainly used to measure the hardness of polymers, elastomers, and rubbers. According to ASTM D2204-00 (Standard Test Method for Rubber Property - Durometer Hardness) in the United States, Durometer Hardness has a total of 12 grades according to the needs of use, namely A, B, C, D, DO, E, M, O, OO, OOO, OOO-S, and R. The most common of these are A and D. A is used for softer materials and D is used for harder materials.
☆How to choose suitable material and suitable hardness tester: There are various forms of hardness tester due to the difference in spring force, size, and shape of probe. At the same time, according to the hardness of the tested object, the characteristics of different materials and the surface shape, and the specifications of various industrial countries, we have designed and produced a full range of models with a wide range of applications. The shore durometer currently used by Everwide Chemical are TPYE OO, A, and D.
OO TYPE：suitable for super-soft rubber, foam rubber, OA machines and other charged rollers, konjac, chewing gum.
A TYPE： Suitable for general rubber, synthetic rubber, soft plastics, tires, rubber rollers, rubber hoses, and when it is less than D20.
D TYPE：used for hard rubber, plastic, hard rubber (ebonite), higher than A90.
☆Measurement method of the tested object: Firmly fix the pressing surface (manometer surface) of the durometer with both hands, and press it vertically on the plane of the tested object at a certain speed from right above. When the pressing surface of the durometer is in close contact with the tested object, immediately read the indicated maximum value, which is called "hardness".
☆Measurement conditions: the choice of the measurement position: the inner side of the edge of the object to be measured is more than 12mm. 1. Distance between test points: more than 6mm. 2. Thickness of the tested object: general type/6mm or more, E type/10mm or more. 3. Hardness value: the average/median value of the five tested points. 4. Representation: If the test result is 50 degrees of A-type, it will be expressed as "A50". 5. Test environment: temperature (23±2℃), humidity (50±5)%RH.
─Author: Assistant R&D Engineer Miss Zhang Shuping Everwide Chemical
Knowledge § What are the main ingredients of UV glue?
Acrylic UV glue is mainly composed of (1) oligomer (Oligomer), (2) monomer (Monomer), and (3) initiator (Initiator), which will be added according to the application category other additives, such as anti-sag agent, defoamer, etc.
Living § Why develop the IMD industry?-My long R&D road(1)
In the past ten years, the utilization rate of mobile phones and notebooks has increased rapidly, which relatively leaves a lot of room for the development of the surface decoration of the case. Therefore, the IMD-related industries are booming, which makes every manufacturer rack their brains to present their ideal laptop and mobile phone cases to everyone. Whether it is the fast mass production IMR process or a small amount of diversified IMF processes, or the presentation of personalized digital printing methods, plastic film manufacturers, mold punching equipment manufacturers, ink manufacturers, automated machinery manufacturers, and printing press manufacturers are all looking forward to there will be breakthroughs in this market. Everwide Chemical Co., Ltd. is a customized chemical formulation factory in Taiwan. We have been entrusted by customers for a long time to develop rubber species suitable for various projects. In the field of IMD, the types of glues we have developed include chemical primer treatment glue for PC plastic sheet, chemical primer treatment glue for metal sheet, UV type extended three-dimensional texture glue, UV type extended Hard Coating texture glue, UV type extended ink, Leather lamination heat transfer glue, mirror silver brightness protective glue, PRIMER between layers, UV type anti-flushing glue, etc. In recent years, we have developed various products to solve related applications in the IMD industry. Customers want to maintain the gloss of mirror silver in the process, so a non-solvent adhesive is developed to protect the silver brightness. I only started to get acquainted with the IMD industry when I developed this group of products 6-7 years ago. For me, such a small amount of glue can't satisfy my curiosity about the overall industry and I hope to develop other ink adhesive markets in the IMD industry. In recent years, I have participated in various seminars at home and abroad and actively exchanged technical knowledge with scholars on both sides of the Taiwan Strait. Only then did I realize that the IMD industry turned out to be a very deep and challenging professional field.
─Author: Ms. Miao-Ling, Lin R&D Engineer, Everwide Chemical
