scholarly journals Manufacture and Characteristics of Oil-Modified Refined Lacquer for Wood Coatings

Author(s):  
Chia-Wei Chang ◽  
Hsiu-Ling Lee ◽  
Kun-Tsung Lu

Oriental lacquer, a natural and renewable polymeric coating, comes from the sap produced by lacquer trees. For practical application, oriental lacquer must be refined to reduce excess water and enhance its quality. In this study, drying oils were blended with oriental lacquer during the refining process to prepare an oil-modified refined lacquer (OMRL). The type and adding amount (0, 10, and 20% by wt.) of drying oils for wood coatings utilization were evaluated. Rhus succedanea oriental lacquer is composed of 54.1% urushiols, 34.3% water, 7.2% plant gum, and 4.4% nitrogenous compounds, and drying oils, including tung oil (TO), linseed oil (LO), and dehydrated castor oil (DCO) were used as materials in this study. The results show that the drying oil acts as a diluent, which reduces the viscosity and enhances the workability and could shorten the touch-free drying time and speed up the hardened drying of the OMRL. The results also indicate that the hardness, mass retention, Tg, tensile strength, abrasion resistance, and lightfastness of OMRL films decrease as more drying oils are blended. Conversely, the bending resistance, elongation at break, impact resistance increase, and particularly, the gloss, is greatly improved through the blending of more drying oils. In conclusion, the LO-modified refined lacquer (RL) has the highest film gloss and the DCO-modified RL has the shortest drying time for coating; otherwise, the film properties are similar among the three types of drying oil.

Coatings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 11 ◽  
Author(s):  
Chia-Wei Chang ◽  
Hsiu-Ling Lee ◽  
Kun-Tsung Lu

Oriental lacquer, a natural and renewable polymeric coating, comes from the sap produced by lacquer trees. For practical applications, oriental lacquer must be refined to reduce its water content and enhance its quality. In this study, drying oils were blended with oriental lacquer during a refining process to produce oil-modified refined lacquer (OMRL). Rhus succedanea lacquer, composed of 54.1% urushiols, 34.3% water, 7.2% plant gum, and 4.4% nitrogenous compounds, and drying oils, including tung oil (TO), linseed oil (LO), and dehydrated castor oil (DCO), were used as materials in this study. The effect of type and amount (0%, 10%, and 20% by wt %) of drying oils added to lacquer on lacquer properties were evaluated. Results show that the drying oils acted as a diluent, which reduced the viscosity, and enhanced workability, shortened touch-free drying time and accelerated the hardened drying of the OMRL. The results also indicated that the hardness, mass retention, Tg, tensile strength, abrasion resistance, and lightfastness of OMRL films decreased as more drying oils were blended with lacquer. Conversely, the bending resistance, elongation at break, impact resistance increased. Gloss was greatly improved through the blending of more drying oils with lacquer. In conclusion, the LO-modified refined lacquer (RL) had the highest film gloss and the DCO-modified RL had the shortest drying time for coating. Otherwise, the film properties were similar among the three types of drying oils.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 990
Author(s):  
Chia-Wei Chang ◽  
Jia-Jhen Lee ◽  
Kun-Tsung Lu

Oriental lacquer is a natural polymeric coating with a satiny texture and excellent characteristics, such as chemical resistance and durability. However, the poor lightfastness resulted in the natural aromatic structures of the urushiol structures limited its suitability for outdoor application. This study aimed at the improvement of the lightfastness by adding the different hindered amine light stafbilizers (HALS) with 2 phr addition as well as the effects on the coating and film property of the refined oriental lacquers (RL). The Cryptomeria japonica plate, glass sheets, and the other substrates were used for finishing. The results showed that the lightfastness of RL film was obviously improved by adding 2 phr HALS of Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (H90) containing -NH group and Bis (1,2,2,6,6-pentamethyl-4-piperidinyl)-[[3,5-bis(1,1-dimethyl ethyl) -4-hydroxyphenyl] methyl] butylmalonate (H60) containing -NCH3 groups. The HALS additions increased the pH value of RL and improved the activities of laccase-catalyzed reaction. Meanwhile, the oxidative polymerization of the side chains of RL was inhibited, caused by a radical scavenging ability of HALS. The changes in the drying process affected not only the curing time, but also the film properties. Among the 2 phr additions of different HALS, the film containing H90 had the best lightfastness. Meanwhile, it kept the most similar properties with RL and shortened the drying time of RL, and it was selected as the best HALS addition under 2 phr in this study.


Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 223 ◽  
Author(s):  
Xiaoxing Yan ◽  
Lin Wang ◽  
Xingyu Qian

The effect of the coating process on the properties of reversible thermochromic waterborne coating on the surface of Chinese fir was examined. The results demonstrated that the most critical process parameter affecting the color difference and gloss of the coating was the way of adding thermochromic ink. The coating process had little influence on the adhesion, impact resistance adding, liquid resistance, and original properties of the coating. There was no obvious gloss variation in the coating under different coating processes. For the (3+3) layered coatings, when the thermochromic ink was added to the topcoats, the discoloration performance was the most obvious and the comprehensive performance of coating was better. Meanwhile, the gloss was 55.6%, the adhesion grade was grade 0, the impact resistance was 5.0 kg·cm, the liquid resistance grade of the coating to sodium chloride, ethanol and detergent was grade 1, and the liquid resistance grade to red ink was grade 3. The discoloration performance of the coating was stable under the conditions of aging and time change. This study provides new insight into preparing thermochromic intelligent waterborne wood coatings with potential practical applications on Chinese fir wood surfaces, and also lays a foundation for its application in furniture engineering.


Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 444 ◽  
Author(s):  
Xiaoxing Yan ◽  
Lin Wang ◽  
Xingyu Qian

The effect of adding wheat straw powder after lignin removal (WSPALR) and high-temperature calcined WSPALR on the hardness, adhesion, and resistance to impact, color difference, and mold resistance of waterborne coatings was studied. The results showed that the hardness was the highest of 6H when the concentration of WSPALR was 1.0%–2.0%. WSPALR and high-temperature calcined WSPALR had little effect on the adhesion and impact resistance of waterborne coatings, and the resistance to impact was about 10.0 kg cm. When both the concentration of WSPALR and high-temperature calcined WSPALR were 0.5%, the waterborne coating had the best adhesion of Level 1. The addition of high-temperature calcined WSPALR maintained the color difference of the original coatings. A high WSPALR concentration showed better mold resistance than a low concentration WSPALR, and the inhibition effect of high-temperature calcined WSPALR on Trichoderma was better than that of WSPALR. When the concentration of WSPALR calcined at a high temperature was 0.5%, it showed a better hardness of 4H, Level 1 adhesion, 10.0 kg cm resistance to impact, and 1.1 color difference of the waterborne coating. This work has important application value for mold resistance of wood coatings.


Author(s):  
Nguyen Trung Thanh

The article introduces the modification of alkyd resin by epoxy resin to make epoxy alkyd ester. The study investigated the effects of reflux xylene content, the proportion of the constituents participating in the esterification reaction on the reaction processing and acidity index of the product. The infrared (IR) spectroscopy results confirmed the formation of ester bonds after the reaction. The paper also studied the mechanical properties of paint film based on the synthesized ester epoxy alkyd and compared them with the alkyd paint, the results showed that impact resistance and hardness of the study sample were higher than those of the alkyd paint sample. In addition, investigation, comparison of thermal stability of alkyd paint and epoxy alkyd paint film were also mentioned. Keywords: Epoxy alkyd esters, mechanical properties, thermal endurance, drying time.


Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 635 ◽  
Author(s):  
Yan ◽  
Chang ◽  
Qian

Wood surface decoration and protection has become a topic of public concern. In this paper, a temperature-sensitive and reversible thermochromic waterborne wood coating was prepared by using Chinese fir board as the base material and a waterborne wood coating with the pigment slurry of thermochromic microcapsules as the paint base. The optical properties, mechanical properties and chemical resistance of the waterborne wood coating were tested, and its microstructure was analyzed. The results showed that when the concentration of thermochromic pigment slurry was 30.0%, the thermochromic property of the waterborne wood coating was best. The gloss of the waterborne wood coating with 15.0% pigment slurry of thermochromic microcapsules was high. The concentration of thermochromic pigment slurry had no effect on the adhesion, impact resistance, or chemical resistance of the waterborne wood coating. Based on the above results, the waterborne wood coating on Chinese fir had the best comprehensive performance when the concentration of thermochromic pigment slurry was 15.0%. This work will provide a technical reference for the industrialization of the thermochromic coating film on wood.


2013 ◽  
Vol 2 (2) ◽  
pp. 81-86 ◽  
Author(s):  
Moh Djaeni ◽  
S.B. Sasongko ◽  
A.J.B. Van Boxtel

Drying is a basic operation in wood, food, pharmaceutical and chemical industry. Currently, several drying methods are often not efficient in terms of energy consumption (energy efficiency of 20-60%) and have an impact on product quality degradation due to the introduction of operational temperature upper 80oC. This work discusses the development of adsorption drying with zeolite to improve the energy efficiency as well as product quality. In this process, air as drying medium is dehumidified by zeolite. As a result humidity of air can be reduced up to 0.1 ppm. So, for heat sensitive products, the drying process can be performed in low or medium temperature with high driving force. The study has been conducted in three steps: designing the dryer, performing laboratory scale equipment (tray, spray, and fluidised bed dryers with zeolite), and evaluating the dryer performance based on energy efficiency and product quality. Results showed that the energy efficiency of drying process is 15-20% higher than that of conventional dryer. In additon, the dryer can speed up drying time as well as retaining product quality.


Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 35 ◽  
Author(s):  
Xiaoxing Yan ◽  
Lin Wang ◽  
Xingyu Qian

An aluminum/waterborne acrylic coating was developed by orthogonal experiments, and the gloss, emissivity, chromatic distortion, hardness, adhesion, impact resistance, and corrosion resistance of the coatings were examined. The results showed that the effect of drying time on the infrared emissivity of coatings was more significant than that of the Al powder concentration and nano-silica slurry. When the drying time was prolonged from 0.5 to 6.0 min, the gloss of the coating decreased slowly and the gloss remained low. The infrared emissivity first decreased and then increased. The infrared emissivity of coatings dried for 2.0 min was better. The L’ value gradually decreased and showed a small change of range. With the increasing of the drying time, the hardness of the coating gradually decreased and was the highest at 0.5–2.0 min. The drying time had no effect on the adhesion level. The impact resistance of the coating was better during the drying period of 1.0–3.0 min. The corrosion resistance of the coating was better at 2.0 min. When the drying time was 2.0 min, the waterborne coating showed the better comprehensive performance. This study provides new prospects in using low infrared emissive coatings for infrared stealth and compatibility with visible light.


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