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Epoxy resin coating is used to crosslink the acid anhydride
2017-5-5 10:59:00
Epoxy resin coating is used to crosslink the acid anhydride. The characteristics of acid anhydride as the crosslinking agent of epoxy resin are: the crosslinking reaction is slow and the heat is gentle, the cross-linking coating is small; High temperature of crosslinked heat deformation, film resistance to chemical properties, ultraviolet and heat resistance. Coating mechanics and excellent performance. As a result, it is mainly used in electronic electrical insulation.
On the other hand, as epoxy crosslinking agent, it has the following disadvantages: it is very wet; In the case of crosslinking, there is a carbon dioxide out, which makes the inside of the coating a pinhole. Most solid acid anhydride is easy to sublimate, the construction has strong pungent smell. Due to poor performance of cross-linked coating, it is less used in ornamental powder coatings.
Because anhydride itself does not contain active hydrogen, cannot be directly react with epoxy group, must add crosslinking accelerator open the anhydride ring first, commonly used promoters have mentioned imidazole and its derivatives as well as on the quaternary ammonium salt, quaternary phosphonium salt Weng salts, etc.
In principle, all low-molecular acid anhydride, such as phthalic anhydride, maleic anhydride and biphthalic anhydride, can be used in epoxy resins. Some varieties, such as trimellitic anhydride (TMA), and all four benzene acid dianhydride, although for can obtain better performance of coating has been widely used, but because of its toxicity and has certain strong excitant and easy sublimation release, therefore has gradually been banned.
Other commonly used there are four hydrogen of benzene anhydride type epoxy crosslinking agent (THPA) dimethyl anhydride, methyl hydrogen dimethyl benzene anhydride (MTHPA), 3, 3 ', 4, 4 '- phenyl ketone four acid dianhydride (BTDA), poly (azelaic acid anhydride and kwai anhydride, etc.
Acid anhydride is the part of an oxygenate that removes a molecule of water or several molecules of water. The common inorganic acid is a molecule of this acid, and the acid anhydride of the acid is formed by the loss of a molecule of water directly from the molecule, which determines the valence of the acid in the acid anhydride. And organic acids are two molecules of this acid or a molecule that is formed by the dehydration of molecules. Only oxygenic anhydride is found in the oxygenic acid. Anoxic acid is without acid anhydride.
Chinese name: Diethyl toluene diamine(DETDA)
Diethyltoluenediamine Raw material ：
TDA industrial, Sichuan production
Ethylene (Et) polymer grade, Shanghai production
TEA industrial imports
A reagent grade additives
Acid anhydride is generally considered to be an oxide of acid, which is not an oxide of organic acids. Many of the acids that can be used again with water.
According to the properties of acids:
(1) the acid anhydride of inorganic acid is reduced by one or two acids. For example, carbon (acid) anhydride is carbon dioxide (CO2), nitric oxide (acid) anhydride, or nitrous oxide N2O5.
(2) the acid anhydride of organic acids is a compound that is reduced by two mono-acid molecules or a divalent molecule, although not oxide, also known as acid anhydride. For example, b (acid) anhydride (CH3CO) and phthalic anhydride (C8H4O3).
"Acid anhydride is the acid oxide" is true in a certain range. Acid anhydride is formed by acid dehydration, and the acid oxide is an oxide that reacts with a base to produce salt and water. Conceptually, the two are not equivalent. Anhydride in inorganic chemistry is the formation of acid dehydration, and the vast majority of oxide, so they can be equal, but in organic chemistry, many organic acids are not oxide after dehydration, such as acetic acid (CH3COOH), dehydrated to form acetic anhydride ((C4H6O3, (CH3CO) 2 o), so it can't be acidic oxides.
A compound of acid dewatering, such as a carbonic acid molecule (H2CO3), that shrinks to a molecule of water (H2O), the remaining carbon dioxide (CO2) is carbonic anhydride. Two vinegar molecules (CH3COOH) are reduced to a molecule of water (CH3CO), which is the acetic anhydride.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
On the other hand, as epoxy crosslinking agent, it has the following disadvantages: it is very wet; In the case of crosslinking, there is a carbon dioxide out, which makes the inside of the coating a pinhole. Most solid acid anhydride is easy to sublimate, the construction has strong pungent smell. Due to poor performance of cross-linked coating, it is less used in ornamental powder coatings.
Because anhydride itself does not contain active hydrogen, cannot be directly react with epoxy group, must add crosslinking accelerator open the anhydride ring first, commonly used promoters have mentioned imidazole and its derivatives as well as on the quaternary ammonium salt, quaternary phosphonium salt Weng salts, etc.
In principle, all low-molecular acid anhydride, such as phthalic anhydride, maleic anhydride and biphthalic anhydride, can be used in epoxy resins. Some varieties, such as trimellitic anhydride (TMA), and all four benzene acid dianhydride, although for can obtain better performance of coating has been widely used, but because of its toxicity and has certain strong excitant and easy sublimation release, therefore has gradually been banned.
Other commonly used there are four hydrogen of benzene anhydride type epoxy crosslinking agent (THPA) dimethyl anhydride, methyl hydrogen dimethyl benzene anhydride (MTHPA), 3, 3 ', 4, 4 '- phenyl ketone four acid dianhydride (BTDA), poly (azelaic acid anhydride and kwai anhydride, etc.
Acid anhydride is the part of an oxygenate that removes a molecule of water or several molecules of water. The common inorganic acid is a molecule of this acid, and the acid anhydride of the acid is formed by the loss of a molecule of water directly from the molecule, which determines the valence of the acid in the acid anhydride. And organic acids are two molecules of this acid or a molecule that is formed by the dehydration of molecules. Only oxygenic anhydride is found in the oxygenic acid. Anoxic acid is without acid anhydride.
Chinese name: Diethyl toluene diamine(DETDA)
Diethyltoluenediamine Raw material ：
TDA industrial, Sichuan production
Ethylene (Et) polymer grade, Shanghai production
TEA industrial imports
A reagent grade additives
Acid anhydride is generally considered to be an oxide of acid, which is not an oxide of organic acids. Many of the acids that can be used again with water.
According to the properties of acids:
(1) the acid anhydride of inorganic acid is reduced by one or two acids. For example, carbon (acid) anhydride is carbon dioxide (CO2), nitric oxide (acid) anhydride, or nitrous oxide N2O5.
(2) the acid anhydride of organic acids is a compound that is reduced by two mono-acid molecules or a divalent molecule, although not oxide, also known as acid anhydride. For example, b (acid) anhydride (CH3CO) and phthalic anhydride (C8H4O3).
"Acid anhydride is the acid oxide" is true in a certain range. Acid anhydride is formed by acid dehydration, and the acid oxide is an oxide that reacts with a base to produce salt and water. Conceptually, the two are not equivalent. Anhydride in inorganic chemistry is the formation of acid dehydration, and the vast majority of oxide, so they can be equal, but in organic chemistry, many organic acids are not oxide after dehydration, such as acetic acid (CH3COOH), dehydrated to form acetic anhydride ((C4H6O3, (CH3CO) 2 o), so it can't be acidic oxides.
A compound of acid dewatering, such as a carbonic acid molecule (H2CO3), that shrinks to a molecule of water (H2O), the remaining carbon dioxide (CO2) is carbonic anhydride. Two vinegar molecules (CH3COOH) are reduced to a molecule of water (CH3CO), which is the acetic anhydride.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
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