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The latent coating crosslinking agent
2017-8-11 23:49:02
The latent coating crosslinking agent
Diethyltoluenediamine Uses:
Latent coating crosslinking agent is to point to room temperature in the epoxy resin has a long shelf life and the action such as by heating or ultraviolet light, can quickly up the crosslinking reaction of compound classification according to additional energy. It is a key raw material for preparing single component epoxy resin adhesive, coating and casting material.
Dicyandiamide is among the first in industry application of epoxy resin latent sexual intercourse agent, as the white crystalline powder, molecular weight 84, 207 ~ 209 ℃, melting point relative density 1.40, soluble in water and ethanol. Because the function of conjugate double bond and cyanotype in the molecule causes the alkyl to replace the alkalinity of guanidine greatly, so that it has a considerable stability at room temperature with the epoxy resin mixture. Due to the high melting point, the high temperature of crosslinking is its biggest drawback, and it is usually used to reduce the crosslinking temperature and increase the crosslinking speed.
The crosslinking of dicyandiamide epoxy resin has good adhesion and non-colouring, and its dosage has an influence on the performance of crosslinking, so it is necessary to choose different dosage according to different USES. In the case of water resistance, the use of a small amount of dicyandiamide is good.
Latent sexual intercourse agent, refers to the join the epoxy resin and its composition of one-component system have certain storage stability at room temperature, and in the heat, light, humidity, pressure and other conditions can quickly on the crosslinking reaction of cross-linking agent. But the latent epoxy resin sex, many different kinds of coupling agent, but each type of cross-linking agent has certain advantages and disadvantages, so far, still have not found a particularly fine performance, the ideal latent sexual coupling agent.
With the current widely used two-component epoxy resin system, compared the latent sexual intercourse agent made from mixed with epoxy resin of one-component epoxy resin system has simplified the operation process, to prevent the pollution of the environment, improve product quality, adapt to the modern large-scale industrialized production, etc.
Chinese name: Diethyl toluene diamine(DETDA)Diethyltoluenediamine Uses:
The product is identical to Ethancure 100 and Lonza DETDA 80, DETDA is very effective polyurethane elastomer chain extender; also be used as polyurethane and epoxy resin curing agent, epoxy resin of an antioxidant, industrial oils and lubricants . In addition, also as intermediates in organic synthesis.Especially for the RIM (reaction injection molding), is important in the field of spray polyurea chain extender species. Also can be used for casting polyurethane elastomer (CPU) and a curing agent, epoxy curing agent, epoxy resin of antioxidants, lubricants and industrial oils other antioxidants.
Latent sexual intercourse agent research generally by physical and chemical means, the common use of low temperature and high temperature of crosslinker crosslinked activity is improved, mainly take the following two improved methods: one is to some high reactivity and the storage stability of crosslinking agent are closed, the reactivity of passivation; The second is to improve the reaction activity of the crosslinking agent with good storage stability and low reaction activity.
Eventually reach the crosslinking agent added to the epoxy resin at room temperature have certain storage stability, when in use by external conditions, such as light, heat will release activity of crosslinking agent, so as to achieve the aim of making quick crosslinked epoxy resin.
Aliphatic amine crosslinking agent such as ethylenediamine, hexamethylenediamine, divinyl three amine, like triethylene tetramine are used in the two-component epoxy crosslinking agent at room temperature, by the methods of chemical modification, with the organic ketone compounds nucleophilic addition reaction, dehydration generated imine is a closed, reduce its crosslinking activity, the effective way of improving its storage stability.
The one-component system of the ketoylamine crosslinking agent and epoxy resin is used to decompose ketosamine into amine by the effect of moisture and moisture, so that the epoxy resin can be cross-linked at normal temperature. However, the average crosslinking speed is not very fast, and the use period is shorter, because the lone pair of electrons on the ammonia nitrogen still have some open-loop activity.
To solve this problem, with ketone carbonyl ends with three-dimensional block groups, 3 - methyl - 2 - butanone and highly reactive diamine methyl cyclohexane reaction of 1, 3 two ammonia ketone imide not only has high cross-linking reactivity, and storage stability is obviously improved.
The polyether modified aliphatic amine and methyl-isobutyl ketone reaction are also a good - performance epoxy resins. By the reaction of acrylonitrile and organic phosphine compounds, the transition metal complexes can reduce the crosslinking reaction activity and thus have some latent latent properties.
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