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Coating crosslinking agent for phenolic resin
2017-7-26 17:57:24
Coating crosslinking agent for phenolic resin
Phenol and formaldehyde in synthetic reaction equipment, through the addition and the appropriate resin obtained by polycondensation reaction, usually is not high molecular weight of oligomer and a variety of hydroxymethyl phenol mixture system, although there are differences of Novolaks and Resoles structure is, but they are all from the physical properties should be soluble and fusible.
Such soluble and meltability makes them easy to dip filler reinforced materials of various types of plastics used in the production form and performance of a variety of plastic products, also facilitate used as adhesives, ChengMo agent, functional additives used in refractory materials, casting molding materials, friction materials, coatings, electronic packaging materials, and other office areas.
Phenolic resin, however, only in the form in network shape (or size) structure before it has excellent performance, including mechanical properties, electrical insulation, chemical stability, thermal stability, etc.
Phenolic resin crosslinking is to make it into a process of mesh structure, show the gelation and crosslinking of two phases completely, the shift is not only a physical process, more is to emphasize that this is a chemical process. So phenolic resin crosslinking is not melt cooling below the melting point of a general sense of crosslinking, but by a line in the polymer chemistry concept (a) type cross-linking (cure) reticulate molecules lead to the loss of soluble, meltability crosslinking.
After the phenolic resin has been crosslinked, it loses its soluble, fusible and can not be machinable after obtaining the fine physical properties. Therefore, the crosslinking process must be completed in the process of using phenolic resin (Novolaks or Resoles) as a binder consisting of plastic, paint coatings and various engineering materials.
Because the crosslinking process of phenolic resin is essentially a chemical reaction process, the following characteristics are shown:
(1) the structural factors (composition, molecular weight, reaction degree, etc.) of resin before crosslinking are significant;
(2) the crosslinking reaction was significantly affected by the catalyst, phenolic resin used crosslinking agent, resin pH value, etc.;
(3) the crosslinking process has a thermal effect;
Chinese name: Diethyl toluene diamine(DETDA)
Diethyltoluenediamine Uses:
Phenol and formaldehyde in synthetic reaction equipment, through the addition and the appropriate resin obtained by polycondensation reaction, usually is not high molecular weight of oligomer and a variety of hydroxymethyl phenol mixture system, although there are differences of Novolaks and Resoles structure is, but they are all from the physical properties should be soluble and fusible.
Such soluble and meltability makes them easy to dip filler reinforced materials of various types of plastics used in the production form and performance of a variety of plastic products, also facilitate used as adhesives, ChengMo agent, functional additives used in refractory materials, casting molding materials, friction materials, coatings, electronic packaging materials, and other office areas.
Phenolic resin, however, only in the form in network shape (or size) structure before it has excellent performance, including mechanical properties, electrical insulation, chemical stability, thermal stability, etc.
Phenolic resin crosslinking is to make it into a process of mesh structure, show the gelation and crosslinking of two phases completely, the shift is not only a physical process, more is to emphasize that this is a chemical process. So phenolic resin crosslinking is not melt cooling below the melting point of a general sense of crosslinking, but by a line in the polymer chemistry concept (a) type cross-linking (cure) reticulate molecules lead to the loss of soluble, meltability crosslinking.
After the phenolic resin has been crosslinked, it loses its soluble, fusible and can not be machinable after obtaining the fine physical properties. Therefore, the crosslinking process must be completed in the process of using phenolic resin (Novolaks or Resoles) as a binder consisting of plastic, paint coatings and various engineering materials.
Because the crosslinking process of phenolic resin is essentially a chemical reaction process, the following characteristics are shown:
(1) the structural factors (composition, molecular weight, reaction degree, etc.) of resin before crosslinking are significant;
(2) the crosslinking reaction was significantly affected by the catalyst, phenolic resin used crosslinking agent, resin pH value, etc.;
(3) the crosslinking process has a thermal effect;
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.
(4) the crosslinking rate is significantly affected by temperature and pressure;
(5) there are by-products (such as water, formaldehyde, etc.) produced by the crosslinking process;
(6) crosslinking is an irreversible process.
Thermoplastic phenolic resin crosslinking. The structure of Novolak resin, n is generally 4 ~ 12, and its value size is related to the excess of phenol and reaction time in the initial reaction material. These resins of industrial production control the size of n, which is the size of the molecular weight, depending on the application domain. For example, when the average bamboo value is 5, the average molecular weight (Mn) is around 500.
Novolak resin synthesis is one of the basic conditions on the mole ratio of phenol, formaldehyde is not enough, so the structure of unreacted hydroxyl methyl basic will not exist, so Novolaks is unlikely to happen on its own crosslinking and crosslinking reaction. However, the phenolic nuclei in the resin structure have an unresponsive activation point, so as long as the formaldehyde is added, the crosslinking reaction can be formed in the heating condition to form a network structure and crosslinking.
In order to make the Novolak resin crosslinking, phenolic resin used crosslinking agent is the most common one is hexamethylenetetramine (uloto), and other polyformaldehyde, Resole phenolic resin and aniline are also available.
Six methylene tetramine (HMTA) is adduct with formaldehyde, ammonia it decompose under more than 100 ℃, 2 methyl alcohol amine and release of formaldehyde and ammonia, which react with linear phenolic resin molecules, crosslinking.
The cross-linking reaction of HMTA as Novolak crosslinking agent has not been studied, but there are some preliminary results.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
(4) the crosslinking rate is significantly affected by temperature and pressure;
(5) there are by-products (such as water, formaldehyde, etc.) produced by the crosslinking process;
(6) crosslinking is an irreversible process.
Thermoplastic phenolic resin crosslinking. The structure of Novolak resin, n is generally 4 ~ 12, and its value size is related to the excess of phenol and reaction time in the initial reaction material. These resins of industrial production control the size of n, which is the size of the molecular weight, depending on the application domain. For example, when the average bamboo value is 5, the average molecular weight (Mn) is around 500.
Novolak resin synthesis is one of the basic conditions on the mole ratio of phenol, formaldehyde is not enough, so the structure of unreacted hydroxyl methyl basic will not exist, so Novolaks is unlikely to happen on its own crosslinking and crosslinking reaction. However, the phenolic nuclei in the resin structure have an unresponsive activation point, so as long as the formaldehyde is added, the crosslinking reaction can be formed in the heating condition to form a network structure and crosslinking.
In order to make the Novolak resin crosslinking, phenolic resin used crosslinking agent is the most common one is hexamethylenetetramine (uloto), and other polyformaldehyde, Resole phenolic resin and aniline are also available.
Six methylene tetramine (HMTA) is adduct with formaldehyde, ammonia it decompose under more than 100 ℃, 2 methyl alcohol amine and release of formaldehyde and ammonia, which react with linear phenolic resin molecules, crosslinking.
The cross-linking reaction of HMTA as Novolak crosslinking agent has not been studied, but there are some preliminary results.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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