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The crosslinking agent of phenol-formaldehyde modified phenolic aldehyde coatings
2017-7-16 17:20:59
The crosslinking agent of phenol-formaldehyde modified phenolic aldehyde coatings
The e-20 epoxy resin, respectively with polyamide resin and cashew phenol, modified phenolic amine crosslinking, exposed the film to the sun, the detection of color difference; Use ultraviolet radiation to detect film performance.
Found that cashew phenol modified phenolic aldehyde amine crosslinking agent than the rate of polyamide make epoxy paint film yellow, ultraviolet (uv) light color on the former influence is bigger, so one polyamide is suitable for epoxy crosslinking agent, cashew phenol modified phenolic aldehyde amine epoxy primer crosslinking agent is suitable for.
Currently, there are two main types of crosslinking agent for epoxy resins: polyamide resin and cashew phenol modified phenolic amine crosslinking agent. Epoxy resin and polyamide resin have good film elasticity and long construction period. The two-component paint, which is prepared by the modified phenolic aldehyde crosslinking agent, can be constructed in low temperature and humid environment, with a high hardness of paint film, but the application period is shorter. The properties of polyamide resin and cashew modified phenolic resin modified epoxy paint have been widely introduced.
Easy pulverization of epoxy resin, the vast majority of epoxy paint used in primer and coating, is not suitable for used as paint, and relevant literature to introduce both the changes of the color of the exposure is less, but sometimes needs to be used as paint, epoxy paint so color changing degree of the components of the crosslinking agent put forward certain requirements.
In this paper, at the same pigment and YanJi than under the condition of same use with epoxy value of epoxy resin as film forming resin, with the same value of polyamide resin and cashew phenol modified phenolic aldehyde amine as crosslinking agent, the epoxy group and lively hydrogen equivalent ratio is 1:1 the preparation of paint film, and in the natural light exposure, test data, the color change of the paint film compared two kinds of color changing speed and ultraviolet light crosslinking agent on the film performance, the influence of crosslinking agent for epoxy anticorrosive system lays an experimental basis for the construction of supporting.
Test instrument color difference instrument, konica minolta cr-10; Film thickness gauge. 2.2 main raw material resin: 60% e-20 epoxy resin; Crosslinking agent: polyamide resin, cashews modified phenolic amine; Pigment: RCL595 titanium white powder; Solvent: xylene, cyclohexanone and butanol; Assistant: byk-300, tego-n.
Chinese name: Diethyl toluene diamine(DETDA)
Chinese alias: aryl, aryl diethyl - aryl - methyl-p-phenylenediamine
English name: Benzenediamine, ar, ar-diethyl-ar-methyl-English aliases:Diethyltoluenediamine; ar, ar-Diethyl-ar-methylbenzenediamine;Diethylmethylbenzenediamine;
CAS No. :68479-98-1
EINECS No. :270 -877-4
Molecular formula: C11H18N2
Molecular Weight: 178.28
Boiling point: 310 ℃
Refractive index: 1.581
Flash Point: > 140 ℃
Inchi: InChI = 1/C11H18N2/c1-4-8-6-7 (3) 10 (12) 11 (13) 9 (8) 5-2/h6H ,4-5,12-13H2 ,1-3H3 density : 1.022
Risk Codes: R10; R35
RIDADR: UN 3082
Safety instructions: S2; S26; S39; S61
Packing Group: III
Chinese name: Diethyl toluene diamine(DETDA)
Chinese alias: aryl, aryl diethyl - aryl - methyl-p-phenylenediamine
English name: Benzenediamine, ar, ar-diethyl-ar-methyl-English aliases:Diethyltoluenediamine; ar, ar-Diethyl-ar-methylbenzenediamine;Diethylmethylbenzenediamine;
CAS No. :68479-98-1
EINECS No. :270 -877-4
Molecular formula: C11H18N2
Molecular Weight: 178.28
Boiling point: 310 ℃
Refractive index: 1.581
Flash Point: > 140 ℃
Inchi: InChI = 1/C11H18N2/c1-4-8-6-7 (3) 10 (12) 11 (13) 9 (8) 5-2/h6H ,4-5,12-13H2 ,1-3H3 density : 1.022
Risk Codes: R10; R35
RIDADR: UN 3082
Safety instructions: S2; S26; S39; S61
Packing Group: III
Hazard Class: 6.1
Paint preparation process
Preparation of group a: the resin, facial filler, solvent and partial defoaming agent were ground to a fine degree of less than 20 mu m, adding the fluidity agent and residual antifoaming agent to filter the filling.
The preparation of group b: the crosslinking agent is put into the well - filled butanol, and after mixing, the filling can be filtered. Preparation of the lacquer film: prepare the paint film according to GB/t9276-1996 "coating natural climate exposure test method", select the steel plate with standard size and material, and deal with steel plate according to standard. After the mixing of the group a and b by 4:1, the paint film was prepared by spraying, and the dry film thickness was controlled at 60 ~ 80 mu m, and the exposure test was conducted after placing 7d.
2 kinds of crosslinking agent crosslinked film exposure compared the data of color difference with polyamide resin crosslinking film model and with cashew phenol modified phenolic aldehyde amine crosslinked film sample placed in liuhe district of nanjing chemical industrial park, the natural conditions for a period of 1 years exposure test, a month will insolate samples compared with standard sample, test film sparkling, rust, pulverization, loss of light and color, the board face blister, rust, pulverization and loss degree of changes in the light, the color difference is bigger, so will change color as the main examine index, testing Δ E (total) color, Δ L (lightness difference), Δ a difference (red/green), Δ b (yellow/blue differences).
In order to further observe the trend of color change, the table 1 data is plotted as a line drawing. Can be seen from the test results, with cashew phenol modified phenolic aldehyde amine crosslinking degree of color change, the film is much larger than in polyamide resin crosslinking degree of color change of paint film, both the ratio of Δ E value of 2 ~ 9, by Δ E = [(Δ L) 2 + (Δ a) 2 + 2] (Δ b) 1/2, it can be seen that cashew phenol modified phenolic aldehyde amine crosslinking degree of color change is bigger, the film is mainly caused by Δ L and Δ b, after exposure is also clear that the example of cashew phenol modified phenolic aldehyde amine become yellow to become dark color degree is greater.
At the same time, the change of color difference between the two is low to high, and the change trend from high to low, which is due to the powder of epoxy film.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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