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Predecessor
Volume 41, Issue 6
Displaying 1-5 of 5 articles from this issue
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Yoshiaki MOTOYAMA, Osamu OHE, Tatsuo SATO1968 Volume 41 Issue 6 Pages 275-278
Published: June 30, 1968
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSA water-soluble resin was synthetized by the addition reaction of fumaric acid (1. 6 moles) to chinese tung oil (1.0 mole), which was neutralized with triethylamine, and its aqueous solution was used for electrodeposition. It was found that the acid. value of the electrodeposited resin was lower (142~150), and that of the resin extracted from the remaining solution was higher (179) than that of the original resin (171). It is suggested that polymer molecules having smaller number of COO-groups. are selectively electrodeposited since these molecules require smaller number of H+ ions to become water-insoluble. Although polymer molecules having larger number of COO-groups would have higher rate of electrophoresis, the rate of diffusion which would arise because of the concentration increase near the anode during the process of electrodeposition is also expected to be high, and thus this pre-equilibrium step would not contribute to the observed selectivity of electrodeposition.View full abstractDownload PDF (464K) -
Yukio NOMURA, Toyohiko YOSHIDA, Toshio KAKURAI, Tatsuya NOGUCHI1968 Volume 41 Issue 6 Pages 279-284
Published: June 30, 1968
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSThe methylol reactions of phenylacetoguanamine, isobutyloguanamine and ω-cyanovaleloguanamine with formaldehyde were studied in dioxane-water mixture (1 : 1 by volume).
The functionalities of these compounds against formaldehyde were found to be 3. 6, 3. 6 and 3. 5, respectively. The rate constants and equilibrium constants were determined under the conditions of formaldehyde/guanamine mol ratio 4. 0 and pH 9.2-9.5, and the following results were obtained.
Guanamine Derivative Reaction Temperature (°C) Rate Constant (mole-1. min-1) Equilibrium Constant
Phenylaceto guanamine 30 2.2 X 10-2 6.67 40 4.4 X 10-2 5.87 50 9.3 X 10-2 5.05 60 27.6 X 10-2 4.31
iso-Butylo guanamine 30 1.1 X 10-2 7.31 40 2.6 X 10-2 6.46 50 6.0 X 10-2 5.21 60 14.1 X 10-2 4.46
w-Cyanovalelo guanamine 30 1.6 X 10-2 7.23 40 3.7 X 10-2 6.38 50 8.6 X 10-2 5.12 60 31.6 X 10-2 4.38
The activation energies were 16. 9, 17.0 and 18.5 kcal/mol, the heats of reaction were 3.1, 3.3 and 3.3 kcal/mol, respectively. It is suggested that the reaction mechanisms for these reactions were essentially the sameView full abstractDownload PDF (598K) -
Osamu OHE1968 Volume 41 Issue 6 Pages 285-289
Published: June 30, 1968
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSStatistical calculations suggested that the poor reactivity of hexakis- (methoxymethyl) -melamine (H MM) as crosslinking agent could be improved if the melamine nuclei were linked together in order to increase the number of methoxy groups per molecule. Since at least two out of six methoxy groups of an HMM molecule have to react for this molecule to provide a crosslinking site, it turned out that most of the HMM molecules would only act as diluent or branching agent at best unless the extent of reaction is very high. If two HMM molecules were linked together, the number of methoxy groups per molecule would become ten, thus increasing the chance for this molecule to become a crosslinking site. The calculations suggested that higher crosslinking densities could be obtained with the latter.
Polycondensation of HMM was carried out by two methods, using a commercial grade HMM (mol. wt. 434). In the first method HMM was heated in the presence of 80% HCOOH (2. 5 wt. %) at 130-140°C for 35 hrs. to give a resinous product of mol. wt. 891. In the second method a mixture of 248 parts ethylene glycol, 7,800 parts HMM and 80% HCOOH (0.1 wt. %) was heated to 120-130°C for 3 hrs. to give another resinous product of mol. wt. 975. For the purpose of estimating the relative crosslinking efficiencies of HMM and its polycondensates, glass transition temperature and pencil hardness of the paint films cured with these crosslinking agents were measured. From the experimental results it has become clear that such polycondensates are better crosslinking agents than HMM when used at the same weight level.View full abstractDownload PDF (611K) -
Takeo IMAI1968 Volume 41 Issue 6 Pages 290-295
Published: June 30, 1968
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSDownload PDF (870K) -
Organic Pigments for Dope DyeingKiyoshi HASHIZUME1968 Volume 41 Issue 6 Pages 296-309
Published: June 30, 1968
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSDownload PDF (1746K)
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