Document ommM7JZEK3a5B0LoXeva4Zy33

OC; Or Bommi KcBurosy, Mils., jv Dr, R,B* Davis, Flint Gross Index? Dr. 1,S`, Stone , Parlin /* Refinish Sales Competition Refinish Enamels Baking Reducer J4y* HP. Ether* Chicago Mr* J*W# Jliff, Lab, Mr*' I# Co Lamport, Lab, Mr* S, L, Go&shalk, Lab, W HETUM Til ittl I 1 fflMTR Philadelphia Laboratory September 3.3 s 1949 "INDEXED" APW58 EVALDATIOH AID DEVELOPMENT OF BAKING REDUCERS Introduction: i*fsfTk:i-Lf:-": ^ As a result of several inquiries from the field, the Wilmington Eefinish Sales office has requested the laboratory to make a comprehensive evaluation of our present urea-formaldehyde baking reducer vs* competitive baking reducers and to survey other readily available nitrogen resins with the possibility of develop ing an improved baking reducer. Conclusions-: As a result of this study, the following conclusions may be made: (a) In many instances, competitive baking reducers re quired shorter baking schedules at given temperatures than our present baking reducer to produce the same degree of dry, (b) A new product based on melamine, E&-4#7> s found to provide shorter baking schedules at given temperatures than our present urea-formaldehyde product. In some cases, competitive products were found to be equivalent to RK-4$7* but none of the baking reducers-examined surpassed this product. (c) Resaraiue G&, Ufonnite M-61, and various U-F/melamine mixtures were examined, but none, of those were found to be as good as melamine alone# (d) It was found that the melamine product, EK-437, can be used at 12-1/2$ reduction of enamels and still provide Biinimua baking schedules such as tack-free dry in 1 3/4 hours at 1203F, 1 1/2 hours at 150F, and 1/2 hour at 175P* Our present baking reducer is used at 25$ reduction RK-487 was also found to pro vide films with satisfactory wrinkle resistance' and moisture re sistance when added to an air dry enamel as a baking reducer* (e) With regard to the differences in -viscosity, it may he noted that our 93 Line and 181 Line enamels thinned with RE-5756 in accordance with current directions {%$$>) produced a very thin reduced enamel, while those enamels reduced at 12-1/2$ with RE-437 will usually be thin enough for spraying* In the few cases, where necessary, "Dulux51 thinner may be added* ' * (f) Calculation of costs to Refinish Sales show RK-487 at 41-94/galo compared to #l*30/gal* for RE-5756* However, since RK-487 is used at half the amount of RE-5756, the cost of using the new product will be considerably less. (g) From this study, it was observed that slight yellowing of whites and discoloration of metallic enamels was evident at the higher bakes* There was no noticeable difference between RK-487 and RE-5756 in this respect* Some of the competitive enamels, how ever, did show more discoloration. fe^rialsjsed!! The materials used in this study included RE-5756 (DuPont urea-formaldehyde baking reducer)j experimental baking reducerspre pared from melamine, mixtures of melamine and urea-formaldehyde, Reearning 881, and Uformite MK6l$ and competitive baking reducers* All of the . above reducers were used with 93-508 and 181-10199 enamels* ' In addition, the competitive baking reducers were evaluated when used with their own white air-dry enamels* All of the experimental reducers and RE-5756 were used at' 25$ and 12-1/2$ reduction with 93*508 and with 181-10199 enamels* In addition, the competitive reducers were used with 93*508, with 181-10199, and with their own respective enamels at the reduction suggested by their package directions. The viscosities of all re ducers. enamels, and reduced enamels were measured at 77*1* (for comparison see fable I)* The reduced enamels were sprayed on aluminum alloy panels in two successive coats so that the final dry film thickness was 1.0 & 0.2 mil. Each enamel was applied to three panels so that each enamel could be baked at 120F.`, at 150F* and at 175F* The time required to reach a given state of dry was recorded as the baking schedule at that temperature for that type of dry* The stages of dry were established asi (a) Lint-Free Time The time required at a given baking temperature fqrarfImto"le dry enough so that r&yon lint (sprink led on after the panel had reached room temperature) can be easily brushed off with a camel hair brush. (b) Tack-Free Time - The time required at a given baking temperature forarllm too dry enough that it does not feel DUP030003150 3 tacky at room temperature. (c) Throngfe-DryT&ae * The time required at a given baking temperature for a fiSto be dry with a hardness equivalent to hardness of the air-dr;/ enamel after an overnight air dry. The state of dry of each panel ms examined at 15 minute intervals and the results of this study are noted in Table XI* The panels were also examined for discoloration compared to the color of the air-dry enamel after overnight dry. This eval uation is also noted on Table II. Inasmuch as it appeared that the 12$ melamine solution R&-4S7 used at 12-1/2$ reduction of jfche enamel would be of most interest' as a result of this study., wrinkle resistance and moisture resistance tests of this reduced enamel were made. It was noted that no wrinkling appeared at 3 mils when the panel was baked for two hours at X75F. and in the water immersion test* the panel showed no film failure after 4$ hours in water at 100F* PHILADELPHIA LABORATORY L. COBLETO LCsmtfb DUP030003151 m&i . VISCOSITIES OP MATERIALS IBBJD II BAKING REDUCER STUBX ( Measured At 77Fo ) PACKAGED ENAMELS M2ag.Ua DuPont 93-500 37" DuPont 1S1-1Q199 37" Ditaler 70" Martin Senour 64" Acme 52" Zac Lac 90" Nason 42" DuPont 93-506 37" DuPont 161-10199 37" RED0CER ft Zaha 25 (RK-5756) 25 (EK-57S&) ' 35" 30" 47" 36" 20" 25" (RK-467) 25 " { " " ) iMMSx REDUCED mum? {&jm MJaua 25 21" 10" (theo.) 25 21" 10" {theo*} 25 27" 17" 12-1/2 46" 29" .10 102" 73" 12*1/2 100" 72" 12-1/2 36" 23" 16"12-1/2 26" 12-1/2 26" 16" * Reduced in accordance with package directions., DUP030003152 mmmM &m g8 gg a * a-3a.3S|33333 rwtHco cHotroioHa oHa crolcHo troltrolrtolHw r<olr<ioH * O; q h h h .n o Mh hn h h h W* <*H * o .lH}>CMO>oqHcOHHfWfl0H5H>6riQrClHOHW SSSSSS2SSBSSSR8*SHfflS8PgS SRSSg^aSRSSaRRSRR^SSSSSSSiSRS' saa4fasssas3aaaHs!3ass SSI388r mmm H a si ^^PPPPc<2.292,3q ooqooqqqooooo w a? ^IsT(vt cfcf cii w cfwww cl w ?a<S?clwcfT w\>Q o *a s u \i?\v \w s o O O O w\AWSiAw>mo O m o imnmo asaMpas^ssasssa3SR9as' ggiSlsggSsSaaigSgSS88gg ^SSSSftj *jj OJ C* HHHri HH Isas sHaI I'lleonti j *> s _ < ei cj O J II Ib b Ss s &J .i b b I __m_ m P3CSHJ^OlV&l I' p +> SSlSsUss J3<5 opw cC <B fij N03 i !$ O P ^Iflg H Ao..a...A...o. _if _A.s_a cnto c\cc> tnto rncnA-co Ato A^oA-toA-eo o ca ts .- O'HP'H O'HO^HQ'HCJNHOx OiOn H Q\HC^H<>HCkH;fc3!aiO3 lllp^sis^||Mf|!sssiii i^q~^JN<nfncncnHfntncn<ncnc^iNSN5>*c^5^^^{NNis^iNiSE^ ttiwrmwvtwtttf-mt'm m o os as P3. as e$ ft? as <*s 85 04 . 03 ca es & os 85 os as os petos p=? p$ DUP030003153