Amino resin composition and varnish, coating layer, and product comprising the same

Abstract

Provided are an amino resin composition, a varnish, a coating layer, and a product. The amino resin composition comprises a repeating unit represented by the following Formula (I): ##STR00001## A .sup.13C-NMR spectrum of the amino resin composition has a first characteristic peak at 159 ppm to 161 ppm and a second characteristic peak at 70 ppm to 80 ppm. Based on the integral value of the first characteristic peak as 1, the integral value of the second characteristic peak is in the range from 0.01 to 0.25. Adopting the amino resin composition can accelerate the drying of the varnish and ensure the coating layer and the product have high hardness, high gloss and excellent color stability.

Claims

1. An amino resin composition comprising a repeating unit represented by the following Formula (I): ##STR00006## wherein R.sup.1 and R.sup.2 are each independently a hydrogen atom or a C1 to C6 alkyl group, and n is an integer from 1 to 15; wherein a .sup.13C-NMR spectrum of the amino resin composition has a first characteristic peak at 159 ppm to 161 ppm and a second characteristic peak at 70 ppm to 80 ppm, and an integral value of the second characteristic peak is in the range from 0.01 to 0.25 based on an integral value of the first characteristic peak as 1.

2. The amino resin composition as claimed in claim 1, wherein the integral value of the second characteristic peak is in the range from 0.01 to 0.20.

3. The amino resin composition as claimed in claim 1, wherein the .sup.13C-NMR spectrum of the amino resin composition has a third characteristic peak located at 54 ppm to 58 ppm and a fourth characteristic peak located at 65 ppm to 69 ppm, and a ratio of an integral value of the third characteristic peak to an integral value of the fourth characteristic peak is in the range from 0.20 to 0.60.

4. The amino resin composition as claimed in claim 1, wherein a viscosity of the amino resin composition is more than or equal to 560 cps at 25 C.

5. The amino resin composition as claimed in claim 4, wherein the viscosity of the amino resin composition is more than or equal to 560 cps and less than or equal to 800 cps tested at 25 C.

6. The amino resin composition as claimed in claim 1, wherein a non-volatile content of the amino resin composition is in the range from 53 wt % to 70 wt %.

7. The amino resin composition as claimed in claim 6, wherein the non-volatile content of the amino resin composition is in the range from 65 wt % to 70 wt %.

8. The amino resin composition as claimed in claim 1, wherein the second characteristic peak is located at 73 ppm to 77 ppm.

9. The amino resin composition as claimed in claim 1, wherein the APHA color of the amino resin composition is more than or equal to 120 and less than or equal to 260.

10. The amino resin composition as claimed in claim 9, wherein the APHA color of the amino resin composition is more than or equal to 150 and less than or equal to 200.

11. A varnish comprising the amino resin composition as claimed in claim 1.

12. The varnish as claimed in claim 11, wherein the varnish comprises a binder resin, a catalyst and a solvent.

13. The varnish as claimed in claim 12, wherein based on a total weight of the varnish, an amount of the amino resin composition is from 20 wt % to 60 wt %, an amount of the binder resin is from 15 wt % to 45 wt %, an amount of the catalyst is from 1 wt % to 20 wt %, and an amount of the solvent is from 10 wt % to 50 wt %.

14. An amino resin coating layer, which is formed by curing the varnish as claimed in claim 11.

15. The amino resin coating layer as claimed in claim 14, wherein the varnish comprises a binder resin, a catalyst and a solvent, wherein based on a total weight of the varnish, an amount of the amino resin composition is from 20 wt % to 60 wt %, an amount of the binder resin is from 15 wt % to 45 wt %, an amount of the catalyst is from 1 wt % to 20 wt %, and an amount of the solvent is from 10 wt % to 50 wt %.

16. The amino resin coating layer as claimed in claim 14, wherein the hardness on the Pencil Hardness Scale of the amino resin coating layer is 1H or higher.

17. The amino resin coating layer as claimed in claim 14, wherein a 60 gloss of the amino resin coating layer is more than 93 gloss units (GU).

18. The amino resin coating layer as claimed in claim 17, wherein the 60 gloss of the amino resin coating layer is in the range from 95 GU to 98 GU.

19. An amino resin product, which is prepared by coating and curing the varnish as claimed in claim 11 on a substrate.

20. The amino resin product as claimed in claim 19, wherein the substrate is a wood substrate, a paper substrate, a textile substrate, a leather substrate, a glass substrate, a plastic substrate, a metal substrate or any combination thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A is a schematic flow chart of preparing amino resin compositions of Examples 1 to 5 and Comparative Examples 1 and 2.

(2) FIG. 1B is a schematic flow chart of preparing an amino resin composition of Comparative Example 3.

(3) FIG. 2 to FIG. 6 are respectively .sup.13C-NMR spectra of the amino resin compositions of Examples 1 to 5.

(4) FIG. 7 to FIG. 9 are respectively .sup.13C-NMR spectra of the amino resin compositions of Comparative Examples 1 to 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(5) In the following, several examples are showed to demonstrate the implementation of an amino resin composition, a varnish, a coating layer and a product comprising the same, and several comparative examples are provided for comparison. One person skilled in the art can easily understand the merits and effects through these examples and comparative examples. It should be understood that the examples in the specification are only for the purpose of illustrating the implementation of the present invention, but shall not be used to limit the range of the present invention. One person skilled in the art can make necessary changes or modifications to implement or apply the content of the present invention without departing from the spirit of the present invention.

(6) Amino Resin Composition

Example 1

(7) As shown in FIG. 1A, the amino resin composition of Example 1 was prepared by adding alcohol all in once, and its reaction formula and preparation were described as follows.

(8) ##STR00004##

(9) First, 362.5 g of 40 wt % glyoxal solution (about 2.5 mol) was weighed and adjusted to about pH 6.3 with 10% sodium bicarbonate aqueous solution. Then 193.5 g of ethylene urea (about 2.25 mol) was added into the foresaid solution, and adjusted to about pH 6.5 with an adequate amount of 1N hydrochloric acid, so as to undergo an addition reaction of the glyoxal and the ethylene urea for 2 hours under the condition of 405 C. and pH 6.5.

(10) Next, about 481.0 g of n-butyl alcohol (about 6.5 mol) and about 416.0 g of methanol (about 13 mol) were added in the abovementioned mixture simultaneously, adjusted to around pH value between around 2.5 and 2.8 with 32% hydrochloric acid, followed by etherification reaction at 5210 C. for 3 hours.

(11) After that, the etherified mixture was distilled under 6510 C. and a reduced pressure of 270 torr to 160 torr, followed by cooling to 30 C. to 40 C., and then adjusted to around pH 4.8 to pH 5.0 with 25% aqueous sodium hydroxide solution. The resulting solution was added with n-butanol to adjust its viscosity, so as to obtain the amino resin composition of Example 1. According to the above method, the preparation of the amino resin composition of Example 1 took totally 7.5 hours.

Example 2

(12) As shown in FIG. 1A, the amino resin composition of Example 2 was also prepared by adding alcohol all in once, and its reaction formula was shown as that in Example 1 and the preparation was described as follows.

(13) First, 362.5 g of 40 wt % glyoxal solution (about 2.5 mol) was weighed and adjusted to about pH 6.3 with 10% sodium bicarbonate aqueous solution. Then 258.0 g of ethylene urea (about 3 mol) was added into the foresaid solution, and adjusted to about pH 6.5 with addition of an adequate amount of 1N hydrochloric acid, so as to undergo an addition reaction of the glyoxal and the ethylene urea under the condition of 405 C. and pH 6.5 for 2 hours.

(14) Next, about 740.0 g of n-butyl alcohol (about 10 mol) and about 480.0 g of methanol (about 15 mol) were added in the abovementioned mixture simultaneously, and adjusted to the pH value between around 2.5 and 2.8 with 32% hydrochloric acid, followed by etherification reaction at 5810 C. for 3 hours.

(15) After that, the etherified mixture was distilled under 6010 C. and a reduced pressure of from 240 torr to 120 torr, followed by cooling to 30 C. to 40 C., and then adjusted to around pH 4.8 to pH 5.0 with 25% aqueous sodium hydroxide solution. The viscosity of the resulting solution was adjusted by the same manner as that of Example 1, so as to obtain the amino resin composition of Example 2. According to the above method, the preparation of the amino resin composition of Example 2 took totally 7.5 hours.

Example 3

(16) As shown in FIG. 1A, the amino resin composition of Example 3 was also prepared by adding alcohol all in once, its reaction formula was shown as that in Example 1 and the preparation was described as follows.

(17) First, 362.5 g of 40 wt % glyoxal solution (about 2.5 mol) was weighed and adjusted to about pH 6.3 with 10% sodium bicarbonate aqueous solution. Then 150.5 g of ethylene urea (about 1.75 mol) was added into the foresaid solution, and adjusted to about pH 6.5 with addition of an adequate amount of 1N hydrochloric acid, so as to undergo an addition reaction of the glyoxal and the ethylene urea under the condition of 405 C. and pH 6.5 for 2 hours.

(18) Next, about 1111.0 g of n-butyl alcohol (about 15 mol) and about 480.0 g of methanol (about 15 mol) were added in the abovementioned mixture simultaneously, and adjusted to the pH value between around 2.5 and 2.8 with 32% hydrochloric acid, followed by etherification reaction at 5810 C. for 3 hours.

(19) After that, the etherified mixture was distilled under 6510 C. and a reduced pressure of from 270 torr to 160 torr, followed by cooling to 30 C. to 40 C., and then adjusted to around pH 4.8 to pH 5.0 with 25% aqueous sodium hydroxide solution. The viscosity of the resulting solution was adjusted by the same manner as that of Example 1, so as to obtain the amino resin composition of Example 3. According to the above method, the preparation of the amino resin composition of Example 3 took totally 7.5 hours.

Example 4

(20) As shown in FIG. 1A, the amino resin composition of Example 4 was also prepared by adding alcohol all in once, and its reaction formula was shown as that in Example 1 and the preparation was described as follows.

(21) First, 362.5 g of 40 wt % glyoxal solution (about 2.5 mol) was weighed and adjusted to about pH 6.3 with 10% sodium bicarbonate aqueous solution. Then 236.5 g of ethylene urea (about 2.75 mol) was added into the foresaid solution, and adjusted to about pH 6.5 with addition of an adequate amount of 1N hydrochloric acid, so as to undergo an addition reaction of the glyoxal and the ethylene urea under the condition of 405 C. and pH 6.5 for 2 hours.

(22) Next, about 740.0 g of n-butyl alcohol (about 10.0 mol) and about 640.0 g of methanol (about 20 mol) were added in the abovementioned mixture simultaneously, and adjusted to the pH value between around 2.5 and 2.8 with 32% hydrochloric acid followed by etherification reaction at 5210 C. for 3 hours.

(23) After that, the etherified mixture was distilled under 5810 C. and a reduced pressure of from 240 torr to 120 torr, followed by cooling to 30 C. to 40 C., and then adjusted to around pH 4.8 to pH 5.0 with 25% aqueous sodium hydroxide solution. The viscosity of the resulting solution was adjusted by the same manner as that of Example 1, so as to obtain the amino resin composition of Example 4. According to the above preparation method, the preparation of the amino resin composition of Example 4 took totally 8 hours.

Example 5

(24) As shown in FIG. 1A, the amino resin composition of Example 5 was also prepared by adding alcohol all in once, its reaction formula was shown as that in Example 1 and the preparation was described as follows.

(25) First, 362.5 g of 40 wt % glyoxal solution (about 2.5 mol) was weighed and adjusted to about pH 6.3 with 10% sodium bicarbonate aqueous solution. Then 215.0 g of ethylene urea (about 2.5 mol) was added into the foresaid solution, and adjusted to about pH 6.5 with addition of an adequate amount of 1N hydrochloric acid, so as to undergo an addition reaction of the glyoxal and the ethylene urea under the condition of 405 C. and pH 6.5 for 2 hours.

(26) Next, about 1110.0 g of n-butyl alcohol (about 15.0 mol) and about 320.0 g of methanol (about 10 mol) were added in the abovementioned mixture simultaneously, and adjusted to the pH value between around 2.5 and 2.8 with 32% hydrochloric acid followed by etherification reaction at 5210 C. for 3 hours.

(27) After that, the etherified mixture was distilled under 5810 C. and a reduced pressure of from 240 torr to 120 torr, followed by cooling from 30 C. to 40 C., and then adjusted to around pH 4.8 to pH 5.0 with 25% aqueous sodium hydroxide solution. The viscosity of the resulting solution was adjusted by the same manner as that of Example 1, so as to obtain the amino resin composition of Example 5. According to the above method, the preparation of the amino resin composition of Example 5 took totally 8 hours.

Comparative Example 1

(28) As shown in FIG. 1A, the amino resin composition of Comparative Example 1 was also prepared by adding alcohol all in once, its reaction formula was shown as that in Example 1 and the preparation was described as follows.

(29) First, 362.5 g of 40 wt % glyoxal solution (about 2.5 mol) was weighed and adjusted to about pH 6.3 with 10% sodium bicarbonate aqueous solution. Then 215.0 g of ethylene urea (about 2.5 mol) was added into the foresaid solution, and adjusted to about pH 6.5 with addition of an adequate amount of 1N hydrochloric acid, so as to undergo an addition reaction of the glyoxal and the ethylene urea under the condition of 405 C. and pH 6.5 for 2 hours.

(30) Next, about 740.0 g of n-butyl alcohol (about 10.0 mol) and about 640.0 g of methanol (about 20 mol) were added in the abovementioned mixture simultaneously, and adjusted to the pH value between around 2.5 to 2.8 with 32% hydrochloric acid, followed by etherification reaction at 7510 C. for 3 hours.

(31) After that, the etherified mixture was distilled under the condition of 7510 C. and a reduced pressure of from 300 torr to 200 torr, followed by cooling to 30 C. to 40 C., and then adjusted to around pH 4.8 to pH 5.0 with 25% aqueous sodium hydroxide solution. The viscosity of the resulting solution was adjusted by the same manner as that of Example 1, so as to obtain the amino resin composition of Comparative Example 1. According to the above method, the preparation of the amino resin composition of Comparative Example 1 took totally 7 hours.

Comparative Example 2

(32) As shown in FIG. 1A, the amino resin composition of Comparative Example 2 was also prepared by adding alcohol all in once, its reaction formula was shown as that in Example 1 and the preparation was described as follows.

(33) First, 362.5 g of 40 wt % glyoxal solution (about 2.5 mol) was weighed and adjusted to about pH 6.3 with 10% sodium bicarbonate aqueous solution. Then 215.0 g of ethylene urea (about 2.5 mol) was added into the foresaid solution, and adjusted to about pH 6.5 with the addition of an adequate amount of 1N hydrochloric acid, so as to undergo an addition reaction of the glyoxal and the ethylene urea under the condition of 405 C. and pH 6.5 for 2 hours.

(34) Next, about 148.0 g of n-butyl alcohol (about 2 mol) and about 640.0 g of methanol (about 20 mol) were added in the abovementioned mixture simultaneously, and adjusted to the pH value between around 2.5 to 2.8 with 32% hydrochloric acid followed by etherification reaction at 5210 C. for 3 hours.

(35) After that, the etherified mixture was distilled under the condition of 5810 C. and a reduced pressure of from 240 torr to 120 torr, followed by cooling to 30 C. to 40 C., and then adjusted to around pH 4.8 to pH 5.0 with 25% aqueous sodium hydroxide solution. The viscosity of the resulting solution was adjusted by the same manner as that of Example 1, so as to obtain the amino resin composition of Comparative Example 2. According to the above method, the preparation of the amino resin composition of Comparative Example 2 took totally 8 hours.

Comparative Example 3

(36) As shown in FIG. 1B, different from the preparation of the amino resin compositions of Examples 1 to 5 and Comparative Examples 1 and 2, the amino resin composition of Comparative Example 3 was prepared by adding alcohol in batches, and its preparation was described as follows.

(37) First, 362.5 g of 40 wt % glyoxal solution (about 2.5 mol) was weighed and adjusted to about pH 6.3 with 10% sodium bicarbonate aqueous solution. Then 172.0 g of ethylene urea (about 2 mol) was added into the foresaid solution, and adjusted to about pH 6.5 with the addition of 1N hydrochloric acid, so as to undergo an addition reaction of the glyoxal and the ethylene urea under the condition of about 405 C. and pH 6.5 for 3 hours.

(38) Next, about 480.0 g of methanol (about 15 mol) was added in the abovementioned mixture, and adjusted to the pH value between around 2.5 to 2.8 with 32% hydrochloric acid to undergo the first etherification reaction at 5210 C. for 3 hours. After the completion of the first etherification reaction, about 1110.0 g of n-butyl alcohol (about 15 mol) was added in the abovementioned mixture, and adjusted to the pH value between around 2.5 to 2.8 with 32% hydrochloric acid to undergo the second etherification reaction at 5210 C. for 1 hour.

(39) Then the etherified mixture after the first and second etherification reactions was concentrated under the condition of 5810 C. and a reduced pressure of from 240 torr to 120 torr to remove 40 wt % of solvent therein, and then adjusted to pH 6.5 to pH 7.0 with 25% aqueous sodium hydroxide solution. The mixture was further distilled under the condition of 5810 C. and a reduced pressure of from 240 torr to 120 torr. The viscosity of the resulting solution was adjusted by the same manner as that of Example 1 to obtain the amino resin composition of Comparative Example 3. According to the above method, the preparation of the amino resin composition of Comparative Example 3 took totally 10 hours.

(40) For convenience of explanation, the usage of glyoxal, ethylene urea, n-butyl alcohol and methanol, the temperature of etherification reaction, temperature and pressure of distillation as well as total time for the preparation of Examples 1 to 5 and Comparative Examples 1 to 3 are listed in Table 1.

(41) TABLE-US-00001 TABLE 1 usage of raw materials and parameters set in the preparation of the amino resin compositions of Examples 1 to 5 (S1 to S5) and Comparative Examples 1 to 3 (C1 to C3). Example Comparative Example S1 S2 S3 S4 S5 C1 C2 C3 Glyoxal 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 (mol) Ethylene 2.25 3 1.75 2.75 2.5 2.5 2.5 2 urea (mol) n-Butyl 6.5 10 15 10 15 10 2 15 alcohol (mol) Methanol 13 15 15 20 10 20 20 15 (mol) Etherifica- 52 10 58 10 58 10 52 10 52 10 75 10 52 10 52 10 tion temp. ( C.) Distillation 65 10 60 10 65 10 58 10 58 10 75 10 58 10 58 10 temp. ( C.) Distillation 270-160 240-120 270-160 240-120 240-120 300-200 240-120 240-120 pressure (torr) Total time 7.5 7.5 7.5 8 8 7 8 10 (hour)

Test Example 1: .SUP.13.C-NMR

(42) In the test example, the amino resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 as samples were tested by using .sup.13C-NMR spectrometer under the following conditions, so as to obtain the .sup.13C-NMR spectra of Examples 1 to 5 and Comparative Examples 1 to 3 respectively.

(43) .sup.13C-NMR analysis conditions: 1. Apparatus: BRUKER AVANCE 500 NMR, 2. Dilution solvent: dimethyl sulfoxide-d6 (DMSO-d6), including 0.03 vol % tetramethylsilane (TMS), 3. Sample preparation: 50050 mg of sample to be tested was diluted with equal weight of DMSO-d6 (error no more than 5 mg), and the solution was charged into a glass tube of 5 mm diameter up to a height at least 5 cm, 4. Operation temperature: 300K, 5. Graph processing software: Nucleomatica iNMR ver. 6.2.2, 6. Spectrometer frequency: 500 megahertz (MHz), 7. Pulse width: 10 microseconds (sec), 8. Acquisition time: 0.55 seconds, 9. Number of points: 32768 dots, 10. Spectral width: 29761 hertz, and 11. Recycle delay: 2 seconds.

(44) FIG. 2 to FIG. 9 are respectively the .sup.13C-NMR spectra of the amino resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 analyzed by the abovementioned methods. The chemical shifts and integral values of the first characteristic peak to the fifth characteristic peak showed in the .sup.13C-NMR spectra are listed in Table 2.

(45) It should be noted that the chemical shift of each characteristic peak in .sup.13C-NMR spectra was calibrated based on the TMS chemical shift as 0 ppm, and permitted the identification of the chemical environments of the respective carbon atoms in the amino resin composition.

(46) The structural formulae of components contained in the amino resin composition were shown as follows.

(47) ##STR00005##

(48) In FIG. 2 to FIG. 9, the first characteristic peak at 159 ppm to 161 ppm may correspond to the carbon atom of the amide group (NCO group) of the main product which was marked as No. 1 carbon site in the above structural formula, the second characteristic peak at 73 ppm to 77 ppm may correspond to the carbon atom of impurities which was marked as No. 2 carbon site in the above structural formula, the third characteristic peak at 54.8 ppm to 56.2 ppm may correspond to the carbon of methoxy (OCH.sub.3 group) of the main product which was marked as No. 3 carbon site in the above structural formula, the fourth characteristic peak at 66 ppm to 68.4 ppm may correspond to the carbon of butoxy group (OCH.sub.2R group) of the main product which was marked as No. 4 carbon site in the above structural formula, and the fifth characteristic peak at 80 ppm to 84 ppm may correspond to the carbon of the CH(NR)(OR) of the main product which was marked as No. 5 carbon site in the above structural formula.

(49) Based on the integral value of the first characteristic peak, the integral values of the second characteristic peak to the fifth characteristic peak were respectively listed in Table 2. The ratio of the integral value of the third characteristic peak to the integral value of the fourth characteristic peak was obtained by dividing the integral value of the third characteristic peak by that of the fourth characteristic peak, and the round-off result was listed in Table 2.

(50) TABLE-US-00002 TABLE 2 chemical shifts and integral values of the 1.sup.st to 5.sup.th characteristic peaks as well as the integral value ratios of 3.sup.rd/4.sup.th characteristic peaks in .sup.13C-NMR spectra of the amino resin compositions of S1 to S5 and C1 to C3. Integral Value Example Comparative Example No. .sup.13C (ppm) S1 S2 S3 S4 S5 C1 C2 C3 1.sup.st 159 ~ 161 1 1 1 1 1 1 1 1 2.sup.nd 73 ~ 77 0.191 0.128 0.152 0.0544 0.0154 0.397 0.709 0.261 3.sup.rd 54.8 ~ 56.2 1.02 0.788 0.832 1.02 0.50 0.63 1.85 1.25 4.sup.th 66 ~ 68.4 1.82 2.09 2.33 2.10 2.03 2.14 0.435 1.77 5.sup.th 80 ~ 84 1.82 1.59 1.46 1.85 0.622 1.77 1.66 2.21 Integral value 0.56 0.38 0.36 0.49 0.25 0.29 4.25 0.71 ratio of 3.sup.rd/4.sup.th characteristic peak

(51) As indicated in Table 2 and FIG. 2 to FIG. 6 of the .sup.13C-NMR spectra of amino resin compositions of Examples 1 to 5, when the integral values of the first characteristic peaks were each set to be 1, the integral values of the second characteristic peaks corresponding to the two impurities were in the range from 0.01 to 0.25. In contrary, as shown in Table 2 and FIG. 7 to FIG. 9 of the .sup.13C-NMR spectra of amino resin compositions of Comparative Examples 1 to 3, the integral values of the second characteristic peaks corresponding to the two impurities were obviously more than 0.25, even reaching 0.4 or 0.7. Therefore, the composition difference between the amino resin compositions of Examples 1 to 5 and those of the Comparative Examples 1 to 3 could be easily identified from the integral values of the first and second characteristic peaks in their respective .sup.13C-NMR spectra. To be specific, the amino resin compositions of the Comparative Examples 1 to 3 contained more impurities, thus their integral values of the second characteristic peaks were obviously more than those of the second characteristic peaks of the amino resin compositions of Examples 1 to 5.

(52) Further, the .sup.13C-NMR spectra of the amino resin compositions of Examples 1 to 5 showed that the integral values of the second characteristic peaks corresponding to the two impurities might be in the range from 0.01 to 0.20 based on the integral value of the first characteristic peak as 1.

(53) From the results of Table 2 and FIG. 2 to FIG. 6, the ratio of the integral value of the third characteristic peak to that of the fourth characteristic peak was 0.20 to 0.60 in each of the .sup.13C-NMR spectra of the amino resin compositions of Examples 1 to 5. In contrary, from the results of Table 2, FIG. 8 and FIG. 9, the ratio of the integral value of the third characteristic peak to that of the fourth characteristic peak was more than 0.60 in the .sup.13C-NMR spectra of the amino resin compositions of Comparative Examples 2 and 3.

(54) Furthermore, the ratio of the integral value of the third characteristic peak to that of the fourth characteristic peak was within 0.30 and 0.60 in each of the .sup.13C-NMR spectra of the amino resin compositions of Examples 1 to 4. In contrary, from the results of Table 2 and FIG. 7 to FIG. 9, the ratio of the integral value of the third characteristic peak to that of the fourth characteristic peak was out of the range from 0.30 to 0.60 in each of the .sup.13C-NMR spectra of the amino resin compositions of Comparative Examples 1 to 3.

(55) As indicated in Table 2 and FIG. 2 to FIG. 6, each of the .sup.13C-NMR spectra of amino resin compositions of Examples 1 to 5 had the third characteristic peak with the integral value from 0.30 to 1.20, the fourth characteristic peak with the integral value from 1.50 to 2.40, and the fifth characteristic peak with the integral value from 0.50 to 2.00 when the integral value of the first characteristic peak was set to be 1.

Test Example 2: Property Analysis

(56) The test example adopted the same standard method to measure the color, non volatile and viscosity of the amino resin compositions of Examples 1 to 5 as well as Comparative Examples 1 to 3, and their results were listed in Table 3.

(57) These three properties were measured based on the following standard methods. 1. Color (APHA chromaticity): DIN EN ISO 6271; 2. Non volatile (NV): DIN 55671 (foil, test for 45 min at 45 C.); and 3. Viscosity: DIN EN ISO 3219.

(58) TABLE-US-00003 TABLE 3 results of property analysis of the amino resin compositions of Examples 1 to 5 and Comparative Examples 1 and 3. Comparative Example Example Item S1 S2 S3 S4 S5 C1 C2 C3 APHA 195.4 247.8 251.9 156.2 155.3 346.2 404.6 263.5 chromaticity Non volatile 69.4 68.9 66.9 65.7 66.2 52.9 70.8 70.6 (wt %) Viscosity 643.9 723.0 603.8 624.0 684.8 533.9 550.0 493.9 (cps @ 25 C.)

(59) As indicated in Table 3, the APHA chromaticity of the amino resin compositions of Examples 1 to 5 might be more than or equal to 120 and less than or equal to 260; more specifically, the APHA chromaticity of the amino resin compositions of Examples 1 to 5 might be more than or equal to 150 and less than or equal to 200. On the contrary, the APHA chromaticity of the amino resin compositions of Comparative Examples 1 to 3 was all more than 260.

(60) In terms of non volatile, as indicated in Table 3, the non volatile of the amino resin compositions of Examples 1 to 5 might be more than or equal to 53 wt % and less than or equal to 70 wt %; more specifically, the non volatile of amino resin compositions of Examples 1 to 5 may be more than or equal to 65 wt % and less than or equal to 70 wt %. On the contrary, the non volatile of the amino resin compositions of Comparative Examples 1 to 3 was out of the range from 53 wt % to 70 wt %.

(61) With regard to viscosity of the amino resin compositions tested at 25 C., the viscosity of the amino resin compositions of Examples 1 to 5 might be more than or equal to 560 cps; more specifically, the viscosity of the amino resin compositions of Examples 1 to 5 might be more than or equal to 560 cps and less than or equal to 800 cps; much more specifically, the viscosity of the amino resin compositions of Examples 1 to 5 might be more than or equal to 560 cps and less than or equal to 750 cps. On the contrary, the viscosity of chromaticity amino resin compositions of Comparative Examples 1 to 3 at 25 C. was all less than 560 cps.

(62) According to the above property analysis results, the color, non volatile or viscosity of the amino resin compositions of Examples 1 to 5 were all different from those of the amino resin compositions of Comparative Examples 1 to 3.

(63) Varnish

Examples 1A to 5A and Comparative Examples 1A to 3A

(64) Examples 1A to 5A and Comparative Examples 1A to 3A respectively adopted the amino resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 as crosslinker, which were respectively mixed with the same binder resin, the same catalyst and the same solvent in the same amounts by the same method to prepare the varnishes. The kinds and amounts of the crosslinker, the binder resin, the catalyst and the solvent were listed in Table 4. That is, the varnishes of Examples 1A to 5A and Comparative Examples 1A to 3A were just distinguished from their adopted amino resin compositions.

(65) TABLE-US-00004 TABLE 4 components and amounts of each reagent in varnishes. Component Amount Crosslinker Amino Resin Composition 40 wt % Binder resin short oil synthetic fatty acid alkyd resin.sup.1 28 wt % Catalyzer para-toluenesulfonic acid solution.sup.2 11 wt % isobutanol 13 wt % Solvent methanol 6 wt % toluene 2 wt % .sup.1short oil synthetic fatty acid alkyd resin, model: A932-80, purchased from Daily polymer. .sup.2para-toluenesulfonic acid solution, pTSA was dissolved in butanol to prepare a 40 wt % pTSA solution.

(66) In the preparation, the short oil synthetic fatty acid alkyd resin was charged into the reaction flask, and then the respective amino resin composition and the three solvents were added and stirred to get an even solution. Next, pTSA solution was added into the solution and stirred to get a 50 wt % non volatile of varnish.

(67) The varnish of Example 1A was prepared by using the amino resin composition of Example 1, the varnish of Example 2A was prepared by using the amino resin composition of Example 2, and then the varnishes of Examples 1A to 5A and Comparative Examples 1A to 3A could be prepared by the similar method.

Test Example 3: Storage Stability

(68) In the instant test example, the varnishes of Example 1A to 5A as samples were measured with a rotary viscometer (manufacturer: AMETEK, model: DV2T HBCJ0) based on the standard method of DIN EN ISO 321 at 25 C., so as to obtain and record their viscosity at 0 day of storage. After that, the samples were stored at 50 C. for 16 days. During the storage at 50 C., the viscosity of the samples was measured after 4 days, 8 days, 12 days and 16 days of storage, and the results were listed in Table 5.

(69) TABLE-US-00005 TABLE 5 viscosity (cps) of varnishes of Examples 1A to 5A (S1A to S5A) with different storage time. Example Storage time S1A S2A S3A S4A S5A 0 day 54.35 68.65 56.35 60.15 60.15 4 days 45.78 61.04 44.73 46.04 46.04 8 days 44.47 61.48 45.78 42.64 42.64 12 days 39.76 55.2 39.24 39.24 39.24 16 days 36.89 47.61 35.32 36.89 36.89

(70) From the results of Table 5, the viscosity variations of varnishes of Examples 1A to 5A were controlled under 25% after 4 days of storage, the viscosity variations of varnishes of Examples 1A to 5A were controlled under 30% after 8 days of storage, the viscosity variations of varnishes of Examples 1A to 5A were controlled under 35% after 12 days of storage, and the viscosity variations of varnishes of Examples 1A to 5A were controlled under 40% after 16 days of storage.

(71) As shown in Table 5, the varnishes of Example 1A to 5A did not exhibit obvious change on viscosity after 16 days of storage at 50 C. The varnishes prepared by using the amino resin compositions of Examples 1 to 5 would not be hardened within a short period, indicating that the varnishes of Examples 1A to 5A could be applicable to be coated on substrates to prepare the amino resin coating layers even if they have been stored for a while. It demonstrates that the varnishes of Examples 1A to 5A all exhibit a good storage stability.

(72) Amino Resin Coating Layer

Examples 1B to 5B and Comparative Examples 1B to 3B

(73) To prepare the amino resin coating layers of Examples 1B to 5B and Comparative Examples 1B to 3B, the varnishes of Examples 1A to 5A and Comparative Examples 1A to 3A were respectively coated on the glass substrates of same model and then cured at 30 C. for 24 hours.

(74) As abovementioned, the amino resin coating layer of Example 1B was prepared by curing the varnish of Example 1A coated on the glass substrate, while the amino resin coating layer of Example 2B was prepared by curing the varnish of Example 2A coated on the glass substrate, and so on, such that the amino resin coating layers of Examples 1B to 5B and Comparative Examples 1B to 3B were respectively prepared by curing their respective varnishes coated on the glass substrates.

Test Example 4: Hardness

(75) The amino resin coating layers of Examples 1B to 5B and Comparative Examples 1B to 3B were tested by the standard method of ASTM 3363. The results of pencil hardness testing were recorded from soft to hard in order as 2B, 1B, HB, F, 1H and 2H, and the results were listed in Table 6.

(76) As shown in Table 6, the hardness of the amino resin coating layers of Examples 1B to 5B all could reach 1H or higher; in comparison, the hardness of the amino resin coating layers of Comparative Examples 1B and 3B was only 1B and the hardness of the amino resin coating layer of Comparative Example 2 was only HB. It indicates that the varnishes prepared by using the amino resin compositions of Examples 1 to 5 were indeed able to raise the hardness of the amino resin coating layers, making the hardness of the amino resin coating layers of Examples 1B to 5B several grades higher than that of the amino resin coating layers of Comparative Examples 1B to 3B.

Test Example 5: Drying Speed

(77) In the instant test example, the varnishes of Examples 1A to 5A and Comparative Examples 1A to 3A were respectively coated on the glass substrates with a wet film thickness of 100 micrometers, and then gradually cured into the amino resin coating layers at 30 C. During curing, the drying speed of the varnishes was measured by the standard method of ASTM D5895, and recorded the set-to-touch time, tack-free time and dry-through time with a drying time recorder (Manufacturer: TQC Sheen, Model: BK-3 SHEEN VF8005). The results were listed in Table 6.

(78) As shown in Table 6, in the process that the varnishes of Examples 1A to 5A was dried and cured into Examples 1B to 5B, the set-to-touch time was all not more than 3 minutes, the tack-free time was all not more than 5 and a half minutes and the dry-through time was not more than 35 minutes. On the contrary, in the process that the varnishes of Comparative Examples 1A to 3A were dried and cured into Comparative Examples 1B to 3B, the required set-to-touch time was at least 3 minutes and 18 seconds, the tack-free time was all longer than 5 and a half minutes and the dry-through time were all longer than 37 minutes. It can be seen that the varnishes prepared by using the amino resin compositions of Examples 1 to 5 were surely able to accelerate the drying speed of varnish, shorten the required time for drying and curing the varnishes into amino resin coating layers, so as to raise the production efficiency and improve the industrial value.

(79) TABLE-US-00006 TABLE 6 pencil hardness, set-to-touch time, tack-free time and dry-through time of the amino resin coating layers of Examples 1B to 5B (S1B to S5B) and Comparative Example 1B to 3B (C1B to C3B) on glass substrates. Example Comparative Example S1B S2B S3B S4B S5B C1B C2B C3B Pencil 1H 1H 1H 1H 1H 1B HB 1B hardness Set-to-touch 235 252 222 248 229 333 318 520 time Tack-free 503 530 526 518 522 554 650 1130 time Dry-through 26.7 35.0 30.1 31.6 29.4 37.6 51.1 43.0 time

Examples 1C to 5C and Comparative Examples 1C to 3C

(80) The varnishes of Examples 1A to 5A and Comparative Examples 1A to 3A prepared by the abovementioned methods were coated on the white wood substrates of same model respectively, and then cured at 30 C. for 24 hours, so as to obtain the amino resin coating layers of Examples 1C to 5C and Comparative Examples 1C to 3C.

(81) As abovementioned, the amino resin coating layer of Example 1C was prepared by curing the varnish of Example 1A coated on the white wood substrate, while the amino resin coating layer of Example 2C was prepared by curing the varnish of Example 2A coated on the white wood substrate, and so on, such that the amino resin coating layers of Examples 1C to 5C and Comparative Examples 1C to 3C were respectively prepared by curing the varnishes coated on white wood substrates.

Test Example 6: Gloss

(82) The amino resin coating layers of Examples 1C to 5C and Comparative Examples 1C to 3C were tested for their gloss at 60 with a micro three-angle gloss meter (manufacturer: BYK, model: mirco-TRI-gloss) based on the standard method of ASTM D523. Three sets of data in the measure area of 75 mm*150 mm were recorded and averaged to give the 60 gloss as listed in Table 7.

(83) TABLE-US-00007 TABLE 7 60 gloss of the amino resin coating layers of Examples 1C to 5C (S1C to S5C) and Comparative Examples 1C to 3C (C1C to C3C) on wood substrates. Comparative Example Example S1C S2C S3C S4C S5C C1C C2C C3C 60 Gloss 97.1 96.2 95.5 97.3 97.0 87.9 93.0 92.6 (GU)

(84) As shown in Table 7, the 60 gloss of the amino resin coating layers of Examples 1C to 5C was all more than 93 GU. On the contrary, the 60 gloss of the amino resin coating layers of Comparative Examples 1C to 3C was all less than or equal to 93 GU, especially, the 60 gloss of the amino resin coating layer of Comparative Example 1C failed to reach 88 GU. It can be seen that the varnishes prepared by using the amino resin compositions of Examples 1 to 5 were surely able to enhance gloss of the amino resin coating layers, so as to improve the appearance and industrial value.

(85) To specify in more detail, the 60 gloss of the amino resin coating layers of Examples 1C to 5C could be all more than or equal to 94 GU, even up to 95 GU to 98 GU, which allows the wood products protected by the amino resin coating layers of Example 1C to 5C to have superior appearance and industrial value.

Test Example 7: Color

(86) The amino resin coating layers of Examples 1C to 5C and Comparative Examples 1C to 3C were adopted as samples and measured by a colorimeter (manufacturer: HunterLab, model: color quest XE) based on the standard method of ISO 7724. Three sets of data were recorded with the average value as the initial brightness (L.sub.1) as well as the initial chromaticity a.sub.1*, b.sub.1* of each amino resin coating layer. The samples were placed at 50 C. for one week to accelerate the aging of the amino resin coating layers at such temperature. After that, each sample was tested according to the above method with three sets of data recorded, and the average value was taken as the brightness (L.sub.2) and chromaticity a.sub.2*, b.sub.2* of each amino resin coating layer after the aging test.

(87) It can be understood for one person skilled in the art that, the color of the amino resin coating layer can be defined according to the color system of L*a*b* of the Commission Internationale de l'Eclairage (CIE). L value refers to the relative degree of brightness and darkness of a coating layer, the higher L value indicates that the coating layer is brighter and closer to white, while the lower L value indicates that the coating layer is darker and closer to black. Chromaticity a* denotes the relative degree of red and green of a coating layer, the higher a* value indicates that the coating layer is closer to red while the lower a* value indicates that the coating layer is closer to green. Chromaticity b* denotes the relative degree of yellow and blue of a coating layer, the higher b* value indicates that the coating layer is closer to yellow while the lower b* value indicates that the coating layer is closer to blue.

(88) The test results of each sample tested before and after aging test were listed in Table 8. The difference of the brightness L.sub.2 of each sample after aging test deducted by the initial brightness L.sub.1 was represented as L, the difference of the chromaticity a.sub.2* of each sample after aging test deducted by the initial chromaticity a.sub.1* was represented as a, and the difference of the chromaticity b.sub.2* of each sample after aging test deducted by the initial chromaticity b.sub.1* was represented as b. In the experiment, the yellowing degree might be evaluated by b, the overall color change might be evaluated by E, and the color stability may be evaluated by both b and E. Herein, E may be calculated by formula:
E=(L.sup.2+a.sup.2+b.sup.2).sup.1/2.

(89) As shown in Table 8, b of the amino resin coating layers of Examples 1C to 5C before and after the aging test were all controlled under 8.0. On the contrary, b of the amino resin coating layers of Comparative Examples 1C to 3C before and after aging test were all as high as 8.11 and more, especially, b of the amino resin coating layer of Comparative Example 1C before and after aging test reached as high as 8.33. The b of Examples 1C to 5C in comparison with those of Comparative Examples 1C to 3C indicated that the amino resin coating layers of Comparative Examples 1C to 3C incurred obvious aging and yellowing after the aging test while the yellowing of the amino resin coating layers of Examples 1C to 5C, which adopted the amino resin compositions of Examples 1 to 5, were effectively mitigated and/or prevented, so that b could be reduced as much as possible.

(90) TABLE-US-00008 TABLE 8 color analysis results of the amino resin coating layers of Examples 1C to 5C (S1C to S5C) and Comparative Examples 1C to 3C (C1C to C3C) before and after aging test. Comparative Example Example S1C S2C S3C S4C S5C C1C C2C C3C L.sub.1 92.41 93.01 92.53 92.46 92.38 92.63 92.40 92.45 a.sub.1* 3.41 2.34 3.15 2.52 2.76 3.13 1.64 2.30 b.sub.1* 6.35 6.82 7.21 6.54 6.41 9.58 9.85 7.35 L.sub.2 91.57 91.71 90.45 91.36 91.43 91.46 92.15 89.09 a.sub.2* 3.93 3.25 3.48 3.16 3.42 4.36 3.49 2.31 b.sub.2* 11.73 13.88 14.14 12.42 12.17 17.91 18.09 15.46 L 0.84 1.3 2.08 1.1 0.95 1.17 0.25 3.36 a 0.52 0.91 0.33 0.64 0.66 1.23 1.85 0.01 b 5.38 7.06 6.93 5.88 5.76 8.33 8.24 8.11 E 5.47 7.24 7.24 6.02 5.88 8.50 8.45 8.78

(91) From the results of E of Examples 1C to 5C in comparison with those of Comparative Examples 1C to 3C, E of the amino resin coating layers of Examples 1C to 5C before and after aging test were all controlled under 7.5; on the other hand, E of the amino resin coating layers of Comparative Examples 1C to 3C before and after aging test were all over 8, more particularly, E of the coating layer of Comparative Example 3C was as high as 8.78. Therefore, the amino resin coating layers of Comparative Examples 1C to 3C incurred obvious color change after aging while color change of the amino resin coating layers of Examples 1C to 5C was effectively mitigated and/or prevented by means of adopting the amino resin compositions of Examples 1 to 5, so that E could be reduced as much as possible.

(92) It can be seen that the varnishes prepared by using the amino resin compositions of Examples 1 to 5 were surely able to mitigate and/or prevent the yellowing or overall color change of the amino resin coating layers as much as possible, so as to improve the color stability of the amino resin coating layers on wood substrates as well as optimize appearance, durability, stability and industrial value of wood products.

Discussion on Results of Test Examples

(93) The results of Test Examples 1 to 7 were all considered. From the results of .sup.13C-NMR analysis, the integral values of the second characteristic peaks of the amino resin compositions of Examples 1 to 5 were obviously lower than those of the second characteristic peaks of the amino resin compositions of Comparative Examples 1 to 3, indicating that the impurity content in the amino resin compositions of Examples 1 to 5 was obviously lower than that of the amino resin compositions of Comparative Examples 1 to 3. Therefore, the varnish (Examples 1A to 5A) prepared from the amino resin compositions of Examples 1 to 5 had good storage stability, furthermore, the amino resin coating layers of Examples 1B to 5B or Examples 1C to 5C also had the merits of high hardness, rapid drying speed, high gloss and improved color stability.

(94) On the contrary, as amino resin compositions of Comparative Examples 1 to 3 contained relatively more impurities, their properties were different from those of Examples 1 to 5, and the amino resin coating layers of Comparative Examples 1B to 3B or Comparative Examples 1C to 3C were all inferior to the amino resin coating layers formed by amino resin compositions of Examples 1 to 5 with regard to hardness, drying speed, gloss or color stability.

(95) In summary, the amino resin composition, which has controlled integral values of the first and second characteristic peaks in its .sup.13C-NMR spectrum, is able to take advantages of high hardness, rapid drying speed, high gloss and good color stability on the amino resin coating layers and amino resin products both prepared by curing the varnish, so as to optimize their production efficiency, appearance, durability and operability. As a result, the industrial values of the amino resin coating layers and amino resin products are overall improved, making them widely applicable to various applications.

(96) Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.