Thermosetting composition, paint finishing method, and method for producing painted articles

Abstract

[Purpose] To provide a thermosetting composition with which it is possible to obtain paint films which not only display stain resistance for a short period after application, but with which excellent stain resistance can also be expected for longer periods, and which comply with the paint film properties required for painted steel sheet such as water resistance and bending workability, and have high environmental protection and safety qualities. [Solution] The present invention relates to a thermosetting composition, wherein it contains, as essential components, (A) a polyester resin of number average molecular weight 1,000-10,000 and hydroxyl value 5-200 mg KOH/g and, (B) 0.5 to 2.0 equivalents, relative to the hydroxyl groups of the aforesaid component (A), of a compound (B) which is a blocked aliphatic polyisocyanate compound having reactivity to the hydroxyl groups of component (A), wherein the blocks are methyl ethyl ketone oxime and/or ε-caprolactam, (C) 0.05 to 5 mass %, relative to the total resin solids mass of component (A) and component (B), of an organotin compound represented by the following general formula (I) [Chem.1] R.sup.1—Sn-(O)C═(O)—R.sup.2).sub.3 (I) (R.sup.1 in the formula represents an organic group wherein it has 1-24 carbons, and is directly bound to the Sn atom via a C atom. R.sup.2 represents an organic group wherein it has 1-24 carbons, and is directly bound to the C atom of the (C═O) via a C atom), and (D) 0.5 to 50 mass %, relative to the total resin solids mass of component (A) and component (B), of an organosilicate represented by the following general formula (II) and/or a condensation product thereof [Chem.2] (R.sup.3, R.sup.4, R.sup.5 and R.sup.6 in the formula are each a hydrogen atom or 1-10 carbon organic group, and may be the same or different, n is 1). ##STR00001##

Claims

1. A thermosetting composition comprising: (A) a polyester resin of number average molecular weight 1,000-10,000 and hydroxyl value 5-200 mg KOH/g and, (B) a blocked aliphatic polyisocyanate compound having reactivity to the hydroxyl groups of component (A), wherein the blocks are methyl ethyl ketone oxime and/or ε-caprolactam, and the blending ratio is in the range 0.5-2.0 equivalents of blocked isocyanate groups of component (B) relative to hydroxyl groups of component (A), (C) 0.05 to 5 mass %, relative to the total resin solids mass of component (A) and component (B), of an organotin compound represented by the following general formula (I)
R.sup.1—Sn—(O(C═O)—R.sup.2).sub.3  (I), wherein R.sup.1 represents an organic group of 1-24 carbons and is directly bound to the Sn atom via a C atom, R.sup.2 represents an organic group of 1-24 carbons and is directly bound to the C atom of the (C═O) via a C atom, (D) 0.5 to 50 mass %, relative to the total resin solids mass of component (A) and component (B), of an organosilicate represented by the following general formula (II) and/or a condensation product thereof ##STR00004## wherein R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are each a hydrogen atom or a 1-10 carbon organic group, and R.sup.4 and R.sup.5 are the same or different, and n is 1, and (E) 0.5 to 20 mass %, relative to the total resin solids mass of component (A) and component (B), of a compound represented by the following general formula (III)
R.sup.7.sub.n—C—(OR.sup.8).sub.4-n  (III) wherein R.sup.7 is a hydrogen atom or a 1-10 carbon organic group, each R.sup.8 is independently a 1-10 carbon organic group, and n is 1 or 2.

2. A metal sheet paint finishing method, the method comprising applying the thermosetting composition according to claim 1 onto a metal sheet and thermally curing the composition.

3. The metal sheet paint finishing method of claim 2, wherein before application of the thermosetting composition an undercoat paint is applied onto the metal sheet and thermally cured and a midcoat paint is optionally applied on top of the undercoat paint film and thermally cured.

4. A painted article comprising a metal sheet painted according to the method of claim 3.

5. The paint finishing method as claimed in claim 2 wherein the thermosetting composition is applied with a roller coater.

6. A painted article comprising a metal sheet painted according to the method of claim 5.

7. The paint finishing method as claimed in claim 2, wherein the metal sheet is a cold-rolled steel sheet, a zinc-plated steel sheet, an aluminum-zinc-plated steel sheet, a zinc-magnesium-plated steel sheet, an aluminum-zinc-magnesium-plated steel sheet, a stainless steel sheet, an aluminum sheet or an aluminum alloy plate.

8. A painted article comprising a metal sheet painted according to the method of claim 7.

9. A painted article comprising a metal sheet painted according to the method of claim 2.

10. A thermoset paint material formed by thermally curing the composition of claim 1.

Description

PRACTICAL EXAMPLES

(1) Below, the present invention is explained in more detail by presenting practical examples, but the present invention is not limited to these. Also, unless specifically stated, parts, % and ratio in these examples respectively represent parts by mass, mass % and mass ratio.

Production Example

(2) Production of Polyester Resin Solutions PE-1 to 13

(3) The monomers shown in table 1 were introduced into a flask equipped with thermometer, Dean-Stark tube, reflux condenser, nitrogen inlet tube and stirrer, and gradually heated to 240° C. with stirring, then the reflux solvent (xylene) was introduced, and a dehydration condensation polymerization reaction was performed. When the acid value reached the values shown in table 1, the mixture was diluted to a solids content of 50% by addition of a mixed solvent (aromatic solvent “Solvesso 100” Exxon-Mobil Chemical Corp.)/cyclohexanone=50/50 (mass ratio). As a result, hydroxyl group-containing polyester resin solutions PE-1 to 13, wherein the solids content had the specific values shown in table 1 were obtained.

(4) TABLE-US-00001 TABLE 1 Polyester resin production examples Polyester resin solutions PE-1 PE-2 PE-3 PE-4 PE-5 PE-6 PE-7 Monomers Polybasic isophthalic acid 22.5 22.5 22.5 22.5 22.5 22.5 22.5 (parts by carboxylic phthalic anhydride 14.8 14.8 14.8 14.8 14.8 14.8 14.8 mass) acid adipic acid 19.43 18.66 18.88 19.3 19.43 19.97 19.45 Polyhydric neopenty glycol 23.6 32.3 29.8 21.6 20.2 41.5 19.5 alcohol 1,6-hexanediol 8.5 8.5 8.5 8.5 8.5 1.1 8.5 trimethylolpropane 11.17 3.24 5.52 13.3 14.57 0.13 15.25 Acid value 10 10 10 3 3 43 2 Percentage solids (%) 50% 50% 50% 50% 50% 50% 50% Properties of solids number average molecular 3,000 1,500 1,750 5,500 8,000 800 11,000 weight (Mn) hydroxyl value (mg KOH) 80 80 80 80 80 80 80 Polyester resin solutions PE-8 PE-9 PE-10 PE-11 PE-12 PE-13 Monomers Polybasic isophthalic acid 24.5 23.5 22.5 22.5 26.5 22.5 (parts by carboxylic phthalic anhydride 18.8 16.8 14.8 14.8 20.8 14.8 mass) acid adipic acid 16.58 18.22 17.41 16.56 14.01 15.53 Polyhydric neopenty glycol 34.1 30.5 13.8 10.2 35.5 6.3 alcohol 1,6-hexanediol 5.5 5.5 8.5 4.4 2.5 1.1 trimethylolpropane 0.52 5.48 22.99 31.54 0.69 39.77 Acid value 25 18 5 5 37 3 Percentage solids (%) 50% 50% 50% 50% 50% 50% Properties of solids number average molecular 3,000 3,000 3,000 3,000 3,000 3,000 weight (Mn) hydroxyl value (mg KOH) 15 45 140 180 4 220

(5) Production of Thermosetting Compositions PA-1 to PA-42

(6) Among the components stated in table 2, titanium dioxide and component (A) were mixed, introduced into a ring mill and dispersed until the titanium dioxide particle size reached 10 μm or less. After this, the other components stated in table 2 were each added and mixed in, and thermosetting compositions PA-1 to PA-42 were obtained. The thermosetting compositions PA-1 to PA-42 obtained were subjected to viscosity adjustment to Ford Cup No. 4 80±10 seconds by means of the mixed solvent (aromatic solvent “Solvesso 100” Exxon-Mobil Chemical Corp.)/cyclohexanone=50/50 (mass ratio).

(7) TABLE-US-00002 TABLE 2A Thermosetting composition production examples Thermosetting composition PA-1 PA-2 PA-3 PA-4 PA-5 PA-6 PA-7 PA-8 PA-9 Titanium dioxide 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 A: polyester resin PE-1 (solids content conversion) 71.2 79.1 77.1 62.2 52.2 89.2 45.4 70.0 66.7 B: blocked isocyanate B-1 28.8 37.8 10.8 (solids content conversion) B-2 20.9 47.8 54.6 B-3 22.9 B-4 30.0 B-5 33.3 C: organotin compound C-1 0.5 0.5 C-2 0.5 0.5 0.5 0.5 0.5 0.5 C-3 0.5 C-4 C-5 D: organosilicate D-1 5.0 5.0 5.0 D-2 5.0 5.0 5.0 D-3 5.0 5.0 5.0 E: compound (E) E-1 5.0 5.0 5.0 E-2 5.0 5.0 5.0 E-3 5.0 5.0 5.0 Equivalents of component (B) 1 0.55 0.7 1.5 1.9 0.3 2.5 1 1 relative to hydroxyl groups of component (A) Total resin solids content X of 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 component (A) and component (B) Mass % of component (C) 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 relative to total content X Mass % of component (D) 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 relative to total content X Mass % of component (E) 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 relative to total content X Thermosetting composition PA-10 PA-11 PA-12 PA-13 PA-14 PA-15 PA-16 PA-17 Titanium dioxide 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 A: polyester resin PE-1 (solids content conversion) 71.2 67.5 70.2 71.2 67.5 70.2 70.2 71.2 B: blocked isocyanate B-1 28.8 28.8 28.8 (solids content conversion) B-2 32.5 32.5 B-3 29.8 29.8 29.8 B-4 B-5 C: organotin compound C-1 0.1 3.0 C-2 0.2 0.03 6.0 C-3 2.0 C-4 0.5 C-5 0.5 D: organosilicate D-1 5.0 5.0 5.0 D-2 5.0 5.0 5.0 D-3 5.0 5.0 E: compound (E) E-1 5.0 5.0 5.0 E-2 5.0 5.0 E-3 5.0 5.0 5.0 Equivalents of component (B) 1 1 1 1 1 1 1 1 relative to hydroxyl groups of component (A) Total resin solids content X of 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 component (A) and component (B) Mass % of component (C) 0.10 0.20 2.00 3.00 0.03 6.00 0.50 0.50 relative to total content X Mass % of component (D) 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 relative to total content X Mass % of component (E) 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 relative to total content X

(8) TABLE-US-00003 TABLE 2B Thermosetting composition production examples Thermosetting composition PA-18 PA-19 PA-20 PA-21 PA-22 PA-23 PA-24 PA-25 PA-26 PA-27 PA-28 PA-29 PA-30 Titanium dioxide 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 A: polyester resin PE-1 (solids content 67.5 70.2 71.2 67.5 71.2 70.2 71.2 67.5 71.2 70.3 71.2 67.5 70.2 conversion) B: blocked B-1 28.8 28.8 28.8 28.8 28.8 isocyanate (solids B-2 32.5 32.5 32.5 32.5 content B-3 29.8 29.8 29.7 29.8 conversion) B-4 B-5 C: organotin C-1 0.5 0.5 0.5 0.5 compound C-2 0.5 0.5 0.5 0.5 0.5 C-3 0.5 0.5 0.5 0.5 C-4 C-5 D: organosilicate D-1 3.0 0.4 5.0 5.0 D-2 10.0 55.0 5.0 5.0 D-3 1.0 20.0 5.0 5.0 E. compound (E) E-1 5.0 5.0 5.0 0.3 2.0 E-2 5.0 5.0 10.0 E-3 5.0 5.0 0.5 20.0 Equivalents of 1 1 1 1 1 1 1 1 1 1 1 1 1 component (B) relative to hydroxyl groups of component (A) Total resin solids 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 content X of component (A) and component (B) Mass % of 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 component (C) relative to total content X Mass % of component 1.0 3.0 10.0 20.0 0.0 0.4 55.0 5.0 5.0 5.0 5.0 5.0 5.0 (D) relative to total content X Mass % of component 5.0 5.0 5.0 5.0 5.0 5.0 5.0 0.0 0.3 0.5 2.0 10.0 20.0 (E) relative to total content X

(9) TABLE-US-00004 TABLE 2C Thermosetting composition production examples Thermosetting composition PA-31 PA-32 PA-33 PA-34 PA-35 PA-36 PA-37 PA-38 PA-39 PA-40 PA-41 PA-42 Titanium dioxide 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 A: polyester resin PE-2 PE-3 PE-4 PE-5 PE-6 PE-7 PE-8 PE-9 PE-10 PE-11 PE-12 PE-13 (solids content conversion) 70.3 71.2 67.5 70.3 71.2 67.5 92.7 81.4 54.2 51.2 98.0 43.1 B: blocked isocyanate B-1 28.8 28.8 18.6 2.0 (solids content conversion) B-2 32.5 32.5 45.8 56.9 B-3 29.7 29.7 7.3 48.8 B-4 B-5 C: organotin compound C-1 0.5 0.5 0.5 0.5 C-2 0.5 0.5 0.5 0.5 C-3 0.5 0.5 0.5 0.5 C-4 C-5 D: organosilicate D-1 5.0 5.0 5.0 5.0 D-2 5.0 5.0 5.0 5.0 D-3 5.0 5.0 5.0 5.0 E: compound (E) E-1 5.0 5.0 5.0 5.0 E-2 5.0 5.0 5.0 5.0 E-3 5.0 5.0 5.0 5.0 Equivalents of component (B) 1 1 1 1 1 1 1 1 1 1 1 1 relative to hydroxyl groups of component (A) Total resin solids content X 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 of component (A) and component (B) Mass % of component (C) 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 relative to total content X Mass % of component (D) 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 relative to total content X Mass % of component (E) 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 relative to total content X

(10) Here, the various components used in table 2 are as follows.

(11) Component (B)

(12) B-1: Desmodur BL3175 Sumika Bayer Urethane Corp., MEK oxime-blocked isocyanate, monomer type HDI, solids content 75%, NCO equivalents 378

(13) B-2: Desmodur BL4265 Sumika Bayer Urethane Corp., MEK oxime-blocked isocyanate, monomer type IPDI, solids content 65%, NCO equivalents 519

(14) B-3: Desmodur BL3272 Sumika Bayer Urethane Corp., ε-caprolactam-blocked isocyanate, monomer type HDI, solids content 72%, NCO equivalents 412

(15) B-4: Desmodur BL3575/1 Sumika Bayer Urethane Corp., dimethylpyrazole-blocked isocyanate, monomer type HDI, solids content 75%, NCO equivalents 400

(16) B-5: Product No. 7951 Baxenden Co, dimethylpyrazole-blocked isocyanate, monomer type IPDI, solids content 65%, NCO equivalents 539

(17) Component (C)

(18) C-1: monoethyltin tris(2-ethylhexanoate)

(19) C-2: monobutyltin tris(2-ethylhexanoate)

(20) C-3: monobutyltin trislaurate

(21) C-4: dibutyltin dilaurate

(22) C-5: dioctyltin dilaurate

(23) Component (D)

(24) D-1: MKC silicate MS56 Mitsubishi Chemical Corp.

(25) D-2: MKC silicate MS58B30 Mitsubishi Chemical Corp.

(26) D-3: EMS-485 Colcoat Corp.

(27) Component (E)

(28) E-1: trimethyl orthoacetate

(29) E-2: triethyl orthoformate

(30) E-3: triethyl orthopropionate

Preparation of Test Pieces

(31) The test pieces were prepared according to the methods (1) to (3) below, via the 2 coat 2 bake or 3 coat 3 bake methods.

(32) (1) Undercoat Painting

(33) (1-1) Painting of Epoxy Resin Type Undercoat

(34) An epoxy resin undercoat paint (brand name “Precolor Primer HP32”, BASF Japan (Corp.)) was applied onto a 0.35 mm thick chemical conversion-treated aluminum/zinc alloy-plated steel sheet (Al 55%) with a bar coater to give a dry film thickness of 5 μm, and the undercoat paint film was formed by baking in a hot air dryer for 40 seconds with a maximum attained sheet temperature of 210° C.

(35) (1-2) Painting of Polyester Urethane Type Undercoat

(36) A polyester urethane undercoat paint (brand name “COILTEC U HP300”, BASF Japan (Corp.)) was applied onto the same material as in (1-1) with a bar coater to give a dry film thickness of 25 μm, and the undercoat paint film was formed by baking in a hot air dryer for 40 seconds with a maximum attained sheet temperature of 230° C.

(37) (2) Midcoat Painting

(38) In practical examples 4 and 5, the thermosetting composition PA-22 was applied as midcoat onto the undercoat painted sheet previously painted by the method of (1-2), to give a dry film thickness of 5 μm, and the midcoat paint film was formed by baking in a hot air dryer for 40 seconds with a maximum attained sheet temperature of 230° C.

(39) (3) Production of Topcoat Painted Sheet

(40) The thermosetting compositions PA-1 to 42 were charged into test roller coaters, and while continuously rotating the pickup roller and applicator roller under the conditions in table 3, under the 3 conditions directly after charging, 2 hours after and 4 hours after, painting was intermittently performed on the undercoat painted sheet of (1), or the midcoat painted sheet of (2), and test pieces were obtained by forming topcoat films by baking in a hot air dryer for 40 seconds with a maximum attained sheet temperature of 230° C.

(41) Table 3

(42) Roller Coater Paint Machine Operating Conditions

(43) TABLE-US-00005 TABLE 3 Pickup Applicator Backing roller circ. roller circ. roller circ. Table 3 speed (m/min) speed (m/min) speed (m/min.) When idling 20 20 — When painting 50 80 65 [circ. = circumferential]

(44) The following paint film performance assessments were performed on the 3 topcoat painted sheets obtained in each practical example and comparative example, and the results are shown in table 4. Those painted sheets which show normal performance not only directly after painting, but also after 2 hours and 4 hours are preferable.

(45) (i) 60 Degree Specular Gloss and % Gloss Retention

(46) The specular gloss of the painted sheets was measured directly afterwards, after 2 hours and after 4 hours, the % gloss retention of the painted sheets 2 hours and 4 hours after painting was calculated by the following equation (Num.1), and assessed by the following criteria.
Gloss retention (%)=(60° specular gloss of target painted sheet)/(60° specular gloss of painted sheet directly after painting)×100  [Num.1]

(47) ⊚: 90% or more

(48) ◯: 80% to less than 90%

(49) X: less than 80%

(50) (ii) Bending Workability (1)

(51) At 20° C. room temperature, a coated test piece cut to 5 cm width were bent around a 10 mmΦ cylindrical rod with the coated side facing outside to form U-shape. 6 coated sheets having the same thickness as that of the test piece were inserted into the inside of the U-shape, and they were pressed so that the test piece was bent to 180 degree. For assessment, the tips were examined with a 10× magnifying glass, and assessed by the following criteria.

(52) ⊚: no cracking

(53) ◯: less than 20% cracking

(54) Δ: 20-50% cracking

(55) X: more than 50% cracking

(56) (iii) Bending Workability (2)

(57) At 20° C. room temperature, the test piece was bent to 180 degree by the same method as Bending workability (1) with the exception that only 2 coated sheets were inserted into the U-shape. For assessment, after this they were peeled with cellophane adhesive tape, and assessed by the following criteria.

(58) ⊚: no peeling

(59) ◯: less than 20% peeling

(60) Δ: 20-50% peeling

(61) X: more than 50% peeling

(62) (iv) Bending Workability (3)

(63) At 20° C. room temperature, test pieces previously immersed in boiling water for 2 hours and then cut to 5 cm width were bent to 180 degree by the same method as Bending workability (1) with the exception that only 2 coated sheets were inserted into the U-shape. For assessment, after this they were peeled with cellophane adhesive tape, and assessed by the following criteria.

(64) ⊚: no peeling

(65) ◯: less than 20% peeling

(66) Δ: 20-50% peeling

(67) X: more than 50% peeling

(68) (v) Hydrophilicity, Carbon Stain Resistance

(69) Each test piece was immersed for 12 hours in distilled water at room temperature, then the following tests were performed.

(70) (v-a) Hydrophilicity

(71) The distilled water contact angle with 2 μl liquid drop volume was measured with a Kyowa Interface Science Corp. DM-501 type contact angle meter.

(72) ⊚: contact angle=less than 40°

(73) ◯: contact angle=40-50°

(74) X: contact angle=more than 50°

(75) (v-b) Carbon Stain Resistance

(76) A mixture of distilled water: carbon black FW200 (Orion Engineered Carbons (Corp.))=90/10 (mass ratio) was applied onto the sheets, then, after drying for 2 hours at 40° C., they were washed in one direction 30 times with a dish-washing sponge scourer under running water. The color change (ΔE) before and after the test was measured and assessed by the following criteria:

(77) ⊚: ΔE=less than 2.0

(78) ◯: ΔE=2.0 to 5.0

(79) X: ΔE=more than 5.0

(80) (vi) Rain Streak Stain Resistance

(81) On a fixed house frontage-modelling platform at the BASF Japan (Corp.) Totsuka Works, test pieces (100 mm×200 mm×0.35 mm) were placed so that the paint surface faced northwards, an exposure test was performed, and test pieces exposed for 6 months were obtained.

(82) The condition of the paint surface of each test piece was observed visually, and assessed according to the following criteria:

(83) ⊚: no rain streak tracks observed

(84) ◯: rain streak tracks observed to slight extent

(85) X: rain streak tracks observed

(86) TABLE-US-00006 TABLE 4A Practical Example 1 2 3 4 5 6 7 8 9 Undercoat type HP32 HP300 HP300 HP300 HP300 HP32 HP32 HP32 HP300 thickness (μm)  5 25 25 25 25  5  5  5 25 Midcoat type PX22 PA-22 thickness (μm)  5  5 Topcoat type PA-1 PA-1 PA-2 PA-1 PA-2 PA-3 PA-4 PA-5 PA-10 thickness (μm) 20 20 20 20 20 20 20 20 20 <Coating performance> Directly bending workability (1) ◯ ⊚ ◯ ⊚ ◯ ⊚ ⊚ ◯ ⊚ after bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ ◯ hydrophilicity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ rain streak ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ stain resistance After % gloss retention ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ 2 hrs bending workability (1) ◯ ⊚ ◯ ⊚ ◯ ⊚ ⊚ ◯ ⊚ bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ ◯ hydrophilicity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ rain streak ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ stain resistance After % gloss retention ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ 4 hrs bending workability (1) ◯ ⊚ ◯ ⊚ ◯ ⊚ ⊚ ◯ ⊚ bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ ◯ hydrophilicity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ rain streak ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ stain resistance Practical Example 10 11 12 13 14 15 16 Undercoat type HP300 HP32 HP32 HP32 HP300 HP300 HP300 thickness (μm) 25  5  5  5 25 25 25 Midcoat type thickness (μm) Topcoat type PA-11 PA-12 PA-13 PA-18 PA-19 PA-20 PA-21 thickness (μm) 20 20 20 20 20 20 20 <Coating performance> Directly bending workability (1) ⊚ ⊚ ⊚ ◯ ⊚ ⊚ ◯ after bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) ◯ ◯ ◯ ◯ ⊚ ⊚ ◯ hydrophilicity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ rain streak ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ stain resistance After % gloss retention ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ 2 hrs bending workability (1) ⊚ ⊚ ⊚ ◯ ⊚ ⊚ ◯ bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) ◯ ◯ ◯ ◯ ⊚ ⊚ ◯ hydrophilicity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ rain streak ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ stain resistance After % gloss retention ⊚ ⊚ ⊚ ◯ ◯ ⊚ ⊚ 4 hrs bending workability (1) ⊚ ⊚ ⊚ ◯ ⊚ ⊚ ◯ bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) ◯ ◯ ◯ ◯ ⊚ ⊚ ◯ hydrophilicity ⊚ ◯ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ◯ ◯ ◯ ◯ ◯ ⊚ ⊚ rain streak ⊚ ◯ ◯ ⊚ ⊚ ⊚ ⊚ stain resistance

(87) TABLE-US-00007 TABLE 4B Practical Example 17 18 19 20 21 22 23 Undercoat type HP300 HP32 HP32 HP300 HP300 HP32 HP32 thickness (μm) 25  5  5 25 25  5  5 Topcoat type PA-25 PA-26 PA-27 PA-28 PA-29 PA-30 PA-31 thickness (μm) 20 20 20 20 20 20 20 <Coating performance> Directly bending workability (1) ◯ ⊚ ⊚ ⊚ ◯ ⊚ ◯ after bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ bending workability (3) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ hydrophilicity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ rain streak ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ stain resistance After % gloss retention ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ 2 hrs bending workability (1) ◯ ⊚ ⊚ ⊚ ◯ ⊚ ◯ bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ bending workability (3) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ hydrophilicity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ◯ ◯ ⊚ ⊚ ⊚ ⊚ ⊚ rain streak ◯ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ stain resistance After % gloss retention ◯ ◯ ◯ ⊚ ⊚ ⊚ ⊚ 4 hrs bending workability (1) ◯ ⊚ ⊚ ⊚ ◯ ⊚ ◯ bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ bending workability (3) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ hydrophilicity ◯ ◯ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining X X ◯ ⊚ ⊚ ⊚ ⊚ rain streak X ◯ ⊚ ⊚ ⊚ ⊚ ⊚ stain resistance Practical Example 24 25 26 27 28 29 30 Undercoat type HP300 HP300 HP32 HP32 HP32 HP300 HP300 thickness (μm) 25 25  5  5  5 25 25 Topcoat type PA-32 PA-33 PA-34 PA-37 PA-38 PA-39 PA-40 thickness (μm) 20 20 20 20 20 20 20 <Coating performance> Directly bending workability (1) ◯ ◯ ⊚ ⊚ ⊚ ◯ ◯ after bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ hydrophilicity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ⊚ ⊚ ◯ ◯ ⊚ ⊚ ⊚ rain streak ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ stain resistance After % gloss retention ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ 2 hrs bending workability (1) ◯ ◯ ⊚ ⊚ ⊚ ◯ ◯ bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ hydrophilicity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ⊚ ⊚ ◯ ◯ ⊚ ⊚ ⊚ rain streak ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ stain resistance After % gloss retention ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ 4 hrs bending workability (1) ◯ ◯ ⊚ ⊚ ⊚ ◯ ◯ bending workability (2) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ hydrophilicity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ⊚ ⊚ ◯ ◯ ⊚ ⊚ ⊚ rain streak ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ stain resistance

(88) TABLE-US-00008 TABLE 4C Comparative Example 1 2 3 4 5 6 7 8 Undercoat type HP32 HP300 HP32 HP300 HP300 HP300 HP32 HP32 thickness (μm)  5 25  5 25 25 25  5  5 Topcoat type PA-6 PA-7 PA-8 PA-9 PA-14 PA-15 PA-16 PA-17 thickness (μm) 20 20 20 20 20 20 20 20 <Coating performance> Directly bending workability (1) ⊚ X ⊚ ◯ ◯ ⊚ ⊚ ⊚ after bending workability (2) ⊚ X ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) X X ⊚ ◯ Δ ⊚ ⊚ ⊚ hydrophilicity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining ◯ ◯ ⊚ ⊚ X ⊚ ⊚ ⊚ rain streak ◯ ⊚ ⊚ ⊚ ◯ ⊚ ⊚ ⊚ stain resistance After % gloss retention ⊚ ⊚ X ◯ ⊚ ◯ X ◯ 2 hrs bending workability (1) ⊚ X ⊚ ◯ ◯ ⊚ ⊚ ⊚ bending workability (2) ⊚ X ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) X X ⊚ ◯ Δ ⊚ ⊚ ⊚ hydrophilicity ⊚ ⊚ X X ⊚ ◯ X X carbon staining X ◯ X X X X X X rain streak X ⊚ X X X X X X stain resistance After % gloss retention ⊚ ⊚ X X ⊚ X X X 4 hrs bending workability (1) ⊚ X ⊚ ◯ ◯ ⊚ ⊚ ⊚ bending workability (2) ⊚ X ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ bending workability (3) X X ⊚ ◯ Δ ⊚ ⊚ ⊚ hydrophilicity ⊚ ⊚ X X ⊚ X X X carbon staining X ◯ X X X X X X rain streak X ◯ X X X X X X stain resistance Comparative Example 9 10 11 12 13 14 15 Undercoat type HP32 HP300 HP300 HP300 HP300 HP32 HP300 thickness (μm)  5 25 25 25 25  5 25 Topcoat type PA-22 PA-23 PA-24 PA-35 PA-36 PA-41 PA-42 thickness (μm) 20 20 20 20 20 20 20 <Coating performance> Directly bending workability (1) ⊚ ⊚ X Δ ⊚ ⊚ Δ after bending workability (2) ⊚ ⊚ X Δ ⊚ ⊚ Δ bending workability (3) ⊚ ⊚ X X Δ Δ X hydrophilicity X ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining X ◯ ⊚ ⊚ X X ⊚ rain streak X ◯ ⊚ ⊚ X X ⊚ stain resistance After % gloss retention ⊚ ◯ ⊚ ⊚ ⊚ ⊚ ⊚ 2 hrs bending workability (1) ⊚ ⊚ X Δ ⊚ ⊚ Δ bending workability (2) ⊚ ⊚ X Δ ⊚ ⊚ Δ bending workability (3) ⊚ ⊚ X X Δ Δ X hydrophilicity X ◯ ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining X X ⊚ ⊚ X X ⊚ rain streak X X ⊚ ⊚ X X ⊚ stain resistance After % gloss retention ⊚ X ⊚ ⊚ ⊚ ⊚ ⊚ 4 hrs bending workability (1) ⊚ ⊚ X Δ ⊚ ⊚ Δ bending workability (2) ⊚ ⊚ X Δ ⊚ ⊚ Δ bending workability (3) ⊚ ⊚ X X Δ Δ X hydrophilicity X X ⊚ ⊚ ⊚ ⊚ ⊚ carbon staining X X ⊚ ⊚ X X ⊚ rain streak X X ⊚ ⊚ X X ⊚ stain resistance