WEATHERABLE AND DURABLE COATING COMPOSITIONS

Abstract

A curable coating composition is provided having multi-functionalized acrylic copolymer and amino-functional silicone resin curing agents. The acrylic copolymer of the curable coating composition has, in polymerized form, epoxy functionalized groups and cure compatibility groups and the amino-functional silicone resin is an aryloxy-containing amino-functional siloxane, which optionally is derived from sterically hindered alcohol-amine precursor moieties. The coating compositions are useful in the field of superior weatherable and durable coatings and are useful to replace isocyanate-containing polyurethane based coatings. Also provided are coated articles produced from the curable composition.

Claims

1. A curable coating composition comprising: (1) an amino-functional silicone resin comprising in polymerized form, structural units of: (i) (R.sub.3SiO.sub.1/2).sub.a; (ii) (R.sub.2Si(OR′).sub.xO.sub.(2-x)/2).sub.b; (iii) (RSi(OR′).sub.y,O.sub.(3-y)/2).sub.c; and (iv) (Si(OR′).sub.zO.sub.(4-z)/2).sub.d wherein each R′ is independently hydrogen, an alkyl group, a functionalized alkyl group, an aryl group or a functionalized aryl group, provided that at least 10 mole percent of all R′ groups are aryl groups or functionalized aryl groups; wherein each R is independently hydrogen, an alkyl group, or a functionalized alkyl group; wherein at least 10 mole percent of the combination of R and R′ groups are amine containing groups of the formula: —R.sub.a—NHR.sub.b where R.sub.a is an alkyl group or an aryl-containing group derived from an amino alcohol and R.sub.b is hydrogen or an alkyl group; wherein a+b+c+d=1.00 (100 mole percent); x is either 0 or 1; y is either 0, 1 or 2; and z is either 0, 1, 2, or 3; and the —NH— equivalent mass of the amino-functional silicone resin is from 50 to 750; and (2) an acrylic copolymer which has, in polymerized form, epoxy functionalized groups and cure compatibility groups; and wherein the coating composition has a molar ratio of amine NH functionality to epoxy functionality in the range of from 0.5 to 1.3.

2. The coating composition of claim 1 having a molar ratio of amine NH functionality to epoxy functionality in the range of from 0.8 to 1.

3. The coating composition of claim 1 wherein at least 20 mole percent of the combination of R and R′ groups of the amino-functional silicone resin are amine containing groups of the formula: —R.sub.a—NHR.sub.b.

4. The coating composition of claim 1 wherein from 5 to 42 mole percent of the combination of R and R′ groups of the amino-functional silicone resin are amine containing groups of the formula: —R.sub.a—NHR.sub.b.

5. The coating composition of claim 1 wherein the amino alcohol is selected from the group which (a) has steric hindrance around the COH moiety; (b) is a secondary or tertiary alcohol; or (c) mixtures thereof.

6. The coating composition of claim 1 wherein the amino alcohol is 1-amino-2-propanol or 1-amino-2-methylpropan-2-ol.

7. The coating composition of claim 1 wherein from 20 to 50 mole percent of all R′ groups are aryl groups or functionalized aryl groups.

8. The coating composition of claim 1 wherein the epoxy functionalized groups of the acrylic copolymer are derived from one or more monomers selected from the group of glycidyl maethacrylate (GMA), glycidyl acrylate, and mixtures thereof; and wherein the acrylic copolymer has an epoxy equivalent weight (EEW) in the range of 200-600.

9. The coating composition of claim 8 wherein the acrylic copolymer comprises in polymerized form, 30-60% glycidyl (meth)acrylate monomer units by weight based on the weight of the total monomer units of the acrylic copolymer.

10. The coating composition of claim 1 wherein the acrylic copolymer comprises in polymerized form, from 2% to 20% cure compatibility group monomer units by weight based on the weight of the total monomer units of the acrylic copolymer.

11. The coating composition of claim 1 wherein the cure compatibility groups of the acrylic copolymer comprise monomer groups, in polymerized form, that contain one or more of alcohol (OH) functionality, a phenolic group, a tertiary amine or an acid group that is either pendant to the backbone or attached as an end group.

12. The coating composition of claim 1 wherein the cure compatibility group is derived from hydroxyethyl methacrylate (HEMA).

13. A coated article comprising one or more layers of a cured coating composition of claim 1.

Description

EXAMPLES AND EXPERIMENTAL METHODS

Acrylic Copolymers

[0050] Xylene was added to a 500 mL 4 neck round bottomed flask, equipped with stir shaft, condenser, thermocouple port and addition ports. A heating mantle was used to bring the temperature of the xylene up to reflux (140° C.). A monomer blend consisting of glycidyl methacrylate (GMA), methyl methacrylate (MMA), 2-ethylhexyl acrylate (EHA), and 2-hydroxyethyl methacrylate (HEMA) was weighed out and mixed in a 500 mL glass jar then divided equally into 50 mL plastic feed syringes with Luer Lock connectors. The initiator, tert-butylperoxyacetate (TBPA, 50% in mineral spirits) was added to a single 50 mL plastic syringe and connected to feed tubing via the Luer Lock connection with long feed needle attachment. A dual syringe pump was used to add monomer mix at a constant feed rate and a single feed syringe pump was used to feed the initiator. The feeds were initiated when the solvent was at reflux. The feed rate time and temperature are dependent on the solvent and the half-life of the initiator. Once feeds were depleted the lines were flushed with small amount of solvent. Run was continued for an additional hour to reduce residual monomer and initiator to acceptable levels. Table 1 shows the acrylic copolymers made.

TABLE-US-00001 TABLE 1 Acrylic copolymers EEW g/mol EEW g/mol Tg epoxy, as epoxy, on Acrylic GMA MMA EHA HEMA TBPA xylene % solids ° C. measured solids A1 Wt % of 50 10 30 10 75% −3 400 300 monomer composition grams 150 30 90 30 36 88 A2 Wt % of 50 15 35 0 72% −2 400 300 monomer composition grams 150 45 105 0 36 88

Acrylic Copolymer Characterization

GPC

[0051] Sample was dissolved 2 mg/mL in tetrahydrofuran (THF); solutions were filtered through 0.2 μm PTFE syringe filter prior to injection. Molecular weight measurements were performed with GPC measured on an Agilent 1100 series with MIXED-D columns (300×7.5 mm) at a flow rate of 1.0 mL/min at 35° C. Agilent refractive index detector is used by Agilent GPC/SEC software. Calibration is performed using 17 narrow PS standards from Polymer labs, fit to a 3rd order polynomial curve over the range of 3,742 kg/mol to 0.580 kg/mol.

EEW

[0052] EEW is measured in accordance with ASTM D1652. The epoxy resin is dissolved in methylene chloride and titrated with standardized 0.1N perchloric acid (HClO4) in glacial acetic acid in the presence of excess tetraethyl ammonium bromide (TEAB) in acetic acid. Measurements were performed using a Metrohm 905 titrator and the associated Tiamo titration software configured for EEW determinations.

Percent Solids

[0053] Label the bottom of a small aluminum pan, place the pan on a scale and record its weight to the closest 0.0001 gram. Distribute approximately 0.5 g-1.5 g of sample evenly in the pan using a pipette. Record that weight as initial (pan+sample). Place on baking pan and clip down with a binder clip before putting sample in oven, cover resin with about 2 grams of toluene using pipette, then carefully place in pre-heated Class A oven. After 2 hours, remove baking pan and samples from the oven. Tare balance and place sample (and pan) on balance and record final weight, and calculate the solids content by the formula:

Solids %=(Final weight−pan weight)/(initial weight−pan weight)*100

Glass Transition Temperature

[0054] The T.sub.g was measured with Differential Scanning Calorimetry DSC Q2000 V24.10 in accordance with ASTM D7426 with a sample size of about 5-10 mg. The temperature profiles performed as followed: Isotherm at 10° C. for 5 minutes, Ramp to −50° C. @ 10° C./minute, isotherm for 5 minutes, ramp to 150° C. @ 10° C./minute, isotherm for 5 minutes, Tg was analyzed with TA software.

Viscosity

[0055] Viscosity measurements were taken using the Brookfield DV-III Ultra viscometer with the Small Sample Adapter (SSA). The Small Sample Adapter's rheologically correct cylindrical geometry provides extremely accurate viscosity measurements and shear rate determinations. For these samples 9 mL of material was deposited into the cylinder and spindles #31 or #34 were used and the speed was varied to achieve a torque of ˜25 Newton meters (N*m). Measurements were reported in unites of centipoises (cP).

Amino-Functional Silicone Resins

[0056] Amino-functional silicone resins S1 to S6 are shown in Table 2. Resins S1-S4 incorporate aryl groups through SiOC grafting, resin S5 incorporates aryl groups through SiC grafting and resin S6 does not incorporate aryl groups. Resins S1, S3 and S4 incorporate amine functionality through SiC bonds, while resins S2, S5 and S6 incorporate amine functionality through SiOC bonds. The procedures for producing resins S1-S6 are provided after Table 2.

TABLE-US-00002 TABLE 2 SiOC Resin Candidate SiC Amine SiC Aryl Amine SiOC Aryl S1 Benzyloxy on Me-T, Aminopropyl- none none benzyl NH.sub.2-T triethoxysilane alcohol S2 Benzyloxy on Me-T, none none 1-amino-2- benzyl SiOC NH.sub.2 propanol alcohol S3 secondary aryloxy on Aminopropyl- none none sec-phenethyl Me-T, NH.sub.2-T triethoxysilane alcohol S4 tertiary aryloxy on Aminopropyl- none none 2-methyl-1- Me-T, NH.sub.2-T triethoxysilane phenyl-2- propanol S5 DT.sup.Ph, SiOC NH.sub.2 none Phenyltrimeth- 1-amino-2- none oxysilane propanol S6 Me-T + amino- none none 1-amino-2- none propanol propanol
S1: D.sub.0.14T.sup.NH2.sub.0.22T.sup.Me.sub.0.64(OBz).sub.0.21, amine equivalent weight 261 g/eq NH, 37 mol % OMe, 20 mol % OEt

Reagents:

[0057] Methyltrimethoxysilane (MTM)—Mw=136.22 [0058] Dimethyldimethoxysilane—Mw=120.22 [0059] Aminopropyltriethoxysilane—Mw=221.37 [0060] Benzyl alcohol—Mw=108.14 g/mol; bp=205° C.

Procedure:

[0061] A 250 mL 2 neck round bottom flask was loaded with: [0062] MTM (80.96 g, 0.594 mols, 1.783 mols OMe) [0063] Dimethyldimethoxysilane (21.88 g, 0.182 mols, 0.364 mols OMe) [0064] 3-Aminopropyl Triethoxysilane, available from The Dow Chemical Company as Dowsil™ Z-6011 (48.78 g, 0.220 mols, 0.660 mols OEt) [0065] benzyl alcohol (22.25 g, 0.206 mols)
The flask was equipped with a magnetic stir bar and a Dean Stark apparatus attached to a water-cooled condenser. The mixture was compatible at room temperature. DI water (16.73 g, 0.929 mols) was added slowly, starting at room temperature. Exotherm to 46° C. and then heated with an aluminum block at a pot temperature of 65° C. for 1 hour. Then increase temperature and distill off alcohols up to a pot temperature of 150° C. Amount of volatiles removed: 73.65 g. Continued to heat at 150° C. for 5 hours. 1.65 g of volatiles were removed within the first hour. No more collected after this time. Stripped product on a rotovapor at an oil bath temperature of 120° C. and ˜1.5-2 mm Hg. The product was a clear, colorless, viscous liquid at room temperature. Isolated Yield: 100.5 g. Calculated amine equivalent weight from .sup.13C NMR spectrum: 261 g/mol NH. NMR Analysis of product:
D.sub.0.136T.sup.PrNH2.sub.0.219T.sup.Me.sub.0.645, OZ content: 79.1 mol % (OMe=36.6 mol %; OEt=19.7 mol %; OBz=21.2 mol %; OH=1.6 mol %).
S2: T.sup.Me.sub.0.99(OBz).sub.0.2(OCH(CH.sub.3)CH.sub.2NH.sub.2).sub.0.18, amine equivalent weight 297 g/eq NH, 32.5 mol % OZ)

Reagents:

[0066] Methyl-T Resin (as described below): D.sub.0.01T.sup.Me.sub.0.99 FW=83.52 g/mol Si; OZ=71.77 mol % (OMe=70.30 mol %, OH=1.47 mol %) [0067] 1-amino-2-propanol—Mw=75.11, bp=160° C. [0068] Benzyl alcohol—Mw=108.14 g/mol, bp=205° C. [0069] Xylenes—ACS grade

Procedure:

[0070] A 250 mL 2 neck round bottom flask was loaded with: [0071] Methyl-T Resin (84.89 g, 1.016 mols Si, 0.729 mols OZ) [0072] 1-amino-2-propanol (16.52 g, 0.220 mols) [0073] Benzyl alcohol (22.21 g, 0.205 mols) [0074] Xylenes (36.67 g)
The flask was equipped with a magnetic stir bar and a Dean Stark apparatus attached to a water-cooled condenser. The amount of xylenes added would result in a theoretical yield of 75 wt % in xylenes. Reaction mixture was initially hazy at room temperature, but turned clear within 5 minutes at room temperature. —theoretical amount of methanol that could be produced if 100% of BzOH & amine reacted: 13.62 g. Heated with an aluminum block at a pot temperature of 135° C. Start time was measured from when volatiles first began to collect in the Dean Stark apparatus which corresponded to a pot temperature of 127° C. Allowed reaction to heat up to 135° C. and then held at this temperature. Total time: 12 hours. Volatiles removed: 30 min-3.81 g; 1 hr-6.28 g; 2 hrs-8.39 g; 3 hrs-10.06 g; 4 hrs-10.55 g; 5 hrs-10.77 g. No more volatiles collected after 5 hours. Sample at 12 hrs was analyzed by 13C NMR and showed ˜89% of the 1-amino-2-propanol had reacted onto silicon. ˜93% of the benzyl alcohol had also reacted onto silicon.
Methyl-T Resin production: T.sup.Me.sub.1 resin with target 75 mol % OMe

Reagents:

[0075] Methyltrimethoxysilane—Mw=136.22 [0076] DI water [0077] Trifluoromethanesulfonic acid, available from 3M as Fluorad™ FC-24—Mw=150.08 g/mol, density=1.696 g/ml [0078] Calcium Carbonate powder≤50 um particle size, Mw=100.09 g/mol

Procedure:

[0079] A 1 L 4 neck round bottom flask was loaded with methylltrimethoxysilane (650.0 g, 4.772 mols Si, 14.315 mols OMe). Added FC24 (0.33 g, 192 uL). This amounts to 500 ppm. Added DI water (96.71 g, 5.368 mols) slowly starting at room temperature. Exotherm to 64° C. Theoretical amount of methanol that could be produced: 344.0 g (assuming 100% hydrolysis and condensation). Heated at 65° C. for 2 hours. Distilled off 320.88 g of methanol up to a pot temperature of 75° C. Added calcium carbonate (1.32 g) to neutralize the FC24. This amounts to 4× the amount of FC24 added (on a weight basis). Mixed for 2 hours while cooling to room temperature. Stripped resin on a rotovapor. Oil bath temp=50° C., ˜50-60 mm Hg. Pressure filtered through a 142 mm diameter Magna, Nylon, Supported, Plain, 0.45 Micron filter at room temperature. Isolated Yield: 394.0 g. Product was a clear, low viscosity liquid at room temperature. Molecular weight: Mn=1,837; Mw=2,838 (relative to polystyrene standards in THF). 29Si NMR Analysis of Product: D.sup.Me2.sub.0.010T.sup.Me.sub.0.990, OZ=71.77 mol % (70.30 mol % OMe, 1.47 mol % OH), FW=83.52 g/mol Si. Methoxy content calculated from 13C NMR using CDCl3 as an internal standard.
S3: An amine siloxane resin with aryl groups added through SiOC using a secondary alcohol and amine functionality added through SiC bonds

Reagents:

[0080] Methyltrimethoxysilane (MTM)—Mw=136.22 [0081] Dimethyldimethoxysilane—Mw=120.22 [0082] Aminopropyltriethoxysilane—Mw=221.37 [0083] DL-sec-Phenethylalcohol (sPhEtOH)—Mw=122.17 g/mol, bp=203-205° C.

Procedure:

[0084] A 250 mL 2 neck round bottom flask was loaded with: [0085] MTM (77.25 g, 0.567 mols, 1.701 mols OMe) [0086] Dimethyldimethoxysilane (20.88 g, 0.174 mols, 0.347 mols OMe) [0087] Z-6011 (48.76 g, 0.220 mols, 0.660 mols OEt) [0088] sec-phenethylalcohol (25.10 g, 0.205 mols)
The flask was equipped with a magnetic stir bar and a Dean Stark apparatus attached to a water-cooled condenser. Mixture was compatible at room temperature. Added DI water (16.17 g, 0.898 mols) slowly starting at room temperature. Exotherm to 43° C. Heated with an aluminum block at a pot temperature of 65° C. for 1 hour. Increase temperature and distilled off alcohols up to a pot temperature of 150° C. Amount of volatiles removed: 67.98 g. Continued to heat at 150° C. for 10 hours. Volatiles removed: 1 hr-2.22 g; 2 hrs-3.57 g; 3 hrs-4.02 g; 4 hrs-4.22 g; 5 hrs-4.42 g. No more volatiles collected after 5 hours. Stripped product on a rotovapor at an oil bath temperature of 120° C. and ˜1.5-2 mm Hg. Results: Product was a clear viscous liquid with a slight yellow tint at room temperature. Isolated Yield: 98.4 g. Calculated amine equivalent weight from .sup.13C NMR spectrum: 258 g/mol NH. NMR Analysis of product: D.sub.0.135T.sup.PrNH2.sub.0.227T.sup.Me.sub.0.638; OZ content: 78.5 mol % (OMe=32.1 mol %; OEt=23.9 mol %; sec-PhEtO=20.1 mol %; OH=2.4 mol %); 8.52 wt % OMe; 9.18 wt % OEt; 20.8 wt % sec-PhEtO; 13.3 wt % Phenyl (from sec-PhEtO) OR values calculated from 13C NMR data using CDCl3 as an internal standard. Si molar fractions for T.sup.PrNH2 and T.sup.Me derived from 13C NMR data.
S4: An amine siloxane resin with aryl groups added through SiOC using a tertiary alcohol and amine functionality added through SiC bonds

Reagents:

[0089] Methyltrimethoxysilane (MTM)—Mw=136.22 g/mol [0090] Aminopropyltrimethoxysilane—Mw=179.29 [0091] 2-Methyl-1-Phenyl-2-Propanol—Mw=150.22, bp=215° C. [0092] Xylenes—ACS grade [0093] KOH (45% in water)—Mw=56.1 g/mol [0094] HCl solution—Diluted 8.0N HCl in water in methanol resulting in a solution containing 0.000742 mols HCl/gram

Procedure:

[0095] A 250 mL 2 neck round bottom flask was loaded with: [0096] MTM (97.01 g, 0.712 mols, 2.136 mols OMe) [0097] Aminopropyltrimethoxysilane (39.40 g, 0.22 mols, 0.659 mols OMe) [0098] 2-Methyl-1-Phenyl-2-Propanol (39.85 g, 0.265 mols)
The flask was equipped with a magnetic stir bar and a Dean Stark apparatus attached to a water-cooled condenser. Added 1.8× MePhPrOH. Added DI water (17.14 g, 0.951 mols) slowly starting at room temperature. Exotherm to 50° C. Heated with an aluminum block at a pot temperature of 65° C. for 1 hour. Hazy the entire time. Increase temperature and distilled off methanol up to a pot temperature of 95° C. Amount of volatiles removed: 53.9 g. Diluted to ˜75% with xylenes (36.67 g). Clear. With mixing added a solution containing (0.122 g of 45% KOH (aq) in 1 g of methanol) at room temperature. This amount of KOH amounts to ˜500 ppm based on the theoretical yield. Heated with an aluminum block. Start time was measured from when volatiles first began to collect in the Dean Stark apparatus which corresponded to a pot temperature of 91° C. Allowed to heat up to 115° C. and then left at this temperature. Volatiles removed: 30 min=9.32 g; 1 hr=10.72 g; 2 hrs=11.86 g; No more volatiles collected afte 2 hours. Total time=12 hrs. 13C NMR analysis of 5 hr sample showed ˜35% of MePhPrOH had reacted onto silicon. 13C NMR analysis of 12 hr sample showed ˜46% of MePhPrOH had reacted onto silicon. At room temperature added HCl solution (1.38 g of solution). Stoichiometry 1.05 mols HCl: 1.0 mols KOH. Mixed overnight at room temperature. Stripped product on a rotovapor at an oil bath temperature of 120° C. and ˜2 mm Hg. Pressure filtered through an Osmonics MAGNA Nylon Supported Plain 0.45 um filter (47 mm diameter) at room temperature. Filtration rate was slow. Only filtered 80-90% of the material.
Results: Product was a clear, light yellow, viscous liquid at room temperature. Isolated Yield: 91.3 g. Calculated amine equivalent weight from .sup.13C NMR spectrum: 229 g/mol NH. NMR Analysis of product: T.sup.PrNH2.sub.0.233T.sup.Me.sub.0.767; OZ content: 63.8 mol %; (51.3 mol % OMe, 12.5 mol % MePhPrO); 17.5 wt % MePhPrO; 9.1 wt % Phenyl (from MePhPrO); Si molar ratios and OR values derived from 13C NMR data.
S5: DTPh resin reacted with amino-propanol

Reagents:

[0099] Dowsil™ 3074, available from The Dow Chemical Company—D.sub.0.337T.sup.Cyclohexyl.sub.0.010T.sup.Ph.sub.0.653; OZ=68.64 mol %; FW-126.5 g/mol Si [0100] 1-amino-2-propanol—Mw=75.11, bp=160° C.

Procedure:

[0101] A 250 mL 1 neck round bottom flask was loaded with: Dowsil™ 3074 (94.19 g, 0.745 mols Si. 0.511 mols OZ) and 1-amino-2-propanol (16.52 g, 0.220 mols, 0.440 mols NH). The flask was equipped with a magnetic stir bar and a Dean Stark apparatus attached to a water-cooled condenser. Mixture was not compatible at room temperature. Heated at an aluminum block temperature of 140° C. for 2 hours. Amount of volatiles collected in 1st hour was 3.35 g and in the 2nd hour was 0.31 g. The reaction mixture turned clear while heating to 140° C. Increased block temperature to 180° C. Held at this temperature for 2 hours. Amount of volatiles collected in 1st hour was 1.85 g and in the 2nd hour was 0.13 g. Stripped product on a rotovapor at an oil bath temperature of 115° C. and ˜1 mm Hg.
Results: Product was a clear viscous liquid at room temperature. Isolated Yield: 100.9 g. Calculated amine equivalent weight from .sup.13C NMR spectrum: 256 g/mol NH. NMR Analysis of product: D.sub.0.333T.sup.Cyclohexyl.sub.0.007T.sup.Ph.sub.0.660; OZ content: 61.95 mol % 26.9 mol % OR; 33.5 mol % OMe. The above two OR values were calculated from 13C NMR by taking the ratio of the OR integral value and dividing that by the integral value of phenyl groups.
S6: Me-T resin reacted with 1-amino-2-propanol without aryl functionality

Reagents:

[0102] Dowsil™ CF-2403 Methyl-T Resin, available from The Dow Chemical Company—D.sub.0.015T.sup.Me.sub.0.985 FW=93.4 g/mol Si; OMe=113.6 mol % [0103] 1-amino-2-propanol—Mw=75.11, bp=160° C.

Procedure:

[0104] A 250 mL 2 neck round bottom flask was loaded with Dowsil™ CF-2403 (80.0 g, 0.857 mols Si, 0.973 mols OMe) and 1-amino-2-propanol (14.47 g, 0.193 mols). The flask was equipped with a magnetic stir bar, a nitrogen blanket was applied, and a Dean Stark apparatus was attached to a water-cooled condenser. Reaction mixture was hazy at room temperature. Heated with an aluminum block. Start time was measured from when volatiles first began to collect in the Dean Stark apparatus which corresponded to a pot temperature of 101° C. Allowed to heat up to 125° C. and then held at this temperature. Total time=4 hrs. Reaction mixture turned clear at ˜60° C. during heating up. Volatiles removed: 30 min-5.97 g; 1 hr-6.00 g. No more volatiles collected after 1 hour. Stripped product on a rotovapor at an oil bath temperature of 70° C. and ˜2 mm Hg.
Results: Product was a clear low viscosity liquid at room temperature. Yield: 76.4 g. Calculated amine equivalent weight from .sup.13C NMR spectrum: 241 g/mol NH. The amine equivalent weight was calculated from 13C NMR data using the average of 2 carbons (˜20 ppm & ˜70 ppm) in the 13C NMR spectra and using CDCl3 as an internal reference. Integral values (9.38 & 8.62). NMR Analysis of product: D.sub.0.010T.sup.Me.sub.0.990 Total OZ content: 100.3 mol % (20.6 mol % OR; 79.7 mol % OMe) OR=1-amino-2-propanol reacted onto silicon.

Coating Formulation: Clear Coatings

[0105] The clear coating compositions of Table 3 were prepared by the following manner: the acrylic copolymer was placed in a MAX 40 SpeedMixer™ cup and the amino-functional silicone resin was added and mixed for 2 minutes at 2000 rpm in FlackTek™ DAC150 SpeedMixer™. In formulating the coating compositions, the acrylic copolymer and amino-functional silicone resin are added in an amount to provide an epoxy/NH molar ratio of 1:1.

TABLE-US-00003 TABLE 3 Silicone Coating Coating Acrylic Silicone Resin Optical Coating Example Copolymer Resin Description Quality Tg (° C.) CTG 1 A1 S1 SiC Amine, Clear 49.4 SiOC Aryl CTG 2 A1 S2 SiOC Amine, Clear 45.5 SiOC Aryl CTG 3 A1 S3 SiC Amine, Slightly Not SiOC s-Aryl Cloudy tested CTG 4 A1 S4 SiC Amine, Clear Not SiOC t-Aryl tested CTG 5 A1 S5 SiOC Amine, Slightly 49.2 SiC Aryl Cloudy CTG 6 A1 S6 SiOC Amine, Milky Not no Aryl Cloudy tested CTG 7 A2 S1 SiC Amine, Clear Not SiOC Aryl tested CTG 8 A2 S2 SiOC Amine, Slightly Not SiOC Aryl Cloudy tested
Coating Tg was determined after 10 days of moisture cure, measured using DSC (1.sup.st heating at 20° C./min).
Comparisons of CTG 1, CTG 2 and CTG 5 in Table 2 illustrate the benefits of the present invention. CTG 1 contains 21 mole % of phenyl groups, CTG 2 contains 22 mole % of phenyl groups and CTG 5 contains 66 mole % of phenyl groups. Although comparative CTG 5 contains a higher mol % of phenyl groups than CTG 1 or CTG 2, and incorporates these groups through SiC bonds, cloudy coatings result which will translate into inferior properties. CTG 1 and CTG 2 show that incorporation of phenyl groups through SiOC bonds can offer high quality, optically clear coatings even with aryl group incorporation amounts that are lower than the SiC bonded version. The industrial applicability of the present invention cannot be understated considering the low cost of SiOC based resins as compared to SiC based resins.

Draw Down Application Method for Clear Coat Applications

[0106] A coating was applied to Q-Panel R-412-I (phosphate treated cold rolled steel) and AL 412 (chromate treated aluminum) panels according to ASTM D4147. The panel was secured on a firm horizontal surface using a magnetic chuck or clamp. A multiple clearance square applicator was used to apply coating to the panel, 5 to 6 mil wet thickness was targeted to achieve the desired dry film thickness of ˜2.5 mils.

Coating Application and Test Methods

Drawdown Procedure

[0107] A coating was applied to metal panels according to ASTM D4147-99(2007). The panel was secured on a firm horizontal surface using a magnetic chuck. An ample amount of coating was poured across the top end of the panel and 5 mil gap wet film applicator is used to draw down the coating with uniform pressure and speed along the length of the panel toward the operator to apply a uniform film. Panels were allowed to cure in the lab at a controlled temperature and humidity of 72° F. and 50% relative humidity.
Dry Time: Coatings were drawn down onto 1″×12″ glass substrates with a wet film thickness of 76 micrometers (μm) and set on a BYK drying time recorder. The set-to-touch, tack-free time, and dry hard were measured by dragging a needle through the coating using a BYK drying time recorder according to ASTM D5895-03.
Pendulum Hardness: Pendulum hardness was measured using a Pendulum Hardness Tester from BYK Gardner equipped with a König pendulum. The tester was run according to ISO 1522 and set to measure hardness in seconds.

Pencil Hardness

[0108] The pencil hardness of a coating film is measured according to the ASTM D3363 method.

[0109] A coating composition is applied on a glass panel to form a 120 micron thick wet film and cured at room temperature for 7 days. The resultant film is then tested by a Zhonghua pencil. The hardness of the pencil used is: 9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H, H, F, HB, B, 2B, 3B, 4B, 5B, 6B, where 9H is the hardest, 6B is the softest Gloss: The 20°, 60°, and 85° gloss of the coatings were measured according to ASTM D-523-89 using a micro-TRI-gloss meter from BYK Gardner.

Methyl Ethyl Ketone Double Rub Test: The methyl ethyl ketone (MEK) double rub test was performed according to ASTM D5402 using the semi-automatic MEK Rub Test machine made by DJH DESIGNS INC. The testing continued until the coating was rubbed through to the substrate or a maximum of 200 double rubs were completed without breakthrough.

[0110] The performance characteristics of the coating compositions are shown in Table 4. Ctg 1 and Ctg 2 as compared to Ctg 7 and Ctg 8 respectively, illustrate the importance of a cure compatibility group (e.g. HEMA) in the acrylic copolymer to provide improved pencil hardness, improved dry time, improved gloss readings, improved hardness and improved MEK Resistance.

TABLE-US-00004 TABLE 4 CTG 2 CTG 1 CTG 8 CTG 7 BY6063-3 BY6063-4 BY6063-10 BY6063-11 Dry times (hr) Set-to-Touch 0.4 0.8 0.5 0.6 Tack-Free 1 2 6 6 Dry-Hard 2 5 18 9 Dry-Through 9 6 >24 16 Gloss 20° Degree 74 74 10 36 Average 60° Degree 95 94 37 78 Average Thickness 3.1 2.5 2.4 2.1 Average (mils) Konig Hardness [sec] 1 Day 28 35 14 13 7 Day 87 73 30 17 MEK Resistance >200 >200 198 50 [double rubs] Pencil F HB 2B 5B