Inorganic coating composition which can be cured at low temperature and a preparation method thereof

Abstract

The present invention relates to coating composition. And in particular, to an inorganic coating composition which can be cured at low temperature and a preparation method thereof. In order to solve the problems that the organic coating is harmful for the environment, the inorganic coating has bad flexibility, and the traditional ceramic coatings need heat and is inconvenient for curing in prior art, the present invention provide an inorganic coating composition which can be cured at low temperature and a preparation method thereof. The inorganic coating composition comprises the ingredient as below: 70-80 wt % of inorganic solution; 5-10 wt % of functional additives, which are potassium titanate, alumina, or a compound thereof; 10-20 wt % of inorganic pigment; 0.5-2.0 wt % of other functional additives. The said inorganic solution comprises the following ingredients: 30-40 wt % of organic alkoxy-silane, 15-20 wt % of organic solvent, and 25-30 wt % of silica sol. The inorganic coating composition is able to be cured at low temperature, the film formed by it has excellent flexibility, and the film will not release harmful organic gases, and is beneficial to the environmental.

Claims

1-11. (canceled)

12. An inorganic coating composition, wherein the inorganic coating composition comprises: 70-80 wt % inorganic solution, wherein the inorganic solution comprises 30-40 wt % organic alkoxy-silane, 15-20 wt % organic solvent, and 25-30 wt % silica sol.

13. The inorganic coating composition of claim 12, wherein the inorganic coating composition further comprises: 10-20 wt % inorganic pigment.

14. The inorganic coating composition of claim 12, wherein the inorganic coating composition further comprises: a first functional additive that is 5-10% wt of the inorganic coating composition,

15. The inorganic coating composition of claim 12, wherein the inorganic coating composition further comprises: an other functional additive that is 0.5-2.0 wt % of the inorganic coating composition.

16. The inorganic coating composition of claim 12, wherein the inorganic coating composition further comprises: a first functional additive that is 5-10% wt of the inorganic coating composition, and an other functional additive that is 0.5-2.0 wt % of the inorganic coating composition.

17. The inorganic coating composition of claim 12, wherein the organic alkoxy-silane is represented by formula R.sup.1.sub.mSi(OR.sup.2).sub.4-m, where R.sup.1 and R.sup.2 represent a substituted or non-substituted alkyl group or aryl group comprising 1-10 carbon atoms, and m is 0-3.

18. The inorganic coating composition of claim 17, wherein R.sup.1 or R.sup.2 are at least one selected from the group including methyl, ethyl, phenyl, CF.sub.3CH.sub.2CH.sub.2, CF.sub.3(CF.sub.2).sub.5CH.sub.2CH.sub.2, and CF.sub.3(CF.sub.2).sub.7CH.sub.2CH.sub.2, and alternatively wherein R.sup.1 and R.sup.2 are at least one of selected from the group including methyl, ethyl, phenyl, CF.sub.3CH.sub.2CH.sub.2, CF.sub.3(CF.sub.2).sub.5CH.sub.2CH.sub.2, and CF.sub.3(CF.sub.2).sub.7CH.sub.2CH.sub.2.

19. The inorganic coating composition of claim 12, wherein the silica sol comprises 20-40 wt % silica (SiO.sub.2) particles, a size of the silica particle is from nanometer-size to micron-size.

20. The inorganic coating composition of claim 14, wherein the first functional additive comprises potassium titanate that is 3-5% wt of the inorganic coating composition.

21. The inorganic coating composition of claim 12, wherein the organic alkoxy-silane is methyl trimethoxy silane, tetraethoxysilane, phenyl trimethoxy silane or a mixture thereof; and the organic solvent is methanol, ethanol, isopropanol or a mixture thereof.

22. The inorganic coating composition of claim 12, wherein ingredients of the inorganic coating composition are treated by ultrasonic waves.

23. The inorganic coating composition of claim 22, wherein a frequency of the ultrasonic waves is greater than or equal to 20 KHz, and the ingredients of the inorganic coating composition are treated by ultrasonic waves for 30-40 minutes.

24. The inorganic coating composition of claim 22, wherein a mixture of organic alkoxy-silane and silica sol are treated with ultrasonic waves during a mixing and reacting step of the organic alkoxy-silane and the silica sol.

25. The inorganic coating composition of claim 12, wherein the inorganic coating composition is curable at low temperature between 10-40 degrees Celsius.

26. The method for preparing the inorganic coating composition of claim 12, wherein the method comprises the following steps: (1) preparing the inorganic solution: mixing the 30-40 wt % organic alkoxy-silane, with the 15-20 wt % organic solvent, and 25-30% silica sol; and stirring the mixture at 40-50 degrees Celsius for 5-10 minutes to get inorganic solution in sol state; (2) preparing the inorganic coating mixture: putting 70-80 wt % the inorganic solution generated in step (1), 5-10 wt % functional additives, 10-20 wt % inorganic pigment, and 0.5-2.0 wt % other functional additives together; and stirring the mixture to get the inorganic coating mixture; (3) placing the inorganic coating mixture generated in step (2) in a homogenizer; and stirring it at a speed sufficient for homogenization for 1-2 hours to make the particles homogenized; and (4) filtering the homogenized matter generated in step (3) pass through a 325-1000 mesh net to remove bigger particles; and obtaining the inorganic coating composition which is curable at a temperature between 10-40 degrees Celsius.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0065] FIG. 1 is a structural schematic diagram of the flexibility test of the film formed by the inorganic coating composition in present invention.

DETAILED DESCRIPTION OF INVENTION

[0066] According to technology solution and the preparing method provide in the present invention, several examples is provided below. These examples are not intended to limit the scope of the invention.

EXAMPLE 1

[0067] The present invention provides an inorganic coating composition, the preparing method thereof is as below:

[0068] (1) preparing inorganic solution: 30 wt % silica sol is mixed with 30 wt % of organic silane and 15 wt % ethanol, and the mixed solution is stirred at 40-50 degrees Celsius for 5-10 minutes. The organic silane is the methyl trimethoxy silane, or tetraethoxy silane, or a mixture thereof. The mixed solution of organic silane and silica sol create chemical reaction, the heat is produced, and the mixed solution changes from a turbid state to a transparent state. At this time, adding methanol, or ethanol, or isopropanol, or the mixture thereof to control the viscosity and the reaction speed of the solution. The inorganic solution in sol state is made through these processes.

[0069] (2) stirring the mixed solution: the inorganic solution generated in step (1), 9 wt % functional additives, which are potassium titanate or alumina, l5 wt % pigment powders of titanium oxide, and 1 wt % other functional additives are mixed and stirred to form an inorganic ceramic mixture.

[0070] (3) homogenizing: the solution generated in step (2) is put in a homogenizer, and is stirred at a high speed for 1-2 hours to homogenize the particles.

[0071] (4) filtering the coatings: the homogenized matter is passed through a 325-1000 mesh net and remove bigger particles to get the inorganic coating composition.

EXAMPLE 2

[0072] The present invention provides an inorganic coating composition which can be cured at low temperature, the composition comprises the ingredient as below:

[0073] 70 wt % inorganic solution. The said inorganic solution comprises the following ingredient:

[0074] 30 wt % tetraethoxvsilane, 15 wt % ethanol, 25 wt % silica sol;

[0075] 10 wt % functional additives, which is the mixture of potassium titanate and alumina, wherein the amount of potassium titanate is 3 wt %.

[0076] 19.5 wt % inorganic pigment;

[0077] 0.5 wt % other functional additives, the other functional additive is tourmaline;

[0078] The percentage above mentioned is the proportion of each ingredient in the whole of inorganic coating composition, by weight.

EXAMPLE 3

[0079] The present invention provide an inorganic coating composition which can be cured at low temperature, the composition comprises the ingredient as below:

[0080] 80 wt % inorganic solution. The said inorganic solution comprises the following ingredient:

[0081] 40 wt % the mixture of tetraethoxysilane and methyl trimethoxysilane, the ratio of tetraethoxysilane and methyl trimethoxysilane is 1:1 by weight, l5 wt % ethanol, 25 wt % silica sol;

[0082] 5 wt % functional additives, which are the mixture of potassium titanate and alumina, the amount of potassium titanate is 4 wt %;

[0083] 13 wt % inorganic pigment;

[0084] 2.0 wt % other functional additives, the other functional additive is tourmaline;

[0085] The percentage above mentioned is the proportion of each ingredient in the whole of inorganic coating composition, by weight.

EXAMPLE 4

[0086] The present invention provide an inorganic coating composition can be cured at low temperature, the composition comprises the ingredient as below:

[0087] 80 wt % inorganic solution. The said inorganic solution comprises the following ingredient:

[0088] 30 wt % methyl trimethoxysilane, 20 wt % ethanol, 30 wt % silica sol;

[0089] 6 wt % functional additives, which are the mixture of potassium titanate and alumina, the amount of potassium titanate is 5 wt %;

[0090] 13 wt % inorganic pigment;

[0091] 1 wt % other functional additives, the other functional additive is rare-earth ore;

[0092] The percentage above mentioned is the proportion of each ingredient in the whole of inorganic coating composition, by weight.

EXAMPLE 5

[0093] The present invention provide an inorganic coating composition which can be cured at low temperature, the composition comprises the ingredient as below:

[0094] 74.5 wt % inorganic solution, the said inorganic solution comprises the following ingredient:

[0095] 30 wt % methyl triethoxy silane, 15 wt % ethanol, 29.5 wt % silica sol;

[0096] 5 wt % functional additives, which are potassium titanate;

[0097] 20 wt % inorganic pigment;

[0098] 0.5 wt % other functional additives, the other functional additive is rare-earth ore;

[0099] The percentage above mentioned is the proportion of each ingredient in the whole of inorganic coating composition, by weight.

EXAMPLE 6

[0100] The present invention provide an inorganic coating composition which can be cured at low temperature, the composition comprises the ingredient as below:

[0101] 77 wt % inorganic solution. The said inorganic solution comprises the following ingredient: 35 wt % organic alkoxy-silane, 15 wt % ethanol, 27 wt % silica sol;

[0102] 7 wt % functional additives, which a potassium titanate;

[0103] 15 wt % of inorganic pigment;

[0104] 1 wt % other functional additives, the other functional additive is the mixture of tourmaline and rare-earth ore, the ratio of tourmaline and rare-earth ore is 1:1 by weight;

[0105] The percentage above mentioned is the proportion of each ingredient in the whole of inorganic coating composition, by weight.

[0106] The alkoxy-silane is represented with a molecular formula R.sup.1.sub.mSi(OR.sup.2).sub.4-m, the R.sup.2 is phenyl, m is 0.

EXAMPLE 7

[0107] An inorganic coating composition as shown in the example 6, wherein, the organic alkoxy-silane is represented with a molecular formula R.sup.1.sub.mSi(OR.sup.2).sub.4-m, the R.sup.1 CF.sub.3CH.sub.2CH.sub.2, the R.sup.2 is CF.sub.3CH.sub.2CH.sub.2, m is 1.

EXAMPLE 8

[0108] An inorganic coating composition as shown in the example 6, wherein, the organic alkoxy-silane is represented with a molecular formula R.sup.1.sub.mSi(OR.sup.2).sub.4-m, the R.sup.1 is CF.sub.3(CF.sub.2).sub.5CH.sub.2CH.sub.2, the R.sup.2 is CF.sub.3(CF.sub.2).sub.5CH.sub.2CH.sub.2, m is 2.

EXAMPLE 9

[0109] An inorganic coating composition as shown in the example 6, wherein, the organic alkoxy-silane is represented with a molecular formula R.sup.1.sub.mSi(OR.sup.2).sub.4-m, the R.sup.1 is CF.sub.3(CF.sub.2).sub.7CH.sub.2CH.sub.2, the R.sup.2 is CF.sub.3(CF.sub.2).sub.7CH.sub.2CH.sub.2, m is 3.

EXAMPLE 10

[0110] An inorganic coating composition as shown in the example 6, wherein, the organic alkoxy-silane is represented with a molecular formula R.sup.1.sub.mSi(OR.sup.2),.sub.4-m, the R.sup.1 is methyl, the R.sup.2 is phenyl, m is 1.

EXAMPLE 11

[0111] An inorganic coating composition as shown in the example 6, wherein, the organic alkoxy-silane is represented with a molecular formula R.sup.1.sub.mSi(OR.sup.2).sub.4-m, the R.sup.1 is ethyl, the R.sup.2 is CF.sub.3CH.sub.2CH.sub.2, m is 1.

EXAMPLE 12

[0112] An inorganic coating composition as shown in the example 6, wherein, the organic alkoxy-silane is represented with a molecular formula R.sup.1.sub.mSi(OR.sup.2).sub.4-m, the R.sup.1 is phenyl, the R.sup.2 is CF.sub.3 (CF.sub.2).sub.7CH.sub.2CH.sub.2, m is 2.

EXAMPLE 13

[0113] An inorganic coating composition as shown in the example 6, wherein, the organic alkoxy-silane is represented with a molecular formula R.sup.1.sub.mSi(OR.sup.2).sub.4-m, the R.sup.1 is CF.sub.3CH.sub.2CH.sub.2, the R.sup.2 is methyl, m is 3.

EXAMPLE 14

[0114] An inorganic coating composition as shown in the example 6, wherein, the organic alkoxy-silane is represented with a molecular formula R.sup.1.sub.mSi(OR.sup.2).sub.4-m, the R.sup.1 is CF.sub.3(CF.sub.2).sub.5CH.sub.2CH, the R.sup.2 is methyl and ethyl, m is 2.

EXAMPLE 15

[0115] An inorganic coating composition as shown in the example 6, wherein, the organic alkoxy-silane is represented with a molecular formula R.sup.1.sub.mSi(OR.sup.2).sub.4-m, the R.sup.1 is CF.sub.3(CF.sub.2).sub.7CH.sub.2CH.sub.2, the R.sup.2 is phenyl, m is 1.

EXAMPLE 16

[0116] An inorganic coating composition as shown in the example 6, wherein, the organic alkoxy-silane is phenyl trimethoxysilane.

[0117] Coat the inorganic coating composition provided by the examples on the substrate, form film, the thick of the film is 305 m, the substrate is aluminum plate. The size of the aluminum plate is 15 cm7.5 cm, the coating is curing at low temperature for 7 days, form hard film.

[0118] The test result and the test data of the film formed by the inorganic coating composition provided by the example 1-16 are shown in table 2 and table 3.

TABLE-US-00002 TABLE 2 The test result of the film formed by the inorganic coating composition provided by the example 1-16 Test item Test result Test condition note Gloss 0-70 Gloss test device (60 standard) Pencil hardness 7-9H Mitsubishi pencil Adhesive force 100/100 one hundred grid method, 1 m/m Shock resistance no 1 kg ball, 50 cm height abnormality abrasive resistance 99.99 abrasive coefficient Pollution resistance non-pollution 5E Max Acid resistance no 5% H.sub.2SO.sub.4, 48 hours abnormality Alkali resistance no 5% Na.sub.2CO.sub.3/15 abnormality minutes 4 times Boiling water no 98 degrees resistance abnormality Celsius 2 hours Heat resistance no 300 degrees abnormality Celsius 1 hours Salt water no 5% NaCl 1000 hours resistance, abnormality Weather resistance no WeatheR1-O-MeteR1, abnormality 1000 hours Color Many kinds

TABLE-US-00003 TABLE 3 The test data of the film formed by the inorganic coating composition provided by the example 1-16 Pencil Adhesive No. gloss % hardness force example1 45-55 7-9H 0 grade example2 45-55 7-9H 0 grade example3 35-45 8-9H 1 grade example4 45-55 7-9H 1 grade example5 40-50 7-9H 0 grade example6 40-50 7-9H 0 grade example7 40-50 7-9H 0 grade example8 45-55 7-9H 0 grade example9 30-35 6-9H 0 grade example10 30-35 6-9H 1 grade example11 45-50 7-9H 0 grade example12 45-55 7-9H 0 grade example13 25-30 6-8H 1 grade example14 30-35 7-8H 0 grade example15 40-50 7-9H 0 grade example16 40-50 7-9H 0 grade

[0119] Flexibility test: The inorganic coating composition in present invention is coated on the soft substrate, and the composition is cured to form a film. The substrate is a bendable aluminum sheet. The thickness of the substrate is 0.3 mm. The thickness of the film is 20-25 m. As shown in FIG. 1, putting the rod 2 on the film 1, the diameter of the rod 2 is 9.5 mm. The substrate is bent along the rod, the substrate with film may be bent to parallel to the horizontal plane to twine around the rod. There are no cracks on the surface of the bent film.

[0120] The flexibility of the film formed by the inorganic coating composition may also be evaluated by the scratch test, or pendulum hardness test. The scratch test and the pendulum hardness test are as below.

[0121] Because the film formed by the water-base PU Acryl coating has excellent flexibility, it is used here as a reference. The flexibility of the film formed by the inorganic coating composition in present invention is tested. The flexibility of the film formed by water-base PU Acryl coating is tested as well for comparing the test results and evaluating the flexibility of the film formed by the inorganic coating composition in present invention.

[0122] Scratch test, use the break through force to represent the test result. The test method includes steps as below:

[0123] (1) Coating the coating composition on steel substrate, forming the film with fixed thickness;

[0124] (2) A needle is placed on the film;

[0125] (3) Applying a force on the needle, and pushing the needle to move on the film: in 60 seconds, the force is increased from 0N to 100N;

[0126] (4) Meanwhile the needle is moved 1 cm on the film;

[0127] (5) Observe and record the data of the force when the film is broken.

[0128] The standard of broke is as below: by washing the film with water, the film is peeled off the substrate and the substrate is seen clearly. When the force of breaking the film is bigger, the film is more resistant to the scratch and the flexibility of the film is better.

[0129] Pendulum hardness test, the test method includes steps as below:

[0130] (1) Coating the coating composition on steel substrate, forming the film with fixed thickness;

[0131] (2) A pendulum is swung on the coated substrate;

[0132] (3) Pendulum is resting on two balls.

[0133] (4) Softness of substrate is damping the oscillation;

[0134] (5) Pendulum hardness is given as time in seconds it takes to decrease the amplitude from 6 to 3.

[0135] When the time is longer, the pendulum hardness of the film is higher and the flexibility of the film is worse.

[0136] Pencil hardness test: fixing the Mitsubishi pencil on the hardness test device at 45 angle, applying force of 1 Kg on the pencil and pushing the pencil moving forward.

[0137] Adhesive force test: use the one hundred grid method.

[0138] Abrasive test: using the abrasive test device (Model KPM-042), the wheel used is CS-10 wheel, putting the sample on the test device, loading 500 g of gravity and turning 500 circles. Then, the UV spectrophotometer is used to test the absorbance of the surface of the sample at 370 nm to observe whether the surface turn to indistinct or not. The abrasive resistance is tested at last step.

COMPARATIVE EXAMPLE 1

[0139] Preparing an inorganic coating composition, the preparation method thereof is as below:

[0140] (1) preparing inorganic solution: 35% silica sol is mixed with 100 wt % methyl trimethoxy silane, and the mixed solution is stirred at 50 degrees Celsius for 10 minutes, ethanol is added to control the viscosity, and the inorganic solution is obtained.

[0141] (2) mixing 60 wt % inorganic solution generated in step (1), with 20 wt % potassium titanate, 8 wt % pigment of iron oxide, and 12 wt % rare-earth ore to form an inorganic ceramic mixture.

[0142] (3) homogenizing: the solution obtained in step (2) is put in a homogenizer, and is stirred at a high speed for 2 hours to homogenize the particles.

[0143] (4) filtering coatings: the homogenized matter generated in step (3) is passed through a 325-1000 mesh net to remove the bigger particles and get the coating composition.

[0144] Coating the composition in comparative example 1 on substrate of aluminum plate. The result is as below: [0145] 1. The film formed has cracks; [0146] 2. Shocking resistance: 1 Kg ball, fall from the height of 50 cm, the film peel off from the substrate.

COMPARATIVE EXAMPLE 2

[0147] Preparing an inorganic coating composition. The composition comprises the ingredient as below:

[0148] 70 wt % inorganic solution,

[0149] 12 wt % functional additives, which is potassium titanate.

[0150] 17.5 wt % inorganic pigment;

[0151] 0.5 wt % other functional additives, the other functional additive is tourmaline;

[0152] The said inorganic solution comprises the following ingredient: 30 wt % methyl trimethoxysilane, 15 wt % ethanol, 25 wt % silica sol;

[0153] The percentage above mentioned is the proportion of each ingredient in the whole of inorganic coating composition, by weight.

[0154] Compared with the composition provided by the present invention, the amount of function additive is higher.

COMPARATIVE EXAMPLE 3

[0155] Preparing an inorganic coating composition. The composition comprises the ingredient as below:

[0156] 80 wt % inorganic solution,

[0157] 3 wt % functional additives, which are alumina;

[0158] 15 wt % inorganic pigment;

[0159] 2.0 wt % other functional additives;

[0160] The said inorganic solution comprises the following ingredient: 40 wt % tetraethoxysilane, 15 wt % isopropanol, 25 wt % silica sol;

[0161] The percentage above mentioned is the proportion of each ingredient in the whole of inorganic coating composition, by weight.

[0162] Compared with the composition provided by the present invention, the amount of function additive is lower.

COMPARATIVE EXAMPLE 4

[0163] Preparing an inorganic coating composition, the composition comprises the ingredient as below

[0164] 80 wt % inorganic solution;

[0165] 9 wt % of functional additives, which are potassium titanate;

[0166] 10 wt % inorganic pigment;

[0167] 1 wt % other functional additives;

[0168] The said inorganic solution comprises the following ingredient: 45 wt % methyl trimethoxysilane, 15 wt % ethanol, 20 wt % silica sol;

[0169] The percentage above mentioned is the proportion of each ingredient in the whole of inorganic coating composition, by weight.

[0170] Compared with the composition provided by the present invention, the amount of organic alkoxy-silane is higher, the amount of silica sol is lower.

COMPARATIVE EXAMPLE 5

[0171] Preparing an inorganic coating composition, the composition comprises the ingredient as below:

[0172] 75 wt % inorganic solution;

[0173] 10 wt % functional additives, which are potassium titanate;

[0174] 13 wt % inorganic pigment;

[0175] 2.0 wt % other functional additives:

[0176] The said inorganic solution comprises the following ingredient: 25 wt % methyl trimethoxysilane, 15 wt % ethanol, 35 wt % silica sol;

[0177] The percentage above mentioned is the proportion of each ingredient in the whole of inorganic coating composition, by weight.

[0178] Compared with the composition provided by the present invention, the amount of organic alkoxy-silane is lower, the amount of silica sol is higher.

COMPARATIVE EXAMPLE 6

[0179] Preparing an inorganic coating composition, the composition comprises the ingredient as below:

[0180] 90 wt % inorganic solution;

[0181] 5 wt % functional additives, which are alumina;

[0182] 3 wt % inorganic pigment;

[0183] 2.0 wt % other functional additives;

[0184] The said inorganic solution comprises the following ingredient: 40 wt % organic alkoxy-silane, 20 wt % isopropanol, 30 wt % silica sol;

[0185] The percentage above mentioned is the proportion of each ingredient in the whole of inorganic coating composition, by weight.

[0186] Compared with the composition provided by the present invention, the amount of inorganic solution is higher, the amount of inorganic pigment is lower.

COMPARATIVE EXAMPLE 7

[0187] Preparing an inorganic coating composition, the composition comprises the ingredient s below:

[0188] 65 wt % inorganic solution;

[0189] 10 wt % functional additives, which are the mixture of potassium titanate and alumina, the ratio of potassium titanate and alumina is 1:1 by weight;

[0190] 23 wt % inorganic pigment;

[0191] 2.0 wt % other functional additives;

[0192] The said inorganic solution comprises the following ingredient: 30 wt % organic alkoxy-silane, 10 wt % isopropanol, 25 wt % silica sol;

[0193] The percentage above mentioned is the proportion of each ingredient in the whole of inorganic coating composition, by weight.

[0194] Compared with the composition provided by the present invention, the amount of inorganic solution is lower, the amount of inorganic pigment is higher.

[0195] The properties of the product of comparative examples 2-7 are shown in the table 4.

TABLE-US-00004 TABLE 4 The properties of the product of comparative examples 2-7 coating and Pencil Adhesive Shock No. the film state Gloss % hardness force resistance Compar- High viscosity, flat 3-5H 2 grade The film ative difficult to gloss peel off example 2 form the film Compar- 40-50 6-7H 1 grade The film ative crack example 3 Compar- High viscosity, flat 4-5H 1-2 grade The film ative the film is gloss peel off example 4 unqualified Compar- High viscosity, flat 4-5H 1-2 grade The film ative the film is gloss peel off example 5 unqualified Compar- Can not cover 10-20 5-6H 1 grade The film ative the substrate crack example 6 Compar- High viscosity, 10-20 4-5H 1-2 grade The film ative the film is peel off example 7 unqualified

[0196] We can conclude from the test results of the examples and the comparative examples, the inorganic coating composition in present invention may cure at low temperature, the film formed has high hardness, acid resistance, alkali resistance, salt water resistance, weather resistance, and has good adhesive force.

[0197] The flexibility of the film formed by the inorganic coating composition in present invention is tested by scratch test and pendulum hardness test. The flexibility of the film formed by water-base PU Acryl coating is tested as well by scratch test and pendulum hardness test. The test results are shown in table 5. The test results can be used to compare and evaluate the flexibility of the film formed by the coating composition in present invention.

TABLE-US-00005 TABLE 5 Test result of the scratch test and pendulum hardness test film formed by the film the inorganic formed by coating compo- water-base sition in pre- PU Acryl sent invention coating Evaluation of the flexibility Break 37 39 Break through force of the film through formed by the coating in the pre- force/N sent invention is very close to the break through force of the film formed by the water-base PU Acryl coating. The test result state: the flexibility of two kinds of films are at the same level. Pendu- 167 180 The time spent on the film formed lum by the coating in the present hard- invention is shorter than the time ness/s spent on the film formed by the water-base PU Acryl coating. The test result state: the flexibility of two kinds of films is at the same level. The film formed by the coating composition in the pre- sent invention may slow down the shock better, that is, The film formed by the coating composition in the present invention has better flexibility.

[0198] We can conclude from the above test result, the film formed by the coating composition in the present invention has excellent flexibility, and the flexibility is very close to the flexibility of the film formed by the water-base PU Acryl coating.

[0199] The above mentioned, only is the preferred examples in the present invention, that is not intend to limit the protective scope. Any changes or modifications according to the present invention, are all covered by the patent scope of the present invention.