JPH02274773A - Weatherable composition - Google Patents

Abstract

PURPOSE:To provide a weatherable composition excellent in coating film hardness, abrasion resistance, resistance to deterioration by ultraviolet rays, water resistance, chemical resistance, etc., and suitable for coating material, joint filling material, lining material, etc., by incorporating metallic flakes into an inorganic binder. CONSTITUTION:Metallic flakes are incorporated into an inorganic binder (e.g. potassium silicate or colloidal silica) to produce a weatherable composition. A suitable content of the metallic flakes if 2 to 80wt.%. It is desirable that the metallic flakes have an average length of 5 to 150mum and an aspect ratio of at least 5. Examples of the preferred metallic flakes include stainless steel flakes and titanium flakes. When there is a necessity for realizing good adhesion to a substrate and the binder, the metallic flakes may be pretreated with a surface treating agent. A dispersant, a pigment, etc., may further be incorporated into the weatherable composition thus obtained.

Description

[Detailed description of the invention] <Industrial application field> The present invention is mainly used as a paint or as a filling material.

The present invention relates to weather-resistant compositions used as linings, putty, caulking materials, etc.

<Prior Art> The purpose of painting is to maintain the beauty of the object to be coated and to prevent corrosion when the object to be coated is steel.

The present inventor has been engaged in the development of paints with excellent corrosion resistance, weather resistance, etc. for many years, and has already published JP-A-61-228073, JP-A-62-67386, and JP-A-62704.
No. 62, patent application No. 329158 of 1988, etc. propose anticorrosive compositions containing metal flakes such as stainless steel flakes in an organic resin binder.

However, since all of these anticorrosion compositions use an organic resin binder, the (+) coating film hardness is 7.
A value of 11 (pencil hardness) or less is insufficient.

(2) Significant deterioration due to ultraviolet rays.

(3) Insufficient fire resistance and heat resistance.

(4) Thin coatings with a film thickness of 20 μm or less have sufficient properties.
I can't do it.

(5) Insufficient wear resistance and scratch resistance.

(6) Because it uses an organic solvent, it is a dangerous substance under the Fire Service Act.

It had various problems such as.

Conventionally, fluorine-based coatings 21 have been developed as a countermeasure against deterioration caused by ultraviolet rays as described in (2) above, but it is difficult to form a film, the coating is extremely soft, and it is expensive. It has the following disadvantages.

<Problems to be Solved by the Invention> The purpose of the present invention is to provide a weather-resistant composition that has poor UV deterioration resistance, water resistance, chemical resistance, abrasion resistance, +11Th color resistance, film forming processability, etc. It is to provide.

<Means for Solving the Problems> The present invention is a weather-resistant composition characterized by containing metal flakes in an inorganic binder, preferably containing 2 to 80% by weight of metal flakes. Yes, or preferably the average major axis of the metal flakes is 5 to 150μ
m and has an aspect ratio of 5 or more, or preferably the metal flakes are stainless steel flakes, or preferably the metal flakes are titanium flakes, or preferably the metal flakes are titanium flakes, or preferably the inorganic binder is It is potassium gayate.

<Function> In the past, many paints with organic properties have been used, but they have poor weather resistance such as UV resistance and deterioration resistance. The present invention focuses on the fact that inorganic binders are inherently excellent in UV deterioration resistance, stain resistance, decolorization resistance, etc., and by incorporating metal flakes such as stainless steel flakes into the inorganic binder,
It has improved water resistance and chemical resistance, which are inherently inferior to inorganic binders.

The present invention will be explained in more detail below.

In the present invention, metal flakes are used as the functional filler. There are various types of metal flakes, such as titanium, stainless steel, nickel, and aluminum, which can be used depending on the purpose.

For example, titanium has better corrosion resistance against acids and alkalis than stainless steel or nickel. In particular, it has high corrosion resistance against chlorine ions. However, it is expensive. Therefore, titanium flakes are suitable for use as heavy duty anti-corrosion fillers.

In addition, the weather-resistant composition of the present invention has not only corrosion resistance, but also rust prevention, acid resistance, alkali resistance, chemical resistance, boiling water resistance, water resistance, moisture resistance, surface 1 swelling property, @t bl 'IJ linearity, hydrogen embrittlement prevention, 111 chipping resistance, 1ii4 seawater resistance (ilii4 chloride ionicity), ash (low temperature resistance, heat resistance,
It has properties such as resistance to various conditions such as thermal shock resistance and durability, and has a metal coloring property.

It also has a metallic luster.

In addition, metal flakes with low specific gravity, such as titanium, have a low i
An inorganic binder composition having a ZI degree of 11 has good paternity, can be made into a composition with low sedimentation, can reduce or eliminate the use of a dispersant in the composition, and can be forced before use of the composition. There is no need for stirring, and the weight of the product to which the 1-surface, 14-surface, 11-surface composition is applied can also be reduced.

In the present invention, it is preferable to use the functional filler having such excellent properties as flat flakes in a predetermined shape depending on the application, and generally the maximum diameter of the metal flakes is 200 pm or less and the average major axis is 5 to 150 pm. , more preferably 15 to 1501 m, and an aspect ratio (average major axis/average thickness) of 5 or more, more preferably 30 or more.
It is better to set it to two. If the maximum diameter exceeds 200 μm or the average major axis exceeds 1100 p, it is not preferable because the nozzle is likely to become clogged during spray painting, and the coating surface becomes rough and tends to aggregate, resulting in lumpiness. On the other hand, if the average major axis is less than 5 pm or the aspect ratio is less than 5, the flakes will not have a sufficient specific surface area, the labyrinth effect and the hiding effect will not be obtained, and the protective effect of the coating film on the object will be reduced. So I don't like it.

Note that the labyrinth effect here refers to the fact that a dried paint film has pinholes (gas/liquid passages 4) caused by degassing of the solvent during the normal paint film drying process, as shown in Figure 2. As shown in FIG. 1, since the titanium flakes 1a have a deciduous layered structure, the passages 4 through which gases and liquids permeate become maze-like, resulting in an effect that the permeability of gases and liquids is reduced.

The metal flakes used in this application crush the solvent degassing path in the resin of the paint film during the drying process of the paint film, and create a deciduous layered structure while promoting the pinball-less process, thereby preventing gas and liquid passages. This results in a labyrinth effect in which the membrane becomes labyrinth-like and its permeability decreases.

Since metal flakes have various characteristics, the weather-resistant composition of the present invention containing metal flakes has various functionalities. By optimizing not only the aspect ratio of the flakes but also the external characteristics such as the ratio of the outer circumference to the major axis, the characteristics can be best exhibited.

Such metal flakes are produced by ball milling 40 to 325 mesh raw metal powder together with a solvent such as naphtha and an additive such as stearic acid.

Note that the metal raw material powder used here is not particularly limited as long as it can be easily turned into flakes in a mill.
It is possible to use granular materials, flat materials, and foil-like materials produced in various manufacturing and processing steps of the metal.

For example, it is possible to use granules obtained from molten metal in the atomization method, crushable granules or agglomerates of granules obtained by refining rutile, ilmenite, high titanium slabs, etc., so metal flakes are relatively It can be obtained cheaply.

The metal flakes may be further surface-treated with a surface-treating agent such as a hydrophilic compound, especially when it is necessary to improve the adhesion to the object to be coated and the binder. The surface treatment makes the surface of the metal flakes highly hydrophilic, so that their integrity with the binder is improved.

The content of metal flakes in the weather-resistant composition depends on the durability and hardness required depending on the usage environment.
It is preferably 2 to 80% by weight.

Particularly preferably, the amount is 5 to 50% by weight.

The reason for this is that if the content is less than 2% by weight, the flake content will be too small to fully exhibit the characteristics of metal flakes, and the composite composition will not be effective. For example, when used as a weather-resistant paint as shown in Figure 2,
This is because the flakes do not overlap sufficiently, making it impossible to form a deciduous deposited layer structure, resulting in insufficient weather resistance and coating strength.

Moreover, if it exceeds 80% by weight, the resin component becomes insufficient and a sufficient coating film cannot be formed.

The inorganic binder used in the present invention may be any binder that is normally used as a vehicle for inorganic paints. For example, silicate, colloidal silica, alkyl silica-1-.

These include colloidal alumina, metal salts of heavy acid, and polyvalent metal alkoxides, as well as mixtures such as colloidal silica-thermoplastic resin emulsions and colloidal silica-P.
Complexes such as VB complexes are also available.

In addition to the above-mentioned metal flakes, surface treatment agents, and resins, the weather-resistant composition of the present invention also contains dispersants such as talc and tankal, extender pigments and coloring pigments for corrosion resistance, reinforcement, coloring, and other purposes. can be added, and generally known solvents or non-reactive diluents can be used.

For example, commonly known resin additives include thixotropy imparting agents such as organic bentonite and silicic anhydride powder.

Metal soap or the like can be used if necessary.

The mixing method for these is not particularly limited, and stirring and mixing may be carried out by a conventional method.

<Examples> The present invention will be specifically described below based on Examples, Comparative Examples, and Conventional Examples.

(Example 1) (Comparative Example 1) The composition shown in Table 1 was prepared, sufficiently kneaded to form a paint, and then applied uniformly to a dull finish steel plate (JIS standard, 5pcC) by air spray, and Dry for 1 hour at C
A coating film of 0 pm was formed.

Table 1 Table 2 *Shape of stainless steel flakes: Thickness/I0.3μm.

Average major axis 3Qμm Aspect ratio 100 (Conventional example 1) The organic composition shown in Table 2 was prepared and uniformly applied to a dull finish steel plate using air spray, and dried at 180°C for 20 minutes to form a coating film of 35pm. Formed.

*Shape of stainless steel flakes: thickness 0.3μm.

Average major axis 30 μm.

Aspect ratio 100 (Example 2) (Comparative Example 2) The composition shown in Table 3 was prepared, thoroughly kneaded and made into a paint, and then uniformly applied to an alumite substrate (55m film treatment) by air spray. Relative humidity 85-90RH115
First harden by holding at 0°C for 30 minutes, then second harden by holding at 180°C for 1 hour.
Ta.

Table 3 Table 4 *Shape of stainless steel flakes: thickness 0, 3pm, average major axis 30μm.

Aspect ratio 100 (Conventional Example 2) The organic composition shown in Table 4 was prepared and uniformly applied to an alumite substrate (5 pm film treatment) by air spray.
It was dried at 80°C for 20 minutes to form a coating film of 30 μm.

*Shape of stainless steel flakes: thickness 0.3 pm, average major axis 30 μm.

Aspect ratio 100 (Example 3) The composition shown in Table 5 was made into a paint, and a dull finish was applied to two steel plates (SPC).
A coating film of 30 pm was made on C). The curing conditions were kept at room temperature for one week.

Table *Flake shape: Average thickness 0.3μm Average major axis
30 pm Asparagus+4t, 100 (Conventional Example 3) The organic composition shown in Table 6 was made into a paint, and a dull finish steel plate (
A coating film of 3.0 μm was made on SPCC). The curing conditions were maintained at room temperature for 1 hour.

*Flake shape: average thickness 0.3μm average major axis
30 pm For the examples, comparative examples, and conventional examples with an aspect ratio of 100 or more, the coating film properties were determined by hardness, boiling water resistance, IICZ, II□SO,
Chemical resistance to Na0II, salt spray test, Xanshine Weather-Ometer, and impact resistance were investigated.

The measurement conditions and evaluation criteria for each are as described below. These results are shown in Table 7.

(1) Hardness (Pencil Scratch Test) (a) The scratch resistance of the paint film is tested by varying the hardness of the pencil lead and the tearing of the paint film is examined.

(b) A JISK5401 standard scratch tester was used.

(C) A Mitsubishi Uni pencil was used.

Sharpen the pencil (approximately 3 mm in advance into a cylindrical shape) Place it on a hard flat surface and polish it according to JISR 6252. Gently sharpen the pencil in a circular motion at right angles with a past 400 grit so that the tip is flat and the corners are sharp.

The tip must be sharpened again each time it is scratched.

(Test method) Attach the test piece to the testing machine, place a load of 1.0 ± 0.05 kg, make sure that the tip of the pencil lead touches the painted surface and the weight is applied to the tip, and rotate the handle (- The specimen was moved horizontally by approximately 3' mm in the opposite direction to the direction of the core, and the coated surface was examined for tears. The speed of movement is approximately 0.5mm
/see.

If the test piece is scratched 5 times in the direction of movement and the paint film reaches the fabric of the test plate, or if it is observed 2 times or more than 2 times out of 5 times, lower the pencil hardness by one level and replace it, and then perform the test. , record the pencil hardness when it is less than 2 times.

(Judgment) For two pencils with hardness symbols next to each other, there are 2 tears.
1 or 2 or more times, and 1 that does not break or breaks once.
The latter case is taken as the pencil scratch value of the paint film.

(2) Boiling water resistance test Using three test pieces, each test plate has II cracks.
Prepare one piece at a time, fill it with water to a depth of 80mm, heat it from the bottom with a heater, and keep it so that 2 to 3 small bubbles appear every second.

A test plate is suspended in this solution so that it is 20 mm above the bottom of the beaker, and is immersed to a depth of 60 mm and continuously heated.

To replenish the evaporated water, gradually use pre-heated hot water to compensate for the evaporated water.

The test values were determined based on the observation results based on the following criteria for three test plates of each paint.

(Judgment) When two or more of the three test panels have wrinkles, blisters, cracks, or peeling of the coating, remove them from the beaker and observe the coating.After draining the coating and leaving it indoors for 2 hours, Furthermore, observe the paint film to see the degree of cloudiness, whitening, and discoloration. Test plates on which any abnormality was observed during the above two observations were compared in advance with the observation photographs taken during the course of the test, and the test of the test plate was carried out at the time when no change was observed when compared with the thick plate. value.

[3) Hydrochloric acid resistance (10% hydrochloric acid) Prepare three test plates and one thick plate in the same way as the boiling water resistance test.

Prepare one glass container for each test plate, fill it with 10% hydrochloric acid solution to a depth of 150 mm, and immerse the test piece at room temperature to a depth of 120 mm to prevent blistering of the coating film.
The occurrence of cracks, peeling, holes, etc. was observed periodically, and the elapsed time was taken as the test value.

(4) Sulfuric acid resistance (10% sulfuric acid) Prepare three test plates and one thick plate in the same way as the boiling water resistance test.

Prepare one glass container for each test plate, fill it with 10% sulfuric acid solution to a depth of 150 mm, and immerse the test piece at room temperature to a depth of 120 mm to prevent blistering of the coating film.
The occurrence of cracks, peeling, holes, etc. was observed periodically, and the elapsed time was taken as the test value.

(5) Alkali resistance (caustic soda IO%) Prepare three test plates in the same manner as the boiling water resistance test.

Prepare one glass container for each test piece, fill it with 10% caustic soda solution to a depth of 150m+n, and immerse the test piece to a depth of 120mm at room temperature to check for blisters, cracks, peeling, holes, etc. in the coating film. Periodic observations were made for occurrence, and the elapsed time at the time of occurrence was used as the test value.

(6) Salt water spray test Prepare three test pieces each in the same manner as those prepared above.

The testing machine specified in JIS Z2371 was used.

Suga Test Machine (CASSER-IR-2F) was used.

On the test piece, two diagonal lines were drawn in advance on the coating film using a cutter knife so as to reach the fabric of the test plate.

This test plate was installed in a predetermined position in the test machine room, and during continuous operation, progress was observed for rusting, blistering, or bulging of the coating film on the test plate, which was 3 mm or more on both sides of the diagonal line, and the test value was taken as a test value.

(7) Sunshine weather meter JISB77
The test was conducted using an ultraviolet carbon arc lamp accelerated weathering tester specified in No. 52. Comparing the paint film of the sample with the naked eye, we checked for discoloration, loss of gloss, wrinkles, blistering, cracking, and peeling, and evaluated the total irradiation time at which chalking occurred by touching the paint surface with a fingertip.

(8) Impact resistance: A steel ball with a weight of 500 g was allowed to fall naturally from various heights to give an impact to the test plate, and evaluation was made at the height at which cracking or peeling of the coating film was observed.

<Effects of the Invention> As described above, the weather-resistant composition according to the present invention has high hardness and excellent impact resistance, so it is clear that it has excellent abrasion resistance, and also has good resistance to ultraviolet deterioration and water resistance. It is a weather-resistant paint with excellent water resistance and chemical resistance.It goes without saying that the inorganic binder has excellent decolorization properties and film-forming processability.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a steel plate coated with the weather-resistant composition of the present invention, and FIG. 2 is a schematic cross-sectional view of a conventional example. 1... Metal flakes, 2... Inorganic binder, 3
...Steel plate, 4...Aisle.

Claims (1)

[Scope of Claims] 1. A weather-resistant composition characterized by containing metal flakes in an inorganic binder. 2. The weather-resistant composition according to claim 1, which contains 2 to 80% by weight of metal flakes. 3. Claim 1, wherein the metal flakes have an average major axis of 5 to 150 μm and an aspect ratio of 5 or more.
Or the weather-resistant composition according to 2. 4. The weather-resistant composition according to claim 1, 2 or 3, wherein the metal flakes are stainless steel flakes. 5. The weather-resistant composition according to claim 1, 2 or 3, wherein the metal flakes are titanium flakes. 6. The weather-resistant composition according to claim 1, 2, 3, 4 or 5, wherein the inorganic binder is potassium silicate.