JPS5850941B2 - Method of forming organic coating film on glass surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides adhesive, adhesive, and adhesive materials to the surfaces of glass structures, such as containers 1, glass plates, etc., for purposes such as decoration, light shielding, and display.
The present invention relates to a method for forming a colored organic coating film having good hardness and excellent performance such as appearance, chemical resistance, and weather resistance.

Conventionally, this type of glass structure has been colored by incorporating a coloring agent into the glass raw material.

However, with this method, the color variation is large and it is difficult to achieve the desired coloring, and products with small lofts require frequent color changes, which not only increases costs due to the depreciation of the raw material melting furnace. However, automation of production may become inefficient or even impossible.

For these reasons, glass structures have recently been colored by painting.

At present, inorganic paints are used for glass structures. For example, there are various methods such as coating low melting glass (frit) with a coloring agent (glass enamel) and baking it. Methods such as coating a glass surface with a resin salt of a metal dissolved in rosmarin oil or lavender oil (raster) and baking it are used.

There are almost no problems with such paints in terms of physical properties such as adhesion and hardness, but in the case of the former, it is possible to color freely to some extent even if the special color of opaque coloring is somewhat unclear, but when transparent coloring, free coloring is not possible. It is possible.

In addition, in the case of transparent coloring, heavy metals are likely to be eluted by acids and alkalis, which is also a problem from a sanitary standpoint.

In the latter case, it is a special coloring that gives an iris color to the glass surface, and it is impossible to freely color the glass surface.

It seems that the only way to freely color transparent or opaque materials and to achieve clear coloring is to use organic paints.

However, when forming an organic coating film on a glass surface, problems arise particularly in terms of physical properties such as adhesion and hardness.

For free coloring, the high hardness of glass must be sacrificed, and glass and organic coatings generally do not blend together, which can lead to serious problems such as peeling of the coating. At the same time, problems such as discoloration and elution of the colorant by the contents may also occur.

Therefore, it is necessary to further improve the coating performance and form an organic coating film on the glass surface to a level that does not cause any practical problems.

From this point of view, the inventor of the present invention has established that the glass surface can be adhesively coated with just one coat by degreasing and air blowing without special surface treatments such as chromic acid mixture treatment, etching with fluorine compounds, or sandblasting. Research began with the aim of forming an organic coating film on the glass surface that has good performance in all aspects, including hardness, appearance, chemical resistance, and weather resistance, and is of a level that does not pose a practical problem.

The present invention was arrived at as a result of extensive research and consideration that paints containing amino resins are promising paints that meet these purposes, particularly from the viewpoint of performance such as hardness and chemical resistance.

The present invention applies the following epoxysilane compounds (wherein R is less than 10 carbon atoms) to paints whose main components are amino-alkyd resin paints, amino-alkyd epoxy resins, and epoxy-amino resin paints. divalent hydrocarbon groups, and C, H and O atoms, containing 1 carbon atom
selected from divalent hydrocarbon radicals containing less than 0 and in which at least one oxygen atom is present in the form of an ether bond, a has the value O or l, and R' has 5 carbon atoms. aliphatic hydrocarbon radicals having less than 100% aliphatic hydrocarbon groups such as methyl, ethyl, propyl, butyl groups and hydrogen;

) and (B) amine silane compounds (wherein R is an alkyl group having 4 carbon atoms or less, a is selected from 1 or 2,3, and b is selected from O or 1.2).

R' contains one or more carbon atoms, and n+1 (however, n
is an integer greater than or equal to 1.

), Z is bonded to R' through a carbon-nitrogen bond, is a monovalent group consisting of hydrogen, carbon and nitrogen atoms and containing at least two amine groups, and the group -R' The ratio of carbon atoms to nitrogen atoms present in Z is 671 or less.

), an organic coating film with good long-term adhesion and good properties such as hardness, appearance, chemical resistance, and weather resistance is formed on untreated glass in one coat. .

The application of a silane compound is the most important point in the present invention, as it significantly improves not only the primary mobility (mainly adhesion) but also the secondary mobility, resulting in a coating film with good performance in all aspects. It can be formed in one coat on treated glass.

The effect on adhesion when a silane compound is added to the paint according to the present invention is as shown in FIG. 1, for example, in the case of an amino-alkyd-epoxy resin paint.

FIG. 1 shows the adhesion properties of amino-alkyd-epoxy resin paints with and without the addition of a silane compound, depending on the instant of immersion in boiling water.

From FIG. 1, the addition of any silane compound significantly improves the secondary physical properties related to adhesion, and in the case of this blended paint, (B) is more effective in improving adhesion than (A).

The use of epoxy silane compounds and amine silane compounds as adhesion promoters for glass fibers, resins, etc. is already known in the liquor industry.

However, in this case, the mechanical strength, electrical properties,
This is used to improve chemical resistance, etc., and is different from the present invention.

Furthermore, when comparing resins used for FRP and resins for organic paints, it is almost impossible for the two resins to have the same resin composition, and the resins themselves also differ in terms of reactive functional groups and their densities.

Depending on the resin composition, it is possible that the adhesion between glass and resin will be extremely good due to the synergistic effect of each resin and silane compound, and also due to the difference in reactive functional groups, the adhesion between the glass and the resin will be excellent due to the action of the silane compound. It is possible that the properties will be very good.

(A) and (B) for paints containing amino resins
The reason for the good adhesion improvement effect of (A) is thought to be that (A) causes such a reaction and forms a strong bond.

In the case of (B), this seems to be because the amino resin is strongly bonded to the epoxy resin or alkyd resin to which it is bonded.

Then, one of (S i −O
R) groups are hydrolyzed and condensed with silanol groups on the glass surface or water molecules strongly chemically adsorbed on the surface to form hydrogen bonds and further siloxane (35i-0-8i) bonds, and the glass and resin This seems to improve the adhesion with.

Silane compounds can be applied directly to paints or used as primers.

When directly blending, the amount is 0.2 to 1 based on the resin content in the paint.
Approximately 0 weight is appropriate, and the optimal addition amount is 1 to 3.0
Weight % is appropriate.

When used as an undercoat, use water, alcohol, or a mixed solution of water and alcohol as a diluent, and adjust the concentration of the epoxysilane compound to 0.2 to IO by weight, by spraying, dipping, or showering onto the glass surface. After applying at 9O-1000C, about 10
Apply after heating and drying for a minute.

Although the adhesion is better when heated, the adhesion can be improved by omitting this and simply performing natural drying.

The silane compounds (A) and (B) can be used alone or in combination.

When used in combination, (A) and (B) are reactive, so it is not appropriate to mix (A) and (B) in advance and then add them. It is preferable to paint without leaving it for too long after stirring.

(A) for any paint containing amino resin
, (B) is effective, but the optimal method of use must be determined by the paint formulation.

In the case of alkyd-based paints containing amino resins, (A) is the best for amino-alkyd resin paints, and a mixture of (A) and (B) for amino-alkyd-epoxy resin paints has the best adhesion. showing the improvement and then (B
) and (A).

When bonding epoxy resin paints containing amino resins and using them as paints for glass, it is not possible to obtain coatings with good performance in all aspects unless the pH is adjusted.

The silane compound is more effective when the amino resin content is high (A), and when the epoxy resin content is high, (A) is more effective.
B) tends to be more effective.

Therefore, in the case of epoxy-amino resin paint, (A)
, (B) in an appropriate ratio showed the best adhesion improvement.

The pH should be adjusted to about 6.5-9.0.

The pH referred to here refers to the hydrogen ion concentration, and is a value directly measured using a glass electrode pH meter for an organic solvent solution containing approximately 55% resin.

The reason why the pH must be about 6.5 to 9.0 is as follows.

In other words, as a result of experiments, the conditions for good performance in all aspects when adjusting the pH of the epoxy-amino resin paint to which (A) was added were the conditions corresponding to the shaded area in FIG.

Figure 2 is based on the following percentage (weight): Epoxy resin 25.0° Butylated amino resin 29.0 Glycol ethers 5.0 Alcohol solvent 16.0 Aromatic hydrocarbon 25.0 100.0% (weight) This figure shows an overview of the range of conditions under which all performances are favorable when (A) 8 is added to the paint and the pH is changed.

As shown in Figure 2, as the pH increases, curing is proportionally delayed, and from about pH 6.5 to 8.0, the baking width becomes wider as the pH increases, and when the pH exceeds about 8.0, the baking width decreases. On the contrary, it tends to become narrower.

If the pH is below 6.5, the chemical resistance, hardness, etc. will be very good, but the adhesion will be poor and the baking width will be narrow, making it impractical.

If the pH is about 9.0 or higher, curing will be too delayed, which is not economical, and the firing width will also become narrow, which is not suitable.

The optimum pH is about 75 to 8.5.

To adjust the pH, acidic substances such as oxuic acid, formic acid, acetic acid,
Pyridine hydrochloride group, diammonium phosphate, organic acids, etc. are used, and as alkaline ones, hexamethylenetetramine, sodium phosphate, etc. are used.

When (B) is used, since (B) itself is alkaline, it is necessary to add a pH adjuster according to the amount added.

When painting by the method of the present invention, the adhesion is very good, so the glass surface does not require special surface treatment during etching and chromic acid mixture treatment, and degreasing with a solvent is sufficient.

However, if these treatments are performed, the adhesion will be even better.

In addition, electrostatic painting of glass has recently been carried out, and at this time, a tin oxide film is formed on the glass surface to make it conductive. However, in the method of this patent,
It can also be applied to this type of painting.

The paint that can be used in the present invention is generally an ordinary organic solvent type paint, but other paints have recently attracted attention due to pollution problems, resource conservation, etc.

Water-soluble paints, emulsion paints, powder paints, ultraviolet curing paints, electron beam curing paints, paints for electrophoretic coating, etc. can also be used as long as they form a coating within the scope of the present invention.

The amino resin that can be used in the present invention includes urea resin melamine resin, berenguanamine resin, urea melamine cocondensation resin, etc. alone or in combination.

Amino resins used in paints are broadly classified into water-soluble types and oil-soluble types.
2RoHCH3OK ' -NCH3OK (II,) The water-soluble one is (1,1
), and the oil-soluble one is the (U) type, which is obtained by etherifying CI) with alcohol.

(Since the 1,1 type has the property of gelling at room temperature, the etherified [■] type is generally used for paints.

Actually, 64 methylol groups and ether groups are mixed in an appropriate ratio.

Alcohols to be etherified can be of the order of C2 to C8, and the exchangeability tends to increase as the number of carbon atoms increases.

Butanol is generally used.

Most commercially available amino resins for paints are butylated amine resins.

Next, an example in which the present invention was specifically implemented will be shown.

All of these examples are 150x7 degreased with acetone.
The mixed paint was applied to a 0 x 2 mm glass plate (window glass) by air spray painting, baked in a hot air dryer, and then tested for coating film performance.

Examples 1 to 8 When alkyd paint is used...Table 1 Examples 9 to 12 When epoxy paint is used...Table 2 The formulations in the table All numerical values indicating amounts are parts by weight.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between adhesion depending on the immersion time in boiling water when an epoxy silane compound and an amine silane compound are added to an amino-alkyd or epoxy resin paint and when they are not added. FIG. 2 is a diagram showing the range of coating film formation with good performance in all aspects depending on the pH difference of the nepoxy amino resin coating.

Claims (1)

[Scope of Claims] 1. The following silane compounds (here, R represents 10 carbon atoms) are added to paints whose main components are amino-alkyd' resin paints, amino-alkyd-epoxy resin paints, and epoxy-amino resin paints. less divalent hydrocarbon radicals, and of divalent hydrocarbon radicals containing C, H, 0, atoms, containing less than 10 carbon atoms, and in which at least one oxygen atom is present in the form of an ether bond; , a has a value of 0 or 1, and R/ is selected from aliphatic hydrocarbon groups having less than 5 carbon atoms and hydrogen (provided that R is an alkyl group having up to 4 carbon atoms) and a is l
Alternatively, b is selected from 2 and 3, and b is selected from O or 1 and 2. R' is an aliphatic hydrocarbon group containing one or more carbon atoms and having a valence of n + 1 (where n is an integer of 1 or more), and Z is bonded to R' through a carbon-nitrogen bond. However, it is a monovalent group consisting of hydrogen, carbon and nitrogen atoms and containing at least two amine groups, and the ratio of carbon atoms to nitrogen atoms present in the group -R'Z is 671 or less. ) alone or by mixing (A) and (B) (however, in the case of epoxy-amino resin paints, a pH adjuster is added to adjust the pH to 6.5 to 9, and (B) alone) Alternatively, use a mixture of (A) and (B).) Add 0.2 to 10% by weight of the resin content in the paint directly to the paint, or use a 0.2 to 10% by weight concentrated solution as an undercoat. A method of forming an organic coating on the untreated glass surface.