JPS6011989B2 - High film thickness paint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-film thickness type paint suitable for wheels, chemical plants, and building materials.

Hitherto, no high film thickness type paint of this type has been provided that combines film performance, workability, and finished appearance.

One of the main reasons for this is that foaming (foaming) occurs under the influence of solvent volatilization during scaling, which severely impairs the finished appearance. Therefore, in the building materials industry, which currently uses a large amount of high film thickness type paints, in most cases, room temperature drying type paints with a high solids content are used at construction sites. Furthermore, the possible coating thickness that can be ensured with at least one coating and with a good finished appearance is about 100 µm. Conventional high-film-thickness paints used on Akatsuki type axles, for example, car intermediate paints for which there is a large demand, currently have a film thickness of 70 mm or less that can be secured in one application. It is said that Therefore, in the paint industry, there is an urgent need to prevent the formation of wrinkles during application, as one of the factors for expanding the market for high film thickness paints. Therefore, an object of the present invention is to provide a highly practical high-film-thickness paint that prevents the occurrence of wrinkles during competition.

The purpose of this invention is to add benzoiso to a high film thickness type paint.
This is achieved by using 0.1 to 2 parts by weight relative to 0 parts by weight.

This invention will be explained in detail below.

First, penzoin, which forms the essential part of this invention, is a compound known as Q-oxybenzylphenylketone in the International Nomenclature System, and also known by its common name penzylphenylcarbinol. Moreover, this chemical structural formula is shown by.

The action of this penzoin is that when the paint thickens due to the volatilization of the solvent during dawn curing, the action of penzoin temporarily lowers the viscosity of the paint film and suppresses the formation of wrinkles. Due to their compatibility, a synergistic effect is produced, and even greater effects can be expected with addition of small amounts.

Next, the high film thickness type paint referred to in this invention has a coating work viscosity of 1000 centipoise (C.P.C.) or more, and a coating thickness of at least 70 to 600 centipoise (C.P.C.) obtained by applying it once to the object to be coated. 〃
Refers to something that is.

This thick, thick paint is made by blending resin, solvent, benzoin, two or more types of pigments, and various compounding agents such as anti-settling agents as necessary in a known mixing device such as a disper, and then combining them. The mixture is uniformly dispersed using a known dispersing machine such as a ball mill, sand grinder, or roll mill, and if necessary, defoamed under reduced pressure to obtain a product. The above pigment is a general term for extender pigments and color pigments, and specifically includes calcium carbonate, silica, alumina, iron oxide (including red iron oxide), aluminum silicate (clay, kaolin, etc.), asbestos, and hydrated silica. magnesium acid (including talc), barium sulfate,
Glass beads, zinc white, and titanium oxide, and in this case, it is preferable to adjust the particle size distribution of the pigment in order to improve other properties other than the pigment, such as sagging during application, spray workability, and chipping resistance. .

The particle size distribution may be within the range of 0.001 to 70 mm, more preferably 100 mm of total pigment.
Pigments distributed within the range of 0.001 to 5 mm in weight parts are adjusted to 3 parts by weight or less, and pigments distributed within the range of 5 to 70 mm are adjusted to 70 parts by weight or more. De*
Most preferably, the amount of pigments distributed within the range of 0.001 to 5 degrees is 3 parts by weight or less, the amount of pigments distributed within the range of 5 to 30 degrees is 35 parts by weight or more, and the amount of pigments distributed within the range of 0.001 to 5 degrees is 30 to 70 degrees. The pigment distributed within the range of 25 parts by weight or less. A smooth coating film can be obtained by simultaneously using a pigment with a small particle size and a pigment with a large particle size. As a method of adjusting the pigment distribution to this particle size, since soft pigments tend to become string particles during the dispersion process using a roll mill or sand glider, adjusting the area with a fine particle size is not a problem. In the above-mentioned dispersion process, at least one type of hard pigment such as silica, alumina, asbestos, etc., is selected and used, and the large particle size is included in the high film thickness type paint. The method is valid. The proportion of pigment in the high film thickness paint is 100 to 500 parts by weight, preferably 150 to 500 parts by weight, based on 10 parts by weight of resin.
40 parts by weight. Although the pigments are generally as described above, the appearance, particle size distribution range, and blending ratio of each pigment used in the present invention are shown in Table 1 below. Table 1 Next, as the resin used in this invention, any well-known paint resin can be used without any particular limitation, but polyester resins, particularly urethane-modified polyester resins, oil-free alkyd resins, urethane resins, and phenol-modified resins are preferable. , acrylic resin, etc., and the blending ratio thereof is 5 to 7 parts by weight, preferably 10 to 50 parts by weight, in 100 parts by weight of the total high film thickness type paint.

Next, regarding the solvent, any known solvent can be used, but preferably at least two or more selected from the group consisting of a low boiling point solvent of 12000 or less and a high boiling point solvent of 12000 or more are used. Most preferably, the high boiling point solvent is used in an amount of 5 parts by weight or more per 10 parts by weight of the total solvent.

Specific examples of the low boiling point solvent are low molecular weight alcohol solvents such as methanol, ethanol, normal butanol and isobutanol, and specific examples of the high boiling point solvent are ethylene glycol monoether, ethylene glycol monobutyl ether, etc. These are glycol ethers such as ether, ketone solvents such as cyclohexanone and isophorone, and aromatic hydrocarbons. The blending ratio of these solvents is 20 to 10 parts by weight, preferably 30 parts by weight, based on 10 parts by weight of the resin.
~8 parts by weight. As mentioned above, the essential ingredients for this invention are the four components of resin, benzoin, pigment, and solvent, and it is even more preferable to use a leveling agent, an anti-settling agent, etc. in addition to these components, if necessary. A high film thickness type paint can be obtained.

The staining agents used include silicone type, non-silicone type, fluorine type, acrylic type and other copolymers. Examples of anti-settling agents include fatty acid ester polymers, synthetic waxes, and silica-based anti-settling agents.
If these compounding agents are used in too large a quantity, other physical properties will be impaired, so it is better to limit the amount to 0.01 to 5 parts by weight based on 10 parts by weight of the resin. Next, the preferred coating work viscosity of the high film thickness type paint in this invention is 1000 to 400. P.
S, preferably 2500 to 3500. P. It is S.

The solid content thereof is 60 to 90 parts by weight, most preferably 65 to 75 parts by weight in the total high film thickness type paint 10.
Parts by weight. Also, when painting, it is preferable to work with hot Ares spray. Next, this invention can be used in any field that requires high film thickness, such as architecture, chemical plants, and automobiles, but it is difficult to improve the finished appearance, workability, and practicality, such as as an inner coating for automobiles. It is particularly effective in fields where it cannot be put to practical use unless high-level conditions such as coating film performance, especially chipping resistance, are met.

As mentioned above, if the particle size distribution of the pigment is adjusted, the preferred solvent and resin are selected, and the blending ratio is satisfied, then penzoin can be omitted and the phosphorization conditions, such as a longer setting time, can be adjusted. If you perform two-stage baking and keep the precure temperature low and leave it for a relatively long time, the problem of armpits will be solved.

However, if Penzoin is not added, the interior coating of automobiles will require harsh working conditions due to the line-based process, which will result in a loss of commercial value of the high film thickness type paint. By blending Penzoin into a high film thickness type paint, it becomes a highly practical high film thickness type paint that overcomes harsh working conditions and increases its commercial value. Example 1 25 parts by weight of a polyester (oil-free alkyd) resin with a non-volatile content of 60%, 9.0 parts by weight of a melamine resin (hardening agent) with a non-volatile content of 70%, and carbonic acid with a particle size distribution of 0.01 to 3 French. Calcium6. 2 parts by weight of titanium oxide with a particle size distribution of 0.2 to 1.0 degrees, 3.0 parts by weight of silica with a particle size distribution of 1 to 50 degrees, and 0.0 parts by weight of benzoin.
parts by weight, and 0.0 parts by weight of dodecylbenzenesulfonic acid (catalyst). 1 part by weight, 0.2 parts by weight of an acrylic antifoaming agent, 5 parts by weight of cyclohexanone, 6 parts by weight of xylol, and 1.5 parts by weight of cellosolve acetate were mixed into a disper.
After mixing with a pestle for 5 minutes and dispersing by passing through a sand glider twice, the mixture was transferred to a defoaming tank and defoamed at a reduced pressure of about 70 Hg to obtain a high film thickness paint.

Examples 2 and 3 The same blending ratio as in Example 1 was used, and the same manufacturing method was used, except that the blending ratio of penzoin was 1.0 and 2 parts by weight, and the blending ratio of xylene was 5.7 and 4.0 parts by weight. Soaring prices were obtained for thick-type paint.

Comparative example Penzoin was not blended, and the xylol blend ratio was 6.0.
A high film thickness type paint was obtained using the same compounding ratio as in Example 1 and using the same manufacturing method except that the parts by weight were changed.

As mentioned above, various tests were conducted to examine the finished appearance and coating performance of the high-rise thick paints obtained in Examples 1 to 3 and Comparative Examples, and the results are shown in Table 2 below.
Table 2 In addition, the test method in Table 2 above is that the high film thickness type paints obtained in Examples 1 to 3 and Comparative Examples were airless sprayed onto a vertically upright iron plate. were applied individually, and the dry film thickness at which the paint first began to flow on the iron plate was recorded by visual observation, and this value was taken as the sagging film thickness.

In addition, the underarm film thickness is 11,000 yen after applying a high-rise thick type paint on an iron plate with an airless sprayer and leaving it at room temperature for 5 minutes.
After baking for 7 minutes at 140:00 pm, the appearance was visually observed, and the lowest dry film thickness at which blisters (foaming) occurred was recorded, and this value was taken as the brink film thickness. In addition, airless sprayability (workability) is determined by the difficulty of the work when spraying a high film thickness type paint using an airless sprayer. Let something be x. Smoothness is determined by applying a high film thickness type paint on an iron plate individually at a film thickness that is approximately 20 degrees less than the film thickness shown in the armpit film thickness, and judging the surface after setting and drying. ○ If the unevenness of the coating surface cannot be visually discerned from a distance of 50 skin.
Those that can be identified are marked with an ×. Chipping resistance was measured using the gravelometer test method (stepping stone test method). 0 indicates that there was no abnormality when a pebble of lk9 was struck against the paint film three times at a 90 degree angle from a position 25 skin away at an air pressure of 4.0 to 4.5k9', and x indicates that an abnormality occurred. It is something.

As is clear from Table 2 above, the present invention provides a high film thickness type paint that can prevent the formation of wrinkles even under severe conditions without impairing other physical properties.

Claims (1)

[Claims] 1 In a high film thickness type paint containing at least a resin, a solvent, a pigment, and an additive, the additive includes benzoin.
0.1 to 2 parts by weight per 00 parts by weight, and the benzoin is compatible with the resin and solvent and is uniformly dispersed. mold paint.