JPS5853968A - Adjustment of viscosity of paint - Google Patents

Abstract

PURPOSE:To adjust the viscosity of a paint finely while keeping the function of surface treatment, by reducing or increasing the carbon numbers of the alkoxy groups of fatty acid esters to treat the surface of finely divided particles of calcium carbonate which is blended with a resin material for the paint. CONSTITUTION:To treat the surface of finely divided particles of calcium carbonate (e.g., precipitated calcium carbonate, etc.), an emulsifying agent (e.g., sulfonic acid type surface active agent, etc.) is added to the calcium carbonate, and the carbon numbers of the alkoxy groups of fatty acid esters (two or more fatty acid esters having different numbers of alkoxy groups are used) for surface treatments are reduced or increased (namely, the viscosity of a paint is reduced when the carbon numbers are increased, and increased when they are reduced), to effect the adjustment of the viscosity. The viscosity adjustment can be carried out corresponding to the change in viscosity based on the properties of calcium carbonate by raising the blending ratio of calcium carbonate and increasing the carbon numbers of the alkoxy groups of the fatty acid esters.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to adjusting the viscosity of a solvent-based paint produced by blending calcium carbonate surface-treated with an emulsifier and a fatty acid ester into a paint resin material.

The solvent-based paint that is the object of the present invention is manufactured by blending calcium carbonate, which is an extender pigment, in a suitable blending ratio with the resin material for paint, which is the main component.

Such paints are required to have gloss and retention, anti-sagging properties (viscosity), weather resistance, chemical resistance, and workability from the viewpoint of both protecting the object to be coated and giving it a beautiful appearance. Ru.

Incidentally, since the physical properties of calcium carbonate have a strong overall influence on all the properties of paints as described above, research on the properties is being continued earnestly.

An excellent conventionally known paint of this type is the one published by the Japanese Patent Publication No. 31. It uses "calcium carbonate surface-treated with a combination system of surfactant and fatty acid ester" as shown in No. 234t7/, etc., and especially when excessive surfactant is used It is highly effective in terms of important properties such as gloss, shine, and anti-sagging properties.

In general, conventional viscosity adjustment for improving sagging properties has been broadly classified into the following types. No. 7 is based on blending calcium carbonate, which is an extender pigment, in an appropriate ratio, and in particular uses calcium carbonate that has been physically improved in terms of anti-sag effect. The improvement is
In most cases, calcium carbonate is surface-treated with a gold N salt of a fatty acid, and other treatments were said to be ineffective.

The other seven are due to thickeners, and as thickeners,
fc, for example, aluminum fatty acid organic pennite,
Examples include fine-grained silica, dimer acid, and alkyl sulfate metal salts.

However, these thickeners generally tend to reduce surface gloss, which tends to have a negative effect, and because they are highly effective in small amounts, they may obscure other properties. However, it is difficult to finely adjust the viscosity.

The present invention aims to reduce the viscosity by increasing the number of carbon atoms in the alkoxy group of a fatty acid ester for surface treatment of fine particle calcium carbonate blended into a resin material for paint, and to increase the viscosity by decreasing the number of carbon atoms. It is an object of the present invention to provide a viscosity adjustment method characterized by the following, thereby making it possible to finely adjust the viscosity while maintaining the surface treatment function of fatty acid ester, which is excellent as a surface treatment agent.

Hereinafter, the present invention will be specifically explained in detail by referring to Examples.

By changing the number of carbon atoms in the alkoxy group of the fatty acid ester used in the present invention as a surface treatment agent for surface treating calcium carbonate, the viscosity of the finished paint can be slightly changed while keeping other properties unchanged. can be done. Increasing the number of carbon atoms in the alkoxy group reduces paint viscosity,
On the contrary, a new law of inverse proportionality was discovered, which states that decreasing the number of carbon atoms increases paint viscosity.

Therefore, the alcohol used is methyl-ether-propylbutyl→60. -Octyl-0°3- 00. −If you replace decyl with alcohol,
The viscosity gradually decreases in this order. In addition, if methyl alcohol ester and decyl alcohol ester are used instead of using methyl alcohol ester alone as the fatty acid ester, the viscosity decreases, and by changing the blending ratio of both alcohol esters, the viscosity can be lowered. Can be finely adjusted. Furthermore, by changing the blending ratio of calcium carbonate and simultaneously changing the ester mentioned above, the viscosity v4 adjustment according to the present invention can be added to match the viscosity change based on the properties of calcium carbonate, and the viscosity can be improved as a whole. It can be changed or kept constant.

As calcium carbonate, precipitated calcium carbonate is usually used. Heavy calcium carbonate, which is obtained by simply mechanically crushing limestone, has poor weather resistance and does not provide appropriate structural viscosity when blended into paint materials, but has a specific surface area of /θ , θ0θcdl/1
If one-goo fine particle heavy calcium carbonate of about 100 g or more is used, it is possible to carry out the method considering the cost, although the properties are inferior.

Precipitated calcium carbonate is not used as is, but after surface treatment. The fatty acid ester, which is the surface treatment agent used in the present invention, is itself insoluble in water and therefore has no activity as a surface treatment agent. Therefore, a suitable emulsifier must be used. Various emulsifiers are known, but when considering the gloss of the coating,
Sulfonic acid-based surfactants are good.

The surface treatment amount of the fatty acid ester is preferably at least 100% by weight relative to the total weight of the fine particles of calcium carbonate. , from evening to 3pm. The amount of emulsifier used at this time is sufficient as long as the fatty acid ester is in a stable emulsified state, but it is desirable to use a slightly excess amount.

Alcohols used for viscosity adjustment can be easily and inexpensively prepared with high purity and have various carbon numbers. On the other hand, although highly pure fatty acids cannot be obtained, a homogeneous mixture of various fatty acids that can be obtained at low cost can be obtained as a mixture, and the above-mentioned law of inverse proportion is related to the type of fatty acid. Therefore, even if highly pure fatty acids are not available, the present invention can be carried out easily and inexpensively.

Next, let's look at the above-mentioned inverse proportionality law using a test example.

Test Example 1 Carbon dioxide gas is blown into calcium hydroxide slurry to produce precipitated calcium carbonate with an average particle diameter θ of 2 μm (slurry volume is 2/, solid content of calcium carbonate is set to A at 0θI). On the other hand, 1 part of each of the fatty acid esters shown in Table 1 was added to 320 ml of hot water at jθ0C, and 2 parts of a polyoxyethylene ether type emulsifier was added to each of them.
Each fatty acid ester is emulsified by injecting two aqueous solutions containing I with strong stirring, and each emulsion is added to each bee force of the above-mentioned calcium carbonate slurry adjusted under the same conditions, respectively, with stirring. After that, it is dehydrated and dried and then passed through a pulverizer to obtain a sample. In the samples thus prepared, the weight ratio of fatty acid ester as a surface treatment agent to calcium carbonate was //θθ. Paints are made from these samples using the following blending ratios.

/Next formulation (weight ratio) Soybean oil modified alkyd resin CP-296-70)
,,201 Minetsuru ,,,, /j♂Titanium White (R-za20) ,27θ Heavy Calcium Carbonate (Extender Pigment) ,73 Sample (Product of the Invention) ,, ,,, Secondary blended soybean oil modified alkyd resin (same as above), 3J mixed dryer, 32 Anti-skin anti-skin agent, 32- Test on this example product Table 1 below shows the results of paint viscosity tests using three commonly used measuring methods.

Table 1: This table can be graphed to make it easier to read, as shown by the solid lines in Figures 1 and 2. The solid lines in Figure 1 indicate the KU values - and - for stearate esters, and the two solid lines in Figure 2 indicate the minute pm values measured by the B-type viscometer.
This shows the viscosity at θrpm. Furthermore, under the same conditions,
In the above test examples, the cases where palmitic acid was used instead of stearic acid are shown by dotted lines in FIGS. 1 and 82.

Such an inverse proportional relationship applies not only to the fatty acids listed above, but also to linoleic acid and liluic acid.

Natural fatty acids such as oleic acid are also found in varying proportions.

Next, examples of implementation (utilization) modes for cost reduction will be described. .

In order to reduce costs, it is best to incorporate as much extender pigment as possible, but adding a large amount of extender pigment with a large particle size, such as heavy calcium carbonate, may cause white nitrification of the lumen, decrease in adhesion, and premature loss of luster. It causes sinking and sedimentation of pigments during paint storage, making it unsuitable for practical use. Average particle diameter θ,! μ
The above disadvantages can be largely overcome by incorporating precipitated calcium carbonate with a small particle size of about 7n or less, but due to the fact that precipitated calcium carbonate is fine particles and has a large oil absorption, it is difficult to use normal surface treatment sedimentation. Calcium carbonate causes the finished paint to thicken too much, and in severe cases, the paint becomes pudding-like, making it impossible to apply smoothly with a brush or roller, or spray with a spray gun. 70K when applied with a brush by diluting the paint with too high viscosity with a solvent
U, 2θ with jOKUc food cupp during spraying
If the viscosity is lowered to about 1.0 seconds, the solid content concentration in the paint will be too low, which will also cause various problems.

By incorporating precipitated calcium carbonate surface-treated with a fatty acid ester with an alkoxy group having 3 or more carbon atoms, preferably ♂ or more into the paint, the cost of the paint can be reduced, desired performance can be maintained, and the paint can be easily applied. It is possible to simultaneously solve the following requirements.

(Embodiment example) From rice bran oil (main components nioleic acid, linoleic acid, palmitic acid) and beef tallow (main components nioleic acid, valmitic acid, stearic acid, myristic acid) as typical naturally occurring fatty acid raw materials. Fatty acid esters having different numbers of carbon atoms in the alkoxy group were prepared, and these were applied to calcium carbonate having an average particle diameter of θ,/μm in the same manner as in Test Example 1. . First, calcium carbonate is surface-treated at a ratio of .

Next, in the two combination ratios described below, the output viscosity normally required for each paint is Fi FfKU for the air-dry type in the 7th formulation example, and the baking viscosity for the mold in the 2nd formulation example. The relationship between the amount of calcium carbonate blended to obtain 70 KU) and the number of carbon atoms in the alkoxy group of the fatty acid ester is investigated. The results are shown in FIG. 3 for the first formulation example and in FIG. 7 for the second formulation example.

1st combination example 7 2θ chiminetsuru /! ! Titanium white (
R, rkoθ) 27θ heavy calcium carbonate
73 Second order resolution 29t-7θ 3! ! Mixed dryer 32 Anti-skinning agent 3 Formulation example/reaction xylene 6θ Titanium white (R♂coθ) 20θD&ti acid-c, 33θO−Otsuθ−X 329J?2θ−OtsuO/G/Xylene θ In contrast to the normal precipitated calcium carbonate formulation, at most 0~!θ, the second formulation In the example, the amount of y is at most 2 for the nonvolatile content/θ0 of the paint resin.
! ~3! However, as is clear from Figures 3 and 3, by incorporating fatty acid ester-treated calcium carbonate with n=6 or more, 2 can be achieved! θ or more, and y is 3
It is clear that it is possible to do more than that. In this case, as described above, various properties desired for the paint can be maintained in a comprehensive manner.

The present invention does not adjust the viscosity by using thickeners, other surface treatment agents, etc. or changing the blending ratio of calcium carbonate, etc., and the number of carbon atoms in the alkoxy group of the fatty acid ester used for surface treatment of calcium carbonate is improved. Since this is an adjustment method that changes the viscosity by changing the viscosity, the viscosity can be adjusted without affecting other properties and performance.
The effect is that the viscosity can be adjusted independently without affecting the excellent performance obtained in polishing and the like.

[Brief explanation of the drawing]

Both FIG. 1 and FIG. 2 are graphs showing the test results, and FIG. 3 and FIG. Z are both graphs showing the test results of the embodiment example. Reeds 1 to 2 stems of the leaves (

Claims (3)

[Claims] (1) The viscosity can be lowered by increasing the number of carbon atoms in the alkoxy group of the fatty acid ester used to surface treat the fine particles of calcium carbonate blended into resin materials for paints, and the viscosity can be increased by decreasing the number of carbon atoms. A unique method for adjusting the viscosity of paint. (2) The method according to claim 1, characterized in that the blending ratio of particulate carbon calcium is increased and at the same time the number of carbon atoms is increased. (3) The method according to claim 1, characterized in that two or more types of lj acid esters having different numbers of carbon atoms in their alkoxy groups are used.