JPS6160767A - Water based paint - Google Patents

Abstract

PURPOSE:To provide a water based paint having excellent viscosity stability and surface gloss imparting property, by blending finely ground limestone having a treated surface as an extender pigment. CONSTITUTION:0.05-10pts.wt. carboxylic acid base anionic surfactant (e.g. fatty acid soap or resin acid soap) is mixed with 100pts.wt. finely ground limestone having an average particle size of 0.4-1mu obtd. by grinding limestone, to obtain finely ground limestone having a treated surface. The obtained ground limestone is blended as an extender pigment by any of conventional methods to obtain a water based paint.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to water-based paints, and more specifically, to water-based paints that have excellent dispersibility as extender pigments and that are surface-treated to provide a clear surface gloss. Heavy weight calcium carbonate (
The present invention relates to a water-based paint containing a microorganism (hereinafter referred to as "fine cal").

``Prior art'' ``Problems to be solved by the invention'' Conventionally, as a method for imparting surface gloss to water-based paints, the primary particle diameter of the surface treated with a grown material was 01O2 to 0.1βm.
Minute precipitation j @ 51 jl! There are two known methods: one using calcium oxide (hereinafter referred to as precipitated charcoal) and the other using a fine calc slurry made by crushing limestone using a wet pulverization method. Not only must it be as dispersed as possible, but it must also be compatible with the vehicle.

Surface-treated fine calcium carbonate, which is commonly used as a filler for rubber, plastic, etc., or fine calcium carbonate treated solely with a carboxylic acid type anionic surfactant such as fatty acid soap or resin acid soap. Calcium carbonate is
When a dispersing machine with a weak crushing force, such as a sand grinder, which is commonly used in the production of paints, is used, it has the disadvantage that it is not easily dispersed in the paint. This is clearly stated in Japanese Patent Publication No. 46-15771 and Japanese Patent Application Laid-open No. 59-1571. Therefore, already microscopic 1
1t! 1! Surface treatment methods for improving the dispersibility of charcoal into paints have been investigated, for example, in Japanese Patent Publication No. 46-1
577L has been reported in JP-A-55-16031, JP-A-59-1571, etc. However, little research has been done in terms of particle size, and few concrete results have been reported.

On the other hand, for water-based paints, for example, as seen in JP-A-58-204061, limestone is crushed using a wet crushing method.
Callus slurry is used. This is 60-7011
It is a slurry with a high concentration of t% or more, and a polymer dispensing agent of sodium polyacrylate is added to reduce the viscosity of the slurry. However, even the carbonate obtained by this method is still far from satisfactory as a material for water-based paints that require high gloss in current coatings.

Currently, fine titanium oxide is used as 111M in water-based paints that require high gloss in the coating film, and extender pigments such as calcium carbonate are hardly used. On the other hand, heavy calcium carbonate with an average particle diameter of 1.5 μm or more is used in large quantities as an extender pigment in water-based paints that do not require high gloss in the coating film.

However, since heavy calcium carbonate is cheap, it is only used as an extender to reduce the cost of water-based paints and to form a single film.Thus, high gloss is required for the paint film. The reality is that there is a desire to develop extender pigments that are fully satisfactory as extender pigments for water-based paints.

"Means for Solving the Problems" In view of the above circumstances, the present inventors surface-treated @Umena Heavy Cal with a carboxylic acid type anionic surfactant and used it in a water-based paint. The present invention was completed based on the discovery that a groundbreaking and unexpected effect not found in sedimentary coal-made coal products or heavy coal slurry products can be obtained.

That is, in the present invention, a carboxylic acid type anionic surfactant is added to fine heavy calcium carbonate having an average particle size of 0.4 to 1.0 μm to form a 100% grade of calcium carbonate. 0.05 per part
The content is a water-based paint containing as an extender pigment fine, heavy calcium carbonate which has been added in an amount of 10 parts by weight to treat the particle surface.

In the present invention, the average particle diameter refers to the length of one side of a cube, which is determined from the specific surface area measured with a constant pressure aeration type specific surface area measuring device, assuming that the Docal particles are cubic particles.

In order to obtain the fine cals used in the present invention, limestone is ground dry or wet to an average particle size of 0.4 to 1.5 mm.
Adjust to fine particles of 0 μm. In the case of a dry method, it may be pulverized with a micron mill, vibrating ball mill, etc., and then classified with an air classifier, and in the case of a wet method, it may be pulverized with a ball mill, etc., and there is no particular restriction. Surface treatment with carboxylic acid type anionic surfactant.

The surface treatment agent used in the present invention is preferably a carboxylic acid type anionic surfactant such as a fatty acid soap, a resin acid soap, or a naphthenic acid soap, and these may be one type or 2J! A mixture of the above is used. The amount added is 0.05 to 10 ifi parts per 100 parts by weight of mlR calcium carbonate, more preferably 1 to 10 parts by weight.
Adding more than 1 part of 1Ofltff of 0 surface treatment agent, which is 4m191+, does not improve the surface treated young fruit, and therefore it is not economical, and in the case of wet treatment, dehydration becomes difficult, which is not preferable, and the amount added is 0.05i. If the amount is less than 10%, it will be difficult to form into a paint.

Wet-pulverized products are surface-treated in a wet state in this P8, but even if they are dry-pulverized, they may be surface-treated in a wet state.
The slurry thus treated is dehydrated, dried, and crushed to produce a product. On the other hand, when performing dry surface treatment, a Henschel mixer or the like is used.

The fine Cal obtained as described above is blended into a water-based paint in a conventional manner to produce a paint.

"Examples" The present invention will be described below with reference to specific examples and comparative examples, but the present invention is not limited by these in any way.

Reference example 1 Solid content of heavy carbon cal with an average particle size of 1.5 μm is 4011
A slurry was dispersed in water using a stirrer to adjust the slurry to L%. Pour this slurry into a sand grinder (
-Manufactured by 8A, DYNO (old LL), rotation speed 300 OR,
P, M, was pulverized at a flow rate of 51/hr. The average particle size of the pulverized heavy coal was 0.55 μm. Add 3 parts of sodium stearate to 100 parts by weight of this heavy coal as a solid content.
．． The surface treatment was carried out by adding 1 part of 0fflff. Sodium stearate was made into a 10wL% solution and the surface treatment of the heavy carbon callus slurry was carried out. This was dehydrated, dried, and ground to make a sample.

Reference Example 2 Average particle pi1. Solid content of Sμm heavy carbon cal is 50
Slurry dispersed in water using l1ll [wt%! I've adjusted everything. This slurry was pulverized using a sand grinder (manufactured by WIlA, DYNOMILL) at a rotation speed of 300 OR, P, M, and a flow rate of 91/hr. The average particle diameter of the pulverized heavy charcoal was 0.8 μm.

2.0 parts by weight of sodium stearate (solid content) was added to 100 parts by weight of this heavy coal for surface treatment.

Sodium stearate was made into a 10wL% solution and the surface of the heavy carbon callus slurry was treated. This was dehydrated, dried, and ground to make a sample.

Reference example 3 Average particle size 10. Omm limestone is crushed with a vibrating ball mill and then classified with a wind classifier to obtain an average particle size of 0.6μ.
m's! I passed the I-quality charcoal test. A slurry was prepared by dispersing this heavy coal in water using a stirrer so that the solid content was 20 wt%. This heavy coal calhoO31z
3.0 parts by weight of sodium stearate was added to 1 part for surface treatment. Sodium stearate is 10wtMf4
The surface treatment of the heavy carbon callus slurry was carried out by converting it into a liquid. This was dehydrated, dried, and ground to make a sample.

Reference example 4 By changing the classification degree of reference example 3, the average particle diameter was 0.75 μm.
of heavy coal was obtained. 3.0 parts of sodium stearate in 100iflE parts of this heavy coal! A certain amount was added, and the surface was treated using a Henschel mixer to prepare a sample.

Reference Example 5 A 15 wt% slurry of precipitated charcoal with a primary particle diameter of 0.07 μm was prepared by the sedimentation method, and the solid content of the resulting slurry was 100! 3.0 parts of sodium stearate per i part
! i parts by weight were added for surface treatment. Sodium stearate was used as a 10wt94 solution to treat the surface of the precipitated charcoal callus slurry. This was dehydrated, dried, and ground to make a sample.

Reference Example 6 Instead of sodium stearate in Reference Example 5, 3 stearic acid was added with 2.0 Jilfm of dodecylbenzenesulfonic acid.
．． A sample was obtained in the same manner as in Reference Example 5 by surface treatment using an emulsion prepared by emulsifying 1 part of 0 μm.

Reference Example 7 The average particle diameter of the powder crushed in Reference Example 1 was 0.55 μm! I!
After dehydrating the coal slurry to a solid content concentration of 70 wt%,
1 part for 100iii of quality 11 coal. Qi weight part sodium polyacrylate was added and slurried using a lab body spar. This heavy coal callus slurry was used as a sample.

Reference Example 8 By changing the degree of classification in Reference Example 3, a m trade coal with an average particle size of 1.2 μm was obtained. All samples (6) were obtained using the same method as Reference Example 3.

Reference Example 9 A heavy coal with the same average particle size as Reference Example 1 was obtained. No surface treatment was performed, and the sample was dehydrated, dried, and ground without any treatment.

Examples 1 to 4, Comparative Examples 1 to 5 Using the samples prepared in Reference Examples 1 to 9 above, paints were formed using the following paint formulation and paint forming method. The results of measuring the physical properties of the paint are shown in No. 111.

(a) Paint formulation primary blending mill base (parts by weight) Dispersant (Daiichi Kogyo 11 drugs; Neugen IIA-120>
2 Dispersant (Daiichi Kogyo Seiyaku; Disco) N-
14) 8 Antifreeze agent (propylene glycol) 5
0 Titanium white (Ishiya Sangyo; R-8301194 sample (Reference examples 1 to 9) 65 Water
522 secondary combination red down (ni1
Part) Mill base 18
6 Emulsion (Dainippon Ink; 222 Boncoat EC-821) Film-forming agent (butyl cellosolve) 35 (b) Paint forming method First interval: i'ii 1 Dispersion was carried out for 20 minutes in an easy type SC mill.

The rotation speed is 800R, P, M.

The mixture was stirred for 5 minutes using a 2-lack Nirabo Disbur.

"Effects of the Invention" As is clear from the results in Table 1, the water-based paint containing the surface-treated fine m-cal of the present invention is different from the water-based paint containing the conventional precipitated charcoal or the wet-pulverized m-char slurry. Remarkable effects on surface gloss and viscosity stability are observed compared to paints.

Claims (1)

[Claims] 1. Add 0.05 to 10 parts by weight of a carboxylic acid type anionic surfactant per 100 parts by weight of ground calcium carbonate to fine ground calcium carbonate with an average particle diameter of 0.4 to 1.0 μm to form particles. A water-based paint containing fine surface-treated heavy calcium carbonate as an extender pigment.