JPH06340828A - Fluorescent white pigment composition - Google Patents

Abstract

PURPOSE:To obtain a fluorescent white pigment compsn. excellent in fluorescence and free of progress of curing with time by blending a fluorescent white pigment with barium sulfate, a water-soluble polymer and water. CONSTITUTION:A fluorescent white pigment and barium sulfate are used as a colorant and an extender pigment, respectively, and blended with water as a solvent and a natural or synthetic water-soluble polymer such as glue or gum arabic as a bonding agent and a vehicle to prepare a fluorescent white pigment compsn. The amt. of the fluorescent white pigment is 20 to 35wt.% based on the total. amt. of the compsn. Precipitated barium sulfate of at most 1mum in particle size is pref. blended as the barium sulfate in an amt. of 10 to 30wt.% based on the total amt. of the compsn. If necessary, use is appropriately made of a wetting agent, an antifreezing agent, etc., and an additive such as a preservative and/or a rust-proofing agent.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a fluorescent white pigment composition used for paints, poster colors and the like. In particular,
The present invention relates to a fluorescent white pigment composition which is excellent in fluorescence emission and hard to cure with time.

[0002]

2. Description of the Related Art Conventionally, pigment compositions used for paints, poster colors and the like include pigments such as carbon black and phthalocyanine blue which are colorants, and extender pigments such as calcium carbonate and silica which are used as extenders and masking agents. , A water-soluble polymer such as gum arabic or dextrin used as a fixing agent or a color-developing agent, and water.

In recent years, a so-called fluorescent pigment that emits fluorescence has been used as a coloring material in addition to the usual color tone such as carbon black and phthalocyanine blue.

[0004]

The reduction in fluorescence and the curing of the pigment composition over time. Among the fluorescent pigments, particularly white pigments have a tendency to cure with time when they are made into an aqueous composition with water. This curing over time is related to the amount of the fluorescent white pigment used, and the larger the amount used, the easier the curing. Therefore, a large amount of fluorescent white pigment cannot be used to obtain a fluorescent white pigment composition that is difficult to cure with time. However, since the fluorescence, that is, the intensity of fluorescence increases as the amount of the white pigment used increases, it is difficult to increase the fluorescence of the fluorescent white pigment composition due to the restriction of the amount of the fluorescent white pigment used.

Moreover, since the fluorescent white pigment has almost no hiding property, it is necessary for the pigment composition used for paints and poster colors to contain an extender pigment used for various purposes such as a hiding agent and a filler. However, since this extender pigment has the property of lowering the fluorescence, the fluorescence of the fluorescent white pigment composition will further decrease. An object of the present invention is to provide a fluorescent white composition which is excellent in fluorescence and does not cause curing over time.

[0006]

DISCLOSURE OF THE INVENTION The gist of the present invention is a fluorescent white pigment composition containing at least a fluorescent white pigment, barium sulfate, a water-soluble polymer, and water.

The details will be described below. The fluorescent white pigment is used as a coloring material. The fluorescent white pigment is generally a pigment obtained by melting a melamine-based resin and a fluorescent whitening agent to form a solid solution and then finely pulverizing it. Examples of commercially available products include NKP-819 (manufactured by Nippon Fluorescent Chemical Co., Ltd.), F
Z-1009 (manufactured by Shin Loihi Co., Ltd.), A-594-5
(Manufactured by DAY-GLO, USA) and the like. The amount used is preferably 20 to 35% by weight with respect to the total amount of the fluorescent white pigment composition.

Barium sulfate is used as an extender pigment.
Barium sulphate has the property of preventing curing with a fluorescent white pigment over time and being less likely to reduce the fluorescence. Barium sulphate includes precipitable barium sulphate and suihi barium sulphate, but precipitable barium sulphate is preferred. The smaller the particle size, the greater the effect obtained,
It is preferably 1 μm or less. Further, the amount used is preferably 10 to 30% by weight based on the total amount of the fluorescent white pigment composition.

The water-soluble polymer is used as a fixing agent and a color developing agent. Natural water-soluble polymers such as glue, gum arabic, and dextrin, carboxymethyl cellulose,
Semi-synthetic water-soluble polymer such as hydroxyethyl cellulose,
Synthetic water-soluble polymers such as polyvinyl alcohol can be used, and the amount thereof is 5 to the total amount of the fluorescent white pigment composition.
20% by weight is preferred.

Water is used as a solvent.

In addition to the above components, a water-soluble organic solvent such as glycerin, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, sorbitol, sorbitan may be used as a wetting agent, an antifreezing agent, a resolubility improving agent, or the like. Additives such as antiseptics, antifungal agents, antirust agents, and defoaming agents may be appropriately used depending on the case.

The fluorescent white pigment composition of the present invention can be easily obtained by mixing and dispersing the above components with a disperser such as a three-roll mill or a horizontal ball mill.

[0013]

In the present invention, it is not clear why the fluorescence is excellent and the curing does not occur over time, but it is presumed as follows. The fluorescent white pigment is a very unstable pigment by itself, and it is known that the pigments come into contact with each other and react to cure, but by using barium sulfate, the contact between the fluorescent pigments is reduced. Curing due to the reaction is suppressed. Further, barium sulfate has a small refractive index and transparency, and thus does not deteriorate the fluorescence.

[0014]

EXAMPLES Examples will be described below. Example 1 A-594-5 (manufactured by DAY-GLO, USA) 28 parts by weight precipitated barium sulfate (average particle size 0.1 μm) 24 parts by weight gum arabic 8 parts by weight water 31 parts by weight glycerin 6 parts by weight Preservative 3 parts by weight The above ingredients are put in a lab mixer and stirred for 15 minutes.
The mixture was passed through a three-roll mill three times to obtain a fluorescent white aqueous pigment composition.

Example 2 A-594-5 (manufactured by DAY-GLO, USA) 32 parts by weight Precipitable barium sulfate (average particle size 0.6 μm) 20 parts by weight Arabic gum 8 parts by weight Water 31 parts by weight Glycerin 6 parts by weight Part preservative 3 parts by weight The above ingredients are put in a lab mixer and stirred for 15 minutes,
The mixture was passed through a three-roll mill three times to obtain a fluorescent white aqueous pigment composition.

Example 3 FZ-1009 (manufactured by Shin Loihi Co., Ltd.) 28 parts by weight barium sulfate (average particle size 0.6 μm) 20 parts by weight Arabic gum 8 parts by weight water 31 parts by weight titanium dioxide 4 parts by weight glycerin 6 Parts by weight preservative 3 parts by weight The above ingredients are put in a lab mixer and stirred for 15 minutes.
The mixture was passed through a three-roll mill three times to obtain a fluorescent white aqueous pigment composition.

Comparative Example 1 A-594-5 (manufactured by DAY-GLO, USA) 52 parts by weight gum arabic 8 parts by weight water 31 parts by weight glycerin 6 parts by weight preservative 3 parts by weight The above ingredients were placed in a lab mixer and blended for 15 parts. After stirring for a minute,
The mixture was passed through a three-roll mill three times to obtain a fluorescent white aqueous pigment composition.

Comparative Example 2 An aqueous pigment composition having a fluorescent white color was obtained in the same manner as in Example 1 except that the precipitated barium sulfate of Example 1 was changed to calcium carbonate (average particle size 1.5 μm).

Comparative Example 3 Except that the precipitated barium sulfate of Example 1 was silica.
A fluorescent white aqueous pigment composition was obtained in the same manner as in Example 1.

Comparative Example 4 Except that the precipitated barium sulfate of Example 1 was changed to clay,
A fluorescent white aqueous pigment composition was obtained in the same manner as in Example 1.

The fluorescent white aqueous pigment compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were tested. The results are shown in Table 1.

[0022]

[Table 1]

* 1 Fluorescence test The fluorescent white pigment compositions obtained in the above-mentioned Examples and Comparative Examples were mixed with water at a weight ratio of 1: 1 and the surface of the drawing paper was coated with a writing brush. Was irradiated with an ultraviolet lamp (black light) and visually compared and judged (the light emission of Comparative Example 1 using only the fluorescent white pigment was set to 5 and judged according to the following criteria). 5: Strong fluorescence emission 4: Slight fluorescence emission 3: Slight fluorescence emission 2: Slow fluorescence emission 1: Almost no fluorescence emission

* 2 Aging test The fluorescent white pigment compositions obtained in the above Examples and Comparative Examples were filled in a bottle with a stopper and left at 50 ° C for 1 month.
Based on K5101 (pigment test method), the hardness of the pigment composition was measured by a spread meter, the diameter of the pigment composition before and after standing was measured (unit: mm), and the difference was determined by the difference between the measured values. ◯: Diameter difference less than 1% Δ: Diameter difference 1% or more and less than 2% X: Diameter difference 2% or more or cured unmeasurable

[0025]

As described above in detail, the fluorescent white pigment composition according to the present invention has excellent fluorescence and does not cure over time. Also used as watercolor paint,
When applied or drawn, it is also good in other characteristics related to the quality of watercolor paint such as color developability and spread.

Claims (1)

[Claims] 1. A fluorescent white pigment composition containing at least a fluorescent white pigment, barium sulfate, a water-soluble polymer, and water.