JPH069787A - Fine polymer particle hardly making dust - Google Patents

Abstract

(57) [Summary] [Structure] A polymer fine particle having an average particle diameter of 0.5 to 50 μm has a melting point of 0.1 to 3.0% by weight based on the polymer.
Polymer particles which are resistant to dust and are characterized by being coated with an organic substance having a boiling point of 160 ° C or higher and 0 ° C or lower. [Effect] Even when the polymer fine particles having an average particle diameter of 50 μm or less of the present invention are used in cosmetics, fillers for paints, resin modifiers, binders for ceramics, etc., dust is difficult to generate, and the operator is not required to work It is easy and has no health problems.
Also, since it is difficult to generate dust, there is no danger of dust explosion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to fine polymer particles which do not easily generate dust.

[0002]

2. Description of the Related Art Recently, polymer fine particles have been widely used in various fields such as cosmetics, paint fillers, resin modifiers, ceramic binders, etc., in place of inorganic fine powders. Those of 0.5 to 50 μm are often used. Acrylic polymer fine particles have an excellent matting effect when added to a paint, for example, and are widely used such as when added to an acrylic resin or PET to give a frosted glass tone. The average particle size of these acrylic polymer fine particles is most preferably 5 to 30 μm, and those having the average particle size are said to exhibit the best effect.

[0003]

However, when a polymer having an average particle size of 50 μm or less is used as a cosmetic, a filler for paints, a resin modifier, a binder for ceramics, etc. instead of the inorganic fine powder, the average Polymers with a particle size of 50 μm or less generate significant dust, making it difficult for operators to work.
And it is not good for your health. Further, since there is a danger of dust explosion due to dust generation, there is a strong demand for polymer fine particles that are difficult to generate dust.

As a result of earnest studies by the present inventors, when a specific organic substance coats and adheres to the surface of polymer fine particles, the organic substance acts as a binder to form a form in which the fine particles adhere to each other. The inventors have found that the generation of dust can be suppressed and have reached the present invention.

[0005]

Means for Solving the Problems The fine polymer particles of the present invention, which are hard to generate dust, are fine polymer particles having an average particle size of 0.5 to 50 μm, and 0.1 to 3.0 of the polymer. It is characterized by being coated with an organic substance having a melting point of 30% or less by weight and a boiling point of 160 ° C or more.

The organic substance of the present invention must have a melting point of 30 ° C. or lower and a boiling point of 160 ° C. or higher. When the melting point exceeds 30 ° C., it is solid at room temperature, and it is difficult to uniformly coat the entire polymer fine particles with the organic substance.
Also, even if the coating is uniformly applied, a sufficient effect of suppressing dust generation cannot be seen. On the other hand, some organic substances with boiling points lower than 160 ° C can suppress dust generation, but
If it is exposed to the sun, it will evaporate during storage and the effect of suppressing dust will be lost. Further, in the case of an organic substance which generates a flammable vapor, there is a risk of ignition, which is a problem in handling, and therefore it is not used in the present invention.

Examples of such an organic substance used in the present invention include methacrylic acid esters such as lauryl methacrylate and tridecyl methacrylate, higher alcohols such as lauryl alcohol, isopropyl palmitate, and the like.
Examples thereof include fatty acid esters such as octyl myristate, liquid paraffin, and silicone oil. These are used alone or in admixture of two or more, and among these, methacrylic acid ester and oleic acid are preferable.

The fine polymer particles used in the present invention include:
Examples thereof include styrene resin fine particles, acrylic acid resin such as methyl methacrylate polymer, and fine particle phenol resin fine particles. Average particle size of polymer particles is 50μ
m or less and 0.5 μm or more means that the average particle size is 0.
5-50 μm cosmetics instead of inorganic fine powder,
It is widely used in various fields such as paint fillers, resin modifiers, ceramic binders, and has an average particle size of 5
This is because dust generation becomes a problem when the thickness is 0 μm or less.

The above-mentioned organic substance having a melting point of 30 ° C. or lower and a boiling point of 160 ° C. or higher is 0.1 to 3.
0% by weight, preferably 0.3-2.0% by weight. If the coating amount is less than 0.1% by weight, the effect of suppressing the generation of fine particles of the polymer particles is reduced, and if it exceeds 3.0% by weight, the fluidity of the polymer particles is deteriorated, resulting in aggregation and agglomeration. Not only is it undesirable, but it is not preferable because it may impair the characteristics of products that are generally used.

The above-mentioned polymer particles are coated with the above-mentioned organic substance, for example, by placing the polymer particles in a container (for example, a screw blender) equipped with a stirring blade, and adding the organic substance while stirring. You can

[0011]

EXAMPLES The present invention will be described in more detail based on the following examples. Examples 1 to 12 Thickness 0.03 mm, width 300 mm, length 450 mm 15
No. Polyethylene bag containing 1000 g of methyl methacrylate fine particles (average particle size: 8.2 μm), the type of organic substance to be coated and its coating amount are changed, mixed for 30 minutes to perform coating treatment, and then taken out. The degree of dust generation of the fine particles of methyl methacrylate resin and the state of the fine particles were examined. The results are shown in Tables 1 and 2.

Comparative Examples 1 to 6 For comparison, the melting point exceeds 30 ° C. or the boiling point is 160.
The degree of dust generation and the state of the fine particles were examined in the same manner as in Examples 1 to 12 using an organic substance having a temperature lower than ° C. The results are shown in Table 3.
And shown in Table 4.

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

[Table 3]

[0016]

[Table 4] The dust generation prevention effect is expressed by using symbols of ⊚, ○, Δ and ×. ⊚: No dust is generated and fine particles are in good condition. ◯: No dust is generated and fine particles are in good condition, but inferior to ◎. Δ: Some dust is generated. X: Dust is generated. The storage stability was evaluated by evaluating the dusting property after 2 weeks (the amount added was 0.5% by weight).

As is clear from the table, polymer fine particles coated with an organic substance having a melting point of 30 ° C. or lower and a boiling point of 160 ° C. or higher of 0.1 to 3.0% by weight with respect to the polymer of the present invention, Compared with the polymer fine particles of Comparative Example, it is superior in the dust-preventing effect and storage stability.

[0018]

EFFECTS OF THE INVENTION Even when the polymer fine particles having an average particle size of 50 μm or less of the present invention are used for cosmetics, paint fillers, resin modifiers, ceramic binders, etc., dust is difficult to generate It is easy to work and has no health problems. Also, since it is difficult to generate dust, there is no danger of dust explosion.

Claims (1)

[Claims] 1. Organic fine particles having an average particle diameter of 0.5 to 50 μm and having a melting point of 0.1 to 3.0% by weight with respect to the polymer, a melting point of 30 ° C. or lower, and a boiling point of 160 ° C. or higher. Fine polymer particles that are resistant to dust and are characterized by being coated with a substance.