JP2831495B2 - Granulation method of flame retardant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for granulating a powdery flame retardant, and more particularly, to a method for granulating a powdery flame retardant with a target particle size and a sharp distribution with good yield. .

[0002]

2. Description of the Related Art Conventionally, various flame retardants have been used to make plastics flame retardant. Flame retardants are generally in the form of powder. When such a powdery flame retardant is used, poor dispersion due to secondary agglomeration, foaming of the product due to classifying moisture absorption after mixing, deterioration of the working environment due to scattering during kneading work, etc. There is a problem. For the purpose of solving these problems, compounding of a flame retardant, making of a master batch of a flame retardant, and granulation of a powdery flame retardant have been carried out.

[0003] Granulation of the flame retardant is generally carried out by a method of preparing a tablet, compact, briquette-like molded product by a tableting or roll-type compression granulator and crushing the molded product into granules. I have. In the crushing step in this granulation, a large amount of fine powder is generated to forcibly crush the molded product,
There is a disadvantage that the yield decreases.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a method of converting a powdery flame retardant into a granular material having a target particle size and a sharp distribution with a sufficiently low generation of fine powder and good yield. The purpose is to do.

The inventor of the present invention has conducted intensive studies to achieve the above object. As a result, when a powdery flame retardant is compression-molded by a tableting type compression granulator, a V-shaped or U-shaped is formed on the surface of the molded product. The present inventors have found that the provision of the groove facilitates crushing, significantly suppresses the amount of fine powder generated, and provides a granular material having a target particle size and a sharp distribution, and has reached the present invention.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method for molding a powdery flame retardant using a tableting type compression granulator and crushing the obtained molded product to produce a granular material. This is a method for granulating a flame retardant, characterized in that a groove is formed on the surface of a molded article when the article is compression molded, and then the obtained molded article is crushed.

The flame retardant targeted in the present invention is in the form of a powder, for example, 2,2-bis (3,5-dibromo-4-).
Hydroxyphenyl) propane [commonly known as tetrabromobisphenol A (hereinafter abbreviated as TBA)], 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane [commonly known as tetrachlorobisphenol A (hereinafter abbreviated as TCA)], Bis (3,5-dibromo-4-hydroxyphenyl) sulfone [commonly known as tetrabromobisphenol S
(Hereinafter abbreviated as TBS)], bis (3,5-dichloro-4-)
Halogen-substituted dihydric phenols such as (hydroxyphenyl) sulfone [commonly referred to as tetrachlorobisphenol S (hereinafter abbreviated as TCS)], halogenated aromatic carbonate oligomers obtained using such halogen-substituted dihydric phenols, and halogen-substituted dihydric phenols Derivatives.

[0008] The halogenated aromatic carbonate oligomer is a carbonate oligomer of a halogen-substituted dihydric phenol or a copolymerized carbonate oligomer of a halogen-substituted dihydric phenol and a non-halogen-substituted dihydric phenol. Can be used as a monohydric phenol. The average value of the repeating unit of the dihydric phenol is preferably 50 or less, particularly preferably 20 or less.

The halogen-substituted dihydric phenols mentioned here include TBA, TCA, TBS, TCS and, for example, 1,1-bis (3,5-dibromo-4-hydroxyphenyl) ethane, 1,1-bis (3, 5-dichloro-4-
Hydroxyphenyl) ethane, 1,1-bis (3,5-
Dibromo-4-hydroxyphenyl) cyclohexane,
1,1-bis (3,5-dichloro-4-hydroxyphenyl) cyclohexane, bis (3,5-dibromo-4-)
(Hydroxyphenyl) sulfide, bis (3,5-dichloro-4-hydroxyphenyl) sulfide, bis (3,5-dibromo-4-hydroxyphenyl) oxide, bis (3,5-dichloro-4-hydroxyphenyl) sulfoxide, Bis (3,5-dibromo-4-hydroxyphenyl) ketone, bis (3,5-dichloro-4)
-Hydroxyphenyl) ketone and the like. As the halogen-unsubstituted dihydric phenol, the halogen-substituted dihydric phenol which is not substituted with halogen is useful. Examples of the monovalent phenol that can be used as a terminal terminator include phenol, cresol, S-butylphenol, tert-butylphenol, nonylphenol, octylphenol, 2,4,6-tribromophenol, pentabromophenol and the like.

The halogen-substituted dihydric phenol derivatives include, for example, TBA epoxy, TBA epoxy oligomer, TBA bromoethyl ether oligomer, TBA
Bis (2,3-dibromopropyl ether), TBA bis (allyl ether), TBA bis (2-hydroxyethyl ether), TBS bis (2,3-dibromopropyl ether) and the like can be mentioned.

Furthermore, in addition to the above flame retardants, for example, decabromodiphenyl ether, octabromodiphenyl ether, tetrabromodiphenyl ether, hexabromocyclododecane, hexabromobenzene, tetrabromophthalic anhydride, tribromophenol, bis (tribromophenoxy) ethane , Polydibromophenylene oxide, bis (pentabromophenoxy) ethane, ethylenebistetrabromophthalimide, brominated polystyrene, poly (pentabromobenzyl) acrylate, chlorinated paraffin, perchlorocyclopentadecane, chlorendic acid, tetrachlorophthalic anhydride, etc. Organic flame retardants,
Phosphorus flame retardants such as phosphate esters, halogen-containing phosphate esters, polyphosphates, etc., aluminum hydroxide, antimony trioxide, antimony pentoxide, guanidine nitride, magnesium hydroxide, zinc borate, zirconium, etc. And inorganic flame retardants. Among these flame retardants, halogenated aromatic carbonate oligomers are the most preferable objects because remarkable effects can be obtained.

The above-mentioned flame retardants can be used alone or in the form of a mixture of plural ones. If necessary, a binder, a lubricant, a stabilizer, a colorant, a flame retardant auxiliary, etc. may be added.

The compression granulator used in the present invention is, for example, a single-shot type, a single-point compression rotary type, a multi-point compression rotary type,
A tableting-type compression granulator such as a multi-stage compression rotary type, inclined roll rotary type, nucleated tableting type, and multilayer tablet type may be mentioned, but a compression-type tableting machine is preferable. The temperature during compression molding may be either heating or room temperature. Although the shape of the obtained molded product is arbitrary, it is usually disk-shaped, its diameter is preferably about 5 to 100 mm, and its thickness is preferably about 1 to 20 mm.

In the present invention, a V-shaped or U-shaped groove is provided on one surface or both surfaces of the molded product when the molded product is compression-molded by a compression granulator using a powdery flame retardant. The depth of the groove is not particularly limited, and may be too deep. However, if it is too shallow, the effect of facilitating crushing is small and the amount of fine powder generated is large. The above is preferred. Further, it is not necessary to limit the distance between the grooves, and it is preferable to adjust the distance according to the size of the target granule. It is preferable to increase the distance between the grooves when obtaining a large particle size, and to shorten the distance between the grooves when obtaining a small particle size. For example, to obtain a granular material that passes through a 6-mesh sieve and passes through a 16-mesh sieve, the distance between the grooves should be selected from a range of about 2 to 30 mm, depending on the thickness of the molded product. preferable.

At the time of compression molding, providing a V-shaped or U-shaped groove on the surface of the molded product can be easily performed by devising the shape of the punch and the shape of the die of the tableting machine. For example, an appropriate V-shaped or inverted U-shaped ridge line of an appropriate height is provided on the powder contact surface of one or both of the upper punch and the lower punch in an appropriate number of parallel or in a grid pattern. Grooves can be easily provided on the surface of the molded article by performing compression molding in an appropriate combination.

The thus obtained molded product having grooves on the surface is subjected to a crushing step. Examples of the crushing device used in the crushing process include, for example, a shredder, a jaw crusher, a gyratory crusher, a cone crusher,
Examples of the crusher include a hammer crusher, a roll crusher, a roller mill, a stamp mill, a fret mill, a cutter mill, a rod mill, an erotic fall mill, a cascade mill, and an oscillator type granulator. The size of the granules obtained by crushing can vary widely depending on the purpose of use, but usually the average particle size is in the range of 0.5 to 5 mm. Here, the particle size means the length of the longest part of the granular material.

[0017]

EXAMPLES The method of the present invention will be described below with reference to examples and comparative examples, but the present invention is not limited thereto.

[0018]

Example 1 Four inverted V-shaped ridges having a height of 2 mm were provided in parallel on the powder contact surface (circle with a diameter of 45 mm) of an upper punch and a lower punch (the highest ridge and the highest ridge adjacent to each other). The distance was 9 mm), and a powdered polycarbonate type flame retardant having an average diameter of 0.05 mm [Teijin Chemical Co., Ltd.] was obtained by a compression molding machine using a mold shown in FIG. FG-8500], at a compression pressure of 200 kg / cm ² at room temperature to obtain a disk having a thickness of 5 mm and a diameter of 45 mm shown in FIG. It was pulverized with a sizing machine. The obtained granules were in the range of 16 mesh to 6 mesh at 87% by weight.

[0019]

Embodiment 2 Four 1 mm heights parallel to each powder contact surface
Performed except that the compression pressure was set to 250 kg / cm ² using a die in which the upper and lower punches provided with inverted V-shaped ridges in a grid pattern were combined so that the ridges of the upper and lower punches overlapped. Compression molding was carried out in the same manner as in Example 1 to obtain a disk having a thickness of 5 mm and a diameter of 45 mm shown in FIG. The obtained granules were in the range of 16 mesh to 6 mesh at 90% by weight.

[0020]

Example 3 Using an upper punch having four inverted V-shaped ridges of 2 mm in height provided in parallel on the powder contact surface and a lower punch having no ridge on the powder contact surface, the compression pressure was increased to 250 kg / cm ² . Except for the above, compression molding was carried out in the same manner as in Example 1 to obtain a disk having a thickness of 5 mm and a diameter of 45 mm shown in FIG. The obtained granules were in the range of 16 mesh to 6 mesh at 87% by weight.

[0021]

[Comparative Example] Using an upper punch and a lower punch with no ridge on the powder contact surface,
Except that the compression pressure was changed to 250 kg / cm ² , compression molding was carried out in the same manner as in Example 1 to obtain a disk having a groove-free thickness of 5 mm and a diameter of 45 mm, and this disk was pulverized as in Example 1. The obtained granules were in the range of 16 mesh to 6 mesh at 50% by weight.

[0022]

According to the present invention, a powdery flame retardant can be easily converted into a granular material having a target particle size and a sharp distribution with a sufficient yield, in which the generation of fine powder is sufficiently suppressed. The industrial effects they produce are extraordinary.

[Brief description of the drawings]

FIG. 1 is a side view of a mold part of a compression molding machine;
Is a side view of the upper punch, (b) is a side view of the mill, and (c) is a side view of the lower punch.

FIG. 2 is a view showing a molded product obtained in Example 1, and FIG.
Is a front view, and (b) is a side view.

FIG. 3 is a view showing a molded product obtained in Example 2;
Is a front view, and (b) is a side view.

FIG. 4 is a view showing a molded product obtained in Example 3;
Is a front view, and (b) is a side view.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B29B 9/02-9/14

Claims (2)

(57) [Claims] 1. A powdery flame retardant is molded using a tableting type compression granulator, and the obtained molded product is crushed to produce a granular material. A method for granulating a flame retardant, comprising providing a groove on the surface of a product and then crushing the obtained molded product. 2. The method for granulating a flame retardant according to claim 1, wherein the powdery flame retardant is a halogenated aromatic carbonate oligomer.