JP3148742B2 - Powder with reduced solidification over time and generation of dust - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder which is hardened with time and has reduced dust generation.

[0002]

2. Description of the Related Art
Various powdered substances are used as fertilizers, resin raw materials, resin additives, pigments, dyes, adhesives, raw materials for pharmaceutical intermediates, and the like. Many of these powdery substances have a property of solidifying with the passage of time or a load, and have a problem that they lose fluidity during use and hinder handling. Many of these powdery substances also generate dust when handled.

Hitherto, as a means for improving the solidification with time, for example, (1) diatomaceous earth, perlite, kaolin, surfactant, mineral oil, wax, silica,
A method of adding or coating zinc stearate, saturated fatty acid, polyethylene glycol, etc. to the target powder (Japanese Patent Laid-Open No.
43353, JP-A-56-152401, JP-A-5-152401
9-216619, JP-A-61-36388, JP-A-6-128101, etc.) and (2) a method for coating a core substance with a lipid powder to prevent solidification and deliquescence by absorbing moisture. JP-A-63-313599) is known.

However, at present, even with these conventional methods, solidification with time cannot be sufficiently improved depending on the type of powder, environmental conditions, load conditions and the like. Further, it is difficult to sufficiently suppress the generation of dust by these conventional methods for preventing solidification. On the other hand, as a method of suppressing dust generation in powder, a method of adding various organic compounds to powder is known. However, such a method has a problem that even if the generation of dust can be suppressed, the fluidity of the powder is easily lost, and the solidification with time is not sufficiently suppressed.

[0005] Therefore, an object of the present invention is to provide a powder that satisfies both solidification over time and suppression of dust generation.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve the above problems, and as a result, completed the present invention. That is, the present invention provides: (a) a step of treating a powder (excluding a blowing agent powder) with a surface treating agent having a property of reacting with water to remove water by heating; The present invention relates to a powder which has been treated in the step of heating at 200 to 200 ° C. and the step of (c) the step of coating with fats and oils, the solidification with time and generation of dust being suppressed. Further, in the step of coating with the fats and oils,
Thus, the amount of the fats and oils with respect to 100 parts by weight of the powder
Solidification over time treated as 0.01 to 1 part by weight;
The present invention relates to a powder in which dust generation is suppressed. As a surface treatment agent having the property of removing water by reacting with water by heating,
The present invention relates to the powder using at least one selected from a coupling agent, an organic acid anhydride, and an inorganic compound anhydride having water of crystallization.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The powder of the present invention (however,
Excluding foaming agent powder) is a powder that has the property of binding and solidifying the powder over time in the presence of moisture, and is fine and easily generates dust during handling. For example, resin such as polyvinyl chloride powder Powder, tetilakis [methicin-3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate] Resin stabilizer powder such as methane, 2-mercaptobenzimidazole zinc salt, inorganic filler powder such as talc, inorganic pigment powder such as titania, vulcanization accelerator powder such as 2-mercaptobenzothiazole zinc salt, fertilizer, Urea powder used as a foaming aid and the like can be exemplified. The particle diameter of the target powder of the present invention (in the present specification, the particle diameter is a median diameter measured using a laser diffraction type particle size distribution meter. The same applies hereinafter) is not particularly limited, It is suitable for particles having a particle diameter of 0.1 to 100 μm, particularly about 0.2 to 30 μm, at which dust generation and solidification occur.

A surface treating agent used in the present invention, which has a property of reacting with and removing moisture in the target powder by heating (hereinafter, this may be simply referred to as a surface treating agent in the present specification). Include those that react with and remove moisture from the surface of the target powder or the interior of the target powder by heating, and those that promote the reaction with the moisture on the surface of the target powder or the interior of the target powder by heating. Examples thereof include a coupling agent, an organic acid anhydride, and an anhydride of an inorganic compound.

Examples of the coupling agent include a silane coupling agent, an aluminum coupling agent, a titanate coupling agent and the like. Conventionally known silane coupling agents can be widely used, and methyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N-phenyl Examples include aminomethyltrimethoxysilane and vinylmethyldiethoxysilane. As the aluminum-based coupling agent, conventionally known ones can be widely used, and examples thereof include aluminum isopropylate, aluminum ethylate, aluminum tris (ethyl acetoacetate), and ethyl acetoacetate aluminum diisopropylate. As the titanate-based coupling agent, conventionally known coupling agents can be widely used, and isopropyl triisostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, bis (dioctyl pyrophosphate) oxy Examples thereof include acetate titanate. These coupling agents can be used alone or in combination of two or more. These coupling agents have the property of strongly reacting with the water present inside or on the surface of the target powder by heating to remove the water of the target powder. Even if a trace amount remains, it is considered that the movement to the powder surface is blocked to keep the powder surface substantially anhydrous, thereby contributing to prevention of solidification and aggregation. Furthermore, the unreacted coupling agent remaining on the surface of the target powder forms a coating on the surface of the target powder to prevent external water absorption,
It is considered that the water supplied from the atmosphere also has a property of keeping the powder surface in an anhydrous state by gradually reacting with the water. Therefore, these coupling agents can be particularly preferably used as the surface treatment agent used in the present invention.

As the organic acid anhydride, conventionally known organic acid anhydrides can be widely used, for example, phthalic anhydride, succinic anhydride,
Glutaric anhydride, benzoic anhydride, trimetic anhydride and the like can be mentioned. These compounds react with and remove water from the target powder by the following mechanism, for example.

(RCO) ₂ O + H ₂ O → 2RCOOH wherein R represents an organic acid residue. ]

As the anhydride of the inorganic compound which can have water of crystallization, any known compounds can be used as long as they can combine with water and have water of crystallization. Examples thereof include anhydrous magnesium sulfate and anhydrous potassium carbonate. , Anhydrous sodium carbonate, anhydrous sodium sulfate, anhydrous sodium sulfite,
Examples thereof include anhydrous magnesium carbonate. These compounds, for example, react with water in the target powder by a mechanism represented below and immobilize this as water of crystallization.

Na ₂ SO ₄ + nH ₂ O → Na ₂ SO ₄ .nH ₂ O [wherein, n represents an integer of 1 or more. ]

The surface treating agent may include one of the above-mentioned coupling agents, organic acid anhydrides, anhydrides of inorganic compounds having water of crystallization, and the like.
Species may be used alone or as a mixture of two or more. These surface treatment agents can be appropriately selected and used depending on the application of the object to be treated.

The above-mentioned surface treating agent is treated on the surface of the target powder, and heated simultaneously with or after the treatment,
It is possible to efficiently react with and remove water contained in the target powder, thereby reducing the water content in the target powder. The surface treating agent is preferably used in a substantially solvent-free state without being dissolved in a solvent, so as not to adversely affect the reaction with moisture or the adsorption of moisture. In particular, the use of an organic solvent containing a large amount of water or water is not suitable because the water content in the target powder may be increased. When a solid surface treatment agent is used, it is preferably used in the form of a fine powder or a melt. As the amount of the surface treatment agent used for the target powder,
It may be used in an amount of usually about 0.01 to 10 parts by weight, preferably 0.05 to 0.5 parts by weight, based on 100 parts by weight of the target powder.

In the present invention, the heat treatment is performed when the surface treating agent is added to the target powder or after the addition, but it is more efficient and preferable to perform the heat treatment simultaneously when adding and mixing the surface treating agent to the target powder. The heating temperature can be appropriately set within a range in which undesired decomposition and deterioration of the target powder and the surface treatment agent are suppressed, depending on the type of the target powder and the surface treatment agent, but is usually 40 to 200 ° C, preferably 80 to 200 ° C. 120
° C can be exemplified. For example, when the target powder is a polyvinyl chloride resin powder and N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, which is a kind of silane coupling agent, is used as the surface treatment agent, a preferable heating temperature is used. 40 to 100 ° C. can be exemplified. Also,
When aluminum tris (ethyl acetoacetate), which is a kind of aluminum-based coupling agent, is used, a preferable heating temperature is, for example, 60 to 120 ° C.

The treatment of the surface treating agent into a powder having a solidifying property over time is preferably performed while mixing the target powder. The mixing device that can be used in the above mixing is not particularly limited, and examples thereof include a screw mixer such as a super mixer, a Hensiel mixer, a Nauta mixer, a pro-share mixer, and a ribbon-type blender. However, since the substantially anhydrous target powder is also pulverized to increase the specific surface area, the hygroscopicity may increase. Therefore, when a relatively brittle powder that is easily crushed is used as the target powder, a Nauta mixer or a pro-share is used. Using a mixer in which a shear (such as a shear blade is removed) or a ribbon-type blender is less likely to be applied, and the pulverization of particles is suppressed, the specific surface area after the treatment is preferably increased by 20% as compared with that before the treatment. %, More preferably within 10%. When a liquid surface treating agent is used, it is preferable to spray the surface treating agent in the form of fine droplets onto the target powder using a pressurizing nozzle or a two-fluid nozzle when adding the liquid. By spraying the surface treatment agent in the form of fine droplets onto the target powder, the anhydrous powder of the present invention can be obtained using a small amount of the surface treatment agent.

Next, in this specification, fats and oils refer to liquid or solid fats and oils, hydrocarbons and fatty acids. As fats and oils, for example, vegetable or animal natural fats and oils such as soybean oil, coconut oil, linseed oil, cottonseed oil, rapeseed oil, drill oil, pine oil, rosin, castor oil, tallow, squalane, lanolin, hydrogenated oil and the like These refined products are mentioned.
As the hydrocarbons, aliphatic hydrocarbons having 20 to 48 carbon atoms collectively referred to as paraffin wax and derivatives thereof,
Aliphatic hydrocarbons having 8 to 19 carbon atoms and derivatives thereof (for example, dialkyl phthalates such as dioctyl phthalate, higher alcohol phthalates such as nonyl alcohol phthalate, etc.), paraffinic, naphthenic or aromatic process oils, and fluids Paraffin and the like. The hydrocarbons also include hydrocarbons isolated and purified from the above natural fats and oils. Examples of the fatty acids include fatty acids such as lauric acid, myristic acid, balmitic acid, stearic acid, oleic acid, and behemic acid, and salts or derivatives thereof. The fatty acids also include fatty acids isolated and purified from the above natural fats and oils.

The oils and fats used in the present invention are preferably oils and fats having a melting point of 90 ° C. or less, and more preferably oils and fats which are liquid at ordinary temperature. Particularly preferred fats and oils are liquid paraffin. In the present invention, fats and oils, as they are,
Alternatively, it can be used by dissolving it in an appropriate solvent. Examples of the solvent include aromatic hydrocarbons such as toluene and xylene. When the fats and oils to be used are in a solid or viscous liquid state at room temperature, it is preferable to adjust the temperature of the fats and oils to a liquid having high fluidity.

In the present invention, the step of coating the powder with fats and oils is preferably performed while mixing the powder. Mixing can be performed by various mixing devices, and specific examples thereof include a high-speed mixer, a super mixer,
Examples include a screw mixer such as a universal mixer and a Nauta mixer, a ribbon-type blender such as a ribocorn mixer, a pro-share mixer, and a die blender. In the present invention, in order to uniformly coat the surface of the powder with a small amount of fat or oil, the coating of the fat or oil is preferably performed by spraying the fat or oil into a target powder by spraying. Examples of a method of applying a fat or oil to a powder by spraying it in a mist form include a method of spraying a liquid fat or oil or a fat or oil liquefied by heating using a spray device. Examples of the spraying device include a two-fluid nozzle, a pressure nozzle, and the like.

The coating amount of the fat or oil with respect to the powder is preferably 0.01 to 1 part by weight, more preferably 0.1 to 0.5 part by weight based on 100 parts by weight of the powder. By setting the coating amount of the fats and oils to 0.01 parts by weight or more, it is possible to obtain a powder in which dust generation is sufficiently suppressed. Further, by setting the coating amount of the fat or oil to less than 1 part by weight, it is possible to prevent the solidification property and the dispersibility from being deteriorated. More specifically, the coating amount of the fats and oils is preferably set appropriately according to the specific surface area of the powder. For example, a powder having a small specific surface area (0.1 to ² m ²⁾
/ G), the coating amount of the fats and oils is small (0.01 to
0.5 part by weight) and a powder having a large specific surface area (2 to 1).
0 m ² / g), the coating amount of fats and oils is preferably set to be relatively large (0.2 to 1 part by weight).

The order of the above-mentioned treatment step with the surface treatment agent and the step of coating the fats and oils is not particularly limited. Alternatively, it is preferable to use a method of simultaneously performing the treatment with the surface treatment agent and the coating of the fats and oils.

The powder provided by the present invention has remarkably improved solidification with time and solidification under load, hardly solidifies even when stored for a long period of time, and has good fluidity and dispersibility immediately after production for a long time. While being held over, dust generation during use is suppressed, which contributes to improvement of the working environment.

[0024]

The present invention will be further clarified with reference to the following examples and comparative examples. Hereinafter, "%" means "% by weight".

Example 1 Urea powder (manufactured by Wako Pure Chemical Industries, Ltd., average particle size 10 μm)
m) 25 kg is charged into a universal mixer (100 l, manufactured by Tsukishima Kikai Co., Ltd.) and mixed at 600 rpm at 90 ° C. 25 g of aluminum tris (ethyl acetoacetate) (trade name: ALCH-TR, manufactured by Kawaken Fine Chemical Co., Ltd.) heated and dissolved at 90 ° C., and unheated liquid paraffin (trade name: P-60,
25 g of an average carbon number 21 (manufactured by Matsumura Oil Research Laboratories Co., Ltd.) was simultaneously coated by spraying over 2 minutes, and the mixture was further mixed under the same conditions for 7.5 minutes to obtain the powder of the present invention. Example 2 titania powder (anatase type titanium powder, manufactured by Teica Co., Ltd., trade name: JR-403, average particle size 0.5 μm)
50 kg is put into a universal mixer (100 l, manufactured by Tsukishima Kikai Co., Ltd.) and mixed at 600 rpm at 90 ° C. 50 g of aluminum tris (ethyl acetoacetate) (trade name: ALCH-TR, manufactured by Kawaken Fine Chemical Co., Ltd.) is heated and dissolved at 90 ° C., added by spraying over 2 minutes, and subsequently, unheated liquid paraffin (Trade name: P-60, average carbon number 21, manufactured by Matsumura Petroleum Institute Co., Ltd.) 50 g was coated by spraying over 2 minutes, and further mixed under the same conditions for 7.5 minutes to obtain a powder of the present invention. Obtained. Comparative Example 1 Untreated urea powder (the same as in Example 1) is used as the powder of Comparative Example 1. Comparative Example 2 Untreated titania powder (the same as in Example 2) was used as the powder of Comparative Example 2.

Test Example 1 For each control powder obtained in the above Examples and Comparative Examples,
A solidification test was performed by the following method. Sample 4
After filling 00 g in a 23 × 13 cm plastic bag and sufficiently evacuating the air bag, heat-sealed openings were stacked, and a load of 0.08 kg / cm ^{2 was} further applied thereto. After 10 days, the sample was taken out, sieved with a 14-mesh sieve, the amount of non-passage was measured, and the value calculated in% was determined as the solidification rate. Table 1 shows the results.

Test Example 2 1 g of a sample was taken for each of the powders of Examples 1 and 2 and Comparative Examples 1 and 2, and the flow rate was 25 l using a Huibach dust meter.
/ Minute, and the measurement time was 5 minutes, and the dust generation rate was measured. The results are shown in Table 1.

[0028]

[Table 1]

[0029]

As described above, according to the powder of the present invention, solidification with time and generation of dust are sufficiently suppressed.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshifumi Tate, Inventor Naruto Plant, Satoura-cho, Naruto City, Tokushima Prefecture (56) References JP-A-63-268752 (JP, A) JP-A-1-259369 (JP, A) JP-A-63-139367 (JP, A) (58) Fields surveyed (Int .Cl. ⁷ , DB name) B01J 2/00 B01J 19/00 C09K 3/22

Claims (3)

(57) [Claims] 1. A step of treating a powder (excluding a foaming agent powder) with a surface treating agent having a property of reacting with water to remove water by heating, at 40 to 200 ° C. in the absence of a solvent.
Powder that has been treated in the step of heating with, and the step of coating with fats and oils, and has been reduced in solidification over time and generation of dust. 2. The method according to claim 1 , wherein the amount of the fats and oils is 100 wt.
2. The composition according to claim 1, wherein the amount is 0.01 to 1 part by weight based on parts.
Powder with reduced solidification and dust generation. 3. The surface treating agent having a property of removing water by reacting with water by heating is at least one selected from a coupling agent, an organic acid anhydride, and an inorganic compound anhydride having water of crystallization. 3. The powder according to 1 or 2.