JPH04190839A - Modified powder - Google Patents

Abstract

PURPOSE:To obtain modified powders having a skin of uniform organosilicones free from secondary aggregation by subjecting a mixture of specific ratio of powders and organosilicones of specific viscosity to two-step heating treatments. CONSTITUTION:Powders and organosilicones having viscosity 1-400cst at 25 deg.C are agitated and mixed at 100:0.3-100:20 weight ratio of powders to organosilicones. Next, the mixture is subjected to a primary heat treatment at 70-130 deg.C for 0.5-4 hours and then to a secondary heat treatment at a higher temperature than that of the primary heat treatment, i.e., 110-200 deg.C, for 1-12 hours to obtain modified powders. As powders, there are colored pigments such as yellow iron oxide, red iron oxide, black iron oxide, chromium oxide, carbon black, etc., and white pigments such as zinc oxide, rutile titanium oxide, anatase titanium oxide, cerium oxide, etc. For mixing powders and organosilicones, powder agitating devices such as Henschel mixer, etc., can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a modified powder obtained by stirring and mixing powders and organosilicones having a specific viscosity and then subjecting the mixture to a heat treatment.

More specifically, it is a modified powder produced by a novel dry method, which is characterized by almost no secondary aggregation of powders caused by organosilicones and which provides powders with excellent water clarity. Regarding.

[Prior art and invention or problem to be solved] Conventionally,
Methods for coating powders with organosilicones include: 1) Using mechanochemicals such as a whole mill 2) Adding organosilicones dissolved in a solvent to the powders and distilling off the solvent as necessary. 3) Wet method in which powders are brought into contact with gaseous organosilicones and then coated 4) Methods in which powders are coated with organosilicones using a spray dryer etc. Generally used. However, the above method using mechanochemicals in 1) has problems in that the coating is non-uniform and that the number of treatments that can be processed at a time is limited, resulting in low productivity. The wet method (2) has the characteristic of being able to uniformly coat the powder with the organosilicone, and has unavoidable problems such as agglomeration of the powder during the process of distilling off the solvent or drying.

3) The gas phase method has problems such as whether it has the ability to form a uniform film on powders or whether it requires a closed type manufacturing equipment. The problem with the spray dryer (4) is that it becomes a large manufacturing device when processing a large amount.

That is, the purpose of the present invention is to eliminate secondary agglomeration of powders,
The object of the present invention is to provide a modified powder having a uniform organosilicon film.

[Failure to solve the problem]

As a result of intensive research in view of the above problems, the inventors of the present invention found that
In the process of coating powders with Organon Ricoh, we found that the cause of secondary aggregation of powders is surprisingly due to the use of solvents, and furthermore, we also discovered that Regarding the mixing ratio of powders and organosilicones and the viscosity of organosilicones, it has been found that by performing a two-step heat treatment, secondary aggregation of powders can be extremely reduced. completed.

That is, the present invention uses powders and a viscosity at 25°C of 1
~400cst of organosilicones, the weight ratio of powder and organosilicones is l' 00:
After stirring and mixing at a ratio of 0.3 to +00:20, 7
Primary heat treatment is performed at 0 to 130°C for 0.5 to 4 hours,
The temperature is higher than that of the primary heat treatment, and 1
It is a modified powder obtained by performing secondary heat treatment at 10 to 200°C for 1 to 12 hours.

The present invention will be explained in detail below.

The powders used in the present invention include colored pigments such as yellow iron oxide, red iron oxide, black iron oxide, chromium oxide, and carphone blank, white pigments such as zinc oxide, rutile type, anatase type titanium oxide, and cerium oxide; Extender pigments such as talc, mica, sericite, and kaolin, pearl pigments such as titanium mica, metal salts such as norium sulfate, calcium carbonate, magnesium carbonate, aluminum silicate, and magnesium silicate, and mica coated with N-anluaspartic acid. Organic substance-coated pigments and metallic soap-treated pigments, polymers such as nylon powder, silk powder, urethane powder, Teflon powder, cellulose powder, inorganic powders such as heptaolide, smectite, silica, alumina, stone powder, glass beads, etc., Blue 404
Examples include pigments such as No. 1, fine-particle titanium oxide, fine-particle zinc oxide, fine-particle black iron oxide, silica-treated fine-particle titanium oxide, and alumina-treated fine-particle titanium oxide.

Preferred particle sizes of the powders used in the present invention are, for example,
0.1-1.2 μm for titanium oxide and 0.1 μm for zinc oxide.
4-1.0. am, 0.1 to 2.0 μm for iron oxide, 0.1 to 5.0 μm for ultramarine, 0.5 to 20.0 μm for sericite, kaolin, talc, and mica, and 0.5 to 20.0 μm for nori beads and glass beads. 0.1 to 1 mm, 0 for fine titanium oxide, fine zinc oxide, fine black iron oxide, and Aerosil.
．． 01~01μm, 10~150 for nylon powder
It is μm.

The organosilicones used in the present invention can be used regardless of whether they are polymerizable or non-polymerizable.

That is, for example, examples of polymerizable organosilicones include olefin-modified silicone, methylhydrodiene polysiloxane, alkylhydrodiene polysiloxane, and Si-OH group-containing methylporinroquesan 5i-H.
Examples include group-containing cyclic organoborin loxane, 5i-H group-containing fluorine-modified noricone, alkylaryl polyoloxane, etc. Non-polymerizable organosilicones include dimethylpolysiloxane and alkylpolysiloxane.

Examples include methylphenyl polyoloxane, cyclic organopolysiloxane, and fluorine-modified silicone. These organosilicones can be used alone or in combination of two or more.

The viscosity of the organosilicones is 1 to 400 cst, preferably 1 to 100 cst.

If it is smaller than 1 cst, the evaporation rate during heating will be too fast, making it difficult to coat the powder. Moreover, when the temperature exceeds 400 cst, powders or agglomerates are formed around organosilicones as a core. This tendency is particularly noticeable in fine powders with a particle size of 0.1 μm or less, such as fine titanium oxide.

The blending ratio of organosilicones and powders is 0.3 to 20 parts by weight, preferably 1 to 12 parts by weight, based on 100 parts by weight of powders.

If the amount of organosilicones is less than 0.3 parts by weight, the effects of organosilicones cannot be obtained.

If the amount of organosilicones exceeds 20 parts by weight, secondary agglomeration of powders may occur.

A conventionally used powder stirring device such as a Henschel mixer can be used to stir and mix the powders and organosilicones used in the present invention. However, for powders that tend to agglomerate, such as titanium oxide, after mixing and stirring with a Henschel mixer, use a grinding device such as an atomizer or free grinder to thoroughly pulverize the powder before heat treatment. It is necessary to release the agglomeration and convert it into primary particles.

If the agglomeration of the powders is not sufficiently released before the heat treatment, secondary agglomerates of the powders will occur after the heat treatment.

The heat treatment used in the present invention is carried out using a blow dryer or the like after leaving the powder treated above in a metal vat, or it is carried out without stirring the powder using a ribbon blender or the like. Moreover, the heat treatment conditions consist of two stages. The primary heat treatment is a process in which the entire powder is uniformly coated using a phenomenon in which organosilicones partially gasify and move through the powder by heating. The primary heat treatment is performed at a heating temperature of 70 to 130°C for 0.5 to 4 hours. When the temperature is 70°C, the heating time is preferably longer, and when the temperature is 130°C, the heating time is preferably shorter. If the heating temperature is higher and the heating time is longer than this, the polymerization reaction of the organosilicones will proceed before the organosilicones are distributed throughout the powder, and secondary agglomerates of the powder may partially form. There are cases where

This phenomenon is particularly observed with powders that tend to agglomerate, such as fine titanium oxide and fine zinc oxide. The secondary heat treatment is a process in which the organosilicones uniformly coated in the primary heat treatment are polymerized using stronger heating conditions to form a strong film on the powder. The secondary heat treatment is performed at a higher temperature than the primary heat treatment and at a temperature of 110 to 200
It is carried out at a heating temperature of 1 to 12 hours.

By carrying out this two-step heat treatment, the secondary agglomeration of the powder is greatly improved, and a modified powder having a uniform organosilicon film can be obtained. This effect is particularly noticeable in fine particle powders with a particle size of 0.01 to 0.1 μm.

Furthermore, the difference between the conventional production method and the present invention lies in the amount of solvent used during powder processing. In conventional manufacturing methods, even if the amount of solvent is relatively small, the amount of solvent for powders is 6 to 15 parts by weight per 100 parts by weight of powder. However, even if the powders and organosilicones were mixed and stirred and then pulverized by an atomizer treatment or the like to reduce the secondary agglomerated particles, the secondary agglomeration of the powders was not completely released. In this case, the agglomerates are only agglomerates that can be loosened by a weak force before the heat treatment, but they change into strong agglomerates by the next heat treatment step. Especially when using polymerizable organosilicones such as methylhydrodiene polysiloxane,
Forms stronger agglomerates. A similar phenomenon occurs when highly viscous organosilicones or oils are used. As a result of considering these causes, the present invention does not use +Sff, uses organosilicones with low viscosity, thoroughly crushes the powder before heat treatment, and performs two-step heat treatment. By doing so, we were able to obtain a modified T1 powder with very little agglomeration even after heat treatment (this was successful).

Furthermore, when the modified powder of the present invention is applied to cosmetics, resins, paints, adhesives, immobilization carriers, column packing materials for chromatography, etc., there is very little secondary aggregation, so it has excellent ultraviolet scattering ability. Moreover, since it has excellent dispersibility, it is possible to obtain a product with excellent storage stability.

〔Example〕

The present invention will be explained below with reference to Examples.

The test methods for cohesion and feel described in the Examples are as follows.

Further, the viscosity described below is the viscosity at 25°C.

(1)-■ (Evaluation of cohesiveness) Particle size distribution measuring device (SK l, ASER + IIICRO
The average particle size of the modified powder was determined using N5IZERPRO-7000 (manufactured by Seinen Enterprises). The measurement conditions were as follows: ethyl alcohol was used as a dispersion solvent, and the modified powder was dispersed by operating the attached ultrasonic transmitter for 60 seconds.

Primary particle size. , the particle size of the modified powder is D, and D/D
Cohesiveness was evaluated from the value of o as follows.

For fine particle powders that could not be measured with this device, the cohesiveness was evaluated by the method indicated by (+)-〇 below.

(I)-■ (Evaluation of cohesiveness of fine particle powder) A photograph of the coated fine particle powder was taken using a transmission electron microscope, and the agglomeration state of the powder was evaluated as follows. The evaluation criteria were as follows: Untreated powder (11) (Method for evaluating the feel of powder) A total of 10 men and women aged 20 to 50 were tested using the powders prepared in each example and comparative example. The feel was evaluated. The numerical value indicates how many out of 10 people judged each evaluation item; 10 indicates that all 10 people judged, and 1 indicates that 1 out of 10 people judged.

Example 1 30 g of methyl hydrodiene polysiloxane (KF-99P, viscosity 19 cst, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 1 kg of titanium oxide (particle size 0.6 μm), mixed with a mixer, and pulverized. The obtained powder was transferred to a stainless steel vat and subjected to primary heat treatment at 100°C for 2 hours using a blow dryer, followed by secondary heating treatment at 180°C for 8 hours to obtain a modified powder. was obtained, and the various tests described above were conducted.

Comparative Example 1 A solution of 30 g of methylhydrodiene polysoloxane (KF-99P) dissolved in 120 g of isopropyl alcohol was added to IKg of titanium oxide (particle size 0.6 μm),
Mixing and pulverization were performed using a mixer. The conditions for pulverization were the same as in Example 1. The obtained powder was transferred to a stainless steel vat, and heat-treated at 180''C for 8 hours using a blow dryer to obtain a powder, which was then subjected to the various tests described above.

Example 2 2 g of methylhydrodiene polysiloxane (KF-99P) was added to 100 g of yellow iron oxide (ffl diameter 0-7 μm), mixed and pulverized using a mixer. The obtained powder was transferred to a stainless steel vat and dried using a blow dryer.
A primary heat treatment was performed at 0° C. for 3 hours, followed by a secondary heat treatment at +40° C. for 5 hours to obtain a modified powder, and the various tests described above were conducted.

Comparative Example 2 A solution of 2 g of methylhydrodiene polysiloxane (KF-99P) dissolved in 10 g of isopropyl alcohol was added to 100 g of yellow iron oxide (particle size 0.7 μm), and the mixture was mixed and pulverized using a mixer. The conditions for pulverization were the same as in Example 2. The obtained powder was transferred to a stainless steel hat and heat-treated at 140° C. for 5 hours using a blow dryer to obtain a powder, and the various tests described above were conducted.

Example 3 Methylhydrodiene polyoloxane (KF-99P) 0.5K to 1Kg of sericite (particle size 10.6μm)
g and methylhydrodiene polysoloxane (KF-99
0.5 kg of a mixture of 0.01 (viscosity: 19 cst, manufactured by Shin-Etsu Chemical Co., Ltd.) was added, and the mixture was mixed and stirred using a Henschel mixer. The obtained powder was transferred to a stainless steel vat, and a primary heat treatment was performed at 130°C for 1 hour using a blow dryer, followed by a secondary heat treatment at 160°C for 6 hours to obtain a modified powder. The various tests mentioned above were conducted.

Comparative Example 3 1 kg of sericite (particle size 10.6 μm) was mixed with 50 g of methylhytronene polysiloxane (KF-99P) and methylhytrononine polysiloxane (KF-9901).
A solution of 50 g of ) dissolved in 100 g of trichloroethane was added, and the mixture was mixed and stirred using a Henschel mixer. The mixing and stirring conditions were the same as in Example 3.

The obtained powder was transferred to a stainless steel vat, and heat-treated at 160° C. for 6 hours using a blow dryer to obtain a powder, and the various tests described above were conducted.

Example 4 Mica titanium (particle size 12.2 μm) l (]Og and 8 g of methylhydrodiene polysiloxane (KF-99P)
was added, mixed and pulverized using a mixer. The obtained powder was transferred to a stainless steel vat and dried using a blow dryer.
A primary heat treatment was performed at 130° C. for 2 hours, followed by a secondary heat treatment at 190° C. for 6 hours to obtain a modified powder, and the various tests described above were conducted.

Comparative Example 4 A solution prepared by dissolving 8 g of methylhydrodiene polysiloxane (KF-99P) in 10 g of trichlene was added to 100 g of mica titanium (particle size 12.2 μm), and the mixture was mixed and pulverized using a mixer. The conditions for pulverization were the same as in Example 4. The obtained powder was transferred to a stainless steel vat and heat-treated at 190° C. for 6 hours using a blow dryer to obtain a powder, and the various tests described above were conducted.

Example 5 Zinc oxide (particle size 0.4 μm) loOg, 4 g of olefin-modified silicone (KF-413 viscosity 100 cst, manufactured by Shin-Etsu Chemical Co., Ltd.) and methylhytrononine polysiloxane (
KF-99P) 4 g was added, mixed and pulverized using a mixer. The obtained powder was transferred to a stainless steel vat and subjected to primary heat treatment at 120"C for 2 hours using a blow dryer, followed by secondary heat treatment at 150"C for 4 hours to obtain a modified powder. The various tests described above were conducted.

Comparative Example 5 A solution of 4 g of olefin-modified silicone (KF-413) and 4 g of methylhytronene polysiloxane (KF-99P) dissolved in 10 g of acetone was added to 100 g of zinc oxide (particle size 0.4 μm), and mixed in a mixer. mixture,
Shredded. The obtained powder was transferred to a stainless steel vat and heat-treated at 150° C. for 4 hours using a blow dryer to obtain a powder, and the various tests described above were conducted.

Example 6 6 g of fluorine-modified noricorn (X-22-822, viscosity 100 cst, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 100 g of silica beads (particle size 0.2 mm), and the mixture was mixed and pulverized using a mixer. The obtained powder was transferred to a stainless steel hat and subjected to primary heat treatment at 130°C for 1 hour using a blow dryer.
The powder was then subjected to secondary heat treatment at 150° C. for 12 hours to obtain a modified powder, and the various tests described above were conducted.

Comparative Example 6 100 g of trichloroethane was added to 100 g of silica beads (particle size 0.2 mm) and 6 g of fluorine-modified soricone (X-22-822), and the mixture was stirred and mixed using a mixer. After distilling off the solvent using an evaporator, the obtained powder was transferred to a stainless steel hat, and heat-treated at 150°C for 12 hours using a blow dryer to obtain a powder, and the various tests described above were carried out. was carried out.

Example 7 Spherical fine particle titanium oxide (average particle size 0.03 μm) IKg
Methylhydrononine polysiloxane (KF-99P)
) 80 g were added and mixed by stirring using a Henschel mixer. Then, a) pulverization was performed using a mixer.

The obtained powder was transferred to a stainless steel container and subjected to primary heat treatment at +00℃ for 2 hours using a blow dryer.
Secondary heat treatment was performed at 50° C. for 8 hours to obtain a modified powder, and the various tests described above were conducted.

Comparative Example 7 Spherical fine particle titanium oxide (average particle size 0.03 μm) 1Kg
Methylhydrodiene polysiloxane (KF-99P)
) A solution of 80 g dissolved in 120 g of isopropyl alcohol was added and mixed by stirring using a Henschel mixer. Then, it was pulverized using an atomizer. The stirring mixing and pulverizing conditions were the same as in Example 7. The obtained powder was transferred to a stainless steel container and dried using a blow dryer.
Heat treatment was performed at 50° C. for 8 hours to obtain powder, and the various tests described above were conducted.

Example 8 Methylhydrodiene polysiloxane (KF-99P>5
g, and mixed and pulverized using a mixer.

The obtained powder was transferred to a stainless steel hat, and a primary heat treatment was performed at 120°C for 1 hour using a blow dryer, followed by a secondary heat treatment at 180°C for 5 hours to obtain a modified powder. The various tests described above were conducted.

Comparative Example 8 5 methyl hydrodiene polysiloxane (KF-99P) was added to 100 g of fine particle zinc oxide (average particle size 0.03 μm).
A solution prepared by dissolving 1.5 g in 7 g of isopropyl alcohol was added, and the mixture was mixed and pulverized using a mixer.

The conditions for pulverization were the same as in Example 8. The obtained powder was transferred to a stainless steel hunt, and dried at 180°C using a blow dryer.
Heat treatment was performed at ℃ for 5 hours to obtain a powder, and the various tests described above were conducted.

Example 9 Particulate black iron oxide (average particle size 0.01 μm) IOKg with 0 methylhytron polyoloxane (KF-99P)
．． 5Kg and methylhydrodiene polysiloxane (KF
-9901) 0.5 Kg of the mixture was added and mixed and stirred using a Hennel mixer. Then, it was pulverized using an atomizer. The obtained powder was transferred to a stainless steel container, and a primary heat treatment was performed at 90°C for 3 hours using a blow dryer, followed by a heat treatment at 120°C for 8 hours to obtain a modified powder. , conducted the various tests mentioned above.

Comparative Example 9 50% of methylhydrodiene polysiloxane (KF-99P) was added to 1kg of fine black iron oxide (average particle size 0.01 μm).
g and methyl hydride polysiloxane (KF-99
01) A solution prepared by dissolving 50 g of cyclohexane in Ikg of cyclohexane was added, and the mixture was mixed and stirred using a mixer.

The solvent was distilled off under reduced pressure, and the resulting powder was pulverized using an atomizer. The powder was transferred to a stainless steel container and heat-treated at 120° C. for 8 hours using a blow dryer to obtain a powder, and the various tests described above were performed.

Example 10 5 g of methyl polysiloxane (KF-56 viscosity 5 cst) to 100 g of fine particle titanium oxide (average particle size 0.06 μm)
was added, mixed and pulverized using a mixer. The obtained powder was transferred to a stainless steel vat and dried using a blow dryer.
A primary heat treatment was performed at 80° C. for 4 hours, followed by a heat treatment at 160° C. for 10 hours to obtain a modified powder, and the various tests described above were conducted.

Comparative Example 10 A solution prepared by dissolving 5 g of methylpolysiloxane (KF-56) in 200 g of trichlene was added to 100 g of fine particle titanium oxide (average particle size: 006 μm), and the mixture was stirred and mixed using a mixer. After distilling off the solvent using an evaporator, the obtained powder was transferred to a stainless steel vat and heat-treated at +60° C. for 10 hours using a blow dryer. The obtained powder is crushed using a mixer to obtain a powder,
The various tests mentioned above were conducted.

Example 11 5i-H group-containing fluorine-modified soricone 2 shown below in 100 g of fine-particle titanium oxide (average particle size 0.06 μm)
g and methylhydrodiene polysiloxane (KF-99
P) 5 g was added, mixed and pulverized using a mixer. The obtained powder was transferred to a stainless steel hat, and a primary heat treatment was performed at 100°C for 2 hours using a blow dryer, followed by a secondary heat treatment at 150°C for 8 hours to obtain a modified powder. The various tests mentioned above were conducted.

The 5i-H group-containing fluorine-modified silicone has the following structure, a:b=5:5, and a viscosity of 100cst.

Comparative Example 11 2 g of the same Si-H group-containing fluorine-modified silicone used in Example 11 and 5 g of methylhydrodiene polysiloxane (KF-99P) were added to 100 g of fine-particle titanium oxide (average particle size 0.06 μm). A solution dissolved in 5 g of methanol was added, and the mixture was mixed and pulverized using a mixer.

The obtained powder was transferred to a stainless steel hat and heat-treated at 150° C. for 8 hours using a blow dryer to obtain a powder, and the various tests described above were conducted.

Example 12 Tetrahydrodienetetramethylcyclotetrasiloxane (viscosity 2.5 cs
t) 200 g was added and mixed and pulverized using a mixer. The obtained powder was transferred to a stainless steel hat and subjected to primary heat treatment at 70°C for 1 hour using a blow dryer.
Then, a secondary heat treatment was performed at 130° C. for 4 hours to obtain a modified powder.

Example 13 Methylhydrodiene polysiloxane (viscosity 350 cst) to 100 g of nylon powder (particle size 14.0 μm)
3 g was added, mixed and pulverized using a mixer. The obtained powder was transferred to a stainless steel hat and subjected to primary heat treatment at 90°C for 2 hours using a blow dryer, and then heated to 140°C.
As is clear from Table 1, the modified powder obtained by this method is different from the powder obtained by the conventional manufacturing method, due to secondary aggregation of powder. You can see that you can use powder with less powder and better texture.

〔Effect of the invention〕

As described above, the present invention is useful as a raw material for cosmetics, resins, paints, adhesives, immobilization carriers, column packing materials for chromatography, etc., with less secondary aggregation and excellent water solubility and dispersibility. It is clear that a modified powder having the following properties can be obtained.

Procedural amendment February 26, 1991

Claims (1)

[Claims] After mixing and stirring powders and organosilicones having a viscosity of 1 to 400 cst at 25°C at a weight ratio of powders and organosilicones of 100:0.3 to 100:20, Obtained by performing primary heat treatment at 70 to 130°C for 0.5 to 4 hours, followed by secondary heat treatment at 110 to 200°C for 1 to 12 hours at a higher temperature than the primary heat treatment. Modified powder.