JPH02249554A - Moldings retentive of chemical - Google Patents

Abstract

PURPOSE:To diffuse a perfume and a drug in uniform concentration for a long period by a method wherein a perfume, a fertilizer, or a drug are carried by a molded product containing optical anisotropic porous carbon microgranular activated coal or microgranular activated coal. CONSTITUTION:A perfume, fertilizer, or a drug is carried to a molded product containing optical anisotropic porous carbon microgranular activated coal or microgranular activated coal. Precursor particles of optical anisotropic porous carbon microgranular activated coal can be manufactured by producing spherulite, in which carbon six-membered ring net surfaces are laminated in parallel in a pitch, in a process of heating petroleum series and coal series pitch. Using activated coal is produced by activating mesocarbon microbeads, being precursor particles, as it is or after an activating assistant is applied on the surface of mesocarbon microbead. Various perfumes, fertilizers, a moldproofing agent, a rustproofing agent, a repellent, and agricultural chemicals are used as a perfume, a fertilizer, and drug, carried to granular activated coal or a molded product containing activated coal, according to application.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a sustained release material that stably and constantly releases fragrances and drugs over a long period of time.

[Prior Art and Problems to be Solved by the Invention] In recent years, the consumption of fragrances in daily life has increased rapidly, causing a wide range of problems. On the other hand, fragrances contain a wide variety of ingredients, and each ingredient is volatile, oxidizing,
Because they differ in terms of degradability, isomerization, etc.,
If the period of use becomes longer, the optimal blending ratio will be disrupted, and the aroma quality will change significantly, causing discomfort.

From this point of view, a method of kneading a fragrance into a resin is known. However, with this method, io
They may be exposed to temperatures above 0.45°C, and some fragrances may cause problems such as thermal decomposition or large losses due to evaporation.

Also known is a sustained release material in which activated alumina supports a fragrance. Furthermore, in order to maintain the unstable blended fragrance (1) stably for a long period of time and to emit it at a uniform concentration over a long period of time, Japanese Patent Application Laid-open No. 52-117444 discloses that granular activated carbon is used as a carrier for supporting the fragrance. was proposed and published in 1974-
Japanese Patent No. 154527 proposes a sustained release material in which activated carbon or the like adsorbing fragrance is covered with a synthetic resin film having continuous pores. Furthermore, Japanese Patent Application Laid-Open No. 60-58153 proposes a sustained release material in which a fragrance is supported on a honeycomb-shaped activated carbon molded body having a specific specific surface area.

However, although the above-mentioned sustained release materials have a strong ability to retain flavor, they all have a small retention capacity, and therefore the amount of the supported flavor is released is also small. Moreover, the amount of emission decreases rapidly with the passage of time, and the emission time is short, making it difficult to maintain aromatic properties over a long period of time.

It is also known to mix agents such as antifungal agents and anticorrosive agents into paint and coat the surface of the object to be protected.

However, with the above method, the retention period of the drug is short, and its effectiveness is lost 12 to 20 months after application. In particular, the amount of drug released is too large immediately after application, and the amount released drastically decreases in the later stages. Therefore, it is difficult to maintain the efficacy of the drug over a long period of time.

In addition, excessive release of drugs not only wastes drugs, but also
It also causes environmental pollution.

An object of the present invention is to provide a sustained release material that can support a large amount of fragrances and drugs, and can diffuse the fragrances and drugs at a uniform concentration over a long period of time while preventing deterioration of the fragrances and environmental pollution. It's about doing.

[Structure of the Invention] The present invention solves the above problems with a sustained release material in which a fragrance, fertilizer, or drug is supported on optically anisotropic porous carbon microgranular activated carbon or a molded article containing the microgranular activated carbon. It is something.

The optically anisotropic porous carbon microgranular activated carbon precursor particles are produced by heating petroleum-based and coal-based pitches during the development of pitch-based needle coke and carbon fiber. It can be manufactured by producing spherulites in which six-membered ring network planes are stacked in parallel. These spherulites form a phase different from the matrix pitch, and are isolated by an antisolvent method, a centrifugation method, or the like. The isolated spherulites are generally called mesocarbon microbeads, and are spheres with a diameter of about 2 to 80 μm.
It has an optically anisotropic structure. Due to their unique shape and properties, carbon microbeads are expected to be a new raw material for highly functional materials, but so far they have only been put into practical use as raw materials for high-density carbon forests. .

The applicant discovered that activated carbon with a new microstructure and characteristics could be obtained by activating men carbon microbeads, and wanted to apply for a patent first.
-158510).

The activation and properties used in the present invention can be obtained by applying an activation aid to the precursor particles or the surface of the carbon microbeads and then activating them. The activated mencarbon microbeads may be in the form of green powder, carbonized powder, or graphitized powder. Examples of the activation aid include KOH, NaOH,
Cs0H1ZnCJ2, H3PO4, K2 SO4, K
2S and the like are exemplified, and at least one of these activation aids is used. The amount of the activation aid applied is preferably about 1 to 10 times the weight of the mesocarbon microbeads, since the degree of activation is approximately proportional to the amount of the activation aid applied.
The specific surface area of activated carbon can be adjusted depending on the amount applied. Note that the activation aid is usually used in liquid form. That is, an activation aid that is solid at room temperature, such as KOH, is used in the form of an aqueous solution, and an activation aid that is liquid at room temperature, such as HiPOm, is not necessarily in the form of an aqueous solution.

In addition, in order to improve the wettability of the activation aid to the surface of mesocarbon microbeads, a surfactant such as acetone, methyl alcohol, or ethyl alcohol may be used in combination. The amount is preferably about 5 to 10% by weight of the total amount of carbon microbeads and the activation aid or the solution containing the activation aid.

Activation is carried out by heating Mencarbon microbeads with or without an activation aid at an appropriate temperature, e.g.
This is done by raising the temperature to about 1200°C. The heating rate and heating holding time are not particularly limited and can be selected within a wide range, but usually, after reaching the above temperature range, it is immediately cooled or held within the same temperature range for a maximum of about 3 hours. This is done by

The atmosphere during activation may be an inert atmosphere such as nitrogen, helium, or argon, or may be an oxidizing 4'11 atmosphere containing water vapor, carbon oxide, oxygen, or the like. Activation in an inert atmosphere gives higher yields.

Inactive'l! To activate in an atmosphere, it is preferable to use an activation aid to heat to a temperature of about 400 to 1200°C at a heating rate of 300 to 1200°C, and hold at the same temperature for about 30 minutes to 1 hour. .

When activating in an oxidizing atmosphere, an activation aid is usually not required, but may be used in combination. When activating without using the activation aid, the temperature is usually 600 to 900°C, and when using the activation aid, the temperature is usually 300 to 900°C.
It is preferable to heat the product to a temperature of about 100°C at a hot water temperature rate of 00 to 600°C/hour and maintain it at the same temperature for 2 to 3 hours. In addition, when using an activation aid, Care must be taken as bumping may occur.

Note that there is an optimum activation temperature depending on the type of activation aid. The optimum activation temperature is, for example, KO)(,K2SO4
and 2S, 800~. About 1000℃, Na
For OH and Cs OH, about 600°C, ZnCJ
In the case of z, the temperature is about 450°C.

After cooling the activated Mencarbon Microphone 17 beads to room temperature, if necessary, unreacted activation aid and activation aid reactant are removed by washing with water, and the optical difference used in the present invention is obtained by drying. Oriental porous carbon microgranular activated carbon (
(hereinafter referred to as live charcoal) is 'IP'. It is presumed that the above-mentioned 1-wiping assistance promotes gasification by oxidation of carbon in the Men Carbon Microphone+7 beads. In other words, it is presumed that the activation aid reacts with the carbon atoms on the carbon hexacyclic network surface constituting the mesocarbon microbeads, and the generated carbon monoxide or carbon dioxide is discharged to the outside of the system.

Furthermore, when activation is carried out in an inert atmosphere, carbonization progresses in the portions that are not involved in the reaction, so that the difference in structure between the reacted portion and the unreacted portion increases and pores are formed. In this case, the carbon microbeads have a regular J-shaped structure, and many of the generated pores are smaller than 208 micropores. Furthermore, when the reaction atmosphere is an inert atmosphere, the selectivity of the surface gas reaction increases and the yield also increases significantly.

Note that the reaction between the activation aid and carbon proceeds very violently, so if carbon fibers are activated in the same way as above instead of mesocarbon microbeads, their shape will change to such an extent that they will no longer retain their original shape and their strength will also decrease. Significantly decreased. On the other hand, the carbon mic + 7 beads were used, and no significant decrease in strength was observed.

The activated carbon obtained as described in 1- above has approximately the same shape as the mesocarbon microbeads used as the original moon, and is (i) optically anisotropic and (ii) entirely More than 90% of the particles are composed of particles with a particle size of 80ρ or less, and (iii
) 85% or more of the total pore volume is constituted by micropores with a pore diameter of 20A or less. The specific surface area of activated carbon is within the range of 500 to 4600 m'/g, and the total pore volume is 0.5 to 3°OL! It is about ll/g.

Therefore, the activated carbon used in the present invention has a significantly smaller pore diameter than conventional activated carbon, and is compliant with JIS K
The benzene adsorption capacity according to 1.474 is O,2~1.
The methylene blue adsorption capacity according to JIS Kl, 470 is about 100 to 650+ml/g,
It has significantly greater adsorption capacity than conventional activated carbon. Among the above activated carbons, the specific surface area is 1000 to 4600n.
i'/g, particularly 2000 to 4600 m'/g, and a total pore volume of 0.8 to 3.0 ml/g are preferred. When the specific surface area and total pore volume of activated carbon are less than the above range,
Incense f1, the ability to carry and retain fertilizers and chemicals is not 11 minutes. Note that when the total pore volume exceeds 0.8 ml/g, the pore size distribution shifts to the larger pore size, so relatively large particles can be adsorbed, and a wider range of blended fragrances, fertilizers, and drugs can be supported. be able to.

The sustained release product of the present invention is composed of granular activated carbon having the above-mentioned characteristics or a molded article containing the activated carbon, and a fragrance, a fertilizer, or a drug.

The above-mentioned molded body can take various forms depending on the purpose, such as granulated form, sheet form, and honeycomb form. In addition, the molded product is usually formed from at least a 6"-type active ingredient and a bread binder, and fibers, additives, etc. Any material can be used as long as it does not adversely affect the adsorption capacity of activated carbon. Examples of such binders include polyvinyl acetate, polyvinyl alcohol, acrylic resin, polyacrylamide, styrene resin, saturated polyester, polyamide,
Polycarbonate, polyurethane, epoxy resin, furan resin, urea resin, melamine resin, unsaturated polyester, diallyl phthalate resin, silicone resin, polyacetal, cellulose resin such as methylcellulose, ethylcellulose, cellulose acetate, nitrocellulose, carboxymethylcellulose, phenolic resin, Polyimide, sodium alginate, glue, gelatin, deacetylated chitin, bentonite, coal tar pitch,
Examples include starch and the like, and at least one of these binders is used.

The granulated molded body may have an irregular shape due to crushing or the like, but it is preferably spherical, polygonal in cross section, or cylindrical in shape because of its excellent fluidity and mechanical strength. The size of the molded body is usually a typical dimension of 0.1 to 5 mmφ, preferably 0.
．． 5 to 4 mInφ, more preferably ≦1 to 3 mInφ.

The granulated molded product can be produced, for example, by mixing the activated carbon and a binder in the presence of a solvent if necessary, extruding the mixture using an extruder, molding it into a predetermined shape and size, and then drying it. It can be manufactured by In addition, the mixture can be dried without using an extruder,
The mixture may be pulverized or the mixture may be granulated using a spray dryer or the like.

Moreover, drying is preferably carried out under reduced pressure.

Further, the sheet-like molded body is usually formed using activated carbon and fibers, as well as the above-mentioned binder and additives as necessary. The fibers may be pulp, natural fibers, synthetic fibers, inorganic fibers, etc. The pulp includes cellulose fibers, for example, mechanical pulps such as water-ruptured pulps and thermomechanical pulps; sulfate pulps, sulfite pulps, etc. chemical pulp; biochemical pulp; waste paper pulp: straw pulp;
Stem culm bulk such as bagasse pulp: Examples include bast pulp made from cord, tripod, stratified, etc. As a natural fiber,
Examples include cotton, linen, silk, and wool.

Synthetic fibers include rayon fiber, acetate fiber, vinylon fiber, nylon fiber, acrylic fiber, polyvinyl chloride fiber, polyester fiber, polyethylene fiber,
Examples include polypropylene fibers. Examples of inorganic fibers include glass fibers, carbon fibers, and metal fibers. One or more types of fibers are used.

As additives, various additives that are commonly used in paper manufacturing, such as sizing agents, internal additive improvers, fillers, and wet strength improvers, can be used.

The sheet-like molded body can be manufactured by a wet papermaking method or a dry papermaking method. The wet papermaking method usually uses activated carbon, fibers, and a water-soluble or water-dispersible binder among the binders.
This is carried out by paper-making together with additives if necessary. This wet papermaking method can be carried out using a conventional papermaking machine.

The dry papermaking method is usually carried out by mixing activated carbon and fibers with the binder as required, forming the sheet into a sheet, and fixing the activated carbon to the fibers while partially embedded therein. Note that when heat-fusible fibers are used as the fibers, activated carbon can be fixed in a partially embedded state in the fibers by heating, so a binder is not necessarily required.

The sheet-like molded body may be formed by laminating a plurality of sheets, and the sheet-like molded body is not limited to a flat plate shape, but may be processed into a corrugated shape, an uneven shape, or the like.

The sheet-like molded body can be formed to have an appropriate thickness, for example, 0.05 to 1 mm. In addition, the basis weight of the sheet-like molded body can be appropriately set depending on the supported amount and emission amount of the fragrance, etc. For example, the basis weight in the dry state is 2.5 to 50 g/-
degree, preferably about 5 to 30 g/+n'.

The honeycomb-shaped molded body is, for example, a corrugated structure in which the above-mentioned sheet-shaped molded body is corrugated into a corrugated shape, and the contact area between the sheet-shaped molded body and the top of the corrugated sheet is joined, or a corrugated cardboard-shaped molded body. It may be a vI structure in which a sheet is wound, or it may be a structure in which a plurality of sheets processed into corrugated or uneven shapes are laminated in a honeycomb shape. A cylindrical molded body is converted into a sheet-shaped molded body 1
- It may be a structure in which it is joined in a parallel state and wound.

The molded bodies in various forms may contain the activated carbon in an appropriate proportion within a range that does not impair strength or carrying capacity, but usually 50 to 90% by weight of activated carbon, preferably 60% by weight. ~
Contains 85% heavy attack.

If the content of activated carbon is less than 60% by weight, the supporting strength will be small, and if it exceeds 90% by weight, the strength will decrease.

Incidentally, the molded body mentioned above, particularly the granular molded body, may be carbonized and fired as necessary. Further, in order to open pores blocked by the binder to increase the specific surface area, or to remove impurities adhering to the surface of the molded article, a slight activation treatment may be performed.

Carbonization calcination is carried out under an inert atmosphere or vacuum, e.g.
It can be carried out at a temperature of about 0 to 1500°C. Activation treatment is carried out under a steam atmosphere or a carbon dioxide atmosphere.
For example, it can be carried out at a temperature of about 800 to 1500°C.

The controlled-release material of the present invention using the molded article described in 4-2 is usually prepared using the nEE" method even if the specific surface area and ml pore volume are sacrificed when forming the molded article using a binder etc. specific surface area to 800, culm degree of 3500 m'/g, total pore volume 0,
It has about 5 to 2.5 ml/g, and is excellent in the amount of loading and sustained release of fragrances, fertilizers, and medicines.

The fragrances, fertilizers, and chemicals supported on the granular activated carbon or the molded body containing the activated/i-charcoal include various fragrances, fertilizers, and chemicals depending on the purpose, such as fungicides, rust preventives, and repellents. and pesticides, etc. are used.

As the fragrance, any of natural fragrances, synthetic fragrances, and mixed fragrances can be used, and the form of the fragrance may be any of liquid, gas, and sublimable solid.As the natural fragrance f1, for example, musk, spirit, etc. Examples of synthetic fragrances include cat incense, chili pepper, anise oil, avinis oil, boar rose oil, orange flower oil, lemon oil, grapefruit oil, peppermint oil, spearmint oil, lavender oil, jasmine absolute oil, etc. For example, hydrocarbons such as limonene and pinene; alcohols such as geraniol, linalool, citronellol, 4-menthol, borneol, phenethyl alcohol, and anis alcohol; phenols such as annenol and eugenol; citral, diroxycitronellal, Citronellal, benzaldehyde, cinnamaldehyde, cyclamenaldehyde,
Aldehydes such as anisaldehyde and vanillin; Ketones such as methylnonylketone 1,2-carvone, menthone, camphor, acetophenone, ionone, and cyclopentadecanone; Lactones or oxides such as aminobutyrolactone, γ-nonyllactone, and cineole : Isoprobyl formate, pentyl acetate, inpentyl acetate, isoamyl acetate, cinnamyl acetate, ethyl acetate, isopentyl butyrate, butyl propionate, isoamyl caprylate, ethyl benzoate, ammonium, acetate, benzyl frate, cinnamyl cinnamate, Examples include esters such as impentyl salicylate, amyl salicylate, benzyl salicylate, ethyl anisate, and methyl anthranate; and ethers such as anisole. Examples of the blended percentage include rose, jasmine, lilac, osmanthus, carnation, and muguet.

Examples of fertilizers include urea, lime nitrogen, ammonium chloride, ammonium sulfate,
Nitrogen fertilizers such as anthracite, superphosphate lime, heavy superphosphate lime,
Phosphate powders such as dissolved phosphide and calcined phosphide, potassium chloride,
Examples of various materials include potassium fertilizers such as potassium sulfate, organic fertilizers, compound fertilizers, and calcareous materials.

Examples of antifungal agents include organic tin compounds such as tributyltin oxide, organic sulfur compounds such as dimethyltetradrothiodiazine-dione, carbamates and isothiazolone derivatives, chlorine compounds such as chlorophthalonitrile, and phenols such as pentachlorophenol. Examples include various fungicides such as compound, dehydroacetic acid, and sorbic acid.

As the rust preventive agent, various rust preventive agents can be used, such as dicyclohexyl ammonium sulfite and dibenzyl ammonium benzoate.

As the repellent, various repellents that are used as rat repellents, crow repellents, snake repellents, etc. are used.

As the agricultural chemicals, various agricultural chemicals that are used as bactericides, insecticides, rodenticides, acaricides, termite control agents, etc. can be used, such as organophosphorus, organic chlorine, and dithiocarbalate compounds.

Fragrances and drugs can be used alone or in combination.

The amount of the perfume or drug supported is appropriately set depending on the desired aroma, medicinal effect, etc., but is usually about 0.5 to 90% by weight, preferably about 1 to 85% by weight. In addition, when the amount of perfume, etc. supported is small, the specific surface area and pore volume of the activated carbon or molded body where no perfume, etc. are supported are large, and the adsorption capacity is large, so when used as a fragrance, etc., unpleasant components may be removed. It can also be removed by adsorption.

Flavors and medicines can be supported on granular activated carbon or compacts by conventional methods such as dipping, spraying, and dropping.

Sustained-release materials that support fragrances, etc. have excellent sustained release properties, and compared to conventional sustained-release materials that have fragrances, etc. supported on powdered activated carbon, they retain a larger amount of fragrances, etc., and have a shorter release time. It can be made about 2 to 10 times longer.

[Effects of the Invention] As described above, according to the sustained release material of the present invention, a fragrance, fertilizer, or drug is supported on the granular activated carbon or a molded article containing the activated carbon, so a large amount of the fragrance, etc. can be supported. At the same time, it is possible to diffuse fragrances, fertilizers, and drugs at a uniform concentration over a long period of time while preventing deterioration of fragrances, fertilizers, and drugs and environmental pollution. The invention will now be described in more detail.

Example 1 and Comparative Example 1.2 50 parts by weight of acetone was added to a mixture of 100 parts by weight of mesocarbon micropieces and 1200 parts by weight of potassium hydroxide solution (400 parts by weight of potassium hydroxide and 800 parts by weight of water). , mixed uniformly to form a slurry. The slurry was then heated from room temperature to 850' in a nitrogen gas atmosphere.
C at a heating rate of 10°C/min and maintained at the same temperature for 1 hour for activation. The reactant was then cooled to below 100°C, washed with water, and dried to form an optically anisotropic porous material. Carbon microparticles (
Example 1) was obtained. Specific surface area after drying is 2800 m'
/g.

100 parts by weight of this activated carbon and 35 parts by weight of a 50% by weight aqueous methylcellulose solution were uniformly mixed in a kneader, and a cylindrical pellet 10 with a diameter of 2.5 to 3 ml was produced using an extruder. Next, the pellet was dried using a vacuum soot dryer at a reduced pressure of 10 torr and a temperature of 120°.
By drying at
Granulated activated carbon of 100 m'/g was produced.

As a comparative example, granular activated carbon (manufactured by Takeda Pharmaceutical ■, trade name Shirasagi GX, particle size 3 to 5III1φ, specific surface area 800m"
7g, Comparative Example 1) and activated alumina particles (manufactured by Suiko Kagaku ■,
Comparative Example 2) having a particle size of 3 to 5 mInφ and a specific surface area of 400 m'/g was subjected to the test as it was without being granulated.

In addition, as fragrances, (1) anisole, (2) amyl salicylate, (3) eugenol, (4) citral, and (
5) Using droxycitronellal, sustained release materials were prepared by carrying these fragrances in saturated adsorption amounts on the above-mentioned activated carbon etc. by an impregnation method.

Then, each sustained-release material was left in a room with a temperature of 20°C and a humidity of 60% RH, and the residual fragrance after 3, 5, 10, and 30 days was extracted with methylene chloride, and the amount supported at the beginning of impregnation was The residual amount was measured by gas chromatography.

The obtained results are shown in FIGS. 1 to 5.

As is clear from these figures, Comparative Example 1 and Comparative Example 2
It was found that the sustained release material of Example 1 had extremely superior retention properties and released fragrance over a long period of time compared to the sustained release material of Example 1.

Example 2 and Comparative Examples 3 to 5 Activated carbon was produced using a manufacturing method similar to Example 1, only the amount of potassium hydroxide was changed, and specific surface area was 250 d/g, 750 m'/g, and 1550 m' as granulated activated carbon. /g, 2
Granulated activated carbon (Example 2) of 520 m'/g and 3500 m'/g were prepared.

In addition, as a comparative example, the granular activated carbon used in Comparative Example 1 (Comparative Example 3) and the granular activated carbon (manufactured by Takeda Pharmaceutical ■, product name Shirasagi G2
(', particle size 3-5 mmφ, specific surface area 1200 m'/g
, Comparative Example 4) and activated alumina ft used in Comparative Example 2
(Comparative Example 5) was used.

Then, the saturated amount of anisole supported on each sample was measured, and the results shown in FIG. 6 were obtained.

As is clear from Fig. 6, the molded body using the optically bound porous carbon microgranular activated carbon obtained by activating the Men Carbon Mic 17 beads has a higher adsorption capacity than granular activated carbon or activated alumina. It was found that it has a high capacity and can support a large amount of fragrance.

[Brief explanation of drawings]

Figures 1 to 5 are diagrams showing the relationship between the standing time and the remaining amount of incense 11 in Example 1, Comparative Example 1, and Comparative Example 2, respectively. FIG. 3 is a diagram showing the relationship between specific surface area and perfume retention.

Claims (1)

[Scope of Claims] 1. A sustained release material characterized in that a fragrance, fertilizer, or drug is supported on optically anisotropic porous carbon microgranular activated carbon or a molded article containing the microgranular activated carbon. 2. Claim 1, wherein the drug is at least one drug selected from the group consisting of fungicides, rust preventives, repellents, and agricultural chemicals.
Delayed release material as described. 3. The sustained release material according to claim 1, wherein the fine particulate activated carbon is activated mesocarbon microbeads.