JPH11302628A - Blowing agent powder and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a blowing agent powder made proof against dusting in working and against agglomeration and solidification with time or under a load and being homogeneous, and having improved dispersibility in a resin by adding an aluminum coupling agent and an oil and fat to a blowing agent powder and mixing them at a temperature equal to or lower than the decomposition temperature of the blowing agent. SOLUTION: 0.01-10 pts.wt., desirably, 0.05-0.5 pt.wt. aluminum coupling agent and 0.001-1 pt.wt., desirably, 0.01-0.5 pt.wt., at least one fat and oil being desirably in the form of a mist of 1-10 μm and selected among liquid or solid fats and oils, hydrocarbons, and fatty acids, and the mixture is mixed under heating to 55 deg.C to the decomposition temperature of the blowing agent under mixing conditions in which the increment of the specific surface area of the blowing agent powder is limited to 20% or below, desirably, 10% or below.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a blowing agent powder and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a foaming agent has been used in the form of fine powder, and there has been a problem of generating dust in a working environment.

As a means for solving such a problem, there has been proposed a method in which a foaming agent powder and a wax are mixed while heating using a mixer having a shearing blade, a mixing blade, and the like, and then granulated (Japanese Patent Laid-Open Publication No. H11-163873). JP-A-52-90543). However, the granulated foaming agent obtained by this method is inferior in homogeneity and dispersibility in a resin, so that it is difficult to obtain a fine and uniform foam, which has not been practically satisfactory.

Furthermore, these conventional foaming agents have the problem that they coagulate and solidify with the passage of time or load, and the fluidity in the step of adding to the resin deteriorates, clogging the hopper and dispersibility in the resin deteriorates. Have. With the recent increase in quality of foamed resin and labor saving in production, improvement of solidification thereof has been further desired.

On the other hand, as a method for suppressing coagulation and solidification of a foaming agent, there have been (1) a method of adding inorganic powder particles such as silica and a metal silicate to a foaming agent as an anti-solidification agent.
(2) A method is adopted in which the drying method is a batch method, a sufficient drying time is taken, and a small amount of water contained in the foaming agent is reduced.

However, when these methods are adopted, various disadvantages occur. That is, in the method (1),
Although some anti-solidification effect is observed, the effect is maintained for only a few months. In addition, since the solidification prevention effect is reduced when the foaming agent becomes fine particles, it is necessary to add more inorganic powder particles, but the addition of a large amount of inorganic powder particles causes coarsening of bubbles during foaming. Therefore, it is not preferable for applications requiring fine cells. On the other hand, in the method (2), since a long time is required for drying, the production capacity is remarkably reduced, the production cost is increased, and it is not possible to cope with continuous production.

JP-A-4-320432 proposes a method of adding a solvent solution of a silane coupling agent to azodicarbonamide to improve the fluidity and dispersibility of the azodicarbonamide in a resin. I have. Further, JP-A-8-295873 discloses that a solvent solution or dispersion of an aluminum-based coupling agent is added to a chemical foaming agent,
Methods for improving fluidity and dispersibility in resin have been proposed. However, none of these methods has an insufficient solidification preventing effect and cannot solve the problem of dust generation.

[0008]

DISCLOSURE OF THE INVENTION The present invention suppresses the generation of dust during each operation such as packaging, transportation, storage and use, suppresses coagulation and solidification due to aging and load, and is homogeneous and dispersible in resin. It is an object of the present invention to provide a modified foaming agent powder excellent in the above and a method for producing the same.

[0009]

In order to solve the above-mentioned problems, the inventors of the present invention have conducted intensive studies and found that solidification of a blowing agent powder such as azodicarbonamide caused a small amount of moisture, more specifically, The trace moisture contained in the agent particles and the water absorbed by the foaming agent particles from the atmosphere during production, transportation and storage serve to bind the particles on the surface of the foaming agent particles, so that coagulation and solidification do not proceed. I thought, and further researched.

As a result, moisture contained in the foaming agent particles is removed by reacting with the aluminum-based coupling agent, and a film of aluminum hydroxide is formed on the surface of the foaming agent powder, thereby solidifying the foaming agent powder. It has been found that a foaming agent having excellent suppression of the properties and excellent fluidity and dispersibility in a resin after a long period of time can be obtained. Also,
It has also been found that by coating the foaming agent powder with fats and oils, dust generation during each operation such as packaging, transportation, storage and use is suppressed. The present invention has been completed based on such findings.

According to the present invention, the foaming agent powder has a surface coated with aluminum hydroxide and at least one oil or fat selected from the group consisting of liquid or solid oils, hydrocarbons and fatty acids. An agent powder is provided.

According to the present invention, the surface of the foaming agent powder is coated with aluminum hydroxide and at least one kind of fat or oil selected from the group consisting of liquid or solid fats and oils, hydrocarbons and fatty acids. (A) a step of adding an aluminum-based coupling agent and fats and oils to the foaming agent powder, and (b) foaming under heating from 55 ° C. to the decomposition temperature of the foaming agent. The present invention provides a method for producing a blowing agent powder, comprising a step of mixing a blowing agent powder, an aluminum-based coupling agent, and fats and oils under a mixing condition in which the agent powder is hardly pulverized.

The foaming agent powder of the present invention has a particularly improved solidification property over time, hardly solidifies even after being stored for a long period of time, and has good fluidity immediately after production and dispersibility in resin for a long time. It has the advantage of being held over.
Further, the foaming performance of the foaming agent powder of the present invention is equal to or higher than that of the conventional foaming agent powder because the solidification property and the dispersibility are improved.

Further, the foaming agent powder of the present invention suppresses the generation of dust during handling such as packaging, storage, transportation and use, so that it does not adversely affect the health of workers. .

The provision of the foaming agent powder of the present invention eliminates anxiety of solidifying the product under load and hardening with time from the production of the foaming agent powder to the use by the user. Since the foaming agent powder of the present invention has good dispersibility in a resin, it can be particularly suitably used for applications requiring uniform fine foaming, for example, for producing foamed sheets for wallpaper.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The foaming agent powder of the present invention is characterized in that the surface of the foaming agent powder is aluminum hydroxide and at least one oil or fat selected from the group consisting of liquid or solid oils and fats, hydrocarbons and fatty acids. Is a blowing agent powder coated with the same.

As the foaming agent component constituting the foaming agent powder of the present invention, conventionally known organic and inorganic foaming agents can be widely used. Examples of the organic foaming agent include azodicarbonamide (ADCA) and hydrazodicarbonamide (HD
CA), p, p'-oxybisbenzenesulfonylhydrazide (OBSH), dinitropentamethylenetetramine (DPT), p-toluenesulfonylhydrazide (T
SH), benzenesulfonyl hydrazide (BSH), 5
-Phenyltetrazole (5-PT) and the like, and salts thereof such as alkaline earth metal salts (eg, calcium salt, barium salt, strontium salt, etc.) and aluminum salts. In addition, examples of the inorganic foaming agent include sodium hydrogen carbonate, anhydrous citric acid monosoda, and the like. Among these, ADCA, OBSH, DPT, TSH, B
Salts such as SH, 5-PT and the like, calcium salts, barium salts, strontium salts, aluminum salts and the like thereof are preferable, and ADCA is particularly preferable.

In the present invention, these foaming agent powders are used alone or as a mixture of two or more.

In the present invention, the particle size of the foaming agent powder is as follows:
Although not particularly limited, it is usually about 1 to 100 μm, preferably about 3 to 30 μm. In addition, in this specification, the particle diameter of a foaming agent powder means a median diameter measured using a laser diffraction type particle size distribution analyzer.

In the blowing agent powder used in the present invention, a stabilizer, a pigment / filler, a foaming inhibitor and the like known in the art may be further added to the above-mentioned blowing agent powder. The blowing agent powder containing the third component is also included in the blowing agent powder of the present invention.

Examples of the stabilizer include tribasic lead sulfate,
Examples include dibasic phosphite, lead stearate, zinc stearate, zinc carbonate, zinc oxide, barium stearate, aluminum stearate, calcium stearate, dibutyltin malate, and urea. Examples of pigments and fillers include chrome yellow, carbon black, titanium dioxide, calcium carbonate, and the like. Further, examples of the foaming inhibitor include maleic acid and the like.

The foaming agent powder of the present invention can be obtained by, for example, (a) a step of adding an aluminum-based coupling agent and fats and oils to the foaming agent powder, and (b) foaming under heating from 55 ° C. to the decomposition temperature of the foaming agent. It is manufactured through a step of mixing a foaming agent powder, an aluminum-based coupling agent, and fats and oils under a mixing condition under which the agent powder is hardly crushed.

In producing the blowing agent powder of the present invention,
The order of adding the aluminum-based coupling agent and the fats and oils in the step (a) is not particularly limited. (1) A method in which an aluminum-based coupling agent is added first, and then the fats and oils are added; Either a method of adding a coupling agent and a fat or oil at the same time, or (3) a method of adding a fat or oil first and then a method of adding an aluminum-based coupling agent may be adopted. In the present invention, it is preferable to use the method (1) or (2) among these methods.

As the aluminum-based coupling agent used in the present invention, conventionally known ones can be widely used, for example, aluminum isopropylate, aluminum ethylate, aluminum tris (ethylacetoacetate), ethylacetoacetate aluminum diisopropylate and the like. Can be mentioned. In the present invention, these aluminum-based coupling agents are used alone or in combination of two or more. Among these aluminum-based coupling agents, aluminum tris (ethyl acetoacetate) is particularly preferred.

The aluminum-based coupling agent reacts with moisture contained in the foaming agent powder by being mixed with the foaming agent powder under heating to form a coating made of aluminum hydroxide on the surface of the foaming agent powder particles. Form. The aluminum hydroxide coated on the surfaces of the foaming agent powder particles has a function of imparting water repellency to the foaming agent powder and suppressing adsorption of moisture.

In the present invention, the aluminum-based coupling agent must be used as it is, without being dissolved or dispersed in a solvent. When the aluminum-based coupling agent is used in a state of being dissolved or dispersed in a solvent, the reaction between water present in the foaming agent and the aluminum-based coupling agent does not sufficiently proceed, and the aluminum-based coupling agent is not used. Only a foaming agent coated on the surface of the foaming agent is obtained, and an aluminum hydroxide film cannot be formed on the surface of the foaming agent. Therefore, when the aluminum-based coupling agent is used in a state of being dissolved or dispersed in a solvent, the foaming agent of the present invention whose surface is coated with aluminum hydroxide cannot be produced.

In the present specification, fats and oils refer to liquid or solid fats and oils, hydrocarbons and fatty acids.

Examples of fats and oils include vegetable or animal natural oils such as soybean oil, coconut oil, linseed oil, cottonseed oil, rapeseed oil, drill oil, pine oil, rosin, castor oil, tallow, squalane, lanolin, and hardened oil. Fats and oils and their purified products.

Examples of the hydrocarbons include aliphatic hydrocarbons having 20 to 48 carbon atoms and derivatives thereof, generally referred to as paraffin wax, and aliphatic hydrocarbons and derivatives thereof having 8 to 19 carbon atoms (eg, dioctyl phthalate and the like). Dialkyl phthalates, higher alcohol phthalates such as nonyl alcohol phthalate, etc.), paraffinic, naphthenic or aromatic process oils, and liquid paraffin. Further, the hydrocarbons also include hydrocarbons isolated and purified from the above-mentioned natural fats and oils.

Examples of the fatty acids include fatty acids such as lauric acid, mystic acid, palmitic acid, stearic acid, oleic acid, and behenic 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 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 solid at normal temperature, it is preferable to adjust the temperature of the fats and oils to be liquid by heating.

In the step (a) of the present invention, the addition of the aluminum-based coupling agent and the fats and oils to the foaming agent powder is carried out by making the aluminum-based coupling agent and the fats and oils into a mist and spraying the foaming agent powder by spraying. It is desirable to carry out by doing. In this way, it is possible to produce a desired foaming agent powder in which generation of dust and coagulation and solidification due to aging or load are significantly suppressed.

When the aluminum-based coupling agent is in a solid state at room temperature, it is important that the aluminum-based coupling agent be heated before adding the aluminum-based coupling agent to the foaming agent powder. By this heat treatment, the solid aluminum-based coupling agent is in a state of being heated and melted.

As a method for treating the foaming agent powder by spraying the aluminum-based coupling agent and the fats and oils in the form of a mist, for example, using a spraying device, the liquid aluminum-based coupling agent and the fats and oils are liquefied by heating or by heating. A method of spraying the formed aluminum-based coupling agent and fats and oils onto the foaming agent powder. Examples of the spraying device include a two-fluid nozzle, a pressure nozzle, and the like.
The size of the mist droplet when spraying is usually 0.1 to 1
The thickness is about 00 μm, preferably about 1 to 10 μm.

The amount of the aluminum-based coupling agent to be added to the blowing agent powder is an amount necessary for completely reacting with the water contained in the blowing agent powder. Specifically, the amount is usually 0.01 to 100 parts by weight of the foaming agent powder.
It may be used in an amount of about 10 to 10 parts by weight, preferably 0.05 to 0.5 part by weight.

The amount of the fats and oils added to the foaming agent powder is 0.001 parts by weight of the fats and oils per 100 parts by weight of the blowing agent powder.
To 1 part by weight, particularly preferably 0.01 to 0.5 part by weight. By setting the amount of the fat or oil to be 0.001 part by weight or more, it is possible to obtain a foaming agent powder in which dust generation is sufficiently suppressed. By setting the amount of the fat or oil to 1 part by weight or less, it is possible to prevent solidification of the foaming agent powder and deterioration of dispersibility in the resin. More specifically, the amount of fats and oils to be added is preferably set appropriately according to the specific surface area of the foaming agent powder. For example, a blowing agent powder having a small specific surface area (0.1 to
2m ² / g), the amount of fats and oils added was small (0.
001 to 0.5 parts by weight), and for a foaming agent powder (2 to 10 m ² / g) having a large specific surface area, the amount of fats and oils to be added is relatively large (0.2 to 1 part by weight). Is good.

In the step (b) of the present invention, when mixing the aluminum-based coupling agent and the fats and oils with the foaming agent powder, a mixing device that does not easily cause pulverization is used. Here, the mixing device that does not easily cause pulverization does not include a shearing blade, a high-speed rotating mixing blade, a pulverizing roll, and the like in the device, so that mixing can be performed without applying a large stress to the foaming agent powder itself. Device. Generally, when a large stress is applied to the blowing agent powder itself, the specific surface area of the blowing agent powder increases. In the present invention, the mixing is preferably performed under such mixing conditions that the rate of increase of the specific surface area of the foaming agent powder is 20% or less, preferably 10% or less. Specific examples of the mixing apparatus used in the present invention include, for example, a ribbon-type blender such as a ribocorn mixer, a screw-type mixer such as a Nauta mixer, and a pro-share mixer (with the chopper blade removed). Among these mixing devices, a ribbon type blender is particularly suitable.

In the present invention, in order to more uniformly mix the foaming agent powder with the aluminum-based coupling agent and the fats and oils, the mixing speed of the mixing apparatus used is set to a range in which pulverization of the foaming agent powder is suppressed. It is desirable to be fast enough. That is, under a mixing condition in which the pulverizing of the foaming agent powder does not occur, it takes a certain time so that the aluminum-based coupling agent and the fats and oils are uniformly applied to the foaming agent powder, in other words, so as not to cause variation. It is desirable to spray.

In the step (b) of the present invention, the foaming agent powder, the aluminum-based coupling agent and the fats and oils are mixed under heating from 55 ° C. to the decomposition temperature of the foaming agent.

The heating temperature is usually from 55 ° C. to the decomposition temperature of the blowing agent, but it is particularly preferable to perform the heating at a temperature of up to 100 ° C. in order to prevent decomposition and deterioration of the blowing agent. Furthermore, the heating temperature is preferably set to about 70 to 90 ° C. from the viewpoint of performing the mixing more efficiently by shortening the heating time and minimizing the energy cost.

In the method of the present invention, the treatment in the step (b) may be performed after the treatment in the step (a), or the treatment in the step (a) may be performed.
The processing of the step and the processing of the step (b) may be performed simultaneously.

More specifically, for example, as a mixing device, a conical ribbon mixing and drying machine having a capacity of 50 liters (trade name: Ribocorn ERME-50, manufactured by Okawara Seisakusho Co., Ltd.)
When using, the number of rotations is 40 to 100 rpm, the spraying speed of the aluminum-based coupling agent is 1 to 200 g / min (preferably 1 to 20 g / min), and the spraying speed of the fats and oils is 1 to
The mixing time is preferably 200 g / min (preferably 1 to 20 g / min) and the mixing time is 1 to 30 min. In addition, a conical ribbon mixing / drying machine with a capacity of 400 liters (trade name: Ribocorn E RM)
When E-400, manufactured by Okawara Seisakusho Co., Ltd.) is used, the number of rotations is 30 to 70 rpm, and the spray flow rate of the aluminum-based coupling agent is 10 to 2000 g / min (preferably 1
0 to 100 g / min), spraying speed of oils and fats 10 to 2000
g / min (preferably 10-100 g / min), mixing time 1
It is preferable to set it to 30 minutes.

The performance of the blowing agent powder of the present invention as a blowing agent is equal to or higher than that of a conventional blowing agent, and can be widely used in fields where the conventional blowing agent is used. The method of use is not different from the method of using a conventional foaming agent.

[0045]

The present invention will be described in more detail with reference to the following Examples, Comparative Examples and Test Examples.

ADCA used in this example is manufactured by Otsuka Chemical Co., Ltd. and has an average particle diameter of 20 μm.

Example 1 250 kg of ADCA was fed into a conical ribbon blender (product name: Ribocorn ERME-400, manufactured by Okawara Seisakusho)
While stirring at 70 rpm and 90 ° C. using aluminum tris (ethyl acetoacetate) (trade name: AL
CH-TR, manufactured by Kawaken Fine Chemical Co., Ltd.) 250
g of non-heated liquid paraffin (trade name: P-60, average carbon number 21, manufactured by Matsumura Petroleum Institute Co., Ltd.) 125 g simultaneously heated and melted at 90 ° C. and sprayed in the form of a mist using a two-fluid nozzle. (Spray flow rate of heat-dissolved aluminum tris (ethyl acetoacetate): 20
g / min, spraying speed of liquid paraffin: 10 g / min),
After completion of the addition, the mixture was further mixed under the same conditions for 7.5 minutes to obtain a foaming agent powder of the present invention.

Example 2 250 kg of ADCA was fed into a conical ribbon blender (product name: Ribocorn ERME-400, manufactured by Okawara Seisakusho)
With stirring at 70 rpm and 90 ° C.
250 g of aluminum tris (ethyl acetoacetate) (trade name: ALCH-TR, manufactured by Kawaken Fine Chemical Co., Ltd.) heated and melted at 200 ° C. by spraying in a mist using a two-fluid nozzle (heat-melted aluminum tris (ethyl Spray flow rate of acetoacetate): 20 g
/ Min), and after completion of addition, after mixing for 10 minutes under the same conditions,
While continuously mixing, 125 g of unheated liquid paraffin (trade name: P-60, average carbon number 21, manufactured by Matsumura Petroleum Institute Co., Ltd.) was added by spraying in the form of a mist using a two-fluid nozzle (spray flow rate of liquid paraffin) : 10 g / min)
After the addition was completed, the mixture was further mixed for 7.5 minutes to obtain a blowing agent powder of the present invention.

Example 3 250 kg of ADCA was fed into a conical ribbon blender (product name: Ribocorn ERME-400, manufactured by Okawara Seisakusho)
While stirring at 70 rpm and 90 ° C. using aluminum tris (ethyl acetoacetate) (trade name: AL
CH-TR, manufactured by Kawaken Fine Chemical Co., Ltd.) 250
g and 90 g of non-heated liquid paraffin (trade name: P-60, average carbon number 21, manufactured by Matsumura Petroleum Laboratories Co., Ltd.) are simultaneously added by dropwise addition of 125 g (heat-dissolved aluminum tris (ethyl Acetoacetate), the dropping rate of liquid paraffin: 10 g / min), and after the addition was completed, 7.5 under the same conditions.
The mixing was continued to obtain a blowing agent powder of the present invention.

Example 4 Aluminum tris (ethyl acetoacetate)
(Trade name: ALCH-TR, manufactured by Kawaken Fine Chemical Co., Ltd.) 250 g and liquid paraffin (trade name: P-6
0, average carbon number 21, manufactured by Matsumura Oil Research Institute Co., Ltd.) 50
0 g was mixed and heated to 90 ° C. to keep a solution. Next, while stirring 250 kg of ADCA using a conical ribbon type blender (product name: Ribocone RME-400, manufactured by Okawara Seisakusho) at 70 rpm and 90 ° C., aluminum tris (ethyl acetoacetate) prepared in advance and The mixture of liquid paraffin was added by spraying in the form of a mist using a two-fluid nozzle (spray flow rate of a mixture of aluminum tris (ethyl acetoacetate) and liquid paraffin: 20 g / min). Mixing was continued for 5 minutes to obtain a blowing agent powder of the present invention.

Example 5 250 kg of ADCA was fed into a conical ribbon blender (product name: Ribocorn ERME-400, manufactured by Okawara Seisakusho)
With stirring at 70 rpm and 90 ° C.
250 g of aluminum tris (ethyl acetoacetate) (trade name: ALCH-TR, manufactured by Kawaken Fine Chemical Co., Ltd.) heated and melted at 0 ° C. is added by spraying in the form of a mist using a pressure nozzle (heat-dissolved aluminum tris (ethyl Spray flow rate of acetoacetate): 40 g /
After the addition, the mixture was mixed under the same conditions for 10 minutes, and 125 g of unheated liquid paraffin (trade name: P-60, average carbon number 21, manufactured by Matsumura Oil Research Institute Co., Ltd.) was added while continuing to mix. By spraying in the form of a mist using a pressure nozzle (spray flow rate of liquid paraffin: 20 g / min),
After the addition, the mixture was further mixed for 7.5 minutes to obtain a foaming agent powder of the present invention.

Example 6 250 kg of ADCA was fed into a conical ribbon blender (product name: Ribocorn ERME-400, manufactured by Okawara Seisakusho)
With stirring at 70 rpm and 90 ° C.
500 g of aluminum tris (ethyl acetoacetate) (trade name: ALCH-TR, manufactured by Kawaken Fine Chemical Co., Ltd.) heated and melted at 0 ° C. by spraying in a mist using a two-fluid nozzle (heat-melted aluminum tris (ethyl Spray flow rate of acetoacetate): 20 g
/ Min), and after completion of addition, after mixing for 10 minutes under the same conditions,
While continuously mixing, 125 g of unheated liquid paraffin (trade name: P-60, average carbon number 21, manufactured by Matsumura Petroleum Institute Co., Ltd.) was added by spraying in the form of a mist using a two-fluid nozzle (spray flow rate of liquid paraffin) : 5 g / min)
After the addition was completed, the mixture was further mixed for 7.5 minutes to obtain a blowing agent powder of the present invention.

Comparative Example 1 An untreated blowing agent powder is referred to as Comparative Example 1.

Comparative Example 2 ADCA 250 kg was conical ribbon-type blender (product name: Ribocorn ERME-400, manufactured by Okawara Seisakusho)
While stirring at 70 rpm and 90 ° C. using aluminum tris (ethyl acetoacetate) (trade name: AL
CH-TR, manufactured by Kawaken Fine Chemical Co., Ltd.) 250
g is heated and dissolved at 90 ° C. only by spraying in the form of a mist using a two-fluid nozzle (spray flow rate of heat-dissolved aluminum tris (ethyl acetoacetate):
20 g / min), and after the addition was completed, mixing was continued for 7.5 minutes under the same conditions to obtain a foaming agent powder.

Comparative Example 3 A 250 kg ADCA was blended with a conical ribbon blender (product name: Ribocorn ERME-400, manufactured by Okawara Seisakusho)
Using a two-fluid nozzle, only 125 g of unheated liquid paraffin (trade name: P-60, average carbon number 21, manufactured by Matsumura Petroleum Laboratories Co., Ltd.) was stirred at 70 rpm and 90 ° C. using a two-fluid nozzle. The mixture was added by spraying (spray flow rate of liquid paraffin: 20 g / min). After the addition, mixing was continued for 7.5 minutes under the same conditions to obtain a foaming agent powder.

Comparative Example 4 100 kg of ADCA was mixed with a super mixer (product name: SM).
V-200, manufactured by Kawata Seisakusho) at 300 rpm,
While stirring at 90 ° C., 100 g of aluminum tris (ethyl acetoacetate) (trade name: ALCH-TR, manufactured by Kawaken Fine Chemical Co., Ltd.) was heated and dissolved at 90 ° C. and unheated liquid paraffin (trade name: P- 6
0, average carbon number 21, manufactured by Matsumura Oil Research Institute Co., Ltd.) 50
g at the same time as a mist using a two-fluid nozzle by spraying (spray flow rate of heat-dissolved aluminum tris (ethyl acetoacetate): 20 g / min, spray rate of liquid paraffin: 10 g / min), and after completion of the addition. Under the same conditions, mixing was further continued for 7.5 minutes to obtain a foaming agent powder.

Test Example 1 (Measurement of solidification property) The foaming agent powders obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were subjected to a deposition solidification test and an actual package solidification test by the following methods. . Table 1 shows the results.

(1) Deposition solidification test: 450 g sample
Into a 23 × 13 cm plastic bag, and after sufficient degassing,
Heat-sealed openings were overlaid, and a load of 0.216 kg / cm ² was applied from above. 14 days later,
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 value.

(2) Actual packaging solidification test: Sample 25k
g into a cardboard case, which is a product distribution package,
It was left for one month under the conditions of a temperature of 40 ° C. and a humidity of 80%, and then sieved with a 14-mesh sieve to measure the amount of non-passage, and the value calculated in% was determined as the solidification value. .

Test Example 2 (Measurement of Foaming Performance) Each of the foaming agent powders obtained in Example 1 and Comparative Example 1 was 15
In parts by weight, low density polyethylene (melt index
2.0) 100 parts by weight and dicumyl peroxide
A composition containing 8 parts by weight was rolled at a roll temperature of 110 to 115.
The mixture was kneaded while being heated at ℃, and was taken out as a sheet having a thickness of 5 mm, and heated at 125 ° C. for 5 minutes under a pressure of 120 kg / cm ² to obtain a pressed sheet. The obtained sheet was foamed using a hot air oven set at 220 ° C. Regarding the foam obtained using the foaming agent powder of any of Example 1 and Comparative Example 1, the cells were uniform and fine, and a good foam having almost the same surface smoothness and decomposition rate was obtained.

From these results, it can be seen that the blowing agent powder of the present invention has the same foaming performance as the untreated blowing agent powder.

Test Example 3 (Measurement of Dust Generation Rate) For each of the foaming agent powders of Examples 1 to 6 and Comparative Examples 1 to 4, 5 g of a sample was taken and measured at a flow rate of 20 liters / minute using a Heubach dust meter. At a time of 5 minutes, the dust generation rate (%) was measured. The results are shown in Table 1.

[0063]

[Table 1]

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshifumi Tate 615 Hanato, Satoura, Satoura-cho, Naruto City, Tokushima Prefecture Inside the Naruto Plant of Otsuka Chemical Co., Ltd. Inside Tokushima Factory

Claims (9)

[Claims] 1. A foaming agent powder in which the surface of the foaming agent powder is coated with aluminum hydroxide and at least one kind of fat or oil selected from the group consisting of liquid or solid fats and oils, hydrocarbons and fatty acids. 2. The blowing agent powder according to claim 1, wherein the particle diameter of the blowing agent powder is 1 to 100 μm. 3. The blowing agent powder according to claim 1, wherein the blowing agent is azodicarbonamide. 4. Production of a foaming agent powder in which the surface of the foaming agent powder is coated with aluminum hydroxide and at least one kind of fat or oil selected from the group consisting of liquid or solid fats and oils, hydrocarbons and fatty acids. (A) a step of adding an aluminum-based coupling agent and fats and oils to the foaming agent powder; and (b) grinding of the foaming agent powder under heating from 55 ° C. to the decomposition temperature of the foaming agent occurs. A method for producing a foaming agent powder, comprising a step of mixing a foaming agent powder, an aluminum-based coupling agent, and fats and oils under difficult mixing conditions. 5. The method according to claim 4, wherein the step (a) is a step of adding an oil or fat after adding an aluminum-based coupling agent to the foaming agent powder. 6. The method according to claim 4, wherein the step (a) is a step of simultaneously adding an aluminum-based coupling agent and fats and oils to the foaming agent powder. 7. The method according to claim 2, wherein the addition of the aluminum-based coupling agent and the fats and oils in the step (a) is carried out in the form of a mist.
7. The method according to 6. 8. The mixing conditions under which the powdering of the foaming agent powder in step (b) is unlikely to occur is such that the rate of increase of the specific surface area of the blowing agent powder is 20%.
%. The method according to any one of claims 4 to 7, wherein the mixing conditions are such that the amount is not more than%. 9. The method according to claim 4, wherein the mixing device used under the mixing condition in which the pulverizing of the blowing agent powder in the step (b) hardly occurs is a ribbon-type blender.