JP6474195B2 - Highly filling boehmite and method for producing the same - Google Patents

Description

  The present invention relates to boehmite that maintains a high decomposition temperature of boehmite and has improved fillability to an object to be filled, and a method for producing the boehmite.

In recent years, as electronic components have been densely integrated and densely packaged, heat generation of electronic components has increased, and electronic components are required to have improved low-expansion and high thermal conductivity properties as well as high flame resistance. ing. In addition, the heat-resistant temperature (thermal decomposition temperature) of heat-resistant resins such as polyimide used for insulating base materials for electronic circuit materials, polybenzimidazole used for electrical and electronic parts, and aramid resin used for aircraft reinforcements is It exceeds 500 ° C.
Conventionally, an inorganic material may be filled as a flame retardant in order to impart flame retardancy to an object to be filled such as a resin. In particular, since the decomposition temperature of boehmite is as high as around 500 ° C., it is suitable as a flame retardant for a resin for a substrate and a flame retardant for a heat-resistant resin that must withstand the soldering temperature. Boehmite is used as a filler for flame retardants such as resins, rubbers and substrates, as well as low expansion agents, thermal conductive agents, high-temperature catalyst carriers, paper coating coating fillers, paint pigments and the like. In order to fill the filling material with boehmite and obtain a desired effect, it is necessary to improve the filling property to the filling material. As such boehmite, there is a proposal of cubic boehmite with high filling properties (Patent Document 1).

JP 2009-126735 A

  However, in order to improve various characteristics of the filling material, it is necessary to further increase the filling properties of boehmite. Further, when considering the heat resistance temperature (thermal decomposition temperature) of the above heat resistant resin, it is necessary to maintain the high decomposition temperature of boehmite and improve the filling property of boehmite.

  This invention is made | formed in view of said situation, and makes it a subject to provide the boehmite with which the high decomposition temperature of boehmite was hold | maintained, and the filling property was improved, and its manufacturing method.

In order to solve the above problems, the present inventors have made various studies and arrived at the present invention. That is, the present invention is a boehmite obtained by pulverizing using glass beads so that the raw material boehmite in a cubic shape becomes too fine and the fine particles are not aggregated to form excessive coarse particles. Boehmite characterized by having a center particle size of 1.84 to 4.49 μm, a BET specific surface area of 1.08 to 3.27 m ² / g and an oil absorption amount of 27 to 31 ml / 100 g in accordance with JIS K5101. The manufacturing method is the gist. Also, the boehmite of the raw material having a rhombus shape becomes too fine, and is pulverized with glass beads so that the fine particles are not aggregated to form large coarse particles. And a BET specific surface area of 3.34 m ² / g and an oil absorption according to JIS K5101 of 33 ml / 100 g. Also, the boehmite used as a raw material in the form of a plate becomes too fine and is pulverized with glass beads so that the fine particles do not aggregate and form large coarse particles. And a BET specific surface area of 2.48 m ² / g and an oil absorption according to JIS K5101 of 37 ml / 100 g. Also, the boehmite of the raw material forming the scale shape becomes too fine, and the fine boehmite is pulverized with glass beads so that the fine particles are not aggregated to form large coarse particles. The main point is a method for producing boehmite, characterized in that the oil absorption is 1.38 to 4.72 μm, the BET specific surface area is 3.48 to 19.84 m ² / g, and the oil absorption according to JIS K5101 is 69 ml / 100 g. .

  Since the high-fillability boehmite of the present invention has a high filling property to the filling material, it can highly impart high flame retardancy, low expansion, and high thermal conductivity of the characteristics of boehmite to the filling material, and the high decomposition temperature of boehmite. Is particularly useful for increasing the flame retardancy of electronic parts and heat-resistant resins.

  The method for producing highly filled boehmite of the present invention can easily produce highly filled boehmite simply by pulverizing raw material boehmite under predetermined pulverization conditions.

  The highly filled boehmite of the present invention can be produced by pulverizing raw material boehmite. Boehmite as raw material is boehmite obtained by hydrothermal synthesis from aluminum hydroxide, boehmite obtained by hydrothermal synthesis by adding additives to aluminum hydroxide, boehmite precursor synthesized from various aluminum salts and aluminum alkoxides Boehmite obtained by synthesis from boehmite, boehmite obtained by hydrating transition alumina by hydrothermal treatment, boehmite obtained by synthesis from aluminum dawsonite, natural boehmite and the like. The raw boehmite may be any shape such as cubic, rhombus, plate, scale, or needle.

The raw boehmite can be pulverized by a known pulverization method. Examples of the apparatus used for wet pulverization include a media medium type pulverizer such as a bead mill, a ball mill, an attritor, a paint shaker, and a sand mill, and a collision type apparatus. Examples of the apparatus used for the dry pulverization include a jet mill pulverizing apparatus and a nano grinding mill pulverizing apparatus. Among these, a bead mill is preferable in terms of filling properties because the raw boehmite can be pulverized into particles having rounded corners. The media used for the bead mill may be glass beads, zirconia beads, alumina beads, tungsten beads, or the like, with glass beads being preferred. This is because the hardness of the glass is close to the hardness of boehmite, and it is easy to set the pulverization conditions so that the raw boehmite does not overgrind (boehmite Mohs hardness: 3.5, glass Mohs hardness: 5). When other media are used, since the hardness is higher than boehmite, it may be difficult to set pulverization conditions that do not cause excessive pulverization (Morse hardness of zirconia: 8, Mohs hardness of alumina: 9, Mohs hardness of tungsten: 7 .5).
Here, over-pulverization means that boehmite obtained by pulverizing raw material boehmite becomes too fine, and the fine particles aggregate to form large coarse particles, which leads to a decrease in the filling property to the filling material. Or pulverization that causes a decrease in the decomposition temperature of boehmite. The diameter of the media is preferably 0.02 to 0.2 mm. If the diameter of the media is smaller than 0.02 mm, boehmite will not be sufficiently pulverized, and separation of boehmite from the media will be difficult. If larger than 0.2 mm, excessive pulverization will occur. is there. When wet pulverization is performed, the highly filled boehmite of the present invention can be obtained by drying the pulverized boehmite.

The high-filling boehmite of the present invention is preferably 105% to 300%, more preferably 105% to 220% of boehmite whose specific surface area is not pulverized. The specific surface area is a value indicating the kneading ability of boehmite into the filling material, and the specific surface area of less than 105% means that the pulverizing treatment is insufficient and the filling property of the high filling boehmite to the filling material is high. Is insufficient, and a specific surface area of more than 300% suggests that the raw boehmite is overmilled. Moreover, it is preferable that the high filling boehmite of this invention is 97% or less of the boehmite which does not grind | pulverize the oil absorption amount based on JISK5101. The oil absorption is a value that is an index of the kneading ability of boehmite into the filling material, and the oil absorption is higher than 97% suggests that the raw boehmite is excessively pulverized. A low oil absorption means that boehmite is easily kneaded into the filling material, so a lower oil absorption is preferable. In addition, the high-filling boehmite of the present invention is preferably 97% to 100% of boehmite whose 1% dehydration temperature is not pulverized. This is because a 1% dehydration temperature lower than 97% is not preferable in view of the high heat resistance required for a resin filled with highly fillable boehmite. Here, 1% dehydration temperature refers to the temperature at which 1% by weight of boehmite dehydrates with respect to its total weight, and is an index for evaluating the decomposition temperature of boehmite. Moreover, it is preferable that the high filling boehmite of this invention is 10 < 5 >% or more of the boehmite with which the filling amount of the boehmite with respect to a resin composition is not grind | pulverized. This is because when the filling amount is lower than 10 5 %, the characteristics of the resin composition cannot be sufficiently improved. Furthermore, an important factor in also improving the kneading property to the filling of the boehmite may not cause coarse grains by pulverization. The coarse particles mentioned here mean secondary particles of 10 μm or more formed by agglomeration of over-milled boehmite particles. When such coarse particles are present, the specific surface area and the oil absorption amount are increased, the kneading ability to the filling material is lowered, and the 1% dehydration temperature is also lowered. In order to prevent generation of coarse particles in the high-filling boehmite of the present invention, the specific surface area or the oil absorption amount preferably satisfies the above value.

  The highly fillable boehmite of the present invention can be suitably filled into a resin composition, particularly a substrate, a semiconductor package or an industrial resin material. Here, the industrial resin material is a resin material that requires corrosion resistance, chemical resistance, workability (particularly cutting, bending, welding) and the like, and examples thereof include an industrial plate. The resin used in the resin composition is not particularly limited, but is not limited to epoxy resin, silicone resin, melamine resin, urea resin, phenol resin, unsaturated polyester, fluororesin, polyimide, polyamideimide, polyetherimide, nylon or other polyamide, poly Polyester such as butylene terephthalate, polyethylene terephthalate, polybenzimidazole, aramid resin, polyphenylene sulfide, wholly aromatic polyester, liquid crystal polymer, polysulfone, polyethersulfone, polycarbonate, maleimide modified resin, ABS resin, acrylonitrile-acrylic rubber / styrene resin, General-purpose resin such as acrylonitrile, ethylene, propylene, diene rubber-styrene resin, polyethylene, polypropylene, polyvinyl chloride, polystyrene The can be exemplified.

  EXAMPLES Next, although an Example is given and this invention is demonstrated, this invention is not limited to a following example.

[Example 1-1 to Example 11] and [Comparative Example 1, Comparative Example 2]
Slurry of raw material boehmite (BMT-3LV, BMT-5LV, BMB-2, BMT-33, BMF-240, BMF-520, manufactured by Kawai Lime Industry Co., Ltd.) with a predetermined water ratio (weight ratio of boehmite to water) ). The obtained slurry was pulverized with boehmite using a bead mill (Star Mill ^™ Nano Getter ^™ , manufactured by Ashizawa Finetech Co., Ltd.). The filling amount of the beads was 40 vol% with respect to the volume of the slurry filled in the vessel. As beads, Example 5 and Comparative Example 2 used zirconia beads, and others used glass beads. The diameter of the beads was 0.05 mm in Example 2-1 and Example 2-2, and 0.1 mm in the other cases. Other pulverization conditions were set as shown in Table 1. Moreover, only in Example 11, a predetermined slurry was put in a 500 ml container and pulverized for 6 hours by a rolling ball mill. The filling amount of the beads was 40 vol% with respect to the volume of the slurry filled in the container. The comparative example 1 is different only in that the number of processes in the fourth embodiment is 1 pass compared to 5 passes. Further, the comparative example 2 is different only in that the number of processes in the fifth embodiment is 1 pass while it is 5 passes. In addition, the blank of Table 1 does not grind raw material boehmite.

The analytical values shown in Table 1 were measured for the boehmite dried after pulverization and blank boehmite.
The measuring method is as follows.
Central particle size: Measured with a particle size distribution measuring device (Microtrac MT3000, manufactured by Nikkiso Co., Ltd.), and the value of D50 was read.
Oil absorption: Oil absorption was determined according to JIS K5101 13-1.
Epoxy filling amount: 30 g of liquid epoxy resin (DER ^TM 331J, manufactured by The Dow Chemical Company) was weighed into a paper cup, and 10 g of boehmite was gradually added thereto. In each case, the liquid epoxy resin and boehmite were kneaded with a planetary stirrer (Awatori Nertaro ^™ , ARE-310, manufactured by Shinkey Co., Ltd.). This was repeated, and the sample was added and kneaded until the fluidity of the liquid epoxy resin and boehmite was reduced. Thereafter, boehmite was added in an amount of 1 g, and the mixture was completely kneaded. The end point of the boehmite kneading was defined as the end point of the boehmite kneading when the fluidity of the paste disappeared, and the value of the epoxy resin filling amount. This paste should not break or become crumbly.
Specific surface area: Using a fully automatic specific surface area measuring device (Macsorb ^™ HM-model 1208, manufactured by Mountec Co., Ltd.), measurement was performed by the BET method after pretreatment at 150 ° C. for 30 minutes.
1% dehydration temperature: Measured with a differential thermal and thermogravimetric simultaneous measurement device (TG-DTA 2000SA, manufactured by Bruker AXS Co., Ltd.). The temperature increase rate was 30 ° C./min, and the temperature decreased by 1.00% by weight with respect to 100 ° C. was read.

Table 1 shows the following.
The raw boehmite was able to obtain highly filled boehmite regardless of the shape such as a cubic shape and a rhombus shape. The larger the bead diameter, the smaller the boehmite particle size and the larger the specific surface area (see Example 1-1 and Example 2-1, Example 1-2 and Example 2-2). As the number of grinding treatments was increased and the peripheral speed of the bead mill was increased, the particle size of boehmite was reduced and the specific surface area was increased (see Example 1-1 to Example 6-2). When glass beads and zirconia beads were pulverized under the same pulverization conditions, the use of zirconia beads reduced the particle size of boehmite and increased the specific surface area (see Examples 1-1 and 5).
In the examples, the specific surface area is in the range of 105% to 300% of the blank, the oil absorption is 97% or less of the blank, the 1% dehydration temperature is in the range of 97% to 100% of the blank, and the epoxy filling amount. Was 104% or more of the blank. On the other hand, in Comparative Example 1, the specific surface area is 516% of the blank, the oil absorption is 109% of the blank, the 1% dehydration temperature is 95% of the blank, about 21 ° C., and the epoxy filling amount is 94%, which is lower than the blank. Was. In Comparative Example 2, the specific surface area is 426% of the blank, the oil absorption is 103% of the blank, and the epoxy filling amount exceeds 102% and 100% of the blank, but the 1% dehydration temperature is 95% of the blank. It was below about 22 ° C.

  Since the high filling boehmite of the present invention can improve the filling property to the filling material, it can improve the properties of the filling material such as flame retardancy, low expansion property, thermal conductivity, This is particularly useful in the field of electronic components such as semiconductor packages and the field of industrial resin materials.

Claims (4)

The boehmite, which is a raw material in the form of a cube, becomes too fine and is pulverized using glass beads so that the fine particles do not aggregate to form large coarse particles. The resulting boehmite has a center particle size of 1 .84 to 4.49 μm, BET specific surface area of 1.08 to 3.27 m ² The boehmite production method is characterized in that the oil absorption amount according to JIS K5101 is 27 to 31 ml / 100 g. The raw boehmite in the shape of rhombus becomes too fine and is pulverized with glass beads so that the fine particles do not aggregate and form large coarse particles, and the resulting boehmite has a central particle size of 1 .53 μm, BET specific surface area of 3.34 m ² / G and the oil absorption amount based on JIS K5101 is 33 ml / 100g, The boehmite manufacturing method characterized by the above-mentioned. The boehmite as a raw material in the form of a plate becomes too fine and is pulverized with glass beads so that the fine particles are not aggregated to form large coarse particles. The resulting boehmite has a center particle size of 2 .65 μm, BET specific surface area of 2.48 m ² / G and the oil absorption amount based on JIS K5101 is 37 ml / 100g, The boehmite manufacturing method characterized by the above-mentioned. The boehmite, which is a raw material in the form of scaly, becomes too fine and is pulverized with glass beads so that the fine particles are not aggregated to form large coarse particles. The resulting boehmite has a central particle size of 1 .38 to 4.72 μm, BET specific surface area of 3.48 to 19.84 m ² / G and a boehmite manufacturing method, wherein the oil absorption according to JIS K5101 is 69 ml / 100 g.