JP2009298461A - Dry silica particle package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide dry silica particle package in which dry silica particles have a superior dispersibility into a resin even if its storage period is extended and an increase in viscosity is restricted, when the package is filled in resin. <P>SOLUTION: Dry silica particle is filled in and stored in a packaging container with a moisture vapor transmission of less than 1 (g/(m<SP>2</SP>×day), 40°C/90%RH) in order to restrict suction of moisture during its storage period. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dry silica fine particle package formed by enclosing dry silica fine particles in a packaging container, and more particularly to a dry silica fine particle package excellent in suppressing the occurrence of aggregation.

  2. Description of the Related Art In recent years, as electronic devices have become higher performance, smaller and lighter, semiconductor devices and semiconductor packages to be mounted have been highly integrated, miniaturized, and thinned. For this reason, the particle diameter of the filler added to the resin for semiconductor encapsulation tends to be gradually reduced, and dry silica fine particles having an average particle diameter of about 100 nm are sometimes used (for example, see Patent Document 1). .)

  Usually, it is different from the silica manufacturer and the person who prepares the resin composition, etc. (final user) regardless of whether it is a fine particle. The manufactured silica particles are subdivided into various packages after manufacture, and the silica manufacturer And distributors store the stock as so-called stock, and the required amount is often shipped according to the order from the end user. It may also be stored under the end user. This storage period can range from a few days to several years.

JP 2008-19157 A

  However, according to the study by the present inventors, the dry silica fine particles having an average particle diameter of about 100 nm as described above are used in the resin composition when the storage period is long compared to silica having other production methods and particle diameters. In this case, the viscosity increase range tends to increase, and finally it becomes difficult to use as a semiconductor sealing resin composition.

  Accordingly, an object of the present invention is to provide a dry silica fine particle package that is excellent in dispersibility in a resin even when the storage period is long, and that can suppress an increase in viscosity when filled in the resin.

  As a result of intensive studies to solve the above technical problems, the present inventors have promoted the aggregation of the dry silica fine particles and the water vapor present in the atmosphere in which the dry silica fine particles are preserved to form a resin composition. It was noticed that the increase in viscosity was increased. Thus, when storing dry silica fine particles, it was found that by increasing the water vapor permeability to a certain value or less, it was possible to suppress an increase in viscosity due to storage, and the present invention was completed.

That is, the dry silica fine particle package of the present invention is characterized in that the dry silica fine particles are sealed in a packaging container having a water vapor permeability of 1 (g / (m ² · day), 40 ° C./90% RH) or less. And

Further, it is particularly suitable for a package of dry silica fine particles having a BET specific surface area of 20 to 55 m ² / g. Furthermore, the packaging container is preferably an aluminum laminated bag.

The dry silica fine particle package of the present invention is a warehouse in which humidity is not controlled by making the package having a water vapor transmission rate of 1 (g / (m ² · day), 40 ° C./90% RH) or less. For example, even if it is stored for a long period of, for example, 6 months or more, an increase due to storage of the viscosity when the resin composition is formed can be suppressed.

  As dry silica in the present invention, a pyrogenic silica produced by thermally decomposing gas or sprayed liquid containing molecules containing Si atoms at high temperature in the gas phase, or metal silicon in a flame or in a high-temperature electric furnace Examples include silica produced by oxidation, or silica produced by once melting a siliceous powder such as pulverized quartz in a flame and re-solidifying it.

  Examples of gases or liquids composed of molecules containing Si atoms include silicon halides such as monochlorosilane, dichlorosilane, trichlorosilane, and tetrachlorosilane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexa Examples thereof include siloxanes such as methyldisiloxane and octamethyltrisiloxane.

  A method for producing pyrogenic silica using such a raw material is known. For example, JP 2008-19157A specifically describes an example of producing pyrogenic silica using siloxanes as a raw material. Has been.

The effect of the dry silica fine particles enclosed in the packaging container in the dry silica fine particle package of the present invention is greater when the dry silica fine particles have a BET specific surface area of 20 to 55 m ² / g. That is, dry silica fine particles having a BET specific surface area in the range of ²⁰ to 55 m ² / g are very prominent in aggregation, so that the viscosity increases during storage, and the packaging form as in the present invention becomes more important. . Examples of the dry silica having such a specific surface area range include silicas described in JP-A-2008-19157.

  Further, the dry silica fine particles enclosed in the packaging container of the dry silica fine particle package of the present invention may be surface-treated or not treated at all, but relatively absorbs moisture. It is easy to obtain the effect of the invention because it is easy to aggregate and thus is more prone to agglomeration upon storage, and is hydrophilic silica. Here, the hydrophilic silica refers to silica that can be completely mixed with water when mixed with water so that the silica concentration is 1.5% by weight.

  As such hydrophilic silica, those which are not surface-treated at all, mainly γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, Silane coupling agents having an epoxy functional group such as γ-glycidoxypropyltripropoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane And those treated with a silane coupling agent having a polar functional group such as a silane coupling agent having an amino group such as γ- (2-aminoethyl) aminopropylmethyldimethoxysilane.

The dry silica fine particle package of the present invention is formed by enclosing the dry silica fine particles as described above in a packaging container having a water vapor transmission rate of 1 (g / (m ² · day), 40 ° C./90% RH) or less. That is, when the water vapor transmission rate exceeds 1 (g / (m ² · day), 40 ° C./90% RH), aggregation of the dry silica fine particles cannot be suppressed, and the resin composition is obtained when the storage period is long. The viscosity increase width at the time tends to increase, and eventually it becomes difficult to use as a semiconductor sealing resin composition. In other words, in a packaging container having a water vapor transmission rate exceeding the above value, long-term storage with the initial performance maintained is difficult. The water vapor transmission rate is a value measured according to JIS-Z-0208.

The smaller the water vapor transmission rate, the longer it can withstand storage, but generally considering the required storage period, the cost required to reduce the water vapor transmission rate, the handleability of the package, etc., it is usually 0.001. ˜1 (g / (m ² · day), 40 ° C./90% RH), especially 0.2 (g / (m ² · day), 40 ° C./90% RH) or less. More preferred.

  Examples of such packaging containers include aluminum laminated bags and metal pail cans, but aluminum laminated bags are preferred in terms of economy, ease of handling of packaging containers, and storage space can be reduced. Specific examples of the aluminum laminated bag include lami zip AL series manufactured by Nippon Shokubai Co., Ltd., an aluminum laminated bag manufactured by Kite Chemical Industries, Ltd., a high barrier bag manufactured by Sunrise, and the like.

  The packing method of dry silica fine particles into the packaging container is a method using an automatic measuring instrument equipped with a quantitative supply device such as a screw feeder or a table feeder, and an operator uses a measuring scoop or the like to put a predetermined weight on the packaging container. A known filling method such as a method of filling dry silica fine particles until it becomes can be employed without any limitation.

  When the packaging container is a pail can with an inner bag, after twisting the end of the inner bag with the opening, it is fastened with vinyl tape or rubber band, and then the pail can lid is fastened to the specified A method of fixing with metal fittings can be adopted. At the time of this sealing operation, the effect of the present invention is more exhibited if the inside of the inner bag or the pail can is replaced with air or nitrogen having a dew point of −20 ° C. or lower before sealing. Moreover, when a packaging container is an aluminum laminated bag, the method of heat-sealing an opening part is employable. At the time of this sealing operation, the effect of the present invention is more exhibited if the inside of the aluminum laminated bag is replaced with air or nitrogen having a dew point of −20 ° C. or lower before sealing.

  Storage of the dry silica fine particle package produced by the above-described method poses no problem as long as it is stored in an environment where ordinary industrial products are stored, that is, in an environment where it is not exposed to wind and rain or direct sunlight. However, when the packaging container is an aluminum laminated bag, there is a possibility that the dry silica fine particles are consolidated by the load and aggregated particles are generated by stacking.

  Examples and comparative examples are shown to specifically describe the present invention, but the present invention is not limited to these examples.

  In addition, various physical property measurements in the following examples and comparative examples are based on the following methods.

(1) BET specific surface area measurement:
Using a specific surface area measuring device (SA-1000) manufactured by Shibata Rikagaku Co., the nitrogen adsorption BET one-point method was used.

(2) Average particle diameter It measured using the Horiba Seisakusho laser diffraction scattering type particle size distribution measuring device (LA-920).

(3) Viscosity characteristics of resin composition An epoxy resin composition was prepared as follows, and the viscosity characteristics of the resin composition were evaluated.

(Preparation of epoxy resin composition)
Dow Chemical's epoxy resin ERL-4221 and dry silica fine particles were blended at a ratio of 1: 1 (weight ratio), and a rotation time and planetary mixer (Sinky AR-250) was used, and the stirring time was 3 minutes. An epoxy resin composition was obtained by kneading under these conditions.

(Viscosity measurement)
Using a Brookfield viscometer (BROOKFIELD DV-2 + VISCOMETER, spindle: S51), the temperature was measured at 25 ° C. and the spindle rotation speed was 3 rpm.

Example 1
A dry silica fine particle having a BET specific surface area of 30 m ² / g, an average particle size of 0.11 μm, and an epoxy resin composition viscosity of 4800 mPa · s, produced by the method described in JP-A-2008-19157, has a water vapor transmission rate of 0.1. It was sealed in an aluminum laminate bag of 1 (g / (m ² · day), 40 ° C./90% RH) and allowed to stand in an air atmosphere for 6 months. After 6 months, the BET specific surface area was 30 m ² / g, the average particle size was 0.11 μm, and the viscosity of the epoxy resin composition was 4800 mPa · s. No change over time due to storage was observed.

Comparative Example 1
The same dry silica fine particles as in Example 1 were sealed in a polyethylene bag having a water vapor transmission rate of 4 (g / (m ² · day), 40 ° C./90% RH) and allowed to stand in an air atmosphere for 6 months. After 6 months, the BET specific surface area was 30 m ² / g, the average particle size was 0.21 μm, the viscosity of the epoxy resin composition was 11000 mPa · s, and the occurrence of aggregation due to storage and the increase in the viscosity of the resin composition were observed. .

Claims (3)

A dry silica fine particle package in which dry silica fine particles are sealed in a packaging container having a water vapor transmission rate of 1 (g / (m ² · day), 40 ° C./90% RH) or less. The dry silica fine particle package according to claim 1, wherein the dry silica fine particles have a BET specific surface area of 20 to 55 m ² / g.   The dry silica fine particle package according to claim 1, wherein the packaging container is an aluminum laminated bag.