JP5612264B2 - Silicon-containing alloy for producing spherical silica powder, method for producing the same, and spherical silica powder - Google Patents

Description

  The present invention relates to a silicon-containing alloy for producing spherical silica powder that can provide spherical silica powder at a low cost, a method for producing the same, and an inexpensive spherical silica powder.

  A semiconductor package is generally sealed with a resin composition containing spherical silica for the purpose of improving thermal properties. In addition, a resin composition containing spherical silica may be employed for a substrate material for mounting electronic components for the purpose of improving thermal stability.

  The spherical silica used in these resin compositions is required not to adversely affect electronic components. For example, it is known that impurities contained in the spherical silica powder are adversely affected on the sealed electronic component by elution or diffusion.

  Conventionally, in order not to affect the electronic components, the amount of impurities contained in the spherical silica powder is reduced to obtain spherical silica having high purity. As a method for producing spherical silica powder, a method of reacting metal silicon as a raw material with oxygen in a flame (VMC method) is known, and in order to obtain high-purity spherical silica, the purity of the raw material is increased. And a method of extracting impurities from the spherical silica after production.

  Since this is a method that does not affect the properties of the produced spherical silica, a method for reducing the impurity concentration in the raw material is widely used. In order to apply to the method for producing spherical silica, various methods have been proposed as methods for producing high-purity metallic silicon (Patent Documents 1 to 3).

Japanese Examined Patent Publication No. 7-61856 Japanese Patent No. 2665437 Japanese Patent No. 3415382

  However, in the conventional manufacturing method, many man-hours are required to obtain high-purity metallic silicon, and high cost is required.

  The present invention has been completed in view of the above circumstances, and when applied to a sealing material, a spherical silica powder can be obtained that can obtain a spherical silica powder that does not adversely affect electronic components even if the purity of silicon is not high. It is an object to be solved to provide a silicon-containing alloy for use in the production of the same, a method for producing the same, and a spherical silica powder produced from such a silicon-containing alloy for producing the spherical silica powder.

The feature of the silicon-containing alloy for producing spherical silica powder according to claim 1 for solving the above-mentioned problem is a silicon-containing alloy which is a raw material for producing spherical silica powder by reacting with oxygen in a flame,
Contains 80% by mass or more of silicon, and the value of (Group 13 element content) / {(Group 5 element content) + (Group 6 element content) + (Group 7 element content)} mass The standard is 4 or more.

The feature of the silicon-containing alloy for producing spherical silica powder according to claim 2 for solving the above problems is a silicon-containing alloy which is a raw material for producing spherical silica powder by reacting with oxygen in a flame,
Contains 80% by mass or more of silicon, and the value of (Group 13 element content) / {(Group 5 element content) + (Group 6 element content) + (Group 7 element content)} mass The standard is 20 or more.

The feature of the silicon-containing alloy for producing spherical silica powder according to claim 3 for solving the above problem is a silicon-containing alloy which is a raw material for producing spherical silica powder by reacting with oxygen in a flame,
80% by mass or more of silicon, and the value of (group 13 element content) / {(vanadium content) + (chromium content) + (manganese content)} is 4 or more on a mass basis. There is.

A feature of the method for producing a silicon-containing alloy for producing spherical silica powder according to claim 4 for solving the above-mentioned problem is a method for producing the silicon-containing alloy for producing spherical silica powder according to any one of claims 1 to 3. And
Aluminum source made of metal aluminum, aluminum alloy and / or aluminum compound based on the sum of the content of group 5 element, group 6 element and group 7 element contained in the coarse material made of metal silicon or silicon-containing alloy based on mass And adjusting the value of (group 13 element content) / {(group 5 element content) + (group 6 element content) + (group 7 element content)}. It is in.

A feature of the method for producing a silicon-containing alloy for producing spherical silica powder according to claim 5 that solves the above problem is a method for producing the silicon-containing alloy for producing spherical silica powder according to any one of claims 1 to 3. And
An aluminum source made of metallic aluminum, an aluminum alloy and / or an aluminum compound is added to silica, and (group 13 element content) / {(group 5 element content) + (group 6 element content) + ( A step of preparing a raw material mixture in which the value of the group 7 element content)} is adjusted;
Reducing the raw material mixture with charcoal;
It is in having.

  The feature of the method for producing a silicon-containing alloy for producing spherical silica powder according to claim 6 for solving the above-mentioned problem is that in claim 5, the aluminum source is based on the sum of masses of the silica and the aluminum source. It exists in adding in the range of 0.1 mass%-20 mass%.

  The feature of the spherical silica powder according to claim 7 that solves the above problem is that the silicon-containing alloy for producing the spherical silica powder according to any one of claims 1 to 3 or the alloy according to any one of claims 4 to 6. The silicon-containing alloy for producing spherical silica powder produced by the method for producing the silicon-containing alloy for producing spherical silica powder is produced by reacting with oxygen in a flame.

  In the invention which concerns on Claim 1, according to content of a 5-7 group element, it becomes possible to exhibit a high performance by containing a 13 group element. If a Group 5-7 element is contained in the silica powder, there is a risk of elution. Eluted group 5-7 elements may have undesirable effects on electronic components, but reducing the risk of elution in group 5-7 elements by including group 13 elements at a predetermined ratio Can do. In particular, as in the invention according to claim 2, by increasing the ratio of the group 13 element, the influence of the group 5-7 element can be reduced more reliably.

  In the invention according to claim 3, the value of (group 13 element content) / {(vanadium content) + (chromium content) + (manganese content)} is particularly controlled to 4 or more. It is possible to provide a silicon-containing alloy for producing spherical silica powder that can produce a more excellent spherical silica powder. Since these elements are mainly used as impurity elements contained in the crude material, it is possible to simplify the measurement of the content of only these elements.

  In the invention which concerns on Claim 4, by adding aluminum sources, such as aluminum, an aluminum alloy, an aluminum compound, to metal silicon and a silicon containing alloy based on the quantity of the 5-7 group element to contain, it is 5-7. The influence of group elements can be reduced.

  In the invention according to claim 5, in the step of producing metal silicon and a silicon-containing alloy by reducing silica with a carbonizing agent, aluminum or aluminum is used depending on the amount of group 5-7 element contained in the silica. By adding an aluminum source such as an alloy or an aluminum compound, the influence of a group 5-7 element can be reduced. In particular, as in the invention according to claim 6, by defining the amount of the aluminum source, it becomes possible to reduce the influence of the group 5-7 elements.

  In the invention which concerns on Claim 7, it manufactures using the silicon-containing alloy for spherical silica powder manufacture manufactured by the manufacturing method of the above-mentioned silicon-containing alloy for spherical silica powder manufacture or the above-mentioned silicon-containing alloy for spherical silica powder manufacture. The effect of the group 5-7 elements is reduced because of the spherical silica made.

It is a graph which shows the relationship between EC of spherical silica powder and the mass ratio of a predetermined element in each test example of an Example.

  The silicon-containing alloy for producing spherical silica powder, the method for producing the silicon-containing alloy for producing spherical silica powder, and the spherical silica of the present invention will be described in detail below based on the embodiments.

  The silicon-containing alloy for producing spherical silica powder according to this embodiment is a raw material used in a method for producing spherical silica in which spherical silica powder is produced by reacting with oxygen in a flame. Hereinafter, an example of the method for producing spherical silica (VMC method) will be described.

  As a method for producing spherical silica, spherical silica is produced by the so-called VMC (Vaperized Metal Combustion) method using the aforementioned silicon-containing alloy (the silicon-containing alloy for producing spherical silica powder of this embodiment is used for this purpose). It is a manufacturing process. The silicon-containing alloy is pulverized by some method (such as pulverization). In the VMC method, a chemical flame is formed by a burner in an oxygen-containing atmosphere, and silicon-containing alloy powder is introduced into the chemical flame in such an amount that a dust cloud is formed, causing deflagration to produce oxide particles. How to get. Specifically, this is a step of introducing the aforementioned silicon-containing alloy into an oxygen-excess oxide flame together with a carrier gas.

The method of the VMC method will be described as follows. First, the container is filled with a gas containing oxygen as a reaction gas, and a chemical flame is formed in the reaction gas. The chemical flame can be formed by burning a combustible gas (a hydrocarbon gas such as methane or propane can be exemplified). Next, silicon-containing alloy powder is introduced into the chemical flame to form a dust cloud with a high concentration (500 g / m ³ or more). Then, thermal energy is given to the surface of the silicon-containing alloy powder by the chemical flame, the surface temperature of the silicon-containing alloy powder rises, and the vapor of metallic silicon spreads from the surface of the silicon-containing alloy powder to the surroundings. The metal silicon vapor reacts with oxygen gas to ignite and produce a flame. The heat generated by this flame further promotes vaporization of the silicon-containing alloy powder, and the generated metal silicon vapor and oxygen gas are mixed and propagated in a chain. At this time, the silicon-containing alloy powder itself is also broken and scattered to promote flame propagation. The product gas is naturally cooled after combustion, thereby forming a cloud of silica particles. The obtained silica particles are collected by a bag filter, an electric dust collector or the like.

  The VMC method uses the principle of dust explosion. According to the VMC method, a large amount of silica particles can be obtained instantaneously. The obtained silica particles are spherical silica powder having a substantially spherical shape. It is possible to adjust the particle diameter of the resulting spherical silica powder by adjusting the particle diameter of the silicon-containing alloy powder to be input, the input amount, the flame temperature, and the like. In addition to the silicon-containing alloy powder, silica powder can also be added as a raw material. The silica powder can maintain the performance of the spherical silica obtained by adopting the spherical silica powder obtained by this method.

  When the obtained spherical silica powder is mixed with a resin composition and used, surface treatment can be performed for the purpose of improving the adhesion to the resin. For example, various silane, titanate, aluminate and zirconate coupling agents, cations, anions, amphoteric and neutral surfactants can be mixed.

  In addition, surface treatment can be performed on the spherical silica with a basic substance and / or a basic mixture. Examples of basic substances and basic mixtures include ammonia, organic amines, silazanes, nitrogen-containing cyclic compounds or solutions thereof, amine-based silane coupling agents or solutions thereof, and the like. Of these basic substances, silazanes are preferably exemplified, and hexamethyldisilazane (HMDS) is particularly preferred.

  The amount of the surface treatment agent added during the surface treatment is not particularly limited, but it is desirable to add an amount that can react with the surface of the spherical silica.

  The silicon-containing alloy of the present embodiment contains 80% by mass or more of silicon. Preferably it contains 95 mass% or more of silicon. The silicon-containing alloy of the present embodiment contains an impurity element that is an element other than silicon. As the impurity element, the value of (Group 13 element content) / {(Group 5 element content) + (Group 6 element content) + (Group 7 element content)} is a predetermined value or more. Other than that, there is no particular limitation. As the predetermined value, 4 may be mentioned, and 20 is desirable. Examples of the method for measuring the content of impurity elements include elemental analysis methods such as XPS and ICP atomic absorption spectrophotometry.

  In order to control the abundance ratio of this element to a predetermined value or more, the amount of the group 13 element is increased with respect to the rough material (metal silicon or silicon-containing alloy) used as the raw material of the silicon-containing alloy for producing spherical silica powder. It is conceivable to reduce the amount of the group 5-7 element, but in order to simplify the operation, a method of adding the group 13 element according to the content of the group 5-7 element may be adopted. desirable.

  Here, the group 13 element includes boron, aluminum, gallium, indium, and thallium, but the group 13 element to be added is preferably boron, aluminum, gallium, or indium, and particularly preferably aluminum.

  In order to add a group 13 element, it can be added as a compound or a mixture as well as an element alone. For example, when aluminum is added, an aluminum-containing material (referred to as an aluminum source) made of metallic aluminum, an aluminum alloy and / or an aluminum compound can be added. As the aluminum alloy, one having a small content (preferably not containing) of a group 5-7 element is employed.

  Although it does not specifically limit as an aluminum compound, It is desirable to employ | adopt aluminum hydroxide and aluminum oxide which do not contain the extra element which is not contained in a silica. When adding a group 13 element, there are a method of adding it in the state of a silicon-containing alloy and a method of adding it at the stage of a material for producing the silicon-containing alloy.

  Instead of considering all the amounts of Group 5-7 elements, which are elements that are desirably low in content, only the sum of vanadium, chromium, and manganese can be considered. That is, a method of adding a group 13 element without considering the contents of elements other than vanadium, chromium, and manganese among the group 5-7 elements can be employed. Since these elements are particularly mixed compared to other elements, it is sufficiently practical to measure the content of only these elements. As a result, the manufacturing operation can be simplified.

  Other elements that should not be included as impurity elements include group 1 elements (particularly alkali metals such as Na and K) and group 2 elements (particularly alkaline earth metals such as Mg and Ca). In particular, it is desirable not to contain a group 1 element. The content of the Group 1 element is desirably 20 ppm or less (more preferably 10 ppm or less). The content of the Group 2 element is preferably 300 ppm or less, or even when it is contained more than that, it is desirable to add Ca so as to be 500 ppm or less. In addition, it is desirable that the contents of P and Mo are small. P is desirably 60 ppm or less. It is desirable that Mo be 20 ppm or less. Including other elements is not particularly disturbed. In particular, Fe, Ti, Cu, Ni, Co, Zn, As, Sb and the like can be contained to some extent.

  The silicon-containing alloy for producing spherical silica powder is manufactured by adjusting the impurity element concentration in the coarse material made of metal silicon or silicon-containing alloy, and after heating the mixture with silica stone and charcoal. It can be manufactured by the method to do. Silica, which is the main component of silica, is reduced by the charcoal to produce metallic silicon. It is desirable to use a silica stone with as few impurities as possible. And a group 13 element (aluminum source) can be added according to the quantity (or total of vanadium, chromium, and manganese) of the group 5-7 element in silica. Thereafter, the silicon-containing alloy in which the abundance ratio of the impurity element is controlled can be obtained by heating together with the charcoal. In addition, after preparing a silicon-containing alloy from silica, the amount of a group 5-7 element (or the sum of vanadium, chromium, and manganese) can be measured, and a group 13 element (aluminum source) can be added.

  Although it will not specifically limit if it is a material containing carbon as a charcoal agent, It is desirable to employ | adopt a thing with a high component ratio of carbon. For example, (petroleum) coke, charcoal, coal, etc. can be illustrated. It is desirable to select an impurity element in the charcoal that has a low content of Group 5-7 elements.

  The mixing ratio of the silica and the charcoal is not particularly limited, but it is desirable to mix an amount capable of sufficiently reducing silicon dioxide contained in the silica. Specifically, the mixing ratio of the charcoal is desirably about 40% by mass to 60% by mass based on the mass of silica.

  Silica and charcoal may be mixed in any way, but it is desirable that both be finely pulverized and mixed. For example, it is desirable to employ 50 cm or less as the particle size of silica and charcoal.

  After mixing the silica stone and the charcoal, heating (for example, heating by energizing) causes the carbon in the charcoal to react with oxygen in the silicon dioxide to produce a silicon-containing alloy. The produced silicon-containing alloy is desirably heated at 1420 ° C. or higher (particularly 1450 ° C. or higher), which is the melting point of metallic silicon. Moreover, it is desirable to heat at 1800 degrees C or less.

  The obtained silicon-containing alloy can segregate impurities by slow cooling. By removing segregated impurities, the content of impurities in the silicon-containing alloy can be reduced. Moreover, by applying an electric field to the silicon-containing alloy in a molten state, it becomes possible to segregate ionized elements among the contained impurity elements. By removing segregated impurities, the content of impurities can be reduced. It is desirable to stir when applying the electric field. In that case, stirring is performed in the central portion, and an electric field can be applied so that impurities move from the central portion toward the radially outer side.

  The silicon-containing alloy for producing spherical silica powder of the present invention, its production method, and spherical silica will be described in detail below based on examples.

(Manufacture of silicon-containing alloys for spherical silica powder production)
70 parts by mass of silica in each test example was mixed with 30 parts by mass of petroleum coke and metal aluminum in the amount of addition shown in Table 1 (based on the mass of silica), and the electric field was applied while maintaining at 1600 ° C. After sufficiently stirring, metallic silicon was obtained by slow cooling. The obtained metal silicon was pulverized to obtain a silicon-containing alloy powder for producing spherical silica powder having an average particle size shown in Table 1. The obtained silicon-containing alloy powder was put together with a carrier gas into an oxygen-excess oxide flame to obtain spherical silica powder having an average particle size and specific surface area shown in Table 2.

  The composition ratio, volume average particle diameter, specific surface area, electrical conductivity and pH of the extract were measured for the obtained silicon-containing alloy for producing spherical silica powder and spherical silica powder. The results of silicon-containing alloys for producing spherical silica powder are shown in Tables 1 and 2, and the results of spherical silica powder are shown in Tables 3 and 4, respectively. Further, the electrical conductivity (EC) in the spherical silica powder and the (group 13 element content) / {(group 5 element content) + (group 6 element content) + in the silicon-containing alloy for producing the spherical silica powder + A graph of the relationship with the mass ratio of the predetermined element represented by (Content of Group 7 element)} is shown in FIG.

  Regarding the electric conductivity and pH, each powder was suspended in ion-exchanged water and made into a 10% slurry, put in a pressure vessel, and shaken at room temperature for 30 minutes. Thereafter, the mixture was centrifuged and the supernatant was measured with a conductivity meter ES-51 manufactured by Horiba, Ltd. The conductivity of ion-exchanged water as a control was 1.4 μS / cm.

  As is clear from the results (particularly FIG. 1), it has been found that the EC decreases as the mass ratio of the predetermined element increases. In particular, it has been found that there is a critical value where the EC greatly changes from the vicinity of 4 to 20 in the mass ratio of the predetermined element. Moreover, it was found from the analysis of the content of each element that there are P, V, Cr, Mn, Mo, Ca, Na, Mg, and K as elements that have a large effect on EC. It has been found that as the amount of these elements increases, the EC also increases. Then, it was found that there are Al, Fe, Ti, Cu, Ni, Co, Zn, As, and Sb as elements having a small influence on EC (or EC can be reduced by addition).

  In addition, although electrical conductivity was similarly measured about the silicon containing alloy (Table 1), the clear relationship with the mass ratio of a predetermined element was not understood.

Claims (3)

A silicon-containing alloy that is a raw material for producing spherical silica powder by reacting with oxygen in a flame, containing silicon by 80% by mass or more, (group 13 element content) / {(group 5 element content ) + (Content of group 6 element) + (content of group 7 element)} is a method for producing a silicon-containing alloy for producing spherical silica powder having a value of 4 or more on a mass basis,
Measuring the content of the group 5 element, the group 6 element and the group 7 element contained in the rough material made of metal silicon or a silicon-containing alloy on a mass basis;
Aluminum source made of metal aluminum, aluminum alloy and / or aluminum compound based on the sum of the content of group 5 element, group 6 element and group 7 element contained in the coarse material made of metal silicon or silicon-containing alloy based on mass And adjusting the value of (group 13 element content) / {(group 5 element content) + (group 6 element content) + (group 7 element content)}. A method for producing a silicon-containing alloy for producing spherical silica powder. A silicon-containing alloy that is a raw material for producing spherical silica powder by reacting with oxygen in a flame, containing silicon by 80% by mass or more, (group 13 element content) / {(group 5 element content ) + (Content of group 6 element) + (content of group 7 element)} is a method for producing a silicon-containing alloy for producing spherical silica powder having a value of 4 or more on a mass basis,
A step of measuring the content of the Group 5 element, Group 6 element and Group 7 element contained in the silica on a mass basis;
An aluminum source made of metallic aluminum, an aluminum alloy and / or an aluminum compound is added to silica, and (group 13 element content) / {(group 5 element content) + (group 6 element content) + ( A step of preparing a raw material mixture in which the value of the group 7 element content)} is adjusted;
Reducing the raw material mixture with charcoal;
A method for producing a silicon-containing alloy for producing spherical silica powder, comprising:   The production of a silicon-containing alloy for producing spherical silica powder according to claim 2, wherein the aluminum source is added in a range of 0.1% by mass to 20% by mass based on the sum of masses of the silica and the aluminum source. Method.

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