JP6265673B2 - Method for producing inorganic particle material-containing composition - Google Patents

Description

The present invention relates to a method for producing inorganic particulate material-containing composition.

  Conventionally, a resin composition in which an inorganic particle material made of silica, alumina or the like is dispersed as a filler in a resin such as a thermosetting resin, and a cured product thereof are known. By including an inorganic particle material in the resin, the heat resistance of the cured product can be improved, or the physical strength can be improved. (Refer patent document 1 etc.). Here, there is a composition in which a filler is dispersed in an organic solvent for the purpose of mixing the filler in the resin.

JP 2011-256243 A

  There are applications in which the particle size of the filler dispersed in the resin composition needs to be precisely controlled. For example, it may be desirable to limit the content of coarse particles as one of the particle size controls. The control of the particle size is generally realized as a classification operation. There are various types of classification operations, such as dry and wet, but it is desirable to carry out classification in order to perform precise classification. In the dry method, particles are agglomerated and classification is difficult, and even if classification is possible, in the case of fine particles, agglomeration etc. progresses until the resin composition is prepared thereafter, resulting in large particles This is because there is a possibility of being regenerated.

  As the classification operation, sieving is preferable in which a predetermined opening is set and particles larger than that in principle cannot pass through, and the restriction of coarse particles can be performed precisely in principle. However, wet sieving greatly changes the ease of classification depending on the viscosity of the sieving object. Specifically, classification is easier when the viscosity is smaller.

  The organic solvent added to classify the inorganic particulate material in a wet manner is not a problem if it is an essential component in the final application (for example, resin composition), but if it is not an essential component, it is removed after classification. It needs to be reduced. Here, it is very difficult to remove the solvent once contained. For example, when the solvent contained is evaporated / removed by decompression or heating, the dispersed inorganic particle material aggregates due to the influence of heat applied at the time of removal and particles having a large particle size (coarse particles) are generated. Sometimes. Also, it is difficult to remove with good reproducibility not to remove all the solvent contained but to leave a controlled and constant proportion of solvent. Therefore, it is desirable to reduce the amount of the solvent contained from the beginning.

This invention is made | formed in view of the said situation, and makes it the subject which should be solved to provide the manufacturing method of the inorganic particle material containing composition which can also reduce the quantity of the organic solvent to contain.

(A) As a result of intensive studies, the present inventors can greatly reduce the viscosity of the resulting mixture by mixing a resin material with a mixture of an inorganic particle material and an organic solvent, It was found that precise classification can be realized by sieving in the state. The present invention has been completed based on the above findings.

The method for producing an inorganic particle material-containing composition of the present invention includes a mixing step of mixing an inorganic particle material, an organic solvent, and a resin material that can be mixed with the inorganic particle material and the organic solvent into a mixture;
A classification step of classifying the mixture;
Have

  The following configuration (b) and / or (c) can be added to the invention (a).

(B) The content of the organic solvent in the mixture is more than the amount that can be classified in the classification performed in the classification step in which the inorganic particle material and the organic solvent are mixed except the resin material. Small amount. By adopting this configuration, the amount of organic solvent added can be minimized.

(C) Classification performed in the classification step is sieving. The classification operation that can be adopted in the classification process is performed by sieving and using the difference in the sedimentation speed of particles (the larger the particle size, the faster the sedimentation) (the sedimentation may be caused to proceed by gravity or by centrifugal force) However, it is desirable to employ a sieving method that enables classification with high accuracy by controlling the size of the openings. Here, sieving is a means for classification depending on whether or not it passes through a sieve having a certain mesh, and as the sieve, it is sufficient if the size of the mesh is controlled, Examples thereof include a cloth, a nonwoven fabric, a porous body, a punching metal, and a column filled with a granular material with a controlled particle size.

In the method for producing the inorganic particle material-containing composition of the present invention, the amount of the solvent to be contained can be reduced.

The method for producing the inorganic particle material-containing composition of the present invention will be described in detail below based on the embodiment. The inorganic particle material-containing composition produced by the production method of the present embodiment can stably exist in a state where the particle size of the inorganic particle material contained is appropriately controlled. This inorganic particle material-containing composition can be used by mixing with a resin material or the like. When a resin composition is mixed with a resin material, it can be used as a sealing material for sealing a semiconductor element in a semiconductor device, an underfill material filled between a semiconductor element and a substrate, or the like. The resin material finally mixed and the resin material contained in the inorganic particle material-containing composition of the present embodiment may be the same or different, but it is desirable that the resin material has high affinity. .

[Method for producing inorganic particle material-containing composition]
The method for producing the inorganic particle material-containing composition of the present embodiment includes (A) a mixing step, (B) a classification step, and other necessary steps. The mixture obtained in the mixing step is classified in the classification step and the amount of coarse particles contained is controlled.

(A) Mixing step In the mixing step, the inorganic particle material, the resin material, and the organic solvent are mixed so as to have a required ratio. By mixing the resin material, the viscosity of the mixture can be reduced while maintaining the ratio between the inorganic particle material and the organic solvent. Therefore, in order to achieve the same level of viscosity in the mixture, the organic solvent can be obtained by adding the resin material. Can be relatively reduced.

  The method for mixing the inorganic particle material, the organic solvent, and the resin material is not particularly limited. For example, it can be mixed and dispersed by a known stirrer / kneader. Further, the order of mixing is not particularly limited.

  The mixing amount of the inorganic particle material, the organic solvent, and the resin material is not particularly limited. It is desirable that the organic solvent is as small as possible. For example, the inorganic particle material can be 65% or more, further 70% or more, 75% or more, or 80% or more based on the total sum of the mixture of the inorganic particle material and the organic solvent. The amount of the organic solvent can be set such that it cannot be classified in the classification step described later when mixed with the inorganic particulate material. Here, when classification is not possible in the classification process, when sieving is adopted as the classification process, when it cannot pass through the adopted sieve, when classification is performed due to a difference in sedimentation speed, it is within a realistic time (for example, A case where a single classification operation cannot be performed within 24 hours) can be exemplified. Moreover, the case where a viscosity is 120 mPa * s or more can also be employ | adopted as a case where classification cannot be performed. As a preferable lower limit of the viscosity, 150 mPa · s, 175 mPa · s, 200 mPa · s, 225 mPa · s, 250 mPa · s, 275 mPa · s, 300 mPa · s, and 325 mPa · s can be exemplified.

  Here, the viscosity presented in the present specification is a value measured with a vibrating viscometer (Viscomate VM-1G, manufactured by Yamaichi Electronics Co., Ltd.) on a sample set at 25 ° C.

  It is sufficient that the resin material is added in such an amount that the viscosity of the mixture is lowered. Even if a resin material of a certain amount or more is added, not only a further decrease in the viscosity is not observed, but also the viscosity of the resin material itself is approached. In many cases, the viscosity tends to increase after the viscosity once decreases (after having the minimum value of the viscosity) as the addition of the resin material increases. Therefore, it is desirable that the amount of the resin material added is close to the minimum value of the viscosity.

  For example, the addition amount of the resin material can be about 1% to 30% based on the sum of the mixture of the inorganic particle material, the organic solvent, and the resin material. Examples of the lower limit of the amount of resin material added include 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, and 13%. Can be 25%, 22.5%, 20%, 18%, 16 %%.

-Inorganic particle material The inorganic particle material is not particularly limited. For example, silica, alumina (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), zeolite, titanium oxide (TiO ₂ ), aluminum nitride (AlN), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), titanic acid Barium (BaTiO ₃ ), strontium titanate (SrTiO ₃ ), calcium titanate (CaTiO ₃ ), aluminum borate, boronite, calcium carbonate, lead oxide, tin oxide, cerium oxide, calcium oxide, trimanganese tetraoxide, magnesium oxide These oxide complex oxides, cerium zirconate, calcium silicate, zirconium silicate, ITO, titanium silicate, and metals can be used alone or in combination. In particular, it is desirable to employ an inorganic particle material having a high sphericity (for example, a sphericity of 0.8 or more, 0.9 or more, or 0.95 or more) from the viewpoint of reducing the viscosity of the mixture. The sphericity is measured by taking a photograph with an SEM, and calculating from (Sphericality) = {4π × (Area) ÷ (Ambient Length) ² } from the area and circumference of the observed particle. calculate. The closer to 1, the closer to a true sphere. Specifically, an average value measured for 100 particles randomly extracted using an image processing apparatus (Sysmex Corporation: FPIA-3000) is employed.

  If the viscosity decreases, a larger amount of inorganic particle material can be contained. The particle size of the inorganic particle material is not particularly limited, but the volume average particle size can be about 0.1 μm to 30 μm. Further, as the desirable particle size, the upper limit is 20 μm, 15 μm, 10 μm, 5 μm, 3 μm, 2 μm, and the lower limit is 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, Examples thereof include 0.8 μm and 1.0 μm. Furthermore, it is desirable to classify and remove coarse particles as much as possible before subjecting to the mixing step.

  The inorganic particle material may be subjected to some surface treatment. By performing the surface treatment, the affinity with the resin material when mixed with the resin material later is adjusted, or the dispersibility in the organic solvent is adjusted. As the surface treatment, for example, the surface treatment can be performed with a silane coupling agent or an organosilazane. Silane coupling agents and organosilazanes are hydrocarbon groups (alkyl groups, alkenyl groups, vinyl groups, phenyl groups, etc.), OH groups, amino groups, organic acid groups (carboxy groups, etc.), epoxy groups, glycidoxy groups, acryloxy groups, It can have a functional group such as a methacryloxy group, a styryl group, an alkoxy group, a ureido group, an isocyanate group, a sulfide group, a mercapto group.

-Organic solvent It does not specifically limit as an organic solvent. Methyl ethyl ketone, alcohol (methanol, ethanol, propanol, etc.), acetone, acetonitrile, hexane, xylene, toluene, ether (diethyl ether, tetrahydrofuran, etc.), organic acid (acetic acid, formic acid, etc.), carbonate, alkyl acetate (methyl acetate, ethyl acetate) Etc.), dimethylformamide, dimethyl sulfoxide and the like.

-Resin material Any resin material that can be dissolved or mixed in the organic solvent described above may be used. That is, any material having fluidity when the mixture is formed may be used. For example, a liquid resin material from the beginning or a material that becomes fluid when dissolved can be employed. Specifically, it may be a thermoplastic resin or a material before being cured by a curing reaction performed later.

  Any resin material may be used as long as it has fluidity at the operating temperature. Examples of the resin material that has fluidity include, for example, a thermoplastic resin that can be used at a temperature equal to or higher than the melting point of the thermoplastic resin, or a material that cures by a subsequent curing reaction. .

  Specifically, it has a polymer material and / or a precursor of the polymer material. The polymer material precursor is a polymer or a low-molecular material, and is a material that can form a cured product by further increasing the molecular weight or proceeding cross-linking as the reaction proceeds. Examples of the cured material formed from the polymer material and the polymer material precursor may include general resin materials such as a thermoplastic resin, a thermosetting resin, and a photocurable resin. The polymer material precursor may have an epoxy group, an oxetane group, a hydroxyl group, a blocked isocyanate group, an amino group, a half ester group, an amic group, a carboxy group, and a carbon-carbon double bond group in the chemical structure. desirable. These functional groups are functional groups (polymerizable functional groups) that can be bonded to each other by setting suitable reaction conditions, and the molecular weight of the mixed material can be improved. Suitable reaction conditions include simple heating and light irradiation, generation of reactive species such as radicals and ions (anions and cations) by heat and light irradiation, and a reaction initiator that binds between these functional groups. (Polymerization initiator) is added and heating or light irradiation is performed. A compound necessary for the polymerization reaction can be added as a curing agent, or a catalyst for the reaction can be added.

  Preferred examples of the polymer material precursor include a monomer that forms a polymer material by polymerization and a polymer material modified with a polymerizable functional group as described above. For example, a prepolymer such as an epoxy resin, an acrylic resin, or a urethane resin before curing is suitable.

  The silane coupling agent or organosilazane that performs the surface treatment of the inorganic particle material is preferably selected according to the material selected as the resin material. For example, a functional group having an affinity for the resin material can be imparted to the surface of the inorganic particle material.

(B) Classification step The classification step is a step of classifying the mixture obtained in the mixing step, and the classification operation is not particularly limited. Examples of the classification operation include sieving and a method using a difference in sedimentation speed. When sieving is employed, the mixture is passed through the sieve. As the sieve, the opening is set so that particles (coarse particles) having a particle diameter to be removed can be removed. For example, when particles having a particle diameter of 5 μm or more are coarse particles, a sieve having an opening (which varies depending on the type and accuracy of the sieve) through which the coarse particles cannot pass is used. The number of times of passing through the sieve is arbitrary. Moreover, coarse particles can be more reliably removed by passing through a sieve having a larger opening and then passing through a sieve having a smaller opening. Examples of the form of the sieve include a mesh-like one, a plate formed with holes, and a nonwoven fabric in which fibers are accumulated.

  As a method using the difference in sedimentation speed, there are a method of preparing a mixture and then allowing it to stand and sedimenting by gravity, a method of rotating and improving a sedimentation speed by centrifugal force, and the like. Since particles with larger particle sizes settle faster, classification is performed by separating the regions where coarse particles are no longer included after sedimentation until particles larger than the target particle size (coarse particles) settle more than a certain amount. Do.

  By repeating these classification operations several times, more precise classification can be realized.

[Inorganic particle material-containing composition]
・ Part 1
The inorganic particle material-containing composition of the present embodiment is an inorganic particle material-containing composition that can be produced by the above-described method for producing an inorganic particle material-containing composition. The content of the organic solvent is more than the amount that can be classified with a sieve having an opening of a predetermined size when the inorganic particle material and the organic solvent are added to the mixture previously mixed with the resin material removed. Is a small amount. Furthermore, the coarse particle which is a particle | grain more than predetermined particle size is not included substantially.

  Classification is performed in a state where the amount of the organic solvent exceeds the above-mentioned range (the amount that is smaller than the amount that can be classified using a sieve having an opening larger than a predetermined particle size when the resin material is not mixed), When the method of removing the organic solvent is employed after the classification, the coarse particles removed by the classification are regenerated. Therefore, there has never been a composition that does not substantially contain coarse particles in a state where the amount of the organic solvent is limited to the above range. Here, “substantially free of coarse particles” means 5 ppm or less, preferably 3 ppm or less, more preferably 1 ppm or less, and particularly preferably less than the detection limit based on the mass of the inorganic particle material (hereinafter the same).

  The form, type, and content of the inorganic particle material, organic matter, and resin material included in the inorganic particle material-containing composition of the present embodiment can be used as they are in the above-described manufacturing method, and further explanation is omitted. .

・ Part 2
The inorganic particle material-containing composition of the present embodiment contains an inorganic particle material, a resin material, and an organic solvent. As the types and forms of the inorganic particle material, the resin material, and the organic solvent, those described in the above manufacturing method can be employed as they are, and further description thereof is omitted.

  The amount of the organic solvent is less than the amount of the organic solvent that can be classified with a sieve having a predetermined size when the inorganic particle material and the organic solvent are mixed without containing the resin material. To. In addition, coarse particles that are particles having a predetermined size or larger are not substantially contained.

  As described in Part 1, the amount of the organic solvent exceeds the above range (the amount that is smaller than the amount that can be classified using a sieve having an opening larger than a predetermined particle size when the resin material is not mixed). In the case of adopting a method in which classification is performed in the state of removing the organic solvent after the classification, coarse particles removed by the classification are regenerated. Therefore, a composition that does not substantially contain coarse particles in a state where the amount of the organic solvent is limited to the above-described range cannot exist so far.

  Hereinafter, the inorganic particle material-containing composition of the present invention will be described in detail based on examples.

  Spherical silica as inorganic particle material (Admafine SO-C4, particle size 1.0 μm), methyl ethyl ketone as organic solvent, epoxy resin as resin material [mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin (mixing Ratio about 1: 1); manufactured by Tohto Kasei Co., Ltd .; product name Epototo ZX1059; liquid) was mixed to obtain a mixture (mixing step). As the mixing ratio, the amount of the resin material was changed with respect to 100 parts by mass of the inorganic particle material and 28.5 parts by mass of the organic solvent. The specific mixing amount of the resin material was 0 part by mass in Test Example 1, 14.3 parts by mass in Test Example 2, 28.6 parts by mass in Test Example 3, and 42.9 parts by mass in Test Example 4. In addition, the resin material added this time assumes the upper limit of the addition amount in the final usage pattern (assumed to be used as an underfill). The inorganic particulate material had a content of slightly over 77% based on the sum of the inorganic particulate material and the organic solvent.

  Thereafter, it was assumed that the sieve was passed through a sieve having an opening of 5 μm as a classification step. The present inventors have found that the viscosity of the mixture that can pass through the sieve quickly is desirably 120 mPa · s or less in the opening of the sieve this time.

  Therefore, the viscosity of the mixture of each test example was measured before performing the classification process. As a result, Test Example 1 was 304 mPa · s, Test Example 2 was 102 mPa · s, Test Example 3 was 164 mPa · s, and Test Example 4 was 363 mPa · s.

  Therefore, it is desirable to use Test Example 2 for use in the classification step, and Test Example 3 has a slightly high viscosity, so that it is possible to classify it although it takes time. The length of the classification time is important when realizing the actual process. This range is a value that varies depending on the size of the sieve mesh.

  Furthermore, when sieving was performed on Test Examples 1 to 4, Test Example 2 was quickly screened, and the progress of sieving was confirmed while Test Example 3 was slow. Excessive time was required for sieving for the samples of other test examples. In the samples of Test Examples 2 and 3 in which sieving could be completed, the presence of coarse particles was 1 ppm or less. For samples whose viscosity has been reduced by adding a large amount of organic solvent (by adding 30% or more of organic solvent, sieving can be performed under the same conditions), the aggregation of inorganic particles progresses by removing the organic solvent. Coarse grains were regenerated.

  Furthermore, as a combination of a resin material whose viscosity is lowered by mixing and an organic solvent, (1) toluene as an organic solvent and silicone resin (liquid) as a resin material, (2) methyl ethyl ketone and propylene as an organic solvent At least one of glycol monomethyl ether (PGM) and methyl isobutyl ketone (MIBK), acrylic resin (liquid) and / or methacrylic resin (liquid) as resin material, (3) N-methyl as organic solvent -2-pyrrolidone (NMP), at least one of N, N-dimethylacetamide (DMAC), polyimide (resin) as resin material, (4) MIBK and / or PGM as organic solvent, resin material The combination of the epoxy resin (solid) as can be illustrated. By adding the resin material in this combination, the viscosity is lower than that of the mixture of the inorganic particle material and the organic solvent.

  From these results, it is considered that any combination of the organic solvent and the resin material can be used in the present invention if the resin material can be dissolved in the organic solvent. Here, the surface of the inorganic particle material is subjected to a surface treatment according to the type of the organic solvent and / or the resin material employed (that is, the same kind and / or a reactive functional group is introduced so as to improve the affinity) It is desirable to introduce a functional group capable of realizing the same hydrophobicity / hydrophilicity).

Claims (4)

And inorganic particulate material, an organic solvent, a mixing step of prior Symbol mixture resin material which is soluble or mixed with an organic solvent, were mixed,
A classification step of classifying the mixture;
Have
The said resin material is a manufacturing method of the inorganic particle material containing composition which is 9% or more and 22.5% or less on the basis of the sum of the mass of the said inorganic particle material and the said organic solvent.   The said classification process is a manufacturing method of the inorganic particle material containing composition of Claim 1 except what performs while performing ultrasonic irradiation. The content of the organic solvent in the mixture is smaller than the amount that can be classified in the classification performed in the classification step in which the inorganic particle material and the organic solvent are mixed first except for the resin material. A method for producing an inorganic particle material-containing composition according to claim 1 or 2 . The method for producing an inorganic particle material-containing composition according to any one of claims 1 to 3, wherein classification performed in the classification step is sieving.