JP5496533B2 - Thermosetting resin composition - Google Patents

Description

  The present invention relates to a thermosetting resin composition that exhibits thixotropic properties before curing.

  A curable resin composition having thixotropic properties, such as a semiconductor dam material, a die attach material, and a hole filling material, is a preferred member. That is, the viscosity decreases during operation and is excellent in operability, but when left standing, the viscosity is increased so that dripping or the like does not occur.

  As a curable resin composition having thixotropy, a mixture of a rheology modifier and a polymer is disclosed (Patent Document 1).

JP 2005-325369 A

  By the way, as a curable resin composition, there exists a thermosetting thing. It has been found that the curable resin composition described in Patent Document 1 decreases in viscosity by heating, and it may be difficult to maintain a sufficient viscosity necessary for the rest of the resin composition. If a sufficient viscosity cannot be maintained during heating, the shape of the curable resin composition cannot be maintained during heat curing, making it difficult to exhibit the desired performance.

  This invention is completed in view of the said situation, and makes it the problem which should be solved to provide the thermosetting resin composition with a little fall of a viscosity by heating.

The rheology modifier comprising a reaction product of an isocyanate compound having one or more isocyanate groups and an organic amine compound having one or more amine structures is characterized by the thermosetting resin composition according to claim 1 that solves the above-mentioned problem. When,
A thermosetting resin in which the rheology modifier is dispersed;
Fine inorganic particles having a particle size of 5 nm to 300 nm;
It is in having.

The feature of the thermosetting resin composition according to claim 2 for solving the above-mentioned problem is that, in claim 1, the isocyanate compound has two or more isocyanate groups,
The organic amine compound has two or more amine structures.

  The feature of the thermosetting resin composition according to claim 3 for solving the above-mentioned problems is that, in claim 1 or 2, the isocyanate compound and the organic amine compound are reacted in the presence of the fine inorganic particles. It is in.

  A feature of the thermosetting resin composition according to claim 4 for solving the above-mentioned problems is that, in any one of claims 1 to 3, the fine inorganic particles are formed from silica.

  A feature of the thermosetting resin composition according to claim 5 for solving the above-mentioned problem is that, in claim 4, the fine inorganic particles are treated with a silane coupling agent.

  The feature of the thermosetting resin composition according to claim 6 for solving the above-mentioned problem is that, in any one of claims 1 to 5, the thermosetting resin composition is formed from silica and / or alumina and has a particle size of 0.3 μm to 50 μm. It has the second fine inorganic particles.

  According to the invention which concerns on Claim 1, the effect that the viscosity fall by a temperature rise can be suppressed by containing a fine inorganic particle can be expressed.

  According to the invention according to claim 2, by having two or more functional groups for each of the isocyanate compound and the organic amine compound, it becomes possible for the rheology modifier to form a high-level network structure and to improve thixotropic properties. be able to.

  According to the invention of claim 3, by reacting the isocyanate compound and the organic amine compound in the presence of the fine inorganic particles, a strong network structure including a chemical bond is formed between the rheology modifier and the fine inorganic particles. Therefore, higher thixotropy can be expressed.

  According to the invention which concerns on Claim 4, the interaction between a rheology modifier and the surface of a micro inorganic particle can be anticipated by employ | adopting a silica and an alumina as a micro inorganic particle, and high thixotropic expression can be anticipated.

  According to the invention of claim 5, by treating and modifying the surface of the inorganic particles with a silane coupling agent, the affinity between the fine inorganic particles and the thermosetting resin is improved, and the fine inorganic particles and the rheology modifier are Various functions such as interaction improvement can be provided.

  According to the invention which concerns on Claim 6, the improvement of physical and chemical performance, such as the further thermal stability after this thermosetting resin composition hardens | cures by containing a 2nd minute inorganic particle. Can be achieved.

It is a graph which shows the share rate dependence of the viscosity of the test sample of Test Example 1 in an Example. It is a graph which shows the time-dependent change of the viscosity of the test sample of Test Example 1 in an Example. It is a graph which shows the share rate dependence of the viscosity of the test sample of Test Example 2 in an Example. It is a graph which shows the time-dependent change of the viscosity of the test sample of Test Example 2 in an Example. It is a graph which shows the time-dependent change of the viscosity of the test sample of Test Example 3 in an Example. It is a graph which shows the share rate dependence of the viscosity of the test sample of Test Example 4 in an Example.

  The thermosetting resin composition of the present invention will be described in detail below based on the embodiment. The thermosetting resin composition of this embodiment has a rheology modifier, a thermosetting resin, fine inorganic particles, and other members that can be included as necessary. The mixing ratio of the rheology modifier, thermosetting resin, and fine inorganic particles is not particularly limited. The rheology modifier can be mixed in an amount of about 0.1 to 20% by weight based on the total amount of the composition. The fine inorganic particles can be mixed with about 1 to 60% by weight based on the total amount of the composition.

(Rheology modifier)
The rheology modifier includes a reaction product of an isocyanate compound and an organic amine compound.
The isocyanate compound has 1 or more (preferably 2 or more) isocyanate groups in its molecular structure. The organic amine compound has one or more (preferably two or more) amine structures in its molecular structure. Since the isocyanate group and the amine structure can form a network structure having a network structure, each of them can be 3 or more. A compound having two isocyanate groups is particularly desirable, and a mixture of a plurality of types of compounds can also be selected. The method for reacting the isocyanate compound with the organic amine compound is not particularly limited, but the rheology modifier such as a bond is formed between the produced rheology modifier and the minute inorganic particles by performing in the presence of the minute inorganic particles described later. It is desirable because fine inorganic particles can be expected to be incorporated into the network structure formed by the above method.
-Cyanate compound The cyanate compound can have an aliphatic, alicyclic, or aromatic skeleton, and an isocyanate group is bonded to the skeleton. Examples of aliphatic isocyanates are trimethylene diisocyanate, tetramethylene diisocyanate, tetramethylxylylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, And 1,3-butylene diisocyanate. Cycloaliphatic isocyanates such as 1,3-cyclopentane diisocyanate and isophorone diisocyanate, aromatic isocyanates such as m-phenylene diisocyanate, p-phenylene diisocyanate and diphenylmethane-4,4-diisocyanate; 2,4- or 2,6 -Aliphatic-aromatic isocyanates such as toluene diisocyanate and 1,4-xylene diisocyanate; Nuclear substituted aromatic isocyanates such as dianisidine diisocyanate and 4,4-diphenyl ether diisocyanate; Triphenylmethane-4,4,4-tri Isocyanates, and 1,3,5-triisocyanatobenzene; and polyisocyanates such as isocyanurates of toluene diisocyanate and hexamethylene diisocyanate Dimers or trimers of also suitable. Mixtures of materials containing both isocyanate groups and isothiocyanate groups can be used as well as the isothiocyanates corresponding to the isocyanates (if they are present). Isocyanates can be obtained from BayerUSA, Inc. under the trademarks MONDUR and DESMODUR. Commercially available. Preferably, the isocyanate of the polyfunctional monomer is 1,6-hexamethylene diisocyanate. Examples of suitable isocyanates are described in US Pat. Nos. 4,311,622 and 4,677,028.
-Organic amine compound An organic amine compound should just have one or more amine structures. The amine structure may be any of primary to tertiary amines. Preferred amines are monoamines, more preferably monoprimary amines. Suitable monoamines include benzylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, methylbutylamine, ethylpurpylamine and ethylbutylamine. Furthermore, hydroxy-containing monoamines (eg 2-aminoethanol, 1-aminoethanol, 2-aminopropanol, 3-aminopropanol, 1-amino-2-propanol, 2-amino-2-methylpropanol, 2-aminobutanol, 2-amino-2-methyl-1,3-propanediol and 2-amino-2-ethyl-1,3-propanediol) may be used. Preferred monoamines are benzylamine or hexylamine. Examples of other amines suitable for use in the preparation of rheology modifiers are those described in US Pat. Nos. 4,311,622 and 4,677,028.

  The equivalent ratio of organic amine compound: isocyanate compound is in the range of 0.7 to 1.5: 1, preferably 1: 1 (primary amines are considered monofunctional).

  Generally, the rheology modifier is an organic amine compound in a suitable reaction vessel in the presence of some diluent, generally between 20 ° C. and 80 ° C., preferably at a temperature between 20 ° C. and 50 ° C. And an isocyanate compound. As the diluent, the above-mentioned thermosetting resin can be used as it is. In carrying out this reaction, it is preferable to add the isocyanate compound after first dispersing the organic amine compound in the diluent.

(Thermosetting resin)
A thermosetting resin is a resin that is cured by heating. That is, prepolymers such as an epoxy resin, an acrylic resin, and a urethane resin before curing are suitable. For example, it is desirable to have an epoxy group, oxetane group, hydroxyl group, blocked isocyanate group, amino group, half ester group, amic group, carboxy group and carbon-carbon double bond group in the chemical structure. These functional groups are functional groups (polymerizable functional groups) that can be bonded to each other by setting suitable reaction conditions, and are polymerized and cured (heat cured) by heating. In other words, it is cured by generating reactive species such as radicals and ions (anions and cations) by heating, or by adding a reaction initiator (polymerization initiator) that bonds between these functional groups and heating. A compound necessary for the polymerization reaction can be added as a curing agent, or a catalyst for the reaction can be added.

(Fine inorganic particles)
The fine inorganic particles are particles having a particle size of 5 nm to 300 nm. Furthermore, it is more desirable that it is 5 nm-50 nm. The materials that make up the fine inorganic particles are inorganic materials, such as metal oxides (silica (colloidal silica), alumina, titania, aluminum hydroxide, clay minerals, etc.) and resin materials (latex, silicone resin, acrylic resin, etc.) Examples thereof include polymers such as polymers, natural polymers such as natural latex, metals (gold, silver, platinum, etc.), ceramics (such as SiC) and nitrides (AlN), carbon materials, and the like. Some surface treatment can also be performed on the surface.

  It is desirable that the fine inorganic particles have high sphericity for the purpose of improving the filling property. For example, the metal oxide can be described by a method (VMC method) obtained by oxidizing metal powder in an oxygen-containing atmosphere, a flame melting method, or the like. In the VMC method, a chemical flame is formed by a burner in an atmosphere containing oxygen, and an amount of metal powder that forms part of the target oxide particles is added to the chemical flame so that a dust cloud is formed. In this method, deflagration is caused to obtain oxide particles. In the flame melting method, the metal oxide constituting the target spherical metal oxide particles is pulverized by pulverization or the like, and then charged and dissolved in a flame. It is a manufacturing method. Colloidal silica can also be synthesized by a conventional method such as gas phase synthesis. For example, colloidal silica formed by polycondensation of tetraalkoxysilane can be employed. By controlling the reaction conditions, a suspension of fine inorganic particles with a controlled particle size can be obtained. Examples of the tetraalkoxysilane include tetraethoxysilane (TEOS) and those having any other alkoxy group. Examples of the colloidal silica thus produced include colloidal silica PL-3 manufactured by Fuso Chemical Industry.

  The fine inorganic particles can also have an elongated shape. For example, the strength of the final product can be improved by having an aspect ratio (ratio between the major axis and minor axis of the particle) of 2 or more (more preferably 10 or more, and may be fibrous). Particles having an aspect ratio in this range can be contained in an amount of 50% or more based on the mass of the entire fine inorganic particles, and can be contained in an amount of 80% or more, and further 90% or more.

  The fine inorganic particles can be treated with a silane coupling agent. As the silane coupling agent, a reactive silane coupling agent having a reactive group, a non-reactive silane coupling agent having no reactive group, and the like can be appropriately used as necessary.

  In addition, when the thermosetting resin composition of the present embodiment is applied to electric / electronic parts such as a semiconductor encapsulant, it is desirable to limit the content of ionic substances in the minute inorganic particles to a predetermined value or less. . This is because an ionic substance is eluted or migrated from the thermosetting resin composition of the present embodiment, which may cause an unexpected influence on the electric / electronic component. Furthermore, in addition to application to electrical / electronic components, it is also desirable to limit the content of the ionic substance to a predetermined value or less when applied to applications where the presence of the ionic substance is undesirable.

  Here, as the predetermined value set as the content of the ionic substance, an appropriate value varies depending on the application, but when used for a semiconductor such as a die attach material, it is preferably 100 ppm or less, and more preferably 50 ppm or less. desirable. Although it does not specifically limit as an ionic substance which should be controlled, Organic substances, such as an inorganic substance, such as an alkali metal, alkaline earth metal, and halogen, and an organic acid, etc. can be illustrated. In particular, it is desirable to control the amount of sodium below a predetermined value. Sodium is most likely as an ionic substance that can be contained in the fine inorganic particles, and it is expected that the content of other ionic substances can be reduced simultaneously by controlling the amount of sodium. The method for measuring the content of the ionic substance in the fine inorganic particles is not particularly limited, but a normal method such as ICP can be adopted. For example, when the fine inorganic particles are silica, they can be subjected to ICP measurement after being dissolved in hydrofluoric acid or the like.

  The method for controlling the content of the ionic substance is not particularly limited, but (a) after controlling the content of the ionic substance (and / or the substance that changes to the ionic substance) in the raw material, Examples thereof include a method for producing fine inorganic particles by synthesis, and (b) a method for removing ionic substances from the fine inorganic particles by washing or the like.

(Members you can have as needed)
Examples of the member that can be included as needed include second fine inorganic particles, a solvent, and the like. Since the second fine inorganic particles are the same as the fine inorganic particles except that the particle diameter is 0.3 μm to 50 μm, description thereof will be omitted. The particle size is more preferably 0.3 μm to 10 μm.

(Production method)
An example is given about a manufacturing method. For example, it can be produced by (a) preparing an aqueous slurry, (b) adding a water-based organic solvent and a thermosetting resin to the aqueous slurry, and (c) adding an isocyanate compound and an organic amine compound. Furthermore, (d) it can also have another process.

  (A) The step of preparing an aqueous slurry is a step of preparing an aqueous slurry in which fine inorganic particles are dispersed in an aqueous medium. The fine inorganic particles are added to the aqueous medium and then dispersed by stirring, ultrasonic irradiation, or the like. In addition, a solution is prepared by dissolving the material constituting the fine inorganic particles in an aqueous medium, and the solubility of the material is controlled by any method (ion exchange, introduction / desorption of substituents by chemical reaction, control of pH, temperature, etc.) ), The fine inorganic particles are precipitated, and an aqueous slurry containing the fine inorganic particles can be obtained. For example, an aqueous colloidal silica slurry can be prepared by ion exchange of a water glass aqueous solution with an ion exchange resin.

  The fine inorganic particles are not particularly limited except that the surface properties are hydrophilic. When the surface is hydrophilic, the surface of the mixed material finally mixed or the like is aggregated when dispersed as it is.

  The aqueous medium is a medium that can disperse fine inorganic particles having high hydrophilicity (the affinity with the mixed material is not sufficient as it is), and is desirably a liquid in the production process. An example is water.

  (B) The aqueous organic solvent has a boiling point higher than that of the aqueous medium and can be mixed with the aqueous medium. Since the boiling point is high, the removal proceeds from the aqueous medium when removing by evaporation or the like, and the medium in which the fine inorganic particles are dispersed can be gradually replaced from the aqueous medium to the aqueous organic solvent. Here, the higher boiling point means that the boiling point in the atmosphere when removing the aqueous medium is high. For example, when the aqueous medium is removed under a reduced pressure atmosphere, the comparison is made with the boiling point under the pressure. In addition, when the boiling point is changed by other additives (formation of an azeotrope, increase in boiling point, etc.), it is desirable to consider the effect.

  The mixing ratio of the aqueous medium and the aqueous organic solvent is not particularly limited, but it is desirable to add the aqueous organic solvent to such an extent that the mixed material that is an organic compound having a higher boiling point than the aqueous organic solvent is dissolved. And when there is too much quantity of an aqueous organic solvent, there exists a possibility that production efficiency may fall.

  When water is employed as the aqueous medium, examples of the aqueous organic solvent include propylene glycol monomethyl ether (propylene glycol-1-methyl ether, boiling point of about 119 ° C .; propylene glycol-2-methyl ether, boiling point of about 130 ° C.), butanol ( Examples include boiling point 117.7 ° C.), N-methyl-2-pyrrolidone (boiling point of about 204 ° C.), γ-butyrolactone (boiling point of about 204 ° C.), and the like.

  (C) Of the isocyanate compound and the organic amine compound, the organic amine compound can be added simultaneously with the addition of the aqueous organic solvent and the thermosetting resin.

  (D) As other steps, there is a step of evaporating and removing the aqueous medium and the aqueous organic solvent. The aqueous medium and the aqueous organic solvent can be evaporated by heating or reducing the pressure.

  By removing the aqueous medium and the aqueous organic solvent, the fine inorganic particles can be mixed or dispersed in the thermosetting resin.

(Test Example 1)
Silica fine particles (colloidal silica OS: 20% by mass of silica: average particle size of about 10 nm: manufactured by Nissan Chemical Co.) as fine inorganic particles are 100 parts by mass and propylene glycol monomethyl ether (PGM) is 200 parts by mass and the surface area of the silica fine particles. A suitable amount of a non-reactive silane coupling agent (vinyltrichlorosilane: KBM-1003: manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed and held at 40 ° C. for 72 hours, and then an epoxy resin (Epicoat 828) as a thermosetting resin. 90 parts by mass of Japan Epoxy Resin Co.) was mixed and dispersed. Thereafter, water and PGM were removed by an evaporator, and colloidal silica was dispersed in the epoxy resin. Further, by adding an epoxy resin, the silica fine particles were adjusted to 10% by mass based on the total mass.

  Thereafter, 10 parts by mass of an organic amine compound (Ethacure 100: manufactured by Albemarle) is added and mixed, and further an isocyanate compound (Duranate TPA-100: manufactured by Asahi Kasei) is added so that the equivalent ratio of amine to isocyanate is about 1: 1. Mixed. Finally, a curing agent (imidazole type: 2PHZ-PW: manufactured by Shikoku Chemicals) was added and defoamed by stirring under reduced pressure to obtain a test sample of this test example.

(Test Example 2)
Silica fine particles (colloidal silica OL: 20% by mass of silica: average particle size of about 50 nm: manufactured by Nissan Chemical Co.) as 100 mass parts and 200 mass parts of propylene glycol monomethyl ether (PGM) as the fine inorganic particles and the second fine inorganic particles 200 parts by mass of Admafine SE2050-SQ (silica: average particle size 0.5 μm: manufactured by Admatex) as a non-reactive silane coupling agent (vinyltrichlorosilane: KBM-1003: (Shin-Etsu Chemical Co., Ltd.) was mixed and held at 40 ° C. for 72 hours, and then 100 parts by mass of an epoxy resin as a thermosetting resin was mixed and dispersed. Thereafter, water and PGM were removed by an evaporator, and the colloidal silica and the second fine inorganic particles were dispersed in the epoxy resin. Further, by adding an epoxy resin, the silica fine particles were adjusted to 60% by mass based on the total mass.

  Thereafter, 2 parts by mass of an organic amine compound (Ethacure 100: manufactured by Albemarle) is added to and mixed with 100 parts by mass of the fine particle-dispersed resin composition, and an isocyanate compound (Duranate TPA-100: manufactured by Asahi Kasei) is added to the equivalent of amine to isocyanate. The mixture was added and mixed so that the ratio was about 1: 1. Finally, a curing agent (imidazole type: 2PHZ-PW: manufactured by Shikoku Chemicals) was added and defoamed by stirring under reduced pressure to obtain a test sample of this test example.

(Test Example 3)
A test sample of this test example was prepared by performing the same operation as in Test Example 1 except that no colloidal silica was added.

(Test Example 4)
Except not adding an isocyanate compound and an organic amine compound, operation similar to Test Example 1 was performed, and it was set as the test sample of this test example.

(Measurement of viscosity)
The viscosity of the test sample of Test Example 1 was measured. The measurement temperature was 25 ° C. and 110 ° C. The results are shown in FIG. As is clear from FIG. 1, it was found that high thixotropy can be expressed even at high temperatures. And the viscosity change at the time of leaving at 70 degreeC was examined (measuring condition: sharerate5S < ^-1 >). The results are shown in FIG. As is clear from FIG. 2, almost no change in viscosity with time was observed when left at 70 ° C.

The viscosity of the test sample of Test Example 2 was measured in the same manner as the test sample of Test Example 1. The measurement temperature was 70 ° C. The results are shown in FIG. As is clear from FIG. 3, as in the test sample of Test Example 1, it was found that high thixotropy can be expressed even at a high temperature. And the viscosity change at the time of leaving at 70 degreeC was examined (measuring condition: sharerate5S < ^-1 >). The results are shown in FIG. As is clear from FIG. 4, almost no change in the viscosity with time was observed when left at 70 ° C.

For the test sample of Test Example 3, the change with time in viscosity at high temperature was measured in the same manner as the test sample of Test Example 1. The measurement temperature was 70 ° C. (measurement condition: sharerate 5S ⁻¹ ). The results are shown in FIG. As is clear from FIG. 5, it was found that the viscosity decreased with time when left at 70 ° C.

  The viscosity of the test sample of Test Example 4 was measured in the same manner as the test sample of Test Example 1. The measurement temperature was 25 ° C. The results are shown in FIG. As is apparent from FIG. 6, the viscosity was constant and thixotropic property was not shown regardless of the share rate.

  From the above results, it was found that thixotropy was improved by adding a rheology modifier (Test Examples 1, 2, and 4). It was found that the thixotropy showed a high value even when left at a high temperature by adding fine inorganic particles (Test Examples 1, 2, and 3).

Claims (5)

A rheology modifier comprising a reaction product of an isocyanate compound having one or more isocyanate groups and an organic amine compound having one or more amine structures;
A thermosetting resin in which the rheology modifier is dispersed;
Fine inorganic particles formed from silica having a particle size of 5 nm to 300 nm;
A thermosetting resin composition comprising:
The isocyanate compound and the organic amine compound are reacted in the presence of the fine inorganic particles,
The content of the rheology modifier in the thermosetting resin composition is 0.1 to 20% by weight, and the content of the fine inorganic particles in the thermosetting resin composition is 1 to 60% by weight. A thermosetting resin composition. The thermosetting resin composition according to claim 1 , wherein the fine inorganic particles are treated with a silane coupling agent. A rheology modifier comprising a reaction product of an isocyanate compound having one or more isocyanate groups and an organic amine compound having one or more amine structures;
A thermosetting resin in which the rheology modifier is dispersed;
Fine inorganic particles formed from silica having a particle size of 5 nm to 300 nm;
A thermosetting resin composition comprising:
The fine inorganic particles are treated with a silane coupling agent,
The content of the rheology modifier in the thermosetting resin composition is 0.1 to 20% by weight, and the content of the fine inorganic particles in the thermosetting resin composition is 1 to 60% by weight. A thermosetting resin composition. The isocyanate compound has two or more isocyanate groups,
The thermosetting resin composition according to any one of claims 1 to 3, wherein the organic amine compound has two or more amine structures.   The thermosetting resin composition according to any one of claims 1 to 4, wherein the thermosetting resin composition has second fine inorganic particles formed of silica and / or alumina and having a particle size of 0.3 µm to 50 µm.

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