JP4477335B2 - SEALING MATERIAL COMPOSITION FOR OPTICAL DEVICE, SEALING STRUCTURE AND OPTICAL DEVICE - Google Patents

Description

  The present invention relates to a sealing material composition for producing an optical element and a molded article thereof, a sealing structure for producing an optical element produced using the composition or the molded article, and a sealing structure of the sealing structure. The present invention relates to a manufacturing method and an optical element in which a laser diode is enclosed in an exterior sealed using the sealing material composition or the like. In particular, the present invention relates to the above-mentioned sealing material composition for producing an optical element such as a light emitting element and a light receiving element capable of entering or emitting light through a light transmitting window hole while maintaining the internal space in a vacuum or a reduced pressure. .

The metal cap of the can seal type semiconductor laser needs to be sealed with a transparent plate such as a glass plate in order to block the semiconductor laser chip placed in the case from the outside air and to emit the emitted laser light to the outside. is there. The sealed semiconductor laser cap is required to have a degree of vacuum of 1.333 × 10 ⁻⁸ Pa (= 10 ⁻¹⁰ Torr).

  Conventionally, low-melting glass is used for hermetic sealing between a metal cap and a glass window of a can-seal type semiconductor laser. For example, PbO-based low-melting glass contains a trace amount of oxygen, for example, nitrogen gas. In an inert gas atmosphere as described above, the temperature was raised to 500 to 600 ° C. over 10 to 20 minutes, and kept at that temperature for 10 to 30 minutes to be melted. The temperature is raised over 10 to 20 minutes until the temperature reaches 500 to 600 ° C., so that an oxide film is formed on the sealing portion of the metal member before the glass melts to facilitate sealing with the glass member. Because. In addition, a small amount of oxygen mixed in the inert gas atmosphere forms an oxide film in the sealed portion, but prevents the oxide film from being formed in other portions. Too much is inappropriate. In addition to the low melting point glass, an epoxy adhesive or solder may be used as the sealing material.

  As a material of the metal member, Kovar (Fe—Ni—Co alloy), iron, copper, 42 alloy, or the like is used. These metal members are preferably plated with nickel, chromium, copper, matte silver or the like. As a material for the glass window, for example, borosilicate glass or the like is used (for example, see Patent Document 1).

  Conventional powder glass for sealing contains lead components to lower the melting point, but lead has been pointed out to be harmful, and recently there has been a demand for sealing materials that do not contain lead, cadmium and other harmful components. In some cases, phosphate glass or the like is used to satisfy this requirement, but the adhesive strength is weak. Further, a material that can be sealed at a lower temperature of less than 400 ° C. is desired from the viewpoint of energy saving.

  The present inventor has proposed a glass sealing material composition containing a curable silicone resin or a refractory filler composed of a curable silicone resin or a modified resin thereof as a sealing material for glass sealing that solves the above problems. (Patent Document 2). Since this curable silicone resin is used as a curing component, this sealing material composition can be sealed at a low temperature, and uses a refractory filler that does not contain harmful components. It is a sealing material in which the problems relating to the problem have been solved. This sealing material is used as a sealing material for bonding glass members together or a glass member and a metal member.

JP-A-6-48782 JP 2001-207152 A

  The glass sealing material composition containing the curable silicone-based resin and the refractory filler is capable of low-temperature adhesion and considerably strong adhesion, but recently, more low-temperature adhesion, stronger adhesion, and higher airtightness. For example, for hermetic sealing between a metal cap of a laser diode (LD) and a glass window, it is necessary to seal in a small area that is not found in conventional sealing objects. It was not satisfactory. Suitable for optical element sealing structures including LDs, with stronger adhesive strength, airtightness, low-temperature adhesiveness, and heat resistance, and after curing, the cured sealing material can flow out of the sealing surface. However, the present situation is that a sealing material having a form maintaining power that does not protrude is required.

As a result of examining the present inventors to solve the above problems, the amount and ratio of methyl groups and phenyl groups in the methylphenyl silicone resin are hermetically sealed by low-temperature sealing between the metal cap and the glass window. The present invention has been completed by finding that the adhesive force and airtightness are affected.
That is, the present invention relates to (a) a curable methylphenyl silicone resin that is cured by a dehydration condensation reaction, (b) spherical silica having an average particle size of 1 to 20 μm, and (c) spherical particles having an average particle size of 50 to 130 μm. A sealing material composition for producing an optical element, comprising silica or barium titanate, wherein (b) and (c) with respect to the sum of (a), (b) and (c) in the sealing material composition ) Is 20 to 75% by mass, the molar ratio of the bifunctional silicon unit to (the total of the bifunctional silicon unit and the trifunctional silicon unit) in (a) is 0.03 to 0.40, The molar ratio of the phenyl group to the methyl group in a) is 0.1 to 1.0, and the amount of (c) relative to the sum of (a), (b) and (c) is 0.1 to 15% by mass ( However, the combination of (b) and (c) Relative amounts sealing material composition for producing an optical element which is a 50 wt% or less) of (c) (hereinafter, also referred to as "a light element sealing material composition".) It is.

Further, the present invention uses the sealing material composition, the metal members to each other, or a glass member and a metal member, characterized in that it is a sealed structure formed by sealing a vacuum or reduced pressure It is the sealing structure for optical elements for forming the internal space of a state.

Further, the present invention provides a method for producing a sealing structure for producing an optical element having an internal space in a vacuum or reduced pressure state, wherein two or more metal members for forming the internal space are combined, or a metal member and a glass member, a manufacturing method of the sealing structure, characterized in that the sealing with the sealing material composition.

  These sealing structures are used as an exterior (case) of an optical element, and an exterior formed by forming a window made of a glass material on a part of the exterior made of a metal material is particularly preferable. The optical element assembled using this exterior has an internal space surrounded by this exterior, and this internal space is maintained in a vacuum or reduced pressure state, from a laser diode or the like enclosed in this internal space. Outgoing light is emitted from this window to the outside.

Further, the present invention has a cap made of a metal material and a window made of a glass material, an exterior in which an internal space is formed, and a laser diode enclosed in the internal space in a vacuum or reduced pressure state, The cap and the window are sealed with a cured product of the optical element sealing material composition.

  According to the present invention, it is difficult to realize with a low-melting-point glass, sealing in a low temperature range of less than 400 ° C. is possible, low-temperature adhesion to glass and metal is good, adhesive strength is high, and workability at the time of sealing is achieved. It is possible to obtain a sealing material composition having excellent characteristics and good airtightness retention. In addition, if a glass material and a metal material or metal materials are sealed using a molded body of a sealing material composition obtained from the composition, for example, an optical element such as an LD cap is produced, A sealing structure with good airtightness can be obtained. In addition, since it does not contain any harmful substances such as lead and cadmium, it has an environmentally friendly advantage.

  The optical element in the present invention includes an exterior having a window and an internal space formed therein, and an optical element sealed in the internal space in a vacuum or reduced pressure state. The window transmits light emitted from the optical element or light incident on the optical element. The exterior is usually made of a metal material, and the window portion is usually made of a glass material. Therefore, the exterior is configured by bonding a member made of a metal material and a window member made of a glass material. Further, the exterior may include a portion formed by bonding two or more members made of a metal material. These adhesive portions in the exterior are required to have sufficient adhesive strength and at the same time, sufficient airtightness to maintain the vacuum or decompressed state of the internal space. Sealing in the present invention means adhesion that maintains the internal space in a vacuum or reduced pressure and prevents leakage of gas from the outside.

Examples of the optical element enclosed in the optical element in the present invention include a light emitting body that converts current into light, a light receiving body that converts light into current, a light projecting and receiving body that converts current and light to each other, and a laser. A light emitting body such as a semiconductor laser such as a diode (LD), a light emitting diode (LED), or an electroluminescence (EL) element is preferred. For example, a laser diode (LD) needs to be sealed with a transparent plate such as a glass plate in order to shield an LD chip enclosed in an exterior from outside air and to emit laser light to the outside. Since the internal space in which the LD chip is enclosed requires a vacuum of about 1.333 × 10 ⁻⁸ Pa, the characteristic required for the sealing part of the exterior is the heat resistance in the process of assembling the exterior by sealing. There are various, diverse and strict ones.

  The sealing material composition of the present invention is a sealing material composition used for sealing for constituting the exterior or the like of the optical element. The sealing structure for an optical element in the present invention means the above-mentioned exterior or the like or a structure having the above-mentioned exterior or the like, and means the above-described exterior itself or a structure composed of the exterior and other elements. . In this sealing structure, two or more members made of a metal material, or a member made of a metal material and a member made of a glass material, a cured product obtained from the sealing material composition of the present invention, or a material described later. It has the site | part formed by sealing with the hardened | cured material obtained from the molded object of the sealing material composition. The sealing material composition of the present invention was partially polymerized and cross-linked semi-cured product, further cured and cross-linked cured product, or partially polymerized and cross-linked by performing a sealing operation. Semi-cured products and cured products that are further polymerized and crosslinked are called sealing materials.

  The sealing material composition of the present invention contains a curable silicone resin composed of a curable methylphenyl silicone resin and a refractory filler. Since the silanol group of the curable methylphenyl silicone resin has affinity with the refractory filler surface, the mixing of the curable methylphenyl silicone resin and the refractory filler can be uniformly and freely controlled. As a result, a semi-cured product capable of sufficiently expressing the characteristics of both the curable methylphenyl silicone resin and the refractory filler is obtained, and the sealing material that is the semi-cured product is particularly used for sealing between a glass member and a metal member. Is preferred. In other words, the glass member has a low temperature, strong adhesion strength, excellent bondability, high mechanical heat resistance, good gas leak resistance, high airtightness retention, good heat resistant dimensional stability, etc. Together with the characteristics.

  Generally, curable silicone resins are excellent in heat resistance, weather resistance, moisture resistance, electrical properties, etc., so they are often used as materials for electrical, electronic, precision equipment, etc., and contain reinforcing fillers such as silica to improve strength. It is also known to plan. In addition, for example, a curable silicone resin modified with an epoxy resin is excellent in strength, heat resistance, moisture resistance, and releasability, and is further blended with a filler such as silica to provide fluidity and a machine for molded products. Compositions with improved mechanical strength are known. The curable silicone resin or its modified resin has a relatively low elastic modulus, can reduce the stress applied to the glass member to be sealed, and can reduce the strain due to the difference in thermal expansion coefficient.

Generally, the curable silicone resin is produced from a bifunctional silicon monomer (R ₂ Si—X ₂ ) and a trifunctional silicon monomer (RSi—X ₃ ), and in some cases, a monofunctional silicon monomer (R ₃ Si—X) or 4 A functional silicon monomer (Si—X ₄ ) may be used in combination (R represents an organic group having a carbon atom at the bonding end, and X represents a hydrolyzable group such as an alkoxy group or a chlorine atom). The curable silicone-based resin is a copolymer obtained by partially hydrolyzing and condensing these monomers, and has a silanol group formed by hydrolysis of X. This curable silicone-based resin can be further condensed by the silanol group (can be cured), and finally cured to be a cured product having substantially no silanol group. The cured product is composed of a bifunctional silicon unit (R ₂ SiO) and a trifunctional silicon unit (RSiO _3/2 ). In some cases, a monofunctional silicon unit (R ₃ SiO _1/2 ) or a tetrafunctional silicon unit (SiO ₂ ). Each silicon unit in the curable silicone resin also means each silicon unit containing silanol groups that are generated by hydrolysis of X together with each silicon unit of these cured products and contribute to the curability of the silicone resin. . For example, a bifunctional silicon unit having a silanol group is represented by (R ₂ Si (OH)-), and a trifunctional silicon unit having a silanol group is represented by (RSi (OH) _2- ) or (RSi (OH) =). expressed. Moreover, it is thought that the molar ratio of each silicon unit in the curable silicone resin is equal to the molar ratio of each silicon monomer as a raw material.

In the present invention, the curable silicone resin that is a raw material of the sealing material composition is a curable methylphenylsilicone resin, and the moles of the bifunctional silicon unit with respect to (total of the bifunctional silicon unit and the trifunctional silicon unit). A methylphenyl silicone resin having a ratio (also simply referred to as a molar ratio of bifunctional silicon units) of 0.03 to 0.40. This curable methyl phenyl silicone resin is a curable silicone resin containing both a methyl group and a phenyl group as the organic group R. This curable methylphenyl silicone resin is produced, for example, by a method of hydrolytic cocondensation of dichlorodimethylsilane and trichlorophenylsilane, a method of hydrolytic cocondensation of dichlorodiphenylsilane and trichloromethylsilane, or the like. The molar ratio of the bifunctional silicon unit of the curable methylphenyl silicone resin in the present invention is more preferably 0.10 to 0.35. Further, it is preferable that the curable methyl phenyl silicone resin is substantially composed of only a bifunctional silicon unit and a trifunctional silicon unit. These curable methyl phenyl silicone resins in the present invention are not easily decomposed or discolored even when kept at a high temperature of 250 ° C. or higher for a long time, and are excellent in heat resistance.
In addition, the molar ratio of the bifunctional silicon unit is obtained from Si-NMR.

Moreover, it is preferable that the value of Si-O / Si-R calculated | required from FT-IR is 12.5 to 16.2 for the curable methyl phenyl silicone resin in this invention. That is, the peak area of Si—O (peak appearing in the range of 1250 to 950 cm ⁻¹ ) (a) is changed to the peak area derived from the methyl group (peak appearing in the range of 1330 to 1250 cm ⁻¹ ) (b), This is a value obtained by dividing the peak area (b) derived from the methyl group and the product of the number of moles of phenyl group / the value of the number of moles of methyl group (c) determined from H-NMR.
(A) / [(b) + (c) × (b)] = 12.5 to 16.2

Generally, the heat resistance decreases as the alkyl group bonded to Si of the curable silicone resin becomes a long chain. An aromatic hydrocarbon group represented by a phenyl group has mechanical heat resistance equal to or higher than that of a methyl group which is the shortest alkyl group, and the resin film becomes harder as its mass ratio increases, Comes plastic. Therefore, the mechanical strength such as heat resistance and bendability of the resin can be adjusted by the ratio of the number of phenyl groups to the total number of R in the resin. As the methyl phenyl silicone resin in the present invention, a methyl phenyl silicone resin having a phenyl group / methyl group molar ratio of 0.1 to 1.0 is preferable. The peak height from a phenyl group obtained from FT-IR (3074cm ^-1) / peak height derived from methyl groups (2996cm ^-1) is preferred methylphenyl silicone resin 0.1 to 1.2.

  The molecular weight of the curable methylphenyl silicone resin in the present invention is not particularly limited, but it is preferable to use a low molecular weight one. As the molecular weight of the methylphenyl silicone resin increases, the sealing material composition containing a curable methylphenyl silicone resin and a refractory filler is partially polymerized and crosslinked at 180 ° C. to about 3000 to 6000 cp, and then cooled to room temperature. Since the solid composition obtained in this way becomes a paste-like sealing material composition having adhesiveness, it is difficult to handle and inferior in workability. In addition, the adhesive paste-like sealing material composition prepared using a high molecular weight methylphenyl silicone resin has a slow heat-curing speed, so it takes a long time for heat-curing to produce a thick film molded body. There is a limitation that it is difficult to do. When using a high molecular weight curable methyl phenyl silicone resin, it is necessary to pay attention to these points.

  When the molecular weight of methylphenyl silicone resin is measured by GPC, a broad molecular weight distribution with several overlapping peaks is observed. From this, it can be seen that methylphenyl silicone resin is a mixture in which several molecular weights are mixed. The low molecular weight methylphenylsilicone resin in the present invention refers to those having a number average molecular weight value of the first peak appearing at the beginning of a broad molecular weight distribution of 100,000 or less. In addition, the number average molecular weight of the entire broad molecular weight distribution of this low molecular weight methylphenyl silicone resin is 2300 or less. On the other hand, the high molecular weight methylphenyl silicone resin indicates that the value of the number average molecular weight of the first peak appearing at the beginning of the broad molecular weight distribution is several hundred thousand. In this case, the number average molecular weight of the entire broad molecular weight distribution is 2500 or more.

  In the curable methylphenyl silicone resin in the present invention, a small amount of a curable diphenylsilicone resin such as dimethylsilicone resin or a curable alkylphenylsilicone resin other than methylphenylsilicone resin such as ethylphenylsilicone resin is blended, and the physical properties Can be adjusted. However, it is usually preferable not to use these curable silicone resins other than methylphenyl silicone resin. Further, the curable methyl phenyl silicone resin can be modified with an epoxy resin, a phenol resin, an alkyd resin, a polyester resin, an acrylic resin, or the like. However, the amount of the resin to be modified is preferably small, and the curable methyl phenyl silicone resin in the present invention is preferably a curable methyl phenyl silicone resin that is not substantially modified.

  The curable methyl phenyl silicone resin is usually handled in a solution (varnish) dissolved in a solvent such as transport and storage. The sealing material composition of the present invention can be produced by using this varnish and mixing it with a refractory filler. The sealing material composition of the present invention containing this solvent becomes a liquid mixture or solid mixture having fluidity. Moreover, after removing a solvent previously from a varnish, curable methylphenyl silicone resin without a solvent and a refractory filler can be mixed, and it can also be set as the sealing material composition of this invention. Furthermore, after mixing a varnish and a refractory filler, the solvent can be removed to obtain the sealing material composition of the present invention.

  The solvent used for varnishing the curable methylphenylsilicone resin is not particularly limited, and any solvent that dissolves the curable methylphenylsilicone resin may be used. For example, an aromatic hydrocarbon solvent xylene, Toluene, benzene and the like can be used. It is preferable that the usage-amount of the solvent in a varnish is 5-50 mass%. If it is less than 5% by mass, the dissolving action of the curable methylphenylsilicone resin is insufficient, and it is difficult to uniformly mix with the refractory filler. When it exceeds 50 mass%, when mixed with a refractory filler, the solvent easily causes phase separation with the refractory filler, and after mixing the refractory filler, a large amount of energy is required.

  The curable methyl phenyl silicone resin can be present as a partially polymerized and crosslinked methyl phenyl silicone resin (also referred to simply as a partially crosslinked methyl phenyl silicone resin) in the sealing material composition. In the partially crosslinked methylphenyl silicone resin, the dehydration condensation reaction of the raw material curable methylphenyl silicone resin has progressed to some extent. Therefore, compared to the raw material methylphenyl silicone resin, the moisture content when sealing the sealed object is reduced. Therefore, the sealing material composition containing the partially crosslinked methylphenyl silicone resin is less likely to generate bubbles when sealing and curing the material to be sealed, compared to the raw material methylphenyl silicone resin. Therefore, the airtightness can be improved. The partially cross-linked methylphenyl silicone resin is a high-viscosity liquid or a solid having a high melt viscosity compared to the raw material methylphenylsilicone resin, and is suitable for use as a molded product of the sealing material composition of the present invention. Have For example, when a molded article of a sealing material composition placed at a predetermined part of an object to be sealed is sealed and cured, the methylphenyl silicone resin is less likely to flow out of the predetermined part. .

  The partially cross-linked methylphenyl silicone resin is a curable methylphenyl silicone resin in which the curing of the curable methylphenylsilicone resin that is the raw material is partially advanced. The curable methyl phenyl silicone resin in the present invention means a curable methyl phenyl silicone resin that is a raw material of the partially crosslinked methyl phenyl silicone resin, and also means this partially crosslinked methyl phenyl silicone resin. Hereinafter, in the production stage of the sealing material composition of the present invention, a part of the curable methyl phenyl silicone resin that has been partially polymerized and crosslinked is referred to as a partially crosslinked methyl phenyl silicone resin.

  The partial polymerization and crosslinking of the curable methylphenylsilicone resin are usually performed by stopping the curing reaction by heating the raw material methylphenylsilicone resin to the extent that it is not completely completed. For example, it can be obtained by partially curing the raw material methylphenylsilicone resin by a method such as heating at a lower temperature than in a normal curing reaction, or heating for a shorter time than the time required for normal curing. The partial cross-linking of the raw material methylphenyl silicone resin can be carried out in the composition in the presence of the refractory filler or in the course of manufacturing the composition.

  Curing of the curable methylphenylsilicone resin by dehydration condensation usually proceeds only by heating, and by dehydration condensation reaction between silanol groups of the resin, and dehydration condensation reaction of silanol groups of the resin and silanol groups on the surface of the refractory filler. A cured product insoluble in the solvent is formed. For example, the sealing material composition applied to an object to be sealed is heated at 140 ° C. or higher, preferably 180 ° C. to 300 ° C. for 1 to 120 minutes, and the resin is cured, insolubilized, and sealed. Become a material. Normally, when a solvent is included in the sealing material composition, it is removed by volatilization at the beginning of heating, and when a non-heat resistant material such as an organic substance is present, it is removed by volatilization or decomposition during curing. .

  A curing catalyst may be used to lower the curing temperature of the curable methylphenyl silicone resin, and as a catalyst, an organic metal salt such as zinc, cobalt, tin, iron, zirconium, quaternary ammonium salt, aluminum, titanium, etc. Examples include chelates, various amines or salts thereof.

  The refractory filler used in the present invention is a heat-resistant inorganic powder, specifically, silica, alumina, mullite, zircon, cordierite, β-eucryptite, β-spodumene, β-quartz solid solution. Forsterite, bismuth titanate, barium titanate and the like. Of course, these can also be used together.

The average particle size of the refractory filler is preferably 0.1 to 130 μm, particularly preferably 0.5 to 90 μm, and particularly preferably 1 to 20 μm. If the average particle size exceeds the upper limit, after the methylphenyl silicone resin is cured, cracks occur at the interface between the refractory filler and the silicone resin, and gas leaks into the internal space of the sealing structure, resulting in a vacuum or desired There is a risk that the reduced pressure cannot be maintained. When the average particle size is less than the lower limit, powder aggregation occurs and the powder is not uniformly dispersed in the curable methylphenyl silicone resin.
A refractory filler having a large average particle size (over 20 μm) may be used as a spacer material, and in that case, it is preferably used in combination with a refractory filler having a small average particle size (1 to 20 μm).

  The refractory filler is preferably silica, especially spherical silica. The average particle diameter of the spherical silica is preferably 0.1 to 130 μm, particularly preferably 0.5 to 90 μm, particularly preferably 1 to 20 μm, and further preferably 1 to 5 μm. When the average particle diameter of the spherical silica is 1 to 20 μm, a sealing material composition having good coating workability can be obtained. When the average particle size is less than the above range, the particles are aggregated to reduce the dispersibility, and a uniform composition cannot be obtained.If the average particle size exceeds the above range, the particles are precipitated, resulting in poor dispersibility. A uniform composition cannot be obtained. Of course, spherical silica having an average particle diameter of 1 to 20 μm and spherical silica having an average particle diameter of other than that can be used in combination, and spherical silica having an average particle diameter of 1 to 20 μm and a refractory filler other than the spherical silica. It can also be used together.

  The compounding quantity of the refractory filler in the sealing material composition of this invention is 10-80 mass% with respect to the total amount of curable methylphenyl silicone resin and a refractory filler. When the amount is less than 10% by mass, sufficient heat resistance is not exhibited, and it is difficult to secure a sealing material layer having a thickness of several tens of μm or more necessary for sealing. If it exceeds 80% by mass, the dispersibility and affinity with methylphenylmethylphenyl silicone resin will deteriorate, and as a result, cracks will occur in the sealing material (cured product), and gas will enter the internal space of the sealing structure. It leaks and cannot maintain a vacuum or a desired reduced pressure. Moreover, the adhesive strength to the sealing site is reduced. A preferable amount of the refractory filler is 20 to 75% by mass.

  The blending amount of the spherical silica in the sealing material composition when containing the spherical silica having an average particle diameter of 1 to 20 μm is 10 to 80% by mass based on the total of the curable methylphenylsilicone resin and the refractory filler. It is preferable that it is 20-75 mass%. If it is less than this range, the heat resistance and light resistance will be inferior, and if this range is exceeded, cracks will occur in the sealing material and gas will leak into the internal space of the optical element sealing structure, resulting in a vacuum or desired It is impossible to maintain the reduced pressure. Moreover, the adhesive strength of the sealing part is reduced.

  Depending on the use of the sealing material composition of the present invention, a small amount of spherical particles having a large particle size (20 μm or more) and a narrow particle size distribution as a spacer material, apart from a refractory filler having a small average particle size (20 μm or less). It can also be blended. For example, in an apparatus such as a plasma display (PDP) in which two glass plates are opposed to each other while maintaining a predetermined interval and the periphery thereof is sealed, a spacer for maintaining the interval between the two glass plates The material can be blended into the sealing material composition.

  The spacer material is preferably a spherical refractory filler having a particle size larger than that of the refractory filler. Specifically, spherical silica or barium titanate having a particle size of 50 to 130 μm. The blending amount of the spacer material is preferably 0.1 to 15% by mass (however, 50% by mass or less based on the total refractory filler) with respect to the total of the curable methylphenylsilicone resin and the refractory filler. Mass% is particularly preferred.

  The sealing material composition of the present invention may contain components other than the curable methyl phenyl silicone resin and the refractory filler. Examples of such other components include components other than the components that finally function as a sealing material, such as the solvent, or components remaining in the sealing material, for example, a coloring pigment for a sealing material. Although content in the sealing material composition of these components is not specifically limited, It is the quantity which does not inhibit the characteristic of the molded object of the sealing material composition of this invention, or the sealing material composition obtained from it. The former component is preferably 20% by mass or less based on the sealing material composition excluding the solvent. The amount of the solvent is arbitrary depending on the method of use, such as using the sealing material composition in a liquid state or using it in a solid state, and is usually 50% by mass with respect to the sealing material composition. The following is preferred. The latter component is preferably 10% by mass or less.

  Specific examples of other components and preferred amounts thereof (however, the amount relative to the sealing material composition excluding the solvent) include the following. 5% by mass or less of an amine-based curing agent for accelerating the curing of the methylphenyl silicone resin, 15% by mass or less of a pigment or the like for the purpose of further increasing the mechanical heat resistance of the sealing material or coloring. To improve pot life of composition, dispersibility of refractory filler and methylphenyl silicone resin, and improve sealing property between sealing material and sealing material composition, imparting tackiness to pine, rosin, rosin derivatives, etc. 5 mass% or less of an agent can be mix | blended.

  The sealing material composition of the present invention can be obtained by mixing the curable methylphenyl silicone resin and the refractory filler into a uniform composition. A solution (varnish) of a curable methylphenyl silicone resin can be used to form a composition containing a curable methylphenyl silicone resin, a solvent, and a refractory filler. Moreover, after mixing a varnish and a refractory filler, a solvent can be removed and it can also be set as the composition which does not contain a solvent substantially. Usually, it is preferable to produce a solid, paste-like or slurry-like composition containing substantially no solvent by mixing the varnish and the refractory filler under heating and stirring and removing the solvent in that state. . The temperature when the varnish and the refractory filler are mixed and the solvent is removed is preferably 100 ° C. or higher, and particularly preferably about 100 to 180 ° C. The sealing material composition of the present invention is preferably a solid composition, but may be a paste or slurry composition containing a solvent or not containing a solvent. The solid composition may be formed into a sheet shape, a wire shape, a stick shape, or the like.

  In producing the sealing material composition, the curable methylphenyl silicone resin can be partially polymerized and crosslinked to obtain a partially crosslinked methylphenyl silicone resin. The partial polymerization and crosslinking of the curable methylphenyl silicone resin may be performed before mixing the refractory filler, or may be performed after mixing the refractory filler. Moreover, when using a varnish, you may carry out in the state in which a solvent exists, and may carry out after removing a solvent. Usually, the varnish and the refractory filler are heated and mixed with stirring as described above, the solvent is removed in that state, and the temperature is further raised in that state to partially polymerize the methylphenyl silicone resin. It is preferable to perform crosslinking. The temperature at which the partial polymerization and crosslinking of the methylphenyl silicone resin is carried out is suitably higher than the temperature at the time of solvent removal and 120 ° C. or higher, and particularly preferably about 150 to 200 ° C.

  The sealing material composition of the present invention containing a partially crosslinked methylphenyl silicone resin is preferably a molded body formed into a sheet shape, a wire shape, a stick shape or the like. For example, a sealing material composition that has been heated as described above to form a partially crosslinked methylphenyl silicone resin becomes a clay-like composition, and can be molded by casting the clay-like composition in a heated state into a mold. . Specifically, it can be formed into molded products having various desired shapes such as a sheet shape, a wire shape, and a stick shape using a mold made of a fluororesin or the like. The obtained molded body of the sealing material composition having a sheet shape, a wire shape, a stick shape, or the like can be applied to sealing an object to be sealed in its shape.

  A solid composition obtained by removing a solvent from a sealing material composition obtained using a varnish containing a curable methylphenyl silicone resin, and further partially polymerizing and crosslinking a curable methylphenyl silicone resin. The form of the resulting solid composition varies depending on the structure of the curable methylphenylsilicone resin as a raw material, and directly the molecular weight. For example, when the number average molecular weight value of the first peak appearing at the beginning of the broad molecular weight distribution of the methylphenyl silicone resin is 100,000 or less (in this case, the number average molecular weight of the entire broad molecular weight distribution is 2300 or less), A solid composition obtained by partially polymerizing and crosslinking the sealing material composition having the curable methylphenyl silicone resin and the refractory filler to about 3000 to 6000 cp at 180 ° C. and then cooling to room temperature, It becomes the moldable sealing material composition without adhesiveness. On the other hand, when the value of the number average molecular weight of the first peak appearing at the beginning of the broad molecular weight distribution is several hundred thousand (in this case, the number average molecular weight of the entire broad molecular weight distribution is 2500 or more), this curable methylphenyl A solid composition obtained by partially polymerizing and crosslinking a sealing material composition having a silicone resin and a refractory filler to about 3000 to 6000 cp at 180 ° C. and then cooling to room temperature is a sticky paste It becomes a sealing material composition in the shape. According to the difference in the characteristics of these compositions, it is possible to use both according to the application of the sealing material composition.

  Usually, in sealing, the sealing material composition is disposed at a predetermined site of one sealed object, and the other sealed object is disposed so that the sealing material composition is sandwiched between the two sealed objects, Preferably, the sealing material composition is pressurized with both of the objects to be sealed, and heated in that state to cure the sealing material composition. In some cases, sealing can be performed by arranging a sealing material composition at a predetermined portion of both objects to be sealed. Also, three or more objects to be sealed can be sealed simultaneously. A paste-like or slurry-like sealing material composition can be applied to an object to be sealed with a brush, a spray, a dispenser, or the like. When the composition contains a solvent, the solvent can be removed by heating after application. . A molded body of the sealing material composition (which also means a molded body containing a partially crosslinked methylphenyl silicone resin) can be applied to sealing an object to be sealed in its shape. For example, it is used by sandwiching a molded body of a sheet-like sealing material composition between objects to be sealed. In addition, when a certain degree of viscosity is developed, there are an advantage that the sealing material composition can be applied thickly, and an advantage that the pretreatment can degas from the sealing material composition at the time of sealing.

  As an optical element configured by applying the sealing material composition of the present invention or a molded body thereof, there is an optical element in which an optical element such as a light emitter, a light receiver, and a light projecting / receiving body is enclosed. In these optical elements, a member made of a metal material and a member made of a glass material are sealed, or two or more members made of a metal material are sealed, and a structure having an internal space is assembled. The internal space is maintained in a vacuum or a reduced pressure, and the optical element is enclosed in the internal space. The sealing material composition of the present invention or the molded body thereof can be used for sealing two or more members made of a glass material. For example, the present invention can be applied to sealing of a panel and funnel in a cathode ray tube, sealing of a substrate made of a glass material in a display element such as a plasma display (PDP), a fluorescent display tube (VFD), and a field emission display (FED).

  The sealing material composition of the present invention or the molded body thereof is particularly suitable for sealing a cap made of a metal material and a window made of a glass material in a semiconductor laser. The present invention is also an optical element that is a semiconductor laser, that is, a cap made of a metal material and a window made of a glass material, and an exterior in which an internal space is formed, and the vacuum or reduced pressure state. An optical element having a laser diode sealed in an internal space, wherein the cap and the window are sealed with a cured product of the sealing material composition or a cured product of the molded body. An optical element.

(Example 1 to Example 7)
In a container equipped with a stirrer, the characteristics shown in Table 1 [molar ratio of bifunctional silicon units (= 2 functional silicon units / (total of bifunctional silicon units and trifunctional silicon units)), molar ratio of phenyl groups (= phenyl group / 40 parts by mass (mass excluding solvent) containing curable methylphenyl silicone resin having a methyl group) and a number average molecular weight], 57 parts by mass of spherical silica having an average particle size of 3 μm, and barium titanate 3 having an average particle size of 90 μm A part by mass was added, heated at 120 to 140 ° C. and stirred to remove the solvent. Next, stepwise heating to 150-180 ° C to partially polymerize and crosslink the curable methylphenyl silicone resin, and then cast into a fluororesin mold to form a stick with a diameter of 10 mm and a length of 100 mm Thus, a molded body of the sealing material composition was obtained. However, Examples 6 and 7 are comparative examples. In addition, the molar ratio of the bifunctional silicon unit was measured by Si-NMR and FT-IR. The molar ratio of the phenyl group was measured by H-NMR and FT-IR. The number average molecular weight was measured by GPC.

A glass window was sealed with a molded body of the sealing material composition on a metal cap for a semiconductor laser, and the adhesive strength of the obtained metal-glass sealing structure was measured. A hole with a diameter of 1.5 mm is opened at the top of a laser cap 7 (inner diameter 3.3 mm, height 2.3 mm) which is made of kovar as shown in FIGS. A glass plate 8 having a diameter of 3.0 mm was sealed in the hole by using the molded body 9 of the sealing material composition. Curing was performed by heating at 180 ° C. for 30 minutes and at 200 ° C. for 30 minutes in a nitrogen atmosphere.
In the measurement of the adhesive strength, a load is applied to the glass window 8 from the upper part of the cap 7, and the load when the glass window 8 peels from the metal cap 7 or the glass window 8 is broken is measured to obtain a breaking load. .
Further, the molded body of the sealing material composition was applied to an aluminum cup heated to 140 to 180 ° C. and spread to an extent that the thickness of the molded body was about 1 to 0.5 mm. Cured for 60 minutes at 250 ° C. for 60 minutes under a nitrogen atmosphere. The amount of mass loss due to thermal decomposition of the molded body of the cured sealing material composition was measured by TG-DTA.

On the other hand, three soda-lime glass substrates of the shape shown in FIG. 1 (lower plate 1: 100 × 100 × 5 mm, upper plate 2: 100 × 100 × 5 mm, with a hole 3 having a diameter of 5 mm in the center, Plate 4: outer diameter 100 × 100 mm, inner diameter 70 × 70 mm, thickness 5 mm) between the lower plate 1 and the middle plate 4, and between the upper plate 2 and the middle plate 4, the stick-like sealing material composition The molded product 6 was sandwiched and pressed in a laminated state (sealing material layer thickness 100 μm) as shown in FIG. The laminate was heated at 110 ° C. for 30 minutes, 150 ° C. for 30 minutes, 180 ° C. for 1 hour, and 210 ° C. for 30 minutes to cure the silicone resin, thereby producing an evaluation test piece. Then, it deaerated using the vacuum pump from the hole 3 of the upper board 2, and the internal space 5 was made into the vacuum of 1.333 * 10 < ^-8 > Pa. Thereafter, the presence or absence of leakage was measured.

The presence or absence of leak was measured by a hood method using a ULVAC helium leak detector HELIOT. First, after evacuating the specimen until the background value becomes 1.5 × 10 ⁻⁹ Pa, helium gas is introduced into the hood, the leak rate of helium gas is measured for 10 minutes, and the leak rate of helium gas The maximum value of was recorded and the presence or absence of a leak was confirmed. The above evaluation results are shown in Table 1.

FIG. 1 is a plan view of a test piece composed of three glass substrates, (a) is a plan view of a lower plate of the test piece, (b) is a plan view of an upper plate of the test piece, (c ) Is a plan view of the middle plate of the test piece. FIG. 2 is a cross-sectional view of the test piece composed of three glass substrates shown in FIG. 1 after sealing. FIG. 3 is an overview of an example of a semiconductor laser cap. FIG. 4 is a cross-sectional view of an example of a sealing structure in which a semiconductor laser cap and a glass plate are sealed.

Explanation of symbols

1: Lower plate 2: Upper plate 3: Hole 4: Middle plate 5: Internal space 6: Sealing material layer 7: Metal cap 8: Glass plate 9: Sealing material layer

Claims (4)

(A) a curable methylphenyl silicone resin that cures by a dehydration condensation reaction;
(B) spherical silica having an average particle diameter of 1 to 20 μm, and
(C) Spherical silica or barium titanate having an average particle size of 50 to 130 μm
In the sealing material composition for manufacturing an optical element, the total amount of (b) and (c) with respect to the total of (a), (b) and (c) in the sealing material composition is 20 to 75% by mass, the molar ratio of the bifunctional silicon unit to (the sum of the bifunctional silicon unit and the trifunctional silicon unit) in (a) is 0.03 to 0.40, and the methyl group in (a) The molar ratio of the phenyl group to 0.1 to 1.0, and the amount of (c) to the sum of (a), (b) and (c) is 0.1 to 15% by mass (provided that (b) And (c) in an amount of 50% by mass or less with respect to the total of (c)), a sealing material composition for producing an optical element. A sealing structure formed by sealing metal members or a glass member and a metal member using the sealing material composition according to claim 1, wherein the vacuum structure or the reduced pressure state is provided. A sealing structure for an optical element for forming an internal space. In a method of manufacturing a sealing structure for manufacturing an optical element having an internal space in a vacuum or a reduced pressure state, two or more metal members for forming the internal space, or a metal member and a glass member, Is sealed using the sealing material composition according to claim 1, a method for producing a sealing structure. An optical element having a cap made of a metal material and a window made of a glass material, and an exterior in which an internal space is formed, and a laser diode sealed in the internal space in a vacuum or reduced pressure state. The optical element, wherein the cap and the window are sealed with a cured product of the sealing material composition according to claim 1.

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