JP2015074772A - Thermosetting resin composition for light reflector, method of manufacturing light reflector, and light reflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting resin composition for a light reflector, which contains a thermosetting resin and is used for manufacturing a light reflector having high adhesion to a metal by an injection molding method.SOLUTION: The thermosetting composition contains an epoxy resin, a phenol novolac resin, a white pigment, and a compound represented by formula (1) and is used for manufacturing a light reflector by an injection molding method. In the formula (1), Y and Z are each independently hydrogen, a halogen, or a lower alkyl group, and each R is independently a lower alkyl group.

Description

  The present invention relates to a thermosetting resin composition for a light reflector suitable for producing a light reflector (reflector), a method for producing a light reflector using the thermosetting resin composition for a light reflector, and this The present invention relates to a light reflector manufactured by the method.

  Conventionally, it is known to use a light reflector (reflector) in order to reflect light emitted from a light emitting element such as a light emitting diode. As one of resins used for producing a light reflector, an unsaturated polyester resin is known (Patent Document 1). Since the unsaturated polyester resin is a thermosetting resin, if it is used, there is an advantage that the heat discoloration of the light reflector is increased. When an unsaturated polyester resin is used, it is possible to adopt not only a transfer molding method but also an injection molding method as a molding method while being a thermosetting resin. In the case of the injection molding method, there is an advantage that it is easier to improve the resin utilization rate than in the case of the transfer molding method.

JP 2012-229393 A

  However, since the unsaturated polyester resin has low adhesion to a metal, when the light reflector is combined with a metal member such as a lead frame, the light reflector may be detached from the metal member. .

  The present invention has been made in view of the above reasons, and includes a thermosetting resin, and is used for producing a light reflector having high adhesion to a metal by an injection molding method. It is an object to provide a resin composition, a method for producing a light reflector using the thermosetting resin composition for a light reflector, and a light reflector produced by this method.

The thermosetting resin composition for a light reflector according to the first aspect of the present invention is a thermosetting resin composition used for producing a light reflector,
Containing an epoxy resin, a phenol novolac resin, a white pigment, and a compound represented by the following formula (1),
Used to manufacture light reflectors by injection molding.

In formula (1), each of Y and Z is independently hydrogen, halogen or an alkyl group, and each of R is independently an alkyl group.

  In the thermosetting resin composition for light reflectors according to the second aspect of the present invention, the compound represented by the above formula (1) contains a compound represented by the following formula (2).

  The light reflecting solar thermosetting resin composition according to the third aspect of the present invention further contains an unsaturated polyester in the first or second aspect.

  In the thermosetting resin composition for light reflectors according to the fourth aspect of the present invention, in any one of the first to third aspects, the ratio of the phenol novolac resin to the epoxy resin is 20 to 120% by mass. The ratio of the compound represented by the above formula (1) to the epoxy resin is in the range of 3 to 20% by mass.

  In the thermosetting resin composition for light reflectors according to the fifth aspect of the present invention, in any one of the first to fourth aspects, the white pigment is titanium oxide, barium titanate, barium sulfate, oxidized One or more materials selected from the group consisting of zinc and zinc sulfide are contained.

  The manufacturing method of the light reflection body which concerns on the 6th aspect of this invention includes the process of injection-molding the thermosetting resin composition for light reflection bodies which concerns on any one 1st thru | or 5th aspect.

  The light reflector according to the seventh aspect of the present invention is manufactured by the method according to the sixth aspect.

  The thermosetting resin composition for light reflectors according to the present invention contains a thermosetting resin and can be molded by an injection molding method, and the thermosetting resin composition for light reflectors is injected. By molding, a light reflector having high adhesion to a metal can be obtained.

It is sectional drawing which shows a light-emitting device provided with the light reflector in one Embodiment of this invention. It is a top view which shows the light-emitting device shown in FIG. It is a perspective view which shows the base material and molded object which are used for the adhesiveness in an Example.

  The thermosetting resin composition for light reflectors according to the present embodiment (hereinafter referred to as composition) is used for producing the light reflector 1. This composition contains an epoxy resin, a phenol novolac resin, a white pigment, and a compound represented by the following formula (1). Moreover, this composition is used in order to manufacture the light reflector 1 by an injection molding method.

  In formula (1), each of Y and Z is independently hydrogen, halogen or an alkyl group. Each R is independently an alkyl group. Each of Y and Z is preferably independently hydrogen, halogen or a lower alkyl group. Each of R is preferably independently a lower alkyl group.

  Since this composition contains an epoxy resin as a thermosetting resin, a phenol novolak resin as a curing agent, and further contains a compound represented by the formula (1) as a curing accelerator, The curing reaction hardly proceeds at around 100 ° C. That is, good fluidity of the composition is maintained around 100 ° C. For this reason, even if the composition is injection-molded, resin clogging in the mold is unlikely to occur. Therefore, the light reflector 1 can be manufactured by injection molding the composition.

  Furthermore, since the composition contains a thermosetting resin, the light reflector 1 made of the cured product has high heat discoloration. Furthermore, since an epoxy resin is used as the thermosetting resin, the adhesion between the light reflector 1 and the metal is high.

  The composition according to this embodiment will be described in more detail.

  The epoxy resin contained in the composition can contain an appropriate compound having two or more epoxy groups in one molecule. In the present embodiment, the compound contained in the epoxy resin may be a low molecule or a high molecule. For example, the epoxy resin can contain a resin synthesized from epichlorohydrin and bisphenol A, various novolacs, an alicyclic epoxy resin, and the like. In particular, the epoxy equivalent of the epoxy resin is preferably in the range of 100 to 300, and the softening point is preferably in the range of 60 to 110 ° C. In order to improve the injection moldability, the epoxy resin preferably contains at least one of a biphenyl type epoxy resin and a novolac type epoxy resin. Moreover, in order to suppress coloring of the light reflector 1, it is preferable that the epoxy resin contains triglycidyl isocyanurate.

  It is also preferable that the epoxy resin contains a compound represented by the following formula (3). In this case, the heat discoloration of the light reflector is particularly improved, and the storage stability of the resin molding material for the light reflector is improved. Moreover, when a composition contains the compound shown by Formula (3), premixing can also be made unnecessary at the time of preparation of a composition.

  Phenol novolac resin is used as a curing agent for epoxy resin. The phenol novolac resin can contain one or more resins selected from the group consisting of resins obtained by reacting phenols such as phenol, cresol, and xylenol with formaldehyde and modified products thereof. Examples of modified products include epoxidized phenol novolac resins and butylated phenol novolac resins. The softening point of the phenol novolac resin is preferably in the range of 60 to 110 ° C.

  The amount of the phenol novolac resin in the composition is appropriately adjusted so that the composition has good curing performance at the time of injection molding. In particular, the ratio of the hydroxyl equivalent of the phenol novolac resin to the epoxy equivalent of the epoxy resin is preferably in the range of 0.5 to 2.0.

  The composition contains a curing accelerator, and the curing accelerator contains a compound represented by the above formula (1). Examples of the compound represented by the formula (1) include 1,1′-phenylene-bis (3,3-dimethylurea) and 1,1 ′-(4-methyl-m-phenylene) -bis (3,3- At least one of dimethylurea) can be contained.

  In particular, the compound represented by the formula (1) is a compound represented by the following formula (2), that is, a dimethylamine adduct of 1,4-tolylene diisocyanate (1,1 ′-(4-methyl-m- (Phenylene) -bis (3,3-dimethylurea)) is preferably contained.

  The ratio of the compound represented by the formula (1) to the epoxy resin in the composition is preferably in the range of 3 to 20% by mass. When this ratio is 3% by mass or more, good curability of the composition at the time of injection molding is maintained, and the molding cycle can be shortened. Further, when the proportion is 20% by mass or less, the fluidity of the composition around 100 ° C. is particularly good, and the injection moldability of the composition is particularly good.

  It is preferable that the hardening accelerator in a composition contains only the compound represented by Formula (1). However, if good injection moldability is ensured, the curing accelerator may contain a compound other than the compound represented by the formula (1). For example, the curing accelerator is a cycloamidine compound / quaternary boron compound complex salt, tetra-n-butylphosphonium o, o-diethyl phosphoroditonate, ethyltriphenylphosphonium bromide, diazabicycloundecene, triphenylphosphine, And one or more selected from 2-methylimidazole.

  It is preferable that the ratio of the compound represented by Formula (1) with respect to all the hardening accelerators in a composition is 50 mass% or more.

  The thermosetting resin in the composition may contain only an epoxy resin and a phenol novolac resin that is a curing agent thereof. Further, the thermosetting resin may further contain a resin other than the epoxy resin and the phenol novolac resin that is the curing agent thereof. In this case, in order to maintain particularly high adhesion between the light reflector 1 and the metal, the ratio of the total amount of the epoxy resin and the phenol novolac resin as the curing agent to the thermosetting resin is 20% by mass. The above is preferable.

  The thermosetting resin may further contain an unsaturated polyester resin. In addition, the unsaturated polyester resin in this embodiment is resin comprised by unsaturated polyester and a crosslinking agent. In this case, burrs are less likely to occur in the light reflector 1 by moderately suppressing the fluidity of the composition during injection molding. In this embodiment, since the composition contains an epoxy resin, a phenol novolac resin, and a compound represented by the formula (1), the fluidity of the composition at the time of injection molding is good, and therefore the moldability is good. However, on the other hand, burrs are likely to occur due to the composition entering the parting surface during molding. However, when the thermosetting resin contains an unsaturated polyester resin, the fluidity of the composition is moderately suppressed, so that the composition is less likely to enter the parting surface during molding, and burrs are generated in the light reflector 1. It becomes difficult. Further, when an unsaturated polyester resin is used, the production cost of the composition can be reduced.

  When the unsaturated polyester resin is used, the ratio of the unsaturated polyester resin in the thermosetting resin is preferably in the range of 5 to 40% by mass. In this case, generation of burrs is particularly suppressed by appropriately controlling the fluidity of the composition while ensuring good moldability of the composition.

  When the thermosetting resin contains an unsaturated polyester resin, the unsaturated polyester can contain at least one of a crystalline unsaturated polyester and an amorphous unsaturated polyester. In particular, when the unsaturated polyester contains a crystalline unsaturated polyester, the storage stability of the composition becomes high and the fluidity of the composition at the time of injection molding becomes particularly high. Further, when the unsaturated polyester contains a crystalline unsaturated polyester, the light reflectivity of the light reflector 1 is particularly high, and this high light reflectivity can be maintained for a long time.

  The unsaturated polyester is preferably solid at 50 ° C. or lower. In that case, the storage shape stability, handleability, and workability of the composition are improved. In particular, when the unsaturated polyester is in a solid state within the range of room temperature to 50 ° C., the composition can be easily pulverized and extruded into pellets. The unsaturated polyester may be solid at 80 ° C. or lower. In that case, the composition can be prepared by powder mixing.

  The softening start temperature of the unsaturated polyester is preferably 50 ° C. or higher. In this case, the injection moldability of the composition is further improved. This softening start temperature may be 200 ° C. or less. The softening start temperature of the unsaturated polyester is more preferably in the range of 60 to 150 ° C, and still more preferably in the range of 80 to 130 ° C. The melt viscosity of the unsaturated polyester is preferably in the range of 1000 to 2500 cP. This melt viscosity is a viscosity at a temperature when the unsaturated polyester is softened and melted. The unsaturated polyester may have an acid value in the range of 5-40 mg-KOH / g. The unsaturated polyester may be what is called an unsaturated alkyd resin.

  The unsaturated polyester is synthesized, for example, by a dehydration condensation reaction between a polybasic acid containing an unsaturated polybasic acid and a glycol.

  The unsaturated polybasic acids are selected from the group consisting of, for example, maleic acid, maleic anhydride, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and glutaconic acid One or more compounds can be included. In particular, the unsaturated polybasic acids preferably contain fumaric acid. In this case, the injection moldability of the composition and the heat discoloration of the light reflector 1 are particularly improved.

  Polybasic acids may contain an unsaturated polybasic acid and a saturated polybasic acid. Saturated polybasic acids are, for example, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, It can contain at least one selected from the group consisting of het acid and tetrabromophthalic anhydride. In particular, the saturated polybasic acid preferably contains at least one of isophthalic acid and terephthalic acid. In this case, the injection moldability of the composition and the heat discoloration of the light reflector 1 are particularly improved.

  Examples of glycols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, propylene glycol, diethylene glycol, and triethylene. It may contain at least one compound selected from the group consisting of glycol, dipropylene glycol, neopentyl glycol, hydrogenated bisphenol A, bisphenol A propylene oxide compound, cyclohexane dimethanol, and dibromoneopentyl glycol. In particular, the glycol is at least one compound selected from the group consisting of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and cyclohexanedimethanol. It is preferable to contain. In this case, the injection moldability of the composition and the heat discoloration of the light reflector 1 are particularly improved.

  The crosslinking agent is a component that builds a crosslinked structure between the chains of the unsaturated polyester by reacting with the unsaturated polyester. Examples of the crosslinking agent include vinyl polymerizable monomers such as styrene, vinyl toluene, divinyl benzene, α-methyl styrene, methyl methacrylate, and vinyl acetate; diallyl phthalate, triallyl cyanurate, diallyl tetrabromophthalate, phenoxyethyl acrylate Polymerizable monomers such as 2-hydroxyethyl acrylate and 1,6-hexanediol diacrylate; and at least one selected from the group consisting of prepolymers obtained by polymerizing at least one of these polymerizable monomers. Compounds can be included. In particular, the crosslinking agent preferably contains one or more compounds selected from the group consisting of diallyl phthalate prepolymer, diallyl phthalate monomer, and styrene monomer.

  The ratio of the crosslinking agent to the total amount of the unsaturated polyester and the crosslinking agent is appropriately set, but is preferably in the range of 1 to 60% by mass, and more preferably in the range of 5 to 55% by mass. More preferably, it is in the range of 10 to 50% by mass.

  When an unsaturated polyester resin is used, the composition may contain a curing catalyst. In this case, a crosslinked structure is efficiently constructed by the reaction between the unsaturated polyester and the crosslinking agent. For this reason, the moldability of the composition and the shape stability of the light reflector 1 are enhanced. The curing catalyst can contain one or more compounds selected from the group consisting of, for example, a curing accelerator and a polymerization initiator.

  The polymerization initiator can contain, for example, a heat decomposition type organic peroxide. Examples of the organic peroxide include t-butylperoxy-2-ethylhexyl monocarbonate, 1,1-di (t-hexylperoxy) cyclohexane, 1,1-di (t-butylperoxy) -3,3, Contains one or more compounds selected from the group consisting of 5-trimethylcyclohexane, t-butylperoxyoctate, benzoyl peroxide, methyl ethyl ketone peroxide, acetylacetone peroxide, t-butylperoxybenzoate, and dicumyl peroxide can do. The organic peroxide preferably contains a compound having a 10-hour half-life temperature of 100 ° C. or higher. Specifically, the organic peroxide particularly preferably contains dicumyl peroxide.

  When the composition contains an unsaturated polyester resin, the composition may contain a polymerization inhibitor for adjusting curing conditions. Polymerization inhibitors include, for example, hydroquinone, monomethyl ether hydroquinone, toluhydroquinone, di-t-4-methylphenol, monomethyl ether hydroquinone, phenothiazine, t-butylcatechol, quinones such as parabenzoquinone, pyrogallol, 2,6-di- t-butyl-p-cresol, 2,2-methylene-bis- (4-methyl-6-t-butylphenol), 1,1,3-tris- (2-methyl-4-hydroxy-5-t-butylphenyl) One or more compounds selected from the group consisting of phenolic compounds such as butane can be contained.

  The white pigment imparts light reflectivity to the light reflector 1 produced from the composition. The white pigment contains one or more materials selected from the group consisting of, for example, titanium oxide, barium titanate, strontium titanate, aluminum oxide, magnesium oxide, zinc oxide, zinc sulfide, barium sulfate, magnesium carbonate, and barium carbonate. can do.

  In particular, the white pigment preferably contains one or more materials selected from the group consisting of titanium oxide, barium titanate, barium sulfate, zinc oxide, and zinc sulfide. It is also preferable that the white pigment contains aluminum oxide having a high thermal conductivity.

  When the white pigment contains titanium oxide, the titanium oxide can contain one or more materials selected from, for example, anatase type titanium oxide, rutile type titanium oxide, and brucite type titanium oxide. In particular, since rutile type titanium oxide is excellent in thermal stability, it is preferable that the titanium oxide contains rutile type titanium oxide.

  The surface of the white pigment may be surface-treated with a fatty acid, a coupling agent or the like. In this case, aggregation, oil absorption and the like of the white pigment are suppressed, and the filling property of the white pigment in the composition is increased.

  The average particle size of the white pigment is preferably 2.0 μm or less. The average particle size is preferably 0.01 μm or more. This average particle size is also preferably in the range of 0.03 to 1.0 μm, preferably in the range of 0.1 to 0.7 μm, and in the range of 0.2 to 0.5 μm. It is also preferable. The average particle diameter of the white pigment is measured by a laser diffraction scattering method.

  The amount of the white pigment relative to 100 parts by mass of the thermosetting resin in the composition is preferably 100 parts by mass or more. In this case, the heat-reflecting color of the light reflector 1 is particularly high, and the light reflectivity of the light reflector 1 is particularly high. The amount of the white pigment is preferably 300 parts by mass or less. In this case, the moldability of the composition is particularly high. It is particularly preferable that the amount of the white pigment is in the range of 150 to 250 parts by mass.

  The composition may further contain an inorganic filler excluding the white pigment. In this case, the light reflectivity of the light reflector 1 is further increased, and the shape stability of the light reflector 1 is further increased. Further, the inorganic filler can increase the thermal conductivity of the light reflector 1. Thereby, discoloration, deterioration, etc. due to heat of the light reflector 1 are further suppressed.

  The inorganic filler can contain, for example, one or more materials selected from the group consisting of silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium hydroxide, aluminum hydroxide, magnesium oxide, barium sulfate, and mica. .

  In particular, the inorganic filler preferably contains silica. In this case, the light reflectivity of the light reflector 1 is further increased, and the shape stability of the light reflector 1 is further increased. Silica can contain, for example, one or more materials selected from fused silica powder, spherical silica powder, crushed silica powder, and crystalline silica powder. In particular, the silica preferably contains fused silica.

  It is also preferable that the inorganic filler contains a thermally conductive inorganic filler. In this case, the thermal conductivity of the light reflector 1 is particularly high, and therefore, discoloration, deterioration, etc. due to heat of the light reflector 1 are further suppressed. The thermally conductive inorganic filler can contain one or more materials selected from the group consisting of thermally conductive fillers such as crystalline silica, alumina, silicon nitride, boron nitride, and aluminum nitride.

  The thermally conductive inorganic filler preferably contains a metal-containing filler, and particularly preferably contains an aluminum-containing filler. The aluminum-containing filler can contain, for example, aluminum hydroxide.

  The inorganic filler may contain hollow particles such as inorganic foam particles and silica balloons.

  The surface of the inorganic filler may be surface treated with a fatty acid, a coupling agent or the like. In this case, aggregation of the white pigment, oil absorption and the like are suppressed, and the filling property of the inorganic filler in the composition is increased.

  The average particle size of the inorganic filler is preferably 100 μm or less. In this case, the moldability of the composition is particularly good and the heat discoloration and moisture resistance of the light reflector 1 are particularly high. This average particle size is preferably 0.1 μm or more. In this case, the handleability of the composition is improved. The average particle size of the inorganic filler is more preferably 80 μm or less, and further preferably 50 μm or less. The average particle size of the inorganic filler is more preferably 0.3 μm or more. Furthermore, when the average particle size of the inorganic filler is in the range of 8 to 20 μm, the injection moldability of the composition is particularly good. The average particle size of the inorganic filler is measured by a laser diffraction scattering method.

  The amount of the inorganic filler with respect to 100 parts by mass of the thermosetting resin in the composition is preferably 40 parts by mass or more. In this case, the shape stability of the light reflector 1 is particularly high. The amount of the inorganic filler is preferably 300 parts by mass or less. In this case, the moldability of the composition is particularly high. It is particularly preferable if the amount of the inorganic filler is in the range of 50 to 250 parts by mass.

  When an inorganic filler contains a heat conductive inorganic filler, it is preferable that the ratio of the heat conductive inorganic filler with respect to the whole inorganic filler is 30 mass% or more. In this case, the thermal conductivity of the light reflector 1 is particularly high.

  The ratio of the total amount of the white pigment and the inorganic filler with respect to the entire composition is preferably in the range of 40 to 80% by mass. In this case, the moldability of the composition becomes particularly high, and the heat discoloration and light reflectivity of the light reflector 1 become particularly high. It is particularly preferable if this ratio is in the range of 50 to 70% by mass.

  The ratio of the white pigment to the total amount of the white pigment and the inorganic filler in the composition is preferably 30% by mass or more. In this case, the light reflectivity of the light reflector 1 is particularly high. This ratio is preferably 95% by mass or less. This ratio is more preferably in the range of 35 to 90% by mass, and further preferably in the range of 40 to 85% by mass.

  The total amount of the white pigment and the inorganic filler with respect to 100 parts by mass of the thermosetting resin in the composition is preferably 500 parts by mass or less. In this case, the fluidity of the composition during injection molding is particularly high. The total amount of the white pigment and the inorganic filler is preferably 100 parts by mass or more. In this case, the light reflectivity of the light reflector 1 is particularly high. The total amount of the white pigment and the inorganic filler is more preferably in the range of 100 to 400 parts by mass, and even more preferably in the range of 200 to 300 parts by mass.

  The composition may contain a reinforcing material. In this case, curing shrinkage during molding of the composition is suppressed, the strength of the light reflector 1 is increased, and the dimensional stability of the light reflector 1 is further increased. The reinforcing material contains an appropriate material applied for reinforcing FRP (Fiber Reinforced Plastics) such as BMC (Bulk Molding Compound) and SMC (Sheet Molding Compound). be able to.

  The reinforcing material contains, for example, one or more materials selected from glass fiber, vinylon fiber, aramid fiber, polyester fiber, wollastonite, potassium titanate whisker, carbonate whisker such as calcium carbonate, and hydrotalcite can do. In particular, the reinforcing material preferably contains glass fiber.

  Glass fiber is, for example, silicate glass, E glass (alkali-free glass for electricity), C glass (chemical alkali-containing glass), A glass (acid-resistant glass), S glass (high strength glass). One or more materials selected from the group consisting of glass fibers and the like can be contained. The glass fiber may be a long fiber (roving) or a short fiber (chopped strand). The glass fiber may be subjected to a surface treatment. In particular, the glass fiber is in the range of 3 to 6 mm in length after the E glass fiber having a fiber diameter of 10 to 15 μm is converged with a sizing agent such as vinyl acetate and subsequently surface-treated with a silane coupling agent. It is preferable to contain chopped strands cut into pieces.

  The amount of the reinforcing material with respect to 100 parts by mass of the thermosetting resin in the composition is preferably in the range of 10 to 200 parts by mass. In this case, the curing shrinkage of the composition is particularly suppressed during molding, and the strength of the light reflector 1 is particularly high. The amount of the reinforcing material is more preferably in the range of 20 to 100 parts by mass, and further preferably in the range of 30 to 80 parts by mass.

  The composition may contain a release agent. The mold release agent can contain one or more materials selected from the group consisting of commonly used fatty acids, fatty acid metal salts, minerals, and the like. In particular, the release agent preferably contains one or more materials selected from the group consisting of fatty acid-based materials and fatty acid metal salt-based materials that are excellent in heat discoloration.

  The release agent preferably contains at least one material selected from the group consisting of stearic acid, zinc stearate, aluminum stearate, and calcium stearate.

  It is preferable that the quantity of a mold release agent with respect to 100 mass parts of thermosetting resins in a composition exists in the range of 1-15 mass parts. In this case, the good releasability of the light reflector 1 during molding and the excellent appearance of the light reflector 1 are compatible, and the light reflectivity of the light reflector 1 is particularly high.

  The composition may contain a thickener for adjusting the melt viscosity. The thickener can contain, for example, nano silica. In this case, the nano silica may also serve as at least a part of the inorganic filler. A specific example of nanosilica is Leolosil CP-102 sold by Tokuyama Corporation. The ratio of the thickener in the composition is preferably 0.15% by volume or less. In this case, the strength of the light reflector 1 is ensured together with the door that ensures good fluidity when the composition is melted.

  The central particle size of the thickener is preferably in the range of 1 nm to 1000 nm. When the center particle size is 1 nm or more, the dispersibility of the thickener in the composition is good. Moreover, the burr | flash of the light reflector 1 is suppressed as a center particle size is 1000 nm or less. It is more preferable if the center particle diameter of the thickener is in the range of 10 nm to 1000 nm.

  The composition may contain an antioxidant. When the composition contains an antioxidant, a temporal decrease in the light reflectance of the light reflector 1 is further suppressed. Moreover, the storage stability of a composition becomes high by containing antioxidant.

  The antioxidant can contain, for example, one or more compounds selected from the group consisting of phenolic antioxidants, thioether antioxidants, and phosphorus antioxidants. In particular, it is preferable that the antioxidant contains a phosphorus-based antioxidant. Phosphorous antioxidants include, for example, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 4,4′-butylidenebis (3-methyl-6-tert-butylphenyl-di-tridecyl) Phosphite) and one or more compounds selected from the group consisting of diphenylisodecyl phosphite. The antioxidant may contain hindered phenol.

  The amount of the antioxidant with respect to 100 parts by mass of the epoxy resin is preferably in the range of 1 to 20 parts by mass. When the amount of the antioxidant is 1 part by mass or more, a sufficient antioxidant effect can be obtained. Further, when the amount of the antioxidant is 20 parts by mass or less, the light reflector 1 is more difficult to discolor. That is, when the amount of the antioxidant is in the range of 1 to 20 parts by mass, the light reflectance of the light reflector 1 is less likely to decrease with time. The amount of the antioxidant is more preferably in the range of 3 to 18 parts by mass, and even more preferably 5 parts by mass or more.

  The composition may contain an optical brightener. When the composition contains a fluorescent brightening agent, the light reflectance of the light reflector 1 becomes higher. The optical brightener can contain one or more compounds selected from the group consisting of, for example, benzoxazole derivatives, coumarin derivatives, imidazole derivatives, and stilbene derivatives. In particular, it is preferable that the optical brightener contains a benzoxazole derivative. The ratio of the optical brightener in the composition is preferably in the range of 0.001 to 1% by mass. In this case, the light reflectance of the light reflector 1 becomes higher.

  The composition may contain additives other than the above components, for example, one or more compounds selected from the group consisting of a colorant, a flame retardant, and a flexibility imparting agent.

  The composition may be in solid form. In this case, the storage stability and handling properties of the composition are enhanced. For example, the composition may be granular, powdery, and the like. In particular, the composition is preferably solid at 30 ° C. or lower. In this case, the composition can be easily processed into granules by pulverization, extrusion pellet processing, or the like. It is also preferred that the composition has shape retention at 50 ° C. or lower. In this case, the handleability of the composition and the workability when using the composition are particularly high.

  The composition can be prepared without solvent. In this case, a solid resin composition can be easily obtained.

  In preparing the composition, for example, the above raw materials are first blended at a predetermined ratio in an appropriate order and mixed with a mixer such as a mixer or a blender to obtain a mixture. When the raw material is solid, the raw material can be easily mixed with a mixer. This mixture is kneaded by a kneader, an extruder or the like capable of being heated and pressurized. As the kneader, for example, a pressure kneader, a heat roll, an extruder, or the like is used. Subsequently, the bulk of the mixture is pulverized and sized, or further granulated as necessary to obtain a composition. The composition is, for example, in the form of granules, powders or pellets.

The light reflector 1 applied to the light emitting device 6 is manufactured by injection molding the composition. The injection molding conditions are appropriately set. For example, the resin temperature is in the range of 60 to 120 ° C., the mold temperature is in the range of 150 to 180 ° C., and the filling pressure is 7.8 to 24.5 MPa (80 to 250 kgf / cm). ^In the range of ² ), the curing time is preferably in the range of 30 to 300 seconds.

  Since the light reflector 1 obtained in the present embodiment is made from a composition containing an epoxy resin, it has high adhesion to a metal member. For this reason, for example, even if the metal lead frame 2 is embedded in the light reflector 1, the metal lead frame 2 is not easily detached from the light reflector 1.

  FIG. 1 and FIG. 2 show an example of a light emitting device 6 including a light reflector 1, a metal lead frame 2, and a light emitting element 3. In this example, a metal lead frame 2 is embedded in the light reflector 1.

  The light reflector 1 includes a base portion 11 and a protruding portion 12 that protrudes from the upper surface of the base portion 11. The protrusion 12 is formed with a recess 13 that opens on the upper surface thereof. The metal lead frame 2 is embedded in the base portion 11. The metal lead frame 2 includes a first lead 21 and a second lead 22. Each of the first lead 21 and the second lead 22 is exposed in the recess 13 at the bottom surface of the recess 13. The first lead 21 and the second lead 22 are disposed with a space in the base portion 11 so that the first lead 21 and the second lead 22 are electrically insulated from each other. . The first lead 21 and the second lead 22 are exposed to the outside also on the lower surface of the base body. An insulating member 5 is provided on the lower surface of the base portion 11 at a position extending from the first lead 21 to the second lead 22, and the member 5 is provided with the first lead 21 and the second lead 22. Suppresses the short circuit between.

  For example, a light emitting diode is used as the light emitting element 3, but is not limited thereto. The light emitting element 3 is mounted on the first lead 21 in the recess 13. Further, in the recess 13, the light emitting element 3 and the first lead 21 are electrically connected by the first wire 41, and the light emitting element 3 and the second lead 22 are connected by the second wire 42. Has been.

  The inner peripheral surface 14 of the recess 13 of the light reflector 1 is inclined so that the inner diameter of the recess 13 increases toward the opening side. For this reason, the light emitted from the light emitting element 3 is easily reflected by the inner peripheral surface 14 of the recess 13 in the light reflector 1, and as a result, the light extraction efficiency from the light emitting device 6 is increased.

  In the light emitting device 6, if necessary, the inside of the recess 13 may be sealed with a transparent resin, and the opening of the recess 13 may be covered with a transparent cover.

  The light reflector 1 in which such a metal lead frame 2 is embedded is manufactured by, for example, an insert molding method. That is, for example, a metal lead is disposed inside an injection mold, and the light reflector 1 is manufactured by injection-molding the composition in the injection mold in this state.

[Examples 1 to 13, Comparative Examples 1 to 3]
The raw materials shown in Tables 1 and 2 were mixed and uniformly mixed with a sigma blender, and then kneaded with a hot roll heated to 100 ° C. to obtain a sheet-like kneaded product. The kneaded product was cooled and then pulverized and sized to obtain a granular composition.

[Examples 14 to 25]
Unsaturated polyester shown in Tables 3 and 4, cross-linking agent, curing catalyst, white pigment and inorganic filler are mixed, and the resulting mixture is uniformly mixed in a sigma blender and then kneaded with a hot roll heated to 100 ° C. As a result, a sheet-like kneaded product was obtained. The kneaded product was cooled and then pulverized and sized to obtain a granular unsaturated polyester resin composition.

  This unsaturated polyester resin composition and the epoxy resin compounded product shown in Tables 3 and 4 are uniformly mixed in a sigma blender, and then kneaded with a hot roll heated to 100 ° C., so that a sheet-like kneaded product is obtained. Got. The kneaded product was cooled and then pulverized and sized to obtain a granular composition.

  Of the epoxy resin blends in the table, “epoxy resin composition A” is the composition of Example 1, “epoxy resin composition B” is the composition of Example 7, and “epoxy resin composition C” is It is the composition of Example 8.

[Comparative Examples 4 and 5]
By mixing the unsaturated polyester, the crosslinking agent, the curing catalyst, the white pigment, and the inorganic filler shown in 4 and mixing the resulting mixture uniformly with a sigma blender, the mixture is kneaded with a hot roll heated to 100 ° C. A sheet-like kneaded product was obtained. The kneaded product was cooled and then pulverized and sized to obtain a granular composition.

[Evaluation test]
(Injection moldability evaluation)
A 150-ton thermosetting injection molding machine manufactured by Matsuda Seisakusho was used as an injection molding machine, and the compositions obtained in the examples and comparative examples were injection molded under conditions of a mold temperature of 180 ° C. and a curing time of 180 seconds. Thereby, the test piece based on JISK6911 was produced.

  This injection molding was repeated using the same injection mold, and the number of moldings until resin clogging occurred in the injection mold was used as an index for continuous moldability. The results are shown in the table below. Note that “> 100” indicates that no resin clogging occurs even if the injection molding is repeated 100 times.

(Liquidity assessment)
The spiral flow length of the composition obtained in each example and comparative example was measured. In this case, a 150-ton thermosetting injection molding machine manufactured by Matsuda Seisakusho was used as an injection molding machine, and measurement was performed under conditions of a mold temperature of 180 ° C. and a curing time of 180 seconds. The results are shown in the table below.

(Bali evaluation)
For each example and comparative example, the maximum protrusion size of the burr produced on the test piece obtained in the above “evaluation of injection moldability” was measured. The results are shown in the table below.

(Adhesion evaluation)
A base material 7 made of a silver-plated copper substrate having a size of 12 mm × 49 mm × 1.5 mm was prepared. By molding the compositions obtained in each of the examples and comparative examples by injection molding (insert molding), a molded body 8 having a size of 12 mm × 49 mm × 3 mm overlapped with the base material 7 was produced as shown in FIG. The overlapping width of the base material 7 and the molded body 8 is 12 mm. The injection molding conditions are a 150-ton thermosetting injection molding machine manufactured by Matsuda Seisakusho as an injection molding machine, a mold temperature of 180 ° C., and a curing time of 180 seconds. The shear adhesion strength was measured by applying stress in the direction of the arrow in FIG. 3 to each of the base material 7 and the molded body 8.

(Defect rate evaluation)
About Examples 14-25 and Comparative Examples 4 and 5, the sample for evaluation was produced by carrying out injection molding of the composition. The injection molding conditions were a mold temperature of 180 ° C. and a curing time of 180 seconds. In this case, insert molding using a silver-plated copper frame (insert portion: width 0.6 mm × thickness 0.25 mm) was performed.

  The obtained 100 samples for evaluation were observed, the case where peeling between the sample for evaluation and the copper frame was observed was evaluated as defective, and the number of occurrences of defects was counted.

(Light reflectance evaluation)
A 150-ton thermosetting injection molding machine manufactured by Matsuda Seisakusho was used as an injection molding machine, and the compositions obtained in the examples and comparative examples were injection molded under the conditions of a mold temperature of 160 ° C. and a curing time of 60 seconds. As a result, a plate-like test piece having a size of 50 mm × 50 mm × 1 mm was obtained.

  Immediately after molding the test piece, the light reflectance of the test piece was measured using a reflectometer (Nippon Denshoku, model number SD6000).

  Subsequently, the test piece was heated at a temperature of 150 ° C. for 1000 hours, and then the light reflectance of the test piece was measured.

  These results are shown in the table below.

  1 Light reflector

Claims (7)

A thermosetting resin composition used for producing a light reflector,
Containing an epoxy resin, a phenol novolac resin, a white pigment, and a compound represented by the following formula (1),
A thermosetting resin composition for a light reflector, which is used for producing a light reflector by an injection molding method.
In formula (1), each of Y and Z is independently hydrogen, halogen or a lower alkyl group, and each of R is independently a lower alkyl group. The thermosetting resin composition for light reflectors according to claim 1, wherein the compound represented by the formula (1) contains a compound represented by the following formula (2).
The thermosetting resin composition for light reflectors according to claim 1 or 2, further comprising an unsaturated polyester. The ratio of the phenol novolak resin to the epoxy resin is in the range of 20 to 120% by mass, and the ratio of the compound represented by the formula (1) to the epoxy resin is in the range of 3 to 20% by mass. The thermosetting resin composition for light reflectors according to any one of claims 1 to 3. The light reflection according to any one of claims 1 to 4, wherein the white pigment contains one or more materials selected from the group consisting of titanium oxide, barium titanate, barium sulfate, zinc oxide, and zinc sulfide. Thermosetting resin composition for body. A method for producing a light reflector, comprising a step of injection molding the thermosetting resin composition for a light reflector according to any one of claims 1 to 5. A light reflector manufactured by the method according to claim 6.