JP2018160655A - Molding material for light reflector and method for producing the same, light reflector, base body and method for producing the same, and light emitting device - Google Patents

Abstract

[PROBLEMS] To produce a light reflector that has high strength, high toughness, and good heat discoloration and light reflectivity even if the glass fiber content is small or no glass fiber. Provided is a molding material for a light reflector that can be used.
A molding material for a light reflector contains a thermosetting resin and rubber particles. The rubber particles include a core part and a shell part that covers the core part. The content of the rubber particles is in the range of 0.1% by mass to 30% by mass with respect to the total amount of the molding material for light reflector.
[Selection] Figure 1

Description

  The present invention generally relates to a molding material for a light reflector and a manufacturing method thereof, a light reflector, a base body and a manufacturing method thereof, and a light emitting device. More specifically, the present invention particularly relates to a molding material for a light reflector suitably used for the production of a side view type light reflector and a method for producing the same, a light reflector, a base body including the light reflector, and a method for producing the same. And a light emitting device.

  In recent years, the use of light-emitting diodes as a light source to replace fluorescent lamps and incandescent lamps has been rapidly expanding. As an example, a light emitting device including a light emitting element such as a light emitting diode and a resin light reflector (reflector) configured to reflect light emitted from the light emitting element is used for lighting applications. . At present, the problem is how long the initial luminance of a light emitting device incorporating such a light emitting diode can be maintained.

  One of the causes of a decrease in luminance of the light emitting device is a decrease in light reflectance due to discoloration of the light reflector due to heat. For this reason, it is considered that the lifetime of the light emitting device can be extended if the light reflector is manufactured from a material with little thermal discoloration.

  For example, ceramics are known as materials having good heat discoloration. However, ceramics have a limit in processing accuracy, are easily brittle fractured, and are expensive, so they are not versatile and are not suitable as a material for a light reflector.

  On the other hand, a polyamide resin generally called nylon is excellent in chemical resistance, heat resistance, wear resistance, and toughness, and is inexpensive as compared with ceramics. Therefore, it is widely used for illumination. However, the light reflector made of nylon is greatly discolored by heat, and the life of the light emitting device cannot be extended as expected.

  Then, manufacturing a light reflector with thermosetting resins, such as unsaturated polyester resin and an epoxy resin, is proposed (for example, refer patent documents 1-3). The light reflector manufactured with the thermosetting resin has an advantage of excellent heat discoloration.

Japanese Patent No. 4844699 Japanese Patent No. 5153952 JP 2014-019747 A

  However, it is difficult to obtain high toughness and high strength comparable to nylon with thermosetting resins such as unsaturated polyester resins and epoxy resins. Generally, high strength is imparted to the light reflector by adding glass fiber to the light reflector, but it is difficult to impart high toughness.

  An object of the present invention is to provide a light reflector that has high strength and high toughness even when the glass fiber content is low or does not contain glass fiber, and also has good heat discoloration and light reflectivity. An object of the present invention is to provide a molding material for a light reflector that can be produced, a production method thereof, a light reflector, a base body, a production method thereof, and a light emitting device.

  The molding material for light reflectors according to one embodiment of the present invention is a molding material for light reflectors, and the molding material for light reflectors contains a thermosetting resin and rubber particles. The rubber particles include a core part and a shell part that covers the core part. Content of the said rubber particle exists in the range of 0.1 mass% or more and 30 mass% or less with respect to the said molding material for light reflectors.

  The manufacturing method of the molding material for light reflectors which concerns on 1 aspect of this invention is a manufacturing method of the said molding material for light reflectors, The mixture containing the said thermosetting resin and the said rubber particle is 60 degreeC or more and 160 degreeC. It includes kneading while heating at a temperature within the following range, and then processing into powder, granules or pellets.

  The light reflector which concerns on 1 aspect of this invention contains the hardened | cured material of the said molding material for light reflectors.

  A base body according to an aspect of the present invention includes the light reflector and a lead.

  The manufacturing method of the base body which concerns on 1 aspect of this invention includes shape | molding the said molding material for light reflectors, and producing a light reflector. At the time of manufacturing the light reflector, the light reflector and the lead are integrated so that a part of the lead protrudes from the light reflector.

  A light emitting device according to an aspect of the present invention includes the light reflector and a light emitting element.

  In one embodiment of the present invention, even if the content of the glass fiber is small or the glass fiber is not contained, the light reflection has high strength, high toughness, and good heat discoloration and light reflectivity. There is an advantage that it is possible to provide a molding material for a light reflector that can manufacture a body and a manufacturing method thereof, a light reflector, a base body and a manufacturing method thereof, and a light emitting device.

FIG. 1 is a perspective view showing a light emitting device and a substrate including a light reflector in an embodiment of the present invention. In FIG. 1, an X axis, a Y axis, and a Z axis indicate directions orthogonal to each other. 2A is a cross-sectional view of the light-emitting device taken along the line AA in FIG. 2B is a cross-sectional view taken along the line BB of the light emitting device in FIG. 2A and 2B, the X axis, the Y axis, and the Z axis indicate directions orthogonal to each other. 3A to 3C are perspective views showing an example of a series of states in which a lead combined with a light reflector is bent. 3A to 3C, the X axis, the Y axis, and the Z axis indicate directions orthogonal to each other. 4A to 4C are perspective views showing another example of a state of bending a lead combined with a light reflector. 4A to 4C, the X axis, the Y axis, and the Z axis indicate directions orthogonal to each other. FIG. 5A is a plan view showing an example of a lead frame. FIG. 5B is a plan view showing the lead frame of FIG. 5A and a light reflector integrally formed on the lead frame. FIG. 6A is a plan view showing a lead frame and a light reflector integrally formed with the lead frame in another embodiment of the present invention. 6B is a cross-sectional view taken along the line CC in FIG. 6A. FIG. 6C is a bottom view of FIG. 6A. FIG. 6D is a side view of FIG. 6A. 6E is a cross-sectional view taken along the line DD in FIG. 6A. FIG. 6F is an enlarged view of the α portion in FIG. 6A. FIG. 7A is a plan view showing a light reflector suspended by a support bar. FIG. 7B is a perspective view showing a light reflector suspended by a support bar. It is typical sectional drawing of a rubber particle.

  Embodiments of the present invention will be described below. In addition, in this specification and drawings, about the substantially same component, the duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

[Molding material for light reflector]
The molding material for light reflectors according to this embodiment can be suitably used for production of the light reflector 1 (reflector). The light reflector molding material contains a thermosetting resin and rubber particles 13. The rubber particle 13 includes a core portion 14 and a shell portion 15 that covers the core portion 14. The content of the rubber particles 13 is in the range of 0.1% by mass to 30% by mass with respect to the total amount of the light reflector molding material.

  For example, the molding material for light reflector contains a thermosetting resin, a polymerization initiator, a filler, a release agent, and rubber particles 13. The molding material for light reflectors is preferably solid at 30 ° C. or lower. The molding material for light reflectors can be processed into granules by pulverization or extrusion pellet processing.

  In the present embodiment, a light reflector having high strength, high toughness, and good heat discoloration can be produced due to the synergistic effect of the components constituting the light reflector molding material.

  That is, since the molding material for light reflectors contains the core-shell type rubber particles 13, it is possible to make the portion with a small thickness of the light reflector 1 soft and suppress brittleness and ensure high toughness. . Furthermore, when the content of the rubber particles 13 is in the range of 0.1% by mass or more and 30% by mass or less with respect to the total amount of the molding material for light reflector, the thin-wall filling property of the molding material for light reflector is improved. In addition, the light reflector 1 having good heat discoloration and high toughness can be obtained.

  Moreover, since the molding material for light reflectors contains a thermosetting resin, the heat discoloration property of the light reflector 1 becomes favorable.

  For this reason, according to the present embodiment, even if the glass fiber content is small or no glass fiber is contained, the strength is high, the toughness is high, and the heat discoloration and light reflectivity are good. The light reflector 1 can be manufactured.

  Below, the structural component of the molding material for light reflectors is demonstrated first.

(Thermosetting resin)
The component contained in the thermosetting resin may be either a monomer or an oligomer (prepolymer). The thermosetting resin preferably has at least one functional group selected from the group consisting of vinyl group, acryloyl group, carboxyl group, hydroxyl group and epoxy group. This functional group can participate in a reaction such as a cross-linking reaction when molding a molding material for a light reflector.

  Incidentally, the light emitting device 6 includes a light reflector 1 and a light emitting element 3 as shown in FIGS. 2A and 2B described later. If the light reflector 1 is formed of a thermoplastic resin, the light reflector 1 may be deformed by heat when the light emitting element 3 generates heat. However, when the light reflector 1 is made of a molding material for a light reflector containing a thermosetting resin, the light reflector 1 can be prevented from being deformed by heat even if the light emitting element 3 generates heat. it can.

  The thermosetting resin preferably contains one or more components selected from the group consisting of unsaturated polyester resins, epoxy resins, and phenol resins. In this case, the moldability of the light reflector molding material is good. Furthermore, in this case, the light reflector can also have high heat discoloration and high strength.

  In particular, the thermosetting resin preferably contains either one or both of an unsaturated polyester resin and an epoxy resin. The unsaturated polyester resin and the epoxy resin impart higher heat discoloration to the light reflector 1 than the phenol resin, and the light reflector 1 can be hardly discolored even at high temperatures.

  Furthermore, it is preferable that the thermosetting resin contains an unsaturated polyester resin. The unsaturated polyester resin can impart higher heat discoloration to the light reflector 1 than the epoxy resin. The reason is that if the molding material for light reflector contains an unsaturated polyester resin, unreacted functional groups that cause discoloration hardly remain inside the light reflector 1. That is, because the unsaturated polyester resin has a high polymerization rate, it is difficult for unreacted functional groups to remain on the light reflector even if the molding cycle during the production of the light reflector 1 is short.

  The unsaturated polyester resin contains, for example, an unsaturated alkyd resin and a crosslinking agent (copolymerizable compound). The unsaturated alkyd resin starts to soften at, for example, 30 ° C. or higher, preferably 50 ° C. or higher.

  Unsaturated alkyd resins are obtained by dehydration condensation of polybasic acids and glycols. The polybasic acids preferably contain unsaturated polybasic acids. Polybasic acids may further contain saturated polybasic acids.

  Unsaturated polybasic acids contain 1 or more types of components chosen from the group which consists of maleic anhydride, fumaric acid, itaconic acid, and citraconic acid, for example.

  Saturated polybasic acids include, for example, phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, It contains one or more components selected from the group consisting of het acid and tetrabromophthalic anhydride.

  Examples of glycols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, and bisphenol. It contains one or more components selected from the group consisting of A propylene oxide compound and dibromoneopentyl glycol.

  The melt viscosity of the unsaturated alkyd resin is preferably in the range of 0.1 Pa · s to 10 Pa · s. For this purpose, the unsaturated alkyd resin is preferably one or both of an isophthalic acid unsaturated alkyd resin and a terephthalic acid unsaturated alkyd resin. When the unsaturated alkyd resin has the above melt viscosity, the light reflector molding material can have high moldability, and the light reflector 1 can have high heat discoloration.

  The cross-linking agent includes, for example, one or more vinyl copolymerizable monomers selected from the group consisting of styrene, vinyl toluene, divinyl benzene, α-methyl styrene, methyl methacrylate, and vinyl acetate. The crosslinking agent is, for example, at least one copolymer selected from the group consisting of diallyl phthalate, triallyl cyanurate, diallyl tetrabromophthalate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, and 1,6-hexanediol diacrylate. May contain a functional monomer. The crosslinking agent may contain a prepolymer obtained by polymerizing one or more components among the monomers listed above. In particular, the crosslinking agent preferably contains one or more components selected from the group consisting of diallyl phthalate prepolymer, diallyl phthalate monomer, and styrene monomer.

  The mass ratio between the unsaturated alkyd resin and the crosslinking agent in the unsaturated polyester resin is preferably in the range of 99: 1 to 50:50. When the crosslinking agent contains a monomer, as the monomer content increases, the light reflector molding material becomes less solid at room temperature. Therefore, the monomer content is 10 masses per 100 parts by mass of the unsaturated polyester resin. Part or less.

  The epoxy resin is not particularly limited as long as it is a resin having two or more epoxy groups (oxirane rings) in one molecule. The epoxy resin can contain one or more components selected from the group consisting of polyphenol type epoxy resins, glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins and alicyclic epoxy resins. The epoxy resin can also contain an epoxy resin having a triazine skeleton. Specific examples of the epoxy resin having a triazine skeleton include triglycidyl isocyanurate.

  A phenol resin is a thermosetting resin synthesized from phenols and formaldehyde. The phenol resin includes, for example, one or both of a novolac type phenol resin and a resol type phenol resin. The novolac type phenol resin is obtained by condensing phenols and formaldehyde with an acidic catalyst. Cures by adding hexamethylenetetramine to a novolac-type phenolic resin and heating. On the other hand, a resol type phenol resin is obtained by condensing phenols and formaldehyde with an alkali catalyst. When a resol type phenol resin is heated, it dehydrates and crosslinks and cures.

  The content of the thermosetting resin is preferably in the range of 14% by mass or more and 40% by mass or less, and in the range of 16% by mass or more and 34% by mass or less with respect to the total amount of the molding material for light reflector. More preferably, it is more preferably in the range of 20% by mass to 28% by mass. When the content of the thermosetting resin is 14% by mass or more, a decrease in light reflectivity of the light reflector 1 can be suppressed. When content of a thermosetting resin is 40 mass% or less, the fall of the intensity | strength of the light reflector 1 can be suppressed.

(Polymerization initiator)
The molding material for light reflectors can contain a polymerization initiator. When the thermosetting resin has radical polymerization reactivity, the light reflector molding material preferably contains a thermal radical polymerization initiator as a polymerization initiator. The polymerization initiator is not particularly limited, and examples thereof include a thermal 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. , 5-trimethylcyclohexane, t-butylperoxyoctate, benzoyl peroxide, methyl ethyl ketone peroxide, acetylacetone peroxide, t-butylperoxybenzoate and dicumyl peroxide contains. In particular, the polymerization initiator preferably contains an organic peroxide having a 10-hour half-life temperature of 100 ° C. or higher, such as dicumyl peroxide. The polymerization initiator may be further improved in safety by being masterbatched from the viewpoint of prevention of fire and explosion.

  The molding material for light reflectors may contain a curing agent. The curing agent is added to accelerate the curing of the thermosetting resin. For example, when the thermosetting resin contains an epoxy resin, the light reflector molding material contains, for example, hexahydrophthalic anhydride as a curing agent. When the thermosetting resin contains a phenol resin, the light reflector molding material contains, for example, hexamethylenetetramine as a curing agent.

(Filler)
The molding material for light reflectors can contain a filler. The filler contains, for example, one or both of an inorganic filler and a white pigment. That is, the molding material for light reflectors can contain an inorganic filler. Moreover, the molding material for light reflectors can contain a white pigment.

  The inorganic filler contains, for example, one or both of silica and aluminum hydroxide. In particular, the inorganic filler preferably contains silica. Silica contains, for example, one or more components selected from the group consisting of fused silica powder, spherical silica powder, crushed silica powder, and crystalline silica powder. Unless the effect of the molding material for light reflectors according to this embodiment is impaired, the inorganic filler includes hollow particles such as oxides, hydrates, inorganic foamed particles, silica balloons and the like other than those listed above. But you can.

  The average particle size of the inorganic filler is preferably 250 μm or less, more preferably 0.05 μm or more and 100 μm or less, and still more preferably 0.1 μm or more and 10 μm or less. When the inorganic filler having such an average particle diameter is contained in the light reflector molding material, the moldability of the light reflector molding material can be improved, and the light reflectivity of the light reflector 1 and Moisture resistance can also be improved. Further, in the light emitting device 6 shown in FIGS. 2A and 2B described later, the light L emitted from the light emitting element 3 is not reflected by the reflecting surface 23 (inner peripheral surface 12 or the like), but the peripheral wall 10 (upper wall portion 18). Even if they enter the lower wall portion 19 and the two side wall portions 20), the number of refractions of the light L can be increased by the minute inorganic filler as described above. As a result, the light L can be prevented from passing through the peripheral wall 10 and the light concealing property can be improved. In the present specification, the average particle diameter means a particle diameter (median diameter (D50)) at an integrated value of 50% in a particle size distribution obtained by a laser diffraction / scattering method. The laser diffraction / scattering method may use Mie scattering or may not use it. The shape of the particle size distribution in this case is not particularly limited.

  The content of the inorganic filler is preferably 32 parts by mass or more, more preferably 50 parts by mass or more and 250 parts by mass or less with respect to 100 parts by mass of the thermosetting resin. In this case, the moldability of the light reflector molding material can be improved, the heat discoloration of the light reflector 1 can be improved, and the light reflectance can be increased. Furthermore, also in this case, in the light emitting device 6 shown in FIGS. 2A and 2B to be described later, the number of refractions of the light L can be increased by the inorganic filler present in a large amount inside the peripheral wall 10 as described above. As a result, the light L can be prevented from passing through the peripheral wall 10 and the light concealing property of the peripheral wall 10 can be improved.

  The white pigment contains, for example, at least one component selected from the group consisting of titanium oxide, barium titanate, strontium titanate, aluminum oxide, magnesium oxide, zinc oxide, and barium carbonate. In particular, the white pigment preferably contains one or more components selected from the group consisting of titanium oxide, aluminum oxide, and barium titanate. Titanium oxide can contain, for example, one or more components selected from the group consisting of anatase-type titanium oxide, rutile-type titanium oxide, and brookite-type titanium oxide. The titanium oxide preferably contains rutile type titanium oxide having excellent thermal stability.

  The average particle diameter of the white pigment is preferably 2 μm or less, more preferably in the range of 0.1 μm to 1 μm, and still more preferably in the range of 0.2 μm to 0.7 μm. Also in this case, as in the case of the inorganic filler, in the light emitting device 6 shown in FIGS. 2A and 2B to be described later, the light L is emitted inside the peripheral wall 10 by the finer white pigment as compared with the inorganic filler as described above. The number of refractions can be increased. As a result, the light L can be prevented from passing through the peripheral wall 10 and the light concealing property can be improved.

  The content of the white pigment is preferably 100 parts by mass or more, more preferably 100 parts by mass or more and 300 parts by mass or less with respect to 100 parts by mass of the thermosetting resin. When the content of the white pigment is 100 parts by mass or more, the light reflectance of the light reflector 1 can be increased. In this case also, in the light emitting device 6 shown in FIGS. 2A and 2B, which will be described later, the number of times the light L is refracted is increased by the white pigment present in a larger amount than the inorganic filler inside the peripheral wall 10 as described above. Can be made. As a result, the light L can be prevented from passing through the peripheral wall 10 and the light concealing property of the peripheral wall 10 can be improved. When the content of the white pigment is 300 parts by mass or less, the thin-wall filling property of the light reflector molding material can be enhanced, and the bending strength of the light reflector 1 can be further enhanced.

  The total content of the inorganic filler and the white pigment is preferably in the range of 33% by mass or more and 74% by mass or less, more preferably 50% by mass or more and 72% by mass with respect to the total amount of the light reflector molding material. Within the following range.

  The total content of the inorganic filler and the white pigment is preferably 500 parts by mass or less, more preferably from 100 parts by mass to 400 parts by mass with respect to 100 parts by mass of the thermosetting resin. In this case, the fluidity at the time of molding of the light reflector molding material can be improved, and the moldability can be improved.

  The inorganic filler and the white pigment are more likely to be aggregated or oil-absorbed as the particle size becomes smaller, and it becomes difficult to uniformly disperse in the molding material for light reflector. Therefore, in order to improve the dispersibility of the inorganic filler and the white pigment in the molding material for the light reflector, the inorganic filler and the white pigment are surface-treated with one or both of a fatty acid and a coupling agent. It is preferable that

(Release agent)
The molding material for light reflectors can contain a mold release agent. The release agent includes, for example, one or more kinds of wax selected from the group consisting of fatty acid waxes, fatty acid metal salt waxes, and mineral waxes. In particular, the release agent preferably contains one or both of a fatty acid wax and a fatty acid metal salt wax that are excellent in heat discoloration. More specifically, the mold release agent contains, for example, one or more waxes selected from the group consisting of stearic acid, zinc stearate, aluminum stearate, and calcium stearate.

  The content of the release agent is preferably in the range of 4 to 15 parts by mass with respect to 100 parts by mass of the thermosetting resin. In this case, the light reflector 1 has a good releasability from the mold, can have an excellent appearance, and can also have a particularly high light reflectivity.

(Rubber particles)
As schematically shown in FIG. 8, the rubber particles 13 have a core-shell structure. That is, the rubber particle 13 includes a core part 14 and a shell part 15. Any one or both of the core part 14 and the shell part 15 should just have elasticity. That is, both the core portion 14 and the shell portion 15 may be formed of a resin that is elastically deformed, or the core portion 14 is formed of a resin that is elastically deformed, and the shell portion 15 is formed of a resin that is plastically deformed. Alternatively, the core portion 14 may be formed of a resin that is plastically deformed, and the shell portion 15 may be formed of a resin that is elastically deformed. When the light reflector 1 is made of the molding material for the light reflector containing the core-shell type rubber particles 13 as described above, the light reflector 1 can have low elasticity and high toughness.

  The core portion 14 may be formed of a resin that is plastically deformed, and the shell portion 15 may be formed of a resin that is elastically deformed. Preferably, the core part 14 is formed of a resin that is elastically deformed. Thereby, the impact resistance and toughness of the light reflector 1 can be further increased, and the occurrence of cracks in the light reflector 1 can be further suppressed. Specific examples of the elastically deformable resin include a resin having a three-dimensional crosslinked structure or a two-dimensional crosslinked structure. Specific examples of the resin having a three-dimensional crosslinked structure include a polymer obtained by adding a crosslinking agent and, if necessary, a filler to a thermosetting resin to cause a crosslinking reaction. Specific examples of the resin having a two-dimensional crosslinked structure include a polymer obtained by adding a crystal nucleating agent and, if necessary, a filler to a thermoplastic resin to cause a crosslinking reaction. More preferably, both the core part 14 and the shell part 15 have elasticity.

  Preferably, the core part 14 is a particulate rubber. The core portion 14 preferably contains one or more components selected from the group consisting of silicone rubber, acrylic rubber, and butadiene rubber. In particular, when the core portion 14 contains silicone rubber, the weather resistance and impact resistance of the light reflector 1 can be improved. Moreover, when the core part 14 contains acrylic rubber, the fluidity | liquidity at the time of shaping | molding of the molding material for light reflectors can be improved, and the chemical resistance of the light reflector 1 can also be improved. Moreover, when the core part 14 contains a butadiene rubber, the impact resistance of the light reflector 1 can also be improved.

  The shell portion 15 covers the core portion 14. The shell portion 15 preferably has a functional group. The shell portion 15 is preferably composed of a plurality of graft chains 16 having a functional group. One end of each graft chain 16 is bonded to the surface of the core 14. The functional group is preferably at the end of the graft chain 16 on the side not bonded to the core 14. The shell portion 15 preferably has reactivity with the thermosetting resin. That is, it is preferable that the shell part 15 reacts with a thermosetting resin and can be combined chemically. In this case, when the light reflector 1 is produced by curing the molding material for the light reflector, the shell portion 15 reacts with the thermosetting resin and is chemically bonded. Even when the shell part 15 does not react with the thermosetting resin when the molding material for light reflector is cured, the shell part 15 has high affinity with the thermosetting resin. For this reason, the rubber particles 13 are chemically bonded to the resin phase formed by curing the thermosetting resin in the light reflector 1 or closely adhered to the resin phase with high affinity. For this reason, the stress between the resin phase and the rubber particles 13 is easily dispersed, and separation at the interface between the resin phase and the rubber particles 13 is less likely to occur. For this reason, the impact resistance of the light reflector 1 is improved. In order for the shell part 15 to have reactivity with the thermosetting resin, the functional group of the shell part 15 has reactivity with the thermosetting resin, that is, chemically reacts with the thermosetting resin. Preferably it is possible. The functional group includes, for example, one or more groups selected from the group consisting of a methacryl group, an acrylic group, a vinyl group, an epoxy group, an amino group, a carbamide group, a ureido group, a mercapto group, an isocyanate group, and a carboxyl group. Can do. When the thermosetting resin is an unsaturated polyester resin, the functional group preferably has reactivity with the unsaturated double bond in the unsaturated polyester resin, and particularly includes one or both of a methacryloyl group and an acryloyl group. It is preferable. When the thermosetting resin is an epoxy resin, the functional group preferably has reactivity with the epoxy group, and particularly preferably includes one or both of a carboxyl group and an amino group.

  The average particle diameter of the rubber particles 13 is preferably in the range of 0.1 μm to 1 mm. If the average particle diameter of the rubber particles 13 is 0.1 μm or more, the impact resistance of the light reflector 1 can be further improved. If the average particle diameter of the rubber particles 13 is 1 mm or less, the rubber particles 13 are easily dispersed uniformly in the light reflector molding material, and are easily dispersed uniformly in the light reflector 1.

  The content of the rubber particles 13 is preferably in the range of 0.1% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and less than 22% by mass with respect to the total amount of the molding material for light reflector. Within range. Thereby, even if the light reflector 1 has a small thickness portion, defects due to unfilling during molding are less likely to occur. That is, the thin-wall filling property of the molding material for light reflector can be improved, and the light reflector 1 can have a portion with a small thickness. Furthermore, when the content of the rubber particles 13 is within the above range, the light reflector 1 having good heat discoloration and high toughness can be obtained. If the content of the rubber particles 13 is less than 0.1% by mass, the highly tough light reflector 1 may not be obtained. For example, if a force is applied to the light reflector 1 by bending the lead 2 or the like, cracks are likely to occur in the light reflector 1. On the other hand, when the content of the rubber particles 13 exceeds 30% by mass, the ratio of the rubber particles 13 in the light reflector molding material is too large, and the light reflector 1 containing the cured product of the light reflector molding material has a large proportion. Strength may be reduced. Furthermore, the thin-wall filling property of the light-reflecting material may be reduced.

  Preferably, the elastic modulus at 25 ° C. of the rubber particles 13 is 1 GPa or less. Thereby, the toughness of the light reflector 1 can further be improved. In addition, the elastic modulus at 25 ° C. of the rubber particles 13 can be measured by a method defined in JIS K 6254.

  By the way, the presence or absence of the rubber particles 13 in the light reflector 1 is determined by, for example, any one of gas chromatography mass spectrometry (GC / MS) and Fourier transform infrared spectroscopy (FT-IR), or a combination of these methods. Can be confirmed. When the core part 14 of the rubber particle 13 contains silicone rubber, qualitative and quantitative analysis of cyclic siloxane by heat desorption is effective. That is, the sample of the light reflector 1 is heated at, for example, 250 ° C. for 3 minutes, the generated gas is injected into a gas chromatograph mass spectrometer, and the detected cyclic siloxane is qualitatively and semi-quantitatively analyzed in terms of toluene. Thereby, the core part 14 can confirm easily the presence or absence of the rubber particle 13 containing a silicone rubber. When the core part 14 contains acrylic rubber or butadiene rubber, the presence or absence of the rubber particles 13 can be confirmed by infrared spectroscopy (IR).

(White fiber material)
In recent years, as the distance between the light emitting element and the light reflector is shortened and the light emitting device is miniaturized, the thickness of the light reflector is reduced. For example, a side view type light reflector has a very thin portion. When the light reflector contains glass fibers, if the light reflector has a portion with a small thickness, the light that reaches the light reflector may not be sufficiently reflected. One of the causes is that the glass fiber is arranged so as to cross the light reflector, so that the glass fiber forms a path of light passing through the light reflector, and the light easily passes through the light reflector. Can be mentioned. Yet another cause is that light that has entered the light reflector is confined in the light reflector as it is. Actually, it is considered that light is attenuated by being absorbed by the light reflector. For this reason, it is difficult for a small light reflector to have a high light reflectance. On the other hand, unless the light reflector contains glass fiber, it is difficult for the light reflector to have sufficient strength.

  Therefore, in order to obtain a molding material for a light reflector that can produce a light reflector 1 that has high strength, high toughness, and good heat discoloration and light reflectivity, The molding material preferably contains a white fiber material. The fiber material being white means that the fiber material does not selectively absorb or reflect light in a specific wavelength region within a range of 400 nm to 700 nm that is a visible light wavelength region. . Specifically, the change rate of the spectral reflectance of the white fiber material in the wavelength region of 400 nm to 700 nm is preferably 20% or less, and more preferably 10% or less. The change rate of the spectral reflectance is the highest reflectance value “A (%)” and the lowest reflectance value “B (%)” in the spectral reflectance in the wavelength range of 400 nm to 700 nm Pa · s. From the above, it is a value calculated by the equation {(A−B) / A} × 100 (%). The white fiber material is preferably not a man-made object such as glass fiber but a natural product or mineral such as wollastonite. Such natural products and minerals have a complex surface, and fine irregularities are formed as compared with glass fiber, so that incident light is likely to diffuse randomly on the surface (that is, whiter than glass fiber). It is easy to see.

  By using a fibrous material made of natural products or minerals, compared to artificially formed glass fibers such as artificially formed fibers, light leakage in the light reflector 1 can be greatly reduced. it can. This is because the surface of the natural product or mineral has a complicated uneven shape, so that it becomes difficult for light to pass through the inside of the natural product or mineral.

The average fiber diameter of the white fiber material is preferably in the range of 0.1 to 30 μm, and more preferably in the range of 0.3 to 20 μm. The average fiber length of the white fiber material is preferably in the range of 5 μm to 400 μm, and more preferably in the range of 50 μm to 150 μm. Since the average fiber length of the white fiber material affects the strength of the light reflector 1, it is more preferable that the white fiber material matches the size of the light reflector 1. That is, the preferable range of the average fiber length of the white fiber material is such that the size of the first molded portion 101 of the light reflector 1 is X ₁₀₁ (0.3 to 0.4 mm, as shown in FIGS. 2A and 2B. ) × Y ₁ (2.8 to 3.2 mm) × Z ₁ (0.25 to 0.40 mm) is particularly effective when the size is within the space. In addition, the average fiber diameter and average fiber length of a white fiber material are the arithmetic mean values of the fiber diameter and fiber length obtained by image-processing the electron micrograph of a white fiber material, respectively.

  The aspect ratio of the white fiber material is defined by the value of the ratio of the average fiber length to the average fiber diameter. The aspect ratio of the white fiber material is preferably in the range of 3 to 500, more preferably in the range of 3 to 20. In this case, the strength of the light reflector 1 is effectively improved, and the surface roughness of the light reflector 1 after the deburring process is effectively suppressed.

The white fiber material preferably contains wollastonite. In this case, the light reflectivity and strength of the light reflector 1 are particularly high. Wollastonite is represented by the chemical formula CaSiO ₃ and is also called calcium metasilicate. The average fiber diameter of wollastonite is preferably in the range of 1 μm to 125 μm. The average fiber length of wollastonite is preferably in the range of 20 μm to 500 μm. The aspect ratio of wollastonite is preferably in the range of 3 or more and 20 or less.

  The white fiber material may contain components other than wollastonite. Components other than wollastonite include inorganic or electrically insulating fibers and whiskers other than wollastonite. Such fibers and whiskers can effectively increase the strength of the light reflector 1 even if the addition amount is small.

  For example, the white fiber material can contain potassium titanate. The average fiber diameter of potassium titanate is preferably in the range of 0.1 μm to 1 μm, and more preferably in the range of 0.3 μm to 0.6 μm. The average fiber length of potassium titanate is preferably in the range of 5 μm to 100 μm, and more preferably in the range of 10 μm to 20 μm. When the average fiber diameter of potassium titanate is in the range of 0.3 μm or more and 0.6 μm or less and the average fiber length is in the range of 10 μm or more and 20 μm or less, the molding material for light reflector has particularly good moldability. Can have.

  The white fiber material may contain an alumina filler. The alumina filler contains acicular boehmite. The average fiber diameter of acicular boehmite is preferably in the range of 0.1 μm to 10 μm, more preferably in the range of 0.4 μm to 2 μm. The average fiber length of acicular boehmite is preferably in the range of 1 μm to 20 μm, more preferably in the range of 2 μm to 10 μm. The aspect ratio of acicular boehmite is preferably in the range of 10 to 100, more preferably in the range of 30 to 50. When the average fiber diameter of the acicular boehmite is in the range of 0.4 μm or more and 2 μm or less and the aspect ratio is in the range of 30 or more and 50 or less, the molding material for light reflector may have particularly good moldability. it can.

  The white fiber material may contain silicon carbide whiskers. The light reflector 1 can have high thermal conductivity and heat dissipation when it contains silicon carbide whiskers. The average fiber diameter of the silicon carbide whisker is preferably in the range of 0.2 μm to 2 μm. The average fiber length of the silicon carbide whisker is preferably in the range of 2 μm to 200 μm. In particular, when the average fiber diameter of silicon carbide whiskers is in the range of 0.45 μm to 0.6 μm and the aspect ratio is in the range of 30 to 50, the light reflector molding material has particularly good moldability. Can have.

The white fiber material is made of silicon nitride whisker, mullite, mullite · δ alumina (Al ₂ O ₃ : SiO ₂ = 72: 28) and α · δ alumina (Al ₂ O ₃ : SiO ₂ = 95: 5). One or more selected components may be contained. The average fiber diameter of the silicon nitride whisker is preferably in the range of 0.1 μm to 1.6 μm. The average fiber length of the silicon nitride whisker is preferably in the range of 5 μm to 200 μm. The average fiber diameter of mullite is preferably in the range of 0.1 μm to 10 μm. The average fiber length of mullite is preferably in the range of 10 μm to 100 μm. The average fiber diameter of mullite / δ alumina is preferably in the range of 2 μm to 10 μm. The average fiber length of mullite / δ alumina is preferably in the range of 10 μm to 100 μm. The average fiber diameter of α · δ alumina is preferably in the range of 2 μm to 10 μm. The average fiber length of α · δ alumina is preferably in the range of 10 μm to 100 μm.

  The white fiber material may contain at least one of basic magnesium sulfate and calcium carbonate. In particular, calcium carbonate has good alkali resistance and is available at low cost. The average fiber diameter of basic magnesium sulfate is preferably in the range of 0.5 μm to 1 μm. The average fiber length of basic magnesium sulfate is preferably in the range of 10 μm to 30 μm. The average fiber diameter of calcium carbonate is preferably in the range of 0.5 μm to 1 μm. The average fiber length of calcium carbonate is preferably in the range of 10 μm to 30 μm.

  The white fiber material may contain tetrapod (registered trademark) zinc oxide such as Panatetra (registered trademark) manufactured by Amtec Corporation. The average fiber length of the needle-like portion in the tetrapod (registered trademark) zinc oxide is preferably in the range of 10 μm to 20 μm.

  The white fiber material may contain various ceramic fibers such as hydrous magnesium silicate and potassium titanate fibers.

  A white fiber material may contain only 1 type of components among the several components enumerated above, and may contain 2 or more types of components. If the white fiber material contains two or more components, the characteristics of the components can be combined well.

  The white fiber material is preferably treated with a silane coupling agent. Specific examples of the method for treating the surface of the white fiber material with a silane coupling agent include a dry method and a wet method. According to the dry method, a white fiber material treated with a silane coupling agent can be obtained in a large amount in a short time, and the productivity is increased. According to the wet method, the surface of the white fiber material can be uniformly treated with the silane coupling agent.

  Specific examples of the silane coupling agent will be described separately for the case where the thermosetting resin contains an unsaturated polyester resin and the case where the thermosetting resin contains an epoxy resin.

  When the thermosetting resin contains an unsaturated polyester resin, the silane coupling agent contains one or more components selected from the group consisting of epoxy silane, vinyl silane, methacryl silane, trimethyl silane, acrylic silane, and amino silane. It is preferable to do. Among these, the silane coupling agent preferably contains at least one of methacryl silane and acryl silane. More specifically, the silane coupling agent preferably contains at least one of 3-methacryloxypropyltrimethoxysilane and 3-acryloxypropyltrimethoxysilane. In this case, the light reflector 1 can have particularly high strength.

  When the thermosetting resin contains an epoxy resin, the silane coupling agent preferably contains one or more components selected from the group consisting of epoxy silane, amino silane, iasocyanate and mercapto silane. In particular, the silane coupling agent preferably contains 3-aminopropyltrimethoxysilane. In this case, the light reflector 1 can have particularly high strength.

  The content of the white fiber material in the molding material for light reflector is preferably in the range of 10 to 240 parts by mass with respect to 100 parts by mass of the thermosetting resin. When the content of the white fiber material is 10 parts by mass or more, the light reflector 1 can have particularly high strength. In particular, since the unsaturated polyester resin has a large shrinkage at the time of curing, when the unsaturated polyester resin is contained in the molding material for light reflector, the white fiber material is contained by 10 parts by mass or more, Curing shrinkage can be suppressed. When the content of the white fiber material is 240 parts by mass or less, a decrease in thin-wall filling property of the molded product is suppressed. It is more preferable that the content of the white fiber material is in the range of 50 parts by mass or more and 100 parts by mass or less.

  The presence or absence of a white fiber material that has been treated with a silane coupling agent can be confirmed by infrared spectroscopy (IR). Further, after the sample of the light reflector 1 is broken, the presence or absence of the white fiber material treated with the silane coupling agent can be confirmed by observing the fractured surface with a scanning electron microscope (SEM) or the like. .

(Other ingredients)
The molding material for light reflectors may contain a fibrous filler (reinforcing material) other than the white fiber material, or may not contain a reinforcing material. The reinforcing material is a component that is not included in the filler. When the molding material for light reflectors contains a reinforcing material, the content of the reinforcing material is preferably in the range of 3 to 50 parts by mass with respect to 100 parts by mass of the thermosetting resin.

  The average fiber diameter of the reinforcing material is preferably in the range of 5 μm to 15 μm, and more preferably in the range of 6 μm to 13 μm. In this case, the strength of the light reflector 1 is particularly high. The average fiber length of the reinforcing material is preferably as small as 0.5 mm or less, 0.2 mm or less, 0.1 mm or less, or 0.05 mm or less. Since the reinforcing material having a longer average fiber length is excellent in handleability, for example, a reinforcing material having an average fiber length of 0.5 mm or more and 3 mm or less may be used as a starting material. In this case, even if the reinforcing material has an average fiber length of 0.5 mm or more and 3 mm or less, the average fiber length is 0.5 mm or less, 0.2 mm or less, 0.1 mm by being cut in the kneading step (described later). Hereinafter, it can be shortened to any of 0.05 mm or less. In the kneading step, the cut surface of the reinforcing material can be wetted with the thermosetting resin, and the adhesion strength between the reinforcing material and the thermosetting resin can be increased. Thus, in the kneading step, when the average fiber length of the reinforcing material is reduced to 0.5 mm or less, the strength of the light reflector 1 is particularly increased, and the light reflectance of the light reflector 1 is particularly improved. The average fiber diameter and the average fiber length of the reinforcing material are arithmetic average values of the fiber diameter and the fiber length obtained by image processing of the electron micrograph of the reinforcing material, respectively.

  The reinforcing material may include a material used for manufacturing a fiber reinforced plastic (FRP). Specific examples of the fiber reinforced plastic include bulk molding compound (BMC) and sheet molding compound (SMC). For example, the reinforcing material includes one or more components selected from the group consisting of glass fiber, vinylon fiber, aramid fiber, and polyester fiber.

  It is preferable that the molding material for light reflectors does not contain glass fiber. Even when the light reflector molding material contains glass fibers, the glass fiber content relative to the total amount of the light reflector molding material is preferably 10% by mass or less. In this case, the light reflectivity of the light reflector 1 is particularly improved by greatly reducing the path of light that can be formed by the glass fiber, and even if the light reflector 1 has a portion with a small thickness, The reflector 1 can have high light reflectivity.

  The molding material for light reflectors may contain appropriate additives such as a polymerization inhibitor, a colorant, a thickener, a flame retardant, and a flexibility imparting agent in addition to the above components.

(Bending characteristics of molding materials for light reflectors)
Preferably, the bending strength at 25 ° C. of the cured product of the light-reflecting molding material is 70 MPa or more. When the light reflector molding material contains a white fiber material, more preferably when the light reflector molding material contains a white fiber material treated with a silane coupling agent, It becomes easy to obtain a large bending strength. Thereby, the intensity | strength of the light reflector 1 can further be raised.

  Preferably, the flexural modulus at 25 ° C. of the cured product of the light-reflecting molding material is in the range of 4 GPa to 15 GPa. The rubber particles 13 including the core portion 14 and the shell portion 15 make it easy to obtain a flexural modulus within the above range. Thereby, the toughness of the light reflector 1 can further be improved.

  More preferably, the bending strength at 25 ° C. of the cured product of the molding material for light reflector is 70 MPa or more, and the bending elastic modulus at 25 ° C. of the cured product of the molding material for light reflector is in the range of 4 GPa to 15 GPa. Is within. When the light-reflecting molding material contains both a white fiber material (preferably a white fiber material treated with a silane coupling agent) and rubber particles 13 including a core portion 14 and a shell portion 15. Thereby, it becomes easy to obtain a large bending strength and a bending elastic modulus within the above range. Thereby, the intensity | strength and toughness of the light reflector 1 can further be improved.

[Method of manufacturing molding material for light reflector]
A method for producing a molding material for a light reflector is, for example, kneading a mixture containing a thermosetting resin and rubber particles 13 while heating at a temperature in the range of 60 ° C. or higher and 160 ° C. or lower. Including processing into pellets.

  More specifically, the manufacturing method of the light reflector molding material includes, for example, the following steps A1 to C1.

  Step A1 is a step of obtaining a mixture by mixing the above-described thermosetting resin and rubber particles 13 and, if necessary, a polymerization initiator, a filler, a release agent, a white fiber material, and the like at a predetermined ratio. is there. As described above, the rubber particle 13 includes the core portion 14 and the shell portion 15 that covers the core portion 14. Mixing can be performed using mixers, such as a mixer and a blender, for example.

  Step B1 is a step in which the mixture obtained in Step A1 is kneaded while being heated at a temperature in the range of 60 ° C. to 160 ° C. When the heating temperature is less than 60 ° C., the mixture obtained in step A1 becomes a solid or very high viscosity liquid, which may adversely affect kneading workability. If the heating temperature exceeds 160 ° C, the thermal polymerization reaction of the mixture obtained in step A1 may start in the kneading step. Kneading can be performed using a kneader such as a pressure kneader, a heat roll, or an extruder.

  In step C1, the mixture after heating and kneading obtained in step B1 is processed into one or more shapes selected from the group consisting of powder, granules and pellets. This processing can be performed using an appropriate granulator, granulator, pelletizer, or the like.

[Light reflector]
An example of the light reflector 1 is shown in FIGS. 1, 2A and 2B. In FIG. 1, FIG. 2A and FIG. 2B, directions indicated by arrows X, Y, and Z indicate directions orthogonal to each other. Hereinafter, the direction indicated by the X arrow is referred to as the X-axis direction, the direction indicated by the Y arrow is referred to as the Y-axis direction, and the direction indicated by the Z arrow is referred to as the Z-axis direction.

The light reflector 1 is, for example, an LED reflector, a laser reflector, or the like. For example, as shown in FIGS. 2A and 2B, the light reflector 1 is X ₁ (0.8 to 1.2 mm) × Y ₁ (2.8 to 3.2 mm) × Z ₁ (0.25 to 0). .40 mm), that is, the dimension X _{1 in the} X-axis direction is in the range of 0.8 mm to 1.2 mm, the dimension Y ₁ in the Y-axis direction is in the range of 2.8 to 3.2 mm, and the Z-axis direction. dimension Z ₁ of but is sized to fit in a rectangular parallelepiped in the space is in the range of 0.25mm or 0.40mm, but are not limited to this size.

  The light reflector 1 includes a cured product of the molding material for light reflector described above. The light reflector 1 can be produced by curing the molding material for light reflector described above. Preferably, the light reflector 1 is manufactured by molding and curing the molding material for the light reflector by compression molding, transfer molding, or injection molding.

  The base body 40 includes a light reflector 1 and leads 2. The light reflector 1 may be combined with the lead 2. The lead 2 is embedded in, for example, the light reflector 1. The lead 2 has internal terminals 211 and 221 and external terminals 212 and 222. The lead 2 is conductive. The lead 2 is usually made of metal. For example, after the lead 2 is processed into a predetermined shape within a range of 10 cm to 50 cm on a side and a thickness of 0.05 mm to 1.00 mm, a surface treatment such as tin plating, nickel plating, or silver plating is performed. It is obtained by doing. The internal terminals 211 and 221 are exposed from the inner surface 8 of the recess 11 of the light reflector 1 (see FIG. 2A). The external terminals 212 and 222 protrude from the outer surface 9 of the light reflector 1 (see FIG. 1).

As shown in FIGS. 2A and 2B, the light reflector 1 includes a peripheral wall 10 and a recess 11. The peripheral wall 10 is a cylindrical wall. The recess 11 is surrounded by the peripheral wall 10. More specifically, the light reflector 1 has a first molding part 101 and a second molding part 102. Among these, the first molding portion 101 includes the peripheral wall 10 and the recess 11. The second molding part 102 and the first molding part 101 are integrated in this order by overlapping in the X-axis direction, and the lead 2 is sandwiched between the second molding part 102 and the first molding part 101. As described above, the first molded portion 101 of the light reflector 1 has the recess 11. The recess 11 is open in the X-axis direction. In other words, the direction in which the recess 11 opens is the X-axis direction. The peripheral wall 10 includes an upper wall portion 18 and a lower wall portion 19 that face each other in the Z-axis direction, and two side wall portions 20 that face each other in the Y-axis direction. The thickness Y ₂ of the front end portion of the peripheral wall 10 (the portion far from the bottom surface 17 of the recess 11) may be, for example, 25 μm or more and 100 μm or less. The peripheral wall 10 includes a portion having a thickness of 100 μm or less, for example. In the present embodiment, in particular, the tip portions of the upper wall portion 18 and the lower wall portion 19 include thin portions having a thickness of 100 μm or less. As shown in FIG. 3A, the recess 11 is surrounded by an upper wall portion 18 and a lower wall portion 19 and two side wall portions 20. As shown in FIG. 3A and the like, the shape of the opening of the recess 11 when viewed in the direction opposite to the X-axis direction is a convex shape, but is not limited to this shape. As shown in FIG. 2A, the lead 2 is exposed on the inner surface 8 (particularly the bottom surface 17) of the recess 11. The inner surface 8 of the recess 11 includes a bottom surface 17 and an inner peripheral surface 12. The inner surface 8 of the recess 11 includes a reflective surface 23, and at least the inner peripheral surface 12 includes the reflective surface 23. The depth of the recess 11 is a distance X ₁₀₁ in the X-axis direction from the bottom surface 17 of the recess 11 to the opening. X ₁₀₁ may be, for example, 0.3 mm or more and 0.4 mm or less. The lead 2 includes a first lead 21 and a second lead 22. The first lead 21 includes an internal terminal 211 exposed at the bottom surface 17 of the recess 11 and an external terminal 212 protruding from the outer surface 9 of the light reflector 1 to the outside of the light reflector 1. The second lead 22 also includes an internal terminal 221 exposed at the bottom surface 17 of the recess 11 and an external terminal 222 protruding from the outer surface 9 of the light reflector 1 to the outside of the light reflector 1. As shown in FIG. 3A, the two external terminals 212 and 222 protrude in the same direction (Z-axis direction). The two external terminals 212 and 222 may protrude in a direction orthogonal to the direction in which the opening of the recess 11 faces (X-axis direction) or with respect to the direction in which the opening of the recess 11 faces (X-axis direction). It may be inclined and projecting.

  In the light reflector 1 described above, the volume of the first molded portion 101 (excluding the volume of the recess 11) is smaller than the volume of the second molded portion 102. Moreover, in the 1st shaping | molding part 101, compared with the volume of the side wall part 20, the volume of the upper wall part 18 and the lower wall part 19 is small. In particular, since the upper wall portion 18 and the lower wall portion 19 are portions having a small thickness, when the molding material for light reflector contains a white fiber material during molding, the white fiber material is in the X-axis direction. Orientation tends to cause anisotropy. Compared to the molding material containing thermoplastic resin, the molding material for light reflectors containing thermosetting resin has a much lower viscosity at the time of molding. It becomes easy to align. As a result of the anisotropy as described above, even a portion having a small thickness (for example, a portion having a thickness of 100 μm or less, further 50 μm or less) such as the upper wall portion 18 and the lower wall portion 19 has high strength. be able to. Compared with the upper wall portion 18 and the lower wall portion 19, the side wall portion 20 is less likely to be anisotropic, but since the volume of the side wall portion 20 is larger, it can have high strength even if it is isotropic. . Further, compared with the first molded part 101, the second molded part 102 is less likely to be anisotropic, but since the volume of the second molded part 102 is larger, the second molded part 102 has high strength even if it is isotropic. it can.

  The presence or absence of anisotropy should be confirmed, for example, by measuring the linear expansion coefficient of the cured product in the direction of flow of the molding material for the light reflector during molding and the direction perpendicular thereto by thermomechanical analysis (TMA). Can do. In FIG. 2B, for example, the flow direction is the X-axis direction, and the perpendicular direction is the Y-axis direction.

[Method of manufacturing light reflector and base body]
The manufacturing method of the light reflector 1 and the base body 40 includes producing the light reflector 1 by molding a molding material for the light reflector. The molding method is, for example, compression molding, transfer molding or injection molding. When the light reflector 1 is manufactured, the light reflector 1 and the lead 2 are integrated so that a part of the lead 2 protrudes from the light reflector 1.

  The manufacturing method according to the present embodiment uses the lead frame 200 including the frame 170 and the leads 2 connected to the frame 170 when the light reflector 1 is manufactured. After the light reflector 1 is manufactured, the leads 2 are removed from the frame 170. It may include detaching. The configuration of the lead frame 200 will be described in detail later.

  The manufacturing method according to the present embodiment may include bending the lead 2 after the light reflector 1 is manufactured.

  In the present embodiment, as described above, the light reflector 1 has high strength and high toughness even if the glass fiber content is low or the glass fiber is not contained. Therefore, even if force is applied to the light reflector 1 by the method of manufacturing the light reflector 1 and the base body including detaching the lead 2 from the frame 170, bending the lead 2, and the like, the light reflector 1 In particular, breakage such as cracks and breaks is difficult to occur.

  Specifically, the method for manufacturing the light reflector 1 includes, for example, the following step A2 and step B2. In the following, a method for manufacturing the light reflector 1 shown in FIGS. 1, 2A, and 2B will be described in detail. However, the light reflector 1 is limited to the one shown in FIGS. 1, 2A, and 2B. Not.

  Step A2 is a step of preparing the above-described molding material for light reflector. The molding material for light reflectors can be manufactured as described above.

  In step B2, the molding material for light reflector prepared in step A2 is cured by compression molding, transfer molding or injection molding and integrated with lead 2, and a part of lead 2 is formed from a cured product of molding material for light reflector. Is a step of projecting.

  FIG. 5A shows an example of the lead frame 200. The lead frame 200 is used for manufacturing the light reflector 1 and the base body. The lead frame 200 is conductive and is usually made of metal. A lead frame 200 shown in FIG. 5A is used for many pieces, and has a frame 170 having a plurality of lattices and a plurality of leads 2 connected to the frame 170. In FIG. 5A, the frame 170 has 20 grids. One lattice is the minimum unit. A lead 2 is provided for each lattice. Each lead 2 has a first lead 21 and a second lead 22. The first lead 21 has an internal terminal 211 and an external terminal 212. The second lead 22 has an internal terminal 221 and an external terminal 222.

  Compression molding is a molding method in which the lead frame 200 and the light reflector molding material are set in a mold heated to an appropriate temperature, the mold is closed, and then heated and pressed.

  In transfer molding, the lead frame 200 is set in a mold heated to an appropriate temperature, the light reflector molding material charged in a portion called a pot is pressurized, poured into the mold through an inlet, and heated. The molding method is to pressurize.

  Injection molding is a molding method in which a lead frame 200 is set in a mold heated to an appropriate temperature, and a molding material for a light reflector is injected under pressure into the mold using an injection molding machine. The molding conditions in this case are, for example, a cylinder temperature in the range of 70 ° C. or higher and 90 ° C. or lower, an injection pressure in the range of 5 MPa or higher and 70 MPa or lower, and a mold temperature in the range of 150 ° C. or higher and 170 ° C. or lower. A post-cure process may be performed as needed.

  Injection molding is described in the JIS industrial terminology dictionary (third edition). Injection molding is a type of method for molding thermoplastic resins and thermosetting resins. The molding material is heated and melted in an injection cylinder, and the fluidized molding material is a mold that is tightly closed by an injection plunger or screw. It is a technology that is injected and molded with pressure. (JIS K 6900).

  When the molding material for the light reflector is molded and cured in the mold by compression molding, transfer molding or injection molding, a plurality of light reflectors 1 are formed in the lead frame 200 as shown in FIG. 5B. The lead 2 is manufactured in an integrated state. The light reflector 1 including a cured product of the light reflector molding material is manufactured for each lattice of the frame 170 of the lead frame 200, and external terminals 212 and 222 that are part of the lead 2 are formed from the light reflector 1. It protrudes. In the conventional molding material, burrs, cracks, breaks and the like are likely to occur in the light reflector 1, but if the molding material for light reflectors of this embodiment is used, the occurrence of burrs, cracks and breaks in the light reflector 1 is suppressed. can do.

  After molding and curing the molding material for the light reflector, the light reflector 1 and the lead frame 200 are taken out from the mold, and the lead frame 200 is cut at the position indicated by the broken line in FIG. Disconnect. Thereby, as shown to FIG. 3A, many light reflectors 1 combined with the lead 2 before a bending process can be obtained.

  The light reflector 1 is preferably subjected to a deburring process. The deburring treatment includes, for example, one or more treatments selected from the group consisting of wet blast treatment, alkaline electrolytic treatment, and alkaline solution treatment. The wet blasting process can be performed by a known method using a wet blasting apparatus. Alkaline electrolytic treatment can be performed by a known method using an electrolytic deburring machine. The alkaline solution treatment can be performed, for example, by treating the surface of the light reflector 1 with an alkaline solution such as an aqueous potassium hydroxide solution or an aqueous sodium hydroxide solution.

  If the molding material for light reflector contains a white fiber material and this white fiber material has been treated with a silane coupling agent, the light reflector 1 will be light reflective even if the light reflector 1 has been deburred. It is difficult for the fiber material to jump out from the surface of the body 1 and to fall off. For this reason, even if it contains a white fiber material, the surface roughness of the light reflector 1 can be suppressed. Therefore, it is easy to keep the surface of the light reflector 1 smooth, whereby the light reflectivity of the light reflector 1 can be kept high.

  FIG. 6A shows a lead frame 200 and a light reflector 1 formed integrally with the lead frame 200 in another embodiment. The lead frame 200 includes a frame 170, leads 2 connected to the frame 170, and a pair of support bars 180 connected to the frame 170.

  Each support bar 180 protrudes toward the side wall 20 of the light reflector 1. Each support bar 180 slightly pierces the light reflector 1 around the boundary between the first molding part 101 and the second molding part 102 (see FIG. 6B). 6A is enlarged and shown in FIG. 6F. As shown in FIG. 6F, the dimension D2 along the protruding direction of the support bar 180 of the portion of the support bar 180 that pierces the light reflector 1 is in the range of 70 μm or more and 80 μm or less, for example.

  7A shows an example of the relationship between the light reflector 1 and the support bar 180 when the light reflector 1 of FIG. 1 is manufactured using the lead frame 200 including the support bar 180, and FIG. The same situation is shown. However, in FIG. 7A, illustration of the external terminal 222 is omitted. In addition, when manufacturing the light reflector 1 similar to FIG. 1 using the lead frame 200 including the support bar 180 as described above, the light reflector 1 has a hole at a location where the support bar 180 is stuck. Is formed. 1, 2A, 3A to 3C, and 4A to 4C show the light reflector 1 manufactured using the lead frame 200 without the support bar 180, so that the hole into which the support bar 180 has been pierced is shown. Parts are not shown.

  A distance D3 (see FIGS. 6F and 7B) between the side surface of the support bar 180 and the side surface of the light reflector 1 is, for example, in the range of 30 μm to 40 μm. FIG. 7B corresponds to the light reflector 1 of FIG. 1 and shows the same state as FIG. 6F.

  When the light reflector 1 is made of a conventional molding material, cracks or the like are likely to occur at the γ portion in FIG. 7B when the support bar 180 is pulled out.

  When the light reflector 1 is manufactured using the lead frame 200 including the support bar 180, the light reflector 1 is suspended by the pair of support bars 180. In this state, the light reflector 1 may be deburred. After the deburring process, the lead frame 200 is cut at the position of the broken line shown in FIGS. 6A and 6C, so that the lead 2 is separated from the frame 170 and the support bar 180 is pulled out from the light reflector 1. Thereby, the light reflector 1 combined with the lead 2 before bending can be obtained. In the conventional molding material, when the support bar 180 is pulled out, the light reflector 1 is likely to be cracked or broken. However, if the molding material for the light reflector of this embodiment is used, the light reflector 1 is cracked or broken. Occurrence can be suppressed. In FIG. 6C, 30 is a gate mark. The gate trace 30 is a protrusion formed on the light reflector 1 as a trace of a gate that is an injection port of resin into the cavity of the mold.

  The manufacturing method of the light reflector 1 and the base body 40 may further include the following step C2.

  Step C2 is a step of cutting or bending a part of the lead 2 protruding from the light reflector 1, which is a cured product of the light reflector molding material. The cutting includes cutting of the lead frame 200 in the case of the above-described multi-piece picking. Below, the bending process in process C2, ie, the terminal bending process, will be described.

  As shown in FIG. 3A, external terminals 212 and 222 that are part of the lead 2 protrude from the light reflector 1. As shown in FIGS. 3B and 3C, the external terminals 212 and 222 are bent so as to be arranged to face the surface of the light reflector 1. The arrows in FIGS. 3B and 3C indicate the direction in which the external terminals 212 and 222 of the lead 2 are bent. Thus, by bending the external terminals 212 and 222 of the lead 2, the lead 2 after the bending process and the light reflector 1 combined therewith are obtained. In the bending process, the external terminals 212 and 222 of the lead 2 may be bent as shown in FIGS. 4A to 4C.

  If the lead frame 200 integrated with the light reflector 1 is cut as described above or the lead 2 integrated with the light reflector 1 is bent, a large load is applied to the light reflector 1. It will take. If the light reflector 1 is made of a conventional molding material, the light reflector 1 is likely to be damaged such as burrs, cracks, and breaks when the lead frame 200 is cut or bent. In particular, cracks and the like are likely to occur at the β portion in FIG. 3B. On the other hand, when the light reflector 1 is made of the molding material for light reflector of the present embodiment, the light reflector 1 has high toughness and high strength. Therefore, the lead frame 200 is cut or bent. In this case, it is possible to prevent the light reflector 1 from being damaged such as burrs, cracks, and breaks. In particular, even if the light reflector 1 has a portion with a small thickness, the light reflector 1 has appropriate elasticity and high strength, so that the light reflector 1 is cut when the lead frame 200 is cut or the terminals are bent. Is hard to break. The light emitting device 6 can be manufactured using such a light reflector 1.

  The manufacturing method of the light reflector 1 may include the following step C3 instead of the step C2.

  Step C3 is a step of simultaneously cutting and bending the lead 2 protruding from the light reflector 1, which is a cured product of the light reflector molding material. The cutting includes cutting of the lead frame 200 in the case of the above-described multi-piece picking. At the same time as this cutting, the external terminals 212 and 222 protruding from the light reflector 1 are arranged so as to face the surface of the light reflector 1 as shown by arrows in FIGS. 3B and 3C. Bend it. In this way, by bending the external terminals 212 and 222 of the lead 2, the light reflector 1 combined with the lead 2 after the bending is obtained.

  As described above, when the lead frame 200 integrated with the light reflector 1 is cut and the lead 2 integrated with the light reflector 1 is bent, the light reflector 1 A large load is applied. If the light reflector 1 is made of a conventional molding material, the light reflector 1 is likely to be damaged such as burrs, cracks, and breaks when it is cut and bent simultaneously. On the other hand, when the light reflector 1 is formed of the molding material for light reflector of the present embodiment, the light reflector 1 has high toughness and high strength. The occurrence of breakage such as breakage can be suppressed. In particular, even if the light reflector 1 has a portion with a small thickness, the light reflector 1 has appropriate elasticity and high strength. The reflector 1 is not easily damaged. The light emitting device 6 can be manufactured using such a light reflector 1.

[Light emitting device]
The light emitting device 6 includes a light reflector 1 and a light emitting element 3. An example of a light emitting device 6 including the light reflector 1 is shown in FIGS. 1, 2A, and 2B. The light emitting device 6 includes a light reflector 1, a light emitting element 3, and a lead 2. In this example, the light reflector 1 and the lead 2 are combined because the lead 2 is embedded in the light reflector 1. That is, the light emitting device 6 includes the base body 40 and the light emitting element 3, and the base body 40 includes the light reflector 1 and the leads 2. The structures of the light reflector 1, the base body 40, and the light emitting device 6 manufactured from the light reflector molding material of the present embodiment are not limited to this example.

  The light emitting element 3 is, for example, a light emitting diode (LED) or a laser diode (LD), but is not limited thereto. As shown in FIGS. 2A and 2B, the light emitting element 3 is electrically connected to the internal terminal 221 exposed at the bottom surface 17 of the recess 11 and mounted inside the recess 11 of the light reflector 1. ing. Specifically, the light emitting element 3 is electrically connected to the internal terminal 211 of the first lead 21 with a wire 41.

  The light reflector 1 shown in FIGS. 2A and 2B is a side view type (side light emission type), and is longer than the top view type (top surface light emission type) from the light emitting element 3 to the inner peripheral surface 12 of the recess 11. The distance D1 is very short. For example, the distance D1 is in the range of 0.01 mm to 0.15 mm (10 μm to 150 μm). Thus, when the distance D1 is short, for example, when the peripheral wall 10 is formed of a conventional molding material, it is likely to be deteriorated by the light L emitted from the light emitting element 3. Further, when the thickness of the peripheral wall 10 is small, the light L emitted from the light emitting element 3 easily passes through the peripheral wall 10 and leaks to the outside. The present embodiment can solve such problems as deterioration and light leakage due to the light L of the light reflector 1.

  That is, in this embodiment, since the light reflector molding material contains a thermosetting resin, even if the distance D1 is very short as described above, specifically, the light emitting element 3 to the recess 11 Even if the shortest distance to the inner peripheral surface 12 is 0.15 mm or less, the deterioration of the peripheral wall 10 due to the light L can be suppressed. Further, when the molding material for the light reflector contains a thermosetting resin, the content of the thermosetting resin can be decreased by relatively increasing the content of the filler, so that the peripheral wall Deterioration due to 10 light L can be further suppressed. Moreover, when the content of the glass fiber with respect to the total amount of the molding material for the light reflector is in the range of 0% by mass to 10% by mass, the light path that can be formed by the glass fiber is greatly reduced, Even if the reflector 1 has a portion with a small thickness, light leakage can be suppressed, and the light reflector 1 can have high light reflectivity.

  As shown in FIGS. 2A and 2B, at least a part of the inner peripheral surface 12 of the recess 11 is inclined with respect to the bottom surface 17 of the recess 11 so as to face the opening side of the recess 11. That is, a part or all of the inner peripheral surface 12 of the recess 11 functions as a reflection surface 23 that reflects the light L emitted from the light emitting element 3 toward the opening side of the recess 11. For this reason, the light L emitted from the light emitting element 3 is easily reflected on the inner peripheral surface 12 of the recess 11 in the light reflector 1. As a result, the extraction efficiency of the light L from the light emitting device 6 is increased. The bottom surface 17 of the recess 11 can also function as the reflecting surface 23.

  The light-emitting element 3 may be sealed with the sealing material 5 by filling the recess 11 of the light-emitting device 6 with the sealing material 5. In this case, the light emitting element 3 can be protected from the outside air by the sealing material 5.

  The sealing material 5 is produced from, for example, a sealing resin composition. The sealing resin composition contains, as the thermosetting resin, for example, one or more resins selected from the group consisting of epoxy resins, modified epoxy resins, silicone resins, modified silicone resins, acrylate resins, and urethane resins. be able to.

  The sealing material 5 may contain a fluorescent material as necessary. That is, the encapsulating resin composition may contain a fluorescent material. In this case, the color tone of the light L emitted from the light emitting device 6 can be controlled by the fluorescent material.

  The light reflector 1 according to the present embodiment is mounted on a substrate 7, for example, as shown in FIG. In this case, for example, the external terminals 212 and 222 in the light reflector 1 are connected to the terminals 71 and 72 on one surface 73 of the substrate 7 with solder or the like, respectively. Thereby, the light reflector 1 is supported by the substrate 7 and electrically connected to the substrate 7. The light reflector 1 shown in FIG. 1 is a side view type (side light emission type). That is, when the light reflector 1 is mounted on the substrate 7, the opening of the recess 11 of the light reflector 1 faces the direction along the surface 73 that supports the light reflector 1 of the substrate 7. The light is emitted in a direction along the surface 73.

  Here, the present inventors have obtained the following knowledge. The light reflectivity depends on the thickness of the portion of the light reflector 1 that is exposed to light. When this thickness increases, the light reflectance increases, but when this thickness decreases, the light reflectance decreases. In fact, the inventors made experiments by preparing samples of various thicknesses using the molding material for light reflector according to the present embodiment and the conventional molding material (nylon or the like). As a result, when the thickness is reduced, the light reflectance is drastically decreased in a sample made of a conventional molding material at about 400 μm. On the other hand, in this embodiment, particularly when a white fiber material is included in the light reflector molding material, the sample made of the light reflector molding material should maintain a high light reflectance. I was able to find out. Furthermore, it has also been found that threading caused by glass fibers causes a decrease in light reflectance. The thread means dirt generated when the glass fiber comes into contact with the mold. Also from such a viewpoint, it is preferable that the molding material for light reflectors does not contain glass fiber. Even when the light reflector molding material contains glass fibers, the glass fiber content relative to the total amount of the light reflector molding material is preferably 10% by mass or less. In this case, in addition to the reduction of the light path that can be formed by the glass fiber, it is also possible to suppress the occurrence of threading (particularly, the dirt on the reflecting surface) due to the glass fiber, thereby improving the light reflectivity of the light reflector 1. Can do. Therefore, even if the light reflector 1 has a portion with a small thickness, the light reflector 1 can have high light reflectivity.

  In particular, the side-view type light reflector 1 as shown in FIGS. 1, 2A and 2B is required to be small and thin. For example, the thickness of the upper wall portion 18 and the lower wall portion 19 is very small near the opening of the recess 11 of the light reflector 1. Thus, even if the light reflector 1 has a small size and a small thickness, in the present embodiment, the light reflector 1 contains the core-shell type rubber particles 13, so that the rubber particles 13 have low elasticity. The toughness of the light reflector 1 can be improved. Furthermore, in this embodiment, when the light reflector 1 contains a white fiber material (preferably a white fiber material that has been treated with a silane coupling agent), the white fiber material reduces light transmission while suppressing light transmission. The strength of the reflector 1 can also be improved.

  For example, the minimum thickness of the peripheral wall 10 surrounding the recess 11 in the light reflector 1 may be in the range of 30 μm or more and 200 μm or less, and may be 100 μm or less. In particular, the thickness of the tip portions (the portions far from the bottom surface 17 of the recess 11) of the upper wall portion 18 and the lower wall portion 19 in the peripheral wall 10 may be within a range of 20 μm or more and 60 μm or less, and further 25 μm or more and 50 μm or less The thickness of the base portion of the upper wall portion 18 and the lower wall portion 19 (portion close to the bottom surface 17 of the recess 11) may be within a range of 40 μm or more and 70 μm or less. It may be within a range of 45 μm or more and 60 μm or less. Thus, even if the light reflector 1 has a portion with a small thickness, in this embodiment, the light reflector 1 can have high toughness and high strength, and also high light reflectivity.

  Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to the following examples.

<Manufacture of molding material for light reflector>
The following were used as the structural components of the molding material for light reflectors.

(1) Thermosetting resin (1-1) Unsaturated polyester resin (1-1-1) Unsaturated alkyd resin ・ Terephthalic acid-based unsaturated alkyd resin (“Iupica 8552” manufactured by Iupika Japan)
(1-1-2) Crosslinking agent Diallyl phthalate prepolymer ("Dup Polymer" manufactured by Osaka Soda Co., Ltd.)
(1-2) Epoxy resin Triglycidyl isocyanurate (“TEPIC-S” manufactured by Nissan Chemical Industries, Ltd., epoxy equivalent 100 g / eq)
(1-3) Phenolic resin-Novolac type phenolic resin ("PDR" manufactured by Panasonic Corporation), weight average molecular weight 4000 to 5000
Each of the above thermosetting resins has a double bond.

(2) Polymerization initiator-Polymerization initiator 1: Dicumyl peroxide ("PARK Mill D-40" manufactured by NOF Corporation, 40% masterbatch)
-Polymerization initiator 2: Hexahydrophthalic anhydride (“Rikacid HH” manufactured by Shin Nippon Rika Co., Ltd.)
-Polymerization initiator 3: Hexamethylenetetramine (Mitsubishi Gas Chemical Co., Ltd.)
(3) Filler (3-1) Inorganic filler Silica (“FB-820” manufactured by Denka Co., Ltd., fused silica, average particle size 25 μm)
(3-2) White pigment Titanium oxide (“Tioxide R-TC30” manufactured by Tyoxide Japan Co., Ltd., rutile titanium oxide, average particle size 0.4 μm)
(4) Release agent Zinc stearate (“SZ-P” manufactured by Sakai Chemical Industry Co., Ltd.)
(5) Rubber particles Rubber particles 1: “S2001” manufactured by Mitsubishi Rayon Co., Ltd., core part: silicone rubber, shell part: acrylic rubber, average particle diameter 200 μm, elastic modulus at 25 ° C. 0.1 GPa
Rubber particle 2: “S2200” manufactured by Mitsubishi Rayon Co., Ltd., core portion: nitrile rubber, average particle diameter 200 μm, elastic modulus 0.5 GPa at 25 ° C.
Rubber particles 3: “C-223A” manufactured by Mitsubishi Rayon Co., Ltd., core part: butadiene rubber, shell part: acrylic rubber, average particle diameter 200 μm, elastic modulus at 25 ° C. 0.2 GPa
Rubber particle 4: “W-377” manufactured by Mitsubishi Rayon Co., Ltd., core part: acrylic rubber, shell part: acrylic rubber, average particle diameter 200 μm, elastic modulus at 25 ° C. 0.8 GPa
Rubber particles 5: “EXL-2311” manufactured by Dow Chemical Co., Ltd., core part: acrylic rubber, shell part: styrene, average particle diameter 200 μm, elastic modulus at 25 ° C. of 1.0 GPa
Each of the rubber particles has a core-shell structure.

(6) Fiber material Fiber material 1: Wollastonite (“SH800” manufactured by Kinsei Tech Co., Ltd., average fiber length 130 μm, average fiber diameter 6.5 μm, aspect ratio 20) is obtained by subjecting it to a surface treatment with methacrylic silane. Fiber material: Fiber material 2: Wollastonite (“SH800” manufactured by Kinsei Tech Co., Ltd., average fiber length 130 μm, average fiber diameter 6.5 μm, aspect ratio 20) is a fiber obtained by surface treatment with acrylic silane. Material: Fiber material 3: Wollastonite surface-treated with methacrylic silane (“FPW # 800” manufactured by Kinsei Matec Co., Ltd., average fiber length 12 μm, average fiber diameter 4 μm, aspect ratio 3)
Fiber material 4: Whisker surface-treated with methacrylic silane (“Tismo N” manufactured by Otsuka Chemical Co., Ltd., average fiber length 20 μm, average fiber diameter 0.6 μm, aspect ratio 33)
Fiber material 5: Acicular alumina not subjected to surface treatment (“Cerasure BMI” manufactured by Kawai Lime Industry Co., Ltd., average fiber length 6 μm, average fiber diameter 1 μm, aspect ratio 6)
Fiber material 6: Acicular alumina surface-treated with methacrylic silane ("Cerasur BMI" manufactured by Kawai Lime Industry Co., Ltd., average fiber length 6 μm, average fiber diameter 1 μm, aspect ratio 6)
Fiber material 7: flake-like alumina treated with methacrylic silane ("Cerasure BMT" manufactured by Kawai Lime Industry Co., Ltd., average fiber length 9 μm, average fiber diameter 0.3 μm, aspect ratio 30)
(7) Reinforcing material Glass fiber (“CS 3J-261S” manufactured by Nitto Boseki Co., Ltd.)
The mixture was obtained by mixing the component shown in the column of the composition of Tables 1-4 with the compounding quantity shown to this Table 1-4 using a mixer.

  Next, the mixture was kneaded while heating at a temperature in the range of 60 ° C. to 160 ° C. using a pressure kneader.

  Next, the mixture after heating and kneading was processed into a pellet using a pelletizer, thereby obtaining a molding material for a light reflector.

<Evaluation method>
(Bending strength and flexural modulus)
A test piece based on JIS K 6911 was produced by injection molding using the molding material for light reflector. The molding conditions were a cylinder temperature of 80 ° C., an injection pressure of 40 MPa, a mold temperature of 160 ° C., and a holding time of 180 seconds. The bending strength and bending elastic modulus at 25 ° C. of the obtained test piece were measured according to JIS K 6911.

(Initial light reflectance)
The molding material for light reflectors was molded by injection molding under the conditions of an injection pressure of 20 MPa, a mold temperature of 150 ° C., and a holding time of 120 seconds to produce a test piece having a thickness of 1 mm. The initial light reflectance at a wavelength of 460 nm of the obtained test piece was measured with a reflectance measuring device (spectral colorimeter manufactured by Nippon Denshoku Industries Co., Ltd.).

(Heat-resistant discoloration)
After heating the test piece whose initial light reflectivity was measured at 150 ° C. for 1000 hours, the light reflectivity of the test piece was measured again with a reflectometer (Nippon Denshoku Industries Co., Ltd. spectral colorimeter). . The measurement results were determined according to the following criteria.
“◎”: The light reflectance is 85% or more.
“◯”: The light reflectance is 80% or more and less than 85%.
“Δ”: The light reflectance is 75% or more and less than 80%.
"X": Light reflectance is less than 75%.

(Light concealment)
A molding material for a light reflector was molded by injection molding under the conditions of an injection pressure of 30 MPa, a mold temperature of 150 ° C., and a holding time of 90 seconds to prepare a test piece having a thickness of 100 μm. The light transmittance at a wavelength of 460 nm of the obtained test piece was measured with a reflectance measuring device (Spectral Colorimeter manufactured by Nippon Denshoku Industries Co., Ltd.). The measurement results were determined according to the following criteria. In addition, as the light transmittance is lower, when a light reflector is manufactured with a molding material for a light reflector, light is less likely to be transmitted through a portion having a small thickness. As a result, the light reflector is reduced in size and thickness. It can be determined that a decrease in light reflectivity is less likely to occur.
“◎”: Light transmittance is less than 1.5%.
“◯”: The light transmittance is 1.5% or more and less than 2.0%.
“Δ”: Light transmittance is 2.0% or more and less than 3.0%.
"X": Light transmittance is 3.0% or more.

(Thin fillability)
A lead frame shown in FIG. 5A is prepared, and with this lead frame set in a mold, a molding material for a light reflector is injection-molded with an injection pressure of 10 MPa, a mold temperature of 150 ° C., and a holding time of 120 seconds. Molded under conditions. Thus, as shown in FIG. 5B, the light reflector was manufactured and the light reflector was integrated with the lead frame. The light reflector and the lead frame were taken out from the mold, and the lead frame was cut at the position of the broken line shown in FIG. 5B to separate the lead from the frame of the lead frame. The thickness of the thinnest part in the light reflector is 30 μm. The presence or absence of unfilled in this light reflector was confirmed. From the result, the thin-wall filling property was evaluated as follows.
“◎”: Unfilled light reflector is not observed.
“◯”: Unfilled portion is recognized in a portion of the light reflector having a thickness of 40 μm or less, and unfilled portion is not recognized in a portion having a thickness larger than 40 μm.
“Δ”: Unfilled portion is recognized in the portion of the light reflector having a thickness of more than 40 μm and not more than 60 μm, and unfilled portion is not recognized in the portion having a thickness of more than 60 μm.
“X”: Unfilled portion is recognized in a portion of the light reflector having a thickness greater than 60 μm and 0.1 mm or less, and unfilled portion is not observed in a portion having a thickness greater than 0.1 mm.

(Fiber orientation)
The light reflector was cut along a surface along the direction in which the molding material for the light reflector flows during the production of the light reflector, and the formed cross section was observed with a scanning electron microscope. Further, the light reflector was cut even on a surface orthogonal to the direction in which the molding material for the light reflector flows during the production of the light reflector, and the formed cross section was observed with a scanning electron microscope. Based on these results, the presence or absence of orientation of the fiber material in the light reflector was confirmed. As a result, the fiber orientation was evaluated as “Yes” when the orientation was recognized, and “None” when the orientation was not recognized.

(Lead bending resistance)
By using a lead frame having 480 lattices, 480 samples including light reflectors and leads were produced. For each sample, the lead was bent as shown in FIGS. 3A to 3C in a state where the light reflector was fixed, and then the presence or absence of cracks was confirmed by observing the light reflector with a microscope. From the results, the lead bending resistance was evaluated as follows.
“◎”: In all the samples, no crack was observed in the light reflector.
“◯”: Cracks are observed in the light reflector in samples within the range of 1 to 5 inclusive.
“Δ”: In 6 to 10 samples, cracks are observed in the light reflector.
“X”: In 11 or more samples, cracks are observed in the light reflector.

DESCRIPTION OF SYMBOLS 1 Light reflector 2 Lead 3 Light-emitting element 6 Light-emitting device 13 Rubber particle 14 Core part 15 Shell part 40 Base body

Claims (21)

A molding material for a light reflector,
The light reflector molding material contains a thermosetting resin and rubber particles,
The rubber particles include a core part and a shell part covering the core part,
The content of the rubber particles is in the range of 0.1% by mass to 30% by mass with respect to the total amount of the molding material for the light reflector.
Molding material for light reflectors. The shell part is reactive to the thermosetting resin;
The molding material for light reflectors according to claim 1. The molding material for light reflectors according to claim 1 or 2 whose average particle diameter of said rubber particles is in the range of 0.1 micrometer or more and 1 mm or less. The core portion includes one or more components selected from the group consisting of silicone rubber, acrylic rubber, and butadiene rubber.
The molding material for light reflectors as described in any one of Claim 1 to 3. The elastic modulus at 25 ° C. of the rubber particles is 1 GPa or less.
The molding material for light reflectors as described in any one of Claim 1 to 4. The bending strength at 25 ° C. of the cured product of the light reflector molding material is 70 MPa or more,
The molding material for light reflectors as described in any one of Claim 1 to 5. The flexural modulus at 25 ° C. of the cured product of the molding material for light reflector is in the range of 4 GPa to 15 GPa.
The molding material for light reflectors as described in any one of Claim 1 to 6. The thermosetting resin includes one or more components selected from the group consisting of an unsaturated polyester resin, an epoxy resin, and a phenol resin.
The molding material for light reflectors as described in any one of Claim 1 to 7. Further containing a white fiber material,
The molding material for light reflectors as described in any one of Claim 1 to 8. The white fiber material is subjected to a silane coupling agent treatment,
The molding material for light reflectors according to claim 9. The aspect ratio of the white fiber material is in the range of 3 to 500.
The molding material for light reflectors according to claim 9 or 10. The white fiber material contains wollastonite,
The molding material for light reflectors as described in any one of Claims 9 to 11. The content of the white fiber material is in the range of 10 parts by weight to 240 parts by weight with respect to 100 parts by weight of the thermosetting resin.
The molding material for light reflectors as described in any one of Claims 9-12. It contains no glass fiber, or contains glass fiber and the content of the glass fiber relative to the total amount of the molding material for light reflector is 10% by mass or less.
The molding material for light reflectors as described in any one of Claim 1 to 13. It is a manufacturing method of the molding material for light reflectors according to any one of claims 1 to 14,
Kneading the mixture containing the thermosetting resin and the rubber particles at a temperature in the range of 60 ° C. or more and 160 ° C. or less, and then processing into a powder, granule, or pellet,
Manufacturing method of molding material for light reflector. A cured product of the light reflector molding material according to any one of claims 1 to 14,
Light reflector. A light reflector according to claim 16 and a lead.
Base body. Forming the light reflector by molding the light reflector molding material according to any one of claims 1 to 14,
When producing the light reflector, the light reflector and the lead are integrated so that a part of the lead protrudes from the light reflector,
Manufacturing method of base body. When producing the light reflector, using a lead frame comprising a frame and the lead connected to the frame,
Cutting off the leads from the frame after making the light reflector,
The manufacturing method of the base body of Claim 18. Including bending the lead after fabrication of the light reflector;
The manufacturing method of the base body of Claim 18 or 19. The light reflector according to claim 16 and a light emitting element.
Light emitting device.