JP6587169B2 - Thermosetting resin composition for light reflector - Google Patents

Description

  The present invention relates to a thermosetting resin composition for a light reflector suitable for forming a light reflector for a light emitting element such as an LED reflector.

  Conventionally, a light reflector (reflector) that is attached to a light emitting element such as an LED (Light Emitting Diode) and reflects light is known. A polyamide resin is generally used as a resin for forming the light reflector. However, although the polyamide resin can form a light reflector at a low cost, it has a tendency to have a large decrease in reflectivity in a high-power light-emitting element that is not good in heat discoloration and has a large heat dissipation. Therefore, a technique using an epoxy resin as a resin other than the polyamide resin has been developed (see Patent Document 1).

International Publication No. 2008/059856

  The light reflector is required to have as high a light reflectance as possible. That is, it is important to show a high reflectance in the initial stage and to maintain the reflectance as much as possible even after use. If coloring or the like derived from the raw material occurs during molding, the initial reflectance is lowered and the performance of the light reflector is deteriorated. In addition, the light reflector may be exposed to heat when the light emitting element is mounted or the light emitting element is used. When exposed to heat, the light reflector may be discolored and the reflectivity may decrease. Therefore, it is important that the light reflector is not easily deteriorated by heat. In addition, the light reflector is obtained by molding a resin composition, but it may be required to be molded into a desired shape for the purpose of light reflection and bonding with other members. It is important to facilitate the molding of the product.

  Patent Document 1 discloses a resin composition for light reflection using an epoxy resin. This document describes a resin composition excellent in light reflectivity and manufacturability. However, a resin composition that has a higher reflectance, can suppress discoloration due to heat, and can be easily molded is desired.

  This invention is made | formed in view of said situation, and it aims at providing the thermosetting resin composition for light reflectors which is easy to shape | mold, has a high reflectance, and is hard to deteriorate with a heat | fever.

  A thermosetting resin composition for a light reflector according to the present invention includes an epoxy resin containing tris- (2,3-epoxypropyl) -isocyanurate, a curing agent, and a white pigment, and the tris- (2,3-epoxypropyl) -isocyanurate has a (2R, 2R, 2R) isomer in which the total amount of (2R, 2R, 2S) isomer and (2S, 2S, 2R) isomer is the optical isomer ratio. And 4 times or more of the total amount of (2S, 2S, 2S) bodies.

  In the thermosetting resin composition for light reflectors, the content of the white pigment is preferably 30% by mass or more.

  In the thermosetting resin composition for light reflectors, the curing agent preferably includes a compound having an isocyanuric acid skeleton.

  In the thermosetting resin composition for light reflectors, the curing agent preferably contains an acid anhydride having a melting point of 35 ° C. or higher.

  In the thermosetting resin composition for light reflectors, the curing agent preferably contains at least one of cyclohexanetricarboxylic acid anhydride and hexahydrophthalic anhydride.

  In the thermosetting resin composition for light reflectors, it is preferable to further contain a fluorescent brightening agent.

  The thermosetting resin composition for light reflectors preferably further contains an antioxidant.

  According to the present invention, it is possible to obtain a thermosetting resin composition for a light reflector that is easy to mold, has a high reflectance, and is hardly deteriorated by heat.

It is sectional drawing which shows an example of the LED illuminating device using a light reflector.

  A thermosetting resin composition for a light reflector (hereinafter also simply referred to as “resin composition”) includes an epoxy resin containing tris- (2,3-epoxypropyl) -isocyanurate, a curing agent, a white pigment, , Including. This tris- (2,3-epoxypropyl) -isocyanurate has an optical isomer ratio such that the total amount of (2R, 2R, 2S) and (2S, 2S, 2R) is (2R, 2R, 2R) and (2S, 2S, 2S) are 4 times or more of the total amount.

  Tris- (2,3-epoxypropyl) -isocyanurate is a compound represented by the following structural formula. Another name for tris- (2,3-epoxypropyl) -isocyanurate is triglycidyl isocyanurate.

トリス−（２，３−エポキシプロピル）−イソシアヌレートには、不斉炭素が３つ存在する。各不斉炭素はエポキシ環を構成する炭素となっている。不斉炭素の立体配置が３つとも揃った、トリス−（２，３−エポキシプロピル）−イソシアヌレートとして、（２Ｒ，２Ｒ，２Ｒ）体と、（２Ｓ，２Ｓ，２Ｓ）体とが存在する。（２Ｒ，２Ｒ，２Ｒ）体は、（２Ｒ，２Ｒ，２Ｒ）−トリス−（２，３−エポキシプロピル）−イソシアヌレートのことである。（２Ｓ，２Ｓ，２Ｓ）体は、（２Ｓ，２Ｓ，２Ｓ）−トリス−（２，３−エポキシプロピル）−イソシアヌレートのことである。

Tris- (2,3-epoxypropyl) -isocyanurate has three asymmetric carbons. Each asymmetric carbon is a carbon constituting an epoxy ring. There are (2R, 2R, 2R) and (2S, 2S, 2S) isomers as tris- (2,3-epoxypropyl) -isocyanurate with all three asymmetric carbon configurations. . The (2R, 2R, 2R) isomer refers to (2R, 2R, 2R) -tris- (2,3-epoxypropyl) -isocyanurate. The (2S, 2S, 2S) isomer refers to (2S, 2S, 2S) -tris- (2,3-epoxypropyl) -isocyanurate.

  Further, as tris- (2,3-epoxypropyl) -isocyanurate having only one of the three asymmetric carbons having different optical anisotropy, (2R, 2R, 2S) and (2S, 2S, 2R) There is a body. The (2R, 2R, 2S) isomer refers to (2R, 2R, 2S) -tris- (2,3-epoxypropyl) -isocyanurate. The (2S, 2S, 2R) isomer refers to (2S, 2S, 2R) -tris- (2,3-epoxypropyl) -isocyanurate.

  The structural formula of (2R, 2R, 2S) -tris- (2,3-epoxypropyl) -isocyanurate, which is a (2R, 2R, 2S) isomer, is shown below.

（２Ｓ，２Ｓ，２Ｒ）体である、（２Ｓ，２Ｓ，２Ｒ）−トリス−（２，３−エポキシプロピル）−イソシアヌレートの構造式を下記に示す。

The structural formula of (2S, 2S, 2R) -tris- (2,3-epoxypropyl) -isocyanurate, which is a (2S, 2S, 2R) isomer, is shown below.

（２Ｒ，２Ｒ，２Ｒ）体である、（２Ｒ，２Ｒ，２Ｒ）−トリス−（２，３−エポキシプロピル）−イソシアヌレートの構造式を下記に示す。

The structural formula of (2R, 2R, 2R) -tris- (2,3-epoxypropyl) -isocyanurate, which is a (2R, 2R, 2R) isomer, is shown below.

（２Ｓ，２Ｓ，２Ｓ）体である、（２Ｓ，２Ｓ，２Ｓ）−トリス−（２，３−エポキシプロピル）−イソシアヌレートの構造式を下記に示す。

The structural formula of (2S, 2S, 2S) -tris- (2,3-epoxypropyl) -isocyanurate, which is a (2S, 2S, 2S) isomer, is shown below.

ここで、光学異性体とは、本明細書では、エナンチオマーとジアステレオマーを合わせたものをいう。例えば、（２Ｒ，２Ｒ，２Ｒ）体と（２Ｓ，２Ｓ，２Ｓ）体とは、エナンチオマーの関係にある。例えば、（２Ｒ，２Ｒ，２Ｓ）体と（２Ｒ，２Ｒ，２Ｒ）体とはジアステレオマーの関係にある。例えば、（２Ｓ，２Ｓ，２Ｒ）体と（２Ｓ，２Ｓ，２Ｓ）体とはジアステレオマーの関係にある。

As used herein, the optical isomer refers to a combination of enantiomers and diastereomers. For example, a (2R, 2R, 2R) isomer and a (2S, 2S, 2S) isomer are in an enantiomeric relationship. For example, the (2R, 2R, 2S) isomer and the (2R, 2R, 2R) isomer are in a diastereomeric relationship. For example, the (2S, 2S, 2R) isomer and the (2S, 2S, 2S) isomer are in a diastereomeric relationship.

  The configuration of three asymmetric carbons in the optical isomer of tris- (2,3-epoxypropyl) -isocyanurate is represented by (2R, 2R, 2S) or (2S, 2S, 2R), for example. . As can be seen from the above structural formula, the notation in parentheses represents carbon in different epoxy rings. Therefore, the configuration of the asymmetric carbon may be expressed as (2R, 2'R, 2 "S), (2S, 2'S, 2" R), or the like.

  In tris- (2,3-epoxypropyl) -isocyanurate, the (2R, 2R, 2R) isomer and the (2S, 2S, 2S) isomer are the (2R, 2R, 2S) isomer and (2S, The melting point is higher than that of 2S, 2R). This difference in melting point is considered to be due to the configuration.

  In tris- (2,3-epoxypropyl) -isocyanurate, a mixture of optical isomers can be usually used. At this time, the melting point is measured at a plurality of locations (for example, two locations) by mixing optical isomers having different melting points as described above. The melting point is measured, for example, by DSC (differential scanning calorimetry).

By the way, the racemic mixture of the (2R, 2R, 2R) isomer and the (2S, 2S, 2S) isomer is generally referred to as β-type. The β type is known to give a high melting point type crystal of about 150 ° C. This is because the two enantiomers form a pair of strong six molecular hydrogen bonds and a crystal lattice having a high degree of hydrogen bond with other molecular lattices. A mixture of (2R, 2R, 2S) isomer and (2S, 2S, 2R) isomer is generally called α-type. The α type does not have a crystal structure like the β type, and therefore has a relatively low melting point. The melting point of α-type is about 100 ° C. In addition, although α type and β type are classified due to crystallinity, in this specification, for convenience, at least one of (2R, 2R, 2R) and (2S, 2S, 2S) is included. Is referred to as β- type, and at least one of (2R, 2R, 2S) and (2S, 2S, 2R) -forms is referred to as α- type.

  In tris- (2,3-epoxypropyl) -isocyanurate, the amount of isomers showing a high-temperature melting point increases when shifted to the β-type with many (2R, 2R, 2R) and (2S, 2S, 2S) isomers. The melting point as a whole is high. On the other hand, when shifting to the α type having many (2R, 2R, 2S) and (2S, 2S, 2R) isomers, the amount of isomers showing a low-temperature melting point increases, and the melting point as a whole decreases.

  Usually, the ratio of α-form to β-form present in tris- (2,3-epoxypropyl) -isocyanurate obtained by the conventional method is 3: 1. That is, the ratio of the total amount of (2R, 2R, 2S) body and (2S, 2S, 2R) body to the total amount of (2R, 2R, 2R) body and (2S, 2S, 2S) body is 3 It is.

  Heretofore, tris- (2,3-epoxypropyl) -isocyanurate has been desired to have a high melting point type. The high melting point type tris- (2,3-epoxypropyl) -isocyanurate has a relatively high β-type content, and not only has a high melting point but also a low solubility in various solvents compared to the α-type and the like. . Therefore, when used as a one-component reactive mixture as a cross-linking agent for heterogeneous compounds or reactive polymers, the reaction does not proceed until it is forcibly heated and cured, and is considered useful for electrical and electronic materials. It was done.

  On the other hand, in the thermosetting resin composition for light reflectors, it is important that curing does not proceed at a low temperature such as a storage temperature, but the raw material melts well in order to improve light reflectivity and moldability. It is also important to exhibit fluidity at relatively low heating temperatures. When the ratio of the high melting point type tris- (2,3-epoxypropyl) -isocyanurate is large, when the materials are mixed, the high melting point type is not uniformly mixed but a melting residue is generated, and the reflectance There is a risk of lowering. For example, the resin composition can be produced by kneading, but at a temperature at which the kneading is low, there is a possibility that the melted residue may be generated without being sufficiently dissolved. In order to increase the mixing property of tris- (2,3-epoxypropyl) -isocyanurate, it is conceivable to increase the mixing temperature, but when the temperature is increased, the curing reaction proceeds during mixing, and the fluidity and Storage stability may be reduced. Further, if the ratio of the high melting point type tris- (2,3-epoxypropyl) -isocyanurate is large, the fluidity when heated is lowered, and the moldability may be lowered. Here, the melting point of tris- (2,3-epoxypropyl) -isocyanurate having an α-type: β-type ratio of 3: 1 is 100 to 115 ° C. For this reason, kneading at about 100 ° C. causes undissolved residue and often causes black spots. Therefore, the total amount of the (2R, 2R, 2S) body and the (2S, 2S, 2R) body is 4 with respect to the total amount of the (2R, 2R, 2R) body and the (2S, 2S, 2S) body. Tris- (2,3-epoxypropyl) -isocyanurate that is twice or more is included. This ratio is higher than the ratio 3 of α type to β type obtained by the conventional method. Therefore, the ratio of the high melting point type tris- (2,3-epoxypropyl) -isocyanurate is lowered, and the melting point of the epoxy resin is lowered. Therefore, the melt residue at the time of kneading can be suppressed and the reflectivity can be enhanced, and the fluidity at the time of heating can be increased, thereby improving the moldability. That is, a black spot can be eliminated by using tris- (2,3-epoxypropyl) -isocyanurate having a high α-type ratio.

  The ratio of optical isomers in tris- (2,3-epoxypropyl) -isocyanurate can be expressed as a molar ratio which is the ratio of the amounts of substances. The ratio of optical isomers in tris- (2,3-epoxypropyl) -isocyanurate may be expressed as a mass ratio. This is because they are optical isomers, and the types and amounts of atoms are the same, so that the molecular weights of the compounds themselves are equal.

  In tris- (2,3-epoxypropyl) -isocyanurate, the (2R, 2R, 2S) isomer and the (2S, 2S) isomer with respect to the total amount of (2R, 2R, 2R) isomer and (2S, 2S, 2S) isomer , 2R) The higher the ratio of the total amount of the body, the better. Thereby, while being able to improve reflectivity, the fluidity | liquidity at the time of shaping | molding increases more. For example, the total amount of (2R, 2R, 2S) and (2S, 2S, 2R) isomers is 5 times the total amount of (2R, 2R, 2R) and (2S, 2S, 2S) isomers The above is preferable. The magnification (ratio) is more preferably 6 times or more, more preferably 7 times or more, still more preferably 8 times or more, still more preferably 9 times or more, still more preferably 10 times or more, and more preferably 15 times or more. Even more preferable, 19 times or more is even more preferable. However, if an optically pure compound is to be obtained, the production may not be easy. Therefore, in tris- (2,3-epoxypropyl) -isocyanurate, the total amount of (2R, 2R, 2S) and (2S, 2S, 2R) isomers is (2R, 2R, 2R) and ( For example, it may be 999 times or less of the total amount of (2S, 2S, 2S) bodies. This magnification (ratio) may be 99 times or less, 50 times or less, or 25 times or less.

  The ratio of (2R, 2R, 2S) isomer and (2S, 2S, 2R) isomer contained in tris- (2,3-epoxypropyl) -isocyanurate is not particularly limited. For example, this ratio may be 1: 4 to 4: 1. In this case, tris- (2,3-epoxypropyl) -isocyanurate can be obtained more easily. Alternatively, an equal amount of a mixture having a ratio of 1: 1 may be used. A mixture of equal amounts of enantiomers is called a racemic mixture.

  The ratio of (2R, 2R, 2R) isomer and (2S, 2S, 2S) isomer contained in tris- (2,3-epoxypropyl) -isocyanurate is not particularly limited. For example, this ratio may be 1: 4 to 4: 1. In this case, tris- (2,3-epoxypropyl) -isocyanurate can be obtained more easily. Alternatively, an equal amount of a mixture having a ratio of 1: 1 may be used. A mixture of equal amounts of enantiomers is called a racemic mixture.

  Tris- (2,3-epoxypropyl) -isocyanurate having a high content ratio of (2R, 2R, 2S) and (2S, 2S, 2R) is tris- (2,3-epoxypropyl) -isocyanurate. Can be obtained by adjusting the ratio by an appropriate method and separating and purifying the isomers to increase the ratio. As an isomer separation method, an appropriate method such as a solvent separation method, a recrystallization method, a column chromatography method, or the like can be used. Here, as described above, it is only necessary to purify the α-form so that the amount of the substance is four times or more that of the β-form, and it may not be required until the isomers are completely separated. The separation of diastereomers can be performed relatively easily than the separation of enantiomers.

  The solvent separation method can be carried out by mixing tris- (2,3-epoxypropyl) -isocyanurate in a solvent having high solubility for α-type and low solubility for β-type. If the dissolved tris- (2,3-epoxypropyl) -isocyanurate is collected, the content ratio of the (2R, 2R, 2S) isomer and the (2S, 2S, 2R) isomer can be increased.

  Examples of the solvent include halogen solvents such as dichloromethane, chloroform and trichloroethane, aprotic polar solvents such as dimethylformamide, dimethyl sulfoxide and dimethylacetamide, nitrile solvents such as acetonitrile and adiponitrile, ether solvents such as dioxane and tetrahydrofuran, A ketone solvent such as acetone and methyl ethyl ketone, an ester solvent such as ethyl acetate, and an aromatic solvent such as benzene and toluene can be used alone or in combination.

  In the recrystallization method, for example, if recrystallization is performed under conditions where crystallization of α-type proceeds, and the recrystallized material is collected, (2R, 2R, 2S) and (2S, 2S, 2R) The body ratio can be increased. Further, if the recrystallization is performed under the condition that the β-type crystallization advances and the recrystallized material is removed, the ratio of the (2R, 2R, 2S) body and the (2S, 2S, 2R) body can be increased. it can. As the recrystallization solvent, for example, a solvent such as methanol can be used. Moreover, you may use what was used for said solvent separation method as a solvent.

  In the column chromatography method, isomers can be separated by filling a column with an isomer mixture of tris- (2,3-epoxypropyl) -isocyanurate. A silica gel column etc. can be used as a column. In column chromatography, isomers can be separated with a high degree of purification. In addition, when an optically active column is used, separation of enantiomers can also be performed.

  As an optical resolution agent used for an optically active column, amylose or a cellulose derivative is mentioned, for example. As amylose or cellulose derivatives, amylose or cellulose triester derivatives or tricarbamate derivatives can be used. Aromatic carbamates and the like are preferably used. For example, cellulose triphenyl carbamate, cellulose tris-p-tolyl carbamate, cellulose tribenzoate, cellulose triacetate, cellulose tricinnamate, cellulose tris (3,5-dimethylphenyl carbamate), cellulose tris (4-chlorophenyl carbamate), cellulose tris (4-methylbenzoate), amylose tris (3,5-dimethylphenylcarbamate), amylose tris (1-phenylethylcarbamate) and the like. Among these, cellulose tris-p-tolyl carbamate, cellulose tris (3,5-dimethylphenyl carbamate), amylose tris (3,5-dimethylphenyl carbamate), and amylose tris (1-phenylethyl carbamate) are particularly preferable. Furthermore, among these, amylose tris (3,5-dimethylphenyl carbamate) and amylose tris (1-phenylethyl carbamate) are preferable.

  In the resin composition, those having different isomer ratios may be appropriately mixed to adjust the optical isomer ratio of tris- (2,3-epoxypropyl) -isocyanurate. Thereby, since the melting point of tris- (2,3-epoxypropyl) -isocyanurate can be adjusted and melted at a suitable temperature, a resin composition having excellent storage stability and high reflectivity and fluidity can be obtained. Obtainable. The isomers are preferably mixed by heating to a temperature at which the isomers melt and mix. For example, it can be melt-mixed at 120 ° C. This mixing is preferably performed with tris- (2,3-epoxypropyl) -isocyanurate before other additives such as curing agents are added. If a curing agent is included, curing may proceed.

  Tris- (2,3-epoxypropyl) -isocyanurate having a high content ratio of (2R, 2R, 2S) and (2S, 2S, 2R) is tris- (2,3-epoxypropyl) -isocyanurate. In manufacturing, the optical purity may be adjusted. Tris- (2,3-epoxypropyl) -isocyanurate can be produced, for example, by a method using isocyanuric acid and epihalohydrin as raw materials. Specifically, for example, there is a method in which isocyanuric acid trialkali metal salt obtained by reacting isocyanuric acid with 3 times the amount of alkali metal hydroxide and epihalohydrin are heated in a solvent to cause dechlorination. . Epihalohydrin is a compound having one asymmetric carbon. For the epihalohydrin, a racemate is usually used. At this time, it is possible to adjust the isomer ratio of tris- (2,3-epoxypropyl) -isocyanurate produced by adjusting the optical purity of epihalohydrin.

  Examples of the epihalohydrin include epichlorohydrin, epibromohydrin, epiiodohydrin, and the like.

  Epihalohydrin exists in R form and S form. Therefore, it is possible to adjust the ratio of isomers by using epihalohydrin in which the ratio of R-form to S-form is appropriate. For example, when an optically active epihalohydrin is used as the epihalohydrin, optically active tris- (2,3-epoxypropyl) -isocyanurate can be obtained. Therefore, by appropriately adjusting the optical purity of epihalohydrin, tris- (2,3-epoxypropyl) -isocyanurate having an appropriate optical purity and isomer ratio can be obtained. Therefore, tris- (2,3-epoxypropyl) -isocyanurate having an increased ratio of (2R, 2R, 2S) isomer and (2S, 2S, 2R) isomer can be obtained.

  For the preparation of tris- (2,3-epoxypropyl) -isocyanurate, isocyanuric acid and epihalohydrin were reacted, and the resulting 2-hydroxy-3-halopropyl ester of isocyanuric acid was converted to an alkali metal hydroxide. Alternatively, a method of adding an alkali metal alcoholate can be used.

  In the reaction of isocyanuric acid and epihalohydrin, epihalohydrin is added in an amount of 3 to 60 mol, preferably 6 to 60 mol, more preferably 10 to 30 mol, per mol of isocyanuric acid. At that time, it is preferable to use at least one compound selected from the group consisting of a tertiary amine, a quaternary ammonium salt, a tri-substituted phosphine and a quaternary phosphonium salt as a catalyst. As a usage-amount of a catalyst, it is 0.001-0.1 mol with respect to 1 mol of isocyanuric acids, Most preferably, it is 0.01-0.05 mol.

  In the reaction of isocyanuric acid and epihalohydrin, the water content of the entire reaction mixture can be reduced to less than 1%. The amount of water is preferably 0.1% or less, more preferably 100 ppm or less. The reaction temperature can be 40-115 degreeC. The reaction temperature is preferably 60 to 100 ° C.

  Tris- (2,3-epoxypropyl) -isocyanurate is produced by adding an alkali metal hydroxide or alkali metal alcoholate to 1 mol of 2-hydroxy-3-halopropyl ester of isocyanuric acid as an intermediate. can do. In this method, side reactions can also be suppressed. The addition amount of the alkali metal hydroxide or alkali metal alcoholate is preferably 3.0 to 6.0 mol, more preferably 3.0 to 4.0 mol.

  In the above reaction, other organic solvents can be used in combination with epihalohydrin, but when adjusting the optical purity, the side reaction that decomposes the target product can be suppressed by using epihalohydrin alone as a reaction reagent and solvent. It is preferable because the reaction rate can be increased.

  The epihalohydrin used in industrial production of ordinary tris- (2,3-epoxypropyl) -isocyanurate is mixed with water for recovery and reuse. Moreover, since the reaction which adds epihalohydrin with respect to isocyanuric acid is accelerated | stimulated by adding water with respect to a reaction liquid mixture, generally about 1-5% of water is added with respect to the whole reaction liquid mixture, and reaction is carried out. Done.

  When epihalohydrin is reacted with isocyanuric acid at a high temperature, it may undergo optical isomerization (such as racemization). Therefore, at least one compound selected from the group consisting of a tertiary amine, a quaternary ammonium salt, a tri-substituted phosphine and a quaternary phosphonium salt may be added as a catalyst in order to allow the reaction to proceed gently. preferable. For example, examples of the tertiary amine include tripropylamine, tributylamine, N, N′-dimethylpiperazine and the like. Examples of the tri-substituted phosphine include tripropylphosphine, tributylphosphine, triphenylphosphine, and tolylphosphine. Further, examples of the quaternary ammonium salt include tetramethylammonium halide, tetraethylammonium halide, tetrabutylammonium halide and the like, and examples of the halide include chloride, bromide, and iodide. Furthermore, examples of the quaternary phosphonium salt include tetramethyl phosphonium halide, tetrabutyl phosphonium halide, methyl triphenyl phosphonium halide, ethyl triphenyl phosphonium halide, and the like. And iodide. Among these compounds, quaternary ammonium salts and quaternary phosphonium salts are preferable because the reactions proceed efficiently with less side reactions under milder conditions. More preferably, it is a quaternary ammonium salt, and among them, tetraethylammonium halide is most preferable. By using chloride or bromide as the halide, side reactions are further suppressed, and removal of the catalyst after the reaction can be easily removed by washing with water. To preferred.

  In the reaction of isocyanuric acid and epihalohydrin, the water content of the entire reaction mixture may be suppressed to less than 1% in order to suppress the optical isomerization reaction of epihalohydrin. Of course, if the isomer ratio of the resulting tris- (2,3-epoxypropyl) -isocyanurate is a desired amount, it is also preferable to carry out the reaction in a system in which water is mixed.

  Alkali metal hydroxide or alkali metal alcoholate is added to cause dehydrohalogenation from 2-hydroxy-3-halopropyl ester of isocyanuric acid. Examples of the alkali metal hydroxide include sodium hydroxide, potassium hydroxide, and lithium hydroxide as the metal hydroxide. Examples of the alkali metal alcoholate include sodium methylate, sodium ethylate, potassium methylate, potassium ethylate, and the like.

  After the formation of 2-hydroxy-3-halopropyl ester of isocyanuric acid, alkali metal hydroxide or alkali metal alcoholate can be added as it is. At that time, the epihalohydrin used in excess may be recovered by distillation before adding the alkali metal hydroxide or alkali metal alcoholate. After the recovery, a solvent is added for dilution, and then an alkali metal hydroxide or alkali metal alcoholate can be added. In addition, after recovering the epihalohydrin used in excess by the distillation method, an inexpensive organic solvent having a racemic epihalohydrin or water solubility of 5% or less is added to 1 part by mass of 2-hydroxy-3-halopropyl ester of isocyanuric acid. On the other hand, it may be diluted by adding 1 part by mass or more. Thereafter, an alkali metal hydroxide can be added under dehydration reflux. As the solvent used here, racemic epihalohydrin is particularly preferable because decomposition of the reaction product can be reduced.

  The reaction treated with the alkali metal hydroxide is preferably performed under reflux dehydration while dropping an aqueous alkali metal hydroxide solution. The amount of the alkali metal hydroxide aqueous solution added is preferably 20 to 60% by mass, more preferably 40 to 55% by mass. The reaction temperature is preferably as low as possible, for example, preferably 10 to 80 ° C, more preferably 20 to 70 ° C. Further, it is preferable to adjust the degree of vacuum so that the reflux amount of the solvent can be increased. When the aqueous alkali metal hydroxide solution is added dropwise, the side reaction that decomposes tris- (2,3-epoxypropyl) -isocyanurate is suppressed by setting the reflux amount to 5 times or more of the added amount. preferable.

  By any of the methods described above, the ratio of optical isomers of tris- (2,3-epoxypropyl) -isocyanurate is adjusted. As a result, a tris- () in which the ratio of the one with different optical anisotropy of the asymmetric carbon (α type) to the one with the same optical anisotropy of the asymmetric carbon (β type) is 4 or more. 2,3-epoxypropyl) -isocyanurate can be produced. Of course, the preparation method and purification separation method described above are examples, and if the ratio of the optical isomers is as described above, the tris- (2,3 obtained by an appropriate preparation method and purification separation method is used. -Epoxypropyl) -isocyanurate can be used as epoxy resin.

  The epoxy resin may further contain an epoxy resin other than tris- (2,3-epoxypropyl) -isocyanurate. In this case, a plurality of epoxy resins are used in combination. Thereby, functionality can be improved by the epoxy resin used together, for example, moldability and reflectivity can be improved.

  The epoxy resin is not particularly limited, and a resin generally used as an epoxy resin molding material can be used. Examples of the epoxy resin include epoxidized phenol and aldehyde novolak resins including phenol novolac type epoxy resins and orthocresol novolak type epoxy resins. Examples of the epoxy resin include diglycidyl ethers such as bisphenol A, bisphenol F, bisphenol S, and alkyl-substituted biphenol. Examples of the epoxy resin include glycidylamine type epoxy resins obtained by reaction of polyamines such as diaminodiphenylmethane and isocyanuric acid with epichlorohydrin. Examples of the epoxy resin include a linear aliphatic epoxy resin obtained by oxidizing an olefin bond with a peracid such as peracetic acid, an alicyclic epoxy resin, and the like. These may be used alone or in combination of two or more. The epoxy resin to be used is preferably colorless or, for example, light yellow and relatively uncolored. Examples of such an epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and diglycidyl isocyanurate.

  The amount of tris- (2,3-epoxypropyl) -isocyanurate with respect to the total amount of the epoxy resin is not particularly limited, but is preferably 30% by mass or more. Thereby, reflectivity and moldability can be improved efficiently. The amount of tris- (2,3-epoxypropyl) -isocyanurate with respect to the total amount of the epoxy resin is more preferably 40% by mass or more, further preferably 50% by mass or more, and still more preferably 60% by mass or more. Yes, more preferably 70% by mass or more, still more preferably 80% by mass or more. The upper limit of the amount of tris- (2,3-epoxypropyl) -isocyanurate relative to the total amount of the epoxy resin is not particularly limited, but may be 95% by mass or less. Thereby, the function of epoxy resins other than tris- (2,3-epoxypropyl) -isocyanurate can be exhibited more. Of course, all of the epoxy resin may be tris- (2,3-epoxypropyl) -isocyanurate.

  An epoxy resin oligomer (epoxy resin oligomer) may be used as the epoxy resin. The epoxy resin oligomer is obtained by oligomerizing an epoxy resin. The epoxy resin oligomer preferably has a viscosity at 100 to 150 ° C. in the range of 100 to 2500 mPa · s. This viscosity is particularly preferred in transfer molding. If the melt viscosity of the resin composition after kneading is low and the fluidity is too high, the air vent of the molding die may be blocked and air and volatile components may remain in the die cavity. Air and volatile components remaining in the cavity cause appearance defects such as molding voids and weld marks. As the number of moldings increases, monomer components remaining on the surface of the cured product adhere to the molding die and contaminate the die. As a result of the accumulation of monomer deposits on the mold, there arises a problem that the releasability of the molded article from the mold deteriorates. On the other hand, by using an oligomer having a specific viscosity as described above, it is possible to increase the melt viscosity of the resin composition after kneading and decrease the fluidity. Further, by using such an oligomer, it is possible to reduce residual monomer components that cause mold contamination. As a result, problems that occur when the melt viscosity is low can be avoided, the transfer moldability of the resin composition can be improved, and a molded product having an excellent appearance can be obtained.

  Prior to the preparation of the thermosetting resin composition, the epoxy resin oligomer is prepared by blending at least an epoxy resin and a curing agent and, if necessary, a curing accelerator. As the epoxy resin, the curing agent, and the curing accelerator used for the epoxy resin oligomer, the same epoxy resin as described above, and the curing agent and the curing accelerator described later can be used.

  More specifically, the epoxy resin oligomer is, for example, an active group (acid anhydride) in the curing agent capable of reacting the epoxy resin and the curing agent with the epoxy group with respect to 1 equivalent of the epoxy group in the epoxy resin. (Group or hydroxyl group) can be blended so as to be 0.3 equivalent or less and kneaded until it becomes clayy. It is preferable to provide a step of subsequently aging the obtained clay-like kneaded material at a temperature in the range of 25 to 60 ° C. for 1 to 6 hours. Moreover, when using a hardening accelerator, it is preferable to mix | blend so that it may become 0.005-0.05 mass part with respect to 100 mass parts of total of an epoxy resin and a hardening | curing agent. In the epoxy resin oligomer, the epoxy resin in the epoxy resin may be reacted to such an extent that it is not completely cured.

  As for an epoxy resin oligomer, it is more preferable that the viscosity in 100 degreeC exists in the range of 100-2500 mPa * s. Thereby, it becomes possible to adjust the burr length at the time of molding shorter. If the viscosity of the epoxy resin oligomer is less than 100 mPa · s, burrs are likely to occur during transfer molding. On the other hand, if the viscosity exceeds 2500 mPa · s, the fluidity at the time of molding tends to be low, and the moldability tends to be poor. The “viscosity” may be a value obtained by measurement using an ICI cone plate viscometer. The epoxy resin oligomer can be suppressed or stopped from increasing in viscosity by being pulverized until the particle size becomes 1 mm or less and stored in an environment at a temperature of 0 ° C. or less. The pulverization method of the epoxy resin oligomer can be performed by an appropriate method such as pulverization with a ceramic mortar.

  The epoxy resin oligomer may be an oligomer of tris- (2,3-epoxypropyl) -isocyanurate or an oligomer of an epoxy resin other than tris- (2,3-epoxypropyl) -isocyanurate. Good. The epoxy resin oligomer may be a mixture of an oligomer of tris- (2,3-epoxypropyl) -isocyanurate and an oligomer of other epoxy resin.

  The resin composition contains a curing agent. The curing agent is not particularly limited as long as it is a compound that can react with the epoxy resin. The curing agent preferably has a molecular weight of about 100 to 400. Further, colorless or, for example, a light yellow and relatively uncolored one is preferable. Specific examples of the curing agent include an acid anhydride curing agent, an isocyanuric acid derivative, and a phenol curing agent.

  It is a preferable embodiment that the curing agent contains a compound having an isocyanuric acid skeleton. The compounds having an isocyanuric acid skeleton are isocyanuric acid and isocyanuric acid derivatives.

  Isocyanuric acid derivatives include 1,3,5-tris (1-carboxymethyl) isocyanurate, 1,3,5-tris (2-carboxyethyl) isocyanurate, 1,3,5-tris (3-carboxypropyl) ) Isocyanurate, 1,3-bis (2-carboxyethyl) isocyanurate and the like.

  In one preferred embodiment, the curing agent contains an acid anhydride. In this case, it is more preferable that the curing agent includes an acid anhydride having a melting point of 35 ° C. or higher. Examples of the acid anhydride include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl nadic anhydride, nadic anhydride, glutaric anhydride, anhydrous Examples thereof include dimethyl glutaric acid, diethyl glutaric anhydride, succinic anhydride, methyl hexahydrophthalic anhydride, and methyl tetrahydrophthalic anhydride.

  More preferably, the acid anhydride includes cyclohexanetricarboxylic acid anhydride. In that case, moldability and reflectivity are improved. Cyclohexane tricarboxylic acid anhydride is classified into a solid type and a highly viscous liquid type at 35 ° C. The difference in type is thought to originate from the ratio of isomers. Any type of cyclohexanetricarboxylic acid anhydride may be used. Preferably, a cyclohexanetricarboxylic anhydride that is solid at 35 ° C. can be used.

  Examples of phenolic curing agents include phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol, aminophenol and other phenols and / or naphthols such as α-naphthol, β-naphthol and dihydroxynaphthalene, and formaldehyde Examples thereof include novolak-type phenol resins obtained by condensation or cocondensation with a compound having an aldehyde group such as benzaldehyde and salicylaldehyde under an acidic catalyst. Examples of the phenolic curing agent include phenol / aralkyl resins synthesized from phenols and / or naphthols and dimethoxyparaxylene or bis (methoxymethyl) biphenyl. Examples of the phenolic curing agent include aralkyl type phenol resins such as biphenylene type phenol aralkyl resin and naphthol aralkyl resin. As the phenolic curing agent, dicyclopentadiene type phenol resins such as dicyclopentadiene type phenol novolak resin and dicyclopentadiene type naphthol novolak resin synthesized by copolymerization of phenols and / or naphthols with dicyclopentadiene Is exemplified. Examples of the phenolic curing agent include triphenylmethane type phenol resin, terpene modified phenol resin, paraxylylene and / or metaxylylene modified phenol resin, melamine modified phenol resin, and cyclopentadiene modified phenol resin. Furthermore, as a phenol type hardening | curing agent, the phenol resin etc. which are obtained by copolymerizing 2 or more types of said phenol type hardening | curing agent are illustrated.

  Among the curing agents exemplified above, phthalic anhydride, trimellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, glutaric anhydride, dimethylglutaric anhydride, Use at least one of an acid anhydride selected from the group consisting of diethylglutaric anhydride and cyclohexanetricarboxylic anhydride and isocyanuric acid derivatives such as 1,3,5-tris (3-carboxypropyl) isocyanurate It is preferable to do. These may be used alone or in combination of two or more. Of these, hexahydrophthalic anhydride is more preferably used as the curing agent.

  In a preferred embodiment of the curing agent, it is preferable to use at least an isocyanuric acid derivative as the curing agent, and it is more preferable to use them in combination with an acid anhydride, particularly an acid anhydride having a melting point of 35 ° C. or higher. The triazine skeleton of the isocyanuric acid derivative has a feature that it is less likely to be oxidized by active oxygen than a normal cyclic methylene skeleton. Therefore, it is possible to improve the heat resistance of the molded resin composition by using an isocyanuric acid derivative and imparting the above characteristics to the resin composition. In addition, the mechanical properties of the molded body can be improved by the triazine skeleton and the trifunctional reactive group. Furthermore, by combining the isocyanuric acid derivative with an acid anhydride, the melt viscosity of the resin composition can be increased, and the burr length that protrudes from the mold during molding can be suppressed. The compounding ratio of the isocyanuric acid derivative and the acid anhydride can be appropriately adjusted within a range of 1: 0 to 1:10. From the viewpoint of cost reduction and suppression of a decrease in reflectance due to yellowing of the resin, a mixing ratio of 1: 1 to 1: 3 is preferable.

  In another preferred embodiment of the curing agent, it is preferable to use at least cyclohexanetricarboxylic acid anhydride as the curing agent. By using cyclohexanetricarboxylic acid anhydride, the melt viscosity of the resin composition can be increased, and the burr length at the time of molding can be shortened. Moreover, since the curing time of the resin composition can be shortened, the molding efficiency can be improved. Specific examples of the cyclohexane tricarboxylic acid anhydride include compounds represented by the structural formulas shown below.

シクロへキサントリカルボン酸無水物と共に硬化剤として先に説明した他の酸無水物、イソシアヌル酸誘導体およびフェノール系硬化剤等を併用してもよい。併用する硬化剤としては、成型時の流動性および成型物の着色の観点から、無水フタル酸、無水トリメリット酸、ヘキサヒドロ無水フタル酸、テトラヒドロ無水フタル酸、メチルヘキサヒドロ無水フタル酸、メチルテトラヒドロ無水フタル酸、無水グルタル酸、無水ジメチルグルタル酸、無水ジエチルグルタル酸、または１，３，５−トリス（３−カルボキシプロピル）イソシアヌレートが好ましい。硬化剤におけるシクロへキサントリカルボン酸無水物の含有率は、特に限定されるものではないが、５質量％以上１００質量％以下の範囲で調整することが好ましい。コストと性能とのバランスの観点から、上記含有率は２５質量％以上７５質量％以下の範囲であることが好ましい。

Other acid anhydrides, isocyanuric acid derivatives, phenolic curing agents, and the like described above may be used in combination with the cyclohexanetricarboxylic acid anhydride as the curing agent. The curing agent used in combination is phthalic anhydride, trimellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydroanhydride from the viewpoint of fluidity during molding and coloring of the molded product. Phthalic acid, glutaric anhydride, dimethyl glutaric anhydride, diethyl glutaric anhydride, or 1,3,5-tris (3-carboxypropyl) isocyanurate is preferred. Although the content rate of the cyclohexane tricarboxylic acid anhydride in a hardening | curing agent is not specifically limited, It is preferable to adjust in 5 to 100 mass%. From the viewpoint of balance between cost and performance, the content is preferably in the range of 25% by mass to 75% by mass.

  The compounding ratio of the epoxy resin and the curing agent is such that the active group (acid anhydride group or hydroxyl group) in the curing agent capable of reacting with the epoxy group is 0.5 to 1 with respect to 1 equivalent of the epoxy group in the epoxy resin. The ratio is preferably 5 equivalents. When the said active group is less than 0.5 equivalent, while the cure rate of an epoxy resin composition becomes slow, the glass transition temperature of the hardened | cured material obtained becomes low, and sufficient elastic modulus may not be obtained. Moreover, when the said active group exceeds 1.2 equivalent, the intensity | strength after hardening may reduce. This ratio is more preferably 0.7 to 1.2 equivalent when no epoxy resin oligomer is used.

  When an epoxy resin oligomer is used alone as an epoxy resin, or when an epoxy resin oligomer and a non-oligomer epoxy resin are used in combination, the blending ratio of the epoxy resin (including the oligomer) and the curing agent is another preferable range. Can be set. In this case, the compounding ratio of the epoxy resin and the curing agent is such that the active group (acid anhydride group or hydroxyl group) in the curing agent capable of reacting with the epoxy group is 0 with respect to 1 equivalent of the epoxy group in the epoxy resin oligomer. It is preferable that it is a ratio which will be 0.5-0.7 equivalent. When the said active group is less than 0.5 equivalent, while the cure rate of an epoxy resin composition becomes slow, the glass transition temperature of the hardening body obtained becomes low, and sufficient elastic modulus may not be obtained. Moreover, when the said active group exceeds 0.7 equivalent, the intensity | strength after hardening may reduce. This ratio is more preferably a ratio that makes 0.6 to 0.7 equivalents. In addition, the equivalent number of the hardening | curing agent in case an epoxy resin contains an epoxy resin oligomer calculates the total amount of the epoxy group contained in each of the epoxy resin contained in an epoxy resin oligomer, and the epoxy resin which is not an oligomer as 1 equivalent. And the sum total of the active group which can react with the said epoxy group contained in a hardening | curing agent and a hardening | curing agent is converted as an equivalent number with respect to an epoxy group.

  The resin composition may contain an appropriate compound as a curing accelerator. Examples of the curing accelerator include tertiary amines such as 1,8-diaza-bicyclo (5,4,0) undecene-7, triethylenediamine and tri-2,4,6-dimethylaminomethylphenol. . Examples of the curing accelerator include imidazoles such as 2-ethyl-4methylimidazole and 2-methylimidazole. Examples of the curing accelerator include phosphorus compounds such as triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetra-n-butylphosphonium-o, o-diethylphosphorodithioate, and tetra-n-butylphosphonium-tetraphenylborate. The Examples of the curing accelerator include quaternary ammonium salts and organometallic salts. Examples of the curing accelerator include derivatives of the compounds shown above. These may be used alone or in combination. Among these curing accelerators, it is preferable to use tertiary amines, imidazoles, and phosphorus compounds.

  The content of the curing accelerator is preferably 0.01 to 8.0% by mass and more preferably 0.1 to 3.0% by mass with respect to the epoxy resin. When the content of the curing accelerator is 0.01% by mass or more, a sufficient curing acceleration effect can be obtained. Moreover, it can suppress more that discoloration generate | occur | produces in the obtained molded object because the content rate of a hardening accelerator will be 8.0 mass% or less.

  The resin composition contains a white pigment. The white pigment can increase the reflectance of light when it becomes a molded body, and a light reflector having excellent reflectivity can be obtained.

  The white pigment is not particularly limited, and an appropriate one can be used. For example, alumina, magnesium oxide, antimony oxide, titanium oxide, zirconium oxide, inorganic hollow particles, and the like can be used. These may be used alone or in combination. Examples of the inorganic hollow particles include sodium silicate glass, aluminum silicate glass, borosilicate soda glass, and shirasu. From the viewpoint of thermal conductivity and light reflection characteristics, at least alumina or magnesium oxide may be used, or a combination thereof may be used. In order to improve light reflectivity, it is preferable to use titanium oxide.

  The white pigment preferably has a central particle size in the range of 0.1 to 50 μm. When the center particle size is less than 0.1 μm, the particles tend to aggregate and the dispersibility tends to deteriorate. On the other hand, if the center particle size exceeds 50 μm, the light reflection characteristics of the cured product may not be sufficiently obtained.

  Although the compounding quantity of a white pigment is not specifically limited, It is preferable that it is 10 mass% or more with respect to the whole resin composition. Thereby, a molded object with a high reflectance can be obtained. As for the compounding quantity of a white pigment, it is more preferable that it is 20 mass% or more with respect to the whole resin composition. It is preferable that the compounding quantity of a white pigment is 80 mass% or less with respect to the whole resin composition. The blending amount of the white pigment is also preferably in the range of 10% by volume to 85% by volume with respect to the entire resin composition.

  The resin composition preferably contains an inorganic filler. Thereby, the moldability can be easily adjusted. The inorganic filler is not particularly limited, and for example, at least one selected from the group consisting of silica, aluminum hydroxide, magnesium hydroxide, barium sulfate, magnesium carbonate, and barium carbonate can be used. From the viewpoint of thermal conductivity, light reflection characteristics and moldability, it is preferable to contain at least silica. Moreover, in order to improve a flame retardance, it is preferable to use combining aluminum hydroxide. As silica, it is preferable to use porous silica. As the silica, it is more preferable to use porous spherical silica.

  In one embodiment of the resin composition, it is preferable that the inorganic filler contains a porous filler or a compound having oil absorption. As the inorganic filler, it is also possible to use at least one selected from the group consisting of porous filler or oil-absorbing silica, aluminum hydroxide, magnesium hydroxide, barium sulfate, magnesium carbonate, and barium carbonate. It is also possible to use a compound having a porous structure and further having oil absorption. The shape of the porous filler or the oil-absorbing compound is not particularly limited, and for example, a spherical shape, a crushed shape, a disk shape, a rod shape, a fiber shape, or the like can be used. Considering the fluidity in the mold at the time of transfer molding, a spherical shape and a crushed shape are preferable, and a true spherical shape is more preferable. An example of the inorganic filler is porous spherical silica.

  The surface of the porous filler or the oil-absorbing compound may be physically or chemically hydrophilized or hydrophobized. The surface is preferably hydrophobized, and more preferably chemically hydrophobized so that the oil absorption (specified amount according to JISK5101) is 50 ml / 100 g or more. Use of a porous filler or oil-absorbing compound with a hydrophobic surface increases adhesion to epoxy resins and curing agents, resulting in mechanical strength of thermosets and fluidity during transfer molding Will improve. In addition, by using a porous filler or a compound having an oil absorption property whose surface is hydrophobized so that the oil absorption amount is 50 ml / 100 g or more, the adhesion with the epoxy resin is improved and the kneaded resin Reduction in pot life of the composition can be suppressed, and coloring can also be suppressed during thermosetting. An example of the porous filler subjected to such a hydrophobization treatment is Silo Hovic 702 sold by Fuji Silysia Chemical Co., Ltd.

The apparent density of the porous filler or a compound having an oil absorbency is not particularly limited, it is preferably 0.4 g / cm ³ or more, more preferably 0.4 to 2.0 g / cm ³ . The apparent density is a density in consideration of the density occupied by the raw material of the porous filler or the oil-absorbing compound and the space occupied by the fine pores (that is, the pore volume). If the apparent density is less than 0.4 g / cm ³ , the particles may be destroyed during melt-kneading such that the mechanical strength of the filler particles is small and shearing force such as a mixing roll mill is generated. is there. On the other hand, when the apparent density exceeds 2.0 g / cm ³ , when molding a tablet for transfer molding, the resin composition tends to adhere to the surface of a mold composed of a mortar mold and a bowl mold. It is in.

  The average particle diameter of the porous filler or the oil-absorbing compound is preferably 0.1 to 100 μm, and more preferably in the range of 1 to 10 μm in view of packing efficiency with a white pigment. If the average particle size is larger than 100 μm or smaller than 0.1 μm, the fluidity of the resin composition tends to be poor at the time of melting during transfer molding.

The specific surface area of the porous filler or a compound having an oil absorbency is preferably 100~1000m ² / g, more preferably 300~700m ² / g. When the specific surface area is smaller than 100 m ² / g, the oil absorption amount of the resin by the filler is decreased, and the resin tends to adhere to the bowl at the time of tablet molding, and when the specific surface area is larger than 1000 m ² / g, The fluidity of the resin composition tends to deteriorate during melting during transfer molding.

  Although content of the said porous filler or the compound which has oil absorption property is not specifically limited, It is preferable that it is the range of 0.1 volume%-20 volume% with respect to the whole inorganic filler. Considering the moldability of the resin composition at the time of melting, it is more preferably 1% by volume to 5% by volume. When this content is less than 0.1% by volume, a part of the resin composition tends to adhere to the surfaces of the mortar mold and the saddle mold, and when it is greater than 20% by volume, transfer molding is performed. The fluidity of the resin composition tends to decrease during melting. For example, when the silophobic 702 is used as the porous filler, the content may be 5% by volume or less from the viewpoint of fluidity when the resin composition is melted and strength of the resin cured product. preferable.

  Although the total compounding quantity of the said inorganic filler and the said white pigment is not specifically limited, It is preferable that it is the range of 10 volume%-85 volume% with respect to the whole resin composition. If the total blending amount is less than 10% by volume, the light reflection characteristics of the cured product may not be sufficiently obtained. On the other hand, when the total blending amount exceeds 85% by volume, the moldability of the resin composition is deteriorated, and the production of the light reflector tends to be difficult.

  A coupling agent can be added to the resin composition. A cup link agent is used as needed. Although a coupling agent is not specifically limited, For example, a silane coupling agent, a titanate coupling agent, etc. can be used. Examples of the silane coupling agent that can be used include epoxy silane, amino silane, cationic silane, vinyl silane, acrylic silane, mercapto silane, and composites thereof. The type and processing conditions of the coupling agent are not particularly limited, and an appropriate method such as a method of adding the resin composition as it is or a method of adding it in advance with an inorganic filler or a white pigment is applied. Also good. The blending amount of the coupling agent is preferably 5% by mass or less with respect to the resin composition. A specific example of the coupling agent is trimethoxyepoxysilane.

  A thickener may be added to the resin composition for the purpose of adjusting the melt viscosity. Although it does not specifically limit as a thickener, For example, a nano silica can be used. Nanosilica is available, for example, as Leolosil CP-102 sold by Tokuyama Corporation. The addition amount of the thickener is preferably 0.15% by volume or less of the total volume of the resin composition. If the addition amount of the thickener is more than 0.15% by volume, the fluidity at the time of melting of the resin composition is impaired, and sufficient material strength may not be obtained after curing. The thickener is preferably a nanoparticle filler having a center particle size of 1 nm to 1000 nm, and more preferably a nanoparticle filler having a center particle size of 10 nm to 1000 nm. A filler having a center particle size smaller than 1 nm tends to aggregate and tends to reduce dispersibility, and is not preferable in terms of properties. When such a thickener is used, nano silica may be used as a part of the inorganic filler. On the other hand, when a filler larger than 1000 nm is added, the burr length tends not to decrease, which is not preferable in terms of characteristics.

  The resin composition preferably contains an antioxidant. Thereby, the fall of a reflectance can be suppressed and a high reflectance can be maintained longer. Moreover, the storage stability of a resin composition can be improved by including antioxidant.

  Although it does not specifically limit as antioxidant, For example, a phenolic antioxidant, a thioether antioxidant, a phosphorus antioxidant, etc. can be used, These may be used independently or are used together. May be. Among these antioxidants, it is preferable to use a phosphorus-based antioxidant. Although it does not specifically limit as phosphorus antioxidant, For example, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 4,4'-butylidenebis (3-methyl-6-tert- Butylphenyl-di-tridecyl phosphite), diphenylisodecyl phosphite and the like. It is also preferable to use hindered phenol as an antioxidant.

  It is preferable that the content rate of antioxidant is 1-20 mass parts with respect to 100 mass parts of epoxy resins, More preferably, it is 3-18 mass parts. If the content of the antioxidant is less than 1 part by mass, a sufficient antioxidant effect may not be obtained, and if it exceeds 20 parts by mass, discoloration may be seen in the resulting colored product. When the amount of the antioxidant falls within the above range, the reflectance can be made more difficult to decrease. The content of the antioxidant is more preferably 5 parts by mass or more with respect to 100 parts by mass of the epoxy resin.

  The resin composition preferably contains a fluorescent brightening agent. Thereby, the reflectance can be increased.

As the fluorescent brightening agent, a benzoxazole-based compound or the like can be preferably used. In addition to benzoxazole derivatives, coumarin derivatives, imidazole derivatives, stilbene derivatives, and the like can also be preferably used as fluorescent brighteners. Among these, it is desirable to use a benzoxazole derivative. The content of the optical brightener is preferably 0.001% by mass or more and 1% by mass or less. When the amount of the fluorescent brightening agent is within this range, the reflectance can be increased efficiently.

  The resin composition preferably contains a release agent. By including a mold release agent, the mold release property can be improved, so that the production becomes easy.

  As the mold release agent, waxes such as fatty acids, fatty acid metal salts, and minerals that are generally used for thermosetting resins can be used. In particular, fatty acid-based and fatty acid metal salt-based materials excellent in heat discoloration can be suitably used.

  Specific examples of the mold release agent include aliphatic ethers, stearic acid, zinc stearate, aluminum stearate, calcium stearate and the like. These mold release agents may be used independently and may use 2 or more types together.

  A mold release agent can be mix | blended in 0.001-1 mass% with respect to the resin composition whole quantity. When the blending amount of the release agent is within this range, it is possible to further achieve both good release properties and an excellent appearance, and to improve the reflectivity of the molded product.

  Other components can be added to the resin composition as necessary. For example, you may add various additives, such as an ion supplement agent, a reinforcing material, and a stabilizer.

  The thermosetting resin composition for light reflectors can be obtained as a solid substance such as a granular or powdery form. That is, the resin composition can be configured as a dry resin composition. Here, the dry type means a solid in a temperature range of 30 ° C. or lower, and can be processed into a granular shape by pulverization or extrusion pellet processing. When the resin composition becomes solid, storage stability and handling properties can be improved. It is preferable that the resin composition which became solid has storage shape stability at the temperature of 50 degrees C or less. Thereby, handling property and workability can be further enhanced.

  The resin composition can be prepared without solvent. By preparing without a solvent, a solid resin composition can be easily obtained.

  The resin composition is manufactured by blending each component and mixing it sufficiently uniformly using a mixer, a blender, etc., and then preparing and granulating it with a kneader, extruder, etc. capable of being heated and pressurized. be able to. The preparation means and conditions of the resin composition are not particularly limited. By using a solid raw material, it can be easily mixed by a powder mixing apparatus. As a kneader, a pressure kneader, a heat roll, an extruder, or the like may be used. In pulverization, after forming a bulk body, it may be crushed and sized. Moreover, you may granulate suitably. The thermosetting resin composition for a light reflector is obtained in the form of granules, powders, pellets, or the like.

  In the above resin composition, a powder mixing method can be used. As a general method, after stirring and mixing various components of a predetermined blending amount sufficiently uniformly with a mixer or the like, kneading is performed using a mixing roll, an extruder, a kneader, a roll, an extruder, and the like, and the obtained kneading is further performed. Mention may be made of methods of cooling and grinding the product. The kneading type is not particularly limited, but melt kneading is preferable. The conditions for melt-kneading may be appropriately determined according to the type and amount of components used, and are not particularly limited. For example, it is preferable to melt knead in the range of 15 to 100 ° C. for 5 to 40 minutes. Furthermore, it is more preferable to melt-knead in the range of 20 to 100 ° C. for 10 to 30 minutes. If the temperature at the time of melt kneading is less than 15 ° C., it is difficult to melt and knead each component, and the dispersibility tends to decrease. On the other hand, when the temperature is higher than 100 ° C., the resin composition has a high molecular weight and the resin composition may be cured. Further, if the melt kneading time is less than 5 minutes, the burr length tends not to be effectively suppressed. If the melt kneading time is longer than 40 minutes, the resin composition increases in molecular weight, and before molding. The resin composition may be cured.

  Here, when preparing a resin composition, it is one preferable method to premix the compound used as a hardening | curing agent with a part or all of an epoxy resin. By carrying out such premixing, the dispersibility of the curing agent with respect to the base resin can be further enhanced. As a result, it is possible to more effectively suppress the occurrence of mold and package contamination due to the dispersion failure of the curing agent. Preliminary mixing may be performed between the total amount of the epoxy resin and the compound used as the curing agent, but sufficient effects can be obtained even by premixing with a part of the epoxy resin. In that case, it is preferable that the quantity of the epoxy resin used for preliminary mixing shall be 10-50 mass% with respect to the total amount of components. The premixing method is not particularly limited as long as the compound used as the curing agent can be dispersed in the epoxy resin. For example, a method in which both components are stirred for 0.5 to 20 hours under a temperature condition of room temperature to 220 ° C. From the viewpoint of dispersibility and efficiency, the stirring time is preferably 1 to 10 hours, more preferably 3 to 6 hours under a temperature condition of 100 to 200 ° C, more preferably 150 to 170 ° C. Preheating mixing performed here, for example, weighs 100 parts by mass of an epoxy resin and 120 parts by mass of a curing agent in a container made of heat-resistant glass, and uses a heater whose medium is a fluid such as silicone oil or water. And a method such as heating in a temperature range of 35 ° C to 180 ° C. The heating method is not limited to the above method, and a known method such as thermocouple or electromagnetic wave irradiation can be used, and ultrasonic waves or the like may be irradiated to promote dissolution.

  The resin composition is preferably aged (aged) for the purpose of increasing the melt viscosity at the time of molding after blending and kneading the above components. More specifically, aging is preferably performed at 0 ° C. to 30 ° C. for 1 to 72 hours. Aging is more preferably performed at 15 to 30 ° C. for 12 to 72 hours. The aging is more preferably performed at 25 to 30 ° C. for 24 to 72 hours. If the aging is shorter than 1 hour, the burr length tends not to be effectively suppressed. If the aging is longer than 72 hours, sufficient fluidity may not be secured at the time of molding. In addition, when aging is performed at a temperature lower than 0 ° C., the curing accelerator is inactivated, the three-dimensional crosslinking reaction of the resin composition does not proceed sufficiently, and the viscosity at the time of melting may not increase. is there. In addition, when aging is performed at a temperature higher than 30 ° C., the resin composition absorbs moisture, and mechanical properties such as strength and elastic modulus of the cured product may tend to be deteriorated.

  The thermosetting resin composition for light reflectors can be molded without a solvent. Since the resin composition is softened and melted by heating, the resin composition that has become liquid by heat can be molded into an appropriate shape even without a solvent. Of course, a solvent may be appropriately added in consideration of moldability. However, no solvent is preferred from the viewpoint of ease of molding.

  Since the resin composition is a thermosetting resin, a cured product can be obtained under appropriate curing conditions for curing the thermosetting resin. Moreover, the molded object which consists of hardened | cured material can be obtained by heat-molding using a shaping | molding die. This molded body becomes a light reflector for a light emitting element. That is, the light reflector for light emitting elements is manufactured by molding the thermosetting resin composition for light reflector.

  When manufacturing the light reflector for light emitting elements, it can manufacture by using the resin composition as a material and using the molding method of a suitable thermosetting resin composition. In the case of a solid resin composition, it can be molded by a dry method. As the molding method, for example, a melt heating molding method such as an injection molding method, an injection compression molding method, or a transfer molding method can be suitably used. Among these, the transfer molding method is a preferred embodiment. By a transfer molding method, a molded body having an excellent appearance can be obtained even with a complicated shape. An injection molding method using an injection molding machine is also suitable. The molding time can be further shortened by the injection molding method, and the light reflector can be easily manufactured with high accuracy even in a complicated shape.

  Thermosetting resin compositions for light reflectors are suitable for these molding methods because of their good thermal stability when melted. The heating condition may be a condition in which the resin composition softens and flows. For example, it can be in the range of 50 to 300 ° C. The resin composition described above is easy to mold because of its high fluidity. The heating temperature is preferably in the range of 100 to 200 ° C.

  By the way, in molding using a liquid composition, that is, a resin composition having viscosity, the molding material cannot be formed into a pellet or the like. In this case, the molding is performed under wet conditions. For this reason, handling properties are poor, and when molding with an injection molding machine, it is necessary to provide a hopper with equipment such as a plunger, which increases manufacturing costs. On the other hand, when a solid composition is used, the storage stability is excellent, and since the molding can be performed only by feeding from the hopper of the injection molding machine, the handling property is excellent. Further, the manufacturing cost can be kept low.

  When burrs are generated on the frame of the molded body after molding, it is preferable to remove the burrs. With the above resin composition, since the adhesiveness of burrs is low, burrs can be easily removed. The generated burrs can be removed by an appropriate method. Cutting or cutting may be used. From the viewpoint of workability, it is preferable to remove burrs by blasting. As the blast treatment, a blast treatment method used for deburring can be used. Examples of these include shot blasting, sand blasting, and glass bead blasting.

  In the light reflector obtained by molding, discoloration due to thermal deterioration is suppressed. The light reflector can be used as an LED reflector for an LED lighting fixture such as an LED bulb. The light reflector obtained from the thermosetting resin composition for light reflector can constitute an inexpensive LED reflector having a long life.

  FIG. 1 shows an example of an LED lighting device using a light reflector obtained by molding a thermosetting resin composition for a light reflector. This light reflector is the LED reflector 1. The light reflector is formed in a frame shape, and has a recess 2 and a hole 3 at the center. The recess 2 is provided as an inclined surface. The wall surface of the recess 2 serves as a reflecting surface that reflects light. The hole 3 is provided at the bottom of the recess 2 so as to penetrate the LED reflector 1. A lead frame 4 on which an LED 5 as a light emitting element is mounted is fitted in the hole 3. The lead frame 4 may be provided with wiring for supplying electricity to the LED 5. The light emitting surface side (upper part in the figure) of the recess 2 is covered with a transparent cover 6. Thereby, LED5 is protected. The cover 6 is joined to the LED reflector 1 at the opening edge of the recess 2. The LED reflector 1 functions as a reflector for efficiently reflecting the light emitted from the LED 5. The shape of the LED reflector 1 is not limited to the shape shown in FIG. 1, and can be appropriately designed in consideration of the light quantity, color, directivity characteristics, and the like of the mounted LED 5. With the thermosetting resin composition for light reflectors described above, since the moldability is good, it is possible to easily obtain a molded body having a desired shape.

[Preparation of thermosetting resin composition for light reflector]
Each component was blended according to the blending ratio shown in Table 1, sufficiently kneaded with a mixer, and then melt-kneaded under a predetermined condition with a mixing roll to obtain a kneaded product. Furthermore, the obtained kneaded material was pulverized to prepare thermosetting resin compositions for light reflectors of Examples and Comparative Examples, respectively. In addition, the unit of the compounding quantity of each component shown in Table 1 is a mass part. A blank in the table means that the corresponding component is not blended.

  Here, for Examples 1 to 6 and Comparative Example 1, resin components were prepared by blending each component at one time without preliminary kneading. For Comparative Example 2, preliminary kneading was performed. In the preliminary kneading, 30% of the epoxy resin and the curing agent were first kneaded at 150 ° C. for 3 hours, and then the other components were added.

  Details of the components used in each example and each comparative example are as follows.

<Epoxy resin>
* Tris- (2,3-epoxypropyl) -isocyanurate (epoxy equivalent 100, manufactured by Nissan Chemical Industries, "TEPIC-L"). The content ratio of the optical isomer is [total amount of (2R, 2R, 2S) isomer and (2S, 2S, 2R) isomer]: [(2R, 2R, 2R) isomer and (2S, 2S, 2S) isomer Total amount] = 95: 5.
* Tris- (2,3-epoxypropyl) -isocyanurate (epoxy equivalent 100, manufactured by Nissan Chemical Co., Ltd., “TEPIC-S”). The content ratio of the optical isomer is [total amount of (2R, 2R, 2S) isomer and (2S, 2S, 2R) isomer]: [(2R, 2R, 2R) isomer and (2S, 2S, 2S) isomer Total amount] = 75: 25.

<Curing agent>
* Hexahydrophthalic anhydride (“Rekajit HH” manufactured by Shin Nippon Rika)
<Curing accelerator>
* Tetra-n-butylphosphonium-o, o-diethyl phosphorodithioate (“PX-4ET” manufactured by Nippon Chemical Co., Ltd.)
* Ethyltriphenylphosphonium bromide ("TPP-EB" manufactured by Hokuko Chemical)
<White pigment>
* Titanium oxide ("RTC-30" manufactured by Taioxide Japan)
* Titanium oxide (“FTR-700” manufactured by Sakai Chemical)
<Inorganic filler>
* Porous spherical silica ("Syrosphere C-150" manufactured by Fuji Silysia)
<Silane coupling agent>
* Trimethoxy epoxy silane ("A187" manufactured by Toray Dow Corning)
<Release agent>
* Aliphatic ether ("Unitox 420" manufactured by Toyo Petrolite)
<Antioxidant>
* Hindered phenol (Adeka "AO-80")
* 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide ("HCA")
<Fluorescent brightener>
* Benzoxazole derivative (“Kayalight OS” manufactured by Nippon Kayaku.

[Evaluation of thermosetting resin composition for light reflector]
<Production of molded product>
Each of the resin compositions of Examples and Comparative Examples was transfer-molded under conditions of a molding die temperature of 180 ° C., a molding pressure of 6.9 MPa, and a curing time of 90 seconds, and then post-cured at 150 ° C. for 2 hours, Test pieces having a thickness of 1.0 mm were prepared. About this molded object, the light reflectance after an initial stage and a heating was measured in accordance with the following procedures. Further, the appearance of the molded product after heating was observed.

<Initial light reflectance>
About each test piece, the light reflectance in wavelength 460nm was measured using the reflectance measuring device (Nippon Denshoku SD6000).

<Light reflectance after heating>
The test piece obtained by the above was left to heat, and the reflectance after the heat history was measured at a wavelength of 460 nm using a reflectance measuring device (SD6000 manufactured by Nippon Denshoku). The heating was allowed to stand at 150 ° C. for 1000 hours. This condition is a temperature condition of an acceleration test assuming a heat load in actual use.

<Appearance after heating>
The test piece obtained by the above was left to stand by heating, and the appearance after the heat history was visually observed. The heating was allowed to stand at 200 ° C. for 100 hours. In appearance observation, when one or more black spots were observed on the test piece, it was judged as “with black spots”, and when no black spot was observed on the test pieces, it was judged as “no black spots”.

<Result>
The results are shown in Table 1.

  According to Table 1, each resin composition of the Examples showed excellent light reflection characteristics and high light reflectivity after heating. In Comparative Example 1, since the ratio of the (2R, 2R, 2R) body and the (2S, 2S, 2S) body was high, the reflectance was low. In Comparative Example 2, black spots were observed after heating, although an improvement in reflectance was observed by performing preliminary kneading. Separately, when a molded product was produced from each resin composition of the example, it was confirmed that burr formation at the time of transfer molding was suppressed and the wire bonding property was excellent.

DESCRIPTION OF SYMBOLS 1 LED reflector 2 Recessed part 3 Hole part 4 Lead frame 5 LED
6 Cover

Claims (8)

An epoxy resin containing tris- (2,3-epoxypropyl) -isocyanurate, a curing agent, and a white pigment;
The tris- (2,3-epoxypropyl) -isocyanurate has a total amount of (2R, 2R, 2S) and (2S, 2S, 2R) in the optical isomer ratio, and (2R, 2R, 2R) body and (2S, 2S, the ratio of the total amount of the 2S) body 95: Ri 5 der,
The content of the white pigment is Ru der least 30 wt%,
Thermosetting resin composition for light reflector.   An epoxy resin containing tris- (2,3-epoxypropyl) -isocyanurate, a curing agent, and a white pigment;
  The tris- (2,3-epoxypropyl) -isocyanurate has a total amount of (2R, 2R, 2S) and (2S, 2S, 2R) in the optical isomer ratio, and (2R, 2R, 2R) and the total amount of (2S, 2S, 2S) isomers are 95: 5,
  The curing agent includes a compound having an isocyanuric acid skeleton,
  Thermosetting resin composition for light reflector.   An epoxy resin containing tris- (2,3-epoxypropyl) -isocyanurate, a curing agent, a white pigment, and a fluorescent whitening agent;
  The tris- (2,3-epoxypropyl) -isocyanurate has a total amount of (2R, 2R, 2S) and (2S, 2S, 2R) in the optical isomer ratio, and (2R, 2R, 2R) and the total amount of (2S, 2S, 2S) isomers are 95: 5,
  Thermosetting resin composition for light reflector. The thermosetting resin composition for light reflectors according to claim 3 , wherein the content of the white pigment is 30% by mass or more. The said hardening | curing agent is a thermosetting resin composition for light reflectors of Claim 1 or 3 containing the compound which has an isocyanuric acid frame | skeleton. The thermosetting resin composition for a light reflector according to any one of claims 1 to 5 , wherein the curing agent includes an acid anhydride having a melting point of 35 ° C or higher. The thermosetting resin composition for a light reflector according to any one of claims 1 to 6 , wherein the curing agent includes at least one of cyclohexane tricarboxylic acid anhydride and hexahydrophthalic anhydride. The thermosetting resin composition for light reflectors according to any one of claims 1 to 7 , further comprising an antioxidant.

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