KR20220034680A - Method for manufacturing light reflective substrate - Google Patents

Abstract

The present invention provides a manufacturing method of a light reflection substrate having satisfactory underlayer adhesion. The manufacturing method of a light reflection substrate comprises the following processes (A) and (B) in the listed order: (A) a process of stacking a support body and a resin composition layer containing white inorganic pigments provided over the support body on a substrate having a conductor layer on at least a portion of the surface thereof such that the resin composition layer is joined to a conductor layer of an underlayer substrate; and (B) a process of thermosetting the resin composition layer in a condition satisfying at least one between (i) and (ii) below. (i) heating processing for maintaining at temperature T_2 higher than temperature T_1 after heating processing for maintaining at temperature T_1. (ii) heating processing for maintaining at temperature T_2 after heating to temperature T_2 at a heating rate of 0.5-30℃/minute.

Description

Method for manufacturing a light reflective substrate {METHOD FOR MANUFACTURING LIGHT REFLECTIVE SUBSTRATE}

The present invention relates to a method of manufacturing a light reflective substrate.

In a printed wiring board, Backlight of liquid crystal displays, such as a portable terminal, a computer, and a television; The use of directly mounting a light emitting diode (LED) emitting light with low power, such as a light source of a lighting fixture, is increasing. In recent years, miniaturization of LEDs has progressed, and there are LEDs called mini-LEDs and micro-LEDs.

In the outermost layer of such a printed wiring board, in order to improve the extraction efficiency of the light emitted from a light source, the reflective sheet for reflecting light is formed. A printed wiring board provided with such a reflective sheet is also called a "light reflective substrate".

As a material for the reflective sheet of such a light reflective substrate, for example, Patent Document 1 discloses a resin composition containing a binder polymer and crosslinked polymer particles containing a white inorganic pigment.

Japanese Patent Publication No. 5797279

However, as the present inventors have studied, when a resin composition containing a white inorganic pigment is thermosetted to form a cured body (reflective sheet), in the obtained light reflecting substrate, the adhesiveness between the cured body and the conductor layer of the underlying substrate ( Hereinafter, it was discovered that there are cases where it is simply referred to as "adhesiveness to the base".

An object of the present invention is to provide a method for manufacturing a light reflective substrate exhibiting good adhesion to a substrate.

As a result of intensive studies to solve the above problems, the present inventors have laminated a resin composition containing a white inorganic pigment on a base substrate, and then thermosetting the resin composition under specific conditions to obtain a light reflective substrate exhibiting good adhesion to the substrate. It has been found that it can be manufactured, and the present invention has been completed.

That is, the present invention includes the following contents.

[1] A method for producing a light reflective substrate comprising the following steps (A) and (B) in this order.

(A) a resin sheet comprising a support and a resin composition layer containing a white inorganic pigment provided on the support on a substrate having a conductor layer on at least a part of its surface (hereinafter referred to as "substrate"), a step of laminating the resin composition layer so as to be bonded to the conductor layer of the underlying substrate; and

(B) a step of thermosetting the resin composition layer under conditions satisfying at least one of (i) and (ii) below:

(i) After heat treatment maintained at temperature T ₁ , heat treatment maintained at temperature T ₂ higher than temperature T ₁ .

(ii) After heating up to temperature T ₂ at a temperature increase rate of 0.5 to 30° C./min, heat treatment maintained at temperature T ₂ .

[2] The method according to [1], wherein the support is peeled between the steps (A) and (B).

[3] The method according to [1] or [2], wherein the resin composition layer further contains a thermosetting resin.

[4] The method according to any one of [1] to [3], wherein when the nonvolatile component in the resin composition layer is 100% by mass, the content of the white inorganic pigment is 20 to 60% by mass.

[5] The method according to [3] or [4], wherein the thermosetting resin contains an epoxy resin.

[6] The method according to [5], wherein when the nonvolatile component in the resin composition layer is 100% by mass, the content of the epoxy resin is 1 to 50% by mass.

[7] The white inorganic pigment is at least one selected from aluminum oxide, titanium oxide, zirconium oxide, magnesium oxide, barium titanate, zinc oxide, cerium oxide and calcium carbonate, according to any one of [1] to [6]. method.

[8] The method according to any one of [1] to [7], wherein the light reflective substrate exhibits a reflectance of 85% or more with respect to light having a wavelength of 460 nm.

[9] The method according to any one of [1] to [8], wherein the adhesive strength between the cured body of the resin composition layer in the light reflective substrate and the conductor layer of the underlying substrate is 0.3 kgf/cm or more.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the light reflection substrate which shows favorable base|substrate adhesiveness can be provided.

1 : is a schematic sectional drawing which shows an example of a light reflection substrate.

Before explaining in detail the manufacturing method of the light reflecting substrate of this invention (hereinafter also simply referred to as "the method of the present invention"), the resin sheet used in the method of the present invention will be described.

<Resin sheet>

The resin sheet used in the method of the present invention includes a support and a layer of a resin composition containing a white inorganic pigment provided on the support.

(resin composition layer)

The resin composition layer contains a white inorganic pigment. Accordingly, the cured product formed by curing the resin composition layer may exhibit light reflection properties. In this invention, a "white inorganic pigment" means an inorganic compound and an inorganic filler whose reflectance with respect to the light of wavelength 500nm is 90 % or more in one Embodiment.

- White inorganic pigment -

Examples of the material of the white inorganic pigment include aluminum oxide (alumina), titanium oxide, zirconium oxide, magnesium oxide, zinc oxide, cerium oxide, antimony oxide, tin oxide, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, white metal oxides such as barium titanate zirconate, barium zirconate, and calcium zirconate; white metal sulfides such as zinc sulfide and strontium sulfide; white metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and calcium hydroxide; white metal nitrides such as boron nitride, aluminum nitride, and manganese nitride; white metal carbonates such as calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, and lead carbonate; white metal sulfates such as barium sulfate, calcium sulfate and lead sulfate; white metal phosphates such as zinc phosphate, titanium phosphate, zirconium phosphate, and zirconium phosphate tungstate; white metal borates, such as aluminum borate; and white minerals such as cordierite, talc, clay, mica, hydrotalcite, and boehmite.

Among these, the white inorganic pigment is preferably selected from aluminum oxide, titanium oxide, zirconium oxide, magnesium oxide, barium titanate, zinc oxide, cerium oxide, and calcium carbonate, and titanium oxide is particularly suitable. As titanium oxide, any of a rutile type, an anatas type, and a brookite type may be used, However, From a viewpoint of improving a reflectance more, a rutile type is preferable. As the titanium oxide, one obtained by a method such as a sulfuric acid method or a chlorine method can be used. One type of the material of a white inorganic pigment may be sufficient, and 2 or more types of mixtures may be sufficient as it. The shape of the white inorganic pigment may be, for example, an irregular shape, a crushed shape, a scale shape, or a spherical shape.

As a commercial item of a white inorganic pigment, "PX3788" by the Sakai Chemical Company, for example; Taipei Ishihara Sangyo Co., Ltd. “CR-50”, “CR-57”, “CR-80”, “CR-90”, “CR-93”, “CR-95”, “CR-97”, “ CR-60”, “CR-63”, “CR-67”, “CR-58”, “CR-85”, “UT771”; Typure manufactured by DuPont "R-100", "R-101", "R-102", "R-103", "R-104", "R-105", "R-108", "R -900", "R-902", "R-960", "R-706", "R-931"; "AHP300" manufactured by Nippon Keikinzoku Corporation; Showa Denko Co., Ltd. alumina beads "CB-P05", "CB-A30S", etc. are mentioned.

The specific surface area of the white inorganic pigment is preferably 0.5 m 2 /g or more, more preferably 1 m 2 /g or more, and particularly preferably 2 m 2 /g or more. Although there is no particular limitation on the upper limit, it is preferably 80 m 2 /g or less, 70 m 2 /g or less, or 60 m 2 /g or less. The specific surface area can be obtained by adsorbing nitrogen gas to the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountec) according to the BET method, and calculating the specific surface area using the BET multi-point method.

The average particle diameter of the white inorganic pigment is preferably 0.01 µm or more, more preferably 0.05 µm or more, still more preferably 0.1 µm or more, and preferably 10 µm or less from the viewpoint of significantly obtaining the desired effect of the present invention. , more preferably 5 µm or less, still more preferably 2 µm or less or 1 µm or less.

The average particle diameter of the white inorganic pigment can be measured by a laser diffraction/scattering method based on the Mie scattering theory. Specifically, it can measure by creating the particle diameter distribution of a white inorganic pigment on a volume basis with a laser diffraction scattering type particle diameter distribution measuring apparatus, and making the median diameter into an average particle diameter. As the measurement sample, 100 mg of the white inorganic pigment and 10 g of methyl ethyl ketone were weighed in a vial and dispersed for 10 minutes by ultrasonic wave can be used. Using a laser diffraction particle size distribution measuring device, the measurement sample was measured for the volume-based particle size distribution of the white inorganic pigment by a flow cell method using a light source wavelength of blue and red, and intermediate from the obtained particle size distribution. As the diameter, the average particle diameter can be calculated. As a laser diffraction type particle size distribution measuring apparatus, "LA-960" by Horiba Corporation, etc. are mentioned, for example.

It is preferable that the white inorganic pigment is treated with a surface treating agent from a viewpoint of improving moisture resistance and dispersibility. A surface treating agent may be used individually by 1 type, and may be used combining two or more types arbitrarily. As the surface treatment agent, for example, a vinyl-based silane coupling agent, an epoxy-based silane coupling agent, a styryl-based silane coupling agent, a (meth)acrylic-based silane coupling agent, an amino-based silane coupling agent, an isocyanurate-based silane coupling agent, Silane coupling agents, such as a layered-type silane coupling agent, a mercapto-type silane coupling agent, an isocyanate-type silane coupling agent, an acid anhydride-type silane coupling agent, an alkylsilane coupling agent, and a phenylsilane coupling agent, are mentioned. In the method of the present invention employing specific curing conditions, the surface treatment agent does not contain nitrogen atoms (nitrogen atoms are not included) from the viewpoint of easily realizing a light reflective substrate that exhibits higher reflectance and has further excellent adhesion to the underlying substrate. ) It is preferable that it is a surface treatment agent, More preferably, it is preferable that it is a silane coupling agent which does not contain a nitrogen atom (it does not contain a nitrogen atom). Examples of the nitrogen atom-free (nitrogen atom-free) silane coupling agent include a phenylsilane coupling agent, an alkylsilane coupling agent, an epoxy-based silane coupling agent, a vinyl-based silane coupling agent, a (meth)acrylic-based silane coupling agent, and a styryl-based silane coupling agent. and a silane coupling agent selected from coupling agents.

As a phenylsilane coupling agent, phenyltrimethoxysilane, phenyltriethoxysilane, etc. are mentioned, for example. Examples of the alkylsilane coupling agent include methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltri Methoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, 1, 6-bis(trimethoxysilyl)hexane, etc. are mentioned. Examples of the epoxy-based silane coupling agent include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, etc. are mentioned.

As a vinyl-type silane coupling agent, vinyl trimethoxysilane, vinyl triethoxysilane, etc. are mentioned, for example. Examples of the (meth)acrylic silane coupling agent include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryl. Oxypropyl triethoxysilane, 3-acryloxypropyl trimethoxysilane, etc. are mentioned. As a styryl-type silane coupling agent, p-styryl trimethoxysilane etc. are mentioned, for example.

As a commercial item of a surface treatment agent, For example, "KBM-103" by a Shin-Etsu Chemical Co., Ltd. product, "KBE-103" (phenylsilane coupling agent); 「KBM-13」, 「KBM-22」, 「KBE-13」, 「KBE-22」, 「KBM-3033」, 「KBE-3033」, 「KBM-3063」, 「KBE-3063」, 「KBE -3083", "KBM-3103C", "KBM-3066", "KBM-7103" (alkylsilane coupling agent); "KBM-1003", "KBE-1003" (vinyl-based silane coupling agent); "KBM-303", "KBM-402", "KBM-403", "KBE-402", "KBE-403" (epoxy silane coupling agent); "KBM-1403" (styryl-based silane coupling agent); "KBM-502", "KBM-503", "KBE-502", "KBE-503", "KBM-5103" ((meth)acrylic-type silane coupling agent) etc. are mentioned.

It is preferable that the grade of the surface treatment by a surface treatment agent falls within a predetermined range from a viewpoint of the dispersibility improvement of a white inorganic pigment. Specifically, 100 parts by mass of the white inorganic pigment is preferably surface-treated with 0.2 parts by mass to 5 parts by mass of a surface treatment agent, preferably from 0.2 parts by mass to 3 parts by mass, and 0.3 parts by mass to 2 parts by mass. It is preferable that it is surface-treated by blowing.

The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the white inorganic pigment. From the viewpoint of improving the dispersibility of the white inorganic pigment, the amount of carbon per unit surface area of the white inorganic pigment is preferably 0.02 mg/m 2 or more, more preferably 0.1 mg/m 2 or more, and still more preferably 0.2 mg/m 2 or more. . On the other hand, from the viewpoint of suppressing an increase in the melt viscosity of the resin varnish and the melt viscosity in the sheet form, 1 mg/m 2 or less is preferable, 0.8 mg/m 2 or less is more preferable, and 0.5 mg/m 2 or less is still more preferable.

The amount of carbon per unit surface area of the white inorganic pigment can be measured after washing the surface-treated white inorganic pigment with a solvent (eg, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the white inorganic pigment surface-treated with a surface treatment agent, followed by ultrasonic cleaning at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of the white inorganic pigment can be measured using a carbon analyzer. As a carbon analyzer, "EMIA-320V" by Horiba Corporation, etc. can be used.

From the viewpoint of realizing a light reflecting substrate exhibiting a high light reflectance, the content of the white inorganic pigment in the resin composition layer is preferably 20 mass% or more, more preferably 20 mass% or more, when the nonvolatile component in the resin composition layer is 100 mass%. Preferably it is 22 mass % or more, More preferably, it is 24 mass % or more, or 25 mass % or more.

In the prior art, when a resin composition layer with a high content of white inorganic pigment is used, the obtained light reflective substrate tends to have poor adhesion to the substrate, but according to the method of the present invention employing specific curing conditions, adhesion to the substrate is not reduced. The content of the white inorganic pigment can be further increased. For example, content of the white inorganic pigment in the resin composition layer is 26 mass % or more, 28 mass % or more, 30 mass % or more, 32 mass % or more, 34 mass % or more, 36 mass % or more, 38 mass % or more, or You may increase it to 40 mass % or more.

The upper limit of the content of the white inorganic pigment in the resin composition layer is preferably 70 mass % or less, more preferably 65 mass % or less, still more preferably 60 mass % or less or 55 mass % or less from the viewpoint of realizing good adhesion to the substrate. % or less.

In one suitable embodiment, when the nonvolatile component in a resin composition layer is 100 mass %, content of a white inorganic pigment is 20-60 mass %.

- Other weapon fillings -

The resin composition layer may contain another inorganic filler as long as it contains a white inorganic pigment at least. It does not specifically limit as such another inorganic filler, as long as it is an inorganic filler different from a white inorganic pigment, For example, you may use the inorganic filler whose reflectance with respect to the light of wavelength 500nm is less than 90%.

Especially, in the method of this invention employ|adopting specific hardening conditions, while showing a higher reflectance, from a viewpoint of being easy to implement|achieve the light reflecting substrate which was further excellent in base adhesion, silica is suitable as another inorganic filler. Examples of the silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Moreover, as a silica, spherical silica is preferable. The specific surface area and average particle diameter of silica are the same as that of a white inorganic pigment. Silica may be used individually by 1 type, and may be used in combination of 2 or more type.

As a commercial item of silica, For example, "UFP-30" by a Denka company; "SP60-05", "SP507-05" by the Nitetsu Chemical & Materials company; "YC100C", "YA050C", "YA050C-MJE", "YA010C" manufactured by Adomatex Corporation; "Silpil NSS-3N", "Silpil NSS-4N", and "Silver NSS-5N" manufactured by Tokuyama Corporation; "SC2500SQ", "SO-C4", "SO-C2", "SO-C1" by the Adomatex company, etc. are mentioned.

It is preferable that other inorganic fillers, such as a silica, are treated with the surface treating agent from a viewpoint of improving moisture resistance and dispersibility. As a surface treatment agent, the thing similar to the surface treatment agent in a white inorganic pigment is mentioned. The grade of the surface treatment by the surface treating agent of another inorganic filler is the same as that of a white inorganic pigment.

The content of the other inorganic filler in the resin composition layer is preferably 1 mass% or more, more preferably 5 mass%, when the nonvolatile component in the resin composition layer is 100 mass% from the viewpoint of significantly obtaining the effect of the present invention. % or more, more preferably 10 mass % or more, particularly preferably 15 mass % or more. The upper limit of content of another inorganic filler becomes like this. Preferably it is 70 mass % or less, More preferably, it is 50 mass % or less, More preferably, it is 40 mass % or less, Especially preferably, it is 35 mass % or less.

The total content of the white inorganic pigment and other inorganic fillers, that is, the total content of the inorganic filler components, is 100 nonvolatile components in the resin composition layer from the viewpoint of realizing a light reflective substrate that exhibits high light reflectance and good adhesion to the underlying substrate. When it is set as mass %, Preferably it is 20 mass % or more, More preferably, it is 30 mass % or more, More preferably, it is 40 mass % or more, Especially preferably, it is 50 mass % or more, Preferably it is 90 mass % or less, More preferably, it is 80 mass % or less, More preferably, it is 75 mass % or less, Especially preferably, it is 70 mass % or less.

The mass ratio of other inorganic fillers such as silica to the white inorganic pigment (mass of other inorganic fillers/mass of white inorganic pigment) is preferably from the viewpoint of realizing a light reflective substrate that exhibits high light reflectance and good adhesion to the underlying substrate is 0.1 or more, more preferably 0.2 or more, still more preferably 0.5 or more, particularly preferably 0.8 or more, preferably 4 or less, more preferably 4 or less, still more preferably 2 or less, particularly preferably 1.5 or less.

The resin composition layer contains a thermosetting resin as a resin. As a thermosetting resin, a conventionally well-known thermosetting resin used when forming the insulating layer of a printed wiring board can be used, Especially, in the method of this invention employ|adopting specific hardening conditions WHEREIN: While exhibiting a higher reflectance, adhesiveness to a base material An epoxy resin is preferable from a viewpoint of being easy to implement|achieve the further excellent light reflection board|substrate. Accordingly, in one embodiment the resin composition comprises a thermosetting resin, and in one suitable embodiment the thermosetting resin comprises an epoxy resin.

- Epoxy resin -

An epoxy resin means curable resin which has an epoxy group. An epoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type.

As the epoxy resin, for example, a bixylenol type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a bisphenol AF type epoxy resin, a hydrogenated bisphenol A type epoxy resin, a dicyclopentadiene type Epoxy resin, trisphenol type epoxy resin, naphthol novolak type epoxy resin, phenol novolak type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidyl Amine type epoxy resin, glycidyl ester type epoxy resin, cresol novolak type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, Heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, naphthylene ether type epoxy resin, trimethylol type epoxy resin, tetraphenylethane type epoxy resin, isocyanurate type epoxy Resin, a phenolphthalimidine type epoxy resin, a phenolphthalein type epoxy resin, etc. are mentioned.

The resin composition layer preferably contains, as an epoxy resin, an epoxy resin having two or more epoxy groups in one molecule. The ratio of the epoxy resin having two or more epoxy groups in one molecule to 100% by mass of the nonvolatile component of the epoxy resin is preferably 50% by mass or more, more preferably 60% by mass or more, particularly preferably 70% by mass. % or more

Epoxy resins include an epoxy resin that is solid at a temperature of 25°C (hereinafter also referred to as “solid epoxy resin”) and an epoxy resin that is liquid at a temperature of 25°C (hereinafter also referred to as “liquid epoxy resin”). In the resin sheet used in the method of the present invention, the resin composition layer may contain, as an epoxy resin, only a solid epoxy resin, or may contain only a liquid epoxy resin, or a solid epoxy resin and a liquid epoxy resin. may be included in combination.

As a solid epoxy resin, the solid epoxy resin which has 3 or more epoxy groups in 1 molecule is preferable, and the aromatic solid epoxy resin which has 3 or more epoxy groups in 1 molecule is more preferable.

Examples of the solid-state epoxy resin include a bixylenol-type epoxy resin, a naphthalene-type epoxy resin, a naphthalene-type tetrafunctional epoxy resin, a naphthol novolac-type epoxy resin, a cresol novolac-type epoxy resin, a dicyclopentadiene-type epoxy resin, and a trisphenol-type epoxy resin. , naphthol type epoxy resin, biphenyl type epoxy resin, naphthylene ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, phenol aralkyl type epoxy resin, tetraphenylethane type epoxy resin, A phenolphthalimidine-type epoxy resin and a phenolphthalein-type epoxy resin are preferable.

As a specific example of a solid-state epoxy resin, "HP4032H" by DIC (naphthalene type epoxy resin); "HP-4700", "HP-4710" by DIC company (naphthalene type tetrafunctional epoxy resin); "N-690" by DIC (cresol novolak-type epoxy resin); "N-695" by DIC (cresol novolak type epoxy resin); "HP-7200", "HP-7200HH", "HP-7200H", "HP-7200L" (dicyclopentadiene type epoxy resin) manufactured by DIC Corporation; "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" by DIC company (naphthylene ether type epoxy resin); "EPPN-502H" by a Nippon Kayaku company (trisphenol type epoxy resin); "NC7000L" by a Nippon Kayaku company (naphthol novolak-type epoxy resin); "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin) by a Nippon Kayaku company; "ESN475V" (naphthalene type epoxy resin) by the Nitetsu Chemical & Materials company; "ESN485" (naphthol type epoxy resin) by the Nitetsu Chemical & Materials company; "ESN375" (dihydroxynaphthalene type epoxy resin) by the Nitetsu Chemical & Materials company; "YX4000H", "YX4000", "YX4000HK", "YL7890" by Mitsubishi Chemical Corporation (bixylenol type epoxy resin); "YL6121" by Mitsubishi Chemical (biphenyl type epoxy resin); "YX8800" (anthracene type epoxy resin) by a Mitsubishi Chemical company; "YX7700" by Mitsubishi Chemical (phenol aralkyl type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals; "YX7760" by a Mitsubishi Chemical company (bisphenol AF type|mold epoxy resin); "YL7800" by Mitsubishi Chemical (fluorene type epoxy resin); "jER1010" by a Mitsubishi Chemical company (bisphenol A epoxy resin); "jER1031S" by Mitsubishi Chemical (tetraphenylethane type epoxy resin); "WHR991S" (phenolphthalimidine type epoxy resin) by a Nippon Kayaku company, etc. are mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more type.

As a liquid epoxy resin, the liquid epoxy resin which has two or more epoxy groups in 1 molecule is preferable.

Examples of the liquid epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, hydrogenated bisphenol A type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin , a phenol novolak-type epoxy resin, an alicyclic epoxy resin having an ester skeleton, a cyclohexane-type epoxy resin, a cyclohexanedimethanol-type epoxy resin, and an epoxy resin having a butadiene structure are preferable.

As a specific example of a liquid epoxy resin, "HP4032", "HP4032D", "HP4032SS" by DIC company (naphthalene type epoxy resin); "828US", "828EL", "jER828EL", "825" (bisphenol A epoxy resin) by Mitsubishi Chemical Corporation; "jER807", "1750" by Mitsubishi Chemical Corporation (bisphenol F-type epoxy resin); "jER152" by Mitsubishi Chemical (phenol novolak type epoxy resin); "630", "630LSD", "604" (glycidylamine type epoxy resin) by Mitsubishi Chemical Corporation; "ED-523T" by ADEKA (glycyrol type epoxy resin); "EP-3950L" by ADEKA, "EP-3980S" (glycidylamine type epoxy resin); "EP-4088S" by ADEKA (dicyclopentadiene type epoxy resin); "ZX1059" (mixture of a bisphenol A epoxy resin and a bisphenol F type epoxy resin) by the Nitetsu Chemical & Materials company; "EX-721" by the Nagase Chemtex company (glycidyl ester type epoxy resin); "Celoxide 2021P" by Daicel (alicyclic epoxy resin which has ester skeleton); "PB-3600" by Daicel, "JP-100" by Nippon Soda, "JP-200" (epoxy resin having a butadiene structure); "ZX1658", "ZX1658GS" (1,4-glycidylcyclohexane type epoxy resin) manufactured by Nittetsu Chemical & Materials, "YX8000" (hydrogenated bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical, Shin-Etsu Chemical Manufactured "KF-101" (epoxy-modified silicone resin), etc. are mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more type.

The epoxy resin may be any of a solid epoxy resin, a liquid epoxy resin, or a combination thereof, but in the method of the present invention employing specific curing conditions, a light reflective substrate that exhibits a higher reflectance and further excellent adhesion to the underlying substrate From a viewpoint of easy realization, it is preferable to contain a solid-state epoxy resin, and it is especially preferable that it is a combination of a solid-state epoxy resin and a liquid epoxy resin.

As the epoxy resin, when a solid epoxy resin and a liquid epoxy resin are used in combination, their mass ratio (solid epoxy resin: liquid epoxy resin) is preferably 20:1 to 1:20, more preferably 10:1 to 1:10, particularly preferably from 3:1 to 1:3.

The epoxy equivalent of the epoxy resin is preferably 50 g/eq. to 5,000 g/eq., more preferably 60 g/eq. to 1,000 g/eq., more preferably 80 g/eq. to 500 g/eq., even more preferably 100 g/eq. to 300 g/eq. Epoxy equivalent is the mass of resin per equivalent of epoxy group. Such an epoxy equivalent can be measured according to JISK7236.

The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, still more preferably 400 to 1,500. The weight average molecular weight of resin can be measured as a value in terms of polystyrene by a gel permeation chromatography (GPC) method.

The content of the epoxy resin is preferably 0.5% by mass or more, more preferably 1% by mass or more, still more preferably when the nonvolatile component in the resin composition layer is 100% by mass from the viewpoint of significantly obtaining the effect of the present invention. Preferably it is 5 mass % or more, More preferably, it is 10 mass % or more, or 15 mass % or more, Preferably it is 50 mass % or less, More preferably, it is 40 mass % or less, More preferably, it is 35 mass % or less, Especially Preferably it is 30 mass % or less. Therefore, in one suitable embodiment, when the nonvolatile component in a resin composition layer is 100 mass %, content of an epoxy resin is 1-50 mass %.

The resin sheet used by the method of this invention WHEREIN: The resin composition layer may contain another component further. Examples of such other components include a curing agent, a thermoplastic resin, a curing accelerator, and other additives. Hereinafter, each component will be described in detail.

- Hardener -

The resin composition layer may contain a curing agent. The curing agent reacts with the epoxy resin and has a function of curing the resin composition. A hardening|curing agent may be used individually by 1 type, and may be used in combination of 2 or more type.

The curing agent is not particularly limited, and for example, a phenol-based curing agent, a carbodiimide-based curing agent, an acid anhydride-based curing agent, an amine-based curing agent, a benzoxazine-based curing agent, a cyanate ester-based curing agent, a thiol-based curing agent, and the like. there is. In the method of the present invention employing specific curing conditions, the curing agent preferably contains a phenol-based curing agent from the viewpoint of easily realizing a light reflective substrate that exhibits a higher reflectance and has further excellent adhesion to the substrate.

The phenol-based curing agent is a curing agent having two or more phenolic hydroxyl groups in one molecule, for example, a bisphenol-based curing agent, a biphenyl-type phenol-based curing agent, a naphthalene-type phenol-based curing agent, a phenol novolac-type phenol-based curing agent, and naphthylene. and ether-type phenol-based curing agents, triazine skeleton-containing phenol-based curing agents, polyphenylene ether-type phenol-based curing agents, phenol aralkyl-type phenol-based curing agents, cresol novolac-type phenol-based curing agents, and bisphenol-type phenol-based curing agents. From the viewpoint of exhibiting a higher reflectance and easily realizing a light reflectance further excellent in adhesion to the substrate, preferably a bisphenol-based curing agent, more preferably a bisphenol compound having a fluorine atom, a bisphenol compound having an alicyclic structure, A bisphenol-based curing agent selected from bisphenol compounds having a fluorene skeleton, more preferably a bisphenol compound having a fluorine atom, particularly preferably bisphenol AF.

As a commercial item of a phenolic hardening|curing agent, Specifically, "BIS-AF", "BIS-Z" by Central Glass Corporation, "BisE" by Honshu Chemical Industry, "BisP-TMC"; "BisA", "BisF", "BisP-M" manufactured by Mitsui Chemical Fine Co., Ltd.; “BisP-AP”, “BisP-MIBK”, “BisP-B”, “Bis-Z”, “BisP-CP”, “o,o’-BPF”, “BisP-IOTD” manufactured by Honshu Chemical Industry Co., Ltd. , "BisP-IBTD", "BisP-DED", "BisP-BA"; “Bis-C”, “Bis26X-A”, “BisOPP-A”, “BisOTBP-A”, “BisOCHP-A”, “BisOFP-A”, “BisOC-Z”, “BisOC” manufactured by Honshu Chemical Industry Co., Ltd. -FL”, “BisOFP-A”, “BisOC-CP”, “BisOCHP-Z”, “MethylenebisP-CR”, “TM-BPF”, “BisOC-F”, “Bis3M6B-IBTD”, “BisOC” -IST", "BisP-IST", "BisP-PRM", "BisP-LV", etc. are mentioned.

The carbodiimide-based curing agent is a curing agent having two or more carbodiimide structures in one molecule, for example, tetramethylene-bis(t-butylcarbodiimide), cyclohexanebis(methylene-t-butylcarbodiimide). aliphatic biscarbodiimides such as mid); biscarbodiimides such as aromatic biscarbodiimides such as phenylene-bis(xylylcarbodiimide); Aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), and poly(isophoronecarbodiimide) ; Poly(phenylenecarbodiimide), poly(naphthylenecarbodiimide), poly(tolylenecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(di ethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly and polycarbodiimides such as aromatic polycarbodiimides such as (methylenediphenylenecarbodiimide) and poly[methylenebis(methylphenylene)carbodiimide].

As a commercial item of a carbodiimide-type hardening|curing agent, "Carbodilite V-02B", "Carbodilite V-03", "Carbodilite V-04K", "Carbodilite" manufactured by Nisshinbo Chemical Co., Ltd. are, for example, V-07” and “Carbodilite V-09”; "Stabakusol P", "Stabakusol P400", "Haikazil 510" etc. by the Line Chemistry company are mentioned.

The acid anhydride curing agent is a curing agent having one or more carboxylic acid anhydride groups (-CO-O-CO-) in one molecule, for example, phthalic anhydride, pyromellitic dianhydride, 1,4,5,8- Naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3',4, 4'-diphenylsulfone tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, methylene-4, Aromatic acid anhydride type hardening|curing agents, such as 4'- diphthalic acid dianhydride; tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, cyclopentanetetracarboxylic acid aliphatic acid anhydride curing agents such as dianhydride and cyclohexane-1,2,4,5-tetracarboxylic dianhydride; Polymer anhydride type hardening|curing agents, such as a styrene/maleic anhydride copolymer, and an alkyl (meth)acrylate/styrene/maleic anhydride copolymer, etc. are mentioned. As a commercial item of an acid anhydride type hardening|curing agent, "HNA-100", "MH-700", "MTA-15", "DDSA", "OSA" by Shin-Nippon Rika Corporation, "YH-306" by Mitsubishi Chemical Corporation , "YH-307", "HN-2200" by Hitachi Kasei Corporation, "HN-5500", etc. are mentioned.

The amine-based curing agent is a curing agent having two or more amino groups, for example, aliphatic amines, polyetheramines, alicyclic amines, aromatic amines, etc., among them, from the viewpoint of showing the desired effect of the present invention, Aromatic amines are preferable. Primary amine or secondary amine is preferable and, as for an amine type hardening|curing agent, primary amine is more preferable. Specific examples of the amine curing agent include 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'- Diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobi Phenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 3,3 -Dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane ), 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis (4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, etc. are mentioned. A commercial item may be used for an amine-type hardening|curing agent, For example, "SEIKACURE-S" by Seika Corporation, "KAYABOND C-200S" by Nippon Kayaku Corporation, "KAYABOND C-100", "Kayahard AA", "Kaya Hard AB", "Kaya Hard AS", "Epicure W" by Mitsubishi Chemical, etc. are mentioned.

As a specific example of a benzoxazine type hardening|curing agent, "JBZ-OP100D" by JFE Chemicals, "ODA-BOZ"; "HFB2006M" by Showa Kobunshi Corporation; "P-d", "F-a" manufactured by Shikoku Kaseiko Co., Ltd., etc. are mentioned.

Examples of the cyanate ester curing agent include bisphenol A dicyanate, polyphenol cyanate (oligo(3-methylene-1,5-phenylene cyanate)), 4,4'-methylenebis(2,6) -Dimethylphenylcyanate), 4,4'-ethylidenediphenyldicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4 -Cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4- Bifunctional cyanate resins such as cyanate phenyl) thioether and bis (4-cyanate phenyl) ether, polyfunctional cyanate resins derived from phenol novolac and cresol novolac, etc., these cyanate resins are partially triazined A prepolymer etc. are mentioned. As a specific example of a cyanate ester type hardening|curing agent, "PT30" and "PT60" (all are phenol novolac type polyfunctional cyanate ester resin), "BA230", "BA230S75" (a part of bisphenol A dicyanate by Ronza Japan) Or the prepolymer which all was triazine-ized and became a trimer) etc. are mentioned.

The thiol-based curing agent is a curing agent having two or more mercapto groups, for example, trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), tris(3-mer). Captopropyl) isocyanurate, etc. are mentioned.

The reactive equivalent weight of the curing agent is preferably 50 g/eq. to 3,000 g/eq., more preferably 100 g/eq. to 1,000 g/eq., more preferably 100 g/eq. to 500 g/eq., particularly preferably 100 g/eq. to 300 g/eq. Reactor equivalent weight is the mass of curing agent per equivalent reactor equivalent. A reactive group is a phenolic hydroxyl group if it is a phenol type hardening|curing agent, for example. In the case of an acid anhydride curing agent, 1 equivalent of a carboxylic acid anhydride group (-CO-O-CO-) corresponds to 2 equivalents of a reactor.

The content of the curing agent is preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably when the nonvolatile component in the resin composition layer is 100% by mass from the viewpoint of significantly obtaining the effect of the present invention. is 15 mass % or less, particularly preferably 10 mass % or less, for example, 0 mass % or more, 0.001 mass % or more, preferably 0.01 mass % or more, more preferably 0.1 mass % or more, still more preferably 1 mass % or more, Especially preferably, it is 3 mass % or more.

- Thermoplastics -

The resin composition layer may contain a thermoplastic resin. A thermoplastic resin may be used individually by 1 type, or may be used in combination of 2 or more type.

Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, acrylic resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamideimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin. , polyetherimide resins, polycarbonate resins, polyetheretherketone resins, and polyester resins, and among these, resins selected from phenoxy resins, acrylic resins and polyphenylene ether resins are preferable.

Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolak skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene. and phenoxy resins having at least one skeleton selected from the group consisting of skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton and trimethylcyclohexane skeleton. Any functional group, such as a phenolic hydroxyl group and an epoxy group, may be sufficient as the terminal of a phenoxy resin. A phenoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type. Specific examples of the phenoxy resin include "1256" and "4250" (both bisphenol A skeleton-containing phenoxy resins), "YX8100" (bisphenol S skeleton-containing phenoxy resin) and "YX6954" (bisphenol acetophenone manufactured by Mitsubishi Chemical Corporation) skeleton-containing phenoxy resin), "FX280" and "FX293" by Nittetsu Chemical & Materials, "YX7200B35", "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30" by Mitsubishi Chemical ', "YL6794", "YL7213", "YL7290", "YL7482", etc. are mentioned.

As polyvinyl acetal resin, polyvinyl formal resin and polyvinyl butyral resin are mentioned, for example, Polyvinyl butyral resin is preferable. As a specific example of polyvinyl acetal resin, "Denka Butyral 4000-2", "Denka Butyral 5000-A", "Denka Butyral 6000-C", "Denka Butyral" manufactured by Denki Chemical Co., Ltd. as a specific example, for example, 6000-EP", Sekisui Chemical Co., Ltd. S-Rec BH series, BX series (eg BX-5Z), KS series (eg KS-1), BL series, BM series, etc. are mentioned. .

An acrylic resin means the polymer formed by superposing|polymerizing the monomer component containing a (meth)acrylic acid ester type monomer. In addition to the (meth)acrylic acid ester-based monomer, the monomer component constituting the acrylic resin may contain a (meth)acrylamide-based monomer, a styrene-based monomer, a functional group-containing monomer, and the like as a copolymerization component. As a specific example of an acrylic resin, "ARUFON UP-1000", "ARUFON UP-1010", "ARUFON UP-1020", "ARUFON UP-1021", "ARUFON UP-1061", "ARUFON UP-" manufactured by Toagosei Co., Ltd. 1080”, “ARUFON UP-1110”, “ARUFON UP-1170”, “ARUFON UP-1190”, “ARUFON UP-1500”, “ARUFON UH-2000”, “ARUFON UH-2041”, “ARUFON UH-2190” ', "ARUFON UHE-2012", "ARUFON UC-3510", "ARUFON UG-4010", "ARUFON US-6100", "ARUFON US-6170", etc. are mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the polyolefin resin include ethylene-based copolymer resins such as low-density polyethylene, ultra-low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer; Polyolefin type elastomers, such as a polypropylene and an ethylene-propylene block copolymer, etc. are mentioned.

Examples of the polybutadiene resin include hydrogenated polybutadiene skeleton-containing resin, hydroxyl group-containing polybutadiene resin, phenolic hydroxyl group-containing polybutadiene resin, carboxyl group-containing polybutadiene resin, acid anhydride group-containing polybutadiene resin, epoxy group-containing poly A butadiene resin, an isocyanate group containing polybutadiene resin, a urethane group containing polybutadiene resin, polyphenylene ether- polybutadiene resin, etc. are mentioned.

As a specific example of polyimide resin, "Ricacoat SN20" and "Ricacoat PN20" by a New Nippon Rica company are mentioned. Specific examples of the polyimide resin include a linear polyimide obtained by reacting a difunctional hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (polyimide described in Japanese Patent Application Laid-Open No. 2006-37083), polysiloxane and modified polyimides such as skeleton-containing polyimide (the polyimide described in JP-A-2002-12667 and JP-A-2000-319386).

As a specific example of polyamideimide resin, "Viromax HR11NN" and "Viromax HR16NN" by Toyo Boseki Co., Ltd. are mentioned. Specific examples of the polyamideimide resin include modified polyamideimides such as "KS9100" and "KS9300" (polyamideimide containing polysiloxane skeleton) manufactured by Hitachi Chemical Co., Ltd.

As a specific example of polyether sulfone resin, the Sumitomo Chemical Company "PES5003P" etc. are mentioned.

As a specific example of polysulfone resin, the polysulfone "P1700" by Solvay Advanced Polymers, "P3500", etc. are mentioned.

Specific examples of the polyphenylene ether resin include oligophenylene ether styrene resins “OPE-2St1200” and “OPE-2St2200” manufactured by Mitsubishi Gas Chemical Company, “Noryl (registered trademark) SA90” manufactured by SABIC. Specific examples of the polyetherimide resin include "Ultem" manufactured by GE Corporation.

Examples of the polycarbonate resin include a hydroxyl group-containing carbonate resin, a phenolic hydroxyl group-containing carbonate resin, a carboxyl group-containing carbonate resin, an acid anhydride group-containing carbonate resin, an isocyanate group-containing carbonate resin, and a urethane group-containing carbonate resin. As a specific example of a polycarbonate resin, "FPC0220" by Mitsubishi Gas Chemicals, "T6002", "T6001" (polycarbonate diol) by Asahi Kasei Chemicals, "C-1090", "C-2090" by Kuraray Corporation ', "C-3090" (polycarbonate diol), etc. are mentioned. As a specific example of polyether ether ketone resin, the Sumitomo Chemical Company "Sumiproy K" etc. are mentioned. As a polyester resin, polyethylene terephthalate resin etc. are mentioned, for example.

The weight average molecular weight of the thermoplastic resin is preferably 8,000 or more, more preferably 10,000 or more, still more preferably 20,000 or more, preferably 100,000 or less, more preferably 70,000 or less, still more preferably 60,000 or less. The weight average molecular weight of resin can be measured as a value in terms of polystyrene by a gel permeation chromatography (GPC) method.

The thermoplastic resin is preferably a thermoplastic resin having a transmittance of 80% or more of light having a wavelength of 450 nm incident from a direction perpendicular to the film surface when the film is formed with a thickness of 20 µm.

The content of the thermoplastic resin is preferably 50 mass% or less, more preferably 40 mass% or less, still more preferably 30 mass% or less, particularly preferably when the nonvolatile component in the resin composition layer is 100 mass%. is 25 mass% or less, for example, 0 mass% or more, 0.1 mass% or more, preferably 1 mass% or more, more preferably 5 mass% or more, particularly preferably 10 mass% or more.

- hardening accelerator -

The resin composition layer may contain a curing accelerator. A hardening accelerator has a function which accelerates|stimulates the hardening reaction of a thermosetting resin. A hardening accelerator may be used individually by 1 type, and may be used in combination of 2 or more type.

As a hardening accelerator, a phosphorus type hardening accelerator, an imidazole type hardening accelerator, an amine type hardening accelerator, a guanidine type hardening accelerator, a metal type hardening accelerator, etc. are mentioned, for example. Especially, as a hardening accelerator, a phosphorus type hardening accelerator and an imidazole type hardening accelerator are preferable from a viewpoint of achieving a higher light reflectance, and a phosphorus type hardening accelerator is more preferable.

It is preferable to contain 1 or more types selected from the group which consists of a phosphonium salt and a phosphine from a viewpoint of achieving a higher light reflectance as a phosphorus type hardening accelerator.

Examples of the phosphonium salt include tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphoniumdecanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyro Mellitate, tetrabutylphosphonium hydrogen hexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenorate, di-tert-butylmethylphosphonium aliphatic phosphonium salts such as tetraphenylborate; Methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra- p-tolyl borate, tetraphenylphosphonium tetraphenyl borate, tetraphenyl phosphonium tetrap-tolyl borate, triphenylethyl phosphonium tetraphenyl borate, tris (3-methylphenyl) ethyl phosphonium tetraphenyl borate, tris (2-methyl Aromatic phosphonium salts, such as oxyphenyl) ethyl phosphonium tetraphenyl borate, (4-methylphenyl) triphenyl phosphonium thiocyanate, tetraphenyl phosphonium thiocyanate, and butyl triphenyl phosphonium thiocyanate, etc. are mentioned. .

As the phosphine, for example, tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl- aliphatic phosphines such as 2-butenyl) phosphine and tricyclohexyl phosphine; Dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolyl Phosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, Tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2, 6-dimethylphenyl)phosphine, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine , tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl- 2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2- aromatic phosphines such as bis(diphenylphosphino)acetylene and 2,2'-bis(diphenylphosphino)diphenyl ether; aromatic phosphine/borane complexes such as triphenylphosphine/triphenylborane; Aromatic phosphine-quinone addition reactants, such as a triphenylphosphine p-benzoquinone addition reactant, etc. are mentioned.

A commercial item may be used as a phosphorus type hardening accelerator, For example, "TBP-DA" by the Hokko Chemical Industry, etc. are mentioned.

Examples of the imidazole-based curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, and 2-ethyl-4-methyl. Imidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methyl Imidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2- Ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimida Zolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-unde Silimidazolyl-(1′)]-ethyl-s-triazine, 2,4-diamino-6-[2′-ethyl-4′-methylimidazolyl-(1′)]-ethyl-s -triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazineisocyanuric acid adduct, 2-phenylimidazoleisocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1, 2-a] imidazole compounds such as benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline and 2-phenylimidazoline, imidazole compounds and epoxy resins of adducts, and 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole are preferable.

A commercial item may be used as an imidazole type hardening accelerator, For example, "P200-H50" by a Mitsubishi Chemical company, "1B2PZ-10M" by a Shikoku Kasei company, etc. are mentioned.

Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8 -diazabicyclo(5,4,0)-undecene etc. are mentioned, 4-dimethylaminopyridine and 1,8- diazabicyclo(5,4,0)- undecene are preferable.

Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine. , trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]deca-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0] Deca-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1, 1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, 1-(o-tolyl)biguanide, etc. are mentioned, dicyandiamide, 1,5,7-triazabicyclo[4.4.0]deca-5-ene is preferred.

As a metal type hardening accelerator, the organometallic complex or organometallic salt of metals, such as cobalt, copper, zinc, iron, nickel, manganese, and tin, is mentioned, for example. Specific examples of the organometallic complex include organocobalt complexes such as cobalt(II)acetylacetonate and cobalt(III)acetylacetonate, organocopper complexes such as copper(II)acetylacetonate, zinc(II)acetylacetonate, and the like. organic zinc complexes, organic iron complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organometallic salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

The content of the curing accelerator is preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably when the nonvolatile component in the resin composition layer is 100% by mass from the viewpoint of significantly obtaining the effect of the present invention. preferably 1 mass % or less, particularly preferably 0.8 mass % or less, for example, 0 mass % or more, 0.001 mass % or more, preferably 0.01 mass % or more, more preferably 0.05 mass % or more, especially Preferably it is 0.1 mass % or more.

- Other additives -

The resin composition layer may further contain other additives. As other additives, For example, photocurable components, such as (meth)acrylic resin and a radically polymerizable compound, a diluent as its preparation, a photoinitiator, etc.; organic fillers such as rubber particles; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentone and montmorillonite; Antifoaming agents, such as a silicone type antifoamer, an acrylic type antifoamer, a fluorine type antifoamer, and a vinyl resin type antifoamer; UV absorbers such as benzophenone UV absorbers, benzotriazole UV absorbers and salicylic acid UV absorbers; adhesion improvers such as urea silane; adhesion-imparting agents such as triazole-based adhesion-imparting agents, tetrazole-based adhesion-imparting agents, and triazine-based adhesion-imparting agents; antioxidants such as hindered phenolic antioxidants; optical brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; Flame retardants such as phosphorus-based flame retardants (eg, phosphoric acid ester compounds, phosphazene compounds, phosphinic acid compounds, red), nitrogen-based flame retardants (eg, melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (eg, antimony trioxide); dispersants such as phosphoric acid ester dispersants, polyoxyalkylene dispersants, acetylene dispersants, silicone dispersants, anionic dispersants, and cationic dispersants; and stabilizers such as borate stabilizers, titanate stabilizers, aluminate stabilizers, zirconate stabilizers, isocyanate stabilizers, carboxylic acid stabilizers, and carboxylic acid anhydride stabilizers. Other additives may be used individually by 1 type, and may be used combining 2 or more types by arbitrary ratios. Content of other additives can be suitably set by a person skilled in the art.

The thickness of the resin composition layer is, from the viewpoint of reducing the thickness of the light reflective substrate, the light reflective substrate produced by the method of the present invention is excellent in light reflectance even if the reflective sheet (cured body of the resin composition layer) is a thin film, so it is preferably 200 ㎛ or less, more preferably 150 ㎛ or less or 100 ㎛ or less, still more preferably 80 ㎛ or less, 60 ㎛ or less or 50 ㎛ or less. Although the lower limit of the thickness of a resin composition layer is not specifically limited, Usually, it can be 10 micrometers or more, 15 micrometers or more, 20 micrometers or more.

In the method of the present invention employing specific curing conditions, the resin composition layer has a minimum melt viscosity of 5,000 poise or less from the viewpoint of easily realizing a light reflective substrate that exhibits a higher reflectance and has further excellent adhesion to the underlying substrate. Preferably, it is 2,000 poise or less, more preferably 1,000 poise or less, and particularly preferably 500 poise or less.

- Support -

As a support body, the film which consists of a plastic material, metal foil, and a release paper are mentioned, for example, The film which consists of a plastic material, and metal foil are preferable.

When a film made of a plastic material is used as the support, as the plastic material, for example, polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate ( Acryl, such as PMMA), cyclic polyolefin, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, a polyimide, etc. are mentioned. Among them, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable.

When using metal foil as a support body, as metal foil, copper foil, aluminum foil, etc. are mentioned, for example, Copper foil is preferable. As the copper foil, a foil made of a single metal of copper may be used, or a foil made of an alloy of copper and another metal (eg, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used. good night.

A support body may give a mat treatment, a corona treatment, and an antistatic treatment to the surface to join with the resin composition layer.

Moreover, as a support body, you may use the support body with a mold release layer which has a mold release layer on the surface to join with the resin composition layer. As a mold release agent used for the mold release layer of a support body with a mold release layer, 1 or more types of mold release agents are mentioned from the group which consists of an alkyd resin, a polyolefin resin, a urethane resin, and a silicone resin, for example. A support with a release layer may use a commercial item, for example, "PET501010", "SK-1", "AL-5" manufactured by Lintec, which is a PET film having a release layer containing an alkyd resin-based mold release agent as a main component, "PET501010", "SK-1", "AL-5", "AL-7"; "Lumira T60" by Tore Corporation; "Purex" by Teijin Corporation; "Uni-pil" manufactured by Unichika Corporation, etc. are mentioned.

Although the thickness of a support body is not specifically limited, The range of 5 micrometers - 75 micrometers is preferable, and the range of 10 micrometers - 60 micrometers is more preferable. Moreover, when using a support body with a mold release layer, it is preferable that the thickness of the whole support body with a mold release layer is the said range.

As a support body, you may use the metal foil with a support base material which bonded together the support base material which can peel further to thin metal foil. In one embodiment, the metal foil with a support base material contains a support base material, the peeling layer provided on the said support base material, and the metal foil provided on the said peeling layer. When a metal foil with a supporting substrate is used as the support, the resin composition layer is provided on the metal foil.

Metal foil with a support base material WHEREIN: Although the material of a support base material is not specifically limited, For example, copper foil, aluminum foil, stainless steel foil, titanium foil, copper alloy foil, etc. are mentioned. When using copper foil as a support base material, an electrolytic copper foil and a rolled copper foil may be sufficient. In addition, the peeling layer will not be specifically limited if metal foil can be peeled from a support base material, For example, An alloy layer of the element chosen from the group which consists of Cr, Ni, Co, Fe, Mo, Ti, W, P; An organic film etc. are mentioned.

Metal foil with a support base material WHEREIN: As a material of metal foil, copper foil and copper alloy foil are preferable, for example.

Metal foil with a support base material WHEREIN: Although the thickness of a support base material is not specifically limited, The range of 10 micrometers - 150 micrometers is preferable, and the range of 10 micrometers - 100 micrometers is more preferable. Moreover, the thickness of metal foil is good also as the range of 0.1 micrometer - 10 micrometers, for example.

In one embodiment, the resin sheet may further contain other layers as needed. As such another layer, the protective film according to the support body etc. which were provided on the surface which is not joined to the support body of a resin composition layer (namely, the surface on the opposite side to a support body), etc. are mentioned, for example. Although the thickness of a protective film is not specifically limited, For example, they are 1 micrometer - 40 micrometers. By laminating|stacking a protective film, adhesion of dust, etc. to the surface of a resin composition layer, and a flaw can be suppressed.

The resin sheet is prepared by, for example, a liquid resin composition as it is or by preparing a resin varnish in which the resin composition is dissolved in an organic solvent, applying this on a support using a die coater or the like, and further drying to form a resin composition layer. can be manufactured.

As an organic solvent, a well-known thing can be used suitably, The kind in particular is not limited. Examples of the organic solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether and diphenyl ether; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; ether ester solvents such as 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene and trimethylbenzene. An organic solvent may be used individually by 1 type, and may be used combining 2 or more types by arbitrary ratios.

You may perform drying by well-known methods, such as a heating and hot air spraying. Although drying conditions are not specifically limited, Content of the organic solvent in a resin composition layer is 10 mass % or less, Preferably it is made to dry so that it may become 5 mass % or less. Although it changes also with the boiling point of the organic solvent in a resin composition (resin varnish), for example, when using the resin composition (resin varnish) containing 30 mass % - 60 mass % of an organic solvent, 50 degreeC - 150 degreeC for 3 minutes A resin composition layer can be formed by drying for -10 minutes.

A resin sheet can be wound up and stored in roll shape. When a resin sheet has a protective film, it becomes usable by peeling off a protective film.

Hereinafter, a method for manufacturing a light reflective substrate of the present invention (hereinafter simply referred to as "the method of the present invention") will be described in detail based on preferred embodiments thereof. However, this invention is not limited to the following embodiment, The range which does not deviate from the range which does not deviate from the claim of this invention and its equivalent range can be implemented by changing arbitrarily.

[Method for manufacturing light reflective substrate]

The manufacturing method of the light reflective substrate of this invention is characterized by including the following steps (A) and (B) in this order.

(A) Bonding a resin sheet comprising a support and a resin composition layer containing a white inorganic pigment provided on the support to a substrate having a conductor layer on at least a part of its surface, the resin composition layer being bonded to the conductor layer of the substrate a process of laminating so as to

(B) a step of thermosetting the resin composition layer under conditions satisfying at least one of (i) and (ii) below:

(i) After heat treatment maintained at temperature T ₁ , heat treatment maintained at temperature T ₂ higher than temperature T ₁ .

(ii) After heating up to temperature T ₂ at a temperature increase rate of 0.5 to 30° C./min, heat treatment maintained at temperature T ₂ .

On the other hand, in the present invention, "included in this order" with respect to the steps (A) and (B) includes the respective steps of the steps (A) and (B), and the steps (A) and (B) As long as each process of ' is performed in this order, it does not prevent the inclusion of other processes.

Hereinafter, the same applies to "included in this order" regarding the process or treatment.

- Process (A) -

In the step (A), a resin sheet including a support and a resin composition layer containing a white inorganic pigment provided on the support is applied to a substrate having a conductor layer on at least a part of its surface, the resin composition layer is formed on the substrate. It is laminated so as to bond with the conductor layer.

The configuration of the resin sheet is as described above.

The substrate used in the step (A) is not particularly limited as long as at least a part of the surface has a conductor layer, for example, a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a heat Those in which a conductor layer was formed on one side or both surfaces of board|substrates, such as a curable polyphenylene ether board|substrate, are mentioned. In addition, the conductor layer may be pattern-processed. A substrate in which a conductor layer (circuit) is formed on one or both surfaces of the substrate is sometimes referred to as an "inner-layer circuit board". In addition, when manufacturing a printed wiring board (light reflecting board), the intermediate product in which an insulating layer and/or a conductor layer should be further formed is also included in the "board|substrate" said in this invention. When the light reflection board is a circuit board with built-in components, a circuit board with built-in components may be used.

In addition, in this invention, the board|substrate with which the conductor layer is provided in at least a part of the surface which is the object on which the resin sheet is laminated|stacked in the process (A) is also simply called "base board|substrate".

Lamination of a board|substrate and a resin sheet can be performed by thermocompression-bonding a resin sheet to a board|substrate from the support body side, for example. As a member (henceforth a "thermal compression bonding member") which heat-compresses a resin sheet to a board|substrate, a heated metal plate (SUS mirror plate etc.), a metal roll (SUS roll), etc. are mentioned, for example. On the other hand, it is preferable not to press the thermocompression-bonding member directly to the resin sheet, but to press through an elastic material, such as a heat-resistant rubber, so that a resin sheet may fully follow the surface unevenness|corrugation of a board|substrate.

You may perform lamination|stacking of a board|substrate and a resin sheet by the vacuum lamination method. In the vacuum lamination method, the thermocompression compression temperature is preferably in the range of 60° C. to 160° C., more preferably 80° C. to 140° C., and the thermocompression compression pressure is preferably 0.098 MPa to 1.77 MPa, more preferably is in the range of 0.29 MPa to 1.47 MPa, and the heat compression time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. Lamination|stacking becomes like this. Preferably it is performed under reduced pressure conditions of pressure 26.7 hPa or less.

Lamination can be performed with a commercially available vacuum laminator. As a commercially available vacuum laminator, the vacuum pressure laminator by the Meiki Sesakusho company, the vacuum applicator by the Nikko Materials company, a batch type vacuum pressure laminator, etc. are mentioned, for example.

After lamination, the laminated resin sheet may be smoothed under normal pressure (under atmospheric pressure), for example, by pressing the thermocompression-bonding member from the support side. The press conditions of the smoothing process can be made into the conditions similar to the thermocompression-bonding conditions of the said lamination|stacking. A smoothing process can be performed with a commercially available laminator. In addition, you may perform lamination|stacking and a smoothing process continuously using the said commercially available vacuum laminator.

The support may peel (remove) between a process (A) and a process (B), and may peel after a process (B). In the method of the present invention employing specific curing conditions, the support is peeled between the steps (A) and (B) from the viewpoint of easily realizing a light reflective substrate that exhibits a higher reflectance and has further excellent adhesion to the underlying substrate. It is preferable to do Therefore, in one suitable embodiment, the support body is peeled between a process (A) and a process (B).

On the other hand, when a reflective sheet (cured body) formed by curing the resin composition layer is used as the interlayer insulating layer and a metal foil is used as the support, the conductor layer may be formed using the metal foil without peeling the support. . In addition, when metal foil with a support base material is used as a support body, what is necessary is just to peel a support base material (and a peeling layer). And the conductor layer can be formed using metal foil.

- Process (B) -

The resin composition layer is thermosetted in a process (B). Thereby, a reflective sheet (hardening body) can be formed on a base board|substrate.

In realizing a light reflective substrate with good underlying adhesion, it is important to thermoset the resin composition layer under conditions satisfying at least one of the following (i) and (ii):

(i) After heat treatment maintained at temperature T ₁ , heat treatment maintained at temperature T ₂ higher than temperature T ₁ .

(ii) After heating up to temperature T ₂ at a temperature increase rate of 0.5 to 30° C./min, heat treatment maintained at temperature T ₂ .

According to the method of this invention employ|adopting such specific hardening conditions, while exhibiting a high reflectance, the light reflection board|substrate with favorable base|substrate adhesiveness can be implement|achieved. When the composition of the cured body formed of the resin composition layer was investigated with respect to the light reflective substrate produced by the method of the present invention, an inorganic filler component-rich phase exists on the surface on the side not in contact with the underlying substrate, but from the surface toward the thickness direction The present inventors have confirmed that the proportion of the inorganic filler component decreases at a constant distance position. Here, "thickness direction" means the thickness direction of a hardening body, and shows the direction perpendicular|vertical to the main surface of a hardening body.

Due to the inorganic filler component rich phase existing in a limited region near the surface on the side not in contact with the underlying substrate, a light reflectance significantly higher than expected from the bulk inorganic filler concentration is realized, while the main surface in contact with the underlying substrate A resin component-rich phase exists in the area|region in the vicinity, and it is estimated that the adhesiveness excellent with respect to an underlying board|substrate can be exhibited.

- thermosetting conditions (i) -

Thermosetting the resin composition layer under the conditions satisfying (i) is sometimes referred to as a “step cure”, and a heat treatment maintained at a temperature T ₁ is “pre-cure”, maintained at a temperature T ₂ higher than the temperature T ₁ The heat treatment to be performed is sometimes referred to as "post-cure".

With respect to the thermosetting conditions (i), the temperature T ₁ also depends on the composition of the resin composition layer, but can usually be 50° C.≦T ₁ <150° C., preferably 60° C.≦T ₁ ≦140° C., more preferably preferably 70°C≤T ₁ ≤130°C, more preferably 80°C≤T ₁ ≤120°C, particularly preferably 80°C≤T ₁ ≤110°C.

The holding time at the temperature T ₁ also depends on the value of the temperature T ₁ , but is preferably from 10 minutes to 150 minutes, more preferably from 15 minutes to 120 minutes, still more preferably from 20 minutes to 120 minutes.

The heat treatment maintained at the temperature T ₁ may be performed under normal pressure or under reduced pressure, but from the viewpoint of easily realizing a light reflective substrate that exhibits higher reflectance and has further excellent adhesion to the underlying substrate, preferably 0.075 mmHg to 3,751 It is preferable to carry out at an air pressure in the range of mmHg (0.1 hPa to 5,000 hPa), more preferably in the range of 1 mmHg to 1,875 mmHg (1.3 hPa to 2,500 hPa).

The temperature T ₂ also depends on the composition of the resin composition layer, but can be usually 150° _C≤T2≤250 °C, preferably 155° _C≤T2≤230 °C, more preferably 160° _C≤T2≤220 °C, more preferably 170 °C≤T ₂ ≤210 °C, particularly preferably 180 °C≤T ₂ ≤200 °C.

Meanwhile, the temperature T ₁ and the temperature T ₂ are preferably 20°C≤T ₂ -T ₁ ≤150°C, more preferably 30°C≤T ₂ -T ₁ ≤140°C, still more preferably 40°C≤T ₂ -T ₁ ≤130°C, particularly preferably 50°C≤T ₂ -T ₁ ≤120°C.

The holding time at the temperature T ₂ also depends on the value of the temperature T ₂ , but is preferably from 10 minutes to 150 minutes, more preferably from 15 minutes to 120 minutes, still more preferably from 20 minutes to 120 minutes.

The heat treatment maintained at the temperature T ₂ may be performed under normal pressure or may be performed under reduced pressure. Preferably, it is preferable to carry out at the same air pressure as the heat treatment maintained at the temperature T ₁ .

After the heat treatment at the temperature T ₁ , the resin composition layer may be once cooled and heat treated at the temperature T ₂ . Alternatively, after the heat treatment at the temperature T ₁ , the resin composition layer may be heat treated at a temperature T ₂ without cooling. The heat treatment at the temperature T ₁ and the heat treatment at the temperature T ₂ may be performed using the same heat treatment apparatus, or the heat treatment at the temperature T ₁ is performed using the first heat treatment apparatus, and the temperature T ₂ . You may perform the heat processing by using the 2nd heat processing apparatus different from the 1st heat processing apparatus. It does not specifically limit as a heat processing apparatus, as long as it can thermoset the resin composition layer on a base substrate to form a hardening body, A conventionally well-known apparatus may be used. For example, you may use an oven, a hot press, etc. as a heat processing apparatus. For example, after heat _- processing _at the temperature T1 using the oven adjusted to the temperature T1, you may transfer a heating object to the oven adjusted by _the temperature T2, and you may heat _- process at the temperature T2. Alternatively, after performing heat treatment at the temperature T ₁ using a heat treatment apparatus capable of temperature programming, the temperature may be increased from the temperature T ₁ to the temperature T ₂ and heat treatment may be performed at the temperature T ₂ . In this case, the temperature increase rate from the temperature T ₁ to the temperature T ₂ is not particularly limited and may be any value or may be within the same range as the temperature increase rate in the thermosetting conditions (ii) described later.

With respect to the thermosetting condition (i), as long as the heat treatment maintained at the temperature T ₁ and the heat treatment maintained at the temperature T ₂ higher than the temperature T ₁ are included in this order, the heat treatment may be maintained at another temperature. . That is, the step cure under the thermosetting condition (i) is not limited to the two-step heat treatment, and may include three or more steps of heat treatment.

- thermosetting conditions (ii) -

Thermosetting the resin composition layer on the condition that (ii) is satisfied is sometimes referred to as "(program) temperature rise cure".

The value of the temperature T ₂ and the time held at the temperature T ₂ may be the same as those described for the thermosetting conditions (i).

With respect to the thermosetting condition (ii), the temperature increase rate when the temperature is raised to the temperature T ₂ is in the range of 0.5 to 30 ° C./min from the viewpoint of realizing a light reflective substrate that exhibits a high reflectance and has good adhesion to the substrate. , preferably at least 1°C/min, more preferably at least 1.5°C/min, at least 2°C/min or at least 2.5°C/min, preferably at most 25°C/min, more preferably at least 20°C/min. or less, 15°C/min or less, 10°C/min or less, 8°C/min or less, or 6°C/min or less.

The temperature increase rate does not need to be constant from the temperature increase start temperature T ₀ to the temperature T ₂ , and may be changed within the suitable range. The temperature increase initiation temperature T ₀ is not particularly limited, and the environmental temperature (room temperature, etc.) at the time of carrying out the method of the present invention may be used.

The temperature rise curing may be performed under normal pressure or may be performed under reduced pressure. Preferably, it is preferable to carry out at the same air pressure as that described for the step cure.

In addition, as a heat processing apparatus used for temperature rise curing, it is not specifically limited as long as it can raise the temperature of the resin composition layer on the base substrate at a predetermined temperature increase rate and it can heat at temperature T2, _A conventionally well-known apparatus may be used. good night. For example, you may use an oven, a hot press, etc. as a heat processing apparatus.

By the process (B), the reflective sheet|seat which consists of a hardening body of a resin composition layer is formed on a base substrate. The light reflective substrate manufactured WHEREIN: The reflective sheet|seat may be contained as an interlayer insulating layer or a soldering resist. When the reflective sheet is included as an interlayer insulating layer, the method of the present invention may also include a step of forming a conductor layer on the reflective sheet. Such a process can be performed according to the various methods well-known to those skilled in the art and used for manufacture of a printed wiring board.

The method of the present invention may further include the step of (C) arranging a light source on the reflective sheet (cured body of the resin composition layer). As a light source, a light emitting diode (LED), a mini LED, a micro LED, etc. are mentioned.

As an example is shown in FIG. 1 , in the light reflective substrate 1 , a reflective sheet 3 is formed on a substrate 2 , and a light emitting diode (LED) or the like is formed on a surface 31 of the reflective sheet 3 . A light source 4 is arranged. On the other hand, the substrate 2 corresponds to the above "substrate" (the conductor layer is not shown in Fig. 1), and the surface 31 of the reflective sheet 3 is on the side not in contact with the above "substrate". surface”.

In the reflective sheet, in order to increase the extraction efficiency of the light emitted from the light source, the surface of the reflective sheet on the light source side may have a concave portion other than the planar shape as shown in FIG. 1 . When the reflective sheet has a concave portion on the surface, it is preferable to arrange the light source in the concave portion.

After electrically connecting a light source as needed, you may perform sealing process etc. to a light source to fix a light source.

The light reflective substrate produced by the method of the present invention exhibits a high light reflectance in order to have an inorganic filler component-rich phase in a region near the surface of the reflective sheet (cured body of the resin composition layer) that is not in contact with the underlying substrate. , For example, with respect to light having a wavelength of 460 nm, preferably 85% or more, more preferably 86% or more or 88% or more, still more preferably 90% or more, 92% or more, 94% or more, or 95% or more represents the reflectance. The upper limit of such light reflectance can be 100% or less. Accordingly, in one suitable embodiment, the light reflective substrate exhibits a reflectance of 85% or more with respect to light having a wavelength of 460 nm. The light reflectance of a hardening body can be measured using the multi-channel spectrometer (the Otsuka Electronics company make, MCPD-7700), for example.

The light reflecting substrate produced by the method of the present invention can achieve such a high light reflectance without lowering the adhesion to the underlying substrate. For example, in the light reflective substrate produced by the method of the present invention, the reflective sheet (cured body of the resin composition layer) with respect to the conductor layer of the underlying substrate, preferably 0.3 kgf/cm or more, more preferably It exhibits adhesion strength of 0.32 kgf/cm or more, 0.34 kgf/cm or more, 0.35 kgf/cm or more, 0.36 kgf/cm or more, 0.38 kgf/cm or more, or 0.4 kgf/cm or more. The upper limit of such adhesion strength can be made into 1 kgf/cm or less, 0.9 kgf/cm or less, etc. Accordingly, in one preferred embodiment, the adhesion strength between the reflective sheet in the light reflective substrate and the conductor layer of the underlying substrate is 0.3 kgf/cm or more.

[Semiconductor device]

A semiconductor device can be manufactured using the light reflective substrate manufactured by the method of the present invention. A semiconductor device can be manufactured by mounting a component (semiconductor chip) in the conduction|electrical_connection location of a light reflection board. For example, the backlight of liquid crystal displays, such as a portable terminal, a computer, and a television; A semiconductor device in which a light emitting diode (LED) emitting light with low power, such as a light source of a lighting fixture, is mounted is mentioned.

[Example]

Hereinafter, the present invention will be specifically described by way of Examples. The present invention is not limited to these examples. In addition, in the following, "part" and "%" which show quantity show "mass part" and "mass %", respectively, unless otherwise indicated. In particular, when no temperature is specified, the temperature and pressure conditions are room temperature (25° C.) and atmospheric pressure (1 atm).

<Production Example 1> Preparation of resin sheet 1

(1) Preparation of resin composition

5 parts of liquid bisphenol A epoxy resin (“jER828EL” manufactured by Mitsubishi Chemical, 180 g/eq. epoxy equivalent), 5 parts of solid fluorine atom-containing epoxy resin (“YX7760” manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent 245 g/eq.) 5 parts, 20 parts of a phenoxy resin containing a biphenyl skeleton and a cyclohexane skeleton (("YX7200B35" manufactured by Mitsubishi Chemical Corporation, a weight average molecular weight of 30,000, a 20 µm film light transmittance (450 nm) 88%, a solid content of 35 mass%) 20 parts, MEK 10 It was dissolved by heating while stirring in the part.Thereto, titanium oxide (“PX3788” manufactured by Sakai Chemical Co., Ltd., phenylsilane coupling agent (“KBM-103”, Shin-Etsu Chemical Co., Ltd.)) treatment was completed, average particle diameter 0.26 μm, ratio Surface area 13.2 m 2 /g, reflectance to light with a wavelength of 500 nm 99%) 10 parts, spherical silica (“SO-C2” manufactured by Adomatex Co., Ltd., methacrylic silane coupling agent (“KBM-503” from Shin-Etsu Chemical Co., Ltd.) ) treatment completed, average particle diameter of 0.5 µm, reflectance with respect to light with a wavelength of 500 nm about 80%) 10 parts, bisphenol AF (solution prepared by adjusting "BIS-AF" manufactured by Central Glass Corporation to 50% of nonvolatile components with MEK) 4 Part and 0.2 parts of a phosphorus-based hardening accelerator ("TBP-DA" by Hokko Chemical Co., Ltd.) were mixed, it disperse|distributed uniformly with a high-speed rotary mixer, and the resin composition (varnish) was prepared.

(2) Preparation of resin sheet

As a support body, the PET film with a mold release layer ("PET501010" by Lintec Corporation, 38 micrometers in thickness) was prepared. On the release layer of the said support body, the resin composition prepared in said (1) was apply|coated uniformly so that the thickness of the resin composition layer after drying might be set to 50 micrometers. Then, the resin sheet 1 containing the 50-micrometer-thick resin composition layer was obtained by heating the resin composition 1 at 80 degreeC for 4 minutes.

<Production Example 2> Preparation of resin sheet 1-RCC

Production Example 1 except that, as a support, an electrolytic copper foil (“3EC-III” manufactured by Mitsui Kinzoku Co., Ltd., 35 μm thick) was used instead of the PET film with a release layer (“PET501010” manufactured by Lintec, 38 μm in thickness) as a support. In the same manner as described above, a resin sheet 1-RCC was prepared. On the other hand, the resin composition was apply|coated on the glossy side of an electrolytic copper foil.

<Production Example 3> Preparation of resin sheet 2

Instead of 5 parts of liquid bisphenol A epoxy resin (“jER828EL” manufactured by Mitsubishi Chemical, 180 g/eq. epoxy equivalent) and 5 parts of solid fluorine atom-containing epoxy resin (“YX7760” manufactured by Mitsubishi Chemical, 245 g/eq. epoxy equivalent) 5 parts of a hydrogenated liquid epoxy resin (“YX8000” manufactured by Mitsubishi Chemical, 205 g/eq. epoxy equivalent) and 5 parts of a biphenyl type epoxy resin (“YX4000H” manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent 195 g/eq.) 5 parts were each used. Except for that, it carried out similarly to Production Example 1, and produced the resin sheet 2.

<Production Example 4> Preparation of resin sheet 3

(1) changing the blending amount of titanium oxide (“PX3788” manufactured by Sakai Chemical Co., Ltd., treated with a phenylsilane coupling agent) from 10 parts to 20 parts, and (2) spherical silica (“SO-C2” manufactured by Adomatex Co., Ltd.) ", methacrylic silane coupling agent treatment complete) was not mix|blended, but it carried out similarly to Production Example 1, and produced the resin sheet 3.

<Production Example 5> Preparation of resin sheet 4

(1) Preparation of resin composition

3 parts of biphenyl-type epoxy resin ("NC3000H" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: about 272 g/eq.), tetrakishydroxyphenylethane-type epoxy resin ("jER1031S" manufactured by Mitsubishi Chemical), epoxy equivalent of about 200 g/eq. ) 2 parts, bisphenol A epoxy acrylate (“ZAR-2000” manufactured by Nippon Kayaku, acid value 99 mg KOH/g, nonvolatile component 70%) 10 parts, diluent (“DPHA” manufactured by Nippon Kayaku Co., Ltd., dipentaerythritol hexa 1 part of acrylate, acrylic equivalent of about 96 g/eq.) was dissolved by heating with 6 parts of MEK and 10 parts of ethyldiglycol acetate while stirring. There, titanium oxide (“PX3788” manufactured by Sakai Chemical Co., Ltd., phenylsilane coupling agent (“KBM-103”, Shin-Etsu Chemical Co., Ltd.)) treatment completed, average particle diameter 0.26 μm, specific surface area 13.2 m 2 /g, wavelength 500 nm of 99% reflectance to light), 8 parts of spherical silica (“SO-C2” manufactured by Adomatex Co., Ltd., treated with a methacrylic silane coupling agent (“KBM-503” from Shin-Etsu Chemical Co., Ltd., average particle diameter of 0.5 μm) , a reflectance of about 80% with respect to light with a wavelength of 500 nm) 8 parts, a photopolymerization initiator ("Irgacure819" manufactured by BASF, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide) 0.04 parts are mixed, and a high-speed rotation mixer and uniformly dispersed therein to prepare a resin composition.

(2) Preparation of resin sheet

Using the resin composition prepared in (1) above, in the same manner as in Production Example 1, a resin sheet 4 was produced. The resin sheet 4 includes a support and a photosensitive resin composition layer provided on the support.

About each produced resin sheet, the composition and support body of the resin composition layer are put together and are shown in Table 1.

<Example 1>

(A) Preparation of substrate A

(A1) Base treatment of circuit board

A circuit pattern is formed on both sides of a glass cloth base epoxy resin double-sided copper clad laminate (copper foil thickness 18 µm, substrate thickness 0.8 mm, “R5715ES” manufactured by Matsushita Denko) by etching, and the copper area in the surface is 30% An inner-layer circuit board was fabricated. After roughening the copper circuit of the obtained inner-layer circuit board with a microetchant ("CZ8100" by Mack Corporation), it was made to dry at 190 degreeC for 30 minute(s).

(A2) Lamination of resin sheet

The resin sheet 1 obtained in the above production example was treated using a batch type vacuum pressurization laminator (“MVLP-500” manufactured by Meiki Sesakusho Co., Ltd.) so that the resin composition layer was bonded to the inner circuit board. Laminated on both sides. Lamination was performed by pressure-reducing for 30 second, making atmospheric|air pressure 13 hPa or less, and crimping|bonding at 120 degreeC, 30 second, and pressure of 0.74 MPa after that.

(A3) Smoothing of the resin sheet

Then, the laminated resin sheet was smoothed by hot pressing under atmospheric pressure at 100° C. and 0.5 MPa for 60 seconds. In this way, the laminate with a support body which has the laminated constitution of a support body/resin composition layer/inner-layer circuit board/resin composition layer/support body was obtained.

(A4) thermosetting of the resin composition layer

The support body was peeled from the laminated body with a support body obtained in said (A3), and the laminated body which has the laminated constitution of a resin composition layer/inner-layer circuit board/resin composition layer was obtained. Then, the laminate was heated in an oven at 100° C. for 30 minutes (pre-cure), and then heated in an oven at 180° C. for 90 minutes (post-cure) to thermoset the resin composition layer. Thereby, the board|substrate A which has the laminated constitution of hardening body/inner-layer circuit board/hardening body was obtained.

(B) Preparation of substrate B

(B1) Substrate treatment of copper foil

The glossy side of the electrolytic copper foil (Mitsui Kinzokuko Co., Ltd. "3EC-III", thickness 35 µm) is immersed in a micro etchant (Mec etch bond "CZ-8101" manufactured by Meg Corporation), and roughening treatment (Ra value) of the copper surface = 1 µm) and subjected to a rust prevention treatment (CL8300). Then, heat treatment was performed in an oven at 130° C. for 30 minutes. The obtained copper foil is hereafter called CZ copper foil.

(B2) Lamination of resin sheet

The resin sheet 1 obtained in the said production example was laminated on the single side|surface of CZ copper foil, and the resin sheet with copper foil which has the laminated constitution of a support body/resin composition layer/CZ copper foil was produced. Lamination conditions were the same as the lamination conditions in said (A2).

(B3) thermosetting of the resin composition layer

The support body was peeled from the resin sheet with copper foil produced in said (B2), and the laminated body which has the laminated constitution of a resin composition layer/CZ copper foil was obtained. Then, the laminate was heated under the same curing conditions as those in (A4) to thermoset the resin composition layer. Thereby, the hardening body with copper foil which has the laminated constitution of hardening body/CZ copper foil was obtained.

(B4) Fixation to the circuit board

The cured body with copper foil obtained in the above (B3) was adhered to both sides of the under-treated circuit board using an adhesive (Aaron Alpha EX) so that the cured body was in contact with the circuit board. The circuit board subjected to the underlying treatment was the same as that prepared in (A1) above.

Then, the cured body with copper foil and the circuit board were laminated on the same conditions as said (A2). Thereby, the board|substrate B which has the laminated constitution of CZ copper foil / hardening body / circuit board / hardening body / CZ copper foil was obtained.

<Example 2>

Substrates A and B were carried out in the same manner as in Example 1, except that the resin composition layer was thermosetted in a state in which the support was attached without peeling off the support during thermosetting of the resin composition layer, and then the support was peeled off. got

<Example 3>

(1) At the time of thermosetting of the resin composition layer, without peeling the support body, the resin composition layer was thermosetted in the state to which the support body was attached, and the point which peeled the support body after that, (2) temperature rising from 25 degreeC in oven Substrates A and B were obtained in the same manner as in Example 1, except that the temperature was raised to 180°C at a rate of 2.6°C/min and then heated at 180°C for 90 minutes to thermoset the resin composition layer.

<Example 4>

(1) At the time of thermosetting of the resin composition layer, without peeling the support body, the resin composition layer was thermosetted in the state to which the support body was attached, and the point which peeled the support body after that, (2) hot press from 25 degreeC Substrates A and B were obtained in the same manner as in Example 1, except that the temperature was raised to 180°C at a temperature increase rate of 2.6°C/min and then heated at 180°C for 90 minutes to thermoset the resin composition layer.

<Example 5>

(1) the resin sheet 1-RCC was used instead of the resin sheet 1, (2) at the time of thermosetting the resin composition layer, without peeling the support body, the resin composition layer was thermosetted while the support body was attached; Then, except the point which peeled the support body, it carried out similarly to Example 1, and obtained the board|substrates A and B.

<Example 6>

Substrates A and B were obtained in the same manner as in Example 1 except that the resin sheet 2 was used instead of the resin sheet 1.

<Example 7>

Substrates A and B were obtained in the same manner as in Example 1 except that the resin sheet 3 was used instead of the resin sheet 1.

<Comparative Example 1>

(1) At the time of thermosetting of the resin composition layer, without peeling the support body, the resin composition layer was thermosetted in a state in which the support body was attached, and thereafter, the support body was peeled off, (2) an oven heated to 180°C Substrates A and B were obtained in the same manner as in Example 1, except that a heating object was placed in the furnace and heated at 180° C. for 90 minutes to thermoset the resin composition layer.

<Comparative Example 2>

(1) The resin sheet 4 (resin sheet including the photosensitive resin composition layer) was used instead of the resin sheet 1, and (2) the resin composition layer was photocured in the following order, except for the substrate in the same manner as in Example 1; A and B were obtained.

(Photocuring procedure): The photosensitive resin composition layer was exposed to the ultraviolet-ray of 100 mJ/cm<2>, and was photocured. Then, on the entire surface of the photosensitive resin composition layer, 30 degreeC 1 mass % sodium carbonate aqueous solution was spray-developed for 2 minutes by the spray pressure of 0.2 MPa as a developing solution. After spray development, 1 J/cm<2> of ultraviolet-ray irradiation was performed, and it heated at 190 degreeC for 90 minutes, and hardened the photosensitive resin composition layer.

Hereinafter, various measurement methods and evaluation methods are demonstrated.

<Measurement of light reflectance>

The substrate A prepared in Examples and Comparative Examples was cut out to a width of 50 mm and a length of 50 mm, and the reflectance (%) with respect to light having a wavelength of 460 nm was measured with a multi-channel spectrometer (manufactured by Otsuka Denshi Corporation, MCPD-7700). It was evaluated as a standard.

Evaluation criteria for light reflectance:

◎: reflectance of 95% or more

○: reflectance of 90% or more and less than 95%

△: The reflectance is 85% or more and less than 90%

×: The reflectance is less than 85%

<Measurement of lower extremity adhesion>

The substrate B obtained in Examples and Comparative Examples was cut into 150 × 30 mm pieces. In the copper foil part of the small piece, using a cutter, a partial incision with a width of 10 mm and a length of 100 mm is made, one end of the copper foil is peeled off, and picked up with a household tool (autocom-type testing machine "AC-50C-SL" manufactured by TSE Co., Ltd.), Instron universal The load at the time of tensile peeling 35 mm in the vertical direction at a speed|rate of 50 mm/min in room temperature using the testing machine was measured based on JIS C6481, and the following criteria evaluated it.

Evaluation criteria for lower extremity adhesion:

◎: adhesion strength of 0.5 kgf/cm or more

○: adhesion strength of 0.3 kgf/cm or more and less than 0.5 kgf/cm

×: adhesion strength less than 0.3 kgf/cm

Table 2 shows the thermosetting conditions of the resin composition layer in Examples and Comparative Examples and the evaluation results of the prepared substrates. In addition, in the substrates manufactured in Examples, an inorganic filler component-rich phase exists in a region near the surface of the cured body (reflective sheet) of the resin composition layer that is not in contact with the underlying substrate, and the reflective sheet's underlying substrate It was confirmed that the resin component-rich phase was present in the region near the main surface in contact with it.

1 light reflective substrate
2 board
3 reflective sheet
31 side of the reflective sheet
4 light source

Claims (9)

A method for producing a light reflecting substrate comprising the following steps (A) and (B) in this order.
(A) A resin sheet comprising a support and a resin composition layer containing a white inorganic pigment provided on the support on a substrate having a conductor layer on at least a part of its surface (hereinafter referred to as "base substrate") a step of laminating the resin composition layer so as to be bonded to the conductor layer of the underlying substrate; and
(B) a step of thermosetting the resin composition layer under conditions satisfying at least one of (i) and (ii) below:
(i) After heat treatment maintained at temperature T ₁ , heat treatment maintained at temperature T ₂ higher than temperature T ₁ .
(ii) After heating up to temperature T ₂ at a temperature increase rate of 0.5 to 30° C./min, heat treatment maintained at temperature T ₂ . The method according to claim 1, wherein the support is peeled between the steps (A) and (B). The method of claim 1 , wherein the resin composition layer further comprises a thermosetting resin. The method according to claim 1, wherein when the nonvolatile component in the resin composition layer is 100% by mass, the content of the white inorganic pigment is 20 to 60% by mass. 4. The method of claim 3, wherein the thermosetting resin comprises an epoxy resin. The method according to claim 5, wherein when the nonvolatile component in the resin composition layer is 100% by mass, the content of the epoxy resin is 1 to 50% by mass. The method according to claim 1, wherein the white inorganic pigment is at least one selected from aluminum oxide, titanium oxide, zirconium oxide, magnesium oxide, barium titanate, zinc oxide, cerium oxide, and calcium carbonate. The method of claim 1 , wherein the light reflective substrate exhibits a reflectance of 85% or more with respect to light having a wavelength of 460 nm. The method according to any one of claims 1 to 8, wherein the adhesive strength between the cured body of the resin composition layer in the light reflective substrate and the conductor layer of the underlying substrate is 0.3 kgf/cm or more.

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