TW202045575A - Light-resistant epoxy resin and uses of the same - Google Patents

Abstract

An epoxy resin and its uses are provided. The epoxy resin has a quantity ratio (B/A) of an aromatic proton (B) to an aliphatic proton (A) measured by means of proton nuclear magnetic resonance spectrum (1H-NMR) of from 0.15 to 0.29.

Description

Light decay resistant epoxy resin and its application

The present invention relates to an epoxy resin, in particular to a light-decay resistant epoxy resin having a specific ratio of the number of aromatic protons to aliphatic protons. The epoxy resin of the present invention can be used to prepare packaging compositions to provide packaging materials, which are particularly suitable for light emitting diodes (LEDs).

With the development of science and technology, optoelectronic materials have been widely studied and applied in various fields. For example, LED is one of the main researches in optoelectronic materials and can be used in outdoor devices such as electronic signage, indicator lights, and detectors. However, due to prolonged exposure to outdoor environments, the LED packaging materials of the aforementioned outdoor devices are likely to suffer from the problem of light transmittance attenuation due to the influence of weather (such as temperature) and light. Therefore, in addition to the high transmittance requirements of LED packaging materials, the requirements for weather resistance and light resistance are becoming stricter.

Currently, LED packaging materials mainly include epoxy resin and silicone. However, the cost of silicone is high and the resulting packaging materials generally suffer from poor mechanical strength. Therefore, the current LED packaging materials are still epoxy Mainly resin. However, the conventional epoxy resin still has the problem of insufficient weather resistance and light resistance. After a long time exposure to high temperature or ultraviolet light, the transparency of the prepared packaging material will be significantly reduced.

The present invention aims to provide an epoxy resin (also referred to as the "first epoxy resin" herein) that is resistant to light decay. Specifically, the present invention relates to a light-decay resistant epoxy resin having a specific ratio of the number of aromatic protons to aliphatic protons. The present invention achieves the technical effect of improving the light resistance and heat resistance of the packaging material made by using the epoxy resin by controlling the ratio of the number of aromatic protons to aliphatic protons in the epoxy resin; in addition, the obtained The packaging material also has appropriate mechanical strength. Therefore, the epoxy resin of the present invention is particularly suitable for LED packaging applications.

Therefore, one object of the present invention is to provide an epoxy resin whose number ratio (B/A) of aromatic protons (B) to aliphatic protons (A) measured by nuclear magnetic resonance hydrogen spectroscopy ( ¹ H-NMR) is 0.15 to 0.29.

In some embodiments of the present invention, the epoxy resin further has an epoxy equivalent (weight per epoxy, WPE) of 500 to 2000 [g/eq].

於式(I)中，R₁為

、

或

，R₂各自獨立為H或甲基，且m為0至2之整數，其中*表示鍵結位置。該具有二個環氧基團之芳香族環氧化物例如可選自以下群組：雙酚A二縮水甘油醚 (bisphenol A diglycidyl ether)、雙酚F二縮水甘油醚(bisphenol F diglycidyl ether)、及其組合。 In some embodiments of the present invention, the epoxy resin contains a structural unit derived from an alicyclic compound having two carboxyl groups and an aromatic epoxide having two epoxy groups (aromatic epoxide) structural unit. More specifically, the alicyclic compound with two carboxyl groups may have the structure of the following formula (I):

In formula (I), R ₁ is

,

or

, R _{2 is} each independently H or methyl, and m is an integer from 0 to 2, where * represents the bonding position. The aromatic epoxide with two epoxy groups can be selected from the following groups, for example: bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, And its combination.

於式(II)中，X₁至X₈、R₁₁及R₁₂各自獨立為H或CH₃。該具有二個環氧基 團之脂環族環氧化物例如可選自以下群組：

、

、及其組合，其中n為1至30之整數。 In some embodiments of the present invention, the epoxy resin contains a structural unit derived from an aromatic compound having two -OH groups and a structural unit derived from an alicyclic compound having two epoxy groups The structural unit of alicyclic epoxide. More specifically, the aromatic compound with two -OH groups may have the structure of the following formula (II):

In formula (II), X ₁ to X ₈ , R ₁₁ and R ₁₂ are each independently H or CH ₃ . The alicyclic epoxide with two epoxy groups can be selected from the following groups, for example:

,

, And combinations thereof, wherein n is an integer from 1 to 30.

Another object of the present invention is to provide a use of the epoxy resin as described above, which is used to prepare an encapsulating composition.

Another object of the present invention is to provide an encapsulating composition, which includes a first epoxy resin and a hardener, wherein the first epoxy resin is the epoxy resin as described above. The hardener may, for example, be selected from the following group: acid anhydrides, phenolic resins, imidazoles, and combinations thereof.

In some embodiments of the present invention, the packaging composition further includes a second epoxy resin selected from the following group: isocyanurate epoxy resin, alicyclic epoxy resin, and combinations thereof.

Another object of the present invention is to provide a packaging material, which is prepared by curing the packaging composition as described above, and the light transmittance of the packaging material after being baked at 150°C for 168 hours is compared with that of baking. The attenuation value of the light transmittance before baking is preferably less than 23%.

In order to make the above objectives, technical features and advantages of the present invention more obvious and understandable, the following is a detailed description of some specific implementation aspects.

The following will specifically describe some specific implementation aspects of the present invention; however, without departing from the spirit of the present invention, the present invention can still be practiced in many different forms, and the protection scope of the present invention should not be limited to the specific embodiments. Implementation status.

Unless otherwise specified in the text, the terms "a", "the" and similar terms used in this specification (especially in the scope of the appended patent application) shall be understood to include singular and plural forms.

In this article, the term "normal temperature and normal pressure" refers to an environment with a temperature of 25°C and a pressure of 1 atmosphere.

In this article, the term "light decay" refers to the attenuation of light transmittance. The term "light decay resistance" refers to the low degree of attenuation of the light transmittance of the material after being exposed to heat or light. In this article, the light transmittance is the light transmittance value measured under 400nm light.

Unless otherwise specified, in this specification (especially in the scope of the patent application described later), the terms "first", "second" and similar terms used are only used to distinguish the described elements or components, and are not themselves It has no special meaning, and it is not intended to refer to the order of priority.

Compared with the prior art, the effect of the present invention is to provide an epoxy resin with a specific ratio of the number of aromatic protons to aliphatic protons, and the epoxy resin is used to provide an encapsulation with suitable mechanical strength and excellent light resistance and heat resistance. material. The following provides a detailed description of the epoxy resin of the present invention and its related applications.

1. Epoxy resin (first epoxy resin)

Herein, epoxy resin is a thermosetting resin with epoxy functional group. The epoxy resin of the present invention (ie "the first epoxy resin") has the following characteristics: the quantitative ratio of aromatic protons (B) to aliphatic protons (A) measured by nuclear magnetic resonance hydrogen spectroscopy ( ¹ H-NMR) (B/A) is 0.15 to 0.29, for example 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, or 0.28. In terms of resistance to light decay, the number ratio (B/A) of aromatic protons (B) to aliphatic protons (A) measured by hydrogen nuclear magnetic resonance spectroscopy ( ¹ H-NMR) of the epoxy resin of the present invention is preferably 0.15 to 0.21. In addition, the epoxy resin of the present invention may further have an epoxy equivalent (WPE) of 500 to 2000 [g/eq], such as 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, or 1950 [g/eq].

As will be explained below, the epoxy resin of the present invention can be prepared by reacting an alicyclic compound with two carboxyl groups and an aromatic epoxide having two epoxy groups, or by reacting with two- OH group aromatic compounds and alicyclic epoxides with two epoxy groups are prepared, so the epoxy resin of the present invention can contain structural units derived from alicyclic compounds with two carboxyl groups and derivatives The structural units derived from aromatic epoxides with two epoxy groups are composed of these structural units, or the structural units derived from aromatic compounds having two -OH groups and those derived from two The structural unit of the alicyclic epoxide of the epoxy group may be composed of these structural units.

1.1. Alicyclic compounds with two carboxyl groups

Herein, the alicyclic compound having two carboxyl groups is a compound having two carboxyl groups and at least one aliphatic ring in one molecule. The number of carbon atoms of the aliphatic ring is at least 3, preferably 3 to 16, more preferably 3 to 8, and may be saturated or unsaturated, preferably saturated. In addition, the aliphatic ring may be substituted or unsubstituted, and the aliphatic ring may contain heteroatoms such as oxygen and sulfur.

In a preferred embodiment of the present invention, the alicyclic compound with two carboxyl groups has the structure of the following formula (I):

、

或

，R₂各自獨立為H或甲基，且m為0至2之整數，其中*表示鍵結位置。 In formula (I), R ₁ is

,

or

, R _{2 is} each independently H or methyl, and m is an integer from 0 to 2, where * represents the bonding position.

The compound having the structure of formula (I) can be obtained by reacting an alicyclic anhydride with an alicyclic diol. Examples of alicyclic anhydrides include, but are not limited to, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, dimethylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and dimethyl Tetrahydrophthalic anhydride. Examples of the alicyclic diols include, but are not limited to, 1,4-cyclohexane dimethanol, tricyclo [5.2.1.0 ^2,6] decane-dimethanol ^{(tricyclo [5.2.1.0 2,6] decanedimethanol)} , 2, 2-bis(4-hydroxycyclohexyl)propane (hydrogenated bisphenol A), bis(4-hydroxycyclohexyl)methane (hydrogenated bisphenol F), 4,4'-bis(hydroxymethyl)bicyclohexane, 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (spiroglycerin), and 5-ethyl- 2-(2-Hydroxy-1,1-dimethylethyl)-5-hydroxymethyl-1,3-dioxane. In the following examples, when preparing the compound with the structure of formula (I), hexahydrophthalic anhydride and methylhexahydrophthalic anhydride are used as alicyclic anhydrides, and 1,4-cyclohexanedimethanol, tricyclo [5.2.1.0 ^2,6] decane-dimethanol ^{(tricyclo [5.2.1.0 2,6] decanedimethanol)} , 2,2- bis (4-hydroxycyclohexyl) -propane (hydrogenated bisphenol A) alicyclic Diol.

1.2. Aromatic epoxides with two epoxy groups

Herein, an aromatic epoxide with two epoxy groups is an epoxide with two epoxy groups and at least one aromatic ring in one molecule. The number of carbon atoms of the aromatic ring is at least 4, preferably 6-24, more preferably 6-18. The aromatic ring may be substituted or unsubstituted, and the aromatic ring may contain heteroatoms such as oxygen, sulfur, and nitrogen.

In some embodiments of the present invention, the diglycidyl ether of an aromatic epoxide-based bifunctional phenol compound with two epoxy groups. Examples of the aforementioned bifunctional phenol compound include but are not limited to bisphenol A (bisphenol A). A, BPA), tetramethyl bisphenol A, dimethyl bisphenol A, bisphenol F, tetramethyl bisphenol F, dimethyl bisphenol F, bisphenol S, tetramethyl bisphenol S, dimethyl bisphenol Bisphenol S, 4,4'-biphenol, tetramethyl-4,4'-biphenol, dimethyl-4,4'-biphenol, 1-(4-hydroxyphenyl)-2-[ 4-(1,1-bis-(4-hydroxyphenyl)ethyl)phenyl)propane, 2,2'-methylene-bis(4-methyl-6-tertiary butylphenol), m Hydroquinone, hydroquinone, 9,9-bis(4-hydroxyphenyl)-9H-茀, and 9,9-bis(4-hydroxy-3-methylphenyl)-9H-茀.

In a preferred embodiment of the present invention, the aromatic epoxide having two epoxy groups is selected from the following group: bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and combinations thereof .

1.3. Aromatic compounds with two -OH groups

Herein, the aromatic compound with two -OH groups is a compound with two -OH groups and at least one aromatic ring in one molecule. In some embodiments of the present invention, the aromatic compound with two -OH groups has the structure of the following formula (II):

In formula (II), X ₁ to X ₈ , R ₁₁ and R ₁₂ are each independently H or CH ₃ . In a preferred embodiment of the present invention, X ₁ to X ₈ are all H, and R ₁₁ and R ₁₂ are both CH ₃ . In the following examples, bisphenol A (ie, in formula (II), X ₁ to X ₈ are all H, and R ₁₁ and R ₁₂ are both CH ₃ ) as having two -OH groups Of aromatic compounds.

1.4. Alicyclic epoxides with two epoxy groups

Herein, an alicyclic epoxide with two epoxy groups is an epoxide with two epoxy groups and at least one aliphatic ring in one molecule. The alicyclic epoxide having two epoxy groups may be the diglycidyl ether of the aforementioned alicyclic diol, but the present invention is not limited thereto. Specifically, examples of alicyclic epoxides with two epoxy groups include, but are not limited to, dicyclopentadiene-based epoxy resin, hydrogenated bisphenol A epoxy resin (hydrogenated bisphenol A-based epoxy resin), and 7-oxabicyclo[4.1.0] heptane-based epoxy resin.

In some embodiments of the present invention, one or more 7-oxabicyclo[4.1.0]heptane epoxy resins with the following formula (III) structure are used:

、或

，其中n為1至30之整數，且*表示鍵結位置。 In formula (III), R ₂₁ is H or CH ₃ , Y is a covalent bond, -CH(CH ₃ )-, -CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )-, -CH ₂ CH ₂ CH ₂ -, -C(=O)OCH ₂ -, -OC(=O)(CH ₂ ) ₄ C(=O)O-, -CH ₂ OC(=O)(CH ₂ ) ₄ C(= O)OCH ₂ -、

,or

, Where n is an integer from 1 to 30, and * represents the bonding position.

Specific examples of 7-oxabicyclo[4.1.0]heptane type epoxy resins with the structure of formula (III) include but are not limited to the following groups:

1.5. Preparation and properties of epoxy resin

The epoxy resin with specific B/A value of the present invention can make the alicyclic or aromatic compound with two -OH groups and the aromatic or aliphatic compound with at least two epoxy groups in the presence of a catalyst The cyclic epoxides react and adjust the ratio of their components to obtain an epoxy resin with the desired B/A value. The type of the aforementioned catalyst is not particularly limited, as long as it can promote the ring opening of the epoxy functional group and lower the reaction temperature. Suitable catalysts include, but are not limited to, amines, imidazoles, and phosphorus-containing compounds. Examples of amines include, but are not limited to, 1,8-diazabicyclo[5.4.0]undec-7-ene (1,8-diazabicyclo[5.4.0]undec-7-ene), triethylenediamine, And 2,4,6-tris(dimethylaminomethyl)phenol (2,4,6-tris(dimethylaminomethyl)phenol). Examples of imidazoles include, but are not limited to, 2-ethyl-4-methylimidazole and 2-methylimidazole. Examples of phosphorus-containing compounds include, but are not limited to, triphenyl-n-butyl phosphonium bromide (TBP), triphenylphosphine, tetraphenyl phosphonium-tetraphenyl borate ( tetraphenylphosphonium-tetraphenylborate), and four - n-butyl phosphonium - o, o - diethyl phosphoramide disulfide salt (tetra-n-butylphosphonium- o, o -diethyl phosphorodithioate). The aforementioned catalysts can be used alone or in combination of multiple types.

In a preferred embodiment of the present invention, the epoxy resin is obtained by reacting an alicyclic compound having two carboxyl groups with an aromatic epoxide having two epoxy groups. First, the alicyclic diol and the alicyclic anhydride are mixed, the temperature is raised to 90°C to 110°C, and the exothermic reaction is carried out so that the temperature reaches 160°C to 180°C. After the exothermic reaction, the temperature is reduced to 140°C to 150°C And kept at this temperature for 2 hours, thereby preparing an alicyclic compound (intermediate product) having two carboxyl groups. Afterwards, the intermediate product is cooled to 100°C to 120°C and an aromatic epoxide having two epoxy groups is added, and the catalyst is added after mixing uniformly. Then, after the temperature was raised to 150°C to 160°C, an exothermic reaction was carried out so that the temperature reached 180°C to 200°C. After the exothermic reaction was completed, the temperature was lowered to 150°C to 170°C and kept at this temperature for 2 hours, thereby producing The epoxy resin of the present invention. Here, it is preferable to control the amount of the alicyclic compound with two carboxyl groups and the aromatic epoxide with two epoxy groups, so that the aromatic protons (B) of the epoxy resin prepared are relative to the aliphatic protons The quantity ratio (B/A) of (A) is not more than 0.21. As shown in the attached examples, in this case, it can provide the most excellent light decay resistance (thermal light decay value less than 15%; UV light decay value less than 3%)

In another embodiment of the present invention, the epoxy resin is obtained by reacting an aromatic compound having two -OH groups with an alicyclic epoxide having two epoxy groups. Firstly, after the alicyclic epoxide with two epoxy groups is heated to 80°C to 100°C, the aromatic compound with two -OH groups is added, and the catalyst is added after mixing uniformly. After that, the temperature was raised to 130°C to 150°C, and an exothermic reaction was performed so that the temperature reached 180°C to 200°C. After the exothermic reaction, the temperature was lowered to 150°C to 170°C and kept at this temperature for 2 hours. Then, the alicyclic epoxide having two epoxy groups is added again, and the reaction is maintained at 150°C to 170°C for 2 hours, thereby obtaining the epoxy resin of the present invention.

In addition to the number ratio (B/A) of aromatic protons (B) to aliphatic protons (A) and the epoxy equivalent value measured by ¹ H-NMR, the epoxy resin of the present invention preferably has a value between The softening point of 60°C to 115°C, such as 65°C, 68°C, 70°C, 75°C, 80°C, 81°C, 85°C, 89°C, 90°C, 92°C, 96°C, 100°C, 105°C, 108°C, 110°C, or 113°C. In addition, the epoxy resin of the present invention is preferably an epoxy resin that is liquid under normal temperature and pressure. Specifically, the epoxy resin of the present invention preferably has less than 1000 Pa under normal temperature and pressure. Viscosity in seconds (Pa.s).

2. Encapsulation composition

The epoxy resin of the present invention can be used to prepare an encapsulating composition. Therefore, the present invention also provides an encapsulation composition, which contains essential components such as a first epoxy resin and a hardener, and other optional components as required, wherein the first epoxy resin has a specific B/A as described above Value of epoxy resin.

In the packaging composition of the present invention, based on the total weight of the packaging composition, the content of the first epoxy resin may be 45% to 65% by weight, such as 47% by weight, 50% by weight, 52% by weight, 54% by weight %, 55% by weight, 56% by weight, 57% by weight, 58% by weight, 59% by weight, 60% by weight, or 63% by weight.

2.1. Hardener

Herein, the hardener refers to a component that can initiate the ring-opening reaction of the epoxy functional group and undergo a crosslinking and curing reaction with the epoxy resin. The type of the hardener is not particularly limited, as long as it can initiate the ring-opening reaction of the epoxy functional group and perform the cross-linking and curing reaction together with the epoxy resin. Examples of hardeners include, but are not limited to, acid anhydrides, phenolic resins, and imidazoles. Each of the aforementioned curing agents can be used alone or in combination of multiple types.

Acid anhydrides include, but are not limited to, monoacid anhydrides, acid dianhydrides, polyanhydrides, and copolymers of the aforementioned acid anhydrides and other copolymerizable monomers. Examples of monoacid anhydrides include, but are not limited to, acetic anhydride, maleic anhydride, succinic anhydride, hexahydrophthalic anhydride, or 4-methylhexahydrophthalic anhydride. Examples of acid dianhydrides include, but are not limited to, naphthalene tetracarboxylic dianhydride or pyromellitic dianhydride. Examples of polyanhydrides include, but are not limited to, mellitic trianhydride. Examples of copolymers of acid anhydrides and other copolymerizable monomers include, but are not limited to, copolymers of styrene and maleic anhydride.

Examples of phenolic resins include, but are not limited to, novolac phenolic resins and resol phenolic resins. Examples of novolak-type phenol resins include, but are not limited to, phenol novolak resin, phenol aralkyl resin, cresol novolak resin, tertiary butyl phenol novolak resin, and nonylphenol novolak resin.

Examples of imidazoles include, but are not limited to, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 1-benzyl-2-phenylimidazole.

In a preferred embodiment of the present invention, the hardening agent is a hardening agent that is liquid at room temperature and pressure, specifically, the viscosity is less than 1000 Pa at room temperature and pressure. Second (Pa.s) hardener. In the following examples, an acid anhydride that is liquid under normal temperature and pressure is used as the hardener.

In the packaging composition of the present invention, the content of the hardener is not particularly limited, as long as it can provide the desired hardening effect. Generally speaking, based on the total weight of the encapsulation composition, the content of the hardener may be 20% to 35% by weight, such as 23% by weight, 24% by weight, 25% by weight, 26% by weight, 27% by weight, 28% by weight %, 30% by weight, or 33% by weight.

2.2. The second epoxy resin

In the encapsulation composition of the present invention, in addition to the first epoxy resin, a second epoxy resin may be further included as an auxiliary hardener (auxiliary hardener) to aid in curing of the encapsulation composition. The second epoxy resin can be any conventional epoxy resin, such as but not limited to epoxy resin with triazine ring, cycloaliphatic epoxy resin, phenol epoxy resin, cresol epoxy resin ( cresol epoxy resin, naphthalene phenolic epoxy resin, and bisphenol phenolic epoxy resin. Examples of epoxy resins having triazine rings include, but are not limited to, isocyanurate-based epoxy resins, such as triglycidyl isocyanurate. Examples of cycloaliphatic epoxy resins include but are not limited to the aforementioned cycloaliphatic epoxides, such as (3',4'-epoxycyclohexane)methyl-3,4-epoxycyclohexylcarboxylate ( (3',4'-epoxycyclohexane)methyl 3,4-epoxycyclohexyl carboxylate). Examples of cresol epoxy resins include, but are not limited to, ortho-cresol epoxy resin, meta-cresol epoxy resin, and p-cresol epoxy resin. Epoxy (para-cresol epoxy resin). Examples of bisphenol epoxy resins include, but are not limited to, bisphenol A epoxy resin and bisphenol F epoxy resin. The aforementioned epoxy resins can be used alone or in combination of multiple types. In the following examples, triglycidyl isocyanurate or (3',4'-epoxycyclohexane) methyl-3,4-epoxycyclohexyl carboxylate is used as the second epoxy resin .

In a preferred embodiment of the present invention, the second epoxy resin is an epoxy resin that is liquid at room temperature and pressure, specifically, the viscosity is less than 1000 Pa at room temperature and pressure. Second (Pa.s) epoxy resin, or epoxy resin that is liquid at least at the preparation temperature of the packaging composition. For example, in the following embodiments, the encapsulating composition is prepared at a temperature of 120°C. In this case, the melting point of the second epoxy resin is preferably lower than 120°C so as to be liquid during the preparation process.

In the packaging composition of the present invention, the content of the second epoxy resin is not particularly limited, as long as it can provide the desired auxiliary effect without adversely affecting the light decay resistance and mechanical strength of the resulting packaging material. can. Generally speaking, based on the total weight of the encapsulation composition, the content of the second epoxy resin may be 10% to 20% by weight, for example, 11%, 12%, 13%, 14%, 15% by weight. , 16% by weight, 17% by weight, 18% by weight, or 19% by weight.

2.3. Other optional ingredients as needed

In the packaging composition of the present invention, other optional components may be further included as needed, such as the catalysts and additives known in the art as exemplified below, so as to adaptively improve the processability of the packaging composition in the manufacturing process, or improve The physical and chemical properties of the material after curing of the packaging composition. Examples of additives known in the art include, but are not limited to, inorganic fillers, flame retardants, carbon black, pigments, defoamers, dispersants, viscosity regulators, thixotropic agents, leveling agents ), coupling agent, mold release agent, antifungal agent, stabilizer, antioxidant, and antibacterial agent. Each additive can be used alone or in any combination.

In some embodiments of the present invention, the encapsulation composition is further added with a catalyst to promote the reaction of epoxy functional groups and reduce the curing reaction temperature of the encapsulation composition. The type of catalyst is not particularly limited, as long as it can promote the ring opening of the epoxy functional group and reduce the curing reaction temperature. Suitable catalysts include but are not limited to amines, imidazoles, phosphorus-containing compounds, and the aforementioned derivatives. The aforementioned catalysts can be used alone or in any combination. In the following examples, triphenyl-n-butylphosphonium bromide (TBP) is used.

2.4. Preparation of encapsulation composition

Regarding the preparation of the encapsulation composition of the present invention, the components of the encapsulation composition can be uniformly mixed with a stirrer and dissolved or dispersed in a solvent to prepare a varnish-like form for subsequent addition. 工utilization. The solvent can be any inert solvent that can dissolve or disperse the components of the packaging composition, but does not react with the components, such as toluene, γ-butyrolactone, methyl ethyl ketone, cyclohexanone, methyl ethyl ketone, acetone, xylene, Methyl isobutyl ketone, N,N-dimethyl formamide (DMF), N,N-dimethyl acetamide (DMAc), and N-methyl-pyrolidone (NMP).

However, the solvent is prone to volatilize during heating and curing, resulting in defects such as bubbles and voids in the material obtained after curing of the packaging composition, which is not conducive to the application of the packaging material. Therefore, in order to avoid the volatilization of the solvent during heating and curing and the generation of bubbles or voids in the cured product, the packaging composition usually does not use solvents during preparation, which is beneficial to the application of packaging materials and is more compatible with low VOC (volatile organic compound) , Volatile organic compound) environmental requirements. In view of this, the encapsulating composition of the present invention without solvent can be prepared in the following manner. First, the first epoxy resin and the second epoxy resin are placed in a glass distillation flask and mixed uniformly at 110°C to 130°C for 30 minutes. Then, the temperature is lowered to 90°C to 110°C, and the hardener and catalyst are added and mixed uniformly at this temperature for 30 minutes, thereby obtaining a semi-cured state (B-stage, B-stage) packaging composition.

3. Packaging materials

The present invention also provides an encapsulation material provided by the above encapsulation composition, which is formed by curing the encapsulation composition as described above, that is, after the encapsulation composition is completely cured (also known as C-stage) Materials obtained. The curing method of the packaging composition is not particularly limited. In some embodiments of the present invention, the packaging composition is cured by heating and pressing.

The packaging material of the present invention can be used for the packaging of optoelectronic components. Examples of the optoelectronic components include, but are not limited to, LEDs, laser diodes, and photodetectors. But the packaging material of the present invention It is not limited to the above-mentioned packaging purposes, and can also be used for packaging of any other items that require surface protection, such as the packaging of wind turbine blades.

The packaging material of the present invention has excellent light decay resistance. Specifically, the light transmittance of the packaging material of the present invention after being baked at 150°C for 168 hours is less than that before baking. 23%, such as 22%, 21%, 20%, 19%, 18%, 16%, 14%, 12%, 11%, 10%, 9%, 8%, 7%, 5%, or 3%, In some implementations, it is especially less than 15%. In addition, the light transmittance of the packaging material of the present invention after 336 hours of continuous irradiation under a UV light source of 200 milliwatts per square centimeter (mW/cm ² ) and a wavelength of 365 nanometers is compared with the light transmittance before irradiation. The value is less than 5%, such as 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, or 0.5%, especially less than 3% in some implementations.

In addition, the packaging material of the present invention has sufficient flexural strength (FS) and flexural modulus (FM). Specifically, the flexural strength of the packaging material of the present invention can reach 8 kgf/mm ² (kgf/mm ² ) to 12 kgf/mm2, such as 8.5 kgf/mm2, 9 kgf/mm2, 9.5 Kilogram force/square millimeter, 10 kilogram force/square millimeter, 10.5 kilogram force/square millimeter, 11 kilogram force/square millimeter, or 11.5 kilogram force/square millimeter. In addition, the flexural modulus of the packaging material of the present invention can reach 230 kgf/mm2 (kgf/mm ² ) to 300 kgf/mm2, such as 235 kgf/mm2, 240 kgf/mm2, 245 kg Force/mm2, 250 kgf/mm2, 255kgf/mm2, 260kgf/mm2, 265kgf/mm2, 270kgf/mm2, 275kgf/mm2, 280kgf /Square millimeter, 285 kgf/square millimeter, 290 kgf/square millimeter, or 295 kgf/square millimeter. For the packaging material of the present invention, the flexural modulus can be regarded as equivalent to the elastic modulus (EM), and the elastic modulus is proportional to the internal stress. Therefore, when the tortuous modulus of the material is lower, the internal stress is also lower, and the material with low internal stress is not easy to crack due to the drastic change of temperature.

4. Example

4.1. Measurement method description

The following specific implementations are used to further illustrate the present invention, in which the measuring instruments and methods used are as follows:

[Hydrogen Nuclear Magnetic Resonance Spectroscopy ( ¹ H-NMR) Test]

The hydrogen nuclear magnetic resonance spectrum ( ¹ H-NMR) of the epoxy resin was measured with a nuclear magnetic resonance spectrometer (model: Unity 400, purchased from Varian). In the epoxy resin of the present invention, the peak between 0.5 ppm and 5.5 ppm (ie, the A zone) represents aliphatic protons, and the peak between 6.5 ppm and 7.5 ppm (ie, the B zone) represents aromatic Family protons. Aliphatic protons (A) can be obtained by calculating the sum of the integral values of all peaks in the A zone, and the number of aromatic protons (B) can be obtained by calculating the sum of the integral values of all the peaks in the B zone.

[Epoxy equivalent (WPE) test]

Take 0.15 g to 0.17 g of epoxy resin as a sample and place it in a beaker, add 55 ml of the corresponding solvent (such as methyl ethyl ketone or toluene) and add an indicator (such as crystal violet). The potentiometric titration method is used for titration, and the titration solution used is 0.1N HBr-glacial acetic acid solution. The end point of the titration is the inflection point in the potential change curve, and WPE is calculated according to the following formula.

其中W為樣品重量、V為HBr的滴定體積、且N為HBr的濃度。

Where W is the weight of the sample, V is the titration volume of HBr, and N is the concentration of HBr.

[Softening point test]

The softening point test method is the ring and ball method, and the test specification is JIS K7232. The related test methods are summarized as follows. First, take 2.02 grams of epoxy resin as a sample and pour it into a preheated copper ring, melt it at the estimated softening point +70°C and remove bubbles. Next, cool the copper ring containing the sample at room temperature for at least 30 minutes. After that, prepare a beaker containing glycerin and place it on the heater, place the copper ring containing the sample in the glycerin in a hanging manner, place an iron ball on the sample, and set an infrared detector. Set the heating rate of the heater to 5°C/min and start heating. The falling of the iron ball is confirmed by an infrared detector. The temperature at which the iron ball falls is the softening point.

[Preparation of cured product sample]

Take 46±2 grams of the packaging composition (stage B) and make into ingots. Set the mold temperature of the molding machine (model: ST-75, purchased from a high-tech enterprise) to 150±2°C. After preheating the ingot to 80±2℃, put it into the feed hole of the molding machine. After that, carry out punching and holding for 1 minute, and solidify the formed specimen in the mold for 4 minutes, and then take out the molded specimen. If necessary, the molded specimen may be post-cured at 150°C for 4 hours to obtain a post-cured specimen.

[Glass transition temperature (Tg) test]

Take 4 to 6 mg of the post-cured sample and place it in the sample pan. A differential scanning calorimeter (DSC) (model: DSC 2910, purchased from TA instrument) was used to determine the Tg of the sample. The test conditions are as follows: set the temperature parameter from 50°C to 250°C, and the heating rate is 20°C/min. Find the inflection point in the obtained temperature versus heat flow curve, and the temperature of the inflection point corresponding to the temperature axis is Tg.

[Thermal light decay test]

The molded sample was cut into a sample with a length of 60 mm, a width of 14 mm, and a thickness of 1 mm. The sample is placed in a UV-Vis spectrometer (model: UV-1700, purchased from Shimadzu), and the light transmittance value (hereinafter referred to as "initial transmittance" Luminosity value"). After that, the sample was placed in an oven and baked continuously at 150±2°C for 168 hours. After taking out the sample and cooling it to room temperature, it is placed in a UV-visible light spectrometer to measure the transmittance value under the 400nm wavelength band (hereinafter referred to as "heat-resistant transmittance value"). The value obtained by subtracting the initial transmittance value from the heat resistance and light resistance value is the heat and light decay value.

[Ultraviolet (UV) light decay test]

The molded sample was cut into a sample with a length of 60 mm, a width of 14 mm, and a thickness of 1 mm. The sample is placed in a UV-visible light spectrometer, and the transmittance value (hereinafter referred to as the "initial transmittance value") under the wavelength of 400 nm is measured. After that, the sample was placed at a distance of 5 cm under a UV light source with an intensity of 200 milliwatts per square centimeter (mW/cm ² ) and a wavelength of 365 nm, and UV light was continuously irradiated for 336 hours. Then, the sample is placed in a UV-visible light spectrometer to measure the transmittance value under the 400nm wavelength band (hereinafter referred to as "UV transmittance resistance value"). The value obtained by subtracting the initial transmittance value from the UV resistance value is the UV light attenuation value.

[Flexural strength and flexural modulus test]

The test specification for flexural strength and flexural modulus is JIS K6911, and the related test methods are summarized as follows. First, cut the post-cured sample into a sample with a length of 80 mm or more, a width of 10 ± 0.2 mm, and a thickness of 4 ± 0.2 mm. Next, the sample is placed in a universal material testing machine for a three-point bending test, where the distance between the lower two pivot points is set to 64 mm, and the moving speed of the upper jig is 2 mm/min. The flexural strength and flexural modulus were measured when the sample broke. The unit of bending strength is kilogram force per square millimeter (kgf/mm ² ). The unit of flexural modulus is kilogram force/square millimeter (kgf/mm ² ).

4.2. List of raw material information used in Examples and Comparative Examples

4.3. Preparation and quality testing of epoxy resin

The epoxy resins of Synthesis Examples 1 to 9 and Comparative Synthesis Examples 1 to 3 were prepared according to the ratios shown in Table 2-1 to Table 2-3, and the preparation method is described as follows.

Regarding Synthesis Examples 1 to 8 and Comparative Synthesis Examples 1 to 3, first, the alicyclic diol and the alicyclic anhydride were mixed, and after the temperature was raised to 100°C, an exothermic reaction was performed so that the temperature reached 170°C. After the exothermic reaction, the temperature was increased The temperature was lowered to 145°C and maintained at that temperature for 2 hours, thereby preparing an alicyclic compound (intermediate product) having two carboxyl groups. After that, the intermediate product is cooled to 110° C. and the diglycidyl ether of the bifunctional phenol compound is added, and the catalyst is added after mixing uniformly. Then, after the temperature was raised to 155°C, an exothermic reaction proceeded to reach a temperature of 190°C. After the exothermic reaction was completed, the temperature was lowered to 160°C and kept at this temperature for 2 hours, thereby obtaining Synthesis Examples 1 to 8 and Comparative Synthesis Example 2 And 3 epoxy resin, comparative synthesis example 1 failed to synthesize epoxy resin.

Regarding Synthesis Example 9, first, 100 parts by weight of alicyclic epoxide was heated to 90° C., 53.8 parts by weight of bifunctional phenol compound was added, and after mixing uniformly, 0.1 part by weight of catalyst was added. After that, the temperature was raised to 140°C, and an exothermic reaction proceeded so that the temperature reached 190°C. After the exothermic reaction was completed, the temperature was lowered to 160°C and kept at this temperature for 2 hours. Next, 7.6 parts by weight of alicyclic epoxide was added and kept at 160° C. for 2 hours for reaction, whereby the epoxy resin of Synthesis Example 9 was obtained.

In addition, commercially available epoxy resins 1 and 2 are prepared, where the commercially available epoxy resin 1 is BE504H, and the commercially available epoxy resin 2 is BE503L.

Measure the B/A value, softening point and WPE of the epoxy resins of Synthesis Examples 1-9, the epoxy resins of Comparative Synthesis Examples 1 to 3, and the commercially available epoxy resins 1 and 2 according to the measurement methods described above, and The results are recorded in Table 2-1 to Table 2-3.

4.4. Preparation and quality test of encapsulation composition (1)

The encapsulation compositions of Examples 1 to 9 and Comparative Examples 1 to 6 were prepared according to the ratios shown in Table 3-1 to Table 3-3. First, put the first epoxy resin and the second epoxy resin in a glass distillation flask , Mixed uniformly at 120°C for 30 minutes. Then, the temperature was lowered to 100° C., the hardener and the catalyst were added, and they were uniformly mixed at this temperature for 30 minutes, thereby obtaining each of the encapsulating compositions (stage B).

The Tg, thermal light decay value, UV light decay value, tortuous strength and tortuous modulus of the cured products of the packaging compositions of Examples 1 to 9 and Comparative Examples 1 to 6 were measured according to the measurement methods described above, and recorded in Table 4 -1 to 4-3.

As shown in Tables 4-1 and 4-2, the cured product formed by the encapsulating composition containing the epoxy resin with a specific B/A value of the present invention has lower heat and light attenuation value and lower UV light attenuation Value, appropriate Tg, sufficient flexural strength and flexural modulus. In other words, the packaging material prepared from the resin composition of the present invention can have particularly excellent light decay resistance while maintaining sufficient mechanical strength. Examples 1 to 3, 7 and 8 show that even if the proportions of the components used to prepare the epoxy resin are different, as long as the B/A value of the epoxy resin is within the specified range, the prepared packaging materials can achieve excellent Light decay resistance and sufficient mechanical strength. Examples 4 to 6 and 9 show that even if the components used to prepare the epoxy resin are different, as long as the B/A value of the epoxy resin is within the specified range, the prepared packaging materials can achieve excellent light decay resistance and Sufficient mechanical strength. In addition, the results of Examples 1 to 7 show that the epoxy resin of the present invention includes a structural unit derived from an alicyclic compound having the structure of formula (I) and an aromatic epoxy having two epoxy groups. The structural unit of the compound, and the number ratio (B/A) of aromatic protons (B) to aliphatic protons (A) is not more than 0.21, it can provide the most excellent light decay resistance (heat and light decay value less than 15% ; UV light attenuation value is less than 3%).

In contrast, as shown in Table 4-3, the cured product formed from the encapsulating composition that does not contain the epoxy resin with a specific B/A value of the present invention cannot simultaneously have a lower heat and light decay value and a higher Low UV light attenuation value, suitable Tg, good bending strength and bending modulus. In particular, Comparative Examples 1 to 6 show that when the B/A value of the epoxy resin is not within the specified range, the heat and UV light attenuation value of the prepared packaging material is greatly improved, showing the light resistance of the packaging material Poor, does not have the characteristics of light decay resistance.

4.5. Preparation and quality testing of packaging composition (2)

The encapsulation compositions of Examples 10 to 11 and Comparative Example 7 were prepared according to the ratio shown in Table 5. First, put the first epoxy resin and the solvent in a glass distillation flask and mix them uniformly at 120°C for 30 minutes. Then, after cooling down to 100°C, add hardener and catalyst. Mix well for 30 minutes to obtain each encapsulated composition (stage B). After coating the encapsulation composition on a glass plate to form a film, it was baked at 100°C for 2 hours to remove the solvent, and then baked at 150°C for 4 hours for post-curing, and cut into a length of 60 mm and a width of 60 mm A sample of 14 mm and a thickness of 100 microns. Then, the thermal and light decay values of the packaging compositions of Examples 10 to 11 and Comparative Example 7 were measured according to the measurement method described above, and recorded in Table 5.

As shown in Table 5, even if the packaging composition of the present invention does not contain the second epoxy resin, as long as the packaging composition contains the epoxy resin with a specific B/A value of the present invention, the cured product formed can also have excellent light resistance. Decay nature.

The above-mentioned embodiments are merely illustrative to illustrate the principles and effects of the present invention, and to illustrate the technical features of the present invention, not to limit the protection scope of the present invention. Any changes or arrangements that can be easily completed by a person familiar with the technology without departing from the technical principles and spirit of the present invention are all subject to this The claimed scope of the invention. Therefore, the protection scope of the present invention is as listed in the attached patent scope.

Claims (14)

An epoxy resin whose number ratio (B/A) of aromatic protons (B) to aliphatic protons (A) measured by nuclear magnetic resonance hydrogen spectroscopy ( ¹ H-NMR) is 0.15 to 0.29. The epoxy resin described in claim 1 further has an epoxy equivalent (weight per epoxy, WPE) of 500 to 2000 [g/eq]. The epoxy resin according to claim 1 or 2, which contains a structural unit derived from an alicyclic compound having two carboxyl groups and an aromatic epoxide having two epoxy groups (aromatic epoxide) structural unit. The epoxy resin according to claim 3, wherein the alicyclic compound having two carboxyl groups has the structure of the following formula (I):

In formula (I), R ₁ is

,

or

, R _{2 is} each independently H or methyl, and m is an integer from 0 to 2, where * represents the bonding position. The epoxy resin according to claim 3, wherein the aromatic epoxide with two epoxy groups is selected from the following group: bisphenol A diglycidyl ether (bisphenol A diglycidyl ether), bisphenol F Diglycidyl ether (bisphenol F diglycidyl ether), and combinations thereof. The epoxy resin according to claim 1 or 2, which contains a structural unit derived from an aromatic compound having two -OH groups and an alicyclic group derived from two epoxy groups The structural unit of alicyclic epoxide. The epoxy resin according to claim 6, wherein the aromatic compound having two -OH groups has the structure of the following formula (II):

In formula (II), X ₁ to X ₈ , R ₁₁ and R ₁₂ are each independently H or CH ₃ . The epoxy resin according to claim 6, wherein the cycloaliphatic epoxide having two epoxy groups is selected from the following group:

,

, And combinations thereof, wherein n is an integer from 1 to 30. A use of the epoxy resin according to any one of claims 1 to 8, which is used to prepare an encapsulating composition. An encapsulating composition comprising a first epoxy resin and a hardener, wherein the first epoxy resin is the epoxy resin according to any one of claims 1 to 8. The packaging composition according to claim 10, further comprising a second epoxy resin selected from the following group: isocyanurate epoxy resin, alicyclic epoxy resin, and combinations thereof. The packaging composition according to claim 10, wherein the hardener is selected from the group consisting of acid anhydrides, phenolic resins, imidazoles, and combinations thereof. An encapsulation material, which is prepared by curing the encapsulation composition according to any one of claims 10 to 12. According to claim 13, the light transmittance after baking for 168 hours at 150° C. is less than 23% compared with the light transmittance before baking.