High reflectivity flame retardant resin composition, prepreg and laminate

Abstract

The present invention discloses a high reflectivity flame retardant resin composition, which includes the following components by weight: 40-80 parts of modified hyaluronic acid epoxy resin polymer, 30-70 parts of basic epoxy resin, 70-150 parts of curing agent, 130-180 parts of titanium dioxide, 0.1-5 parts of accelerator and 0.1-3 parts of coupling agent; wherein, the modified hyaluronic acid epoxy resin polymer is prepared by compounding phosphoric acid modified hyaluronic acid epoxy resin and DOPO modified hyaluronic acid epoxy resin. The present invention applies for the use of a modified hyaluronic acid epoxy resin polymer of a specific structure, which has no phenolic hydroxyl group that is easy to change color at high temperature in its molecular structure and has good yellowing resistance. At the same time, the modified hyaluronic acid epoxy resin polymer introduces P element and more polar groups, which can realize the synergistic flame retardancy of P and N in the resin system, improve the flame retardant efficiency of the system, and has high Tg after curing, good toughness, and is not easy to pulverize. It can be made into a carrier suitable for LED packaging, and a copper-clad laminate that meets the backlight application requirements of various Mini led circuit boards.

Description

Technical Field

[0001] The invention relates to the field of copper-clad laminate technology, in particular to a high-reflectivity flame-retardant resin composition, a prepreg and a laminate. Background Art

[0002] A light-emitting diode (LED) is a semiconductor device that can directly convert electrical energy into light energy. It has the characteristics of fast response speed, low energy consumption, long service life, small size, and durability. It is widely used in lighting, display, signal indication and other fields. However, with the continuous advancement of LED technology and the increasing expansion of application scenarios, the performance requirements for its packaging materials are becoming more and more stringent. The white copper-clad laminate material used for LED packaging not only requires a higher initial reflectivity, but also needs to be able to stably maintain the reflectivity under extreme environments such as high temperature and high humidity. In addition, LED lighting has developed towards multi-functional, miniaturized, high-efficiency, and high-integration load-bearing brackets. The white PCB board material used for LED packaging has high yellowing resistance and high heat resistance, while also putting forward V0 level requirements for flame retardancy.

[0003] The flame retardant design of the resin composition for copper clad laminates usually adopts the method of adding flame retardants, but they are easy to migrate or seep out of the system, and a high amount of addition is often required to achieve excellent flame retardant effects, and it is easy to have a negative impact on other physical properties of the substrate. The white copper clad laminate designed on the basis of ordinary FR4 copper clad laminates has the defects of poor yellowing resistance, low initial reflectivity, and greatly reduced reflectivity after long-term use during LED packaging processing and use. At the same time, under the halogen-free requirements, the flame retardant performance can usually only reach HB level. Therefore, it has become a trend in the current industry to develop a halogen-free and environmentally friendly resin composition with high reflectivity, high yellowing resistance, high flame retardancy and other properties suitable for LED packaging applications. Summary of the invention

[0004] In view of this, the present invention aims at the deficiencies in the prior art, and its main purpose is to provide a high-reflectivity flame-retardant resin composition, a semi-cured sheet and a laminate, which can effectively solve the problems that the existing resin composition for copper clad laminates needs to add a large amount of flame retardants to achieve excellent flame retardant effects, which has a negative impact on other properties of the substrate, and has poor yellowing resistance, low initial reflectivity, and a significant decrease in reflectivity after long-term use.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A high reflectivity flame retardant resin composition comprises the following components by weight: 40-80 parts of modified hydantoin epoxy resin polymer, 30-70 parts of basic epoxy resin, 70-150 parts of curing agent, 130-180 parts of titanium dioxide, 0.1-5 parts of accelerator and 0.1-3 parts of coupling agent; wherein the modified hydantoin epoxy resin polymer is prepared by compounding phosphoric acid modified hydantoin epoxy resin and DOPO modified hydantoin epoxy resin, and the weight ratio of phosphoric acid modified hydantoin epoxy resin to DOPO modified hydantoin epoxy resin is 1:(4-5).

[0007] As a preferred embodiment, the structural formula of the phosphoric acid-modified hydantoin epoxy resin is

[0008]

[0009] The structural formula of the DOPO modified hydantoin epoxy resin is

[0010]

[0011] As a preferred embodiment, the base epoxy resin is one or more of hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol F epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol A novolac epoxy resin and bisphenol F novolac epoxy resin.

[0012] As a preferred embodiment, the curing agent is at least one of hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, nadic anhydride, styrene maleic anhydride copolymer, methylphthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride and trimellitic anhydride.

[0013] As a preferred solution, the titanium dioxide is surface-treated rutile titanium dioxide.

[0014] As a preferred embodiment, the accelerator is at least one of imidazole, 1-benzylbenzene-2-ethylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-aminoethyl-2-methylimidazole and 1-cyanoethylimidazole.

[0015] As a preferred solution, the coupling agent is at least one of a silane coupling agent, a titanate coupling agent and an aluminate coupling agent.

[0016] A prepreg is prepared from the above-mentioned high-reflectivity flame-retardant resin composition.

[0017] A laminated board is made from the aforementioned prepreg.

[0018] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that:

[0019] The present invention applies to a modified hyaluronic acid epoxy resin polymer with a specific structure. Compared with ordinary hyaluronic acid epoxy resin, its molecular structure does not have phenolic hydroxyl groups that are prone to high-temperature discoloration, and has good yellowing resistance. At the same time, the modified hyaluronic acid epoxy resin polymer introduces P elements and more polar groups, which can achieve synergistic flame retardancy of P and N in the resin system, improve the flame retardancy efficiency of the system, and has a high Tg after curing, good toughness, and is not easy to pulverize; at the same time, it is combined with hydrogenated bisphenol-type epoxy resin to form a "double-peak" resin system, so that the prepared laminate has excellent comprehensive performance, and the surface-treated rutile titanium dioxide is selected as a filler, which can improve the compatibility with the resin, and can make the substrate have a higher reflectivity and initial whiteness, and can be made into a carrier suitable for LED packaging, and a copper-clad laminate that meets the backlight application requirements of various Mini LED circuit boards.

[0020] In order to more clearly illustrate the effects of the present invention, the present invention is described in detail below in conjunction with specific embodiments. DETAILED DESCRIPTION

[0021] The invention discloses a high reflectivity flame retardant resin composition, which comprises the following components by weight: 40-80 parts of modified hyaluronic acid epoxy resin polymer, 30-70 parts of basic epoxy resin, 70-150 parts of curing agent, 130-180 parts of titanium dioxide, 0.1-5 parts of accelerator and 0.1-3 parts of coupling agent.

[0022] The modified hydantoin epoxy resin polymer is prepared by compounding a phosphoric acid-modified hydantoin epoxy resin and a DOPO-modified hydantoin epoxy resin, wherein the weight ratio of the phosphoric acid-modified hydantoin epoxy resin to the DOPO-modified hydantoin epoxy resin is 1:(4-5), and the structural formula of the phosphoric acid-modified hydantoin epoxy resin is

[0023]

[0024] The structural formula of the DOPO modified hydantoin epoxy resin is

[0025]

[0026] The base epoxy resin is one or more of hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol F epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol A novolac epoxy resin and bisphenol F novolac epoxy resin.

[0027] The curing agent is at least one of hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, nadic anhydride, styrene maleic anhydride copolymer, methylphthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride and trimellitic anhydride.

[0028] The titanium dioxide is rutile titanium dioxide that has been surface treated.

[0029] The accelerator is at least one of imidazole, 1-benzylbenzene-2-ethylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-aminoethyl-2-methylimidazole and 1-cyanoethylimidazole.

[0030] The coupling agent is at least one of a silane coupling agent, a titanate coupling agent and an aluminate coupling agent.

[0031] The present invention also discloses a prepreg, which is prepared from the above-mentioned high reflectivity flame-retardant resin composition. The preparation process is as follows: firstly, the above-mentioned raw material components are mixed according to the components, and then mixed evenly by stirring to obtain the above-mentioned modified epoxy resin composition. Then, 2116 glass cloth is immersed in the modified epoxy resin composition, and then baked in an oven at 171°C for 2 minutes to obtain the prepreg.

[0032] A laminate is made from the aforementioned prepreg, and its production process is as follows: a prepreg made from two sheets of 2116 glass cloth is covered with a 12 μm thick HTE copper foil on both sides, and then placed in a laminator for hot pressing to obtain a laminate; this preparation method is used in subsequent embodiments, and the obtained laminate is tested for performance.

[0033] The raw materials used in the following examples and comparative examples are shown in Table 1.

[0034]

[0035]

[0036] Table 1

[0037] The preparation method of modified hydantoin epoxy resin polymer is as follows:

[0038] (1) Add hydantoin epoxy resin, phosphotungstic acid catalyst and butanone solvent into a three-necked flask, heat to 60° C., add phosphoric acid, continue stirring and mixing, keep the temperature constant for 3 hours until the reaction is completed, and cool to room temperature to obtain phosphoric acid-modified hydantoin epoxy resin. The phosphoric acid-modified hydantoin epoxy resin has the structural formula:

[0039]

[0040] (2) Add hydantoin epoxy resin and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide into a three-necked flask, then place the flask in an oil bath, slowly heat to 130° C., then add dibutyltin dilaurate catalyst, continue stirring to ensure that the reactants are evenly mixed, keep the temperature constant for 4 hours until the reaction is completed, and cool to room temperature to obtain DOPO-modified hydantoin epoxy resin. The structural formula of the DOPO-modified hydantoin epoxy resin is

[0041]

[0042] (3) Add the prepared phosphoric acid-modified hydantoin epoxy resin and DOPO-modified hydantoin epoxy resin into a three-necked flask at a mass ratio of 1:(4-5), and stir and mix them thoroughly for 1 hour to obtain the modified hydantoin epoxy resin composition.

[0043] The component ratios of the embodiments and comparative examples are shown in Table 2:

[0044] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example A 35 35 15 25 45 A1 35 B 65 65 85 75 55 65 C1 120 120 120 120 120 C2 120 D 140 140 140 140 140 140 E 0.2 0.2 0.2 0.2 0.2 0.2 F 0.4 0.4 0.2 0.25 0.35 0.15 G 15

[0045] Table 2.

[0046] The above multiple embodiments and comparative examples were subjected to performance tests, and the test methods were as follows:

[0047] Glass transition temperature (Tg): measured using dynamic mechanical analysis (DMA).

[0048] Peel strength (PS): tested according to IPC-TM-650 2.4.9 method.

[0049] Reflectivity: After etching the substrate, the initial reflectivity at 450nm of the sample was measured using a spectrophotometer according to JIS Z-8722. The reflectivity at 450nm was then measured after treatment at 260°C for 3min and UV irradiation for 24h. The difference between the initial reflectivity and the initial reflectivity was used to characterize the yellowing resistance.

[0050] Flame retardancy: measured according to the vertical combustion method of UL94 standard.

[0051] The test results are shown in Table 3.

[0052]

[0053]

[0054] Table 3.

[0055] Analyzing the above data, Examples 1-5 have a high initial reflectivity at room temperature, and can still maintain a high reflectivity even after baking at a high temperature of 260°C for 3 minutes. At the same time, the peel strength is high, and the flame retardancy level can reach V0, which can fully meet the requirements of white laminates for LED packaging. Compared with Example 1, the resin system of the comparative example does not contain aromatic ring chromophores, so its initial reflectivity and reflectivity after heating are both high, but the peel strength and flame retardancy are poor. In addition, compared with Example 2, Example 1 uses methyl hexahydrophthalic anhydride without benzene ring as a curing agent for curing. , the generated product has a higher reflectivity, but a lower Tg; and, compared with Examples 3-5, it can be seen from Example 1 that as the addition ratio of the modified hyaluronic acid epoxy resin polymer decreases, the flame retardancy will deteriorate, and if the addition ratio is too much, the polar groups will increase, the peel strength will increase, but the high-temperature yellowing resistance will decrease; in summary, therefore, the resin composition applied for in the present invention not only requires the modified hyaluronic acid epoxy resin polymer, the basic epoxy resin, the curing agent and the additives such as titanium dioxide to react with each other, but also requires each component to meet a specific ratio in order to obtain a white copper clad laminate for LED packaging with excellent comprehensive performance.

[0056] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A high reflectivity flame retardant resin composition, characterized in that: The invention comprises the following components by weight: 40-45 parts of modified hydantoin epoxy resin polymer, 55-70 parts of base epoxy resin, 70-150 parts of curing agent, 130-180 parts of titanium dioxide, 0.1-5 parts of accelerator and 0.1-3 parts of coupling agent; wherein the modified hydantoin epoxy resin polymer is prepared by compounding phosphoric acid modified hydantoin epoxy resin and DOPO modified hydantoin epoxy resin, and the weight ratio of phosphoric acid modified hydantoin epoxy resin to DOPO modified hydantoin epoxy resin is 1:(4-5); the structural formula of the phosphoric acid modified hydantoin epoxy resin is The structural formula of the DOPO modified hydantoin epoxy resin is The base epoxy resin is one or more of hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol F epoxy resin, bisphenol A epoxy resin, and bisphenol F epoxy resin.

2. The high reflectivity flame retardant resin composition according to claim 1, characterized in that: The curing agent is at least one of hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, nadic anhydride, methylphthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride and trimellitic anhydride.

3. The high reflectivity flame retardant resin composition according to claim 1, characterized in that: The titanium dioxide is surface-treated rutile titanium dioxide.

4. The high reflectivity flame retardant resin composition according to claim 1, characterized in that: The accelerator is at least one of imidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-aminoethyl-2-methylimidazole and 1-cyanoethylimidazole.

5. The high reflectivity flame retardant resin composition according to claim 1, characterized in that: The coupling agent is at least one of a silane coupling agent, a titanate coupling agent and an aluminate coupling agent.

6. A prepreg, characterized in that: The invention is prepared from the high reflectivity flame retardant resin composition according to any one of claims 1 to 5.

7. A laminated board, characterized in that: Made from the prepreg according to claim 6.

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