Optical epoxy resin molding compound and its preparation method and application

Abstract

The present invention relates to the field of epoxy resin technology, and more specifically, to an optical epoxy resin molding compound, its preparation method, and application. The components include: a colorant, an epoxy resin, an antioxidant, a curing agent, and an auxiliary agent; the colorant includes a UV absorber and a blue light absorber; and the epoxy resin includes a triazine skeleton epoxy resin. The colorant includes a UV absorber and a blue light absorber, and the epoxy resin includes a triazine skeleton epoxy resin, which can effectively shield light below 460nm and increase the transmittance of light above 500nm to more than 85%, while achieving excellent high-temperature resistance. The UV absorber includes a triazine-type UV absorber, and the blue light absorber includes a triazine-derived structure with an isoindolinone heterocyclic skeleton, which can reduce the value of 460nm transmittance / 500nm transmittance to less than 0.5.

Description

Technical Field

[0001] The present invention relates to the technical field of epoxy resins, and in particular to an optical epoxy resin molding compound and a preparation method and application thereof. Background Art

[0002] Wearable technology, especially those devices that combine medical, sports monitoring, entertainment, and defense industry applications, is gradually becoming an indispensable part of modern life. In the application process of wearable devices, the selection of optical materials is particularly critical. In order to improve monitoring accuracy and reduce environmental interference, a material that can effectively block blue light and allow light of specific wavelengths to penetrate is required. Currently, the optical epoxy resin molding compounds on the market have obvious shortcomings in resisting high temperatures and maintaining transparency. In particular, the transmittance after long-term use is often lower than expected. This not only affects the aesthetics and practicality of the device, but also limits the widespread use of wearable technology in medical applications and daily health monitoring. Therefore, developing a high-performance optical epoxy resin molding compound to meet the special material requirements of wearable health monitoring devices has become a technical challenge that needs to be solved urgently.

[0003] Chinese invention patent CN112625217B discloses a method for preparing a high-refractive-index optical resin containing a sulfur-containing and fluorene-containing structure. First, 9,9-bis(2,3-epoxypropyloxy)phenyl]fluorene and 4'4-dimercaptodiphenyl sulfide are polymerized at room temperature via an epoxysulfur "click" reaction in the presence of a catalyst to synthesize a high-refractive-index epoxy resin. Then, o-dichlorobenzyl and thiourea react to produce 1,2-benzenedimethanethiol, a high-refractive-index curing agent for the epoxy resin. Finally, a high-refractive-index optical resin containing a sulfur-containing and fluorene-containing structure is prepared by thermal curing. However, this invention does not address research on the ability of the resin material to block blue light while allowing light of specific wavelengths to penetrate. Summary of the Invention

[0004] The first aspect of the present invention provides an optical epoxy resin molding compound, the components of which include: a colorant, an epoxy resin, an antioxidant, a curing agent and an auxiliary agent; the colorant includes an ultraviolet absorber and a blue light absorber; and the epoxy resin includes a triazine skeleton epoxy resin.

[0005] The present application study found that the colorant includes a UV absorber and a blue light absorber, and the epoxy resin includes a triazine skeleton epoxy resin, which can effectively shield light below 460nm and increase the light transmittance above 500nm to more than 85%, while achieving excellent high temperature resistance. The UV absorber and the blue light absorber are superimposed to achieve high-precision shielding of light below 460nm, while avoiding excessive absorption of visible light above 500nm; the triazine skeleton epoxy resin has a planar conjugated system, which not only gives the resin excellent thermal stability, but also the nitrogen atoms in the triazine ring may provide short-wavelength absorption, naturally blocking part of the blue light, forming a complementary absorption with the colorant. The rigid network of the triazine skeleton can physically fix the small molecule colorant, prevent the colorant from aggregating or precipitating at high temperature, and further enhance the high temperature resistance; in addition, the colorant is bonded to the triazine ring through hydrogen bonds or π-π stacking, which can also avoid the performance degradation caused by high-temperature thermal decomposition of the resin.

[0006] The components of the optical epoxy resin molding compound include, by weight, 1-8 parts of a colorant, 150-250 parts of an epoxy resin, 2-8 parts of an antioxidant, 100-300 parts of a curing agent, and 1-10 parts of an auxiliary agent.

[0007] Optionally, the components of the optical epoxy resin molding compound include, by weight, 3-8 parts of colorant, 180-220 parts of epoxy resin, 2-6 parts of antioxidant, 150-250 parts of curing agent and 2-6 parts of auxiliary agent.

[0008] Optionally, the triazine skeleton epoxy resin contains 3 epoxy groups.

[0009] Optionally, the triazine skeleton epoxy resin includes triglycidyl isocyanurate,

[0010] Optionally, the triglycidyl isocyanurate is selected from Tepic-s or Tepic-ss produced by Nissan Chemical.

[0011] The epoxy resin further comprises at least one of bisphenol A epoxy resin, epoxy diluent and hydrogenated bisphenol A epoxy resin.

[0012] Optionally, the epoxy resin includes at least one of bisphenol A epoxy resin and hydrogenated bisphenol A epoxy resin.

[0013] Optionally, the weight ratio of the ultraviolet absorber to the blue light absorber is 1:(1-2).

[0014] Optionally, the number of epoxy groups in the epoxy diluent is ≥2.

[0015] Optionally, the softening point of the bisphenol A epoxy resin is ≥60°C.

[0016] Optionally, the bisphenol A epoxy resin is selected from at least one of the following brands of Mitsubishi Chemical Corporation: JER1001, JER1002, and JER1004.

[0017] Optionally, the hydrogenated bisphenol A epoxy resin is selected from Japan Mitsubishi YX-8000.

[0018] The ultraviolet absorber includes a triazine ultraviolet absorber.

[0019] Optionally, the liquid triazine ultraviolet absorber includes UV-400 (CAS: 153519-44-9).

[0020] The blue light absorber comprises a triazine derivative structure of an isoindolinone heterocyclic skeleton.

[0021] Optionally, the blue light absorber includes Yellow 109 (CAS: 5045-40-9).

[0022] Optionally, the weight ratio of the antioxidant to the colorant is 1:(0.8-1.5).

[0023] The antioxidant comprises a hindered phenol antioxidant and a phosphorus antioxidant, and the weight ratio of the hindered phenol antioxidant to the phosphorus antioxidant is 3:(1-5).

[0024] The hindered phenol antioxidant includes at least one of the following brands: antioxidant 1076, antioxidant 2246, antioxidant 1098, antioxidant 3114, and antioxidant 1010.

[0025] The phosphorus antioxidant includes at least one of the following brands: antioxidant 168, P-EPQ, Ethanox 398, and Ultrinox 641.

[0026] Optionally, the weight ratio of the hindered phenol antioxidant to the phosphorus antioxidant is 3:(1-3).

[0027] The curing agent includes at least one of tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, phthalic anhydride, trimellitic anhydride, and polynonanoic anhydride.

[0028] The auxiliary agent includes at least one of a release agent, a accelerator, and a catalyst.

[0029] Optionally, the release agent includes at least one of carnauba wax, polyethylene wax, polypropylene wax, stearic acid, and chlorinated paraffin.

[0030] Optionally, the catalyst includes at least one of imidazole and amine.

[0031] A second aspect of the present invention provides a method for preparing an optical epoxy resin molding compound, comprising the following steps: preparing a colorant into a colorant masterbatch using a solvent method; uniformly mixing an epoxy resin, an antioxidant, a curing agent, and an additive to obtain an epoxy resin composition; and uniformly mixing the colorant masterbatch and the epoxy resin composition, followed by pulverization, molding, and curing to obtain an epoxy resin molding compound.

[0032] The solvent method comprises the following steps: mixing the colorant and the solvent and stirring them evenly.

[0033] The solvent includes at least one of acetone, dimethyl sulfoxide, methanol, ethanol, and acetonitrile.

[0034] The solvent in the colorant masterbatch is volatilized during the mixing process with the epoxy resin, antioxidant, curing agent and auxiliary agent, and the epoxy resin molding compound does not contain solvent.

[0035] Optionally, the molding temperature is 140° C.-180° C. and the molding time is 2-5 minutes.

[0036] Optionally, the mold curing temperature is 140° C.-180° C. and the curing time is 2-5 hours.

[0037] A third aspect of the present invention provides an application of an epoxy resin molding compound for the preparation of a wearable sensor.

[0038] Beneficial effects

[0039] 1. The colorant includes a UV absorber and a blue light absorber, and the epoxy resin includes a triazine skeleton epoxy resin, which can effectively shield light below 460nm and make the transmittance of light above 500nm reach more than 85%, while achieving excellent high temperature resistance.

[0040] 2. The UV absorber includes a triazine UV absorber and the blue light absorber includes a triazine derivative structure of an isoindolinone heterocyclic skeleton, which can reduce the value of the 460nm transmittance / 500nm transmittance to below 0.5.

[0041] 3. The weight ratio of the ultraviolet absorber to the blue light absorber is 1:(1-2), which can further reduce the value of 460nm transmittance / 500nm transmittance to 0.1.

[0042] 4. The antioxidant includes a hindered phenol antioxidant and a phosphorus antioxidant, wherein the weight ratio of the hindered phenol antioxidant to the phosphorus antioxidant is 3:(1-5), which can reduce the value of 460nm transmittance / 500nm transmittance and at the same time increase the transmittance at 500nm after three reflow soldering.

[0043] 5. This application avoids the problem of colorant fading caused by long-term exposure to high temperature conditions by first preparing the colorant masterbatch and then dispersing it in the epoxy resin composition. The transmittance reaches more than 90% after three reflow soldering cycles.

[0044] 6. The optical epoxy resin molding compound prepared in this application can meet the application of wearable sensors, making the device more anti-interference (shielding wavelengths below 460nm), and at the same time can detect smaller signal fluctuations, thereby enabling more precise signal judgment (high transmittance above 500nm). BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a test curve of the light transmittance of the optical epoxy resin molding compound prepared in Example 1.

[0046] Figure 2 This is the transmittance test curve of the optical epoxy resin molding compound prepared in Comparative Example 4.

[0047] Figure 3 This is the transmittance test curve of the optical epoxy resin molding compound prepared in Comparative Example 5.

[0048] Figure 4 This is the transmittance test curve of the optical epoxy resin molding compound prepared in Comparative Example 1.

[0049] Figure 5 This is the transmittance test curve of the optical epoxy resin molding compound prepared in Comparative Example 2.

[0050] Figure 6 This is the transmittance test curve of the optical epoxy resin molding compound prepared in Comparative Example 3. DETAILED DESCRIPTION

[0051] Examples 1-3, Comparative Examples 1-5

[0052] An optical epoxy resin molding compound, the components of which are shown in Table 1 in parts by weight, wherein blank spaces indicate zero addition amount:

[0053] Table 1

[0054]

[0055] Among them is P-EPQ (Clariant antioxidant, Sandostab P-EPQ).

[0056] Release agent: Carnauba wax, saponification value 78-95, melting point 80-85°C, purchased from Clariant.

[0057] Colorant 1: blue light absorber (a triazine derivative structure containing an isoindolinone heterocyclic skeleton), Yellow 109 (CAS: 5045-40-9).

[0058] Colorant 2: UV absorber (triazine UV absorber), UV400 (CAS: 153519-44-9).

[0059] Colorant 3: blue light absorber, Yellow 5 (inorganic colorant, zinc chrome yellow).

[0060] A method for preparing an optical epoxy resin molding compound comprises the following steps: preparing a colorant from a colorant masterbatch by a solvent method: mixing the colorant and a solvent (dimethyl sulfoxide) at a weight ratio of 1:3 at room temperature, and dispersing the mixture with high-speed stirring at 100 rpm; uniformly mixing an epoxy resin, an antioxidant, a curing agent, and an auxiliary agent to obtain an epoxy resin composition; and uniformly mixing the colorant masterbatch and the epoxy resin composition, crushing, molding (160°C, 3 minutes), and curing (150°C, 4 hours) to obtain an epoxy resin molding compound.

[0061] Performance testing methods

[0062] The molding compounds (thickness 1 mm) prepared in the examples and comparative examples were subjected to the following performance tests, and the test data are listed in Table 2.

[0063] 1. 400-1000nm band transmittance test;

[0064] 2. After three reflow cycles (260°C × 30s × 3 times), the transmittance test in the 400-1000nm band was conducted.

[0065] 3. Use a press to mold the resin onto a 0603 chip at 150°C for 5 minutes. Curing at 150°C for 4 hours, cut the LEDs into individual pieces, and perform a temperature cycle test (-40°C to 105°C, 300 cycles). After the test is complete, light up the LEDs. If they light up normally, it passes. If they light up dimly or are dead, it fails.

[0066] Performance test data

[0067] Table 2

[0068] Test items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Transmittance at 460nm 0.1% 0.3% 0.4% 38.9% 15.8% 0.5% 70.8% 0.7% Transmittance at 500nm 90.0% 90.0% 90.0% 73.9% 52.8% 6.3% 93.5% 90.0% Transmittance at 460nm / Transmittance at 500nm 0.1% 0.3% 0.4% 52.6% 30.0% 7.9% 76.0% 0.8% Transmittance at 500nm after three reflows 90.0% 90.0% 90.0% 73.9% 52.8% 6.3% 93.5% 89.0% Temperature cycle (-40~105℃, 300 cycles) performance pass pass pass pass pass Failed pass pass

[0069] Combined with the data in Table 2, Figure 1 As shown in FIG, the molding compound of Example 1 can effectively shield light below 460 nm and improve the light transmittance at 500 nm; Figure 2 As shown, in Comparative Example 4, no blue light absorber was used, and the transmittance at 460nm was significantly improved; Figure 3 As shown, in Comparative Example 5, no UV absorber was used, and the transmittance at 460 nm was slightly improved. At the same time, the transmittance at 500 nm decreased after three reflows. Figure 4 As shown, Comparative Example 1 does not use hindered phenol antioxidants, such as Figure 5As shown, comparative example 2 does not use phosphorus antioxidants, which results in an increase in the transmittance below 460nm and a decrease in the transmittance at 500nm; Figure 6 As shown, in Comparative Example 3, no triazine skeleton epoxy resin was added and an inorganic colorant was used, and the transmittance at 500 nm was less than 20%.

Claims

1. An optical epoxy resin molding compound, characterized in that: The components of the optical epoxy resin molding compound include, by weight, 1-8 parts of a colorant, 150-250 parts of an epoxy resin, 2-8 parts of an antioxidant, 100-300 parts of a curing agent, and 1-10 parts of an auxiliary agent; the colorant includes an ultraviolet absorber and a blue light absorber; the epoxy resin includes a triazine skeleton epoxy resin; the antioxidant includes a hindered phenol antioxidant and a phosphorus antioxidant, and the weight ratio of the hindered phenol antioxidant to the phosphorus antioxidant is 3:(1-5); the ultraviolet absorber includes a triazine ultraviolet absorber; the blue light absorber contains a triazine derivative structure of an isoindolinone heterocyclic skeleton; and the weight ratio of the ultraviolet absorber to the blue light absorber is 1:(1-2).

2. The optical epoxy resin molding compound according to claim 1, characterized in that: The epoxy resin further comprises at least one of bisphenol A epoxy resin and hydrogenated bisphenol A epoxy resin.

3. The optical epoxy resin molding compound according to claim 1, characterized in that: The weight ratio of the antioxidant to the colorant is 1:(0.8-1.5).

4. A method for preparing the optical epoxy resin molding compound according to any one of claims 1 to 3, characterized in that: The following steps are involved: The colorant is prepared into a colorant masterbatch by a solvent method; the epoxy resin, antioxidant, curing agent and auxiliary agent are evenly mixed to obtain an epoxy resin composition; the colorant masterbatch and the epoxy resin composition are evenly mixed, crushed, molded and cured to obtain an epoxy resin molding compound.

5. An application of the optical epoxy resin molding compound according to any one of claims 1 to 3, characterized in that: Used in the preparation of wearable sensors.

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