Filling type epoxy resin crystal ball preparation method

Abstract

The invention discloses a preparation method of filled epoxy resin crystal balls. The preparation method comprises the following steps: S1, providing a transparent container made of high borosilicate glass or organic glass; s2, mixing bisphenol A epoxy resin and a curing agent according to a weight ratio of 3: 1 or 1: 1; s3, spraying a fluorine release agent less than or equal to 0.1 mu m on the inner wall of the container or depositing a fluorine-containing plasma film of 50-100nm on the inner wall of the container; s4, performing vacuum defoaming or centrifugal defoaming; s5, gradient curing; and S6, directly obtaining a finished product taking the transparent container as the permanent shell. According to the technology, the four necessary procedures of demolding, cutting, grinding and polishing in a traditional silica gel mold technology are thoroughly eliminated, the original single-piece machining time exceeding four hours is shortened to be less than thirty minutes, and the production efficiency is improved by more than eight times. In the production process, use of an organic silicon release agent is completely avoided, the problem of emission of volatile organic compounds is eradicated, and meanwhile solid waste generated in the cutting process and micron-sized dust pollution formed in the polishing process are completely eradicated.

Description

Technical Field

[0001] The invention relates to the technical field of epoxy resin crystal ball preparation, in particular to a method for preparing filled epoxy resin crystal balls. Background Art

[0002] The conventional production process for epoxy resin crystal balls relies on the use of silicone molds. This process first requires the creation of a split silicone mold, with a mold development cycle typically taking three to seven days. During production, epoxy resin and curing agent are mixed in a 3:1 or 1:1 ratio. After injection into the mold, the mixture is left to cure at 25°C for 48 to 72 hours. After curing, the mold is removed, requiring the use of a silicone release agent, which can leave residue adhering to the product surface. After demolding, the semi-finished product undergoes gate overfill removal, a process that produces lumpy waste. Mechanical polishing is then performed to remove the parting line, generating micron-sized dust. Finally, the finished product is polished.

[0003] Silicone molds have a lifespan of approximately 20 to 50 cycles, necessitating frequent mold replacements for large-scale production. Release agents contain volatile organic compounds, including xylene. The cutting process results in material loss, with a single 10-centimeter-diameter crystal ball generating approximately 80 grams of waste. During the polishing process, over 90% of dust particles are less than 10 microns in size, with dust concentrations in the working environment exceeding 50 mg per cubic meter.

[0004] Existing technologies attempt to replace silicone molds with metal molds. Metal molds have a lifespan of up to 100,000 cycles, but demolding requires a high-pressure mechanical ejector. Another technical solution uses UV-curable resin to shorten the curing time to 1 hour, but this is only suitable for thin-walled products with a thickness of less than 2 cm. The current production process involves more than six steps, and single-piece processing takes more than 4 hours. The probability of surface bubbles or hidden cracks appearing during product demolding is 15% to 25%, and the light transmittance of the finished product is generally less than 88%. Therefore, a method for preparing filled epoxy resin crystal balls is now needed. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing filled epoxy resin crystal balls, which permanently replaces the silicone mold with a glass container and completely eliminates the four core processes of demolding, cutting, grinding and polishing, so as to solve the technical problems mentioned in the background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for preparing a filled epoxy resin crystal ball, comprising the following steps:

[0007] S1. Provide a transparent container made of borosilicate glass or organic glass with a closed cavity structure, inner wall roughness Ra ≤ 0.1 μm, wall thickness 1.5-5 mm, and meet the following requirements: borosilicate glass transmittance ≥ 91% or organic glass haze ≤ 1%;

[0008] S2. Mix bisphenol A epoxy resin and curing agent in a weight ratio of 3:1 or 1:1, add 0.1-0.5wt% polysiloxane defoamer and 0.05-0.3wt% benzotriazole UV absorber, and stir at 200-500rpm for 3-5 minutes;

[0009] S3. Perform vacuum degassing (-0.095~-0.1MPa, 3-8min) or centrifugal degassing (800-1500rpm, 2-4min);

[0010] S4, gradient curing: 20-30℃ / 12-24h to 35-40℃ / 12-36h to 45-50℃ / 6-12h, so that the hardness reaches Shore D 80-85;

[0011] S5. The finished product with the transparent container as the permanent shell is directly obtained, and the demoulding, cutting, grinding and polishing processes are omitted throughout the process.

[0012] Preferably, the container is a spherical structure, and when made of organic glass, the following conditions must be met:

[0013] Polymethyl methacrylate (PMMA) molecular weight ≥ 50,000, or polycarbonate (PC) pencil hardness ≥ 3H;

[0014] The inner wall was treated with oxygen plasma (50 W, 20 sccm O2, 10 min) to make the surface energy ≥60 mN / m;

[0015] 1-3 wt% glycidyl methacrylate compatibilizer is added to the mixed solution.

[0016] Preferably, the mixed solution coloring scheme includes:

[0017] Add 0.01-0.1wt% phthalocyanine blue / green dye or iron oxide red paste, color difference ΔE≤1.5;

[0018] Premix 0.01-0.05wt% fluorescent dye, excitation wavelength 500-600nm under 365nm UV light;

[0019] When LED is built-in, add 0.02-0.05wt% silicone light diffuser (particle size 2-5μm), and the transmittance is ≥85%.

[0020] Preferably, the gradient curing needs to meet the following requirements:

[0021] In the first stage, the heat release rate is ≤0.5℃ / min and the cross-linking density is ≥30%;

[0022] At the end of the second stage, the cross-linking density is ≥85%, and the gel time is shortened by more than 40% compared with single curing;

[0023] In the third stage, the internal stress elimination rate is ≥90% and the thermal deformation temperature is ≥80℃.

[0024] Preferably, the epoxy resin system is expanded to:

[0025] 1:1 type: 0.8-1.2 parts of curing agent (epoxy equivalent weight EEW = 180-200g / eq), mixed viscosity 300-500cP;

[0026] 3:1 type: 0.3-0.4 parts of curing agent (EEW=450-500g / eq), viscosity 500-800cP;

[0027] Alicyclic epoxy resin (epoxy value 0.45-0.55eq / 100g) is combined with methyl hexahydrophthalic anhydride curing agent (active hydrogen equivalent 82-85g / eq).

[0028] Preferably, the secondary processing of the finished product surface includes:

[0029] Screen printing UV curing ink (thickness 10-20μm, resolution ≥150dpi);

[0030] Magnetron sputtering deposition of SiO2 / TiO2 antireflection film (400-700nm reflectivity ≤ 0.5%);

[0031] The bottom is hot-pressed into a brass threaded sleeve (tolerance H7 / g6) to fit the wooden / metal base.

[0032] Preferably, the interfacial bonding strength between the organic glass container and the epoxy resin is ≥8 MPa, and the verification method includes:

[0033] No delamination after high and low temperature cycle test (-20℃~80℃, 100 times);

[0034] After immersion test (50℃ deionized water, 168h), the adhesion decrease is ≤10%;

[0035] Yellowing index ΔYI≤2 after UV aging (QUV 500h).

[0036] Preferably, when pre-setting the LED components:

[0037] Adopting 450-460nm wavelength blue light chip + YAG phosphor package, color temperature 5000-6000K;

[0038] Light diffuser makes the luminous uniformity greater than 90% and the viewing angle greater than 170°;

[0039] The drive circuit is integrated into the base and connected to the container lead through magnetic contacts.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] This preparation method, through the innovative design of using borosilicate glass or plexiglass containers directly as the curing mold and permanent shell, has achieved a fundamental transformation in the production process of epoxy resin crystal balls. This technology completely eliminates the four steps required in traditional silicone mold making: demolding, cutting, grinding, and polishing. This reduces the processing time of a single piece from over four hours to less than 30 minutes, increasing production efficiency by more than eight times. The production process completely avoids the use of silicone release agents, eradicating volatile organic compound emissions. It also eliminates solid waste generated by the cutting process and micron-level dust pollution generated by the grinding process, reducing the dust concentration in the workshop environment from 50 milligrams per cubic meter to zero.

[0042] In terms of product quality, the roughness of the container's inner wall is controlled at a precision level of Ra ≤ 0.1μm. Combined with the precise implementation of the gradient curing process, the finished product's light transmittance has reached a breakthrough of over 92%, and the surface finish is five times better than that of traditional processes. The bonding strength between the epoxy resin and the container interface is stable at over 8MPa, and there is no delamination after 100 high and low temperature cycle tests. The yellowing index ΔYI ≤ 2.0 after 500 hours of QUV ultraviolet aging, and the product life is extended by more than three times. The protection of built-in decorations has been significantly enhanced, and the fracture rate of biological specimens has been reduced from over 50% to less than 5%. This is due to the key limitation that the volume of the built-in objects does not exceed one-third of the cavity and the precise control of shrinkage stress by gradient curing. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is produced by the process diagram. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] The present invention provides: a method for preparing a filled epoxy resin crystal ball, such as Figure 1 , including the following steps:

[0046] S1. Provide a transparent container made of borosilicate glass or organic glass with a closed cavity structure, an inner wall roughness Ra ≤ 0.1 μm, a wall thickness of 1.5-5 mm, and the following requirements: borosilicate glass transmittance ≥ 91% or organic glass haze ≤ 1%; S2. Mix bisphenol A epoxy resin and curing agent in a weight ratio of 3:1 or 1:1, add 0.1-0.5wt% polysiloxane defoamer and 0.05-0.3wt% benzotriazole UV absorber, and stir at 200-500 rpm for 3-5 minutes; S3. Perform vacuum degassing (-0.095 to -0.1 MPa, 3-8 minutes) or centrifugal degassing (800-1500 rpm, 2-4 minutes); S4. Gradient curing: 20-30℃ / 12-24 hours to 35-40℃ / 12-36 hours to 45-50℃ / 6-12 hours, to achieve a hardness of Shore D 80-85; S5, directly obtain the finished product with a transparent container as the permanent shell, omitting the demoulding, cutting, grinding, and polishing steps throughout the process, using a glass container instead of a mold to achieve "one-piece molding". The roughness of the container inner wall Ra ≤ 0.1μm ensures that the transmittance after the resin is cured is greater than 92%; the wall thickness is 1.5-5mm. Thermal stress simulation verification: the cure cracking rate of less than 1.5mm exceeds 30%, and the light transmission loss of more than 5mm is 15%. The injection volume is 95-98% because the thermal expansion coefficient of epoxy resin is 60×10⁻ 6 / K, reserving space to avoid cracking the container and omitting processes such as demoulding not only improves efficiency but also eliminates surface oil stains caused by silicone release agents, which is the main reason for excessive haze (>5%) in traditional processes.

[0047] Preferably, the container is a spherical structure, and the organic glass material must meet the following requirements: polymethyl methacrylate (PMMA) molecular weight ≥ 50,000, or polycarbonate (PC) pencil hardness ≥ 3H; the inner wall is treated with oxygen plasma (50W, 20sccm O2, 10min) to achieve a surface energy ≥60mN / m; 1-3wt% glycidyl methacrylate compatibilizer is added to the mixture to provide triple protection to address the industry pain point of poor compatibility between organic glass (PMMA / PC) and epoxy resin; Molecular weight ≥50,000: Experiments show that for every 10,000 decrease in molecular weight, PMMA's solvent resistance decreases by 40%, and it is prone to swelling and cracking after contact with resin; Oxygen plasma treatment: Raises the surface energy from 40mN / m to over 60mN / m, increasing the resin adhesion from 3MPa to 8MPa (ASTMD4541); Addition of glycidyl methacrylate (GMA): Its epoxy groups react with the resin, and the acrylate segments entangle with PMMA, forming "molecular bridges" to inhibit delamination.

[0048] Furthermore, the mixed liquid coloring scheme includes: adding 0.01-0.1wt% phthalocyanine blue / green dye or iron oxide red paste, with a color difference ΔE≤1.5; premixing 0.01-0.05wt% fluorescent dye, with an excitation wavelength of 500-600nm under 365nm ultraviolet light; adding 0.02-0.05wt% silicone light diffuser (particle size 2-5μm) when built-in LED, with a transmittance ≥85%. The parameter settings of the colorant and light diffuser directly target the industry pain points: E≤1.5: If the color difference exceeds this value, the naked eye can see the color difference, resulting in batch returns; the fluorescent dye excitation wavelength is 500-600nm: avoiding the resin aging sensitive area (300-400nm), extending the life by 3 times; the light diffuser particle size is 2-5μm: when it is greater than 5μm, the transmittance plummets to below 70%, and when it is less than 2μm, the LED will have obvious light spots.

[0049] Specifically, the gradient curing must meet the following requirements: heat release rate ≤ 0.5°C / min in the first stage, cross-linking density ≥ 30%; cross-linking density ≥ 85% at the end of the second stage, and gel time is shortened by more than 40% compared to single curing; stress elimination rate ≥ 90% in the third stage, and thermal deformation temperature ≥ 80°C. The gradient curing parameters are derived from the reaction exothermic model: heat release rate ≤ 0.5°C / min: if it exceeds the limit, the local temperature difference will be > 15°C, causing the glass to crack due to heat; cross-linking density ≥ 85%: if it is lower than this value, the hardness is insufficient (Shore D < 75), and it is easy to be scratched; thermal deformation temperature ≥ 80°C: to ensure that there is no deformation during summer transportation (carriage temperature 70°C).

[0050] As a preferred embodiment, the epoxy resin system is expanded to: 1:1 type: curing agent 0.8-1.2 parts (epoxy equivalent weight EEW = 180-200g / eq), mixed viscosity 300-500cP; 3:1 type: curing agent 0.3-0.4 parts (EEW ​​= 450-500g / eq), viscosity 500-800cP; alicyclic epoxy resin (epoxy value 0.45-0.55eq / 100g) with a Hexahydrophthalic anhydride curing agent (active hydrogen equivalent 82-85g / eq), with a ratio range extended to ±20% deep logic: 0.8-1.2 parts of curing agent: covers the metering error of amine curing agents (active hydrogen equivalent 160-200g / eq) and acid anhydrides (150-180g / eq); alicyclic epoxy resin: its UV resistance makes the yellowing index after 500 hours of QUV aging only 1.2, while the bisphenol A type is as high as 6.0.

[0051] Specifically, the secondary processing of the finished product surface includes: screen printing UV curing ink (thickness 10-20μm, resolution ≥150dpi); magnetron sputtering deposition of SiO2 / TiO2 anti-reflection film (reflectivity ≤0.5% at 400-700nm); hot pressing and embedding a brass threaded sleeve (tolerance H7 / g6) on the bottom, adapted to the wooden / metal base, and the surface treatment parameter settings are bound to the high-end market: ink thickness 10-20μm: when it is less than 10μm, the friction resistance is insufficient (RCA test <50 times), and when it is greater than 20μm, the edge will be piled with ink; the reflectivity of the anti-reflection film is ≤0.5%: the industry standard is 2%. This parameter increases the transmittance of the crystal ball from 91% to 98%, achieving an "invisible effect"; H7 / g6 tolerance: the interference is 0.02-0.05mm, and manual assembly cannot achieve this precision.

[0052] It is worth noting that the interfacial bonding strength between the organic glass container and the epoxy resin is ≥8MPa. The verification methods include: no delamination after high and low temperature cycle testing (-20℃~80℃, 100 times); adhesion loss ≤10% after immersion test (50℃ deionized water, 168h); yellowing index ΔYI ≤2 after UV aging (QUV 500h). Quantitative indicators build infringement detection barriers: Bonding strength ≥8MPa: can be quantified by tensile testing machine, while traditional processes only have 5-6MPa; -20℃~80℃ cycle: simulates the transportation environment from the Arctic to the equator, and failed products will have annular cracks; ΔYI ≤2: a colorimeter detection value exceeding 2 is considered infringement, avoiding subjective judgment disputes.

[0053] Preferably, when pre-installing LED components: use a blue light chip with a wavelength of 450-460nm + YAG phosphor package, with a color temperature of 5000-6000K; the light diffuser makes the luminous uniformity greater than 90%, and the viewing angle ≥170°; the driving circuit is integrated into the base, and the container leads are connected through magnetic contacts, forming a technological generation gap in the limitation of LED components: color temperature 5000-6000K: matches high-end decorative light environment (lower than 4500K is yellowish, higher than 6500K is bluish); uniformity > 90%: requires special integrating sphere detection, and small workshops cannot forge it; magnetic contact connection: breaks the traditional welding solution (heat damages the resin) and plug-in solution (water leakage rate 30%).

[0054] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a filled epoxy resin crystal ball, characterized in that: The following steps are involved: S1. Provide a transparent container made of borosilicate glass or organic glass with a closed cavity structure, inner wall roughness Ra ≤ 0.1 μm, wall thickness 1.5-5 mm, and meet the following requirements: borosilicate glass transmittance ≥ 91% or organic glass haze ≤ 1%; S2. Mix bisphenol A epoxy resin and curing agent in a weight ratio of 3:1 or 1:1, add 0.1-0.5wt% polysiloxane defoamer and 0.05-0.3wt% benzotriazole UV absorber, and stir at 200-500rpm for 3-5 minutes; S3. Perform vacuum degassing (-0.095~-0.1MPa, 3-8min) or centrifugal degassing (800-1500rpm, 2-4min); S4, gradient curing: 20-30℃ / 12-24h to 35-40℃ / 12-36h to 45-50℃ / 6-12h, so that the hardness reaches Shore D80-85; S5. The finished product with the transparent container as the permanent shell is directly obtained, and the demoulding, cutting, grinding and polishing processes are omitted throughout the process.

2. The method according to claim 1, wherein: The container is a spherical structure, and when made of organic glass, it must meet the following requirements: Polymethyl methacrylate (PMMA) molecular weight ≥ 50,000, or polycarbonate (PC) pencil hardness ≥ 3H; The inner wall was treated with oxygen plasma (50 W, 20 sccm O2, 10 min) to make the surface energy ≥60 mN / m; 1-3 wt% glycidyl methacrylate compatibilizer is added to the mixed solution.

3. The method according to claim 1, wherein: The mixed solution coloring scheme includes: Add 0.01-0.1wt% phthalocyanine blue / green dye or iron oxide red paste, color difference ΔE≤1.5; Premix 0.01-0.05wt% fluorescent dye, excitation wavelength 500-600nm under 365nm UV light; When LED is built-in, add 0.02-0.05wt% silicone light diffuser (particle size 2-5μm), and the transmittance is ≥85%.

4. The method according to claim 1, wherein: The gradient curing must meet the following requirements: In the first stage, the heat release rate is ≤0.5℃ / min and the cross-linking density is ≥30%; At the end of the second stage, the cross-linking density is ≥85%, and the gel time is shortened by more than 40% compared with single curing; In the third stage, the internal stress elimination rate is ≥90% and the thermal deformation temperature is ≥80℃.

5. The method according to claim 1, wherein: The epoxy resin system is expanded to: 1:1 type: 0.8-1.2 parts of curing agent (epoxy equivalent weight EEW = 180-200g / eq), mixed viscosity 300-500cP; 3:1 type: 0.3-0.4 parts of curing agent (EEW=450-500g / eq), viscosity 500-800cP; Alicyclic epoxy resin (epoxy value 0.45-0.55eq / 100g) is combined with methyl hexahydrophthalic anhydride curing agent (active hydrogen equivalent 82-85g / eq).

6. The method according to claim 1, wherein: Secondary processing of finished product surface includes: Screen printing UV curing ink (thickness 10-20μm, resolution ≥150dpi); Magnetron sputtering deposition of SiO2 / TiO2 antireflection film (400-700nm reflectivity ≤ 0.5%); The bottom is hot-pressed into a brass threaded sleeve (tolerance H7 / g6) to fit the wooden / metal base.

7. The method according to claim 1, wherein: The interfacial bonding strength between organic glass container and epoxy resin is ≥8MPa. The verification method includes: No delamination after high and low temperature cycle test (-20℃~80℃, 100 times); After immersion test (50℃ deionized water, 168h), the adhesion decrease is ≤10%; Yellowing index ΔYI≤2 after UV aging (QUV 500h).

8. The method according to claim 1, wherein: When pre-setting LED components: Adopting 450-460nm wavelength blue light chip + YAG phosphor package, color temperature 5000-6000K; Light diffuser makes the luminous uniformity greater than 90% and the viewing angle greater than 170°; The drive circuit is integrated into the base and connected to the container lead through magnetic contacts.

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