Preparation method of silica gel label with function of autonomously emitting light at night

Abstract

The invention relates to the technical field of silica gel product preparation, and discloses a preparation method of a silica gel label with a night self-luminous function, and the preparation method comprises the following steps: raw material preparation, material premixing, mold injection molding, vacuum defoaming, staged curing and post-treatment, by adopting a nano dispersion technology, nano fluorescent powder is subjected to hydrotalcite stripping pretreatment, and the silica gel label with the night self-luminous function is obtained. Vacuum stirring is carried out in the material premixing process, so that the problem of agglomeration of the fluorescent material is effectively solved, the dispersity of the noctilucent powder is improved, and the product is uniform in luminescence; high-transmittance liquid silica gel is selected as a base material, and key parameters such as light transmittance are controlled to ensure that the product has high light transmittance, so that the luminous efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of silicone product preparation, and specifically to a preparation method of a silicone label with a night self-luminous function. Background Art

[0002] Currently, luminous silicone products have broad application prospects in night or low-light environments, such as scenarios like keychains, pet collar tags, etc. However, there are some problems in the preparation process of existing luminous silicone products. For example, fluorescent materials are prone to agglomeration, resulting in uneven luminescence; the light transmittance is relatively low, affecting the luminescence efficiency; during the curing process, insufficient or excessive crosslinking is likely to occur, affecting the product performance, etc. Therefore, a new preparation method is needed to solve these problems.

[0003] In view of this, we have proposed a preparation method of a silicone label with a night self-luminous function. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of a silicone label with a night self-luminous function to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A preparation method of a night self-luminous silicone product, including the following steps:

[0006] S1. Raw material preparation: Prepare high-transparency liquid silicone, rare earth complex, nano-fluorescent powder, KH-560 coupling agent, two-component curing agent, and hot melt adhesive. Among them, the light transmittance of the high-transparency liquid silicone is ≥90%, the rare earth complex is Eu 3+ / Ce 3 + , with a quantum efficiency ≥80%, the particle size of the nano-fluorescent powder is ≤50nm, and it is pretreated by hydrotalcite exfoliation;

[0007] S2. Material premixing: Add luminous powder, silicone substrate, and two-component curing agent into a container according to the mass ratio of luminous powder: silicone: curing agent = 5:100:1, and stir for 10 minutes in an environment with a vacuum degree ≤ -0.095MPa, and control the key parameters of the luminous powder. The luminous powder includes the rare earth complex and nano-fluorescent powder;

[0008] S3. Mold injection molding: Use the LSR process for mold injection molding, with an injection pressure of 0.5 - 1.0MPa and a mold temperature of 40°C;

[0009] S4. Vacuum degassing: Place the injection-molded mold in an environment with a vacuum degree ≤ -0.095MPa for degassing for 5 - 10 minutes until no visible bubbles;

[0010] S5. Stage-by-stage curing: First, perform pre-curing. The pre-curing temperature is 60°C ± 2°C, and the pre-curing time is 20 ± 1 minute. Then, perform post-curing. The post-curing temperature is 180 - 200°C, and the post-curing time is 15 - 18 seconds;

[0011] S6. Post-treatment: Remove the burrs and polish the surface of the cured product.

[0012] Optionally, the critical parameter control includes the dispersion degree of luminous powder, the vacuum degassing degree, the curing temperature / time, and the light transmittance. Among them:

[0013] The agglomeration particle size of the dispersion degree of the luminous powder ≤ 100 nm, and it is detected by a laser particle size analyzer;

[0014] The residual amount of air bubbles in the vacuum degassing degree ≤ 0.1%, and it is detected by microscopic observation and density method;

[0015] The light transmittance ≥ 85% (wavelength 450 - 650 nm), and it is detected by a spectrophotometer.

[0016] Optionally, in the material premixing step, the mass ratio of the rare earth complex to the nano-fluorescent powder is 1:1 - 3:2.

[0017] Optionally, in the vacuum degassing step, the degassing time is adjusted according to the mold size. For every 100 cm 3 increase in volume, the degassing time is extended by 1 - 2 minutes.

[0018] Optionally, in the stage-by-stage curing process, the temperature difference between the post-curing temperature and the pre-curing temperature ≥ 120°C to ensure sufficient cross-linking of the silicone substrate.

[0019] Optionally, in the post-treatment step, the surface polishing uses silica abrasive with a particle size ≤ 50 μm, and the polishing pressure ≤ 0.2 MPa.

[0020] Optionally, the addition amount of the coupling agent is 1% - 3% of the mass of the luminous powder, which is used to improve the interfacial compatibility between the fluorescent material and the silicone substrate.

[0021] Optionally, the performance of the cured product needs to meet:

[0022] The luminous intensity ≥ 300 cd / m 2 (integrating sphere test);

[0023] The persistent luminous time ≥ 8 hours (after 1000 lux excitation);

[0024] The attenuation rate ≤ 5% after 1000 hours at high temperature and high humidity (85°C / 85% RH);

[0025] No corrosion or delamination after 48 - hour salt spray test (ASTM B117);

[0026] Tensile strength ≥ 1.5 MPa, elongation at break ≥ 200%;

[0027] The environmental protection performance passes the RoHS test, and Pb / Cd / Cr 6+ is not detected.

[0028] Compared with the prior art, the present invention provides a preparation method of a silica gel label with a night - self - luminous function, having the following beneficial effects:

[0029] 1. For the preparation method of the silica gel label with a night - self - luminous function, by adopting the nano - dispersion technology, the nano - fluorescent powder is pretreated by hydrotalcite exfoliation and vacuum stirring is carried out during the material premixing process, effectively solving the problem of fluorescence material agglomeration, improving the dispersion degree of the luminous powder, and making the product emit light evenly; by selecting high - transparency liquid silica gel as the base material and controlling key parameters such as light transmittance, etc., it ensures that the product has a high light transmittance, thus improving the luminous efficiency.

[0030] 2. The preparation method of the silica gel label with a night - self - luminous function adopts a staged curing process, first pre - curing and then post - curing, enabling the silica gel base material to cross - link gradually, avoiding the situation of insufficient or excessive cross - linking, and improving the performance stability of the product; the silica gel label has the advantages of passive luminescence, long lifespan (≥ 5 years), good flexibility (bending radius ≤ 2 mm), environmental protection, etc., passes the RoHS test, and Pb / Cd / Cr 6+ is not detected, meeting the environmental protection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] As Figure 1 shown, the present invention provides a technical solution: a preparation method of a night - self - luminous silica gel product, including the following steps:

[0034] S1. Raw material preparation: Prepare high-transparency liquid silicone, rare earth complex, nano-fluorescent powder, KH-560 coupling agent, two-component curing agent and hot melt adhesive. Among them, the light transmittance of the high-transparency liquid silicone is ≥90%, and the rare earth complex is Eu 3+ / Ce 3 + , the quantum efficiency is ≥80%, the particle size of the nano-fluorescent powder is ≤50nm, and it is pretreated by hydrotalcite exfoliation; the addition amount of the coupling agent is 1%-3% of the mass of the luminous powder, which is used to improve the interfacial compatibility between the fluorescent material and the silicone substrate.

[0035] S2. Material premixing: Add luminous powder, silicone substrate and two-component curing agent into a container according to the mass ratio of luminous powder: silicone: curing agent = 5:100:1, and stir for 10 minutes in an environment with a vacuum degree ≤ -0.095MPa to control the key parameters of the luminous powder. The luminous powder includes the rare earth complex and nano-fluorescent powder; the mass ratio of the rare earth complex to the nano-fluorescent powder is 1:1 - 3:2

[0036] The key parameter control includes the dispersion degree of the luminous powder, the vacuum degassing degree, the curing temperature / time and the light transmittance. Among them:

[0037] The agglomeration particle size of the dispersion degree of the luminous powder is ≤100nm, and it is detected by a laser particle size analyzer;

[0038] The bubble residue amount of the vacuum degassing degree is ≤0.1%, and it is detected by microscopic observation and density method;

[0039] The light transmittance is ≥85% (wavelength 450 - 650nm), and it is detected by a spectrophotometer.

[0040] S3. Mold injection molding: Use the LSR process for mold injection molding, the injection pressure is 0.5 - 1.0MPa, and the mold temperature is 40°C;

[0041] S4. Vacuum degassing: Put the injection-molded mold into an environment with a vacuum degree ≤ -0.095MPa for degassing for 5 - 10 minutes until no visible bubbles; the degassing time is adjusted according to the mold size. For every 100 cm increase in volume 3 , the degassing time is extended by 1 - 2 minutes.

[0042] S5. Staged curing: First, perform pre-curing, the pre-curing temperature is 60°C ± 2°C, the pre-curing time is 20 ± 1 minute, and then perform post-curing, the post-curing temperature is 180 - 200°C, and the post-curing time is 15 - 18 seconds; the temperature difference between the post-curing temperature and the pre-curing temperature is ≥120°C to ensure sufficient cross-linking of the silicone substrate.

[0043] S6. Post-treatment: Remove the burrs and polish the surface of the cured product. For surface polishing, silica abrasives with a particle size ≤ 50 μm are used, and the polishing pressure ≤ 0.2 MPa.

[0044] Meanwhile, the properties of the cured product shall meet the following requirements:

[0045] The initial luminous intensity after excitation ≥ 300 cd / m 2 (Integrating sphere test);

[0046] The persistent luminous time ≥ 8 hours (after excitation at 1000 lux);

[0047] The attenuation rate after 1000 hours at high temperature and high humidity (85°C / 85% RH) ≤ 5%;

[0048] No corrosion or delamination after 48 hours of salt spray test (ASTM B117);

[0049] The tensile strength ≥ 1.5 MPa, and the elongation at break ≥ 200%;

[0050] The environmental friendliness passes the RoHS test, and Pb / Cd / Cr 6+ Not detected.

[0051] As an application of this embodiment:

[0052] By adopting the nano-dispersion technology, the nano-fluorescent powder is pretreated by hydrotalcite exfoliation and vacuum stirring is carried out during the material premixing process, effectively solving the problem of agglomeration of the fluorescent material, improving the dispersion degree of the luminous powder, and making the product emit light evenly; by selecting high-transparency liquid silicone as the base material and controlling key parameters such as light transmittance, etc., it is ensured that the product has a high light transmittance, thereby improving the luminous efficiency; the preparation method of the silicone label with the function of autonomous light emission at night adopts a staged curing process, first pre-curing and then post-curing, enabling the silicone base material to crosslink gradually, avoiding the situation of insufficient or excessive crosslinking, and improving the performance stability of the product.

[0053] The above text generally describes the present invention in detail. However, based on the present invention, some modifications or improvements can be made, which are obvious to those of ordinary skill in the art. Therefore, the modifications or improvements made without departing from the spirit of the present invention are within the protection scope of the present invention.

Claims

1. A preparation method of a self-luminous silicone product at night, characterized in that, It includes the following steps: S1. Raw material preparation: Prepare high-transparency liquid silicone, rare earth complex, nano-fluorescent powder, KH-560 coupling agent, two-component curing agent and hot melt adhesive. Among them, the light transmittance of the high-transparency liquid silicone is ≥90%, and the rare earth complex is Eu 3+ / Ce 3+ , the quantum efficiency is ≥80%, the particle size of the nano-fluorescent powder is ≤50 nm, and it is pretreated by hydrotalcite exfoliation; S2. Material premixing: Add luminous powder, silicone substrate and two-component curing agent into a container according to the mass ratio of luminous powder: silicone: curing agent = 5:100:1, stir for 10 minutes in an environment with a vacuum degree ≤ -0.095 MPa, and control the key parameters of the luminous powder. The luminous powder includes the rare earth complex and nano fluorescent powder; S3. Mold injection molding: Use the LSR process for mold injection molding, with an injection pressure of 0.5 - 1.0 MPa and a mold temperature of 40 °C; S4. Vacuum degassing: Put the injection-molded mold into an environment with a vacuum degree ≤ -0.095 MPa for degassing for 5 - 10 minutes until no visible bubbles; S5. Stage-by-stage curing: First, perform pre-curing with a pre-curing temperature of 60 °C ± 2 °C and a pre-curing time of 20 ± 1 minute, and then perform post-curing with a post-curing temperature of 180 - 200 °C and a post-curing time of 15 - 18 seconds; S6. Post-treatment: Perform flash removal and surface polishing on the cured product.

2. The preparation method of a night self-luminous silica gel product according to claim 1, characterized in that, The key parameter control includes luminous powder dispersion, vacuum degassing degree, curing temperature / time and light transmittance, where: The agglomeration particle size of the luminous powder dispersion ≤ 100 nm, and it is detected by a laser particle size analyzer; The bubble residue amount of the vacuum degassing degree ≤ 0.1%, and it is detected by microscopic observation and density method; The light transmittance ≥ 85% (wavelength 450 - 650 nm), and it is detected by a spectrophotometer.

3. The preparation method of a noctilucent self-luminous silica gel product according to claim 1, characterized in that, In the material premixing step, the mass ratio of the rare earth complex to the nano fluorescent powder is 1:1 - 3:

2.

4. The preparation method of a night self-luminous silica gel product according to claim 1, characterized in that, In the vacuum degassing step, the degassing time is adjusted according to the mold size. For every 100 cm 3 increase in volume, the degassing time is extended by 1 - 2 minutes.

5. The preparation method of a night self-luminous silica gel product according to claim 1, characterized in that, In the stage-by-stage curing process, the temperature difference between the post-curing temperature and the pre-curing temperature ≥ 120 °C to ensure sufficient cross-linking of the silicone substrate.

6. The preparation method of a night self-luminous silica gel product according to claim 1, characterized in that, In the post-treatment step, the surface polishing uses silica abrasive with a particle size ≤ 50 μm and a polishing pressure ≤ 0.2 MPa.

7. The preparation method of a night self-luminous silica gel product according to claim 1, characterized in that The addition amount of the coupling agent is 1% - 3% of the mass of the luminous powder, which is used to improve the interfacial compatibility between the fluorescent material and the silicone substrate.

8. The preparation method of the night self-luminous silica gel product according to claim 1, characterized in that The performance of the cured product needs to meet: The luminous intensity is ≥300 cd / m² after initial excitation 2 (Integrating sphere test); The persistent luminous time ≥ 8 hours (after being excited by 1000 lux); The attenuation rate ≤ 5% after 1000 hours at high temperature and high humidity (85 °C / 85% RH); No corrosion or delamination after 48 hours of salt spray test (ASTM B117); The tensile strength ≥ 1.5 MPa and the elongation at break ≥ 200%; The environmental friendliness has passed the RoHS test, and Pb / Cd / Cr 6+ was not detected.

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