A method for indicating the aging degree of room temperature vulcanized silicone rubber

Abstract

The present invention discloses a method for indicating the aging degree of room temperature vulcanized silicone rubber, comprising: (1) preparing a photoluminescent material mixture; (2) preparing room temperature vulcanized silicone rubber; (3) spraying / coating the room temperature vulcanized silicone rubber on the object to be coated; (4) after the room temperature vulcanized silicone rubber is cured, exciting the photoluminescent material in the room temperature vulcanized silicone rubber with light to obtain an original image, and recording the relevant data when the image is collected; (5) after the object to be coated is aged, exciting the photoluminescent material in the room temperature vulcanized silicone rubber at the part where the aging degree of the silicone rubber to be detected is to be determined with light; (6) comparing with the original image obtained in step (4), and determining the aging degree of the room temperature vulcanized silicone rubber through color change. The evaluation method of the present invention can realize the online, convenient and non-destructive evaluation of the aging degree of room temperature vulcanized and high temperature vulcanized silicone rubber without power outage, and has good application prospects.

Description

Technical Field

[0001] The present invention relates to a method for indicating the aging degree of room temperature vulcanized silicone rubber, and particularly to a method for indicating the aging degree of a pollution flashover prevention coating material made of room temperature vulcanized silicone rubber. Background Art

[0002] The room temperature vulcanized silicone rubber pollution flashover prevention coating has excellent electrical insulation and hydrophobicity, and can effectively prevent the occurrence of pollution flashover accidents. As an effective means of preventing pollution flashover, the room temperature vulcanized pollution flashover prevention coating has been widely used in the power industry. However, after a certain operation time, under the action of continuous environmental factors such as fog, rain, and snow, the silicone rubber will age, the surface of the umbrella skirt will be wetted and damp, the surface resistivity of the insulator will decrease, the leakage current will increase, resulting in uneven voltage distribution on the insulator string, local discharge will occur, and the generated arc will further damage the surface of the coating, becoming a major hidden danger for the safe operation of the power grid. For the problem of aging of the room temperature vulcanized silicone rubber pollution flashover prevention coating, at present, methods such as manual inspection by workers and regular re-spraying are adopted. For the maintenance, upkeep and renewal of such a large number of pollution flashover prevention coatings, a large amount of manpower, material resources and financial resources are required.

[0003] CN113777070A discloses a method for evaluating the aging degree of silicone rubber by the degree of inorganicization, including the following steps: Step 1: Select the silicone rubber product to be tested as a test sample, and select inorganic SiO2 as a control sample; Step 2: Use an infrared spectrometer to perform infrared spectral characterization on the test surface of the test sample and the surface of the control sample to obtain the infrared characteristic spectral diagram of Si-O-Si of the test sample and the infrared characteristic spectral diagram of inorganic SiO2; Step 3: Judge the degree of inorganicization of the silicone rubber product according to the displacement difference of the infrared characteristic peak of Si-O-Si relative to the infrared characteristic peak of inorganic SiO2 in terms of wave number, and further evaluate the aging degree of the silicone rubber product through the degree of inorganicization.

[0004] CN216117319U discloses a silicone rubber aging and damage detection system based on terahertz pulse rays, including: a terahertz pulse ray parameter simulation unit; a terahertz pulse ray parameter control unit connected to the terahertz pulse ray parameter simulation unit; a terahertz pulse ray emission unit connected to the terahertz pulse ray parameter control unit; a silicone rubber sample arranged on the outgoing path of the terahertz pulse ray, and a terahertz pulse ray receiving unit arranged on the path of the terahertz pulse ray reflected and / or scattered by the silicone rubber sample.

[0005] CN112924395A discloses a method and system for judging the aging degree of silicone rubber based on RGB components. The method includes: obtaining a sliced image of the outer surface of the silicone rubber of the cable accessory; processing the sliced image of the outer surface of the silicone rubber of the cable accessory to obtain the target RGB components, and depicting spatial color distribution data points according to the target RGB components; comparing the spatial color distribution data points with a preset aging degree data point set; if any preset aging degree data point in the spatial color distribution data points and the preset aging degree data point set meets the similarity condition, the aging degree of the silicone rubber of the cable accessory is the same as the aging degree corresponding to the preset aging degree data point.

[0006] CN111610249A discloses a method for evaluating the aging state of high-temperature vulcanized silicone rubber, which uses the mass spectrometry peak height ratio of SiCH3 + and SiC3H9 + as the aging judgment basis to evaluate the aging state. This method conducts time-of-flight secondary ion mass spectrometry detection and quantitative analysis on the characteristic products during the aging process of silicone rubber, so as to accurately judge the life state of the material.

[0007] CN111007340A discloses a method, system and device for diagnosing the aging of silicone rubber of cable accessories, including the following steps: using the pulse echo method to perform ultrasonic detection on the silicone rubber of the cable accessory; collecting the ultrasonic signal reflected by the silicone rubber of the cable part and preprocessing the ultrasonic signal; intercepting the bottom surface wave B from the preprocessed ultrasonic signal, calculating and analyzing the bottom surface wave B to obtain the aging degree parameter pad; judging the aging condition of the silicone rubber of the cable accessory according to the aging degree parameter pad.

[0008] CN109521037A discloses a method for quantitatively detecting the aging depth of silicone rubber based on cross-sectional element analysis, which is mainly used for quantitatively detecting the aging depth of silicone rubber and measuring the aging degree of silicone rubber thereby. It mainly includes steps such as sample preparation, scanning electron microscope observation, EDS line scanning analysis, and aging depth analysis.

[0009] CN108267411A discloses a field of analyzing and detecting the aging degree of silicone rubber. More specifically, it provides a method for judging the aging degree of silicone rubber based on the color difference analysis between the inner and outer layers. A sample with a certain size is cut from the silicone rubber umbrella skirt, with the upper surface being the outer layer of the umbrella skirt and the lower surface being the inner layer of the umbrella skirt. Then, the brightness L* of the inner and outer layers of the sample is measured respectively by a color difference meter, and the aging degree of the silicone rubber is judged based on the difference between the inner and outer layers.

[0010] CN108195866A discloses a method for determining the aging degree of silicone rubber of a composite insulator, comprising the following steps: S1, cutting a sample from the silicone rubber shed of the composite insulator to be tested, performing X-ray photoelectron spectroscopy analysis on the sample, and obtaining the Si 2p energy spectrum of the sample; S2, using the peak fitting method to perform peak fitting on the Si 2p energy spectrum obtained in step S1 to obtain four sub-peaks corresponding to four configurations of silicon-oxygen functional groups in which Si atoms exist in the silicone rubber shed; S3, calculating the peak area of each sub-peak, and determining the relative ratio between the silicon-oxygen functional groups of each configuration according to the ratio of the peak areas of each sub-peak; S4, calculating the average number of O atoms around one Si atom according to the relative ratio between the silicon-oxygen functional groups of each configuration obtained in step S3; S5, determining the aging degree of the silicone rubber in the sample according to the average number of O atoms.

[0011] CN107817258B discloses a method for evaluating the aging degree of liquid silicone rubber based on peak fitting of X-ray diffraction patterns, and the specific steps are as follows: 1S Sampling from the liquid silicone rubber to be detected. 2S Performing X-ray diffraction analysis on the sample, performing peak fitting on the X-ray diffraction patterns of the inner layer and the surface layer, calculating the ratio of the integral areas of the diffraction peaks corresponding to PDMS and silica, comparing this ratio of the surface layer and the inner layer, so as to judge the aging degree of the liquid silicone rubber; the ratio of the integral areas of the diffraction peaks corresponding to silica and PDMS is denoted as XSiO2 / PDMS; 3S Judging the aging degree of the sample. The advantages are that it gives a more accurate evaluation of the aging degree of the liquid silicone rubber material of power station equipment, improves the aging evaluation procedure of the equipment, and thus lays a foundation for the operation and maintenance department to formulate a reliable maintenance strategy.

[0012] CN106199246A discloses a method for quickly evaluating the aging degree of a composite insulator: First, applying a DC voltage to a high-temperature vulcanized silicone rubber sample cut from the shed surface of the composite insulator to be evaluated by using a high-voltage loading device; then measuring the surface charge of the sample by using a surface charge measuring device, and further calculating the average surface charge density of the sample; finally, quickly judging the aging degree of the composite insulator according to the magnitude of the calculated average surface charge density. This method judges the aging degree of the composite insulator according to the magnitude of the average surface charge density of the composite insulator after pressurization.

[0013] CN105740582A discloses a method for predicting the aging state of a composite insulator, establishing a multi-dimensional prediction model of trap parameters (trap charge amount) with respect to environmental factors (pollution degree, humidity and ultraviolet intensity) and operation years, testing the trap charge amounts of multiple samples, and calculating the equivalent equivalent time of each environmental factor according to the operating environment and operation years of the composite insulator, so as to determine the prediction formula and obtain the influence factor of environmental factors on the aging of the composite insulator.

[0014] CN105699802A discloses a method for evaluating the artificial aging test of composite insulators based on the thermally stimulated current characteristics: First, confirm that the peak temperature of the TSC curve of the composite insulator is between 300 and 350 K; then calculate the correlation coefficient r between the aging time and the trap charge amount, and take the maximum trap charge growth amount Q = 30 nC as the demarcation value for distinguishing the effectiveness of the artificial aging test; then compare and analyze. If r < 0.6, it indicates that the effectiveness of this aging test method is poor; if r ≥ 0.6, but the maximum trap charge growth amount Q < 30 nC, it indicates that this aging test method is feasible, but the aging time is insufficient, resulting in an unclear aging effect; if r ≥ 0.6 and the maximum trap charge growth amount Q ≥ 30 nC, the effectiveness of this aging test method is high.

[0015] CN105699859A discloses a method for evaluating the aging state of composite insulators based on hygroscopicity and dielectric characteristics: Cut a shed at the high-voltage end of the composite insulator to be tested, and take the surface silicone rubber material to make a circular thin-film sample with a diameter of 3 cm and a thickness of 0.7 ± 0.1 mm. After the sample is surface-treated and dried, perform dielectric loss tests during the moisture absorption process with a humidity of 80%, and obtain the saturated dielectric loss factor. Calculate the aging score of the sample according to the saturated dielectric loss factor and the scoring formula to judge the aging degree of the composite insulator.

[0016] CN105403777A discloses a method for classifying and discriminating the aging state of composite insulators. This method uses the clustering analysis method to select five variables, namely the mean value X1 of the loss static contact angle, the minimum value X2 of the loss static contact angle in the hydrophobicity loss test, the mean value X3 of the restored static contact angle in the hydrophobicity recovery test, the trap charge amount X4 of the thermally stimulated current (TSC), and the trap energy level X5, to quantitatively classify the aging state of 18 samples; and use the discriminant analysis method to discriminate 3 samples with unknown aging states to obtain the discriminant functions for each aging grade; among them, the discrimination criteria are given according to the size of the trap charge amount by the clustering analysis results, and the accuracy of the aging state classification results is verified by the discriminant analysis method.

[0017] For the above methods, sampling is required and destructive tests are carried out in the laboratory, that is, power outage sampling is required and it cannot be carried out online. Therefore, a method for evaluating the aging degree of room temperature vulcanized silicone rubber without power outage, online, non-destructive and convenient is needed. Summary of the Invention

[0018] Object of the Invention: The present invention aims to provide a method for directly evaluating online the aging degree of the anti-fouling flashover coating material of room temperature vulcanized silicone rubber.

[0019] Technical Solution: A method for indicating the aging degree of room temperature vulcanized silicone rubber according to the present invention includes the following steps:

[0020] (1) Prepare a photoluminescent material mixture;

[0021] (2) Prepare a room temperature vulcanizing silicone rubber containing the photoluminescent material mixture;

[0022] (3) Spray / coat the above-mentioned room temperature vulcanizing silicone rubber on the object to be coated;

[0023] (4) After the room temperature vulcanizing silicone rubber is cured, excite the photoluminescent material in the room temperature vulcanizing silicone rubber with light to obtain the original image, and record the lighting conditions when the image is collected, the model of the collection device, and the distance from the target when the image is collected;

[0024] (5) After the object to be coated ages, excite the photoluminescent material in the room temperature vulcanizing silicone rubber at the part where the aging degree of the silicone rubber to be detected is to be detected with light;

[0025] (6) Compare with the original image obtained in step (4), and determine the aging degree of the room temperature vulcanizing silicone rubber through color change;

[0026] Among them, the photoluminescent material mixture described in step (1) contains at least two photoluminescent materials that emit light of different colors under the same light excitation conditions, and at least one photoluminescent material that is sensitive to water and easily loses its photoluminescent efficiency after contacting water. The photoluminescent material is a material that emits light under light stimulation, and can be an organic photoluminescent material and / or an inorganic photoluminescent material and / or a photoluminescent material formed after hybridization, compounding, or modification.

[0027] Preferably, the photoluminescent materials described in step (1) are spiropyrans, spirooxazines, benzopyrans, fulgides, azo compounds, diarylethenes, xanthones, oxazines, styrenes, cyanides, anilines, polycyclic quinones, viologens, aluminates, silicates, phosphates, borates, sulfides, sulfur oxides, nitrides, rhodamines, rhodamine 6G, rhodamine 123, rhodamine B, perchlorates, oxazine 720 perchlorate, pyridine 1 perchlorate, SrAl2O4:Eu 2+ ,Dy 3+ ,CaAl2O4:Eu 2+ ,Dy 3+ 、Sr4Al 14 O 25 :Eu 2+ ,Dy 3+ 、Sr2MgSi2O7:Eu 2+ ,Dy 3+ 、Ca2MgSi2O7:Eu 2+ ,Dy 3+ 、MgSiO3:Mn 2+ ,Eu 2+, Dy 3+ , Cd2Ge7O 16 : Mn 2+ , MgSnO4: Mn 2+ , Sr2P2O7: Eu 2+ , Y 3+ 。

[0028] Among them, the photoluminescent material mixture can be granular, paste-like, powder and / or liquid, etc.

[0029] Among them, the wavelength and intensity of the excitation light in step (4) depend on the characteristics of the photoluminescent material to be excited.

[0030] Among them, steps (5)-(6) can be repeated multiple times after the coating has been used for different times (i.e., after different aging times).

[0031] The excitation time in step (5) is 10 s - 20 min, preferably 15 s - 10 min, more preferably 30 s - 3 min.

[0032] Among them, the room temperature vulcanized silicone rubber in step (2) contains the following raw materials in mass percentages:

[0033]

[0034]

[0035] Among them, the mass fraction of the photoluminescent material mixture is preferably 0.1% - 20%, more preferably 1% - 10%.

[0036] Among them, the polymer-based glue is polysiloxane, including at least one of hydroxyl-terminated polydimethylsiloxane, vinyl-terminated polydimethylsiloxane, and methyl vinyl polysiloxane. The viscosity of hydroxyl-terminated polydimethylsiloxane is 500 - 40000 mPa·s, preferably 1000 - 30000 mPa·s, more preferably 3000 - 20000 mPa·s. The viscosity of vinyl-terminated polydimethylsiloxane is 300 - 100000 mPa·s, preferably 800 - 20000 mPa·s, further preferably 1000 - 15000 mPa·s. The molecular weight of methyl vinyl polysiloxane is 400000 - 800000, preferably the molecular weight is 500000 - 700000, and the vinyl content is 0.1% - 0.5%, preferably 0.12% - 0.3%.

[0037] Among them, the reinforcing filler is at least one of precipitated silica, fumed silica, and ultrafine calcium carbonate.

[0038] Among them, the electric erosion-resistant filler is at least one of aluminum hydroxide, magnesium hydroxide, double metal hydroxide, silicon oxide, aluminum oxide, boron nitride, layered silicate, ammonium polyphosphate, melamine cyanurate, preferably aluminum hydroxide, double metal hydroxide, ammonium polyphosphate, melamine cyanurate, and more preferably aluminum hydroxide, double metal hydroxide.

[0039] Among them, the inorganic filler is one or several of pigment, titanium oxide, magnesium oxide, antimony oxide, iron oxide, copper oxide, zinc oxide, silicon carbide, silicon nitride, calcium carbonate, mica, talcum powder, kaolin, glass powder, montmorillonite, wollastonite, barium sulfate, calcium sulfate, preferably pigment, titanium oxide, antimony oxide, iron oxide, calcium carbonate, mica, kaolin, montmorillonite, and more preferably pigment, titanium oxide, iron oxide, calcium carbonate, mica, montmorillonite.

[0040] Among them, the silicone oil is one or several of methyl silicone oil, ethyl silicone oil, phenyl silicone oil, cyanide-containing silicone oil, methyl hydrogen-containing silicone oil, methyl phenyl silicone oil, methyl chlorophenyl silicone oil, methyl ethoxy silicone oil, methyl trifluoropropyl silicone oil, methyl vinyl silicone oil, methyl hydroxy silicone oil, ethyl hydrogen-containing silicone oil, hydroxy hydrogen-containing silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, polyether-modified silicone oil, carboxyl-modified silicone oil, preferably methyl silicone oil, phenyl silicone oil, methyl hydrogen-containing silicone oil, methyl phenyl silicone oil, methyl vinyl silicone oil, methyl hydroxy silicone oil, ethyl hydrogen-containing silicone oil, hydroxy hydrogen-containing silicone oil, amino-modified silicone oil, and more preferably methyl silicone oil, phenyl silicone oil, methyl phenyl silicone oil, methyl hydroxy silicone oil, hydroxy hydrogen-containing silicone oil.

[0041] Among them, the silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidyletheroxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, hexamethyldisilazane, preferably γ-aminopropyltriethoxysilane, γ-glycidyletheroxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, hexamethyldisilazane, and more preferably γ-aminopropyltriethoxysilane, γ-glycidyletheroxypropyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, hexamethyldisilazane.

[0042] Among them, the crosslinking agent is at least one of methyl tributanone oxime silane, vinyl tributanone oxime silane, phenyl tributanone oxime silane, tetrabutanone oxime silane, methyl triacetone oxime silane, and vulcanizing agent bis(2,5-dimethyl-2,5-di(t-butylperoxy)hexane).

[0043] Among them, the catalyst is dibutyltin diacetate, a delayed platinum complex, stannous octoate, and / or a Kast catalyst.

[0044] In the process of preparing the silicone rubber coating, solvent gasoline, trichloropropane, trichloroethane, a composite solvent, etc. can be used as the dissolving medium.

[0045] In the process of preparing the silicone rubber coating, other functional fillers can also be added. For example, there are stabilizers (such as 1-ethynylcyclohexanol, 3,7,11-trimethyl-3-dodecyne-1-ol, tetramethyltetravinylcyclotetrasiloxane), flame retardants (such as hydrotalcite, antimony trioxide, decabromodiphenylethane, a platinum-containing flame retardant, a rhodium-containing flame retardant). When comparing with the original image obtained in step (4) in step (6), ensure that the lighting conditions when collecting the image, the model of the collection device, the distance from the target when collecting the image, etc. are the same as or similar to those in step (4).

[0046] Among them, when comparing with the original image obtained in step (4) in step (6), a machine-assisted method or an artificial method can be used. For example, a digital camera, a video recording device, a mobile phone, etc. can be used to obtain an image and then make a comparison; it can also be directly observed with the naked eye and then compared with the original image. Preferably, when using a machine-assisted method to obtain an image in step (6), various image processing tools (such as the CIE L*a*b color space) can be used for image analysis and comparison. It can also be directly observed and compared with the naked eye.

[0047] Beneficial effects: Compared with the prior art, the present invention has the following remarkable advantages: (1) It can evaluate the aging degree of room temperature vulcanized and high temperature vulcanized silicone rubber in an online, convenient, and non-destructive manner without power outage; (2) The test is a non-destructive test; (3) Multiple evaluations can be carried out. Description of the Drawings

[0048] Figure 1 is a flowchart of the method of the present invention;

[0049] Figure 2 shows the color change of the sample before and after aging in Example 1 of the present invention. Detailed Embodiments

[0050] The technical solution of the present invention will be further described below with reference to the drawings.

[0051] The flowchart of the indication method of the present invention is shown in Figure 1 .

[0052] Example 1

[0053] Sample preparation:

[0054] (1) Dissolve tetraethyl orthosilicate in a mixed solution of water and alcohol. First, adjust the pH value to 1 - 2 with nitric acid, and then adjust the pH value to 5 - 7 with an alkali to obtain a dilution solution; add (Sr,Ca)2MgSi2O7:Eu 2+ , Dy 3+ powder, stir and continue to adjust the pH value to 7 - 8 with an alkali to prepare organosilicon-coated (Sr,Ca)2MgSi2O7:Eu 2+ , Dy 3+ powder dispersed in the dilution solution. Mix the prepared organosilicon-coated (Sr,Ca)2MgSi2O7:Eu 2+ , Dy 3+ powder with SrAl2O4:Eu 2+ , Dy 3+ powder in a mass ratio of 1.5:1 to form a photoluminescent material mixture;

[0055] (2) Place 100 kg of hydroxyl-terminated polydimethylsiloxane with a viscosity of 5000 mPa·s, 0.5 kg of hydroxyl silicone oil, and 10 kg of hydrophobic modified nano-silica in a vacuum kneader, and knead at 120 - 140 °C and -0.1 MPa. After stirring and kneading evenly, add 2 kg of the photoluminescent material mixture, 90 kg of aluminum hydroxide, and 20 kg of silica, fully knead evenly, and process with a three-roll mill 3 times to further disperse evenly until it becomes a particle-free viscous liquid;

[0056] (3) Add the above-kneaded and evenly mixed rubber compound to a planetary disperser, add 200 kg of solvent gasoline, 2 kg of vinyltrimethoxysilane, 2 kg of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, 5 kg of methyltributanone oxime silane, and 0.3 kg of dibutyltin diacetate, disperse evenly at a stirring speed of 2000 rmp, perform vacuum degassing, and then discharge and can to obtain a uniform mixture;

[0057] (4) Coat the obtained mixture on a glass sheet to prepare a sample of 1.5 cm × 1.5 cm × 0.3 mm for standby.

[0058] Aging process:

[0059] Store the obtained sample in a dry environment at 180 °C for 24 h, and then place it in a humid and hot environment at 90 °C and 100% RH for 12 h to accelerate the aging of the sample. Take the above process as one cycle and perform this cycle 80 times.

[0060] Perform image acquisition and hydrophobicity testing respectively after preparing the sample and after the aging process.

[0061] Image acquisition: Irradiate the sample with an ultraviolet lamp for 15 s, and take a photo after waiting for 2 s.

[0062] Hydrophobicity test: The test was carried out according to DL / T 627-2018 "Room Temperature Curing Silicone Rubber Anti-fouling Flashover Coating for Insulators".

[0063] Example 2

[0064] Sample preparation:

[0065] (1) Tetraethyl orthosilicate was dissolved in a mixed solution of water and alcohol. First, the pH value was adjusted to 1-2 with nitric acid, and then the pH value was adjusted to 5-7 with an alkali to obtain a dilution solution. Zn2GeO4:Mn 2+ powder was added to the dilution solution, stirred, and the pH value was continuously adjusted to 7-8 with an alkali to obtain Zn2GeO4:Mn 2+ powder coated with silicone and dispersed in the dilution solution. After filtration and washing 3 times, Zn2GeO4:Mn 2+ powder coated with silicone was obtained and reserved;

[0066] 2-[4-[4-(Dimethylamino)phenyl]-1,3-butadienyl]-1-ethyl-pyridinium perchlorate (CAS: 87004-02-2) was mixed with two equal parts of cyanostar (Chem, 2020, 6, 1978-1997, Plug-and-Play Optical Materials from Fluorescent Dyes and Macrocycles). The materials would form co-crystals (CCDC: 1892439) in a layer-by-layer self-assembly manner (J. Am. Chem. Soc. 2017, 139, 17, 6226-6233, Ion-Pair Oligomerization of Chromogenic Triangulenium Cations with Cyanostar-Modified Anions That Controls Emission in Hierarchical Materials). After filtration and washing 3 times, co-crystalline powder was obtained and reserved;

[0067] The Zn2GeO4:Mn 2+ powder coated with silicone and the co-crystalline powder were mixed at a mass ratio of 2:1 to form a photoluminescent material mixture;

[0068] (2) placing 100 kg of hydroxyl-terminated polydimethylsiloxane with a viscosity of 5000 mPa.s, 0.5 kg of hydroxyl silicone oil, and 10 kg of hydrophobically modified nano-silica in a vacuum kneader, and kneading at 120-140° C. and −0.1 MPa, stirring and kneading uniformly, adding 2 kg of a photoluminescent material mixture, 90 kg of aluminum hydroxide, and 20 kg of silicon oxide, kneading thoroughly and uniformly, and processing three times with a three-roll mill to further disperse uniformly until it becomes a particle-free viscous liquid;

[0069] (3) adding the uniformly kneaded rubber material into a planetary disperser, adding 200 kg of solvent gasoline, 2 kg of vinyl trimethoxysilane, 2 kg of γ-(2,3-epoxypropoxy)propyl trimethoxysilane, 5 kg of methyl tributylidene oxime silane, and 0.3 kg of dibutyltin diacetate, and uniformly dispersing at a stirring speed of 2000 rpm, vacuum degassing, and discharging and canning to obtain a uniform mixture;

[0070] (4) The obtained mixture was coated on a glass sheet to prepare a sample of 1.5 cm×1.5 cm×0.3 mm for later use.

[0071] The aging process, image acquisition and water repellency test were carried out according to the steps in Example 1.

[0072] Example 3

[0073] Sample preparation:

[0074] (1) Weigh ZrO2:Ti 4+ And dissolved in chloroform, the two are stirred vigorously, mixed and dispersed thoroughly, and the obtained emulsion is in the shape of milk tea. Finally, the system is stirred and heated to evaporate the organic solvent completely to obtain an aqueous solution, which is reacted for 2 hours under stirring, and then the raw material ethyl orthosilicate is added dropwise and the reaction is continued for 1 hour. After the reaction is completed, it is cooled to room temperature. The product is repeatedly centrifuged and washed 3 times with a 30% ethanol aqueous solution, freeze-dried, and mesoporous silica-loaded composite nanoparticles are obtained (Materials Guide B, 2016, 30, 18-23, Preparation of fluorescent mesoporous silica nanoparticles and exploration of their properties). The prepared mesoporous silica-loaded composite nanoparticles are mixed with rhodamine B in a mass ratio of 1.7:1 to form a photoluminescent material mixture;

[0075] (2) Place 50 kg of hydroxyl-terminated polydimethylsiloxane with a viscosity of 1000 mPa·s, 50 kg of vinyl-terminated polydimethylsiloxane with a viscosity of 5000 mPa·s, 2 kg of hexamethyldisilazane, 0.6 kg of γ-glycidoxypropyltrimethoxysilane, 100 kg of aluminum hydroxide, and 10 kg of hydrophobically modified nano-silica into a vacuum kneader, and knead at 120 - 160 °C and -0.1 MPa. After stirring and kneading evenly, add 5 kg of the photoluminescent material mixture and 20 kg of silica, fully knead evenly, and process with a three-roll mill 3 times to further disperse evenly until it becomes a particle-free viscous liquid;

[0076] (3) Add the above evenly kneaded rubber compound into a planetary disperser, add 200 kg of solvent gasoline, 2 kg of hydrogen-containing silicone oil, 0.1 kg of 1-ethynylcyclohexanol, and 0.3 kg of Karstedt catalyst, disperse evenly at a stirring speed of 2000 rmp, perform vacuum degassing, and then discharge and can to obtain a uniform mixture;

[0077] (4) Coat the obtained mixture on a glass slide to make a sample of 1.5 cm × 1.5 cm × 0.3 mm for standby.

[0078] Carry out the aging process, image acquisition, and hydrophobicity test according to the steps in Example 1.

[0079] Example 4

[0080] Sample preparation:

[0081] (1) Dissolve tetraethyl orthosilicate in a water and alcohol mixed solution, first adjust the pH value to 1 - 2 with nitric acid, and then adjust the pH value to 5 - 7 with an alkali to obtain a dilution solution; add ZnSiN2:Mn 2+ powder into the dilution solution, stir and continue to adjust the pH value to 7 - 8 with an alkali to prepare Zn2GeO4:Mn 2+ powder coated with silicone in the dilution solution, filter, and wash 3 times to prepare ZnSiN2:Mn 2+ powder for standby;

[0082] Mix the ZnSiN2:Mn 2+ powder coated with silicone, BaZrSi3O9:Ti 4+ , and Zn2GeO4:Mn 2+ in a mass ratio of 1.6:1:1 to prepare a photoluminescent material mixture;

[0083] (2) Add 100 kg of methyl vinyl silicone rubber, 6 kg of hydroxy silicone oil, and 0.2 kg of γ-glycidoxypropyltrimethoxysilane to 20 kg of hydrophobically modified fumed silica and 100 kg of aluminum hydroxide in a vacuum kneader, and knead at 120-160 °C and -0.1 MPa. After stirring and kneading evenly, add 7 kg of photoluminescent material mixture, knead thoroughly until evenly dispersed, and process with a three-roll mill three times to further disperse evenly until it becomes a particle-free viscous liquid;

[0084] (3) Add the above-kneaded and evenly dispersed rubber compound to a planetary disperser, add 200 kg of solvent gasoline and 0.1 kg of vulcanizing agent bis(2,5-dimethyl-2,5-di(t-butylperoxy)hexane), disperse evenly at a stirring speed of 2000 rmp, and after vacuum degassing, discharge and can to obtain a uniform mixture;

[0085] (4) Coat the obtained mixture on a glass sheet to make a sample of 1.5 cm × 1.5 cm × 0.3 mm for standby.

[0086] Conduct the aging process, image acquisition, and hydrophobicity test according to the steps in Example 1.

[0087] From Figure 2 It can be seen that the unaged sample in Example 1 showed cyan after excitation, and the aged sample showed green after excitation, with an obvious difference. This is because the unaged sample showed the superposition of the light emitted by the two photoluminescent materials after light excitation, presenting indigo-cyan. After the sample was aged, the hydrophobicity decreased (Table 1), and water penetrated into the sample, resulting in the failure of SrAl2O4:Eu 2+ ,Dy 3+ , and only (Sr,Ca)2MgSi2O7:Eu 2+ ,Dy 3+ emitted light, presenting green.

[0088] The color changes and hydrophobicity classification changes of the samples before and after aging in each example are listed in Table 1.

[0089] Table 1 Color and hydrophobicity classification of the samples before and after aging

[0090] Sample Color before and after aging Hydrophobicity classification before and after aging Example 1 Indigo - Green HC1 - HC2 -> HC6 Example 2 Yellow - Green HC1 - HC2 -> HC6 Example 3 Purple - Blue HC1 - HC2 -> HC6 Example 4 White - Red HC1 - HC2 -> HC6

[0091] It can be seen from the above examples that the aging degree of the silicone rubber material can be clearly and obviously indicated by using the method of the present invention.

Claims

1. A method for indicating the aging degree of room temperature vulcanized silicone rubber, characterized in that It includes the following steps: (1) Prepare a photoluminescent material mixture; (2) Prepare a room temperature vulcanizing silicone rubber containing the photoluminescent material mixture; (3) Spray / coat the above room temperature vulcanizing silicone rubber on the object to be coated; (4) After the room temperature vulcanizing silicone rubber is cured, excite the photoluminescent material in the room temperature vulcanizing silicone rubber with light to obtain the original image, and record the illumination conditions when the image is collected, the model of the collection device, and the distance from the target when the image is collected; (5) After the object to be coated is aged, excite the photoluminescent material in the room temperature vulcanizing silicone rubber at the part where the aging degree of the silicone rubber to be detected is to be detected, and collect the image of the aged sample; (6) Compare the collected image of the aged sample in step (5) with the original image obtained in step (4), and determine the aging degree of the room temperature vulcanizing silicone rubber through the color change; Among them, the photoluminescent material mixture in step (1) contains at least two photoluminescent materials that emit light of different colors under the same light excitation conditions, and at least one of the photoluminescent materials that emit light of different colors under the same light excitation conditions is sensitive to water, that is, it is easy to lose the photoluminescent efficiency after contacting water.

2. The method for indicating the aging degree of room temperature vulcanized silicone rubber according to claim 1, characterized in that, The photoluminescent material described in step (1) is selected from spiropyrans, spirooxazines, benzopyrans, fulgides, azo compounds, diarylethenes, xanthones, oxazines, styrenes, cyanides, anilines, polycyclic quinones, viologens, aluminates, silicates, phosphates, borates, sulfides, sulfur oxides, nitrides, rhodamines, rhodamine 6G, rhodamine 123, rhodamine B, perchlorates, oxazine 720 perchlorate, pyridine 1 perchlorate, SrAl2O4:Eu 2+ ,Dy 3+ , CaAl2O4:Eu 2+ ,Dy 3+ , Sr4Al 14 O 25 :Eu 2+ ,Dy 3+ , Sr2MgSi2O7:Eu 2+ ,Dy 3+ , Ca2MgSi2O7:Eu 2+ ,Dy 3+ , MgSiO3:Mn 2+ ,Eu 2+ ,Dy 3+ , Cd2Ge7O 16 :Mn 2+ , MgSnO4:Mn 2+ , Sr2P2O7:Eu 2+ ,Y 3+ .

3. The method for indicating the aging degree of room temperature vulcanized silicone rubber according to claim 1, wherein, The room temperature vulcanizing silicone rubber in step (2) contains the following raw materials in mass percentage:

4. The method for indicating the aging degree of room temperature vulcanized silicone rubber according to claim 3, characterized in that, The polymer-based glue is polysiloxane, including at least one of hydroxyl-terminated polydimethylsiloxane, vinyl-terminated polydimethylsiloxane, and methyl vinyl polysiloxane; the viscosity of the hydroxyl-terminated polydimethylsiloxane is 500-40000 mPa·s, the viscosity of the vinyl-terminated polydimethylsiloxane is 300-100000 mPa·s, the molecular weight of the methyl vinyl polysiloxane is 400000-800000, and the vinyl content is 0.1%-0.5%.

5. The method for indicating the aging degree of room temperature vulcanized silicone rubber according to claim 3, characterized in that, The reinforcing filler is at least one of precipitated silica, fumed silica, and ultrafine calcium carbonate.

6. The method for indicating the aging degree of room temperature vulcanized silicone rubber according to claim 3, characterized in that, The electric erosion-resistant filler is at least one of aluminum hydroxide, magnesium hydroxide, double metal hydroxide, silicon oxide, aluminum oxide, boron nitride, layered silicate, ammonium polyphosphate, and melamine cyanurate.

7. The method for indicating the aging degree of room temperature vulcanized silicone rubber according to claim 3, characterized in that, The inorganic filler is one or several of pigments, titanium oxide, magnesium oxide, antimony oxide, iron oxide, copper oxide, zinc oxide, silicon carbide, silicon nitride, calcium carbonate, mica, talc powder, kaolin, glass powder, montmorillonite, wollastonite, barium sulfate, and calcium sulfate.

8. The method for indicating the aging degree of room temperature vulcanized silicone rubber according to claim 3, characterized in that The silicone oil is at least one of methyl silicone oil, ethyl silicone oil, phenyl silicone oil, cyanide-containing silicone oil, methyl hydrogen-containing silicone oil, methyl phenyl silicone oil, methyl chlorophenyl silicone oil, methyl ethoxy silicone oil, methyl trifluoropropyl silicone oil, methyl vinyl silicone oil, methyl hydroxyl silicone oil, ethyl hydrogen-containing silicone oil, hydroxyl hydrogen-containing silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, polyether-modified silicone oil, and carboxyl-modified silicone oil.

9. The method for indicating the aging degree of room temperature vulcanized silicone rubber according to claim 3, characterized in that The silane coupling agent is at least one of γ-aminopropyltriethoxysilane, γ-glycidyletheroxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, and hexamethyldisilazane.

10. The method for indicating the aging degree of room temperature vulcanized silicone rubber according to claim 1, characterized in that, The excitation time in step (5) is 10 s-20 min.

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