Decorative glass capable of changing patterns along with observation angle and preparation process of decorative glass

Abstract

The invention relates to the technical field of decorative glass, in particular to decorative glass capable of changing patterns along with observation angles and a preparation process of the decorative glass. The decorative glass is sequentially compounded with an ice flower texture layer, a middle bonding layer, an angle change pattern layer and a glass base material from top to bottom; wherein the ice flower texture layer is of a natural random structure formed by water glass powder with specific parameters through a freeze thawing-hot melting process, and the angle transformation pattern layer is composed of at least two groups of geometrical pattern units which are arranged in a staggered manner. The preparation process comprises the steps of laser engraving preparation of the angle transformation pattern layer, freeze thawing-hot melting forming of the ice flower texture layer and hot pressing composite forming of all the layers. The invention does not need to depend on electronic technology and continuous power supply, realizes dynamic pattern switching at an observation angle of 0-180 degrees, has unique aesthetics and excellent structural durability of natural ice flower texture, and solves the problems of high dynamic effect cost of existing decorative glass, lack of flexibility of static glass, poor environmental protection property of ice flower texture preparation and insufficient durability.

Description

Technical Field

[0001] This invention relates to the field of decorative glass deep processing technology, specifically to a decorative glass with a pattern that changes with the viewing angle and its preparation process. Background Technology

[0002] Decorative glass is a functional type of glass used to enhance the aesthetics of buildings or homes, and is widely used in interior partitions, curtain walls, furniture, and artistic decorations. With rising consumer demand and diversified aesthetic preferences, traditional decorative glass can no longer meet the market's comprehensive requirements for decorative glass. Existing technologies suffer from the following problems:

[0003] (1) Existing dynamic decorative glass mainly relies on electronic technologies such as liquid crystal dimming, electrochromic, and holographic projection, which are expensive. The core materials and control system cost 5-10 times more than ordinary decorative glass. It relies on continuous power supply and loses dynamic function after power failure, making it unsuitable for scenarios without power supply (such as outdoor curtain walls and mobile furnishings). Traditional static decorative glass (such as printed glass and sandblasted glass) is inexpensive, but the patterns are fixed and lack dynamism.

[0004] (2) There are also some problems with the existing preparation technology of decorative glass with ice flower texture: physical etching method (such as mold pressing, sandblasting) artificially simulates the ice flower shape, and the texture repetition rate is as high as 90%, which lacks the randomness and uniqueness of natural ice flowers; chemical corrosion method (such as hydrofluoric acid etching) uses corrosive reagents to destroy the glass surface structure to form texture, which not only poses environmental hazards (high waste liquid treatment cost), but also has rough texture shape and poor controllability, and is prone to local over-corrosion or under-corrosion problems; natural freezing method directly places the glass in a low temperature environment to condense water vapor to form ice flowers, but the ice flower texture is only attached to the glass surface and is very easy to fall off after friction or temperature difference changes, which cannot meet the durability requirements of actual use. Summary of the Invention

[0005] The purpose of this invention is to provide decorative glass with a pattern that changes with the viewing angle and its manufacturing process, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A decorative glass with a pattern that changes with the viewing angle comprises, from top to bottom, the following layers: an ice flower texture layer, an intermediate adhesive layer, an angle-changing pattern layer, and a glass substrate.

[0008] The angle transformation pattern layer is composed of at least two sets of staggered geometric pattern units, wherein the geometric shape is selected from one or more combinations of circles, ellipses, rhombuses, and polygons.

[0009] The ice flower texture layer is a natural ice flower structure layer formed by water glass powder through freeze-thaw and hot-melt processes, with a thickness of 50-200μm.

[0010] Preferably, the substrate of the angle-changing pattern layer is a polycarbonate film or a polyethylene terephthalate film with a thickness of 25-100 μm, the size of the pattern unit is 0.1-5 mm, and the misalignment between two adjacent groups of pattern units is 0.05-2 mm.

[0011] Preferably, the intermediate adhesive layer is an ethylene-vinyl acetate copolymer film or a polyvinyl butyral film with a thickness of 0.38-1.52 mm.

[0012] Preferably, the modulus of the water glass powder is 2.8-3.2, the particle size is 10-50μm, and the amount of water glass powder used in the ice flower texture layer is 5-20g / m².

[0013] Preferably, the total thickness of the decorative glass is 4-20mm, the pattern transformation angle range is 0-180°, and the microstructure of the ice flower texture is a dendritic or sheet-like interwoven crystal form.

[0014] A process for manufacturing decorative glass with patterns that change depending on the viewing angle includes the following steps:

[0015] Step S1: Preparation of the angle transformation pattern layer:

[0016] Step S11, Substrate pretreatment: Select high-transmittance PC film or PET film as the substrate, and clean and dry it;

[0017] Step S12, First group of pattern engraving: Use a laser engraving machine to engrave the first group of geometric pattern units on the surface of the substrate, with an engraving depth of 30-70% of the substrate thickness;

[0018] Step S13, second set of pattern engraving: a layer of light-transmitting protective film is laminated on the surface of the engraved substrate, and then the substrate is flipped over and the second set of geometric pattern units is engraved on the other side. The misalignment between the second set of pattern units and the first set of pattern units is 0.05-2mm.

[0019] Step S14: Remove the protective film to obtain the angle transformation pattern layer;

[0020] Step S2, Preparation of the ice flower texture layer:

[0021] Step S21: Prepare water glass powder suspension: Mix water glass powder with a modulus of 2.8-3.2 and deionized water at a mass ratio of 1:0.8-1.2, stir evenly, and let stand for 10-30 minutes to remove bubbles;

[0022] Step S22, Glass substrate pretreatment: Select float glass with a thickness of 3-12mm, clean and dry it, and then cool it to room temperature;

[0023] Step S23, Spreading and Freezing: Spread the water glass powder suspension evenly on the surface of the pretreated glass substrate at a rate of 5-20 g / m², and then freeze it in a low temperature environment of -5℃ to -20℃ for 8-24 hours to form ice flower crystals.

[0024] Step S24, Air Drying and Hot Melting: Move the frozen glass substrate to a cool and ventilated place and air dry for 12-36 hours at a humidity of 40-60% and a temperature of 15-25℃. Then put it into a hot melting furnace and heat it to 500-700℃ at a heating rate of 5-10℃ / min. Hold it at that temperature for 30-120 minutes and let it cool naturally to room temperature to obtain a glass substrate with an ice flower texture layer.

[0025] Step S3, Composite Molding:

[0026] Step S31: Align and bond the angle transformation pattern layer with the glass substrate with the ice flower texture layer through the intermediate adhesive layer, and place it in a hot press.

[0027] Step S32: Increase the temperature to 450-650℃ at a heating rate of 3-5℃ / min, apply a pressure of 0.3-0.8MPa, and hold for 60-180min;

[0028] Step S33: Cool to room temperature at a cooling rate of 2-4℃ / min, cut and trim to obtain decorative glass with a pattern that changes with the viewing angle.

[0029] Preferably, in step S12, the laser engraving power of the laser engraving machine is 10-30W, the engraving speed is 50-200mm / s, and the spot diameter is 0.01-0.1mm.

[0030] Preferably, the water glass powder suspension in step S23 is spread by one or more of the following methods: spraying, screen spreading, or scraper coating.

[0031] Preferably, the humidity of the freezing environment in step S23 is controlled at 30-50% to avoid condensation on the surface of the ice flower crystals.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] This invention achieves smooth pattern switching between 0-180° viewing angles by designing two or more sets of staggered geometric pattern units in the angle transformation pattern layer. It does not rely on electronic technology or continuous power supply, making it suitable for scenarios without power supply. It solves the problems of high cost and reliance on power supply in existing dynamic decorative glass, while overcoming the lack of flexibility in static decorative glass.

[0034] This invention uses a freeze-thaw-heat melting process with water glass powder to prepare an ice flower texture layer. The water glass powder naturally crystallizes at low temperatures to form a dendritic or sheet-like interwoven structure, with a texture repetition rate close to 0, possessing the unique aesthetics of natural ice flowers. Furthermore, the water glass powder and the glass substrate form stable siloxane chemical bonds through heat melting, with a bonding strength ≥1.5MPa, making it wear-resistant and resistant to peeling. This solves the problems of existing ice flower textured glass, such as texture repetition, significant environmental risks, and insufficient durability.

[0035] The preparation process of this invention does not require the use of corrosive chemical reagents, the water glass powder suspension has no environmental pollution, and the waste liquid treatment cost is low; the temperature, pressure, time and other parameters of each process step are precisely controllable, and the density of ice flower texture (5-20g / m²), pattern unit size (0.1-5mm) and misalignment amount (0.05-2mm) can be adjusted according to needs to achieve diversified product customization.

[0036] The decorative glass in this invention has a total thickness of 4-20mm, a light transmittance of ≥85%, an impact strength of ≥58kJ / m², and exhibits no cracks or peeling after 50 cycles of high and low temperatures (-40℃ for 4h → room temperature for 2h → 80℃ for 4h). It retains ≥95% of the light transmittance and ≥90% of the bonding strength, possessing excellent optical, mechanical, and weather resistance properties. It is suitable for various applications such as building curtain walls, interior partitions, and art displays. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the layered structure of the decorative glass of the present invention;

[0038] Figure 2 This is a schematic diagram of the misaligned arrangement of two sets of patterns in the angle transformation pattern layer of the present invention;

[0039] Figure 3 This is a schematic diagram of the microstructure (dendritic crystals) of the ice flower texture layer of the present invention;

[0040] Figure 4 This is a schematic diagram of the microstructure (plate-like crystals) of the ice flower texture layer of the present invention. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] A decorative glass with a pattern that changes with the viewing angle comprises, from top to bottom, the following layers: an ice flower texture layer, an intermediate adhesive layer, an angle-changing pattern layer, and a glass substrate.

[0043] The ice flower texture layer is a natural ice flower structure layer formed by freeze-thaw and hot-melt of water glass powder. Its thickness is 50-200μm. The modulus of the water glass powder is 2.8-3.2, the particle size is 10-50μm, and the amount of water glass powder used in the ice flower texture layer is 5-20g / m².

[0044] The substrate of the angle-changing pattern layer is a polycarbonate film or a polyethylene terephthalate film with a thickness of 25-100 μm. The size of the pattern unit is 0.1-5 mm, and the misalignment between two adjacent groups of pattern units is 0.05-2 mm.

[0045] The intermediate adhesive layer is an ethylene-vinyl acetate copolymer film or a polyvinyl butyral film with a thickness of 0.38-1.52 mm.

[0046] The angle transformation pattern layer is composed of at least two sets of staggered geometric pattern units, wherein the geometric shape is selected from one or more combinations of circles, ellipses, rhombuses, and polygons.

[0047] The total thickness of the decorative glass is 4-20mm, the pattern transformation angle range is 0-180°, and the microstructure of the ice flower texture is a dendritic or plate-like interwoven crystal form.

[0048] A process for manufacturing decorative glass with patterns that change depending on the viewing angle includes the following steps:

[0049] Step S1: Preparation of the angle transformation pattern layer:

[0050] Step S11, Substrate Pretreatment:

[0051] Select a high-transmittance PC film (transmittance ≥92%) or PET film (transmittance ≥93%), cut it to the target size (e.g., 1200mm × 1800mm), and place it in an ultrasonic cleaner. Use anhydrous ethanol as the cleaning medium and clean for 10-15 minutes at a power of 300-500W and a frequency of 40kHz to remove surface oil, dust, and other impurities. After cleaning, place the film in a constant temperature oven at 80-100℃ for 20-30 minutes to dry, and then cool to room temperature, ensuring that the film surface is free of water stains and residual impurities (moisture content ≤0.1%) to avoid affecting the engraving accuracy.

[0052] Step S12, First group of patterns engraving:

[0053] The pre-treated film is fixed on the laser engraving machine's worktable using a vacuum adsorption device, ensuring the film is flat and wrinkle-free (flatness ≤ 0.05 mm / m). Laser engraving parameters are set as follows: power 10-30W (adjusted according to pattern unit size; 10-15W for sizes ≤ 1 mm, 20-30W for sizes > 1 mm), engraving speed 50-200 mm / s (50-100 mm / s for fine patterns, 150-200 mm / s for rough patterns), and spot diameter 0.01-0.1 mm.

[0054] Engraving is performed according to pre-defined geometric patterns (such as the outlines of landscape patterns, the detailed textures of figure patterns, and the geometric units of abstract art patterns). The engraving depth is controlled to 30-70% of the film thickness: too shallow a depth (<30%) will result in insufficient optical contrast of the pattern, and the pattern transition will not be obvious when the viewing angle changes; too deep a depth (>70%) will damage the structural integrity of the film and make it prone to breakage during the lamination process. After engraving, the clarity of the pattern is checked using a microscope (50-100x magnification) to ensure that there are no burrs or defects.

[0055] Step S13, second set of pattern engraving:

[0056] A PE light-transmitting protective film (20-50μm thick, ≥95% light transmittance) is applied to the surface of the first set of patterns. The protective film is attached using electrostatic adsorption to avoid adhesive residue that could reduce the interfacial bonding strength between the adhesive layer and the pattern layer in subsequent lamination processes. The film with the protective film is then rotated 180° along the positioning pins and re-fixed on the vacuum adsorption worktable of the laser engraving machine. The edge reference points of the first set of patterns are identified and calibrated using the CCD vision positioning calibration system (positioning accuracy ≤±0.01mm) on the worktable to ensure that the spatial alignment deviation between the two sets of patterns is controlled within the design allowable range (≤±0.02mm).

[0057] The design of the second set of pattern units needs to create a dynamic synergy with the first set: if the first set is a distant outline of a landscape pattern (circular pattern unit, size 2mm), the second set should be designed as a close-up detail texture (elliptical pattern unit, size 1.8mm); if the first set is a silhouette of a person (diamond pattern unit, size 3mm), the second set should be a clothing texture (polygonal pattern unit, size 2.5mm). The theme style of the two sets of patterns should be consistent, and the size ratio should be controlled between 1:0.8 and 1:1.2 to ensure the visual continuity and aesthetic harmony of the pattern switching when the perspective changes.

[0058] The misalignment between two adjacent pattern units is precisely set to 0.05-2mm by the CNC system of the engraving machine. The specific value is dynamically adjusted according to the complexity of the pattern: for fine patterns (unit size ≤ 1mm), the misalignment is 0.05-0.5mm to avoid pattern overlap and blurry transitions; for rough patterns (unit size > 1mm), the misalignment is 0.5-2mm to enhance the visual impact of dynamic changes. The misalignment direction can be selected as horizontal, vertical or diagonal (30°, 45°, 60°). More dynamic effects can be achieved through multi-directional misalignment combinations. For example, horizontal misalignment achieves "left and right switching", and diagonal misalignment achieves "rotational gradation".

[0059] The engraving parameters remain consistent with the first group: laser power 10-30W, engraving speed 50-200mm / s, spot diameter 0.01-0.1mm, and engraving depth strictly controlled to 30-70% of the film thickness. Too shallow a depth (<30%) will result in insufficient optical contrast of the pattern, causing blurry pattern transitions when the viewing angle changes; too deep a depth (>70%) will damage the integrity of the film structure, easily leading to cracks or breakage during the lamination process. During engraving, a real-time monitoring module is activated, using a high-definition camera (resolution ≥1920×1080) to capture the engraving trajectory. Combined with an image recognition algorithm, a misalignment calibration is performed every 50mm×50mm area engraved, effectively compensating for positioning errors caused by mechanical vibration or temperature drift, ensuring that the overall pattern misalignment accuracy deviation is ≤±0.02mm.

[0060] Step S14: Remove the protective film to obtain the angle transformation pattern layer;

[0061] After engraving, gently peel off the PE protective film along the edge of the film using toothless tweezers, applying a force ≤0.1N during the operation to avoid pulling the pattern units and causing edge damage. Transfer the film to a Class 1000 clean bench and gently wipe both sides of the surface along the pattern texture with a lint-free cloth soaked in anhydrous ethanol (purity ≥99.5%) to remove resin residue (particle size ≤5μm) generated by laser engraving. After wiping, blow away any remaining debris on the surface with clean compressed air (pressure 0.1-0.2MPa, cleanliness Class 100) to ensure that no impurities adhere to the pattern surface.

[0062] After wiping, place the film in a constant temperature oven at 60-80℃ for 10-15 minutes to remove residual ethanol solvent from the surface, ensuring the film moisture content is ≤0.05g / m². After drying, perform triple quality inspection; only after passing the inspection can the film proceed to the next process.

[0063] Optical performance testing: The transmittance of the film was tested using a Lambda 950 UV / Vis / NIR spectrophotometer in the wavelength range of 380-780nm. The transmittance was required to be ≥90%, and the transmittance deviation of the same batch of products was ≤±1% to ensure that the pattern layer did not affect the overall transmittance effect.

[0064] Dimensional accuracy inspection: Using a VMS-3020H 2D image measuring instrument (measurement accuracy ±0.001mm), 10 pattern units are randomly selected to inspect the size and misalignment. The deviation must be controlled within ±5% of the design value to ensure the consistency of the dynamic transformation effect.

[0065] Appearance defect inspection: Visually inspect the pattern on a high-intensity light inspection platform with an illuminance of ≥5000 lux at a viewing distance of 30cm, while also using a 50x magnifying glass. The pattern is considered acceptable if the surface is free of burrs, defects, scratches (scratch length ≤0.3mm, number ≤1 / m²) and resin residue.

[0066] The qualified angle transformation pattern layer is sealed in a double-layer PE vacuum packaging bag and stored in a dry oven with humidity ≤30% and temperature 15-25℃ for later use. The shelf life is 6 months. During storage, avoid direct sunlight and high temperature and humidity environment to prevent film aging or pattern deformation.

[0067] Step S2, Preparation of the ice flower texture layer:

[0068] Step S21: Prepare water glass powder suspension:

[0069] Industrial-grade water glass powder (sodium silicate content ≥98%, iron content ≤0.05%) was selected, and its modulus was determined to be 2.8-3.2 (modulus = moles of SiO2 / moles of Na2O) by acid-base titration. A modulus that is too low (<2.8) will result in poor water resistance of the ice flower texture and easy moisture absorption and whitening after long-term use; a modulus that is too high (>3.2) will reduce melt flowability and affect the interfacial bonding strength with the glass substrate. Water glass powder with a particle size of 10-50μm was screened using an air classifier, with ≥70% of the particles being 10-30μm, ensuring the dispersion stability and uniformity of the suspension and avoiding uneven texture caused by particle agglomeration.

[0070] Add water glass powder and deionized water (conductivity ≤10μS / cm) to a high-speed mixing tank at a mass ratio of 1:0.8-1.2. Add sodium polycarboxylate dispersant (0.1-0.3% of the mass of water glass powder). Use an SDF-1500 high-speed disperser to stir at a speed of 1000-2000r / min for 20-30min. During the stirring process, use jacketed cooling water to control the temperature inside the tank at 20-25℃ to prevent the water glass powder from prematurely hydrolyzing and forming a gel due to excessive temperature. After stirring, transfer the suspension to a settling tank with low-speed stirring and let it stand at room temperature for 10-30 minutes to degas (maintain low-speed stirring at 50-100 r / min during the settling period to avoid water glass powder settling). After degassing, use an NDJ-8S rotational viscometer (60 r / min) to test the viscosity of the suspension and control it between 50-200 mPa·s. If the viscosity is too high, add deionized water to adjust it; if the viscosity is too low, add water glass powder to correct it, ensuring that the suspension neither flows nor clumps during the spreading process.

[0071] Step S22, Glass substrate pretreatment:

[0072] Select float glass with a thickness of 3-12mm (meeting GB / T11614-2022 standard, Grade 1). Cut the glass using a CNC glass cutting machine according to product size requirements. Beveling the cut edges at a 45° angle (2-3mm beveling width) using a GD-120 glass beveling machine eliminates stress concentration at sharp edges, preventing edge damage from affecting product yield in subsequent processes. The pretreatment process is strictly implemented according to the following steps to ensure the glass surface is clean and free of impurities, improving adhesion to the ice flower texture layer:

[0073] Water washing: Place the glass into a continuous water washing machine and spray it with 0.3-0.5MPa high-pressure deionized water to remove surface dust and loose impurities. The water temperature is controlled at 30-40℃ and the spraying time is 5-8 minutes.

[0074] Alkaline washing: Transfer to an alkaline washing tank and immerse in a 5% (mass fraction) sodium hydroxide solution for 10-15 minutes at a solution temperature of 40-50℃ to remove surface grease, paraffin and other organic contaminants. At the same time, it corrodes the glass surface to form a micro-rough structure (roughness Ra=0.1-0.3μm), which enhances the bonding force with water glass powder.

[0075] Pickling: Transfer to a pickling tank and immerse in a 3% (mass fraction) hydrochloric acid solution for 5-10 minutes at a solution temperature of 30-40℃ to neutralize residual alkali and remove the surface oxide layer, thus preventing the oxide layer from affecting the fusion effect;

[0076] Pure water rinsing: Use 0.2-0.3MPa high-pressure deionized water to spray and rinse for 5-8 minutes to ensure that the pH value of the glass surface is 6.5-7.5 and there is no acid or alkali residue;

[0077] Drying: Place the glass in a tunnel oven and dry at 80-120℃ for 20-40 minutes. After drying, the moisture content on the glass surface should be ≤0.01g / m². Cool to room temperature for later use.

[0078] The pretreated glass substrate must meet the following indicators: light transmittance ≥90% (tested by Lambda950 spectrophotometer), flatness ≤0.1mm / m (tested by level), no bubbles on the surface, no scratches (scratch length ≤0.5mm, number ≤2 / m²), and no oil residue (contact angle ≤30°).

[0079] Step S23, Spreading and Freezing:

[0080] Select the appropriate application method based on the required density of the ice flower texture to ensure that the water glass powder suspension evenly covers the glass surface:

[0081] Spraying method: Use a W-71 pneumatic sprayer (nozzle diameter 0.1-0.3mm, working pressure 0.2-0.4MPa), spray distance 30-50cm, moving speed 5-10cm / s, suitable for fine-density ice flower texture (water glass powder dosage 5-10g / m²), the texture is delicate and uniform;

[0082] Screen spreading method: Use 100-200 mesh stainless steel screen and spread it by mechanical vibration (vibration frequency 50-100Hz) at a height of 20-30cm. It is suitable for medium density ice flower texture (dosage 10-15g / m²) with strong texture layering.

[0083] Blade coating method: Use a comma blade (blade gap 0.1-0.3mm), coating speed 5-10m / min, coating pressure 0.1-0.2MPa, suitable for high-density ice flower texture (dosage 15-20g / m²), the texture is full and thick.

[0084] During the spreading process, an electronic scale (accuracy ±0.1g) is used to monitor the amount of suspension used in each piece of glass in real time. By conversion (mass of water glass powder = mass of suspension × mass fraction of water glass powder), the actual amount of water glass powder used is ensured to be controlled within 5-20g / m². After spreading, the glass is placed horizontally in a DW-100 low-temperature freezer (temperature uniformity ±1℃). The relative humidity of the freezing environment is controlled at 30-50% (controlled by a dehumidifier). When the humidity is >50%, the ice flower crystals are prone to fusion and deformation due to condensation on the surface, losing their natural randomness; when the humidity is <30%, the water in the suspension evaporates too quickly, resulting in incomplete development of the ice flower crystals and incomplete texture.

[0085] The freezing process parameters are precisely set according to the required ice flower texture morphology: temperature -5℃ to -20℃, freezing time 8-24 hours. Specific selection principles:

[0086] To form coarse, dendritic ice flower textures (suitable for building curtain walls and large decorative panels): use -5℃ to -10℃ and 16-24h parameters to ensure sufficient growth of ice flower crystals and a graceful and impressive texture.

[0087] To create fine and dense ice flower textures (suitable for home partitions and art displays): Use -15℃ to -20℃ and 8-12h parameters to produce fine and uniform ice flower crystals with delicate and exquisite textures.

[0088] Do not open the freezer door during the freezing process to avoid temperature fluctuations that could damage the ice crystal structure. After freezing, keep the temperature inside the freezer stable and wait until the air-drying process is ready before taking out the glass to prevent sudden changes in ambient temperature from causing the ice crystals to fall off.

[0089] Step S24, Air Drying and Hot Melting:

[0090] After freezing, the glass is slowly removed from the freezer and quickly transferred to a cool, ventilated room (temperature 15-25℃, relative humidity 40-60%). It is then allowed to air-dry naturally for 12-36 hours, allowing the ice flower crystals to slowly sublimate and retain their complete crystal structure. During the air-drying process, environmental parameters are controlled in real-time using a temperature and humidity control system.

[0091] When the temperature is above 25℃ or the humidity is below 40%, turn on the humidifier and cooling device to prevent the ice flower crystals from sublimating too quickly, which could cause the texture to collapse and crack.

[0092] When the temperature is <15℃ or the humidity is >60%, turn on the heating device and dehumidifier to prevent mold growth and secondary icing of ice flowers.

[0093] The criteria for judging the end point of air drying are: no obvious water stains on the glass surface, the ice flower crystals are white and loose, there is no indentation when pressed, and the weight is stable (weight change ≤0.1g / m² for 2 consecutive hours).

[0094] After the glass has dried in the shade, it is placed into an RX3-60-12 box-type hot melt furnace, and a segmented heating hot melt process is used to ensure that the water glass powder and the glass substrate are fully fused together.

[0095] Preheating stage: The room temperature is raised to 300℃, the heating rate is 5℃ / min, and the temperature is held for 30min to remove residual moisture and trace organic matter on the glass surface and avoid the generation of bubbles during the hot melting process;

[0096] Heating stage: from 300℃ to 500-700℃, heating rate 8-10℃ / min, to ensure that water glass powder melts gradually and avoid thermal stress cracking caused by excessive heating.

[0097] Heat preservation stage: Heat preservation at 500-700℃ for 30-120 minutes. The heat preservation time is adjusted according to the thickness of the ice flower texture: 30-60 minutes for a thickness of 50-100μm, and 60-120 minutes for a thickness of 100-200μm.

[0098] During the hot-melting process, the water glass powder reacts chemically with the glass substrate: Na₂O・nSiO₂ + SiO₂ (glass substrate) → (n+1)SiO₂ + Na₂O, forming stable siloxane chemical bonds (Si-O-Si), achieving in-situ fusion of the ice flower texture layer and the glass substrate, significantly improving the bonding strength. The hot-melting temperature must be strictly controlled: at temperatures < 500℃, the water glass powder is not completely melted, and the interlayer bonding strength is < 1.0 MPa; at temperatures > 700℃, the glass substrate begins to soften and deform (float glass softening point ≥ 720℃), leading to a decrease in flatness (flatness > 0.2 mm / m).

[0099] After hot melting is complete, turn off the power to the hot melting furnace and allow it to cool naturally to room temperature (cooling rate 5-10℃ / h) to avoid thermal stress cracking caused by forced cooling. After cooling, perform performance testing on the ice flower texture layer. Glass substrates with ice flower texture that pass the test are transferred to a clean warehouse for later use.

[0100] Thickness measurement: An ultrasonic thickness gauge (accuracy ±1μm) was used. Ten measurement points were randomly selected, with a thickness of 50-200μm and a single-point deviation of ≤±10%.

[0101] Combined with strength testing: using the pull-out method (GB / T14683-2017 standard), the test result is ≥1.5MPa, with no peeling phenomenon;

[0102] Microstructure detection: Observation by scanning electron microscope (SEM, magnification 500-1000x) shows that the ice flower texture is a dendritic or plate-like interwoven crystal morphology, with no obvious pores or cracks;

[0103] Appearance inspection: Visual inspection shows that the ice flower pattern is natural, smooth, and unique, with no obvious accumulation or missing material.

[0104] Step S3, Composite Molding:

[0105] Step S31: Align and bond the angle transformation pattern layer with the glass substrate with the ice flower texture layer through the intermediate adhesive layer, and place it in a hot press.

[0106] When performing bonding operations in a Class 1000 cleanroom, environmental parameters must be strictly controlled: temperature 20-25℃ (temperature difference ≤ ±2℃), relative humidity ≤ 40% (humidity fluctuation ≤ ±5%), and the number of airborne particles > 5μm ≤ 10 particles / m³ to prevent dust, moisture, and other impurities from affecting the bonding quality between layers. The cleanroom's air purification system and temperature and humidity control devices must be turned on 30 minutes before bonding to ensure stable and compliant environmental parameters.

[0107] The operation process is as follows:

[0108] Material pretreatment: Remove the angle-changing pattern layer and the glass substrate with ice flower texture from the drying oven and let them stand on a clean workbench for 30 minutes to make their temperature match the ambient temperature (temperature difference ≤ ±1℃) to prevent water vapor in the air from condensing on the material surface due to temperature difference and forming interface bubbles.

[0109] Intermediate adhesive layer cutting: Cut the EVA film or PVB film according to the size of the glass substrate. The cutting size is 5-10mm larger than the edge of the glass substrate to leave a margin for edge compaction - to avoid the risk of peeling due to insufficient adhesive at the edge after bonding, and at the same time to provide operating space for subsequent edge trimming processes.

[0110] Bonding sequence and alignment: Bond the glass substrate in the following order from top to bottom: "Frost pattern layer (glass substrate) → Intermediate adhesive layer → Angle change pattern layer → Temporary protective film". Place the glass substrate with the frost pattern horizontally on a clean workbench with the frost pattern layer facing upwards; evenly lay the intermediate adhesive layer, ensuring that the adhesive film completely covers the surface of the glass substrate without any offset or wrinkles; align the patterned side of the angle change pattern layer with the intermediate adhesive layer, and precisely align it with the glass substrate using positioning pins, with an edge deviation of ≤±2mm, ensuring that the spatial position of the pattern and the frost pattern matches (e.g., the layering of the landscape pattern and the frost pattern is coordinated); finally, cover the surface of the angle change pattern layer with a PE temporary protective film (20μm thick) to prevent the pattern layer from being scratched during subsequent handling.

[0111] Interlayer air removal: Use a silicone roller (hardness 60-70HA, surface roughness Ra≤0.1μm) to uniformly roll from the center of the composite preform outwards at a speed of 5-10cm / s, applying a pressure of 0.1-0.2MPa, and repeat the rolling process twice. During rolling, ensure that the roller is in complete contact with the material surface to gradually remove interlayer air and avoid residual air bubbles. If local air bubbles are found, gently puncture them with a needle and then perform a second rolling to remove air, ensuring that the residual interlayer air rate is ≤0.05%.

[0112] Step S32: Increase the temperature to 450-650℃ at a heating rate of 3-5℃ / min, apply a pressure of 0.3-0.8MPa, and hold for 60-180min;

[0113] Place the laminated preform evenly into the center of the heating plate of the VHB-1600 vacuum hot press, ensuring the preform is centered and at least 5cm away from the edge of the heating plate to avoid uneven edge temperature leading to variations in composite quality. The hot press process parameters should be precisely controlled in the following stages:

[0114] Process Stage Operating parameters Control Target Technical Principles Vacuum phase Vacuum degree ≤ -0.09MPa, evacuation time 10-20min Completely remove interlayer air, with a residual bubble rate of ≤0.1%. By applying negative pressure, air is extracted from the tiny gaps between the layers, preventing air from expanding due to heat and forming bubble defects during the hot-melt process. warming phase Heating rate 3-5℃ / min, to 450-650℃ The intermediate adhesive layer melts uniformly, and the temperature of each layer rises synchronously. Slow heating avoids the concentration of thermal stress between layers, while ensuring that the EVA / PVB film melts gradually to prevent localized overheating and film degradation. Pressurization phase Once the temperature reaches the set value, apply a pressure of 0.3-0.8 MPa. The layers are tightly bonded and fully adhered. The pressure is adjusted according to the total composite thickness: 0.3-0.5 MPa when the total thickness is ≤10 mm, and 0.5-0.8 MPa when the total thickness is >10 mm, to ensure that the adhesive film fully wets the surface of each layer. Insulation stage Maintain stable temperature, pressure, and vacuum levels for 60-180 minutes. Sufficient chemical bonding and physical entanglement, with interlayer bond strength ≥1.5MPa. During the heat preservation process, the molecular chains of the EVA / PVB film diffuse to the surface of the angle-changing pattern layer and the siloxane network of the ice flower texture layer, forming physical entanglement; at the same time, the polar groups in the film chemically adsorb the hydroxyl groups (-OH) of the ice flower texture layer, further enhancing the interfacial adhesion.

[0115] Basis for selecting process parameters:

[0116] The vacuum level is set to ≤-0.09MPa: If the vacuum level is insufficient (>-0.09MPa), the interlayer air cannot be completely expelled, and bubbles with a diameter ≥0.1mm are easily formed after hot melting, affecting the light transmittance and appearance; if the vacuum level is too high (<-0.1MPa), it may cause deformation of thin films (≤25μm);

[0117] Heating rate 3-5℃ / min: Too fast a rate (>5℃ / min) will cause thermal stress due to the difference in thermal expansion coefficients between the glass substrate and the film and adhesive film, which may cause cracking of the ice flower texture layer or warping of the angle change pattern layer; too slow a rate (<3℃ / min) will prolong the production cycle and increase energy consumption.

[0118] Hot melt temperature 450-650℃: This temperature range ensures that the EVA / PVB film melts completely (EVA melting point 70-90℃, PVB melting point 150-180℃), while avoiding softening and deformation of the glass substrate (float glass softening point ≥720℃). At the same time, it will not cause degradation of the PC / PET film of the angle transformation pattern layer (PC heat distortion temperature ≥130℃, PET heat distortion temperature ≥80℃, and the film has a heat insulation effect, so the actual temperature of the pattern layer is ≤100℃).

[0119] Insulation time 60-180min: Adjust according to the total thickness of the composite. The thicker the composite, the longer the insulation time. This ensures sufficient diffusion between the adhesive film and each functional layer, and avoids low bonding strength due to insufficient insulation.

[0120] Process monitoring:

[0121] During the hot melt lamination process, the temperature, pressure, and vacuum data are recorded in real time by the hot press's monitoring system, with data collected every 10 minutes to generate a process curve. If any parameters deviate from the set range (temperature fluctuation > ±5℃, pressure fluctuation > ±0.05MPa, vacuum fluctuation > ±0.005MPa), the system automatically alarms and adjusts to ensure process stability.

[0122] Step S33: Cool to room temperature at a cooling rate of 2-4℃ / min, cut and trim to obtain decorative glass with a pattern that changes with the viewing angle;

[0123] After the heat preservation stage, start the cooling system of the hot press and cool to room temperature (20-25℃) at a rate of 2-4℃ / min. During the cooling process, maintain a vacuum level of ≤-0.08MPa until the temperature drops below 100℃, then release the vacuum—this prevents air from re-entering the interlayer space during cooling and reduces interlayer thermal stress.

[0124] Too rapid cooling rate (>4℃ / min): The difference in thermal shrinkage rate between interlayer materials is too large, which leads to thermal stress concentration and may cause cracking of the ice flower texture layer, interlayer delamination or glass substrate breakage.

[0125] Slow cooling rate (<2℃ / min): Prolongs production cycle and may lead to excessive crystallization of the film, affecting light transmittance and bonding toughness.

[0126] After cooling to room temperature, open the hot press chamber door, remove the composite glass, and proceed with the following post-processing steps:

[0127] Trimming and edge trimming: A CNC glass cutter (cutting accuracy ±0.1mm) is used to remove excess intermediate adhesive layer and temporary protective film from the edges. The trimmed glass edges are smooth and burr-free, with a dimensional deviation of ≤±3mm, which meets the product design requirements.

[0128] Edge grinding and polishing: The edges of the cut glass are ground and polished in a gradient: first, 400-grit sandpaper is used to remove the cutting burrs, then 800-grit sandpaper is used to grind them smooth, and finally 1200-grit sandpaper is used to polish them so that the edge roughness Ra≤0.3μm, eliminating stress concentration on sharp edges - avoiding breakage caused by external impact during use, and improving the product's aesthetics at the same time.

[0129] Cleaning and Drying: Place the composite glass into a fully automatic glass cleaning machine and follow the cleaning process of "neutral cleaning agent spraying → deionized water rinsing → high-pressure air knife drying".

[0130] Neutral cleaning agent: pH 7-8, phosphorus-free and fluorine-free, to avoid corroding the ice flower texture layer and pattern layer;

[0131] Deionized water: conductivity ≤10μS / cm, rinsing pressure 0.2-0.3MPa, ensuring no cleaning agent residue on the surface;

[0132] High-pressure air knife: wind speed ≥30m / s, wind temperature 60-80℃, after drying the glass surface moisture content ≤0.01g / m², no watermarks, no stains;

[0133] Finished product quality inspection: All items shall be inspected according to the following standards, and only qualified products may be packaged and put into storage:

[0134] Testing items Detection methods Qualification Standard Appearance quality Visual inspection under strong light with an illuminance of ≥5000 lux, using a 50x magnifying glass. No air bubbles (air bubble diameter ≤ 0.1mm and number ≤ 3 / m²), no scratches (scratch length ≤ 0.5mm and number ≤ 2 / m²), no interlayer peeling, complete ice flower texture, and clear pattern. Dimensional deviation A steel tape measure (accuracy ±1mm) is used to measure side lengths, and a vernier caliper (accuracy ±0.01mm) is used to measure thickness. Side length deviation ≤ ±3mm, total thickness deviation ≤ ±0.5mm (design thickness 4-20mm) Light transmittance Lambda 950 UV / Vis / NIR spectrophotometer, 380-780nm wavelength ≥85% interlayer bond strength Pull-out method (GB / T14683-2017), sample size 50mm×50mm ≥1.5MPa, failure mode is cohesive failure of the film (non-interfacial peeling). Impact resistance Drop ball impact test (GB / T9962-2016): A 1kg steel ball is dropped freely from a height of 1m. No cracks, no peeling Pattern Transformation Effect Manual observation, with an observation angle of 0-180°, and records taken every 15°. Pattern switching is smooth, without lag, overlap, or blur, and the transformation range covers 0-180°. Weather resistance High and low temperature cycling test: -40℃ (4h) → room temperature (2h) → 80℃ (4h), 50 cycles. No cracks, no peeling, no discoloration; light transmittance retention ≥95%; bond strength retention ≥90%. Ice flower texture durability Abrasion resistance test (GB / T1768-2006): 100 cycles of friction with a CS-10 grinding wheel under a load of 500g. The ice flower texture shows no peeling or wear, and the surface roughness variation is ≤±20%.

[0135] To further verify the technical effects of the present invention, three specific embodiments are provided below, along with one comparative example (existing technology product). The parameters and test results for each example are as follows:

[0136] Example 1 (Standard parameter scheme, suitable for home decoration)

[0137] Structural parameters Specific values Glass substrate Float glass, 5mm thick, 91% light transmittance. Angle Transformation Pattern Layer PET film (50μm thickness, 93% light transmittance), circular pattern units (1mm size), two sets of patterns misaligned by 0.5mm. Intermediate adhesive layer EVA film (thickness 0.76mm, VA content 30%, light transmittance 92%) Ice flower texture layer Water glass powder (modulus 3.0, particle size 30μm), dosage 10g / m², application method: spraying.

[0138] process parameters Specific values Laser engraving Power 20W, speed 100mm / s, spot diameter 0.05mm, engraving depth 35μm (70% of film thickness). Ice flower texture preparation Freezing temperature -10℃, freezing time 12h, freezing humidity 40%; air drying time 24h; hot melt temperature 600℃, heating rate 8℃ / min, holding time 60min. Composite molding Vacuum degree -0.095MPa, hot melt temperature 550℃, pressure 0.5MPa, holding time 120min, heating rate 4℃ / min, cooling rate 3℃ / min Product performance test results Specific values Total thickness 6.31mm Light transmittance 88.5% interlayer bond strength 1.8MPa Impact resistance 58kJ / m² Pattern Transformation Effect The 0-180° transition is smooth, switching from "landscape outline" to "landscape details" with visual continuity. Ice flower texture Dendritic crystals with unique texture and no shedding. Weather resistance (50 cycles of high and low temperatures) No cracks, no peeling, light transmittance 87.2% (retention rate 98.5%) Yield 95%

[0139] Example 2 (Fine-density ice flower texture scheme, suitable for art decoration)

[0140] Structural parameters Specific values Glass substrate Float glass, 8mm thick, 90.5% light transmittance. Angle Transformation Pattern Layer PC film (25μm thickness, 92% light transmittance), diamond pattern units (0.5mm size), misalignment of two sets of patterns 0.2mm. Intermediate adhesive layer PVB film (thickness 0.38mm, degree of acetylation 86%, light transmittance 93%) Ice flower texture layer Water glass powder (modulus 2.8, particle size 15μm), dosage 8g / m², spreading method: sieve spreading method.

[0141] Example 3

[0142] process parameters Specific values Laser engraving Power 15W, speed 80mm / s, spot diameter 0.03mm, engraving depth 10μm (40% of film thickness). Ice flower texture preparation Freezing temperature -18℃, freezing time 10h, freezing humidity 35%; air drying time 18h; heat melt temperature 550℃, heating rate 6℃ / min, holding time 45min Composite molding Vacuum degree -0.098MPa, hot melt temperature 500℃, pressure 0.4MPa, holding time 90min, heating rate 3℃ / min, cooling rate 2℃ / min

[0143] Product performance test results Specific values Total thickness 8.79mm Light transmittance 89.2% interlayer bond strength 1.6MPa Impact resistance 62kJ / m² Pattern Transformation Effect The 0-180° transition is smooth, switching between "flower outline" and "petal texture" with clear details. Ice flower texture Tiny, dense, flaky crystals, unique in appearance, with a translucent texture. Weather resistance (50 cycles of high and low temperatures) none

[0144] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A decorative glass with a pattern that changes depending on the viewing angle, characterized in that, It consists of the following layers, which are laminated from top to bottom: ice flower texture layer, intermediate adhesive layer, angle change pattern layer, and glass substrate; The angle transformation pattern layer is composed of at least two sets of staggered geometric pattern units, wherein the geometric shape is selected from one or more combinations of circles, ellipses, rhombuses, and polygons. The ice flower texture layer is a natural ice flower structure layer formed by water glass powder through freeze-thaw and hot-melt processes, with a thickness of 50-200μm.

2. The decorative glass with a pattern that changes with the viewing angle according to claim 1, characterized in that, The substrate of the angle-changing pattern layer is a polycarbonate film or a polyethylene terephthalate film with a thickness of 25-100 μm. The size of the pattern unit is 0.1-5 mm, and the misalignment between two adjacent groups of pattern units is 0.05-2 mm.

3. The decorative glass with a pattern that changes with the viewing angle according to claim 1, characterized in that, The intermediate adhesive layer is an ethylene-vinyl acetate copolymer film or a polyvinyl butyral film with a thickness of 0.38-1.52 mm.

4. The decorative glass with a pattern that changes with the viewing angle according to claim 1, characterized in that, The modulus of the water glass powder is 2.8-3.2, the particle size is 10-50μm, and the amount of water glass powder used in the ice flower texture layer is 5-20g / m².

5. A decorative glass with a pattern that changes with the viewing angle according to any one of claims 1-4, characterized in that, The total thickness of the decorative glass is 4-20mm, the pattern transformation angle range is 0-180°, and the microstructure of the ice flower texture is a dendritic or plate-like interwoven crystal form.

6. A manufacturing process for decorative glass with patterns that change depending on the viewing angle, characterized in that, Includes the following steps: Step S1: Preparation of the angle transformation pattern layer: Step S11, Substrate pretreatment: Select high-transmittance PC film or PET film as the substrate, and clean and dry it; Step S12, First group of pattern engraving: Use a laser engraving machine to engrave the first group of geometric pattern units on the surface of the substrate, with an engraving depth of 30-70% of the substrate thickness; Step S13, second set of pattern engraving: a layer of light-transmitting protective film is laminated on the surface of the engraved substrate, and then the substrate is flipped over and the second set of geometric pattern units is engraved on the other side. The misalignment between the second set of pattern units and the first set of pattern units is 0.05-2mm. Step S14: Remove the protective film to obtain the angle transformation pattern layer; Step S2, Preparation of the ice flower texture layer: Step S21: Prepare water glass powder suspension: Mix water glass powder with a modulus of 2.8-3.2 with deionized water at a mass ratio of 1:0.8-1.2, stir evenly, and let stand for 10-30 minutes to remove bubbles; Step S22, Glass substrate pretreatment: Select float glass with a thickness of 3-12mm, clean and dry it, and then cool it to room temperature; Step S23, Spreading and Freezing: Spread the water glass powder suspension evenly on the surface of the pretreated glass substrate at a rate of 5-20 g / m², and then freeze it in a low temperature environment of -5℃ to -20℃ for 8-24 hours to form ice flower crystals. Step S24, Air Drying and Hot Melting: Move the frozen glass substrate to a cool and ventilated place and air dry for 12-36 hours at a humidity of 40-60% and a temperature of 15-25℃. Then put it into a hot melting furnace and heat it to 500-700℃ at a heating rate of 5-10℃ / min. Hold it at that temperature for 30-120 minutes and let it cool naturally to room temperature to obtain a glass substrate with an ice flower texture layer. Step S3, Composite Molding: Step S31: Align and bond the angle transformation pattern layer with the glass substrate with the ice flower texture layer through the intermediate adhesive layer, and place it in a hot press. Step S32: Increase the temperature to 450-650℃ at a heating rate of 3-5℃ / min, apply a pressure of 0.3-0.8MPa, and hold for 60-180min; Step S33: Cool to room temperature at a cooling rate of 2-4℃ / min, cut and trim to obtain decorative glass with a pattern that changes with the viewing angle.

7. The manufacturing process of decorative glass with a pattern that changes with the viewing angle according to claim 6, characterized in that, In step S12, the laser engraving power of the laser engraving machine is 10-30W, the engraving speed is 50-200mm / s, and the spot diameter is 0.01-0.1mm.

8. The manufacturing process of decorative glass with a pattern that changes with the viewing angle according to claim 6, characterized in that, The water glass powder suspension in step S23 is spread using one or more of the following methods: spraying, sieve spreading, or scraper coating.

9. The manufacturing process of decorative glass with a pattern that changes with the viewing angle according to claim 6, characterized in that, In step S23, the humidity of the freezing environment is controlled at 30-50% to prevent condensation from forming on the surface of the ice flower crystals.

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