Frit for promoting color development of automobile glass ink as well as preparation method and application of frit

Abstract

The invention relates to the field of glass decoration, and provides a frit for promoting color development of black automobile glass ink, which is prepared from the following raw materials in percentage by mass: 28%-35% of bismuth oxide (Bi2O3), 20%-26% of boric oxide (B2O3), 18%-24% of silicon oxide (SiO2), 4%-7% of lithium carbonate (Li2CO3), 4%-7% of sodium carbonate (Na2CO3) and 6%-11% of zinc oxide (ZnO). The frit is an important component material of automotive glass ink. The prepared frit can promote the color development of the inorganic pigment copper chromium black, solves the problem of incorrect color hue of black color development, has a large melting temperature range, and can firmly connect the pigment and a glass substrate. The black automobile glass ink prepared from the frit belongs to high-temperature inorganic glass ink and can print clear patterns and trademarks on automobile glass.

Description

[Technical Field]

[0001] This invention relates to the field of glass decoration, and the invention prepares a frit that promotes the color development of black automotive glass ink, which is an important component of automotive glass ink. [Background Technology]

[0002] In the field of decorative and functional processing of automotive glass, glass ink printing technology, with its advantage of precise printhead positioning, can achieve pattern forming with micron-level precision. Compared with traditional screen printing technology, it offers significant improvements in both precision and production efficiency, and can meet personalized customization needs, gradually becoming the mainstream process. The core component of glass ink is frit, which is ground into nanoscale particles (average particle size ≤400nm) using a sand mill. These nanoscale particles differ significantly in physicochemical properties from the micron-sized frit (particle size 1-10μm) used in traditional screen printing, making it difficult for existing printing ink frits to be adapted to nanoscale ink systems. Specific technical bottlenecks are as follows:

[0003] 1. The challenge of color development control in nanoscale frits;

[0004] Traditional frit formulations are designed for micron-sized particles, whose surface activity and dispersibility differ fundamentally from those of nano-sized particles. When frit is ground to the nanoscale, the specific surface area increases dramatically (≥10m²). 2 / g), the number of surface unsaturated bonds increases dramatically, leading to changes in the interfacial interaction with copper chromium black pigment: on the one hand, the coating efficiency of the nano-fuse on copper chromium black is improved, but excessive surface hydroxyl groups easily react with Cr in the pigment. 3+ Cu 2+ The formation of coordinate bonds hinders the transition of valence states, causing a shift in black hue (such as a brownish or grayish tint), and the color brightness (L* value) fluctuates by more than 20%, failing to meet the stringent requirements for black purity in automotive glass. On the other hand, the dispersion stability of nano-fuse in ink depends on specific surface modification. Existing formulations have not been optimized for surface energy matching at the nanoscale, leading to fuse agglomeration during the color development process and the formation of local color differences.

[0005] 2. Insufficient bonding strength over a wide temperature range;

[0006] The tempering process for automotive glass requires the frit to melt rapidly within the range of 580-620℃ and form a chemical bond with the glass substrate. Traditional frits have a narrow melting temperature range (≤30℃), and after nano-sizing, the dispersion of their softening point distribution increases (±15℃). As a result, during the tempering holding stage (usually 10-15 minutes), the frit cannot melt uniformly and spread between the nano-sized copper chromium black particles and the glass substrate. Only mechanical interlocking is formed at the interface, rather than Si-O-Bi covalent bonding. The tensile bond strength is ≤5MPa, far below the requirements for automotive glass (≥8MPa). Pattern peeling is prone to occur after long-term vibration or temperature cycling.

[0007] 3. Bottlenecks in the production efficiency of traditional printing technology;

[0008] Traditional screen printing relies on contact transfer via a screen, which has the following inherent drawbacks:

[0009] Pattern precision is limited: Due to the screen mesh count (maximum 200dpi), it is difficult to print complex curved surfaces or fine markings;

[0010] Time-consuming changeover: Each time a pattern is changed, a new screen printing plate needs to be made, and the sampling cycle can take up to 24 hours, which cannot be adapted to small-batch, multi-variety production.

[0011] Material waste: The residual ink on the screen accounts for more than 15%, and cleaning the screen generates a large amount of wastewater.

[0012] 4. Lack of full lifecycle traceability function;

[0013] Current traceability markings on automotive glass rely on post-application or laser etching, which presents the following problems:

[0014] Labeling solution: Labels are susceptible to environmental corrosion (such as ultraviolet rays and moisture) and have a lifespan of only 2-3 years, which cannot cover the more than 10-year service life of automotive glass;

[0015] Laser etching: can only form shallow markings on the glass surface, is not strong enough and damages the integrity of the glass, and is not suitable for load-bearing areas.

[0016] Traditional frit systems are not compatible with the embedding process for traceable markings, and cannot simultaneously form weather resistance markings during the tempering process, resulting in a data gap throughout the entire process of automotive glass production and after-sales service. [Summary of the Invention]

[0017] The purpose of this invention is to overcome the shortcomings of the prior art and provide a frit that promotes the color development of black automotive glass ink. This frit is an important component of automotive glass ink. The prepared frit can promote the color development of inorganic pigment copper chromium black, solving the problem of inaccurate black color tone. Simultaneously, the frit has a wide melting temperature range, enabling a strong bond between the pigment and the glass substrate. The black automotive glass ink prepared from this frit is a high-temperature inorganic glass ink, capable of printing clear patterns and logos on automotive glass.

[0018] This invention discloses a frit for automotive glass ink, the raw material composition of which is as follows by mass percentage:

[0019] Bismuth oxide (Bi2O3): 28%-35%, boron oxide (B2O3): 20%-26%, silicon oxide (SiO2): 18%-24%, lithium carbonate (Li2CO3): 4%-7%, sodium carbonate (Na2CO3): 4%-7%, and zinc oxide (ZnO): 6%-11%.

[0020] Method for preparing frit:

[0021] Step 1, Raw material pretreatment: Crush each raw material to a particle size ≤100μm, weigh them according to the ratio and put them into a planetary mixer, mix at 300r / min for 60 minutes to obtain a uniform mixed powder;

[0022] Step 2, High-temperature melting: Put the mixed powder into a corundum crucible, place it in a resistance furnace, heat it to 900-1200℃ at 10℃ / min, and hold it for 0.5 hours until it is completely melted;

[0023] Step 3, quenching and granulation: Pour the molten liquid into deionized water for water quenching to form glassy particles with a particle size of 0.5-2mm;

[0024] Step 4, Drying and Sieving: The granules are dried at 120℃ for 3 hours and then passed through an 80-mesh sieve.

[0025] The target molten metal is obtained.

[0026] A formula for a glass ink,

[0027] By weight percentage, the glass ink composition includes: the above-mentioned frit: 35%-45%, copper chromium black pigment: 12%-18%, dispersant (sodium polyacrylate): 2%-4%, wetting agent (polyoxyethylene alkylphenol ether): 1%-3%, thickener (hydroxyethyl cellulose): 1%-2%, solvent (deionized water: propylene glycol = 3:2, volume ratio): balance.

[0028] Glass ink preparation process,

[0029] Step 1, Solvent preparation: Mix deionized water and propylene glycol in a volume ratio and stir until homogeneous;

[0030] Step 2, Dispersion process: Add dispersant and wetting agent to solvent, stir at 800 r / min for 30 minutes, add copper chromium black pigment and the prepared glass frit powder, continue stirring for 60 minutes, and then grind the pigment particles to ≤500nm using a sand mill.

[0031] Step 3, Ink preparation: Add thinner, stir at low speed for 45 minutes, adjust the viscosity to 20-30 mPa·s, filter and obtain glass ink that can be printed by printhead.

[0032] A printing and tempering process for automotive glass.

[0033] Step 1, Substrate treatment: Use an ethanol-deionized water mixture (volume ratio 1:1) to clean the surface of the automotive glass. After drying, perform corona treatment to enhance ink affinity.

[0034] Step 2, Ink Printing: Use a piezoelectric printhead (50μm aperture) to eject ink at a pressure of 50-80kPa to form a preset pattern on the glass surface with a resolution of ≥600dpi;

[0035] Step 3, Tempering and Tracking Embedding: Place the printed glass into a tempering furnace and heat it to 600℃ at a rate of 5-10℃ / min. Hold the temperature for 10-15 minutes. The melting temperature range is 580-620℃. At the same time, print an invisible QR code containing a traceability code in the blank area of ​​the pattern. The code is visible when excited by infrared light and is bonded to the glass substrate during the tempering process.

[0036] Step 4, Cooling and Shaping: Air-cool to room temperature at a rate of 50℃ / s to form a clear and traceable pattern on the automotive glass.

[0037] Compared with existing technologies, the present invention has the following advantages:

[0038] 1. Precise color control: Bismuth oxide and zinc oxide form a composite flux system, which reduces the activation energy of copper chromium black and stabilizes the peak black wavelength at 590-610nm, solving the problem of incorrect hue. The color brightness (L value) is ≤15 and the saturation (C value) is ≥40.

[0039] 2. Wide temperature range bonding strength: Lithium carbonate and sodium carbonate work together to lower the softening point of the molten block, forming a wide melting range of 580-620℃. The molten block forms a chemical bond with the glass substrate through Si-O-Bi bonds, with a tensile bonding strength ≥8MPa.

[0040] 3. High-efficiency production adaptation: The ink viscosity and surface tension (25-30mN / m) are adapted to printhead printing, which improves production efficiency by 60% compared with traditional screen printing, and the jaggedness of the pattern edge is ≤5μm;

[0041] 4. Full lifecycle traceability: The invisible QR code embedded in the tempering process is heat resistant to ≥700℃ and can be read by special equipment, enabling full-process tracking of automotive glass from production to after-sales service.

Detailed Implementation Methods

[0042] Example 1:

[0043] Preparation and application of standard formulation frits;

[0044] Fused raw materials (mass%):

[0045] Bi2O3: 30%, B2O3: 28%, SiO2: 20%, Li2CO3: 6%, Na2CO3: 6%, ZnO: 10%;

[0046] Preparation steps:

[0047] 1. After mixing the raw materials, melt them at 1120℃ for 0.5 hours, then quench and dry them in water to obtain a molten mass;

[0048] 2. Prepare an ink with the following composition: 40% frit, 15% copper chromium black, 3% dispersant, 2% wetting agent, 1.5% thickener, and 38.5% solvent;

[0049] 3. After printing, the pattern is tempered at 600℃, resulting in a pure black color (L*=12, C*=45), a bonding strength of 8.5MPa, and a 100% accuracy rate for QR code reading.

[0050] Example 2: Optimization of high bismuth oxide ratio;

[0051] Fused raw materials (mass%):

[0052] Bi2O3: 35%, B2O3: 22%, SiO2: 23%, Li2CO3: 7%, Na2CO3: 5%, ZnO: 8%;

[0053] Performance characteristics:

[0054] With a melting onset temperature of 585℃ and a peak color wavelength of 600nm, it is suitable for rapid tempering of thin automotive glass (heating time of 10 minutes) and has a pattern edge accuracy of ±3μm.

[0055] Example 3: Low-sodium lithium ratio adaptation;

[0056] Fused raw materials (mass%):

[0057] Bi2O3: 28%, B2O3: 26%, SiO2: 24%, Li2CO3: 4%, Na2CO3: 4%, ZnO: 10%;

[0058] Performance characteristics:

[0059] Melting temperature range 590-620℃, water resistance (ISO719) ≤0.5mg / cm³ 2 Suitable for automotive glass in high humidity environments, the pattern will not change color with long-term use.

[0060] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, various changes, modifications, substitutions and variations can be made to these embodiments without departing from the technical principles of the present invention. These changes, modifications, substitutions and variations should also be considered within the protection scope of the present invention.

Claims

1. A frit for automotive glass ink, characterized in that, By mass percentage, the raw material composition includes: bismuth oxide (Bi2O3) 28%-35%, boron oxide (B2O3) 20%-26%, silicon oxide (SiO2) 18%-24%, lithium carbonate (Li2CO3) 4%-7%, sodium carbonate (Na2CO3) 4%-7%, and zinc oxide (ZnO) 6%-11%.

2. A method for preparing the frit according to claim 1, characterized in that: Includes the following steps: After the raw materials are crushed and mixed, they are melted at 900-1200℃ for 0.5 hours; the melt is then quenched with water, dried, and sieved to obtain glassy particles.

3. An automotive glass ink comprising the frit as described in claim 1, characterized in that, The composition, by mass percentage, includes: 35%-45% of the frit, 12%-18% of copper chromium black pigment, 2%-4% of dispersant, 1%-3% of wetting agent, 1%-2% of thickener, and the balance being a mixed solvent of deionized water and propylene glycol in a volume ratio of 3:

2.

4. The glass ink according to claim 3, characterized in that, The dispersant is sodium polyacrylate, the wetting agent is polyoxyethylene alkylphenol ether, and the thickener is hydroxyethyl cellulose.

5. The method of applying the glass ink of claim 3 to automotive glass, characterized in that, include: Ink is printed onto the glass surface through a printhead to form a pattern with a resolution of ≥300dpi; It is tempered within a temperature range of 580-620℃, and a traceable mark is embedded to achieve a firm bond between the pattern and the substrate and subsequent traceability.

6. The method for applying the glass ink to automotive glass according to claim 5, characterized in that, The traceable identifier is an infrared-excited visible QR code or barcode that chemically bonds with the glass substrate during the tempering process.