Laminated glass and preparation method thereof

Abstract

The invention discloses laminated glass and a preparation method thereof. According to the preparation method, before an initial pressing process, an antifouling coating is applied to at least part of the area of the surface of one side, in contact with a vacuum rubber ring or a vacuum bag, of pre-laminated glass, and a layer of protective film is formed after drying; the protective film at least completely covers a predetermined area (generally a gluing area and an edge covering area), and the predetermined area requires that the surface energy does not decline after the laminated glass is prepared; the protective film is then completely removed by washing, and the surface of the fresh glass or the black glaze layer of the glass is exposed.

Description

Technical Field

[0001] This invention relates to the field of glass manufacturing, and more specifically to a laminated glass and its manufacturing method. Background Technology

[0002] In the production of automotive laminated glass, after the inner and outer glass sheets are laminated, a preliminary pressing process involving vacuum extraction is required. This process is initially carried out at room temperature, and then heated to approximately 120°C. The extraction method typically involves using a vacuum rubber ring or vacuum bag and then drawing air through a vacuum device. The rubber ring or vacuum bag is in direct, tight contact with the glass or its black enamel layer. After removing the rubber ring or vacuum bag during the preliminary pressing process, a significant decrease in surface energy occurs in the area where the glass or enamel layer contacts the rubber ring or vacuum bag. Furthermore, organic vapors evaporating from the interlayer of the laminated glass can also contaminate the glass surface, leading to a further decrease in surface energy. This significantly increases the risk of glass failure after it is bonded to the vehicle body. Summary of the Invention

[0003] To address the above technical problems, this invention provides laminated glass and its preparation method to ensure that the surface energy of a predetermined area of ​​the laminated glass does not decrease.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention provides a method for preparing laminated glass, comprising the following steps:

[0006] An antifouling coating is applied to at least a portion of the surface of the pre-laminated glass that contacts the vacuum rubber ring or vacuum bag, and after drying, a protective film is formed; the protective film at least completely covers a predetermined area, which is required to maintain its surface energy after the laminated glass is prepared;

[0007] The glass sheets are joined together to obtain a glass assembly;

[0008] The glass assembly is fitted with a vacuum rubber ring or vacuum bag for initial pressing.

[0009] After the initial pressing process is completed, the vacuum rubber ring or vacuum bag is removed, and the glass assembly is sent into the autoclave to complete the high-pressure process.

[0010] After the high-pressure process is completed, the protective film on the glass assembly is washed away.

[0011] According to the preparation method of the present invention, preferably, the surface energy of the predetermined region is required to be ≥40 mJ / m 2 .

[0012] The predetermined area requires high surface energy and is typically the area for applying adhesive to bond the laminated glass to other components (such as the vehicle body), as well as the edge-sealing area. The adhesive application area is a pre-defined area for applying adhesive to fix the laminated glass to other components (such as the vehicle body), and the adhesive used is generally polyurethane adhesive. The edge-sealing area is the area that needs to be injection-molded with polyvinyl chloride (PVC) or polyurethane (PU) for edging.

[0013] In the production of laminated glass, the initial pressing process generally involves two methods: one is to use vacuum rubber rings to evacuate air from the laminated glass assembly and then heat it; the other is to enclose the entire glass assembly in a vacuum bag, evacuate air, and then heat it. In the first method, the vacuum rubber rings only contact the edges of the glass; in the second method, the vacuum bag contacts the entire glass surface. For windshields, the sealing area is usually at the four edges of the glass, while for sunroofs it is usually further inside the edges. Sunroofs generally require edge sealing, while windshields do not. The edge sealing area is usually at the four edges of the glass, but can extend to a larger area.

[0014] There are always areas for applying adhesive or edge binding around the glass edges. Using the first initial pressing method will result in contact with the vacuum rubber ring, while using the second initial pressing method will result in contact with the vacuum bag. Therefore, regardless of whether a vacuum rubber ring or a vacuum bag is used, the protective film must at least cover the predetermined area (usually the adhesive and edge binding areas). In a preferred embodiment, the protective film is only applied to the predetermined area, and at non-glass edges, the edge of the protective film extends 0-10 cm beyond the edge of the predetermined area.

[0015] In another preferred embodiment, when a vacuum rubber ring is used in the initial pressing process, the protective film completely covers the contact area between the pre-laminated glass and the vacuum rubber ring; and

[0016] When the predetermined area is completely located within the contact area, at the non-glass edge, the edge of the protective film extends 0-10 cm beyond the edge of the contact area;

[0017] When the predetermined area extends beyond the contact area, the protective film still completely covers the predetermined area, and at the non-glass edge, the edge of the protective film extends 0-10 cm beyond the edge of the predetermined area.

[0018] In another preferred embodiment, the protective film completely covers the surface of the pre-laminated glass that is in contact with the vacuum rubber ring or vacuum bag. Whether a vacuum rubber ring or vacuum bag is used, because the protective film is ultimately washable and removable, it can directly cover the entire surface of the glass that is in contact with the vacuum rubber ring or vacuum bag.

[0019] When the surface of the pre-laminated glass in contact with the vacuum rubber ring or vacuum bag has a black glaze layer, in the above scheme, if the protective film and the black glaze layer overlap, the protective film can be formed on top of the black glaze layer. The black glaze layer is formed by ink.

[0020] According to the preparation method of the present invention, preferably, the antifouling coating comprises: 92-99.5 parts by weight of solvent and 0.5-8 parts by weight of water-soluble polymer; the water-soluble polymer is resistant to temperatures above 140°C and does not undergo cracking or softening.

[0021] When the content of the water-soluble polymer is higher than 8 parts by mass, the drying and film-forming speed will be slow, and the final washing and removal will be slower; when the concentration is lower than 0.5 parts by mass, the protective film formed will be too thin, and the anti-fouling performance will be reduced.

[0022] According to the preparation method of the present invention, preferably, the water-soluble polymer is selected from at least one of natural water-soluble polymers and synthetic water-soluble polymers; the natural water-soluble polymers include carboxymethyl cellulose and carboxymethyl chitosan; the synthetic water-soluble polymers include polyacrylamide (PAM) and its derivatives, polyvinylpyrrolidone, polyvinyl alcohol, sodium polyacrylate, and sodium poly(4-styrene sulfonate). The polyacrylamide (PAM) derivatives include anionic polyacrylamide, cationic polyacrylamide, and nonionic polyacrylamide.

[0023] More preferably, the degree of polymerization N of the water-soluble polymer satisfies: 200≤N≤20000; a suitable degree of polymerization can ensure that the coating forms a film after drying, thus providing a protective effect, and can also allow the protective film to be washed off quickly, meeting the requirements of rapid production.

[0024] According to the preparation method of the present invention, preferably, the solvent is selected from at least one of deionized water, ethanol, ethylene glycol, methanol, and isopropanol. More preferably, the solvent contains at least one of ethanol, methanol, and isopropanol to increase the drying rate and reduce the surface tension of the coating to promote its spreading.

[0025] According to the preparation method of the present invention, preferably, the antifouling coating further includes 0.01 to 0.05 parts by weight of a surfactant, which can promote the removal of contaminants from the surface of glass or glass black glaze, thereby increasing the surface energy.

[0026] More preferably, the surfactant is selected from at least one of fatty acid polyoxyethylene ester, coconut oil fatty acid diethanolamide, fatty alcohol polyoxyethylene ether, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium secondary alkyl sulfonate, dodecyl betaine, olive oil extract, and tea polyphenols.

[0027] According to the preparation method of the present invention, preferably, the thickness of the protective film is 0.01~3μm, more preferably 0.3~3μm.

[0028] According to the preparation method of the present invention, preferably, the initial pressing process includes: putting a vacuum rubber ring or vacuum bag over the glass assembly to evacuate the air, gradually raising the temperature to 110°C~125°C, and evacuating the vacuum to below 0.95 bar.

[0029] According to the preparation method of the present invention, preferably, the temperature of the high-pressure process is 125℃~140℃, the holding time is 0.5 h~1.5 h, and the pressure is greater than 1.2~1.5 MPa.

[0030] According to the preparation method of the present invention, preferably, after the high-pressure process, the protective film is removed by washing with water. For example, the glass assembly is sent to a spray washing machine for washing to remove the protective film.

[0031] According to the preparation method of the present invention, preferably, the antifouling coating is applied by wiping or spraying.

[0032] According to the preparation method of the present invention, preferably, the drying is accelerated by using a fan or an infrared lamp to evaporate the solvent.

[0033] The antifouling coating of this invention does not contain crosslinking agents. It relies on the strong intermolecular forces within the water-soluble polymer to form a film, enabling the coating to form a dense film layer that protects against pollutants. The polymer has a degree of polymerization N satisfying 200 ≤ N ≤ 20000, ensuring that the coating has low surface tension, allowing it to spread on glass to form a protective film layer, and that the film layer can be quickly washed away with water.

[0034] In another aspect, the present invention provides laminated glass obtained by any of the above-described preparation methods.

[0035] The key to this invention lies in applying an anti-fouling coating to at least a predetermined area of ​​the surface of the pre-laminated glass that contacts the vacuum rubber ring or vacuum bag before the initial pressing process, forming a protective film. This film is then removed by washing after preparation. Therefore, the protective film can at least temporarily protect the predetermined area from contamination during preparation, ensuring that its surface energy does not decrease. This provides reliable adhesion when later bonding the glass to the vehicle body or other components through this predetermined area. Detailed Implementation

[0036] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0037] Example 1:

[0038] This embodiment provides a method for preparing laminated glass:

[0039] 1) Apply the prepared antifouling coating to the pre-laminated glass surface by spraying.

[0040] The composition of the antifouling coating is as follows: 95 parts by weight of solvent (1:1 deionized water and anhydrous ethanol), 1 part by weight of sodium poly(4-styrene sulfonate) (degree of polymerization 1 ± 0.1 million), and 4 parts by weight of polyacrylamide (PAM, degree of polymerization 1 ± 0.1 million) water-soluble polymer.

[0041] 2) The solvent evaporation is accelerated by a fan or infrared lamp, and the thickness of the dry film after evaporation is between 0.8 micrometers and 1.2 micrometers.

[0042] 3) Initial pressing process: The glass is assembled, then a vacuum rubber ring is put on, and after evacuation at room temperature, it is heated to 115℃ and evacuated to less than 0.95 bar.

[0043] 4) After the initial pressing process is completed, remove the vacuum rubber ring and send it into the autoclave to complete the high-pressure process. The high-pressure temperature is 125℃, the time is 0.5h, and the pressure is 1.2MPa.

[0044] 5) After being subjected to high pressure, the glass is sent to a spray washing machine to wash and remove the protective film.

[0045] Record the drying time and cleaning removal time, and measure the surface energy of the glass.

[0046] Example 2:

[0047] This embodiment provides a method for preparing laminated glass:

[0048] 1) Apply the prepared antifouling coating to the black glaze layer on the pre-laminated glass by spraying.

[0049] The composition of the antifouling coating is: 96 parts by weight of solvent (4:6 ratio of deionized water and methanol), 0.5 parts by weight of carboxymethyl chitosan (degree of polymerization 200~500), and 3.5 parts by weight of polyvinylpyrrolidone water-soluble polymer (degree of polymerization 200~500).

[0050] 2) The solvent evaporation is accelerated by using a fan or infrared lamp, and the thickness of the dried film after evaporation is between 0.5 micrometers and 1 micrometer;

[0051] 3) Next, the glass is subjected to the initial pressing process: the glass is assembled, then a vacuum bag is placed on it, the air is extracted at room temperature, and then heated to 120°C and the air is extracted to less than 0.95 bar.

[0052] 4) After the initial pressing process is completed, remove the vacuum bag and send it into the autoclave to complete the high-pressure process. The high-pressure temperature is 125℃, the time is 0.5h, and the pressure is 1.2MPa.

[0053] 5) After being subjected to high pressure, the glass is sent to a spray washing machine to wash and remove the protective film.

[0054] Record the drying time and cleaning removal time, and measure the surface energy of the black glaze layer.

[0055] Example 3:

[0056] This embodiment provides a method for preparing laminated glass:

[0057] 1) Apply the prepared antifouling coating to the black glaze layer on the pre-laminated glass by spraying.

[0058] The composition of the antifouling coating is as follows: 96.45 parts by weight of solvent (3:7 ratio of deionized water and anhydrous ethanol), 3.5 parts by weight of sodium polyacrylate water-soluble polymer (degree of polymerization 2000~3000), and 0.05 parts by weight of coconut oil fatty acid diethanolamide.

[0059] 2) The solvent evaporation is accelerated by a fan or infrared lamp, and the thickness of the dry film after evaporation is between 0.3 micrometers and 0.6 micrometers.

[0060] 3) Next, the glass is subjected to the initial pressing process: the glass is assembled, then a vacuum rubber ring is put on, the air is evacuated at room temperature, and then heated to 120°C and the air is evacuated to less than 0.95 bar.

[0061] 4) After the initial pressing process is completed, remove the vacuum rubber ring and send it into the autoclave to complete the high-pressure process. The high-pressure temperature is 140℃, the time is 0.5h, and the pressure is 1.2MPa.

[0062] 5) After being subjected to high pressure, the glass is sent to a spray washing machine to wash and remove the protective film.

[0063] Record the drying time and cleaning removal time, and measure the surface energy of the black glaze layer.

[0064] Example 4:

[0065] This embodiment provides a method for preparing laminated glass:

[0066] 1) Apply the prepared antifouling coating to the black glaze layer on the pre-laminated glass by spraying.

[0067] The composition of the antifouling coating is as follows: 97.45 parts by weight of solvent (2:8 ratio of deionized water and anhydrous ethanol), 2.5 parts by weight of polyvinyl alcohol water-soluble polymer (degree of polymerization 5000~6000), and 0.05 parts by weight of dodecyl betaine.

[0068] 2) The solvent evaporation is accelerated by a fan or infrared lamp, and the thickness of the dry film after evaporation is between 1 micrometer and 2 micrometers.

[0069] 3) Next, the glass is subjected to the initial pressing process: the glass is assembled, then a vacuum bag is placed on it, the air is extracted at room temperature, and then heated to 125°C to continue evacuating until the pressure is less than 0.95 bar.

[0070] 4) After the initial pressing process is completed, remove the vacuum bag and send it into the autoclave to complete the high-pressure process. The high-pressure temperature is 135℃, the time is 1 hour, and the pressure is 1.2MPa.

[0071] 5) After being subjected to high pressure, the glass is sent to a spray washing machine to wash and remove the protective film.

[0072] Record the drying time and cleaning removal time, and measure the surface energy of the black glaze layer.

[0073] Comparative Example 1:

[0074] Compared with Example 4, there is no coating. The glass is directly subjected to the initial pressing process, high pressure process and washing process of the above examples, and the surface energy of the black glaze layer is measured.

[0075] The experimental results obtained from the above embodiments and comparative examples are shown in Table 1 below.

[0076] Table 1. Experimental results obtained from the examples and comparative examples.

[0077]

[0078] As shown in Table 1 above, the laminated glass preparation method of the present invention can prevent the glass or the black glaze layer from contacting the vacuum rubber ring or vacuum bag during the initial pressing process, thereby avoiding a decrease in its surface energy. In Examples 3 and 4, due to the addition of surfactants to the antifouling coating, the surface energy increased slightly after removing the protective film.

[0079] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for preparing laminated glass, wherein, The preparation method includes the following steps: An antifouling coating is applied to at least a portion of the surface of the pre-laminated glass that contacts the vacuum rubber ring or vacuum bag, and after drying, a protective film is formed; the protective film at least completely covers a predetermined area, which is required to maintain its surface energy after the laminated glass is prepared; The glass sheets are joined together to obtain a glass assembly; The glass assembly is fitted with a vacuum rubber ring or vacuum bag for initial pressing. After the initial pressing process is completed, the vacuum rubber ring or vacuum bag is removed, and the glass assembly is sent into the autoclave to complete the high-pressure process. After the high-pressure process is completed, the protective film on the glass assembly is washed away.

2. The preparation method according to claim 1, wherein, The surface energy requirement for the predetermined area is ≥40mJ / m². 2 .

3. The preparation method according to claim 1, wherein, The protective film is only applied to the predetermined area, and at the non-glass edge, the edge of the protective film extends 0-10 cm beyond the edge of the predetermined area.

4. The preparation method according to claim 1, wherein, When using a vacuum rubber ring in the initial pressing process, the protective film completely covers the contact area between the pre-laminated glass and the vacuum rubber ring; and When the predetermined area is completely located within the contact area, at the non-glass edge, the edge of the protective film extends 0-10 cm beyond the edge of the contact area; When the predetermined area extends beyond the contact area, the protective film still completely covers the predetermined area, and at the non-glass edge, the edge of the protective film extends 0-10 cm beyond the edge of the predetermined area.

5. The preparation method according to claim 1, wherein, The protective film completely covers the side of the pre-laminated glass that is in contact with the vacuum rubber ring or vacuum bag.

6. The preparation method according to any one of claims 1-5, wherein, The antifouling coating comprises 92-99.5 parts by weight of solvent and 0.5-8 parts by weight of water-soluble polymer; the water-soluble polymer can withstand temperatures above 140°C without cracking or softening.

7. The preparation method according to claim 6, wherein, The water-soluble polymer is selected from at least one of carboxymethyl cellulose, carboxymethyl chitosan, polyacrylamide and its derivatives, polyvinylpyrrolidone, polyvinyl alcohol, sodium polyacrylate, and sodium poly(4-styrene sulfonate); and / or The solvent is selected from at least one of deionized water, ethanol, ethylene glycol, methanol, and isopropanol.

8. The preparation method according to claim 6, wherein, The degree of polymerization N of the water-soluble polymer satisfies: 200≤N≤20000.

9. The preparation method according to claim 6, wherein, The antifouling coating also includes 0.01 to 0.05 parts by weight of a surfactant.

10. The preparation method according to claim 9, wherein, The surfactant is selected from at least one of fatty acid polyoxyethylene ester, coconut oil fatty acid diethanolamide, fatty alcohol polyoxyethylene ether, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium secondary alkyl sulfonate, dodecyl betaine, olive oil extract, and tea polyphenols.

11. The preparation method according to any one of claims 1-5, wherein, The thickness of the protective film is 0.01~3μm.

12. The preparation method according to any one of claims 1-5, wherein, The initial pressing process includes: putting a vacuum rubber ring or vacuum bag over the glass assembly to remove air, gradually raising the temperature to 110°C~125°C, and evacuating the vacuum to below 0.95 bar.

13. The preparation method according to any one of claims 1-5, wherein, The high-pressure process has a temperature of 125℃~140℃, a holding time of 0.5 h~1.5 h, and a pressure greater than 1.2~1.5 MPa.

14. The preparation method according to any one of claims 1-5, wherein, After the high-pressure process is completed, the protective film is removed by washing with water.

15. A laminated glass obtained by the preparation method according to any one of claims 1-14.

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