JP7779091B2 - Manufacturing method for automotive window glass structure and evaluation method for dry processing - Google Patents

Description

The present invention relates to a method for manufacturing an automotive window glass structure and a method for evaluating dry processing.

Structures are known in which resin parts such as brackets are bonded to automobile window glass via an adhesive. In the manufacture of such structures, it is also known to modify the bonding surface of the resin part by subjecting it to a dry treatment such as plasma treatment in order to improve adhesion between the resin part and the adhesive. For example, Patent Document 1 describes a surface treatment method for a component containing a crystalline thermoplastic resin, in which the surface condition before and after the dry treatment is treated by dry treatment to satisfy a predetermined relationship based on the contact angle and the surface free energy of the surface.

Japanese Patent Application Laid-Open No. 2008-127428

In the technology described in Patent Document 1, dry treatments applied to component surfaces are evaluated by measuring the contact angle and surface tension of a specified liquid. However, because contact angle measurements involve dripping a liquid onto the surface, the condition of the component's surface may change depending on the material that makes up the component and the type of liquid used for measurement. Therefore, there is a need for a method that can appropriately evaluate dry treatments applied to bonding surfaces without contact.

In view of the above, one aspect of the present invention aims to provide a method for non-contact evaluation of the dry treatment of the resin surface of a component in the manufacture of an automotive window glass structure in which a component having a resin surface is bonded to an automotive window glass.

To solve the above problem, a method for manufacturing an automobile window glass structure in which a component having a resin surface is bonded to an automobile window glass is provided. A fluorescent substance is attached to the bonding surface of the component having the resin surface, the bonding surface is subjected to a dry treatment, and the dry treatment is evaluated by observing the fluorescence emitted from the bonding surface. The component is then bonded to the automobile window glass via the adhesive applied to the bonding surface.

According to one aspect of the present invention, in the manufacture of an automotive window glass structure in which a component having a resin surface is bonded to an automotive window glass, the dry treatment of the component's resin surface can be evaluated without contact.

1 is a plan view of an automotive glazing structure according to one embodiment of the present invention; FIG. 2 is a partial cross-sectional view taken along line II of FIG. 1. FIG. 1 is a flow diagram of an evaluation method or a manufacturing method according to an embodiment of the present invention.

The following describes embodiments of the present invention, but the present invention is not limited to the following embodiments.

<Automotive window glass structure>
In this specification, the term "automotive window glass structure" refers to a structure in which a component having a resin surface is bonded to a main surface of an automotive window glass with an adhesive. More specifically, the automotive window glass may be a windshield, rear glass, side glass, etc.

Glass sheets used in automotive window glass may be inorganic glass sheets such as soda-lime silicate glass, aluminosilicate glass, borate glass, lithium aluminosilicate glass, and borosilicate glass. These glass sheets may be untempered or may have been tempered by air-cooling or chemical strengthening. Untempered glass is produced by forming molten glass into a sheet and slowly cooling it. Tempered glass is produced by forming a compressive stress layer on the surface of untempered glass. When tempered glass is air-cooled tempered glass, the glass surface may be strengthened by rapidly cooling a uniformly heated glass sheet from a temperature near its softening point, thereby generating compressive stress on the glass surface due to the temperature difference between the glass surface and the glass interior. On the other hand, when tempered glass is chemically strengthened glass, the glass surface may be strengthened by generating compressive stress on the glass surface using an ion exchange method or the like. Furthermore, glass sheets that absorb ultraviolet or infrared light may be used for vehicle glass. Transparent glass is preferable, but colored glass may also be used to the extent that transparency is not impaired. Organic glass may also be used for vehicle glass. Examples of organic glass include transparent resins such as polycarbonate.

Automotive window glass may be laminated glass comprising multiple glass sheets as described above, for example, laminated glass comprising two glass sheets bonded together via an interlayer film. Examples of interlayer films placed between the glass sheets include ethylene vinyl acetal and polyvinyl butyral.

The planar shape of automotive window glass is not limited to a rectangle, and it may be processed into various shapes. Furthermore, automotive window glass may be curved, with no particular limitation on its curvature. Curvature can be achieved by bending the glass sheet used using gravity forming, press forming, or other bending techniques. The shape and curvature of automotive window glass are set so that components can be bonded to its main surfaces and sufficient dry processing can be performed on the bonding surfaces.

Specific examples of structures in which components having a resin surface are bonded to the above-mentioned automotive window glass include structures in which components such as resin brackets or bases for mounting on-board equipment (on-board cameras, on-board sensors, mirrors, etc.) or resin temporary fixing pins are bonded to the surface that faces the interior of the vehicle when the windshield is installed in the vehicle. Also suitable are structures in which components such as resin door sliders or resin door holders are bonded to the side glass. In this way, it is preferable that components bonded to automotive window glass have at least a plate-shaped bonded portion, with an adhesive surface that corresponds to the shape of the adhesive surface on the main surface of the automotive window glass.

When the part having a resin surface is a part for mounting on-board equipment, the on-board equipment that can be mounted may be an on-board camera, a rain sensor, a defrost sensor, an infrared sensor, a millimeter-wave radar, etc. It may also be a resin base for mounting an interior mirror. Furthermore, the automotive window glass structure manufactured in this embodiment is suitable for use in automobiles equipped with a Driving Safety Support System (DSSS) or an Advanced Driver-Assistance System (ADAS).

The part to be attached to the automobile window glass may have a resin surface, i.e., at least the surface is formed from resin, or is formed primarily from resin. Furthermore, the part may have a resin surface at least on the surface that adheres to the automobile window glass. Therefore, a part with a resin surface may be a molded body formed entirely from resin or primarily from resin, or a molded body made from a material other than resin, with part or all of its surface covered with a resin layer. Note that "formed primarily from resin" refers to a resin content that maintains the inherent properties of the resin, e.g., a resin content of 50% by weight or more. Furthermore, in this specification, a part with a resin surface may be referred to as a "resin part" or "resin component."

Resin materials used for parts with resin surfaces are not particularly limited, but include polyesters such as polybutylene terephthalate (PBT) and polyethylene terephthalate (PET), polyolefins such as polyethylene (PE) and polypropylene (PP), polycarbonate (PC), polyamides (PA) such as nylon 6 and nylon 6,6, high-heat-resistant polyamides based on terephthalic acid or isophthalic acid (PA6T, PA6I, PA6T/6I, etc.), polyimide (PI), polyetherimide (PEI), acrylonitrile-butadiene-styrene (ABS), polyacetal (POM), polyvinyl chloride (PVC), and epoxy (EP). These resin materials may be used as homopolymers or as copolymers combining one or more of the above. Resin materials may also be polymer alloys combining one or more of the above, such as a polymer alloy of polybutylene terephthalate and styrene-acrylonitrile.

The resin material may also contain components other than the resin components, such as fillers, pigments, and resin modifiers. For example, the resin material may be a reinforced resin that is reinforced with fillers such as fibers and inorganic particles. Examples of reinforcing fibers include glass fiber and carbon fiber. Preferred fiber-reinforced resins are polybutylene terephthalate and polyetherimide reinforced with glass fiber. When the resin contains reinforcing fibers, the fiber content can be 5% by weight or more and 70% by weight or less, and preferably 30% by weight or more and 50% by weight or less, of the total resin.

When a part with a resin surface is a molded product made entirely or mainly from resin, the molding method is not limited, and the part may be molded using the above-mentioned resin materials by methods such as injection molding, casting, extrusion, or blow molding. It may also be insert molded using an insert material made from a material other than resin (such as metal).

Furthermore, when a component having a resin surface is a molded body made of a material other than resin, the surface of which is partially or entirely coated with resin, it may be, for example, an electrodeposition-coated body formed by electrodeposition coating a substrate made of metal or the like using an electrodeposition paint containing a resin. An electrodeposition-coated body is formed by passing an electric current through an electrolytic cell to deposit resin paint particles on the surface of the component, which is then heated and cured in a curing oven to form a film. When a resin surface is formed by electrodeposition coating, the electrodeposition paint is preferably a cationic electrodeposition paint. Furthermore, the resin contained in the electrodeposition paint may be a thermosetting resin such as an epoxy resin, and preferably contains an epoxy resin modified with an amine or ammonium. Meanwhile, the substrate may be a metal molded body, particularly a plate-shaped molded body, made of steel, aluminum, or the like. An example of an electrodeposition-coated body is a cationic electrodeposition-coated steel plate manufactured by Aoki Electric Industrial Co., Ltd. (using Kansai Paint Co., Ltd.'s Elecron HG-305E Black electrodeposition paint). Resin surfaces can also be formed by applying a resin-containing solution or dispersion, or a resin melt, to the substrate, by depositing a pre-formed sheet-like resin layer, or by electroless plating. In the case of such parts whose surfaces are partially or entirely coated with resin, it is sufficient that at least a portion of the surface that will be bonded to the automotive window glass (bonding surface) is covered with the resin layer, and it is preferable that the entire bonding surface is covered with the resin layer.

Figure 1 shows an example of an automobile window glass structure 1 formed by bonding an automobile window glass to a component having a resin surface. In the structure shown in Figure 1, a resin bracket 20 for on-board equipment is bonded to the interior surface of the windshield 10. The bracket 20 is configured to support, for example, an on-board camera. Figure 2 also shows a partial cross section taken along line I-I in Figure 1. As shown in Figure 2, the windshield 10 and bracket 20 are bonded via an adhesive layer 30.

As shown in Figures 1 and 2, a shielding layer 15 may be provided around the periphery of the interior surface of the glass 10. If the glass 10 is laminated glass, the shielding layer 15 may be provided on both the exterior and interior glass sheets, or on only one of them. The shielding layer 15 functions to protect urethane sealants and other materials that adhere and hold the vehicle transparent substrate to the vehicle body from UV degradation. The shielding layer 15 is formed, for example, by applying and firing a ceramic color paste containing a fusible glass frit containing a black pigment. The thickness of the shielding layer 15 is preferably 3 μm to 15 μm. The width of the shielding layer 15 is not particularly limited, but is preferably 20 mm to 300 mm. In the illustrated example, the bracket 20 is bonded to the shielding layer 15 on the interior surface of the glass 10. However, the bracket 20 may also be bonded directly to the interior surface of the glass 10. It is preferable that the bracket 20 be adhered in a position that is hidden by the shielding layer 15 when viewed from outside the vehicle. Adhering the bracket 20 in a position that is hidden by the shielding layer 15 not only makes the bracket 20 and adhesive layer 30 less visible from outside the vehicle, but also prevents the adhesive layer 30 from being deteriorated by ultraviolet rays.

<Method for manufacturing an automobile window glass structure>
One embodiment of the present invention is a method for manufacturing the above-mentioned automotive window glass structure. Figure 3 shows an example of a flow of the manufacturing method according to this embodiment. As shown in Figure 3, the manufacturing method according to this embodiment includes evaluating a dry treatment applied to a surface (adhesion surface) of a part having a resin surface that will be bonded to the automotive window glass (S10), and bonding the adhesion surface of the part to the automotive window glass via an adhesive (S20).

Dry treatments such as plasma treatment modify the surface of components, thereby increasing their adhesive affinity (described in detail below). This allows for the elimination of the need to apply a primer to the surface of components during the manufacture of automotive window glass structures. Conventionally, determining whether dry treatment has been performed properly involves dripping a specified liquid onto the surface and measuring the contact angle and surface tension. However, this method of dripping liquid involves contact with the surface of the component, which can potentially alter the surface condition of the component depending on the component's material, the type of liquid, and other factors. In contrast, this method uses the emission of fluorescent substances to evaluate dry treatment of the component surface without contact, thereby minimizing changes to the component's surface quality due to the evaluation process and achieving higher adhesion quality. Furthermore, while conventional methods using contact angles and other factors only evaluate a very limited area of the resin surface, this method allows for a comprehensive evaluation of the entire adhesive surface. This makes it possible to determine, for example, whether there is any incomplete treatment in areas that require dry treatment. Therefore, this embodiment allows for more reliable evaluation of dry processing than conventional methods, and ultimately allows for more reliable production of automotive window glass structures.

The evaluation of the dry treatment (S10) involves attaching a fluorescent substance to the bonding surface of the component (S11), performing the dry treatment (S12), and evaluating the dry treatment by observing the fluorescence emitted from the bonding surface (S13).

The following describes each step in the manufacturing method of this embodiment.

(Attachment of fluorescent substance (S11))
In this method, a fluorescent material is applied to the bonding surfaces of the components before the dry treatment of the bonding surfaces. The fluorescent material may be applied directly to the bonding surfaces of the components, or may be dissolved in a solvent to prepare a solution, which is then applied to the bonding surfaces. Applying the fluorescent material in solution form is preferable because it allows the fluorescent material to be evenly applied to the desired area and the amount of fluorescent material used can be kept small.

The solvent used to prepare the phosphor solution is not particularly limited and can be selected appropriately depending on the solubility of the phosphor used and the type of resin material on the resin surface. The solvent may be, for example, an organic solvent, water, etc. Among these, an organic solvent is preferable because it volatilizes easily after application. Furthermore, the organic solvent is preferably a solvent with high degreasing properties that can be used as a cleaning solution for cleaning or washing resin surfaces. The organic solvent may be one or a mixture of two or more alkanes and alcohols that are liquid at room temperature (15-25°C). Specific examples include n-hexane, ethanol, 1-propanol, and 2-propanol. The solvent may be a single component or a combination of two or more components. It may also be a mixture of lower alcohols primarily containing ethanol (e.g., a mixture of ethanol, 1-propanol, and 2-propanol), known as mixed ethanol.

The fluorescent substance is not particularly limited as long as its fluorescence can be observed visually or by some means, such as a fluorescence detection device, when the resin surface of a component to which the fluorescent substance is attached is observed. Any fluorescent substance can be used as long as the difference between areas where the fluorescent substance is present and areas where it is not present can be recognized during observation. Furthermore, fluorescent substances whose fluorescence can be visually confirmed, i.e., substances that emit light in the visible range, are preferred because they facilitate observation. In this embodiment, the preferred fluorescent substance is at least one of 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene (hereinafter also referred to as BBOT) and methylene blue (also referred to as 3,7-bis(dimethylamino)phenothiazinium chloride, or MeB). These fluorescent substances are preferred because they have high quantum yields and low toxicity. They also dissolve well in organic solvents such as n-hexane, ethanol, 1-propanol, and 2-propanol.

When using a phosphor solution, the phosphor can be applied by, for example, soaking a wipe in the solution and stroking or wiping the adhesive surface of the component with the wipe. The wipe may be made of a fibrous or porous material capable of absorbing and retaining the solvent, such as a sheet-like material such as cloth or nonwoven fabric, or a bulk material such as a sponge. The phosphor solution can also be applied to the component surface by spraying the solution onto the adhesive surface of the component, or by contacting or immersing at least the adhesive surface of the component in the phosphor solution.

The concentration of the phosphor solution may be, relative to the total volume of the phosphor solution, preferably from 1×10 ⁻⁶ mol/L to 1×10 ⁻² mol/L, more preferably from 1×10 ⁻⁵ mol/L to 1×10 ⁻³ mol/L, and even more preferably from 1×10 ⁻⁵ mol/L to 1×10 ⁻⁴ mol/L. In particular, when 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene is used as the phosphor, it is preferable that the concentration of the solution be from 1×10 ⁻⁵ mol/L to 1×10 ⁻⁴ mol/L. Using a solution with a concentration within this range allows for sufficient fluorescence for observation and minimizes any adverse effects on the adhesion between the bonding surfaces of the components and the adhesive. For example, by using a solution having a concentration within the above range, adhesive quality can be obtained such that when the adhesive is applied and tested, the cohesive failure rate (adhesive adhesion area rate) is preferably 30% or more, more preferably 40% or more, and even more preferably 60% or more.

When using a phosphor solution to attach a phosphor to a resin surface, a cleaning liquid for cleaning the component surface can be used as the solvent for dissolving the phosphor. By using a liquid that is suitable for use as a cleaning liquid for cleaning component surfaces, as described above, as the solvent for the phosphor solution, the bonding surface of the component can also be cleaned with the phosphor solution during the phosphor attachment process. In this case, dust or dirt that may be present on the component surface can be dispersed or dissolved in the solution or solvent during the phosphor attachment process and removed from the component surface. Alternatively, the dust or dirt can be decomposed by the solution, and the substances resulting from that decomposition can be dispersed or dissolved in the solution or solvent and removed from the component surface.

In other words, in this embodiment, by adding a fluorescent substance to the cleaning solution used in the component surface cleaning process, the fluorescent substance can be attached simultaneously during the component surface cleaning process. Therefore, the fluorescent substance can be applied to the bonding surface during cleaning without significantly changing the cleaning or washing process performed before dry processing from the conventional process.

When wiping a component surface with a wipe soaked in a fluorescent solution, the wipe may be wiped without applying pressure to the component surface, or with a pressure of 0.2 kPa to 60 kPa. Wiping with pressure ensures that dirt on the component surface is removed. Dust and dirt can be removed from the resin surface by mechanical force while the solvent breaks down or dissolves the dirt in the solvent.

It is also preferable to apply the fluorescent substance over a wider area than the area to be dry-processed in the subsequent dry process (S12) (the area that has been preset to be dry-processed). For example, it is preferable that the area to which the fluorescent substance is applied be formed in an area that extends beyond the periphery of the area to be dry-processed.

(Dry processing (S12))
The dry treatment is performed on the bonding surface after the step (S11) of attaching the fluorescent material to the bonding surface of the component as described above. The dry treatment is performed on at least the region of the bonding surface that is to be dry treated, more specifically, on the region that includes the region to be coated with adhesive in the subsequent step (S20).

Specific examples of dry treatments include plasma treatment, corona treatment, flame treatment, itro treatment, ultraviolet irradiation treatment, and excimer treatment, of which at least one of plasma treatment and corona treatment is preferred. When the dry treatment is plasma treatment, the means of generation is not particularly limited, and may be a high-frequency plasma generator or a low-frequency plasma generator. Furthermore, plasma generated by irradiation with laser, microwaves, etc. may also be used.

Dry processing allows for the introduction or formation of hydrophilic functional groups, such as hydroxyl, carbonyl, and carboxyl groups, on the resin surface, increasing the number of hydrophilic functional groups per unit area. This increases the number of sites where the hydrophilic functional groups on the surface can interact with the adhesive components through chemical bonds or intermolecular forces, strengthening the bond (interfacial bond) between the component and the adhesive when the resin surface of the component is used as the bonding surface and bonded to an automotive window glass via an adhesive. Dry processing also decomposes and removes substances on the component surface that could interfere with adhesion (contaminants that could not be completely removed by the above-mentioned cleaning). Therefore, dry processing (S12) can also be considered a dry cleaning or washing process. In this case, if cleaning is performed simultaneously with the fluorescent substance deposition process (S11), this embodiment can also be considered to perform two-stage cleaning.

Since dry processing can improve adhesion between the part and the adhesive, automotive window glass structures can be manufactured without applying a primer to the part surface. However, it is also possible to apply a primer after dry processing, and then apply an adhesive to the primer to bond the part to the automotive window glass. In this case, adhesion between the dry-treated surface and the primer can be improved, thereby improving adhesion between the part and the automotive window glass.

The conditions for the dry treatment can be adjusted as appropriate depending on the type of resin and adhesive used on the surface of the part, the purpose of use of the part, the location of use in the automobile, the desired adhesive strength, etc. The specific conditions for the dry treatment cannot be generalized because they depend on the type of equipment used for the dry treatment and the configuration of the part. However, when the dry treatment is a plasma treatment, for example, the frequency of the applied voltage of the power supply of the plasma generating means may be 50 GHz or higher and 2.45 GHz or lower, preferably 50 Hz or higher and 25 kHz or lower, and the irradiation distance (the distance between the electrode and the surface of the molded body) may be 50 mm or lower, preferably 10 mm or higher and 30 mm or lower. The lower limit of the distance between the opposing nozzle and the workpiece (molded body) is not particularly limited, but may be, for example, 0.5 mm or higher. The output power density may be 15 W/cm ² or higher, preferably 20 W/cm ² or higher. The irradiation time is determined by the nozzle movement speed. The nozzle movement speed may be 0.01 m/min or higher and 50 m/min or lower, preferably 2.5 m/min or higher and 10 m/min or lower.

When performing plasma treatment, if the surface temperature of the resin-surfaced part is raised by, for example, heating the molded body with a heater before plasma irradiation, the adhesion between the part and the adhesive in the structure obtained through subsequent steps can be further improved. The surface temperature of the part before plasma irradiation can be set to, for example, a temperature above room temperature, and may be set to, for example, 60°C or higher.

(Evaluation of dry processing (S13))
After the surface to which the fluorescent substance is attached is subjected to dry treatment (S12) as described above, the dry treatment is evaluated by observing the fluorescence emitted from the bonding surface of the components (S13). This observation may be performed on the entire bonding surface, but it can also be performed on at least the region of the bonding surface that is to be dry treated (the region including the region where the adhesive is actually scheduled to be applied).

It is believed that when an appropriate dry treatment is applied to an area where a fluorescent substance has been attached, the fluorescent substance decomposes and loses its ability to emit fluorescence. Therefore, in the evaluation step (S13), by measuring the fluorescence intensity of the adhesive surface, it can be determined whether or not the adhesive surface has been appropriately dry treated. For example, if the fluorescence intensity detected during observation after dry treatment is zero or is below a predetermined value, it can be determined that the dry treatment has been appropriately applied.

Here, appropriate dry processing may mean that the part has been subjected to dry processing, or that the area to be dry processed (an area previously designated as requiring dry processing) has been subjected to dry processing. Furthermore, appropriate dry processing may mean that the degree of dry processing actually performed in the area to be dry processed is appropriate, and/or that the range of dry processing is appropriate. Therefore, users of the method according to this embodiment can appropriately set the standard for the intensity of fluorescent light and/or the standard for the range of detectable fluorescent light intensity required to determine appropriate dry processing, depending on the desired degree of dry processing. Therefore, depending on the configuration, dry processing may be determined to have been appropriate even if fluorescent material remains in the area to be dry processed. Here, appropriate dry processing may be processing that results in adhesive quality such that, when tested with an applied adhesive, the cohesive failure rate (adhesive adhesion area rate) is preferably 30% or higher, more preferably 40% or higher, and even more preferably 60% or higher.

When measuring fluorescence intensity, it is preferable to have a control area on the adhesive surface for comparison. For example, a region adjacent to the area to be dry-processed can be created where the fluorescent substance is applied under the same conditions as the area to be dry-processed, but where no dry processing is performed. Such a control area where no dry processing is performed can be created, for example, by covering the area with a mask during dry processing. If the component itself is not subjected to the dry processing process due to a malfunction of the dry processing equipment, or if a surface other than the adhesive surface of the component is dry-processed, no fluorescent substance will be applied to any area of the adhesive surface. Therefore, observing the fluorescence in the control area allows for accurate judgment even in such cases. When a control area is provided, the ratio of the fluorescence intensity in the area to be dry-processed to the fluorescence intensity in the control area can be calculated, and the dry processing, i.e., whether or not the dry processing was performed appropriately, can be evaluated based on this ratio. Furthermore, if the area to which the fluorescent substance is applied in the fluorescent substance application step (S11) is formed so that it extends beyond the periphery of the area to be dry-processed, the contrast area can be made to surround the area to be dry-processed, which is preferable because it makes the contrast area easier to identify.

In the fluorescent substance application step (S11), if a fluorescent substance solution using a cleaning solution as a solvent is used to both clean the resin surface and apply the fluorescent substance, it is possible to determine whether the dry treatment was performed properly, as well as whether cleaning has been performed. For example, if the fluorescent substance solution is applied to areas other than the area to be dry treated, such as the control area described above, it is possible to determine whether cleaning has been performed by observing the fluorescence in those areas.

Fluorescence observation in the dry processing evaluation step (S13) may be performed, for example, visually. Direct visual observation is preferable and practical from the standpoints of simplicity and low cost, as it does not require large-scale equipment. When observing visually, a light irradiation device may be placed nearby to emit light. For example, a UV-LED light generator can be used to irradiate ultraviolet light onto the adhesive surface, allowing for visual observation of the fluorescence. When BBOT is used as the fluorescent substance, visual observation can be easily achieved by irradiating it with ultraviolet light.

Fluorescence observation may also be performed using equipment capable of detecting fluorescence, such as a fluorescence microscope or a fluorescent filter. Observing through such equipment allows detection of fluorescence even when the fluorescence intensity is low, which is preferable from the perspective of potentially reducing the amount of fluorescent material used in the fluorescent material application step (S11) described above. When using equipment such as a fluorescence microscope, the fluorescence intensity may be confirmed visually through an eyepiece, or the adhesion surface may be photographed using a camera or the like, and the image data may be imported into a personal computer or the like and displayed on a display device to confirm the fluorescence intensity. Furthermore, image processing can be performed using the imported image data, allowing for more accurate measurement of fluorescence intensity. Furthermore, when using equipment, the determination of whether or not appropriate dry processing has been performed may be automated.

In this way, in this evaluation step (S13), the dry treatment performed in the previous step (S12) can be evaluated by visually or instrumentally observing the fluorescent emission state. Therefore, one embodiment of the present invention may be a dry treatment evaluation method that includes attaching a fluorescent substance to the bonding surface of a component having a resin surface (S11), performing dry treatment (S12), and evaluating the dry treatment by observing the fluorescent emission state of the dry-treated bonding surface (S13). The evaluation method in this embodiment is non-contact, meaning that no object is brought into contact with the bonding surface after dry treatment. Therefore, the component can be subjected to the subsequent bonding step (S20) without changing the state of the dry treatment. Furthermore, because the entire area to be dry-treated can be easily observed, any remaining processing can be detected, enabling a more reliable evaluation than conventional methods that were only able to perform localized evaluation.

(Adhesion to automobile window glass (S20))
If it is determined through the evaluation (S10) including the above-mentioned steps S11 to S13 that the area to be dry-treated has actually been properly dry-treated (dry-treated area), an adhesive can be applied to the dry-treated area of the bonding surface and bonded to the automotive window glass (S20). During bonding, a primer can also be applied to the bonding surface of the automotive window glass.

If the evaluation (S10) determines that the dry treatment was not performed appropriately, for example, if the dry treatment was not performed to a sufficient degree or if there are undesired areas left untreated in the area that should have been dry treated, then the dry treatment (S12) may be performed again. The newly performed dry treatment is then evaluated (S13), and if it is confirmed to have been appropriate, the process can proceed to the bonding step (S20).

The adhesive used in the bonding step (S20) is preferably a one- or two-component moisture-curing adhesive, and more preferably a urethane-based adhesive, modified silicone-based adhesive, or the like. In addition to moisture-curing adhesives, photo-curing adhesives and heat-curing adhesives can also be used.

After bonding the automotive window glass and the component with a resin surface with the adhesive, the components may be stored, i.e., cured, in a specified environment. This curing can also improve the adhesion between the automotive window glass and the component. For example, curing can be carried out by storing the components for a specified period of time under conditions of temperature and humidity appropriate for the type of adhesive.

The following examples further illustrate embodiments of the present invention. In these examples, the surface of a resin molded body was cleaned using a solution of a fluorescent substance, followed by dry processing. The dry processing was evaluated by observing the fluorescence on the surface after the dry processing. An adhesive was then applied to the surface of the resin molded body, and the adhesion between the resin molded body and the adhesive was evaluated. Examples 1 to 6 are examples, and Example 7 is a comparative example.

(Example 1)
A plate-shaped molded body (25 mm x 150 mm x 5 mm) made of glass fiber-reinforced polybutylene terephthalate (PBT GF-30) (Polyplastics Co., Ltd., 733LD) containing 30% glass fiber was used as the resin molded body. A solution of 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene (BBOT) with a concentration of 1 x 10 ^-4 mol/L (0.0065 wt%) was prepared by dissolving it in n-hexane (Wako Pure Chemical Industries, Ltd., special grade). The resin molded body was cleaned by wiping almost the entire surface with a nonwoven fabric wiper (Asahi Kasei Corporation, Bemcot®) soaked in the solution. After visually confirming that the solution had evaporated, one half of the cleaned area was subjected to plasma treatment (dry treatment) using an atmospheric pressure plasma treatment device (Wedge Corporation, PS-601SW). The distance between the head and the surface of the component during the plasma treatment was 10 mm, and the irradiation time was 4 seconds. The plasma treatment was evaluated using the method described below, and then an adhesive was applied to the plasma-treated area, and the adhesion was evaluated using the method described below.

(Example 2)
The resin molded body was cleaned and plasma treated in the same manner as in Example 1, except that the concentration of the solution was 1×10 ⁻⁵ mol/L (0.00065% by weight), and the plasma treatment and adhesion were evaluated.

(Example 3)
The resin molded body was cleaned and plasma-treated in the same manner as in Example 1, except that a solution of BBOT dissolved in mixed ethanol (Mixed Ethanol NP, manufactured by Yamaichi Chemical Industry Co., Ltd.) with a concentration of 1 × ¹⁰ -4 mol/L (0.0065 wt %) was used, and the plasma treatment and adhesion evaluation were carried out.

(Example 4)
The resin molded body was cleaned and plasma treated in the same manner as in Example 3, except that the concentration of the solution was 1×10 ⁻⁵ mol/L (0.00065% by weight), and the plasma treatment and adhesion were evaluated.

(Example 5)
The resin molded body was cleaned and plasma treated in the same manner as in Example 1, except that the concentration of the solution was 1×10 ⁻³ mol/L (0.065% by weight), and the plasma treatment and adhesion were evaluated.

(Example 6)
A resin molded body was cleaned in the same manner as in Example 1, except that a solution of methylene blue (MeB) dissolved in mixed ethanol (Mixed Ethanol NP, manufactured by Yamaichi Chemical Industry Co., Ltd.) with a concentration of 1 × 10 ^-5 mol/L (0.00065 wt %) was used. Thereafter, the body was subjected to plasma treatment and evaluated.

(Example 7)
In this example, n-hexane (solute concentration 0 wt%) was used instead of the solution, and plasma treatment was not performed. Other than that, cleaning was performed in the same manner as in Example 1. Then, plasma treatment was performed, and adhesion was evaluated.

<Evaluation of plasma treatment (dry treatment)>
In Examples 1 to 5, in which BBOT was used as the fluorescent material, and Example 7, in which no fluorescent material was used, the dry-treated surface of the resin molded body was irradiated with UV-LED light at a wavelength of 365 nm using an LED light (LED-UV365P, manufactured by Optocord Corporation), and the fluorescence intensity in the plasma-treated area was confirmed visually. In these examples, if the fluorescence intensity in the plasma-treated area was determined to be zero by visual inspection, it was deemed that no fluorescence was detected, and it was determined that the plasma treatment had actually been performed appropriately. Note that, when making this determination, the light emission state of the plasma-treated area was compared with the light emission state of the adjacent area that was not plasma-treated.

In Example 6, in which methylene blue was used as the fluorescent substance, the dry-treated surface of the resin molded body was observed using a fluorescence microscope, and the images obtained through the fluorescence microscope were analyzed. Then, based on this image analysis, the fluorescence intensity in the plasma-treated area was measured. In this example, if the fluorescence intensity in the plasma-treated area was zero, it was determined that no fluorescence was detected, and that the plasma treatment had actually been performed appropriately. Note that, as with the above, when making this determination, the light emission state of the plasma-treated area was compared with the light emission state of the adjacent area that was not subjected to plasma treatment.

<Evaluation of Adhesion>
A urethane adhesive (WS292, manufactured by Yokohama Rubber Co., Ltd.) was applied to the plasma-treated area, and evaluation was performed based on the adhesive adhesion area ratio (the ratio of the area where the adhesive remained, or the cohesive failure rate) after a knife-cutting operation using a method in accordance with JASO M338-89 Standard 9.11 Pot Life Test. An adhesive adhesion area ratio of 0% indicates that the adhesive has not undergone cohesive failure at all and interfacial peeling has occurred, while a ratio of 100% indicates that cohesive failure has occurred over the entire surface where the adhesive has been applied. The higher the adhesive adhesion area ratio, the greater the proportion of cohesive failure that has occurred in the adhesive, and the better the adhesion between the resin molded product and the adhesive can be evaluated.

Table 1 shows the conditions and evaluation results for each example.

As shown in Table 1, in all of Examples 1 to 6, it was found that cleaning with a solution of a fluorescent substance before dry processing made it possible to evaluate the dry processing (determine whether or not plasma processing had been performed) and also ensured adhesion between the test piece and the glass plate. Furthermore, when the concentration of the fluorescent substance in the cleaning solution was 1 × 10 ^-4 mol/L or less (Examples 1 to 4 and Example 6), the adhesive adhesion area ratio exceeded 40%, and it was found that particularly good adhesion could be obtained.

1 Automotive window glass structure 10 Glass 15 Shielding layer 20 Resin part (bracket)
30 Adhesive layer

Claims (13)

A method for manufacturing an automobile window glass structure in which a component having a resin surface is bonded to an automobile window glass, comprising:
A fluorescent substance is attached to the adhesive surface of the component having the resin surface;
performing a dry treatment on the adhesive surface to which the fluorescent material is attached ;
evaluating the dry treatment by observing fluorescence emitted from the adhesive surface;
The component is bonded to an automobile window glass via an adhesive applied to the bonding surface. The manufacturing method described in claim 1, wherein the fluorescent material is attached using a solution of the fluorescent material. The manufacturing method described in claim 2, wherein the fluorescent substance is applied while the adhesive surface is cleaned. The manufacturing method of claim 3, wherein the cleaning step includes soaking a wipe material in the solution and wiping the adhesive surface. The manufacturing method described in any one of claims 2 to 4, wherein the solution is a solution obtained by dissolving the fluorescent substance in an organic solvent. 6. The method according to claim 2, wherein the concentration of the fluorescent substance in the solution is 1×10 ⁻⁶ mol/L or more and 1×10 ⁻² mol/L or less. The manufacturing method described in any one of claims 1 to 6, wherein the fluorescent substance is at least one of 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene and methylene blue. The manufacturing method described in any one of claims 1 to 7, wherein the dry treatment is at least one of plasma treatment and corona treatment. The manufacturing method described in any one of claims 1 to 8, wherein observing the fluorescence includes irradiating it with UV light and directly observing it visually. The manufacturing method described in any one of claims 1 to 9, wherein observing the fluorescence includes observing with a fluorescence microscope. 11. The manufacturing method according to claim 1, wherein the deposition of the fluorescent material is performed over a range wider than the area to be dry-processed by the subsequent dry process, and the area to which the fluorescent material is deposited is formed in a range extending beyond the periphery of the area to be dry-processed. a control area is provided on the adhesive surface for evaluating the dry treatment by measuring fluorescence intensity;
The manufacturing method according to claim 11 , wherein the control region is provided adjacent to the region to be dry-processed and surrounds the region to be dry-processed. 1. A method for evaluating a dry treatment applied to a part having a resin surface to be bonded to an automobile window glass, comprising:
A fluorescent substance is attached to the adhesive surface of the component having the resin surface;
performing a dry treatment on the adhesive surface to which the fluorescent material is attached ;
The dry treatment is evaluated by observing the fluorescence emitted from the adhesive surface.