CN114591697A

CN114591697A - Laser-assisted adhesive tape and sealing structure comprising same

Info

Publication number: CN114591697A
Application number: CN202011436447.5A
Authority: CN
Inventors: 程啸 G·玛耶兹刘磊; 刘磊; 程啸; G·玛耶兹
Original assignee: Tesa SE
Current assignee: Tesa SE
Priority date: 2020-12-07
Filing date: 2020-12-07
Publication date: 2022-06-07
Also published as: EP4255997A1; WO2022122774A1

Abstract

The invention relates to a laser-assisted adhesive tape and a sealing structure comprising the same. Specifically, under the action of the laser, the adhesive tape can directionally and quantitatively foam and expand to fill gaps between components bonded by the adhesive tape. The adhesive tape is particularly suitable for filling irregular gaps.

Description

Laser-assisted adhesive tape and sealing structure comprising same

Technical Field

The invention relates to the field of materials, in particular to a laser-assisted adhesive tape and a sealing structure comprising the same.

Background

In mobile phones or related electronics industries such as tablet, wearing, etc., more and more front cases or back covers of devices transition from a flat surface to a curved surface. For example, almost all of the flag carrier grades of the mobile phone terminal brands use a curved back cover design, which we often say a 3D back cover. The material of these 3D back covers may be glass, plastic or even ceramic, and the corresponding middle frame is also a curved surface design, and the curved back cover and the curved middle frame need to be bonded together in the production process of the mobile phone (as shown in fig. 1 and fig. 2). However, due to the limitations of the state of the art, there is always a relatively large clearance tolerance when the two are mated, which may be in the cross-sectional direction or in the direction of the rear cover edge. Handset manufacturers need to fill this gap with tape and the corresponding gap tolerances.

The main solution adopted at present is to use a thicker foam tape (e.g. 250-.

Whether the gap is tight or tight is important for preventing water, dust and chemical substances from entering the mobile phone and the like and for the reliability of the mobile phone and the like during use (for example, falling). Therefore, there is a great need in the art to develop a solution that can achieve complete filling of irregular gaps.

Disclosure of Invention

The invention aims to provide a laser-assisted adhesive tape and a sealing structure comprising the same, wherein the adhesive tape can rapidly and directionally and controllably expand under the action of laser so as to realize sufficient adhesion among components with irregular shapes, and has important significance for improving the curved surface bonding performance of electronic products such as mobile phones and the like.

In a first aspect of the invention, there is provided a laser-assisted adhesive tape comprising at least one expandable tape layer,

the expandable adhesive tape layer comprises pressure-sensitive adhesive and unfoamed microspheres and/or partially foamed microspheres distributed in the pressure-sensitive adhesive;

the unfoamed microspheres and/or the partially foamed microspheres can be directionally and quantitatively foamed in situ under the action of laser.

In another preferred embodiment, the weight content of the unfoamed microspheres in the expandable adhesive tape layer is 0.1-15.0 wt% based on the total weight of a single expandable adhesive tape layer; and/or

In the expandable adhesive tape layer, the weight content of the partially foamed microspheres is 0.1-5.0 wt%.

In another preferred example, the thickness of the expandable tape layer before laser action is t0, the thickness of the expandable tape layer after laser action is t1, and t1/t0 is 1.01-5.

In another preferred embodiment, the adhesive tape comprises a reinforcing layer and expandable tape layers adhered to both major surfaces of the reinforcing layer.

In another preferred embodiment, the adhesive tape comprises a reinforcing layer, a first adhesive layer without microspheres bonded to one major surface of the reinforcing layer, and an expandable tape layer bonded to the other major surface of the reinforcing layer.

In another preferred embodiment, the adhesive tape comprises an expandable tape layer and a microsphere-free adhesive layer adhered to two main surfaces of the expandable tape layer.

In a second aspect of the present invention, there is provided a sealing structure comprising, in order from the outside to the inside: a first component, an adhesive tape according to the first aspect of the invention and a second component, wherein,

the first component is an outer layer and the first component is laser-permeable or laser-heatable;

the adhesive tape is an intermediate layer and is used for bonding and sealing the first component and the second component;

the second component is an inner layer.

In another preferred embodiment, the material of the first component and the material of the second component are the same or different and are each independently selected from the group consisting of: glass, ceramic, plastic, coating, or combinations thereof.

In another preferred embodiment, the shape of the first component and the shape of the second component do not match.

In another preferred example, the area formed by assembling the first component and the second component has irregular gaps, and the irregular gaps have at least two different heights.

It is to be understood that within the scope of the present invention, the above-described features of the present invention and those specifically described below (e.g., in the examples) may be combined with each other to form new or preferred embodiments. Not to be reiterated herein, but to the extent of space.

Drawings

Fig. 1 is a schematic diagram showing the shape change of components and the assembly result of electronic products such as mobile phones.

Fig. 2 is a schematic view of a conventional tape fitting slit.

FIG. 3 is a schematic representation of an adhesive tape according to one form of the present invention before and after foaming.

FIG. 4 is a schematic representation of the foam of a form two tape of the present invention before and after foaming.

FIG. 5 is a schematic representation of a three-adhesive tape of the present invention before and after foaming.

FIG. 6 is a schematic representation of a four-sided tape of the present invention before and after foaming.

FIG. 7 is a schematic representation of a five-part tape of the present invention before and after foaming.

Fig. 8 is a schematic view of a laser treated tape.

Fig. 9 shows the thickness test results of the adhesive tape after laser treatment.

Fig. 10 is a schematic diagram of gap filling performance test.

Fig. 11 is a gap test chart of tape No. 1, in which a and b are photographs taken after lamination, and c and d are photographs taken after storage at room temperature for 24 hours after lamination.

Fig. 12 is a gap test chart of tape No. 2, in which a and b are photographs taken after lamination, and c and d are photographs taken after storage at room temperature for 24 hours after lamination.

Fig. 13 is a gap test chart of tape No. 3, in which a and b are photographs taken after lamination, and c and d are photographs taken after storage for 4 hours at room temperature after lamination and after laser treatment of the ink edge.

Fig. 14 is a gap test chart of tape No. 4, in which a and b are photographs taken after lamination, and c and d are photographs taken after storage at room temperature for 4 hours after lamination and after laser treatment of the ink edge.

Figure 15 illustrates a seal according to the present invention.

Figure 16 illustrates the seal structure of the present invention after laser treatment.

Fig. 17 is an infrared treatment gap test chart of tape No. 3.

Fig. 18 is an infrared treatment gap test chart of tape No. 4.

Detailed Description

Through long-term and intensive research, the inventor realizes the efficient filling of gaps when the curved surface components are attached by adopting an expandable adhesive tape layer containing unfoamed microspheres and/or partially foamed microspheres and a laser auxiliary technology, and remarkably improves the attachment performance between the curved surface components. On this basis, the inventors have completed the present invention.

Unexpanded microspheres/partially expanded microspheres

The unexpanded microspheres useful in the present invention include, but are not limited to, expandable polymeric microspheres comprising a polymeric shell and a gas entrapped therein, wherein the polymeric shell, which is a thermoplastic material, softens when heated to a temperature (e.g., 80-200 ℃ or greater, preferably 95-110 ℃, more preferably 130-160 ℃) and the gas expands within the shell, thereby causing the microspheres to rapidly increase in volume.

In general, the particle size of the polymer microspheres is generally 5 to 40 μm (preferably 8 to 38 μm) when unfoamed, and after foaming, the particle size can be increased to 1.01 to 5 times (preferably 1.1 to 3 times) depending on the amount of heat absorbed.

Materials from which the polymeric shell is formed include, but are not limited to: polyacrylonitrile, polypropylene, or a combination thereof.

Typically, the thickness of the polymeric shell, when unfoamed, is from 1 to 5 μm, preferably from 2 to 3 μm.

Typically, the unexpanded microspheres and/or partially expanded microspheres useful in the present invention include, but are not limited to: expancel 551 WU40, Expancel 920DU120, Expancel 093 DU120, Expancel031 DU40, Expancel 053DU40, or combinations thereof.

It is to be understood that in the present invention, "blowing agent", "unexpanded microspheres", "unexpanded polymeric microspheres" and "expandable polymeric microspheres" may be used interchangeably.

It is to be understood that "partially expanded microspheres" as used herein refers to microspheres that are intermediate between unfoamed microspheres and fully expanded microspheres.

Expandable adhesive tape layer (also known as foam tape or expansion tape)

The expandable adhesive tape layer mainly comprises pressure-sensitive adhesive, unfoamed polymer microspheres and/or partially foamed microspheres, and the expandable adhesive tape layer is obtained by coating, drying, slitting and die cutting the mixture of the two or the mixture of the three.

It should be understood that the coating, drying, slitting and die cutting are performed by the conventional process of pressure sensitive adhesive tape, and those skilled in the art are familiar with the process and will not be described in detail herein.

The pressure-sensitive adhesive is selected from the group consisting of: acrylates, rubbers, silicones, polyurethanes, or combinations thereof.

It should be understood that the embodiments of the present invention have been made using pressure-sensitive adhesive of the kind self-developed by the applicant for convenience, but it should be noted that commercially available pressure-sensitive adhesives of the kind described above are also equally applicable to the technical solution of the present invention, and the technical effects thereof are not significantly changed by using commercially available pressure-sensitive adhesives (i.e. comparable technical effects can be obtained by using commercially available pressure-sensitive adhesives).

The amount of unfoamed polymeric microspheres in an individual expandable tape layer is from about 0.1 to about 15 wt%, preferably from about 0.3 to about 10 wt%, and most preferably from about 0.5 to about 8 wt%, based on the total weight of the expandable tape layer.

The partially foamed microspheres may be present in an amount of about 0.1 to about 5 wt%, preferably about 0.1 to about 3.5 wt%, and most preferably about 0.1 to about 2.5 wt%, based on the total weight of the expandable tape layer.

The thickness t0 of the expandable tape layer before application of the laser (i.e., when unfoamed or partially foamed) is generally 30-500 μm, preferably 50-300 μm.

The thickness t1 of the expandable tape layer after laser heating (i.e., after laser foaming) is generally from 32 to 800 μm, preferably from 50 to 500 μm.

Before and after the laser action, t1/t0 is 1.01-5, preferably 1.05-3, more preferably 1.1-2.5, most preferably 1.2-2.

It should be understood that the expandable adhesive tape layer of the present invention does not need further cross-linking reaction in the subsequent use process, and the whole subsequent expansion bonding process has the advantages of safety and controllability.

In the present invention, the laser intensity of the laser action is 0.01% to 20% of the rated power, preferably 0.01% to 10% of the rated power, and more preferably 0.01% to 5% of the rated power. The laser power rating is 100W.

In the present invention, the laser treatment time of the above laser action is 0.5s to 20s, preferably 0.5s to 15s, more preferably 0.5s to 10 s.

It should be understood that, in order to realize directional and quantitative foaming, the regulation precision of the laser intensity of the laser action is 0.01-0.1% of the rated power, and the regulation precision of the laser processing time of the laser action is 0.1s-1s, so as to realize optimal regulation and control.

Adhesive tape

The structure of the adhesive tape of the present invention includes, but is not limited to, the following five forms:

the first form: as shown in fig. 3, the adhesive tape includes only one expandable tape layer and optionally release layers on both sides of the expandable tape layer. Preferably, the thickness of the expandable adhesive tape layer before expansion is 30-500 μm, preferably 100-400 μm, and more preferably 200-350 μm. After laser heating, the microspheres expand to increase the volume of the adhesive tape, and the thickness of the expandable adhesive tape layer is 31-700 μm, preferably 50-500 μm.

The thickness of the expandable adhesive tape layer varies from 1 to 500%, preferably from 5 to 300%, before and after the application of the laser. For example, a 100 μm thick expandable tape layer may be changed to 101-500 μm, preferably 105-300 μm by laser.

The second form: as shown in fig. 4, the adhesive tape comprises a reinforcing layer and expandable tape layers on both major surfaces of the reinforcing layer; the reinforcing layer is a material including, but not limited to, the following group: a polyolefin, polyester, polyimide, polyurethane, rubber, or a combination thereof; the thickness of the strengthening layer is less than or equal to 150 μm, preferably less than or equal to 100 μm, and most preferably less than or equal to 50 μm (such as 5-50um, preferably 10-20 um); the thickness of the single-side expandable adhesive tape layer is 30-200 μm (preferably 50-150 μm); after laser heating, the microspheres expand to increase the volume of the adhesive tape, and the thickness of the single-side expandable adhesive tape layer expands to 31-1000 μm (preferably 32-600 μm); preferably, the strengthening layer is laser-permeable; preferably, the ratio of the thickness of the single-sided expandable tape layer to the thickness of the reinforcing layer prior to application of the laser is from 0.5 to 100 (preferably from 5 to 75).

The polyester includes, but is not limited to, the following group of materials: polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polymethyl methacrylate, or a combination thereof.

It is to be understood that the presence of the reinforcing layer in the adhesive tape of the present invention not only significantly enhances the mechanical strength of the adhesive tape, but also greatly facilitates the removal and rework of the adhesive tape.

The third form: as shown in fig. 5, the difference between the two forms is: the upper side of the reinforcing layer is provided with a glue layer (without unfoamed microspheres) and the lower side is provided with an expandable adhesive tape layer, the thickness of the glue layer (without unfoamed microspheres) before and after expansion is 30-200 mu m (preferably 50-150 mu m), the thickness of the expandable adhesive tape layer before expansion is 50-300 mu m (preferably 50-200 mu m), and the thickness of the expandable adhesive tape layer after expansion is 51-1500 mu m (preferably 53-600 mu m); preferably, the glue layer is laser-permeable or laser-heatable;

form four: as shown in fig. 6, the same as the second form, the difference is: the upper side of the reinforcing layer is an expandable adhesive tape layer, the lower side of the reinforcing layer is an adhesive layer (not containing unfoamed microspheres), the thickness of the adhesive layer before and after expansion is 30-200 mu m (preferably 50-150 mu m), the thickness of the expandable adhesive tape layer before expansion is 50-300 mu m (preferably 50-200 mu m), and the thickness of the expandable adhesive tape layer after expansion is 51-1500 mu m (preferably 53-600 mu m);

the fifth form: as shown in fig. 7, the adhesive tape comprises an expandable tape layer and a glue layer 1 and a glue layer 2 located on both major surfaces of the expandable tape layer, wherein the thickness of the expandable tape layer before expansion is 30-500 μm (preferably 100-: acrylate, rubber, silica gel or their combination, and the thickness of the single side glue layer is 5-100 μm (20-70 μm is better), after laser heating, the microsphere expands to increase the volume of the adhesive tape. Preferably, the glue layer is laser permeable or laser heatable.

Laser assisted technique

The laser has the characteristics of good directionality, extremely high brightness, extremely pure color and extremely high energy.

In the invention, after the adhesive tape is preliminarily attached to the component, the adhesive tape can be treated by laser with high directionality according to the position of the gap, and the adhesive tape can be controllably expanded in a fixed-point and quantitative mode to fill the gap as required.

In order to transmit the energy of the laser to the adhesive tape efficiently, the energy transmission may be performed as follows:

mode A: during the formation of the expandable tape layer, a first substance is added to the mixture to assist in absorbing heat, including (but not limited to): carbon black, a dye, or a combination thereof; the weight ratio of the first substance to the microspheres is 1-10, preferably 1.5-5;

mode B: coating a material (namely forming a heat absorbing material layer) which is easy to absorb heat such as an ink layer on the inner side of a component close to the outer side of a finally obtained product (such as a mobile phone) and a partial area (such as an edge area of an adhesive tape) or the whole area of an acting surface of the adhesive tape; the thickness of the heat absorbing material layer is 10-60 μm, preferably 20-50 μm.

In the present invention, the laser intensity of the laser action is 0.01% -20% of the rated power, preferably 0.01% -10% of the rated power, more preferably 0.01% -5% of the rated power.

Sealing structure (or bonding sealing structure)

The invention provides a sealing structure, which sequentially comprises the following components from outside to inside: a first component, an adhesive tape, and a second component, wherein,

the first component is located on the outer layer and the first component is laser-permeable or heatable by a laser;

the adhesive tape is positioned in the middle layer, and the adhesive tape is used for bonding and sealing the first component and the second component;

the second component is located in the inner layer.

In another preferred embodiment, the second component is laser-permeable or laser-heatable.

In another preferred embodiment, the shape of the first component and the shape of the second component do not match. The "mismatch" refers to: when the first assembly and the second assembly are assembled, a gap with an irregular shape exists between the first assembly and the second assembly.

In another preferred embodiment, the material of the first component and the material of the second component are the same or different and are each independently selected from the group consisting of: glass, ceramic, plastic, coating, metal, or combinations thereof.

In another preferred embodiment, the material of the coating is selected from the following group: acrylates, polyurethanes, silicones, or combinations thereof.

In another preferred example, the first component is a curved rear cover of an electronic product.

In another preferred example, the second component is a curved middle frame or a flat middle frame of the electronic product.

In another preferred example, the first member has an irregular shape.

In another preferred example, the second member is irregular in shape.

In another preferred embodiment, the thickness of the adhesive tape is 50-500 μm, preferably 100-.

In the present invention, after the sealing structure is provided, in order to achieve complete filling, bonding and sealing of the irregular gap between the first component and the second component, the adhesive tape is acted on by laser light directed, positioned and penetrated through the first component (or heated first component) to enable the adhesive tape to expand in fixed points to fill, bond and seal the irregular gap, thereby achieving complete adhesive sealing of the first component and the second component.

Illustratively, the irregular gap means that the gap has at least two (e.g., 2-100, 5-80, or 10-60) height values. The more height values the gap exists, the more irregular the shape thereof, and the more prominent and significant the bonding advantages of the adhesive tape of the present invention will be.

It will be appreciated that the adhesive tape of the present invention is particularly suitable for adhesively filling first and second components that are assembled with irregular gaps that are difficult to completely fill, bond and seal with existing physically fixed tapes.

When the sealing structure is a part of elements in electronic products such as mobile phones and the like, because electronic parts of the electronic products cannot resist the temperature exceeding 80 ℃, after assembly, the laser heating effect can be limited to a target area only through the high-directionality effect of laser, and a non-target area can be completely free from the influence of laser heating.

For ease of understanding, fig. 15 illustrates the seal structure. It can be seen that the directly bonded seal arrangement has a significant gap between the first and second components due to the mismatch of the first and second components.

Fig. 16 illustrates the sealing structure after laser treatment. It can be seen that after the laser-oriented, aligned treatment of the adhesive tape in the area portion containing the voids, the adhesive tape is aligned to expand, thereby achieving complete adhesion of the first component and the second component.

Compared with the existing structure, the adhesive tape in the sealing structure can be positioned and quantitatively expanded according to the actual filling and bonding requirements by adjusting the laser acting power, acting time and acting position so as to realize excellent filling and bonding of irregular gaps and realize excellent filling, bonding and sealing effects. The high directionality of the laser allows the laser action to be applied accurately to the target area without affecting the surrounding area. The high energy of laser can realize the rapid action, greatly improves the packaging efficiency.

The sealing structure can be conformed on site under the action of laser, and is particularly suitable for bonding and sealing of components with irregular shapes.

By using the laser-assisted adhesive tape, the overall waterproof and dustproof performance of the electronic equipment can be obviously improved after the laser-assisted expansion, and the buffering and anti-seismic performance of the equipment can be obviously improved.

Bonding apparatus

In order to cooperate with laser heating expansion, bonding and sealing of an adhesive tape in the sealing structure, the present invention also provides a bonding apparatus comprising:

1) the processing cavity is used for carrying out laser processing on the adhesive tape in the sealing structure;

2) the laser action unit is used for providing directional and quantitative laser required by heating expansion of the adhesive tape in the sealing structure;

3) and the control unit is used for controlling the laser heating process and the operation of the whole equipment.

Typically, the control unit controls the laser heating process by a temperature control mode or a power control mode.

Compared with the prior art, the invention has the following main advantages:

(1) the laser treatment can be used for accurately and highly selectively expanding the expandable adhesive tape layer in the sealing structure in a fixed-point and quantitative manner so as to fully fill irregular gaps;

(2) because the laser treatment has extremely high precision, the action area can be limited to the adhesive tape area needing to be expanded, and other heat-related adverse effects on other parts of the electronic product are not generated basically;

(3) the expansion precision of the laser treatment can be controlled at a micron level (such as 1-5 um);

(4) the laser treatment can be directly added into the original processing technology of electronic products, and the adaptability is very good;

(5) the laser processing has extremely high directional processing performance, so that the processing method is particularly suitable for the condition that the shape of the gap is complex, such as a step gap or other irregular gaps.

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out according to conventional conditions or according to conditions recommended by the manufacturers. Unless otherwise indicated, percentages and parts are by weight.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In addition, any methods and materials similar or equivalent to those described herein can be used in the methods of the present invention. The preferred embodiments and materials described herein are intended to be exemplary only.

Raw materials

Example 1 adhesive tape 1

As shown in fig. 3, the adhesive tape 1 comprises only the expandable tape layer 1, and the expandable tape layer 1 is made of a mixture comprising acrylate pressure sensitive adhesive 1 and Expancel 053DU40 by coating, drying, slitting, and die cutting.

In the mixture, the weight ratio of the pressure sensitive adhesive to the foaming agent is 98: 2.

the thickness of the expandable adhesive tape layer 1 is 100 μm.

Example 2 adhesive tape 2

As shown in fig. 4, the adhesive tape 2 includes, from top to bottom: a first expandable tape layer formed from 98: 2, a mixture of acrylate pressure-sensitive adhesive 1 and Expancel 920DU120, with a thickness of 100 μm;

the strengthening layer is made of polyethylene glycol terephthalate and has the thickness of 12 mu m;

a second expandable tape layer formed from 97: 3 of acrylate pressure-sensitive adhesive 1 and Expancel 920DU120, with a thickness of 100 μm.

Example 3 adhesive tape 3

As shown in fig. 5, the adhesive tape 3 includes, from top to bottom: the first adhesive layer is made of acrylate pressure-sensitive adhesive 2 and has the thickness of 100 mu m;

an expandable adhesive tape layer, comprising 97: 3 of acrylate pressure-sensitive adhesive 1 and Expancel 920DU120, with a thickness of 100 μm.

Example 4 adhesive tape 4

As shown in fig. 6, the adhesive tape 4 includes, from top to bottom: an expandable adhesive tape layer, comprising 97: 3 of acrylate pressure-sensitive adhesive 1 and Expancel 920DU120, with a thickness of 100 μm;

the first adhesive layer is made of acrylate pressure-sensitive adhesive 2 and has a thickness of 100 mu m.

Example 5 adhesive tape 5

As shown in fig. 7, the adhesive tape 5 includes, from top to bottom: the first adhesive layer is made of acrylate pressure-sensitive adhesive 2 and has a thickness of 50 microns;

an expandable adhesive tape layer, comprising 97: 3 of acrylate pressure-sensitive adhesive 1 and Expancel 920DU120, with a thickness of 100 μm;

the second adhesive layer is made of acrylate pressure-sensitive adhesive 2 and has a thickness of 50 microns.

Example 6 adhesive tape 6

The difference from example 1 is that: expancel 920DU120 was used as the unexpanded microspheres instead of Expancel 053DU 40.

The thickness of the expandable tape layer in the adhesive tape 6 was 100 μm.

Example 7 laser treatment

Taking the adhesive tape 1 of example 1 as an example, the adhesive tape 1 was irradiated with a laser intensity of 0.5% of the rated power (the rated laser power was 100W) for 10 seconds, and the thickness of the laser-affected zone of the tape was changed from 100 μm to 135 μm.

Fig. 8 is a schematic view of a laser-treated tape, and fig. 9 is a thickness test result of the laser-treated tape.

The thickness of the tape of the present invention was tested as follows:

the sample was placed on a microscope platform at room temperature and height scans were performed using a 3D laser scanning microscope (instrument model Keyence VK-X200K) on the foamed and unfoamed areas while the height changes of the sample surface during the computer recordings scans. And selecting a required area on the obtained height change curve, and automatically calculating the height difference of the selected area by software.

Example 8 gap filling Performance test

Test method

A test tape and a glass plate having a 40 μm thick printed ink were attached and then attached to another piece of flat glass (as shown in fig. 10), bubbles and bright lines generated due to ink steps were observed, and edge areas of the printed ink were treated with laser light for samples nos. 3 and 4, and then bubbles and bright lines were observed for improvement and compared with samples nos. 1 and 2.

Wherein, samples No. 1-4 are shown in the following table:

sample numbering	Description of the samples
		1	100 mu m acrylic foam adhesive tape 75410
2	150 μm acrylic foam adhesive tape 75415
		3	100 μm adhesive tape 1 (foaming agent 053DU40)
4	100 μm adhesive tape 6 (foaming agent 920DU120)

As can be seen from fig. 11: after being stored for 24 hours after lamination, bright lines and bubbles which are not completely attached still exist on the edge of the ink.

As can be seen from fig. 12: after being stored for 24 hours after lamination, bright lines and bubbles which are not completely attached still exist on the edge of the ink.

Fig. 13 is a gap test chart of tape No. 3, in which a and b are photographs taken after lamination, and c and d are photographs taken after storage for 4 hours at room temperature after lamination and after laser treatment (treatment power 1%, treatment time 15s) of the ink edge.

As can be seen from fig. 13: after laser treatment, the bright lines and bubbles at the edges of the ink substantially disappear.

FIG. 14 is a gap test chart of tape No. 4, in which a and b are photographs taken after lamination, and c and d are photographs taken after storage at room temperature for 4 hours after lamination and laser treatment (treatment power 1%, treatment time 10s) of the ink edge.

As can be seen from fig. 14: after laser treatment, the bright lines and bubbles at the edges of the ink substantially disappear.

Comparative example 1 Infrared treatment

In the same manner as in example 8, the samples laminated with tapes No. 3 and No. 4 were subjected to infrared treatment at a treatment power of 100W for a treatment time of 10 seconds.

Fig. 17 is an infrared treatment gap test chart of tape No. 3.

Fig. 18 is an infrared treatment gap test chart of tape No. 4.

As can be seen from fig. 17 and 18: after infrared treatment, the thickness of the expandable adhesive tape layer is not obviously changed, bright lines and bubbles existing at the edge of the ink are not obviously disappeared, the effect of filling joints cannot be realized, and the effect of full adhesion and sealing cannot be realized. Meanwhile, accurate positioning and quantitative processing cannot be realized by infrared.

All documents referred to herein are incorporated by reference into this application as if each were individually incorporated by reference. Furthermore, it should be understood that various changes or modifications of the present invention can be made by those skilled in the art after reading the above teachings of the present invention, and these equivalents also fall within the scope of the appended claims of the present application.

Claims

1. A laser-assisted adhesive tape, characterized in that the adhesive tape comprises at least one expandable tape layer,

2. The adhesive tape of claim 1 wherein the unfoamed microspheres are present in the expandable tape layer in an amount of 0.1 to 15.0 wt.% based on the total weight of the expandable tape layer alone; and/or

3. The adhesive tape of claim 1 wherein the expandable tape layer has a thickness t0 before application of the laser and a thickness t1 after application of the laser, and t1/t0 is 1.01-5.

4. The adhesive tape of claim 1 wherein the adhesive tape comprises a reinforcing layer and expandable tape layers adhered to both major surfaces of the reinforcing layer.

5. The adhesive tape of claim 1 wherein the adhesive tape comprises a reinforcing layer, a first layer of microspheres-free adhesive bonded to one major surface of the reinforcing layer, and an expandable tape layer bonded to the other major surface of the reinforcing layer.

6. The adhesive tape of claim 1 wherein the adhesive tape comprises an expandable tape layer and a microsphere-free subbing layer adhered to both major surfaces of the expandable tape layer.

7. A sealing structure, comprising in order from the outside inwards: a first component, the adhesive tape of claim 1, and a second component,

the second component is an inner layer.

8. The seal structure of claim 7, wherein the material of the first component and the material of the second component are the same or different and are each independently selected from the group consisting of: glass, ceramic, plastic, coating, or combinations thereof.

9. The seal structure of claim 7, wherein the shape of the first component and the shape of the second component do not match.

10. The seal structure of claim 7, wherein the first and second components are assembled to form an area having irregular gaps that are at least two different heights.