Adhesive, bonding structure and structural component

Abstract

Provided in the present application are an adhesive, a bonding structure and a structural component. The adhesive comprises an adhesive filler having an expandable volume, and the adhesive filler comprises a spherical polymer material having a pore structure. During the curing reaction process of the adhesive, the shape of the polymer material can be gradually restored, and the volume of the adhesive filler can be expanded to a certain extent, such that the volume shrinkage caused by a resin main agent, etc. of the adhesive during the curing reaction process can be compensated to a certain extent, and the curing volume shrinkage rate of the adhesive is reduced. The curing volume shrinkage rate of the adhesive containing the adhesive filler is low, the deformation, displacement, internal stress, etc. caused during the curing reaction process are lower, the structure of a structural member using the adhesive is reliable, and the function of a device is stable.

Description

Adhesives, bonded structures and structural components

[0001] This application claims priority to Chinese Patent Application No. 202411974607.X, filed on December 26, 2024, entitled "Adhesive, Bonding Structure and Structural Component", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of materials, and more specifically, to an adhesive, adhesive structure, and structural component. Background Technology

[0003] Adhesives, as bonding materials, enable the connection between two structural components. During the curing process, adhesives undergo volume shrinkage, which can lead to displacement or localized stress between the two connected components. For structural assemblies, electronic devices, or apparatuses containing these two components, such displacement and / or localized stress can adversely affect their function or performance.

[0004] Taking a camera module as an example, adhesives can be used to fix the lens barrel to the plastic parts used to fix the lens. When the adhesive cures and shrinks, the plastic parts connected to the adhesive may deform. Consequently, the lens fixed within the plastic parts may also deform. This deformation of the lens will severely affect the propagation path of the imaging light incident on the camera module, thus affecting the image quality. Furthermore, adhesives can also be used to fix the lens barrel to the motor, which can be used to move the lens to achieve functions such as focusing or image stabilization. When the adhesive cures and shrinks, the relative position between the lens and the photosensitive element inside the lens barrel will shift. This will shift the position of the imaging light as it passes through the lens and strikes the photosensitive element, thus degrading the image quality of the camera module.

[0005] The reason for adhesive curing shrinkage is that the distance between molecules in the resin matrix and curing agent, which participate in the curing reaction, decreases after the curing reaction. Adding fillers such as metal powders, metal oxides, and inorganic substances to the adhesive, which do not participate in the curing reaction, and reducing the volume proportion of the resin matrix and curing agent, can improve the curing shrinkage rate of the adhesive to some extent. However, the amount of filler in an adhesive is limited; excessive filler content will affect the adhesive properties, thus limiting the ability to improve the curing shrinkage problem using the above methods. Summary of the Invention

[0006] This application provides an adhesive, an adhesive structure, and a structural component. The adhesive includes a volume-expanding filler. During the curing process, the filler increases in volume to compensate for the volume shrinkage of the resin base, resulting in a low curing volume shrinkage rate. Structural components bonded using this adhesive exhibit low internal stress, good structural stability, and reliable function of structural components incorporating this adhesive structure.

[0007] In a first aspect, an adhesive is provided, comprising a resin base and an adhesive filler, the adhesive filler comprising a polymeric material, the adhesive filler being spherical and containing one or more porous structures.

[0008] It is understood that the spherical adhesive filler in this solution refers to a spherical or irregularly shaped sphere (e.g., ellipsoidal, oblate, elongated, icosahedral, etc.). The surface of the spherical adhesive filler in this solution can be a smooth curved surface, or the surface of the adhesive filler can also include one or more planes. The surface of the spherical adhesive filler in this solution can include one or more recessed structures, and / or, the surface of the spherical adhesive filler can also include one or more raised structures.

[0009] Compared to dense fillers, fillers with porous structures have a lower density. Incorporating such fillers into adhesives helps reduce the density of the adhesive mixture, resulting in a smaller overall mass of the structural components using the adhesive. The porous structure of polymers provides more flexibility in pretreatment, facilitating the preparation of expandable adhesive fillers.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, the pore structure of the adhesive filler is open-cell and / or closed-cell.

[0011] For open-cell spherical adhesive fillers, during the adhesive mixing process, organic molecules such as resin main agents can enter the open pores of the adhesive filler and fill these pore structures. In this way, the porosity of the cured adhesive product is smaller, and the mechanical properties of the adhesive, such as strength, modulus, and hardness, are more superior.

[0012] For closed-cell spherical adhesive fillers, the aforementioned adhesive fillers after volume shrinkage can be incorporated into the adhesive. During the curing process of the adhesive, the gas molecules in the closed-cell spherical adhesive fillers expand due to heat, and the filler recovers from a temporary shape to a permanent shape. This helps the spherical adhesive filler maintain its expanded volume and reduces the curing volume shrinkage rate of the adhesive.

[0013] In conjunction with the first aspect, in some implementations of the first aspect, the porosity of the adhesive filler is greater than or equal to 10% and less than or equal to 70%.

[0014] Generally, when the molecules constituting adhesive fillers are loosely arranged in space, the porosity of the adhesive filler is higher; conversely, when the molecules are densely arranged in space, the porosity of the adhesive filler is lower. For spherical polymer materials, a loose spatial arrangement means that, under the same processing conditions, the volume shrinkage of the spherical polymer material is greater, and its volume expansion during shape recovery is also greater. Conversely, a dense spatial arrangement means that, under the same processing conditions, the volume shrinkage of the spherical polymer material is smaller, and its volume expansion during shape recovery is smaller. From a mechanical property perspective, loosely arranged molecules in a material result in relatively lower strength, modulus, and hardness; densely arranged molecules result in relatively higher strength, modulus, and hardness.

[0015] This technical solution uses adhesive fillers with a porosity of 10%-70%, which helps to reduce the volume shrinkage rate during the adhesive curing process while maintaining good mechanical properties of the cured adhesive product.

[0016] In conjunction with the first aspect, in some implementations of the first aspect, the adhesive filler undergoes compression pretreatment, wherein the ratio of the volume of the adhesive filler after compression to the volume of the adhesive filler before compression is greater than or equal to 0.1 and less than or equal to 0.8.

[0017] Compression pretreatment of adhesive fillers causes them to shrink in volume. During the curing process of the adhesive resin and other main components, the fillers that have shrunk in volume can expand, thereby compensating for the volume shrinkage of the resin and reducing the curing volume shrinkage rate of the adhesive.

[0018] In conjunction with the first aspect, in some implementations of the first aspect, the ratio of the compressed volume of the adhesive filler to the uncompressed volume of the adhesive filler is greater than or equal to 0.3 and less than or equal to 0.5.

[0019] Controlling the compression ratio of adhesive fillers within the range of 0.3-0.5 serves two purposes. First, it allows for volume expansion during shape recovery, compensating for volume shrinkage caused by the resin and other components of the adhesive. Second, a higher compression ratio typically implies greater pressure during pretreatment, which can damage the microstructure of the polymer material, preventing shape recovery and volume expansion under changing conditions. Maintaining the compression ratio within this range helps reduce the likelihood of volume expansion failure due to pretreatment.

[0020] In conjunction with the first aspect, in some implementations of the first aspect, the polymeric material is one or more of the following: a thermo-induced shape memory polymer, a photo-induced shape memory polymer, an electro-induced shape memory polymer, and a chemically induced shape memory polymer.

[0021] By using shape memory polymers as adhesive fillers, and by controlling the shape of the shape memory polymer to be a temporary shape before it is incorporated into the adhesive, and controlling the shape of the shape memory polymer to be a permanent shape after the adhesive is cured, the volume of the shape memory polymer can expand to a certain extent during the curing process of the adhesive, thereby reducing the overall curing volume shrinkage rate of the adhesive.

[0022] In conjunction with the first aspect, in certain implementations of the first aspect, the polymeric material includes one or more of the following: cross-linked polyethylene, cross-linked polypropylene, polyvinyl chloride, polystyrene, polycaprolactone, polyacrylamide, phenolic resin, polyether ether ketone, epoxy resin, unsaturated polyester resin, polyoxymethylene, polycarbonate, polysulfone, polyimide, polyaryl ether, polyarylamide, and polyacrylate.

[0023] In conjunction with the first aspect, in some implementations of the first aspect, the adhesive filler further includes at least one of a metallic element, a metallic compound, a non-metallic element, and a non-metallic compound, wherein the metallic element, metallic compound, non-metallic element, or non-metallic compound is located inside the polymer material.

[0024] In one possible implementation, the aforementioned inorganic material can be a powder structure, and the particle size of the inorganic material can be smaller than the diameter of the spherical polymer material. In this case, the smaller inorganic material powder can fill the interior of the spherical polymer material, or the polymer material in the adhesive filler can wrap around the periphery of these inorganic materials.

[0025] By incorporating smaller inorganic powder particles within spherical polymer materials, two materials with different properties can form a microscopic composite structure. This structure results in a stronger bond between the polymer and inorganic materials, and offers advantages such as volume shrinkage and excellent mechanical properties. Using materials containing this microscopic composite structure as fillers in adhesives allows for control over the cured volume shrinkage rate of the adhesive and reduces the adverse effects of the adhesive filler provided in this application on the mechanical properties of the cured adhesive product.

[0026] In conjunction with the first aspect, in some implementations of the first aspect, the particle size of the adhesive filler is greater than or equal to 10 nanometers and less than or equal to 500 micrometers.

[0027] Adhesive fillers can be prepared through polymerization reactions. Achieving smaller particle sizes and more uniform particle size distributions in the reaction products often requires more precise control of the chemical reaction. The adhesive filler particle size provided by this technical solution helps reduce the difficulty and efficiency of its preparation. Furthermore, smaller particle sizes also make it easier to control the thickness of the adhesive applied to structural components during application.

[0028] In conjunction with the first aspect, in some implementations of the first aspect, the glass transition temperature or crystallization temperature of the adhesive filler is greater than or equal to 0°C and less than or equal to 150°C.

[0029] In conjunction with the first aspect, in some implementations of the first aspect, the true density of the adhesive filler is greater than or equal to 0.20 g / cm³. 3 And less than or equal to 5.0 g / cm³ 3 .

[0030] In conjunction with the first aspect, in some implementations of the first aspect, the storage temperature of the adhesive is less than or equal to the glass transition temperature or crystallization temperature of the adhesive filler.

[0031] The glass transition temperature is the temperature at which the microscopic molecular arrangement of an amorphous material changes; the crystallization temperature is the temperature at which the microscopic molecular arrangement of a crystallizable material changes.

[0032] Storing adhesives at lower temperatures prevents the adhesive fillers from regaining their shape and expanding in volume before use, thus preventing them from expanding during the application of the adhesive.

[0033] In conjunction with the first aspect, in some implementations of the first aspect, the resin main agent includes one or more of the following: epoxy resin, phenolic resin, urea-formaldehyde resin, polyurethane, and silicone.

[0034] In conjunction with the first aspect, in some implementations of the first aspect, the adhesive filler is synthesized by one or more of the following methods: suspension polymerization, emulsion polymerization, solution polymerization, and microemulsion polymerization.

[0035] In a second aspect, a pretreatment method for an adhesive filler is provided, the method comprising: heating the adhesive filler to a first temperature, wherein the filler shape is referred to as a permanent shape, the first temperature being higher than the glass transition temperature or crystallization temperature of the adhesive filler; simultaneously compressing the adhesive filler in multiple directions; while compressing the adhesive filler to a reference volume, maintaining pressure and cooling the adhesive filler to a second temperature, wherein the second temperature is lower than the glass transition temperature or crystallization temperature of the adhesive filler, wherein the filler is referred to as a temporary shape; releasing pressure and storing the adhesive filler at a third temperature, wherein the third temperature is lower than the glass transition temperature or crystallization temperature of the adhesive filler.

[0036] In conjunction with the second aspect, in some implementations of the second aspect, the ratio γ of the reference volume to the volume of the adhesive filler before compression can be 0.1-0.8.

[0037] Spherical polymer materials, including those with porous structures, can deform and shrink in multiple spatial directions. Based on this, during pretreatment, the adhesive filler is simultaneously compressed in multiple directions. The porous structures at different locations on the adhesive shrink under compression, resulting in a reduction in the volume of the adhesive filler. The greater the volume reduction during pretreatment, the greater the volume expansion during adhesive use. Therefore, simultaneously compressing the adhesive filler in multiple directions can, to some extent, enhance its volume expansion capability.

[0038] Thirdly, an adhesive structure is provided, including a first structural member, a second structural member, and an adhesive portion located between the first structural member and the second structural member, the adhesive portion including a cured product formed by curing an adhesive from the first aspect and any possible implementation thereof.

[0039] Fourthly, a structural component is provided, which includes the adhesive structure found in the third aspect and any possible implementation thereof.

[0040] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the structural component is a lens module.

[0041] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the first structural component is a lens barrel, and the second structural component is a lens holder or a drive motor.

[0042] When the adhesive provided in this application embodiment is applied to the relative fixation of the lens barrel and the lens holder, the volume shrinkage rate during the curing process of the adhesive is small, the relative displacement between the lens barrel and the lens holder or the internal stress between the connection interfaces is small, the lens barrel and the lens holder are not easy to deform, the probability of deformation of one or more lenses fixed on the lens holder is small, the optical path of the imaging light in the lens is not easy to change, and the imaging quality of the lens module is high.

[0043] The adhesive provided in this application embodiment is applied to fix the lens barrel and the drive motor in a relatively fixed manner. The volume shrinkage rate of the adhesive during the curing process is small, the relative displacement between the drive motor and the lens barrel or the internal stress between the connection interfaces is small, the drive motor can drive the lens to move along the optical axis or along the direction perpendicular to the optical axis according to the preset running track, the relative position between the lens and the photosensitive element is fixed, the position of the incident point of the imaging light on the photosensitive element after passing through the lens is relatively fixed, and the imaging quality of the lens module is high. Attached Figure Description

[0044] Figure 1 is a schematic diagram of the microstructure of an adhesive filler provided in an embodiment of this application.

[0045] Figure 2 is a partial enlarged view of the adhesive filler in Figure 1.

[0046] Figure 3 is a schematic diagram of the process of preparing adhesives according to an embodiment of this application.

[0047] Figure 4 is a flowchart of the pretreatment method for adhesive fillers provided in the embodiments of this application.

[0048] Figure 5 is a schematic diagram of the microstructure of a pretreated adhesive filler provided in the embodiment of the application.

[0049] Figure 6 is a partial enlarged view of the pretreated adhesive filler in Figure 5.

[0050] Figures 7 and 8 are schematic diagrams of a method for testing the curing shrinkage of an adhesive according to an embodiment of this application.

[0051] Figure 9 is a schematic diagram showing the results of another test of the curing shrinkage of the adhesive provided in an embodiment of this application. Detailed Implementation

[0052] The embodiments of this application will now be described in conjunction with the accompanying drawings.

[0053] It should be noted that in this application, "-" indicates a numerical range, including two endpoint values. For example, "40%-60%" includes the two endpoint values ​​of 40% and 60%, as well as all values ​​between these two endpoint values.

[0054] This application mainly relates to an adhesive, which includes an adhesive filler. During the curing reaction of the adhesive, the aforementioned adhesive filler can compensate for the volume shrinkage caused by the resin main agent, etc. The overall volume shrinkage of the adhesive is controllable and can be controlled to around 0.

[0055] The adhesive provided in this application can be used to bond internal structural components of electronic devices such as mobile phones, tablets, watches, and laptops, and this application does not limit its use. For example, the adhesive can be used to bond the lens barrel and voice coil motor in a mobile phone lens module. As another example, the adhesive can be used to bond adjacent circuit boards in a multilayer circuit board within a tablet. For another example, the adhesive can be used to bond the chip and substrate in a laptop. For another example, the adhesive can also be used to bond the screen cover and display screen of a watch screen assembly. When two structural components are connected using the adhesive provided in this application, the displacement and deformation between the structural components are small during the adhesive curing process, resulting in good structural stability and high reliability of the device using this adhesive.

[0056] The adhesive provided in this application embodiment may include adhesive filler, which may include polymer material. The molecular morphology of the adhesive filler may be spherical, and the spherical adhesive filler may contain one or more pore structures.

[0057] Here, polymeric materials are materials composed of compounds with relatively high molecular weights. In some contexts, polymeric materials are also called aggregate materials, which are materials composed of polymeric compounds as a matrix, supplemented with other additives (auxiliaries).

[0058] In the process of mixing adhesive fillers with resin main agents, curing agents and other components, spherical adhesive fillers are conducive to the mixing of fillers with these components. The materials of different components can be dispersed relatively evenly, so that the material composition of different parts of the cured adhesive is relatively consistent, and the performance of different parts of the cured adhesive is relatively consistent.

[0059] Compared to metallic or inorganic non-metallic fillers, polymeric fillers have a relatively lower density. Therefore, when incorporating the same volume of these types of fillers into an adhesive, the total mass of the adhesive containing polymeric fillers is smaller. Furthermore, compared to metallic and inorganic non-metallic materials, the molecular arrangement of polymeric materials is relatively loose, allowing them to exhibit different spatial structures under different conditions. By utilizing this property of polymeric materials, the curing volume shrinkage rate of adhesives containing polymeric fillers can be controlled to some extent.

[0060] Compared to dense fillers, fillers with porous structures have a lower density. Incorporating such fillers into adhesives helps reduce the density of the adhesive mixture, resulting in a smaller overall mass of structural components using these adhesives. The porous structure of adhesive fillers provides more flexibility in pretreatment, facilitating the preparation of expandable adhesive fillers.

[0061] In some examples, the pore shape of the adhesive filler can be open or closed.

[0062] For open-cell spherical adhesive fillers, during the adhesive mixing process, organic molecules such as resin main agents can enter the open pores of the adhesive filler and fill these pore structures. In this way, the porosity of the cured adhesive product is smaller, and the mechanical properties of the adhesive, such as strength, modulus, and hardness, are more superior.

[0063] For closed-cell spherical adhesive fillers, the aforementioned adhesive fillers after volume shrinkage can be incorporated into the adhesive. During the curing process of the adhesive, the gas molecules in the closed-cell spherical adhesive fillers expand due to heat, which helps the spherical adhesive fillers maintain their expanded shape and volume, and helps reduce the curing volume shrinkage rate of the adhesive.

[0064] It is understood that the spherical adhesive filler in this solution refers to a spherical or irregularly shaped sphere (e.g., ellipsoidal, oblate, elongated sphere, icosahedral, etc.). The surface of the spherical adhesive filler in this solution can be a smooth curved surface, or the surface of the adhesive filler can also include one or more planes. The surface of the spherical adhesive filler in this solution can include one or more recessed structures, and / or, the surface of the spherical adhesive filler can also include one or more raised structures. This application does not impose any limitations in this regard.

[0065] In some examples, the polymeric material that makes up the adhesive filler can be a shape memory polymer (SMP). This polymeric material can have an initial shape, which, after its initial conditions are changed and fixed under certain conditions, becomes a temporary shape, and can be restored to its initial shape by external stimuli (such as heat, electricity, light, chemical induction, etc.).

[0066] In other words, the polymeric materials that make up adhesive fillers can include a stationary phase that remembers its initial shape and a reversible phase that can reversibly cure and soften under changing conditions. The stationary phase can be a cross-linked structure of the polymer, a partially crystalline structure, a glassy state of the polymer, or an entanglement of ultrapolymer chains, etc.; the reversible phase can be a partially crystalline phase that undergoes reversible changes between crystallization and crystal melting, or a phase structure that undergoes reversible changes between a glassy state and a rubbery state.

[0067] As an example, the aforementioned polymeric material can be a thermotropic shape memory polymer, or in other words, the shape of such a polymeric material can be changed by controlling the temperature.

[0068] As an example, the aforementioned polymer material can be an electro-shaped shape memory polymer, or in other words, the shape of the polymer material can be changed by controlling the current introduced into it.

[0069] As an example, the aforementioned polymer material can be a photo-induced shape memory polymer, or in other words, the shape of the polymer material can be changed by controlling the light irradiating it.

[0070] As an example, the aforementioned polymer material can be a chemically induced shape memory polymer, or in other words, the shape of the polymer material can be changed by controlling the environment in which the polymer material is located (such as pH value).

[0071] By using shape memory polymers as adhesive fillers, and by controlling the shape of the shape memory polymer to be a temporary shape before it is incorporated into the adhesive, and controlling the shape of the shape memory polymer to be a permanent shape after the adhesive is cured, the volume of the shape memory polymer can expand to a certain extent during the curing process of the adhesive, thereby reducing the overall curing volume shrinkage rate of the adhesive.

[0072] In some examples, adhesive fillers may also include one or more of inorganic materials such as elemental metals, metal compounds, elemental nonmetals, and nonmetal compounds.

[0073] Generally, the aforementioned inorganic materials can have better mechanical properties than polymer materials. Adding inorganic materials to adhesive fillers can, to some extent, enhance the mechanical properties of the cured adhesive products, such as strength, modulus, and hardness.

[0074] For example, the aforementioned inorganic material can be a powder structure, and the particle size of the inorganic material can be smaller than the diameter of the spherical adhesive filler. In this case, the inorganic material powder with a smaller particle size can fill the interior of the spherical adhesive filler, or in other words, the polymer material in the adhesive filler can wrap around the outer periphery of these inorganic materials.

[0075] By incorporating smaller inorganic powder particles within spherical adhesive fillers, two materials with different properties can form a microscopic composite structure. This structure results in a stronger bond between the polymer and inorganic materials, and offers advantages such as volume shrinkage and excellent mechanical properties. Using materials containing this microscopic composite structure as adhesive fillers allows for control over the cured volume shrinkage of the adhesive and reduces the adverse effects of polymer incorporation on the mechanical properties of the cured adhesive product.

[0076] In some examples, the glass transition temperature Tg or crystallization temperature Tc of the adhesive filler is 0℃-150℃, for example, 50℃, 70℃, 90℃, 110℃, 130℃, 150℃, etc.

[0077] In some examples, the porosity of the adhesive filler The percentage ranges from 10% to 70%, for example, 20%, 30%, 40%, 50%, 60%, etc.

[0078] Generally, when the molecules constituting an adhesive filler are loosely arranged in space, the filler has higher porosity; conversely, when the molecules are densely arranged, the filler has lower porosity. For spherical adhesive fillers, a loose molecular arrangement means that under the same processing conditions (such as pressure), the filler will experience greater volume shrinkage and greater volume expansion during shape recovery. Conversely, a dense molecular arrangement means that under the same processing conditions, the filler will experience less volume shrinkage and less volume expansion during shape recovery. From a mechanical properties perspective, a loosely arranged molecular structure results in relatively lower strength, modulus, and hardness; a densely arranged molecular structure results in relatively higher strength, modulus, and hardness.

[0079] This technical solution uses adhesive fillers with a porosity of 10%-70%, which reduces the volume shrinkage rate during the adhesive curing process while helping to maintain the good mechanical properties of the cured adhesive product.

[0080] In some examples, the particle size d of the adhesive filler is 10 nanometers to 500 micrometers, for example, 50 nanometers, 100 nanometers, 500 nanometers, 1 micrometer, 10 micrometers, 50 micrometers, 100 micrometers, 200 micrometers, 400 micrometers, etc.

[0081] Adhesive fillers can be prepared through polymerization reactions. Achieving smaller particle sizes and more uniform particle size distributions in the reaction products often requires more precise control of the chemical reaction. The adhesive filler particle size provided by this technical solution helps reduce the difficulty and efficiency of its preparation. Furthermore, smaller particle sizes also make it easier to control the thickness of the adhesive applied to structural components during application.

[0082] In some examples, the true density ρ of the adhesive filler is 0.2 g / cm³. 3 -5.0g / cm 3 For example, 0.5g / cm 3 1.0g / cm 3 1.5g / cm 3 2.0g / cm 3 2.5g / cm 3 3.5g / cm 3 4.5g / cm 3 wait.

[0083] As a result, the polymeric materials that make up the adhesive filler may include cross-linked polystyrene.

[0084] For example, the cross-linked polystyrene described above can be closed-cell cross-linked polystyrene.

[0085] One possibility is that the particle size d1 of the aforementioned closed-cell cross-linked polystyrene is 100-120 micrometers, for example, 105 micrometers, 110 micrometers, 115 micrometers, etc.

[0086] One possibility is that the porosity of the aforementioned closed-cell cross-linked polystyrene... The percentage is 40%-60%, for example, 44%, 48%, 52%, 56%, etc.

[0087] One possibility is that the true density ρ1 of the aforementioned closed-cell cross-linked polystyrene is 0.50 g / cm³. 3 -0.70g / cm 3 For example, 0.55g / cm 3 0.60g / cm 3 0.65g / cm 3 wait.

[0088] One possibility is that the glass transition temperature Tg1 of the aforementioned closed-cell crosslinked polystyrene is 55℃-65℃, for example, 57℃, 60℃, 63℃, etc.

[0089] For example, the cross-linked polystyrene described above can be open-cell cross-linked polystyrene.

[0090] One possibility is that the particle size d2 of the aforementioned open-cell cross-linked polystyrene is 50 micrometers to 110 micrometers, for example, 60 micrometers, 75 micrometers, 90 micrometers, 105 micrometers, etc.

[0091] One possibility is that the porosity of the aforementioned open-cell cross-linked polystyrene... It ranges from 50% to 80%, for example, 54%, 58%, 62%, 66%, 72%, 76%, etc.

[0092] One possibility is that the true density ρ2 of the aforementioned open-cell cross-linked polystyrene is 0.92 g / cm³. 3 -1.12g / cm 3 For example, 0.95g / cm 3 1.00g / cm 3 1.05g / cm 3 wait.

[0093] One possibility is that the glass transition temperature Tg2 of the aforementioned open-cell crosslinked polystyrene is 65℃-85℃, for example, 67℃, 70℃, 73℃, 78℃, 82℃, etc.

[0094] As a result, the polymeric materials constituting the adhesive filler may include cross-linked polyacrylamide.

[0095] One possibility is that the particle size d3 of the aforementioned cross-linked polyacrylamide is 10 micrometers to 70 micrometers, for example, 20 micrometers, 30 micrometers, 40 micrometers, 50 micrometers, 60 micrometers, etc.

[0096] One possibility is that the porosity of the aforementioned cross-linked polyacrylamide... The percentage is 40%-60%, for example, 43%, 47%, 50%, 54%, 57%, etc.

[0097] One possibility is that the true density ρ3 of the aforementioned cross-linked polyacrylamide is 0.95 g / cm³. 3 -1.15g / cm 3 For example, 0.98 g / cm³ 3 1.00g / cm 3 1.05g / cm 3 1.09 g / cm 3 1.13 g / cm 3 wait.

[0098] One possibility is that the crystallization temperature Tc3 of the aforementioned crosslinked polyacrylamide is 55℃-65℃, for example, 58℃, 60℃, 62℃, etc.

[0099] As a result, the polymeric materials constituting the adhesive filler may also include one or more of the following: cross-linked polyethylene (PE), cross-linked polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polycaprolactone (PCL), polyacrylamide (PAM), phenolic resin, polyether ether ketone, epoxy resin, unsaturated polyester resin, polyoxymethylene (POM), polycarbonate (PC), polysulfone, polyimide (PI), polyaryl ether, polyarylamide, polyacrylate, etc.

[0100] In some examples, one or more of the adhesive fillers described above can be pretreated before being incorporated into the adhesive to shrink the pore structure within the adhesive filler, thereby reducing the overall volume of the adhesive filler.

[0101] As an example, the ratio (compression ratio) γ of the volume of adhesive filler after pretreatment to its volume before pretreatment can be 0.1-0.8, for example, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, etc.

[0102] As an example, the compression ratio γ of the adhesive filler can be 0.3-0.5.

[0103] Controlling the compression ratio of adhesive fillers within the range of 0.3-0.5 serves two purposes. First, it allows for volume expansion during shape recovery, compensating for volume shrinkage caused by the resin and other components of the adhesive. Second, a higher compression ratio typically implies greater pressure during pretreatment, which can damage the microstructure of the polymer material, preventing shape recovery and volume expansion under changing conditions. Maintaining the compression ratio within this range helps reduce the likelihood of volume expansion failure due to pretreatment.

[0104] The adhesive provided in this application embodiment may further include a resin base and a curing agent.

[0105] For example, the resin main agent can be epoxy resin, and the corresponding curing agent can be amine curing agent (e.g., aliphatic amine, aromatic amine, cyclofin amine, etc.), acid anhydride curing agent (e.g., phthalic anhydride, etc.), imidazole curing agent (e.g., 2-methylimidazolium, etc.), polyamide curing agent, etc.

[0106] For example, the resin main agent can be acrylic resin, and the corresponding curing agent can be isocyanate (e.g., toluene diisocyanate), amino resin (e.g., melamine-formaldehyde resin, urea-formaldehyde resin, etc.).

[0107] For example, the resin main agent can be polyurethane acrylic resin, and the corresponding curing agent can be isocyanate (e.g., toluene diisocyanate), amine curing agent (e.g., fatty amine), etc.

[0108] The adhesives provided in the embodiments of this application may also include inorganic fillers, such as one or more of the following: calcium carbonate, silicon dioxide, aluminum hydroxide, barium sulfate, etc.

[0109] Adding a certain proportion of inorganic fillers to adhesives can, on the one hand, reduce the amount of materials such as resin main agents that may shrink in volume during the curing process, thereby reducing the volume shrinkage rate of the adhesive during curing; on the other hand, it can also improve the mechanical properties of the cured adhesive products.

[0110] The adhesives provided in the embodiments of this application may also include other types of additives, such as one or more of initiators, catalysts, accelerators, solvents, antioxidants, ultraviolet absorbers, colorants, etc., and this application does not limit them.

[0111] The following example illustrates the synthesis method of the adhesive mentioned above. It is understood that, based on the disclosure in the following example, any person skilled in the art can provide more technical solutions through simple changes or substitutions, and this part should also be covered within the protection scope of this application.

[0112] The synthesis process of the adhesive provided in this application embodiment can be roughly divided into three stages: the synthesis stage of the adhesive filler, the pretreatment stage of the adhesive filler, and the synthesis stage of the adhesive. Figure 3 shows a schematic diagram of the adhesive synthesis process: through polymerization reaction, organic monomers can form porous spherical adhesive fillers as shown in the above example. Pretreatment of this reaction product can reduce the volume of the spherical adhesive filler. Mixing the reduced-volume spherical adhesive filler with resin main agent, etc., yields the adhesive.

[0113] First, the synthesis method of the adhesive filler is described. As an example, the adhesive filler provided in this application can be prepared by one or more of the following synthesis methods: suspension polymerization, emulsion polymerization, solution polymerization, microemulsion polymerization, etc. During the synthesis process, materials such as elemental metals, metal compounds, inorganic non-metallic elements, and inorganic non-metallic compounds can be added to form a microscopic composite structure with the polymer material, thereby improving the mechanical properties of the cured product of the adhesive using the filler to a certain extent.

[0114] Example 1

[0115] Preparation of open-cell cross-linked polystyrene

[0116] In a container equipped with a stirring device, first add an appropriate amount of water and emulsifier to ensure that the two are fully mixed to form a homogeneous aqueous system.

[0117] Next, under continuous stirring, styrene monomer and a certain proportion of divinylbenzene crosslinking agent are slowly added, along with an initiator solution and silica powder. At this point, due to the action of the emulsifier, the monomer is dispersed into tiny droplets suspended in the water, forming a stable emulsion state.

[0118] The emulsion was transferred to a reaction flask equipped with a condenser, thermometer and magnetic stirrer, and heated to allow the initiator to decompose and release free radicals.

[0119] Free radicals diffuse into the monomer droplets and undergo a chain reaction with the monomers, gradually generating polystyrene segments. As the reaction proceeds, some segments cross-link due to the presence of a cross-linking agent, ultimately forming cross-linked polystyrene particles with a three-dimensional network structure.

[0120] Maintaining a constant temperature and an appropriate stirring speed promotes efficient heat transfer and good mixing of materials, ensuring the smooth progress of the reaction.

[0121] Once the reaction reaches the desired extent, heating is stopped and the system is allowed to cool naturally. The open-cell cross-linked polystyrene particles are collected by centrifugation or filtration, then washed with water to remove residual monomers and other impurities, and finally dried to obtain the final open-cell cross-linked polystyrene particles.

[0122] The open-cell cross-linked polystyrene particles prepared by the above method were observed using scanning electron microscopy. Figure 1 shows a schematic diagram of the microstructure of the open-cell cross-linked polystyrene, and Figure 2 shows a magnified view of the area A1 marked with a dashed box in Figure 1.

[0123] The particle size distribution of open-cell cross-linked polystyrene was measured by laser diffraction as described in ISO 13320:20, and the particle size d2 of the open-cell cross-linked polystyrene was found to be 52.3 μm-85.8 μm.

[0124] The porosity and true density of open-cell cross-linked polystyrene were measured using the liquid hydrometer method as described in ISO 1183-1:2019. The results showed that the porosity of the open-cell cross-linked polystyrene was 68% and the true density was 1.01 g / cm³. 3 .

[0125] The glass transition temperature of open-cell cross-linked polystyrene was determined by differential scanning calorimetry according to ISO 11357-1:2023, and the glass transition temperature of open-cell cross-linked polystyrene was found to be 72℃.

[0126] Example 2

[0127] Preparation of closed-cell cross-linked polystyrene

[0128] In a reaction flask equipped with a stirrer, first add an appropriate amount of solvent and ensure that the temperature is at room temperature.

[0129] Next, under continuous stirring, the predetermined amounts of styrene monomer, divinylbenzene crosslinking agent, calcium carbonate powder, and initiator are added sequentially. At this point, all components should be fully dissolved in the solvent to form a homogeneous and transparent solution system.

[0130] The solution was transferred to a reaction flask equipped with a condenser, thermometer, and magnetic stirrer, and nitrogen gas was introduced to remove oxygen from the air and prevent it from inhibiting the polymerization reaction.

[0131] Heating causes the initiator to decompose and release free radicals.

[0132] Free radicals react with monomers in a chain reaction, gradually generating polystyrene segments. As the reaction proceeds, some segments cross-link due to the presence of cross-linking agents, eventually forming cross-linked polystyrene with a three-dimensional molecular network structure.

[0133] Maintaining a constant temperature and an appropriate stirring speed promotes efficient heat transfer and good mixing of materials, ensuring the smooth progress of the reaction.

[0134] Once the reaction reaches the desired extent, heating is stopped and the system is allowed to cool naturally. Closed-cell cross-linked polystyrene particles are separated from the solvent by precipitation, filtration, or centrifugation. These particles are then washed with water to remove residual monomers and other impurities, and finally dried to obtain the final closed-cell cross-linked polystyrene particles.

[0135] The particle size of closed-cell cross-linked polystyrene was measured by laser diffraction as described in ISO 13320:20, and the particle size d1 of closed-cell cross-linked polystyrene was found to be 105.4 μm-119.5 μm.

[0136] The porosity and true density of closed-cell cross-linked polystyrene were measured according to the liquid hydrometer method described in ISO 1183-1:2019. The results showed that the porosity of the closed-cell cross-linked polystyrene was 42% and the true density was 0.63 g / cm³. 3 .

[0137] The glass transition temperature of closed-cell cross-linked polystyrene was determined by differential scanning calorimetry according to ISO 11357-1:2023, and the glass transition temperature of closed-cell cross-linked polystyrene was found to be 58℃.

[0138] Example 3

[0139] Preparation of crosslinked polyacrylamide

[0140] In a container equipped with a stirring device, a certain proportion of water, emulsifier, and co-emulsifier are first mixed evenly to form a transparent basic microemulsion.

[0141] Slowly add acrylamide monomer and silica powder to the above-mentioned basic microemulsion while maintaining strong stirring to ensure that the monomer is well dispersed into nano-sized droplets, forming a stable microemulsion system.

[0142] The monomer-containing microemulsion was transferred to a reaction flask equipped with a condenser, thermometer, and magnetic stirrer.

[0143] Add an appropriate amount of ammonium persulfate as an initiator, and purge with nitrogen gas to remove oxygen from the air and prevent it from inhibiting the polymerization reaction.

[0144] When the temperature is raised to around 70°C, the initiator begins to decompose and generate free radicals, which in turn initiate the polymerization reaction of acrylamide monomers.

[0145] Maintaining a constant temperature and an appropriate stirring speed promotes efficient heat transfer and good mixing of materials, ensuring the smooth progress of the reaction.

[0146] Once the reaction reaches the desired extent, heating is stopped and the system is allowed to cool naturally. After removing moisture and other volatile components through evaporation, the resulting product undergoes a series of post-processing steps, including drying, to obtain cross-linked polyacrylamide particles.

[0147] According to the laser diffraction method described in ISO 13320:20, the particle size of cross-linked polyacrylamide was measured, and the particle size d3 of open-cell cross-linked polystyrene was found to be 13.5 μm-66.2 μm.

[0148] The porosity and true density of cross-linked polyacrylamide were measured according to the liquid hydrometer method described in ISO 1183-1:2019. The results showed that the porosity of the cross-linked polyacrylamide was 49% and the true density was 1.05 g / cm³. 3 .

[0149] The glass transition temperature of cross-linked polyacrylamide was determined to be 61℃ by differential scanning calorimetry as described in ISO 11357-1:2023.

[0150] The following describes the pretreatment method for adhesive fillers. The flowchart shown in Figure 4 roughly illustrates the pretreatment process for adhesive fillers.

[0151] As an example, the adhesive filler is heated to above the glass transition temperature or crystallization temperature (e.g., temperature T1); the heated adhesive filler is moved to a compression fixture, and the adhesive filler is simultaneously compressed in multiple directions (e.g., X and Y directions, X and Z directions, Y and Z directions, X, Y and Z directions) by a pressurizing device to compress the filler to a certain volume; after compression, the pressure is maintained and the temperature is cooled down to below the glass transition temperature or crystallization temperature (e.g., temperature T2); then the pressure is released and the compressed adhesive filler is stored at low temperature.

[0152] Among them, any two of the X, Y, and Z directions are perpendicular to each other.

[0153] In some examples, the ratio of the volume of the adhesive filler after compression to its volume before compression (compression ratio) γ can be 0.1-0.8. For example, γ can be 0.3, 0.5, 0.7, etc.

[0154] As an example, open-cell cross-linked polystyrene (Tg = 72°C) filler is heated to 92°C, and 50 kgf pressure is applied in the X direction, Y direction, and Z direction in a compression fixture. The compression ratio is controlled at 0.5. Under the pressure condition, the temperature is reduced to 20°C and the pressure is released.

[0155] Figure 5 shows a schematic diagram of the microstructure of the open-cell cross-linked polystyrene in Figure 1 above after being treated by the above pretreatment method. Figure 6 shows a partial enlarged view of area A2 marked with a dashed box in Figure 5.

[0156] Comparing Figure 5 and Figure 1, the pretreated spherical open-cell cross-linked polystyrene exhibits a smaller particle size and volume. Comparing Figure 6 and Figure 2, the surface lamellar polymers of the pretreated spherical open-cell cross-linked polystyrene are more tightly packed, and the width of the gaps (pores) between the lamellar polymers is reduced. The porosity of the pretreated cross-linked polystyrene is lower than that of the untreated cross-linked polystyrene.

[0157] Understandably, for the same particle, the porosity decreases after pretreatment, and the true density increases accordingly. In other words, the true density of cross-linked polystyrene after pretreatment is greater than the true density of cross-linked polystyrene before pretreatment.

[0158] As an example, closed-cell cross-linked polystyrene (Tg = 58°C) filler is heated to 78°C, and 50 kgf pressure is applied in the X direction, Y direction, and Z direction in a compression fixture. The compression ratio is controlled at 0.5. Under the pressure condition, the temperature is reduced to 20°C and the pressure is released.

[0159] As an example, cross-linked polylactone (Tm = 50°C) filler is heated to 70°C, and 80 kgf pressure is applied in the X direction, Y direction, and Z direction in a compression fixture. The compression ratio is controlled at 0.3. Under the pressure condition, the temperature is reduced to 10°C and the pressure is released.

[0160] Spherical adhesive fillers, including those with porous structures, can deform and shrink in multiple spatial directions. Based on this, during pretreatment, the adhesive filler is simultaneously compressed in multiple directions. The porous structures at different locations on the adhesive shrink under compression, resulting in a reduction in the volume of the adhesive filler. The greater the volume reduction during pretreatment, the greater the volume expansion during adhesive use. Therefore, simultaneously compressing the adhesive filler in multiple directions can, to some extent, enhance its volume expansion capability.

[0161] The following describes the synthesis method of adhesives.

[0162] Adhesive fillers, resin main agents, curing agents, and other additives are mixed and stirred to form an uncured adhesive. During the mixing process, the mixing temperature can be controlled to not exceed the glass transition temperature Tg or crystallization temperature Tc of the adhesive filler to reduce the probability of shape recovery of the adhesive filler during the mixing process. The uncured adhesive can be stored at low temperature before use. Specifically, the storage temperature can not exceed the glass transition temperature Tg or crystallization temperature Tc of the adhesive filler.

[0163] In some examples, the resin main agent may include one or more of the following: epoxy resin, phenolic resin, urea-formaldehyde resin, polyurethane, silicone, etc.

[0164] As an example 1, the composition is: 20% epoxy resin, 10% amine curing agent, 40% cross-linked polyethylene filler, 20% calcium carbonate filler, 3% accelerator A, and 7% other additives.

[0165] As an example 2, the composition is: 20% epoxy resin, 10% amine curing agent, 30% cross-linked polyethylene filler, 30% calcium carbonate filler, 3% accelerator A, and 7% other additives.

[0166] As a control 1, the composition was 20% epoxy resin, 10% amine curing agent, 60% calcium carbonate filler, 3% accelerator A, and 7% other additives.

[0167] As an example 3, the composition is 30% acrylic resin, 50% crosslinked polypropylene filler, 10% silica filler, 4% accelerator B, and 6% other additives.

[0168] As an example 4, the composition is 30% acrylic resin, 40% crosslinked polypropylene filler, 20% silica filler, 4% accelerator B, and 6% other additives.

[0169] As a control 2, the composition was 30% acrylic resin, 60% silica filler, 4% accelerator B, and 6% other additives.

[0170] As an example 5, the polyurethane acrylate is 40%, the cross-linked polystyrene filler is 40%, and other additives are 20%.

[0171] As an example 6, the polyurethane acrylate is 40%, the cross-linked polystyrene filler is 30%, the silica filler is 10%, and other additives are 20%.

[0172] As a control 3, the composition was 40% polyurethane acrylate, 40% silica filler, and 20% other additives.

[0173] According to the method described in ISO 527-2:2012, standard specimens were prepared from the adhesives of different components in the above examples, and the tensile strength, tensile modulus and tensile elongation at break of these specimens were tested.

[0174] The adhesive strength of the different components of the adhesives in the above examples was tested according to the method described in ISO 4587:2003.

[0175] According to the method described in ISO 3521-1997, the curing shrinkage rate of the adhesives with different components in the above examples was tested. Specifically, the true density ρ0 before curing and the true density ρ1 after curing of the adhesives were measured respectively. The curing volume shrinkage rate λ of the adhesives can be calculated according to the following formula (1):

[0176] In some examples, the shrinkage during the adhesive curing process can be analyzed by measuring the normal shrinkage force after the adhesive has cured. For example, using a rheometer, with the thickness between the rotor and the base plate controlled at 1 mm, uncured adhesive is completely filled between the rotor and the base plate, cured using standard methods, and the shrinkage force in the thickness direction of the adhesive (or the axial direction of the rotor) is measured to determine the shrinkage during the adhesive curing process.

[0177] In some examples, shrinkage during the adhesive curing process can be analyzed by applying uncured adhesive to filter paper and measuring the deformation of the cured filter paper. Referring to Figures 7 and 8, Figure 7 shows filter paper coated with uncured adhesive, and Figure 8 shows filter paper after the adhesive has cured. The left schematic diagram is a top view of the filter paper (in a curled state), and the right schematic diagram is a front view of the filter paper.

[0178] For example, using 90mm diameter filter paper, an uncured adhesive with a thickness of 200µm and a width of 30mm×40mm is coated on the center of the filter paper and cured using standard methods. The maximum width of the curl of the deformed filter paper after the adhesive is fully cured is measured (L in Figure 8) to determine the shrinkage during the curing process of the adhesive.

[0179] The glass transition temperatures of the adhesives with different components in the above examples were tested according to the method described in ISO 11357-1:2023.

[0180] According to the method described in ISO 11359-1:2023, the coefficient of thermal expansion (CTE) of the different components of the adhesive in the above examples was tested. The coefficient of thermal expansion of the adhesive below the glass transition temperature Tg or crystallization temperature Tc was denoted as CTE1, and the coefficient of thermal expansion of the adhesive above the glass transition temperature Tg or crystallization temperature Tc was denoted as CTE2.

[0181] The test results of the above experiment are recorded in Table 1 below.

[0182] Table 1

[0183] In Examples 1, 2, and Control 1 above, epoxy resin is used as the main resin component of the adhesive. In Control 1, the adhesive exhibits a relatively large curing volume shrinkage rate and curing normal force, but a relatively small curing curl width. In Examples 1 and 2, the adhesive exhibits a relatively small curing volume shrinkage rate and curing normal force, but a relatively large curing curl width. This indicates that without the cross-linked polyethylene filler provided in this application, the volume shrinkage during adhesive curing is significant, resulting in substantial stress. With the addition of cross-linked polyethylene filler, the volume shrinkage during adhesive curing decreases, leading to less stress. Comparing Examples 1 and 2, as the amount of polystyrene in the adhesive increases, the curing volume shrinkage rate and curing normal force decrease, while the curing curl width increases.

[0184] Similarly, in Examples 3, 4, and Comparative 2 above, acrylic resin is used as the main resin agent. Without the cross-linked polypropylene filler provided in this application, the volume shrinkage during adhesive curing is significant, resulting in substantial stress. As the amount of polypropylene in the adhesive increases, the cured volume shrinkage rate and curing normal force of the adhesive decrease, while the cured curl width increases.

[0185] Similarly, comparing Examples 5 and 6 with Control 3 above, polyurethane acrylate is used as the resin. Without the cross-linked polystyrene filler provided in this application, the volume shrinkage during adhesive curing is significant, resulting in substantial stress. As the amount of polystyrene in the adhesive increases, the cured volume shrinkage rate and curing normal force of the adhesive decrease, while the cured curl width increases.

[0186] Figure 9 provides an exemplary schematic diagram of the change in normal force during the curing process of the adhesive in Example 1 above. The change in normal force during the curing process of the adhesive in Examples 2 to 6 is similar. Referring to Figure 9, during the time period from 0 to t11, the normal force is approximately maintained at the level of 0 N. During this process, the temperature of the adhesive gradually increases and the viscosity gradually decreases, and the molecules constituting the adhesive do not solidify. During the time period from t11 to t5, the temperature of the adhesive is basically stable, the viscosity of the adhesive gradually increases, and the normal force gradually decreases, indicating that the volume of the adhesive expands during the curing process.

[0187] The above experimental results demonstrate that incorporating the spherical adhesive filler with a porous structure provided in the embodiments of this application into the adhesive can improve the volume shrinkage problem during the adhesive curing process and control the overall curing volume shrinkage rate of the adhesive to around 0.

[0188] During the application of adhesives, the temperature of the application environment can be controlled to be less than or equal to the glass transition temperature or crystallization temperature of the adhesive filler. During the subsequent curing process of the adhesive (e.g., heat curing, UV curing, etc.), the adhesive reaction is exothermic and the temperature gradually rises. The curing temperature of the adhesive can be controlled to be higher than the glass transition temperature or crystallization temperature of the adhesive filler, so that the shape of the adhesive filler can be fully restored and its volume expands to compensate for the volume shrinkage of the resin main agent and other components in the adhesive during the curing process.

[0189] Based on the adhesive provided in the above examples, this application embodiment also provides an adhesive structure, which includes a first structural member and a second structural member, and an adhesive portion located between the first structural member and the second structural member. The adhesive portion may include a cured product formed by curing the adhesive provided in this application embodiment.

[0190] This application also provides a structural component that may include the above-described adhesive structure.

[0191] In some examples, the structural component can be a lens module, which may include one or more of a lens barrel, lens, photosensitive element, drive motor, etc. Imaging light passes through one or more lens elements in the lens module and then enters the photosensitive element to form an image.

[0192] For example, the first structural component of the above-mentioned adhesive structure can be the lens barrel of the lens module, and the second structural component can be the lens holder of the lens module. The lens holder can be used to load one or more lenses in the lens module, and the adhesive part can be located between the inner wall of the lens barrel and the lens holder.

[0193] When the adhesive provided in this application embodiment is applied to the relative fixation of the lens barrel and the lens holder, the volume shrinkage rate during the curing process of the adhesive is small, the relative displacement between the lens barrel and the lens holder or the internal stress between the connection interfaces is small, the lens barrel and the lens holder are not easy to deform, the probability of deformation of one or more lenses fixed on the lens holder is small, the optical path of the imaging light in the lens is not easy to change, and the imaging quality of the lens module is high.

[0194] For example, the first structural component of the aforementioned adhesive structure can be the lens barrel of a lens module, and the second structural component can be a drive motor. This drive motor can be used to implement the focusing and / or image stabilization functions of the lens module. For instance, the drive motor can be used to drive the lens to move along the optical axis of the lens module, or it can be used to drive the lens to move within a plane corresponding to the optical axis of the lens module. The adhesive portion can be located between the inner wall of the lens barrel and the drive motor.

[0195] The adhesive provided in this application embodiment is applied to fix the lens barrel and the drive motor in a relatively fixed manner. The volume shrinkage rate of the adhesive during the curing process is small, the relative displacement between the drive motor and the lens barrel or the internal stress between the connection interfaces is small, the drive motor can drive the lens to move along the optical axis or along the direction perpendicular to the optical axis according to the preset running track, the relative position between the lens and the photosensitive element is fixed, the position of the incident point of the imaging light on the photosensitive element after passing through the lens is relatively fixed, and the imaging quality of the lens module is high.

[0196] In some examples, the structural component can be a display module, which may include a display panel, a cover plate, a polarizer, etc., and the display panel can display images when powered on.

[0197] For example, the first structural component of the above-mentioned adhesive structure can be the display panel of the display module, and the second structural component can be the cover plate of the display module. The display panel can be used to realize the display function of the display module, and the cover plate can be used to protect the display panel. The adhesive part can be located between the display panel and the cover plate.

[0198] When the adhesive provided in this application embodiment is applied to the relative fixation between the display panel and the cover plate, the volume shrinkage rate during the curing process of the adhesive is small, the relative displacement between the display panel and the cover plate or the internal stress between the connection interface is small, the structure of the display module is more robust, and the probability of structural damage or functional failure caused by local stress concentration at the connection interface is small.

[0199] For example, the first structural component of the above-mentioned adhesive structure can be a polarizer of the display module, the second structural component can be a cover plate of the display module, the display panel can be used to realize the display function of the display module, the polarizer can be used to adjust the propagation mode of ambient light in the display module, and the adhesive part can be located between the polarizer and the cover plate.

[0200] In some examples, the structural component can be a circuit board assembly, which may include one or more circuit boards, one or more electronic components (e.g., resistors, capacitors, inductors, diodes, transistors, chips, etc.). The circuit boards may include electrical connection lines to enable electrical connections between the electronic components. Multiple circuit boards may be stacked along the thickness direction of the circuit boards. When the circuit board assembly is powered on, the electronic components on the circuit board assembly can receive signals input from external circuits, output signals to external circuits, and process input signals.

[0201] For example, the first structural component of the adhesive structure may be an electronic component (such as a chip) on a circuit board assembly, and the second structural component may be a circuit board included in the circuit board assembly. The adhesive portion may be located between the electronic component and the circuit board and be used for the relative fixation of the electronic component and the circuit board.

[0202] For example, the circuit board assembly can be formed by bonding multiple circuit boards upward along the thickness direction of the circuit board. The first structural member included in the bonding structure can be the first circuit board in two adjacent circuit boards, and the second structural member can be the second circuit board in two adjacent circuit boards. The bonding part can be located between the first circuit board and the second circuit board and is used to fix the first circuit board and the second circuit board relative to each other.

[0203] This application also provides an electronic device that uses one or more adhesives provided in this application, or that includes one or more structural components provided in this application.

[0204] In some examples, the aforementioned electronic devices can be portable electronic devices such as mobile phones, tablets, and laptops; in some examples, the aforementioned electronic devices can be wearable electronic devices such as wristbands, watches, earphones, glasses, and rings; in some examples, the aforementioned electronic devices can also be electronic devices in home or office scenarios such as smart screens, smart speakers, and routers; in some examples, the aforementioned electronic devices can also be devices such as central control displays, digital dashboards, head-up displays, and smart seats in smart cockpit scenarios.

[0205] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An adhesive, characterized in that, It includes a resin base and an adhesive filler, wherein the adhesive filler comprises a polymer material, the adhesive filler is spherical, and contains one or more pore structures.

2. The adhesive according to claim 1, characterized in that, The adhesive filler has an open-cell and / or closed-cell pore structure.

3. The adhesive according to claim 1 or 2, characterized in that, The porosity of the adhesive filler is greater than or equal to 10% and less than or equal to 70%.

4. The adhesive according to any one of claims 1 to 3, characterized in that, The adhesive filler undergoes compression pretreatment, and the ratio of the volume of the adhesive filler after compression to the volume of the adhesive filler before compression is greater than or equal to 0.1 and less than or equal to 0.

8.

5. The adhesive according to claim 4, characterized in that, The ratio of the compressed volume of the adhesive filler to the uncompressed volume of the adhesive filler is greater than or equal to 0.3 and less than or equal to 0.

5.

6. The adhesive according to any one of claims 1 to 5, characterized in that, The polymeric material includes one or more of the following: thermo-induced shape memory polymer, photo-induced shape memory polymer, electro-induced shape memory polymer, and chemically induced shape memory polymer.

7. The adhesive according to claim 6, characterized in that, The polymeric material includes one or more of the following: cross-linked polyethylene, cross-linked polypropylene, polyvinyl chloride, polystyrene, polycaprolactone, polyacrylamide, phenolic resin, polyether ether ketone, epoxy resin, unsaturated polyester resin, polyoxymethylene, polycarbonate, polysulfone, polyimide, polyaryl ether, polyarylamide, and polyacrylate.

8. The adhesive according to any one of claims 1 to 7, characterized in that, The adhesive filler further includes at least one of elemental metal, metal compound, elemental nonmetal, and nonmetal compound, wherein the elemental metal, metal compound, elemental nonmetal, and nonmetal compound are located inside the polymer material.

9. The adhesive according to any one of claims 1 to 8, characterized in that, The particle size of the adhesive filler is greater than or equal to 10 nanometers and less than or equal to 500 micrometers.

10. The adhesive according to any one of claims 1 to 9, characterized in that, The glass transition temperature or crystallization temperature of the adhesive filler is greater than or equal to 0°C and less than or equal to 150°C.

11. The adhesive according to any one of claims 1 to 10, characterized in that, The true density of the adhesive filler is greater than or equal to 0.20 g / cm³. 3 And less than or equal to 5.0 g / cm³ 3 .

12. The adhesive according to any one of claims 1 to 11, characterized in that, The storage temperature of the adhesive is less than or equal to the glass transition temperature or crystallization temperature of the adhesive filler.

13. The adhesive according to claim 12, characterized in that, The resin main agent includes one or more of the following: epoxy resin, phenolic resin, urea-formaldehyde resin, polyurethane, and silicone.

14. The adhesive according to any one of claims 1 to 13, characterized in that, The adhesive filler is synthesized by one or more of the following methods: suspension polymerization, emulsion polymerization, solution polymerization, and microemulsion polymerization.

15. A pretreatment method for adhesive fillers, characterized in that, The method includes: The adhesive filler is heated to a first temperature, which is higher than the glass transition temperature or crystallization temperature of the adhesive filler. The adhesive filler is compressed simultaneously in multiple directions; While compressing the adhesive filler to a reference volume, the pressure is maintained and the adhesive filler is cooled to a second temperature, which is lower than the glass transition temperature or crystallization temperature of the adhesive filler. The pressure is released, and the adhesive filler is stored at a third temperature, which is lower than the glass transition temperature or crystallization temperature of the adhesive filler.

16. The pretreatment method according to claim 15, characterized in that, The ratio γ of the reference volume to the volume of the adhesive filler before compression is 0.1-0.

8.

17. An adhesive structure, characterized in that, include: A first structural member, a second structural member, and an adhesive portion located between the first structural member and the second structural member, the adhesive portion comprising a cured product formed by curing the adhesive according to any one of claims 1 to 14.

18. A structural component, characterized in that, include: The adhesive structure as described in claim 17.

19. The structural component according to claim 18, characterized in that, The structural component is a lens module.

20. The structural component according to claim 19, characterized in that, The first structural component is a lens barrel, and the second structural component is a lens holder or a drive motor.

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