Low-temperature foaming type thermal adhesion-reducing adhesive tape and preparation method and application thereof

Abstract

The application provides a low-temperature foaming type heat tack-reducing adhesive tape and a preparation method and application thereof. The low-temperature foaming type heat tack-reducing adhesive tape comprises, from top to bottom, a substrate layer, a glue layer and a release film layer; the material of the substrate layer is a PET heat shrinkable film; the preparation raw material of the glue layer comprises the following components in parts by weight: acid-free acrylic resin 100 parts; curing agent 3-6 parts; low-temperature foaming microspheres 3-6 parts; color paste 2-5 parts. The heat tack-reducing adhesive tape of the application can automatically fall off in 40s in a 70 DEG C water bath, and does not pollute the surface of electronic components.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of adhesive tape, and relates to a low-temperature foaming type heat adhesion-reducing adhesive tape as well as a preparation method and application thereof. BACKGROUND

[0002] The heat adhesion-reducing adhesive tape is also known as heat peeling film, which is made of a special adhesive glue and has certain adhesion at normal temperature. As long as the temperature is heated to a set temperature, the adhesion disappears, and simple peeling, no residual glue and no pollution of the adherend can be achieved. In the production process of patch electronic components and spare parts, because some parts are not resistant to high temperature, and in order to meet the demand of efficient operation, a heat adhesion-reducing adhesive tape capable of quickly losing adhesion and falling off at low temperature is needed to realize automation, save manpower and material resources, and improve efficiency.

[0003] The adhesion reduction is divided into water bath adhesion reduction and adhesion reduction in an oven. At present, it is found that the water bath adhesion reduction is faster, and is suitable for the protection of LED screens, mobile phones and metal shells such as tablets.

[0004] At present, most of the heat adhesion-reducing adhesive tapes on the market need high temperature of 100 DEG C or above and long time baking to completely lose adhesion, which is very unfavorable for the production efficiency on the assembly line. Moreover, some electronic components cannot withstand high temperature of 100 DEG C or above, and cannot be improved in temperature to accelerate foaming and falling off, which is not conducive to the improvement of production efficiency.

[0005] CN111647365A discloses a low-temperature heat adhesion-reducing adhesive tape, which comprises a base film, a heat adhesion-reducing adhesive layer and a release film. The base film is subjected to vulcanization treatment. The raw materials of the heat adhesion-reducing adhesive include resin 50.0-80.0 parts, curing agent 0.1-15.0 parts, foaming agent 1.0-20.0 parts, solvent 5.0-30.0 parts and colorant 0.1-1.0 parts by weight. The adhesive tape has good adhesion before adhesion reduction, and can quickly lose adhesion after low-temperature heating at 80-160 DEG C, so that the adhesive tape and the adherend can be easily separated and no residual glue is left. However, the temperature of the heat adhesion-reducing adhesive tape of the application for quickly losing adhesion still needs to be further reduced.

[0006] Therefore, in the field, it is desirable to develop a low-temperature foaming type heat adhesion-reducing adhesive tape to further improve the production efficiency. SUMMARY

[0007] In view of the deficiencies of the prior art, the purpose of the application is to provide a low-temperature foaming type heat adhesion-reducing adhesive tape as well as a preparation method and application thereof. The low-temperature foaming type heat adhesion-reducing adhesive tape of the application can automatically fall off in 40 seconds in a 70 DEG C water bath, and does not pollute the surface of electronic components, greatly accelerating the production efficiency.

[0008] To achieve this purpose, the application adopts the following technical solutions:

[0009] In a first aspect, the present application provides a low-temperature foaming type thermal adhesion-reducing tape, which comprises, from top to bottom, a substrate layer, an adhesive layer and a release film layer;

[0010] The material of the substrate layer is a PET (polyethylene terephthalate) heat shrinkable film.

[0011] The preparation raw material of the adhesive layer comprises the following components in parts by weight:

[0012]

[0013] In the present application, the low-temperature foaming microspheres can start foaming at 60℃, and the PET heat shrinkable film substrate and the low-temperature foaming microspheres in the adhesive layer work together to make the thermal adhesion-reducing tape automatically fall off in 40s in a 70℃ water bath, without contaminating the surface of electronic components.

[0014] In the present application, the low-temperature foaming type thermal adhesion-reducing tape refers to the low-temperature foaming type thermal adhesion-reducing tape of the present application, which can automatically fall off in 40s in a 70℃ water bath.

[0015] In the present application, the amount of the curing agent in the preparation raw material of the adhesive layer can be 3 parts, 3.3 parts, 3.5 parts, 3.8 parts, 4 parts, 4.3 parts, 4.5 parts, 4.8 parts, 5 parts, 5.3 parts, 5.5 parts, 5.8 parts or 6 parts, etc.

[0016] If the amount of the curing agent is too small, the initial peeling force of the tape is high, affecting the foaming speed, and if the amount of the curing agent is too large, the initial peeling force of the tape is low, failing to achieve the fixing effect.

[0017] In the present application, the amount of the low-temperature foaming microspheres in the preparation raw material of the adhesive layer can be 3 parts, 3.3 parts, 3.5 parts, 3.8 parts, 4 parts, 4.3 parts, 4.5 parts, 4.8 parts, 5 parts, 5.3 parts, 5.5 parts, 5.8 parts or 6 parts, etc.

[0018] If the amount of the low-temperature foaming microspheres is too small, the foaming efficiency is reduced, and if the amount of the low-temperature foaming microspheres is too large, the initial peeling of the tape is low, the adhesion is poor, and the fixing effect cannot be achieved.

[0019] In the present application, the amount of the color paste in the preparation raw material of the adhesive layer can be 2 parts, 2.3 parts, 2.5 parts, 2.8 parts, 3 parts, 3.3 parts, 3.5 parts, 3.8 parts, 4 parts, 4.3 parts, 4.5 parts, 4.8 parts or 5 parts, etc.

[0020] In the present application, the acid-free acrylic resin can be prepared by itself or purchased directly (brand: Panyu Xinyi Chemical DS-3017P). Exemplarily, the raw materials for preparing the acid-free acrylic resin include the following components: 30-40 parts of isooctyl acrylate, 1-2 parts of acrylic acid, 8-10 parts of acrylamide, 8-10 parts of polyethylene glycol diacrylate, 40-50 parts of ethyl acetate, 0.1-1.5 parts of light stabilizer, 0.1-1 part of initiator, 0-0.5 part of defoaming agent, and 0-0.3 part of leveling agent.

[0021] Preferably, the thickness of the substrate layer is 25-36 μm, such as 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 31 μm, 32 μm, 33 μm, 34 μm, 35 μm, or 36 μm, etc.

[0022] If the thickness of the substrate layer is less than 25 μm, the initial peeling force of the adhesive tape becomes large, which may cause pollution to the surface of the adherend and has the risk of substrate rupture; if the thickness of the substrate layer is greater than 36 μm, the shrinkability of the PET heat-shrinkable film is poor, which affects the foaming rate.

[0023] Preferably, the low-temperature foaming microspheres are of the brand Matsumoto Foaming Microspheres HF-36D.

[0024] Preferably, the curing agent includes any one or a combination of at least two of toluene diisocyanate, isophorone diisocyanate trimer, or tris(4-phenyl isocyanate) phosphorothioate.

[0025] Preferably, the thickness of the adhesive layer is 24-35 μm, such as 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 31 μm, 32 μm, 33 μm, 34 μm, or 35 μm, etc.

[0026] If the thickness of the adhesive layer is greater than 35 μm, the foaming microspheres have a low foaming particle size at low temperature, and it is difficult for the foaming microspheres to push open the adhesive layer when the adhesive layer is thick, which affects the foaming efficiency.

[0027] Preferably, the material of the release film layer is a single-silicon release film.

[0028] In a second aspect, the present application provides a preparation method of the low-temperature foaming type heat-adhesion-reducing adhesive tape, which comprises the following steps:

[0029] (1) mixing the formula amount of acid-free acrylic resin, curing agent, low-temperature foaming microspheres, and color paste, and then adding a solvent to obtain an adhesive liquid;

[0030] (2) coating the adhesive liquid obtained in step (1) on the release surface of the release film, and baking to obtain an adhesive layer;

[0031] (3) laminating a substrate on the glue layer of step (2), and curing to obtain the low-temperature foaming type heat-adhesion-reducing adhesive tape.

[0032] Preferably, the solvent comprises toluene and / or ethyl acetate.

[0033] Preferably, the solid content of the glue liquid of step (1) is 30%-35%, for example, 30%, 31%, 32%, 33%, 34% or 35%, etc.

[0034] Preferably, the temperature of the baking of step (2) is 60-80℃, for example, 60℃, 63℃, 65℃, 68℃, 70℃, 73℃, 75℃, 78℃ or 80℃, etc., and the baking time is 2-4min, for example, 2min, 2.5min, 3min, 3.5min or 4min, etc.

[0035] Preferably, the temperature of the curing of step (3) is 30-50℃, for example, 30℃, 33℃, 35℃, 38℃, 40℃, 43℃, 45℃, 48℃ or 50℃, etc., and the curing time is 48-72h, for example, 48h, 50h, 52h, 54h, 56h, 58h, 60h, 62h, 64h, 66h, 68h, 70h or 72h, etc.

[0036] In a third aspect, the present application provides the use of the low-temperature foaming type heat-adhesion-reducing adhesive tape of the first aspect in electronic components.

[0037] Compared with the prior art, the present application has at least the following beneficial effects:

[0038] In the present application, the low-temperature foaming microspheres can start foaming at 60℃, and the PET heat-shrinkable film substrate and the low-temperature foaming microspheres in the glue layer work together to make the heat-adhesion-reducing adhesive tape automatically fall off in 40s (33-40s) in a 70℃ water bath, and there is no pollution to the surface of the electronic components. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application, and should not be regarded as specific limitations on the present application.

[0040] In the examples and comparative examples of the present application, if not specifically stated, the brand of the acid-free acrylic resin used is Panyu Xunyi Chemical DS-3017P, and the brand of the low-temperature foaming microspheres is Matsumoto Foaming Microspheres HF-36D.

[0041] Example 1

[0042] In this embodiment, a low-temperature foaming heat-reducing adhesive tape is provided, which comprises a substrate layer, an adhesive layer and a release film layer from top to bottom.

[0043] The material of the substrate layer is PET heat shrinkable film (brand name TO575) with a thickness of 36 μm;

[0044] The raw materials for preparing the adhesive layer include the following components in parts by weight:

[0045]

[0046] Among them, the curing agent is toluene diisocyanate, the thickness of the adhesive layer is 24μm, and the material of the release film layer is single crystal silicon release film, brand HM36T10.

[0047] The preparation method of the low-temperature foaming heat-reducing adhesive tape comprises the following steps:

[0048] (1) mixing the formulated amount of acid-free acrylic resin, curing agent, low-temperature foaming microspheres and color paste, and then adding toluene to obtain a glue solution with a solid content of 35%;

[0049] (2) coating the release surface of the release film with the glue solution obtained in step (1), and baking at 70° C. for 3 min to obtain a glue layer with a thickness of 24 μm;

[0050] (3) Compounding a substrate on the adhesive layer of step (2), and curing at 45° C. for 48 hours to obtain the low-temperature foaming heat-reducing adhesive tape.

[0051] Example 2

[0052] In this embodiment, a low-temperature foaming heat-reducing adhesive tape is provided, which comprises a substrate layer, an adhesive layer and a release film layer from top to bottom.

[0053] The substrate layer is made of PET heat shrinkable film (brand ZAHP035T) with a thickness of 25 μm.

[0054] The raw materials for preparing the adhesive layer include the following components in parts by weight:

[0055]

[0056] Among them, the curing agent is toluene diisocyanate, the thickness of the adhesive layer is 35μm, and the material of the release film layer is single crystal silicon release film, brand HM36T10.

[0057] The preparation method of the low-temperature foaming heat-reducing adhesive tape comprises the following steps:

[0058] (1) mixed the formula amount of acid-free acrylic resin, curing agent, low-temperature foaming microspheres and color paste, and then added toluene to obtain a glue liquid with a solid content of 35%;

[0059] (2) coated the glue liquid obtained in step (1) on the release surface of the release film, baked at 70°C for 3 min to obtain a glue layer with a thickness of 35 μm;

[0060] (3) compounded the substrate on the glue layer of step (2), cured at 45°C for 48 h to obtain the low-temperature foaming type thermal adhesion-reducing tape.

[0061] Example 3

[0062] In this embodiment, a low-temperature foaming type thermal adhesion-reducing tape is provided, which comprises, in order from top to bottom, a substrate layer, a glue layer and a release film layer;

[0063] The material of the substrate layer is a PET heat shrinkable film (brand ZAHP035T) with a thickness of 25 μm;

[0064] The raw materials for preparing the glue layer include the following components by weight fraction:

[0065]

[0066] Among them, the curing agent is toluene diisocyanate, the thickness of the glue layer is 35 μm, and the material of the release film layer is a single crystal silicon release film with a brand of HM36T10.

[0067] The preparation method of the low-temperature foaming type thermal adhesion-reducing tape comprises the following steps:

[0068] (1) mixed the formula amount of acid-free acrylic resin, curing agent, low-temperature foaming microspheres and color paste, and then added toluene to obtain a glue liquid with a solid content of 35%;

[0069] (2) coated the glue liquid obtained in step (1) on the release surface of the release film, baked at 70°C for 3 min to obtain a glue layer with a thickness of 35 μm;

[0070] (3) compounded the substrate on the glue layer of step (2), cured at 45°C for 48 h to obtain the low-temperature foaming type thermal adhesion-reducing tape.

[0071] Example 4

[0072] The difference between this embodiment and Example 1 is only that the thickness of the glue layer is 30 μm, and the other conditions are the same as those of Example 1.

[0073] Example 5

[0074] The difference between this example and Example 1 is only that the thickness of the substrate layer (PET heat shrinkable film, brand LL-216) is 20 μm, and other conditions are the same as those in Example 1.

[0075] Example 6

[0076] The difference between this example and Example 1 is only that the thickness of the substrate layer (PET heat shrinkable film, brand ZAHP025T) is 40 μm, and other conditions are the same as those in Example 1.

[0077] Example 7

[0078] The difference between this example and Example 1 is only that the thickness of the adhesive layer is 40 μm, and other conditions are the same as those in Example 1.

[0079] Comparative Example 1

[0080] The difference between this comparative example and Example 1 is only that the amount of the curing agent in the raw material for preparing the adhesive layer is 2 parts, and other conditions are the same as those in Example 1.

[0081] Comparative Example 2

[0082] The difference between this comparative example and Example 1 is only that the amount of the curing agent in the raw material for preparing the adhesive layer is 8 parts, and other conditions are the same as those in Example 1.

[0083] Comparative Example 3

[0084] The difference between this comparative example and Example 1 is only that the amount of the low-temperature foaming microspheres in the raw material for preparing the adhesive layer is 2 parts, and other conditions are the same as those in Example 1.

[0085] Comparative Example 4

[0086] The difference between this comparative example and Example 1 is only that the amount of the low-temperature foaming microspheres in the raw material for preparing the adhesive layer is 8 parts, and other conditions are the same as those in Example 1.

[0087] Comparative Example 5

[0088] The difference between this comparative example and Example 1 is only that the material of the substrate layer is a common PET film (PD-XY) without heat shrinkability, and the thickness is 36 μm, and other conditions are the same as those in Example 1.

[0089] Comparative Example 6

[0090] The difference between this comparative example and Example 1 is only that the low-temperature foaming microspheres are replaced by an equal amount of foaming microspheres (brand: Xin Zong F).

[0091] The heat-adhesion-reducing adhesive tapes prepared in the examples and comparative examples are subjected to performance tests, and the test methods are as follows:

[0092] (1) Hot tack tape and SUS304 20min adhesion: the sample with a width of 25mm was attached to SUS304, and after standing for 20min at 23℃, 65% RH, ∠180° peeling was performed;

[0093] (2) Hot tack tape and GLASS 20min adhesion: the sample with a width of 25mm was attached to GLASS, and after standing for 20min at 23℃, 65% RH, ∠180° peeling was performed;

[0094] (3) Hot tack tape attached to GLASS 70℃ water bath falling-off time: a hot tack tape with a size of 10cm*10cm was attached to GLASS, and placed in a 70℃ water bath, and the time required for the tape to completely fall off from GLASS was observed;

[0095] (4) Hot tack tape attached to copper plate 70℃ water bath falling-off time: a hot tack tape with a size of 10cm*10cm was attached to a copper plate, and placed in a 70℃ water bath, and the time required for the tape to completely fall off from the copper plate was observed;

[0096] (5) Contamination: after the hot tack tape was attached to a copper plate and fell off after 70℃ water bath, whether there was residual glue on the surface of the copper plate was observed.

[0097] The performance test results are shown in Table 1.

[0098] Table 1

[0099]

[0100]

[0101] As can be seen from Table 1, the hot tack tape provided by the application has the characteristics of automatically falling off in 40s in a 70℃ water bath and no contamination to the surface of electronic components by selecting a PET heat shrink film in combination with low-temperature foamed microspheres. As can be known from Examples 1-4, the initial adhesion of the hot tack tape provided by the application to SUS304 is 202.08-880.25g / 25mm, the initial adhesion to GLASS is 199.36-897.46g / 25mm, the 70℃ water bath tape falling-off time is 33-40s, the tape has a short falling-off time after foaming, no residual glue, and is suitable for use in processing the front surface of a metal shell of an LED screen, a mobile phone, a tablet computer and the like for protection.

[0102] From the comparison of Example 1 and Examples 5-7, it can be seen that when the thickness of the substrate layer (PET heat shrinkable film) is too small (Example 5), the base peeling force of the adhesive tape is increased, which causes pollution to the surface of the copper plate; and when the thickness of the substrate layer (PET heat shrinkable film) is too large (Example 6) or the thickness of the adhesive layer is too large (Example 7), the foaming efficiency of the adhesive tape is reduced.

[0103] From the comparison of Comparative Example 1 and Example 1, the amount of curing agent is reduced, which causes the base adhesion of the heat-adhesion-reducing adhesive tape to be increased, which causes pollution to the surface of the adherend and the foaming and falling-off efficiency to be reduced; from the comparison of Comparative Example 2 and Example 1, the amount of curing agent is increased, which causes the initial peeling force of the adhesive tape to be low, which causes the adhesive tape to not adhere to the adherend, and the adhesive tape to be warped during operation, which cannot play a good protection role; from the comparison of Comparative Example 3 and Example 1, the amount of low-temperature foaming microspheres is reduced, which causes the base peeling force of the adhesive tape to be large, the foaming efficiency to be low, and the copper plate surface to be polluted; from the comparison of Comparative Example 4 and Example 1, the amount of low-temperature foaming microspheres is increased, which causes the base adhesion of the heat-adhesion-reducing adhesive tape to be too low, which causes the adhesive tape to not adhere to the adherend, and the adhesive tape to be warped during operation, which cannot play a good protection role; from the comparison of Comparative Example 5 and Example 1, when the substrate is replaced by a common PET film, the foaming efficiency is greatly reduced, which is not conducive to the continuity of operation; from the comparison of Comparative Example 6 and Example 1, after the foaming microspheres are replaced, the foaming efficiency of the adhesive tape is also greatly reduced.

[0104] In summary, by selecting the PET heat shrinkable film and the low-temperature foaming microspheres, and by controlling the addition amount of the curing agent and the foaming microspheres within a certain range, the adhesive tape has good adhesion and good foaming effect, can be fallen off in a short time after foaming and has no residual glue, greatly speeds up the operation efficiency in the assembly line, and is suitable for the fields of component processing and metal shell processing of mobile phones, tablets and the like.

[0105] The applicant declares that the low-temperature foaming type heat-adhesion-reducing adhesive tape, the preparation method and the application thereof are illustrated by the above examples, but the present application is not limited to the above examples, i.e., it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement on the present application, equivalent replacement of each raw material of the product of the present application, addition of auxiliary ingredients, selection of specific modes, etc., all fall within the protection scope and disclosure scope of the present application.

Claims

1. Application of a low-temperature foaming heat-reducing adhesive tape in electronic components, characterized in that: The low-temperature foaming heat-reducing adhesive tape comprises a substrate layer, an adhesive layer and a release film layer from top to bottom; The material of the substrate layer is PET heat shrink film; The raw materials for preparing the adhesive layer are composed of the following components in parts by weight: The thickness of the substrate layer is 25 μm; The brand of the low-temperature foaming microspheres is Songben foaming microspheres HF-36D; The acid-free acrylic resin is Panyu Runyi Chemical DS-3017P; The thickness of the adhesive layer is 35 μm; The release film layer is made of single crystal silicon release film, brand HM36T10; The initial adhesion of the low-temperature foaming type heat-reducing adhesive tape to SUS304 is 202.08g / 25mm, and the initial adhesion to glass is 199.36g / 25mm. The heat-reducing adhesive tape peels off in 35s on glass in a 70°C water bath, and in 33s on copper plate in a 70°C water bath. The preparation method of the low-temperature foaming heat-reducing adhesive tape comprises the following steps: (1) mixing the formulated amount of acid-free acrylic resin, curing agent, low-temperature foaming microspheres and color paste, and then adding toluene to obtain a glue solution with a solid content of 35%; (2) coating the glue liquid obtained in step (1) on the release surface of the release film, and baking at 70° C. for 3 min to obtain a glue layer with a thickness of 35 μm; (3) Compounding a substrate on the adhesive layer of step (2), and curing at 45° C. for 48 hours to obtain the low-temperature foaming heat-reducing adhesive tape.

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