High-surface-resistivity pressure-sensitive adhesive tape for photoelectric material and preparation method of high-surface-resistivity pressure-sensitive adhesive tape

Abstract

The invention relates to the technical field of pressure-sensitive adhesives, in particular to a high-surface-resistivity pressure-sensitive adhesive tape for photoelectric materials and a preparation method of the high-surface-resistivity pressure-sensitive adhesive tape. The silicon dioxide with lower cost is used as insulating filler, the silane coupling agent is used for modifying the surface of the filler to introduce a carbon-carbon double bond, and then the acrylic copolymer is introduced to the surface of the filler through free radical polymerization, so that the surface resistivity of the prepared adhesive tape reaches 1015 omega.m, and the defects that the surface resistivity of a traditional acrylic insulating pressure-sensitive adhesive tape is low, and the adhesive tape is difficult to deform are overcome. And the method is not suitable for special photoelectric application and high-sensitivity component protection.

Description

Technical Field

[0001] The invention relates to the technical field of pressure-sensitive adhesives, in particular to a high surface resistivity pressure-sensitive adhesive tape for photoelectric materials and a preparation method thereof. Background Art

[0002] Insulating pressure-sensitive tape has the functions of protecting electronic components, enhancing insulation performance and preventing current leakage. It is an indispensable type of functional tape in optoelectronic materials and is widely used. Acrylic pressure-sensitive adhesive has the advantages of excellent bonding performance, good transparency, aging resistance and low cost, and is widely used in the preparation of insulating pressure-sensitive tape.

[0003] For example, a Chinese patent with publication number CN110218539B discloses a silicone-modified acrylate high temperature resistant and insulating pressure-sensitive adhesive, which includes the following raw materials: methyl methacrylate, 2-hydroxypropyl methacrylate, 2-ethylhexyl acrylate, isobutyl acrylate, functional monomer, silane containing acryloxy, crosslinking agent, heat-resistant filler, initiator, and solvent. This pressure-sensitive adhesive uses silicone-modified acrylate pressure-sensitive adhesive, and improves the insulation of the acrylate pressure-sensitive adhesive by introducing a silica gel component, and at the same time adds insulating mica powder as an inorganic filler to further improve the resistance value of the pressure-sensitive adhesive.

[0004] This invention uses acryloxy-containing silane to modify the filler mica powder, which can improve the compatibility with acrylic glue to a certain extent, but there is still a risk of filler precipitation during the glue aging process.

[0005] For example, a Chinese patent with publication number CN117186796A discloses a high thermal conductivity acrylic pressure-sensitive adhesive and a preparation method thereof, which is prepared by ultrasonically mixing 60 to 80 parts by mass of a polyacrylate solution, 3 to 10 parts by mass of an epoxidized tackifying resin, 5 to 10 parts by mass of a modified thermally conductive filler and 0.3 to 1.0 parts by mass of a cross-linking agent, and then coating and drying. The invention uses thermally conductive and insulating boron nitride and highly branched thermally conductive and electrically conductive dendritic silver-coated copper as fillers, which are ultrasonically mixed with a polyacrylate solution, an epoxy resin and a cross-linking agent to obtain a thermally conductive and insulating pressure-sensitive adhesive.

[0006] This invention does not modify the filler, but simply physically mixes it with acrylic glue after stirring. There is a risk of uneven dispersion of the filler in the glue, resulting in poor performance stability of the tape.

[0007] Including the above two pressure-sensitive adhesives, the surface resistivity of existing acrylic pressure-sensitive adhesive tapes is usually 10 13 Ω·m, for some special optoelectronic applications and highly sensitive component protection, the surface resistivity of traditional acrylic pressure-sensitive tape is low, and there are still problems of current leakage and electrical breakdown. Therefore, it is necessary to develop a higher surface resistivity (surface resistivity of 1015 Ω·m), and can not affect the optical properties of optoelectronic materials (such as transmittance and haze, etc.) of pressure-sensitive tape.

[0008] In order to solve the above problems, the present invention provides a high surface resistivity pressure-sensitive adhesive tape for optoelectronic materials and a preparation method thereof. Summary of the invention

[0009] The object of the present invention is to provide a high surface resistivity pressure-sensitive adhesive tape for optoelectronic materials and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0011] A high surface resistivity pressure-sensitive adhesive tape for photoelectric materials, comprising the following substances by weight:

[0012] 100 parts of acrylic acid copolymer;

[0013] 5-10 parts of filler;

[0014] Curing agent 0.1-0.2 parts;

[0015] The filler is modified silica modified by acrylic polymer;

[0016] The molecular weight of the acrylic copolymer is 1 million.

[0017] More optimally, the acrylic copolymer comprises the following substances by weight:

[0018] 8-12 parts of butyl acrylate;

[0019] 1-3 parts of isooctyl acrylate;

[0020] 1.5-2 parts of methyl acrylate;

[0021] 0.1-0.3 parts of acrylic acid;

[0022] 100 parts of ethyl acetate;

[0023] 0.1 parts of azobisisobutyronitrile.

[0024] More optimally, the modified silica is synthesized from the following weight components:

[0025] 100 parts of silicon dioxide powder;

[0026] 500 parts of ethanol;

[0027] 10-30 parts of silane coupling agent;

[0028] 15-20 parts of butyl acrylate;

[0029] 1 part of acrylic acid;

[0030] Initiator 0.1 parts.

[0031] More optimally, the particle size of the silica powder is 0.5 to 2 μm.

[0032] More optimally, the initiator is azobisisobutyronitrile; the silane coupling agent is KH-570.

[0033] The present invention also provides a method for preparing a high surface resistivity pressure-sensitive adhesive tape for photoelectric materials, which is used to prepare any of the above-mentioned high surface resistivity pressure-sensitive adhesive tapes for photoelectric materials, comprising the following steps:

[0034] S1, Synthesis of acrylic polymer modified silica: Take a certain amount of silica powder, dissolve it in 500 parts of ethanol, add a certain amount of silane coupling agent, stir it under nitrogen protection for 8-16 hours, and collect the silica modified by silane coupling agent by centrifugation after stirring, which is recorded as SiO 2 -570, and redissolved in 500 parts of ethanol;

[0035] In SiO 2 A certain amount of butyl acrylate and acrylic acid were added to the 570 solution, and after thorough mixing, 0.1 part of initiator azobisisobutyronitrile was added. The mixture was reacted for 6 to 10 hours under nitrogen protection. After the reaction was completed, the acrylic acid polymer-modified silica filler was collected by centrifugation and recorded as SiO 2 -AA, redissolved in ethanol for later use;

[0036] S2, synthesis of acrylic glue: taking a certain amount of butyl acrylate, isooctyl acrylate, methyl acrylate, acrylic acid, ethyl acetate and azobisisobutyronitrile, reacting for 6 to 10 hours under nitrogen protection at a reaction temperature of 65 to 70° C. to obtain an acrylic copolymer with a molecular weight of about 1 million;

[0037] S3, tape preparation: taking a certain amount of acrylic copolymer, modified filler SiO 2 -AA and curing agent, fully stir and evenly coat them on the surface of optical grade PET and stick a release film on it, bake at 120℃ for 2-5min, and then mature at 60℃ for 1-3 days to obtain the finished tape.

[0038] More optimally, in step S1, SiO 2 -570, the stirring temperature is room temperature; preparation of SiO 2 -AA, the stirring temperature is 65-70°C.

[0039] More optimally, the curing agent is 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane.

[0040] More optimally, in step S3, the coating thickness is 10-15 μm.

[0041] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0042] (1) In the present invention, low-cost silica is used as an insulating filler, the filler surface is modified by using silane coupling agent KH-570 to introduce carbon-carbon double bonds, and then an acrylic copolymer is introduced on the filler surface by free radical polymerization. On the one hand, the modification of the acrylic polymer can improve the compatibility of the insulating filler with the pressure-sensitive adhesive matrix, promote its uniform distribution inside the colloid, and avoid the problems of poor appearance and large performance deviation caused by filler agglomeration; on the other hand, the acrylic component on the filler surface can participate in the cross-linking system of the glue, so that it is chemically bonded in the colloid, thereby reducing the risk of precipitation during aging and long-term use.

[0043] (2) In the present invention, the surface resistivity of the tape obtained reaches 10 15 Ω·m, which improves the problem that the traditional acrylic insulating pressure-sensitive tape has a low surface resistivity and is not suitable for special optoelectronic applications and the protection of highly sensitive components.

[0044] (3) In the present invention, the obtained adhesive tape has excellent resistivity and will not affect the optical properties of the optoelectronic material. 15 Under the condition of Ω·m, its haze after aging is as low as 1.7%, and the transmittance can reach 90.4%; at the same time, the peeling force after aging changes little, and its comprehensive performance is much higher than that of the same tape on the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0046] Figure 1 Schematic diagram of the film structure obtained in the embodiment.

[0047] Among them, 1. Optical grade PET layer; 2. PSA layer; 3. Release film layer. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In the present invention, the adhesive tape is prepared by the following steps:

[0050] S1, Synthesis of acrylic polymer modified silica: 100 parts of silica powder (with a particle size of 0.5-2 μm, preferably 1 μm) was dissolved in 500 parts of ethanol, and 20 parts of silane coupling agent KH-570 were added. The mixture was stirred for 8-16 hours at room temperature under nitrogen protection. After the stirring was completed, the silane coupling agent modified silica (denoted as SiO 2 -570), and redissolved in 500 parts of ethanol;

[0051] In SiO 2 19 parts of butyl acrylate and 1 part of acrylic acid were added to the 570 solution, and after thorough mixing, 0.1 parts of initiator azobisisobutyronitrile were added. The mixture was reacted at 65-70°C for 6-10 hours under nitrogen protection. After the reaction, the acrylic acid polymer-modified silica filler was collected by centrifugation and recorded as SiO 2 -AA, redissolved in ethanol for later use.

[0052] S2, synthesis of acrylic glue: take 10 parts of butyl acrylate, 2 parts of isooctyl acrylate, 1.8 parts of methyl acrylate, 0.2 parts of acrylic acid, 100 parts of ethyl acetate and 0.1 parts of azobisisobutyronitrile, react for 6 to 10 hours under nitrogen protection at a reaction temperature of 65 to 70°C to obtain an acrylic copolymer with a molecular weight of about 1 million.

[0053] S3, tape preparation: 100 parts of acrylic copolymer, 10 parts of modified filler SiO 2 -AA and 0.2 parts of curing agent, the curing agent is 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, after being fully stirred and evenly coated on the surface of optical grade PET and affixed with a release film, the coating thickness is 10-15μm, preferably 13μm, baked at 120℃ for 3min, and then aged at 60℃ for 1-3 days to obtain a finished tape.

[0054] In order to verify the performance of the prepared tape, the present invention prepared several examples and comparative examples and conducted performance tests. 2 -AA was used as filler. In the comparative example, unmodified SiO 2 As fillers, the formulas of various embodiments and comparative examples are shown in Table 1:

[0055] Table 1 Formulation of adhesive tapes in various embodiments and comparative examples

[0056]

[0057] The performance test of the finished tapes prepared in each embodiment and comparative example was carried out before and after tape aging (double 85X10 days). The specific results are shown in Table 2.

[0058] Table 2 Performance test table of the adhesive tape before and after aging in each embodiment and comparative example

[0059]

[0060]

[0061] It can be seen from the data in Table 2 that compared with Comparative Examples 1-4, the use of SiO 2 -AA as a filler will not have a significant effect on the bonding performance of the main glue. After aging for 10 days in double 85, the bonding performance, optical performance (haze and transmittance) and surface resistivity of Examples 1-4 changed slightly; in detail, from the comparison between Example 1 and Example 3, and Example 2 and Example 4, it can be seen that the optical properties of the tape increase with the increase in the amount of modified filler added; from the comparison between Example 1 and Example 2, and Example 3 and Example 4, it can be seen that the change in the optical properties of the tape decreases with the increase in the amount of curing agent used.

[0062] This is because the surface of the filler is modified by acrylic polymer, and the introduced modified component can react with the curing agent and participate in the curing process of the glue, making it firmly and evenly combined inside the glue; while for comparative examples 1-4 with unmodified fillers, the filler is only physically mixed inside the glue, and there are problems of poor distribution uniformity and easy precipitation, so it is difficult to maintain stable performance in rigorous aging experiments.

[0063] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0064] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high surface resistivity pressure-sensitive adhesive tape for optoelectronic materials, characterized in that: The components by weight include the following substances: 100 parts of acrylic acid copolymer; 5-10 parts of filler; Curing agent 0.1-0.2 parts; The filler is modified silica modified by acrylic polymer; The molecular weight of the acrylic copolymer is 1 million.

2. A high surface resistivity pressure-sensitive adhesive tape for optoelectronic materials according to claim 1, characterized in that: The acrylic copolymer comprises the following components by weight: 8-12 parts of butyl acrylate; 1-3 parts of isooctyl acrylate; 1.5-2 parts of methyl acrylate; 0.1-0.3 parts of acrylic acid; 100 parts of ethyl acetate; 0.1 parts of azobisisobutyronitrile.

3. The high surface resistivity pressure-sensitive adhesive tape for optoelectronic materials according to claim 1, characterized in that: The modified silicon dioxide is synthesized from the following weight components: 100 parts of silicon dioxide powder; 500 parts of ethanol; 10-30 parts of silane coupling agent; 15-20 parts of butyl acrylate; 1 part of acrylic acid; Initiator 0.1 parts.

4. A high surface resistivity pressure-sensitive adhesive tape for optoelectronic materials according to claim 3, characterized in that: The particle size of the silicon dioxide powder is 0.5 to 2 μm.

5. A high surface resistivity pressure-sensitive adhesive tape for optoelectronic materials according to claim 4, characterized in that: The initiator is azobisisobutyronitrile; the silane coupling agent is KH-570.

6. A method for preparing a high surface resistivity pressure-sensitive adhesive tape for photoelectric materials, for preparing any one of claims 1 to 5, characterized in that: The steps include: S1, synthesis of acrylic polymer modified silica: take a certain amount of silica powder, dissolve it in 500 parts of ethanol, add a certain amount of silane coupling agent, stir for 8-16 hours under nitrogen protection, collect the silane coupling agent modified silica by centrifugation after stirring, record it as SiO2-570, and redissolve it in 500 parts of ethanol; Add a certain amount of butyl acrylate and acrylic acid to the SiO2-570 solution, mix thoroughly, add 0.1 parts of initiator azobisisobutyronitrile, react for 6 to 10 hours under nitrogen protection, collect the acrylic polymer modified silica filler by centrifugation after the reaction, record it as SiO2-AA, and redissolve it in ethanol for later use; S2, synthesis of acrylic glue: taking a certain amount of butyl acrylate, isooctyl acrylate, methyl acrylate, acrylic acid, ethyl acetate and azobisisobutyronitrile, reacting for 6 to 10 hours under nitrogen protection at a reaction temperature of 65 to 70° C. to obtain an acrylic copolymer with a molecular weight of about 1 million; S3, preparation of adhesive tape: take a certain amount of acrylic copolymer, modified filler SiO2-AA and curing agent, mix them thoroughly and evenly, then apply them on the surface of optical grade PET and stick a release film on it, bake at 120°C for 2 to 5 minutes, and then mature at 60°C for 1 to 3 days to obtain the finished adhesive tape.

7. The method for preparing a high surface resistivity pressure-sensitive adhesive tape for optoelectronic materials according to claim 6, characterized in that: In the step S1, when preparing SiO2-570, the stirring temperature is at room temperature; when preparing SiO2-AA, the stirring temperature is 65-70°C.

8. The method for preparing a high surface resistivity pressure-sensitive adhesive tape for optoelectronic materials according to claim 6, characterized in that: The curing agent is 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane.

9. The method for preparing a high surface resistivity pressure-sensitive adhesive tape for optoelectronic materials according to claim 6, characterized in that: In the step S3, the coating thickness is 10 to 15 μm.

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