Bonding composition, preparation method thereof and cover tape containing bonding composition

Abstract

The invention provides a bonding composition and a preparation method thereof, and a cover tape containing the composition. The bonding composition is prepared from 50 to 85 parts of acrylate terpolymer, 5 to 25 parts of saturated SBS (Styrene Butadiene Styrene) resin, 1 to 8 parts of antistatic agent and 0.1 to 2 parts of antioxidant; a polymeric monomer of the acrylate terpolymer comprises an acrylic monomer and a functional monomer; the functional monomer is prepared by reacting 3-allyl salicylaldehyde, an aniline derivative and a silane coupling agent; by carrying out structural design modification on the polymerized functional monomer, introducing silane and fluorocarbon structures and taking the functional monomer as a crosslinking site, the adhesive force and bonding stability are enhanced, the peel strength is stable, the generation of soft flocks is reduced, and the adhesive is suitable for being used in the field of electronics.

Description

Technical Field

[0001] The present invention relates to the technical field of laminated products for packaging electronic components, and particularly relates to an adhesive composition, a preparation method thereof, and a cover tape containing the composition. Background Art

[0002] A cover tape is usually referred to as a "cover film" or "encapsulation cover tape", and is an important material for protecting components during the packaging process of electronic components. It is generally made of plastic, metal or other composite materials, and is mainly used to cover and protect electronic components such as chips, sensors and discrete components. The cover tape is mainly applied to the electronic component mounting industry. According to the shape requirements of the carrier tape, it can be designed into an H-shaped cover tape, which is used in cooperation with the carrier tape to carry and store electronic components such as resistors, capacitors, transistors, and diodes in the pockets of the carrier tape. The cover tape is sealed above the pockets formed by the carrier tape to form a closed package, which is used to protect the electronic components from being contaminated and damaged during transportation. In order to increase the adhesion between the cover tape and the carrier tape, glue can also be applied to the carrier tape by means of intermittent gluing to increase the effective bonding between the cover tape and the carrier tape. When the electronic components are mounted, the cover tape is peeled off, and the automatic mounting equipment accurately positions through the indexing holes of the carrier tape, and sequentially takes out the components placed in the pockets and mounts them on the integrated circuit board.

[0003] In recent years, the miniaturization, light weight and thinness of various electronic components such as capacitors, resistors, ICs, LEDs, and connectors have been significantly developed. For microelectronic components, paper carrier tapes are often used for storage. At this time, when the electronic components are taken out of the package and the cover tape is peeled off, higher requirements are imposed on the peeling stability and peeling debris of the cover tape. In addition, when the electronic component package is stored and transported in a rolled manner, sticking of materials often occurs under the changes of storage environment and transportation conditions, especially under high temperature and high temperature and high humidity, that is, the electronic components adhere to the cover tape when the cover tape is peeled off, resulting in the failure of the chip mounter to pick up smoothly.

[0004] It has been found through research that the performance of the adhesive resin used to form the heat-sealing layer of the cover tape plays a decisive role in the above-mentioned performance of the cover tape. Therefore, more and more research has been carried out on the cover tape adhesive composition.

[0005] For example, the invention patent application with the publication number CN104212381 A discloses a hot melt adhesive for producing resistor tapes, which is composed of 22-27 parts by weight of low-density polyethylene, 42-47 parts by weight of ethylene-vinyl acetate copolymer, 0.5-1.0 part by weight of oleic acid amide, 0.2-0.6 part by weight of stearic acid amide, 0.1-0.6 part by weight of silicon oxide, 37-42 parts by weight of resin tackifier, and 17-23 parts by weight of high molecular antistatic agent.

[0006] However, the cover tape made of the above-mentioned heat-sealing cover tape or the heat-sealing layer made of the above-mentioned hot-melt adhesive still has problems such as unstable peel strength, a large amount of fluff pulled up, adhesion of electronic components, and unwinding and sticking.

[0007] Some prior arts also disclose an adhesive resin composition that can be used for carrier tapes. For example, the adhesive resin in CN113677771A contains ethylene-vinyl acetate copolymer (A). The content of the structural unit derived from vinyl acetate in the ethylene-vinyl acetate copolymer (A) is 3% by mass or more and 18% by mass or less, and the melt mass flow rate (MFR, JIS K7210:1999, 190 °C, 2160 g load) is 5 g / 10 min or more and 40 g / 10 min or less; tackifying resin (B); and ethylene-vinyl acetate copolymer (C). The viscosity of the ethylene-vinyl acetate copolymer (C) measured at 180 °C using a Brookfield viscometer is 15,000 mPa·s or more and 300,000 mPa·s or less.

[0008] The adhesive resin in CN107207927A contains ethylene-unsaturated carboxylic acid ester copolymer A. The content of the structural unit derived from unsaturated carboxylic acid ester in the ethylene-unsaturated carboxylic acid ester copolymer A is more than 0% by mass and less than 10% by mass; ethylene-unsaturated carboxylic acid ester copolymer B. The content of the structural unit derived from unsaturated carboxylic acid ester in the ethylene-unsaturated carboxylic acid ester copolymer B is 10% by mass or more and 40% by mass or less; resin C, and the resin C is at least incompatible with the above-mentioned ethylene-unsaturated carboxylic acid ester copolymer A.

[0009] Although the cover film made of the above two adhesive resins can achieve good sealing and easy peelability with the paper substrate, there are still certain defects. Especially in high-temperature and high-temperature and high-humidity environments, adhesion between electronic components and the cover tape is likely to occur, and there are many fluff problems during peeling.

[0010] Therefore, we urgently need to develop a bonding composition that can be used for heat-sealing cover tapes, has stable peeling, and excellent antistatic and weather resistance properties. Summary of the Invention

[0011] Object of the Invention: By improving the components of the bonding composition, the present invention obtains a bonding composition for the heat-sealing layer of a cover tape. After being sealed with a paper carrier tape, it has stable peel strength, less fluff pulled up in high-temperature and high-temperature and high-humidity environments, and excellent antistatic performance, solving the technical problems proposed in the background art.

[0012] Technical Solution of the Present Invention:

[0013] In a first aspect, the present invention provides an adhesive composition. By mass parts, the adhesive composition comprises 50 to 85 parts of an acrylate terpolymer, 5 to 25 parts of a saturated SBS resin, 1 to 8 parts of an antistatic agent, and 0.1 to 2 parts of an antioxidant;

[0014] The polymerization monomers of the acrylate terpolymer include acrylic monomers and functional monomers; the functional monomers are prepared by reacting 3-allylsalicylaldehyde, an aniline derivative, and a silane coupling agent.

[0015] In some embodiments, the acrylic monomers are selected from one or more combinations of isobornyl acrylate (IBOA), isobutyl methacrylate (IBMA), methyl methacrylate (MMA), isooctyl acrylate (2-EHA); further, the acrylic monomers are selected from one or two combinations of isobornyl acrylate (IBOA) and methyl methacrylate (MMA). The combined use of IBOA and MMA can improve the thermal stability of the acrylate terpolymer.

[0016] In some embodiments, the aniline derivative has a benzene ring, at least one amino group, and at least one halogen atom in its structural formula; specifically, the aniline derivative is selected from one or more combinations of 2,3,4,5-tetrafluoroaniline, 2,3,5,6-tetrafluoroaniline, 2,3,5-trifluoroaniline, 2,3,4-trifluoroaniline, 2,3,4,5,6-pentafluoroaniline, 2,4,5,6-tetrafluoro-1,3-benzenediamine, 2,4,5,6-tetrafluoro-1,3-benzenediamine.

[0017] In some embodiments, the silane coupling agent is selected from one or more combinations of KH-560, KH-570, KH-590, A-171.

[0018] In some embodiments, the sum of the number of amino groups on the aniline derivative and the number of double bonds on the silane coupling agent should be greater than or equal to 2. Ensure that the final obtained functional monomer has crosslinking sites.

[0019] In some embodiments, the preparation method of the functional monomer comprises the following steps:

[0020] Step 1: Add 3-allylsalicylaldehyde and a solvent to a reactor, then add molecular sieves and an inorganic base, dropwise add the silane coupling agent under stirring, raise the temperature and stir for reaction, and obtain intermediate 1 after purification;

[0021] Step 2: Add intermediate 1 and a solvent to another reactor, then add the aniline derivative and a catalyst, heat and reflux for reaction, cool after the reaction is completed, and perform recrystallization to obtain the functional monomer.

[0022] In some embodiments, the reaction temperature of the heating and stirring reaction in Step 1 is 60 - 70°C, and the stirring reaction is carried out for 8 - 12 hours.

[0023] In some embodiments, the reaction temperature of the reaction by heating under reflux in Step 2 is 40 - 60°C, and the reaction time is 1 - 4 h.

[0024] In some embodiments, the molar ratio of the acrylic monomer to the functional monomer is 10 - 5:1.

[0025] In some embodiments, the degree of polymerization of the acrylate ternary copolymer is 50 - 10,000.

[0026] In some embodiments, the saturated SBS resin is selected from any one or a mixture of at least two of SEBS 503T of Yueyang Petrochemical Company, China, SEBS 6151, 6154, 6153 of Taixiang Company, Taiwan Province, China, SEBS 7551, 7554, 7550 of Lee Chang Yung Company, Taiwan Province, China, SEBS G1651, G1654, G1650 of Kraton Corporation, USA, and SEEPS 4033, 4044, 4055 of Kuraray Co., Ltd., Japan.

[0027] In some embodiments, the antistatic agent is selected from one or a combination of lauramidopropyltrimethylamine, polyether ester amide, and octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate.

[0028] In some embodiments, the antioxidant is selected from one or a combination of antioxidant 1010, antioxidant 1035, antioxidant 1076, and antioxidant 1135.

[0029] In a second aspect, the present application provides a method for preparing the bonding composition as described above, specifically including the following steps:

[0030] Adding the acrylate ternary copolymer, saturated SBS resin, antistatic agent, and antioxidant into a blender and mixing them to obtain the bonding composition.

[0031] In a third aspect, the present application further provides a cover tape containing the above bonding composition.

[0032] In some embodiments, the cover tape at least includes a substrate layer and a heat-sealing layer formed on the substrate layer, and the raw material of the heat-sealing layer is the bonding composition.

[0033] In some embodiments, as long as the substrate layer has the mechanical strength to withstand the external forces applied during tape processing, heat sealing on the carrier tape, etc., and has the heat resistance to withstand heat sealing, it can be applied to films processed from various suitable materials according to the use. Specifically, as raw materials for the substrate layer film, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, nylon 6, nylon 66, polypropylene, polymethylpentene, polyvinyl chloride, polyacrylate, polymethacrylate, polyimide, polyetherimide, polyarylate, polysulfone, polyethersulfone, polyphenylene ether, polycarbonate, ABS resin, etc. can be cited. To improve the mechanical strength, polyethylene terephthalate, nylon 6, and nylon 66 are preferred. In addition, as the substrate layer, a laminate of two or more layers formed from the above-exemplified raw materials for the substrate layer film can be used.

[0034] Regarding the thickness of the substrate layer, it is preferably 15 μm or more and 40 μm or less, more preferably 20 μm or more and 35 μm or less, and particularly preferably 30 μm.

[0035] In some embodiments, the thickness of the heat-sealing layer is preferably 1 μm or more and 10 μm or less, and more preferably 5 μm.

[0036] Beneficial effects:

[0037] 1. By structurally designing and modifying the polymerized functional monomers, introducing silane and fluorocarbon structures, enhancing the adhesion to various substrates and the bonding stability, and the peel strength is stable.

[0038] 2. By introducing a design for the functional groups of the functional monomers, using the functional monomers as cross-linking sites, improving the stability of the cover tape, and reducing the generation of lint.

[0039] 3. By matching the functional monomers and acrylic monomers, improving the thermal stability of the cover tape itself, making it suitable for use in the electronic field. Specific embodiments

[0040] The present invention will be described below in conjunction with specific implementation schemes. It should be noted that the following examples are examples of the present invention, only for illustrating the present invention, and not for limiting the present invention. Other combinations and various improvements within the concept of the present invention can be made without departing from the gist or scope of the present invention.

[0041] Unless otherwise specified, the chemical reagents used in the present invention are all ordinary commercially available analytical pure.

[0042] Preparation example of functional monomer 1

[0043] Step 1: Add 5 mmol of 3-allylsalicylaldehyde and 20 ml of anhydrous toluene to the reactor, and then add 200 mg Molecular sieve and 0.7 mmol of triethylamine were added with 1.18 g of silane coupling agent KH-560 under stirring. The temperature was raised to 65 °C and stirred for 10 h under sealed conditions. The molecular sieve was removed by filtration, the solvent was removed by concentration under reduced pressure, and the intermediate 1 was obtained after purification by silica gel column chromatography;

[0044] Step 2: Add 0.3 g of the above intermediate 1 and 10 ml of anhydrous DMF solvent to another reactor, then add 0.090 g of 2,4,5,6-tetrafluoro-1,3-phenylenediamine and 0.7 mmol of acetic acid, heat to 50 °C and reflux for 6 h. After the reaction, it was cooled and recrystallized to obtain functional monomer 1.

[0045] It can be seen from the 1H NMR data that the phenolic hydroxyl disappeared, the signals of Si–CH2 and Si–O–Ar appeared, the aldehyde peak (~9.8 ppm) disappeared, and the -CH=N- peak (~8.2 - 8.7 ppm) appeared, indicating that functional monomer 1 was successfully prepared by reaction.

[0046] Preparation example of functional monomer 2

[0047] Basically the same as the preparation example of functional monomer 1, the difference is that in step 1, silane coupling agent KH-570 was used to replace KH-560; in step 2, 2,3,4,5-tetrafluoroaniline was used to replace 2,4,5,6-tetrafluoro-1,3-phenylenediamine. Functional monomer 2 was prepared.

[0048] Preparation example of functional monomer 3

[0049] Basically the same as the preparation example of functional monomer 1, the difference is that in step 2, 2,3,4,5-tetrafluoroaniline was used to replace 2,4,5,6-tetrafluoro-1,3-phenylenediamine. Functional monomer 3 was prepared.

[0050] Examples 1 - 5

[0051] Weigh acrylate monomers and functional monomers, add them to the reactor according to the ratio in Table 1, add 1.5 L of toluene, then add 0.1 g of AIBN initiator, and stir well to dissolve evenly; introduce nitrogen for 30 min and maintain the nitrogen atmosphere, raise the temperature to 65 °C, control the reaction time for 12 h, cool to room temperature after the reaction, and open the ventilation to terminate the free radical reaction; pour the reaction mixture into methanol for precipitation, and obtain acrylate ternary copolymer after filtration, washing and drying; the DP of the acrylate ternary copolymer was measured by gel permeation chromatography to be approximately 8000.

[0052] 80 parts of acrylate ternary copolymer, 20 parts of saturated SBS resin (SEBS 503T from Yueyang Chemical Co., China), 4 parts of antistatic agent (lauramidopropyltrimethylamine) and 2 parts of antioxidant (antioxidant 1010) were added to the blender for mixing to obtain the adhesive composition respectively.

[0053] Table 1

[0054]

[0055]

[0056] Comparative Example 1

[0057] Basically the same as Example 4, except that functional monomer 3 is used to replace functional monomer 1.

[0058] Comparative Example 2

[0059] Basically the same as Example 4, except that 3 - allylsalicylaldehyde is used to replace functional monomer 1.

[0060] Comparative Example 3

[0061] Basically the same as Example 4, except that polyacrylate (Feiyue Chemical Industry, grade 9003 - 01 - 4) is used to replace the saturated SBS resin.

[0062] Application Example

[0063] This application example provides a batch of cover tapes, which are composed of a base material layer, a heat - seal layer, and a base material layer in sequence. Among them, the heat - seal layer is formed by coating the adhesive compositions of Examples 1 - 5 and Comparative Examples 1 - 3 respectively, and the thickness of the heat - seal layer is 5 μm. The base material layer of the cover tape is made of polybutylene terephthalate, and its thickness is 30 μm.

[0064] Testing Method:

[0065] The cover tapes corresponding to the above - mentioned examples and comparative examples are cut into a width of 5.25 mm, and heat - sealed onto a 42 - mm - thick paper carrier tape under the following heat - seal conditions (heat - seal temperature: 190 °C, heat - seal pressure: 2 - 3 Mpa, heat - seal speed: 3300 pcs / min).

[0066] The cover tapes are respectively peeled off, and the maximum peeling force (gf) and minimum peeling force (gf) are detected, and it is observed whether there is a phenomenon of pulling up fluff or base paper fibers on the upper cover tape.

[0067] Table 2

[0068]

[0069]

[0070] As can be seen from Table 1, the heat - seal cover tape provided by the present invention has obvious improvements in terms of peeling force and fluffing phenomenon; at the same time, when the hot - melt cover tape is released from the paper carrier tape surface after heat - sealing, its peeling force is stable and there is no surface fluffing phenomenon; it can effectively achieve the characteristics of good sealing with the paper substrate and easy peeling;

[0071] It can be seen from the comparison of the examples that when the molar ratio of IBOA: MMA: functional monomer 2 is 3:2:1, due to the compounding of the three, both the peel strength and the peel stability increase.

[0072] The functional monomer 3 used in Comparative Example 1 has only one double bond, so a more stable cross-linked structure cannot be formed; therefore, the peel strength and glass stability of the heat-sealing cover tape prepared are relatively low compared to the examples. In the examples, by introducing silane and fluorocarbon structures, the adhesion and bonding stability of the cover tape are enhanced, the peel strength is stable, the stability of the cover tape is further improved, and the generation of lint is reduced.

[0073] The present invention can also have various other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present invention.

Claims

1. A bonding composition, characterized in that The bonding composition comprises, by weight, 50 to 85 parts of an acrylic ester terpolymer, 5 to 25 parts of a saturated SBS resin, 1 to 8 parts of an antistatic agent, and 0.1 to 2 parts of an antioxidant; The polymerization monomers of the acrylic ester terpolymer include acrylic monomers and functional monomers; the functional monomers are prepared by reacting 3-allyl salicylaldehyde, aniline derivatives and silane coupling agents.

2. The bonding composition according to claim 1, characterized in that: The acrylic monomer is selected from one or more combinations of isobornyl acrylate, isobutyl methacrylate, methyl methacrylate, and isooctyl methacrylate.

3. The bonding composition according to claim 1, characterized in that: The aniline derivative structurally comprises a benzene ring, at least one amine group and at least one halogen atom.

4. The bonding composition according to claim 1, characterized in that: The aniline derivative is selected from one or more combinations of 2,3,4,5-tetrafluoroaniline, 2,3,5,6-tetrafluoroaniline, 2,3,5-trifluoroaniline, 2,3,4-trifluoroaniline, 2,3,4,5,6-pentafluoroaniline, 2,4,5,6-tetrafluoro-1,3-phenylenediamine and 2,4,5,6-tetrafluoro-1,3-phenylenediamine.

5. The bonding composition according to claim 1, characterized in that: The sum of the number of amine groups on the aniline derivative and the number of double bonds on the silane coupling agent is greater than or equal to 2.

6. The bonding composition according to claim 1, characterized in that: The preparation method of the functional monomer comprises the following steps: Step 1: Add 3-allylsalicylic aldehyde and a solvent into a reactor, then add a molecular sieve and an inorganic base, dropwise add a silane coupling agent under stirring, heat and stir to react, and purify to obtain an intermediate 1; Step 2: Add intermediate 1 and a solvent to another reactor, then add an aniline derivative and a catalyst, heat under reflux to react, cool after the reaction, and recrystallize to obtain a functional monomer.

7. The bonding composition according to claim 6, characterized in that: The reaction temperature of the heating and stirring reaction in step 1 is 60-70° C., and the stirring reaction is performed for 8-12 hours; the reaction temperature of the heating and reflux reaction in step 2 is 40-60° C., and the reaction time is 1-4 hours.

8. The method for preparing the bonding composition according to any one of claims 1 to 7, characterized in that: The steps include: The acrylic ester terpolymer, saturated SBS resin, antistatic agent and antioxidant are added into a mixer and mixed to obtain a bonding composition.

9. A heat-sealed cover tape, characterized in that: The invention comprises the bonding composition according to any one of claims 1 to 8.

10. The heat-sealing cover tape according to claim 9, characterized in that: The cover tape comprises a substrate layer and a heat-sealing layer formed on the substrate layer, and the raw material of the heat-sealing layer is the bonding composition.

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