TWI703197B - Preparation method of self-adhesive composite conductive tape - Google Patents

Abstract

The present invention relates to a method for preparing a self-adhesive composite conductive adhesive tape, which prepares a release protective layer and an adhesive layer, which combines elastomer and tackifier to form a pressure-sensitive adhesive. A self-adhesive composite conductive tape containing a plurality of conductive particles; and a conductive substrate layer; wherein, the elastomer is synthetic rubber, the tackifier is terpene resin; or, the elastomer is natural rubber, the The tackifier is modified rosin. In this way, the self-adhesive composite conductive tape prepared is used to solve the problem that the acrylic self-adhesive conductive tape cannot meet the requirements for bonding high surface energy and low surface energy materials at the same time, and has the ability to meet the high surface energy and The effect of low surface energy material demand.

Description

Preparation method of self-adhesive composite conductive tape

The present invention relates to a preparation method of self-adhesive composite conductive tape, in particular to a self-adhesive composite conductive tape prepared, which has good bonding strength to materials with high surface energy and effectively improves the performance of materials with low surface energy. Designer of bonding strength.

According to, with the development of the consumer electronics industry, consumer electronics products are increasingly showing thinner, lighter and diversified design features. With the advent of the 5G communication era, the number of antennas in consumer electronic devices has increased significantly. However, the design of lightweight and thinning is the mainstream trend of the market; then, how to solve the electromagnetic radiation interference and electrostatic breakdown problems caused by the increase of antennas in a small space is very important to the design of consumer electronics; traditional consumer electronics conduction The countermeasures are usually welding, metal shrapnel compression contact or cable fixing, but because these solutions require a lot of space, especially the height part; therefore, more and more consumer electronics manufacturers are beginning to choose self-adhesive conductive design Tape to replace traditional conductive materials such as welding, metal shrapnel or cables.

Second press, because acrylic has good heat resistance and oxidation resistance, it is often selected as the basic material of pressure-sensitive adhesive for self-adhesive conductive tape; and in order to ensure the bonding strength, the use of self-adhesive conductive tape requires a certain amount of space. However, as the design of consumer electronics becomes thinner and thinner, the space inside the electronic device is getting smaller and smaller, and the self-adhesive conductive tape cannot be completely pasted on the metal surface with high surface energy, and special-shaped bonding methods such as cross-sticking and folding are appearing; In order to avoid electromagnetic interference in 5G high-frequency communication, it is required to avoid the use of metal conductive materials as structural parts in non-essential occasions, resulting in a large number of plastics, ceramics, and glass being used in consumer electronic equipment, including low surface energy materials; However, in the face of the requirement for self-adhesive conductive tape to straddle or fold high surface energy metals and low surface energy materials, because the surface tension of polyacrylic acid itself is 36.9*10 ³ /(N/m), it is a relatively high surface tension type. As a result, the acrylic-based self-adhesive conductive tape cannot meet the needs of bonding high surface energy and low surface energy materials at the same time.

The main purpose of the present invention is to prepare a self-adhesive composite conductive tape to solve the problem that the acrylic self-adhesive conductive tape cannot meet the simultaneous bonding of high surface energy and low surface energy materials, and has the ability to meet the simultaneous bonding of high surface energy. And low surface energy material requirements.

In order to achieve the above-mentioned effects, the structural feature of the present invention is to sequentially laminate a release protective layer; an adhesive layer that mixes the elastomer and the tackifier to form a pressure sensitive adhesive, and the pressure sensitive adhesive contains a plurality of Conductive particles; and a conductive substrate layer; wherein, the elastomer is a synthetic rubber, the tackifier is a terpene resin, and the synthetic rubber elastomer may be a styrene thermoplastic elastomer; or, the elastomer It is natural rubber, and the tackifier is modified rosin.

Furthermore, the weight percentage of each component is: 22%-30% of the release protective layer, 15%-30% of the pressure-sensitive adhesive, 3%-10% of the conductive particles, and 37.5%-65% of the conductive substrate; The thickness of the protective layer is 25-150 microns, the thickness of the adhesive layer is 10-70 microns, and the thickness of the conductive substrate layer is 10-200 microns; the release force of the release protective layer is 5-30gf/inch, the The conductive substrate layer is pure metal foil or porous fibrous material with metal plating.

However, the feature of the method of the present invention includes the following steps: Step 1, the elastomer is the main body, the tackifier and the solvent are added, and the mixture is stirred at a speed of 2000 rpm for 30 minutes, and the weight percentage is: 30% of the elastomer- 40%, tackifier 10%-15%, solvent 44%-54%; step two, let the mixture that completes step one stand for 24 hours at 50℃ and take it out; step three, set the weight percentage to 3%-10 % Of a plurality of conductive particles are mixed with the mixture that has completed step two, and stirred at a speed of 1000 rpm for 30 minutes; step four, will complete the mixing of step three The compound is coated with a PET release protective film of 10-70 microns in the range of 25-150 microns, and sent into the oven at a speed of 8 m/min to expel the solvent; and step 5, after leaving the oven, attach a conductive substrate of 10-200 microns, The self-adhesive composite conductive tape can be obtained; wherein the elastomer is synthetic rubber or natural rubber, the tackifier is terpene resin or modified rosin, the solvent is ethyl acetate, and the synthetic rubber can be styrene thermoplastic Elastomer.

As a result, because the pressure-sensitive adhesive composed of styrene thermoplastic elastomer (or natural rubber) mixed with terpene resin (or modified rosin) has lower surface tension, it not only has good adhesion to high surface energy materials Strength, while effectively improving the bonding strength to low surface energy materials.

10: Release protection layer

20: Adhesive layer

21: Pressure sensitive adhesive

22: conductive particles

30: Conductive substrate layer

[Figure 1] is a schematic diagram of the structure of the present invention.

First of all, please refer to [Figure 1]. The first embodiment of the self-adhesive composite conductive tape of the present invention is to sequentially laminate a release protective layer 10 with a thickness of 25-150 microns and a release force of 5-30gf/ inch; an adhesive layer 20 with a thickness of 10-70 microns, and a styrene-based thermoplastic elastomer (SBS polymer) and terpene resin are mixed to form a pressure-sensitive adhesive 21, and the pressure-sensitive adhesive is mixed A plurality of conductive particles 22; and a conductive substrate layer 30, which can be pure metal foil or porous fibrous material with metal plating, with a thickness of 10-200 microns; wherein, the weight percentage of each component is: release protective layer 22%-30%, pressure-sensitive adhesive 15%-30%, conductive particles 3%-10%, conductive substrate 37.5%-65%.

Furthermore, the difference between the second embodiment of the self-adhesive composite conductive tape of the present invention and the first embodiment is that the adhesive layer is changed from mixing natural rubber and modified rosin to form a pressure-sensitive adhesive.

Next, the preparation method of the self-adhesive composite conductive tape of the present invention includes the following steps Step: Step 1: Take styrene thermoplastic elastomer (or natural rubber) as the main body, add terpene resin (or modified rosin) and solvent (such as ethyl acetate), and stir for 30 minutes at a speed of 2000 rpm To form a mixture, the weight percentage is: styrene thermoplastic elastomer (or natural rubber) 30%-40%, terpene resin (or modified rosin) 10%-15%, ethyl acetate 44%-54%; Step two, let the mixture completed in step one stand for 24 hours at 50°C and take it out; step three, mix a plurality of conductive particles with a weight percentage of 3%-10% with the mixture completed in step two at 1000 rpm Stir at a speed of 30 minutes; step four, coat the mixture of step three with a 20 micron and 75 micron PET release protective film, and send it into the oven at a speed of 8 m/min to expel the solvent; and step five, after leaving the oven, attach 23 With a micron conductive substrate, the self-adhesive composite conductive tape of the present invention can be obtained.

Refer to the People’s Republic of China National Standard GB2792-81 Pressure Sensitive Adhesive Tape 180° Peeling Strength Test Method, respectively test the conductive tape prepared by the present invention and the conductive tape sold in the common market on the high surface energy 304 stainless steel plate and low surface energy polymerization 180° peeling force of vinyl PE plastic sheet.

Based on this structure, the pressure sensitive adhesive composed of styrene thermoplastic elastomer (or natural rubber) mixed with terpene resin (or modified rosin) has lower surface tension (can reach 24.8*10 ³ / (N/m)), and from the results of the lifting test, the self-adhesive composite conductive tape of the present invention not only has good bonding strength to the high surface energy metal 304 stainless steel, but also effectively improves the adhesion to low surface energy. The bonding strength of vinyl PE plastic has the effect of meeting the needs of bonding high surface energy and low surface energy materials at the same time.

In summary, the technical means disclosed in the present invention do have the requirements of invention patents such as "novelty", "progressiveness" and "available for industrial use". I pray that the Jun Bureau will grant patents to encourage invention without any responsibility. Sense of virtue.

However, the drawings and descriptions disclosed above are only preferred embodiments of the present invention. Anyone familiar with the art should still include modifications or equivalent changes made in accordance with the spirit of the case in the scope of the patent application in this case.

10: Release protection layer

20: Adhesive layer

21: Pressure sensitive adhesive

22: conductive particles

30: Conductive substrate layer

Claims (3)

A method for preparing a self-adhesive composite conductive adhesive tape includes the following steps: Step 1, using elastomer as the main body, adding a tackifier and solvent, and stirring at 2000 rpm for 30 minutes to form a mixture, the weight percentage is: elastomer 30 %-40%, tackifier 10%-15%, solvent 44%-54%; step two, let the mixture completed in step one stand for 24 hours at 50°C and take it out; step three, set the weight percentage to 3% -10% of a plurality of conductive particles are mixed with the mixture that has completed step two, and stirred for 30 minutes at a speed of 1000 rpm; step four, coat the mixture of step three with 10-70 micron and 25-150 micron PET release protection The film is fed into the oven at a speed of 8 m/min to expel the solvent; and step 5, after leaving the oven, a 10-200 micron conductive substrate is attached to obtain a self-adhesive composite conductive tape. As described in item 1 of the scope of patent application, the self-adhesive composite conductive tape preparation method, wherein the elastomer is synthetic rubber or natural rubber, the tackifier is terpene resin or modified rosin, and the solvent is ethyl acetate. For the preparation method of self-adhesive composite conductive tape described in item 2 of the scope of patent application, the synthetic rubber is selected from styrene thermoplastic elastomer.

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