JPS633075A - Heat-resistant adhesive tape or sheet - Google Patents

Abstract

PURPOSE:To obtain the titled film or tape outstanding in tenacity, young's modulus, dimensional stability, etc., suitable for surface protection, winding of electric wires, etc., explosion-proofing, etc., by providing an adhesive layer on the surface of a para-orientation type aromatic polyamide film with its end tear resistance exceeding a specified value. CONSTITUTION:The objective tape or sheet can be obtained by providing an adhesive layer on the surface of a para-orientation type aromatic polyamide [pref. poly(p-phenylene terephthalamide)] film (pref. >=20mum thick) with its end tear resistance >=0.6kgf (pref. >=0.8kgf) per 1mum thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat-resistant adhesive tape or sheet (for example, capable of being used continuously at high temperatures of 150 C or higher).

[Conventional technology]

The base materials conventionally used for adhesive tapes or sheets are thermoplastic resin films such as polypropylene, polyvinyl chloride, polyester, and polystyrene, and cellulose films such as cellophane, and although these are inexpensive, they have poor heat resistance. It is not a material that is satisfactory in terms of all aspects, and there are significant limitations in its use at high temperatures.

On the other hand, polyimide, polyphenylene sulfide, polyether ether ketone, etc. have been developed as heat-resistant high-grade engineering solaskets and their films, but these are extremely expensive or have a low heat resistance. It has disadvantages such as: Therefore, the industrial value of using these materials as adhesive tapes is low.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a heat-resistant adhesive tape that eliminates the above-mentioned drawbacks. Another object is to provide an adhesive tape with excellent chemical resistance and mechanical performance.

[Means for resolving issues]

The present invention has an end tear resistance of at least 0.6 per 1 μm thickness.
KL? This is a tape or sheet in which an adhesive layer is provided on one or both sides of a para-oriented aromatic polyamide film.

The aromatic polyamide film used in the present invention has an end tear resistance of at least 0.6 K9f/μ thickness, preferably an end tear resistance of at least 0.8 K9f/μ thickness.
Kq f. A film with an end tear resistance of less than 0.6 Kqf will be easily torn and will have little value as an adhesive tape (or sheet).Furthermore, the film used in the present invention is made of Nosora-oriented aromatic polyamide. . Films made of para-oriented aromatic polyamides have excellent heat resistance and, thanks to a special manufacturing method, have good mechanical properties.As para-oriented aromatic polyamides, poly(P-phenylene terephthalamide ) (hereinafter referred to as PPTA) is most preferably used.

PPT used as the most preferred polymer for the present invention
A is a polymer substantially represented by the following, and is conveniently produced from conventionally known rough ethylene diamine and terephthaloyl chloride by a low-temperature solution polymerization method.

If the degree of polymerization of the -elephant-oriented aromatic polyamide of the present invention is too low, a film with good mechanical properties cannot be obtained. Therefore, the logarithmic viscosity ηinh (sulfuric acid 0 polymer per 100t/
．． A degree of polymerization is selected that gives a value measured at 30° C. after dissolving 5 g of the polymer.

The film used in the invention has an edge tear resistance of 1 μm.
It should be at least 0.6 Kff per thickness, preferably at least 0.8-f per micron thickness. This is because adhesive tapes or sheets made of films with low end-tear resistance easily tear, which tends to cause practical problems. An oriented aromatic polyamide film having a high resistance to tearing can be obtained by drying the film while causing a slight dimensional shrinkage in the drying process during production by a wet method.

The film used in the present invention has a thickness of about 10 μn.
The above are useful, and even more useful are films with a thickness of 20 μm or more.

The film used in the present invention is preferably 4 to 10
/1m" or more, more preferably 12-/m" or more in any direction.Also, preferably 400
It has a Young's modulus of KQ/rm" or more in at least one direction. Furthermore, it preferably has an elongation of F'i of 6% or more, more preferably an elongation of 8% or more in any direction. There is.

The film used in the present invention preferably has transparency, for example, the transmittance of visible light at a wavelength of 600 nm is 45% or more.

The film used in the present invention is manufactured, for example, by the following special method. That is, an optically anisotropic dope consisting essentially of a para-oriented West/J aromatic polyamide and 95% by weight or more of sulfuric acid is cast onto a supporting surface that moves from the goo while maintaining its optical anisotropy. In the process of converting the dope to optical isotropy by moisture absorption and/or heating, solidifying it, then washing and drying, the shrinkage of the film that occurs during drying is 0. The elephant-oriented aromatic polyamide film produced in this way can be conveniently produced by drying it at a temperature in the range of .6 to 0.9. By applying layers, the heat-resistant adhesive tape or sheet of the present invention can be obtained.

The adhesive used in the present invention is not particularly limited, and includes, for example, rosin resin, hydrogenated rosin resin, terpene resin, terpene-phenol resin, alkylphenol resin, coumaronindene resin, alicyclic resin,
or mixtures of these tackifying resins and liquid plasticizers,
Alternatively, a mixture of these tackifying resins and gum, a material containing an acrylic acid ester copolymer as a main component, a silicone resin, etc. may be used. Particularly, in order to exhibit the heat resistance that is a feature of the present invention, crosslinked or thermosetting adhesives are preferably used.

In addition, as the adhesive tape or sheet of the present invention, for example,
It is also one of the preferred embodiments to use one adhesive layer made electrically conductive as disclosed in Japanese Patent Publication No. 60-49236.

〔Example〕

13% PPTA with ηinh of 4.8 in 99.5% sulfuric acid
A dope of 7600 poise with optical anisotropy was obtained by melting at 65°C.After degassing and filtering, 0.25BX300
This dope was cast onto a tantalum belt from a die having a slit (1). At this time, the linear velocity of dope discharge from the die was set to 15 m/min, and the # receiving speed of the belt was set to 5 m/min.
m/min. The cast dope was converted to a clear optically isotropic dope by blowing air at about 110°C with a relative humidity of about 80°C, and then coagulated with a 10% aqueous sulfuric acid solution at 0°C. After peeling off the coagulated film from the belt, soak it in room temperature water, 2
It was washed with an aqueous solution of Tikaseinoda and then with water at about 30 to 40°C.

Next, in a tenter blowing hot air at 200°C, the water-washed film was heated to 8 (I
JK was dried while shrinking. The obtained film had a thickness of 52 μm 1 η 1 n h 4.5, a strength of 16 to 9/m, an elongation of 46, a Young's modulus of 520 Kg/2, an end tear resistance of t,
It was a transparent film with IKpf/μm.

97% by weight of butyl acrylate and 3% by weight of acrylic acid
Using a knife coater, an acrylic adhesive solution consisting of 97 parts by weight of a copolymer containing as a copolymer component and 200 parts by weight of ethyl acetate as a solvent was coated on the film with a dry adhesive layer of about 80 microns thick. The solvent was dried, and crosslinking treatment was performed by irradiation with an electron beam of 2 Mrad to produce a pressure-sensitive adhesive sheet.

The resulting pressure-sensitive adhesive sheet had a good peeling force of 190 g/10 m.

The peeling force was determined by pasting a sample with a width of 10 cm on a stainless steel plate, pressing a 2 Kf rubber roll back and forth 5 times, leaving it at 20 cK for 15 minutes, and then applying a tensile speed of 30 cm.
Peeling was performed at 1800 m/min at 0 m/min, and the force against peeling of the sample was measured.

Another sample made under the same conditions was immersed in a solder bath kept at 310°C for about 25 seconds, pulled up, and then tested for peel strength.The peel strength was 185 g/10 m, which was almost the same as the sample that was not placed in the solder bath. [Effects of the Invention] The adhesive tape or sheet of the present invention has excellent heat resistance, and is therefore particularly valuable for high-temperature applications. Furthermore, the adhesive tape or sheet of the present invention has excellent chemical resistance, and in particular, the film is extremely stable against chemicals other than strong acids and strong alkalis. Furthermore, the tape or sheet of the present invention has excellent mechanical properties (eg, strength, Young's modulus, dimensional stability, etc.).

The adhesive tape or sheet of the present invention can be used for surface mining, for winding east wires and optical fibers, for explosion protection, for simple copying, for stationery, etc., and by taking advantage of the above characteristics, it can be used for electrical parts, electronic parts, etc. Soldering is especially useful for temporary fixing and end fixing in the manufacturing process of industrial products.

In particular, in the case of conductive adhesive tapes, it can be used for computers, terminals, communication equipment, etc. 17@ for the purpose of electromagnetic shielding or keeping the potential constant by pasting it on the inside of a plastic box housing electronic devices such as 17@, fixing and vibration prevention of electrical parts with adhesive, removing leakage current of the parts, and grounding. When both adhesion and conductivity are required, such as when used as a wire, static electricity caused by friction can prevent danger by attaching it to parts made of insulating materials that can cause static sparks to ignite or discharge shock to the human body. The purpose of
It is useful for the purpose of preventing problems as a weak heating element by pasting it on areas where condensation or freezing due to cooling is a problem and energizing the conductive tape.

Claims (1)

[Claims] A tape or sheet comprising an adhesive layer on one or both sides of a para-oriented aromatic polyamide film having an edge tear resistance of at least 0.6 Kgf per 1 μm thickness.