JPH068406B2 - Light opaque adhesive tape or sheet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a light-impermeable adhesive tape or sheet having excellent heat resistance, which is used for blocking light rays to an IC storage element.

[Conventional technology and its problems]

Light-shielding pressure-sensitive adhesive tapes or sheets (hereinafter collectively referred to as tapes) used for photolithography are well known, but in recent years, tapes having light-shielding properties have been used in new fields including the field of electronic devices. The demand is increasing.

Particularly in the field of IC storage elements, there is a demand for the supply of an adhesive tape capable of maintaining heat resistance and light impermeability over a long period of time.

The IC storage element has a property that the stored contents are erased by ultraviolet rays. Therefore, when the sun rays including ultraviolet rays hit the IC storage element, it is not preferable that the stored contents are erased or abnormal. A phenomenon will occur and seriously hinder the operation of the computer.

The pressure-sensitive adhesive tape used for such a purpose is not only light-shielding but also important in terms of adhesive performance. That is, it goes without saying that the tape should not be peeled or floated from the adherend during use of the tape so as not to impair the light-shielding effect, but on the other hand, the tape should be peeled off when it is necessary to erase or change the stored contents. At this time, it is necessary that the tape can be easily peeled off from the adherend, and the tape should not be easily peeled off or the adhesive should not remain on the adherend. The environmental temperature of the adherend to which the adhesive tape is adhered does not usually rise to 70 to 80 ° C or higher, but it is assumed that the ambient temperature will be 120 to 130 ° C under abnormal conditions. In consideration of safety in case of reaching a state, a durability test at 150 ° C. for 2000 hours may be performed.

The pressure-sensitive adhesive used for the pressure-sensitive adhesive tape is generally of three types, which are called rubber-based, acrylic-based, and silicone-based pressure-sensitive adhesives. In the endurance test at 2000 ° C for 2000 hours, the adhesive softens or deteriorates and easily floats or peels from the adherend. Conversely, when it becomes necessary to peel off the adhesive tape, the adhesive hardens or solidifies. There is a problem that it is difficult to peel off, or the adhesive remains on the adherend during peeling.

Silicone-based adhesives are available as adhesives that can solve such problems, but conventional adhesive tapes that use silicone-based adhesives mainly require heat resistance, cold resistance, or chemical resistance. However, the one having a light-shielding property for protecting the IC memory element and the like from light has not yet been developed.

[Object of the Invention]

It is an object of the present invention to provide an adhesive tape which has excellent heat resistance and removability even under severe conditions and also has a light shielding property.

[Structure of Invention]

The present invention is a heat-resistant synthetic black pressure-sensitive adhesive prepared by mixing (a) a pressure-sensitive adhesive mainly composed of silicone rubber and silicone resin with (b) black iron oxide, cobalt black and / or titanium black. A light-impermeable pressure-sensitive adhesive tape or sheet formed by coating one side of a resin film or paper.

The heat-resistant synthetic resin film that can be used as the support in the present invention is polyimide, polyamideimide, polyetherimide, polysulfone, polyethersulfone, polyetheretherketone, polyphenylene sulfide, polyethylene terephthalate, polyethylene naphthalate, polyparaban. Any acid, aromatic polyamide, polytetrafluoroethylene or copolymer of ethylene tetrafluoride and other unsaturated monomers can be used as long as it can be used for a long time at 120 ° C or higher. Good. These films have a thickness commonly used in the art, ie 1
Those having a thickness of about 2 to 150 μm are used.

The pressure-sensitive adhesive used in the present invention includes a silicone rubber component having a linear polysiloxane structure having a degree of polymerization of several thousand to tens of thousands and a silicone having a three-dimensional structure although the molecular weight is smaller than that of the silicone rubber component. What is commonly called a silicone-based pressure-sensitive adhesive composed of both a resin component and a resin component is used.

The coating layer of these adhesives on the support material is 10-100 μm
It is preferable to apply it to a thickness of 20 to 70 μm.

The black pigment used to impart light impermeability to the pressure-sensitive adhesive includes carbon black, black iron oxide, cobalt black, titanium black, aniline black, and the like. Satisfactory are black iron oxide, cobalt black and titanium black.

That is, when carbon black, which is generally most widely used as a black pigment, is mixed with a silicone-based adhesive,
The curing action of benzoyl peroxide, which is a curing agent used for the purpose of imparting appropriate cohesive force and heat resistance to the silicone-based adhesive, is significantly reduced, and satisfactory adhesive performance cannot be obtained. Also, aniline black does not hinder the curing of the adhesive unlike carbon black, but it has the property of discoloring by heat and cannot be used for applications requiring heat resistance.

The pigments used in the present invention are black iron oxide, cobalt black and titanium black, and their particle size is 0.
Those having a thickness of 1 μm to 10 μm are used, and particularly 0.1 μm to
The range of 5 μm is preferable. These pigments may be used alone or as a mixture of two or more kinds in an arbitrary ratio, and 15 to 50 parts by weight, preferably 20 to 40 parts by weight, relative to 100 parts by weight of the silicone adhesive. Used in proportion. A pressure-sensitive adhesive tape obtained by applying a pressure-sensitive adhesive mixed with these black pigments to a heat-resistant film to a thickness of 25 to 70 μm completely blocks visible rays and ultraviolet rays of 900 to 190 nm and has excellent adhesive performance and heat resistance. There is.

The pressure-sensitive adhesive tape of the present invention may be supplied by winding the back surface of which is treated with a release agent such as a fluorine-based release agent, or when it is used in the form of a sheet, it is treated with a fluorine-based release agent, for example. The film may be supplied as a release paper by temporarily adhering it to the adhesive surface.

Next, examples of the present invention will be described.

Example 1 Silicone adhesive (60% by weight solution) 160 parts by weight (Toray SH4280) Black iron oxide 35〃 Benzoyl peroxide 2 parts by weight Toluene 100〃 Example 2 Silicone adhesive 160 parts by weight (Shin-Etsu Silicone KR-101) -10) Cobalt black 40 〃 Benzoyl peroxide 2 parts by weight Toluene 100 〃 Polyimide film with a thickness of 50 μm (Kapton film 200 manufactured by Toray Deyupon)
H) was coated on one surface with an applicator so that the thickness of the dried glue was 50 μm, and dried at 150 ° C. for 3 minutes.

A heating test and a light transmission test were performed on the obtained tape.

The test method is as follows.

1. Heating test: A sample of 20 mm × 20 mm was made to reciprocate once with a 2 kg rubber roller at a speed of 300 mm / min, and pressed onto a stainless plate and a glass plate. Thereafter, this sample was heated in an oven dryer at 150 ° C. for 1000 hours, and after 1000 hours, the sample was discolored, the adhesive remained on the adherend,
And the fall (peeling) from the adherend was tested.

2. Transmittance test: Using a UV10EC-510 type double beam self-recording spectrophotometer manufactured by JASCO Corporation, the transmittance before and after the heating test was measured in the range of 2000 Å to 9000 Å.

The results of the heating test are shown in Table 1.

As can be seen from the results shown in Table 1, the pressure-sensitive adhesive tape of the present invention is excellent in discoloration resistance by heating and the like.

In addition, the light transmittance is 0, which is extremely excellent before and after heating.

Similar results were obtained for titanium black.

Claims (1)

[Claims] 1. A black pressure-sensitive adhesive obtained by mixing (a) a pressure-sensitive adhesive mainly composed of silicone rubber and a silicone resin with (b) black iron oxide, cobalt black and / or titanium black. Light-impermeable pressure-sensitive adhesive tape or sheet coated on one side of a synthetic resin film or paper.