JPS5913346B2 - Polyimide heat-resistant film with surface treatment layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyimide heat-resistant film which has a polyamino acid resin layer on a predetermined surface to be bonded, and which has excellent adhesive properties.

Polyimide-based polyparapanic acid films and polyhydantoin films, which have a series of polyimide structures represented by aromatic polyimide resins obtained by the reaction of pyromellitic anhydride and 4,4'-diaminodiphenyl ether, are electrically It is expected to have many uses, including as an insulating material.

In other words, because heat-resistant films such as the polyimide film mentioned above have excellent heat resistance, electrical insulation, and toughness, their use as magnet wires for electrical equipment, flexible printed boards, flat cables, insulating tubes, spacers, etc. is being developed. It is being

Therefore, when using the above heat-resistant film, 5.
Generally, it is necessary to adhere to a metal material such as copper or iron, or to mold and fix it into a predetermined shape.

When bonding heat-resistant films such as polyimide films, attempts have been made to use polyimide resins or polybenzimidazole resins as adhesives in order to effectively utilize their good heat resistance, but the curing reaction process This involves dehydration and ring closure, which is disadvantageous in that the adhesion operation is complicated in terms of dehydration and removal. In addition, although adhesives that have traditionally been called heat-resistant adhesives, such as maleimide adhesives and epoxy adhesives, have excellent heat resistance, they still do not adhere well to heat-resistant films such as polyimide films. It has the disadvantage of being less powerful.

In order to improve the adhesive strength of heat-resistant films such as polyimide films, the surface to which the film is adhered should be mechanically roughened, for example, by sandplast, or an alkaline aqueous solution may be used. Attempts have also been made to improve the quality of the product, but practically satisfactory results have not yet been obtained.

H5. As a result of repeated studies to address these points, the present inventors have discovered that polyimide heat-resistant films have a surface treatment layer that can easily impart excellent adhesion to polyimide heat-resistant films. We have found the film and are presenting it here.

No. 30 relates to a polyimide heat-resistant film having a surface treatment layer, in which a polyamino acid resin layer is formed on a predetermined surface of the polyimide heat-resistant film to be adhered.

The present invention will be described in detail below. A predetermined surface of a heat-resistant film such as polyimide 35 to be adhered is slightly roughened with sandpaper or sandplast, if necessary, and then a polyamino acid resin solution is applied. The present invention relates to a polyamide heat-resistant film in which a layer is formed on a predetermined surface.

More specifically, in the present invention, a predetermined adhesive surface of a polyimide film, a polyhydant in film, a polyparapanic acid film, etc. is slightly roughened with sandpaper, and then a polyamino acid resin solution is applied and a polyamino acid resin thin film layer is formed. Later, they discovered that adhesion using an adhesive based on a urethane-modified epoxy resin significantly improved the adhesive properties, and thus arrived at the present invention.

In other words, this material can sufficiently withstand solder immersion at 260° C. for 60 seconds or more. It has been found that, in addition to the above-mentioned urethane-modified epoxy resin adhesive, the adhesive exhibits excellent TS adhesion to Epibis epoxy resin and polyester resin adhesives. In the present invention, the coating resin solution for the polyamino acid resin layer, which is applied after roughening with sandpaper or the like on the predetermined surface of the heat-resistant film to be bonded, is Azikoat A-2000, Azikoat XB-900, Azikoat TC-10, Examples include Azikoat S-30 (both manufactured by Ajinomoto Co., Inc., trade names).

These polyamino acid resins (hereinafter abbreviated as PMG) may be used in a mixed system of one type or two or more of these polyamino acid resins (however, levorotatory L-P
Polyamino acid resin solution containing MG and dextrorotatory D-PMG
To dissolve these polyamino acid resins, which cannot be mixed with solutions containing However, it is preferable to use a high boiling point solvent such as DMF in a small amount as much as possible.

Such a polyamino acid resin solution is applied to a predetermined surface of a polyimide resin film to be bonded and dried to form a thin layer of polyamino acid resin, and then an adhesive such as the above-mentioned urethane-modified epoxy resin adhesive is applied to this thin layer surface. Apply.

When such a heat-resistant polyimide film having a polyamino acid resin layer of the present invention is bonded, excellent adhesive properties can be maintained for a long time without impairing the initial excellent adhesive properties.

For example, for a urethane-modified epoxy resin adhesive as an adhesive, 100 (fl) when non-invention is not used.
The above is also 30% or more for Epibis epoxy resin adhesive and 40% for polyester resin adhesive.
% or more, the adhesive strength is improved and a product with excellent adhesive properties is obtained. The heat-resistant film of the present invention does not impair the flexibility of the polyimide resin film, and does not blister even after being immersed in solder at 260°C for 60 seconds or more.
It is possible to obtain an excellent heat-resistant polyimide film that exhibits excellent heat resistance without causing any problems, is easy to handle, and significantly expands the uses of polyimide heat-resistant films compared to conventional ones.

Next, the present invention will be explained in more detail with Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 Take 107% of Azikote TC-10, add 10f7 of methyl ethyl ketone, and 20% of toluene. was added and sufficiently stirred at room temperature to uniformly dissolve, to prepare a polyamino acid resin solution (solid content: 5%).

Next, a polyparabanic acid film with a thickness of 50 μm, whose predetermined surface to be bonded was lightly roughened with sandpaper, was wiped with gauze soaked in toluene to remove dust. When the excess resin solution stopped dripping, it was placed in a dryer at 170°C and heated for 15 minutes to volatilize the solvent almost completely. Take it out of the dryer, pour-coat the epoxy resin adhesive prepared as follows on the surface coated with the polyamino acid resin layer to a thickness of 20 to 30μ, heat dry at 120°C for 18 minutes, and create a B stage. That is, the epoxy resin adhesive used at this time was urethane-modified epoxy resin EPU-6 (manufactured by Asahi Denka Kogyo Co., Ltd.,
Product name》24r and diaminodiphenyl ether 5y 2
9? An epoxy resin adhesive was obtained by dissolving the epoxy resin in methyl ethyl ketone and stirring sufficiently to dissolve it uniformly at room temperature.

Further, as a method for adhering the copper foil, a 35 μm copper foil was bonded onto the adhesive layer that had already been B-staged at 170° C. for 15 minutes at a pressure of 40 mm. The adhesive strength, solder heat resistance, and flexibility of this copper-clad laminate are shown in Table 1.As Comparative Example 1, all the treatments were performed in the same manner as in Example 1, except that the polyamino acid resin layer was not applied. Comparative example 1 of copper laminate product
It is shown in Table 1 as follows. As described above, the polyimide heat-resistant film having the surface treatment layer of the present invention has excellent properties,
In particular, it has been confirmed that particularly excellent properties can be obtained when a urethane-modified epoxy resin is used as an adhesive.

Examples 2 and 3 A polyparabanic acid film was treated in the same manner as in Example 1,
Of these, Example 2 used an adhesive prepared with Epikote 828 (manufactured by Ciel Kagaku Co., Ltd., trade name) and Epomate B-001 (manufactured by Mainomoto Co., Ltd., trade name). In No. 3, copper-clad laminates were produced using polyester adhesives.

On the other hand, copper laminate products of Comparative Examples 2 and 3 were produced which were subjected to the same treatment as those of Examples 2 and 3 above, except that the polyamino acid resin layer was not provided.

The adhesive strength of these samples was measured and Table 2 was obtained.

As described above, compared to the adhesive of Example 1 using the urethane-modified epoxy resin adhesive under the optimum conditions, the adhesive strength of Examples 2 and 3 is slightly inferior, but the adhesive strength of Comparative Examples 2 and 3 without the polyamino acid resin layer is slightly inferior. It shows superior adhesion strength of 20% or more compared to conventional products. Examples 4 and 5 Examples 4 and 5 were obtained by performing the same treatment as in Example 1, but using a heat-resistant film, a polyamino acid resin solution, and an epoxy resin with different combinations of various resins. The adhesive strength was compared and the results shown in Table 3 were obtained.

Note: *1 = polyimide film manufactured by DuPOnt *2, *3 = trade name of urethane-modified epoxy resin manufactured by Asahi Denka Kogyo Co., Ltd. As can be seen from Examples 4 and 5, in the present invention, urethane-modified epoxy resin is used. It has been confirmed that the use of adhesives produces copper-clad laminates with extremely high adhesion.

It is clear that the copper-clad laminate products of Examples 2 and 3 are also far superior to the conventional products.

Claims (1)

[Claims] 1. A polyimide heat-resistant film having a surface treatment layer, characterized in that a polyamino acid resin layer is formed on a predetermined surface of the polyimide heat-resistant film to be adhered.