JPH0455438A - Polyparabanic acid film treated with ultraviolet light - Google Patents

Abstract

PURPOSE:To obtain the subject film, improved in adhesion and useful as electrical insulating materials, etc., while utilizing characteristics such as essential excellent heat resistance, electrical characteristics and mechanical strength by irradiating the surface of a polyparabanic acid film with ultraviolet light. CONSTITUTION:The objective film is obtained by irradiating the surface of a polyparabanic acid film (preferably having 0.8-1.4 dl/g intrinsic viscosity [eta]) with ultraviolet light (preferably 100-400 nm wavelength) in a vacuum or a gas atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a surface-modified polyparabanic acid film and a composite thereof, which are useful as electrical insulating materials and the like.

[Prior art] Polyparabanic acid (PPA) film has excellent heat resistance, electrical properties, mechanical strength, etc., and has excellent adhesive properties with other materials.
It is actually superior to films with similar performance such as polyimide films, but by further improving adhesion, it can be used even more appropriately for known applications, and its By improving adhesion,
New uses can be developed.

For example, when making a copper-clad board for a flexible circuit board, there is a method of bonding copper foil and PPA film together using an adhesive. In this case, depending on the type of adhesive, it may be possible to improve adhesion (adhesion) by roughening the surface by sandblasting, but this is expensive or does not improve adhesion. However, it may degrade the physical properties of the film.

Other surface modification methods for imparting or improving adhesion include corona discharge treatment and plasma treatment.

However, corona discharge treatment generally has little effect on heat-resistant films typified by polyimide and super engineering plastics, and the same is true for PPA films, which often have extremely poor permanence.

Plasma treatment has a complicated treatment process, high initial costs (equipment costs) and running costs (operating costs), and it is difficult to control the treatment conditions, and overtreatment may deteriorate physical properties.

[Problems to be solved by the invention] The present invention solves the problems of the PPA film, which has excellent heat resistance, electrical properties,
The purpose is to further improve the adhesiveness while taking advantage of properties such as mechanical strength.

[Means for Solving the Problems] The present invention provides an ultraviolet-treated polyparabanic acid film with improved adhesiveness, which is formed by irradiating the surface of the polyparabanic acid film with ultraviolet rays, and the above-mentioned ultraviolet-treated polyparabanic acid film, The present invention relates to a polyparabanic acid film composite characterized in that it is formed by laminating laminates with or without an adhesive layer.

PPA in the present invention is a synthetic resin represented by the following symbol.

OO This PPA is usually, for example,
As described in the above publications, hydrogen cyanide and the formula CN-R-NGO [R represents a divalent organic group]. It can be produced by hydrolyzing the poly(iminoimidazolidinedione) shown below, which is obtained by reacting the following diisocyanate.

or [R is the same as above. ] In the present invention, the above poly(iminoimidazolidinedione)
75% or more of partial hydrolyzate (P I P
A) can also be used.

R in the general formula of PPA above is R', R
", R", R', R', and R@ are a hydrogen atom or a methyl group, and X and xl are a bond, CH,, an oxygen atom, a sulfur atom, SO□, CO or HB C- CH, .

The diisocyanate includes m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4
'-Biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 2.4- and 2.6-toluene diisocyanate (TDI), p-xylylene diisocyanate, m-xylylene diisocyanate, tolidine diisocyanate (TODI), 3.3'- dimethyl-
4,4'-biphenylene diisocyanate, 3-3'-
Dimethoxy-4,4'-biphenylene diisocyanate, 4,4'-diphenylmethane diisocyanate) (M
DI), 4,4'-diphenyl-isopropylidene diisocyanate, 4-(4-isocyanatecyclohexyl)phenyl isocyanate, 4-incyanate benzyl isocyanate, 4,4' diphenylsulfone diisocyanate, 4,4' diphenyl ether diisocyanate, Tetrafluoro-p-phenylene diisocyanate, tetrafluoro-m-phenylene diisocyanate, 4,4' diisocyanate octafluoro-biphenyl and durenidisocyanate, 3.3'-dimethyl-4,4'-methylenebis(cyclohexyl isocyanate), 1.4 -diisocyanates cyclohexane, isophorone diisocyanate, 4,4'-dicyclohexyl diisocyanate and 1,3-bis[α,α'
-dimethylisocyanatemethyl]benzene; groups such as alkylene groups, arylene groups, and cycloalkylene groups having 2 to 10 carbon atoms, such as hexamethylene diisocyanate, dodecamethylene diisocyanate, and 2,2°4-trimethylhexamethylene isocyanate; Examples include diisocyanates whose main chain is a group derived from , and diisocyanates having an aliphatic hydrocarbon group in which an alkyl group is bonded with a divalent group or atom, such as di(3-isocyanatepropyl) ether. .

These diisocyanates are not limited to one type, and two or more types can be used. When two or more types are used, a copolymer with different R in the general formula of the PPA will be obtained. In the present invention, these copolymers can also be used.

The polyparabanic acid obtained as described above and used in the present invention usually has a degree of polymerization of 20 to 4000, and the intrinsic viscosity of polyparabanic acid with such a degree of polymerization [η] (25
°C, 0.5 g/l 00 ℃ 2 dimethylformamide)
is usually within the range of 0.1 to 3.0 df2/g,
η is 0.5 to 3.0 dff/g, preferably 0.8 to 1
．． It is better to use one with a value of 4dβ/g.

The polyparabanic acid in the present invention may have its terminal modified with a modifier. Examples of modifiers include carboxylic acid anhydrides, allyl group-containing compounds such as allyl alcohol, and allyl amine.

The ultraviolet treatment of the PPA film surface in the present invention can be carried out by irradiating the PPA film surface with ultraviolet rays in a vacuum or in a gas atmosphere.

The processing gas includes air, 0□, N2. H-1A, , N, etc. can be used. The ultraviolet treatment may be carried out in one of these gases, in a mixture of gases, or in an atmosphere in which these gases are sequentially introduced. The processing equipment (including power source, power frequency, etc.) and processing conditions (gas flow rate, processing time, pressure, irradiation power, etc.) are not particularly limited. However, when irradiating ultraviolet light, the wavelength of the ultraviolet lamp should be set at an energy level appropriate for breaking chemical bonds (preferably,
7 eV). Specifically, 10
0 to 400 nm is preferred.

Through this ultraviolet treatment, various functional groups are added to the PPA film surface and the film surface is etched, improving adhesion and increasing the chemical and physical bond strength with the laminate to be laminated thereon. Good adhesion can be obtained.

Irradiation of ultraviolet rays onto the PPA film surface in a vacuum or in an inert gas atmosphere causes radicals on the film surface generated during etching and processing of the PPA film surface to be removed by gases in the atmosphere (particularly O, etc.). The parent tree group resulting from 02, such as ゝC=O-COOH-OH/, is formed.

Air, 0. In the ultraviolet treatment in the atmosphere, \C=O-COOH-OH/ is formed on the surface of the PPA film.

The ultraviolet treatment in the N2 atmosphere forms -NH on the surface of the PPA film.

In the present invention, examples of the laminate to be laminated on the surface of the ultraviolet-treated PPA film include plastic films such as polyester film, nylon film, and polycarbonate film. Examples include metal materials such as metal foil and ceramic materials.

To obtain the polyparabanic acid film of the second invention, a laminate is laminated on the ultraviolet-treated PPA film obtained as described above, with or without an adhesive layer.

At this time, an adhesive may be used, or if the laminate has adhesive properties, it can be laminated without using an adhesive. An adhesive such as an epoxy adhesive sheet (film) may be used as the adhesive.

In the present invention, the ultraviolet-treated PPA film and the laminate may be laminated by, for example, a method in which the laminate is brought into contact with the ultraviolet-treated surface of the PPA film via an adhesive layer, and the laminated body is heated and pressurized. I can do it.

[Example] Hereinafter, the present invention will be explained in detail with reference to Examples.

In addition, the ultraviolet treatment conditions and the surface analysis method of the ultraviolet-treated film in the following examples are as follows. Further, the surface analysis results are shown in Table 1.

Furthermore, a method for measuring the contact angle of the film is shown after the surface analysis results.

+1 + Ultraviolet treatment conditions Ultraviolet lamp: wavelength 100-400 nm, 100W frequency: 1OOHz irradiation distance: 2cm Under the above conditions, PPA film (5
The treatment was carried out by irradiating ultraviolet rays for a predetermined period of time (0 μm).

(2) Surface analysis of ultraviolet-treated PPA film X-ray photoelectron spectrometer (manufactured by KRATO3, model XSAM800, X-ray source: MgKa) i, l: Measure the area of each peak of CIl+ O+a and N11, and calculate the peak area. estimated the ratio.

Table 1 shows the results of surface analysis (XPS) of PPA films treated with ultraviolet rays in air and 02.

It was confirmed that oxygen and nitrogen were introduced into the surface molecules of the PPA film by ultraviolet ray treatment in air and 02. As the treatment time increased, the amount of oxygen and nitrogen introduced increased. In particular, it was confirmed that the introduction of oxygen was caused by the formation of a carbonyl group (C=0).

Next, a method for measuring the contact angle of a film in the following example will be described.

(3) Measurement of contact angle of film The contact angle of water was measured as a measure of the surface characteristics of the PPA film. When decreased from the value of untreated PPA film,
Indicates that the surface has become hydrophilic. Measurement was carried out using a contact angle meter (KYOWA C0NTACT manufactured by Kyowa Interface Science Co., Ltd.)
ANGLERCA-D) using ion-exchanged water using the droplet method.

Example 1 A modified epoxy adhesive (BX-60, manufactured by Toagosei Kagaku Kogyo Co., Ltd.) was applied onto a fluororesin (Teflon) sheet, air-dried for 2 minutes, and heated at 80°C for 2 minutes. The obtained adhesive film was sandwiched between two PPA films that had been treated with ultraviolet light for 2 minutes and 15 seconds in the air, with the treated surfaces facing each other, and heated at 130°C for 20 minutes at a pressure of 50 K gf/cm''. Then, 13
Curing was performed by heating at 0° C. for 40 minutes.

The adhesive strength of the thus obtained test piece consisting of the ultraviolet-treated PPA/adhesive/ultraviolet-treated PPA was measured by a 180 degree beer test.

The measurement results of adhesive strength are shown in Table 2.

Comparative Example 1 A test piece was prepared in the same manner as in Example 1, except that a PPA film that had not been treated with ultraviolet light or a sandblasted film was used, and its adhesive strength was measured by a 180 degree beer test.

The measurement results of adhesive strength are shown in Table 2.

Example 2 PPA films treated with ultraviolet light for 2 minutes and 15 seconds in the air were placed with the treated surfaces facing each other, and a glass epoxy adhesive sheet (manufactured by Arisawa Seisakusho, NBG030-170-100) was placed.
Bonding was performed using 0). Bonding is done at a pressure of 3K.
gf/cm'' at 130° C. for 1 hour.

The adhesive strength was measured by the method shown in FIG. 1 using a tensile tester.

That is, FIG. 1 is an explanatory diagram of the method for measuring the adhesive strength. In FIG. 1, 1 is a stainless steel adhesive strength evaluation jig, 2 is a tensile tester, 3 is a load cell, 4 is a PPA film, 5 is an adhesive made of a glass epoxy resin sheet, 6
is instant adhesive. When measuring the adhesive strength, the adhesive is pulled in the direction of the arrow at a pulling speed of 0.5 mm/min.

The measurement results of adhesive strength are shown in Table 3.

Comparative Example 2 A test piece was prepared in the same manner as in Example 2, except that a PPA film that had not been treated with ultraviolet light was used, and the adhesive strength was measured.

The measurement results of adhesive strength are shown in Table 3.

Example 3゜Epoxy adhesive [Mitsui Petrochemical C Co., Ltd.], product name A
PPA films treated with ultraviolet light for 2 minutes and 15 seconds in the air using [H-651Y] were bonded together, and heated at 150°C and 50°C.
Kgf/am'' Thermocompression bonding was performed by heating for 10 minutes.

Adhesive strength was measured by a 180 degree beer test.

Comparative Example 3 Test pieces were prepared in the same manner as in Example 3, except that a PPA film that had not been treated with ultraviolet light and a PPA film that had been sandblasted were used, and the adhesive strength was measured.

Table 4 shows the measurement results of the adhesive strength of Example 3 and Comparative Example 3.

Table 1 Table 3 [Effects of the Invention] According to the present invention, it was possible to further improve the adhesive properties of PPA film while taking advantage of its excellent properties such as heat resistance, electrical properties, and mechanical strength. .

The present invention can be applied to various applications, such as copper clad boards for flexible circuit boards, printed circuit boards used in conjunction with heat transfer metal plates, flexible board coverlay films, metal plating [sputtering, ion blating, CVD (chemical vapor deposition)] (including film growth using phase reactions), heat-resistant insulating films used for planar heating elements, industrial films that require adhesion and easy peelability from other materials, and other performance films. Composite films bonded or laminated with plastic films, composite films coated with ceramics, etc. to improve gas barrier properties, etc. can be mentioned.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a method for measuring adhesive strength in an example of the present invention. Adhesive strength evaluation jig Tensile tester Load cell PPA film adhesive Adhesive Patent applicant Tonen Petrochemical Co., Ltd. Nitto Chemical Industry Co., Ltd. Representative patent attorney Yoshihiro Sato

Claims (1)

[Scope of Claims] 1. An ultraviolet-treated polyparabanic acid film with improved adhesiveness, which is obtained by irradiating the surface of the polyparabanic acid film with ultraviolet rays. 2. A polyparabanic acid film composite, characterized in that it is formed by laminating a laminate on the ultraviolet-treated polyparabanic acid film according to claim 1, with or without an adhesive layer.