TW201634540A - Method for preparation of polyimide film using porous particles and polyimide film having low permittivity - Google Patents

Abstract

The present invention provides a method for preparation of polyimide film by using porous particles and to a polyimide film having a low permittivity produced by the method, wherein the polyimide film contains porous particles having an average diameter of 10 [mu]m or less and a true density of 95% or less relative to the true density of the material itself of the porous particles, thereby enabling the polyimide film to have a lower permittivity than those of conventional polyimide films. Therefore, the polyimide film can be advantageously used in the manufacture of electric/electronic devices and components requiring a low permittivity such as printed circuit boards.

Description

Method for preparing polyimine using porous particles and polyimine film having low dielectric constant Field of invention

The present invention relates to a method for producing a polyimine by using a porous particle and a polyimide film having a low dielectric constant produced according to the method.

Background of the invention

In short, polyimine (PI) resin refers to a high heat resistant resin prepared by the following method, and a polyglycine derivative is obtained by solution polymerization of an aromatic dianhydride with an aromatic diamine or an aromatic diisocyanate. And then, the poly-proline derivative is subjected to ring closure and dehydration at a high temperature to imidize the oxime.

Polyimine resins are ultra-high heat resistant resins that are insoluble and infusible. It has been widely used in a variety of industries due to its excellent properties in terms of resistance to thermal oxidation, heat resistance, radiation resistance, low temperature properties, and chemical resistance, for example, as advanced in automotive, aerospace, and space applications. A heat resistant material and an electronic material used as a dielectric coating layer, a coating film, and an electrode passivation film for a semiconductor and a TFT-LCD.

In recent years, with the high information society requiring electronic devices to store large amounts of information and to process and transmit such information quickly, the polyimine resins used in such devices also need to have high performance, especially low dielectric constant and low. The dissipation factor is taken as the desired electrical property in order to respond to high frequencies.

The intention of lowering the dielectric constant of the polyimide resin is proposed. For example, in Japanese Patent Laid-Open Publication No. 2000-44719, a hydrophilic polymer is dispersed in a polyimide precursor resin which is soluble in an organic solvent which is removed by sintering or solvent extraction. A pore is formed in the polyimide precursor of the polyimide to thereby produce a porous polyimide resin. In the method in which the pores are formed by removing the hydrophilic polymer, when the pores are formed, it is desirable that the microstructure in which the hydrophilic polymer is dispersed and separated from the precursor of the polyimide resin is not maintained. change. However, after the hydrophilic polymer is removed by sintering or solvent extraction, when the pores are formed by imidization, the pores will be flattened or clogged, causing the porosity to be lower than the ideal value, resulting in dielectric The reduction in the constant is not sufficient.

Korean Patent No. 1299652 discloses a method of using fluoropolymer particles in the preparation of a flexible metal laminate. However, the fluoropolymer particles did not disperse well during the preparation process.

In order to solve the aforementioned problems, the inventors have developed a method for preparing a polyimine film having a lower dielectric constant of a dielectric constant than a conventional polyimide film by using porous particles to achieve electrical characteristics of air. The present invention has been completed. The present invention is also improved in the dispersion and deposition of porous particles in the preparation of a polyimide film.

Summary of invention

SUMMARY OF THE INVENTION The object of the present invention is to provide a process for preparing a polyimine by using a porous particle and a polyimide film having a low dielectric constant produced by the method.

The invention provides a method for preparing a polyimide film comprising: 1) preparing a polyimide precursor; 2) mixing the polyimide precursor with a ruthenium reagent containing a porous particle; Forming a gel film; and 3) heat treating the gel film to imidize the ruthenium thereof, Wherein the porous particles have an average diameter of 10 μm or less and a true density (or particle density) of 95% or less with respect to the material of the porous particles themselves.

The present invention also provides a polyimide film having porous particles having an average diameter of 10 μm or less and a true density of 95% or less with respect to the material of the porous particles themselves. True density.

According to the present invention, a porous polyimide particle can be used to produce a polyimide film having an extremely low dielectric constant, and thus can be excellently used for an internal insulator of an electronic device, a shock absorbing material, and a circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a scanning electron micrograph (SEM) photograph of a cross section of a polyimide film according to the present invention.

Fig. 2 is a SEM photograph showing a state in which a porous particle daughter system is dispersed on the surface of a polyimide film according to the present invention.

Figure 3 is an enlarged SEM photograph showing the state of the particles in Figure 2.

Detailed description of the preferred embodiment

The invention provides a method for preparing a polyimide film, which comprises: 1) preparing a polyimide precursor; 2) using the polyimide precursor with a ruthenium reagent containing porous particles Mixing to form a gel film; 3) heat treating the gel film to imidize the ruthenium thereof, wherein the porous particles have an average diameter of 10 μm or less and true to the material of the porous particles themselves A true density of 95% or less.

The method for preparing a polyimide film according to the present invention comprises preparing a polyimide precursor.

The polyimine precursor used in the present invention may be any substance which becomes a polyimine resin by its imidization. For example, it may be a polyamic acid produced by a conventional method in which an acid dianhydride component and a diamine component are copolymerized in the presence of an organic solvent.

The acid dianhydride component and the diamine component are each suitably selected from those conventionally used in the manufacture of polyaminic acid.

Examples of the acid dianhydride component may include, but are not limited to, biphenyltetracarboxylic dianhydride or a derivative thereof, pyromellitic dianhydride (PMDA), 3,3',4,4'-benzophenone Tetracarboxylic anhydride, and p-phenyl-indole-trimellitic dianhydride.

Examples of the diamine component may include, but are not limited to, p-phenylenediamine (pPDA), diaminophenyl ether, o-phenylenediamine, m-phenylenediamine, 4,4. - Diaminodiphenyl ether (ODA), 3,4-diaminodiphenyl ether, and 2,4-diaminodiphenyl ether.

The acid dianhydride component and the diamine component may be mixed in a molar ratio of 1:0.9 to 1:1.1.

Examples of the organic solvent may include, but are not limited to, N,N'-dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), and N-methyl-pyrrolidine. Ketone (NMP).

The method for preparing a polyimine film according to the present invention comprises mixing the polyimine precursor with a hydrazide-containing reagent containing a porous particle to form a gel film.

First, a ruthenium imidization reagent is uniformly mixed with a polyimine resin, that is, poly-proline, and a porous particle is uniformly dispersed and mixed therein to produce a resin for quinone imidization.

The quinone imidization reagent can be any material commonly used for chemical curing. The guanidine imidization reagent can be, for example, selected from the group consisting of a dehydrating agent, a catalyst, a polar organic solvent, and combinations thereof. Preferably, the hydrazide reagent may be a mixture of a dehydrating agent, a catalyst, and a polar organic solvent.

More specifically, the guanidine imidization reagent may be a mixture comprising: a dehydrating agent such as acetic anhydride; and a catalyst such as selected from the group consisting of pyridine, β-methylpyridine, isoquinoline, and mixtures thereof. And the polar organic solvent is selected from N-methyl-pyrrolidone, dimethylformamide, dimethyl a group of indoleamines, and mixtures thereof.

The quinone imidization reagent may be used in an amount of from 30 to 70 parts by weight, preferably from 40 to 55 parts by weight, based on 100 parts by weight of the polyimine precursor. The amount of the quinone imidization reagent may vary depending on the type of the polyimide precursor, the thickness of the polyimide film to be formed, and the like.

The porous particles may have an average diameter of 10 microns or less, preferably 1 to 10 microns, or 1 to 7 microns, or 2 to 5 microns.

Further, the porous particles may have a true density of 95% or less, preferably 30% to 95%, more preferably 50% to 90%, relative to the material itself of the porous particles which do not contain pores. True density.

The term "true density" as used herein refers to the density of the particles themselves calculated as the weight per unit volume of a particle. The term "material itself" of particles refers to the materials that make up the particles in which no voids are present.

The porous particles may comprise from 2 to 30% by weight, preferably from 5 to 20% by weight, or, for example, from 5 to 10% by weight, based on the total weight of the film. If the amount of the porous particles is 30% by weight or less, the mechanical properties of the polyimide film will not be impaired. If the amount of the porous particles is 2% by weight or more, the dielectric constant of the polyimide film may be lowered.

The porous particles are particles having micropores, which may be hollow or mesoporous particles, and are selected from the group consisting of ceria, alumina, titania, zeolites, and mixtures thereof. Hollow ceria can be preferred.

Porous particles can be added as such. Further, since the porous particles are preferably uniformly dispersed and mixed in the resin for quinone imidization, the porous particles can be dispersed in a polar organic solvent and added as a dispersion or a colloid.

Then, the hydrazide reagent is uniformly mixed into the polyaminic acid, and the porous particle system is uniformly dispersed and mixed therein. Then, the resin for oxime imidization can be formed into a gel film.

More specifically, the resin for hydrazide can be applied to a support (for example, a stainless steel plate, a glass plate, an aluminum foil, a circulating stainless steel belt, or a stainless steel drum, etc.) and then subjected to a first heat treatment and Drying, thereby producing a partially chemically imidized gel film.

The first heat treatment for partial oxime imidization can be carried out at a temperature of from 100 ° C to 200 ° C for 5 to 15 minutes.

The method for preparing a polyimide film according to the present invention comprises heat-treating a gel film to imidize its oxime.

Then, the partially chemically imidized gel film prepared as above can be removed from the support and subjected to a second heat treatment for its complete oxime imidization.

The second heat treatment for complete hydrazine imidization can be carried out at a temperature of from 250 ° C to 850 ° C for 5 to 25 minutes. The second heat treatment is preferably carried out under constant tension to eliminate internal residual stress that has been generated during film formation.

According to an embodiment of the present invention, the present invention provides a method for preparing a polyimide film, the method comprising: preparing poly-proline as a polyimide precursor; mixing the polyamic acid with the ruthenium An aminating agent in which a porous particle is uniformly dispersed to obtain a resin for quinone imidization; the resin for quinone imidization is applied to a support to form a gel film; followed by the gel First heat treatment and drying of the film; and accepting the gel film The polyimine film is produced by a second heat treatment, wherein the porous particles have an average diameter of 10 μm or less and a true density of 95% or less with respect to the material itself of the porous particles.

Meanwhile, the present invention provides a polyimide film having porous particles having an average diameter of 10 μm or less and a true density of 95% or less with respect to the material of the porous particles themselves. True density.

More specifically, the polyimine film comprising the porous particles may be a polyimine film obtained from a resin for polyimidization, and the resin for polyamidation is from polyamine. The preparation of an acid and a ruthenium-containing reagent containing a porous particle having an average diameter of 10 μm or less and a true density of 95% or less with respect to the material itself of the porous particles .

The polyimide film according to the present invention has a thickness of 5 μm to 200 μm.

Further, the polyimide film according to the present invention has a dielectric constant of 3.0 or less at 1 GHz, preferably a low dielectric constant of 2.0 to 2.9, and has a dielectric constant of less than 0.002, preferably 0.0005 to 0.001. Dissipation factor. Thus, the polyimide film according to the present invention can be excellently used for internal insulators, shock absorbing materials, and circuit boards of electronic devices.

Invention mode

The invention will be described in detail below with reference to the embodiments. The following examples are intended to further illustrate the invention and not to limit its scope.

[Preparation example] Preparation Example 1: Preparation of Polyproline Solution

320 g of dimethylformamide (DMF) was fed into a 0.5 liter reactor at a temperature of 20 °C. Then 27.59 g of diaminodiphenyl ether (ODA) was added to it and dissolved. Thereafter, 20.03 g of pyromellitic dianhydride (PMDA) was added thereto twice and dissolved. When the dissolution was completed, 3.97 g of p-phenylenediamine (pPDA) was added to the reactor and allowed to react for 30 minutes. The solution was then sampled to measure its molecular weight. When the reaction was completed, the reactor temperature was raised to 30 ° C, and then 1.00 g of pPDA was added thereto to adjust the molar ratio of [diamine]: [acid dianhydride] to 1:1. Once the addition of the starting materials is complete, the resulting mixture is allowed to react at 40 ° C for a sufficient period of time, for example 2 hours, to obtain a polyaminic acid solution.

Preparation Example 2: Preparation of hydrazine imidation reagent containing porous particles (1)

13.4 g of hollow cerium oxide dispersion (DMF liquid mixture contains 6% solids content, hollow cerium oxide: trade name VHSN-1000, manufactured by BAEKSAN STEEL CO., LTD., average particle diameter: 3 Micron, and average particle diameter of the particles: 200 nm) added to a mixed solution containing 2.8 g of β-methylpyridine (melting point 144 ° C) as a curing catalyst for the ruthenium iodide reagent, 21.2 g of acetic anhydride as a dehydrating agent And 13.4 g of DMF was used as a polar organic solvent, and then the mixture was stirred to obtain 50.8 g of a hydrazide-containing reagent containing a porous particle.

Preparation Example 3: Preparation of hydrazine imidation reagent containing porous particles (2)

26.7 g of hollow cerium oxide dispersion (DMF liquid mixture contains 6% solids content, hollow cerium oxide: trade name VHSN-1000, manufactured by Baker Steel, average particle diameter: 6 microns, and average particle porosity Diameter: 200 nm) added to a mixed solution containing 2.8 g of β-methylpyridine (melting point 144 ° C) as a curing catalyst for the ruthenium iodide reagent, 21.2 g of acetic anhydride as a dehydrating agent, and 0.9 g of DMF as A polar organic solvent was then stirred to obtain 51.6 g of a hydrazide-containing reagent containing a porous particle.

Preparation Example 4: Preparation of an oxime imidization reagent containing non-porous ceria particles (1)

13.3 g of spheroidal cerium oxide dispersion (DMF liquid mixture contains 6% solid content, spherical cerium oxide: trade name KEP-250, manufactured by Nippon Catalyst Co., Ltd. (NIPPON SHOKUBAI CO., LTD.), average particle diameter : 3 μm, and no pores) added to a mixed solution containing 2.8 g of β-methylpyridine (melting point 144 ° C) as a curing catalyst for the ruthenium iodide reagent, 21.2 g of acetic anhydride as a dehydrating agent, and 13.4 g DMF was used as a polar organic solvent, and then the mixture was stirred to obtain 50.8 g of a ruthenium imidization reagent containing spherical cerium oxide particles.

Preparation Example 5: Preparation of ruthenium imidization reagent containing non-porous ceria particles (2)

26.7 g of spheroidal cerium oxide dispersion (DMF liquid mixture containing 6% solid content, spherical cerium oxide: trade name KEP-250, manufactured by Nippon Shokubai Co., Ltd., average particle diameter: 3 μm, and no pores) added The mixed solution contains 2.8 g of β-methylpyridine (melting point 144 ° C) as a curing catalyst for the hydrazide reagent, 21.2 g of acetic anhydride as a dehydrating agent, and 0.9 g of DMF as a polar organic solvent, and then the mixture 51.6 g of a ruthenium imidization reagent containing spherical cerium oxide particles was obtained by stirring.

Preparation Example 6: ruthenium imidization reagent containing non-porous fluoropolymer particles preparation

26.7 g of polytetrafluoroethylene (PTFE) dispersion (manufactured by DAIKIN Industries, Ltd., DMF liquid mixture containing 6% solid content, fluoropolymer particles: average particle diameter 22 μm and no pores) added The mixed solution contained 2.8 g of isoquinoline (melting point 242 ° C) as a curing catalyst for the ruthenium iodide, 21.2 g of acetic anhydride as a dehydrating agent, and 0.9 g of DMF as a polar organic solvent, and then the mixture was stirred. 51.6 g of a ruthenium amide containing fluoropolymer particles were obtained.

Preparation Example 7: Preparation of an imidization reagent containing no particles

3.3 g of β-methylpyridine (melting point 144 ° C) as a curing catalyst for the ruthenium iodide reagent, 21.5 g of acetic anhydride as a dehydrating agent, and 25.2 g of DMF as a polar organic solvent, mixed and stirred to obtain 50 Azyl imidization reagent.

[Examples] Example 1: Preparation of Polyimine Film Using Porous Particles (1)

100 g of the polylysine polymerization solution obtained in Preparation Example 1 was mixed with 50.8 g of the hydrazide reagent obtained in Preparation Example 2, and the mixture was applied to a stainless steel plate and dried in an oven at 120 ° C for 3 minutes with hot air to prepare. Gel film.

The gel film thus prepared was removed from the stainless steel plate and fixed with a frame pin. The frame to which the gel film was fixed was subjected to heat treatment at 450 ° C for 7 minutes. The film was then removed from the frame, thereby obtaining a polyimide film having an average thickness of 25 microns.

The SEM photograph of the cross section of the polyimide film prepared as above Shown in Figure 1.

Example 2: Preparation of a polyimide film using porous particles (2)

The same procedure as in Example 1 was repeated to obtain a polyimide film having an average thickness of 25 μm, except that 51.6 g of the oxime imidization reagent obtained in Preparation Example 3 was used instead of the ruthenium reagent obtained in Preparation Example 2.

Comparative Example 1: Preparation of a polyimide film using non-porous particles (1)

The same procedure as in Example 1 was repeated to obtain a polyimide film having an average thickness of 25 μm, except that 50.8 g of the oxime imidization reagent obtained in Preparation Example 4 was used instead of the ruthenium reagent obtained in Preparation Example 2.

Comparative Example 2: Preparation of a polyimide film using non-porous particles (2)

The same procedure as in Example 1 was repeated to obtain a polyimide film having an average thickness of 25 μm, except that 51.6 g of the oxime imidization reagent obtained in Preparation Example 5 was used instead of the ruthenium reagent obtained in Preparation Example 2.

Comparative Example 3: Preparation of a polyimide film in which non-porous fluoropolymer particles were used

The same procedure as in Example 1 was repeated to obtain a polyimide film having an average thickness of 25 μm, except that 51.6 g of the quinone imidization reagent obtained in Preparation Example 6 was used instead of the quinone imidization reagent obtained in Preparation Example 2.

Comparative Example 4: Preparation of a polyimide film in which no particles were used

The same procedure as in Example 1 was repeated to obtain a polyimide film having an average thickness of 25 μm, except that 50.0 g of the oxime imidization reagent obtained in Preparation Example 7 was used instead of the ruthenium reagent obtained in Preparation Example 2.

Experimental Example 1: Measurement of density ratio

Particles added in the preparation of the polyimide film in the present invention The true density (A) and the true density (B) of the materials of these particles are determined according to the standard (KS M 6020:2010). The true density of the natural cerium oxide constituting the hollow cerium oxide used in Examples 1 and 2 and the spherical cerium oxide used in Comparative Examples 1 and 2 was a product purchased from Nippon Shokubai Co., Ltd. (model name) :KEP-250) Measurement.

Then, the ratio (%) of the true density of the porous particles to the true density of the material itself was calculated by the following formula 1, and the results are shown in Table 1 below.

[Formula 1] Density ratio = true density of porous particles (A) / true density of material itself (B) x 100%

Experimental Example 2: Measurement of the average diameter of porous particles

The average diameter of the porous particles used in the present invention is measured using a laser diffraction particle size analyzer (SHIMADZU Corp., model name SALD-2201), and the average diameter of the measured porous particles is shown. In the following table 1.

Experimental Example 3: Measurement of particle content in a film

The particle content in the polyimide film prepared in Examples 1 and 2 and Comparative Examples 1 to 4 was measured by an ash (ASH) method. In the ash method, the particle content was measured from the weight of the residue remaining in the crucible after the film was burned at 900 ° C for 3 hours in a crucible furnace. The measured particle content (% by weight) is shown in Table 1 below.

Experimental Example 4: Observation of Dispersion Profile of Porous Particles in Membranes

The dispersion profile of the porous particles in the polyimide film according to Example 1 was produced using a scanning electron microscope FE-SEM (JEOL). Model name: JSM-6700F) Observed and displayed as SEM image.

An SEM photograph of a cross section of the polyimide film according to Example 1 of the present invention is shown in Fig. 1.

Further, Fig. 2 shows a state in which the porous particles are dispersed on the surface of the polyimide film, and Fig. 3 is a photograph showing an enlarged view thereof.

As shown in Fig. 2, the porous particle sub-system for the polyimide film according to the present invention was uniformly dispersed throughout the film, indicating a good dispersion state.

Experimental Example 5: Measurement of dielectric constant and dissipation factor

The dielectric constant and dissipation factor of the polyimide films prepared in Examples 1 and 2 and Comparative Examples 1 to 4 were based on a split-substrate dielectric resonator from Keysight Technologies, Inc. (SPDR) assay. The measured dielectric constant and dissipation factor are shown in Table 1 below.

As shown in the above Table 1, it was found that the polyimide film according to Examples 1 and 2 containing porous hollow ceria particles had a low dielectric constant of 3 or less.

Further, it was found that the polyimide film according to Examples 1 and 2 has excellent electrical properties in terms of low dielectric constant and low dissipation factor, and even with Comparative Examples 1 to 4, it has a density ratio of more than 95%. It also contains fluoropolymer particles or does not contain particles at all, as is the case. Accordingly, such polyimide films are suitable for use in the manufacture of electrical/electronic devices and components requiring low dielectric constant such as printed circuit boards.

Claims (6)

A method for preparing a polyimide film, comprising: 1) preparing a polyimide precursor; 2) mixing the polyimine precursor with a ruthenium reagent containing a porous particle to form a gel film; and 3) heat treating the gel film to imidize the ruthenium, wherein the porous particles have an average diameter of 10 μm or less and a true density of the material itself relative to the porous particles True density of 95% or less. The method of claim 1, wherein the porous particles have an average diameter of from 1 to 10 μm and a true density of from 30% to 95% with respect to the material itself of the porous particles. The method of claim 1, wherein the porous particles are used in an amount of from 2 to 30% by weight based on the total weight of the polyimide film. The method of claim 1, wherein the porous particles are hollow or mesoporous particles and are selected from the group consisting of cerium oxide, aluminum oxide, titanium dioxide, zeolites, and mixtures thereof. A polyimine film comprising porous particles, wherein the porous particles have an average diameter of 10 μm or less and a true density of 95% or less with respect to the material itself of the porous particles. The polyimine film according to claim 5, wherein the polyimide film has a dielectric constant of 3.0 or less at 1 GHz.