WO2015093749A1

WO2015093749A1 - Polyimide film and manufacturing method therefor

Info

Publication number: WO2015093749A1
Application number: PCT/KR2014/011634
Authority: WO
Inventors: 조성일; 이길남; 김성원
Original assignee: 에스케이씨코오롱피아이 주식회사
Priority date: 2013-12-18
Filing date: 2014-12-01
Publication date: 2015-06-25
Also published as: TWI661004B; KR101503332B1; CN106062049A; CN106062049B; TW201529729A

Abstract

The present invention relates to a polyimide film and a manufacturing method therefor, and the polyimide film of the present invention, comprising: a polyimide resin; and fluorine-based particles including first particles having a mean particle diameter of at most 300 nm and second particles containing pores having a mean diameter of at most 300 nm by agglomerating first particles, and having a mean particle diameter of at most 10 µm and a mean apparent specific gravity of at most 1.2 g/ml, can be effectively used for manufacturing electric/electronic devices such as a printed circuit board requiring a low dielectric constant and components by having excellent physical properties and simultaneously expressing a lower dielectric constant.

Description

Specification

FIELD OF THE INVENTION The present invention relates to a low dielectric constant polyimide film having excellent physical properties and a method for producing the same. Background Art of the Invention Generally, a polyimide (PI) resin is a high heat-resistant resin prepared by solution polymerization of an aromatic acid dianhydride and an aromatic diamine or an aromatic diisocyanate to prepare a polyamic acid derivative, and then imidization by ring dehydration at high temperature. Refers to.

Polyimide resins are widely used in electrical / electronic materials, space / aviation and telecommunications because of their excellent mechanical and thermal dimensional stability and chemical stability. In particular, since polyimide resins have high insulation performance, they are widely used in printed circuit boards and the like as components and members requiring reliability.

In accordance with the recent trend of high informatization, in the electronic device for accumulating a large amount of information, processing such information at high speed, and delivering it at high speed, the polyimide resin used in them has a high dielectric constant, particularly as an electrical characteristic for high frequency. Anger is required.

As an attempt to lower the dielectric constant of such a polyimide resin, for example, Korean Patent No. 0859275 disperses a dispersible compound in a polyimide resin precursor solution and then forms a film using the dispersion, and extracts the dispersible compound from the film. It is disclosed to prepare a porous polyimide resin by removing and porousizing the same. However, the porous polyimide resin prepared by the above method has a limit in implementing a thin polyimide film because it has pores of a micro unit size. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a low dielectric constant polyimide film having excellent physical properties and having nano-sized pores and a method for producing the same.

The present invention to achieve the above object, Polyimide resin; And primary particles having an average particle diameter of 300 nm or less, and secondary particles having an average particle diameter of 10 mm or less and an average porosity specific gravity of 1.2 g / ml or less, having primary pores of which the primary particles are concaved and having an average diameter of 300 nm or less. It provides a polyimide film comprising a.

The present invention also provides a polyimide precursor, an imidization conversion liquid, and primary particles having an average particle diameter of 300 nm or less, and the primary particles having pores with an average diameter of 300 nm or less, having an average particle diameter of 10 or less and an average apparent specific gravity of 1.2. Provided is a method for producing the polyimide film, comprising imidating and then mixing fluorine-based particles composed of secondary particles of g / ml or less. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and features of the present invention will become apparent from the following description of the invention in conjunction with the accompanying drawings.

Figure 1 shows a SEM picture of the fluorine-based primary particles applied for the implementation of the present invention.

Figure 2 shows a SEM photograph of the secondary particles formed by coarse fluorine-based primary particles applied for the implementation of the present invention. Figure 3 shows a cross-sectional SEM photograph of a polyimide film (prepared in Example 1) prepared by applying the secondary particles formed by forming the fluorine-based primary particles for the implementation of the present invention. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be described in more detail.

The polyimide film of the present invention is a polyimide resin; And primary particles having an average particle diameter of 300 nm or less, and secondary particles having an average particle diameter of 10 / m or less and an average specific gravity of 1.2 g / ml or less, having primary pores of which the primary particles are concaved and having an average diameter of 300 nm or less. Particles, characterized in that the fluorine-based particles are preferably uniformly dispersed in the polyimide resin.

The polyimide film of the present invention has a polyimide precursor, an imidization conversion liquid, and primary particles having an average particle diameter of 300 nm or less, and the primary particles having pores with an average diameter of 300 nm or less, having an average particle diameter of 10 or less and an average. It is prepared by mixing the fluorine-based particles composed of secondary particles having a specific gravity of 1.2 g / ml or less and then performing an imidization process.

The method for producing the fluorine-based particles used in the present invention is not particularly limited as long as it can be produced by implementing the above-mentioned parameters.

Preferably, the primary particles constituting the fluorine-based particles may have an average particle diameter of 50 to 300 nm, the secondary particles have an average particle diameter of 3 to 10 and pores of an average diameter of 50 to 300 mm 3 and 0.4 to 1.2 It may have an average apparent specific gravity of g / ml.

The fluorine-based particles added to implement the dielectric constant of the polyimide is

Fluorine resins having a melting point of 200 ^° C. or higher are preferred, and specific examples thereof include polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA) and It may be at least one selected from the group consisting of fluorinated ethylene propylene (FEP).

The polyimide film of the present invention may include the fluorine-based particles in an amount of 5 to 40% by weight, preferably 10 to 30% by weight, based on the total weight of the film. When the fluorine-based particles having the above characteristics are included in the above content range, the dielectric constant characteristics of the polyimide film to be implemented may be exhibited by preventing the degradation of the fluorine-based particles due to the high temperature of the polyimide film manufacturing process. By adding a large amount of particles, the mechanical strength of the polyimide film can be maintained. The polyimide precursor used in the present invention can be used as long as it can be a polyimide resin by imidization, preferably a polyamic acid obtained by copolymerizing an acid dianhydride component and a diamine component in a conventional manner. .

The acid dianhydride component and the diamine component may be appropriately selected from those commonly used.

Specifically, biphenylcarboxylic dianhydride or derivatives thereof, pyromellitic dianhydride or derivatives thereof, and the like may be used as the acid dianhydride component, and phenylenediamine or a derivative thereof, diaminophenyl ether or the like may be used as the diamine component. Its derivatives and the like can be used.

The imidization conversion liquid used in the present invention may be used as long as it is a material commonly used to cause chemical curing, and may be three mixed solutions such as a dehydrating agent, a catalyst, and a polar organic solvent. More specifically, the imidization conversion liquid may be a dehydrating agent such as acetic dianhydride; Tertiary amine catalysts such as pyridine, betapicolin and isoquinoline; And a polar organic solvent such as N-methylpyrrolidone (NMP), dimethylformamide (DMF), and dimethylacetamide (DMAc). The imidization conversion solution may be used in an amount of 30 to 70 parts by weight based on 100 parts by weight of the polyimide precursor, but may vary depending on the type of polyimide precursor and the thickness of the polyimide film to be produced.

As a more specific example, the polyimide film of the present invention may be prepared by conventional methods known in the art as follows.

First, the acid dianhydride component and the diamine component are copolymerized in an organic solvent to obtain a polyamic acid solution. In this case, the organic solvent is generally an aprotic polar solvent, such as Ν, Ν '-dimethylformamide, Ν, Ν' —dimethylacetamide, N-methyl-blood as the amide solvent. Redon, or a combination thereof may be used.

In this case, a filler may be added to the polyamic acid solution in order to improve various properties such as the slidability, thermal conductivity, conductivity, and corona resistance of the polyimide film. Examples of layering agents that may be used include, but are not limited to, silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, mica, and the like.

To the polyamic acid solution obtained above, an imidization conversion solution containing a dehydrating agent, a catalyst, and a polar organic solvent was added and mixed firstly, and primary particles having an average particle diameter of 300 nm or less and the primary particles were condensed and averaged. The fluorine-based particles composed of secondary particles having a pore diameter of 300 nm or less and an average particle diameter of 10 // m or less and an average apparent specific gravity of 1.2 g / ml or less are added and then mixed.

At this time, the timing of adding the imidization conversion liquid and the fluorine particles may proceed simultaneously without time difference, and may be added in a dispersion liquid dispersed in a polar organic solvent when the bloso particles are added.

This mixed solution is applied to a support (eg, glass plate, aluminum foil, circulating stainless belt, stainless drum, etc.), and then imidized to obtain a desired polyimide film. The desired polyimide film can be obtained by chemically partially imidating the polyamic acid coating layer formed on the support by primary heat treatment and then completely imidating it by secondary heat treatment. Primary heat treatment for chemical partial imidization may be performed at 100 to 200 ^° C. for 5 to 15 minutes, and secondary heat treatment for complete imidization may be performed at 250 to 850 ^° C. for 5 to 15 minutes. . In this case, the polyamic acid film subjected to the first heat treatment of the chemical partial imidization state may be separated from the support and subjected to the second heat treatment, and the residual force in the film generated in the film forming process may be removed by heat treatment under a constant tension during the second heat treatment.

The polyimide film according to the present invention prepared as described above is 2.3 to 1 腿 z

Has a low dielectric constant of 2.9.

In addition, since the coefficient of thermal expansion of the film depends on the characteristics of the polyimide varnish (varni sh), the polyimide film of the present invention containing fluorine-based particles uniformly in the film is relatively compared to the polyimide film produced by applying the fluorine monomer The low coefficient of linear expansion can be realized, and the fluorine-based particles do not directly protrude on the surface of the film to realize high adhesion of the film, which can be applied to FPCB materials such as copper foil laminates and reinforcement plates.

The polyimide film of the present invention uniformly includes fluorine-based particles having pores of a specific size in the film, thereby exhibiting electrical characteristics of the single fluorine particles, and at the same time embodying a porous form due to the pores to express a lower dielectric constant. It can be used in the manufacture of electrical and electronic devices and components, such as a printed circuit board that requires a low dielectric constant. In addition, by selectively using fluorine-based particles having pores and capable of achieving the required average specific specific gravity, fluorine-based particles in the product are prevented from sinking due to the application of fluorine particles having high specific gravity. It is advantageous in that the particles can be uniformly distributed and there is no need to add a separate dispersant to improve dispersibility. Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the following Examples. Production Example 1 Preparation of Polyamic Acid Solution

Into a 0.5L reactor, 320 g of dimethylformamide (DMF) was added and the temperature was set at 20 ^° C. Then, 27.59 g of diaminophenyl ether (ODA) was added to dissolve and 20.03 g of pyromellitic dianhydride (PMDA) was dissolved. Dissolved after adding twice each. After dissolving, 3.97 g of phenylenediamine (pPDA) was added thereto and reacted for 30 minutes, and then the solution was sampled to measure molecular weight. After the reaction was completed, the temperature of the reaction was raised to 30 ^° C, and then pPDA l.OOg was added to adjust the molar ratio of [diamine] / [acid dianhydride] to 1: 1. When the input of the raw material was completed, the reaction mixture was heated at 40 ^° C. for 2 hours to obtain a polyamic acid solution. Production Example 2: Preparation of imidization conversion liquid containing fluorine particles (1)

4.5 g of isoquinoline (boiling point 242 ^° C) as a catalyst for curing imide, 17.0 g of acetic anhydride as dehydrating agent, and 9.3 g of polytetrafluoroethylene (PTFE) dispersion in 17.0 g of dimethylformamide (DMF) as a polar organic solvent SAMIL CORP. SS-5000CR, average particle diameter of primary particles: 200ηιΐι, average particle diameter of secondary particles, pores, average apparent specific gravity: 10, 200nm, 0.6g / ml, PTFE solids 30%) 46.9 g of the obtained imidization conversion liquid was obtained. Production Example 3 Preparation of Imidization Conversion Liquid Containing Fluorine Particles (2)

4.5 g of isoquinoline (boiling point 242 ^° C) as a catalyst for imide curing, 17.Og of acetic anhydride as dehydrating agent, and 12.3 g of PTFE dispersion (14.3 g of tribasic acid SS-5000CR, primary particles) in 14.9 g of DMF as a polar organic solvent Particle size: 200nm, average particle diameter of secondary particles ， Pore, average apparent specific gravity: 10 /, 200 nm, 0.6 g / ml, PTFE solid content 30%), followed by stirring to obtain 48.7 g of an imidized conversion solution containing fluorine particles. Production Example 4 Preparation of Imidization Conversion Solution Added with Fluorine Particles (2006.01)

4.5 g of isoquinoline (boiling point 242 ^° C) as the imide curing catalyst, 17.Og of acetic anhydride as the dehydrating agent, and 2.8 _g of PTFE particles milled to 22.6 g of DMF as the polar organic solvent (DAIKIN Co., average particle diameter 22; And average apparent specific gravity of 0.4 g / ml) were mixed and stirred to obtain 46.9 g of an imidized conversion solution containing fluorine particles. Production Example 5: Preparation of imidization conversion liquid containing fluorine particles (4)

4.5 g of isoquinoline (boiling point 242 ^° C) as a catalyst for curing imide, 17.Og of acetic anhydride as a dehydrating agent, and 3.7 g of PTFE particles milled to 23.5 g of DMF as a polar organic solvent (DAIKIN, average particle diameter 22, average Step specific gravity 0.4 g / ml) was mixed and stirred to obtain 48.7 g of an imidization conversion solution containing fluorine particles. Production Example 6: Preparation of imidization conversion liquid without addition of fluorine particles (1)

4.5 g of isoquinoline (boiling point 242 ^° C) as an imide curing catalyst, 17.Og of acetic anhydride as a dehydrating agent, and 23.5 g of DMF as a polar organic solvent were mixed and stirred to obtain 45 g of imidized conversion solution. Production Example 7: Preparation of imidization conversion liquid without addition of fluorine particles (2)

4.4 g of beta picoline (boiling point 144 ^° C.) as an imide curing catalyst, 16.7 g of acetic anhydride as a dehydrating agent, and 23. 1 g of DMF as a polar organic solvent were mixed and stirred to obtain an imidized conversion solution 4. Example 1: fluorine particle application polyimide film production 100 g of the polyamic acid polymerization solution obtained in Preparation Example 1 was mixed with 45 g of the imidization conversion solution obtained in Preparation Example 2, and then applied to a stainless plate, dried for 3 minutes by hot air in a 120 ^° C. oven, and then the film was removed from the stainless plate. Fixed with. After heat-treating the frame to which the film was fixed for 7 minutes at 45 CTC, the film was removed and the polyimide film of average thickness 2 / m was obtained. A cross-sectional SEM photograph of the prepared polyimide film is shown in FIG. 3. Example 2: fluorine particle application polyimide film manufacture

A polyimide film having an average thickness of 25 was obtained in the same manner as in Example 1, except that 45 g of the imidization conversion solution obtained in Production Example 3 was used instead of the imidization conversion solution obtained in Production Example 2. Comparative Examples 1 and 2: Manufacture of Polyimide Films Applying Fluorine Particles with Different Particle Sizes and Mole Density

A polyimide film having an average thickness of 25 / was obtained in the same manner as in Example 1 except that 45 g of the imidization conversion solution obtained in Production Example 4 or 5 was used instead of the imidization conversion solution obtained in Production Example 2. Comparative Examples 3 and 4: Manufacture of Polyimide Film without Fluorine Particles

A polyimide film having an average thickness of 25 was obtained in the same manner as in Example 1, except that 45 g of the imidization conversion solution obtained in Production Example 6 or 7 was used instead of the imidization conversion solution obtained in Production Example 2. Corona treatment of the film

Corona treatment was performed on the polyimide films prepared in Examples 1 to 2 and Comparative Examples 1 to 4 using a corona discharge treatment apparatus (model names AGI: 060M, 063M, manufactured by Kasuga Denki Co., Ltd.) at the 4 kW output. Carried out. Test Example 1 Determination of Average Particle Size and Average Diameter of Pore The average particle diameter and average diameter of pores of the primary particles of the fluorine-based particles used for the present invention can be obtained from a scanning electron microscope FE-SEM (JEOL (zeol)). Using the model JSM-6700F), images of 200 primary particles and pores were randomly selected from the SEM image, and their size was measured to calculate an average. The measured values are shown in Table 1 below, and SEM pictures of the fluorine-based primary particles are shown in FIG. 1. Test Example 2 Measurement of Average Particle Size of Secondary Particles

The average particle diameter of the secondary particles of the fluorine-based particles used for the present invention was measured using a laser diffraction particle size analyzer (Laser Difactact Particle Size Analyzer, SHIMADZU, Model SALD-2201). The measured values are shown in Table 1 below, and SEM images of secondary particles formed by condensation of fluorine-based primary particles are shown in FIG. 2. Test Example 3: Measurement of average apparent specific gravity of secondary particles

The average apparent specific gravity of the secondary particles of the fluorine-based particles used for the present invention was measured using a volume densi ty meter and a density cup (Dens i ty cup, YASUDA, model 536, 558). The measured values are shown in Table 1 below. Test Example 4 Measurement of permittivity and dielectric loss tangent

The 1 MHz dielectric constant and dielectric loss tangent of the polyimide films prepared in Examples 1 to 2 and Comparative Examples 1 to 4 were measured using Lacerta's DS-6000. The measured permittivity and dielectric loss tangent values are shown in Table 1 below. Test Example 5 Measurement of the coefficient of thermal expansion (linear expansion coefficient)

The polyimide film prepared in Examples 1 to 2 and Comparative Examples 1 to 4 was cut to a width of 5 mm X length 16 mm and TA thermal analysis apparatus (Thermal mechani cal apparatus) The coefficient of thermal expansion (CTE) was measured using a Q400. Samples were heated at a rate of 10 ^° C./min from 30 ^° C. to 420 ^° C., and coefficients of thermal expansion were obtained within the range of 50 ^° C. to 200 ^° C. The measured coefficient of thermal expansion (linear expansion coefficient) is shown in Table 1 below. Test Example 6 ： Adhesion Measurement

Bonding sheet (lmi l, Epoxy type, Hanwha L & C product) was placed between the polyimide film prepared in Examples 1 to 2 and Comparative Examples 1 to 4 and copper foil (2 / 3oz, Iljin Materials). The protective film was placed and heated to 180 ° C., and then thermally compressed at a pressure of 3 Mpa for 30 minutes. Then, the pressure was released to further cure in an oven at 200 ^° C. for 30 minutes to obtain a flexible substrate. After the obtained flexible substrate was cut to a width of 5 mm and cut, the adhesive force was measured by a 90 ^° wheel test of the IPC TM 659 2.4.9D method. The measured adhesive values are shown in Table 1 below.

Table 11

From the results of Table 1, it can be seen that the polyimide films of Examples 1 and 2 of the present invention can express a low dielectric constant compared to the polyimide films of Comparative Examples 1 to 4 while showing excellent physical properties. Therefore, the polyimide film of the present invention It can be usefully used for the production of electrical and electronic devices and components such as printed circuit boards requiring low dielectric constant.

Claims

Claims: Claim 1. Polyimide resin; And fluorine-based particles composed of primary particles having an average particle diameter of 300 nm or less and secondary particles having an average particle diameter of 10 or less and an average apparent specific gravity of 1.2 g / ml or less, having primary pores of which the primary particles are concaved and having an average diameter of 300 nm or less. Polyimide film. 2. The method according to claim 1, wherein the fluorine-based particles have a primary particle having an average particle diameter of 50 to 300 nm, and an average particle diameter of 3 to 10 and an average apparent specific gravity of 0.4 to 1.2 g / ml. Polyimide film comprising a secondary particle having pores having an average diameter, it comprises in an amount of 5 to 40% by weight based on the total weight of the film. 3. The polyimide film of claim 1, wherein the fluorine-based particle is a fluorine-based resin having a melting point of 200 ^° C. or higher. 4. The method of claim 3, wherein the fluorine resin is selected from the group consisting of polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA) and fluorinated ethylene propylene (FEP). The polyimide film characterized by the above. 5. The polyimide film of claim 1 wherein the polyimide film has a low dielectric constant of 2.3 to 2.9 at 1 MHz. 6. A polyimide precursor, an imidization conversion liquid, and primary particles having an average particle diameter of 300 nm or less, and the primary particles having pores having an average diameter of 300 nm or less, having an average particle diameter of 10 or less and an average apparent specific gravity of 1.2 g / Fluorine system consisting of up to 2 ml of secondary particles The manufacturing method of the polyimide film of any one of Claims 1-5 which imides after mixing particle | grains.