JPH09316199A - Method for measuring imidization ratio of polyimide compound and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for measuring the imidization ratio of a polyimide compd. whereby the measurement can be performed accurately under every conditions by imidizing unreacted parts and measuring a substance generated then. SOLUTION: Imidization ratio is calculated from the amt. of water generated when unreacted parts contained in a polyimide compd. are imidized. A polyimide compd., having imide bonds in the molecule, is exemplified by a thermoplastic polyimide, a thermosetting polyimide, a polyimidesiloxane, or a composite of these compds. Pref. the imidization degree is calculated from the amt. of water generated when a polyimide compd. is heated at 200 deg.C or higher. The amt. of water is pref. measured with e.g. a Karl-Fischer moisture meter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring method that can be used as an analytical method for confirming the degree of imidization reaction in a process for producing a polyimide compound.

[0002]

2. Description of the Related Art Conventionally, a method for measuring the imidization ratio of a polyimide compound has been carried out by measuring and comparing infrared absorption amounts derived from imide bonds using an infrared absorption measuring device.

Specifically, the infrared absorption of a small amount of a polyimide compound was measured, and the peak (for example, 720 cm ^-1 ) derived from an imide bond in the obtained chart was measured for the absorbance [(of incident light). Intensity / intensity of transmitted light). Next, the absorbance is similarly determined for a peak that does not change before and after the reaction and is not affected by the surrounding environment. Then, the imidization ratio is obtained from the change in the ratio of the two.

The imidation ratio calculated by such a method is not reliable because the absolute amount of imide bond cannot be confirmed. Also, in some cases it is difficult to specify the infrared absorption derived from the imide bond,
In some cases, it was not possible to select a peak whose infrared absorption did not change before and after the reaction and which was not affected by the surrounding environment. In either case, the imidization ratio could not be measured.

That is, it has been difficult or impossible to obtain an accurate imidization rate by the conventional technique except for some polyimide compounds. However, in order to stably guarantee the quality of the polyimide compound, a method capable of accurately measuring the imidization ratio in any state has been required.

[0006]

With the rapid improvement of wiring technology for electronic substrates in recent years, a polyimide compound having heat resistance and excellent electrical characteristics is widely used as an electronic substrate, and a polyimide compound is used. There is an increasing need to guarantee the quality of the products in a stable manner.

Therefore, in imidation measurement of a polyimide compound, a problem that the conventional analysis method has is solved, and a method capable of accurately measuring the imidization rate of the polyimide compound in any environment is provided. As a result of earnest research aimed at, the present invention was completed.

[0008]

The present invention is characterized by calculating the imidization ratio from the amount of water generated when the unreacted portion contained in the polyimide compound is imidized. Regarding the method of measuring the rate.

The present invention also relates to a method for stabilizing the performance of a polyimide compound, which is carried out by measuring the imidization ratio by the above method.

The polyimide compound in the present invention is not particularly limited as long as it is a polyimide having an imide bond in the molecule (including a part or a large proportion of it is an amic acid). Any material such as thermosetting polyimide, polyimide siloxane, or a composite thereof may be used.

These polyimide compounds are obtained by, for example, reacting an aromatic tetracarboxylic dianhydride with a diamine, for example, an aromatic diamine or diaminopolysiloxane in an organic solvent or in a solid mixture to form a polyamic acid, In the presence or absence of a known chemical imidizing agent consisting of a combination of a known anhydride dehydrating substance such as acetic acid and a tertiary amine such as pyridine, isoquinoline or β-picoline, or a compound releasing these during the process. It can be obtained by imidizing all or part of the polyamic acid below. There is no particular limitation on the process for producing this polyamic acid or polyimide.

The aromatic tetracarboxylic dianhydride is not particularly limited and various aromatic tetracarboxylic dianhydrides can be used, preferably pyromellitic dianhydride,
2,3,3 ', 4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic acid Examples thereof include dianhydride and 4,4′-oxydiphthalic acid dianhydride.

The diamine is not particularly limited, and various aromatic diamines and various diaminopolysiloxanes can be used, and preferably 4,4'-diaminobenzene (p-
Phenylenediamine), 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether,
2,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis (3-aminophenoxybenzene), 1,3-bis (4-aminophenoxybenzene), dimethylphenylenediamine, α, ω-bis (3
-Aminopropyl) polydimethylsiloxane and the like. Further, other substituted diamines can be used as long as they do not impair the physical properties of the polyimide.

Examples of the organic solvent include N-methylpyrrolidone, dimethylacetamide and dimethylformamide. When diaminopolysiloxane is used as the diamine, an ether solvent such as tetrahydrofuran, diethylene glycol dimethyl ether, or triethylene glycol dimethyl ether may be used as the organic solvent.

The polyimide compound of the present invention is obtained by polymerizing an aromatic tetracarboxylic dianhydride and a diamine in an organic solvent, preferably at 0 to 80 ° C., to form a polyamic acid, and then in that system. After heating to about 120 to 250 ° C. for imidization, a powdery polyimide recovered by charging in an inert solvent or a solution containing polyamic acid (polyamic acid solution) is applied and cast on a support. It can be obtained as a film-shaped or film-shaped polyimide that is imidized by heating. In the present invention, a chemical imidizing agent may be added to the polyamic acid solution and heated.

Alternatively, a phenolic solvent such as p-chlorophenol is used to obtain a polyimide compound in one step from an aromatic tetracarboxylic dianhydride and a diamine, and then a powder is prepared from the polyimide solution. Alternatively, the polyimide solution can be cast on a support and further heated to obtain a film-shaped polyimide.

Various inorganic or organic additives can be added depending on the purpose during or after the production of the above-mentioned polyimide compound. Examples of the inorganic additive include a particulate or flat inorganic filler. The usage amount and shape (size, aspect ratio) are preferably selected according to the purpose of use of the polyimide compound. For example, in the case of a film-like material, an inorganic filler having an average particle system of about 0.1-10 μm is preferably used. In the case of a powdery substance (when the final use is a varnish or an adhesive), 0.01 to
An inorganic filler of about 0.2 μm is preferably used.

In the present invention, preferably, a predetermined amount of the above-mentioned polyimide compound (including a part of which is imidized) is taken out into a container and measured by using, for example, a Cal-Fisher-moisture meter. Is preferred. According to the present invention, the measured water content can be accurately determined without being affected by the imidization environment of the polyimide compound (whether thermal imidization or chemical imidization, the type of organic solvent, the degree of imidization). Compared to the infrared spectrophotometer method that was generally used for imidization measurement, for polyimide compounds with known components of aromatic tetracarboxylic dianhydride and diamine, the imidization rate was calculated accurately by calculation. Can be asked for.

Further, the above-mentioned imidization ratio measuring method is applied to stabilize the performance (strength, imidization ratio, elongation, etc.) of a polyimide compound to obtain a higher quality polyimide film, polyimide adhesive, polyimide varnish. Can be obtained. As a method of applying the method of the present invention for stabilizing the quality of a polyimide compound, in an initial stage of mass-producing a polyimide compound of a desired quality, an accurate imidization ratio is determined by the method of the present invention, and a production condition Can be carried out by modifying the above condition to a more preferable condition.

[0020]

Embodiments of the present invention will be described below. Example 1 1) Synthesis of polyamic acid solution In a separable flask having a capacity of 500 ml, 2, 3, 3 ',
4'-biphenyltetracarboxylic dianhydride 33.16
g, 4,4'-diaminodiphenyl ether 22.50
g and N-methyl-2-pyrrolidone 333.99 g were added, and the mixture was stirred in a nitrogen atmosphere at room temperature (25 ° C.) for 3 hours to obtain a polyamic acid solution.

2) Preparation of Polyimide Film The polyamic acid solution was cast on a glass plate,
A raw film was obtained by vacuum drying at ° C. After peeling this raw film from the glass plate, it is placed in a beaker and further 2
Drying with hot air at 00 ° C, 250 ° C, 300 ° C and 350 ° C for 30 minutes each gave a polyimide film.

3) Measurement of imidization ratio by Cal-Fisher moisture meter The imidization ratio of each of the above-mentioned polyimide films was measured by Mitsubishi Chemical Corporation Cal-Fisher moisture meter (CA-06, VA).
-06). Measurement conditions Pretreatment: 50 ° C., vacuum drying for 8 hours Measurement: Measurement of water content generated at 300 ° C. Atmosphere: Nitrogen gas 250 ml / min Measurement result 150 ° C. dry raw film; imidization rate = 70% 200 ° C. dry film; Imidization rate = 81% 250 ° C. dry film; Imidization rate = 90%

Example 2 1) Synthesis of polyimide by p-chlorophenol (PCP) one-step synthesis method In a separable flask having a capacity of 500 ml, 2, 3, 3 ',
4'-biphenyltetracarboxylic dianhydride 33.16
g, 4,4'-diaminodiphenyl ether 22.50
g, p-chlorophenol 333.32 g was added, and the mixture was heated in a nitrogen atmosphere while stirring, and after reaching 180 ° C., stirring was continued for 6 hours to obtain a polyimide solution.

2) Preparation of Polyimide Film The polyimide acid solution was cast on a glass plate and heated at 160 ° C.
Vacuum drying was carried out to obtain a raw film. After peeling this raw film from the glass plate, the raw film was put in a beaker and further 20
A polyimide film was obtained by hot-air drying at 0 ° C., 250 ° C., 300 ° C., and 350 ° C. for 30 minutes each.

3) Measurement of imidization ratio by a Cal-Fisher-water meter The imidization ratio of each of the above films was measured in the same manner as in Example 1. Measurement results 160 ° C dry green film; imidization rate = 96% 200 ° C dry film; imidization rate = 97% 250 ° C dry film; imidization rate = 98%

Comparative Example 1 When the imidation ratio of the polyimide film obtained in Example 2 was measured by infrared absorption method, the absorption of phenyl group was p-.
Since there was no peak that overlapped with the absorption of the phenyl group of chlorophenol and became a reference, it was impossible to measure.

Example 3 1) Synthesis of polyamic acid solution In a separable flask having a capacity of 500 ml, 2, 3, 3 ',
4'-biphenyltetracarboxylic dianhydride 33.16
g, 4,4'-diaminodiphenyl ether 22.50
g and N-methyl-2-pyrrolidone 333.99 g were added, and the mixture was stirred in a nitrogen atmosphere at room temperature (25 ° C.) for 3 hours to obtain a polyamic acid solution.

2) Addition of chemical imidizing agent 3.70 g of isoquinoline (0.25 mol per 1 amide group) was added to this polyamic acid solution and stirred for 6 hours. Thereafter, 22.90 g of acetic anhydride (equal moles to the amide group) was added, and the mixture was stirred for 30 minutes.

3) Preparation of Polyimide Film The above polyamic acid solution was cast on a glass plate to give 100
A raw film was obtained by vacuum drying at ° C. After peeling this raw film from the glass plate, 150 ° C, 200 ° C, 250
Drying with hot air at 30 ° C., 300 ° C. and 350 ° C. for 30 minutes each gave a polyimide film.

4) Measurement of imidization ratio by Cal-Fisher-water meter The imidization ratio of each of the above polyimide films was measured in the same manner as in Example 1. Measurement results 100 ° C. dry green film; imidization rate = 62% 150 ° C. dry film; imidization rate = 71% 200 ° C. dry film; imidization rate = 88% 250 ° C. dry film; imidization rate = 91%

Comparative Example 2 The polyimide film obtained by the method of Example 3 was treated with KBr.
The imidization ratio measured by FT-IR by the tablet method was measured in the same manner as in Comparative Example 1. The following absorbance ratio is 720 cm
^-1 / 1500 cm ^-1 is meant. Measurement result 100 ° C. dry raw film; absorbance ratio = 0.10590
Imidization rate = 30% 150 ° C. dry film; Absorbance ratio = 0.13397 Imidization rate = 38% 200 ° C. dry film; Absorbance ratio = 0.17488 Imidization rate = 50% 250 ° C. dry film; Absorbance ratio = 0. 22447 Imidization rate = 64% 300 ° C dry film; Absorbance ratio = 0.24778 Imidization rate = 70% 350 ° C dry film; Absorbance ratio = 0.35289 Imidization rate = 100%

The results of Comparative Example 2 show that, in the case of a polyimide film obtained by using a chemical imidizing agent, the imidization ratio of the low temperature treated film was affected by the solvent contained in the film when measured by an infrared absorption method. Is lower than the original value.

Example 4 150 ° C. dry film of Example 3 (imidization ratio = 71
%) To obtain a film having an imidization ratio of 90%, was further dried with hot air at 200 ° C. for 30 minutes. When the imidation ratio was measured in the same manner as above, the imidization ratio was 88%. This result indicates that according to the method of the present invention, by measuring the imidization ratio of the film at the stage where the manufacturing conditions are not fixed, it is possible to stably manufacture a film having a target imidization ratio. Show.

[0034]

According to the method of the present invention, it is possible to measure an absolute imidization ratio including a polyimide compound having a composition that cannot be measured by the infrared absorption method, and the measurement accuracy is very high. is there.

According to the method of the present invention, it is possible to accurately measure the imidization ratio at each stage before complete imidization, so that it is possible to stabilize the quality of the polyimide compound and the manufacturing conditions. it can.

Continuation of the front page (72) Inventor Tetsuji Hirano 12-12-32 Nishihonmachi, Ube City, Yamaguchi Prefecture Ube Institute of Polymer Research (Ube)

Claims (5)

[Claims] 1. A method for measuring the imidization ratio of a polyimide compound, which comprises calculating the imidization ratio from the amount of water generated when an unreacted portion contained in the polyimide compound is imidized. 2. The measuring method according to claim 1, wherein the imidization ratio is calculated from the amount of water generated when the polyimide compound is heated at a temperature of 200 ° C. or higher. 3. The measuring method according to claim 2, wherein the amount of water generated is measured by using a Cal-Fisher moisture meter. 4. The measuring method according to claim 1, wherein the polyimide compound is a film having a thickness of 25 μm or more, a film obtained by chemical imidization, or a film obtained by using an aromatic organic solvent. 5. A method for stabilizing the performance of a polyimide compound by measuring the imidization ratio by the method according to claim 1.