KR20230052524A - Manufacturing method of polyimide resin using photopolymerization - Google Patents

Abstract

The present invention relates to a method for preparing polyimide using photopolymerization. The technical gist of the present invention is to include the steps of: preparing a reaction solution by adding a solvent and a siloxane monomer to a reactor, and cooling the reaction solution while stirring the same; preparing an amic acid solution containing siloxane amic acid by adding mixing an anhydride monomer to the cooled reaction solution and mixing the same; preparing an imide solution containing siloxane imide by adding at least one of pyridine and acetic anhydride to the amic acid solution, mixing the same, and imidizing the siloxane amic acid; preparing a polyimide solution containing a polyimide having a structure represented by chemical formula 1 below by irradiating the imide solution with ultraviolet rays and polymerizing the siloxanimide; and obtaining polyimide from the polyimide solution. According to the present invention, polyimide which not only has excellent optical transparency but also has excellent flexibility can be prepared. (Chemical formula 1) Here, R_1, R_2, R_3, R_4, and R_5 are alkyl groups having 1 to 5 carbon atoms.

Description

Manufacturing method of polyimide using photopolymerization {MANUFACTURING METHOD OF POLYIMIDE RESIN USING PHOTOPOLYMERIZATION}

The present invention relates to a method for producing a polyimide resin using photopolymerization.

Recently, with the advent of foldable displays, rollable displays, and wearable displays, weight reduction and flexibility of display materials are becoming more important. In particular, interest in polyimide is increasing as the need for a material requiring excellent mechanical strength, flexibility and transparency, such as a window display, increases.

Conventionally, a polyamic acid solution is prepared by polymerizing a dianhydride monomer and a diamine monomer in a polar solvent, and then heat-treating the amic acid at a high temperature to imidize the polyimide. It was prepared by thermal imidization or chemical imidization by treating amic acid with pyridine and acetic anhydride to chemically imidize it.

However, polyimide prepared by thermal imidation or chemical imidation according to the prior art has a problem of poor transparency and poor flexibility due to its yellow to brown color.

In addition, in the display field or semiconductor field, after preparing a polyamic acid solution, the prepared polyamic acid solution is applied to a device, and the polyamic acid solution applied to the device is treated with a thermal imidation method or a chemical imidation method to obtain polyimide in the device. When the film is laminated, when the polyimide film is laminated on the device using the thermal imidization method according to the prior art, there is a problem of causing defects in the device due to moisture generation in the process of causing a condensation reaction after applying the polyamic acid solution to the device. there was.

In addition, when a polyimide film is laminated on a device using a chemical imidation method according to the prior art, a polyimic acid solution is applied to the device and then outgassing occurs due to pyridine and acetic anhydride in the process of imidization. There was a problem that caused the defect of

KR 10-2020-0115264 A KR 10-2016-0105378 A

An object of the present invention is to solve the above problems, and to provide a method for manufacturing polyimide using photopolymerization so as to manufacture polyimide having high optical transparency and flexibility while not causing defects in devices during the manufacture of polyimide. Its purpose is to provide

The object of the present invention is not limited to the object mentioned above, and other objects not mentioned will be clearly understood from the description below.

In order to achieve the above object, a method for producing polyimide using photopolymerization according to an aspect of the present invention includes preparing a reaction solution by introducing a solvent and a siloxane monomer into a reactor, and cooling the reaction solution while stirring; preparing an amic acid solution containing a siloxane amic acid by adding an anhydride monomer to the cooled reaction solution and mixing; preparing an imide solution containing siloxaneimide by imidizing the siloxaneamic acid by adding at least one of pyridine and acetic anhydride to the amic acid solution and mixing the mixture; preparing a polyimide solution including polyimide having a structure represented by Chemical Formula 1 below by irradiating the imide solution with ultraviolet rays to polymerize the siloxaneimide; and obtaining polyimide from the polyimide solution.

(Formula 1)

Here, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are alkyl groups having 1 to 5 carbon atoms.

The method for producing polyimide using photopolymerization according to an embodiment of the present invention according to the above configuration can expect the following effects.

Polyimide with excellent optical transparency and excellent flexibility can be produced.

Instead of preparing a polyamic acid solution, applying the prepared polyamic acid solution to a device, and then imidating the applied polyamic acid solution to produce polyimide, a resin obtained by preparing polyimide and then dissolving the prepared polyimide in a solvent. Since it can be used in the form of an imidation reaction, no moisture or gas is generated, which may not cause defects in the device.

1 is a flow chart showing the sequence of a method for manufacturing polyimide using photopolymerization according to an embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and those skilled in the art in the art to which the present invention belongs It is provided to fully inform the person of the scope of the invention. Meanwhile, terms used in this specification are for describing embodiments, and are not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase.

Hereinafter, a method of manufacturing polyimide using photopolymerization according to embodiments of the present invention will be described with reference to the drawings.

The method for producing polyimide using photopolymerization according to an embodiment of the present invention includes a reaction solution preparation step (S100), an amic acid preparation step (S200), an imidation step (S300), a polyimide preparation step (S400), and an obtaining step ( S500).

The reaction solution preparation step (S100) may be a step of preparing a reaction solution by introducing a reaction solvent and a siloxane monomer into a reactor, and cooling the prepared reaction solution while stirring.

In this case, the siloxane monomer may be a compound having a siloxane group in the molecular structure and an amine group at both terminal groups.

Preferably, the siloxane monomer introduced into the reactor in the reaction solution preparation step (S100) may have a structure represented by Formula 1 below.

(Formula 1)

Here, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are alkyl groups having 1 to 5 carbon atoms.

If the carbon number of R ₁ , R ₂ , R ₃ , R ₄ and R ₅ is less than 1, the mechanical properties of the polyimide prepared according to the embodiment of the present invention may be deteriorated, and if it exceeds 5, the number of carbon atoms of the present invention may be reduced. The flexibility of the polyimide prepared according to the above may be deteriorated, and it may be difficult to prepare the polyimide in a resin form by dissolving the polyimide in a reaction solvent in the resin manufacturing step (S600) to be described later.

More preferably, the siloxane monomer introduced into the reactor in the reaction solution preparation step (S100) is 1,3-bis (3-aminopropyl) tetramethyldisiloxane (1,3-Bis ( 3-aminopropyl) tetramethyldisiloxane).

(Formula 2)

When the 1,3-bis(3-aminopropyl)tetramethyldisiloxane is used as the siloxane monomer in the reaction solution preparation step (S100), the polyimide prepared according to the embodiment of the present invention not only has high flexibility, but also has optical properties. Transparency can be improved.

In the reaction solution preparation step (S100), the reaction solvent is not limited as long as it is an organic solvent capable of dissolving the siloxane monomer and the anhydride monomer mixed in the amic acid preparation step (S200) and the additives mixed in the imidation step (S300). For example, it may include at least one of dimethylformamide (DMF) and dimethylacetamide (DMAc), preferably dimethylacetamide.

In the reaction solution preparation step (S100), 20 to 40 parts by weight of a siloxane monomer may be mixed with 100 parts by weight of a reaction solvent, and preferably, 30 parts by weight of a siloxane monomer may be mixed with 100 parts by weight of a reaction solvent.

If the amount of the siloxane monomer mixed with 100 parts by weight of the reaction solvent in the reaction solution preparation step (S100) is less than 20 parts by weight, the amount of the siloxane monomer is too small and the amount of polyimide prepared according to the embodiment of the present invention is less than the amount of the reaction solvent. It is small compared to the amount and may lead to waste of the reaction solvent.

If the amount of the siloxane monomer mixed with 100 parts by weight of the reaction solvent in the reaction solution preparation step (S100) exceeds 40 parts by weight, the reaction solution, amic acid solution, and imide solution in the process of preparing polyimide according to an embodiment of the present invention And the viscosity of the polyimide solution is too high, making it difficult to prepare the polyimide.

In the reaction solution preparation step (S100), the reaction solution prepared by adding the reaction solvent and the siloxane monomer may be cooled to -5 to 5°C.

In the amic acid production step (S200), when an amic acid solution is prepared by adding an anhydride monomer to the reaction solution, reaction heat is instantaneously generated. Therefore, it may be difficult to synthesize siloxane amic acid.

When the reaction solution is cooled to -5 to 5 ° C in the reaction solution preparation step (S100), the reaction heat is effectively removed in the amic acid preparation step (S200), so that the synthesis of siloxane amic acid can be smoothly performed.

Preferably, in the reaction solution preparation step (S100), the reaction solution may be cooled to 0°C.

In the reaction solution preparation step (S100), stirring of the reaction solution prepared by adding the reaction solvent and the siloxane monomer may be performed using a magnetic bar, and at this time, the stirring speed may be 100 to 150 rpm, preferably 120 rpm. .

An amic acid solution is prepared by adding an anhydride monomer to the reaction solution prepared in the reaction solution preparation step (S100) and mixing (S200).

The anhydride monomer introduced into the reaction solution in the amic acid production step (S200) may be maleic anhydride having a structure represented by Formula 3 below.

(Formula 3)

When maleic anhydride is used as the anhydride monomer in the amic acid preparation step (S200) and the siloxane monomer having the structure represented by Formula 1 is used in the reaction solution preparation step (S100), in the amic acid preparation step (S200), the following chemical formula is used. An amic acid solution containing siloxane amic acid having a structure represented by 4 may be prepared.

(Formula 4)

Here, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are alkyl groups having 1 to 5 carbon atoms.

In the amic acid preparation step (S200), maleic anhydride is used as an anhydride monomer, and 1,3-bis(3-aminopropyl)tetramethyldisiloxane having a structure represented by Formula 2 is prepared in the reaction solution preparation step (S100). If used, in the amic acid production step (S200), an amic acid solution including siloxane amic acid having a structure represented by Chemical Formula 5 below can be prepared.

(Formula 5)

When the anhydride monomer is added to the reaction solution prepared in the reaction solution preparation step (S100), the siloxane monomer and the anhydride monomer may react, and accordingly, reaction heat may be instantaneously generated.

In the amic acid preparation step (S200), an anhydride monomer is added to the reaction solution prepared in the reaction solution preparation step (S100), reaction heat generated in the reaction solution is removed, and the reaction solution is stirred for 10 to 15 hours to obtain an amic acid solution. It may be a manufacturing step.

Preferably, in the amic acid preparation step (S200), an anhydride monomer is added to the reaction solution prepared in the reaction solution preparation step (S100), reaction heat generated in the reaction solution is removed, and the reaction solution is stirred for 12 hours to obtain an amic acid solution. It may be a step of manufacturing.

At this time, the removal of the reaction heat generated in the reaction solution can be achieved by maintaining the temperature of the reaction solution cooled in the reaction solution preparation step (S100), the temperature at which the reaction solution is cooled may be -5 to 5 ℃, preferably may be 0°C.

If the temperature at which the reaction solution is cooled in the amic acid production step (S200) is less than -5°C or exceeds 5°C, the reaction between the siloxane monomer and the anhydride monomer may not be smoothly performed in the reaction solution.

That is, in the amic acid preparation step (S200), the anhydride monomer is added to the reaction solution prepared in the reaction solution preparation step (S100), and then the reaction solution is cooled until the reaction heat is not generated to increase the temperature of the reaction solution to -5 to 5 When the reaction heat is no longer generated after maintaining the temperature, the reaction solution may be stirred for 10 to 15 hours to mix the reaction solution and an anhydride monomer to prepare an amic acid solution.

On the other hand, when the anhydride monomer is added to the reaction solution prepared in the reaction solution preparation step (S100) in the amic acid preparation step (S200) and mixed, if moisture is present, the siloxane monomer and the anhydride monomer may not be smoothly mixed. .

In the amic acid preparation step (S200), the anhydride monomer is added to the reaction solution prepared in the reaction solution preparation step (S100) while nitrogen is refluxed inside the reactor so that the mixing of the siloxane monomer and the anhydride monomer is not affected by moisture present in the air. It may be to add and mix.

In the reaction solution preparation step (S100), the input amount of maleic anhydride may be 1.8 to 2.2 equivalents compared to the siloxane monomer added to the reaction solvent when preparing the reaction solution in the reaction solution preparation step (S100).

If the amount of maleic anhydride added in the reaction solution preparation step (S100) is less than 1.8 equivalents, the amount of maleic anhydride added to the siloxane monomer used in the reaction solvent during preparation of the reaction solution in the reaction solution preparation step (S100) is insufficient, resulting in polymerization of siloxaneamic acid. It may not be made smoothly, and thus the mechanical properties of the polyimide manufactured according to the embodiment of the present invention may be deteriorated.

If the amount of maleic anhydride added exceeds 2.2 equivalents in the reaction solution preparation step (S100), the amount of maleic anhydride added to the siloxane monomer added to the reaction solvent during preparation of the reaction solution in the reaction solution preparation step (S100) is greater than the amount of maleic anhydride added, resulting in polymerization of siloxaneamic acid. It may not be made smoothly, and thus the mechanical properties of the polyimide manufactured according to the embodiment of the present invention may be deteriorated.

Preferably, the amount of maleic anhydride added in the reaction solution preparation step (S100) may be 2 equivalents compared to the siloxane monomer added to the reaction solvent when preparing the reaction solution in the reaction solution preparation step (S100).

The imidization step (S300) may be a step of preparing an imide solution by introducing and mixing at least one of pyridine and acetic anhydride into the amic acid solution prepared in the amic acid preparation step (S200).

Preferably, in the imidization step (S300), pyridine and acetic anhydride may be added to the amic acid solution prepared in the amic acid preparation step (S200), and mixing may be performed while refluxing the inside of the reactor with nitrogen.

At this time, the input amount of pyridine may be 1.2 to 1.5 equivalents, preferably 1.3 equivalents, relative to 1 equivalent of siloxane amic acid contained in the amic acid solution prepared in the amic acid preparation step (S200).

In the imidization step (S300), when the input amount of pyridine is less than 1.2 equivalents or exceeds 1.5 equivalents compared to 1 equivalent of the siloxane amic acid contained in the amic acid solution prepared in the amic acid preparation step (S200), the siloxane contained in the amic acid solution Imidation of mix acid may not be performed smoothly.

In addition, the amount of acetic anhydride added may be 2.5 to 3 equivalents, preferably 2.7 equivalents, relative to 1 equivalent of siloxane amic acid contained in the amic acid solution prepared in the amic acid preparation step (S200).

In the imidization step (S300), when the amount of acetic anhydride added is less than 2.5 equivalents or greater than 3 equivalents compared to 1 equivalent of the siloxane amic acid contained in the amic acid solution prepared in the amic acid preparation step (S200), the siloxane contained in the amic acid solution Imidization of acid-amic acid may not be performed smoothly.

In the imidization step (S300), when pyridine and acetic anhydride are added to the amic acid solution prepared in the amic acid production step (S200) and mixed, the siloxane amic having a structure represented by Formula 4 or Formula 5 included in the amic acid solution Siloxane imide may be generated by an acid imidation reaction, and thus, an imide solution containing siloxane imide may be prepared.

In the imidization step (S300), when pyridine and acetic anhydride are added to the amic acid solution containing the siloxane amic acid having the structure represented by Chemical Formula 4 and mixed, siloxaneimide having the structure represented by Chemical Formula 6 below is included. An imide solution can be prepared.

(Formula 6)

Here, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are alkyl groups having 1 to 5 carbon atoms.

In the imidization step (S300), when pyridine and acetic anhydride are added to the amic acid solution containing the siloxane amic acid having the structure represented by the above-described formula (5) and mixed, the siloxaneimide having the structure represented by the formula (7) below is included. An imide solution can be prepared.

(Formula 7)

In the imidation step (S300), at least one of pyridine and acetic anhydride was added to the amic acid solution prepared in the amic acid preparation step (S200), and the inside of the reactor was stirred at room temperature for 90 to 150 minutes while refluxing with nitrogen, and then 70 The imide solution may be prepared by stirring and mixing at a temperature of 90 to 90° C. for 90 to 150 minutes, and cooling the imide solution to 25° C. when the preparation of the imide solution is completed.

The imide solution obtained in the imidization step (S300) is irradiated with electromagnetic waves to prepare a polyimide solution (S400).

In the polyimide manufacturing step (S400), the electromagnetic wave irradiated to the imide solution may have a wavelength of 365 to 436 nm, and preferably may have a wavelength of any one of 365, 405, and 436 nm.

In the polyimide manufacturing step (S400), when the imide solution is irradiated with electromagnetic waves having a wavelength of 365 to 436 nm, the siloxane imide having the structure represented by the above-mentioned formula 6 or 7 undergoes a 2+2 cycloaddition reaction (2+2 cycloaddition reaction) may cause polyimide to polymerize.

In the polyimide manufacturing step (S400), when electromagnetic waves having a wavelength of 365 to 436 nm are irradiated to an imide solution containing siloxaneimide having a structure represented by the above-described formula (6), a polyimide having a structure represented by formula (8) is obtained. It is possible to prepare a polyimide solution containing

(Formula 8)

Here, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are alkyl groups having 1 to 5 carbon atoms.

In the polyimide production step (S400), when electromagnetic waves having a wavelength of 365 to 436 nm are irradiated to an imide solution containing siloxaneimide having a structure represented by the above-described formula (7), polyimide having a structure represented by formula (9) below is produced. It is possible to prepare a polyimide solution containing

(Formula 9)

In the polyimide manufacturing step (S400), a photoinitiator is mixed with the amic acid solution obtained in the imidization step (S300) so that the siloxaneimide can smoothly undergo a 2+2 cycloaddition reaction, and then the photoinitiator is mixed with the amic acid solution. Electromagnetic waves may be irradiated to prepare a polyimide solution.

Here, the input amount of the photoinitiator may be 0.1 to 5 equivalents relative to 1 equivalent of siloxaneimide contained in the imide solution prepared in the imidation step (S300) so that the siloxaneimide can smoothly cause a 2+2 cycloaddition reaction. And, as the photoinitiator, one commonly used in a 2+2 cycloaddition reaction may be used.

Polyimide is obtained from the polyimide solution prepared in the polyimide production step (S400) (S500).

The obtaining step (S500) may be a step of obtaining polyimide by crystallizing the polyimide included in the polyimide solution prepared in the polyimide manufacturing step (S400).

The obtaining step (S500) may be a step of crystallizing polyimide by injecting the polyimide solution prepared in the polyimide manufacturing step (S400) into water, and drying the crystallized polyimide to obtain polyimide.

At this time, it is preferable that the water into which the polyimide solution prepared in the polyimide production step (S400) is introduced is deionized water, and the volume of water is 90% of the volume of the polyimide solution prepared in the polyimide production step (S400). to 110 times is preferred.

When the polyimide solution prepared in the polyimide production step (S400) is put into pure water, impurities present in the polyimide solution are removed by the pure water, and the polyimide included in the polyimide solution can be crystallized.

The method for manufacturing polyimide using photopolymerization according to an embodiment of the present invention may further include a resin manufacturing step (S600).

The resin preparation step (S600) may be a step of preparing a polyimide resin by dissolving the polyimide obtained in the obtaining step (S500) in a solvent.

In the resin preparation step (S600), a polyimide resin may be prepared by adding 25 to 35 parts by weight of the polyimide obtained in the obtaining step (S500) to 100 parts by weight of a solvent.

If the amount of polyimide added to 100 parts by weight of the solvent in the resin manufacturing step (S600) is less than 25 parts by weight, the viscosity of the polyimide resin to be produced is too low, so that the polyimide resin may not be smoothly applied to the device. there is.

In the resin manufacturing step (S600), if the amount of polyimide added to 100 parts by weight of the solvent exceeds 35 parts by weight, the viscosity of the polyimide resin to be produced is too high, making it difficult to apply the polyimide resin to the device.

Preferably, in the resin preparation step (S600), a polyimide resin may be prepared by adding 30 parts by weight of the polyimide obtained in the obtaining step (S500) to 100 parts by weight of a solvent.

In the resin manufacturing step (S600), the solvent is not limited as long as it is an organic solvent capable of dissolving the polyimide obtained in the obtaining step (S500), but is preferably dimethylacetamide and propylene glycol methyl ether acetate. can be either

In the resin manufacturing step (S600), polyimide is dissolved in a solvent to prepare a polyimide resin having a resin form, and when necessary in the display field and semiconductor field, the polyimide resin is applied to the device and dried to perform a separate imidation reaction. It is possible to simply coat the element with polyimide without the need to accompany it.

Those skilled in the art to which the present invention pertains will understand that the present invention can be embodied in other specific forms without changing its technical spirit or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. The scope of the present invention is indicated by the claims to be described later rather than the detailed description above, and all changes or modifications derived from the scope of the claims and equivalent concepts should be construed as being included in the scope of the present invention.

S100: reaction solution preparation step,
S200: amic acid manufacturing step,
S300: imidization step,
S400: polyimide manufacturing step,
S500: obtaining step,
S600: Resin manufacturing step.

Claims (7)

preparing a reaction solution by introducing a solvent and a siloxane monomer into a reactor, and cooling the reaction solution while stirring;
preparing an amic acid solution containing a siloxane amic acid by adding an anhydride monomer to the cooled reaction solution and mixing;
preparing an imide solution containing siloxaneimide by imidizing the siloxaneamic acid by adding at least one of pyridine and acetic anhydride to the amic acid solution and mixing the mixture;
preparing a polyimide solution including polyimide having a structure represented by Chemical Formula 1 below by irradiating the imide solution with ultraviolet rays to polymerize the siloxaneimide; and
comprising; obtaining polyimide from the polyimide solution;
Method for producing polyimide using phosphorus photopolymerization.
(Formula 1)

Here, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are alkyl groups having 1 to 5 carbon atoms. The method of claim 1, wherein the cooling step
Preparing the reaction solution by adding 100 parts by weight of a solvent containing at least one of the above and 20 to 40 parts by weight of the siloxane monomer to the reactor, and cooling the reaction solution to -5 to 5 ° C.
Method for producing polyimide using phosphorus photopolymerization. According to claim 1,
The siloxane monomer has a chemical structure according to Formula 2 below
Method for producing polyimide using phosphorus photopolymerization.
(Formula 2)

Here, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are alkyl groups having 1 to 5 carbon atoms. The method of claim 1, wherein the step of preparing the amic acid solution
Maleic anhydride, which is the anhydride monomer, is added to the reaction solution, and when maleic anhydride is added, 1.8 to 2.2 equivalents are added to 1 equivalent of the siloxane monomer, and the reaction solution is mixed while nitrogen is refluxed in the reactor to mix the maleic anhydride. A step for preparing a mix acid solution
Method for producing polyimide using phosphorus photopolymerization. The method of claim 1, wherein the step of adding and mixing at least one of pyridine and acetic anhydride into the amic acid solution
1.2 to 1.5 equivalents of the pyridine and 2.5 to 3 equivalents of the acetic anhydride relative to 1 equivalent of the siloxane amic acid contained in the amic acid solution were introduced into the amic acid solution, and the amic acid solution at room temperature while refluxing nitrogen into the reactor for 90 to 150 minutes and then stirring the amic acid solution at 70 to 90 ° C. for 90 to 150 minutes to prepare the imide solution
Method for producing polyimide using phosphorus photopolymerization. The method of claim 1, wherein preparing the polyimide solution
Preparing the polyimide solution by irradiating the imide solution with electromagnetic waves having a wavelength of 365 to 436 nm
Method for producing polyimide using phosphorus photopolymerization. The method of claim 1, after the step of obtaining the polyimide,
Dissolving the polyimide in a solvent containing at least one of dimethylacetamide and propylene glycol methyl ether acetate to prepare a polyimide resin
Method for producing polyimide using phosphorus photopolymerization.

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