CN107365414A - Polyimide precursor composition, preparation method of polyimide and polyimide - Google Patents

Abstract

The invention relates to a polyimide precursor composition, a preparation method of polyimide and polyimide. The polyimide precursor composition includes polyamic acid and monomer compounds. The aforementioned polyamic acid is prepared from a monomer mixture through a first reaction, wherein the monomer mixture includes a diamine compound and a dianhydride compound. The aforementioned monomer compound has two carboxyl groups and two ester groups. The prepared polyimide precursor composition can be further reacted to prepare polyimide with good mechanical properties and film properties.

Description

Polyimide precursor composition, preparation method of polyimide and polyimide

technical field

The present invention relates to a polyimide precursor composition and its application, in particular to provide a polyimide precursor composition capable of preparing polyimide with good mechanical properties and film properties.

Background technique

Polyimide has the advantages of thermal oxidation resistance, heat resistance, radiation resistance and chemical resistance, so polyimide is often used in automotive materials, aerospace materials, insulating materials and liquid crystal alignment films and other applications. Polyimide is generally prepared by performing a cyclization reaction (ie imidization reaction) on polyamic acid. Among them, the polyamic acid is formed by reacting a dianhydride compound and a diamine compound.

However, based on the total amount of diamine compound used as 100 mole percent, when the total amount of dianhydride compound used is not less than 98 mole percent, the formed polyamic acid chain segment will be extended indefinitely, thereby increasing the polyamide produced. The molecular weight of the acid, thereby greatly increasing its viscosity. Therefore, when the polyamic acid is coated to form a polyimide, too high viscosity will reduce the coating property of the polyamic acid, making it difficult to coat and form a film.

In order to solve the above-mentioned coating defects caused by excessive viscosity, by adjusting the reaction conditions of the above-mentioned reaction, the molecular weight of polyamic acid can be reduced, so that it has an appropriate viscosity, and can be coated to form a film, and then can be prepared by cyclization reaction. A polyimide film was obtained. However, when the molecular weight of the polyamic acid decreases, the mechanical properties of the prepared polyimide film also decrease, which cannot meet the requirements of the application.

In addition, in the aforementioned reaction, in order to obtain an appropriate coating viscosity, it is necessary to obtain appropriate parameter conditions through complicated experiments, which consumes a lot of time and cost, and increases the production cost unnecessarily. Furthermore, the prepared polyamic acid still cannot balance the coatability and mechanical properties.

In view of this, it is urgent to provide a polyimide precursor composition and its application to improve the defects of the known polyimide precursor composition and its application.

Contents of the invention

Therefore, one aspect of the present invention is to provide a polyimide precursor composition, which reacts monomeric compounds with polyamic acid to prepare polyimide with good mechanical properties and film properties.

Another aspect of the present invention is to provide a method for preparing polyimide, which is formed by reacting the aforementioned polyimide precursor composition.

Another aspect of the present invention is to provide a polyimide prepared by the aforementioned preparation method.

Another aspect of the present invention is to provide a polyimide, which is prepared by the aforementioned preparation method and has specific repeating units.

According to one aspect of the present invention, a polyimide precursor composition is provided. The polyimide precursor composition includes polyamic acid and monomer compounds, wherein the polyamic acid is prepared from a monomer mixture through the first reaction, and the monomer mixture includes diamine compounds and dianhydride compounds. This monomer compound has two carboxyl groups and two ester groups.

According to an embodiment of the present invention, the aforementioned monomer compound has the structure shown in the following formula (I):

In formula (I), R ₁ represents And R ₂ represents an alkyl group with a carbon number of 1 to 16.

According to another embodiment of the present invention, based on the total usage amount of the aforementioned diamine compounds being 100 mole percent, the usage amount of the monomer compound is 1 mole percent to 10 mole percent.

According to another aspect of the present invention, a method for preparing polyimide is proposed. In this method, a monomer mixture is provided first, and the monomer mixture is subjected to a first reaction to obtain polyamic acid. Wherein, the monomer mixture contains diamine compound and dianhydride compound.

Then, the monomer compound and the polyamic acid are mixed to form a polyimide precursor, wherein the monomer compound has two carboxyl groups and two ester groups. Next, a second reaction is performed on the polyimide precursor to obtain polyimide.

According to an embodiment of the present invention, the aforementioned dianhydride compounds include pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'- Benzophenone tetracarboxylic dianhydride, 4,4'-oxydiphosphophthalic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, ethylene glycol-bis-trimellitic anhydride Or bisphenol A type diether dianhydride.

According to another embodiment of the present invention, the aforementioned diamine compound includes p-phenylenediamine or 9,9'-bis(4-aminophenyl)fluorene.

According to another embodiment of the present invention, the aforementioned monomer compound has the structure shown in the following formula (I):

In formula (I), R ₁ represents And R ₂ represents an alkyl group with a carbon number of 1 to 16.

According to yet another embodiment of the present invention, based on the total usage amount of the aforementioned diamine compounds being 100 mole percent, the usage amount of the dianhydride compound is greater than or equal to 90 mole percent and less than 98 mole percent, and the usage amount of the monomer compound is 1 Mole percent to 10 mole percent.

According to still another aspect of the present invention, a polyimide is provided. The polyimide is prepared by reacting the monomer mixture and the monomer compound through the aforementioned method. Wherein, the monomer mixture contains diamine compound and dianhydride compound.

According to still another aspect of the present invention, a polyimide is provided. This polyimide has repeating units shown in the following formula (II-1) and formula (II-2):

In formula (II-1), Ar ₁ represents And A represents a divalent organic group derived from the diamine compound;

In formula (II-2), Ar ₂ represents a divalent organic group derived from the dianhydride compound, and A represents a divalent organic group derived from the diamine compound.

The polyimide precursor composition of the present invention and application thereof, firstly, by making polyamic acid and monomer compound produce reaction, to extend the molecular chain length of the obtained polyimide, and can make it have good mechanical properties and film properties. Secondly, through the introduction of monomer compounds, the prepared polyimide has an appropriate molecular weight, which can suppress the increase in viscosity caused by the extension of the molecular chain, and is easy to process.

Description of drawings

1 is a flow chart illustrating a method for preparing polyimide according to an embodiment of the present invention;

FIG. 2 is a side view illustrating a polyimide laminate according to an embodiment of the present invention.

Its reference signs are:

100: Method

110: Step of providing monomer mixture

120: The step of performing the first reaction on the monomer mixture to obtain polyamic acid

130: Step of mixing monomer compound and polyamic acid to form polyimide precursor

140: The step of performing the second reaction on the polyimide precursor

150: Steps to obtain polyimide

200: polyimide laminate

210: The first copper foil

220: first thermoplastic polyimide layer

230: polyimide layer

240: Second thermoplastic polyimide layer

250: second copper foil

210a/220a/230a/240a: Side

detailed description

The preparation and use of the examples of the invention are discussed in detail below. It should be appreciated, however, that the embodiments provide many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are illustrative only, and do not limit the scope of the invention.

Please refer to FIG. 1 , which is a flowchart illustrating a method for preparing polyimide according to an embodiment of the present invention. In one embodiment, the method 100 firstly provides a monomer mixture, and performs a first reaction on the monomer mixture to obtain polyamic acid, as shown in steps 110 and 120 .

The aforementioned monomer mixture may include a diamine compound and a dianhydride compound. This diamine compound may include but not limited to 3,4'-diaminodiphenyl ether (3,4'-diaminodiphenyl ether), 4,4'-diaminodiphenyl ether (4,4'-diaminodiphenyl ether) , p-phenylenediamine, m-phenylenediamine, 3,5-diaminobenzoic acid, 2,2'-bis(4-aminobenzene base) propane [2,2'-bis(4-aminophenyl)propane], 4,4'-diaminodiphenylmethane (4,4'-diaminodiphenylmethane), 4,4'-diaminodiphenyl sulfone (4,4'-diaminodiphenyl sulfone), 3,3'-diaminodiphenyl sulfone (3,4'-diaminodiphenyl sulfone), 4,4'-diaminodiphenyl sulfide (4,4'-diaminodiphenyl sulfide), 1,3-bis(4-aminophenoxy)benzene[1,3-bis(4-aminophenoxy)benzene], 1,3-bis(3-aminophenoxy)benzene[1,3- bis(3-aminophenoxy)benzene], 1,4-bis(4-aminophenoxy)benzene[1,4-bis(4-aminophenoxy)benzene], 4,4-bis(4-aminophenoxy) )-biphenyl[4,4-bis(3-aminophenoxy)biphenyl], 2,2'-bis[4-(4-aminophenoxy)phenyl]propane{2,2'-bis[4-( 4-aminophenoxy)phenyl]propane}, 2,2'-bis[4-(3-aminophenoxyphenyl)yl]propane {2,2'-bis[4-(3-aminophenoxy)pheny]propane}, 2,2'-dimethyl-4,4'-diaminobiphenyl (2,2'-dimethyl-4,4'-diamino biphenyl), 3,3'-dimethyl-4,4'-biphenyl Aminobiphenyl (3,3'-dimethyl-4,4'-diaminobiphenyl), 3,3'-dihydrocarbyl-4,4'-diaminobiphenyl (3,3'-dihydroxybiphenyl-4,4'-diamino ), 9,9'-bis(4-aminophenyl)fluorene[9,9'-bis(4-aminophenyl)fluorene], 2,2'-bis(4-[3-aminophenoxy]phenyl )sulfone[2,2'-bis(4-(3-aminopheno xy)phenyl)sulfon], 2,6-diaminopyrimidine (2,6-diaminopyridine), polypropylene ether diamine (polyoxypropylenediamine), 4,4'-(1,3-diisopropylbenzene) diphenylamine [ 4,4'-(1,3-phenylenediisopropylidene) bisaniline; Bisaniline-M], 4,4'-(1,4-diisopropylbenzene) diphenylamine [4,4'-(1,4-phenylenediisopropylidene) bisaniline; Bisaniline-P], norbornane dimethylamine (NBDA), other suitable diamine compounds or any mixture of the above diamine compounds.

Dianhydride compounds may include, but are not limited to, pyromellitic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride (3,3',4,4'-biphenyl tetracarboxylic dianhydride), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (3,3',4,4'-benzophenone tetracarboxylic dianhydride), 4,4'-oxydiphthalic acid di Anhydride (4,4'-oxydiphthalic dianhydride), 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride (3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride), ethylene glycol- Bistrimellitate anhydride (ethylene glycol-bis-trimellitate anhydride), bisphenol A type diether dianhydride {2,2-Bis[4-(3,4-dicarboxyphenoxy)phenyl]propanedianhydride}, other appropriate dianhydride compounds or the above-mentioned dianhydride Any mix of anhydride compounds.

Based on the total usage amount of diamine compounds being 100 mole percent, the usage amount of this dianhydride compound can be greater than or equal to 90 mole percent and less than 98 mole percent, preferably greater than or equal to 94 mole percent and less than 98 mole percent, and More preferably, it can be 96 mole percent and 97 mole percent (that is, greater than or equal to 96 mole percent and less than or equal to 97 mole percent).

If the amount of dianhydride used is not less than 98 mole percent, the molecular chain length of the prepared polyamic acid is likely to increase, which in turn increases its molecular weight, thereby increasing the viscosity of the polyamic acid and easily forming a semi-solid gel. , so it cannot be coated into a film.

If the amount of dianhydride compound used is less than 95 mole percent, although the terminal group of the prepared polyamic acid can be a diamine group, only the molecular weight of the polyamic acid is relatively low. After the subsequent second reaction, the formed High-grade polyimides have low viscosity and poor processability, making it difficult to effectively meet the needs of applications.

When the usage amount of the dianhydride compound is within the aforementioned range, the prepared polyamic acid can have an appropriate molecular chain, have an appropriate molecular weight, and then have an appropriate viscosity, thus contributing to the formation of subsequent polyamic acid by coating. imine layer.

In one embodiment, the molecular weight of the prepared polyamic acid may be 50,000 to 150,000. According to the requirements of the application, the molecular weight of the polyamic acid can be adjusted appropriately, only the polyamic acid can be further reacted with the subsequent monomer compound to form a polyimide or a polyimide layer.

After step 120 is performed, a monomer compound and the aforementioned polyamic acid are mixed to form the polyimide precursor of the present invention, as shown in step 130 .

The aforementioned monomer compound has two carboxyl groups and two ester groups. In one embodiment, the monomeric compound may have the structure shown in the following formula (I):

In formula (I), R ₁ represents And R ₂ represents an alkyl group with a carbon number of 1 to 16.

The aforementioned monomer compounds may be used alone or in combination.

The aforementioned R ₁ is preferably and better be The aforementioned R ₂ is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably an alkyl group having 2 carbon atoms.

Please continue to refer to Figure 1. After step 130 is performed, the polyimide precursor of the polyimide is subjected to a second reaction to obtain the polyimide of the present invention, as shown in steps 140 and 150 .

In steps 130 and 140, the monomer compound can carry out a second reaction with the end groups (i.e. amine groups) of the two polyamic acid segments through the carboxyl group and the ester group respectively, and the obtained polyimide can be extended. Molecular chains, and then the polyamic acid with a lower molecular weight reacts to form a polyimide with a higher molecular weight, so the mechanical properties of the obtained polyimide can be improved.

Accordingly, through the introduction of monomeric compounds, the present invention can effectively overcome the defect that known polyimides cannot balance mechanical properties and film properties.

Therefore, based on the total usage of the aforementioned diamine compounds being 100 mole percent, the usage of the monomer compound may be 1 to 10 mole percent, preferably 1 to 5 mole percent, and more preferably 2 mole percent. to 3 mole percent.

If the usage amount of monomeric compound is less than 1 mole percent, too little monomeric compound limits the combination of polyamic acid segment, and shortens the molecular chain length of polyimide that makes, and then reduces its film-forming property, therefore Has poor film properties.

In one embodiment, in steps 140 and 150, the aforementioned polyimide may have repeating units represented by the following formulas (II-1) and (II-2):

In formula (II-1), Ar ₁ may represent a divalent organic group derived from a monomer compound having two carboxyl groups and two ester groups, and A may represent a divalent organic group derived from the aforementioned diamine compound group; and

In formula (II-2), Ar ₂ may represent a divalent organic group derived from the aforementioned dianhydride compound, and A may represent a divalent organic group derived from the aforementioned diamine compound.

In one embodiment, the aforementioned polyimide can be composed of repeating units represented by formula (II-1) and formula (II-2), wherein the polyimide can be a block copolymer (block copolymer) or Random copolymer (random copolymer).

Ar1 may have different structures based on the difference of the aforementioned monomer compounds used.

In one embodiment, Ar ₁ can represent When Ar ₁ represents the aforementioned groups, the mechanical properties of the prepared polyimide can be further improved due to the relatively rigid structure of the aforementioned groups. It should be noted that, although its structure is relatively rigid, the polyimide laminated board (the preparation method of the polyimide laminated board is as follows, here Not to be described in detail) can still have good flexibility (Flexural Endurance). The flexibility of this polyimide laminate can be greater than 10000, and its flexibility is measured by the detection method of Japanese Industrial Standards (Japanese Industrial Standards; JIS) No. C-50168.7, wherein when the flexibility During the test, the copper foil of the polyimide laminate needs to undergo an etching process to form a circuit layer that meets the requirements of the application.

In another embodiment, the aforementioned Ar ₁ is preferably and better be

Wherein, based on the polyimide as 100%, the content of the repeating unit shown in formula (II-1) in the prepared polyimide can be 1% to 10%, preferably 1% to 5%, And more preferably 2% to 3%.

In a specific example, the flexibility (Flexural Endurance) of the polyimide laminated board prepared by the present invention can be greater than 10,000.

Preparation method of polyimide laminated board

The preparation method of the polyimide laminated board is well known to those with ordinary knowledge in the technical field to which this case belongs. Therefore, the following is only briefly stated.

Please refer to FIG. 2 , which is a side view illustrating a polyimide laminate according to an embodiment of the present invention. This polyimide laminate 200 includes a first copper foil 210, a first thermoplastic polyimide layer 220 disposed on the first copper foil 210, a polyimide polyimide layer disposed on the first thermoplastic polyimide layer 220 The imide layer 230 , the second thermoplastic polyimide layer 240 disposed on the polyimide layer 230 , and the second copper foil 250 disposed on the second thermoplastic polyimide layer 240 .

Wherein, in the preparation method of the polyimide laminated board 200, the thermoplastic polyamic acid solution is first coated on the side 210a of the first copper foil 210, and the solvent is removed at a temperature of 80°C to 190°C, and the A first thermoplastic polyamic acid layer is formed.

Then, the polyimide precursor composition prepared in the present invention is coated on the side 220a of the first thermoplastic polyamic acid layer. Heating to 80° C. to 190° C. removes the solvent to form a polyamic acid layer.

Similarly, the second thermoplastic polyamic acid layer can be formed by coating the second thermoplastic polyamic acid on the side 230 a of the aforementioned polyamic acid layer and heating to remove the solvent.

Next, carry out cyclization reaction (i.e. imidization reaction) on the laminated board with the first copper foil, the first thermoplastic polyamic acid layer, the polyamic acid layer and the second thermoplastic polyamic acid layer, and then A laminate having a first thermoplastic polyimide layer 220, a polyimide layer 230, and a second thermoplastic polyimide layer 240 is produced.

Afterwards, the second copper foil 250 is disposed on the side surface 240a of the second thermoplastic polyimide layer 240, and a pressing process is performed to obtain the polyimide laminate 200 of the present invention. Wherein, the temperature of the pressing process may be 320°C to 380°C, and the pressure thereof may be 50kgf/cm ² to 100kgf/cm ² .

The following examples are used to illustrate the application of the present invention, but they are not intended to limit the present invention. Anyone skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention.

Preparation of polyamic acid

Synthesis Example 1

In a 1000 ml four-port reactor with nitrogen, add 19.630 g (0.182 mol) of p-phenylenediamine, 2.639 g (0.0075 mol) of 9,9'-bis(4-aminophenyl)fluorene and 425 gram of N-methyl-2-pyrrolidone, and mixed uniformly at 20°C to 30°C to form a diamine compound solution.

Then, 7.434 g (0.034 mol) of pyromellitic dianhydride was added to the diamine compound solution to perform a preliminary reaction to form a reacted solution. Next, divide 44.565 grams (0.151 moles) of 3,3',4,4'-diphenyltetracarboxylic dianhydride into three equal parts, and add it to the aforementioned solution by adding in batches , and keep stirring to carry out the reaction.

After 4 hours, the polyamic acid of Synthesis Example 1 was obtained.

Synthesis example 2

In a 1000 ml four-port reactor with nitrogen gas, 26.112 grams (0.242 moles) of p-phenylenediamine, 3.511 grams (0.01 moles) of 9,9'-bis(4-aminophenyl)fluorene and 400 gram of N-methyl-2-pyrrolidone, and mixed uniformly at 20°C to 30°C to form a diamine compound solution.

Then, 9.888 g (0.045 mol) of pyromellitic dianhydride was added to this diamine compound solution to perform a preliminary reaction to form a reacted solution. Next, divide 58.54 grams (0.199 moles) of 3,3',4,4'-diphenyltetracarboxylic dianhydride into three equal parts, and add it to the aforementioned solution by adding in batches , and keep stirring to carry out the reaction.

After 4 hours, the polyamic acid of Synthesis Example 2 was obtained.

Synthesis example 3

In a 1000 ml four-port reactor with nitrogen gas, add 32.491 g (0.3 mol) of p-phenylenediamine, 4.368 g (0.013 mol) of 9,9'-bis(4-aminophenyl)fluorene and 375 gram of N-methyl-2-pyrrolidone, and mixed uniformly at 20°C to 30°C to form a diamine compound solution.

Then, 12.304 g (0.056 mol) of pyromellitic dianhydride was added to this diamine compound solution to perform a preliminary reaction to form a reacted solution. Next, divide 70.995 grams (0.241 moles) of 3,3',4,4'-diphenyltetracarboxylic dianhydride into three equal parts, and add it to the aforementioned solution by adding in batches , and keep stirring to carry out the reaction.

After 4 hours, the polyamic acid of Synthesis Example 3 was obtained.

Preparation of polyimide precursor composition

The polyimide precursor compositions of Examples 1 to 3 and Comparative Examples 1 to 3 are prepared according to Table 1 as follows. Wherein, for the convenience of comparison, the amounts of dianhydride compounds and diamine compounds used in Synthesis Examples 1 to 3 corresponding to Examples 1 to 3 are listed in Table 1 together.

Example 1

The polyimide precursor composition of embodiment 1 is that 0.731 grams (about 0.002 mol) of 3,3',4,4'-diethyl diphenyl dicarboxylate is added to the polyamic acid of synthesis example 1 After uniform mixing, the polyimide precursor composition of Example 1 can be prepared. It has a viscosity of about 12000 cps and a solids content of 15%. The obtained polyimide precursor composition was evaluated by the following evaluation methods of coating properties and film properties, and the obtained results are shown in Table 1.

Example 2

The polyimide precursor composition of embodiment 2 is that 1.945 grams (about 0.005 mol) of 3,3',4,4'-diethyl diphenyl dicarboxylate is added to the polyamic acid of synthesis example 2 After uniform mixing, the polyimide precursor composition of Example 2 can be prepared. It has a viscosity of about 12000 cps and a solid content of 20%. The obtained polyimide precursor composition was evaluated by the following evaluation methods of coating properties and film properties, and the obtained results are shown in Table 1.

Example 3

The polyimide precursor composition of embodiment 3 is that 4.841 grams (about 0.013 moles) of 3,3',4,4'-diethyl diphenyl dicarboxylate is added to the polyamic acid of synthesis example 3 After uniform mixing, the polyimide precursor composition of Example 3 can be prepared. It has a viscosity of about 12000 cps and a solids content of 25%. The obtained polyimide precursor composition was evaluated by the following evaluation methods of coating properties and film properties, and the obtained results are shown in Table 1.

Comparative example 1

In a 1000 ml four-port reactor with nitrogen, add 19.675 grams (0.182 moles) of p-phenylenediamine, 2.645 grams (0.008 moles) of 9,9'-bis(4-aminophenyl)fluorene and 425 gram of N-methyl-2-pyrrolidone, and mixed uniformly at 20°C to 30°C to form a diamine compound solution.

Then, 7.451 g (0.034 mol) of pyromellitic dianhydride was added to this diamine compound solution to perform a preliminary reaction to form a reacted solution. Next, divide 45.225 grams (0.154 moles) of 3,3',4,4'-diphenyltetracarboxylic dianhydride into three equal parts, and add it to the aforementioned solution by adding in batches , and keep stirring to carry out the reaction.

After 4 hours, the polyimide precursor composition of Comparative Example 1 can be prepared, but the polyimide precursor composition (ie, polyamic acid) is in the form of a semi-solid gel. Its solids content is 15%. The prepared polyimide precursor composition could not be coated to form a film, so its coatability and film properties were not measured.

Comparative example 2

In a 1000 ml four-port reactor with nitrogen, add 26.431 grams (0.245 moles) of p-phenylenediamine, 3.554 grams (0.01 moles) of 9,9'-bis(4-aminophenyl)fluorene and 400 gram of N-methyl-2-pyrrolidone, and mixed uniformly at 20°C to 30°C to form a diamine compound solution.

Then, 10.009 g (0.046 mol) of pyromellitic dianhydride was added to this diamine compound solution to perform a preliminary reaction to form a reacted solution. Next, divide 60.005 grams (0.204 moles) of 3,3',4,4'-diphenyltetracarboxylic dianhydride into three equal parts, and add it to the aforementioned solution by adding in batches , and keep stirring to carry out the reaction.

After 4 hours, the polyimide precursor composition of Comparative Example 2 can be prepared, but the polyimide precursor composition (ie, polyamic acid) is in the form of a semi-solid gel. Its solid content is 20%. The prepared polyimide precursor composition could not be coated to form a film, so its coatability and film properties were not measured.

Comparative example 3

In a 1000 ml four-port reactor with nitrogen, add 19.824 grams (0.183 moles) of p-phenylenediamine, 2.665 grams (0.008 moles) of 9,9'-bis(4-aminophenyl)fluorene and 425 gram of N-methyl-2-pyrrolidone, and mixed uniformly at 20°C to 30°C to form a diamine compound solution.

Then, 7.507 g (0.034 mol) of pyromellitic dianhydride was added to this diamine compound solution to perform a preliminary reaction to form a reacted solution. Next, divide 45.005 grams (0.153 moles) of 3,3',4,4'-diphenyltetracarboxylic dianhydride into three equal parts, and add it to the aforementioned solution by adding in batches , and keep stirring to carry out the reaction.

After 4 hours, the polyimide precursor composition of Comparative Example 3 (that is, the polyamic acid referred to in the present invention) can be prepared. It has a viscosity of about 12000 cps and a solids content of 15%. The obtained polyimide precursor composition was evaluated by the following evaluation methods of coating properties and film properties, and the obtained results are shown in Table 1.

Preparation of polyimide laminates

The polyimide laminates of Application Example 1 to Application Example 3 and Comparative Application Example 1 are prepared according to Table 2 as follows.

Application example 1

The preparation method of the polyimide laminated board of Application Example 1 is as described above, and will not be repeated here. Wherein, the polyimide precursor composition of the application example 1 is the composition of the aforementioned example 1. The prepared polyimide laminates were evaluated by the following evaluation methods of film properties and mechanical properties, and the results are shown in Table 2.

Application Example 2 and Comparative Application Example 1

Application example 2 and comparative application example 1 use the same preparation method as the polyimide laminate of application example 1, the difference is that application example 2 uses the polyimide precursor composition of the aforementioned example 2, In addition, Comparative Application Example 1 uses the polyimide precursor composition of Comparative Example 3, and its conditions and evaluation results are shown in Table 2, which will not be repeated here.

Evaluation method

1. Coatability

The coatability of the polyimide layer is to apply the polyimide precursor compositions of the aforementioned Examples 1 to 3 and Comparative Example 1 to Comparative Example 2 on 1/3 oz (about 0.012 mm in thickness) respectively. On the copper foil, and further heating to carry out the cyclization reaction to form a polyimide layer, and judge its coatability according to whether the polyimide precursor composition can be coated to form a film.

2. Thin film properties

thermal properties

The thermal properties of the polyimide layer are obtained by measuring the polyimide layers prepared in the aforementioned Examples 1 to 3 and Comparative Examples 1 to 2 by means of instruments and methods well known to those skilled in the art of the present invention. Coefficient of Thermal Expansion (CTE), glass transition temperature (T _g ) and thermal decomposition temperature (T _d ) of 5% weight loss of the amine layer. The results are shown in Table 1, and will not be repeated here.

Dimensional stability

The dimensional stability of the polyimide layer is obtained by measuring the polyimides prepared in the foregoing Examples 1 to 3 and Comparative Examples 1 to 2 by methods well known to persons of ordinary skill in the technical field of the present invention. Dimensional stability of the layer in the machine direction (Machine Direction; MD) and the transverse direction (Transverse Direction; TD). The results are shown in Table 2, and will not be repeated here.

3. Mechanical properties

The mechanical properties of the polyimide layer are obtained by measuring the polyimide layers prepared in the aforementioned Examples 1 to 3 and Comparative Examples 1 to 2 by means of instruments and methods well known to those skilled in the art of the present invention. Tensile strength, elongation and flexibility of the amine layer. The results are shown in Table 2, and will not be repeated here.

Wherein, the tensile strength is measured by using the test method of IPC-TM-650 No. 2.4.19 in the American Electronic Circuit Forming Standard (Association Connecting Electronics Industries). The rupture test of flexibility is to visually observe the surface of the polyimide layer after flexure, and evaluate according to the following criteria:

○: No cracks appeared on the surface.

╳: Cracks appeared on the surface.

Please refer to Table 1. In polyamic acid, based on the total amount of diamine compound used as 100 mole percent, when the total amount of dianhydride compound used is not less than 98.0 mole percent (i.e. Comparative Example 1 and Comparative Example 2), the prepared polyamide The acid is easy to form a semi-solid gel, which cannot be coated into a film, and thus polyimide cannot be prepared.

Please refer to Table 1 and Table 2 at the same time. Based on the total usage of diamine compound is 100 mole percent, when the total usage of dianhydride compound is greater than or equal to 95 mole percent and less than 98 mole percent (i.e. embodiment 1 to embodiment 3, the prepared polyamic acid Have suitable viscosity, and can have good applicability.Wherein, in order to further promote the mechanical property of the polyimide that makes, embodiment 1 to embodiment 3 import the monomeric compound of 1 mole percent to 5 mole percent , and through the reaction of two carboxyl groups and two ester groups of the monomer compound with polyamic acid, the molecular chain of the obtained polyimide can be extended, thereby increasing its molecular weight and improving its mechanical properties. Therefore, application examples 1 and application example 2 can have better flexibility, and have good tensile strength and elongation strength.

In comparative application example 1, the total usage amount of the diamine compound based on comparative example 3 is 100 mole percent, and the total usage amount of dianhydride compound is 97.9 mole percent, but the polyimide precursor composition of comparative example 3 is not No monomeric compound was added. Accordingly, although the polyimide precursor composition (i.e. polyamic acid) of Comparative Example 3 can still be coated to form a film, the prepared polyimide (i.e. Comparative Application Example 1) has poor flexibility. Curvature.

Accordingly, when the total usage amount of diamine compounds is 100 mole percent, when the total usage amount of dianhydride compounds is within the aforementioned range of the present invention, the prepared polyamic acid can have better coatability. Secondly, the polyimide precursor composition of the present invention can be formed by mixing polyamic acid and monomer compounds, so as to obtain polyimide with good mechanical properties and film properties.

Although the present invention has been disclosed above in terms of implementation, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field of the present invention can make various changes without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined by the appended claims.

Claims (10)

1. a polyimide precursor composition, is characterized in that, this polyimide precursor composition comprises: Polyamic acid is prepared by a monomer mixture through a first reaction, wherein the monomer mixture includes a diamine compound and a dianhydride compound; and A monomeric compound with two carboxyl groups and two ester groups. 2. polyimide precursor composition as claimed in claim 1, is characterized in that, this monomeric compound has the structure shown in following formula (I): In formula (I), R ₁ represents And R ₂ represents an alkyl group with a carbon number of 1 to 16. 3. polyimide precursor composition as claimed in claim 1, is characterized in that, based on the total usage amount of this diamine compound is 100 mole percent, the usage amount of this monomer compound is 1 mole percent to 10 mole percent percentage. 4. a preparation method of polyimide, is characterized in that, the preparation method of this polyimide comprises: providing a monomer mixture, wherein the monomer mixture comprises a diamine compound and a dianhydride compound; performing a first reaction on the monomer mixture to obtain polyamic acid; mixing a monomer compound and the polyamic acid to form a polyimide precursor, wherein the monomer compound has two carboxyl groups and two ester groups; and A second reaction is performed on the polyimide precursor to obtain the polyimide. 5. the preparation method of polyimide as claimed in claim 4 is characterized in that, this dianhydride compound comprises pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dicarboxylic acid anhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 4,4'-oxydiphosphophthalic dianhydride, 3,3',4,4'-diphenylsulfone Tetracarboxylic dianhydride, ethylene glycol-bistrimellitic anhydride, or bisphenol A type diether dianhydride. 6. The preparation method of polyimide as claimed in claim 4, is characterized in that, the diamine compound comprises p-phenylenediamine or 9,9'-bis(4-aminophenyl)fluorene. 7. the preparation method of polyimide as claimed in claim 4 is characterized in that, this monomer compound has the structure shown in following formula (I): In formula (I), R ₁ represents And R ₂ represents an alkyl group with a carbon number of 1 to 16. 8. the preparation method of polyimide as claimed in claim 4 is characterized in that, based on the total usage amount of this diamine compound is 100 mole percent, the usage amount of this dianhydride compound is greater than or equal to 90 mole percent and less than 98 mole percent, and the monomer compound is used in an amount of 1 mole percent to 10 mole percent. 9. a polyimide, it is characterized in that, this polyimide is to make by the reaction of a monomer mixture and a monomer compound by the method described in any one of claim 4 to 8, Wherein the monomer mixture includes a diamine compound and a dianhydride compound. 10. A polyimide, characterized in that, the polyimide has repeating units shown in the following formula (II-1) and formula (II-2): In formula (II-1), Ar ₁ represents And A represents a divalent organic group derived from the diamine compound; In formula (II-2), Ar ₂ represents a divalent organic group derived from the dianhydride compound, and A represents a divalent organic group derived from the diamine compound.