KR100193384B1 - New soluble polyimide resins and preparation method thereof - Google Patents

Abstract

The present invention relates to a novel soluble polyimide resin and a method for preparing the same, and more particularly, to a new type of poly having excellent solubility as well as heat resistance using aromatic diamine containing an aromatic tetracarboxylic anhydride and an aliphatic ring group. A mid resin and its manufacturing method are related.

That is, instead of the aromatic diamines conventionally used in the production of polyimide resins, trimethylcyclohexylidene dianiline (TMCH-DA) is used as a monomer to produce various kinds of aromatic tetracarboxylic dianhydrides. Polyimide resin has a glass transition temperature of 300 ~ 400 ℃ and shows excellent dissolution properties for various organic solvents.

Description

New soluble polyimide resins and preparation method thereof

The present invention relates to a novel soluble polyimide resin and a method for preparing the same, and more particularly, to a new type of poly having excellent solubility as well as heat resistance using an aromatic diamine containing an aromatic tetracarboxylic dianhydride and an aliphatic ring group. A mid resin and its manufacturing method are related.

In general, the polyimide (hereinafter, referred to as PI) resin refers to a high heat-resistant resin prepared by condensation polymerization of an aromatic tetracarboxylic acid or a derivative thereof with an aromatic diamine or an aromatic diisocyanate, followed by imidization. However, these PI resins have insoluble properties that do not dissolve in a solvent and insoluble properties that do not melt by heating.

In addition, the PI resin may have various molecular structures depending on the type of monomer used. Generally, the aromatic tetracarboxylic acid component is used by polycondensation using pyromellitic dianhydride (PMDA) or biphthalic dianhydride (BPDA) and the aromatic diamine component using ODA (oxydianiline) or p-PDA (p-phenylene diamine). The most typical PI resin has the following structural formula (I) as a repeating unit.

The PI resin having the structural formula (I) as a repeating unit is an insoluble and insoluble ultra high heat resistant resin, and has the following characteristics: (1) excellent thermal oxidation resistance (2) a very high usable temperature and a long service life Is about 260 ℃, and the short-term use temperature is about 480 ℃ and has excellent heat resistance (3) Excellent electrochemical and mechanical properties (4) Excellent radiation and low temperature properties (5) Inherent flame retardancy (6) Excellent chemical property.

The PI resin having the structural formula (I) as a repeating unit has excellent heat resistance, but has a disadvantage in that processing is difficult due to insolubility and insolubility.

As a method for improving the disadvantages of the PI resin, a method of introducing a polar group into the polymer backbone or a side chain, a method of introducing a bulky linking group or a pedant group, and increasing the flexibility of the polymer main chain The method of making it have been reported.

In particular, as a study to increase the solubility of PI resin, T. Kurosaki et al. Have published a method for preparing a soluble PI coating solution using alicyclic anhydride as a monomer [Macromolecules, 1994, 27, 1117 And 1993, 26, 4961. Also in 1993, Qiu Jin et al. Produced soluble PI using cyclic diamine [J.P.S. Part A. Polym. Chem. Ed., 31, 2345-2351].

However, most of the soluble PI resins modified by the above method have the advantage that the solubility is improved due to the increased flexibility of the chain, but since the biggest advantage of the PI resin is severely deteriorated, high thermal stability, mechanical properties, etc. Has a problem.

On the other hand, the representative soluble PI resin (Matrimid 5218) developed by ciba Geigy has been reported to exhibit excellent heat resistance and excellent dissolution characteristics by introducing trimethylindane group into the polymer main chain. have. However, since the PI resin has to go through several steps in the preparation of the monomer, there are many restrictions on its universal use.

As a part of such research, the present inventors have studied through the past several years to improve the processing characteristics of existing aromatic high heat-resistant polymers to improve the dissolution and melting characteristics of polyamideimide resin, which is a representative thermoplastic high heat-resistant resin. The study was conducted. As a result, it is found that the solubility of the polymer can be greatly increased by introducing an isophorone diamine (hereinafter referred to as IPDA), an aliphatic diamine compound containing a trimethylcyclohexyl group, into the main chain of the polymer. [US Patent No. 5,5521,276, Korean Patent Application No. 93-12717].

Based on the above research results, the present inventors have tried to prepare a PI resin which is more heat-resistant and soluble than PAI resin containing IPDA, and as a result, trimethylcyclohex, which is an aromatic diamine compound containing trimethylcyclohexyl group Various types of single PI and copolymerized PI having excellent physical properties could be prepared by using a silicide denian (trimethylcyclohexylidene dianiline: hereinafter referred to as TMCH-DA) as a monomer. Here, TMCH-DA was prepared according to the preparation method of German Patent No. 4,014,847.

The present invention is to introduce a new PI resin having excellent heat resistance and excellent dissolution properties by introducing TMCH-DA instead of the aromatic diamine used in the production of the existing PI resin and reacted with various kinds of aromatic tetracarboxylic dianhydride. Was completed.

Thus, in the present invention, while maintaining the properties of the existing PI resin as it is excellent in the molding and processing, such a new soluble PI resin that can be used as a core heat-resistant material of high-tech industries such as electrical, electronic, space, aviation.

Accordingly, an object of the present invention is to provide a PI resin containing a TMCH-DA structure.

1 is the thermogravimetric analysis (TGA) curves of new soluble polyimide resins,

2 is the differential scanning column (DSC) curves of new soluble polyimide resins,

3 is a storage stability curve of the novel soluble polyimide resins.

The present invention is prepared from TMCH-DA, and characterized by a PI resin having the following structural formula (I) as a repeating unit.

은

및

중에서 선택된 하나 이상의 4가기이고,

은

및

중에서 선택된 하나 이상의 2가지로서 반드시

기를 포함한다.In the above formula,

silver

And

One or more selected from

silver

And

One or more selected from two

Contains groups.

In addition, the present invention is a method for producing a polyimide resin by solution polymerization of a diamine component and a dicarboxylic acid, wherein the diamine component contains TMCH-DA as an essential component, in addition to oxydianiline, methylenedianiline, metabis It contains one or two or more compounds selected from aminophenoxydiphenyl sulfone and parabisaminophenoxy diphenyl sulfone, wherein the dicard acid component is pyromellitic dianhydride (hereinafter referred to as PDMA), benzophenone Tetracarboxylic dianhydride (hereinafter referred to as HFDA), oxydiphthalic dianhydride (hereinafter referred to as ODPA), nonphthalic dianhydride (hereinafter referred to as BPDA) and hexafluoroisopropylidenediphthalic acid It includes a method for producing a polyimide resin having a repeating unit of the following structural formula (I), characterized in that it contains one or two or more selected from dianhydrides (hereinafter referred to as HFDA). The.

PI resin according to the present invention has a weight average molecular weight (M / W) of about 60,000 ~ 150,000 g / mol, maintains the intrinsic viscosity in the range of 0.3 ~ 1.5 dl / g, and the glass transition temperature of 300 ~ 400 ℃ Have In addition, the PI resin of the present invention is dimethyl acetamide (hereinafter referred to as DMAc), dimethylformamide (hereinafter referred to as DMF), N-methyl-2-pyrrolidone (hereinafter referred to as NMP) and Easily soluble at room temperature for organic solvents such as m-cresol, including aprotic polar solvents. In addition, it exhibits high solubility of 10% by weight or more at room temperature with respect to tetrahydrofuran (hereinafter referred to as THF), low boiling point solvents such as chloroform, and low absorbing solvents such as γ-butyrolactone. Moreover, high solubility is shown also about these mixed solvents.

The present invention will be described in more detail based on the following examples, but the present invention is not limited thereto.

Example 1

After slowly passing nitrogen gas through a 50 ml reactor equipped with a stirrer, a temperature controller, a nitrogen injector, a dropping funnel and a cooler, TMCH-DA (3.08 g, 0.01 mol) was dissolved in DMAc (36 ml) as a reaction solvent. While passing the gas, solid BTDA (3.2 g, 0.01 mol) was added slowly. At this time, the concentration of the solid content (solic content) was fixed to 15% by weight, the reaction temperature was adjusted not to exceed 10 ℃. Subsequently, after stirring at room temperature for 24 hours, an excess of acetic anhydride (0.03 mol) and pyridine (0.05 mol) was added as an imidization catalyst, and the imidization reaction was performed while stirring for 24 hours. After the reaction was completed, the reaction mixture was precipitated in excess methanol (hereinafter referred to as MeOH) using a waring blender, and the filtered polymer was washed several times with water and MeOH. Drying under reduced pressure at temperature synthesized a new PI resin (hereinafter referred to as P-1). The yield of polymerization was quantitative. The intrinsic viscosity measured at 30 ° C at a concentration of 0.5 g / dl with DMAc as a solvent was 0.66 dl / g.

Example 2

After dissolving TMCH-DA (3.08 g, 0.01 mol) and PMDA (2.18 g, 0.01 mol) in DMAc, PI resin (hereinafter, referred to as P-2) was synthesized in the same manner as in Example 1. The PI resin thus prepared was dissolved in DMAc at a concentration of 0.5 g / dl, and the inherent viscosity measured at 30 ° C. was 0.68 dl / g.

Example 3

After dissolving TMCH-DA (3.08 g, 0.01 mol) and ODPA (3.10 g, 0.01 mol) in CMAc, PI resin (hereinafter referred to as P-3) was synthesized in the same manner as in Example 1. The PI resin thus prepared was dissolved in DMAc at a concentration of 0.5 g / dl, and the inherent viscosity measured at 30 ° C. was 0.55 dl / g.

Example 4

After dissolving TMCH-DA (3.08 g, 0.01 mol) and BPDA (2.94 g, 0.01 mol) in DMAc, PI resin (hereinafter referred to as P-4) was synthesized in the same manner as in Example 1. The PI resin so prepared was dissolved in DMAc at a concentration of 0.5 g / dl, and the inherent viscosity measured at 30 ° C. was 0.56 dl / g.

Example 5

After dissolving TMCH-DA (3.08 g, 0.01 mol) dhk HFDA (4.44 g, 0.01 mol) in DMAc, PI resin (hereinafter referred to as P-5) was synthesized in the same manner as in Example 1. The PI resin thus prepared was dissolved in DMAc at a concentration of 0.5 g / dl, and the inherent viscosity measured at 30 ° C. was 0.55 dl / g.

Example 6

TMCH-DA (2.31 g, 7.5 mmol) and oxydianiline (hereinafter referred to as ODA: 0.5 g, 2.5 mmol) are dissolved in DMAc (34 ml), then BTDA (3.22 g, 0.01 mol) is added and the PI resin (hereinafter, referred to as P-6) was synthesized in the same manner as in Example 1. The PI resin thus prepared was dissolved in DMAc at a concentration of 0.5 g / dl, and the inherent viscosity measured at 30 ° C. was 1.05 dl / g.

Example 7

After dissolving TMCH-DA (1.54 g, 5.0 mmol) and ODA (1.0 g, 5.0 mmol) in DMAc, BTDA (3.22 g, 0.01 mol) was added and PI resin (hereinafter, P-7) were synthesized. The PI resin thus prepared was dissolved in DMAc at a concentration of 0.5 g / dl, and the inherent viscosity measured at 30 ° C. was 1.33 dl / g.

[Comparative Example]

PI resin (hereinafter, referred to as P-8) was synthesized in the same manner as in Example 1 except that ODA (2.00 g, 0.01 mmol) and BTDA (2.88 g, 0.01 mol) were reacted. The PI resin thus prepared was dissolved in DMAc at a concentration of 0.5 g / dl, and the inherent viscosity measured at 30 ° C. was 0.85 dl / g (measured in the state of polyamic acid).

Experimental Example 1

[Measurement of molecular weight, thermal analysis, and tensile strength]

The molecular weight, thermal analysis, and tensile strength measurement results of the PI resins prepared in Examples 1 to 7 and Comparative Examples are shown in Table 1 below.

As shown in Table 1, the PI resins prepared in Examples 1 to 7 according to the present invention were all obtained in an amorphous transparent resin, and the tensile strength could be easily measured in a film state. In addition, the tensile strength of about 1,000 ~ 1,400 kg / ㎠ showed a very good mechanical strength.

On the other hand, in order to evaluate the thermal properties of the PI resins in the present invention, the pyrolysis temperature and the glass transition temperature were measured using TGA (thermogravimetric analysis) and differential scanngin calorimeter (DSC).

As can be seen in Table 1, the novel polymers prepared in the present invention show a high glass transition temperature (T / g) of 320 ° C. or more, depending on the structure of the acid anhydride used. Considering that Kapton, a typical wholly aromatic PI resin, exhibits a glass transition temperature around 380 ° C., the results of the study may have important meanings.

In other words, the PI resin according to the present invention exhibits long-term heat resistance characteristics that are soluble and inferior to the wholly aromatic PI resin. This has advantages in the machining process. That is, since the PI resin of the present invention is dissolved in the imidized state, it is not necessary to perform a separate amidation reaction after applying the resin solution, and the processing temperature can be lowered to 200 ° C or lower, which is the solvent evaporation temperature. Therefore, the thermal aging of the peripheral parts can be prevented. In addition, there is an advantage in reducing the bubble generation due to the generation of side reactions at a high temperature. Therefore, it can greatly contribute to expanding the applicability of the PI resin in the future.

1 is a TGA analysis result measured by heating up at a rate of 10 ° C./min under a stream of nitrogen. The initial decomposition temperature of the PI resins prepared in Examples 1 to 5 was more than 500 ° C., and showed a very good value, and the residual weight at 800 ° C. was about 37 to 46%, which was somewhat lower than that of the wholly aromatic PI resin. Indicated. This is due to the presence of the methyl group introduced as a substituent, and it can be seen that the methyl group is substituted in the benzene ring of the total aromatic PI resin. Therefore, the PI resin according to the present invention turned out to be somewhat short in heat resistance at high temperature in the short term, but was excellent in long term heat resistance at around 300 ° C.

In addition, looking at the heat resistance shown in Table 1, the glass transition temperature (T / g) shows a tendency to increase as the amount of TMCH-DA is increased. This is presumably because TMCH-DA has a more rigid structure compared to ODA. Figure 2 is a DSC curve for each PI resin prepared in Examples 1, 6, 7 and Comparative Examples.

Experimental Example 2

As is well known, one of the disadvantages of using PI resin is poor storage stability. In other words, the amide bond present in the polyamic acid is in a thermal equilibrium state decomposed into an amine group and an anhydride group even at room temperature. As a result, there is a problem that the molecular weight gradually decreases during long-term storage of the PI resin solution, which is a lot of obstacles to the expansion of the application of the PI resin solution. Therefore, studies on improving the storage stability of the PI resin (or polyamic acid) solution are actively underway, and the development of polyamic acid ester or polyamic acid is a representative example. However, since these PI precursors are too expensive, they are not suitable for practical use.

Since the soluble PI resin synthesized in the present invention not only uses a low cost monomer but also has already undergone the imidization reaction, the ratio of amic acid in an unstable state is minimized. Therefore, the storage stability is greatly improved compared to the existing polyamic acid solution (polyamic acid solution).

Figure 3 shows the intrinsic viscosity change with time variation of the polyamic acid as an intermediate in the BTDA-ODA polymerization system and PI-1, the PI resin according to the present invention. At this time, the concentration of the solution was 0.5% by weight, and the temperature was adjusted to 80 ° C. The choice of solution concentration is very important in storage stability evaluation experiments. If the solution concentration is very high (more than 15% by weight), there is no visible decrease in molecular weight and in some cases an increase in molecular weight due to gelation may occur. Because there is. As a result, as shown in FIG. 3, in the case of the BTDA-ODA-based polyamic acid solution, the decrease in the intrinsic viscosity with time was remarkable, but in the case of the soluble PI resin prepared in the present invention, the molecular weight was not nearly decreased, so that the storage stability It was found that this was significantly improved.

Experimental Example 3

The PI resin of the present invention prepared from TMCH-DA exhibited very good dissolving power in most organic solvents, unlike the conventional wholly aromatic PI resins.

As shown in Table 2 below, in addition to aprotic solvents such as NMP, DMAc, and DMF, the present invention shows a preferable result of being easily dissolved at room temperature in a general organic solvent such as THF.

Unlike the conventional wholly aromatic PI resin, the soluble PI resin according to the present invention exhibits excellent solubility even when polymerized with any kind of dianhydride. This is important for expanding the applicability of the PI resins of the present invention. In other words, when the PI resin of the present invention is used as an adhesive material, it is possible to produce a PI film at a low temperature of 200 ° C. or lower because it has excellent dissolving power even in a completely imidized state, and in the future, when H _{2 is} bonded by heating. Since the generation of by-products such as O is low, the generation of bubbles can be reduced. Thus, the PI resin of the present invention can be applied to a liquid crystal-oriented film or a soluble photosensitive PI resin.

The PI resin of the present invention is not only excellent in heat resistance characteristics but also excellent in dissolution and melting characteristics, and thus can be applied as heat and insulation film of electrical and electronic parts, which require low temperature processing, and are useful as various advanced heat resistant structural materials.

Claims (6)

A polyimide resin prepared from trimethylcyclohexylidene dianiline, wherein the following structural formula (I) is a repeating unit.

In the above formula,

silver

And

One or more selected from

silver

And

One or more selected from two

Contains groups. The polyimide resin according to claim 1, wherein the intrinsic viscosity of the polyimide resin is maintained in a range of 0.3 to 1.5 dl / g. The polyimide resin according to claim 1, wherein the polyimide resin maintains a molecular weight distribution in the range of 60,000 to 150,000 g / mol. The polyimide resin according to claim 1, wherein the polyimide resin has a glass transition temperature of 300 to 400 ° C. The polyimide resin according to claim 1, wherein the polyimide resin is a single solvent or a mixed solvent selected from dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, tetrahydrofuran, chloroform and γ-butyrolactone. Polyimide resin, characterized in that dissolved at room temperature. In the method for producing a polyimide resin by solution polymerization of a diamine component and a dicarboxylic acid, the diamine component is trimethylcyclohexylidene diamine, oxydianiline, methylenedianili, metabisaminophenoxydiphenylsulfone and parabis At least one diamine compound selected from aminophenoxydiphenyl sulfone necessarily includes trimethylcyclohexylidene diamine, wherein the dicarboxylic acid component is pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, oxydiphthalic dianhydride A method for producing a polyimide resin having the following structural formula (I) as a repeating unit, characterized by containing at least one selected from water, nonphthalic dianhydride and hexafloorisopropylidene diphthalic dianhydride.

Where

and

Are as defined in claim 1, respectively.

Images