WO2009099039A1 - Stabilized polyamideimide resin solution, and method for production thereof - Google Patents

Abstract

Disclosed is a polyamideimide resin solution having improved storage stability. Specifically disclosed is a polyamideimide resin solution which is produced by adding a glycidyl ether compound to a polyamideimide resin solution which has been polymerized in N,N'-dimethylacetamide and reacting the mixture, and which is useful for a paint, an adhesive agent, a coating solution or a film. The storage stability of a polyamideimide resin solution can be improved by adding preferably a monofunctional glycidyl ether compound to the polyamideimide resin solution preferably in an amount of 0.5- to 20-fold equivalent relative to the acid value of the polyamideimide resin and reacting the mixture.

Description

Stabilized polyamideimide resin solution and method for producing the same

The present invention relates to a stabilized polyamideimide resin solution, and more particularly to a polyamideimide resin solution having improved storage stability at high temperatures.

Polyamideimide resins are usually polymerized in amide solvents such as N-methyl-2-pyrrolidone, N, N′-dimethylacetamide, N, N′-dimethylformamide and aprotic polar solvents such as γ-butyrolactone.
When the polyamideimide resin is stored in the above solvent, there is a problem that the molecular weight decreases during storage. A similar phenomenon is known that the molecular weight of the polyimide precursor decreases when the N, N′-dimethylacetamide solution is stored.
In particular, when N, N′-dimethylacetamide is used as the polymerization solvent, the tendency is remarkable. Conventionally, the polyamideimide resin solution has been stored at a low temperature to reduce the reactivity and suppress the decrease in the molecular weight.

Latest polyimide-Basics and applications-Page 11 Published by TNS Co., Ltd. (January 28, 2002)

Since N, N′-dimethylacetamide has a lower boiling point than N-methyl-2-pyrrolidone and γ-butyrolactone, it has advantages in that it is excellent in drying property when processing a polyamideimide resin solution and is inexpensive. However, although there are such advantages, as described in the background art, when N, N′-dimethylacetamide is used as the polymerization solvent, there is a problem that the molecular weight tends to decrease during storage, Improvement of the storage stability of a polyamideimide solution polymerized with N, N′-dimethylacetamide has been desired.
The inventor of the present invention usually contains several tens of ppm to several hundreds of ppm of water in the solvent. Further, when the solvent is added to the reaction vessel, some water may be mixed from the atmosphere. The present inventors have found that moisture introduces an excessive amount of carboxyl groups into the polyamide-imide resin and lowers the molecular weight during storage, and as a result, the storage stability of the polyamide-imide resin solution decreases, leading to the present invention.

That is, the present invention is as follows.

(1) A polyamideimide resin solution obtained by blending a polyamideimide resin solution with a glycidyl ether compound and reacting with the polyamideimide resin.
(2) The polyamideimide resin solution according to (1), wherein the polyamideimide resin solution contains N, N′-dimethylacetamide.
(3) The production of the polyamideimide resin solution according to (1) or (2), wherein a monofunctional glycidyl ether compound in an amount equivalent to 0.5 to 20 times the acid value of the polyamideimide resin is blended. Method.
(4) A polyamide-imide resin, characterized in that a glycidyl ether compound is bonded to a molecular chain terminal of the polyamide-imide resin and / or a carboxyl group present in the molecular chain.

The present invention relates to an improvement in the storage stability of a polyamideimide resin solution. In particular, the present invention is characterized in that a glycidyl ether compound is blended and reacted with a polyamideimide resin solution polymerized in N, N′-dimethylacetamide. A polyamide-imide resin solution useful for an agent, a coating agent, and a film application is provided.

The present invention is described in detail below. The present invention relates to a polyamideimide resin solution having improved storage stability. In particular, it relates to improving the storage stability at high temperatures of polyamideimide resin solutions polymerized in N, N′-dimethylacetamide and having a high acid value.
The polyamide-imide resin used in the present invention is not particularly limited, and includes those synthesized from either a normal isocyanate method or an acid chloride method.

Trimellitic acid and its anhydrides and chlorides are mainly used as the acid component used in the production of polyamideimide resin. Other than these, pyromellitic acid, biphenyltetracarboxylic acid, biphenylsulfonetetracarboxylic acid, benzophenone Tetracarboxylic acids such as tetracarboxylic acid, biphenyl ether tetracarboxylic acid, ethene glycol bis trimellitate and propylene glycol bis trimellitate and their anhydrides, oxalic acid, adipic acid, malonic acid, sebacic acid, azelaic acid, dodecanedicarboxylic acid Acids, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 4,4'-dicyclohexylmethanedicarboxylic acid, aliphatic dicarboxylic acids such as dimer acid, terephthalic acid, isophthalic acid, diphenyl Ruhonjikarubon acid, diphenyl ether dicarboxylic acid, aromatic dicarboxylic acids such as naphthalene dicarboxylic acid.

Examples of diamines (diisocyanates) used in the production of polyamideimide resins include aliphatic diamines such as ethylenediamine, propylenediamine, and hexamethylenediamine, and their diisocyanates, isophorone diamine, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 4 , 4'dicyclohexylmethanediamine and the like, and diisocyanates thereof, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'- Aromatic diamines such as diaminodiphenylsulfone, benzidine, o-tolidine, 2,4-tolylenediamine, 2,6-tolylenediamine, xylylenediamine, naphthalenediamine and their diiso Aneto and the like.

Polyamideimide resin can copolymerize a diol component in addition to the acid component and amine (diisocyanate) component. Examples of the diol component include ethylene glycol, propylene glycol, tetremethylene glycol, butanediol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyester diol, and carbonate diol.

The polyamideimide resin solution of the present invention includes aprotic polar solvents such as N, N′-dimethylformamide, N, N′-dimethylacetamide, N-methyl-2-pyrrolidone and γ-butyrolactone, isophorone, cyclohexanone, cyclopentanone, etc. It can be produced by stirring while heating at 60 ° C. to 200 ° C. in one or more solvents of aromatic hydrocarbons such as ketones and xylene.
In order to accelerate the reaction during polymerization, alkali metals such as sodium fluoride, potassium fluoride, sodium methoxide, amines such as triethylamine, diethanolamine, diazabicycloundecene, and catalysts such as dibutyltin dilaurate should be used. Can do.

The polyamideimide resin solution of the present invention is usually about 10 to 40% by weight of the polyamideimide resin with respect to the resin solution, but there is no particular limitation.

The polyamideimide resin solution produced in this way has a high moisture content in the solvent before polymerization, and particularly when N, N'-dimethylacetamide is used as the solvent, a polyamideimide resin having a high acid value is produced. The storage stability of the polyamideimide resin solution is impaired.
In particular, when the solvent contains 10% by weight or more of N, N′-dimethylacetamide, the storage stability of the polyamideimide resin solution tends to be impaired.
When the acid value of the polyamideimide resin is high, the storage stability decreases because in the case of the isocyanate method, a part of the acid anhydride is ring-opened by water in the solvent to form an amic acid, and the carboxyl derived from the amic acid It is presumed that the group promotes the decomposition of the adjacent amide bond. Further, in the case of the acid chloride method, it is presumed that molecular weight reduction occurs for the same reason when imidization of the amic acid is insufficient.
Therefore, although the subject of the present invention depends on the molecular weight, it is particularly effective for a polyamideimide resin having an acid value of 150 eq / 10 ⁶ g or more. Is also effective. In this case, the logarithmic viscosity is 0.2 dl / g or more.

The present invention is to improve storage stability by blending one or more glycidyl ethers with the polyamideimide resin solution having a high acid value.
In addition to glycidyl ether, triethylamine, carbodiimide, and the like can be used, but glycidyl ether is most preferable because triethylamine has little stabilizing effect and carbodiimide has problems such as thickening and is difficult to use.
Examples of the glycidyl ether compound used in the present invention include ethyl glycidyl ether, butyl glycidyl ether, hexyl glycidyl ether, octyl glycidyl ether, aliphatic monoglycidyl ethers such as higher alcohol glycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether , Aliphatic diglycidyl ethers such as hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polyfunctional glycidyl ether such as glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, phenyl glycidyl ether, etc. Aromatic glycidyl ethers Butyl glycidyl ether and phenyl glycidyl ether monofunctional low boiling point is preferred.
In the case of using a bifunctional or higher functional glycidyl ether compound, it is necessary to react under careful conditions so as not to gel. Since a bifunctional or higher functional glycidyl ether compound may be gelled, it is desirable to use a monofunctional glycidyl ether compound.

The addition amount of the glycidyl ether is preferably 0.5 to 20 times equivalent to the acid value of the polyamideimide resin, more preferably 1 to 15 times equivalent, still more preferably 3 to 10 times equivalent, most preferably 3 to 5 equivalents. If it is less than 0.5 times equivalent, the effect of the storage stability of the polyamideimide resin solution tends to be small. Moreover, even if it adds excessively, the effect beyond it will not be acquired, and various physical properties of subsequent polyamideimide resin, for example, film | membrane intensity | strength, heat resistance, etc. may be adversely affected, and 20 times equivalent or less is preferable.

The addition of the glycidyl ether compound is carried out in the latter half or after completion of the production of the polyamideimide resin solution, and the mixture is heated and stirred at room temperature or higher, preferably 50 ° C. or higher, more preferably 80 ° C. or higher, and most preferably 100 ° C. or higher. If it is less than 50 ° C., the reaction may not proceed easily. The glycidyl ether compound reacts with the terminal of the polyamideimide, a carboxyl group present in the molecular chain. The acid value of the polyamideimide resin after the reaction with the glycidyl ether compound is preferably 330 eq / 10 ⁶ g or less, more preferably 250 eq / 10 ⁶ g or less, and even more preferably 200 eq / 10 ⁶ g or less. When the carboxyl group which exists in the molecular chain of polyamideimide exists, there exists a tendency for solution stability to fall especially.

The polyamideimide resin solution with improved storage stability of the present invention can be used as a film, paint, ink, coating agent, adhesive or other vehicle, or as a processing agent for fibers, film, paper, etc. It is useful for coating agents and adhesives such as plastic films that need to be dried at low temperatures. Moreover, although the polyamideimide resin solution of the present invention can be used as it is, a higher degree of water resistance, adhesion and heat resistance can be imparted by blending a crosslinking agent. Examples of the crosslinking agent include phenol-formaldehyde resin, amino resin, polyfunctional epoxy resin, melamine-formaldehyde resin, polyfunctional isocyanate compound and the like. *

Moreover, a flame retardant, a pigment, dye, an antifoamer, an antistatic agent, a leveling agent, etc. can be mix | blended with the polyamide-imide resin solution of this invention as needed.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples. Note that. The measured values in the examples are values measured by the following method.
The solution viscosity, logarithmic viscosity, and acid value of the polyamideimide resin solution immediately after production produced in each Example and Comparative Example and the polyamideimide resin solution stored in the resin solution state at 40 ° C. for 1 month were examined.
The polyamideimide resin solution was stored in a sealed state in a metal can.
Comparing the solution viscosity immediately after production and the solution viscosity after storage at 40 ° C. for 1 month, if the numerical value is maintained at 50% or more, it is preferable as storage stability, more preferably 75% or more, and further preferably 80% or more. . When the logarithmic viscosity immediately after production and the logarithmic viscosity after storage at 40 ° C. for 1 month are compared and the numerical value is maintained at 83% or more, it is preferable as storage stability, and more preferably 85% or more.
-Solution viscosity It measured at 25 degreeC using the Brookfield viscometer.
-The logarithmic viscosity polymerized polyamideimide resin solution was poured into water, re-precipitated, washed with water three times or more, and then dried at 60 ° C for 10 hours or more. A solution obtained by dissolving 0.5 g of a dry polymer in 100 ml of NMP was measured at 30 ° C. using an Ubbelohde viscosity tube.
-The acid-polymerized polyamideimide resin solution was poured into water, re-precipitated, washed with water three times or more, and then dried at 60 ° C for 10 hours or more. 0.125 g of the dried polymer was dissolved in 50 ml of N, N′-dimethylformamide and titrated with 1/50 N sodium methoxide in methanol using phenolphthalein as an indicator.
-Film strength and elastic modulus A film having a thickness of about 30 μm produced by applying and drying a resin solution was measured using a Tensilon made by Toyo Baldwin at room temperature at a pulling speed of 50 mm / min.

(Examples 1 to 4)
In a flask equipped with a condenser, nitrogen inlet tube, and stirrer, trimellitic anhydride (TMA) 1 mol, diphenylmethane-4,4′-diisocyanate (MDI) 1.03 mol, potassium fluoride (KF) 0.01 Mole was dissolved in N, N′-dimethylacetamide (DMAc) so as to have a solid concentration of 30% by weight, and reacted at 100 ° C. for 1 hour and at 150 ° C. for 3 hours. Then, after cooling to 100 ° C., it is diluted with DMAc so that the solid content concentration becomes 20% by weight, and at the same time, phenyl glycidyl ether is 300 equivalents, 600 equivalents, 900 equivalents per 10 ⁶ g of polyamideimide resin solids, 1500 equivalents were added and heated and stirred at 100 ° C. for 2 hours.

(Examples 5 to 6)
Using the same apparatus as described above, TMA 0.67 mol, dimer acid 0.2 mol, dicarboxyacrylonitrile-butadiene 0.03 mol, and MDI 1.02 mol were charged together with DMAc so that the solid concentration was 50% by weight. After reacting at 130 ° C. for 5 hours, after cooling to 100 ° C., it was diluted with xylene so that the solid content concentration was 30% by weight, and n-butyl glycidyl ether was 350 etc. per 10 ⁶ g of polyamideimide resin solid content. An amount of 1650 equivalents was added and the mixture was heated and stirred at 100 ° C. for 2 hours.

(Example 7)
Using the same apparatus as described above, DMAc was added to 1 mol of TMA, 0.8 mol of o-tolidine diisocyanate, 0.2 mol of tolylene diisocyanate and 0.01 mol of diazabicycloundecene so that the solid content concentration was 20% by weight. The mixture was charged and reacted at 100 ° C. for 5 hours. Subsequently, 300 equivalents of phenyl glycidyl ether per 10 ⁶ g of the solid resin was added at the same temperature and stirred for 2 hours.

(Comparative Example 1)
A solution in which phenylglycidyl ether was not added to the polyamideimide resin solution used in Examples 1 to 4 was measured.

(Comparative Example 2)
A solution in which n-butyl glycidyl ether was not added to the polyamideimide resin solution used in Examples 5 to 6 was measured.

(Comparative Example 3)
A solution in which phenylglycidyl ether was not added to the polyamitoimide resin solution used in Example 7 was measured.

(Comparative Example 4)
In Example 1, a polyamide-imide resin solution was obtained under the same conditions except that 130 equivalents of phenyl glycidyl ether was added per 10 ⁶ g of the solid polyimide resin solid content.

(Comparative Example 5)
A polyamideimide resin solution was obtained under the same conditions as in Example 1 except that 7450 equivalents of phenylglycidyl ether per 10 ⁶ g of the solid polyimide resin solid content was added. Although the solution viscosity after storage at 40 ° C. for 1 month did not decrease, the strength of the film was 76 MPa with respect to 110 MPa in Example 1, and the elastic modulus was greatly decreased to 1.5 GPa with respect to 2.8 GPa in Example 1. did.

The results of the above examples are summarized in Table 1.

The present invention relates to an improvement in the storage stability of a polyamideimide resin solution, and in particular, a polyamideimide resin solution polymerized in N, N′-dimethylacetamide is mixed with a glycidyl ether compound and reacted, and thus a paint, an adhesive A polyamide-imide resin solution useful for an agent, a coating agent and a film application is provided.

Claims (4)

A polyamideimide resin solution comprising a polyamideimide resin solution mixed with a glycidyl ether compound and reacted with the polyamideimide resin. The polyamideimide resin solution according to claim 1, wherein the polyamideimide resin solution contains N, N'-dimethylacetamide. The method for producing a polyamideimide resin solution according to claim 1 or 2, wherein the monofunctional glycidyl ether compound is added in an amount of 0.5 to 20 times the equivalent of the acid value of the polyamideimide resin. A polyamideimide resin, characterized in that a glycidyl ether compound is bonded to a carboxyl group present in the molecular chain terminal and / or molecular chain of the polyamideimide resin.