JPH0749524B2 - Polyamic acid composition and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyamic acid composition which is a precursor of polyimide as a heat resistant resin preferably used in the electric and electronic fields, and a method for producing the same. .

[Prior Art] Polyimide-based polymers have excellent mechanical properties in a wide temperature range, and also have good electrical properties and chemical resistance, and therefore electrical / electronic parts, automobile parts, hygiene / food equipment. Used for parts and medical equipment parts. Particularly in the field of electric / electronic parts mentioned above, the polyimide polymer film is mounted on an electric insulator or a semiconductor integrated circuit used for a flexible printed circuit board, various electric motors, transformers, generators, etc. due to its excellent heat resistance. It has been put to practical use in film carrier tapes and the like.

However, in general, organic polymers have a drawback that they have a higher coefficient of thermal expansion than inorganic substances, and polyimide polymers are no exception. Therefore, for example, in the case of application to a flexible printed circuit board, when bonding a metal foil to a polyimide film, in order to prevent curling that occurs due to the difference in the coefficient of thermal expansion, another material is used between the polyimide film and the metal foil. It is necessary to provide an adhesive layer that Therefore, the material used for such an adhesive layer is generally inferior in heat resistance, and the heat resistance of the polyimide film cannot be fully utilized.

Therefore, many attempts have been made to improve the coefficient of thermal expansion of polyimide polymers, and polyimides having various structures have been proposed. For example, JP-A-60-250031 discloses that a material having a low expansion property is A polyimide obtained from a polyamic acid using a diamine component selected from is disclosed. Another example is an attempt to improve dimensional stability by using a compound having a special structure as an acid dianhydride or a diamine component which is a constituent of polyimide. However, use of a compound having a special structure as described above leaves problems such as difficulty in obtaining raw materials and toxicity.

[Problems to be Solved by the Invention] The present invention has been made in view of the above problems, in which an aromatic tetracarboxylic dianhydride and an aromatic diamine, which are easily available, are used as a silane coupling agent. The present invention provides a polyamic acid composition comprising a polyamic acid, a metal alkoxide and / or a partial condensate of a metal alkoxide obtained by reacting in the presence of an organic polar solvent, and a method for producing the same.

Thus, the polyimide-based polymer molded product obtained from the polyamic acid composition of the present invention is excellent in properties such as dimensional stability, heat resistance, and mechanical strength. It is an object of the present invention to newly provide a polyamic acid composition and a method for producing the same, which gives a polyimide-based polymer molded product having properties that can be suitably used as various parts including parts and structural materials.

[Means for Solving the Problems] That is, the present invention provides a polyamic acid, a metal alkoxide and / or a polyamic acid obtained by reacting an aromatic tetracarboxylic dianhydride and an aromatic diamine in the presence of a silane coupling agent. The present invention provides a polyamic acid composition comprising a partial condensate of a metal alkoxide and an organic polar solvent.

Furthermore, the present invention provides a method for producing the above polyamic acid composition, one of which is obtained by reacting an aromatic tetracarboxylic dianhydride and an aromatic diamine, and then reacting with a silane coupling agent. After the polyamic acid is obtained by adding the metal alkoxide and / or the partial condensate of the metal alkoxide to the polyamic acid, the other one reacts an aromatic tetracarboxylic dianhydride with a silane coupling agent. And then reacting with an aromatic diamine to obtain a polyamic acid, and then adding a metal alkoxide and / or a partial condensate of the metal alkoxide to the polyamic acid, which is a method for producing a polyamic acid composition.

The aromatic tetracarboxylic dianhydride used in the present invention has the following general formula [I] (However, Ar ¹ is Will be chosen more. ), And preferable examples thereof include pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, and the like. These may be used in combination of two or more. You can In the above-exemplified aromatic tetracarboxylic dianhydride, the inclusion of biphenyltetracarboxylic dianhydride improves chemical resistance and water / moisture resistance. Therefore, it is preferable to include this as an essential component.

The aromatic diamine used in the present invention is represented by the following general formula [II] H ₂ N-Ar ² -NH ₂ [II] (wherein Ar ² is R is an alkyl group having 1 to 3 carbon atoms, an alkoxy group, or halogen; X is a single bond, -O-, -S-, -SO.
_2- , An alkylene group having 1 to 6 carbon atoms and a perfluoroalkylene group are shown; m and n each represent an integer of 0 to 2. ) And a compound represented by the formula (1) and (2) or more. 4,4'-diaminodiphenyl ether is suitable as the aromatic diamine,
2,2-bis [4- (4-aminophenoxy) phenyl]
Propane etc. are illustrated.

Furthermore, the silane coupling agent used in the present invention is
It is useful for improving the dispersibility and mixability of metal alkoxides and other substances to be mixed with polyamic acid, and in the molded product from the composition, the coefficient of thermal expansion such as the thermal expansion coefficient in comparison with the molded product not containing it. The dimensional stability based on the properties is significantly improved. As the silane coupling agent, various known silane coupling agents may be used, but those having an appropriate functional group as well as a function as a dispersion improving agent and a dispersion stabilizer for improving the dispersibility and mixing property. By selecting, it becomes possible to bond with the functional group of the polymer, and the physical properties of the resulting molded article can be further improved. Such silane coupling agents include, for example, γ-aminopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, and one having one or more amino groups, especially primary and / or secondary amino groups. For example, γ- having the above glycidyl group
Glycidoxypropyltrimethoxysilane, or 1
Suitable examples include γ-mercaptopropyltriethoxysilane having at least one mercapto group. In addition, phenyl-based silane coupling agents such as phenyltrimethoxysilane, halogen-based silane coupling agents such as trimethylchlorosilane, silylamine-based silane coupling agents such as dimethyltrimethylsilylamine, and acyloxysilane-based silane cups such as vinyltriacetoxysilane. A ring agent, an acetamidosilane-based silane coupling agent such as N-trimethylsilylacetamide, and the like can also be exemplified.
In these silane coupling agents, especially polyamic acid or a functional group of a polyimide-based polymer, for example,
COOH, −NH ₂ , It is important to use a silane coupling agent having reactivity with the above.

Further, even if a titanium coupling agent, an aluminum coupling agent or the like is used as the silane coupling agent depending on the kind of the metal alkoxide in the polyamic acid composition, the same effect can be observed.

The composition ratio of the aromatic tetracarboxylic dianhydride, the aromatic diamine and the silane coupling agent is 100 / molar ratio.
It is preferably 99.9-80 / 0.01-40.

Examples of the metal alkoxide in the polyamic acid composition of the present invention include, for example, silicon alkoxide compounds such as silicon tetramethoxide and silicon tetraethoxide,
Zr alkoxide compounds such as zirconium tetrapropoxide and zirconium tetrabutoxide, titanium alkoxide compounds such as titanium tetralipropoxide and titanium tetrabutoxide, Al alkoxide compounds such as aluminium Sec-butoxy, and Sn such as tin tetrabutoxide. Alkoxide compounds and partial condensates obtained by precondensing them can be used. These metal alkoxides undergo a heat treatment of the composition and a condensation reaction progresses to form a metal oxide when formed into a formed product. Here, in order to allow the condensation reaction to proceed smoothly, water and a catalyst may be added to carry out hydrolysis of the metal alkoxide while further promoting the condensation by heat treatment.

The amount of the metal oxide derived from the metal alkoxide contained in the polyamic acid composition of the present invention is 1-2 with respect to 100 parts by weight of the polyimide component formed from the polyamic acid.
It is preferably 00 parts by weight. Further, when the molded product obtained by molding the composition is formed into a film, for example, the composition depends on the viscosity of the polymer, but the solid content concentration is 5 to 50% by weight.
Is preferred. Although the heat resistance and dimensional stability are improved according to the amount of the metal oxide in the molded product, if the amount is too small, the effect is difficult to be exhibited, and if the amount is too large, it tends to become brittle. Therefore, it is preferably 10 to 100 parts by weight.

The following two methods can be applied to the method for producing the polyamic acid composition of the present invention.

The first method is to react an aromatic tetracarboxylic acid dianhydride with an aromatic diamine, and then to react a silane coupling agent to obtain a polyamic acid, and to this polyamic acid, a metal alkoxide and / or a metal alkoxide. The partial condensate is mixed. In such a method, the production can be carried out by the two-step reaction substantially as described above, but it is more preferable to adopt the following three-step reaction. That is, as the reaction in the first step, the amount (mol) of the aromatic diamine is increased with respect to the amount (mol) of the aromatic tetracarboxylic dianhydride, preferably 100/105 to 145, and reacted. After that, as a reaction in the second step, the reaction system is supplemented with aromatic tetracarboxylic dianhydride so that the molar ratio of aromatic tetracarboxylic dianhydride and aromatic diamine becomes 100 / 99.9 to 80 as described above. React. Next, in the reaction of the third step, the residue of the aromatic tetracarboxylic dianhydride in the reaction of the second step is reacted with a silane coupling agent. Thus, in the reaction of the first step, the residue of the aromatic tetracarboxylic dianhydride in which the molar ratio of the aromatic tetracarboxylic dianhydride and the aromatic diamine is equivalent is eliminated, and the reaction with the silane coupling agent is eliminated. Is not done.

The second method is to react an aromatic tetracarboxylic acid dianhydride with a silane coupling agent, and then to react an aromatic diamine to obtain a polyamic acid, and add the metal alkoxide and / or the metal alkoxide moiety to the polyamic acid. A condensate is blended. In this method, the amount of the aromatic diamine is increased with respect to the amount (mol) of the aromatic tetracarboxylic dianhydride and the reaction is performed. on the other hand,
A product obtained by previously reacting an aromatic tetracarboxylic dianhydride with a silane coupling agent is reacted with a product obtained by the reaction between the aromatic tetracarboxylic dianhydride and the aromatic diamine to give a polyamic acid. Acid. In this case, finally, the molar ratio of the aromatic tetracarboxylic dianhydride and the aromatic diamine is set to 100 / 99.9 to 80, which is the same as in the first method.

A metal alkoxide and / or a partial condensate of a metal alkoxide is added to the polyamic acid that is the product thus obtained. The compounding method is not particularly limited and may be a usual method. Since the polyamic acid is in the form of a varnish as a polymer solution depending on the organic polar solvent used in the reaction, the method of mixing the metal alkoxide or its partial condensate with the polymer solution is the most uniformly dispersed composition. It is preferable in that it can be obtained.

The metal alkoxide used here or its partial condensate can be used without any other treatment,
A suitable solvent may be added for the purpose of improving the mixing property and the dispersibility. Further, it may be further condensed by adding water or a catalyst or by heat treatment. The amount of water to be added is not particularly limited, but is preferably 0.1 to 4 equivalents per 1 equivalent of the alkoxy of the metal alkoxide, and if it is more than this, the stability of the composition of the polyimide polymer or polyamic acid polymer is stable. Is reduced. Examples of the catalyst include acids known as hydrolysis catalysts such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid and toluenesulfonic acid, inorganic bases such as sodium hydroxide, and organic bases such as alkylamines.

The polyamic acid composition of the present invention is obtained by the above-mentioned production method, but since an organic polar solvent is used in the production, it is in the form of a varnish as a polymer solution due to the solvent. Therefore, the solid content concentration is preferably 60% by weight or less, and the concentration can be adjusted separately with an organic polar solvent. Organic polar solvents include N, N-dimethylacetamide (hereinafter referred to as DMAC) and N-methyl-
It is preferable to use 2-pyrrolidone (hereinafter, referred to as NMP), N, N-dimethylformamide (hereinafter, referred to as DMF) and the like.

The polyamic acid composition of the present invention can be formed into a polyimide molded product by molding and heat treating the composition. The molding method is not particularly limited, but a cast molding method such as casting on a flat glass surface or a steel belt is preferable. As a heat treatment condition in cast molding, heating to 50 ° C. to 500 ° C. is desirable, and at this time, imidization and polycondensation of metal alkoxide are performed. When the heating temperature is too low, the contribution of heating to the above reaction is small, while when it is too high, thermal decomposition occurs, so that the temperature is preferably 100 ° C to 400 ° C. The physical properties of the molded product obtained by such a method can be further improved by performing post-treatments such as stretching and curing treatment.

As the molded article in the present invention, for example, the film has heat resistance and high strength, and is used as a printed wiring board by laminating with a metal foil, an insulating film for various motors, a transformer /
It can be suitably used as an electrically insulating film such as an insulating film for a generator. Further, a glass cloth, carbon fiber, aramid cloth, glass paper, carbon paper, aramid paper, or the like may be impregnated with the composition, or dispersed in the composition and molded into a molded article. In addition, it should be applied to flexible wiring substrates, liquid crystal alignment films, LSI passivation films, α-ray shielding films, multilayer wiring interlayer insulating films for semiconductor devices such as silicon gallium arsenide, etc., in which the above composition is directly applied to a metal foil. You can

[Action] The action mechanism relating to the excellent heat resistance, high strength, and dimensional stability of the molded product obtained by casting the polyamic acid composition of the present invention is not clear, but the metal alkoxide is in the monomer state. Alternatively, since it is mixed with the polyimide component in the form of a partial condensate, the metal oxide produced by condensation by heat treatment during molding is dispersed in an extremely uniform state, and at this time, since the silane coupling agent is contained, the metal It is presumed that this is due to the fact that the oxide promotes some kind of interaction or chemical bond with the polyimide component.

[Examples] Next, the present invention will be described in more detail with reference to Examples, but it goes without saying that the present invention is not limited to these Examples.

Preparation Example 1 Preparation of metal alkoxide (1) In a reactor equipped with a stirrer and a dropping funnel, 80 g of N, N-dimethylacetamide and 69.4 g of silicon tetraethoxide (Tokyo Chemical Industry Co., Ltd.) were charged and stirred vigorously. A mixture of 0.69 g of p-toluenesulfonic acid and 24.0 g of water was added dropwise at room temperature over 30 minutes. Further, stirring was continued all day and night to prepare a homogeneous and transparent partial condensation product of silicon tetraethoxide (SiO ₂ conversion concentration: 11.5%).

Preparation Example 2 Preparation of Metal Alkoxide (2) In the same reactor as in Preparation Example 1, 56.0 g of N, N-dimethylacetamide and 71.4 g of titanium tetra-i-propoxide (Nippon Soda Co., Ltd.) were charged and stirred vigorously. On the other hand, 25.1 g of acetylacetone and 4.5 g of water were added at room temperature, and stirring was continued for a whole day and night to prepare a homogeneous transparent partial condensate of titanium tetra-i-propoxide (concentration of TiO ₂ converted: 12.8%).

Preparation Example 3 Preparation of metal alkoxide (3) In the same reactor as in Preparation Example 1, 67.6 g of N, N-dimethylacetamide and 49.4 g of zirconium tetra-n-butyroxide (Matsumoto Trading Co., Ltd.) were charged and stirred vigorously. While
Acetylacetone (12.9 g) and water (2.32 g) were added at room temperature, and stirring was continued for a whole day and night to obtain a homogeneous transparent partial condensate of zirconium tetra-n-butyroxide (concentration of ZrO ₂ equivalent: 1
2.0%) was prepared.

Example 1 In a reactor equipped with a stirrer and a reflux condenser, 19.8 g of 4,4′-diaminodiphenyl ether and 213 g of DMAC were charged as a solvent, and while stirring vigorously through nitrogen gas, 10.2 g of pyromellitic dianhydride at 10 ° C. Was added over 2 hours. Then, after continuing the reaction for 2 hours, further adding 3.61 g of pyromellitic dianhydride and reacting for 1 hour, 0.44 g of γ-aminopropyltriethoxysilane was added, and continuously at room temperature. The mixture was stirred for 6 hours to obtain a silane-modified polyamic acid solution.

Silane-modified polyamic acid solution thus obtained
100 g was charged into a reactor similar to the above, and 32.8 g of metal alkoxide (1) (partial condensate of silicon tetraethoxide) prepared in Preparation Example 1 was added dropwise over 30 minutes while stirring vigorously with nitrogen gas. A brown viscous liquid was obtained. This is cast on a glass plate with a knife coater, heated to 50 ° C, 100 ° C, 170 ° C, 320 ° C in sequence, heat-treated at each temperature for 2 hours, cooled, and then film-shaped molded product. Was peeled from the glass plate to obtain a film having a thickness of 50 μm.

Regarding the properties of the film thus obtained, the tensile strength as mechanical strength is determined by ASTM D-882-64, the flex resistance (MTT) is determined by ASTM D2176-63T, and the linear expansion coefficient is
It was measured by the TMA method. The results are shown in Table 1.

Example 2 In the same reactor as in Example 1, 20.02 g of 4,4′-diaminodiphenyl ether and 220 g of N, N-dimethylacetamide were charged, and pyromellitic dianhydride was stirred at 10 ° C. with vigorous stirring through nitrogen gas. 15.2 g of the product and 4.60 g of biphenyltetracarboxylic dianhydride were added over 2 hours.
Then, after continuing the reaction for 2 hours, 3.2 g of pyromellitic dianhydride was further added and the reaction was carried out for 1 hour.
-1.42 g of glycidoxypropyltrimethoxysilane was added and stirred at room temperature for 6 hours to obtain a silane-modified polyamic acid solution.

A viscous liquid was prepared in the same manner as in Example 1 except that 100 g of this silane-modified polyamic acid solution was used, and the solution was cast on a glass plate and heat-treated to give a thickness of 50 μm.
I got a film of.

The characteristics of this film were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 3 100 g of the silane-modified polyamic acid solution obtained in Example 1
And 18.6 g of metal alkoxide (1) (partial condensate of silicon tetraethoxide) prepared in Preparation Example 1 and metal alkoxide (2) prepared in Preparation Example 2 (part of titanium tetra-i-propoxide) Condensate) A viscous liquid was prepared in the same manner as in Example 1 except that a mixed solution with 39.0 g was used.
Further, it was cast on a glass plate and heat-treated to obtain a film having a thickness of 50 μm.

The characteristics of this film were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 4 100 g of the silane-modified polyamic acid solution obtained in Example 1
And a mixed solution of 18.6 g of the metal alkoxide (1) (partial condensate of silicon tetraethoxide) prepared in Preparation Example 1 and 39.4 g of Preparation Example (3) (partial condensate of zirconium tetra-n-butyroxide) A viscous liquid was prepared in the same manner as in Example 1 except that it was used and cast on a glass plate.
A heat treatment was performed to obtain a film having a thickness of 50 μm.

The characteristics of this film were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 5 20.02 g of 4,4′-diaminodiphenyl ether and 190 g of DMAC were charged in the same reactor as in Example 1, and 14.1 g of pyromellitic dianhydride and biphenyltetracarboxylic dianhydride were stirred vigorously with nitrogen gas. 8.9 g was added over 2 hours. Then, the reaction was continued for 2 hours. on the other hand,
1.2 g of pyromellitic dianhydride, 0.5 g of γ-anilinopropyltrimethoxysilane and 30 g of DMAC were placed in the same reactor as in Example 1 and reacted for 3 hours. Then, this was added to the solution by the above reaction, and then reacted for 6 hours.

Silane-modified polyamic acid solution thus obtained
100 g was charged into the same reactor as above, and 16.4 g of metal alkoxide (1) (partial condensate of silicon tetraethoxide) prepared in Preparation Example 1 was added dropwise over 30 minutes while stirring vigorously with nitrogen gas. A brown viscous liquid was obtained. Using this viscous liquid, a thickness of 50 was obtained in the same manner as in Example 1.
A film of μ was obtained.

The characteristics of this film were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 A polyamic acid solution was prepared in the same manner as in the method of obtaining the silane-modified polyamic acid solution in Example 1, except that γ-aminopropyltriethoxysilane was not added.

A viscous liquid was prepared in the same manner as in Example 1 using this polyamic acid solution, and then cast on a glass plate and heat-treated to obtain a film having a thickness of 50 μm.

The characteristics of this film were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 By adding only this polyamic acid solution to the polyamic acid solution prepared in Comparative Example 1 without using a metal alkoxide, casting on a glass plate and performing heat treatment in the same manner as in Example 1 A film having a thickness of 50 μm was obtained.

The characteristics of this film were measured in the same manner as in Example 1. The results are shown in Table 1.

[Effects of the Invention] The present invention provides a polyamic acid composition comprising a polyamic acid polymer, which is a precursor of a polyimide polymer containing a silane coupling agent, and a metal alkoxide, and a method for producing the same. A metal oxide-containing polyimide-based polymer molded product obtained by molding the composition, which is suitable, for example, in a molded product such as a film or sheet formed by cast molding, in which the metal oxide is uniformly and in a large amount. It is characterized by being contained. Thus, a molded product such as a film or a sheet is excellent not only in heat resistance but also in mechanical strength, and in particular, it is recognized that dimensional stability is significantly improved as compared with a molded product of a polyimide polymer alone. This effect is exhibited by the inclusion of the silane coupling agent together with the metal oxide, and has been newly discovered.

Claims (4)

[Claims] 1. A polyamic acid obtained by reacting an aromatic tetracarboxylic dianhydride with an aromatic diamine in the presence of a silane coupling agent, a metal alkoxide and / or
Alternatively, a polyamic acid composition comprising a partial condensate of a metal alkoxide and an organic polar solvent. 2. The polyamic acid composition according to claim 1, wherein the aromatic tetracarboxylic dianhydride contains biphenyltetracarboxylic dianhydride as an essential component. 3. A polyamic acid is obtained by reacting an aromatic tetracarboxylic dianhydride with an aromatic diamine and then a silane coupling agent to obtain a polyamic acid, and then a metal alkoxide and / or a partial condensation of a metal alkoxide. A method for producing a polyamic acid composition, which comprises blending a product. 4. An aromatic tetracarboxylic dianhydride is reacted with a silane coupling agent, and then an aromatic diamine is reacted to obtain a polyamic acid, and then a metal alkoxide and / or a partial condensation of a metal alkoxide is obtained. A method for producing a polyamic acid composition, which comprises blending a product.