JPH06207024A - Low-modulus polyimide-siloxane conjugate product and its production - Google Patents

Abstract

PURPOSE:To obtain a uniform, transparent and low-modulus polyamide-siloxane conjugate product excellent in combustibility by incorporating a specified alkoxysilane into an organic solvent containing a specified polyamic acid to effect hydrolysis and condensation, applying the obtained solution to a base plate, and baking it. CONSTITUTION:An organic solvent (e.g. N,N-dimethylacetamide) containing a polyamic acid having structural units of formula I [wherein R<1> is a tetravalent organic group; R<2> is CH3, C2H5 or phenyl; R<3> is 1-8C alkyl; R<4> is (trifluoro) methyl or trimethylsilyl; m<1> is 0 to 3; m<2> is 0 to 4; and n is 0 to 2] is mixed with at least one alkoxysilane of formula II (wherein p is 1 or 2) to effect hydrolysis and condenstion. The obtained solution is applied to a base plate (e.g. glass plate) and baked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide resin having a low elastic modulus.

[0002]

2. Description of the Related Art A polyimide-based resin is a resin which is basically obtained by preparing a polyamic acid from a tetracarboxylic dianhydride component and a diamine component and heating the polyamic acid. Widely used for alignment film and various adhesives. It is well known that aromatic polyimide resins are generally super engineering plastics having high heat resistance, high strength and high elastic modulus.
However, a resin having a low elastic modulus and flexibility may be required depending on the use. For such use, a part or all of the diamine component may be represented by the general formula (III)

[Chemical 6] (However, in the general formula (III), m is 1 to 100). A polyimide substituted with a dimethylsiloxane oligomer having a 3-aminopropyl group at both ends thereof has been used (for example, JP-A-57-143328).
JP-A-58-7473, JP-A-58-1
No. 3631). However, although such a polyimide resin has a low elastic modulus, its heat resistance is lowered to around 300 ° C., so that it has a drawback that its use is limited. On the other hand, JP-A-62-283153 and JP-A-63-9.
9234, JP-A-63-99235, JP-A-63-99236, JP-A-63-99536, etc., describe hydrolysis and condensation products of alkoxysilane obtained by the sol-gel method. Attempts to improve the properties of the polyimide by mixing it with a polyamic acid solution have been disclosed. However, in such a method, since the condensate of the alkoxysilane does not form a chemical bond with the polyimide, the dispersibility of the condensate in the polyimide is not sufficient, and the unevenness of the coating film, whitening, and reduction of elongation are Such defects tend to appear.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and a uniform and transparent polyimide resin having a low elastic modulus without lowering heat resistance. To provide.

[0004]

As a result of various studies, the inventors of the present invention have found that a polyamic acid having a specific structure is used to obtain a low-modulus polyimide siloxane composite without lowering heat resistance. Heading out, the present invention has been completed. That is,

The low modulus polyimide siloxane composite of the present invention has the general formula (I)

[Chemical 7] In a solution containing a polyamic acid having a structural unit represented by the formula (II)

[Chemical 8] It is characterized in that it is obtained by adding at least one kind of alkoxysilane represented by the formula (1) and condensing at the same time as hydrolysis, applying the resulting solution to a substrate, and then baking.

Further, the method for producing the low elastic modulus polyimide siloxane composite of the present invention is represented by the general formula (I)

[Chemical 9] In a solution containing a polyamic acid having a structural unit represented by the formula (II)

[Chemical 10] One or more alkoxysilanes represented by the formula (3) are added to cause hydrolysis and condensation at the same time, and the resulting solution is applied to a substrate and then baked at a temperature of 200 to 500 ° C. In this case, when the dialkoxysilane with p = 2 in the alkoxysilane represented by the general formula (II) is 40 to 100% of the total alkoxysilane, a polyimide siloxane composite having a particularly low elastic modulus can be obtained, which is preferable. (However, in the general formulas (I) and (II), R ¹ is a tetravalent organic group, R ² independently represents a methyl group, an ethyl group or a phenyl group, and R ³ independently has a carbon number of 8 or less. Represents an alkyl group, R ⁴ independently represents a methyl group, a trifluoromethyl group or a trimethylsilyl group, m ¹ is 0, ¹ , 2 or 3, m ² is 0, 1, ² , 3 or 4, n is 0. 1 or 2, p is a value of 1 or 2.)

The general formula (I) in the composite of the present invention and the process for producing the same is shown.

[Chemical 11] The polyamic acid having a structural unit represented by the general formula (I
V)

[Chemical 12] It can be obtained by reacting the diamine represented by and tetracarboxylic dianhydride according to a conventional method. At this time, a polyamic acid in which different structural units are introduced can also be obtained by allowing the diamine represented by the general formula (IV) to coexist with another diamine and carrying out the reaction. (However, in the general formulas (I) and (IV), R ¹ is a tetravalent organic group, R ² independently represents a methyl group, an ethyl group or a phenyl group, and R ³ independently has a carbon number of 8 or less. Represents an alkyl group, R ⁴ independently represents a methyl group, a trifluoromethyl group or a trimethylsilyl group, m ¹ is 0, ¹ , 2 or 3, m ² is 0, 1, ² , 3 or 4, n is 0. 1 or 2).

Specific examples of the tetracarboxylic dianhydride used to obtain the polyamic acid include pyromellitic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, and 2 , 2 ', 3,3'-biphenyltetracarboxylic dianhydride, 2,3,3', 4'-biphenyltetracarboxylic dianhydride, 3,3 ', 4
4'-benzophenone tetracarboxylic dianhydride, 2,
2 ', 3,3'-benzophenone tetracarboxylic acid dianhydride, 2,3,3', 4'-benzophenone tetracarboxylic acid dianhydride, bis- (3,4-dicarboxyphenyl) ether dianhydride, Bis- (3,4-dicarboxyphenyl) sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2, 2-bis-
Known compounds such as (3,4-dicarboxyphenyl) hexafluoropropane dianhydride can be mentioned.
However, it is not necessarily limited to these.

Specific examples of the diamine which can be used together with the diamine represented by the general formula (IV) include 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane,
4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4,4'-di (metaaminophenoxy) diphenyl sulfone, 4,4'-di (paraaminophenoxy) diphenyl sulfone, orthophenylenediamine, meta Phenylenediamine, paraphenylenediamine, benzidine, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 4,
4'-diaminodiphenyl-2,2-propane, 1,5
-Diaminonaphthalene, 1,8-diaminonaphthalene,
4,4'-bis (4-aminophenoxy) biphenyl,
2,2-bis {4- (4-aminophenoxy) phenyl} hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4 ′ -Diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, 4,
Known compounds such as 4'-diamino-3,3 ', 5,5'-tetramethyldiphenylmethane, 1,4-diaminotoluene, metaxylylenediamine and 2,2'-dimethylbenzidine can be mentioned. However, it is not necessarily limited to these.

The organic solvent in the complex of the present invention and the method for producing the same is used as a reaction solvent for reacting the above-mentioned raw material compounds. Specific examples of preferable solvents (hereinafter sometimes referred to as reaction solvents) include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, tetramethylurea, pyridine, hexamethyl. Phosphoramide, methylformamide, N-acetyl-2-pyrrolidone, cyclopentanone, methylcyclopentanone, cyclohexanone, cresol, γ-butyrolactone, isophorone, N, N-diethylacetamide, N, N-diethylformamide, Examples thereof include N, N-dimethylmethoxyacetamide, tetrahydrofuran, N-methyl-ε-caprolactam, tetrahydrothiophene dioxide {sulpholane} and the like.

The polyamic acid used in the composite of the present invention and the method for producing the same is prepared by using one or more tetracarboxylic dianhydrides represented by the general formula (IV) in the above solvent.

[Chemical 13] Can be synthesized by reacting with one or more kinds of diamines including the diamine represented by At this time, the ratio of the diamine represented by the general formula (IV) in all the diamines is preferably 5 mol% or more, particularly preferably 30 mol% or more. When it is less than 5 mol%, the uniformity of the obtained polyimidesiloxane composite may be poor, which is not preferable.

In the solution of the obtained polyamic acid, the above-mentioned general formula (II)

[Chemical 14] A mixture of one or more alkoxysilanes represented by the formula (1) is added and the mixture is hydrolyzed and condensed by the sol-gel method. The resulting solution is a precursor solution of the polyimidesiloxane complex.

The conditions for carrying out the sol-gel reaction may be known reaction conditions and is necessary for hydrolyzing the alkoxy group (OR ³ ) of the polyamic acid of the formula (I) and the alkoxysilane of the formula (II). Add more or more water,
The reaction may be performed at room temperature to 150 ° C. for several hours to 100 hours. In order to accelerate the reaction, a small amount of acids such as hydrochloric acid and acetic acid, or a tertiary amine can be used as a catalyst, if necessary.

The polysiloxane formed on the basis of the alkoxy groups of formula (I) and formula (II) contained in the polyimidesiloxane composite of the present invention has a larger content ratio, the elastic modulus of the polyimidesiloxane composite is higher. Is greatly reduced. The content of polysiloxane is preferably 5% by weight or more. However, if it exceeds 80% by weight, the heat resistance decreases, which is not preferable.

Next, a method for producing the polyimidesiloxane composite of the present invention will be described. The precursor solution of the polyimidesiloxane composite synthesized by the above-mentioned method, as it is,
The coating solution is prepared by a method such as dilution, concentration, and replacement with another solvent. This coating solution is applied onto the substrate by a known method such as spin coating, dipping, printing, or dispensing to form a coating film. The coating film is heated at 200 to 500 ° C., preferably 30 ° C., using a heating means such as an electric furnace, a hot plate, and far infrared rays.
The polyimidesiloxane composite of the present invention can be obtained by heating at 0 to 450 ° C for about 0.5 to 10 hours.

The coating film of the polyimidesiloxane composite of the present invention thus obtained is uniform and has a low elastic modulus, so that it is flexible and has excellent heat resistance. As such, parts such as electronic equipment, communication equipment, heavy electric equipment, and transportation equipment are conceivable. More specifically, various protective films for semiconductors, flattening films, buffer coating materials, insulating films, liquid crystal alignment films, color filter substrates, their protective films, thermal head parts, coupling agents, adhesives, and reinforcing agents. , And impregnants for various fiber molded products.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 As the diamine represented by the general formula (IV), 4 '-(dimethylethoxysilyl) -3,5-
0.66 g (2 mmol) of diaminobenzanilide and 3.60 g (18 mmol) of bis (4-aminophenyl) ether as another coexisting amine were added to N, N under a nitrogen stream.
-Dimethylacetamide (hereinafter abbreviated as DMAc) 8
Dissolve in 0 ml, add 4.36 g (20 mmol) of pyromellitic dianhydride while stirring with a mechanical stirrer, and stir at room temperature for 8 hours to give 10% by weight of polyamic acid D
A MAc solution was obtained. 10.0 g of this solution was taken, and water 1.
0 ml was added and stirred at room temperature until uniform, 1.18 ml of methyltriethoxysilane as an alkoxysilane represented by the general formula (II) was further added, and stirred at room temperature to obtain a precursor solution of a polyimidesiloxane complex. It was This solution was cast on a glass plate and dried in a dryer at 60 ° C. overnight to form a film. This film was further heat-treated under reduced pressure at 100 ° C. for 1 hour, 200 ° C. for 1 hour, and 300 ° C. for 1 hour to obtain a polyimidesiloxane composite film of the present invention.

The film thus obtained was tested by the following method. (Tensile test) Based on ASTM D882-64T, the strength, elongation, and elastic modulus were measured by a Tensilon UTM-11-20 type tension tester manufactured by Toyo Baldwin. The results are shown in Table 2.

(Thermal properties) The thermal decomposition starting temperature (hereinafter abbreviated as T _d ) and the temperature at 10% weight reduction (hereinafter abbreviated as T ₁₀ ) were measured by a Shimadzu TGA-40M type heat distribution device. The results are shown in Table 2.

(Examples 2 to 6) Polyimide siloxane of the present invention was prepared in the same manner as in Example 1 except that the kind and addition amount of the alkoxysilane represented by the general formula (II) were changed as shown in Table 1. Composite films were obtained and subjected to tensile tests and thermal property measurements. The results are shown in Table 2.

Comparative Example 1 Bis (4-aminophenyl)
A polyamic acid was synthesized from 4.00 g (20 mmol) of ether and 4.36 g (20 mm 0 l) of pyromellitic dianhydride in the same manner as in Example 1 to prepare a polyimide film. The tensile test and the measurement of thermal properties were conducted in the same manner, and the results are shown in Table 2.

Comparative Example 2 Bis (4-aminophenyl)
1.97 g (9.9 mmol) ether, general formula (III)
A diaminosiloxane (m = 9.92) represented by 3.5
A polyamic acid was synthesized from 9 g (4.2 mmol) and 3.07 g (14.1 mmol) of pyromellitic dianhydride in the same manner as in Example 1 to prepare a polyimide film. The tensile test and the measurement of thermal properties were conducted in the same manner, and the results are shown in Table 2.

[0024]

[Table 1]

[0025]

[Table 2]

From the results of the tensile test and the thermal test shown in Table 2, it is apparent that the polyimidesiloxane composite of the present invention maintains good heat resistance and has a low elastic modulus.

[0027]

Industrial Applicability The polyimidesiloxane composite of the present invention has been successfully produced in a low elastic modulus without lowering the heat resistance, which is the most excellent characteristic of polyimide, in its production method. The meaning is great.

Claims (3)

[Claims] 1. A compound represented by the general formula (I): In an organic solvent solution containing a polyamic acid having a structural unit represented by the formula (II) A low-modulus polyimide siloxane composite obtained by adding one or more alkoxysilanes represented by the formula (1) and allowing them to condense at the same time as hydrolysis, coating the resulting solution on a substrate, and then baking. (However, general formulas (I) and (II)
R ¹ is a tetravalent organic group, R ² is independently a methyl group, an ethyl group or a phenyl group, R ³ is independently an alkyl group having 8 or less carbon atoms, and R ⁴ is independently a methyl group. , Trifluoromethyl group or trimethylsilyl group, m ¹ is 0, ¹ , 2 or 3, m ² is 0, 1, ² , 3
Or 4, n is 0, 1 or 2, and p is 1 or 2.) 2. General formula (II): In the alkoxysilane represented by, the dialkoxysilane with p = 2 is 40 to 100 of the total alkoxysilane.
%, The low elastic modulus polyimide siloxane composite according to claim 1. (However, in the general formula (II), R
² independently represents a methyl group, an ethyl group or a phenyl group, R ³ independently represents an alkyl group having 8 or less carbon atoms, p
Is 1 or 2). 3. A compound represented by the general formula (I): In a solution of an organic solvent containing a polyamic acid having a structural unit represented by the formula (II): A low-modulus polyimide siloxane composite obtained by adding one or more alkoxysilanes represented by the formula (1) and causing them to condense at the same time as hydrolysis, coating the resulting solution on a substrate, and then baking at a temperature of 200 to 500 ° C. Body manufacturing method. (However, in the general formulas (I) and (II), R ¹ is a tetravalent organic group, R ² independently represents a methyl group, an ethyl group or a phenyl group, and R ³ independently has a carbon number of 8 or less. Represents an alkyl group, R ⁴ independently represents a methyl group, a trifluoromethyl group or a trimethylsilyl group, and m ¹ represents 0, 1,
2 or 3, m ² is 0, 1, ² , 3 or 4, n is 0,
1 or 2, p is 1 or 2.)