JP2003261823A - Method for producing coating fluid for forming porous film and the coating fluid, a method for producing porous film and porous film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating fluid for forming a porous film and a method for producing the coating fluid capable of producing a uniform porous film at an nano level which excels in heat resistance, mechanical strength, permittivity, elasticity, and flexibility and can be used for semiconductor materials such as an interlaminar insulating film and, in addition, packages of various electric and electronic components requiring insulating properties and strength, protective films and the like. <P>SOLUTION: The method for producing a coating fluid for forming a porous film comprises further adding water and an acidic catalyst to a mixed solution containing (A) an alkoxysilane and/or its partial hydrolysis condensate, (B) a polyamic acid, and an amide based solvent to prepare a reaction solution, then adding (D) a glycol polymer having a constituting unit to be represented by the formula: -CH<SB>2</SB>CH<SB>2</SB>O and, simultaneously, a number average molecular weight of 1,000-5,000 to the reaction solution to mix them. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a coating liquid for forming a porous film used as a package for various electrical and electronic materials, a protective film, etc., as well as a semiconductor material such as an interlayer insulating film, and the coating. The present invention relates to a liquid, a method for producing a porous membrane, a porous membrane and its use.

[0002]

BACKGROUND OF THE INVENTION Conventionally, a porous material obtained from a polysiloxane compound is excellent in heat resistance, and further, a porous material obtained from polysiloxane having a structure partially substituted with an organic group. The material is used in applications requiring insulation due to its low dielectric constant.

However, a porous film obtained from such a polysiloxane has a low dielectric constant, but its mechanical strength is significantly lowered, so that it has characteristics that combine low dielectric constant and high mechanical strength. It was wanted. Therefore, in order to solve such a problem, an attempt has been made to supplement the mechanical strength of the porous film by compositing polysiloxane and an organic compound and producing a porous film from the composite.
As a result, a porous film obtained from a composite of polysiloxane and polyimide having heat resistance equivalent to that of polysiloxane is formed by porosity of polysiloxane while maintaining the heat resistance and low dielectric constant of polysiloxane. It was expected to prevent the deterioration of mechanical strength. In this case, the composition of the porous film needs to be a composition mainly composed of polysiloxane, which is generally stronger than polyimide.

However, the higher the polysiloxane content ratio, the more difficult it becomes to form a composite of polysiloxane and polyimide. On the other hand, from the viewpoint of mechanical strength of the porous film, the content ratio of polysiloxane is 50 when all the precursors are polysiloxane or polyimide.
It is necessary to control the amount to be not less than wt%, but it was difficult to obtain a uniform porous film from the polysiloxane-polyimide composite obtained under such conditions. Further, even if the porous film obtained from such a composite has a homogeneity at a macro level such that phase separation is not observed by an optical microscope, the mechanical strength of the composite is improved. Was not recognized.

Therefore, in order to obtain the effect as a composite, that is, a porous film having a low dielectric constant, excellent heat resistance and mechanical strength, a transmission electron microscope (TEM) is used.
It was considered necessary to have nano-level homogeneity such that phase separation was not observed by.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, and is excellent in heat resistance, mechanical strength, low dielectric constant, elasticity, and flexibility, and has interlayer insulation. A method for producing a coating solution for forming a porous film capable of producing a porous film that can be used for a package of various electric / electronic materials, a protective film, etc., in addition to a semiconductor material such as a film, the coating solution, and a porous film The present invention provides a method for producing a porous membrane, a porous membrane having so-called nano-level uniformity, and its use.

[0007]

SUMMARY OF THE INVENTION The method for producing a coating liquid for forming a porous film according to the present invention comprises (A) an alkoxysilane represented by the following general formula [I], and / or a partial hydrolyzed condensate thereof, and (B) A reaction solution is prepared by adding water and an acidic catalyst to a mixed solution containing a polyamic acid and an (C) amide solvent, and then (D) -CH ₂ CH ₂ O-.
And has a number average molecular weight of 1
It is characterized in that a glycol-based polymer of 000 to 5000 is added and mixed.

[0008]

[Chemical 4]

(In the formula [I], n = 1 to 4 is an integer,
R ¹ and R ² are each independently a hydrogen atom or a carbon number of 1 to
When 10 represents an alkyl group or a phenyl group and a plurality of R ¹ or R ² are present, R ^{1 s} or R ^{2 s} may be the same or different from each other. ) The (B) polyamic acid has a unit represented by the following general formula [II], and optionally one or two polyamic acids which may have a terminal group represented by the following general formula [III]. It is preferable to contain at least one species.

[0010]

[Chemical 5]

(In the formula [II], m represents an integer of 10 to 50, R ³ represents a tetravalent organic group, and R ⁴ represents a divalent organic group.)

[0012]

[Chemical 6]

(In the formula [III], R ⁵ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group, and a plurality of R ^{5 s} may be the same or different from each other. ) In the mixed solution, assuming that all of the component (A) is polysiloxane and all of the polyamic acid (B) is polyimide, the total amount of the polysiloxane and the polyimide is 100% by weight. It is preferable that the mixed solution contains the component (A) and the polyamic acid (B) such that the amount of polysiloxane is 50% by weight or more.

The coating solution for forming a porous film according to the present invention is characterized by being manufactured by the above method. The method for producing a porous film according to the present invention is characterized in that the above-mentioned coating liquid for forming a porous film is applied to a substrate and then baked at a temperature of 400 to 450 ° C. The porous film according to the present invention is characterized by being manufactured by the above-described method for manufacturing a porous film.

The interlayer insulating film according to the present invention is characterized by comprising the above-mentioned porous film.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The method for producing a coating solution for forming a porous film according to the present invention, the coating solution, the method for producing a porous film, the porous film and the use thereof will be specifically described. The method for producing a coating liquid for forming a porous film according to the present invention comprises (A) an alkoxysilane and / or a partial hydrolysis condensate thereof, (B) a polyamic acid, and (C) an amide solvent. This is a method in which water and an acidic catalyst are added to the mixed solution to obtain a reaction solution, and then the (D) glycol-based polymer is further added and mixed.

First, the (A) alkoxysilane and / or its partial hydrolysis-condensation product (hereinafter also referred to as the (A) component) and (B) polyamic acid used in the production of the coating solution for forming a porous film of the present invention. The acid and (D) glycol-based polymer will be described. The (C) amide solvent will be described later. (A) Alkoxysilane and / or partial hydrolysis thereof
Decondensate The alkoxysilane used in the present invention is represented by the following general formula [I].

[0018]

[Chemical 7]

(In the formula [I], n is an integer of 1 to 4,
R ¹ and R ² are each independently a hydrogen atom or a carbon number of 1 to
10 represents an alkyl group or a phenyl group, R ¹ or R ²
When a plurality of R ^1's are present, R ^1's or R ^2's may be the same or different. In the present invention, the alkoxysilane represented by the general formula [I] can be used alone or in combination of two or more. When two or more kinds of alkoxysilane are used, it is preferable to use at least one kind of alkoxysilane having a group represented by R ¹ in the above general formula [I]. Since the polysiloxane obtained from such an alkoxysilane contains a group represented by R ¹ in the molecule, the porous film formed from the composite of polysiloxane and polyimide has a low dielectric constant.

The alkoxysilane is not particularly limited, but tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane. , Phenyltrimethoxysilane, diphenyldimethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, decyltrimethoxysilane, and the like. As the alkoxysilane in the present invention, these can be used alone or in combination of two or more.

The partially hydrolyzed condensate of alkoxysilane used in the present invention refers to a condensate obtained by partially hydrolyzing the above-mentioned alkoxysilanes and mutually dehydrating and condensing. Such a partially hydrolyzed condensate of alkoxysilane is prepared by adding and mixing water and, if necessary, a predetermined amount of an acidic catalyst to the above alkoxysilane. After the addition, by mixing for a predetermined time, a mixture of alkoxysilane and its partial hydrolysis-condensation or a partial hydrolysis-condensation product of alkoxysilane is obtained. When it is obtained as a mixture of alkoxysilane and its partial hydrolysis-condensation product, the mixing ratio thereof is not particularly limited.

The acidic catalyst is not particularly limited,
Any solution may be used as long as it exhibits acidity in the state of an aqueous solution, and examples thereof include hydrochloric acid, hydrobromic acid, nitric acid, sulfuric acid and the like. The alkoxysilane may contain a part of the alkoxysilane which is partially hydrolyzed and condensed during storage. (B) Polyamic Acid Polyamic acid (B), which is a precursor of the polyimide used in the present invention, has a unit represented by the following general formula [II] and, if necessary, a terminal group represented by the following general formula [III]. The polyamic acid which may have 1 or 2 or more types is contained.

[0023]

[Chemical 8]

(In the formula [II], m represents an integer of 10 to 50, R ³ represents a tetravalent organic group, and R ⁴ represents a divalent organic group.)

[0025]

[Chemical 9]

(In the formula [III], R ⁵ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group, and a plurality of R ^{5 s} may be the same or different.) Examples of the tetravalent organic group represented by R ³ in the above formula [II] include organic groups represented by the following formula [IV].

[0027]

[Chemical 10]

Further, 2 represented by R ⁴ in the above formula [II]
Examples of the valent organic group include organic groups represented by the following formula [V].

[0029]

[Chemical 11]

The above organic groups represented by R ³ and R ⁴ may be contained in one molecule of the polyamic acid in one kind or in two kinds or more, and any combination thereof may be used. Examples of the polyamic acid having a terminal group represented by the above general formula [III] (hereinafter, also referred to as a terminal modified polyamic acid) include one terminal or both terminal modified polyamic acids. As the polyamic acid (B) used in the present invention, it is preferable to use a terminal-modified polyamic acid, more preferably a both-terminal-modified polyamic acid. As a result, a porous film having particularly excellent mechanical strength is formed.

In the present invention, such a polyamic acid (B) is specifically used as an amide solvent solution of the polyamic acid (B). Examples of the amide-based solvent include N, N-dimethylformamide, N, N
-Diethylformamide, N, N-dimethylacetamide, N-methylformamide, N-methylacetamide, N-methylpropionamide, ε-caprolactam, formamide, acetamide and the like.

A method for producing such a polyamic acid (B) will be described later. (D) Glycol-based polymer The glycol-based polymer (D) used in the present invention is -C.
H is a ₂ CH ₂ O- in the polymer having the structural unit represented by a number average molecular weight of, 400 to 10,000, preferably 1,0
00 to 5,000 is preferable. By using such a glycol-based polymer (D), miscibility between the glycol-based polymer (D) and the polysiloxane-polyamic acid composite in the coating liquid can be improved. Furthermore, the film formed from the polysiloxane-polyimide composite can be made porous by itself thermally decomposing.

The glycol-based polymer (D) is
It may be a random copolymer, a block copolymer or a graft copolymer formed from a structural unit represented by —CH ₂ CH ₂ O— and another alkylene oxide unit. Furthermore, it is preferable that this glycol-based polymer (D) has a hydroxyl group at at least one terminal.

Since the glycol-based polymer (D) has a hydroxyl group, a dealcohol reaction occurs between the hydroxyl group and the alkoxide group remaining in the polysiloxane, resulting in a polysiloxane-glycol-based polymer. It is considered that a composite of the polymer (D) is formed and the miscibility with the polysiloxane-polyamic acid composite is improved. Also,
The glycol polymer (D) has —CH ₂ as a constitutional unit.
Since it has a structural unit represented by CH ₂ O-, a hydrogen bond is generated between the structural unit and the polysiloxane or polyamic acid, which improves the miscibility with the polysiloxane-polyamic acid complex. Conceivable.

Specific examples of the glycol-based polymer (D) include polyethylene glycol, ethylene oxide / propylene oxide copolymer, polyethylene glycol ether, polyethylene glycol ester, polyethylene glycol dimethyl ether and the like. Glycol-based polymer (D) used in the present invention
Can be used alone or in combination of two or more.

Method for Producing Coating Solution for Forming Porous Film The method for producing a coating solution for forming a porous film according to the present invention comprises the above alkoxysilane and / or its partial hydrolysis-condensation product (A) and the above polyamic acid ( B) and the amide-based solvent (C) are mixed to obtain a mixed solution, and then water and an acidic catalyst are further added to the mixed solution to prepare a reaction solution. It is a method of adding the glycol polymer (D).

First, a method for producing the above mixed solution will be described. In order to produce the above mixed solution, first, the component (A) and the polyamic acid (B) are added in an amide solvent.
And are mixed evenly. Specifically, the component (A) and the amide solvent (c-1) are added to and mixed with the amide solvent solution of the polyamic acid (B) to obtain a mixed solution.
The component (A) and the amide solvent (c-1) may be added separately or after mixing.

The addition amount of the amide solvent solution of the component (A) and the polyamic acid (B) is calculated on the assumption that the alkoxysilane is all changed to polysiloxane and the polyamic acid (B) is changed to all polyimide. . When the component (A) contains a partial hydrolysis-condensation product of an alkoxysilane, it is calculated from the amount of the alkoxysilane that is the raw material.

Specifically, all of the alkoxysilanes represented by the following general formula [I] are changed to the constitutional unit of polysiloxane represented by the following general formula [VI], and from the constitutional unit,
Suppose a polysiloxane is formed.

[0040]

[Chemical 12]

(In the formulas [I] and [VI], n, R ¹ and R
² is the same as above. Further, it is assumed that all the polyamic acid (B) of the following general formula [II] is changed to a polyimide represented by the following general formula [VII].

[0042]

[Chemical 13]

(In the formulas [II] and [VII], m, R ³ and R ⁴
Is the same as above. In this case, 50% by weight or more, preferably 60 to 90% by weight, of the "polysiloxane" is based on 100% by weight of the total of "polysiloxane" and "polyimide".
Therefore, it is desirable to use an alkoxysilane and an amide solvent solution of polyamic acid (B). When the polyamic acid (B) contains a terminal-modified polyamic acid, all the groups represented by the following general formula [III] at the terminal are changed as shown in the following general formula [VIII]. And calculated as a constitutional unit of polysiloxane.

[0044]

[Chemical 14]

(In the formula [III], R ⁵ is the same as above.) By mixing the component (A) and the polyamic acid (B) under such conditions, excellent mechanical strength can be obtained. A porous film is formed. Further, the polyamic acid (B) is
It is preferable to contain a terminal-modified polyamic acid, and more preferably a both-terminal-modified polyamic acid. As a result, a porous film having particularly excellent mechanical strength is formed.

Further, as the amide solvent (c-1),
The same solvent as the amide-based solvent used for the synthesis of the polyamic acid (B) can be used alone or in combination of two or more. This added amide solvent (c-
1) may be the same as the amide solvent contained in the polyamic acid (B) solution, or may be a different amide solvent.

In the mixed solution thus obtained,
The amide solvent (C) (total of the amide solvent in the amide solvent solution of the polyamic acid (B) and the amide solvent (c-1)) is 20% by weight based on 100% by weight of the mixed solution.
Or more, preferably 30% by weight or more, more preferably 3
It is preferably contained in an amount of 0 to 80% by weight. If the amount of the amide solvent (C) is less than 20% by weight, the polyamic acid (B) cannot be mixed with the alkoxysilane or its partially hydrolyzed condensate.

Next, water and an acidic catalyst are added to the mixed solution obtained as described above. This acidic catalyst can be added by mixing with water, or can be added separately from water. The amount of water added to this mixed solution is 4 to 1 with respect to 1 mol of the alkoxyl group of the alkoxysilane.
The amount is 0 times mol, preferably 6 to 8 times mol. That is, when the component (A) contains a “partially hydrolyzed condensate of alkoxysilane”, the water used for producing the condensate is added to the amount of water added to the mixed solution. Calculated. Further, when the above-mentioned acidic catalyst is used as an aqueous solution, the amount of water contained therein is also added.

When the amount of water is less than 4 times the molar amount, phase separation of polysiloxane and polyimide tends to occur in the resulting porous film. When the amount of water is more than 10 times the molar amount, the polyamic acid tends to precipitate in the mixed solution of the component (A) and the polyamic acid (B). The method of adding water is not particularly limited, and may be added at once or may be added twice or more. Also, the dropping speed is not particularly limited.

The acidic catalyst is not particularly limited,
Any substance that exhibits acidity in an aqueous solution state may be used, for example,
Examples thereof include hydrochloric acid, hydrobromic acid, nitric acid, sulfuric acid and the like. The amount of addition is such that the reaction solution after mixing has a pH of 2.4 to 3.0 and is added dropwise. Further, the dropping speed is not particularly limited. Thus, by adding water and an acidic catalyst to the mixed solution, the alkoxysilane is gradually hydrolyzed and then dehydrated and condensed as shown in the following reaction formula [IX]. It is considered that polysiloxane is formed by repeating such a reaction and polymerizing.

[0051]

[Chemical 15]

As the polyamic acid (B), it is preferable to use an end-modified polyamic acid. Since such a terminal-modified polyamic acid has a group represented by the above general formula [III] at its terminal, the group represented by the general formula [III] is hydrolyzed by addition of water and an acidic catalyst, It becomes a silanol group. On the other hand, silanol groups remain in the stage where the component (A) forms polysiloxane. Therefore, it is considered that the silanol groups of the end-modified polyamic acid are dehydrated and condensed with each other, and the silanol groups of the polysiloxane and the silanol groups of the end-modified polyamic acid are dehydrated and condensed to form a stronger porous film. .

Further, as the end-modified polyamic acid, both-end-modified polyamic acid is more preferable. Since the polyamic acid modified at both ends has silanol groups at both ends, a particularly strong porous film can be formed. After adding water and an acidic catalyst to the above mixed solution, hydrolysis and dehydration condensation of the alkoxyl groups in this mixed solution proceed, and the pH rises slightly. pH measurement
It is carried out under the temperature condition of 25 ± 1 ° C. using the same pH meter after three-point calibration.

Further, stirring is continued, and the change in the pH value of the mixed solution after 24 hours is within ± 0.5 is used as the reaction solution. Next, the glycol polymer (D) is added to and mixed with the above reaction solution to obtain a coating solution for forming a porous film. This glycol-based polymer (D) is further
You may use together with another thermally decomposable polymer. Other thermally decomposable polymers include polystyrene, polyvinyl alcohol,
Examples thereof include polyethylene, polypropylene, polyacrylic acid, saccharides and the like.

To improve the miscibility of the glycol polymer (D) with the polysiloxane-polyamic acid complex in the coating solution by adding the glycol polymer (D) to the above reaction solution. You can Further, the effect of making the film formed from the polysiloxane-polyimide composite porous is obtained. Such an effect is obtained because the glycol-based polymer (D) and the polysiloxane-polyamic acid complex have excellent affinity at the molecular level, and the glycol-based polymer (D ) Is uniformly dispersed.

The affinity at the molecular level is specifically represented by the hydroxyl group present at the terminal of the glycol polymer (D) and the general formula [III] remaining in the polysiloxane-polyamic acid complex. A dealcoholization reaction with a group, a hydrogen bond between a hydroxyl group present at the end of a glycol-based polymer (D) and a polysiloxane-polyamic acid complex, and -CH ₂ which is a constituent unit of the glycol-based polymer (D).
And CH ₂ O-hydrogen bond with the polysiloxane or polyamic acid, and amide solvents, hydrogen bonding, etc. between the polysiloxane or polyamic acid is considered to be due to are partially caused.

As described above, in the glycol-based polymer (D), assuming that all of the component (A) is polysiloxane and all of the polyamic acid (B) is polyimide, polyimide and polysiloxane are combined. It is desirable to use 0.1 to 2 times, preferably 0.5 to 1 times the total weight. By adding the glycol-based polymer (D) in such an amount, a porous film having nano-level uniformity can be obtained. The homogeneity at the nano level means that substantially no phase separation is observed when the surface of the porous film is observed by a transmission electron microscope (TEM).

Further, the coating solution for forming a porous film of the present invention may further contain a filler, if necessary, as other components.
A pigment, a conductive material, etc. can be added. In this way, the coating liquid for forming a porous film according to the present invention is manufactured. Here, a method for producing the polyamic acid (B) used for producing the coating liquid for forming a porous film according to the present invention will be described.

Method for Producing Polyamic Acid (B) The polyamic acid (B) used in the present invention contains a polyamic acid having a unit represented by the following general formula [II]. Such a polyamic acid is It is synthesized as follows.

[0060]

[Chemical 16]

(In the formula [II], m represents an integer of 10 to 50, R ³ represents a tetravalent organic group, and R ⁴ represents a divalent organic group.) Such a polyamic acid is It is synthesized by a polycondensation reaction of a tetracarboxylic dianhydride and a diamine compound in an organic solvent. Specifically, either an tetracarboxylic dianhydride or a diamine compound is dissolved in an organic solvent under an inert atmosphere such as nitrogen. After completely dissolving, the other compound is added and stirred for 1 to 24 hours.

The tetracarboxylic acid dianhydride used in the synthesis of this polyamic acid is, for example, 3,3 ′,
4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3', 4,4
4′-biphenyltetracarboxylic dianhydride, ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanecarboxylic dianhydride, pyromellitic dianhydride, 2,2 ′, 3,3 '-Benzophenonetetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-
Dicarboxyphenyl) propane dianhydride, bis (3,3
4-dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride,
Bis (3,4-dicarboxyphenyl sulfone) dianhydride, bis (2,3-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 4,4 ′-(p-phenylenedioxy) diphthalic acid dianhydride, 4,4 ′-(m-phenylenedioxy) diphthalic acid dianhydride, 2, 3, 6, 7-
Naphthalenetetracarboxylic dianhydride, 1,4,5,8
-Naphthalenetetracarboxylic dianhydride, 1,2,5
6, -naphthalenetetracarboxylic dianhydride, 1,2,
3,4-benzenetetracarboxylic dianhydride, 3,4
9,10-perylenetetracarboxylic dianhydride, 2,
3,6,7-anthracene tetracarboxylic dianhydride,
1,2,7,8-phenanthrene tetracarboxylic acid dianhydride and the like can be mentioned. These can be used alone or in combination of two or more.

As the diamine compound used for the synthesis of polyamic acid, for example, 1,3-bis (3-
Aminophenoxy) benzene, 4,4'-bis (3-aminophenoxy) biphenyl, 3,3'-diaminobenzophenone, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p- Aminobenzylamine, bis (3-aminophenyl) sulfide, (3-aminophenyl) (4
-Aminophenyl) sulfide, bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfoxide, (3-aminophenyl) (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfone, (3-aminophenyl) ) (4-Aminophenyl) sulfone, bis (4 aminophenyl) sulfone, 3,4 ′
-Diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,
4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-
Diaminodiphenyl ether, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4-
(3-Aminophenoxy) phenyl] ethane, 1,1-
Bis [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane,
2,2-bis [4- (3-aminophenoxy) phenyl] butane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane , 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,4 -Bis (3-aminophenoxy)
Benzene, 1,4'-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4 -Aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfoxide, Bis [4- (aminophenoxy) phenyl] sulfoxide, bis [4-
(3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone,
Bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1,4-bis [4- (3-aminophenoxy)
Benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 4,4′-bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [3- (3-Aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4
-Amino-α, α-dimethylbenzyl) phenoxy] diphenyl sulfone, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) -α , -Dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene and the like. These can be used alone or in combination of two or more.

Thus, the ratio of the tetracarboxylic acid dianhydride and the diamine compound used for the polyamic acid synthesis reaction is such that the tetracarboxylic acid dianhydride is used in an amount of 1 mol of the amino group in the diamine compound. The acid anhydride group of is preferably 0.5 to 2 mol, more preferably 0.8 to
It is preferably used in an amount of 1.2 mol. The synthesis reaction of the polyamic acid (B) is usually carried out in an amide-based solvent under temperature conditions of 10 to 70 ° C, preferably 20 to 40 ° C.

As the organic solvent used in the synthesis reaction of polyamic acid, it is preferable to use an amide solvent, for example, N, N-dimethylformamide, N, N.
-Diethylformamide, N, N-dimethylacetamide, N-methylformamide, N-methylacetamide, N-methylpropionamide, ε-caprolactam, formamide, acetamide and the like. These can be used alone or in combination of two or more.

The amide-based solvent has a high solubility in both the tetracarboxylic dianhydride and the diamine compound and has a high boiling point. Therefore, when the solution temperature rises due to the heat of dissolution and the heat of reaction during the synthesis. However, the solid content concentration hardly changes due to the evaporation of the solvent, and precipitation of the raw materials and the reaction product is unlikely to occur, which is preferable. As described above, by polycondensing the tetracarboxylic dianhydride and the diamine compound, an amide solvent solution of polyamic acid is obtained.

Further, the polyamic acid (B) used in the present invention contains, if necessary, an end-modified polyamic acid having a terminal group represented by the following general formula [III] at the end of the above polyamic acid. Good.

[0068]

[Chemical 17]

(In the formula [III], R ⁵ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group, and a plurality of R ^{5 s} may be the same or different.) Such end-modified polyamic acid has, at its end,
Since it has a group represented by the general formula [III], the affinity with the polysiloxane and the glycol polymer (D) is improved.

The method for synthesizing such a terminal-modified polyamic acid is not particularly limited.
A silane coupling agent is added to the amide solvent solution of the polyamic acid obtained above, and the mixture is stirred. Thereby, the silane coupling agent reacts with the polyamic acid terminal, and the group represented by the above general formula [III] can be introduced into the terminal.

The silane coupling agent is X to Si.
A compound represented by the chemical formula (OR ⁵ ) ₃ and having two or more different functional groups in the molecule. Of these, X is an organic group containing a functional group such as an amino group, a glycidyl group, an epoxy group, and a succinic anhydride group, and another OR ⁵ is a hydrolyzable group. This R ⁵ is the same as above.

Since X of the silane coupling agent is the organic functional group as described above, the polyamic acid terminal amic acid group (that is, the free carboxyl group and the amide formed from the tetracarboxylic dianhydride and the diamine compound). It is possible to introduce a group represented by the above general formula [III] at the end of the polyamic acid by reacting with a group). Examples of such silane coupling agents include trialkoxysilanes having an amino group such as 3-aminopropyltriethoxysilane and N- (2-aminoethyl) 3-aminopropyltrimethoxysilane; 3-glycidoxypropyl Trialkoxysilanes having glycidyl groups such as trimethoxysilane and 3-glycidoxypropyltriethoxysilane; trialkoxysilanes having epoxy groups such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; 3- ( Examples thereof include trialkoxysilane having a succinic anhydride group such as triethoxysilyl) propylsuccinic anhydride.

The above silane coupling agent is preferably used in an amount of 0.1 to 2 mol, and more preferably 0.5 to 2 mol, based on 1 mol of polyamic acid. In order to produce a single-end substituted type or both-end substituted type polyamic acid, the reaction rate varies depending on the type of the polyamic acid and the silane coupling agent, so the addition amount of these is not particularly limited.

As described above, a coupling agent is added to an amide-based solvent solution of polyamic acid, and the mixture is stirred to produce a terminal-substituted polyamic acid having a group represented by the above general formula [III] introduced at its terminal. An amide solvent solution of the acid is obtained. In the present invention, the end-substituted polyamic acid is preferably a both-end substituted polyamic acid, which further improves the affinity with the polysiloxane and the glycol-based polymer (D).

Method for Producing Porous Membrane The method for producing a porous membrane according to the present invention is one in which the above coating solution for forming a porous membrane is applied to a substrate and then baked.
Examples of the method of applying the coating liquid to the base material include general methods such as spin coating, casting, and dip coating. In the case of spin coating method,
Place the substrate on the spinner, drop the sample on the substrate, and
Rotate at 00-10,000 rpm.

As the above-mentioned base material, any base material can be used as long as it is generally used. For example, glass,
Quartz, a silicon wafer, stainless steel, etc. are mentioned.
Further, it may have any shape such as a plate shape and a dish shape. The coating is applied as described above and then baked, and the temperature is preferably 400 to 450 ° C, and more preferably 420 to 450 ° C. The firing atmosphere is not particularly limited. By firing at a temperature in this range, the polyamic acid undergoes dehydration ring closure as in the following reaction formula to become a polyimide as shown in the following general formula [VII], forming a polysiloxane-polyimide composite, and The glycol-based polymer (D) is removed to obtain the porous membrane of the present invention.

[0077]

[Chemical 18]

If the baking temperature is lower than 400 ° C., the glycol polymer (D) is not removed and the coating film does not become porous, so that the porous film of the present invention cannot have a low dielectric constant. Further, in the range exceeding 450 ° C., in the case of polysiloxane containing an organic group, the organic group is separated, and the effect of lowering the dielectric constant due to the inclusion of the organic group is lost. The porous membrane of the present invention can be obtained in a state of being fixed to the above base material or in a state of being peeled from the base material.

Porous Membrane and Uses Thereof When the surface of the porous membrane of the present invention thus obtained is observed by a transmission electron microscope (TEM), substantially no phase separation is observed, and the nano-level is obtained. It has uniformity in. Therefore, it has excellent properties such as heat resistance, mechanical strength, low dielectric constant, elasticity, and flexibility, and is used for semiconductor materials such as interlayer insulating films, as well as packages for various electrical and electronic materials, protective films, etc. In particular, it is preferably used as an interlayer insulating film.

The film thickness of the porous film according to the present invention is not particularly limited because the preferred range varies depending on the application. For example, when a porous silica film is used for the interlayer insulating film, the film thickness is 0.01 to 1.0 μm.
m, preferably 0.1 to 0.5 μm.

[0081]

According to the coating solution for forming a porous film and the method for producing the coating solution of the present invention, it is possible to provide a coating solution for forming a porous film capable of producing a porous film that is uniform at the nano level. You can Furthermore, the porous film of the present invention produced by using the above coating solution is excellent in heat resistance, mechanical strength, low dielectric constant, elasticity, and flexibility, and has insulation properties other than semiconductor materials such as an interlayer insulating film. It can be used for various electrical / electronic material packages, protective films, etc. that require high strength.

[0082]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The porous membranes obtained in the following examples and comparative examples were evaluated as follows. Unless otherwise specified, "part" means "part by weight".

<Observation of Appearance> The porous film was visually observed, and its transparency and surface uniformity were evaluated according to the following evaluation criteria. Evaluation Criteria ◯: Transparent and its surface is uniform.

X: White turbidity or unevenness is recognized on the surface. <Film Thickness> A part of the film was completely peeled off to expose the substrate on the film surface. Then, the step difference between the substrate surface and the film was measured by a surface shape measuring device (manufactured by Nippon Vacuum Technology Co., Ltd., model DEKTAK3030) to obtain the film thickness.

<Surface Uniformity (Macro Level)> The surface of the obtained porous film was observed with an optical microscope (× 2500). The surface uniformity (macro level) was evaluated as follows. Evaluation Criteria ◯: Transparent and no phase separation is observed.

X: Any of the above is observed. <Surface Uniformity (Nano Level)> After embedding the film in epoxy resin, the film was cleaved, and the cross section was observed by TEM (× 400,000 times). The surface uniformity (nano level) was evaluated as follows. Evaluation Criteria: Phase separation is not observed.

X: Phase separation is observed. <Relative permittivity> After forming an aluminum electrode having a thickness of about 0.2 μm on the back surface of the substrate having the porous film formed thereon, an aluminum electrode having a diameter of about 1 mmφ is formed on the porous film by the sputtering method. A sample for evaluation of relative permittivity was prepared. In order to obtain the relative permittivity εr, the electrode formed on the insulating film was measured by using a 4284A precision LCR meter (manufactured by HP)-
It measured by the CV method which measures the capacitor C, applying a voltage of 40V- + 40V. The relative permittivity εr is C = ε
_It was calculated by ₀ ε _r S / d.

<Mechanical Strength> The hardness and elastic modulus of the porous film were measured by the nanoindentation method.

[0089]

[Production Example 1] Synthesis of polyamic acid 250 g of dimethylacetamide (hereinafter, also referred to as DNAc) and 14.4 g of pyromellitic dianhydride were put in a well-dried 500 ml separa flask, and transparent and uniform under a nitrogen atmosphere. Stir until a good solution is obtained. Thereafter, 13.7 g of 4,4-oxydianiline is added along with 14.8 g of dimethylacetamide. Further, the mixture was stirred at room temperature under a nitrogen atmosphere for 5 hours to obtain a reaction solution containing unmodified polyamic acid at the end.

Next, 1.4 g of 3- (triethoxysilyl) propylsuccinic anhydride was added to the above reaction solution, and the mixture was further stirred overnight. A polyamic acid solution having a solid content of 10 wt% and containing the end-modified polyamic acid represented by the following general formula [X] was obtained. In addition, it was confirmed by FT-IR and GPC that it was a terminal-modified polyamic acid represented by the general formula [X].

[0091]

[Chemical 19]

In Examples 1 to 4 and Comparative Examples 2 to 5, all the alkoxysilanes became polysiloxanes,
Assuming that the polyamic acid is entirely polyimide, the total of the polysiloxane and the polyimide is 10
The alkoxysilane and the polyamic acid were added so that the amount of polysiloxane was 80 wt% with respect to 0 wt%.

In Examples 1 to 4 and Comparative Examples 1 to 5, all the alkoxysilanes were polysiloxanes,
Assuming that the polyamic acid was entirely polyimide, the total amount of the polysiloxane and the polyimide and the glycol polymer were added in the same amount.

[0094]

Example 1 Each raw material was used so that the composition of the coating liquid would meet the following conditions. Weight ratio; polysiloxane / polyimide / glycol polymer = 8/2/10 Molar ratio; tetraethoxysilane / dimethyldiethoxysilane = 6.5 / 3.5 Water addition amount; 6.7 times the theoretical water addition amount The polyamic acid used in Example 1 (hereinafter, P
Also called AA. ), Alkoxysilane (tetraethoxysilane (hereinafter, also referred to as TEOS), dimethyldiethoxysilane (hereinafter, also referred to as DMDES)), polyethylene glycol (hereinafter also referred to as PEG), and water are added under the above conditions. Was calculated as follows.

<Calculation method> 1) Weight change rate (A) when PAA is polyimidized Weight change rate (A) = (abc) /a=0.90a: General formula [X] The molecular weight of PAA represented by = 1
3,360 b: Molecular weight of water x number of amide bonds in PAA molecule = 18 x 62
= 1116 c: change in molecular weight when the terminal alkoxysilane is silanized = 2 × [(28 + 3 × 45) − (28 + 16 × 1.5)] = 222 2) Weight change rate when the alkoxysilane is polysiloxane (B 2-1) Weight change rate (B1) when DMDES is converted to polysiloxane as in the following formula [A] Weight change rate (B1) = d / e = 0.50 d: (CH ₃ ) ₂ SiO Molecular weight of = 74 e: molecular weight of DMDES = 148

[0096]

[Chemical 20]

2-2) Weight change rate (B2) when TEOS is polysiloxane as shown in the following formula [B] Weight change rate (B2) = f / g = 0.29 f: Molecular weight of SiO ₂ = 60 g: TEOS molecular weight = 148

[0098]

[Chemical 21]

3) Addition amount of each composition Addition amount of DMDES, TEOS, PAA and PEG According to the above condition "molar ratio" and the above formulas [A] and [B], the weight composition ratio of polysiloxane is as follows. Was calculated as (CH ₃ ) ₂ SiO / SiO ₂ = (74 × 3.5) / (60 × 6.5) = 259/390
= 3.2 / 4.8 Therefore, from the above condition “weight ratio”, it can be expressed as (CH ₃ ) ₂ SiO / SiO ₂ /polyimide=3.2/4.8/2.

Converting this into an addition amount, the addition amount ratio of each composition is calculated as follows. DMDES / TEOS / PAA / PEG = [3.2 / weight change rate (B1)] / [4.8 / weight change rate (B2)] / [2 / weight change rate (A)] / 10.0 = 6.4 / 16.6 / 2.2 / 10.0 Based on the addition ratio of each composition, PA of the general formula [X]
The amount of addition of the other compositions when 1.47 parts of A is added is shown below.

Addition amount of TEOS; 16.6 × (1.47 / 2.2) = 11.0 parts Addition amount of DMDES; 6.4 × (1.47 / 2.2) = 4.3 parts Addition amount of PEG is 10.0 × (1.47 / 2.2) = 6.6 parts In the case where the PAA of the general formula [X] is polyimidized, the terminal SiO _1.5 is 1% by weight or less with respect to the entire polyimide, and in this system containing a polysiloxane component as a main component, the amount is very small. Not added to ingredients.

Addition amount of water Addition amount of water = 6.7 × (theoretical addition amount of TEOS water + DM
DES theoretical water addition) -0.5N HCl water content = 6.7 x
(3.8 + 1.0) −8.6 = 23.5 parts Theoretical addition amount of water of TEOS; number of moles of alkoxide group × water Mw = (11.1 / 208) × 4 × 18 = 3.
Theoretical amount of water of 8 parts DMDES; number of moles of alkoxide group x Mw of water = (4.3 / 148) x 2 x 18 = 1.0
Part 0.5N HCl water content; added 8.8 parts 0.5N HCl, 8.8 parts
× 0.975 = 8.6 parts of water is included.

A porous membrane was prepared as follows using DMDES, TEOS, PAA, PEG and water in the above amounts. <Preparation of Porous Membrane> 14.7 parts of the 10 wt% PAA solution obtained in Production Example 1 was further added with 11.0 parts of TEOS and DMDES4.
3 parts and DMAc 37.7 parts were added and stirred for 1 hour to obtain a mixed solution.

Water and 0.5 N HCl were gradually added dropwise to this mixed solution. 0.5N HCl was added dropwise after adjusting the pH of the mixed solution to 2.4. The amount of water added, including the water contained in 0.5N HCl, was added dropwise so as to be 6.7 times the theoretical amount. As a result, the dropping amount of only water was 23.5 parts, and the dropping amount of 0.5N HCl was 8.8 parts. When stirring was continued at room temperature 25-30 ° C, the pH of the mixture was
Was 2.5 after 24 hours, and the pH increased thereafter. Then, it took 5 days for the pH to stabilize at 2.8. In this way, a reaction solution was obtained. When the pH was measured at intervals of 24 hours or more, the difference was within ± 0.2, so it was determined that the pH was stable.

Next, the number average molecular weight of the reaction solution was 2,000.
6.6 parts of PEG of 0 was added and dissolved. In this way
A coating liquid was prepared. The composition of this coating liquid is shown in Table 1.
The solid content concentration of this coating solution was 12.4 wt%. Using the coating solution thus obtained, the specific resistance is about 9Ω · c
Place 5 ml on the surface of an n-type 8-inch silicon wafer of m,
Rotate for about 300 seconds at about 2,000 rotations using a spin coater,
A coating film was formed on the surface of the silicon wafer. Then, this coating film was baked in a vacuum atmosphere at a temperature of 420 ° C. for 1 hour to prepare a porous film formed from a polysiloxane-polyimide composite.

The appearance, surface uniformity (macro level), surface uniformity (nano level), relative dielectric constant, and mechanical strength of this porous film were evaluated according to the above-mentioned methods. The results are shown in Table 1. Further, FIG. 1 shows a cross-sectional photograph when observing the surface uniformity (nano level) of the obtained porous film.

[0107]

Example 2 The solid content concentration of Example 1 was changed to 9.0 wt%. Specifically, the PEG of Example 1 was replaced with 14.5 wt% PEG
A coating solution was prepared in the same manner as in Example 1 except that the solution (solvent: DMAc) was changed to 45.5 parts. The composition of this coating liquid is shown in Table 1. The solid concentration of this coating solution is 9.0 wt%
Met.

Using the coating liquid thus obtained, a porous membrane was prepared in the same manner as in Example 1. The appearance, surface uniformity (macro level), surface uniformity (nano level), relative dielectric constant, and mechanical strength of this porous film were evaluated according to the above-mentioned methods. The results are shown in Table 1.

[0109]

Example 3 A 10 wt% PAA solution (solvent: dimethylformamide) was obtained in the same manner as in Production Example 1 described above except that DMAc was changed to dimethylformamide. This 10wt% P
14.3 parts of AA solution, 10.7 parts of TEOS and DMD
4.1 parts of ES and 34.6 parts of dimethylformamide were added and stirred for 1 hour to obtain a mixed solution.

Water and 0.5N HCl were gradually added dropwise to this mixed solution. 0.5N HCl was added dropwise after adjusting the pH of the mixed solution to 2.5. The amount of water added, including the water contained in 0.5N HCl, was dropped so that the amount was 7.2 times the theoretical amount. In addition, it was calculated that 0.5N HCl contained 97.5 wt% of water. As a result, the drop amount of only water was 22.9 parts, and the drop amount of 0.5N HCl was 11.4 parts.
It was a department.

When stirring was continued at room temperature of 25 to 30 ° C., the pH of the mixed solution was 2.6 after 24 hours, and the pH increased thereafter. Then, it took 5 days for the pH to stabilize at 2.9. In this way, a reaction solution was obtained. When the pH was measured at intervals of 24 hours or more, the difference was within ± 0.2, so it was determined that the pH was stable.

Next, the number average molecular weight of the reaction solution was 2,000.
6.6 parts of PEG of 0 was added and dissolved. In this way
A coating liquid was prepared. The composition of this coating liquid is shown in Table 1.
The solid content concentration of this coating solution was 12.1 wt%. Using the coating liquid thus obtained, a porous membrane was prepared in the same manner as in Example 1.

With respect to this porous film, the appearance was observed, the surface uniformity (macro level), the surface uniformity (nano level), the relative dielectric constant, and the mechanical strength were evaluated according to the above methods. The results are shown in Table 1.

[0114]

Example 4 10 wt% PAA solution 15.2 obtained in Production Example 1 above
Further, 11.4 parts of TEOS, 4.4 parts of DMDES and 38.7 parts of DMAc were added to the parts and stirred for 1 hour to obtain a mixed solution. Water and 0.5 N HCl were gradually added dropwise to this mixed solution. 0.5N HCl was added dropwise after adjusting the pH of the mixed solution to 3.0. The amount of water added, including the water contained in 0.5N HCl, was dropped so that the amount was 6.0 times the theoretical amount. In addition, it was calculated that 0.5N HCl contained 97.5 wt% of water. As a result, the dropping amount of only water was 24.2 parts, and the dropping amount of 0.5N HCl was 6.1 parts.

When stirring was further continued at room temperature of 25 to 30 ° C., the pH of the mixed solution was 3.1 after 24 hours, and the pH increased thereafter. Then, it took 5 days for the pH to stabilize at 3.2. In this way, a reaction solution was obtained. When the pH was measured at intervals of 24 hours or more, the difference was within ± 0.2, so it was determined that the pH was stable.

Next, the reaction solution was mixed with a number average molecular weight of 2,000.
35 wt% PEG solution prepared by dissolving PEG in DMAc for 19.4
A part was added and dissolved. In this way, the coating liquid was prepared. The composition of this coating liquid is shown in Table 1. The solid content concentration of this coating solution was 11.4 wt%. Using the coating liquid thus obtained, a porous membrane was prepared in the same manner as in Example 1.

With respect to this porous film, the appearance was observed, the surface uniformity (macro level), the surface uniformity (nano level), the relative dielectric constant, and the mechanical strength were evaluated according to the above methods. The results are shown in Table 1.

[0118]

Comparative Example 1 A mixed solution of 4.0 parts of DMDES and 10.4 parts of TEOS was mixed with 5.6 parts of water adjusted to pH 1.3 with HCl (DM
(1.2 times mol based on the total mol of the alkoxy groups of DES and TEOS) and 3.2 parts of DMAc were added dropwise. The pH of the mixed solution after the dropping was 2.4.

When stirring was further continued at room temperature of 25 to 30 ° C., the pH of the mixed solution was 2.8 after 24 hours, and the pH did not change thereafter, so that a reaction solution was obtained.
Thus, it took one day for the pH to stabilize at 2.8. Next, PEG with a number average molecular weight of 2,000 was added to this reaction solution.
6.2 parts and 70.6 parts of DMAc were added and dissolved. In this way, the coating liquid was prepared. The composition of this coating liquid is shown in Table 1.

A porous membrane was prepared in the same manner as in Example 1 using the coating liquid thus obtained. The appearance, surface uniformity (macro level), surface uniformity (nano level), relative dielectric constant, and mechanical strength of this porous film were evaluated according to the above-mentioned methods. The results are shown in Table 1.

[0121]

[Comparative Example 2] A mixed solution of 4.0 parts of DMDES and 10.3 parts of TEOS was mixed with 5.6 parts of water adjusted to pH 1.3 with HCl (TEO).
1.2 based on the total moles of S and DMDES alkoxy groups
And a mixed solution of 3.2 parts of DMAc was added dropwise. The pH of the mixed solution after the dropping was 2.4.

After continuing stirring at room temperature of 25 to 30 ° C. for 5 days, 14.0 parts of the 10 wt% PAA solution obtained in the above Production Example was mixed. Further, 6.2 parts of PEG having a number average molecular weight of 2000 and 56.7 parts of DMAc were added and dissolved. In this way, the coating liquid was prepared. The composition of this coating liquid is shown in Table 1. The pH of this coating solution was 2.8. Using the coating liquid thus obtained, a porous membrane was prepared in the same manner as in Example 1.

The appearance, surface uniformity (macro level), surface uniformity (nano level), relative dielectric constant, and mechanical strength of this porous film were evaluated according to the methods described above. The results are shown in Table 1. FIG. 2 shows a cross-sectional photograph when observing the surface uniformity (nano level) of the obtained porous film.

[0124]

Comparative Example 3 In Example 1, the number average molecular weight is 2,000.
A coating solution was prepared in the same manner as in Example 1 except that the PEG of was changed to polypropylene glycol having a number average molecular weight of 2,000. The composition of this coating liquid is shown in Table 1. Using the coating liquid thus obtained, a porous membrane was prepared in the same manner as in Example 1.

When the appearance of this porous film was observed,
It was clouded, and irregularities were confirmed on the surface.
The results are shown in Table 1.

[0126]

Comparative Example 4 DMAc was changed to N-methylpyrrolidone, and a 10 wt% PAA solution (solvent: N-methylpyrrolidone) was obtained in the same manner as in Production Example 1 above. In Example 1, 10 wt% PAA solution (solvent: N-methylpyrrolidone)
Except that the DMAc was changed to N-methylpyrrolidone, and a coating solution was prepared in the same manner as in Example 1. The composition of this coating liquid is shown in Table 1.

Using the coating liquid thus obtained, a porous film was prepared in the same manner as in Example 1. When the appearance of this porous film was observed, it was cloudy and irregularities were confirmed on the surface. The results are shown in Table 1.

[0128]

[Comparative Example 5] In Example 1, the amount of water alone was adjusted to 4.3 so that the amount of water added was 5.8 parts (1.2 times the molar amount based on the total moles of the alkoxy groups of TEOS and DMDES). Parts, a coating liquid was prepared in the same manner as in Example 1 except that the amount of 0.5N HCl added was 1.5 parts. The composition of this coating liquid is shown in Table 1.

Using the coating solution thus obtained, a porous film was prepared in the same manner as in Example 1. When the appearance of this porous film was observed, it was cloudy and irregularities were confirmed on the surface. The results are shown in Table 1.

[0130]

[Table 1]

[Brief description of drawings]

1 is a T of a cross section of a porous membrane obtained in Example 1. FIG.
It is an EM photograph.

FIG. 2 is a T of a cross section of a porous membrane obtained in Comparative Example 2.
It is an EM photograph.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01B 3/30 H01B 3/30 MN H01L 21/312 H01L 21/312 C (72) Inventor Nakamura Setsu Child 580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals Co., Ltd. F-term within the company (reference) 4G072 AA28 BB09 BB15 CC02 EE07 FF06 GG02 GG03 HH30 JJ41 KK01 LL14 LL15 RR05 SS10 4J038 DF011 DF012 DJ021 DJ022 AC4A04A17F04A019F04A04A10F04A019F04A0F17A04F19A04A0F17A04F19A04F04A0F17A04 AG01 AH02 5G305 AA06 AA11 AB10 AB17 AB24 BA09 BA14 BA18 CA13 CA21 CB26 CD07 CD12 DA22

Claims (7)

[Claims] 1. A mixture comprising (A) an alkoxysilane represented by the following general formula [I] and / or a partial hydrolysis-condensation product thereof, (B) a polyamic acid, and (C) an amide solvent. solution, the reaction solution was prepared by further adding water and an acid catalyst and _{then, (D) -CH 2 CH 2} O-
And has a number average molecular weight of 1
A method for producing a coating solution for forming a porous film, which comprises adding and mixing a glycol-based polymer of 000 to 5000. [Chemical 1] (In the formula [I], n = 1 to 4 represents an integer, and R ¹ and R ²
Each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group, and when there are a plurality of R ¹ or R ² , R ^{1 s} or R ^{2 s} may be the same as each other. It may be different. ) 2. A polyamic acid (B) having a unit represented by the following general formula [II] and optionally a terminal group represented by the following general formula [III]. The method for producing a coating solution for forming a porous film according to claim 1, wherein the method comprises one or more types. [Chemical 2] (In the formula [II], m represents an integer of 10 to 50, and R ³ is 4
Represents a divalent organic group, and R ⁴ represents a divalent organic group. ) [Chemical 3] (In the formula [III], R ⁵ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group, and a plurality of R ^{5 s} may be the same or different from each other.) 3. When it is assumed that all of the component (A) is polysiloxane and all of the polyamic acid (B) is polyimide, the total amount of the polysiloxane and the polyimide is 100% by weight. 3. The porous film formation according to claim 1 or 2, which is a mixed solution containing the component (A) and the polyamic acid (B) such that the amount of siloxane is 50% by weight or more. Method for producing coating liquid for use in cosmetics. 4. A coating solution for forming a porous film, which is produced by the method according to claim 1. 5. A method for producing a porous film, which comprises applying the coating solution for forming a porous film according to claim 4 onto a substrate and then firing the substrate at a temperature of 400 to 450 ° C. 6. A porous membrane produced by the method according to claim 5. 7. An interlayer insulating film comprising the porous film according to claim 6.