JP2009269988A - Silicon-containing polyimide and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new silicon-containing polyimide capable of introducing silicon atoms into a molecule in an optional amount, and excellent in transparency, optical characteristics, adhesion to a silicon substrate and mechanical properties such as expansion coefficient and elastic modulus, while maintaining characteristics peculiar to polyimide such as heat resistance, chemical resistance, electrical insulation and mechanical strength, and to provide a film containing the silicon-containing polyimide and a silicon-containing polyamide acid as a precursor of the new silicon-containing polyimide. <P>SOLUTION: The polyimide is produced from the silicon-containing polyamide acid that is a block copolymer obtained by copolymerizing a polyamide acid having a structural unit represented by general formula (I) (wherein Y is a tetravalent organic group, and Z is a divalent organic group) with a silicon-containing polymer having a specific structural unit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a novel silicon-containing polyimide, a method for producing the same, and a film of the silicon-containing polyimide. More specifically, the present invention relates to a silicon-containing polyamic acid formed by block copolymerization of a polyamic acid and a silicon-containing polymer, a novel silicon-containing polyimide formed by firing this, a method for producing the same, and the method The present invention relates to a novel silicon-containing polyimide film.

  Polyimide resins are known as heat resistant resins with excellent mechanical strength, chemical resistance, electrical insulation, etc., and are considered useful as heat resistant films, adhesives, coating agents, molding resins, and coating resins. ing. In particular, in the field of electrical or electronic materials, enameled wire coatings, copper-clad printed circuit board films, insulating films or sheets, various insulating coating agents, α-ray shielding films, cloth impregnations and adhesives, Used in various fields such as liquid crystal display (LCD) alignment films and sealants, plasma display panel (PDP) partition walls and dielectric layers, thin film semiconductor (TFT) interlayer insulation films, etc. is doing. However, the polyimide resin has a drawback in that it has poor adhesion to substrates such as glass, ceramics, and silicon wafers. In recent years, introduction of silicon into polyimide has been studied in order to improve mechanical properties such as expansion coefficient and elastic modulus of polyimide, adhesion, and the like. At this time, there are many cases where silica obtained from the sol-gel method is introduced (see, for example, Patent Documents 1 and 2), but the amount of silicon introduced is limited. In addition, a polyimide into which a fluorine atom is introduced (for example, see Patent Document 3) is transparent, and the possibility of optical use is expanding. If silicon atoms can be introduced arbitrarily, new physical properties can be imparted in both optical and mechanical aspects.

JP-A-8-73739 JP 2002-293933 A JP-A-3-72528

  Therefore, the present invention does not have the above-mentioned problems, that is, it is possible to introduce silicon atoms into the molecule in any amount, and the heat resistance, chemical resistance, electrical insulation, mechanical strength of conventional polyimides Is maintained as it is, and also has excellent optical properties such as excellent transparency and low optical anisotropy, and includes new silicon containing excellent mechanical properties such as adhesion to silicon substrate, expansion coefficient and elastic modulus. An object of the present invention is to provide polyimide, the silicon-containing polyimide film, and silicon-containing polyamic acid which is a precursor of the novel silicon-containing polyimide.

  The inventors of the present invention made extensive studies to solve the above problems, and found that silicon can be introduced into the polyimide in an arbitrary amount by block copolymerization of a silicon-containing polymer and a polyamic acid.

  That is, the present invention relates to a silicon-containing polyamic acid comprising a block copolymer of a polyamic acid represented by general formula (I) and a silicon-containing polymer containing at least one structural unit of general formulas (II) to (VI). About.

（式Ｉ中、Ｙは四価の有機基を表し、Ｚは二価の有機基を表す。）

(In formula I, Y represents a tetravalent organic group, and Z represents a divalent organic group.)

(In the formulas II to VI, A is NH or O, and R ^{1 to} R ⁶ and R ⁸ are each independently an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkylamino group, an alkylsilyl group. Represents a group or an alkoxy group, R ⁷ represents a divalent group, and R ⁹ represents a divalent aromatic group, alicyclic group or heterocyclic group.)

  Further, the present invention is characterized in that the ratio of Si—O bond and Si—N bond in the silicon-containing polymer is Si—O / (Si—N + Si—O) = 0.01 to 0.99. The above-mentioned silicon-containing polyamic acid.

  Further, the present invention provides a silicon-containing polyamide, wherein the blending ratio of the polyamic acid having the structural unit represented by the general formula (I) and the silicon-containing polymer is in the range of 0.99 to 0.01. Concerning acid.

The present invention also relates to a silicon-containing polyamic acid, wherein the silicon-containing polymer further contains a structural unit represented by the following general formula (XIII).
_{- (SiH 2 NH) n- (} XIII)
(In the formula, n is an integer of 1 or more.)

  The present invention also relates to a silicon-containing polyimide obtained by firing any of the above silicon-containing polyamic acids.

  The present invention also relates to a film made of the above silicon-containing polyimide.

  Further, the present invention provides a block copolymer of the polyamic acid having the structural unit represented by the general formula (I) and the silicon-containing polymer containing at least one structural unit of the general formulas (II) to (VI). The present invention relates to a method for producing a silicon-containing polyamic acid.

  The present invention also relates to a method for producing a silicon-containing polyamic acid, wherein the silicon-containing polymer further contains a structural unit represented by the general formula (XIII).

  The present invention also relates to a method for producing a silicon-containing polyimide, characterized by firing the silicon-containing polyamic acid obtained by any one of the above-described methods for producing a silicon-containing polyamic acid.

  The novel silicon-containing polyamic acid of the present invention can contain silicon atoms in any proportion and is useful as a silicon-containing polyimide precursor. Further, the novel silicon-containing polyimide of the present invention obtained by firing the novel silicon-containing polyamic acid of the present invention has low heat resistance, chemical resistance, electrical insulation, mechanical strength, transparency and optical anisotropy. It has excellent optical properties such as adhesion to silicon substrate, mechanical properties such as expansion coefficient and elastic modulus.

Specific embodiments of the invention

Hereinafter, the present invention will be described more specifically.
The polyamic acid used in the present invention may be any polyamic acid represented by the above general formula (I) that has been conventionally used as a polyimide precursor. The polyamic acid represented by the above general formula (I) may be prepared by any method, and usually a tetracarboxylic acid represented by the following general formula (VII) or a derivative thereof and the following general formula (VIII) It is manufactured from the diamine represented by this. Examples of the tetracarboxylic acid derivatives include acid anhydrides, acid chlorides, esterified compounds, and the like.

（式中、Ｙは四価の有機基である。）

(In the formula, Y is a tetravalent organic group.)

_{H 2 N-Z-N 2} H (VIII)
(In the formula, Z is a divalent organic group.)

  The group Y in the above general formulas (I) and (VII) is a tetravalent organic group, but may have an aliphatic group which may have a substituent, an alicyclic group which may have a substituent, a substituted group. An aromatic ring group which may have a group and a heterocyclic group which may have a substituent may be mentioned as preferred groups. Specific examples of the group Y include the following groups, but the group Y is not limited to the groups exemplified below.

  The tetracarboxylic acids are preferably acid anhydrides such as pyromellitic acid anhydride, 1,2,3,4-benzenetetracarboxylic acid anhydride, 1,4,5,8-naphthalenetetracarboxylic acid anhydride. 2,3,6,7-naphthalenetetracarboxylic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,3,3 ′, 4′-benzophenonetetra Carboxylic dianhydride, 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride, 2,3,3 ′, 4′-diphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4 '− Phenylsulfonetetracarboxylic dianhydride, 2,3,3 ′, 4′-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis (3,3 ′, 4,4′-tetracarboxyphenyl) tetrafluoro Propane dianhydride, 2,2'-bis (3,4-dicarboxyphenoxyphenyl) sulfone dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, cyclopentanetetracarboxylic anhydride, butane-1,2,3,4-tetracarboxylic acid, 2,3,5-tricarboxycyclopentylacetic anhydride, cyclobutane Tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, cyclohexane tetracarboxylic dianhydride, etc. These may be used alone or in combination of two or more kinds.

  Further, in the diamine represented by the general formula (VIII), the group Z may be a divalent organic group, such as an optionally substituted aromatic group, an optionally substituted alicyclic group, Preferred examples include an optionally substituted heterocyclic group and an optionally substituted aliphatic group. Specific examples thereof include, for example, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminophenylmethane, 3,3′-dimethyl-4,4′-diaminodiphenylmethane, 4 , 4′-diaminodiphenylsulfone, 4,4′-di (m-aminophenoxy) diphenylsulfone, 4,4′-diaminodiphenyl sulfide, 1,4-diaminobenzene, 2,5-diaminotoluene, isophoronediamine, 4 -(2-aminophenoxy) -1,3-diaminobenzene, 4- (4-aminophenoxy) -1,3-diaminobenzene, 2-amino-4- (4-aminophenyl) thiazole, 2-amino-4 -Phenyl-5- (4-aminophenyl) thiazole, benzidine, 3,3 ', 5,5'-tetrame Rubenzidine, octafluorobenzidine, o-tolidine, m-tolidine, p-phenylenediamine, m-phenylenediamine, 1,2-bis (anilino) ethane, 2,2-bis (p-aminophenyl) propane, 2,2 -Bis (p-aminophenyl) hexafluoropropane, 2,6-diaminonaphthalene, diaminobenzotrifluoride, 1,4-bis (p-aminophenoxy) benzene, 4,4'-bis (p-aminophenoxy) biphenyl , Diaminoanthraquinone, 1,3-bis (anilino) hexafluoropropane, 1,4-bis (anilino) octafluoropropane, 2,2-bis [4- (p-aminophenoxy) phenyl] hexafluoropropane, etc. These can be used alone or in combination of two or more. It is.

  The tetracarboxylic acid and diamine as described above may have a substituent if necessary. For example, when a tetracarboxylic dianhydride having a fluorine substituent and a diamine having a fluorine substituent are used, the obtained polyamic acid Becomes a so-called fluorinated polyamic acid having a fluorine-containing substituent in a repeating structural unit. This fluorinated polyamic acid is preferable from the viewpoint of moisture resistance. Moreover, it is suitable also from a viewpoint of light transmittance, and is particularly suitable from a viewpoint of transparency in an optical communication wavelength region having a wavelength of 1.0 to 1.7 μm. The polyamic acid represented by the general formula (I) can be obtained by reacting the above tetracarboxylic acids and diamines in a polar solvent, usually at −20 ° C. to 60 ° C.

  On the other hand, the silicon-containing polymer used in the present invention is a silicon-containing polymer having a structural unit represented by the above general formulas (II) to (VI), and further having a structural unit represented by the above general formula (XIII). Any polymer may be used, and it may be a homopolymer or a copolymer, but contains at least Si—O bond and Si—N bond in the molecule. For example, JP 2002-293941 A or JP 2005-36089 A The silicon-containing copolymer described in the publication is preferred. Specifically, the following silicon-containing copolymer polymers (1) to (3) are preferably used in the present invention.

(1) A silicon-containing copolymer comprising at least structural units represented by the following general formulas (II) and (III).

[Wherein R ^{1 to} R ⁷ and A are as defined above. Further, the structural units (II) and (III) are random, and the molar ratios p and q are q / (p + q) = 0.01 to 0.99, and the Si—O bond and Si in the polymer The proportion of —N bonds is Si—O / (Si—N + Si—O) = 0.01 to 0.99. ]

(2) The silicon-containing copolymer of (1) above, wherein the copolymer further comprises a structural unit represented by the following general formula (IV).

[Wherein R ⁸ and A are as defined above. Further, the structural units (II) to (IV) in the polymer are random, and the molar ratios p, q, and r have the following relationship.
q / (p + q + r) = 0.01-0.99]

(3) The silicon-containing copolymer as described in (1) or (2) above, wherein the copolymer further contains at least one structural unit of the following general formulas (V) and (VI) .

[Wherein R ¹ , R ² , R ⁸ , R ⁹ are as defined above. The structural units (II), (III), (V), (VI), or (II) to (VI) are random. ]

In the above general formula, the divalent aromatic group represented by R ⁹ is preferably an aralkylene group, a naphthylene group, or a group represented by the following general formula (A).

[Wherein, R ¹⁰ is a halogen atom or a lower alkyl group, a is an integer of 0 to 4, and V is a direct bond or a group represented by the following general formula (B).

(In the formula, R ¹¹ is a halogen atom or a lower alkyl group, b is an integer of 0 to 4, and W is a direct bond or a divalent group.)]

  The bonding order of the structural units of the general formulas (II) to (VI) constituting the silicon-containing polymer used in the present invention may be random, and the ratios p, q, r or p, q, r, s and t can take the following ranges.

p / (p + q + r) = 0.01-0.99, preferably 0.1-0.5
q / (p + q + r) = 0.01-0.99, preferably 0.2-0.75
r / (p + q + r) = 0-0.99, preferably 0.1-0.5
Or
p / (p + q + r + s + t) = 0.01-0.99, preferably 0.1-0.5
q / (p + q + r + s + t) = 0.01-0.99, preferably 0.1-0.75
s / (p + q + r + s + t) = 0-0.99, preferably 0.01-0.2
(R + t) / (p + q + r + s + t) = 0-0.99, preferably 0.1-0.75

  Further, the ratio of Si—O bonds and Si—N bonds in the silicon-containing polymer is preferably Si—O / (Si—N + Si—O) = 0.01 to 0.99, more preferably 0.1 to 0.99. 0.95. Furthermore, the blending ratio of the polyamic acid having the structural unit represented by the general formula (I) and the silicon-containing polymer is preferably in the range of 0.99 to 0.01.

  The copolymer polymer described in the above (1) is a suitable solvent containing a mixture containing at least an organopolyhalosilane represented by the following general formula (IX) and a disilyl compound represented by the following general formula (X). It is produced by reacting with water dispersed in the solution and then reacting with ammonia to completely react the unreacted halosilane.

(In the above formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group, alkenyl group, cycloalkyl group, aryl group, aralkyl group, alkylamino group, alkylsilyl group. Or an alkoxy group, R ⁷ is a divalent group, and X is a halogen atom.)

  In the above production method, the organopolyhalosilane represented by the general formula (IX) and the disilyl compound represented by the general formula (X) are further mixed with the organo represented by the following general formula (XI). By containing polyhalosilane, the silicon-containing copolymer described in (2) above can be produced.

(In the above formula, R ⁸ is an alkyl group, alkenyl group, cycloalkyl group, aryl group, aralkyl group, alkylamino group, alkylsilyl group or alkoxy group, and X is a halogen atom.)

Further, in each of the above production methods, first, in the first stage of the reaction, a mixture containing the organopolyhalosilane represented by the general formula (IX) and the disilyl compound represented by the general formula (X) or this mixture is further added. A mixture containing the organopolyhalosilane represented by the general formula (XI) is converted into the following general formula (XII):
H ₂ N—R ⁹ —N ₂ H (XII)
(In the formula, R ⁹ represents a divalent aromatic group, alicyclic group or heterocyclic group.)
And then reacting with water dispersed in a suitable solvent, followed by reaction with ammonia to completely react with unreacted halosilane, as described in (3) above. A silicon-containing copolymer can be produced.

More specifically, the method for producing the silicon-containing copolymer will be described. In the organopolyhalosilane represented by the general formulas (IX) and (XI) used as a starting material when producing the silicon-containing copolymer, , R ¹ , R ² and R ⁸ have 1 to 7 carbon atoms, preferably 1 to 5 carbon atoms, more preferably 1 to 2 alkyl groups, 2 to 7 carbon alkenyl groups, and 5 to 7 carbon atoms. In general, a cycloalkyl group and an aryl group are generally used, and X is usually a fluorine, chlorine, bromine or iodine atom, preferably a chlorine atom. As the aryl group, phenyl group, tolyl group, xylyl group, cumenyl group, benzyl group, phenethyl group, α-methylbenzyl group, benzhydryl group, trityl group, styryl group, cinnamyl group, biphenyl group, naphthyl group, etc. should be used. Can do. As the alkylsilyl group (mono, di, tri-substituted product), alkylamino group (mono, di-substituted product), and alkoxy group, those having 1 to 7 carbon atoms are usually used. R ¹ and R ² may be the same or different from each other. The compound represented by the general formula (IX) is preferably diphenyldichlorosilane, and the compound represented by the general formula (XI) is preferably phenyltrichlorosilane.

On the other hand, R ^{3 to} R ⁶ and X of the disilyl compound represented by the general formula (X) used as a starting material when the silicon-containing copolymer is produced are R in the general formulas (IX) and (XI). The same groups as those for R ¹ , R ² , R ⁸ and X can be mentioned as preferable examples. Further, the divalent group of R ⁷ is preferably a divalent aromatic group such as an aralkylene group, a naphthylene group or a group represented by the general formula (A), specifically, for example, an alkylene group or an alkenylene group. A cycloalkylene group, an arylene group, an alkylimino group, an alkylsilylene group, and the like, and an arylene group is preferable. Examples of the arylene group include a phenylene group, a tolylene group, a xylylene group, a benzylidene group, a phenethylidene group, an α-methylbenzylidene group, a cinnamylidene group, and a naphthylene group. Specifically, the compound represented by the general formula (X) is preferably 1,4-bis (dimethylchlorosilyl) benzene or the like.

If necessary, a mixture of these organopolyhalosilanes and a disilyl compound is first reacted with a diamine (NH ₂ —R ⁹ —NH ₂ ) of the general formula (XII). R ⁹ is preferably an aralkylene group, a naphthylene group, or a group represented by the general formula (A). Specific examples of the diamine represented by the general formula (XII) include the following.

As shown in this specific example, the diamine group R ⁹ of the general formula (XII) is preferably an arylene group such as a phenylene group or various divalent aromatic groups such as a biphenylene group, and more preferably an arylene group. In addition, the illustration of the said diamine is only shown as a preferable example, and the diamine represented by the general formula (XII) of the present invention is not limited to the above. Among these diamines, para-phenylenediamine (p-PDA), meta-phenylenediamine (m-PDA), and 4,4′-diphenyldiaminoether (oxydianiline, ODA) are particularly preferable.

  As the reaction solvent, either a Lewis base or a non-reactive solvent alone or a mixture thereof may be used. In this case, examples of the Lewis base include tertiary amines (tolualkylamines such as trimethylamine, dimethylethylamine, diethylmethylamine, and triethylamine, pyridine, picoline, dimethylarinin, and derivatives thereof), and sterically hindered groups. Secondary amines, phosphine, stipin, arsine and derivatives thereof (for example, trimethylphosphine, dimethylethylphosphine, methyldiethylphosphine, triethylphosphine, trimethylarsine, trimethylstipin, trimethylamine, triethylamine, etc.) be able to. Among them, bases having a low boiling point and less basic than ammonia (for example, pyridine, picoline, trimethylphosphine, dimethylethylphosphine, methyldiethylphosphine, triethylphosphine) are preferable, and pyridine and picoline are particularly preferable in terms of handling and economy. preferable.

  Non-reactive solvents include aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbon hydrocarbon solvents; halogenated hydrocarbons such as halogenated methane, halogenated ethane, and halogenated benzene; aliphatic ethers Ethers such as alicyclic ethers can be used. Among these, preferred are halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, bromoform, ethylene chloride, ethylidene chloride, trichloroethane, tetrachloroethane, ethyl ether, isopropyl ether, ethyl butyl ether, butyl ether, 1,2- Ethers such as dioxyethane, dioxane, dimethyldioxane, tetrahydrofuran, tetrahydropyran, pentane, hexane, isohexane, methylpentane, heptane, isoheptane, octane, isooctane, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, benzene, toluene, xylene , Hydrocarbons such as ethylbenzene, N-methyl-2-pyrrolidone and diglyme. Of these solvents, dichloromethane, xylene and N-methyl-2-pyrrolidone are preferable from the viewpoint of safety. A pyridine / dichloromethane mixed solvent is also preferable.

  In the above reaction, the mixing ratio of the organopolyhalosilane represented by the general formula (IX) and the general formula (XI) used if necessary and the disilyl compound represented by the general formula (X) is 1 in molar ratio. : 99-99: 1 may be sufficient, Preferably it is 90: 10-10: 90, More preferably, it is 80: 20-40: 60. Further, the use ratio of the halosilicon compound and the diamine may be in the range of 100: 0 to 10:90 in terms of molar ratio, preferably 100: 0 to 25:75, and more preferably 100: 0. ~ 40: 60. The amine modification amount by diamine is preferably 0 to 50 mol% of the theoretical reaction amount of the halosilicon compound. Although the density | concentration of the halo silicon compound in a solvent can be selected arbitrarily, it is good to set it as the range of 1 to 25 weight%. The temperature may be any as long as the reaction system is a liquid (typically −40 ° C. to 300 ° C.). Further, the pressure is generally from normal pressure to increased pressure, but is preferably pressurized with nitrogen.

After the reaction between the halosilicon compound and the diamine, or without the reaction with the diamine, water dispersed in an appropriate solvent is added to the halosilicon compound to cause a reaction, thereby generating a Si—O bond. At this time, as the solvent in which water is dispersed, the same solvent as that used in the reaction with the diamine can be used. In particular, pyridine and picoline are preferable from the viewpoint of handling and economy. In addition, in the reaction with water, the rate of water injection into the reaction system greatly affects the production of the polymer. If the injection rate is high, the polymer may not be sufficiently produced. The water injection rate is preferably 0.1 mol H ₂ O / min or less. Furthermore, the reaction temperature also plays an important role in polymer formation. The temperature of the hydrolysis reaction is usually -40 ° C to 20 ° C, more preferably -20 ° C to 5 ° C. When the reaction temperature is high, the polymer may not be sufficiently formed.

  After the reaction with water is completed, an aminolysis reaction is carried out by adding ammonia to completely react the halosilane. The conditions such as the reaction solvent and reaction temperature in this case are the same as in the case of the diamine in the previous stage. The amount of ammonia added depends on the amount of halogen atoms remaining without reacting. That is, the theoretical amount necessary for ammonolysis of the halosilicon compound can be calculated from the amount of diamine added and the amount of water, but ammonia may be excessive, so that it is usually used in an amount exceeding the theoretical amount. The pressure is generally from normal pressure to pressurization, but nitrogen pressurization is preferred. In this reaction, HCl is generated. This can be separated from the target substance by forming a salt with a base such as triethylamine or ammonia. The copolymer polymer thus produced and the by-product ammonium chloride or amine salt are filtered off, and the solvent is removed from the filtrate under reduced pressure to obtain the above-mentioned silicon-containing copolymer polymers (1) to (3). Of polysiloxazan is obtained.

  The silicon-containing copolymer (1) to (3) thus obtained includes aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbon hydrocarbon solvents, halogenated hydrocarbons, ethers, alcohols, It is soluble in common organic solvents such as esters and ketones.

In addition, at least one polysiloxazan (a) of the above (1) to (3) and general formula (XIII): — (SiH ₂ NH) n — (where n is an integer of 1 or more). A copolymer obtained by polymerizing a silazane compound (b) containing a structural unit represented by formula (1) is also preferable as a silicon-containing polymer that is block copolymerized with polyamic acid. The copolymer copolymerized with the silazane compound containing the structural unit of the general formula (XIII) has a number average molecular weight of 500 to 1,000,000, and is based on the weight of the polysiloxazan (a). Those containing 1 to 90% by weight of the silazane compound (b) are preferred.

The silazane compound containing the structural unit represented by the general formula — (SiH ₂ NH) _n — is not necessarily polymerized, and is polymerized when the polysiloxazan (a) reacts with the silazane compound. There may be. Furthermore, when bonding to the polysiloxazan (a), only one structural unit of — (SiH ₂ NH) — may be bonded independently.

  The end group of the silazane compound (b) is not particularly limited, but is generally a silyl group, methyl group, amino group, methoxy group, alkoxy group or trimethylsilyl group. Moreover, in order to couple | bond with other components, such as other polysiloxazan (a) and a crosslinking agent, the terminal may have a carboxyl group, an amino group, a hydroxyl group, and a carbonyl group.

  In the reaction of the polysiloxazan (a) and the silazane compound (b), as necessary, the polysiloxazan (a), the silazane compound (b), or the polysiloxazan (a) and the silazane. A crosslinking agent for crosslinking the compound (b) may be included.

Examples of such a crosslinking agent include a silicon-containing crosslinking agent and a compound that generates an acid by heat. Examples of the silicon-containing crosslinking agent include (1) tetraisocyanate silane represented by the general formula: Si (NCO) ₄ ,
(2) General formula: Triisocyanate silane represented by R ¹¹ Si (NCO) ₃
(3) General formula: Si tetraalkoxysilane represented by (OR ¹²⁾ ₄ and (4) the general formula: trialkoxysilanes represented by R ¹³ Si (OR ^l4) ₃ may be mentioned as preferred. In the above formula, R ¹¹ represents an alkyl group, an aryl group, an alkenyl group, an aralkyl group, or the like, and preferably a methyl group, an ethyl group, or a phenyl group. Also, R ^l2, R ^l4 represents an alkyl group each independently, preferably a methyl group, an ethyl group or a butyl group. R ¹³ represents a hydrogen atom, an alkyl group, an aryl group, an alkenyl group or the like, and preferably a hydrogen atom, a methyl group, an ethyl group, a phenyl group, or a vinyl group. These silicon-containing crosslinking agents may be used alone or in combination of two or more.

  Moreover, as a crosslinking agent which consists of a compound which generate | occur | produces an acid, the peroxide which has a benzene ring in which the principal chain is comprised with the benzene ring with high heat resistance is preferable. Examples of the peroxide having a benzene ring include 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 4,4′-bis (t-butylperoxycarbonyl) benzophenone, 3, Preferable examples include 3′-bis (t-butylperoxycarbonyl) benzophenone. These compounds that generate an acid may be used alone or in combination of two or more.

  The amount of the crosslinking agent used varies depending on the desired degree of crosslinking, the type of crosslinking agent used, the crosslinking temperature, the ambient atmosphere, and the like, and the amount of Si-H groups in the polysiloxazan (a) and the silazane compound (b). It depends on the situation. However, in general, considering the curing rate and the heat resistance of the cured product, the amount is usually 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the total of the polymerizable components.

  The silicon-containing polyamic acid of the present invention is a silicon-containing polymer containing a polyamic acid represented by the general formula (I) and any structural unit of the general formulas (II) to (VI), preferably a silicon-containing copolymer polymer, More preferably, it is formed by blocking reaction with the polysiloxazan. Specifically, first, polyamic acid is dissolved in a solvent, and a solution containing a silicon-containing polymer, preferably polysiloxazan, in a solvent is added to this solution, and a blocking reaction is performed with stirring as necessary. The reaction is preferably carried out at room temperature to 170 ° C. under normal pressure, more preferably from room temperature to 100 ° C. Solvents that can be used may be the same as those shown in the production of polysiloxazan, such as aromatic hydrocarbons, alicyclic hydrocarbons, aliphatic hydrocarbons, halogenated methane, halogenated ethane, halogenated benzene, etc. Preferred examples include halogenated hydrocarbons, aliphatic ethers, and alicyclic ethers. The mixing ratio of the polyamic acid and the silicon-containing polymer may be arbitrary, but is preferably in the range of 0.99 to 0.01 (that is, 99: 1 to 1:99 by weight).

  A silicon-containing polyamic acid, which is a block polymer of the polyamic acid of the present invention and a silicon-containing polymer, is applied onto a substrate, and in the air or an inert atmosphere such as nitrogen or argon, for example, at 250 ° C. to 550 ° C. By baking for 05 to 2.0 hours, a polyimide coating film containing silicon at an arbitrary ratio is obtained. Moreover, a film simple substance can also be obtained by peeling a coating film from a glass substrate. Furthermore, it can be used not only in the form of a coating film but also in various forms applied to conventional polyimides such as a molded body and a cloth-impregnated body, a silicon-containing polymer, and a polysiloxazan fired body.

  As a method for applying the silicon-containing polyamic acid, a method conventionally used for applying a resin solution, for example, a spin coating method, a spray method, a dipping method, a roller coating method, or a printing method may be used. Good. In order to form a patterned thin film, the resin solution may be printed by screen printing or the like, or after forming a uniform thin film by coating, etching may be performed using a photolithographic method. Alternatively, a photoacid generator and a dissolution inhibitor such as diazonaphthoquinone are mixed in the silicon-containing polyamic acid solution and prebaked, and then exposed, post-baked, and developed, or a photobase generator is mixed in the silicon-containing polyamic acid solution. Then, after pre-baking, a method for forming a patterned thin film can be used by exposure, post-baking and development.

The thus obtained silicon-containing polyimide of the present invention has the following characteristics as compared with existing polyimides not containing silicon.
(1) Low refractive index (low dielectric constant)
(2) Small birefringence (small dielectric anisotropy)
(3) Light transmittance over the entire visible wavelength range (4) High heat resistance (pyrolysis start temperature and glass transition temperature)
(5) Low thermal expansion coefficient (6) High elastic modulus and low elongation at break (7) High thermal diffusivity (thermal conductivity)

  That is, the silicon-containing polyimide of the present invention is excellent in heat resistance, chemical resistance, electrical insulation, mechanical strength, mechanical properties such as thermal expansion coefficient and elastic modulus, and adhesion to silicon-containing films or substrates and metals. In addition, it has excellent optical properties such as transparency and small optical anisotropy. In addition, the thermal diffusivity is high and the thermal conductivity is excellent. Therefore, enameled wire coating agents, copper-clad printed circuit board films, insulating films or sheets, various insulating coating agents, α-ray shielding films, cloth impregnation and adhesives, LCDs that have conventionally used polyimide resins Alignment films, PDP barrier ribs, dielectric layers, thin-film semiconductor interlayer insulation films, etc., flattening films for LCDs, optical waveguides, CMOS / CCD inners that require high transparency and low optical anisotropy It is particularly suitable for use as a material such as a lens and a transparent resin (die bond material) for LED sealing.

  Next, in order to explain the present invention in more detail, examples and comparative examples will be given, but it goes without saying that the present invention is not limited to these examples. In Examples and Comparative Examples, “part” is based on weight unless otherwise specified.

Synthesis Example 1 (Synthesis of polyamic acid 1)
In a glove box whose atmosphere was replaced with dry nitrogen, 19.6 g (0.1 mol) of 4,4′-diaminodiphenyl ether (ODA) was dissolved in 422 g of dehydrated dimethylacetamide (DMAc) and put into a three-necked flask. And cooled to about 10 ° C. Next, 2,2-bis (3,3 ′, 4,4′-tetracarboxyphenyl) tetrafluoropropane dianhydride (hexafluoroisopropylidene-2,2-bis (phthalic anhydride)) 43. 8 g was added little by little. By stirring for 24 hours at room temperature under a nitrogen flow, a highly viscous polyamic acid 1 solution was obtained.

Synthesis Example 2 (Synthesis of polyamic acid 2)
In a glove box whose atmosphere was replaced with dry nitrogen, 19.6 g (0.1 mol) of 4,4′-diaminodiphenyl ether (ODA) was dissolved in 422 g of dehydrated dimethylacetamide (DMAc) and put into a three-necked flask. And cooled to about 10 ° C. Next, 19.6 g (0.1 mol) of cyclobutanetetracarboxylic dianhydride (CBDA) was added little by little. The mixture was stirred at room temperature for 24 hours under a nitrogen flow to obtain a highly viscous polyamic acid 2 solution.

Synthesis Example 3 (Synthesis of polysiloxazan)
After replacing the inside of the reaction vessel installed in the high-temperature tank with dry nitrogen, 47 g (0.222 mol) of phenyltrichlorosilane, 28 g (0.111 mol) of diphenyldichlorosilane and 1,4-bis (dimethylchlorosilyl) were added to 1000 ml of xylene. were charged which is dissolved benzene 11.6g (0.0444mol). Next, the reaction vessel was set at -5 ° C., reaches the predetermined temperature, pure water (H ₂ O) 6.8g (0 .377 mol) in 1000 ml of pyridine was injected at a rate of about 30 ml / min for 20 minutes, at which time the reaction between halosilane and water occurred, and the temperature in the reaction vessel rose to −2 ° C. Water and pyridine After the injection of the mixed solution was completed, stirring was continued for 1 hour, and then ammonia was reacted to completely react with unreacted chlorosilane. Injection was performed at a rate of 2 N liters / min for 20 minutes, and formation of a white precipitate of ammonium chloride was confirmed with the addition of ammonia, and after the reaction was completed, dry nitrogen was blown to remove unreacted ammonia, and then a nitrogen atmosphere was obtained. The filtrate was subjected to pressure filtration at about 1900 ml, and the filtrate was subjected to solvent substitution under reduced pressure to obtain a transparent high-viscosity resin, which was measured for molecular weight by GPC. This transparent resin was diluted with xylene and adjusted to 20 wt%.

Example 1
To 14 g of a 15 wt% DMAc solution of polyamic acid 1, 2.1 g of a 20 wt% xylene solution of polysiloxazan (DEN) was mixed, and 34.3 g of DMAc was added thereto and reacted at room temperature for 24 hours. Immediately after the addition of polysiloxazan, the compatibility was poor and a gel-like lump was formed. However, after the reaction for 24 hours, a uniform solution was formed, and it was confirmed that a copolymerization reaction occurred. As a result of measuring the molecular weight by GPC, Mw was 30,000. Since the chart shows a bimodal distribution, it is a block copolymer. This was concentrated to about 15 wt% and applied onto a silicon wafer by spin coating (spin coating) to form a film. This film was prebaked on a hot plate at 150 ° C. for 3 minutes to remove the solvent, and then cured at 350 ° C. for 1 hour in a nitrogen atmosphere to obtain a colorless and transparent silicon-containing polyimide film.

For this film, a Fourier transform infrared absorption spectrum (FT-IR) was measured. As a measuring device, Thermo Nicolet AVATAR-340 was used. The results are shown in FIG. 1 (see DEN 20%). A peak due to the Si—O bond was observed in the vicinity of 1080 cm ⁻¹ . Further, the polarization direction dependency (TE refractive index and TM refractive index) of the refractive index at a wavelength of 1.32 μm was measured using a prism coupler (PC-2010, manufactured by Metricon). The results are shown in Table 1. Birefringence is calculated as the difference between the TE refractive index and the TM refractive index.

Example 2
A silicon-containing polyimide film was prepared in the same manner as in Example 1 except that the reaction amount of polysiloxazan (DEN) was changed to 4.2 g. The colorless and transparent polyimide film thus obtained was subjected to FT-IR measurement in the same manner as in Example 1. The results are shown in FIG. 1 (see DEN 40%). A peak due to the Si—O bond was observed in the vicinity of 1080 cm ⁻¹ . Further, the polarization direction dependence of the refractive index at a wavelength of 1.32 μm was measured in the same manner as in Example 1. The measurement results and the calculated birefringence are shown in Table 1.

Example 3
A silicon-containing polyimide film was prepared in the same manner as in Example 1 except that the reaction amount of polysiloxazan (DEN) was changed to 6.3 g. The colorless and transparent polyimide film thus obtained was subjected to FT-IR measurement in the same manner as in Example 1. The results are shown in FIG. 1 (see DEN 60%). A peak due to the Si—O bond was observed in the vicinity of 1080 cm ⁻¹ . Further, the polarization direction dependence of the refractive index at a wavelength of 1.32 μm was measured in the same manner as in Example 1. The measurement results and the calculated birefringence are shown in Table 1.

Comparative Example 1
A 15 wt% DMAc solution of polyamic acid 1 obtained in Synthesis Example 1 was applied onto a silicon wafer by spin coating (spin coating) to form a film. This film was prebaked on a hot plate at 150 ° C. for 3 minutes to remove the solvent, and then cured at 350 ° C. for 1 hour in a nitrogen atmosphere to obtain a colorless and transparent polyimide film (6FDA-ODA) containing no silicon. . The obtained polyimide film was subjected to FT-IR measurement in the same manner as in Example 1. The results are shown in FIG. 1 (see DEN 0%). Further, the polarization direction dependence of the refractive index at a wavelength of 1.32 μm was measured in the same manner as in Example 1. The measurement results and the calculated birefringence are shown in Table 1.

Comparative Example 2
A 20 wt% xylene solution of polysiloxazan (DEN) was applied onto a silicon wafer by spin coating (spin coating) to form a film. This film was prebaked on a hot plate at 150 ° C. for 3 minutes to remove the solvent, and then cured at 400 ° C. for 1 hour in a nitrogen atmosphere to obtain a colorless and transparent organic silica film. When FT-IR measurement was performed on the FT-IR of this film in the same manner as in Example 1, a peak due to the Si—O bond was strongly observed in the vicinity of 1080 cm ⁻¹ . Further, the polarization direction dependence of the refractive index at a wavelength of 1.32 μm was measured in the same manner as in Example 1. The measurement results and the calculated birefringence are shown in Table 1.

  From Table 1, the silicon-containing polyimides of Example 1, Example 2, and Example 3 all showed a decrease in refractive index and a decrease in birefringence as compared to polyimide not containing silicon (Comparative Example 1). It can be seen that the structure is optically uniform. Moreover, the organic silica of Comparative Example 2 was confirmed to have an optically uniform structure with a large decrease in refractive index and negative birefringence compared to polyimide.

  Further, in FIG. 1 (comparison of infrared absorption spectra of the silicon-containing polyimide film of Examples 1 to 3 and the silicon-free polyimide film of Comparative Example 1 (DEN = 0%)), Examples 1 to 3 and Comparative Example When the FT-IR spectrum of the polyimide film obtained in 1 is compared, it can be seen that the intensity of the peak due to the Si—O bond is substantially proportional to the charged amount of DEN.

  The light absorption spectra of the colorless and transparent polyimide films of Examples 1 to 3 and the silicon-free polyimide film of Comparative Example 1 were measured. The results are shown in FIG.

  From FIG. 3, it can be seen that the silicon-containing polyimide using the polyamic acid 1 has improved transparency on the short wavelength side as compared with the polyimide not containing silicon.

Examples 4-6
When a silicon-containing polyimide film was formed in the same manner as in Examples 1 to 3 except that the polyamic acid 2 obtained in Synthesis Example 2 was used as the polyamic acid, a colorless and transparent polyimide film was obtained. About the polyimide film obtained in each Example, it carried out similarly to Example 1, and performed FT-IR measurement. The results are shown in FIG. In the figure, DEN 20% shows the measurement result of the film of Example 4, DEN 40% shows the measurement result of the film of Example 5, and DEN 60% shows the measurement result of the film of Example 6. Further, the polarization direction dependence of the refractive index of each film at a wavelength of 1.32 μm was measured in the same manner as in Example 1. The measurement results and the calculated birefringence are shown in Table 2.

Comparative Example 3
When a polyimide film containing no silicon was formed in the same manner as in Comparative Example 1 except that the polyamic acid 2 obtained in Synthesis Example 2 was used as the polyamic acid, a colorless and transparent polyimide film (CBDA-ODA) was obtained. It was. The polyimide film was subjected to FT-IR measurement in the same manner as in Example 1. The results are shown in FIG. 2 (see DEN 0%). Further, the polarization direction dependence of the refractive index at a wavelength of 1.32 μm was measured in the same manner as in Example 1. The measurement results and the calculated birefringence are shown in Table 2.

  From Table 2 above, all of the silicon-containing polyimides of Examples 4 to 6 show a decrease in refractive index and birefringence as compared with polyimide not containing silicon (Comparative Example 3), and are optically uniform. It can be seen that it has a structure.

  Moreover, as shown in FIG. 2 (comparison diagram of infrared absorption spectra of the silicon-containing polyimide film of Examples 4 to 6 and the silicon-free polyimide film of Comparative Example 3 (DEN = 0%)), Examples 4 to In the silicon-containing polyimide film of No. 6, similarly to Examples 1 to 3, peaks due to Si—O bonds were clearly observed.

  Further, the light absorption spectra of the colorless and transparent polyimide films of Examples 4 to 6 and the silicon-free polyimide film of Comparative Example 3 were measured. The results are shown in FIG.

Various characteristic values (thermal decomposition temperature, glass transition temperature, linear thermal expansion coefficient, thermal diffusivity) of the polyimide films obtained in Examples 1 to 6 and Comparative Examples 1 and 3 were evaluated by the following test methods. The evaluation results are shown in Tables 3-4.

(1) Thermal decomposition temperature Using the said polyimide membrane, it measured with the temperature increase rate of 10 degree-C / min by nitrogen gas stream with the simultaneous differential-heat and thermogravimetric measuring apparatus (Shimadzu Corporation make, DTG-60 / 60H). The temperature when the weight reduction rate was 5% was defined as the thermal decomposition temperature.

(2) Glass transition temperature Using the polyimide film, the elongation under a nitrogen stream was measured with a thermomechanical analyzer (manufactured by Seiko, TMA / SS6100). The temperature at which the elongation increases rapidly was taken as the glass transition temperature.

(3) Linear thermal expansion coefficient Using the polyimide film, the thermal mechanical analysis device (Seiko Co., Ltd., TMA / SS6100) was used to measure the elongation under a nitrogen stream, and the average linear thermal expansion coefficient at 70 ° C to 250 ° C. (Ppm / ° C.) was determined.

(4) Thermal diffusivity Using the polyimide film, the thermal diffusivity (m ² / s) in the film thickness direction was measured by temperature wave thermal analysis (manufactured by Eye Phase Co., Ltd., Eye Phase Mobile 1u).

  From Table 3 and Table 4, it can be seen that the silicon-containing polyimide film of the present invention has high heat resistance.

It is a comparison figure of the infrared absorption spectrum of the silicon-containing polyimide film of Examples 1-3 and the silicon non-containing polyimide film of Comparative Example 1 (DEN = 0%). It is a comparison figure of the infrared absorption spectrum of the silicon containing polyimide film of Examples 4-6 and the silicon non-containing polyimide film (DEN = 0%) of the comparative example 3. It is a comparison figure of the light absorption spectrum of the silicon containing polyimide film of Examples 1-3 and the silicon non-containing polyimide film of Comparative Example 1 (DEN = 0%). It is a comparison figure of the light absorption spectrum of the silicon containing polyimide film of Examples 4-6 and the silicon non-containing polyimide film (DEN = 0%) of the comparative example 3.

Claims (9)

Silicon-containing polyamide comprising a block copolymer of a polyamic acid having a structural unit represented by the following general formula (I) and a silicon-containing polymer containing at least one structural unit of the following general formulas (II) to (VI) acid.

(In formula I, Y represents a tetravalent organic group, and Z represents a divalent organic group.)

(In the formulas II to VI, A is NH or O, and R ^{1 to} R ⁶ and R ⁸ are each independently an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkylamino group, an alkylsilyl group. Represents a group or an alkoxy group, R ⁷ represents a divalent group, and R ⁹ represents a divalent aromatic group, alicyclic group or heterocyclic group.)   The ratio of Si-O bonds and Si-N bonds in the silicon-containing polymer is Si-O / (Si-N + Si-O) = 0.01-0.99. Silicon-containing polyamic acid.   3. The silicon according to claim 1, wherein the compounding ratio of the polyamic acid having the structural unit represented by the general formula (I) and the silicon-containing polymer is in the range of 0.99 to 0.01. Containing polyamic acid. The silicon-containing polyamic acid according to any one of claims 1 to 3, wherein the silicon-containing polymer further contains a structural unit represented by the following general formula (XIII).
_{- (SiH 2 NH) n- (} XIII)
(In the formula, n is an integer of 1 or more.)   A silicon-containing polyimide obtained by firing the silicon-containing polyamic acid according to claim 1.   A film comprising the silicon-containing polyimide according to claim 5.   2. The silicon-containing composition according to claim 1, comprising the polyamic acid according to claim 1 having a structural unit represented by the general formula (I) and at least one structural unit selected from the general formulas (II) to (VI). A method for producing a silicon-containing polyamic acid, comprising block copolymerizing a polymer.   The method for producing a silicon-containing polyamic acid according to claim 7, wherein the silicon-containing polymer further contains a structural unit represented by the general formula (XIII).   A method for producing a silicon-containing polyimide, comprising firing the silicon-containing polyamic acid obtained in claim 7 or 8.

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