JP6365307B2 - Thermoplastic polyimide - Google Patents

Description

  The present invention relates to a thermoplastic polyimide excellent in transparency, heat resistance, melt heat stability, solvent non-volatility, and the like and a thermoplastic polyimide molded body obtained by melt extrusion molding of the thermoplastic polyimide.

  Polyimide has excellent properties in terms of heat resistance, mechanical properties, chemical resistance, electrical properties, etc., so it is widely used in the fields of automobiles, aerospace industry, electricity, electronics, batteries, etc. Yes.

  Polyimide is generally a thermosetting resin that does not have a clear glass transition temperature, while having a characteristic of excellent heat resistance. When used as a molding material, a special method such as sintering is used. There must be. Moreover, in order to obtain a processed product having a complicated shape by a sintering molding method, a complicated and complicated processing step such as cutting out a target shape from a polyimide block using a cutting machine such as an NC lathe is required. There is a problem of high cost. Furthermore, since a polyimide generally has a wholly aromatic skeleton, the molded product is colored. For this reason, there is a problem that it cannot be used in applications where transparency is required.

  Therefore, in order to improve the moldability, thermoplastic polyimides have been developed that can be melt-molded at a certain temperature or higher, like general-purpose thermoplastic resins. For example, Patent Document 1 describes a thermoplastic polyimide having a 3,3 ', 4,4'-diphenyl ether tetracarboxylic acid skeleton as a basic skeleton. Patent Document 1 discloses a method for imidizing a polyamic acid resin solution, which is a polyimide precursor, in a solution as a method for producing polyimide.

  On the other hand, in order to improve transparency, a transparent polyimide using at least one of an alicyclic tetracarboxylic dianhydride and an aliphatic diamine has been developed. For example, Patent Document 2 describes a transparent polyimide using a 3,4,3 ′, 4′-dicyclohexyltetracarboxylic dianhydride skeleton, and as a production method thereof, solution casting of a polyamic acid solution is described. A method of obtaining a transparent polyimide molded body by molding by a method and heat imidization is described. Patent Document 3 describes a method of obtaining a polyimide by imidizing a polyamic acid resin having an aliphatic tetracarboxylic acid skeleton in a solution.

Japanese Unexamined Patent Publication No. 4-331231 Japanese Unexamined Patent Publication No. 8-104750 Japanese Unexamined Patent Publication No. 2005-15629 Japanese Unexamined Patent Publication No. 2008-297360

  Since the polyimide described in Patent Document 1 has a high glass transition temperature and crystallinity, it is difficult to obtain a molten state at the upper limit of the melting temperature in a normal industrial process, and the molding method is usually a solvent cast. Limited by law. In addition, the polyimide obtained because it has many aromatic skeletons also has problems in color tone and transparency.

  The technique disclosed in Patent Document 2 is a technique for forming a polyamic acid solution by a solvent casting method (solution casting method) in order to obtain a polyimide film, but only a thin film can be produced. However, there are problems such as limited applications and poor productivity due to the time required to dry the solvent. In addition, since the polyamic acid solution is easily hydrolyzed by moisture in the air, there is a problem in that the molecular weight changes during storage and the viscosity decreases. Furthermore, according to the study by the present inventors, the imidization ratio of polyimide is insufficient, and the primary amino group remains at the terminal, so that the heat stability is insufficient, There was also a problem that it could cause coloring.

  On the other hand, Patent Document 3 describes a solvent casting method in which polyimide is mixed with a solvent in a solution state. However, as in Patent Document 2, only a thin film can be produced, and its use Is limited, it takes time to dry the solvent, and therefore the cost is high, and further, the primary amino group remains at the end of the polyimide, which causes coloring. Problems were also found. Also, in the method of obtaining a polyimide molded body by melt-molding a polyimide solution mixed with a solvent, since the solvent is contained in polyimide, problems such as remarkable foaming at the time of melting and generation of flammable gas may occur. This point also needs improvement.

  Furthermore, Patent Document 4 describes that a polyimide having excellent solubility in an organic solvent is obtained by controlling the three-dimensional structure of a polyimide having an alicyclic structure. However, in Patent Document 4, a conventional molding method using a solvent casting method is used, and there are problems as described in Patent Documents 2 and 3 above.

  Polyimides having an alicyclic structure as described in Patent Documents 2 to 4 are thermoplastic, and because they are excellent in transparency and heat resistance, they should be used as polyimide films used in applications such as flexible devices and organic EL. However, productivity is insufficient with methods such as the solvent casting method conventionally used for molding polyimide, and it is difficult to thicken the polyimide film only as a thin film, It has been found that there are problems such as the possibility of generating flammable gases.

  The present inventors can solve the problems in the solvent casting method as described above by a melt extrusion molding method, but on the other hand, a polyimide having an alicyclic structure as described in Patent Documents 2 to 4 Was found not to have melt heat stability to the extent that melt extrusion can be applied.

  The present invention has been made in view of the above-mentioned problems of the prior art. An object of the present invention is to provide a thermoplastic polyimide excellent in transparency, heat resistance, melt heat stability, solvent non-volatility, and the like, and a thermoplastic polyimide molded body obtained by melt extrusion molding the thermoplastic polyimide. .

  The present invention has been made in view of the above problems. As a result of intensive studies by the present inventors, the problem of the melt heat stability of polyimide as described in Patent Documents 2 to 4 is that the imidation ratio of polyimide is insufficient, and the terminal amino group remains. It came to the conclusion that it originates in being. Aromatic polyimide as described in Patent Document 1 has a rigid structure, so that an amic acid structure hardly remains and imidization proceeds easily, whereas Patent Documents 2 to 4 describe alicyclic rings. Since it has a structure, it is presumed that the degree of freedom of the structure is increased and the amic acid structure is likely to remain.

As described above, in the polyimide having an alicyclic structure, the present inventors have excellent melt heat stability that can be applied to melt extrusion molding by increasing the imidization rate and increasing the amino group sealing rate. As a result, the inventors have found that a polyimide can be obtained.
That is, the gist of the present invention resides in the following [1] to [9].

[1] A thermoplastic polyimide having an alicyclic structure, a terminal amino group sealing ratio of 95.0% or more, and an imidization ratio of 95.8% or more.

[2] The thermoplastic polyimide according to [1], wherein the weight average molecular weight (Mw) is 10,000 to 500,000.

[3] The thermoplastic polyimide according to [1] or [2], wherein the alicyclic structure is a cyclohexane ring structure.

[4] The thermoplastic polyimide according to any one of [1] to [3], wherein the alicyclic structure is a structure adjacent to and sharing two carbon atoms with the imide ring structure.

[5] In any one of [1] to [4], the alicyclic structure includes at least one of a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2). The thermoplastic polyimide as described.

[6] The thermoplastic polyimide according to any one of [1] to [5], further having a structural unit represented by the following formula (3).

(In the above formula (3), R ^{1 to} R ⁸ may be different from each other, and are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group, and X is Direct bond, oxygen atom, sulfur atom, alkylene group having 1 to 4 carbon atoms, sulfonyl group, sulfinyl group, sulfide group, carbonyl group, amide group, ester group or secondary amino group, n is an integer of 0 to 4 .)

[7] The thermoplastic polyimide according to any one of [1] to [6], wherein a complex shear viscosity (η ^* ) at 310 ° C. is 1 × 10 ^{2 to} 5 × 10 ⁵ Pa · s.

[8] The thermoplastic polyimide according to any one of [1] to [7], wherein the change rate of the complex shear viscosity before and after passing for 60 minutes at 310 ° C. is 300% or less.

[9] A thermoplastic polyimide molded article obtained by melt extrusion molding the thermoplastic polyimide according to any one of [1] to [8].

  According to the present invention, there is provided a thermoplastic polyimide that is excellent in transparency, heat resistance, solvent non-volatility, and the like, and particularly excellent in melt heat stability such that melt extrusion molding is possible. Moreover, according to this invention, the thermoplastic polyimide molded object obtained by melt-extruding this thermoplastic polyimide is provided.

[Thermoplastic polyimide]
The thermoplastic polyimide of the present invention has an alicyclic structure, the terminal amino group sealing rate is 95.0% or more, and the imidization rate is 95.8% or more.

  The thermoplastic polyimide of the present invention has an effect that the thermal stability of the melt is remarkably excellent as compared with the conventional polyimide having an alicyclic structure as described in Patent Documents 2 to 4. According to detailed studies by the present inventors, in Patent Documents 2 to 4, imidization does not proceed sufficiently, amic acid remains, and the terminal amino group sealing rate is not sufficient. I understood it. In such a thermoplastic polyimide, when it is heated to 300 ° C. or higher, a reaction occurs between the amic acid in the polyimide molecule and the terminal amino group, and a reaction between the amic acids between the polyimide molecules occurs. Etc. are considered to affect the heat stability of melting.

[Chemical structure]
The thermoplastic polyimide of the present invention has an alicyclic structure. The alicyclic structure is not particularly limited, but is usually an alicyclic structure having 5 to 12 carbon atoms, preferably an alicyclic structure having 6 to 10 carbon atoms, and particularly preferably a cyclohexane ring structure. Since the thermoplastic polyimide of the present invention has an alicyclic structure, it becomes a polyimide having thermoplasticity and excellent transparency. The “alicyclic structure” in the present invention is meant to include those having a hetero atom in the ring structure, but preferred is an alicyclic structure having no hetero atom in the ring structure.

  The thermoplastic polyimide of the present invention can usually be obtained using a carboxylic dianhydride (hereinafter referred to as “acid dianhydride”) diamine compound as a raw material, as will be described later. The alicyclic structure in the thermoplastic polyimide of the present invention may be derived from an acid dianhydride or a diamine compound, but preferably an alicyclic structure derived from an acid dianhydride. It is a structure.

  In the thermoplastic polyimide of the present invention, the alicyclic structure is preferably adjacent to the imide ring structure sharing two carbon atoms. When the alicyclic structure is adjacent to the imide ring structure sharing two carbon atoms, the transparency based on the alicyclic structure and the heat resistance and chemical stability derived from the imide ring structure are easy to achieve at the same time. preferable. Preferred examples of the structure in which the alicyclic structure is adjacent to and sharing two carbon atoms with the imide ring structure include those in which the alicyclic structure is a cyclohexane ring structure (structure represented by the following formula (4)). Can be mentioned.

  Furthermore, it has at least one of the structural unit represented by the structural unit represented by following structural formula (1) and the structural unit represented by following formula (2) as an alicyclic structure in the thermoplastic polyimide of this invention. preferable. It is preferable to have at least one of the structural unit represented by the formula (1) and the structural unit represented by the formula (2) because it is particularly excellent in transparency and toughness. The structural unit represented by the formula (1) can usually be introduced from an acid dianhydride represented by the formula (5) described later, and the structural unit represented by the formula (2) is Usually, it can introduce | transduce derived from the acid dianhydride represented by Formula (6) mentioned later.

  The thermoplastic polyimide of the present invention has a terminal amino group sealing rate of 95.0% or more and an imidation rate of 95.8% or more, so that it is excellent enough to enable melt extrusion molding. Melting heat stability can be obtained.

  The thermoplastic polyimide of the present invention has a terminal amino group sealing rate of preferably 96.0% or more, more preferably 97.0% or more, from the viewpoint of further improving the melt heat stability. Yes, and more preferably 98.0% or more. The upper limit of the sealing ratio of the terminal amino group of the thermoplastic polyimide is not limited and is usually 100%.

As will be described later, the terminal amino group sealing rate is the ratio of the acid dianhydride and diamine compound used as raw materials, the amount and type of terminal blocking agent used in the terminal blocking reaction step, and the chemical imidation reaction step. It can be controlled by the type of catalyst and dehydrating agent and the amount of these used. Further, the terminal amino group sealing rate can be determined by ¹ H-NMR measurement. Specific examples thereof are shown in Examples. In the present invention, “sealing the terminal amino group” means not only that the hydrogen atom bonded to the terminal primary amino group is replaced by the terminal blocking agent, but also in the chemical imidation reaction step. It is used in the meaning including unintended end capping, such as reaction between a terminal amino group and a dehydration condensing agent.

Moreover, the thermoplastic polyimide of the present invention has an imidation ratio of preferably 96.0% or more, more preferably 96.5% or more, from the viewpoint of further improving the melt heat stability. More preferably, it is 97.0% or more, and particularly preferably 98.0% or more. The upper limit of the imidization ratio of the thermoplastic polyimide is not limited and is usually 100%.

In the present invention, the imidization rate can be controlled by the conditions of the terminal blocking step, the chemical imidation reaction step, and the like, as will be described later. In order to increase the imidization rate without going through the end-capping step, the imidization rate can be increased by using a relatively large amount of the dehydration condensing agent used in the chemical imidation reaction step as described later. Furthermore, the fraction of imide units of the thermoplastic polyimide of the present invention is determined by ^{the 1 H-NMR} measurement, it shows a specific example in the examples. In the case where the imidization ratio can not be determined by ^{1 H-NMR} measurement can be determined by NMR measurement based on atoms other than hydrogen atoms.

  The thermoplastic polyimide of the present invention preferably has a structural unit represented by the following formula (3). It is preferable to have the structural unit represented by the formula (3) because heat resistance and toughness tend to be better.

In Formula (3), R ^{1 to} R ⁸ may be different from each other, and are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group. Among these, a hydrogen atom or a methyl group is preferable.

  In the formula (3), X is a direct bond, oxygen atom, sulfur atom, alkylene group having 1 to 4 carbon atoms, sulfonyl group, sulfinyl group, sulfide group, carbonyl group, amide group, ester group or secondary amino group. . Among these, a direct bond, an oxygen atom, a sulfur atom, an alkylene group having 1 to 4 carbon atoms, a sulfonyl group, or an amide group is preferable, and an oxygen atom is particularly preferable.

  In Formula (3), n is an integer of 0-4. n is preferably an integer of 1 to 4.

In the structural unit represented by the formula (3) in one molecule of the thermoplastic polyimide, R ^{1 to} R ⁸ , X, and n are not necessarily all the same. In particular, when n is an integer of 2 or more, X may have a different structure.

  Among the structural units represented by the formula (3), those represented by any of the structural units represented by the following formulas (3-1) to (3-6) are preferable. In addition, even if these structural units are contained only by 1 type in one molecule | numerator thermoplastic polyimide, multiple types may be contained in combination.

  The thermoplastic polyimide of the present invention may have other structural units in addition to the structural units represented by the formulas (1) to (3) listed above. Other structural units can be introduced based on raw materials other than the compounds represented by formulas (5) to (7) listed in the production method described later.

[Physical properties]
The thermoplastic polyimide of the present invention has a weight average molecular weight (Mw) of preferably 10,000 or more, more preferably 30,000 or more, particularly preferably 45,000 or more, while preferably 500, 000 or less, more preferably 300,000 or less, still more preferably 150,000 or less, and particularly preferably 130,000 or less. When the weight average molecular weight of the polyimide is not less than the above lower limit value, it is preferable from the viewpoint of toughness when a polyimide molded body is obtained, and when it is not more than the above upper limit value, it is preferable from the viewpoint of fluidity and moldability. In addition, the weight average molecular weight of the thermoplastic polyimide of the present invention can be measured by a gel permeation chromatography method (GPC method). More detailed conditions for GPC measurement will be described in the examples below.

The thermoplastic polyimide of the present invention preferably has a complex shear viscosity (η ^* ) at 310 ° C. of 1 × 10 ² Pa · s or more, more preferably 1 × 10 ³ Pa · s or more, and 5 ×. it is preferably 10 ⁵ Pa · s or less, and more preferably less 1 × ¹⁰ 5 Pa · s. It is preferable that the complex shear viscosity is in the above-mentioned range in order to obtain appropriate fluidity for molding. The complex shear viscosity can be controlled by the molecular weight, the molecular composition, etc. Usually, the complex shear viscosity increases as the molecular weight increases. The complex shear viscosity can be measured by the method described in Examples below.

Furthermore, the thermoplastic polyimide of the present invention is excellent in melt heat stability. Specifically, the thermoplastic polyimide of the present invention has an initial complex shear viscosity (η ^* ₀ ) immediately after melting at 310 ° C. for 60 minutes and a complex shear viscosity (η ^* ₆₀ ) after 60 minutes. The change rate of the complex shear viscosity is preferably 300% or less, more preferably 200% or less, and still more preferably 100% or less. The rate of change of the complex shear viscosity indicates the flow stability during melting. For this reason, it is preferable from the viewpoint of melt stability that the change rate of the complex shear viscosity is not more than the above upper limit, and it is preferable because the film thickness can be easily controlled when the film is formed. The lower limit of the rate of change in complex shear viscosity is usually 0. The rate of change in complex shear viscosity tends to decrease as the terminal amino group sealing rate increases. In the present invention, the rate of change in complex shear viscosity is defined by the following equation, and can be measured by the method described in the examples below.
(Change rate of complex shear viscosity) = [(η ^* ₆₀₋ η ^* ₀ ) / η ^* ₀ ] × 100

  The thermoplastic polyimide of the present invention has a glass transition temperature (Tg) by a DMS method (dynamic thermomechanical measuring device) of preferably 150 ° C. or higher, more preferably 200 ° C. or higher, particularly preferably 250 ° C. or higher. It is. It is preferable from a heat resistant viewpoint that a glass transition temperature is more than the said lower limit. On the other hand, the upper limit of the glass transition temperature is not particularly limited, but is usually 350 ° C. or lower. In addition, the glass transition temperature by DMS method can be measured by the method as described in an Example mentioned later.

  The thermoplastic polyimide of the present invention preferably has a coefficient of thermal expansion of 100 ppm / ° C. or less, more preferably 70 ppm / ° C. or less in the range of 100 to 200 ° C. It is preferable that the coefficient of thermal expansion is not more than the above upper limit in that a polyimide molded body with high dimensional accuracy can be produced.

[Method for producing thermoplastic polyimide]
Although the method for producing the thermoplastic polyimide of the present invention is not limited, for example, after undergoing a thermal imidization reaction step as a specific acid dianhydride and a specific diamine compound and raw materials described below, an end-capping reaction step and It can be obtained through a chemical imidization step. The end-capping reaction step and the chemical imidization step can be performed in any order, and these may be performed simultaneously, but after the end-capping reaction step, the chemical imidation reaction step may be performed. preferable.

[material]
The thermoplastic polyimide of the present invention can be usually obtained using an acid dianhydride and a diamine compound as raw materials. As the raw material for the thermoplastic polyimide of the present invention, a compound having an alicyclic structure is used for at least one of an acid dianhydride and a diamine compound, but using an acid dianhydride having an alicyclic structure is a raw material procurement, It is preferable from the viewpoint of productivity and the like.

  As raw materials for the thermoplastic polyimide of the present invention, an acid dianhydride represented by the following formula (5) (hereinafter sometimes referred to as “H-BPDA”) and an acid dianhydride represented by the following formula (6). It is preferable to use at least one of anhydrides (hereinafter sometimes referred to as “H-PMDA”). H-BPDA is a known compound and can be obtained, for example, by the method described in Japanese Patent Application Laid-Open No. 2011-45877. H-PMDA is also a known compound and can be obtained, for example, by the method described in Japanese Patent Application Laid-Open No. 2009-191253.

  Moreover, it is preferable to use the diamine compound represented by following formula (7) as a raw material of the thermoplastic polyimide of this invention.

In the formula (7), R ^{1 ′ to} R ^{8 ′} are defined in the same manner as R ^{1 to} R ⁸ in the formula (3), and X ′ is defined in the same manner as X. N ′ is defined similarly to n.

  Examples of the diamine compound represented by the formula (7) include 4,4′-diaminodiphenyl ether (hereinafter sometimes referred to as ODA), 2,2′-dimethyl-4,4′-diaminobiphenyl, 1,4-bis (4-aminophenoxy) benzene, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 4,4′-bis (4-aminophenoxy) biphenyl, 2,2′-bis (trifluoromethyl) -4,4′- Diaminobiphenyl, 4,4′-diaminobenzoylanilide, 4-aminophenyl-4-aminobenzoate, bis (4-aminophenyl) terephthalate, Scan (4- (4-aminophenoxy) phenyl) sulfone, bis (4-amino-3-carboxyphenyl) methane, and the like. Among these, 4,4'-diaminodiphenyl ether, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl and the like are preferable. These acid dianhydrides may be used alone or in combination of two or more.

  In the thermoplastic polyimide of the present invention, an acid dianhydride other than H-BPDA and H-PMDA may be used in combination. Examples of acid dianhydrides other than H-BPDA and H-PMDA include ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, 1,2,3,4- Cyclohexanetetracarboxylic dianhydride, pyromellitic dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexa Fluoropropane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, bis (3,4-dicarboxyphenyl) sulfone Dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride 2,2 ′, 3,3′-benzophenonetetracarboxylic dianhydride, 4,4- (p-phenylenedioxy) diphthalic dianhydride, 4,4- (m-phenylenedioxy) diphthalic acid Dianhydride, 1,2,5,6-naphthalenedicarboxylic dianhydride, 1,4,5,8-naphthalenedicarboxylic dianhydride, 2,3,6,7-naphthalenedicarboxylic dianhydride, , , 3,4-benzenetetracarboxylic dianhydride, 2,2 ′, 6,6′-biphenyltetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3 , 6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, and the like. These may be used alone or in combination of two or more. May be. Further, when an acid dianhydride other than H-BPDA and H-PMDA is used, it is usually 20 mol% or less, preferably 10 mol% or less, more preferably 5 mol% or less with respect to all acid dianhydrides used as raw materials. Used in

  The thermoplastic polyimide of this invention may use together diamine compounds other than the diamine compound represented by said Formula (7) as a raw material. Examples of the diamine compound other than the diamine compound represented by the formula (7) include 1,2-phenylenediamine, 1,3-phenylenediamine, 3,4′-diaminodiphenyl ether, 1,3′-bis (4- Aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) benzophenone, 4,4′-bis (3-aminophenoxy) biphenyl, 1,3- Bis [4- (3-aminophenoxy) benzoyl] benzene, bis (4- (3-aminophenoxy) phenyl) sulfone, 1,3-bis (4-aminophenoxy) neopentane, bis (4-amino-3-carboxy) Phenyl) methane, 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 4, '-Methylenebis (2-methylcyclohexylamine), 2- (4-aminophenyl) -5-amino-1H-benzimidazole, 2- (4-aminophenyl) -5- 1H-benzoxazole, 2,2-bis (3-amino-4-hydroxylphenyl) propane, 2,2-bis (3-amino-4-hydroxylphenyl) hexafluoropropane, bis (3-amino-4-hydroxylphenyl) sulfone, and the like are mentioned. Only one type may be used, or a plurality of types may be used in combination. When a diamine compound other than the diamine compound represented by the formula (7) is used, it is usually 20 mol% or less, preferably 10 mol% or less, more preferably 5 mol% or less, based on all diamine compounds used as raw materials. Used in

  In the thermoplastic polyimide of the present invention, the usage ratio of the acid dianhydride and the diamine compound used as raw materials is preferably 0.8 mol or more of the diamine compound with respect to 1 mol of the acid dianhydride. More preferably more than 0.0 mol. On the other hand, it is preferably used at 1.2 mol or less, more preferably 1.1 mol or less. When the ratio of the acid dianhydride used as the raw material to the diamine compound is in such a range, a polyimide having a large molecular weight is easily obtained, and the toughness of the polyimide is obtained, which is preferable. In particular, by using more than 1.0 mol of the diamine compound relative to the acid dianhydride, the terminal amino group is controlled to be more than the terminal of the acid anhydride, and finally obtained by end-capping this. It is preferable in order to increase the sealing rate of the terminal amino group of the polyimide obtained. When there are more acid dianhydrides than diamine compounds, it becomes easier to obtain polyimides with terminal acid anhydrides, and to seal the acid anhydride terminal, it is necessary to use a sealing agent having an amino group It is because there is.

[Thermal imidization reaction process]
In the present invention, the “thermal imidation reaction step” means a step of performing an imidization reaction (condensation and dehydration cyclization reaction) by mixing and heating the above-mentioned raw materials and, if necessary, a solvent and a catalyst. .

  Examples of the solvent used in the thermal imidization reaction include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide. Among these, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like are preferable. These solvents may be used alone or in combination of two or more. In addition, it is preferable to leave the solvent used here as it is, and to perform terminal blocking reaction or chemical imidation reaction.

  Catalysts used in the thermal imidization reaction include trimethylamine, triethylamine, tripropylamine, tributylamine, triethanolamine, pyridine, N, N-dimethylethanolamine, N, N-diethylethanolamine, triethylenediamine, and N-methyl. Examples include pyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, imidazole, quinoline, isoquinoline and the like. These catalysts may be used alone or in combination of two or more.

  The reaction temperature in the thermal imidization reaction is preferably 120 to 200 ° C, more preferably 130 to 190 ° C. The thermal imidization reaction may be performed under normal pressure (0.1 MPa), reduced pressure, or increased pressure, but is usually performed under normal pressure. The reaction time for the thermal imidization reaction is usually 2 hours or longer, preferably 4 to 20 hours.

  Moreover, it is preferable to perform thermal imidation reaction in inert gas atmosphere, for example, it is preferable to carry out in nitrogen atmosphere. Furthermore, in order to allow the thermal imidization reaction to proceed sufficiently, it is preferable to remove water generated by the imidization reaction, and when an azeotropic dehydrating agent such as toluene or xylene is added to the solvent, the water removal efficiency is improved. Can do.

[End-capping reaction step]
In the present invention, the “end capping reaction step” means a step of capping a terminal amino group of polyimide with a terminal capping agent.

  The end capping agent used in the end capping reaction step is not particularly limited as long as it reacts with an amino group to form a stable structure. For example, phthalic anhydride, succinic anhydride, 1,2- Acid anhydrides such as cyclohexanedicarboxylic acid anhydride, 4-methylcyclohexane-1,2-dicarboxylic acid anhydride, (2-methyl-2-propenyl) succinic acid anhydride; organic acid chlorides such as benzoic acid chloride and the like It is done. The end capping agents mentioned above may be used alone or in combination. In addition, when sealing the terminal acid anhydride group of the thermoplastic polyimide of this invention, amine compounds, such as 3-aminophenyl acetylene, aniline, a cyclohexylamine, can also be used as terminal blocker. However, the sealing of the terminal acid anhydride group does not correspond to the sealing of the terminal amino group in the present invention.

  The amount of terminal blocking agent used is preferably 1 to 10 times the number of equivalents of the difference between the number of moles of the diamine compound used as a raw material and the number of moles of acid dianhydride (the amount of unreacted primary amino group). More preferably, the equivalent number is 2 to 8 times. When the amount of the terminal blocking agent used is not less than the above lower limit value, it is preferable for increasing the sealing rate of the terminal amino group. On the other hand, when it is not more than the above upper limit value, there is little purification treatment of the unreacted terminal blocking agent. This is preferable. In addition, when not performing the chemical imidation reaction process mentioned later, increasing the usage-amount of terminal blocker is preferable in order to raise the sealing rate of a terminal amino group.

  The end-capping reaction is preferably performed in a solvent. Examples of the solvent used in the end-capping reaction include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide and the like. Among these, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like are preferable. These solvents may be used alone or in combination of two or more.

  The reaction temperature in the end-capping reaction step is usually 80 to 200 ° C, preferably 120 to 200 ° C. The thermal imidization reaction may be performed under normal pressure (0.1 MPa), reduced pressure, or increased pressure, but is usually performed under normal pressure. The reaction time for the end-capping reaction is usually 1 hour or longer, preferably 2 hours to 10 hours.

[Chemical imidization reaction process]
In the present invention, the “chemical imidation reaction step” usually means a step of mixing a polyimide, an organic amine compound, and a dehydrating condensing agent in a solvent to perform an imidization reaction.

  Examples of organic amine compounds used in the chemical imidation reaction step include tertiary alkylamines such as trimethylamine, triethylamine, tripropylamine, and tributylamine; triethanolamine, N, N-dimethylethanolamine, N, N-diethyl Alkanolamines such as ethanolamine; alkylenediamines such as triethylenediamine; pyridines such as pyridine; pyrrolidines such as N-methylpyrrolidine and N-ethylpyrrolidine; piperidines such as N-methylpiperidine and N-ethylpiperidine; Examples thereof include imidazoles such as imidazole; quinolines such as quinoline and isoquinoline. These catalysts may be used alone or in combination of two or more. The amount of the organic amine compound used is preferably 0.1% by weight or more and less than 15% by weight, more preferably 0.5% by weight or more and less than 5% by weight, based on the solid content of the polyimide resin.

  Examples of the dehydrating condensing agent used in the chemical imidation reaction step include acid anhydrides such as acetic anhydride, trifluoroacetic anhydride, and chloroacetic anhydride; N, N- such as N, N-dicyclohexylcarbodiimide and N, N-diphenylcarbodiimide. Examples thereof include 2-substituted carbodiimide. These dehydrating agents may be used alone or in combination of two or more. The amount of the dehydrating agent used is preferably 0.1% by weight or more, more preferably 0.5% by weight or more based on the solid content of the polyimide resin. In order to obtain the thermoplastic polyimide of the invention, it is preferable to use a large amount of a dehydrating condensing agent, and specifically, it is preferable to use 15% by weight or more. On the other hand, the upper limit of the amount of the dehydrating condensing agent is preferably 30% by weight or less, more preferably 25% by weight or less.

  Examples of the solvent used in the chemical imidation reaction step include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide and the like. Among these, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like are preferable. These solvents may be used alone or in combination of two or more.

  The reaction temperature in the chemical imidation reaction step is usually 40 to 200 ° C, preferably 50 to 160 ° C. The chemical imidization reaction may be performed under normal pressure (0.1 MPa), under reduced pressure, or under pressure, but is usually performed under normal pressure. Moreover, the reaction time of chemical imidation reaction is 30 minutes or more normally, Preferably it is 1 to 6 hours.

  In addition, it is preferable to refine | purify the obtained polyimide by reprecipitation, washing | cleaning, filtration, etc. By this purification, the raw material and catalyst remaining in the system can be removed.

[Combination of additives]
You may mix | blend various additives with the thermoplastic polyimide of this invention in the range which does not impair the effect of this invention. Examples of the additive include an antioxidant, an ultraviolet absorber, a light stabilizer, and an antistatic agent.

  Among the additives mentioned above, it is preferable to use an antioxidant. Examples of the antioxidant include phenol-based antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants. These antioxidants may be used alone or in combination of two or more.

[Polyimide molded product]
A polyimide molded body can be obtained by molding the thermoplastic polyimide of the present invention.

[Molding method]
In the present invention, the method for molding the thermoplastic polyimide molded body is not particularly limited. The molding method can be adopted according to various applications, and examples thereof include an extrusion molding method, an injection molding method, a hollow molding method, and a compression molding method. Furthermore, the thermoplastic polyimide formed body formed by these methods can be processed by a processing method such as a lamination molding method, a roll processing method, a stretching processing method, a stamp processing method, or a hot press method. Among these, as described above, the thermoplastic polyimide of the present invention is remarkably excellent in melt heat stability, so that it is possible to perform molding by melt extrusion molding. From the viewpoint, it is preferable because it can be efficiently produced.

  There are no particular restrictions on the molding conditions of the thermoplastic polyimide molded body. When performing extrusion molding, either a single screw extruder or a twin screw extruder can be used. The temperature of the cylinder of the extruder is usually 280 ° C. to 380 ° C., and the polyimide extruded from the die is cooled by a cooling roll. The temperature of a cooling roll is 0 degreeC-60 degreeC normally.

[Physical properties]
The thermoplastic polyimide molded body of the present invention is excellent in transparency. The transparency of the thermoplastic polyimide molded body is evaluated by the total light transmittance according to JIS K7105 (1981), preferably 70% or more, more preferably 75% or more, still more preferably 80% or more, Particularly preferably, it is 85% or more. The thickness of the thermoplastic polyimide film at this time is not particularly limited, but is usually 0.01 to 10 mm, preferably 0.02 to 5 mm, and particularly preferably 0.03 to 1 mm.

[Usage]
The thermoplastic polyimide molded body obtained from the thermoplastic polyimide of the present invention is excellent in transparency, heat resistance, solvent resistance, moldability, solvent non-volatility, and the like. For this reason, the application to a wide use is possible not only for the film use which is a typical use of a polyimide molded object. For example, flexible solar cell members, display members, IC packaging trays, IC manufacturing trays, IC sockets, wafer carriers, connectors, sockets, hard disk carriers, liquid crystal display carriers, crystal oscillator manufacturing trays, copier separation Claw, heat insulation bearing for copy machine, gear for copy machine, thrust washer, transmission ring, piston ring, oil seal ring, bearing retainer, pump gear, conveyor chain, slide bush for stretch machine, heat-resistant insulating tape, heat-resistant adhesive tape, high density It can be used for a magnetic recording base, a capacitor or a film for a flexible printed circuit board. Moreover, it is used also for manufacture of the molded product of the structural member reinforced with glass fiber, carbon fiber, etc., the bobbin of a small coil, or the terminal insulation tube, for example. Further, it can be used for the production of laminated materials such as insulating spacers, magnetic head spacers or transformer spacers. Moreover, it can be used for manufacture of enamel coating materials such as electric wire / cable insulation coating materials, low-temperature storage tanks, space insulation materials, and integrated circuits. Furthermore, it can be used for the production of heat-resistant yarns, woven fabrics or nonwoven fabrics.

  EXAMPLES The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In addition, the value of various manufacturing conditions and evaluation results in the following examples has a meaning as a preferable value of the upper limit or the lower limit in the embodiment of the present invention, and the preferable range is the above-described upper limit or lower limit value. A range defined by a combination of values of the following examples or values of the examples may be used.

[Polyimide evaluation method]
Evaluation methods for the structure, physical properties and the like of the polyimide produced in the following examples are as follows.

[Terminal amino group sealing rate]
The terminal amino group sealing rate was determined by ¹ H-NMR measurement as follows.
The integrated value of the ortho-position peak (6.75 ppm) with respect to the terminal amino group by the ODA constitutional unit in the polyimide is S ₁ , and the integrated value of the peak (7.61 ppm) shifted by sealing the amino terminal is S ₂ . did. From these values, the terminal amino group sealing rate was determined by the following formula.
(Terminal amino group sealing rate) = 100 × [S ₂ / (S ₁ + S ₂ )]
⁽¹ H-NMR measurement conditions)
Solvent: DMF-d7 (N, N-dimethylformamide-d7)
Frequency: 400MHz
Standard substance: DMF-d7 2.74 ppm
Integration count: 256 times Relaxation time: 1 second

[Imidation rate]
The imidization rate was calculated | required from the amic acid residual rate as follows from the NMR chart obtained in the measurement of the sealing rate of a terminal amino group.
Of the H-BPDA structural units in the polyimide, 5 protons were observed at 1.0-2.0 ppm.
The total integrated value of the peak groups was S _3. An integral value of the peak (9.3~10.3ppm) by amide hydrogen of amic acid structure remaining in the polyimide was _{S 4.} From these values, the imidization ratio was determined by the following formula.
(Imidization rate) = 100 × [1- (5S ₄ / S ₃ )]

[Weight average molecular weight (Mw)]
The polystyrene equivalent weight average molecular weight of the polyimide according to the present invention was determined by gel permeation chromatography (GPC) by the following method. First, GPC of standard polystyrene was measured under the following conditions to prepare a calibration curve. Subsequently, GPC of the sample (polyimide) was measured under the same conditions, and an average molecular weight in terms of polystyrene was obtained.
(GPC measurement conditions)
Column: Shodex AD-80M / S, 3 manufactured by Showa Denko Precolumn: Shodex KF-G, 1 manufactured by Showa Denko, Solvent: N, N-dimethylformamide (including LiBr 50 mmol / L)
Flow rate: 1.0 mL / min
Temperature: Column 35 ° C
Sample concentration: 0.5% by weight
Detector: UV detector Calibration sample: Monodisperse standard polystyrene

[Complex shear viscosity (η ^* ) / Change rate of complex shear viscosity]
Using a rotary rheometer (TA Instruments, ARES-100), the initial complex shear viscosity (η ^* ₀ ) at a frequency of 1 Hz and the complex shear viscosity after 60 minutes (η ^* ₆₀ ) are measured under the following measurement conditions. did.
(Rotating rheometer measurement conditions)
A horizontal plate having a diameter of 25 mm was used as a jig for time dispersion measurement of a rotary rheometer (ARES).
Measurement temperature: 310 ° C
Angular frequency: 1 rad / s
Distortion: 1%
Preheating time: 5 minutes Measurement time: 0-60 minutes

[Synthesis of 3,3 ′, 4,4′-bicyclohexyltetracarboxylic dianhydride (H-BPDA)]
<Synthesis Example 1>
150 parts by weight of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (Mitsubishi Chemical Co., Ltd.) was dissolved in a solution prepared by dissolving 83.3 parts by weight of sodium hydroxide in 593 parts by weight of water. Then, an aqueous solution of 3,3 ′, 4,4′-biphenyltetracarboxylic acid tetrasodium salt was prepared, and the aromatic ring was hydrogenated at 120 MPa at 10 MPaG (relative pressure to the atmosphere) using a ruthenium / carbon catalyst. Turned into. Subsequently, 429 parts by weight of a 49% sulfuric acid aqueous solution was added dropwise, and the precipitated solid was filtered to obtain 3,3 ′, 4,4′-bicyclohexyltetracarboxylic acid (H-BTC).

  33.7 parts by weight of the resulting H-BTC and 90 parts by weight of acetic anhydride were added to the reactor under nitrogen. The mixture was heated with stirring and reacted at reflux temperature (130 ° C. to 140 ° C.) for 3 hours. After the reaction, the reaction solution was cooled to 10 ° C., and the solid was filtered to obtain white crystals. The obtained crystals were washed with toluene and dried with a vacuum drier to obtain 3,3 ′, 4,4′-bicyclohexyltetracarboxylic dianhydride (H-BPDA).

[Production of polyimide]
<Example 1-1>
In a reactor equipped with a dry nitrogen gas introduction tube, a cooler, a condenser, and a stirrer, 60.0 parts by weight of H-BPDA obtained in Synthesis Example 1 and 40.0 of 4,4-diaminodiphenyl ether (ODA) were added. Part by weight, 200 parts by weight of N, N-dimethylacetamide and 95 parts by weight of toluene were added. Subsequently, the inside of a reactor was made into nitrogen atmosphere, internal temperature was heated to 145 degreeC, and the thermal imidation reaction was performed. Water generated accompanying imidization was removed azeotropically with toluene. When heating, refluxing, and stirring were continued for 12 hours, generation of water was not observed.

  Subsequently, 2.2 parts by weight of phthalic anhydride was added, and the mixture was stirred at 145 ° C. for 3 hours to perform end-capping reaction. After stirring for 3 hours, the mixture was heated for 1 hour while removing toluene under reduced pressure. After cooling the internal temperature to 60 ° C., 1.0 part by weight of triethylamine and 2.0 parts by weight of acetic anhydride were added, and the mixture was stirred at 60 ° C. for 3 hours to carry out a chemical imidation reaction to obtain a polyimide solution. The obtained polyimide solution was dropped into methanol, and the deposited polyimide was collected by filtration, dried at 80 ° C. under reduced pressure for 3 hours, and then dried at 150 ° C. under reduced pressure for 3 hours to obtain a polyimide solid. Table 1 shows the physical properties of the obtained polyimide.

<Example 1-2>
In Example 1-1, except having changed the raw material composition into the composition shown in Table 1, it manufactured like Example 1-1 and obtained polyimide. Table 1 shows the physical properties of the obtained polyimide.

<Example 1-3>
In Example 1-1, polyimide was obtained in the same manner as in Example 1-1 except that pyridine was used instead of triethylamine and the raw material composition was changed to the composition shown in Table 1-1. Table 1 shows the physical properties of the obtained polyimide.

<Example 1-4>
In a reactor equipped with a dry nitrogen gas introduction tube, a condenser, a condenser, and a stirrer, 59.1 parts by weight of H-BPDA obtained in Synthesis Example 1 and 40.9 of 4,4-diaminodiphenyl ether (ODA) were obtained. Part by weight, 200 parts by weight of N, N-dimethylacetamide and 95 parts by weight of toluene were added. Subsequently, the inside of a reactor was made into nitrogen atmosphere, the internal temperature was heated to 145 degreeC, and the water generated with imidation was removed azeotropically with toluene. When heating, refluxing, and stirring were continued for 12 hours, generation of water was not observed.

  Subsequently, 6.0 parts by weight of phthalic anhydride was added and stirred at 145 ° C. for 3 hours. After stirring for 3 hours, the mixture was heated for 1 hour while removing toluene under reduced pressure to obtain a polyimide solution. The obtained polyimide solution was dropped into methanol, and the deposited polyimide was collected by filtration, dried at 80 ° C. under reduced pressure for 3 hours, and then dried at 150 ° C. under reduced pressure for 3 hours to obtain a polyimide solid. Table 1 shows the physical properties of the obtained polyimide.

<Examples 1-5 to 1-7>
In Example 1-1, except having changed the raw material composition into the composition shown in Table 1, it manufactured like Example 1-1 and obtained polyimide. Table 1 shows the physical properties of the obtained polyimides.

<Example 1-8>
In a reactor equipped with a dry nitrogen gas introduction tube, a cooler, a condenser, and a stirrer, 60.0 parts by weight of H-BPDA obtained in Synthesis Example 1 and 40.0 of 4,4-diaminodiphenyl ether (ODA) were added. Part by weight, 200 parts by weight of N, N-dimethylacetamide and 95 parts by weight of toluene were added. Subsequently, the inside of a reactor was made into nitrogen atmosphere, the internal temperature was heated to 145 degreeC, and the water generated with imidation was removed azeotropically with toluene. When heating, refluxing, and stirring were continued for 12 hours, generation of water was not observed.

  Then, after cooling internal temperature to 60 degreeC, 10 weight part of triethylamine and 20 weight part of acetic anhydride were added, and it stirred at 60 degreeC for 3 hours, and obtained the polyimide solution. The obtained polyimide solution was dropped into methanol, and the deposited polyimide was collected by filtration, dried at 80 ° C. under reduced pressure for 3 hours, and then dried at 150 ° C. under reduced pressure for 3 hours to obtain a polyimide solid. Table 1 shows the physical properties of the obtained polyimides.

<Example 1-9>
In Example 1-4, except having changed the raw material composition into the composition shown in Table 1, it manufactured like Example 1-1 and obtained the polyimide. Table 1 shows the physical properties of the obtained polyimide.

<Example 1-10>
In Example 1-1, except having changed the raw material composition into the composition shown in Table 1, it manufactured like Example 1-1 and obtained polyimide. Table 1 shows the physical properties of the obtained polyimide.

<Example 1-11>
In Example 1-8, except having changed the raw material composition into the composition shown in Table 1, it manufactured like Example 1-1 and obtained the polyimide. Table 1 shows the physical properties of the obtained polyimide.

<Comparative Examples 1-1 to 1-5>
In Example 1-1, the raw material composition was changed to the composition shown in Table 2, and the production was performed in the same manner as in Example 1-1 except that the terminal capping step and the chemical imidization step were not performed to obtain a polyimide. It was. Table 2 shows the physical properties of the obtained polyimide.

  As can be seen from Tables 1 and 2, all of the polyimides obtained in Examples 1-1 to 1-11 have a complex shear viscosity change rate of 300% or less, and Comparative Examples 1-1 to 1-5. It was a polyimide excellent in melt heat stability and suitable for melt extrusion molding. In particular, in Examples 1-1 to 1-8, the change rate of the complex shear viscosity was 100% or less, and the melt heat stability was remarkably excellent.

[Evaluation of molded polyimide]
Evaluation methods for the structure, physical properties and the like of the polyimide produced in the following examples are as follows.

[Heat resistance: Glass transition temperature (Tg)]
Using a dynamic thermomechanical measurement device (DII / SS6100, manufactured by SII Nanotechnology Co., Ltd.), the storage elastic modulus and loss elastic modulus of the sample with respect to the vibration load of the sample are measured under the following measurement conditions. The temperature (Tg) was determined. It is evaluated that the higher the Tg, the better the heat resistance.
(DMS measurement conditions)
The peak top of the loss tangent (tan δ) obtained by dividing the storage elastic modulus (E ′) of the test piece by the loss elastic modulus (E ″) was defined as the glass transition temperature.
Measurement temperature range: 50 ° C to 400 ° C (temperature increase rate: 2 ° C / min)
Tensile load: 5g
Sample shape: 10mm x 10mm
Sample thickness: listed in Table 3

[Transparency: Total light transmittance]
The total light transmittance of the polyimide film was measured in accordance with JIS standard K7105 (1981). It was evaluated that the higher the total light transmittance was, the better the transparency was. If the total light transmittance was 70% or more, it was judged as acceptable.

[Solvent non-volatility: amount of residual solvent]
It measured according to the following measurement conditions using the differential thermal-thermogravimetry apparatus (TG / DTA6200 by SII nanotechnology Co., Ltd.). After heating 20 mg of a polyimide piece or a polyimide melt-molded product from 40 ° C. to 100 ° C. at a rate of temperature increase of 20 ° C./min, the mixture was allowed to stand at 100 ° C. for 30 minutes. Then, it heated from 100 degreeC to 350 degreeC with the temperature increase rate of 10 degree-C / min, and the weight reduction from 150 degreeC to 300 degreeC was defined as residual solvent content. The lower this value, the better the solvent non-volatility.

[Production of polyimide molded body]
<Example 2-1>
The polyimide obtained in Example 1-1 was supplied to a single screw extruder, melted at 330 ° C., then extruded onto a cooling roll set at 120 ° C., and cooled and solidified to obtain a polyimide film having a thickness of 100 μm. . Said evaluation was performed about the obtained polyimide film. The results are shown in Table 3.

<Example 2-2>
The polyimide obtained in Example 1-2 was supplied to a biaxial stretching extruder, the resin strand obtained by melting at 330 ° C. was water-cooled, and then the strand was cut with a pelletizer to obtain polyimide pellets. The obtained polyimide pellets were supplied to a single screw extruder, melted at 330 ° C., then extruded onto a cooling roll set at 120 ° C., and cooled and solidified to obtain a polyimide film having a thickness of 100 μm. Said evaluation was performed about the obtained polyimide film. The results are shown in Table 3.

<Example 2-3>
A polyimide film was obtained in the same manner as in Example 2-2 except that the thickness of the polyimide film was 50 μm. Moreover, said evaluation was performed about the obtained polyimide film. The results are shown in Table 3.

  As can be seen from Table 3, the polyimide films obtained in Examples 2-1 to 2-3 are excellent in transparency and heat resistance. In particular, it can be seen that there is little weight loss before and after heating and that the solvent is non-volatile.

  Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application filed on Dec. 17, 2012 (Japanese Patent Application No. 2012-274901), the contents of which are incorporated herein by reference.

Claims (5)

A structural unit derived from an acid dianhydride derived and di amine compounds seen including,
The terminal amino group sealing rate is 95.0% or more, and the imidization rate is 95.8% or more,
Structural units derived from previous SL dianhydride represented by the following formula (1),
Thermoplastic polyimide structural units from the previous SL diamine compound represented by the following formula (3).

(In the above formula (3), R ^{1 to} R ⁸ may be different from each other, and are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group, and X is An oxygen atom or an alkylene group having 1 to 4 carbon atoms, and n is an integer of 0 to 4.)   The thermoplastic polyimide according to claim 1, wherein the weight average molecular weight (Mw) is 10,000 to 500,000. 3. The thermoplastic polyimide according to claim 1, wherein the complex shear viscosity (η ^* ) at 310 ° C. is 1 × 10 ^{2 to} 5 × 10 ⁵ Pa · s.   The thermoplastic polyimide according to any one of claims 1 to 3, wherein the rate of change of the complex shear viscosity before and after 60 minutes at 310 ° C is 300% or less.   A thermoplastic polyimide molded body obtained by melt extrusion molding of the thermoplastic polyimide according to any one of claims 1 to 4.