JP5010357B2 - Novel polyamic acid, polyimide and their uses - Google Patents

Description

  The present invention relates to a novel polyimide and its precursor polyamic acid. Furthermore, it is related with the film and adhesive agent using this polyimide and a polyamic acid. Moreover, it is related with the circuit board obtained using the laminated board obtained from those films or adhesives, and this laminated board.

Conventionally, a polyimide is generally obtained by a method in which a diamine and tetracarboxylic dianhydride are reacted in a solvent to form a polyamic acid, which is dehydrated and cyclized. The properties of the polyamic acid and polyimide thus obtained are determined by the selection of the diamine and tetracarboxylic dianhydride to be used and the combination thereof, and various properties are known such as excellent heat resistance and excellent dimensional stability. Among them, many polyimides using aromatic tetracarboxylic dianhydrides as tetracarboxylic dianhydrides have excellent heat resistance and mechanical properties, and are excellent in heat resistance but insoluble insoluble. It may be difficult to use because it may have problems in terms of workability, such as its melting point and extremely high melting point. In recent years, polyimide has been used as an insulating layer and surface protective layer as a circuit material. In general, these are often used by applying a polyamic acid, which is a precursor soluble in an organic solvent, to a substrate, removing the solvent by heat treatment, and proceeding with imidization. The acid amide solvent used at this time has a high boiling point and may cause foaming of the film. Moreover, in order to volatilize a solvent completely, the high temperature drying process of 250 degreeC or more is required, and there exists a problem that it is difficult to process in a general purpose process. In addition, the appearance of aromatic polyimide is colored brown due to oxidative degradation of impurities contained in these high-temperature processing processes, and formation of intramolecular and intermolecular complexes called charge transfer complexes (CT complexes). There are many.

  In addition, polyimide has been applied to various fields and has been used in various parts of electronic devices. In addition to semiconductor packaging materials, circuit base materials, films can be used to protect parts and circuits, or as adhesives for bonding various electronic parts and circuit materials. Among these various applications, in addition to the heat resistance and insulation properties conventionally required, properties such as transparency and workability at a low temperature have been required.

  Furthermore, since the conventional aromatic polyimide material has a rigid skeleton in order to improve heat resistance, there are problems such as large warp and brittleness when formed into a film by shrinkage after imidation, and these can be solved. Development of a new polyimide has been desired.

A polyimide precursor having both low-temperature processability and low colorability is disclosed in Patent Document 1. In patent document 1, in order to provide the low coloring polyimide which can be processed at a relatively low temperature, a solution is prepared by mixing another compound with the precursor solution. However, this only suppresses the dew generation of the nature of the original skeleton of the polyimide by diluting with other compounds, and has not led to an essential solution of the problem. Further, although Patent Documents 2 to 4 propose polyimides that can be processed at a low temperature and have low warpage, the performance thereof is insufficient. On the other hand, a polyimide that is transparent and has no warpage is disclosed in Patent Document 5, but this requires processing at a high temperature of 300 ° C. or higher and is not satisfactory.
Japanese Unexamined Patent Publication No. 9-012883 Japanese Patent Laid-Open No. 2002-145981 JP 2005-36025 A JP 2005-154502 JP 2004-149724 A

  The present invention is to obtain a polyimide resin which is highly transparent, excellent in warping and bending resistance, soluble in a low boiling point organic solvent, and imidizable at a low temperature, and its precursor polyamic acid. As a result of intensive studies, it has been found that a polyimide resin having a specific structure solves the above problems, and has reached the present invention.

The present inventors have intensively studied to solve the above-mentioned problems, and as a result, completed the present invention.
That is, the present invention
(A) a tetracarboxylic dianhydride represented by the following formula (1) as a structural unit;

Diamine (I) represented by the following formula (2) and

(Wherein R ₁ , R ₂ , R ₄ , R ₅ , R ₇ , R ₈ , R ₁₀ , R ₁₁ , R ₁₃ , R ₁₄ are each independently a hydrogen atom or a C ₁ -C ₅ alkyl group. R ₃ , R ₆ , R ₉ , R _{12 and} R ₁₅ each represent a C _{1 to} C ₅ alkylene group, and m, n and p are each independently an integer of 0 or more. Represents.)
A novel polyamic acid characterized in that it contains as an essential component.

  (B) an acid dianhydride represented by the following formula (1) as a structural unit;

Diamine (I) represented by the following formula (2) and

(Wherein R ₁ , R ₂ , R ₄ , R ₅ , R ₇ , R ₈ , R ₁₀ , R ₁₁ , R ₁₃ , R ₁₄ are each independently a hydrogen atom or a C ₁ -C ₅ alkyl group. R ₃ , R ₆ , R ₉ , R _{12 and} R ₁₅ each represent a C _{1 to} C ₅ alkylene group, and m, n and p are each independently an integer of 0 or more. Represents)
Diamines represented by the following formula (3) as other diamines (II)

A novel polyamic acid characterized in that it contains as an essential component.

(C) the polyamic acid of (B),
Novel polyamic acid in which the ratio (x: y) of the number of moles x of amino groups of diamine (I) to the number of moles y of amino groups of other diamine (II) is in the range of 100: 0 to 35:65 .

(D) Polyamic acid of (A) to (C),
The ratio (a: b) of the total mole number a of acid dianhydride a to the sum b of moles of amino groups of diamine (b = x + y) is from 0.8: 1 to 1.25: 1 A novel polyamic acid characterized by being in the range.

(E) A polyimide in which part or all of the amide acid of the polyamic acid of (A) to (D) is imidized.
(F) A film comprising the polyamic acid of (A) to (D) and / or the polyimide of (E).
(G) An adhesive comprising the polyamic acid of (A) to (D) and / or the polyimide of (E).
(H) A laminate comprising the film layer of (F).
(I) A laminate comprising the adhesive layer of (G).
(J) A circuit board comprising the laminate of (H) and / or (I).
About.

  The polyamic acid and polyimide of the present invention are excellent in warpage resistance and flex resistance, soluble in a low boiling point organic solvent, and excellent in moldability.

  Hereinafter, the present invention will be described in detail. The polyamic acid of the present invention is 4,4′-oxydiphthalic dianhydride (the following formula (1)) as a raw material.

It is essential to use. Although there is no restriction | limiting in particular as 4,4'- oxydiphthalic dianhydride, Since it is easy to obtain a high molecular weight thing as a polyamic acid and a polyimide, it is preferable to use a high purity thing. Specifically, a ring closure rate of 98%, more preferably 99% or more is preferable.

  In addition to the above tetracarboxylic dianhydride, the polyamic acid of the present invention may be used in combination with a known acid dianhydride as long as the effect is not impaired. Examples thereof include 1,2,4,5-benzenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, and the like, which are generally used as raw materials for polyimide. The tetracarboxylic dianhydride can be used. The amount is 50% by weight or less, preferably about 30% by weight or less, of the total tetracarboxylic dianhydride used.

  The polyamic acid of the present invention contains a diamine represented by the following general formula (2) as a raw material diamine.

(Wherein R ₁ , R ₂ , R ₄ , R ₅ , R ₇ , R ₈ , R ₁₀ , R ₁₁ , R ₁₃ , R ₁₄ are each independently a hydrogen atom or a C ₁ -C ₅ alkyl group. R ₃ , R ₆ , R ₉ , R _{12 and} R ₁₅ each represent a C _{1 to} C ₅ alkylene group, and m, n and p are each independently an integer of 0 or more. Represents.)
In the formula, examples of the C ₁ -C ₅ alkyl group include a methyl group and an ethyl group, and a methyl group is preferable. R ₃ , R ₆ , R ₉ , R _{12 and} R ₁₅ are C _{1 to} C ₅ alkylene groups such as methylene group, ethylene group, propylene group, butylene group, preferably ethylene group, It is a butylene group. m, n, and p are each independently an integer of 0 or more, preferably 0-20, more preferably 0-10.

  Specific examples of the diamine represented by the general formula (2) include polyoxyethylenediamine such as 1,8-diamino-3,6-dioxyoctane, polyoxypropylenediamine, and other oxyalkylene groups having different lengths. Examples include polyoxyalkylene diamines and the like. As polyoxyalkylene diamines, polyoxyethylene diamines such as Jeffamine EDR-148 and EDR-176 by Huntsman, Inc., polyoxypropylene diamines such as Jeffamine D-230, D-400, D-2000, and D-4000, Those having different oxyalkylene groups such as HK-511, ED-600, ED-900, ED-2003, XTJ-542, etc. can be exemplified as those that are commercially available. In particular, low molecular weight materials such as EDR-148, D-230, D-400, and HK-511 can be polymers with a relatively high glass transition temperature, and can be used in applications where heat resistance, chemical resistance, etc. are required. be able to. On the other hand, those having a relatively high molecular weight such as D-2000 are excellent in flexibility, low boiling point solvent solubility and the like. In addition, it is easier to obtain a high molecular weight polyamic acid and polyimide by using one having a high purity. The purity is preferably 95% or more, more preferably 97% or more, and further preferably 98.5% or more.

  In the polyamic acid of the present invention, it is also preferable to use 1,3-bis (3-aminophenoxy) benzene (APB) represented by the following formula (3) as the other diamine (II).

  The 1,3-bis (3-aminophenoxy) benzene is not particularly limited, but it is easier to obtain a high molecular weight polyamic acid and polyimide by using one having a high purity. The purity is preferably 95% or more, more preferably 97% or more, and further preferably 98.5% or more.

  In the polyamic acid of the present invention, other diamines may be used in addition to the above two kinds of diamines. Examples of preferred diamines that can be used in combination include aromatic diamines, aliphatic diamines, alicyclic diamines, and siloxane diamines. Examples of aromatic diamines include diamines common to polyimide synthesis such as 4,4'-diaminodiphenyl ether and 4,4'-diaminobenzophenone. Examples of the aliphatic diamine include alkylene diamines such as hexamethylene diamine. Examples of the alicyclic diamine include diamines containing a norbornene ring or the like in the main skeleton. These diamines can be used in a range that does not change the properties of the polyamic acid of the present invention (usually 30% by weight or less in the total amount of diamines added).

  In the case of obtaining the polyamic acid of the present invention, the ratio (x: y) of the number of moles x of amino groups of diamine (I) to the number of moles y of amino groups of other diamine (II) is from 100: 0 to 35: Preferably it is within the range of up to 65. More preferably, it is in the range of 100: 0 to 50:50. The range of 90:10 to 60:40 is more preferable. When it is within these ranges, the polyimide obtained by imidizing the polyamic acid of the present invention can have sufficient transparency and flexibility. When it is out of this range, the warp resistance and flex resistance of the resulting polyimide may not be sufficient.

  In obtaining the polyamic acid of the present invention, the polyoxyalkylene portion of the diamine (I) acts as a so-called soft segment as compared to a rigid polymer segment such as an aromatic ring. When the amount of the soft segment, that is, the amount of the diamine containing the polyoxyalkylene part is sufficient, a polyimide having good warpage resistance and flex resistance is provided. On the other hand, if the amount is too large, a polyimide having poor solvent resistance and chemical resistance is provided. It will be. Therefore, the weight of diamine (I) is preferably in the range of 10% to 70% by weight with respect to the weight of the polyamic acid. More preferably, it is in the range of 30 wt% to 60 wt%.

  In the polyamic acid of the present invention, the ratio (a: b) of the total number of moles a of acid anhydrides of acid dianhydrides to the sum b of moles of amino groups of diamine (b = x + y) is from 0.80: 1. Preferably it is in the range up to 1.25: 1. More preferably, it is in the range of 0.85: 1 to 1.18: 1, more preferably in the range of 0.90: 1 to 1.11: 1. Within these ranges, a polyamic acid or polyimide having a sufficiently high molecular weight and excellent heat resistance, flex resistance and the like is obtained.

  Reaction of tetracarboxylic dianhydride and diamine can be performed by a well-known method in an aprotic polar solvent. Examples of the aprotic polar solvent include N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as NMP), tetrahydrofuran (THF). ), Diglyme, cyclohexanone, 1,4-dioxane and the like. Only one type of aprotic polar solvent may be used, or two or more types may be used as a mixture. At this time, there is no problem even if a non-polar solvent compatible with the aprotic polar solvent is used, and aromatic hydrocarbons such as toluene, xylene, mesitylene, and solvent naphtha are often used. The ratio of the nonpolar solvent in the mixed solvent is preferably 30% by weight or less. This is because when the amount of the nonpolar solvent is 30% by weight or more, the dissolving power of the solvent is lowered and polyamic acid may be precipitated. The reaction between tetracarboxylic dianhydride and diamine is preferably a method in which a well-dried diamine component is dissolved in the above-mentioned reaction solvent obtained by dehydration and purified, and a well-dried tetracarboxylic dianhydride is added to advance the reaction. .

  The polyamic acid of the present invention may be used after synthesizing by heating and dehydrating a part of the constituent components in a high boiling point solvent during synthesis. Since the water generated by the imidization reaction hinders the ring-closing reaction, an organic solvent that is incompatible with water is added to the system and azeotroped to use the equipment such as Dean-Stark tube. To discharge. The use of compounds such as acetic anhydride, β-picoline and pyridine as a catalyst for the imidization reaction is not precluded.

  Since the polyamic acid of the present invention is a polyimide precursor, it can be used after being converted into a polyimide. There is no restriction | limiting in particular as the method of imidization, Any well-known methods of so-called thermal imidation and chemical imidization can be used. In the present invention, a method for performing a dehydration cyclization reaction by heating will be described more specifically, but the method is not particularly limited. The imidization by heating is not particularly limited. For example, a film obtained by applying and drying a polyamic acid solution obtained by dissolving the obtained polyamic acid in a solvent on a substrate and heating the obtained film in an oven or the like. Can be obtained.

  In the present invention, the polyamic acid and polyimide obtained as described above are dissolved in an organic solvent, and the solution can be used as it is as a coating varnish. Moreover, these solutions can be put into a poor solvent to reprecipitate the resin to remove the unreacted monomer and purified, dried and used as a solid resin. In applications where high temperature processes are disliked, and particularly in applications where impurities and foreign matters are problematic, it is preferable to dissolve in an organic solvent again to obtain a filtered and purified varnish. The solvent used at this time can be selected from a solvent having a low boiling point in consideration of workability.

  Examples of organic solvents that can be used include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone as ketone solvents, and 1,4-dioxane, tetrahydrofuran, diglyme, and the like as ether solvents. These solvents may be used alone or in combination of two or more.

  Although the usage method of the polyamic acid of this invention is not specifically limited, For example, it can use as an adhesive agent as a single solution or the solution which mixed various additives. Moreover, the said solution can be used by forming into a film by apply | coating and drying on a base material. Further, these adhesives and films can be further cured in an oven or the like to obtain polyimide, which can be used as a base film, a cover film, or an adhesive film used for circuit materials. In particular, it is possible to obtain a circuit material that is excellent in flexibility and excellent in folding resistance and bending resistance. In this case, additives that can be added are not particularly limited, but inorganic fillers, flame retardants, other additives, and the like can be added.

(Inorganic filler)
The type of inorganic filler is not particularly limited, and examples thereof include silica, alumina, titanium oxide, talc, calcined talc, kaolin, calcined kaolin, mica, clay, aluminum nitride, and glass. When these inorganic fillers use a coupling agent, the adhesion between the resin and the filler improves. There is no restriction | limiting in particular as a coupling agent used in that case. The inorganic filler content is generally used in the range of 10 to 150 parts by mass with respect to 100 parts by mass of the total amount of resin components.

(Flame retardants)
The type of flame retardant is not particularly limited, and examples thereof include halogen-containing compounds, phosphorus-containing compounds, and inorganic flame retardants. These may be used alone or in combination of two or more. For example, in the case of a halogen-containing organic compound, the content is generally in the range of about 0.1 to 10% by mass as the content of bromine atoms with respect to the total amount 100 of resin components. Moreover, in the case of a phosphorus-containing organic compound, it is generally used in the range of about 0.1 to 5% by mass as the phosphorus atom content with respect to the total amount of resin components of 100. In the case of an inorganic flame retardant, it is generally used in the range of 25 to 150 parts by mass with respect to 100 parts by mass of the total amount of resin components.

(Additive)
Although there is no restriction | limiting in particular as a kind of additive, The additive etc. which are generally used as an antifoamer, a leveling agent, and a surface tension regulator are mention | raise | lifted. The content is generally used in the range of 0.0005 to 10 parts by mass with respect to 100 parts by mass of the total amount of the resin components.

(Mixed with thermosetting resin)
Moreover, the polyamic acid of this invention can be used as a thermosetting adhesive sheet by mixing with thermosetting resins, such as an epoxy resin and a thermosetting polyimide, and shape | molding it in a film form, for example. Adhesiveness, thermocompression bonding, and the like can be obtained by controlling the molecular weight of the polyamic acid and / or polyimide. The thermosetting rate can be controlled by controlling the amic acid concentration (partial imidization ratio). There is no restriction | limiting in particular as an epoxy resin, All the epoxy compounds which have two or more epoxy groups in a molecule | numerator can be used. There is no restriction | limiting in particular as a thermosetting polyimide, All thermosetting polyimides, such as a bismaleimide or polybismaleimide resin, BT resin, and a polyimide resin with a nadic acid terminal, can be used. These thermosetting resins can be used singly or as a mixture of two or more. When mixing a thermosetting resin, additives, such as a hardening | curing agent and a hardening accelerator, can also be mixed suitably. The content of these thermosetting resins is generally used in the range of 10 to 90% with respect to the total amount 100 of resin components.

(Mixed with photo-curing resin)
Further, the polyamic acid of the present invention can be used as a photosensitive polyimide film that can be exposed and developed by mixing with a photocurable resin such as an acrylic acid compound and molding the mixture into a film. At this time, the developability to various organic solvents and aqueous alkali solutions can be controlled by controlling the amount of amine (II) in the polyamic acid skeleton and the concentration of amic acid. The acrylate is not particularly limited, and any acrylic acid compound having two or more acrylic acid groups or methacrylic acid groups in the molecule can be used. These photocurable resins can be used singly or as a mixture of two or more. When mixing a photocurable resin, additives, such as a photoinitiator, a photoinitiator auxiliary agent, and a sensitizer, can also be mixed suitably. As content of these photocurable resins, generally it is used in 10 to 90% of range with respect to the total amount 100 of a resin component.

(Laminated board)
The polyamic acid and the polyimide of the present invention can be made into a laminate by forming a film as a single or a mixture as described above and then appropriately laminating. In that case, it can be used by making it the base substrate of a flexible printed wiring board by laminating | stacking with a well-known polyimide film and copper foil, or making it the cover film of the processed flexible printed wiring board.

(Circuit board)
The polyamic acid and the polyimide of the present invention can be used as a circuit board using the above-mentioned laminated plate. In that case, the above-mentioned base substrate can be processed into a circuit and covered with a known cover film, or the known base substrate can be processed into a circuit substrate covered with the above-described cover film.

Examples of the present invention will be described below. Evaluation in Examples was performed as follows.
Imidization rate: Polyamide acid was applied and dried on copper foil, and the thickness was set to 20 μm. After curing in an oven at 160 ° C. for 30 minutes, the absorption strength of the amide group was measured with an infrared absorption measuring device, before curing. The residual ratio of amide groups was taken as the standard. The imidization rate was calculated by using the imidation rate as the following formula.

  Solubility: After curing on copper foil, the film was immersed in NMP solution and observed whether it completely dissolved within 1 hour.

  Transmittance: The film coated and dried on glass was further cured in an oven at 160 ° C. for 30 minutes, and then a transmittance of 365 nm was determined using a UV-VIS absorbance measuring apparatus.

Warpage: A sample made up to a cure on a polyimide (Kapton (registered trademark) EN, manufactured by Toray DuPont Co., Ltd.) film (25 μm) was cut into a 5 cm square, and the amount of lift at the four ends was measured on a horizontal table. Folding resistance with an average value of “warp”: A polyamic acid solution was applied and dried on a PET film and dried to a thickness of 20 μm. A flexible printed circuit board material (Neoflex (registered trademark), manufactured by Mitsui Chemicals, Inc.) Then, a polyimide having a thickness of 18 μm, a copper foil thickness of 9 μm, and a double-sided board) subjected to circuit processing of L / S = 50/50 μm was laminated at a lamination temperature of 60 ° C. using a vacuum laminator (manufactured by Meiki Co., Ltd.). Further, imidization was performed in an oven at 160 ° C. for 30 minutes, and the resultant circuit board was subjected to a folding test at a load of 100 g and R = 0.3 mm. The case where cracks did not occur on the laminate film 10 times or more was marked as ◯, and the case where cracks occurred 10 times or less was marked as x.

Example 1
450 g of dehydrated and purified NMP was placed in a four-necked flask equipped with a dry nitrogen gas inlet tube, a thermometer, and a stirrer, and stirred vigorously for 10 minutes while flowing nitrogen gas. Next, 81.1 g (0.332 mol) of Jeffamine D230 (average molecular weight 243.9) manufactured by Huntsman Co. was charged and stirred until uniform. Further, 100.0 g (0.322 mol) of 4,4′-oxydiphthalic dianhydride (ODPA, molecular weight 310.2) was added little by little while cooling the system to 5 ° C. in an ice water bath. Thereafter, stirring was continued for 12 hours. During this time, the flask was kept at 5 ° C. With respect to the polyamic acid solution thus prepared, physical properties such as imidization rate, solubility, transmittance, warpage, and folding resistance were measured using the methods described above. The composition and evaluation results are shown in Table 1.

Example 2
In a four-necked flask equipped with a dry nitrogen gas inlet tube, a thermometer, a condenser, a stirrer, and a Dean-Stark tube, 100.0 g (0.322 mol) of 4,4′-oxydiphthalic dianhydride (ODPA, molecular weight 310.2) Weigh and add. Add 135 g of 1,3,5-trimethylbenzene and stir to form a slurry. 315 g of dehydrated and purified NMP was added thereto and further stirred. Next, 56.7 g (0.232 mol) of Jeffamine D230 (average molecular weight 243.9) manufactured by Huntsman was slowly added dropwise with vigorous stirring. The system was heated to 175 ° C. using an oil bath, and generated water was removed from the system. When heated for 4 hours, no water was observed from the system. The system was cooled to 25 ° C. with an ice-water bath. To the cooled portion, 26.7 g (0.09 mol) of 1,3-bis (3-aminophenoxy) benzene (APB, molecular weight 292.3) was added little by little in powder form, and stirring was continued for 12 hours. During this time, the flask was kept at 30 ° C. Evaluation was performed in the same manner as in Example 1.

Examples 3-7
Synthesis and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1
Under the same conditions as in Example 1, 4,4′-oxydiphthalic dianhydride and 4,4′-diaminophenyl ether were reacted to obtain a polyamic acid solution. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

Comparative Examples 2-3
In the same manner as in Example 1, the polyamic acid obtained by performing the reaction with the formulation shown in Table 2 was evaluated.

Explanation of abbreviations in the table:
ODPA: 4,4′-oxydiphthalic dianhydride, manufactured by Manac (product name ODPA-M), molecular weight 310.2
PMDA: 1,2,4,5-benzenetetracarboxylic dianhydride, manufactured by Daicel Chemical Industries, molecular weight 218
Jeffamine D230: Polyoxypropylenediamine, manufactured by Huntsman (product name Jeffamine D230), average molecular weight of about 230 Jeffamine D400: Polyoxypropylenediamine, manufactured by Huntsman (product name: Jeffamine D400), average molecular weight of about 400 Jeffamine EDR148: Poly Oxyethylenediamine, manufactured by Huntsman (product name Jeffermin EDR148), molecular weight of about 148 Jeffamine XTJ542: a product obtained by dimerizing a copolymer of polytetramethylene ether glycol and propylene glycol, manufactured by Huntsman (product name Jeffermin XTJ542), average About 1000 molecular weight APB: 1,3-bis (3-aminophenoxy) benzene, manufactured by Mitsui Chemicals (product name APB-N), molecular weight 292.3
ODA: 4,4'-diaminophenyl ether, molecular weight 200.2
DODA: 1,12-diaminododecane, molecular weight 200

  The polyamic acid of the present invention can complete imidization at a low temperature of 160 ° C. for 30 minutes, has high ultraviolet light transmittance, and is excellent in warpage resistance and folding resistance. On the other hand, in a general polyamid (Comparative Example 1), the imidation rate is low at 160 ° C. for 30 minutes, and the transmittance of ultraviolet light is also very low. In addition, there is a problem that the warp is severely curled, and since it is brittle, a crack is generated in the folding test. Further, when diamine (I) is not used (Comparative Example 2), the warp is severely curled. Further, when other than ODPA is used as the tetracarboxylic dianhydride (Comparative Example 3), there are problems such as low transmittance of ultraviolet light and cracks in the folding resistance test.

  The polyamic acid and polyimide of the present invention have excellent warpage resistance and folding resistance, and can be imidized at a low temperature and in a short time, so that insulation for electronic circuit boards such as flexible printed boards can be used as films and adhesives. Can be used for materials and is useful. Moreover, since transparency is favorable, it can be used as a photocurable film or an adhesive by mixing with a photocurable resin, and is also useful as a coating material for circuit boards.

Claims (10)

As a structural unit , an acid dianhydride represented by the following formula (1) ;

And diamines represented by the following general formula (2) as the diamine (I),

Wherein R ₁ , R ₂ , R ₄ , R ₅ , R ₇ , R ₈ , R ₁₀ , R ₁₁ , R ₁₃ , R ₁₄ are each independently a hydrogen atom or a C ₁ -C ₅ alkyl group. a represents, rather it may also be the same or different,
R ₃ , R ₆ , R ₉ , R ₁₂ , R _{15 each} represents a C _{1 to} C ₅ alkylene group;
m, n and p each independently represents an integer of 0 or more )
Diamines represented by the following formula (3) as other diamines (II) ,

Including, Polyamide acid as an essential component. The other diamine (II) comprises a diamine represented by the formula (3),
A number x of moles amino group of the diamine (I), the ratio of the molar number y of the amino group of the other diamine (II) (x: y) is less than 100: 0 than in the range of up to 50:50 Oh Ru, polyamides acid of claim 1. The other diamine (II) comprises a diamine represented by the formula (3) and an alkylene diamine,
The ratio (x: y) of y, which is the sum of the number of moles of amino groups of the diamine (I) and the number of moles of amino groups of the other diamines (II), is less than 100: more than 0 to 50:50 The polyamic acid according to claim 1, which is within the range of The ratio of the total molar number a number of moles of amino groups of a diamine of the sum b of the acid anhydride of the acid dianhydride (b = x + y) ( a: b) is 0.8: 1 to 1.25: to 1 The polyamic acid as described in any one of Claims 1-3 which is in the range. The polyimide which a part or all of the amide acid of the polyamic acid as described in any one of Claims 1-4 imidated. In any one of claims 1 to 4 comprising a polyimide according to the polyamic acid and / or claim 5, wherein, full Irumu. In any one of claims 1 to 4 comprising a polyimide according to the polyamic acid and / or claim 5, wherein, adhesives. At least one layer including a product layer plate film layer according to claim 6. At least one layer including a product layer plate an adhesive layer according to claim 7. 8. or is Ru manufactured from laminate according to 9, circuitry board.