JP2008308550A - Novel polyamic acid, polyimide, and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyimide resin with high transparency useful as a circuit material, excellent in warpage-proof property, soluble in an organic solvent of a low boiling point and capable of being imidized at a low temperature, and a polyamic acid, i.e., its precursor. <P>SOLUTION: The novel polyamic acid contains a tetracarboxylic acid dianhydride represented by formula (1) and a diamine (I) represented by formula (2) (wherein, R represents a divalent bonding group selected from a 1-4C alkylene group which may be substituted by a halogen atom, an ether group, a thioether group, a carbonyl group and an imino group, and n represents 0 or 1) as essential components. <P>COPYRIGHT: (C)2009,JPO&INPIT

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 conventional aromatic polyimide materials have a rigid skeleton to improve heat resistance, there are problems such as large warpage when formed into a film due to shrinkage after imidization, and a novel polyimide that can solve these problems Development of was 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 has been intensively studied to obtain a polyimide resin having high transparency, excellent warpage resistance, soluble in a low boiling point organic solvent, and imidizable at low temperature, and its precursor polyamic acid. As a result, the inventors have found that a polyimide resin having a specific structure can solve the above-mentioned problems, and have 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),

(In the formula, R represents a divalent linking group selected from an alkylene group, an ether group, a thioether group, a carbonyl group, and an imino group, which may be substituted with a C ₁ -C ₂ halogen atom, A novel polyamic acid characterized by containing 0 or 1 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

(In the formula, R represents a divalent linking group selected from an alkylene group, an ether group, a thioether group, a carbonyl group, and an imino group, which may be substituted with a C ₁ -C ₂ halogen atom, Represents 0 or 1),
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 (A) or (B),
The ratio (x: y) of the number of moles x of amino groups of diamine (I) to the total number of moles y of amino groups of other diamines (II) is in the range from 100: 0 to 35:65. And a new polyamic acid.
(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 include 1,2,4,5-benzenetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, etc. Carboxylic dianhydrides can be used. The amount thereof is 50% by weight or less, preferably 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.

(In the formula, R represents a divalent linking group selected from an alkylene group, an ether group, a thioether group, a carbonyl group, and an imino group, which may be substituted with a C ₁ -C ₂ halogen atom, Represents 0 or 1)
As specific examples of the diamine compound represented by the general formula (2), when n is 1, 2,5-bis (aminomethyl) bicyclo [2,2,1] heptane, 2,5-bis (amino) Methyl) bicyclo [2,2,2] octane, 2,5-bis (aminomethyl) -7,7-difluorobicyclo [2,2,1] heptane, 2,5-bis (aminomethyl) -7,7 , 8,8-tetrafluorobicyclo [2,2,2] octane, 2,5-bis (aminomethyl) -7-oxabicyclo [2,2,1] heptane, 2,5-bis (aminomethyl)- 7-thiabicyclo [2,2,1] heptane, 2,5-bis (aminomethyl) -7-oxobicyclo [2,2,1] heptane, 2,5-bis (aminomethyl) -7-azabicyclo [2 , 2,1] heptane, 2,6-bis (aminomethyl) ) Bicyclo [2,2,1] heptane, 2,6-bis (aminomethyl) bicyclo [2,2,2] octane, 2,6-bis (aminomethyl) -7,7-difluorobicyclo [2,2 , 1] heptane, 2,6-bis (aminomethyl) -7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2,6-bis (aminomethyl) -7-oxybicyclo [ 2,2,1] heptane, 2,6-bis (aminomethyl) -7-thiobicyclo [2,2,1] heptane, 2,6-bis (aminomethyl) -7-oxobicyclo [2,2,1 Heptane, and 2,6-bis (aminomethyl) -7-iminobicyclo [2,2,1] heptane, and when n is 0, 2,5-diaminobicyclo [2,2,1] heptane, 2,5-diaminobicyclo [2,2,2] o Kutan, 2,5-diamino-7,7-difluorobicyclo [2,2,1] heptane, 2,5-diamino-7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2 , 5-Diamino-7-oxabicyclo [2,2,1] heptane, 2,5-diamino-7-thiabicyclo [2,2,1] heptane, 2,5-diamino-7-oxobicyclo [2,2 , 1] heptane, 2,5-diamino-7-azabicyclo [2,2,1] heptane, 2,6-diaminobicyclo [2,2,1] heptane, 2,6-diaminobicyclo [2,2,2] ] Octane, 2,6-diamino-7,7-dimethylbicyclo [2,2,1] heptane, 2,6-diamino-7,7-difluorobicyclo [2,2,1] heptane, 2,6-diamino -7,7,8,8-tetrafur Robicyclo [2,2,2] octane, 2,6-diamino-7-oxybicyclo [2,2,1] heptane, 2,6-diamino-7-thiobicyclo [2,2,1] heptane, 2,6 -Diamino-7-oxobicyclo [2,2,1] heptane and 2,6-diamino-7-iminobicyclo [2,2,1] heptane. However, the aminomethyl group when n is 1 and the stereoisomers of the amino group when n is 0 are not distinguished and are the same. Further, there are two kinds of substitution positions, 2, 5 and 2, 6 positions, but in the present invention, a mixture of them is treated as one kind without distinction. Therefore, the purity of the aliphatic diamine represented by the general formula (2) is a value obtained by summing them without distinguishing stereoisomers and substitutional position isomers.

  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 99.5% 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, the following may be used as the other diamine (II) in addition to the two kinds of diamines described above. Examples of preferable diamines 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 aliphatic diamines include alkylene diamines such as hexamethylene diamine, and polyoxyalkylene diamines. 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).

  When 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 total number of moles y of amino groups of other diamine (II) is from 100: 0 to 35. : It is preferable to be within the range 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.

  When obtaining the polyamic acid of this invention, the norbornene part of diamine (I) acts as a segment with high transparency compared with polymer segments, such as an aromatic ring. When the amount of the diamine containing the norbornene portion is sufficient, a good polyimide with high transparency is provided. On the other hand, when too large, a polyimide which is brittle and inferior in bending resistance is provided. 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. Aprotic polar solvents are 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 proportion 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 then 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: The cured film on the copper foil was immersed in an NMP solution, and it was observed whether it completely dissolved within 1 hour.

    Transmittance: Similarly, a 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 measurement device.

Warpage: Similarly polyimide (Kapton (registered trademark) EN, manufactured by Toray DuPont Co., Ltd., cut to 5 cm square on a film (25 μm), cut into 5 cm square, and measured the amount of lift at the four ends on a horizontal table The average value was “warp”. Folding resistance: 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), Mitsui Chemicals ( Co., Ltd., polyimide thickness 18 μm, copper foil thickness 9 μm, double-sided board) with L / S = 50/50 μ circuit processing, using a vacuum laminator (made by Meiki Co., Ltd.) at a laminating temperature of 60 ° C. Further, imidization was performed in an oven at 160 ° C. for 30 minutes, and the resulting circuit board was subjected to a folding test at a load of 100 g and R = 0.3 mm. A case where the crack does not enter ○, if the crack in less than 10 times was × to.

Example 1
400 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, 48.2 g (0.313 mol) of 2,5-bis (aminomethyl) bicyclo [2,2,1] heptane (hereinafter sometimes abbreviated as NBDA (molecular weight 154)) is added until the mixture becomes uniform. Stir. Further, 100.0 g (0.322 mol) of 4,4′-oxydiphthalic dianhydride (ODPA, molecular weight 310) 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. The polyamic acid solution thus obtained was measured for physical properties such as imidization rate, solubility, transmittance, warpage, and folding resistance. 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, thermometer, condenser, stirrer, and Dean-Stark tube, 100.0 g (0.322 mol) of 4,4′-oxydiphthalic dianhydride (ODPA, molecular weight 310) Weighed and added. 135 g of 1,3,5-trimethylbenzene was added and stirred to form a slurry, and 315 g of dehydrated and purified NMP was added thereto and further stirred. Next, 33.7 g (0.219 mol) of NBDA (molecular weight 154) 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 about 25 ° C. with an ice-water bath, and 27.4 g (0.094 mol) of 1,3-bis (3-aminophenoxy) benzene (APB, molecular weight 292) was added little by little while being cooled. . Stirring was then continued for 12 hours, during which time the flask was kept at 30 ° C. Evaluation was performed in the same manner as in Example 1.

Examples 3-6
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
NBDA: Mixture of 2,5-bis (aminomethyl) bicyclo [2,2,1] heptane and 2,6-bis (aminomethyl) bicyclo [2,2,1] heptane, manufactured by Mitsui Chemicals, Inc., molecular weight 154
APB: 1,3-bis (3-aminophenoxy) benzene, manufactured by Mitsui Chemicals (product name APB-N), molecular weight 292
ODA: 4,4'-diaminophenyl ether, molecular weight 200
HMDA: 1,6-diaminohexane, molecular weight 116
DODA: 1,12-diaminododecane, molecular weight 200
14EL: Polyoxyalkylene-containing diamine, manufactured by Ihara Chemical Co. (product name Elastomer 14EL), average molecular weight of about 1250

  When the polyamic acid of the present invention is used, imidization can be completed in a short time at 160 ° C. for 30 minutes, and the transmittance of ultraviolet light is high, and the warpage resistance and folding resistance are excellent. On the other hand, a general polyamic acid (Comparative Example 1) has a low imidization rate at 160 ° C. for 30 minutes and a very low transmittance for ultraviolet light. 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 are excellent in warping 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)

A tetracarboxylic dianhydride represented by the following formula (1) as a structural unit;

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

(In the formula, R represents a divalent linking group selected from an alkylene group, an ether group, a thioether group, a carbonyl group, and an imino group, which may be substituted with a C _{1 to} C ₄ halogen atom; A novel polyamic acid characterized by containing 0 or 1 as an essential component. An acid dianhydride represented by the following formula (1) as a structural unit;

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

(In the formula, R represents a divalent linking group selected from an alkylene group, an ether group, a thioether group, a carbonyl group, and an imino group, which may be substituted with a C _{1 to} C ₄ halogen atom; Represents 0 or 1),
As other diamine (II), a diamine represented by the following formula (3)

A novel polyamic acid characterized in that it contains as an essential component. The polyamic acid according to claim 2, wherein
The ratio (x: y) of the number of moles x of amino groups of diamine (I) to the total number of moles y of amino groups of other diamines (II) is in the range from 100: 0 to 35:65. And a new polyamic acid. The polyamic acid according to claim 1,
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 Novel polyamic acids that are in range. A polyimide in which a part or all of the amic acid of the polyamic acid according to claim 1 is imidized. A film comprising the polyamic acid according to claim 1 and / or the polyimide according to claim 5. An adhesive comprising the polyamic acid according to claim 1 and / or the polyimide according to claim 5. A laminate comprising at least one film layer according to claim 6. A laminate comprising at least one adhesive layer according to claim 7. A circuit board manufactured from the laminate according to claim 8 and / or 9.