JP4967465B2 - Polyimide resin, polyimide film and polyimide laminate - Google Patents

Description

  The present invention relates to a polyimide resin exhibiting good heat resistance, solvent solubility, thermoplasticity and low water absorption, the polyimide resin film, and a metal-clad laminate using an adhesive comprising the polyimide resin. The metal-clad laminate is processed into a printed wiring board, a surface heating element, an electromagnetic shielding material, a flat cable, or the like.

  Some metal-clad laminates are manufactured by bonding an insulating substrate and a metal layer through an adhesive or an adhesive film. For example, a metal-clad laminate having a three-layer structure in which an insulating base material made of an aromatic polyimide resin film and a metal layer are bonded via an adhesive film has been proposed (see Patent Document 1).

  Conventionally, as an adhesive or an adhesive film, an adhesive or an adhesive film mainly composed of an epoxy resin or an acrylic resin has been used. However, since these resins are inferior in heat resistance, the heat resistance of the product after bonding becomes insufficient, and the subsequent processing conditions and use conditions are restricted.

  For this reason, the adhesive agent and adhesive film which are excellent in heat resistance are calculated | required. For example, a method of applying a polyimide resin or polyamic acid solution to an insulating substrate, then removing the solvent and optionally imidizing, and forming a thermocompression bonding layer, a polyimide resin or polyamic acid solution A method of forming a thermocompression-bonding film by applying to a glass plate and thereafter performing solvent removal and, in some cases, imidization, and the adhesive layer and adhesive film thus formed, a metal layer, etc. A method for thermocompression bonding of the adherend is disclosed (see Patent Documents 2 and 3). The adhesive layer forming method described above is roughly classified into a method using a polyimide resin solution and a method using a polyamic acid solution.

  In the method using a polyamic acid solution, after the polyamic acid solution is applied to an insulating substrate or a glass plate, an imidization process at a high temperature exceeding 300 ° C. must be performed to form an adhesive layer or an adhesive film. . The heat resistance of the metal-clad laminate formed by omitting the imidization step is extremely low. In the method using a polyimide resin solution, it is only necessary to volatilize the solvent after coating, and an adhesive layer or adhesive film can be formed at a low temperature up to about 200 ° C. Therefore, a method using a polyimide resin solution is advantageous in producing a highly heat-resistant metal-clad laminate. Many of the conventional adhesive layers made of wholly aromatic polyimide resins have been formed using a polyamic acid solution. In order to obtain a polyimide resin solution, it is necessary to be a solvent-soluble polyimide resin.

  In metal-clad laminates, if there are many residual volatile components in the adhesive layer placed between the insulating substrate and the metal layer, the adhesive layer will be whitened, swollen, foamed, etc. during the soldering process that reaches a high temperature of 250 ° C or higher. And the adhesion between the insulating substrate and the metal layer is significantly impaired (see Patent Document 4). The residual volatile components of the adhesive layer are imidization when forming the adhesive layer or adhesive film, moisture and solvent that were not removed in the solvent removal process, moisture absorbed from the manufacturing environment, and when the aqueous solution was immersed in the etching process. For example, absorbed moisture. Of these, moisture is a particular problem. In order to solve the above problems, it is desired to reduce the water absorption rate, which is an index of the moisture content of polyimide.

  In addition, a 1,2,4,5-cyclohexanetetracarboxylic acid skeleton obtained from 1,2,4,5-cyclohexanetetracarboxylic dianhydride and its reactive derivative has a 1,2,4,5-cyclohexanetetracarboxylic acid skeleton in the heat-meltable molecular main chain. A polyimide resin is disclosed (see Patent Document 6). In Example 1, 1,2,4,5-cyclohexanetetracarboxylic dianhydride and a reactive derivative thereof were reacted with diaminodiphenylmethane to form an amic acid, which was coated and then heated to imidize. A transparent yellow polyimide resin film having a glass transition temperature of 304 ° C. formed by heating and pressing is disclosed. Patent Document 5 discloses that a polyimide resin film that is transparent and has little coloration at a glass transition temperature of 300 ° C. or higher can be obtained from a polyimide resin solution obtained by using diaminodiphenyl ether.

The polyimide resin having the 1,2,4,5-cyclohexanetetracarboxylic acid skeleton is relatively easy to increase in molecular weight, and a flexible film is easily obtained, and the solubility in a solvent is sufficiently high. This is advantageous in terms of film forming. Further, it is extremely useful because it can easily form a flexible adhesive layer having sufficient thickness and durability by application.
However, since the polyimide resin film described in Patent Document 6 is formed through a high-temperature imidization step as in the past, the film is colored, and the polyimide resin films described in Patent Documents 5 and 6 have a high water absorption rate. It had a drawback of poor moisture absorption dimensional stability.

JP-A-55-91895 JP-A-5-32950 JP-A-5-59344 JP 2001-329246 A JP 2003-168800 A US Pat. No. 3,639,343

  The object of the present invention is to solve the problems of wholly aromatic polyimide resins that have been used in conventional adhesive layers, and have good thermoplasticity, solvent solubility and heat resistance, low water absorption, and excellent adhesion. The object is to provide a metal-clad laminate including a resin, a production method thereof, a film containing the polyimide resin, and an adhesive layer made of the polyimide resin.

  As a result of intensive studies to solve the above problems, the present inventors have found that a polyimide resin composed of a specific repeating unit has good thermoplasticity, adhesiveness, solvent solubility and heat resistance, and low water absorption. I found. Furthermore, it discovered that the adhesiveness with respect to a metal layer and an insulation base material was improved by using together the compound which has a specific structure or a specific functional group as a diamine component. Based on these findings, the present invention has been achieved.

That is, the present invention provides the following formula (1):
Or a repeating unit represented by the formula (1) and the following formula (2):
(In the formula, X is a divalent aliphatic group having 2 to 39 carbon atoms, a divalent alicyclic group having 3 to 39 carbon atoms, a divalent aromatic group having 6 to 39 carbon atoms, or these. A main chain of X includes —O—, —SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —OSi (CH ₃ ) ₂ —, At least one bonding group selected from the group consisting of —C ₂ H ₄ O— and —S— may intervene, and X is at least one selected from the group consisting of a carboxyl group, a hydroxyl group or a carbonyl group. It may have a kind of functional group)
The polyimide resin which consists of at least 1 type of repeating unit represented by these, Comprising: The ratio of the repeating unit of said Formula (1) provides the polyimide resin exceeding 50 mol% of all the repeating units.

  Furthermore, this invention provides the manufacturing method of the said polyimide resin.

  Moreover, this invention provides the manufacturing method of the polyimide resin film including the process of casting the solution of the said polyimide resin on a support body, and evaporating and removing an organic solvent.

  Furthermore, the present invention is a metal-clad laminate including an insulating base material, a metal layer, and an adhesive layer disposed between the insulating base material and the metal layer, and the adhesive layer is formed of the polyimide resin. A metal-clad laminate is provided.

  The polyimide resin of the present invention has good thermoplasticity, solvent solubility and heat resistance, and is excellent in low water absorption and further adhesiveness. Since it is soluble in the solvent, the production method can be solution-polymerized, and when forming the adhesive layer from the obtained polyimide resin solution of the present invention, it is only necessary to remove the solvent and does not require the conventional high temperature of 300 ° C. or higher. . The metal-clad laminate obtained by using the polyimide resin of the present invention as an adhesive layer is excellent in adhesion and solder heat resistance.

Hereinafter, the present invention will be described in detail.
The polyimide resin of the present invention (hereinafter appropriately referred to as polyimide A) has the following formula (1):
Or a repeating unit represented by the above formula (1) and the following formula (2):
The ratio of the repeating unit represented by the formula (1) exceeds 50 mol%, preferably 70 mol% or more, more preferably 80 mol% or more (each 100 mol). % Is included). When the proportion of the repeating unit represented by the formula (1) exceeds 50 mol% of all repeating units, low water absorption can be achieved, but when it is 50 mol% or less, depending on the structure of the formula (2), the water absorption may be The solder heat resistance of the metal-clad laminate using the polyimide as an adhesive may be lowered. Polyimide A may be either a block copolymer or a random copolymer.

X in the above formula (2) is the following formula (4):
2 which is composed of a divalent aliphatic group having 2 to 39 carbon atoms, a divalent alicyclic group having 3 to 39 carbon atoms, a divalent aromatic group having 6 to 39 carbon atoms, or a combination thereof. Is a valent group. The main chain of X includes —O—, —SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —OSi (CH ₃ ) ₂ —, —C ₂ H ₄ O—, and —S. At least one linking group selected from the group consisting of — may intervene. X may have at least one functional group selected from the group consisting of a carboxyl group, a hydroxyl group and a carbonyl group (included in the main chain of X). Specific examples of X include polyalkylene, polyoxyalkylene, xylylene and their alkyl-substituted, halogen-substituted, carboxy-substituted, and hydroxy-substituted divalent aliphatic groups; cyclohexane, dicyclohexylmethane, dimethylcyclohexane, Divalent alicyclic groups derived from isophorone, norbornane and their alkyl-substituted, halogen-substituted, carboxy-substituted, hydroxy-substituted, etc .; and benzene, naphthalene, biphenyl, diphenylmethane, diphenyl ether, diphenylsulfone, benzophenone And divalent aromatic groups derived from these alkyl-substituted, halogen-substituted, carboxy-substituted, hydroxy-substituted and the like. In order to improve the adhesive strength while maintaining the balance of various properties of the adhesive layer, it is preferably a m-xylylene group or a structure represented by the following formula (3).

  Since polyimide A is used as a solution, its molecular weight is preferably expressed by viscosity, particularly logarithmic viscosity. The logarithmic viscosity η (measured at 30 ° C. using a 0.5 g / dL N-methyl-2-pyrrolidone solution) of polyimide A is 0.3 to 2 dL / g. If it is less than 0.3 dL / g, the strength of the polyimide resin itself is weak and a metal-clad laminate having sufficient peel strength cannot be obtained. If it exceeds 2.0 dL / g, the solution (varnish) becomes highly viscous and difficult to apply, requiring significant dilution, making handling difficult. In order to improve the adhesive strength while keeping the balance of various properties of the adhesive layer, the logarithmic viscosity η is preferably 0.3 to 1.5 dL / g.

  Usually, the molecular terminal of the polyimide A is an amino group, a carboxyl group, or a carboxylic anhydride group. By reacting a compound having a carboxylic acid anhydride group or amino group at the molecular end, the functional group at the molecular end is reduced as much as possible, or an intentionally functional group such as an amino group or a carboxyl group at the molecular end. Groups and other substituents can be introduced. In order to reduce the water absorption rate, a substituent having a small polarity (substituent having no functionality) may be introduced at the molecular end. The water absorption rate of polyimide A measured by the method described later is preferably 2.5% or less. The minimum value of water absorption that can be achieved industrially is usually about 1%.

  Polyimide A consists of 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic dianhydride (HPMDA) and 1,2,4,5-cyclohexanetetracarboxylic acid esters. It is obtained by reacting at least one tetracarboxylic acid component (Y) selected from reactive derivatives such as diamine and at least one diamine component (Z) selected from diamines and reactive derivatives thereof. As the tetracarboxylic acid component (Y), HPMDA is preferable. In addition, the tetracarboxylic acid component (Y) and the diamine component (Z) include isomers.

Examples of the diamine component (Z) include diamine, diisocyanate, and diaminodisilane, and diamine is preferred. The diamine component (diamine component (Z1)) for forming the repeating unit of the above formula (1) is 4,4′-bis (4-aminophenoxy) biphenyl (BAPB) and a reactive derivative thereof. The diamine component (diamine component (Z2)) for forming the repeating unit (2) is NH ₂ —X—NH ₂ (X is the same as described above) and a reactive derivative thereof.

  The diamine component (Z2) may be an aromatic diamine, an aliphatic diamine, an alicyclic diamine, a reactive derivative of the diamine, or a mixture thereof, including a carboxyl group, a hydroxyl group, and a carbonyl group (included in the main chain of X). It may have at least one functional group selected from the group consisting of: In the present invention, “aromatic diamine” means a diamine in which an amino group is directly bonded to an aromatic ring, and an aliphatic group, an alicyclic group, an aromatic group, other It may contain a substituent. “Aliphatic diamine” refers to a diamine in which an amino group is directly bonded to an aliphatic group, and the structure includes an aliphatic group, an alicyclic group, an aromatic group, and other substituents. May be. “Alicyclic diamine” refers to a diamine in which an amino group is directly bonded to an alicyclic group, and an aliphatic group, an alicyclic group, an aromatic group, and other substituents are partly included in the structure. It may be included. For example, 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP) is an aromatic diamine because the amino group is directly bonded to the aromatic ring (benzene ring), and m-xylyl. Range amine (MXDA) is an aliphatic diamine because the amino group is directly bonded to an aliphatic group (methylene group).

  In general, when tetracarboxylic dianhydride is reacted with an aliphatic diamine or alicyclic diamine, the polyamic acid as an intermediate product and the amino group derived from the aliphatic diamine or alicyclic diamine form a strong salt. In addition, it is difficult to obtain a high molecular weight polyimide. Therefore, it is necessary to devise such as using a solvent having a relatively high salt solubility, such as cresol. However, when 1,2,4,5-cyclohexanetetracarboxylic dianhydride is used as the tetracarboxylic dianhydride, the amino group derived from the polyamic acid and the aliphatic diamine or alicyclic diamine is relatively weak. Thus, the imidization reaction proceeds relatively easily, and the molecular weight can be easily increased.

  Examples of the aliphatic diamine include ethylene diamine, hexamethylene diamine, polyethylene glycol bis (3-aminopropyl) ether, polypropylene glycol bis (3-aminopropyl) ether, 1,3-bis (aminomethyl) cyclohexane, 1,4. -Bis (aminomethyl) cyclohexane, p-xylylenediamine, m-xylylenediamine, siloxane diamines and the like.

  Examples of the alicyclic diamine include 4,4'-diaminodicyclohexylmethane, isophorone diamine, norbornane diamine, and the like.

  Examples of the aromatic diamine include 1,4-phenylenediamine, 1,3-phenylenediamine, 2,4-toluenediamine, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, and 4,4′-. Diaminodiphenylmethane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, α, α′-bis (4 -Aminophenyl) -1,4-diisopropylbenzene, α, α'-bis (3-aminophenyl) -1,4-diisopropylbenzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 4,4′-diaminodiphenylsulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3 Aminophenoxy) phenyl] sulfone, 2,6-diaminonaphthalene, 1,5-diaminonaphthalene and the like.

  Examples of the diamine having a functional group include 3,3′-dicarboxy-4,4′-diaminodiphenylmethane, 3,5-diaminobenzoic acid, 3,3′-dihydroxy-4,4′-diaminobiphenyl, 2,4-diaminophenol, 4,4′-diaminobenzophenone, 3,3′-diaminobenzophenone, and in particular, 3,3′-dicarboxy-4,4′-diaminodiphenylmethane (MBAA), 3,5 -Diaminobenzoic acid (DBA), 3,3'-dihydroxy-4,4'-diaminobiphenyl (HAB), 4,4'-diaminobenzophenone (4,4'-DBP) are preferred.

  By using MXDA or BAPP as the diamine component (Z2), the adhesive force of the polyimide resin can be improved.

  Polyimide A is the above-mentioned tetracarboxylic acid component (Y) with respect to 1 mol of the diamine component (Z) (diamine component (Z1) or diamine component (Z1) + diamine component (Z2)), preferably 0.00. It is produced by reacting 66 to 1.5 mol, more preferably 0.9 to 1.1 mol, and still more preferably 0.97 to 1.03 mol.

  For example, a polyimide A having a logarithmic viscosity η within the above range is produced by adjusting at least one condition such as the ratio of raw material used, reaction temperature and time, presence / absence and usage of a terminal terminator, and the amount of catalyst. can do. Those skilled in the art can easily adjust the conditions by performing a preliminary reaction or the like. For example, when the logarithmic viscosity η is adjusted by the molar ratio of the tetracarboxylic acid component (Y) and the diamine component (Z) and the reaction time, the closer the molar ratio is to 1, the longer the reaction time, The logarithmic viscosity η increases within the above range. As the molar ratio is far from 1 in the range of 0.66 to 1.5 and the reaction time is shorter, the logarithmic viscosity η is smaller in the range. In the solution polymerization method, the relationship between the viscosity of the reaction solution, the reaction time, and other reaction conditions, and the logarithmic viscosity corresponding thereto are obtained in advance, and the end point of the reaction is determined based on this relationship, thereby obtaining a predetermined value. Polyimide A having a logarithmic viscosity η can be produced. The reaction time is preferably 2 to 12 hours, and the reaction temperature is preferably 180 to 205 ° C.

Polyimide A is usually produced as an organic solvent solution.
Although it does not specifically limit as an organic solvent, For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, N, N-diethylformamide, N-methyl Caprolactam, hexamethylphosphoramide, tetramethylene sulfone, dimethyl sulfoxide, m-cresol, phenol, p-chlorophenol, 2-chloro-4-hydroxytoluene, diglyme, triglyme, tetraglyme, dioxane, γ- Butyrolactone, dioxolane, cyclohexanone, cyclopentanone and the like can be used, and two or more kinds may be used in combination. However, considering the performance of polyimide varnish composed of polyimide A and a solvent, N-methyl-2-pyrrolidone (NMP), N, N-dimethylacetamide (DMAC), and γ-butyrolactone (GBL) may be used alone or in combination. preferable. The organic solvent is used in such an amount that the polyimide A concentration in the obtained organic solvent solution is preferably 1 to 50% by weight, more preferably 5 to 40% by weight. In addition, in the case of production by solution polymerization, a poor solvent such as hexane, heptane, benzene, toluene, xylene, chlorobenzene, o-dichlorobenzene and the like can be used together with the above solvent to such an extent that the polymer does not precipitate.

  Polyimide A is obtained by (1) a solution polymerization method, (2) a method of preparing a polyamic acid solution, forming a film and imidizing it, and (3) obtaining a salt or imide oligomer such as a half ester salt of HPMDA. It can be produced by a method of performing phase polymerization, (4) a method of reacting tetracarboxylic dianhydride and diisocyanate, or other conventionally known methods. You may use each method together. The reaction between the tetracarboxylic acid component (Y) and the diamine component (Z) may be carried out in the presence of a conventionally known catalyst such as an acid, a tertiary amine or an anhydride.

Among these methods, since an organic solvent solution of polyimide A is obtained directly, the following solution polymerization methods (1) to (3) are preferable.
(1) A mixture containing a diamine component (Z), an organic solvent, and, if necessary, a catalyst is stirred at 10 to 600 rpm to form a homogeneous solution, which is maintained at a temperature of 30 to 90 ° C., and the tetracarboxylic acid component (Y) And if necessary, a catalyst is added.
(2) A mixture containing a tetracarboxylic acid component (Y), an organic solvent, and, if necessary, a catalyst is stirred at 10 to 600 rpm to obtain a uniform solution, which is kept at a temperature of 30 to 90 ° C., and a diamine component (Z) And if necessary, a catalyst is added.
(3) After the method (1) or (2), the temperature is raised to 160 to 230 ° C, preferably 180 to 205 ° C over 0.1 to 6 hours. This temperature depends on the boiling point of the organic solvent used. While collecting the components to be removed outside the reaction system, the temperature is kept substantially constant for 0.5 to 24 hours, preferably 2 to 12 hours. Thereafter, if necessary, an organic solvent is further added and cooled to an appropriate temperature.

  Solution polymerization for producing polyimide A includes trimethylamine, triethylamine (TEA), tripropylamine, tributylamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, triethylenediamine, N- The reaction may be performed in the presence of at least one catalyst selected from tertiary amine compounds such as methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, imidazole, pyridine, quinoline and isoquinoline. When using, the usage-amount of a catalyst has preferable 0.1-100 mol% of the tetracarboxylic-acid component (Y), and 1-10 mol% is more preferable.

  A surfactant such as fluorine or polysiloxane may be added to the organic solvent solution of polyimide A. This makes it easy to obtain an adhesive layer and a polyimide resin film with good surface smoothness.

  The polyimide resin film is obtained by applying (casting) the organic solvent solution of polyimide A on a smooth support such as a glass plate or a metal plate to which releasability is imparted, and heating the organic solvent to 50 to 350 ° C. It can be manufactured by evaporating off. After evaporating the solvent at a temperature of 120 ° C. or less to form a self-supporting film, the film is peeled off from the support, the edges of the film are fixed, and dried at the boiling point of the organic solvent used to 350 ° C. It is preferable to manufacture a polyimide resin film. The pressure in the dry atmosphere may be any of reduced pressure, normal pressure, and increased pressure. 1-100 micrometers is preferable and, as for the thickness of a polyimide resin film, 2-50 micrometers is more preferable. A polyimide resin film can also be produced by applying a polyamic acid solution on a smooth support instead of the organic solvent solution of polyimide A and heating to 50 ° C. to 350 ° C. to carry out a dehydration imidation reaction.

The metal-clad laminate of the present invention includes an insulating base material, a metal layer, and an adhesive layer made of polyimide A disposed therebetween.
The metal-clad laminate is formed by applying an organic solvent solution of polyimide A to one or both of the insulating base and the metal layer, evaporating and removing the organic solvent at 50 to 350 ° C., and forming an adhesive layer. It can be manufactured by a method in which a metal layer is superposed through an adhesive layer and then thermocompression bonded, or a method in which the polyimide resin film is disposed between an insulating substrate and a metal layer and thermocompression bonded. Also, a metal thin film is directly formed on one side of the polyimide resin film by sputtering, vapor deposition, electroless plating, etc., an insulating base is placed on the other side and thermocompression bonded, and the surface of the insulating base is adhered. Forming a metal-clad laminate in which the insulating substrate and the metal layer are firmly bonded to each other by a method of forming a metal thin film on the surface of the adhesive layer by sputtering, vapor deposition, electroless plating, or the like. Can do.
The thickness of the adhesive layer is preferably 1 to 100 μm, more preferably 2 to 50 μm. The glass transition temperature of polyimide A varies depending on the selected diamine, but is usually 200 to 350 ° C, preferably 230 to 300 ° C. Since polyimide A exhibits adhesion at a temperature equal to or higher than the glass transition temperature, if the glass transition temperature is too high, the thermocompression bonding temperature becomes too high, and if the glass transition temperature is too low, the heat resistance of the film itself is insufficient.

  The metal layer may be formed of a metal foil obtained by a method such as electrolysis or rolling, or may be directly formed on the surface of the polyimide resin film or the surface of the adhesive layer formed on the insulating base as described above. May be. Although the thickness of a metal layer does not have a restriction | limiting in particular, The range of 1-100 micrometers is preferable. The material of the metal layer is preferably copper. Moreover, you may surface-treat so that the surface roughness Rz may be set to 0.1-12 micrometers on one side (adhesion surface) or both surfaces of metal foil. In the case of a copper foil generally called a low profile, Rz is preferably 0.1 to 2 μm, more preferably 0.4 to 2 μm, and still more preferably 1.0 to 2 μm. In addition, since the surface of metal foil that has not been subjected to surface treatment for bonding is usually treated with a rust preventive agent, etc., the surface was wiped with a cloth soaked with acetone or other organic solvent. It is preferable to use it later.

  The insulating substrate of the present invention is not particularly limited as long as it can electrically insulate the metal layer. Insulating base materials include a flexible type and a rigid type, both of which can be used. Although the thickness of an insulating base material changes with the said types, 3-2000 micrometers is preferable. Flexible insulating base materials include polyimide resin (excluding polyimide A), polybenzimidazole, polybenzoxazole, polyamide (including aramid), polyetherimide, polyamideimide, polyester (including liquid crystalline polyester), polysulfone , Polyethersulfone, polyetherketone, polyetheretherketone, etc., but preferably a polyimide resin film, specifically, “Kapton EN”, “Kapton V”, “Kapton H”. (Manufactured by Toray DuPont Co., Ltd.), trade names “Apical NPI”, “Apical AH” (manufactured by Kaneka Corporation), and the like. Although thickness in particular is not restrict | limited, 3-150 micrometers is preferable and 7.5-75 micrometers is more preferable.

  Rigid type insulating base materials include glass plates, ceramic plates, plastic plates, etc. and metal plates with insulating coatings, liquid crystal polymers, phenolic resins, epoxy resins, and other thermoplastic and thermosetting materials. Examples include molded products obtained by impregnating and kneading various resins with reinforcing agents such as glass fiber cloth, plastic fiber cloth, and short glass fiber. The thickness is not particularly limited, but is preferably 30 to 2000 μm.

As a method for thermocompression bonding, a method using a multistage (vacuum) press machine, a continuous press method using a pressure roll or the like can be employed as appropriate.
The thermocompression bonding temperature is preferably 200 to 400 ° C., more preferably 250 to 350 ° C., and is selected in consideration of the glass transition temperature of the polyimide A used as described above. The pressure for thermocompression bonding is preferably 0.01 to 20 MPa, more preferably 0.1 to 10 MPa. It is also preferable to perform thermocompression bonding in a reduced pressure atmosphere to remove the solvent and bubbles.
The peel strength of the metal layer of the metal-clad laminate of the present invention measured by the method described below can be practically used if it is 0.5 N / mm or more, but is preferably 0.8 N / mm or more.

Hereinafter, the present invention will be described specifically by way of examples. However, this invention is not restrict | limited at all by these Examples.
A method for measuring physical properties is shown below.

(1) IR spectrum It measured using JEOL Co., Ltd. product JIR-WINSPEC50.

(2) Logarithmic viscosity η
A 0.5 g / dL polyimide N-methyl-2-pyrrolidone solution was prepared. The liquid surface drop time between the marked lines of this solution was measured with a Canon Fenceke viscometer in a constant temperature water bath at 30 ° C., and determined by the following formula.
η = ln (solution falling time / N-methyl-2-pyrrolidone falling time) /0.5
The logarithmic viscosity has a value that approximates the intrinsic viscosity and can be easily obtained.

(3) Glass transition temperature Determined by the DSC method. Using a DSC-50 manufactured by Shimadzu Corporation, the midpoint glass transition temperature Tmg obtained by measurement at 40 to 350 ° C. and a heating rate of 10 ° C./min was defined as the glass transition temperature.

(4) Water absorption rate of polyimide It was determined according to the method of IPC-TM-650 2.6.2.1.
A polyimide film of 50.8 × 50.8 mm was dried at 120 ° C. for 1 hour, and then the weight (W ₀ ) was measured. This film was immersed in distilled water at 23 ° C. for 24 hours, wiped off the moisture on the surface, and immediately measured for weight (W ₁ ).
Water absorption (%) = (W ₁ −W ₀ ) ÷ W ₀ × 100

(5) Peel strength of metal layer It was determined according to the peel strength measurement method for copper foil by 90 ° peel according to JIS C6471 (method A using a rotating drum type support fitting for peel strength measurement).

(6) Solder heat resistance The following tests were conducted with reference to JIS C6471.
A 10 × 50 mm test piece was cut from the metal-clad laminate and left in a constant temperature room at 50% humidity and 23 ° C. for 24 hours. Subsequently, it floated in the solder bath (260 degreeC and 280 degreeC) for 20 seconds. The case where no abnormality in appearance such as swelling or peeling occurred was A, and the case where abnormality in appearance occurred was C.

Example 1
In a 300 mL 5-neck glass round bottom flask equipped with a stainless steel half-moon stirring blade, a nitrogen inlet tube, a Dean Stark fitted with a cooling tube, a thermometer, and a glass end cap, 4,4′-bis (4 -Aminophenoxy) biphenyl (BAPB, Wakayama Seika Kogyo Co., Ltd.) 26.48 g (0.07187 mol), γ-butyrolactone (GBL, Mitsubishi Chemical Co., Ltd.) 51.11 g, and triethylamine (TEA) as a catalyst , Produced by Kanto Chemical Co., Ltd.) was stirred at 100 rpm in a nitrogen atmosphere to obtain a solution.
To this, 16.11 g (0.07187 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride (HPMDA, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and dimethylacetamide (DMAC, manufactured by Mitsubishi Gas Chemical Co., Ltd.) ) 12.78 g of each was added in one batch, and then heated with a mantle heater, and the temperature in the reaction system was raised to 180 ° C. over about 20 minutes. While collecting the components to be distilled off, the reaction system internal temperature was maintained at 180 ° C. for 3.5 hours.
After adding 96.11 g of DMAC, the mixture was stirred at about 130 ° C. for about 30 minutes to obtain a uniform solution, and air-cooled to 100 ° C. in about 10 minutes to obtain a polyimide A solution having a solid content concentration of 20% by weight.

The obtained polyimide A solution was coated on a smooth glass plate coated with a very small amount of a release agent with a coater, and then heated on a hot plate at 100 ° C. for 1 hour to form a self-supporting film. After fixing the film peeled from the glass plate to the stainless steel mold with clips, it was left in a vacuum dryer at 200 ° C. for 5 hours to remove the solvent almost completely (less than 1% by weight), and polyimide A film Got. When the IR spectrum of this polyimide A film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1779 and 1704 (cm ⁻¹ ). The logarithmic viscosity of this polyimide A was 1.28 dL / g, the glass transition temperature was 297 ° C., and the water absorption was 2.2%.

A polyimide resin film having a thickness of 25 μm (trade name: Kapton 100EN, manufactured by Toray DuPont) is used as an insulating base, and the polyimide A solution obtained above is applied to one side, and then heated at 100 ° C. for 0.5 hour on a hot plate. After heating, it was dried in a vacuum dryer at 200 ° C. for 5 hours to form an adhesive layer having a thickness of 4 μm on the insulating substrate. Using an electrolytic copper foil (product name; F2-WS, manufactured by Furukawa Circuit Foil Co., Ltd.) having a thickness of 9 μm, which is obtained by roughening the surface for bonding with Rz = 1.5 μm, as a metal layer, formed on an insulating substrate An electrolytic copper foil was overlaid on the adhesive layer through the roughened surface. This was sandwiched between stainless mirror plates, placed between hot plates of a hot press machine having a temperature of 330 ° C., held at a contact pressure (0 MPa) for 3 minutes, and then thermocompression bonded under conditions of 330 ° C., 5 MPa, and 5 minutes. Subsequently, the metal-clad laminate was obtained by putting it between hot plates of a normal temperature press and cooling it under conditions of 5 MPa for 2 minutes.
The peel strength of the metal layer of the obtained metal-clad laminate was 0.80 N / mm, and the solder heat resistance was A.

Example 2
In a five-neck glass round bottom flask similar to that used in Example 1, BAPB 24.869 g (0.06750 mol), m-xylylenediamine (MXDA, manufactured by Mitsubishi Gas Chemical Co., Ltd.) 1.021 g (0.00750 mol) and 50.000 g of N-methyl-2-pyrrolidone (NMP, manufactured by Mitsubishi Chemical Corporation) were stirred at 100 rpm in a nitrogen atmosphere to obtain a solution.
To this, 16.813 g (0.07500 mol) of HPMDA and 14.054 g of NMP were added all at once, and then heated with a mantle heater, and the temperature in the reaction system was raised to 190 ° C. over about 20 minutes. The temperature inside the reaction system was maintained at 190 ° C. for 5 hours while collecting the components to be distilled off.
After adding 95.946 g of DMAC, the mixture was stirred for about 30 minutes at a temperature of about 130 ° C. to obtain a uniform solution, and air-cooled to about 100 minutes in about 10 minutes to obtain a polyimide A solution having a solid content concentration of 20% by weight.

A polyimide A film was obtained in the same manner as in Example 1 except that the obtained polyimide A solution was used. When the IR spectrum of this polyimide A film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1776 and 1704 (cm ⁻¹ ). The polyimide A had a logarithmic viscosity η of 0.97 dL / g, a glass transition temperature of 289 ° C., and a water absorption of 2.2%.
A metal-clad laminate was obtained in the same manner as in Example 1 except that the obtained polyimide A solution was used. The peel strength of the metal layer of the obtained metal-clad laminate was 0.95 N / mm, and the solder heat resistance was A.

Example 3
In a five-neck glass round bottom flask similar to that used in Example 1, 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP, manufactured by Wakayama Seika Kogyo Co., Ltd.) 11.455 g (0.02790 mol), BAPB 15.421 g (0.04186 mol), GBL 51.007 g, and TEA 0.353 g were stirred at 100 rpm in a nitrogen atmosphere to obtain a solution.

HPMDA (15.638 g, 0.06976 mol) and DMAC (12.754 g) were added all at once, and then heated with a mantle heater to raise the temperature in the reaction system to 180 ° C. over about 20 minutes. While collecting the components to be distilled off, the temperature in the reaction system was maintained at 180 ° C. for 4 hours.
After adding 96.229 g of DMAC, the mixture was stirred at a temperature of about 130 ° C. for about 30 minutes to obtain a homogeneous solution, and then cooled to 100 ° C. in about 10 minutes to obtain a polyimide A solution having a solid content concentration of 20% by weight.

A polyimide A film was obtained in the same manner as in Example 1 except that the obtained polyimide A solution was used. When the IR spectrum of this polyimide A film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1779 and 1704 (cm ⁻¹ ). The polyimide A had a logarithmic viscosity η of 0.98 dL / g, a glass transition temperature of 282 ° C., and a water absorption of 2.0%.
A metal-clad laminate was obtained in the same manner as in Example 1 except that the obtained polyimide A solution was used. The peel strength of the metal layer of the obtained metal-clad laminate was 0.85 N / mm, and the solder heat resistance was A.

Comparative Example 1
In a 5-neck glass round bottom flask similar to that used in Example 1, 20,624 g (0.10299 mol) of 4,4′-diaminodiphenyl ether (ODA, manufactured by Wakayama Seika Kogyo Co., Ltd.) GBL (52.45 g) and TEA (0.52 g) were stirred at 100 rpm in a nitrogen atmosphere to obtain a solution.
HPMDA (23.088 g, 0.10299 mol) and DMAC (13.11 g) were added all at once, and then heated with a mantle heater, and the reaction system internal temperature was raised to 180 ° C. over about 20 minutes. While collecting the components to be distilled off, the temperature in the reaction system was maintained at 180 ° C. for 5 hours.
After adding 94.43 g of DMAC, the mixture was stirred for about 30 minutes at a temperature of about 130 ° C. to obtain a uniform solution, and air-cooled to about 100 minutes in about 10 minutes to obtain a polyimide resin solution having a solid content concentration of 20% by weight.

A polyimide resin film was obtained in the same manner as in Example 1 except that the obtained polyimide resin solution was used. When the IR spectrum of this polyimide resin film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1772 and 1700 (cm ⁻¹ ). The logarithmic viscosity η of this polyimide was 1.06 dL / g. The glass transition temperature was 316 ° C. and the water absorption rate was 5.5%.
A metal-clad laminate was obtained in the same manner as in Example 1 except that the obtained polyimide resin solution was used. The metal layer of the obtained metal-clad laminate could be easily peeled by hand, and the peel strength was extremely low.

Comparative Example 2
In a 5-neck glass round bottom flask similar to that used in Example 1, α, α′-bis (3-aminophenyl) -1,4-diisopropylbenzene (Bisaniline M, manufactured by Mitsui Chemicals, Inc.) ) 19.404 g (0.05633 mol), GBL 38.44 g, and TEA 0.28 g were stirred at 100 rpm in a nitrogen atmosphere to obtain a solution.
To this, 12.627 g (0.05633 mol) of HPMDA and 9.61 g of DMAC were added all at once, and then heated with a mantle heater, and the reaction system internal temperature was raised to 180 ° C. over about 20 minutes. While collecting the components to be distilled off, the temperature in the reaction system was maintained at 180 ° C. for 12 hours.
After adding 71.96 g of DMAC, the mixture was stirred at a temperature of about 130 ° C. for about 30 minutes to obtain a uniform solution, and then cooled to 100 ° C. in about 10 minutes to obtain a polyimide resin solution having a solid content concentration of 20% by weight.

A polyimide resin film was obtained in the same manner as in Example 1 except that the obtained polyimide resin solution was used. When the IR spectrum of this polyimide resin film was measured, characteristic absorption of the imide ring was observed at ν (C═O) 1774 and 1704 (cm ⁻¹ ). The polyimide had a logarithmic viscosity η of 0.52 dL / g, a glass transition temperature of 220 ° C., and a water absorption of 1.5%.
A metal-clad laminate was obtained in the same manner as in Example 1 except that the obtained polyimide resin solution was used. The peel strength of the metal layer of the obtained metal-clad laminate was 0.45 N / mm, and the solder heat resistance was A.

Claims (14)

Following formula (1):

In repeating units and formula represented (2):

(In the formula, X is an m-xylylene group or a group represented by the following formula (3) ).
The polyimide resin which consists of a repeating unit represented by these, Comprising: The ratio of the repeating unit of said Formula (1) exceeds 50 mol% of all repeating units.
A polyimide resin solution comprising the polyimide resin according to claim 1 and an organic solvent. Selected from the group consisting of 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic dianhydride and reactive derivatives of 1,2,4,5-cyclohexanetetracarboxylic acid Including the step of reacting at least one tetracarboxylic acid component (Y) thus obtained with a diamine component (Z) that is a mixture of the diamine component (Z1) and the diamine component (Z2):

In repeating units and formula represented (2):

(In the formula, X is an m-xylylene group or a group represented by the following formula (3) ).

In it a repeating unit represented, the proportion of the repeating units is a method for producing a polyimide resin of greater than 50 mol% of all repeating units of the formula (1),
(A) The diamine component (Z1) is at least one compound selected from the group consisting of 4,4′-bis (4-aminophenoxy) biphenyl and reactive derivatives thereof;
(B) Unlike the diamine component (Z1), the diamine component (Z2) is selected from the group consisting of a diamine represented by NH ₂ —X—NH ₂ (X is the same as described above) and reactive derivatives thereof. At least one compound;
(C) The amount of the diamine component (Z1) the production of a polyimide resin according to claim 1, characterized in that more than 50 mole% of the total amount of the diamine component (Z1) and the diamine component (Z2) Method. The method for producing a polyimide resin according to claim 3 , wherein the reaction is carried out in an organic solvent solution with heating in the presence or absence of a catalyst to obtain a polyimide resin solution. The method for producing a polyimide resin according to claim 4 , wherein the catalyst is a tertiary amine. The method for producing a polyimide resin according to claim 4 or 5, wherein the heating is performed at a temperature of 180 to 205 ° C for 2 to 12 hours. A method for producing a polyimide resin film comprising a step of casting the polyimide resin solution according to claim 2 or the polyimide resin solution obtained by the production method according to claim 4 on a support and evaporating and removing an organic solvent. The organic solvent is evaporated and removed at a temperature of 120 ° C. or lower to form a self-supporting film, the end of the film peeled off from the support is fixed, and dried at a boiling point of the organic solvent to 350 ° C. 8. Manufacturing method of polyimide resin film. Insulating base material, a metal layer, and is formed of a polyimide resin obtained by the method according to the polyimide resin or claim 3 according to claim 1, disposed between the insulating substrate and the metal layer adhered A metal-clad laminate comprising layers. The adhesive layer is coated on one or both of the insulating substrate and the metal layer with the polyimide resin solution according to claim 2 or the polyimide resin solution obtained by the production method according to claim 4 , and then the organic solvent is removed by evaporation. The metal-clad laminate according to claim 9, which is formed as follows. The adhesive layer, according to claim 9 metal-clad laminate according to form a polyimide resin film obtained by the production method according to claim 7. The metal-clad laminate according to any one of claims 9 to 11 , wherein the polyimide resin has a glass transition temperature of 310 ° C or lower. The metal-clad laminate according to any one of claims 9 to 12 , wherein the surface roughness Rz of the surface of the metal layer facing the adhesive layer is 0.1 to 2 µm. The metal-clad laminate according to any one of claims 9 to 13 , wherein the peel strength of the metal layer measured by a copper foil peel strength measuring method by 90 ° peeling of JISC6471 is 0.5 N / mm or more.