JP2005120317A - Adhesive composition and method for curing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new imide type adhesive composition, aiming to improve adhesiveness, and bringing improvement in heat resistance and low dielectric property. <P>SOLUTION: This adhesive composition contains (1) a first imide oligomer having 3-aminobenzonitrile units at the both terminals, (2) a second imide oligomer having maleic anhydride units at the both terminals and (3) a cross-linking agent consisting of an oligomer having the maleic anhydride unit at one terminal and a diamine unit at another end or a mixture of components forming such oligomer. Since the adhesive composition exhibits an excellent adhesiveness, heat resistance and low dielectric property, it can be suitably used for a printed circuit substrate used for an electric or electronic materials, a sealing agent, an over-coating agent, etc. Also, it can be used as a structural material and a composite materials, by impregnating a glass fiber or Kevlar with the same. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an adhesive composition and a method for curing the same.

  In recent years, the density, size and weight of electrical and electronic equipment have been increased, and it has also been used in places where usage conditions are severe. Accordingly, electrical and electronic equipment materials are desired to have improved heat resistance as well as low dielectric properties, insulating properties, and adhesion.

  Addition-type imide resins based on aromatic diamines and aromatic bismaleimides have excellent heat resistance, good processability, and excellent cost performance, but these cured products tend to be hard and brittle. As an interlayer material, there is a defect that the peel strength is weak and the peel strength with the copper foil is also weak. Attempts to change the types of bismaleimides and aromatic diamines raise the molding temperature and have difficulties in processability. Diaminomaleonitrile was added to unsaturated bismaleimide and aromatic diamine to improve adhesion (Patent Document 1).

Attempts have been made to reduce the dielectric constant, heat resistance, and electrical properties by mixing polyimide with polyfunctional cyanate ester (Patent Document 2). Furthermore, there is a low dielectric thermosetting resin containing siloxane (Patent Documents 3 and 4).
JP-A-3-131628 JP2001-200197 JP-A-11-92719 JP2001-6427

  The addition-type imide resin adhesive produced from an aromatic diamine and a bismaleimide compound undergoes two types of reactions in the processing step. The main reaction is an addition reaction between a maleimide group and an amino group, and a side reaction is Michael addition by self-condensation between bismaleimides. Since the flexible defect is caused by the generation of this side reaction, means for suppressing the side reaction has been studied.

An object of the present invention is to provide a novel imide-type adhesive composition that suppresses this side reaction, improves adhesion, and improves heat resistance and low dielectric constant.

  As a result of earnest research, the inventors of the present application have found that a first imide oligomer having 3-aminobenzonitrile units at both ends, a second imide oligomer having maleic anhydride units at both ends, and maleic anhydride at one end. It has been found that a composition comprising a unit and a crosslinking agent oligomer having a diamine unit at the other end is excellent in adhesiveness, heat resistance and low dielectric constant, and has completed the present invention.

  That is, the present invention comprises (1) a first imide oligomer having 3-aminobenzonitrile units at both ends, (2) a second imide oligomer having maleic anhydride units at both ends, and (3) at one end. There is provided an adhesive composition comprising a maleic anhydride unit, an oligomer having a diamine unit at the other end, or a cross-linking agent comprising a mixture of components that form the oligomer. The present invention also relates to (1) a molten mixture obtained by melt-mixing a first imide oligomer having 3-aminobenzonitrile units at both ends and a second imide oligomer having maleic anhydride units at both ends. And (2) an adhesive composition comprising an oligomer having a maleic anhydride unit at one end and a diamine unit at the other end or a mixture of components that form the oligomer. Furthermore, this invention provides the hardening method of the said adhesive composition including apply | coating the adhesive composition of the said this invention in a liquid form to a base | substrate, and making it harden | cure by heating.

  Since the adhesive composition of the present invention exhibits excellent adhesiveness, heat resistance and low dielectric properties, it can be suitably used for printed wiring boards, sealants, overcoat agents, etc. used in electrical and electronic materials. Can do. Moreover, it can also be impregnated into glass fiber or Kevlar fiber and used as a structural material or composite material.

  As described above, the adhesive composition of the present invention includes a first imide oligomer having 3-aminobenzonitrile units at both ends, a second imide oligomer having maleic anhydride units at both ends, and maleic acid at one end. Including an anhydride unit, a crosslinking agent oligomer having a diamine unit at the other end, or a melt mixture obtained by melt-mixing the first imide oligomer and the second imide oligomer, and the crosslinking agent oligomer .

  The first imide oligomer is an imide oligomer having 3-aminobenzonitrile units at both ends. The imide oligomer is obtained by polycondensation of a diamine component (both ends, as described above, a 3-aminobenzonitrile unit that is a monoamine) and a tetracarboxylic acid component, which are bonded through an imide bond. The melting point of the first imide oligomer is preferably 150 ° C. or lower from the viewpoint of enabling construction at a low temperature. The degree of polymerization of the first imide oligomer is not particularly limited, but is preferably a degree of polymerization at which the melting point of the oligomer is 150 ° C. or less. Therefore, usually, the weight average molecular weight is about 2000 to 7000, preferably 3000 or more. It is about 5000 or less. The first imide oligomer may be a mixture of oligomers having different degrees of polymerization.

As a preferred example of the first imide oligomer, the general formula (I)
3BN-BTDA-X-BTDA-3BN (I)
(However, 3BN is 3-aminobenzonitrile unit, BTDA is benzophenone tetracarboxylic dianhydride unit, X is 1,3-bis (3-aminophenoxy) benzene unit (APB), 4,4'-bis (3 -Aminophenoxy) Indicates diphenylsulfone unit (mBAPS) or diaminosiloxane unit (DAS), and adjacent units are imide-bonded by polycondensation of amino group and dicarboxylic anhydride contained in each unit)
The thing which has the structure represented by these can be mentioned. The structure of each unit is represented by the chemical formula as follows.

（ただし、DASの化学式中、ｎは３〜３０の整数を示す）

(However, in the chemical formula of DAS, n represents an integer of 3 to 30)

  As described above, the adjacent units in the general formula (I) are imide-bonded by polycondensation of the amino group and dicarboxylic anhydride contained in each unit. The structure when X is BTDA is shown by the following structural formula.

（この構造式は、スペースの都合上２行で表されているが、１行目の右端と２行目の左端がつながっている）。

(This structural formula is represented by two lines for the sake of space, but the right end of the first line and the left end of the second line are connected).

  The second imide oligomer is an imide oligomer having maleic anhydride units at both ends. The imide oligomer is obtained by polycondensing a diamine component and a tetracarboxylic acid component (however, both ends are maleic anhydride units which are dicarboxylic acid anhydrides as described above) and bonded by an imide bond. The melting point of the second imide oligomer is preferably 150 ° C. or lower from the viewpoint of enabling construction at a low temperature. The degree of polymerization of the second imide oligomer is not particularly limited, but is preferably a degree of polymerization at which the melting point of the oligomer is 150 ° C. or lower. Therefore, usually, the weight average molecular weight is 2000 or more and 8000 or less, preferably 3000 or more and 6000. It is as follows. The second imide oligomer may be a mixture of oligomers having different degrees of polymerization.

As a preferable example of the second imide oligomer, the general formula (II)
MA-mBAPS-Y-mBAPS-MA (II)
(However, MA is maleic anhydride unit, mBAPS is 4,4'-bis (3-aminophenoxy) diphenylsulfone unit as above, Y is BTDA (above), biphenyltetracarboxylic dianhydride unit (BPDA) , Pyromellitic dianhydride unit (PMDA), 1,4-bis (dicarboxyphenyl) ether dianhydride unit (ODPA) or bicyclo (2,2,2) oct-7-ene-1,2,3 , 6-Tetracarboxylic acid dianhydride unit (BCD), adjacent units are imide-bonded by polycondensation of amino group and dicarboxylic acid anhydride contained in each unit)
It has the structure represented by these. The structure of each unit is represented by the chemical formula as follows.

  As described above, adjacent units in the general formula (II) are imide-bonded by polycondensation of an amino group and a dicarboxylic anhydride contained in each unit. The structure when Y is BTDA is shown by the following structural formula.

（この構造式は、スペースの都合上２行で表されているが、１行目の右端と２行目の左端がつながっている）。

(This structural formula is represented by two lines for the sake of space, but the right end of the first line and the left end of the second line are connected).

  In the adhesive composition of this invention, the said 1st imide oligomer and the 2nd imide oligomer may be contained in the respectively independent state, and the 1st imide oligomer and the 2nd imide oligomer are included. A molten mixture obtained by melt mixing may be included. Since both the first and second imide oligomers preferably have a melting point of 150 ° C. or lower, in that case, melt mixing is performed at a temperature of 150 ° C. or lower or higher than 150 ° C., preferably even at a temperature of 200 ° C. or lower. It can be carried out. When melt mixing is performed at 150 ° C. or lower, no reaction occurs, and a uniform mixture of the first imide oligomer and the second imide oligomer is obtained. When melt mixing is performed at a temperature exceeding 150 ° C. and not more than 200 ° C., preferably about 180 ° C., the benzonitrile structure of the first imide oligomer and the maleimide structure of the second imide oligomer react to form a pyrimidine-based compound. A compound is formed. That is, 2 mol of the first imide oligomer and 1 mol of the second imide oligomer react to produce a pyrimidine-based compound. The outline of this reaction is shown in the following reaction formula (i).

反応式(i)

Reaction formula (i)

  In this reaction formula (i) (the same applies to other reaction formulas described in this specification), the “formula (I) moiety” is a part of the above formula (I), and this reaction formula Are the abbreviations showing the structure of the portion whose structure is not clearly shown by the structural formula. Similarly, the “formula (II) portion” is a part of the above formula (II), This is an abbreviation that shows the structure of a part whose structure is not explicitly shown by the structural formula.

  In addition, a triazine compound is partially produced from 3 mol of the first imide oligomer according to the following reaction formula (ii), and tends to increase as the melting temperature increases.

反応式(ii)

Reaction formula (ii)

  In the adhesive composition of the present invention, a pyrimidine compound represented by the above reaction formula (i) obtained by melt-mixing the first imide oligomer and the second imide oligomer, or the above reaction formula (ii) It is preferable to include a molten mixture containing at least a part of the triazine compound, in particular, a melt in which the melt mixing is performed at a temperature of 150 ° C. to 200 ° C. and at least partly forms the pyridine compound or the triazine compound. It is preferred to include a mixture. In this case, the melt mixing time is preferably about 30 minutes to 180 minutes. However, the above reaction between the first imide oligomer and the second imide oligomer partially occurs even when the curing reaction is performed in the presence of the crosslinking agent, and a satisfactory cured product can be obtained. The imide oligomer and the second imide oligomer need not necessarily be melt-mixed, and may contain an unreacted molten mixture obtained by melt-mixing at a low temperature of 150 ° C. or lower. The “molten mixture” is a mixture obtained by mixing each imide oligomer in a molten state, and does not need to be in a molten state in the composition. A solid material obtained by cooling and solidifying the molten mixture is pulverized. The obtained powder can be preferably used.

As the crosslinking agent, an oligomer having a maleic anhydride unit at one end and a diamine unit at the other end is used. Maleic anhydride units (MA) are as described above. The diamine unit is a unit having _two amino groups (—NH ₂ ). A maleic anhydride unit and a diamine unit are preferably polycondensed to form an imide oligomer (in this case, a dimer) (maleimide) (for example, formula (III) described later). In this case, one of the two amino groups of the diamine unit is used for polycondensation to form an imide bond, and the other amino group remains in a free state. Therefore, the crosslinking agent used in the present invention has a maleimide group at one end and a free amino group at the other end unit. The diamine unit is preferably an aromatic diamine, and particularly preferably the above-described mBAPS, dianilinomethane, diaminodiphenyl ether (DADE), or 2,2′-bis [4- (4-aminophenoxy) phenyl] propane (BAPP). Since the double bond in maleimide binds by reacting with an amino group, the imide dimer may be self-polymerized into an oligomer, or a mixture of a dimer and an oligomer of tetramer or higher. The melting point of the crosslinking agent is preferably 150 ° C. or less from the viewpoint of enabling construction at a low temperature. The cross-linking agent oligomer may be a mixture of oligomers having different degrees of polymerization. The structure of each of the aromatic diamines is represented by the chemical formula as follows.

The crosslinking agent oligomer has the formula (III)
MA-mBAPS (III)
(However, MA and mBAPS have the same definitions as in general formula (II) above)
It is preferable to have the structure shown by these. As mentioned above, the double bond in maleimide of the dimer represented by the formula (III) and the free amino group in mBAPS are bonded (details will be described later), so dimer self-polymerized tetramer or higher oligomer is included. It may be.

  Since adjacent units in formula (III) are imide-bonded by polycondensation of the amino group and dicarboxylic anhydride contained in each unit, the structure of formula (III) is represented by the following structural formula: .

Moreover, as a crosslinking agent, the mixture of the component which produces | generates the oligomer which has a maleic anhydride unit at one end and a diamine unit at the other end can also be used. Preferably, a mixture of an imide oligomer represented by the following general formula (IV) and an aromatic diamine can be used.
MA-mBAPS-MA (IV)
(However, MA and mBAPS have the same definitions as in general formula (II) above)
Preferable examples of the aromatic diamine include mBAPS, dianilinomethane, DADE, and BAPP as described above. Since the double bond of maleimide at one end of the imide oligomer of formula (IV) is bonded to one amino group of the aromatic diamine, an oligomer having a maleic anhydride unit at one end and an aromatic diamine unit at the other end during coating Is produced in situ, which functions as a cross-linking agent.

  As described above, the crosslinking agent oligomer has a maleimide structure at one end and a free amino group at the other end. As detailed later, the maleimide structure reacts with and binds to the terminal benzonitrile of the first imide oligomer, while the free amino group reacts with the maleimide structure at the terminal of the second imide oligomer. Thus, the crosslinking agent oligomer functions as a crosslinking agent.

  The mixing ratio of the first imide oligomer, the second imide oligomer, and the crosslinking agent oligomer is not particularly limited, but is preferably 1 to 4: 0.5 to 2: 2 to 8 in terms of molar ratio.

  In addition to the above components, the adhesive composition of the present invention preferably further contains a catalyst that promotes a crosslinking reaction. The catalyst is not particularly limited as long as it can promote the crosslinking reaction and does not adversely affect the effects of the present invention. However, at least one selected from triphenylphosphine, zinc octylate, tin octylate and cobalt naphthenate is used. Triphenylphosphine is particularly preferable. The content of these catalysts in the composition is not particularly limited, but is suitably about 0.1% by weight to 5% by weight with respect to the total amount of the first and second imide oligomers and the crosslinking agent oligomer.

  When applying the adhesive composition of the present invention, the composition is preferably in a liquid state. In order to make it liquid, the composition may be heated and melted, or it may be in the form of a solution including a solvent. When a solvent is used, a low boiling point solvent that easily evaporates at the time of coating is preferable, and preferred examples include cyclohexanone, dioxane, dioxolane and the like. The amount of the solvent used is not particularly limited as long as it can dissolve all the components, and is usually about 50 to 80% by weight in the whole composition.

  Each above-mentioned component can be manufactured by a well-known method. Although the preferable manufacturing method of each component is demonstrated concretely below, it cannot be overemphasized that other manufacturing methods are employable.

  As the first imide oligomer, a method for producing an imide oligomer in which X is mBAPS in the above formula (I) will be described. The imidization reaction is directly performed in a polar solvent in the presence of an acid catalyst, and the product is added to water or water-methanol to precipitate, filtered and recovered to form a powder. As an example, 2 mol BTDA and 1 mol mBAPS were added and reacted in a polar solvent at 180 ° C. for 2 hours, then 2.2 mol (3BN) was added, reacted at 180 ° C. for 2 hours, and the formula ( This produces the compound 3BN-BTDA-X-BTDA-3BN of I). Similarly, X = APB, diaminosiloxane, diaminodiphenyl ether, BAPP, m-TPE and the like can be synthesized.

  The second imide oligomer compound can be synthesized in the same manner as described above. An example of a method for synthesizing the imide oligomer of the above formula (II) (where Y is BTDA) is shown. 2 mol of mBAPS and 1 mol of BTDA were reacted in a polar solvent at 180 ° C. for 2 hours, then 2.2 mol MA was added, reacted at 160 ° C. for 2 hours, and the product was in water or water-methanol. In addition to precipitation, it is filtered and dried to obtain a powder.

  Crosslinking agent oligomers can also be synthesized in the same manner as described above. One example of a method for synthesizing the maleimide of the above formula (III) will be described. 1 mol of (MA) and 1 mol of mBAPS are reacted in a polar solvent at 180 ° C. for 2 hours in the presence of an acid catalyst. The produced water is removed from the system by azeotropy with toluene. The product is precipitated in water or water-methanol, filtered, dried and powdered.

Next, the preferable preparation method and usage method of the adhesive composition of this invention are demonstrated. First, a 1st imide oligomer and a 2nd imide oligomer are mixed by said preferable molar ratio, Most preferably, it is a molar ratio of 2: 1, and it stirs well. Then, it moves to a metal container, moves to a metal container, and melts by heating to 100 to 150 ° C. in a hot plate or an oil bath. Next, air-cool and pulverize. The obtained cross-linking agent oligomer and the catalyst are added to the obtained powder, mixed and stirred, and used as an adhesive or the like. The powder adhesive is melted and cast on the adherend and heated. Alternatively, the adhesive on the powder can be dissolved in a low boiling point solvent (cyclohexanone, dioxane, dioxolane, etc.) and applied onto the adherend, and the solvent can be heated and removed, and then heated and melted for processing. . It is applied to a film, a metal foil or the like. Glass fiber or carbon fiber is impregnated and used as a structure. The curing temperature is 150 to 200 ° C., and in the case of lamination, heating and compression are preferably performed to 1 to 50 kg / cm ² . The curing time is suitably about 3 minutes to 10 hours. In addition, when it is desired to simplify the process, the melt mixing of the first imide oligomer and the second imide oligomer is omitted, and the first and second imide oligomers are included in the composition as they are. You may heat. Even in this case, the reactions shown in the above reaction formulas (i) and (ii) occur at least partially, and can be used practically.

  Pyrimidine compounds produced according to reaction formula (i) and triazine compounds produced according to reaction formula (ii) have a plurality of benzonitrile groups in one molecule. The maleimide group on one end of the cross-linking agent oligomer reacts and bonds with two benzonitrile groups as shown in the following reaction formula (iii). This bonding reaction also occurs between the two unreacted first imide oligomer molecules and the maleimide group of the crosslinking agent oligomer.

  On the other hand, the maleimide group present in the pyrimidine compound produced by the above reaction formula (i) and the maleimide group at both ends of the unreacted second imide oligomer are free amino groups at one end of the crosslinking agent oligomer. And react as shown in the following reaction formula (iv) (bonding to a benzamino group in the reaction formula (iv)).

  Thus, since the crosslinking agent oligomer reacts with both the maleimide group and the two benzonitrile groups, the melt reaction product of the first and second imide oligomers represented by the reaction formulas (i) and (ii) Or it couple | bonds with the unreacted 1st and / or 2nd imide oligomer, and bridge | crosslinking occurs. In addition, since the cross-linking agent oligomer itself has a maleimide group and a free amino group, a reaction in which the cross-linking agent oligomers self-bond also occurs, and this reaction and other reactions other than the reactions described above may also occur partially. However, in any case, each component in the composition is crosslinked by the occurrence of the crosslinking reaction, and the composition is cured and adhered to the substrate.

  The above-mentioned adhesive composition of the present invention can be used as an adhesive as it is, but it is desirable to contain a polyimide resin in order to improve flexibility, heat resistance, low dielectric constant, and adhesion. The polyimide to be used is preferably a low melting point polyimide having a melting point or softening point of 200 ° C. or lower, preferably 150 to 100 ° C.

  As the low melting point polyimide, a polyimide containing the above diaminosiloxane unit (DAS) is usually used. The following can be illustrated as an example of the preferable low melting point polyimide containing DAS. The temperature in parentheses is the melting point or softening point.

(3BPDA + DAS) (m-DADE + BAPP) [105 ℃]
(BPDA + 2DAS) (2BTDA + mBAPS) [135-155 ℃]
(2BPDA + DAS (Molecular weight 1600)) (BTDA + 2mBAPS) [180 ~ 190 ℃]
3BPDA + 2DAS + mBAPS [105-110 ℃]
3BPDA + 2DAS + 0.5mBAPS + 0.5DABz [90-100 ℃] (DABz is 3,5-diaminobenzoic acid)
(7BPDA + 3DAS) (6mBAPS + 2DABz) [110 ~ 115 ℃]
(4BPDA + DAS) (4BCD + 7APB) [190 ℃]
(The melting point changes with the change in the molecular weight of the polyimide. Generally, the higher the molecular weight, the higher the melting point.)
In the above-mentioned notation, for example, “(3BPDA + DAS) (m-DADE + BAPP)” at the beginning of the reaction is the condensation of 3 mol parts of BPDA and 1 mol part of DAS, and then the reaction product. 1 shows a block copolymer obtained by adding 1 mol part of m-DADE and 1 mol part of BAPP, followed by condensation.

  The low melting point polyimide can be produced by a known method. The low melting point polyimide is obtained by using a mixture of 160- Direct imidization by heating at 200 ° C, preferably 180 ° C. The generated water is removed from the system by azeotropy with toluene used as a solvent. When the imidation reaction is completed, the mixture is poured into water or water-methanol to be filtered, recovered and dried as a polyimide powder. The powder can be used as it is, but can also be used by dissolving in a low boiling point solvent (cyclohexanone, dioxane, dioxolane) or the like. When used by dissolving in a low boiling point solvent, the first and second imide oligomers and the crosslinking agent oligomer are also dissolved in the low boiling point solvent. The addition amount of the low melting point polyimide can be appropriately set according to the purpose, but is usually about 20 to 80% by weight, preferably about 30 to 60% by weight, based on the total amount of solid components of the adhesive composition.

  An adhesive obtained by mixing a low melting point polyimide with an imide-based adhesive is partially decomposed at 400 ° C., and the adhesive strength is remarkably reduced. Therefore, use in an environment of 400 ° C. or lower is preferable.

  When intended for use in a higher temperature environment, it is used with a heat-resistant polyimide having a high glass transition temperature and a decomposition temperature of 450 ° C. or higher. These polyimides are hardly soluble in cyclohexanone, dioxane, dioxolane and the like. A solvent-soluble polyimide synthesized in a polar solvent such as NMP, DMF, or sulfolane is used.

  Many of these polyimides are known. In order to obtain a polyimide solution in which the catalyst involved in the reaction does not remain after the reaction, it is preferable not to use a catalyst that remains as a catalyst like conventional p-toluenesulfonic acid. Valerolactone and pyridine or methylmorpholine are used as catalysts. The reaction is carried out at 180 ° C. in a polar solvent such as NMP to directly imidize. The generated water is removed from the system by azeotropy with toluene. Block copolymerized polyimide is synthesized by utilizing sequential reaction. This method is known and is described in, for example, WO99 / 19771, US Pat. No. 5,502,143 and the like.

In order to increase the heat resistance of the adhesive, a solvent-soluble polyimide having a carboxylic acid group, a phenol group, an amino group, and a double bond is effective. The molecular weight by GPC measurement is preferably a polyimide having a weight average molecular weight of 30,000 to 400,000. Such polyimide often has a glass transition temperature of 250 ° C. or higher. The following can be mentioned as a preferable example of such a solvent-soluble heat-resistant polyimide.
(BTDA + 2p-DADE) (2BPDA + m-DADE), (BTDA + 2m-DADE) (2BTDA + p-DADE), (BPDA + 2m-DADE) (3BPDA + HO-AB + p-DADE), ( (2BPDA + BAPP) (m-TPE), (2BTDA + BAPP) (BPDA + m-DADE-p-DADE), (2BCD + DABz) (BTDA + HO-AB + mBAPS), (2 PMDA+Si) (2BPDA + HO-AB + 2m-DADE), (2BTDA + DAT) (BPDA + BAPS + DABz), (PMDA + 2DAT) (2BTDA + BAPS) (however, HO-AB is 3,3'-dihydroxy-benzidine, m- TPE is 1,4-bis (4-aminophenoxybenzene), DAT is 2,4-diaminotoluene)

  When heat-resistant solvent-soluble polyimide is used, a polyimide solution in which the polyimide is dissolved in a polar solvent such as NMP is used. In this case, the first and second imide oligomers and the crosslinking agent oligomer are also dissolved in the polar solvent. The addition amount of the heat-resistant solvent-soluble polyimide can be appropriately set according to the purpose, but is usually 20 to 80% by weight, preferably about 30 to 60% by weight, based on the total amount of solid components of the adhesive composition. In the case of a composition containing a heat-resistant solvent-soluble polyimide, the curing temperature can be set to 200 ° C. to 300 ° C., which is higher than the above temperature range.

  To the adhesive composition of the present invention, a resin used in a relatively high temperature state such as a phenol resin, a polyamide resin, a polyurethane resin, or a polymer alloy can be added. Moreover, an inorganic filler, an organic filler, a silicon filler, etc. can also be added in order to improve electroconductivity, water resistance, and a weather resistance. The addition amount of these additives is not particularly limited as long as it does not adversely affect the effects of the present invention, but is usually 20 to 60% by weight, preferably about 25 to 50% by weight, based on the total amount of the solid components. .

  The adhesive composition of the present invention exhibits heat resistance, flexibility, adhesion, and low dielectric properties, and is used as an adhesive in various electrical and electronic materials such as printed wiring boards, as well as sealing agents and overcoats. It can be used as an agent. Further, it can be used as a structural material or a composite material by impregnating glass fiber or Kevlar fiber.

  Hereinafter, the present invention will be specifically described based on synthesis examples and examples, but the present invention is not limited thereto.

1. Synthetic synthesis example 1 of each component; synthesis of formula (I) (X = APB) 1 L capacity three-necked separable flask on stainless steel vertical stirrer, nitrogen introduction tube and trap with stopcock A reflux condenser equipped with a ball condenser was attached and reacted in a nitrogen stream. 96.66 g (300 mmol) of 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride (BPDA), 43.8 g (150 mmol) of bis (3-aminophenoxy) -1,3-benzene (APB) ), 3.0 g (30 mmol) of valerolactone, 4.8 g (60 mmol) of pyridine, 350 g of N-methylpyrrolidone (NMP), and 60 g of toluene were placed in a three-necked flask. The mixture was heated in a silicon bath at 170 ° C. and rotated at 175 rpm for 85 minutes while passing nitrogen. The reaction temperature is the temperature of the silicon bath. The three-necked flask was air-cooled for 30 minutes, 37.17 g (315 mmol) of 3-aminobenzonitrile (3BN) and 43 g of NMP were added, and the mixture was heated and stirred at 170 ° C. and 170 rpm for 2 hours. The reaction solution was dropped into water and stirred to precipitate a precipitate. Decanted. Further, warm water was added and decantation was repeated twice. The remaining powder was washed with methanol and dried. Yield 85% or higher, melting point 130-155 ° C. The molecular weight was measured by GPC. Maximum molecular weight (Mm) 3840, number average molecular weight (Mn) 2340, weight average molecular weight (Mw) 3750, Z average molecular weight (Mz) 5350, Mw / Mn 1.60. FIG. 1 shows the GPC curve. Four isomeric peaks are observed.

Synthesis Example 2 Synthesis of Formula (I) (X = Diaminosiloxane, Molecular Weight 860) Reaction was performed in the same manner as in Synthesis Example 1. 3,4,3 ′, 4′-benzophenonetetracarboxylic dianhydride (BTDA) 32.2 g (100 mmol), diaminosiloxane 43 g (50 mmol), valerolactone 1.0 g, pyridine 1.6 g, NMP 150 g, toluene 40 g was added and reacted at 160 ° C. for 1 hour. After air cooling, 13 g (110 mmol) of 3-aminobenzonitrile and 104 g of NMP were added and reacted at 170 ° C. for 3 hours and 30 minutes. It processed like the synthesis example 1 and obtained 70g of powders. Mp 95-115 ° C. As a result of molecular weight measurement by GPC, Mm1510, Mn2150, Mw3430, Mz5280, Mw / Mn1.59. It is an oligomer shown in FIG.

Synthesis Example 3 Synthesis of Formula (I) (X = mBAPS) According to Synthesis Example 1. BTDA 96.68 g (300 mmol), 4,4′-bis (3-aminophenoxy) -diphenylsulfone (mBAPS) 64.85 g (150 mmol), valerolactone 3.0 g, pyridine 4.8 g, NMP 332 g, toluene 50 g added. The mixture was reacted at 170 ° C. for 1 hour, and 39 g (330 mmol) of 3-aminobenzonitrile, 100 g of NMP, and 30 g of toluene were added, and reacted at 170 ° C. for 2 hours. It processed like the synthesis example 1, and obtained the powder. Mp 85-95 ° C. The average weight of the three isomers is shown by molecular weight measurement by GPC. Mm5032, Mn3000, Mw4860, Mz7060, Mw / Mn1.62.

Synthesis Example 4 Synthesis of bis-maleimide oligomer represented by formula (II) BTDA 64.44 g (200 mmol), mBAPS 173 g (400 mmol), p-toluenesulfonic acid monohydrate 7.6 g (40 mmol), NMP 480 g, toluene 60 g was added. The reaction was carried out at 180 ° C. for 1 hour and cooled with air. Subsequently, 49.04 g (500 mmol) of maleic anhydride (MA), 56 g of NMP, and 20 g of toluene were reacted at 150 ° C. for 3 hours and 30 minutes. The same treatment as in Synthesis Example 1 was performed. The powder was vacuum dried at 60-70 ° C. 254 g was obtained. Mp 85-95 ° C. The results of molecular weight measurement by GPC are shown in FIG. Mm5030, Mn2300, Mw4860, Mz7060, Mw / Mn1.62.

Synthesis Example 5 Synthesis of Crosslinker Oligomer of Formula (III) According to Synthesis Example 1. 19.6 g (20 mmol) of maleic anhydride (MA), 86 g (20 mmol) of mBAPS, 4 g (2 mmol) of p-toluenesulfonic acid / monohydrate, 212 g of NMP, and 40 g of toluene were added at 165 ° C. for 3 hours and 15 minutes. Stir with heating. The same treatment as in Synthesis Example 1 was performed. White powder. Mp 95-105 ° C.

2. Synthesis of mixed compound of 3-aminobenzonitrile imide oligomer and bis-maleimide oligomer (A) 11.0 g of formula (I) (X = APB, effective molecular weight 1101) synthesized as described above, (II) (effective molecular weight) 1444) 7.2 g was placed in a stainless steel container and heated and stirred for 10 minutes on a hot plate (150 ° C. in the container). After melting, it was air-cooled and solidified. The solid was crushed. According to GPC measurement, Mm4270, Mn4480, Mw4780, Mz6150, Mw / Mn1.93

(B) 17.7 g of the formula (I) (X = diaminosiloxane, effective molecular weight 1773) synthesized as described above and 14.4 g of the formula (II) (effective molecular weight 1444) are mixed and heated and stirred on a hot plate for 10 minutes. And melted at 150 ° C. It solidified when cooled with air. Crushed. Oligomer mixture, Mn 2330, Mw 7160.

(C) 13.0 g of the formula (I) (X = mBAPS, effective molecular weight 1313) synthesized as described above and 7.2 g of the formula (II) (effective molecular weight 1444) are mixed and mixed on a hot plate for 150 minutes. Melted at ℃. Air-cooled to solidify and pulverize. It was an oligomer. Mn2800, Mw4980.

Copper foil-copper foil adhesion. (A 35-μm Mitsui Kinzoku copper foil was used.)
(B) Synthesis of polyimide (2.5BTDA + mBAPS + 0.5DABz) (DAS) exhibiting a low melting point.
According to Synthesis Example 1. BTDA 80.55 g (250 mmol), mBAPS 43.3 g (100 mmol), 3.5-diaminobenzoic acid 7.61 g (50 mmol), valerolactone 2.5 g, pyridine 4.0 g, NMP 277 g and toluene 30 g in a three-necked flask. I put it in. While flowing nitrogen, the mixture was heated and stirred at 180 ° C. and 170 rpm for 1 hour. The water produced was removed out of the system by azeotropy with toluene. After cooling with air for 1 hour, 86.0 g (100 mmol) of diaminosiloxane (amine number 430), 70 g of toluene, and 200 g of NMP were added, followed by stirring at room temperature, followed by heating and stirring at 180 ° C. and 170 rpm for 2 hours and 25 minutes. It was a 30% polyimide solution. Pour into methanol, precipitate, filter, wash with methanol and dry. Mm22,900, Mn14,700, Mw23,400, Mz34,800, Mw / Mn1.59.

(B) 5 g of the polyimide was dissolved in 20 g of cyclohexanone. To this, 1.25 g of the powder of Example (1-2 (I)) was warmed and dissolved. 0.59 g of the compound of formula (III) (Example 1-Synthesis Example 5) was dissolved in this. Further, 0.15 g of triphenylphosphine was added to make a solution. This liquid was apply | coated to the surface of copper foil, and it heated and stirred at 90 degreeC for 5 minutes (10-20 micrometers of imide adhesives on copper foil). It was found that the copper foil coated surfaces were clipped and heated in a 180 ° C. oven for 30 minutes, so that the copper foil adhered strongly.

(C) The above adhesive solution is also applied to a 35 μm copper foil, heated at 90 ° C. for 10 minutes and 180 ° C. for 5 minutes, and the coated surfaces of the copper surfaces are combined at 200 ° C., 50 kg, 30 minutes (sample is 5 × 5 cm) Crimped. An adhesive strength of 1.2 kg / cm is shown. The applied copper foil was heated and dried at 90 ° C. for 10 minutes and then at 180 ° C. for 60 minutes to try to bond the copper surface in the same manner, but adhesion was hardly noticed.

Adhesion of glass epoxy and copper foil.
Adhesion by hot pressing was performed at 100 kg and 180 ° C. for 30 minutes. The sample was 6.5 cm × 8 cm = 52 cm ² . Therefore, a pressure of ² kg / cm ² is applied.

(A) 11.8 g of the low melting point polyimide of (Example 2-I) was dissolved in 20 g of cyclohexanone with stirring (48% polyimide concentration). To this, 2.8 g of the powder of Example (1-2 (I)) was dissolved, and 3.8 g of the powder of formula (III) and 0.1 g of triphenylphosphine were added to make a solution. The glass epoxy surface was wiped with a paper file. The adhesive mixed solution was applied on a copper foil having a thickness of 35 μm. It dried at 90 degreeC for 30 minute (s), and match | combined the glass epoxy surface and the adhesive surface of copper foil. Pressure bonding was performed with a hot press at 180 ° C. and 100 kg for 30 minutes. The bond strength was 2.2 kg / cm ² (180 ° C. peel strength).

(B) (2BPDA + Si) (2BTDA + 2mBAPS + DABz) was used as the polyimide powder. Mm 36,600, Mn 23,000, Mw 42,800, Mz 71,400, Mw / Mn 1.86. Dissolve 5.9 g of this powder in 10.0 g of cyclohexanone, dissolve 1.4 g of (Example 1-2 (A)), add 1.9 g of MA-mBAPS (crosslinking agent), and then add 0.05 g of triphenylphosphine. And dissolved. The adhesive solution was applied to the copper surface, dried at 90 ° C. for 30 minutes, and glass-epoxy was bonded to this surface and adhered by hot pressing. Pressure bonding was performed at 180 ° C. and 100 kg for 30 minutes. The adhesive strength of the 180 ° C. peel is 2.2 kg / cm. The adhesion force curve is shown in FIG. The measured values are shown in Table 1 below.

(D) Glass fiber was impregnated with the above adhesive solution and dried at 90 ° C. for 30 minutes. The copper foils were combined and dried at 180 ° C. and 100 kg for 30 minutes. The adhesive force (180 ° C. peel) was 2.0 kg / cm. A laminate was obtained.

"High temperature bonding experiment"
(A) Polyimide in 10% NMP of (BTDA + 2p-DADE) (2BPDA + m-DADE) was used. Mm38,100, Mn18,100, Mw50,600, Mz101,200, Mw / Mn2.8. To 122 g of polyimide solution (polyimide content is 12.2 g), 3.2 g of (Example 1-2 (b)) powder was added and dissolved. To this was added 2.0 g of a crosslinking agent oligomer (formula (III)), and then 0.1 g of triphenylphosphine was dissolved to prepare an adhesive composition solution. A solution of the adhesive composition was applied onto a 35 μm thick copper foil and heated in an infrared furnace at 90 ° C. for 1 hour and then at 180 ° C. for 2 hours to obtain a polyimide-coated copper foil. The 180-degree angle bend bending was passed, and the go board was cut and no separation was observed. The adhesive layer was not changed by heating in an oven at 400 ° C. for 1 hour.

(B) Collect 81 g of a 15% NMP solution of (BPDA + 2m-DADE) (3BPDA + HO-AB + p-DADE) (polyimide content is 12.2 g). Mm44,300, Mn26,200, Mw45,900, Mz70,000, Mw / Mn1.75. In the same manner as described above, 3.2 g of (Example 1-2 (b)) and 2.0 g of a crosslinking agent (MA-mBAPS) were dissolved, and 0.1 g of triphenylphosphine was added to obtain a polyimide adhesive solution. It apply | coated on copper foil and it heated at 90 degreeC 1 hour and 180 degreeC 1 hour in the infrared furnace, and obtained the 15-micrometer polyimide copper two-layer board | substrate. Passed 180 ° angle bending test. Passed the Go board test. Although it was heated in an oven at 400 ° C. for 1 hour, no deterioration of the polyimide film was observed.

  The heat-cured adhesive obtained by heating the adhesive composition of the present invention is excellent in adhesiveness, heat resistance, electrical insulation, and low dielectric constant. Adhesive, printed wiring board, sealing agent, laminated product And can be used for structural materials and the like.

The GPC curve of the product of Synthesis Example 1 is shown. The GPC curve of the product of the synthesis example 2 is shown. The GPC curve of the product of Synthesis Example 4 is shown. The adhesive force curve of the thermosetting material of Example 3 is shown.

Claims (19)

  (1) a first imide oligomer having 3-aminobenzonitrile units at both ends, (2) a second imide oligomer having maleic anhydride units at both ends, and (3) a maleic anhydride unit at one end, An adhesive composition comprising an oligomer having a diamine unit at the other end or a cross-linking agent comprising a mixture of components that form the oligomer.   (1) a molten mixture obtained by melt-mixing a first imide oligomer having 3-aminobenzonitrile units at both ends and a second imide oligomer having maleic anhydride units at both ends, and (2) one end A cross-linking agent comprising a maleic anhydride unit, an oligomer having a diamine unit at the other end, or a mixture of components that form the oligomer.   The composition according to claim 2, wherein the melt mixing is performed at a temperature of 150C to 200C.   The composition according to any one of claims 1 to 3, wherein the melting points of the first and second imide oligomers and the crosslinking agent are 150 ° C or lower. The first imide oligomer is represented by the general formula (I)
3BN-BTDA-X-BTDA-3BN (I)
(However, 3BN is 3-aminobenzonitrile unit, BTDA is benzophenonetetracarboxylic dianhydride unit, X is 1,3-bis (3-aminophenoxy) benzene unit, 4,4'-bis (3-aminophenoxy unit) ) Indicates a diphenylsulfone unit or a diaminosiloxane unit, and adjacent units are imide-bonded by polycondensation between an amino group contained in each unit and a dicarboxylic anhydride)
The composition of any one of Claims 1 thru | or 4 which has a structure represented by these. The second imide oligomer is represented by the general formula (II)
MA-mBAPS-Y-mBAPS-MA (II)
(However, MA is maleic anhydride unit, mBAPS is 4,4'-bis (3-aminophenoxyphenyl) diphenylsulfone unit, Y is benzophenonetetracarboxylic dianhydride unit, biphenyltetracarboxylic dianhydride unit, Pyromellitic dianhydride unit, 4,4'-bis (dicarboxyphenyl) ether dianhydride unit or bicyclo (2,2,2) oct-7-ene-1,2,3,6-tetracarboxylic acid Indicates a dianhydride unit, and adjacent units are imide-bonded by polycondensation between an amino group contained in each unit and a dicarboxylic anhydride)
The composition of any one of Claims 1 thru | or 5 which has a structure represented by these. The crosslinking agent is of formula (III)
MA-mBAPS (III)
(However, MA and mBAPS have the same definitions as in general formula (II) above)
The composition according to any one of claims 1 to 6, which is an imide oligomer having a structure represented by formula (1) and / or an imide oligomer obtained by polymerization thereof. The crosslinking agent is represented by the formula (IV)
MA-mBAPS-MA (IV)
The composition according to any one of claims 1 to 6, which is a mixture of an imide oligomer represented by the formula (1) and an aromatic diamine.   The composition according to any one of claims 1 to 8, wherein a molar ratio of the first imide oligomer, the second imide oligomer, and the crosslinking agent in the composition is 1 to 4: 0.5 to 2: 2 to 8. Stuff.   The composition according to any one of claims 1 to 9, further comprising a catalyst for promoting a crosslinking reaction by the crosslinking agent.   The composition according to claim 10, wherein the catalyst is at least one selected from the group consisting of triphenylphosphine, zinc octylate, tin octylate and cobalt naphthenate.   The composition of claim 11, wherein the catalyst is triphenylphosphine.   The composition according to any one of claims 1 to 12, further comprising a polyimide having a melting point or softening point of 200 ° C or lower.   The composition according to any one of claims 1 to 12, further comprising a solvent-soluble polyimide having a glass transition temperature of 250 ° C or higher.   The composition according to claim 14, wherein the solvent-soluble polyimide has a double bond, a carboxyl group or an amino group, and has a weight average molecular weight of 30,000 to 300,000 as measured by GPC.   The composition according to any one of claims 1 to 15, which comprises a solvent and is in the form of a solution.   A method for curing the adhesive composition, comprising applying the adhesive composition according to any one of claims 1 to 16 to a substrate in a liquid form and curing by heating.   The method according to claim 17, wherein the heating temperature is 150 ° C. to 200 ° C. A cured product obtained by curing by the method according to any one of claims 17 to 18.

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