Maleimide resin, maleimide resin composition, and method for producing maleimide resin

Abstract

To provide a maleimide resin having high photocurability, high heat resistance, and superior compatibility with resins, and to provide a cured resin composition having sufficient photocurability without impairing heat resistance and insulation properties.SOLUTION: The above problem can be solved by a maleimide resin represented by the following formula (I) and a resin composition containing the same. (Each R1 is independently the same or different, and at least one is a hydrocarbon group having an alicyclic structure, and n is a repetition number representing a real number of 0≤n<10).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a maleimide resin, a composition containing the same, and a method for producing a maleimide resin.

Background Art

[0002] Electronic components used in electronic devices such as smartphones and notebook personal computers are progressing in high-density integration and high-density mounting, and the materials used for substrates, adhesives, encapsulants, and wiring agent protectants required for these components are required to have heat resistance, insulation properties, and hydrolysis resistance. Conventionally, bis-maleimide resins have been used in printed wiring boards, adhesives, encapsulants, etc. to impart heat resistance and insulation properties. However, bis-maleimide resins are derived from a rigid skeleton and have problems in solubility in solvents and compatibility with resins. In addition, photocurability has been a problem for use as a semiconductor protective film or an insulating film.

[0003] In recent years, a bis-maleimide resin having a cyclic imide bond obtained by reacting an amine compound (dimer diamine) derived from dimer acid, a tetracarboxylic dianhydride, and maleic anhydride has been developed. It has low solubility in solvents and a low tensile elastic modulus, and the photosensitive resin composition containing the bis-maleimide resin has been shown to have photocurability, adhesion to a metallic wiring material, and high insulation properties.

[0004] However, having a dimer diamine with a long-chain branched alkyl results in a lower glass transition temperature (Tg) compared to conventional bis-maleimide resins, and there are still problems in solubility and compatibility with other resins.

[0005] Therefore, there is a demand for a new maleimide resin that has good solubility in solvents, excellent compatibility with resins, high photocurability, and high heat resistance after curing.

[0006]

Patent Document 1

Patent Document 2

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] Accordingly, an object of the present invention is to provide a maleimide resin having high photocurability, high heat resistance, and excellent compatibility with resins. Another object of the present invention is to provide a cured resin composition having sufficient photocurability without impairing heat resistance and insulation properties.

MEANS FOR SOLVING THE PROBLEMS

[0008] As a result of intensive studies to solve the above problems, the present inventors have found that a maleimide resin having a specific structure and a resin composition containing the same can solve the above problems, and have completed the present invention.

[0009] That is, the present invention relates to the following [1] to [5].

[0010] [1] A maleimide resin represented by the following formula (I).

[0011]

CHEMICAL

[0012] (R1 is independently of each other, may be the same or different, and at least one is a hydrocarbon group having an alicyclic structure, n is the number of repetitions, and represents a real number of 0 ≦ n < 10.)

[0013] [2] The maleimide resin according to [1], wherein at least one of R1 in the formula (I) is a divalent hydrocarbon group represented by (A-1) to (A-4).

[0014]

CHEMICAL

[0015] (In formulas (A-1) to (A-4), the wavy lines indicate the bonding sites with nitrogen atoms.)

[0016] The maleimide resin according to [3][1] or [2], wherein the weight average molecular weight of the maleimide resin is 2000 or less.

[0017] The maleimide resin composition containing the maleimide resin according to [4][1] to [3], a curable resin, and / or a polymerization initiator.

[0018] A method for producing a maleimide resin, [5] an isocyanate compound represented by the following formula (II),

[0019]

Chemical formula

[0020] (R1 are independently of each other, may be the same or different, and at least one is a hydrocarbon group having an alicyclic structure, n is the number of repetitions, and represents a real number of 0 ≦ n < 10.) A reactant obtained by reacting a tertiary alcohol represented by the following formula (III) or a substituted benzyl alcohol represented by the following formula (IV),

[0021]

Chemical formula

[0022] (R2 are independently of each other, may be the same or different organic groups.)

[0023]

Chemical formula

[0024] (R3 is an organic group.) A method for producing a maleimide resin represented by the following formula (I) obtained by reacting maleic anhydride under acidic conditions.

[0025]

Chemical formula

[0026] (R1 are each independently the same or different, and at least one is a hydrocarbon group having an alicyclic structure, n is the number of repetitions, and represents a real number of 0 ≦ n < 10.)

Brief Description of the Drawings

[0027]

Figure 1

Mode for Carrying Out the Invention

[0028] Hereinafter, a mode for carrying out the present invention (hereinafter referred to as "this embodiment") will be described in detail. The following embodiments are examples for explaining the present invention and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of its gist.

[0029] The maleimide resin of the present invention is represented by the following formula (I).

[0030]

Chemical formula

[0031] R1 are each independently the same or different, and at least one is a hydrocarbon group having an alicyclic structure, n is the number of repetitions, and represents a real number of 0 ≦ n < 10.

[0032] In the formula (I), it is preferable that at least one of R1 is a hydrocarbon group having a cyclohexane structure, and it is more preferable that at least one is a divalent hydrocarbon group represented by (A-1) to (A-4).

[0033]

Chemical formula

[0034] In formulas (A-1) to (A-4), the wavy line represents the bonding site with the nitrogen atom.

[0035] When R1 in the formula (I) contains a divalent hydrocarbon group represented by the formulas (A-1) to (A-4), it is excellent in heat resistance and photocurability. It is more preferable that all of R1 in the formula (I) are divalent hydrocarbon groups represented by (A-1) to (A-4), and it is particularly preferable that R1 in the formula (I) is the same.

[0036] In the formula (I), n is preferably 0 ≦ n < 8, and more preferably 0 ≦ n < 5.

[0037] <Method for producing maleimide resin> A specific synthesis method of maleimide will be described. For example, a polyisocyanate having an isocyanurate ring represented by the following formula (II) is carbamated to obtain a carbamate compound represented by the following formula (V), then an amine or an amine salt is obtained under acidic conditions, and then maleic anhydride and maleimidation are carried out to obtain a maleimide resin (I).

[0038]

Chemical formula

[0039]

Chemical formula

[0040] R1 and n in the above formulas (II) and (V) have the same meanings as R1 and n in the formula (I).

[0041] In the above formula (V), X represents a residue obtained by removing a hydrogen atom from the hydroxy group of a tertiary alcohol represented by the following formula (III) or a residue obtained by removing a hydrogen atom from the hydroxy group of a substituted benzyl alcohol represented by the following formula (IV).

[0042]

Chemical formula

[0043] R2 is, independently of each other, an organic group which may be the same or different.

[0044]

Chemical formula

[0045] R3 is an organic group.

[0046] The reaction can be carried out without a solvent or with a solvent. The solvents that can be used are not particularly limited. For example, aromatic solvents such as toluene and xylene, aliphatic solvents such as cyclohexane and n-hexane, ethers such as diethyl ether and diisopropyl ether, ester solvents such as ethyl acetate and butyl acetate, and non-aqueous solvents such as ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone can be mentioned, but are not limited thereto, and two or more kinds may be used in combination. In addition to the non-aqueous solvent, an aprotic polar solvent can also be used in combination. For example, dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N-methylpyrrolidone, etc. can be mentioned, and two or more kinds may be used in combination.

[0047] Examples of the polyisocyanate having an isocyanurate ring include, without particular limitation, tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate (TMDI), lysine diisocyanate (LDI), 1,4-cyclohexane diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane 4,4'-diisocyanate (H12MDI), trimethylhexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate (H12MDI), norbornene diisocyanate (NBDI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), 1,4-diphenyl diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate (TDI), 2,4-diphenylmethane diisocyanate (MDI), 4,4-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, o-tolidine diisocyanate, polyphenylmethane polyisocyanate (crude MDI), triphenylmethane triisocyanate, and polyisocyanates formed by trimerizing one or more oligomer polyisocyanates such as tris(isocyanatophenyl) thiophosphate by a known method.Tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate (TMDI), lysine diisocyanate (LDI), trimethylhexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate (H12MDI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), 1,4-diphenyldiisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate (TDI), 2,4-diphenylmethane diisocyanate (MDI), 4,4-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, o-tolidine diisocyanate, polyphenylmethane polyisocyanate (crude MDI), triphenylmethane triisocyanate, tris(isocyanatophenyl) thiophosphate are preferred. Among these, particularly 1,4-cyclohexane diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane 4,4'-diisocyanate (H12MDI), and polyisocyanate obtained by trimerizing norbornene diisocyanate (NBDI) are particularly preferred because they result in a maleimide resin excellent in heat resistance and photocurability.

[0048] The polyisocyanate can be reacted with a tertiary alcohol compound and / or a substituted benzyl alcohol to synthesize a carbamate reaction product.

[0049] Examples of the tertiary alcohol compound include tert-butanol, 1-methylcyclohexanol, 2-methyl-2-butanol, 2-methyl-2-pentanol, 3-quinuclidinyl benzoate, 3-methylpentanol, 2-methylisoborneol, 1-adamantanol, acetocyanohydrin, 1,3-adamantanediol, diacetone alcohol, triacetone alcohol, triphenylmethanol, and the like.

[0050] Examples of the substituted benzyl alcohol include p-methoxybenzyl alcohol, p-ethoxybenzyl alcohol, p-acetoxybenzyl alcohol, p-chlorobenzyl alcohol, p-cyanobenzyl alcohol, p-nitrobenzyl alcohol, p-sulfonylbenzyl alcohol, and the like.

[0051] In the above carbamation reaction, it can be carried out without a catalyst or a known catalyst can be used. Examples of the catalyst include metal catalysts such as butyltin dilaurate (DBTL), bismuth neodecanoate, and zinc octanoate, and basic catalysts such as triethylamine (TEA), imidazole, diazabicyclooctane (DABCO), and tertiary amines.

[0052] In the above carbamation reaction, the reaction temperature can be 40°C to 150°C. A range of 60°C to 120°C is more preferable. By reacting at the above reaction temperature, the target compound can be efficiently obtained. If the reaction temperature is too low, the reaction time may be long, and if the reaction temperature is too high, decomposition of the reacted carbamate moiety may occur.

[0053] A method for obtaining a maleimide compound from the above carbamate reaction product will be described. By using an acid catalyst for the carbamate reaction product, an amine or an amine salt can be generated in the reaction system.

[0054] The acid catalyst is not particularly limited, and examples include hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, p-toluenesulfonic acid, methanesulfonic acid, Lewis acids such as aluminum chloride and zinc chloride, solid acids such as activated clay, acid clay, white carbon, zeolite, and silica alumina, and acidic ion exchange resins. These can be used alone or in combination of two or more. From the viewpoint of being able to be used as the same acid catalyst in the subsequent maleimidation step, methanesulfonic acid and p-toluenesulfonic acid are preferred. The amount of the acid catalyst used is 0.01 to 10.0 moles, preferably 0.05 to 5.0 moles, per 1.0 mole of the amine group produced. If the amount of the catalyst is too small, there is a risk that the carbamate reaction product will remain, and if the amount of the catalyst is too large, purification after the reaction may become difficult.

[0055] Next, a maleimide resin is obtained by a maleimidation reaction using maleic anhydride with respect to an amine or an amine salt. In the maleimidation reaction, the reaction temperature can be carried out at 80°C to 150°C. From the viewpoint of discharging the water generated during the reaction out of the system, a range of 100°C to 130°C is more preferable. Also, by reacting at the above reaction temperature, the target maleimide resin can be obtained. If the reaction temperature is too low, the reaction may not proceed, and if the reaction temperature is too high, there is a risk of polymerization due to the polymerization of unsaturated groups.

[0056] The weight average molecular weight Mw of the maleimide resin of the present invention is preferably 200 or more and 4000 or less, and more preferably 300 or more and 3000 or less. By setting the value of the weight average molecular weight Mw within the above upper limit, the handleability and solubility can be further enhanced. The weight average molecular weight Mw of the maleimide resin of the present invention can be determined as a polystyrene equivalent value by gel permeation chromatography analysis, and can be determined by the method described in the following examples.

[0057] The maleimide resin composition of the present invention is characterized by containing a maleimide resin represented by formula (I). As a curable resin, if necessary, an epoxy resin, a phenol resin, a benzoxazine resin, a polyimide resin, a polyamideimide resin, a cyanate resin, an active ester resin, a radically polymerizable resin, an acid anhydride resin, a carbodiimide resin, and an amine resin can be used in combination.

[0058] When blending a curable resin, its content is 0.1 to 400 parts by weight, preferably 0.1 to 200 parts by weight, more preferably 0.1 to 100 parts by weight, based on 100 parts by weight of the maleimide resin. If it exceeds 400 parts by weight, it may have an adverse effect on heat resistance and curability.

[0059] The maleimide resin composition of the present invention can use a photoinitiator if necessary. The polymerization initiator that can be used is not particularly limited, and examples include benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, diethylthioxanthone, benzophenone, 2-ethylanthraquinone, 2-hydroxy-2-methylpropiophenone, 2-methyl-〔4-(methylthio)phenyl〕-2-morpholino-1-propane, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, camphorquinone, 9-fluorenone, diphenyldisulfide, etc. Specifically, IRGACURE (registered trademark) 651, 184, 2959, 127, 907, 369, 379EG, 819, 784, 754, 500, OXE01, OXE02, OXE03, OXE04, DAROCURE (registered trademark) 1173, LUCIRIN (registered trademark) TPO (all manufactured by BASF), Seikoal (registered trademark) Z, BZ, BEE, BIP, BBI (all manufactured by Seiko Chemical Co., Ltd.) and the like can be mentioned. As such a photoinitiator, one kind may be used alone or two or more kinds may be used in combination.

[0060] When a photoinitiator is blended, its content is 0.1 to 50 parts by weight, preferably 0.1 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the maleimide resin. If it exceeds 50 parts by weight, it may have an adverse effect on heat resistance. .01 parts by weight, and preferably 0.21

Examples

[0061] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples.

[0062] <Gel Permeation Chromatography (GPC)> Using a polystyrene standard solution, the weight average molecular weight (Mw) and number average molecular weight (Mn) were calculated in terms of polystyrene. GPC: HLC-8320GPC (manufactured by Tosoh Corporation) Column: TSKgel SuperMultipre HZ-M Mobile phase: Tetrahydrofuran Column temperature: 40 °C Detection: RI (Differential Refractive Index Detector)

[0063] <Infrared Absorption Spectroscopy (IR)> Apparatus: IRAffinity-1S (manufactured by Shimadzu Corporation)

[0064] Example 1 Into a four-necked flask equipped with a stirring device, a thermometer, a condenser, and a nitrogen line, 110.5 g of toluene, 242.8 g of an isocyanurate-modified product of isophorone diisocyanate (''VESTANAT T-1890 / 100'' manufactured by EVONIK, isocyanate group content 17.3% by mass), and 145.0 g (1.0 mol) of 4-methoxybenzyl alcohol were added. 36.8 g of N-methylpyrrolidone and 11.2 g (0.1 mol) of 1,4-diazabicyclo[2,2,2]octane were added, and the temperature was raised to 110 °C while blowing nitrogen into the system, and the reaction was carried out at the same temperature for 10 hours. It was confirmed by infrared spectrum that the absorption at 2250 cm -1 which is the characteristic absorption of the isocyanate group completely disappeared. Subsequently, 150 g of toluene and 150 g of N-methylpyrrolidone were added, 96.1 g of methanesulfonic acid was added dropwise at 40 °C for 2 hours, and then the temperature was raised to 60 °C. 0.4 g of dibutylhydroxytoluene and 117.6 g of maleic anhydride were added and stirred at 80 °C for 1 hour. Then, the temperature was further raised, and a reflux dehydration reaction was carried out for 14 hours and then cooled. Toluene was added to the obtained solution, and it was washed with ion-exchanged water and an aqueous sodium hydroxide solution until the pH of the aqueous layer became neutral, and the organic layer was dried under reduced pressure to obtain 240 g of maleimide resin A1 as a white powder. The 1H-NMR is shown in Figure 1. The number average molecular weight Mn by GPC analysis was 920, and the weight average molecular weight Mw was 1140. The maleimide resin A1 obtained in Example 1 is a mixture containing the compound of the formula (I) where n = 0 represented by the following formula (A1), and the compounds represented by the formula (I) where n = 1, n = 2, etc. and n ≤ 1 can also be synthesized simultaneously.

[0065]

Chemical formula

[0066] Comparative Example 1 The isocyanurate-modified product of isophorone diisocyanate in Example 1 ((VESTANAT T-1890 / 100 manufactured by EVONIK, isocyanate group content 17.3% by mass) was changed to 518.5 g of the isocyanurate-modified product of toluene diisocyanate (CORONATE 3070 manufactured by Tosoh Corporation, isocyanurate group content 8.1%), and the operation was carried out under the same conditions. 320 g of maleimide resin A2, which is a brown powder, was obtained. The number average molecular weight Mn by GPC analysis was 1150, and the weight average molecular weight Mw was 2055. The maleimide resin A2 obtained in Comparative Example 1 is represented by the following formula (A2).

[0067] [Chemical formula]

[0068] Comparative Example 2 The acid catalyst in Example 1 was changed from methanesulfonic acid to the amine catalyst triethylamine, and the operation was carried out under the same conditions. However, the deprotection of carbamate did not proceed, and no maleimide resin was obtained.

[0069] [Solvent solubility] The maleimide resin A1 obtained in Example 1, the maleimide resin A2 obtained in Comparative Example 1, and 4,4'-diphenylmethane bismaleimide (manufactured by Tokyo Chemical Industry) as a bismaleimide resin were adjusted to 50% by weight in various solvents, and those that were completely dissolved were evaluated as ○, and those with precipitates, deposits, or turbidity were evaluated as ×.

[0070] [Table 1]

[0071] [Preparation of cured product] The resin composition shown in Table 2 was applied to a polyimide film (manufactured by Toray, Kapton) to a film thickness of 50 μm, dried at 80°C for 30 minutes, and exposed using a "USHIO ultra-high pressure mercury lamp 500W multi-light" at 1000 mJ / cm 2 Exposure was carried out, and then it was heated at 180°C for 60 minutes to be cured, and then the substrate was removed to obtain a cured product.

[0072] Materials used in Table 2 HDDA: Hexamethylene diacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) A-200: Polyethylene glycol #200 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) Bismaleimide resin: 4,4'-Diphenylmethane bismaleimide (manufactured by Tokyo Chemical Industry Co., Ltd.) Irgacure OXE-02: Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) (manufactured by BASF Japan Ltd.)

[0073] [Glass transition temperature: Tg] The cured product prepared was cut out with a width of 5 mm, and then set in a viscoelasticity measuring device RSA-G2 manufactured by TA instruments. In an air atmosphere, at a frequency of 10 Hz and a heating rate of 2 °C / min, tanδ was measured, and the temperature at the maximum value of tanδ was taken as Tg.

[0074] [Evaluation of thermal decomposition resistance: Td5] For 3 mg of the sample on which the cured product was prepared, the temperature at which the weight decreased by 5% was measured using TGA / DSC1 manufactured by METTLER in an air flow of 100 ml per minute.

[0075] [Evaluation of curability: Film thickness change rate] The prepared film was immersed in an acetone solution and ultrasonically cleaned, and the film thickness change rate was calculated. Film thickness change rate = Cured film thickness after acetone cleaning ÷ Cured film thickness before acetone immersion

[0076] [Table 2]

[0077] [Table 3]

[0078] As shown in Table 1, the maleimide resins of Comparative Examples 1 and 2 were inferior in solvent solubility, while the maleimide resin of the present invention showed high solvent solubility. Further, as shown in Table 3, since the resin composition of Comparative Example 4 did not have high photocurability, the cured film did not show sufficient heat resistance. Also, the resin composition of Comparative Example 5 was incompatible, and the resin precipitated, failing to form a cured film. It was shown that the maleimide resin composition of the present invention has high photocurability and sufficient heat resistance.

Claims

1. A maleimide resin represented by the following general formula (I). 【Chemical Formula 1】 (R １ may be the same or different and independent of each other, and at least one is a hydrocarbon group having an alicyclic structure, n is the number of repetitions, and represents a real number of 0 ≦ n < 10.)

2. In the formula (I), R １ The maleimide resin according to claim 1, wherein at least one of them is a divalent hydrocarbon group represented by (A-1) to (A-4). [Chemical Formula 2] (In formulas (A-1) to (A-4), the wavy line indicates the bonding site with the nitrogen atom.)

3. The maleimide resin according to Claim 1, wherein the weight average molecular weight of the maleimide resin of the formula (I) is 2000 or less.

4. A maleimide resin composition comprising the maleimide resin according to any one of Claims 1 to 3, a curable resin and / or a photoinitiator.

5. A method for producing a maleimide resin, comprising an isocyanate compound represented by the following formula (II), [Chemical 3] (R １ may be the same or different and independent of each other, and at least one is a hydrocarbon group having an alicyclic structure, n is the number of repetitions, and represents a real number of 0 ≦ n < 10.), a tertiary alcohol represented by the following formula (III), or a reaction product obtained by reacting a substituted benzyl alcohol represented by the following formula (IV), and 【Chemical Formula 4】 (R ２ are organic groups which may be the same or different and independent of each other.) [Chemical Formula 5] (R ３ is an organic group.) A method for producing a maleimide resin represented by the following formula (I), which is obtained by reacting maleic anhydride under acidic conditions. 【Chemical Formula 6】 (R １ may be the same or different and independent of each other, and at least one is a hydrocarbon group having an alicyclic structure, n is the number of repetitions, and represents a real number of 0 ≦ n < 10.)

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