Modified bismaleimide resin and preparation method thereof

Abstract

The invention provides a preparation method of modified bismaleimide resin. The preparation method comprises the following steps: preparing modified bismaleimide resin; maleic anhydride and a diamine compound are mixed to form a corresponding mixture. And heating the mixture. The diamine compound has a main chain structure or fragment represented by [formula A], [formula B] or [formula C] as described in the description.

Description

Technical Field

[0001] The invention relates to a maleimide resin, in particular to a modified maleimide resin. Background Art

[0002] With the advancement of technology, electronic components are developing towards the goal of being light, thin, short and small. In addition, the fifth generation of mobile communication technology (5 th generation mobile networks; 5G for short; and even the sixth generation of mobile communication technology (6 th With the advent of 6G (6th generation mobile networks), the industry has been increasing its demand for high-frequency transmission, high-speed signal transmission, and low latency. Therefore, the relevant fields are currently committed to developing substrate materials with high glass transition temperature (glass transition temperature, Tg), low dielectric constant (dielectric constant, Dk), low dielectric loss (dissipation factor, Df) and good heat resistance to meet the requirements of electronic substrates for dielectric properties (low dielectric constant, low dielectric loss) and heat resistance.

[0003] General bismaleimide resins (mostly aliphatic molecular structures) have good processability, but their moisture resistance may be poor. They may not be applicable or may be difficult to apply in high humidity environments or underwater environments, and thus may not be applicable to high-end products or special-specification products. Summary of the invention

[0004] The present invention relates to a modified bismaleimide resin and a preparation method thereof.

[0005] According to an embodiment of the present invention, the structural formula of the modified bismaleimide resin is Wherein R1 is a C1-C3 alkyl group, and R2 is a C1-C16 substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aryl group. [Formula B]: [Formula C]:

[0006] According to an embodiment of the present invention, a method for preparing a modified bismaleimide resin comprises the following steps: mixing maleic anhydride and a diamine compound to form a corresponding mixture; heating the mixture; and the diamine compound having a main chain structure or fragment as shown in [Formula A], [Formula B] or [Formula C] as described above.

[0007] Based on the above, the modified maleimide resin of the present invention has at least a specific main chain structure or segment, and thus has lower water absorption (ie, good moisture resistance), lower thermal expansion coefficient and dielectric properties, and has good applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a partial flow diagram of a method for preparing a polyphenylene ether bismaleimide resin according to an embodiment of the present invention.

[0009] Description of Reference Numerals

[0010] S10, S20, S30: steps. DETAILED DESCRIPTION

[0011] In the following detailed description, for the purpose of illustration and not limitation, exemplary embodiments that disclose specific details are set forth to provide a thorough understanding of the various principles of the present invention. However, it will be apparent to one of ordinary skill in the art that, with the benefit of this disclosure, the present invention may be practiced in other embodiments that depart from the specific details disclosed herein. In addition, descriptions of well-known devices, methods, and materials may be omitted to avoid obscuring the description of the various principles of the present invention.

[0012] Ranges may be expressed herein as from "about" one particular value to "about" another particular value, which may also be expressed directly as one particular value and / or to another particular value. When expressing the range, another embodiment includes from the one particular value and / or to another particular value. Similarly, when a value is expressed as an approximation via the use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each range may be clearly related to or independent of the other endpoint.

[0013] In this document, non-limiting terms (such as: may, can, for example or other similar terms) mean that implementation, inclusion, addition or existence are optional or necessary.

[0014] Herein, a "substituted" functional group or compound may be a non-reactive hydrogen atom in the functional group or compound that is substituted with an isotope or with a corresponding non-reactive group (eg, an alkyl group).

[0015] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. It will also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the relevant technical context and should not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0016] [Preparation of modified maleimide resin]

[0017] like Figure 1 As shown, in this embodiment, the preparation method of the modified maleimide resin may include the following steps.

[0018] Step S10 includes a mixing reaction, which is to prepolymerize maleic anhydride and a diamine compound under nitrogen.

[0019] In one embodiment, the diamine compound and the solvent may be mixed first to form a raw material mixture.

[0020] In one embodiment, the solvent is selected from the group consisting of toluene, methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), dimethylacetamide (DMAC), dimethylformamide (DMF) and proprylene glycol monomethyl ether (PM). However, the present invention is not limited to the above examples. Considering the solubility of the corresponding diamine compound, it is better to use a hydrophobic solvent; or, directly use a hydrophobic solvent.

[0021] In one embodiment, the ratio of the diamine compound in the raw material mixture is about 30 wt % to 60 wt %.

[0022] In one embodiment, the diamine compound may be a primary amine compound (or also called a primary amine compound).

[0023] In one embodiment, the diamine compound may have a non-polar main chain structure as shown in the following [Formula A]. That is, the diamine compound may be a diamine compound having a fragment as shown in the following [Formula A].

[0024] [Formula A]

[0025]

[0026] In [Formula A], R1 may be the same or different from each other. R1 may be an alkyl group having one to three carbon atoms (calculated as: C1-C3).

[0027] In [Formula A], R2 may be the same or different from each other. R2 may be a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aryl group (e.g., a phenyl group or a phenyl group) having from 1 to 16 carbon atoms (calculated as: C1-C16).

[0028] In one embodiment, the diamine compound may include a non-polar main chain structure shown in the following [Formula A-1]. In one embodiment, the diamine compound having the fragment shown in [Formula A-1] is one of the diamine compounds having the fragment shown in [Formula A].

[0029] [Formula A-1]

[0030]

[0031] In one embodiment, the diamine compound having the fragment represented by [Formula A-1] may include the diamine compound represented by the following [Formula A-1-1].

[0032] [Formula A-1-1]

[0033]

[0034] In one embodiment, the diamine compound may include a non-polar main chain structure shown in the following [Formula A-2]. In one embodiment, the diamine compound having the fragment shown in [Formula A-2] is one of the diamine compounds having the fragment shown in [Formula A].

[0035] [Formula A-2]

[0036]

[0037] In one embodiment, the diamine compound having the fragment represented by [Formula A-2] may include the diamine compound represented by the following [Formula A-2-1].

[0038] [Formula A-2-1]

[0039]

[0040] In one embodiment, the diamine compound may include a non-polar main chain structure shown in the following [Formula A-3]. In one embodiment, the diamine compound having the fragment shown in [Formula A-3] is one of the diamine compounds having the fragment shown in [Formula A].

[0041] [Formula A-3]

[0042]

[0043] In one embodiment, the diamine compound having the fragment represented by [Formula A-3] may include the diamine compound represented by the following [Formula A-3-1].

[0044] [Formula A-3-1]

[0045]

[0046] In one embodiment, the diamine compound may have a non-polar main chain structure as shown in the following [Formula B]. That is, the diamine compound may be a diamine compound having a fragment as shown in the following [Formula B].

[0047] [Formula B]

[0048]

[0049] In one embodiment, the diamine compound having a fragment represented by [Formula B] may include a diamine compound represented by the following [Formula B-1].

[0050] [Formula B-1]

[0051]

[0052] In one embodiment, the diamine compound may have a non-polar main chain structure as shown in the following [Formula C]. That is, the diamine compound may be a diamine compound having a fragment as shown in the following [Formula C].

[0053] [Formula C]

[0054]

[0055] In one embodiment, the diamine compound having a fragment represented by [Formula C] may include a diamine compound represented by the following [Formula C-1].

[0056] [Formula C-1]

[0057]

[0058] Next, maleic anhydride is added to the raw material mixture.

[0059] In one embodiment, the molar number of the diamine compound is about 2 to about 3 times the molar number of maleic anhydride that is usually added. In other words, the molar ratio of maleic anhydride to the diamine compound is about 1:2 to 1:3. The maleic anhydride can be a maleic anhydride solution with a concentration of 30 to 40 weight percent.

[0060] After the diamine compound and the maleic anhydride are mixed, the diamine compound and the maleic anhydride may be subjected to a pre-condensation reaction at room temperature under a nitrogen atmosphere.

[0061] In one embodiment, the reaction rate of the aforementioned prepolymerization reaction can be increased by adding a catalyst. In one embodiment, the corresponding catalyst can be added to the raw material mixture before the diamine compound and maleic anhydride are mixed. In one embodiment, the corresponding catalyst can be added all at once or in batches at an appropriate time or in an appropriate amount after the diamine compound and maleic anhydride are mixed, depending on the reaction conditions.

[0062] In one embodiment, the catalyst may include triphenylphosphine (TPP; CAS: 603-35-0). In one embodiment, the catalyst is added to the raw material mixture in an amount of about 7-10 wt %.

[0063] In one embodiment, the reaction rate or reactivity of the aforementioned prepolymerization reaction can be increased by adding a dehydrating agent (e.g., a corresponding closed loop reaction). In one embodiment, after the diamine compound and maleic anhydride are mixed, the corresponding dehydrating agent can be added all at once or in batches at an appropriate time or in an appropriate amount depending on the reaction conditions.

[0064] In one embodiment, the dehydrating agent may include anhydrous p-toluenesulfonic acid (4-methylbenzenesulfonicacid, PTS / PTSA; CAS: 104-15-4).

[0065] Step S20 includes a heating reaction, which is a step of placing the aforementioned mixture (eg, a mixture including a diamine compound and maleic anhydride; or, further including an initial product after a prepolymerization reaction thereof) in a constant temperature stirring reactor for heating.

[0066] In one embodiment, the aforementioned heating step may include heating from room temperature to a set temperature (about 90° C. to 150° C.).

[0067] In one embodiment, the temperature range may be set to continue for about 10 hours to about 20 hours to fully react and obtain a viscous imide resin including the modified maleimide resin composition (ie, step S30 ).

[0068] The structural formula of the modified maleimide resin formed by the above method can be shown as the following [general formula].

[0069] [general formula]

[0070]

[0071] In the [general formula], L can be the aforementioned [Formula A], [Formula B] or [Formula C], corresponding to the type of diamine compound used.

[0072] Taking the diamine compound used as a diamine compound having a main chain structure shown in [Formula A] as an example, the modified maleimide resin formed can have a main chain structure shown in [Formula A]; for example, the structural formula of the modified maleimide resin can include the following [Formula 1].

[0073] [Formula 1]

[0074]

[0075] In [Formula 1], R1 and R2 are as defined above.

[0076] Specifically, taking the diamine compound used as a diamine compound having a main chain structure represented by [Formula A-1] as an example, the formed modified maleimide resin may have a main chain structure represented by [Formula A].

[0077] Taking the diamine compound used as [Formula A-1-1] as an example, the formed modified maleimide resin may include the structural formula shown in the following [Formula 2].

[0078] [Formula 2]

[0079]

[0080] Taking the diamine compound used as [Formula A-2-1] as an example, the formed modified maleimide resin may include the structural formula shown in the following [Formula 3].

[0081] [Formula 3]

[0082]

[0083] Taking the diamine compound used as [Formula A-3-1] as an example, the formed modified maleimide resin may include the structural formula shown in the following [Formula 4].

[0084] [Formula 4]

[0085]

[0086] Taking the diamine compound used as [Formula B-1] as an example, the formed modified maleimide resin may include the structural formula shown in the following [Formula 5].

[0087] [Formula 5]

[0088]

[0089] Taking the diamine compound used as [Formula C-1] as an example, the formed modified maleimide resin may include the structural formula shown in the following [Formula 6].

[0090] [Formula 6]

[0091]

[0092] Based on the modified maleimide resin disclosed in the above embodiment, compared with the traditional maleimide resin (i.e., the unmodified maleimide resin, which is different from the modified maleimide resin of the present case), the present invention performs a corresponding reaction through a specific diamine compound and maleic anhydride, so that the non-polar main chain structure of the aforementioned diamine compound replaces the main chain structure of the traditional maleimide resin. In this way, the formed modified maleimide resin can still have the same or similar low dielectric constant and / or low dielectric loss characteristics. In addition, through the chain type and / or non-polar structure of the non-polar main chain structure of the aforementioned diamine compound, the modified maleimide resin can have a corresponding main chain type (main-chain-type) and / or partial non-polar characteristics, and the free volume and non-polar region of the overall structure of the modified maleimide resin can be increased (such as: reducing the influence of polar functional groups). Therefore, the modified maleimide resin can have a lower water absorption rate and / or a lower coefficient of thermal expansion (coefficient of thermal expansion, CTE).

[0093] In one embodiment, the number-average molecular weight (Mn) of the modified maleimide resin may be between about 400 g / mol and about 700 g / mol; preferably, between about 450 g / mol and about 600 g / mol.

[0094] In one embodiment, the glass transition temperature (Tg) of the modified maleimide resin may be between about 150°C and about 300°C.

[0095] In one embodiment, the dielectric constant (Dk) of the modified maleimide resin may be between about 2.5 and about 3.5.

[0096] In one embodiment, the consumption coefficient (Df) of the modified maleimide resin may be between about 0.0035 and about 0.0065.

[0097] In one embodiment, the water absorption rate of the modified maleimide resin can be less than or equal to about 3.4%; preferably, it can be less than or equal to about 3.1%; more preferably, it can be less than or equal to about 2.5%; even more preferably, it can be less than or equal to about 1.6%; and even more preferably, it can be less than or equal to about 0.5%.

[0098] In one embodiment, the free volume of the modified maleimide resin may be between about to about

[0099] In one embodiment, it can be applied to the manufacture of electronic components (such as copper foil substrates). For example, the modified maleimide resin can be applied to dielectric materials in electronic components (such as dielectric materials in copper foil substrates).

[0100] [Examples and Comparative Examples]

[0101] The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples at all.

[0102] The modified maleimide resin can be prepared by the above-mentioned method. The difference between the examples mainly lies in the use of different diamine compounds.

[0103] [Example 1] is a modified maleimide resin formed by a diamine compound represented by [Formula C-1]. The modified maleimide resin may include a structural formula represented by the following [Formula 6].

[0104] [Example 2] is a modified maleimide resin formed by a diamine compound represented by [Formula B-1]. The modified maleimide resin may include a structural formula represented by the following [Formula 5].

[0105] [Example 3] is a modified maleimide resin formed by a diamine compound represented by [Formula A-3-1]. The modified maleimide resin may include a structural formula represented by the following [Formula 4].

[0106] [Example 4] is a modified maleimide resin formed by a diamine compound represented by [Formula A-2-1]. The modified maleimide resin may include a structural formula represented by the following [Formula 3].

[0107] [Example 5] is a modified maleimide resin formed by a diamine compound represented by [Formula A-1-1]. The modified maleimide resin may include a structural formula represented by the following [Formula 2].

[0108] The prepared modified maleimide resin or a resin composition containing the same can be applied to the manufacture of copper foil substrates.

[0109] [Comparative Example 1] is to directly use a commercially available bismaleimide resin composition (e.g., trade name BMI; manufactured or sold by KI Chemicals Co., Ltd., Japan, the weight average molecular weight of the resin composition as a whole is about 385), which includes an unmodified maleimide resin (e.g., 4,4'-diphenylmethanebismaleimide; CAS: 13676-54-5).

[0110] The method of manufacturing the copper foil substrate is described in detail as follows.

[0111] The modified maleimide resin of each of the above examples and the maleimide resin of the comparative example are mixed in the same manner and in the same formula composition ratio to form a varnish resin varnish composition, and a copper foil substrate is prepared by a conventional method. The conventional method for preparing the copper foil substrate can be: impregnating the 2116 fiberglass cloth with the above resin varnish composition, and then drying it at about 170°C (impregnation machine temperature) for several minutes, and adjusting and controlling the drying time to obtain a prepreg having a melt viscosity of about 4000 to 12000 poise after drying. Then, four prepregs are stacked layer by layer between two copper foils of about 35μm thickness to perform a lamination step.

[0112] The conditions / process of the pressing step are exemplified as follows:

[0113] Step 1: Raise the temperature from about 80°C to about 195°C at a rate of about 0.5 hours (recorded as: 85↗195°C, 0.5hr).

[0114] Step 2: Reduce the pressure from about 7 kg / cm 2 Increase to about 25kg / cm 2 (It can be recorded as: 7↗25kg / cm 2 , 0.5hr).

[0115] Step 3: At a temperature of about 195°C and a pressure of about 25 kg / cm 2 Press for about 2.0 hours (can be recorded as: 195℃ / 25kg / cm 2 , 2.0hr).

[0116] The manufactured corresponding copper foil substrate can be subjected to corresponding tests (eg, dielectric constant (Dk) test or dissipation factor (Df) test).

[0117] The properties of the modified maleimide resin of each example and the unmodified maleimide resin of the comparative example are shown in the following [Table 1]. In addition, for simplicity, the electrical property tests of the copper foil substrates made from the modified or unmodified maleimide resins are also directly listed in [Table 1].

[0118] [Table 1]

[0119]

[0120] Each test method can adopt the commonly used methods in the general related resin field, and is exemplified as follows.

[0121] Number-average Molecular Weight (Mn): The modified or unmodified maleimide resin was analyzed by gel chromatography (GPC) and calibrated with a standard molecular weight of polystyrene.

[0122] Glass transition temperature (Tg) test: The modified or unmodified maleimide resins were analyzed using a differential scanning calorimeter (DSC) at a heating rate of about 20°C / min. For most maleimide resin materials, the glass transition temperature is slightly negatively correlated with the thermal expansion coefficient. Therefore, when comparing two different maleimide resin materials, if the glass transition temperature of one is higher than the glass transition temperature of the other, it can be inferred that the thermal expansion coefficient of one is lower than the thermal expansion coefficient of the other.

[0123] Dielectric constant test: The test method is to bake a 5cm×5cm square test piece of copper foil substrate with the copper foil removed in an oven at about 105℃ for about 2 hours, measure the thickness with a thickness meter, and then clamp the test piece into an impedance analyzer (Agilent E4991A), measure the dielectric constant Dk data at 3 points and take the average value.

[0124] Dielectric loss (Dissipation factor) test: The test method is to bake a 5cm×5cm square test piece of the copper foil substrate with the ketone foil removed in an oven at about 105℃ for about 2 hours, measure the thickness with a thickness meter, and then clamp the test piece into an impedance analyzer (Agilent E4991A), measure the dissipation factor Df data at 3 points and take the average value.

[0125] Water absorption test: Place the modified or unmodified maleimide resin in a constant temperature and humidity chamber at a temperature of about 85°C and a humidity of about 85% for 5 minutes, and measure the water absorption. The water absorption is the weight difference of the sample before and after the autoclave ÷ the initial weight of the sample × 100%.

[0126] Free volume (unit: ): It can be simulated and estimated through general commercial software (such as: MaterialsStudio / BIOVIA Materials Studio; other similar software may include but is not limited to: Chemistry atHARvard Macromolecular Mechanics (CHARMm)). The above simulation estimation method can refer to the official help document (Help-Tutorials) of the corresponding software, which will not be described in detail here. For most maleimide resin materials, their free volume and water absorption rate are slightly negatively correlated. Therefore, when comparing two different maleimide resin materials, if the free volume of one of them is higher than the free volume of the other, it may be inferred that the water absorption rate of one of them is lower than the water absorption rate of the other. Therefore, if a maleimide resin material has not yet been tested for water absorption (such as: only in the evaluation stage, and no actual synthesis has been carried out), it may be possible to evaluate the water absorption rate through the above simulation method.

[0127] As shown in [Table 1], compared with the commercially available maleimide resin commonly used in the manufacture of electronic components (as shown in the comparative example), the modified maleimide resin of the present invention has a comparable level in terms of electrical properties (for example, the Very Low Loss level of the circuit board in terms of the loss factor (Df) is 0.0030 to 0.0065). In fact, as shown in [Example 1], the corresponding loss factor can be even lower.

[0128] As shown in [Table 1], compared with commercially available maleimide resins commonly used in electronic component manufacturing (as shown in the comparative examples), the modified maleimide resin of the present invention can have a lower capacitance effect in terms of electrical properties (eg, a smaller dielectric constant (Dk)).

[0129] As shown in [Table 1], the thermal expansion coefficient of the modified maleimide resin of the present invention may be comparable to the thermal expansion coefficient of the commercially available maleimide resin (as shown in the comparative example) commonly used in the manufacture of electronic components. Even, as shown in [Example 1] to [Example 4], the corresponding thermal expansion coefficient may be even lower. Even, as shown in [Example 1] to [Example 4], the thermal expansion coefficient of the modified maleimide resin of the present invention may be even lower. Therefore, the modified maleimide resin of the present invention may be more suitable for the manufacture or application of electronic components.

[0130] As shown in [Table 1], the water absorption rate of the modified maleimide resin of the present invention can be lower. Therefore, the modified maleimide resin of the present invention can be more suitable for the manufacture or application of electronic components.

[0131] In summary, the modified maleimide resin of the present invention has at least a specific main chain structure or segment, and thus has lower water absorption (ie, good moisture resistance), lower thermal expansion coefficient and dielectric properties, and has good applicability.

[0132] [Practicality]

[0133] In addition, the bismaleimide resin formed by the method for producing the bismaleimide resin of the aforementioned embodiment of the present invention can be directly or indirectly applied to a copper foil substrate, and can be further processed to become other consumer, industrial or suitable electronic products.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified bismaleimide resin, characterized in that: The structural formula is: Wherein L is represented by the following [Formula A], [Formula B] or [Formula C]: wherein R1 is a C1-C3 alkyl group, and R2 is a C1-C16 substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aryl group; 2. The modified bismaleimide resin according to claim 1, characterized in that Wherein [Formula A] is represented by the following [Formula A-1]:

3. The modified bismaleimide resin according to claim 1, characterized in that: Wherein [Formula A] is represented by the following [Formula A-2]:

4. The modified bismaleimide resin according to claim 1, characterized in that Wherein [Formula A] is represented by the following [Formula A-3]:

5. The modified bismaleimide resin according to claim 1, characterized in that: The water absorption may be less than or equal to about 3.4%.

6. A method for preparing a modified bismaleimide resin, characterized in that: include: mixing maleic anhydride and a diamine compound to form a corresponding mixture; as well as The mixture is heated, wherein the diamine compound has a main chain structure or fragment shown in the following [Formula A], [Formula B] or [Formula C]: wherein R1 is a C1-C3 alkyl group, and R2 is a C1-C16 substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aryl group; 7. The method for preparing the modified bismaleimide resin according to claim 6, characterized in that: The step of mixing the maleic anhydride and the diamine compound is performed at room temperature.

8. The method for preparing modified bismaleimide resin according to claim 6, characterized in that: The step of mixing the maleic anhydride and the diamine compound is performed under a nitrogen atmosphere.

9. The method for preparing a modified bismaleimide resin according to claim 6, wherein: The step of heating the mixture is heating to 90°C to 150°C.

10. The method for preparing the modified bismaleimide resin according to claim 6, characterized in that: The step of heating the mixture is continued for 10 to 20 hours.

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