JP2017179310A - Carbodiimide compound, resin composition, prepreg, resin sheet and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel carbodiimide compound, and a resin composition, a prepreg, a resin sheet and a laminate comprising the same.SOLUTION: A carbodiimide compound (1) contains at least one carbodiimide group and at least one maleimide group in one molecule or (2) has a first peak at 2120±5 cmin an infrared absorption spectrum and a second peak at 1710±5 cm.SELECTED DRAWING: None

Description

  The present invention relates to a carbodiimide compound, a resin composition, a prepreg, a resin sheet, and a laminate.

  The thermosetting resin exhibits high heat resistance and dimensional stability due to a unique cross-linked structure contained in the cured product of the thermosetting resin. Therefore, thermosetting resins are widely used in fields such as electronic parts. Among these electronic components, particularly in copper-clad laminates and interlayer insulation materials, high copper foil adhesion and heat resistance as well as good low cure shrinkage and low heat are required due to recent demands for higher density and reliability of wiring. Swellability is required. In addition, due to environmental problems in recent years, mounting of electronic components using lead-free solder and flame resistance using halogen-free are required. For this reason, the thermosetting resin is required to have higher heat resistance and flame retardancy than conventional ones. Furthermore, in order to improve the safety of the product and the working environment, there is a demand for a thermosetting resin composed of components having low toxicity and generating no toxic gas, and a composition thereof.

  The cyanate compound, which is a thermosetting resin, is a resin that is excellent in dielectric properties and flame retardancy, but when used in an epoxy curable thermosetting resin composition, there is a problem that the curing shrinkage ratio increases. . Furthermore, there is a problem that heat resistance and toughness are insufficient. Moreover, the low thermal expansion required for the next generation was also insufficient.

  Patent Documents 1 to 3 disclose resin compositions comprising a cyanate compound and an inorganic filler and exhibiting low thermal expansion. Patent Documents 4 and 5 disclose examples relating to thermosetting resin compositions containing a cyanate resin and an aralkyl-modified epoxy resin as essential components.

JP 2003-268136 A JP 2003-73543 A JP 2002-285015 A JP 2002-309085 A JP 2002-348469 A

  An object of the present invention is to provide a novel carbodiimide compound, and a resin composition, a prepreg, a resin sheet, and a laminate using the same.

Specific means for achieving the above object includes the following embodiments.
<1> A prepreg comprising a carbodiimide compound having at least one carbodiimide group and at least one maleimide group in one molecule.
<2> includes a first peak at 2120 ± ^{5 cm -1} in the infrared absorption spectrum, and a second peak at 1710 ± ^{5 cm -1,} a carbodiimide compound having the prepreg.
<3> A resin composition comprising a carbodiimide compound having at least one carbodiimide group and at least one maleimide group in one molecule, and a curing agent.
<4> A resin composition comprising a carbodiimide compound having a first peak at 2120 ± 5 cm ⁻¹ and a second peak at 1710 ± 5 cm ⁻¹ in the infrared absorption spectrum, and a curing agent.
A prepreg comprising a <5> substrate and the resin composition according to <3> or <4>.
<6> A resin sheet, which is a molded product of the resin composition according to <5>.
<7> A laminate comprising the prepreg according to <1>, <2> or <5>.
<8> A carbodiimide compound having at least one carbodiimide group and at least one maleimide group in one molecule.
<9> A carbodiimide compound having a first peak at 2120 ± 5 cm ⁻¹ and a second peak at 1710 ± 5 cm ⁻¹ in the infrared absorption spectrum.
<10> The carbodiimide compound according to <8> or <9>, which has a structure represented by the following general formula (1).

In the general formula (1), each R ₁ is independently a divalent aromatic group or an aliphatic group, and m is a positive number.
<11> The method for producing a carbodiimide compound according to any one of <8> to <10>, comprising a step of reacting a carbodiimide compound having at least one carbodiimide group in one molecule with maleic anhydride.

  ADVANTAGE OF THE INVENTION According to this invention, the novel resin composition, prepreg, resin sheet, and laminated board using a novel carbodiimide compound and a carbodiimide compound are provided.

Hereinafter, the carbodiimide compound, the resin composition, the prepreg, the resin sheet, and the laminate of the present embodiment will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the components (including element steps and the like) are not essential unless otherwise specified. The same applies to numerical values and ranges thereof, and the present invention is not limited thereto.
In this specification, the term “process” includes a process that is independent of other processes and includes the process if the purpose of the process is achieved even if it cannot be clearly distinguished from the other processes. It is.
In the present specification, the numerical ranges indicated by using “to” include numerical values described before and after “to” as the minimum value and the maximum value, respectively.
In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical range. Good. Further, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples.
In the present specification, the content rate or content of each component in the composition is such that when there are a plurality of substances corresponding to each component in the composition, the plurality of kinds present in the composition unless otherwise specified. It means the total content or content of substances.
In this specification, the particle size of each component in the composition is a mixture of the plurality of types of particles present in the composition unless there is a specific indication when there are a plurality of types of particles corresponding to each component in the composition. Means the value of.
In this specification, the term “layer” refers to the case where the layer is formed only in a part of the region in addition to the case where the layer is formed over the entire region. Is also included.
In this specification, the term “lamination” indicates that layers are stacked, and two or more layers may be combined, or two or more layers may be detachable.

<(A) Carbodiimide compound>
The carbodiimide compound of the present embodiment (hereinafter also referred to as a specific carbodiimide compound) satisfies at least one of the following conditions (1) or (2).
(1) It has at least one carbodiimide group and at least one maleimide group in one molecule.
(2) It has a first peak at 2120 ± 5 cm ⁻¹ and a second peak at 1710 ± 5 cm ⁻¹ in the infrared absorption spectrum.

  The carbodiimide group of the specific carbodiimide compound is a divalent group represented by “—N═C═N—”. The number of carbodiimide groups in one molecule is preferably 1 or more from the viewpoint of heat resistance and low curing shrinkage, and from the viewpoint of aging stability in a varnish state, the number of carbodiimide groups in one molecule The number is preferably 10,000 or less.

  The position of the maleimide group that the specific carbodiimide compound has is not particularly limited, and may be, for example, the end (one end or both ends) of the main chain of the specific carbodiimide compound. The maleimide group may or may not have a substituent.

  The first peak in the infrared absorption spectrum is a peak derived from a carbodiimide group, and the second peak is a peak derived from a maleimide group. The first peak and the second peak may be peaks derived from a carbodiimide group and a maleimide group contained in the carbodiimide compound before curing, or a cured product in which a part of the carbodiimide compound is cured (that is, It may be a peak derived from a carbodiimide group and a maleimide group contained in the semi-cured product.

  In the present embodiment, the infrared absorption spectrum can be measured using infrared spectroscopy. For example, BioRad Laboratories, FT-IR FTS6000 type is used as an infrared spectroscopic device, and the number of integrations is measured using a transmission method with 256 times.

The specific carbodiimide compound may be an aromatic carbodiimide compound or an aliphatic carbodiimide compound. From the viewpoint of high reactivity, an aromatic carbodiimide compound is preferable.
In the present embodiment, the aromatic carbodiimide compound refers to a carbodiimide compound in which a nitrogen atom of a carbodiimide group is bonded to a carbon atom constituting an aromatic ring such as a benzene ring. On the other hand, in the present embodiment, the aliphatic carbodiimide group refers to a carbodiimide compound in which a nitrogen atom of a carbodiimide group is bonded to a carbon atom constituting an alkylene group. For example, when an aromatic isocyanate compound is used for the synthesis of a specific carbodiimide compound, it becomes an aromatic carbodiimide compound, and when an aliphatic isocyanate compound is used, it becomes an aliphatic carbodiimide compound.

  In one embodiment, the specific carbodiimide compound has a structure represented by the following general formula (1).

In the general formula (1), each R ₁ is independently a divalent aromatic group or an aliphatic group, and m is a positive number. m is preferably 1 or more from the viewpoint of heat resistance and low curing shrinkage, and is preferably 10,000 or less from the viewpoint of aging stability in a varnish state.

In the general formula (1), the structure of R ₁ varies depending on the structure of the isocyanate compound used for the synthesis of the specific carbodiimide compound. For example, when an aromatic isocyanate compound is used, R ₁ is a divalent group derived from the aromatic group of the aromatic isocyanate compound, and when an aliphatic isocyanate compound is used, R ₁ is an aliphatic isocyanate compound. This is a divalent group derived from an aliphatic group.

Examples of the divalent aromatic group represented by R ₁ include a divalent group containing one or more phenylene groups. Examples of the divalent aliphatic group represented by R ₁ include an alkylene group (for example, Alkylene group having 2 to 1,000 carbon atoms).

Specific examples in the case where R ₁ is a divalent aromatic group include those represented by the following general formula (2) or general formula (3).

In the general formula (2), R ₂ is a single bond, a divalent saturated hydrocarbon group having 1 to 5 carbon atoms or an oxygen atom, and R _2a and R _2b are each independently a monovalent having 1 to 5 carbon atoms. A saturated hydrocarbon group or a halogen atom, and s and t are each independently an integer of 0 to 4; Also, * in the general formula (2) shows a position bonded with the nitrogen atom to which R ₁ is adjacent in the general formula (1).
Examples of the divalent saturated hydrocarbon group represented by R ₂ include a methylene group, an ethylene group, a propylene group, an isobutylene group, a butylene group, a pentylene group, a cyclopropylene group, a cyclobutylene group, and a cyclopentylene group.
R ₂ is preferably a methylene group, an isobutylene group or a single bond from the viewpoint of low thermal expansion, more preferably a methylene group or a single bond from the viewpoint of heat resistance, and still more preferably a methylene group.
Examples of the monovalent saturated hydrocarbon group represented by R _2a and R _2b include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopropyl group, a cyclobutyl group, A cyclopentyl group etc. are mentioned.
Examples of the halogen atom represented by R _2a and R _2b include fluorine, chlorine, bromine and the like.
R _2a and R _2b are preferably a fluorine atom or a methyl group from the viewpoint of chemical resistance. s and t are each independently preferably 0 or 1. When s is 1, R _2a is preferably a methyl group or a fluorine atom from the viewpoint of resin compatibility. When t is 1, R _2b is preferably a methyl group or a fluorine atom from the viewpoint of resin compatibility.

In the general formula (3), each R ₃ is independently a monovalent saturated hydrocarbon group having 1 to 5 carbon atoms, and y is an integer of 0 to 4. Also, * in the general formula (3) shows a position bonded with the nitrogen atom to which R ₁ is adjacent in the general formula (1).
Examples of the monovalent saturated hydrocarbon group represented by R ₃ include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopropyl group, a cyclobutyl group, and a cyclopentyl group. Is mentioned.

  From the viewpoint of easy adjustment of the molecular weight when synthesizing the polycarbodiimide and stability over time in the varnish state, the specific carbodiimide compound may include a specific carbodiimide compound represented by the following general formula (4). preferable.

In the general formula (4), R ₄ is each independently a divalent aromatic group or aliphatic group defined in the same manner as R ₁ in the general formula (1), and m is a positive number. m is preferably 1 or more from the viewpoints of heat resistance and low curing shrinkage, and is preferably 10,000 or less from the viewpoint of aging stability in the state of the resin composition.

In General Formula (4), R ₅ and R ₆ are each independently a maleimide group, a halogen atom, a monovalent saturated hydrocarbon group having 1 to 5 carbon atoms, or a trifluoromethyl group, and each x is independently It is a number from 1 to 5. However, at least one of R ₅ and R ₆ is a maleimide group. Preferably, at least one of R ₅ is a maleimide group and at least one of R ₆ is a maleimide group.

(Method for producing specific carbodiimide compound)
The method for producing the specific carbodiimide compound is not particularly limited. From the viewpoint of aging stability in the state of polycarbodiimide compound or varnish, a step of reacting a compound having at least one carbodiimide group in one molecule (hereinafter also referred to as carbodiimide compound) and maleic anhydride. A method comprising is preferred. In this case, the synthesis process of the carbodiimide compound and the reaction process of the carbodiimide compound and maleic anhydride may be performed continuously or separately.

  Examples of the carbodiimide compound include carbodiimide compounds having a structure represented by the following general formula (5).

In the general formula (5), R ₇ is a divalent aromatic group or aliphatic group defined in the same manner as R ₁ in the general formula (1), and n is a positive number. n is preferably 1 or more from the viewpoint of heat resistance and low curing shrinkage, and preferably 10,000 or less from the viewpoint of aging stability in a varnish state.

  When synthesizing a carbodiimide compound, the method is not particularly limited. For example, it can be synthesized by reacting (carbodiimidization) a compound having two isocyanate groups in one molecule (hereinafter also referred to as a diisocyanate compound).

The kind of the diisocyanate compound used for the synthesis of the carbodiimide compound is not particularly limited, and can be selected according to the structure of the desired carbodiimide compound. For example, a carbodiimide compound in which R ₁ is a divalent aromatic group is obtained by using an aromatic diisocyanate compound as the diisocyanate compound, and R ₁ is a divalent aliphatic group by using an aliphatic isocyanate compound as the diisocyanate compound. A carbodiimide compound is obtained.

  Examples of the diisocyanate compound include aromatic diisocyanate compounds represented by the following general formula (6) or the following general formula (7).

In General Formula (6), R ₈ is a single bond, a divalent saturated hydrocarbon group having 1 to 5 carbon atoms or an oxygen atom, and R _8a and R _8b are each independently a monovalent having 1 to 5 carbon atoms. A saturated hydrocarbon group or a halogen atom, and s and t are each independently an integer of 0 to 4;

In the general formula (6), the divalent saturated hydrocarbon group having 1 to 5 carbon atoms represented by R ₈ may be linear, branched, or cyclic. Also good.
Examples of the divalent saturated hydrocarbon group represented by R ₈ include a methylene group, an ethylene group, a propylene group, an isobutylene group, a butylene group, a pentylene group, a cyclopropylene group, a cyclobutylene group, and a cyclopentylene group.
R ₈ is preferably a methylene group, an isobutylene group or a single bond from the viewpoint of low thermal expansion, more preferably a methylene group or a single bond from the viewpoint of heat resistance, and still more preferably a methylene group.
Examples of the monovalent saturated hydrocarbon group represented by R _8a and R _8b include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopropyl group, a cyclobutyl group, A cyclopentyl group etc. are mentioned.
Examples of the halogen atom represented by R _8a and R _8b include fluorine, chlorine, bromine and the like.
R _8a and R _8b are preferably a fluorine atom or a methyl group from the viewpoint of chemical resistance. s and t are each independently preferably 0 or 1. When s is 1, R _8a is preferably a methyl group or a fluorine atom from the viewpoint of resin compatibility. When t is 1, R _8b is preferably a methyl group or a fluorine atom from the viewpoint of resin compatibility.

In General formula (7), R < ₉ > is a C1-C5 monovalent | monohydric saturated hydrocarbon group each independently, and y is an integer of 0-4.

In the general formula (7), the monovalent saturated hydrocarbon group having 1 to 5 carbon atoms represented by R ₉ may be linear, branched, or cyclic. Also good.
Examples of the monovalent saturated hydrocarbon group represented by R ₉ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, and an isopentyl group. Is mentioned. R ₉ is preferably a methyl group from the viewpoint of yield during synthesis.
In general formula (7), from the viewpoint of chemical resistance, y is preferably 0 to 2, more preferably 0 or 1, and when y is 1, R ₉ is preferably a methyl group.

  Specific examples of the aromatic diisocyanate compound represented by the general formula (6) or the general formula (7) include diphenylmethane-4,4′-diisocyanate, diphenylmethane-2,4′-diisocyanate, diphenylether-4,4′-. Diisocyanate, 3,3′-dimethylbiphenyl-4,4′-diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3,5-triisopropyl-2,6-diisocyanate benzene, p -Benzene diisocyanate etc. are mentioned. A diisocyanate compound (a) can be used individually by 1 type or in combination of 2 or more types.

  Among these, unreacted isocyanate groups are unlikely to remain, and diphenylmethane-4,4′-diisocyanate, diphenylmethane-2,4′-diisocyanate, 2,4-tolylene diisocyanate, 2,6- Tolylene diisocyanate and the like are preferable, and diphenylmethane-4,4′-diisocyanate, diphenylmethane-2,4′-diisocyanate and the like excellent in low curing shrinkage are more preferable.

  From the viewpoint of facilitating adjustment of the molecular weight of the carbodiimide compound, a specific carbodiimide compound is synthesized using a diisocyanate compound and a compound having one isocyanate group in one molecule (hereinafter also referred to as a monoisocyanate compound). It is preferable.

  A carbodiimide compound synthesized using a diisocyanate compound and a monoisocyanate compound is considered to have, for example, a structure in which the monoisocyanate compound is bonded to the end of the main chain formed by bonding the diisocyanate compound. Therefore, it is considered that the molecular weight of the synthesized carbodiimide compound can be adjusted by controlling the ratio of the diisocyanate compound and the monoisocyanate compound used in the synthesis.

  The kind of monoisocyanate compound is not particularly limited and can be selected according to the structure of the desired carbodiimide compound. For example, by using an aromatic monoisocyanate compound as the monoisocyanate compound, a carbodiimide compound having an aromatic group bonded to the end of the main chain is obtained, and by using an aliphatic isocyanate compound as the diisocyanate compound, the end of the main chain is obtained. A carbodiimide compound having an aliphatic group bonded thereto is obtained.

  As a monoisocyanate compound, the aromatic monoisocyanate compound represented by following General formula (8) is mentioned.

In General formula (8), R < ₁₀ > is respectively independently a halogen atom, a C1-C5 monovalent saturated hydrocarbon group, or a trifluoromethyl group, and x is an integer of 0-5.

In the general formula (8), the monovalent saturated hydrocarbon group having 1 to 5 carbon atoms represented by R ₁ may be linear, branched, or cyclic. Also good.
Examples of the monovalent saturated hydrocarbon group represented by R ₁₀ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, and an isopentyl group. Is mentioned.
Examples of the halogen atom represented by R ₁₀ include fluorine, chlorine, bromine and the like.
In general formula (8), x is preferably 0 to 3, and more preferably 0 from the viewpoint of yield during synthesis.

  Specific examples of the aromatic monoisocyanate compound represented by the general formula (8) include phenyl isocyanate, 2,6-dimethylphenyl isocyanate, 3,5-dimethylphenyl isocyanate, 2,6-diisopropylphenyl isocyanate, 4-fluoro Examples include phenyl isocyanate, 2,4-difluorophenyl isocyanate, 2,4,6-trifluorophenyl isocyanate, 3- (trifluoromethyl) phenyl isocyanate, 4- (trifluoromethyl) phenyl isocyanate and the like. An aromatic monoisocyanate compound can be used individually by 1 type or in combination of 2 or more types.

  Among these, phenyl isocyanate, 2,6-dimethylphenyl isocyanate and 3,5-dimethylphenyl isocyanate are preferable because the molecular weight and viscosity of the specific carbodiimide compound to be synthesized can be easily adjusted and are commercially inexpensive. These are commercially available from Tosoh Corporation, BASF INOAC Polyurethane Corporation, Chuo Kasei Co., Ltd., Junsei Chemical Co., Ltd., Wako Pure Chemical Industries, Ltd.

  As a raw material for producing the carbodiimide compound used in the present embodiment, a polymethylene polyphenyl polyisocyanate having a high polynuclear body, which is a compound represented by the following general formula (9), may be used as necessary. Furthermore, if necessary, an isocyanate compound in which a part of the isocyanate group is modified with various polyhydric alcohol compounds, phenol compounds, ε-caprolactam or the like may be used in combination. In the general formula (9), r is a positive number.

  The ratio in the case of synthesizing a specific carbodiimide compound using at least a diisocyanate compound and a monoisocyanate compound is not particularly limited, and can be selected according to the structure of the desired carbodiimide compound.

For example, in the case where the diisocyanate compound is the component (a) and the monoisocyanate compound is the component (b), the number of isocyanate groups in the component (a) (the amount used of the component (a) / the isocyanate group equivalent of the component (a)), The ratio of the number of isocyanate groups in component (b) (the amount used of component (b) / the equivalent of isocyanate group in component (b)) (the number of isocyanate groups in component (a) / the number of isocyanate groups in component (b)) is 0.4. It is preferably ˜20.0, more preferably 0.5 to 20, and still more preferably 0.5 to 10.
If the ratio of the number of isocyanate groups in component (a) to the number of isocyanate groups in component (b) (number of isocyanate groups in component (a) / number of isocyanate groups in component (b)) is 0.4 or more, the resulting carbodiimide compound is There exists a tendency for the heat resistance and chemical resistance of the laminated board produced using the resin composition to contain to improve. If the ratio (number of isocyanate groups in component (a) / number of isocyanate groups in component (b)) is 20.0 or less, gelation tends not to occur during the synthesis of the carbodiimide compound.

  An organic solvent may be used for this carbodiimidization reaction. The amount of the organic solvent used is preferably 0 to 1000 parts by mass per 100 parts by mass of the sum of the components (a) and (b) and other components used as necessary. It is more preferable to set it as a part-1000 mass parts, and it is still more preferable to set it as 10 mass parts-500 mass parts. If component (a), component (b), other components used as needed, and the carbodiimide compound synthesized by carbodiimidization reaction are low-viscosity liquid substances, they are synthesized without using an organic solvent. May be. On the other hand, when these components are solid or highly viscous viscous bodies, it is preferable to use an appropriate amount of an organic solvent. However, if the amount of the organic solvent used is too large, synthesis may take a long time and the production cost may increase.

Examples of organic solvents used in the carbodiimidization reaction include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, ether solvents such as tetrahydrofuran, aromatic solvents such as toluene, xylene, and mesitylene, and hydrocarbon solvents. And petroleum solvents, N atom-containing solvents such as dimethylformamide and dimethylacetamide, S atom-containing solvents such as dimethyl sulfoxide, and ester solvents such as γ-butyrolactone.
These organic solvents can be used individually by 1 type or in combination of 2 or more types. Among these, from the viewpoint of being highly soluble and volatile and hardly remaining as a residual solvent at the time of production of the prepreg, and from the viewpoint of moisture resistance and heat resistance, copper foil adhesion and low dielectric constant of the obtained laminate, toluene, Aromatic solvents such as xylene and mesitylene, and ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone are more preferable.

In the carbodiimidization reaction, a reaction catalyst for carbodiimidization can be arbitrarily used as necessary, and is not particularly limited. Examples of the reaction catalyst include organophosphorus compounds such as 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, 3 -Methyl-1-phenyl-2-phospholene-2-oxide and the like. Among these, 3-methyl-1-phenyl-2-phospholene-2-oxide is particularly preferable because it has high reactivity and can provide a high yield.
Here, the amount of the reaction catalyst used is based on the total number of isocyanate groups of the component (a), the number of isocyanate groups of the component (b), and the number of isocyanate groups of other components used as necessary. 0.05 mol% to 2.0 mol% is preferable. When the amount of the reaction catalyst used is 0.05 mol% or more, the carbodiimidization reaction does not take a long time, and a desired reaction rate tends to be realized. Moreover, if the usage-amount of a reaction catalyst is 2.0 mol% or less, the reaction rate of carbodiimidization reaction will not become high too much, and it exists in the tendency for end point management of reaction to become easy.

  A carbodiimide compound is produced by charging the above-mentioned synthesis raw materials and, if necessary, an organic solvent and a reaction catalyst in a synthesis kettle, stirring for 0.1 to 10 hours while heating and keeping heat as necessary, and causing a carbodiimidation reaction with decarboxylation. Is done. The synthesis temperature is preferably 5 ° C to 180 ° C. When the synthesis temperature is 5 ° C. or higher, the reaction rate of the carbodiimidization reaction does not become too slow, and the reaction tends to be completed in an acceptable time. Moreover, if the synthesis temperature is 180 ° C. or lower, the possibility of causing a side reaction tends to be reduced.

The end point of the carbodiimidization reaction and the confirmation that the carbodiimide compound has been produced can be obtained by taking a small amount of sample after the reaction for a predetermined time and performing FT-IR (Fourier transform infrared spectroscopy) measurement.
When confirming the end point of the carbodiimidization reaction by FT-IR measurement, etc., confirm the disappearance of the 2260 ± 5 cm ⁻¹ peak due to the isocyanate group of the component (a) and the component (b), The appearance of a peak at 2120 ± 5 cm ⁻¹ due to the generated carbodiimide group is confirmed.

  The method for reacting the carbodiimide compound with maleic anhydride is not particularly limited. For example, a carbodiimide compound having a maleimide group can be obtained by synthesizing a carbodiimide compound represented by the general formula (5) by the above-described method and subjecting the carbodiimide group and maleic anhydride to substitution reaction. About the method of carrying out the substitution reaction of the carbodiimide group and maleic anhydride, for example, the polyimide described in the literature (J. Mater. Res., Vol. 13, No. 7, Jul 1998, pp. 1840-1847). The synthesis method can be referred to.

  In said method, the usage-amount of a carbodiimide compound and maleic anhydride is not restrict | limited in particular, It can select according to the structure of a desired specific carbodiimide compound, etc.

  For example, when maleic anhydride is the component (c) and the carbodiimide compound is the component (d), the number of acid anhydride groups of maleic anhydride (the amount of (c) used / the molecular weight of (c)) and the carbodiimide compound Equivalent ratio (number of acid anhydride groups in (c) / number of carbodiimide groups in (d)) of reaction with the number of carbodiimide groups (amount of (d) used / equivalent carbodiimide group of (d)) is 0.01 or more Is preferable, and the range of 0.01 to 0.9 is more preferable.

  When the above ratio is 0.01 or more, the elastic modulus, glass transition temperature (Tg) and heat resistance of the laminate produced using the specific carbodiimide compound are sufficiently maintained, and the curing shrinkage rate, thermal expansion coefficient, etc. The rise tends to be suppressed. Moreover, it exists in the tendency for the storage stability of the specific carbodiimide compound after a synthesis | combination to be maintained favorable. Moreover, when the above ratio is 0.9 or less, there is a tendency that a decrease in dielectric properties and heat resistance of a laminate produced using a specific carbodiimide compound is suppressed.

  An organic solvent may be used for the reaction (substitution reaction) between the carbodiimide compound and maleic anhydride, and the amount used is 0 per 100 parts by mass of the total of polycarbodiimide (a) and maleic anhydride (b). It is preferable to set it as a mass part-1000 mass parts. The kind in particular of organic solvent is not restrict | limited, For example, it can select from what was illustrated as an organic solvent which may be used for the synthesis | combination of a carbodiimide compound.

If necessary, a reaction catalyst may be used to promote the substitution reaction of maleic anhydride to the carbodiimide group of the carbodiimide compound. The type of the reaction catalyst is not particularly limited, and examples thereof include imidazoles and derivatives thereof, tertiary amines and quaternary ammonium salts, and phosphorus-based reaction catalysts such as triphenylphosphine.
When a reaction catalyst is used, the amount used is preferably more than 0 mol% and 2.0 mol% or less with respect to the number of carbodiimide groups of the carbodiimide compound. When the amount of the reaction catalyst used is 2.0 mol% or less with respect to the number of carbodiimide groups, the reaction rate is not too high, and the end point of the synthesis tends to be easily managed.

  By adding the above-mentioned synthetic raw materials and, if necessary, an organic solvent and a reaction catalyst to the synthesis kettle, stirring for 0.1 to 10 hours while heating and keeping heat as necessary, and substitution reaction of maleic anhydride with the carbodiimide group of the carbodiimide compound A carbodiimide compound having a maleimide group is produced. The synthesis temperature is preferably 60 ° C to 160 ° C. If the synthesis temperature is 60 ° C. or higher, the reaction rate of the substitution reaction does not become too slow, and the reaction tends to be completed in an acceptable time. Further, when the synthesis temperature is 160 ° C. or lower, side reactions such as dimerization of carbodiimide groups tend to be suppressed.

The confirmation of the end point of the substitution reaction and the confirmation that the specific carbodiimide compound has been produced can be obtained by taking a small amount of sample after the reaction for a predetermined time and performing FT-IR (Fourier transform infrared spectroscopy) measurement.
The determination in the case of confirming the end point of the substitution reaction by FT-IR measurement is, for example, whether or not the 1847 ± 5 cm ⁻¹ peak due to maleic anhydride has disappeared or decreased, or 2120 ± due to the carbodiimide group. It can be carried out by confirming whether or not the peak at 5 cm ⁻¹ is reduced, and whether or not a peak at 1710 ± 5 cm ⁻¹ due to the maleimide group appears due to the formation reaction of the maleimide group.

The weight average molecular weight of the specific carbodiimide compound is preferably 500 to 200,000, more preferably 1,000 to 100,000, and still more preferably 1,000 to 50,000.
In the present embodiment, the weight average molecular weight of the specific carbodiimide compound refers to a value measured by the following method.
A measurement object is dissolved in tetrahydrofuran (for liquid chromatograph), and a PTFE (polytetrafluoroethylene) filter (manufactured by Kurabo Industries, for HPLC (high performance liquid chromatography) pretreatment, chromatodisc, model number: 13N, pore size: 0.00. 45 μm) to remove insoluble matter. GPC [Pump: L6200 Pump (manufactured by Hitachi, Ltd.), Detector: Differential refractive index detector L3300 RI Monitor (manufactured by Hitachi, Ltd.), Column: TSKgel-G5000HXL and TSKgel-G2000HXL (2 in total) ( (Both manufactured by Tosoh Corporation) in series, column temperature: 30 ° C., eluent: tetrahydrofuran, flow rate: 1.0 ml / min, standard substance: polystyrene], and the weight average molecular weight is measured.

(Use of specific carbodiimide compounds)
The specific carbodiimide compound can be suitably used as a component of the resin composition. In particular, it can be suitably used as a component of a resin composition used in the production of electronic materials such as prepregs and laminates.

<Resin composition>
The resin composition of the present embodiment includes a carbodiimide compound and a curing agent, and the carbodiimide compound includes at least the specific carbodiimide compound described above. The resin composition may contain other components such as an inorganic filler as necessary.
The use of the resin composition of the present embodiment is not particularly limited, and can be suitably used, for example, as a thermosetting resin composition for producing a laminated board or the like.

The proportion of the carbodiimide compound in the solid content of the resin composition is preferably 10% by mass to 90% by mass, more preferably 20% by mass to 80% by mass, and 30% by mass to 80% by mass. More preferably.
In addition, in this embodiment, solid content means the non-volatile component of the components which comprise a resin composition.
The proportion of the specific carbodiimide compound in the carbodiimide compound contained in the resin composition is preferably 5% by mass to 100% by mass, more preferably 10% by mass to 100% by mass, and more preferably 20% by mass to More preferably, it is 100 mass%.

(B) Curing Agent The resin composition of the present embodiment contains a curing agent. The curing agent used in the present embodiment is not particularly limited as long as it is a compound having a functional group capable of undergoing a curing reaction with a carbodiimide compound.
The curing agent used in the present embodiment preferably includes at least one selected from the group consisting of carboxylic acid, epoxy compound, phenol compound and amine. Among these, it is preferable to use an epoxy compound as a curing agent from the viewpoint of moisture resistance and heat resistance.

  When a carboxylic acid is used as the curing agent, specific examples of the carboxylic acid include known dicarboxylic acid compounds such as maleic acid, phthalic acid, and succinic acid.

  When a phenol compound is used as the curing agent, specific examples of the phenol compound include known phenol compounds such as a phenol novolac resin.

  When amine is used as the curing agent, specific examples of amines include, for example, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, m-xylenediamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, diethylaminopropylamine, Isophoronediamine, 1,3-bisaminomethylcyclohexane, bis (4-aminocyclohexyl) methane, norbornenediamine, 1,2-diaminocyclohexane, laromine, diaminodiphenylmethane, metaphenylenediamine, diaminodiphenylsulfone, polyoxypropylenediamine, poly Mention may be made of oxypropylene triamine, polycyclohexyl polyamine mixtures and N-aminoethylpiperazine.

When an epoxy compound is used as the curing agent, the epoxy compound is preferably a compound having at least two epoxy groups in one molecule.
Compounds having at least two epoxy groups in one molecule include bisphenol A, bisphenol F, biphenyl, novolac, dicyclopentadiene, polyfunctional phenol, naphthalene, aralkyl modified, alicyclic Examples thereof include glycidyl ethers such as glycidyl ethers, glycidyl amines, and glycidyl ester types, which can be used alone or in combination of two or more.

As an epoxy compound, the cured product has high rigidity, dielectric properties, heat resistance, flame resistance, moisture resistance and low thermal expansion, and is solid at room temperature (20 ° C to 23 ° C). A naphthalene ring-containing epoxy resin, a biphenyl group-containing epoxy resin, and a dicyclopentadiene-type epoxy resin are preferable from the viewpoint that tackiness is reduced and handling becomes easy.
The epoxy compound is preferably a naphthalene type epoxy resin, a biphenyl type epoxy resin, a naphthol aralkyl / cresol copolymer type epoxy resin or a biphenyl aralkyl type epoxy resin from the viewpoint of solubility in an aromatic organic solvent.
In addition, as epoxy compounds, in recent years, there has been an increase in the number of multilayered laminates using build-up materials, etc., for multilayering, high wiring density, etc. From the point of formability at this time, naphthol has increased. Aralkyl / cresol copolymer epoxy resins and biphenyl aralkyl epoxy resins are preferred.

  When a naphthol aralkyl / cresol copolymer epoxy resin is used as the epoxy compound, the naphthol aralkyl / cresol copolymer epoxy resin is preferably a compound containing two structural units represented by the following general formula (10).

In the general formula (10), m and n are positive numbers that may be different from each other.
The ratio of the two structural units represented by the general formula (10) is not particularly limited.
The weight average molecular weight of the compound represented by the general formula (10) is preferably 200 to 50,000, more preferably 200 to 20,000, and still more preferably 200 to 10,000.
As the naphthol aralkyl / cresol copolymer epoxy resin, NC-7000L manufactured by Nippon Kayaku Co., Ltd. is available.

  When a biphenyl aralkyl epoxy resin is used as the epoxy resin, a compound containing two structural units represented by the following general formula (11) is preferable.

In the general formula (11), p and q are positive numbers that may be different from each other.
The ratio of the two structural units represented by the general formula (11) is not particularly limited.
The weight average molecular weight of the compound represented by the general formula (11) is preferably 500 to 50,000, more preferably 500 to 20,000, and still more preferably 500 to 10,000.
As a biphenyl aralkyl epoxy resin, NC-3000H manufactured by Nippon Kayaku Co., Ltd. is available.

When an epoxy compound is used as the curing agent, the content of the carbodiimide compound per 100 parts by mass of the carbodiimide compound and the epoxy compound is in the range of 10 parts by mass to 90 parts by mass, and the content of the epoxy compound is 90 parts by mass. The content of the carbodiimide compound is preferably in the range of 30 parts by mass to 90 parts by mass, and the content of the epoxy compound is more preferably in the range of 70 parts by mass to 10 parts by mass. More preferably, the content of the carbodiimide compound is in the range of 30 to 80 parts by mass, and the content of the epoxy compound is in the range of 70 to 20 parts by mass.
If the content of the carbodiimide compound per 100 parts by mass of the total of the carbodiimide compound and the epoxy compound is 10 parts by mass or more, the elastic modulus, low thermal expansion, moisture and heat resistance of the laminate formed using the resin composition, Dielectric properties, adhesion, flame retardancy, etc. tend to improve. If the content of the carbodiimide compound per 100 parts by mass of the carbodiimide compound and the epoxy compound is 90 parts by mass or less, the moldability of the resin composition is improved or the laminate formed using the resin composition Chemical resistance such as plating solution resistance tends to be improved.

  When carboxylic acid is used as the curing agent, the content of carboxylic acid in the resin composition is preferably 0.1% by mass to 50% by mass, and preferably 0.1% by mass to 40% by mass. More preferably, it is still more preferably 0.1% by mass to 30% by mass.

  When a phenol compound is used as the curing agent, the content of the phenol compound in the resin composition is preferably 0.1% by mass to 50% by mass, and preferably 0.1% by mass to 40% by mass. More preferably, it is still more preferably 0.1% by mass to 30% by mass.

  When an amine is used as the curing agent, the content of the amine compound in the resin composition is preferably 0.1% by mass to 50% by mass, and more preferably 0.1% by mass to 40% by mass. Preferably, it is 0.1 mass%-30 mass%.

(C) Inorganic filler The resin composition of this embodiment may contain an inorganic filler. The inorganic filler used in the present embodiment is not particularly limited. For example, silica (fused silica, crushed silica, deflagration silica, etc.), mica, talc, glass (glass short fiber, glass fine powder, hollow glass, etc.) , Calcium carbonate, quartz, metal hydrate and the like. An inorganic filler can be used individually by 1 type or in combination of 2 or more types.
Among these, silica is preferable from the viewpoint of drill workability and low thermal expansion, and from the viewpoint of low thermal expansion of the cured product, copper foil adhesion, heat resistance, moisture resistance, flame resistance, low dielectric loss tangent, etc. Spherical silica such as fused silica and deflagration silica is more preferred.

  The inorganic filler preferably has an average particle size of 0.3 μm to 5.0 μm, more preferably 0.3 μm to 2.0 μm, and still more preferably 0.5 μm to 1.0 μm.

  When silica is used as the inorganic filler, the silica preferably has an average particle size of 5.0 μm or less, more preferably an average particle size of 0.3 μm to 5.0 μm, and an average particle size of 0.001. What is 3 micrometers-2.0 micrometers is still more preferable, and what is average particle diameter is 0.5 micrometer-1.0 micrometer is especially preferable.

  When spherical silica is used as the inorganic filler, the spherical silica has an average particle diameter of 5.0 μm or less, and the thermal expansion of the cured product, copper foil adhesion, heat resistance, moisture resistance, flame resistance, low From the viewpoint of dielectric loss tangent, etc., those having an average particle size of 0.3 μm to 5.0 μm are more preferable, those having an average particle size of 0.3 μm to 2.0 μm are still more preferable, and average particle size is 0 Those having a thickness of 0.5 μm to 1.0 μm are particularly preferable.

  In the present embodiment, the average particle diameter is a particle diameter (volume average) in which the integrated distribution is 50% in the integrated distribution expressed by the accumulation of the frequencies, where the particle diameter is a class and the volume is a frequency using the following method. Particle size). As a method of measuring the particle size of the inorganic filler, for example, using a device such as laser diffraction, dynamic light scattering, and small-angle X-ray scattering, a method of simultaneously measuring a large number of particles, an electron microscope, an atomic force microscope, etc. And a method of measuring the particle size of each particle. Using a method such as liquid phase centrifugation, field flow fractionation, particle size exclusion chromatography, fluid dynamics chromatography, or the like, a pretreatment for separating particles of 100 μm or more may be performed before measuring the particle size. When the measurement sample is a cured product of the resin composition, for example, the ash obtained as a residue after processing at a high temperature of 800 ° C. or higher in a muffle furnace or the like can be measured by the above method.

In the present embodiment, other inorganic fillers may be used in combination with silica as the inorganic filler. As other inorganic fillers, metal hydrates such as aluminum hydroxide and magnesium hydroxide are preferable from the viewpoint of low thermal expansion, high elasticity, heat resistance, flame retardancy, etc. of the cured product. Among these, metal hydrates having a thermal decomposition temperature of 300 ° C. or higher are more preferable from the viewpoint of achieving both high heat resistance and flame retardancy of the cured product, and boehmite type aluminum hydroxide (AlOOH), gibbsite type aluminum hydroxide (Al (OH) ₃ ) is a boehmite type compound that has a thermal decomposition temperature adjusted to 300 ° C. or higher by heat treatment, magnesium hydroxide or the like, is inexpensive, has a thermal decomposition temperature of 350 ° C. or higher, and high chemical resistance. Aluminum hydroxide (AlOOH) is particularly preferred. In this embodiment, even when silica is not used as the inorganic filler, other fillers may be used as the inorganic filler.

  When other inorganic fillers are used in combination with silica as the inorganic filler, the mass-based content ratio of silica and other inorganic fillers (silica: other inorganic fillers) is 100: 0 to 10:90. Preferably, it is 100: 0 to 20:80, more preferably 100: 0 to 30:70.

The inorganic filler used in this embodiment may be surface-treated with a silane coupling agent.
The kind in particular of a silane coupling agent is not restrict | limited, A commercially available thing can be used normally. In consideration of compatibility with the carbodiimide compound, it is preferable to use a silane coupling agent having an epoxy group, amino group, mercapto group, ureido group or hydroxyl group at the terminal.
Specific examples of the silane coupling agent include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropylmethyl. Dimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3- Examples include mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane and 3-ureidopropyltriethoxysilane. These silane coupling agents can be used alone or in combination of two or more.
Among these, 3-glycidoxypropyltrimethoxysilane is preferable from the viewpoints of copper foil adhesiveness and heat resistance of the cured product.

The treatment method of the inorganic filler with the silane coupling agent is not particularly limited, and may be a wet treatment or a dry treatment, and is preferably a wet treatment.
An inorganic filler surface-treated with a silane coupling agent is also commercially available. For example, as a spherical silica having an average particle size of 0.5 μm or less that has been surface-treated (wet-treated) with 3-glycidoxypropyltrimethoxysilane, there is a trade name SC-2050MTE manufactured by Admatechs.

  As content of the inorganic filler in the resin composition of this embodiment, 10 mass parts-300 mass parts with respect to 100 mass parts of the total mass of the carbodiimide compound, the hardening | curing agent, and the below-mentioned maleimide compound used as needed. It is preferable to set it as 100 mass parts-250 mass parts, and it is still more preferable to set it as 150 mass parts-250 mass parts. If content of an inorganic filler is 10 mass parts or more, it exists in the tendency for the elasticity modulus, low thermal expansibility, moisture heat resistance, and low dielectric loss tangent of hardened | cured material to improve. If the content of the inorganic filler is 300 parts by mass or less, chemical resistance such as moldability of the resin composition and plating solution resistance of the cured product tends to be improved.

When the resin composition of this embodiment uses silica as an inorganic filler, the content of silica is 100 parts by mass of the total mass of a carbodiimide compound, a curing agent, and a later-described maleimide compound used as necessary, The amount is preferably 10 parts by mass to 300 parts by mass, more preferably 100 parts by mass to 250 parts by mass, and particularly preferably 150 parts by mass to 250 parts by mass.
When the silica content is 10 parts by mass or more, the elastic modulus, low thermal expansion, moisture and heat resistance, and low dielectric loss tangent of the cured product tend to be improved. Moreover, if content of a silica is 300 mass parts or less, it exists in the tendency for chemical resistance, such as the moldability of a resin composition and the plating solution resistance of hardened | cured material, to improve.

  When the resin composition of this embodiment uses other fillers together with silica as the inorganic filler, the content of the other fillers is the total of the carbodiimide compound, the curing agent, and the later-described maleimide compound used as necessary. It is preferable to set it as 0 mass part-200 mass parts with respect to 100 mass parts of mass, and it is more preferable to set it as 0 mass parts-150 mass parts. By setting the content of other fillers to 200 parts by mass or less, chemical resistance such as moldability of the resin composition and plating solution resistance of the cured product tends to be improved.

  When the resin composition of the present embodiment uses other fillers together with silica as an inorganic filler, the content of silica and other fillers includes a carbodiimide compound, a curing agent, and a maleimide compound described later used as necessary. The silica is 10 parts by mass to 300 parts by mass, the other filler is preferably 0 parts by mass to 200 parts by mass, and the silica is 100 parts by mass to 250 parts by mass with respect to 100 parts by mass of the total mass. More preferably, the other filler is 0 to 150 parts by mass, the silica is 150 to 250 parts by mass, and the other filler is 0 to 150 parts by mass. preferable.

(D) Maleimide compound The resin composition of this embodiment may contain a maleimide compound from the viewpoints of low thermal expansion, low curing shrinkage, heat resistance, moisture resistance, low dielectric loss tangent, and the like of the cured product. The maleimide compound used in the present embodiment is not particularly limited, and a maleimide compound having at least two maleimide groups in one molecule is preferable.

  Examples of maleimide compounds having at least two maleimide groups in one molecule include bis (4-maleimidophenyl) methane, polyphenylmethanemaleimide, bis (4-maleimidophenyl) ether, bis (4-maleimidophenyl) sulfone, 3,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, m-phenylene bismaleimide and 2,2-bis (4- ( 4-maleimidophenoxy) phenyl) propane. Among these, bis (4-maleimidophenyl) methane, polyphenylmethanemaleimide, 3,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethanebismaleimide from the viewpoint of solubility in solvents 2,2-bis (4- (4-maleimidophenoxy) phenyl) propane is preferable, and 2,2-bis (4- (4-maleimide) is more preferable because of its high reaction rate and lower cure shrinkage. More preferred are phenoxy) phenyl) propane, polyphenylmethanemaleimide, and bis (4-maleimidophenyl) methane.

  When the resin composition of this embodiment contains a maleimide compound, the use amount of the carbodiimide compound per 100 parts by mass of the total of the carbodiimide compound, the epoxy compound, and the maleimide compound is in the range of 10 parts by mass to 90 parts by mass. When the amount used is in the range of 90 parts by mass to 10 parts by mass, the amount of maleimide compound used is preferably in the range of 0 parts by mass to 70 parts by mass, and in the range of 0 parts by mass to 60 parts by mass. More preferably, it is more preferable to set it as the range of 0 mass part-50 mass parts. If the amount of the maleimide compound used is 70 parts by mass or less, the moldability of the resin composition is improved and the chemical resistance such as the plating solution resistance of the cured product tends to be improved.

(solvent)
When handling the resin composition of this embodiment as a varnish, the resin composition of this embodiment may contain a solvent.
The solvent used in the present embodiment is not particularly limited. Solvents that can be used in this embodiment include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, ether solvents such as tetrahydrofuran, aromatic solvents such as toluene, xylene, and mesitylene, and hydrocarbon solvents. , Petroleum solvents, N atom-containing solvents such as dimethylformamide and dimethylacetamide, S atom-containing solvents such as dimethyl sulfoxide, and ester solvents such as γ-butyrolactone.
These solvents can be used alone or in combination of two or more.
When the resin composition of this embodiment contains a solvent, the content of the solvent in the resin composition is preferably 10% by mass to 90% by mass, and more preferably 20% by mass to 80% by mass. Preferably, it is 30 mass%-80 mass%.

(Curing accelerator)
The resin composition of this embodiment may contain a curing accelerator. When an appropriate curing accelerator is used in combination, the molding temperature becomes 200 ° C. or lower, and low temperature curability can be imparted to the resin composition of the present embodiment. The cured product has low curing shrinkage, high elasticity, flame retardancy, There exists a tendency for copper foil adhesiveness etc. to improve further.

  Examples of the curing accelerator include imidazole compounds and derivatives thereof, tertiary amine compounds, and quaternary ammonium salts. Among them, an imidazole compound and a derivative thereof are preferable from the viewpoint of heat resistance of the cured product, flame retardancy, copper foil adhesiveness, and the like, and the following formula is an addition reaction product of hexamethylene diisocyanate resin and 2-ethyl-4-methylimidazole The compound shown in (12) is more preferable because it is excellent in curing moldability at a relatively low temperature at 200 ° C. or lower, and the aging stability of the varnish and prepreg of the resin composition, and is also commercially inexpensive. .

  The compound represented by formula (12) is commercially available from Daiichi Kogyo Seiyaku Co., Ltd.

  When the resin composition of this embodiment contains a hardening accelerator, content of a hardening accelerator is 0 mass with respect to 100 mass parts of the total mass of a carbodiimide compound, a hardening | curing agent, and the maleimide compound used as needed. Part to 20 parts by weight, preferably 0 part by weight to 10 parts by weight, more preferably 0 part by weight to 5 parts by weight. By making content of a hardening accelerator into 20 mass parts or less, it is suppressed that the gel time of the varnish of the resin composition of this embodiment becomes too short, and moldability is formed when shape | molding a laminated board with a press. It tends to improve.

(Flame retardants)
The resin composition of this embodiment may contain a flame retardant. Examples of the flame retardant used in the present embodiment include triphenyl phosphate, tricresyl phosphate, trisdichloropropyl phosphate, phosphoric ester compounds, phosphazenes, phosphorous flame retardants such as red phosphorus, antimony trioxide, zinc molybdate, and the like. And inorganic flame retardant aids. A halogen-containing flame retardant containing bromine, chlorine, or the like that may cause environmental problems is not suitable for the purpose of this embodiment. A flame retardant can be used individually by 1 type or in combination of 2 or more types.
As a flame retardant, an inorganic flame retardant in which zinc molybdate is supported on an inorganic filler such as talc is a preferable flame retardant because it improves not only the flame retardancy but also the drill workability of the cured product.

  When the resin composition of this embodiment contains a flame retardant, the content of the flame retardant is 0 part by mass with respect to 100 parts by mass of the total mass of the carbodiimide compound, the curing agent, and the maleimide compound used as necessary. It is preferable to set it as -20 mass parts, It is more preferable to set it as 0 mass parts-15 mass parts, It is still more preferable to set it as 0 mass parts-10 mass parts. If the content of the flame retardant is 20 parts by mass or less, the gel time of the varnish of the resin composition of the present embodiment will not be too short, and the moldability tends to be improved when a laminate is formed by pressing. It is in.

(Other ingredients)
The resin composition of this embodiment may contain other components as necessary. Examples of other components include thermoplastic resins, elastomers, and organic fillers.
Examples of the thermoplastic resin include tetrafluoroethylene resin, polyethylene resin, polypropylene resin, polystyrene resin, polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyester resin, polyamide resin, polyimide resin, xylene resin, petroleum resin, and silicone resin. Can be mentioned.
Examples of the elastomer include polybutadiene, acrylonitrile, epoxy-modified polybutadiene, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene, and carboxy-modified acrylonitrile.
Examples of the organic filler include organic particles such as silicone powder, tetrafluoroethylene, polyethylene, polypropylene, polystyrene, and polyphenylene ether.

To the resin composition of the present embodiment, an ultraviolet absorber, an antioxidant, a photopolymerization initiator, a fluorescent whitening agent, an adhesion improver, and the like may be added as other components.
These materials include UV absorbers such as benzotriazoles, antioxidants such as hindered phenols and styrenated phenols, photopolymerization initiators such as benzophenones, benzyl ketals, and thioxanthones, and fluorescence enhancements such as stilbene derivatives. Examples thereof include whitening agents, urea compounds such as urea silane, and adhesion improvers such as silane coupling agents.

(Production method of resin composition)
The resin composition of the present embodiment can be prepared by any method as long as the various components can be dispersed and mixed. As a general technique, the resin composition of the present embodiment can be obtained by weighing the components, mixing and kneading using a roughing machine, a mixing roll, a planetary mixer, etc., and defoaming as necessary. Yes, but not limited to this.

<Prepreg>
The prepreg of the present embodiment includes a base material and the resin composition of the present embodiment described above. The resin contained in the prepreg may be in a semi-cured (B-stage) state by heating or the like.

In this specification, “B stage” means a state defined in JIS K6900: 1994.
The prepreg can be produced, for example, by impregnating a substrate with a resin composition by a known method.

The average thickness of the prepreg can be appropriately selected according to the purpose. For example, it can be set to 50 μm to 500 μm, and is preferably 60 μm to 300 μm from the viewpoint of thermal conductivity and flexibility.
Here, the average thickness of the prepreg is a value given as an arithmetic average value obtained by measuring the thicknesses of five points of the target prepreg using a micrometer or the like.

  The kind in particular of base material is not restrict | limited, The well-known thing used for the laminated board for various electrical insulation materials can be used. Specific examples of the material of the substrate include inorganic fibers such as E glass, D glass, S glass, and Q glass, organic fibers such as polyimide, polyester, and tetrafluoroethylene, and mixtures thereof. These base materials may have the shape of a woven fabric, a nonwoven fabric, a robink, a chopped strand mat, and a surfacing mat, for example. The material and shape of the base material are selected depending on the intended use and performance of the molded product, and one kind or a combination of two or more kinds of materials and shapes can be combined as necessary.

The thickness in particular of a base material is not restrict | limited, For example, it can be 0.03 mm-0.5 mm. The base material is preferably surface-treated with a silane coupling agent or the like or mechanically subjected to fiber opening treatment from the viewpoints of heat resistance, moisture resistance, workability, and the like.
The amount of the resin composition attached to the substrate is preferably 20% by mass to 90% by mass, more preferably 30% by mass to 90% by mass, and more preferably 35% by mass to 85% as the proportion of the resin composition in the prepreg after drying. More preferred is mass%.
After impregnating the base material with the resin composition so that the amount of the resin composition attached to the base material is within the above range, it is usually heated and dried at a temperature of 100 ° C. to 200 ° C. for 1 to 30 minutes, and semi-cured ( The prepreg of the third embodiment can be obtained.
There is no restriction | limiting in particular in the method of impregnating a resin composition to a base material, For example, the method of apply | coating with a coating machine can be mentioned. Specifically, for example, a vertical coating method in which the base material is pulled through the varnish of the resin composition, and the resin composition is coated on the support film, and then the support film coated with the resin composition is applied. A horizontal coating method in which a substrate is pressed and impregnated can be mentioned. From the viewpoint of suppressing the uneven distribution of the inorganic filler in the substrate, the horizontal coating method is preferable.

  The solvent residual amount in the prepreg is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, and further preferably 0.7% by mass or less. The solvent residual amount of the prepreg is obtained from the mass change before and after drying when the prepreg is cut into 40 mm square and dried in a thermostatic bath preheated to 190 ° C for 2 hours.

The prepreg may be used after the surface is flattened by hot pressing. As a method of hot pressurization, a method such as a hot press, a hot roll, and a laminator can be arbitrarily selected.
When hot pressing is performed by a hot press method, the heating temperature is preferably set as appropriate according to the type of carbodiimide compound used in the resin composition, the type of curing agent, and the like. In general, the heating temperature is preferably 60 to 180 ° C, more preferably 120 to 150 ° C. The degree of vacuum is preferably 3 Pa to 0.1 kPa. The pressing pressure is preferably 0.5 MPa to 4 MPa, and more preferably 1 MPa to 2 MPa.

<Resin sheet>
The resin sheet of the present embodiment is a molded product of the resin composition of the present embodiment described above. The resin sheet of this embodiment can be manufactured by, for example, applying the resin composition of this embodiment on a release substrate and drying it. At this time, both sides of the resin sheet according to the present embodiment are smoothed on both sides by applying hot pressure in a state where two of the resin sheets of the present embodiment face each other after drying or a state where a release substrate is applied to the resin sheet. It is preferable because pinholes during construction can be eliminated.

  The release substrate is not particularly limited as long as it can withstand the temperature during drying, and is generally used as a polyethylene terephthalate film with a release agent, a polyimide film, a resin film such as an aramid film, and a release agent. A metal foil such as an attached aluminum foil can be used.

  The average thickness of the resin sheet is not particularly limited and can be appropriately selected according to the purpose. For example, the average thickness of the resin sheet is preferably 100 μm to 500 μm, and more preferably 100 μm to 300 μm. In addition, the average thickness of the resin sheet is obtained as an arithmetic average value by measuring the thickness of five points using a micrometer.

  The resin sheet is obtained as follows, for example. First, each component which comprises the resin composition of this embodiment is mixed, melt | dissolved, disperse | distributed, etc., and the varnish containing the resin composition of this embodiment is prepared. And the prepared varnish is provided on a mold release base material. The application of the varnish can be performed by a known method. Specific examples of the varnish application method include a comma coating method, a die coating method, a lip coating method, and a gravure coating method. As an application method for forming a resin sheet with a predetermined thickness, a comma coating method for passing an object to be coated between gaps, a die coating method for applying a varnish with a flow rate adjusted from a nozzle, or the like can be applied.

The drying temperature is preferably set as appropriate depending on the solvent used for the varnish, and is generally about 80 ° C to 180 ° C. The drying time can be determined by considering the varnish gelation time and the thickness of the resin sheet, and is not particularly limited. After drying, the release substrate is removed to obtain a resin sheet.
The solvent residual amount in the resin sheet is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, from the viewpoint of concern about bubble formation during outgas generation during curing. More preferably, it is 0.7 mass% or less. The residual amount of solvent in the resin sheet is determined from the change in mass before and after drying when the resin sheet is cut into a 40 mm square and dried in a thermostat preheated to 190 ° C. for 2 hours.

The resin sheet of the present embodiment may be used after the surface has been flattened before being laminated or pasted by hot pressing with a press, a roll laminator or the like. As a method of hot pressurization, a method such as a hot press, a hot roll, and a laminator can be arbitrarily selected.
When hot pressing is performed by a hot press method, the heating temperature is preferably set as appropriate according to the type of carbodiimide compound used in the resin composition, the type of curing agent, and the like, and generally 60 ° C to 180 ° C. It is preferable to carry out, and it is more preferable to set it as 120 to 150 degreeC. The degree of vacuum is preferably 3 Pa to 0.1 kPa. The pressing pressure is preferably 0.5 MPa to 4 MPa, and more preferably 1 MPa to 2 MPa.

  The resin sheet of this embodiment includes a first resin layer containing the resin composition of this embodiment and a second resin layer containing the resin composition of this embodiment laminated on the first resin layer. It is preferable. For example, the resin sheet of this embodiment is a laminate of a first resin layer formed from the resin composition of this embodiment and a second resin layer formed of the resin composition of this embodiment. It is preferable. Thereby, the withstand voltage can be further improved. The resin composition of this embodiment forming the first resin layer and the second resin layer may have the same composition or different compositions. It is preferable that the resin composition of this embodiment which forms the said 1st resin layer and 2nd resin layer is the same composition.

  This can be considered as follows, for example. That is, by overlapping two resin layers, a thinned portion (pinhole or void) that may exist in one resin layer is compensated by the other resin layer. Thereby, it can be considered that the minimum insulation thickness can be increased and the withstand voltage is further improved. The probability of occurrence of pinholes or voids in the resin sheet manufacturing method is not high, but by overlapping two resin layers, the probability of overlap of thin parts becomes the square, and the number of pinholes or voids approaches zero. become. Since dielectric breakdown occurs at a place where the insulation is weakest, it can be considered that the effect of further improving the withstand voltage can be obtained by overlapping two resin layers.

<Laminated plate>
The laminate of this embodiment includes the prepreg of this embodiment.
Due to recent demands for higher density and reliability of wiring, the laminated board material requires high copper foil adhesion and heat resistance, and low thermal expansion coefficient (low thermal expansion). For example, for the formation of fine wiring, the adhesiveness of a metal foil such as a copper foil to a laminated board is preferably 0.7 kN / m or more as a copper foil peeling strength, and 0.9 kN / m or more It is more preferable that In addition, it is necessary to make the laminate more multilayered by using a build-up material or the like in order to increase the wiring density, and high reflow heat resistance is required. The heat resistance with copper, which is a guideline for reflow heat resistance evaluation, is preferably free from blistering for 30 minutes or more. Furthermore, as the wiring density is increased, the laminate is in the direction of being made thinner, and the warp of the laminate during heat treatment is required to be small. In order to reduce the warp of the laminate, it is effective that the laminate is highly elastic. When the flexural modulus of the laminate is used as an index, the flexural modulus is preferably 30 GPa or more, and 32 GPa or more. It is more preferable that Further, in order to reduce warpage, it is effective that the laminate has a low thermal expansion property. Particularly, it is effective that the thermal expansion coefficient in the plane direction is low, and the linear thermal expansion coefficient in the plane direction is 7 ppm / ° C. Or less, more preferably 5 ppm / ° C. or less. In order to reduce warpage, it is also effective that the laminate has low cure shrinkage, and in particular, it is effective that the cure shrinkage rate in the plane direction is small, and the cure shrinkage rate in the plane direction is 0.5. % Or less is preferable, and 0.3% or less is more preferable. In addition, as the wiring density increases, the laminated board is in a direction that requires more reliability, and the inner wall roughness of the drill hole during drilling is required to be small. The evaluation of the inner wall roughness of the drill hole is evaluated by the penetration of plated copper into the inner wall of the drill hole, and the maximum plating penetration length is preferably 20 μm or less, and more preferably 15 μm or less. Furthermore, the demand for high-speed response continues to increase, and it is preferable that the relative dielectric constant of the laminate is 4.3 or less and the dielectric loss tangent is 0.007 or less.

The laminated board of this embodiment can be manufactured by shape | molding the prepreg of this embodiment, for example in the state which piled 1-20 sheets, and has arrange | positioned the metal foil on the single side | surface or both surfaces.
The metal foil is not particularly limited as long as it is used for electrical insulating material applications. Specific examples of the metal foil include gold foil, copper foil, aluminum foil and the like, and copper foil is generally used. The thickness of the metal foil is not particularly limited as long as it is 1 μm to 400 μm. A suitable thickness can be selected according to the power used. As the metal foil, nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy, etc. are used as intermediate layers, and 0.5 μm to 15 μm copper layer and 10 μm to 150 μm on both surfaces. A composite foil having a three-layer structure provided with copper layers, or a composite foil having a two-layer structure in which an aluminum foil and a copper foil are combined can also be used.

As for the molding conditions of the laminated body, for example, the technique of a laminated board for an electrical insulating material and a multilayer board can be applied, and a multistage press, a multistage vacuum press, continuous molding, autoclave molding, etc. are used, the temperature is 100 ° C. to 250 ° C. There ^{2kg / cm 2 ~100kg / cm 2} , heating time may range from 0.1 to 5 hours. Moreover, a multilayer board can also be manufactured in the state which combined the prepreg of this embodiment, and the wiring board for inner layers.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, these Examples do not restrict | limit this invention in any meaning.

<Production Example 1: Synthesis of specific carbodiimide compound 1>
Diphenylmethane-4,4′-diisocyanate (produced by Wako Pure Chemical Industries, Ltd., isocyanate equivalent) was added to a 1 liter reaction vessel having a thermometer, a stirrer, a reflux condenser, and a nitrogen gas introduction pipe capable of heating and cooling. 125 g / eq): 125.00 g, phenyl isocyanate (manufactured by Wako Pure Chemical Industries, Ltd., isocyanate equivalent; 119 g / eq): 14.88 g, cyclohexanone: 327.13 g, and then 3-methyl as a reaction catalyst -1-phenyl-2-phospholene-2-oxide (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight; 192): 0.324 g was charged. The equivalent ratio of the reaction of diphenylmethane-4,4′-diisocyanate and phenylisocyanate (the number of isocyanate groups of diphenylmethane-4,4′-diisocyanate / the number of isocyanate groups of phenylisocyanate) was 8.00.

Next, introduction of nitrogen gas into the reaction vessel and stirring were started, the temperature was raised to 80 ° C., a carbodiimidization reaction was performed at about 80 ° C. for 5 hours, and then cooled to room temperature. When a small amount of the reaction product was taken out from the reaction solution after the reaction and subjected to FT-IR measurement, the peak near 2260 cm ⁻¹ due to the isocyanate group disappeared, and further, 2120 cm due to the generated carbodiimide group. The appearance of a peak near ^-1 could be confirmed. This confirmed that the carbodiimide compound was synthesize | combined.

  Next, maleic anhydride (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight; 98): 11.03 g was added to the polycarbodiimide compound solution little by little, nitrogen gas introduction and stirring were started, and the temperature was raised to 100 ° C. The substitution reaction was carried out at about 100 ° C. for 4 hours. In addition, the equivalent ratio (number of anhydride groups of maleic anhydride / number of carbodiimide groups of carbodiimide compound) of the reaction of maleic anhydride and carbodiimide compound was 0.20.

When the reaction solution after the substitution reaction was cooled to room temperature, a small amount of the reaction product was taken out and subjected to FT-IR measurement, a peak near 1847 cm ⁻¹ due to maleic anhydride disappeared. The appearance of a peak around 1710 cm ⁻¹ due to the maleimide group produced by the substitution reaction could be confirmed. This confirmed that the polycarbodiimide which has a maleimide group was synthesize | combined.

<Production Example 2: Synthesis of specific carbodiimide compound 2>
Diphenylmethane-2,4′-diisocyanate (trade name; Millionate NM100, manufactured by Tosoh Corporation) was added to a reaction vessel having a volume of 1 liter which can be heated and cooled, equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas introduction pipe. Isocyanate equivalent: 125 g / eq): 125.00 g, phenyl isocyanate (manufactured by Wako Pure Chemical Industries, Ltd., isocyanate equivalent; 119 g / eq): 29.75 g, cyclohexanone: 361.92 g, and then reaction catalyst 3-methyl-1-phenyl-2-phospholene-2-oxide (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight; 192): 0.360 g was added. The equivalent ratio of the reaction of diphenylmethane-2,4′-diisocyanate and phenylisocyanate (the number of isocyanate groups of diphenylmethane-2,4′-diisocyanate / the number of isocyanate groups of phenylisocyanate) was 4.00.

Next, introduction of nitrogen gas into the reaction vessel and stirring were started, the temperature was raised to 80 ° C., a carbodiimidization reaction was performed at about 80 ° C. for 5 hours, and then cooled to room temperature. When a small amount of the reaction product was taken out from the reaction solution after the reaction and subjected to FT-IR measurement, the peak near 2260 cm ⁻¹ due to the isocyanate group disappeared, and further, 2120 cm due to the generated carbodiimide group. The appearance of a peak near ^-1 could be confirmed. This confirmed that the carbodiimide compound was synthesize | combined.

Next, maleic anhydride (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight; 98): 30.63 g was added to the carbodiimide compound solution little by little, introduction of nitrogen gas and stirring were started, and the temperature was raised to 100 ° C. Then, a substitution reaction was performed at about 100 ° C. for 8 hours. The equivalent ratio of the reaction of maleic anhydride and carbodiimide compound (number of anhydride groups of maleic anhydride / number of carbodiimide groups of carbodiimide compound) is 0.50. Next, the reaction solution was cooled to room temperature and a small amount of the reaction product was taken out from the reaction solution and subjected to FT-IR measurement. As a result, the peak near 1847 cm ⁻¹ due to maleic anhydride disappeared, and maleic anhydride Appearance of a peak near 1710 cm ⁻¹ due to the maleimide group produced by the substitution reaction of was confirmed. This confirmed that the carbodiimide compound which has a maleimide group was synthesize | combined.

<Production Example 3: Synthesis of specific carbodiimide compound 3>
In a reaction vessel with a volume of 1 liter that can be heated and cooled, equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas introduction pipe, 2,4′-tolylene diisocyanate (produced by Tokyo Chemical Industry Co., Ltd., isocyanate equivalent; 87 ): 87.00 g, polymethylene polyphenyl polyisocyanate (manufactured by Tosoh Corporation, trade name: Millionate MR-200, isocyanate equivalent; 136 g / eq): 13.60 g, phenyl isocyanate (manufactured by Wako Pure Chemical Industries, Ltd.) , Isocyanate equivalent; 119 g / eq): 130.90 g, cyclohexanone: 541.65 g, and then 3-methyl-1-phenyl-2-phospholene-2-oxide (manufactured by Wako Pure Chemical Industries, Ltd.) Molecular weight; 192): 0.634 g was charged. The equivalent ratio of the reaction of 2,4′-tolylene diisocyanate, polymethylene polyphenyl polyisocyanate, and phenyl isocyanate (total number of isocyanate groups of 2,4′-tolylene diisocyanate and polymethylene polyphenyl polyisocyanate / phenyl isocyanate The number of isocyanate groups was 1.00.

Next, introduction of nitrogen gas into the reaction vessel and stirring were started, the temperature was raised to 80 ° C., a carbodiimidization reaction was performed at about 80 ° C. for 5 hours, and then cooled to room temperature. When a small amount of the reaction product was taken out from the reaction solution after the reaction and subjected to FT-IR measurement, the peak near 2260 cm ⁻¹ due to the isocyanate group disappeared, and further, 2120 cm due to the generated carbodiimide group. The appearance of a peak near ^-1 could be confirmed. This confirmed that the carbodiimide compound was synthesize | combined.

Next, 21.56 g of maleic anhydride (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight; 98): 21.56 g was added little by little to the solution of the carbodiimide compound, nitrogen gas introduction and stirring were started, and the temperature was raised to 100 ° C. Then, a substitution reaction was performed at about 100 ° C. for 4 hours. The equivalent ratio of the reaction of maleic anhydride and carbodiimide compound (number of anhydride groups of maleic anhydride / number of carbodiimide groups of carbodiimide compound) is 0.20. Next, the reaction solution was cooled to room temperature and a small amount of the reaction product was taken out from the reaction solution and subjected to FT-IR measurement. As a result, the peak near 1847 cm ⁻¹ due to maleic anhydride disappeared, and maleic anhydride The appearance of a peak in the vicinity of 1710 cm ⁻¹ due to the maleimide group produced by the substitution reaction can be confirmed. Thus, it was confirmed that a carbodiimide compound having a maleimide group at the resin terminal was synthesized.

<Production Example 4: Synthesis of Reference Carbodiimide Compound>
Diphenylmethane-4,4′-diisocyanate (produced by Wako Pure Chemical Industries, Ltd., isocyanate equivalent) was added to a 1 liter reaction vessel having a thermometer, a stirrer, a reflux condenser, and a nitrogen gas introduction pipe capable of heating and cooling. 125 g / eq): 125.00 g, phenyl isocyanate (manufactured by Wako Pure Chemical Industries, Ltd., isocyanate equivalent; 119 g / eq): 14.88 g, cyclohexanone: 327.89 g, and then 3-methyl as a reaction catalyst -1-phenyl-2-phospholene-2-oxide (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight; 192): 0.648 g was added. The equivalent ratio of the reaction of diphenylmethane-4,4′-diisocyanate and phenylisocyanate (the number of isocyanate groups of diphenylmethane-4,4′-diisocyanate / the number of isocyanate groups of phenylisocyanate) was 8.00.

Next, introduction of nitrogen gas into the reaction vessel and stirring were started, the temperature was raised to 80 ° C., a carbodiimidization reaction was performed at about 80 ° C. for 5 hours, and then cooled to room temperature. When a small amount of the reaction product was taken out from the reaction solution after the reaction and subjected to FT-IR measurement, the peak near 2260 cm ⁻¹ due to the isocyanate group disappeared, and further, 2120 cm due to the generated carbodiimide group. The appearance of a peak near ^-1 could be confirmed. This confirmed that the carbodiimide compound was synthesize | combined.

<Examples 1-6, Comparative Examples 1-3, Reference Example 1>
The materials shown in Table 1 were mixed at the blending ratio shown in Table 1 (parts by mass, excluding the solvent) to prepare varnishes of Examples, Comparative Examples, and Reference Examples. At this time, a diluting solvent (methyl ethyl ketone) was used so that the solid content in the varnish (total of components other than the solvent) was 60% by mass. “-” In Table 1 means that the corresponding component is not included.

Details of the material names in Table 1 are as follows.
(A) Carbodiimide compound A-1. Specific carbodiimide compound 1 synthesized in Production Example 1
A-2: Specific carbodiimide compound 2 synthesized in Production Example 2
A-3: Specific carbodiimide compound 3 synthesized in Production Example 3
A-4: reference carbodiimide compound synthesized in Production Example 4 (B) curing agent B-1 naphthol aralkyl cresol copolymerized epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name: NC-7000L)
B-2: biphenyl aralkyl epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name: NC-3000H)
(C) Inorganic filler-C-1 ... Spherical silica (Fused spherical silica, manufactured by Admatechs Co., Ltd., trade name: SO-25R)
C-2: spherical silica surface-treated with 1.0% by mass of 3-glycidoxypropyltrimethoxysilane (spherical silica front-treated with 3-glycidoxypropyltrimethoxysilane, manufactured by Admatech Co., Ltd. , Trade name: SC-2050MTE, diluent solvent: methyl ethyl ketone)
C-3: Boehmite type aluminum hydroxide (manufactured by Kawai Lime Industry Co., Ltd., trade name: BMT-3L)
(D) Maleimide compound D-1 ... 2,2-bis (4- (4-maleimidophenoxy) phenyl) propane (manufactured by Daiwa Kasei Co., Ltd., trade name: BMI-4000)
D-2: Polyphenylmethane maleimide (manufactured by Daiwa Kasei Co., Ltd., trade name: BMI-2300)
・ Flame retardant: Inorganic flame retardant aid with zinc molybdate supported on talc (Sherwin Williams, trade name: Chemguard 1100)
Curing accelerator: addition reaction product of hexamethylene diisocyanate resin and 2-ethyl-4-methylimidazole (Daiichi Kogyo Seiyaku Co., Ltd., trade name: G-8809L)
Cyanate resin for comparison: Bisphenol A type cyanate resin (Lonza Japan, trade name: Primaset BADCy)

Subsequently, the varnish was impregnated and applied to an S glass cloth having a thickness of 0.2 mm and dried by heating at 160 ° C. for 10 minutes to obtain a prepreg having a resin content of 55% by mass. Next, four prepregs are stacked to prepare a prepreg laminate, and electrolytic copper foils with a thickness of 12 μm are arranged above and below, respectively, and a press is performed for 90 minutes at a pressure of 25 kg / cm ² and a temperature of 185 ° C. A copper clad laminate was obtained. Using this copper clad laminate, measurement and evaluation were performed according to the following items. Table 2 shows the results.

(1) Evaluation of copper foil adhesion (copper foil peel strength) By immersing a copper clad laminate in a copper etching solution, a 1 cm wide and 5 cm long copper foil (evaluation pattern) is formed to produce an evaluation substrate. Then, the peel strength (kN / m) of the copper foil was measured using a tensile tester (manufactured by Shimadzu Corporation, EZTest).

(2) Measurement of glass transition temperature (Tg) A 5-mm square evaluation substrate was prepared using a prepreg laminate in which a copper foil on both sides was removed by immersing a copper-clad laminate in a copper etching solution. Next, the thermal expansion characteristics in the surface direction of the evaluation substrate were observed using a TMA (Thermal Mechanical Analysis) test apparatus (manufactured by DuPont, TMA2940) and evaluated by the method defined in JIS K 0129 (2005).

(3) Measurement of linear thermal expansion coefficient A 5-mm square test piece was produced from the prepreg laminate from which the copper foil on both sides was removed by immersing the copper-clad laminate in a copper etching solution. Subsequently, the linear thermal expansion coefficient (ppm / degreeC) of 30 to 100 degreeC of the surface direction of an evaluation board | substrate was measured using the TMA test apparatus (The Du Pont company make, TMA2940).

(4) Evaluation of solder heat resistance A 5 cm square test piece was prepared from a prepreg laminate from which a copper foil on both sides was removed by immersing a copper clad laminate in a copper etching solution. Next, using a pressure cooker test apparatus (manufactured by Hirayama Seisakusho Co., Ltd.), pressure cooker treatment was performed for up to 4 hours under the conditions of 121 ° C. and 2 atm (0.2 MPa). Then, after immersing the evaluation substrate in a solder bath at a temperature of 300 ° C. for 20 seconds, the heat resistance of the solder was evaluated by observing the appearance. When there was no bulging visible in the appearance, it was judged as “good”, and when there was a bulging visible, it was judged as “bulging”.

(5) Evaluation of heat resistance with copper A test piece of 5 mm square was prepared from a copper-clad laminate. Next, according to the test method defined in IPC TM650, using a TMA test apparatus (manufactured by DuPont, TMA2940), measure the time (minutes) until the evaluation substrate swells in an environment of 300 ° C. It was evaluated by. When the time until blistering was 60 minutes or longer, “> 60” was set.

(6) Evaluation of flame retardance A test piece having a length of 127 mm and a width of 12.7 mm was prepared from a prepreg laminate obtained by removing a copper foil on both sides by immersing a copper clad laminate in a copper etching solution. Using this test piece, flame retardancy was evaluated according to the UL94 test method (Method V).

(7) Measurement of relative dielectric constant and dielectric loss tangent A test piece having a length of 20 mm and a width of 20 mm was prepared from a prepreg laminate in which the copper foil on both sides was removed by immersing the copper-clad laminate in a copper etching solution. Using this test piece, the relative dielectric constant and dielectric loss tangent at a frequency of 1 GHz were measured using a relative dielectric constant measuring apparatus (manufactured by Hewlett-Packard, product name: HP4291B).

(8) Drill workability Using a drill having a diameter of 0.105 mm (Union Tool MV J676), rotating speed: 160,000 times / min (rpm), feeding speed: 0.8 m / min, number of stacked sheets: 1 Under conditions, the copper-clad laminate was drilled and 6000 hits were made to produce an evaluation board. Using this evaluation substrate, the inner wall roughness of the drill hole was evaluated. The inner wall roughness was evaluated by performing electroless copper plating (plating thickness: 15 μm) and measuring the maximum value (μm) of the plating penetration length into the hole wall.

(9) Measurement of curing shrinkage rate A 5 mm square test piece was prepared from a prepreg laminate from which the copper foil on both sides was removed by immersing the copper-clad laminate in a copper etching solution. Using this test piece, the dimensional change rate (%) in the surface direction of the evaluation substrate after heating and cooling was measured using a TMA test apparatus (manufactured by DuPont, TMA2940). The temperature increase and cooling were performed by increasing the temperature from 20 ° C. to 260 ° C. at a rate of 10 ° C./min, and then decreasing the temperature from 260 ° C. to 20 ° C. at a rate of 10 ° C./min.

(10) Measurement of flexural modulus A test piece having a length of 40 mm, a width of 25 mm, and a thickness of 0.4 mm was prepared from a prepreg laminate obtained by removing a copper foil on both sides by immersing a copper-clad laminate in a copper etching solution. . Using this test piece, the bending elastic modulus (GPa) at room temperature (20 ° C. to 23 ° C.) was measured using a bending test apparatus (Orientec Co., Ltd., 5-ton Tensilon RTC-1350A).

As is clear from the results shown in the table, the prepreg or copper clad laminate produced in the examples is copper foil peel strength, glass transition temperature, solder heat resistance, thermal expansion coefficient, flame resistance, heat resistance with copper, ratio Good results were shown in all evaluation items of dielectric constant, dielectric loss tangent, drill workability, cure shrinkage, and flexural modulus. On the other hand, the prepreg or copper clad laminate produced in the comparative example had a low evaluation of at least one of these evaluation items.
Furthermore, the prepreg produced in the Example tended to have a higher glass transition temperature than the prepreg of Reference Example 1 produced using a carbodiimide compound having no maleimide group.

Claims (11)

  A prepreg comprising a carbodiimide compound having at least one carbodiimide group and at least one maleimide group in one molecule. A first peak at 2120 ± ^{5 cm -1} in the infrared absorption spectrum, including carbodiimide compound having a 1710 ± ^{5 cm -1} and a second peak, the prepreg.   A resin composition comprising a carbodiimide compound having at least one carbodiimide group and at least one maleimide group in one molecule, and a curing agent. It includes a first peak at 2120 ± ^{5 cm -1} in the infrared absorption spectrum, and a second peak at 1710 ± ^{5 cm -1,} and a carbodiimide compound having a curing agent, the resin composition.   The prepreg containing a base material and the resin composition of Claim 3 or Claim 4.   A resin sheet, which is a molded product of the resin composition according to claim 5.   A laminate comprising the prepreg according to claim 1, claim 2 or claim 5.   A carbodiimide compound having at least one carbodiimide group and at least one maleimide group in one molecule. A carbodiimide compound having a first peak at 2120 ± 5 cm ⁻¹ and a second peak at 1710 ± 5 cm ⁻¹ in the infrared absorption spectrum. The carbodiimide compound of Claim 8 or Claim 9 which has a structure represented by following General formula (1).

In the general formula (1), each R ₁ is independently a divalent aromatic group or an aliphatic group, and m is a positive number.   The manufacturing method of the carbodiimide compound of any one of Claims 8-10 including the process of making the carbodiimide compound which has at least 1 carbodiimide group in 1 molecule react with maleic anhydride.