JP2021160335A - Cured resin and method for producing the same, metal-clad laminate, and printed wiring board - Google Patents

Abstract

To provide a cured product having excellent processability, heat resistance, thermal shock resistance and electric characteristics (low dielectric constant and low dielectric loss tangent), a metal-clad laminate, a laminate and a printed wiring board.SOLUTION: The present disclosure provides a cured product having a hard segment ratio (H ratio) controlled to be more than 10% to less than 60% and a uniformity parameter (T value) controlled to be 0.10-0.64.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cured resin product, a method for producing the same, a metal-clad laminate, and a printed wiring board.

In recent years, with the remarkable progress of information network technology and the expansion of services utilizing information networks, electronic devices are required to have a large amount of information and a high processing speed. In order to meet these demands, substrate materials such as printed wiring boards have low dielectric constant and low dielectric constant in addition to the characteristics such as heat resistance, flame retardancy, and peel strength with copper foil that have been conventionally required. Direct contact is required. Therefore, further improvement of the resin composition used for a substrate such as a printed wiring board is being studied.

Since the polyphenylene ether (PPE) resin has a low dielectric constant and a low dielectric loss tangent, it is suitable as a material for a printed wiring board that can meet the above-mentioned requirements. For example, Patent Document 1 attempts to reduce the dielectric constant and the low dielectric loss tangent by using a PPE resin in which a methacrylic group is introduced as a curable functional group.

Japanese Unexamined Patent Publication No. 2017-82200

However, when the crosslinked resin precursor having a PPE molecular chain is cured, the cured product causes irregular dimensional changes when the obtained cured product is heated, and the plating applied to the laminated board cracks. Through chemical and physical processing such as drilling, desmearing, and plating to form a laminated board as a multi-layer printed wiring board. There was a problem of workability such as plating infiltrating from the surface of the hole.

Patent Document 1 attempts to put it into practical use by blending a cross-linking agent, an elastomer, etc. typified by triallyl isocyanurate (TAIC) having a structure different from that of PPE into a resin composition. However, although the problem of plating cracks in the cured product showed a large tendency to improve, there were cases where the plating penetrability was not sufficient.

Therefore, an object of the present invention is to solve a problem of processability such as plating cracks or plating infiltration due to irregular dimensional change or non-uniformity when heated, and at the same time, it is an original object of low dielectric constant and low dielectric constant. An object of the present invention is to provide a cured resin product, a metal-clad laminate, and a printed wiring board having excellent dielectric loss tangent performance.

As a result of diligent studies to solve the above problems, the present inventors have solved the above problems by controlling the ratio of hard segments of the cured resin product and increasing the uniformity of the cured PPE resin forming the cured resin product. We have found that it can be solved and have completed the present invention. That is, some aspects of the present invention are listed below.
[1]
A cured resin product having a crosslinked structure in which a polyphenylene ether resin containing a curable functional group is crosslinked.
The hard segment ratio (H ratio) measured by the solid echo method of pulse NMR is more than 10% and less than 60.0%, and in the dynamic viscoelasticity measurement, the tan δ value at the glass transition temperature (Tg) and (Tg + 30). ) From the ratio of the tan δ value at ° C, the following formula (I):
T value = tanδ _{(Tg + 30)} / tanδ _(Tg) (I)
A cured resin product having a uniformity parameter (T value) defined by 0.10 to 0.64.
[2]
The cured resin product according to item 1, wherein the polyphenylene ether resin contains an acrylic group as the curable functional group.
[3]
Item 2. The cured resin product according to Item 2, wherein the polyphenylene ether resin has a curing rate of 30% or more.
[4]
The cured resin product according to any one of items 1 to 3, wherein the polyphenylene ether resin has a branched structure.
[5]
The cured resin product according to any one of Items 1 to 4, wherein the polyphenylene ether resin has a number average molecular weight of 500 or more and 15,000 or less.
[6]
The cured resin product according to any one of items 1 to 5, wherein the polyphenylene ether resin has an average of 2.5 to 5.0 curable functional groups per molecule.
[7]
Item 1 to 6, which comprises a step of curing the curable composition containing a polyphenylene ether resin containing a curable functional group in a temperature range of 140 ° C. to 170 ° C. with a hold time of 1 minute to 30 minutes. The method for producing a cured resin product according to any one of the following items.
[8]
A metal-clad laminate containing a metal foil and a cured resin product according to any one of items 1 to 6.
[9]
The metal-clad laminate according to item 8, wherein the metal foil is a copper foil.
[10]
A printed wiring board containing the cured resin product according to any one of items 1 to 6.

According to the present invention, it is possible to provide a laminated board, a metal-clad laminated board, and a printed wiring board having excellent workability and electrical characteristics (low dielectric constant and low dielectric loss tangent property).

It is a cross-sectional observation photograph of the through hole before the hot oil test of Example 1. It is a cross-sectional observation photograph of the through hole after the hot oil test of Example 1. FIG. It is a cross-sectional observation photograph of the through hole before the hot oil test of Comparative Example 1. It is a cross-sectional observation photograph of the through hole after the hot oil test of Comparative Example 1. It is a graph which shows the TMA measurement result of the laminated board of Example 1 and Comparative Example 1. ^{It is a 1} H-NMR measurement result of the modified polyphenylene ether 1 (modified PPE-1) used in Examples 5 to 7 and Comparative Examples 8 to 9.

Hereinafter, embodiments of the present invention will be described in detail, but it is not intended that the present invention be limited to these aspects.

[Resin cured product]
The cured resin product of the present embodiment is a cured resin product having a crosslinked structure in which a polyphenylene ether (PPE) resin containing a curable functional group is crosslinked.
The hard segment ratio (H ratio) measured by the solid echo method of pulse NMR is more than 10% and less than 60.0%, and in the dynamic viscoelasticity measurement, the tan δ value at the glass transition temperature (Tg) and (Tg + 30) ° C. From the ratio of the tan δ values in the above, the uniformity parameter (T value) defined by the following formula (I) is 0.10 to 0.64.
T value = tanδ _{(Tg + 30)} / tanδ _(Tg) (I)

In the cured resin product of the present embodiment, for example, a curable composition containing a PPE resin containing a curable functional group is cured in a temperature range of 140 ° C. to 170 ° C. with a hold time of 1 minute to 30 minutes. It can be manufactured by a manufacturing method including a step.

[Suppression of hard segment]
As a result of examining the curing process of the crosslinked resin precursor having a PPE skeleton in detail, the present inventors have identified the cause of the irregular dimensional change of the cured PPE resin and solved the problem by taking countermeasures. Completed the present invention.

That is, since the PPE molecular chain tends to be relatively easily oriented, the phenylene group is partially oriented during the curing process to form a hard segment. As a result, for example, after manufacturing a laminated board, it is further processed to make a printed wiring board, and further, in the process of manufacturing a mounting board, a heat history, especially when a sudden heat is applied in a short time, a hard segment. The whole starts to move together while maintaining a large elastic modulus, causing a local dimensional change. In recent years, the majority of laminated boards have been put into practical use as printed wiring boards by multi-layering, and holes called through holes are made to ensure the continuity of wiring between layers, and the surface is plated with metal. However, as described above, when a local dimensional change occurs due to a hard segment, a large stress is applied to the plating applied to the through hole, which causes a problem that the plating cracks and the wiring is broken. It was made clear that it would end up.

In the present invention, the curing temperature is increased when the glass transition temperature (Tg) of the cured resin approaches the curing temperature as the curing progresses so that the phenylene group is not oriented according to the structure of the PPE resin. By suppressing the ratio of hard segments, it was possible to solve problems such as plating cracks caused by irregular dimensional changes in the cured product.

[Suppression of non-uniformity of cured product]
On the other hand, conventionally, as described in Patent Document 1, an approach has been made in which a cross-linking agent having a small molecular weight, an elastomer having a flexible structure, or the like is blended together with PPE into which a methacrylic group has been introduced, and a certain effect has been reported. However, in this case as well, there are industrial problems such as the remarkable plating penetrability as described above.

As a result of detailed examination of the conventional approach, the present inventors may find that the laminated plate obtained by curing becomes non-uniform due to the difference in reactivity between the functional group introduced into PPE and the cross-linking agent or the like. It was possible to solve the workability problem by finding out that it was the cause of the processability problem such as plating penetration and adjusting the curing profile to suppress the non-uniformity.

（式（２）中、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４は、各々独立して、水素原子、ハロゲン原子（例えば、フッ素原子、塩素原子及び臭素原子）、置換基を有してもよいアルキル基（例えば、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、ｔｅｒｔ−ブチル基等の炭素数１〜６の直鎖状若しくは分岐状のアルキル基、シクロヘキシル基等の炭素数６〜１０の環状のアルキル基）、置換基を有してもよいアルコキシ基（例えば、メトキシ基、エトキシ基、ブトキシ基等の炭素数１〜６のアルコキシ基）、置換基を有してもよいアリール基（例えば、フェニル基及びナフチル基）、置換基を有してもよいアミノ基、ニトロ基又はカルボキシル基を表す。） [PPE resin]
The PPE resin of the present embodiment has a repeating structure (polyphenylene ether structure) represented by the following formula (2) and contains a curable functional group. In the PPE resin, the portion having a curable functional group is not limited, but for example, a curable functional group can be provided at the end.

(In the formula (2), R ¹ , R ² , R ³ and R ⁴ may independently have a hydrogen atom, a halogen atom (for example, a fluorine atom, a chlorine atom and a bromine atom), and a substituent. A good alkyl group (eg, a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a cyclohexyl group, etc. It has a cyclic alkyl group having 6 to 10 carbon atoms), an alkoxy group which may have a substituent (for example, an alkoxy group having 1 to 6 carbon atoms such as a methoxy group, an ethoxy group, and a butoxy group), and a substituent. Represents an aryl group (eg, a phenyl group and a naphthyl group), an amino group which may have a substituent, a nitro group or a carboxyl group.

The fact that the cured resin product according to the present embodiment contains a PPE resin is in the vicinity of ^{1021,1189,1306,1471,1603 cm -1} in the spectrum obtained when the cured resin product is measured by FT-IR (ATR method). This can be confirmed by detecting a relatively strong peak.

Specific examples of PPE include poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), and poly (2-methyl-6). -Phenyl-1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether), 2,6-dimethylphenol and other phenols (eg, 2,3,6-trimethylphenol, A copolymer with 2-methyl-6-butylphenol, etc.), a polyphenylene ether copolymer obtained by coupling 2,6-dimethylphenol with biphenols or bisphenols, and poly (2,6-). Dimethyl-1,4-phenylene ether) or the like is heated in a solvent such as toluene in the presence of a phenol compound such as bisphenols or trisphenols and an organic peroxide, and is redistributed to obtain a linear chain. Examples thereof include polyphenylene ether having a structure or a branched structure.

[Preferable structure of PPE]
Among these PPEs, PPEs having a branched structure in the molecular chain are preferable because phenylene groups are difficult to stack and hard segments are difficult to form, and as a result, thermal shock resistance tends to be high.

Examples of such PPEs are monofunctional phenols such as 2,6-dimethylphenol, 2,3,6-trimethylphenol and tris (4-hydroxyphenyl) methane, 1,1,3-tris (2-methyl-). 4-Hydroxy-5-tert-butylphenyl) butane, 1,1,1-tris (4-hydroxyphenyl) ethane, α, α, α', α'-tetrakis (4-hydroxyphenyl) -p-xylene, etc. Polyphenylene ether copolymer obtained by coupling with a polyfunctional phenol compound having a branched structure of, and poly (2,6-dimethyl-1,4-phenylene ether) and the like are tris (4-hydroxyphenyl) methane, 1,1,3-Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,1-Tris (4-hydroxyphenyl) ethane, α, α, α', α'- Polyphenylene having a branched structure obtained by heating in a solvent such as toluene in the presence of a phenol compound having a branched structure such as tetrakis (4-hydroxyphenyl) -p-xylene and an organic peroxide and causing a redistribution reaction. Examples include ether.

[Preferable molecular weight of PPE resin]
When the molecular weight of the PPE resin is low, a cured product having high uniformity tends to be formed and the T value tends to decrease, and the wettability between the glass fiber and the cured resin tends to be good, and as a result, the plating penetration property tends to be high. It is preferable because there is.

The preferred molecular weight and molecular weight distribution depend on the structure of the PPE.

In the case of a linear structure in which the PPE does not contain a branched structure, the number average molecular weight is preferably 500 to 15,000, more preferably 700 to 5,000, and 2,000 to 2,700. It is more preferable, and it is particularly preferable that it is 2,300 to 2,450. Further, in that case, for example, as the molecular weight distribution is smaller, the smaller the Mw / Mn, the higher the fluidity and the higher the wettability with the glass fiber. The specific Mw / Mn is preferably 1.1 to 5.0, more preferably 1.2 to 3.0, and even more preferably 1.3 to 2. It is 0, and particularly preferably 1.35 to 1.40.

When the PPE contains a branched structure, the number average molecular weight is preferably 500 to 15,000, more preferably 700 to 5,000, and even more preferably 1,000 to 3,000. It is particularly preferably 1,450 to 2,800.

[Content ratio of PPE resin in cured resin]
The ratio of the PPE resin in the cured resin product of the present embodiment is preferably 20% or more, or 30% or more, more preferably 40% or more, still more preferably 50% or more, and particularly preferably 60% or more. be.

[Hard segment ratio (H rate)]
The cured resin product of the present embodiment has a hard segment ratio (H ratio) of more than 10% and less than 60.0%. When the H ratio is less than 60.0%, the dimensional change of the laminated board when a thermal shock of 240 ° C. or higher is applied is small, which is preferable. If the H ratio is 60.0% or more, a large dimensional change occurs when a thermal shock of 240 ° C. or higher is applied to the laminated board, so that, for example, the laminated board itself swells or the plating applied to the through hole cracks. There is a risk that it will not be put to practical use. From such a viewpoint, the H ratio is less than 60.0%, preferably less than 59.7%, more preferably less than 59.5%, and particularly preferably less than 59%.

When the H ratio is within the above range, plating cracks are prevented. The hard segment is due to a higher order structure formed by orienting and overlapping several PPE chains. Such structures tend to lead to the rigidity of the molecular chains, resulting in higher Tg in the matrix. On the other hand, such a structure has a high elastic modulus because when the matrix is rapidly heated to a temperature of Tg or higher, it forms a higher-order structure and the oriented PPE chains start segmental motion all at once. It leads to macroscopically large volume expansion in the temperature range. As a result, in the printed wiring board obtained by drilling the laminated board and plating the through holes thereof, the plating cannot follow the dimensional change of the laminated board and the plating cracks.

[H rate control method]
The above H ratio can be controlled by adjusting the blending amount of the PPE resin in the curable composition and the curing conditions. That is, the curable composition is composed of a PPE resin, a reinforcing material, a cross-linking agent, a flame retardant, a stress relaxant, etc., and among them, has a component related to a curing reaction, specifically, a curable functional group. It can be controlled by the content of crosslinked PPEs in the components (they are called matrices) and the curing profile.

Specifically, there is a tendency that the H rate can be adjusted to less than 60.0% by combining the following methods.

When the content of PPE resin in the matrix constituting the curable composition is adjusted to be higher than 80% (for example, in the case of a composition consisting of only PPE resin and a radical initiator), the final curing temperature is set to 180 ° C. The H ratio tends to be less than 60.0% by setting the temperature higher than that, which is preferable. It is more preferably 190 ° C. or higher, further preferably 200 ° C. or higher, and particularly preferably 220 ° C. or higher.

The faster the temperature rise rate, the lower the H rate tends to be, so the temperature rise rate is preferably faster than 1 ° C./min, more preferably 2 ° C./min or more, still more preferably 3 ° C./min. Minutes or more, particularly preferably 5 ° C./min or more.

Further, even when the final curing temperature is set to 180 ° C. or lower, the H rate tends to be reduced by setting the heating rate from room temperature or higher to a high rate, preferably 5 ° C./min or higher, more preferably 10 ° C. The H ratio tends to be less than 60.0% by setting the temperature to / min or more, more preferably 20 ° C./min or more, and particularly preferably 50 ° C./min or more.

When the content of PPE resin in the matrix constituting the curable composition is adjusted to 80% or less (for example, in the case of (PPE resin / TAIC) = (80/20) composition), the rate of temperature rise is increased. The more the setting is made, the more the curing reaction proceeds before the molecular chains are oriented, so that the hard segment tends to be low, which is preferable. From such a viewpoint, the temperature is preferably raised at a rate faster than 1 ° C./min, preferably 2 ° C./min or higher, more preferably 3 ° C./min or higher, and even more preferably 5 ° C./min or higher.

Further, the higher the final curing temperature, the higher the motility of the molecular chain at the curing stage, so that the H ratio tends to be low, which is preferable. The final curing temperature is preferably 160 ° C. or higher, more preferably 170 ° C. or higher, still more preferable. Is 180 ° C. or higher, particularly preferably 200 ° C. or higher.

As described above, the Tg of the cured resin increases as the curing progresses so that the phenylene group is not oriented according to the structure of the PPE resin, and the curing temperature is sufficient before the movement of the molecular chain is suppressed. It is considered that the H rate can be suppressed by increasing the amount.

[H rate quantification method]
The H ratio of the cured resin product can be obtained by measuring the laminated plate by pulse NMR. Specifically, it can be measured by the solid echo method described in the examples.

[Uniformity parameter (T value)]
The cured resin product of the present embodiment has a uniformity parameter (T value) of 0.10 to 0.64.
The T value is defined by the following formula (I) from the ratio of the tan δ value at Tg (° C.) and the tan δ value at (Tg + 30) ° C. in the dynamic viscoelasticity (hereinafter referred to as DMA) measurement of the cured resin product. The smaller the value, the more uniform the cured product.
T value = tanδ @ (Tg + 30) / tanδ @ Tg (I)

Even if the cross-linked network is uniform at the stage of the composition before cross-linking, when the gel point is reached, the inside of the system is phase-separated into a liquid and a solid, and becomes more or less non-uniform. In particular, if the network formation reaction rate is too fast compared to the moving rate of the constituent molecules, the degree of this non-uniformity becomes remarkable, and the difference between the dense part and the sparse part of the crosslinked network becomes remarkable. Normally, in the DMA measurement of a crosslinked polymer, tan δ is considered to be a completely rubber-like elastic body at (Tg + 30) ° C. (for example, network polymer Vol.36 No. 3 (2015)), but it is non-uniform. In the cured product, a portion having insufficient cross-linking is detected as a viscous component at a temperature higher than Tg, and tan δ shows a large value. Therefore, the above T value is a measure of uniformity, and the smaller the value, the more uniform the cured product.

The insufficiently cured region is eluted by chemical treatment such as desmear treatment or plating treatment of the laminated board to form voids, which causes deterioration of plating penetration. Therefore, it is considered that a laminated board having good workability can be obtained from a cured product having a low T value.

From such a viewpoint, the preferable T value is 0.11 to 0.63, more preferably 0.12 to 0.60, still more preferably 0.13 to 0.55, and particularly preferably 0.13 to 0.55. It is 0.14 to 0.52, and particularly preferably 0.15 to 0.5.

[T value control method]
The T value of the cured resin product can be controlled within the above numerical range by adjusting the curing conditions according to the composition of the resin composition. That is, it is assumed that the temperature is raised from room temperature at a relatively low speed, the temperature is maintained in the same temperature range as the expected Tg or at a temperature slightly lower than that of the room temperature for several minutes, and then the curing further progresses and the Tg gradually increases. The T value can be adjusted within the above range by curing in the same temperature range as Tg. Further, when modified PPE is used, the lower the molecular weight of the modified PPE, the easier it is to adjust the T value to be equal to or less than the upper limit of the above numerical range.

One of the objects of the present embodiment is to improve processability such as plating penetration by forming a crosslinked structure having high uniformity. In order to form such a highly homogeneous crosslinked structure, the curing reaction is carried out by the molecular chains having appropriate motility, rather than the molecular chains exercising excessively at the stage when the curing reaction starts. It is thought to be achieved by proceeding mildly.

Therefore, it is extremely effective to hold for a certain period of time at a temperature equal to the temperature at which the curing reaction starts or at a temperature as high as 5 ° C. to 10 ° C. Such a temperature depends on the type and amount of reaction initiator used, but is 140 ° C. to 170 ° C., preferably 155 ° C. to 165 ° C. for general substrate materials.

The longer the hold time is, the higher the uniformity is, preferably 1 minute to 30 minutes, more preferably 2 minutes to 15 minutes, and further preferably 3 minutes to 10 minutes. When it is 30 minutes or less, the H ratio tends to be high without becoming too high, and when it is 1 minute or more, the hold effect tends to be sufficiently exhibited, which is preferable.

The slower the rate of temperature rise, the smaller the T value tends to be, so it is preferable, specifically, 50 ° C./min or less, more preferably 20 ° C./min or less, still more preferably 10 ° C./min or less, and particularly. It is preferably 5 ° C./min or less. From the viewpoint of adjusting the H ratio to a suitable range and from the viewpoint of industrial productivity, 2 ° C./min to 5 ° C./min is particularly preferable. Further, when the temperature is raised at a rate of 50 ° C./min or more (including direct curing at the final curing temperature without raising the temperature), the T value becomes larger than 0.64 and processability such as plating penetration is possible. May decrease.

[Curing conditions for producing a cured resin product that satisfies both H rate and T value]
It is preferable to combine the above-mentioned H rate control method and T value control method to adjust a cured resin product having an H rate of more than 10% and less than 60.0% and a T value of 0.10 to 0.64. The following conditions can be mentioned as the conditions.

1. 1. When the PPE content in the matrix constituting the composite material is prepared to be higher than 80% (for example, in the case of a composition consisting of only a crosslinked PPE resin and a radical initiator).
By setting the final curing temperature to a temperature higher than 180 ° C., a laminated board having an H ratio of more than 10% and less than 60% and a T value of 0.10 to 0.64 tends to be obtained. It is more preferably 190 ° C. or higher, further preferably 200 ° C. or higher, and particularly preferably 220 ° C. or higher.

The rate of temperature rise is preferably faster than 1 ° C./min because the H rate tends to be low, and the rate of temperature rise of 50 ° C./min or less is preferable because the T value tends to be low. It is more preferably 1.5 ° C./min or more and 20 ° C./min or less, further preferably 1.8 ° C./min or more and 5 ° C./min or less, and particularly preferably 2 ° C./min or more and 3 ° C./min or less.

The T value tends to be lowered by holding the temperature at 140 ° C. to 170 ° C. for a certain period of time during the heating and curing. The holding temperature is preferably 150 ° C. to 165 ° C., particularly preferably 158 ° C. to 165 ° C. The holding time (holding time) is preferably 1 minute to 30 minutes, more preferably 2 minutes to 20 minutes, further preferably 1 minute to 10 minutes, and particularly preferably 2 minutes to 5 minutes.

When the final curing temperature is set to 180 ° C. or lower, the H ratio is more than 10% and less than 60% by curing at 5 ° C./min or more and 50 ° C./min or less, and the T value is 0.10 to 0.64. There is a tendency to obtain a cured resin product. More preferably, it is 10 ° C./min or more and 45 ° C./min or less, and particularly preferably 20 ° C./min or more and 40 ° C./min or less.

The T value tends to be lowered by holding the temperature at 140 ° C. to 170 ° C. for a certain period of time during the heating and curing. The holding temperature is preferably 150 ° C. to 165 ° C., particularly preferably 158 ° C. to 165 ° C. The holding time is preferably 1 minute to 30 minutes, more preferably 2 minutes to 20 minutes, further preferably 1 minute to 10 minutes, and particularly preferably 2 minutes to 5 minutes.

2. When the PPE content in the matrix constituting the composite material is prepared to be 80% or less (for example, (PPE resin / TAIC) = (80/20) composition)
By setting the final curing temperature to 160 ° C. or higher and 250 ° C. or lower, a laminated board having an H ratio of more than 10% and less than 60% and a T value of 0.10 to 0.64 tends to be obtained. It is more preferably 180 ° C. or higher and 240 ° C. or lower, particularly preferably 190 ° C. or higher and 220 ° C. or lower, and particularly preferably 195 ° C. or higher and 210 ° C. or lower.

The rate of temperature rise is preferably faster than 1 ° C./min and 50 ° C./min or less. It is more preferably 1.5 ° C./min or more and 20 ° C./min or less, further preferably 1.8 ° C./min or more and 5 ° C./min or less, and particularly preferably 2 ° C./min or more and 3 ° C./min or less.

The T value tends to be lowered by holding the temperature at 140 ° C. to 170 ° C. for a certain period of time during the heating and curing. The holding temperature is preferably 150 ° C. to 165 ° C., particularly preferably 158 ° C. to 165 ° C. The holding time is preferably 1 minute to 30 minutes, more preferably 2 minutes to 20 minutes, further preferably 1 minute to 10 minutes, and particularly preferably 2 minutes to 5 minutes.

[Acryloyl group]
The PPE resin, which is a constituent requirement of the present embodiment, can contain an acrylic group as a curable functional group as an example of the embodiment.

（式（３）中、ｎは、０又は１の整数を示し、Ｒ^５は、１〜８の炭素数を有する飽和アルキレン基又は不飽和アルキレン基を示し、Ｒ^６は、水素原子又は１〜８の炭素数を有する飽和アルキル基又は不飽和アルキル基を示す。）
式（３）において、ｎは０であることが好ましく、硬化性官能基としては、β位にＣ_１−８アルキル基を有するα，β−不飽和カルボン酸エステル基が好ましい。そのような基としては、例えば、アクリレート基、メタクリレート基、エタクリレート基、プロパクリレート基、ブタクリレート基などが挙げられる。 Examples of the acrylic group in the present embodiment include functional groups represented by the following formula (3).

(In the formula (3), n represents an integer of 0 or 1, R ⁵ represents a saturated alkylene group or an unsaturated alkylene group having 1 to 8 carbon atoms, and R ⁶ is a hydrogen atom or 1 to 1 Indicates a saturated alkyl group or an unsaturated alkyl group having 8 carbon atoms.)
In the formula (3), n is preferably 0, and the curable functional group is preferably an α, β-unsaturated carboxylic acid ester group having a _{C 1-8 alkyl group at the β position.} Examples of such a group include an acrylate group, a methacrylate group, an etacrylate group, a propacrylate group, a butacrylate group and the like.

The method for introducing an acrylic group into the terminal of the polyphenylene ether is not limited, and is obtained, for example, by a reaction of forming an ester bond between the hydroxyl group at the terminal of the polyphenylene ether and a carboxylic acid having an acrylic group (hereinafter referred to as carboxylic acid). As a method for forming an ester bond, various known methods can be used. For example, a. Reaction of carboxylic acid halide with hydroxyl group at the end of polymer, b. Formation of ester bonds by reaction with carboxylic acid anhydride, c. Direct reaction with carboxylic acid, d. Examples thereof include a method based on a transesterification reaction.

[Number of curable functional groups]
The PPE resin of the present embodiment preferably has an average of 2.5 to 5.0 curable functional groups in one molecule.

The larger the number of curable functional groups (average value) in one PPE molecule, the higher the heat resistance tends to be, and the smaller the number, the higher the toughness tends to be. When the number of curable functional groups is 2.5 or more, the heat resistance of the obtained laminated board tends to be sufficient, and when it is 5.0 or less, the through-holes obtained when drilling are performed. There is a tendency that it is possible to prevent the unevenness of the inner wall surface from becoming remarkable, and it is possible to prevent the flowability of the resin at the time of producing the laminated board from being lowered and the uniformity of the laminated board from being lowered. The number of curable functional groups is more preferably 2.5 to 4.

[Curing rate]
When the PPE resin of the present embodiment contains a methacrylic acid group, the higher the curing rate of the PPE resin, the more preferable. The higher the curing rate, the higher the Tg, which tends to be lower, and the water absorption rate tends to be lower, which is preferable, and the heat impact resistance such as solder heat resistance is higher, which is preferable. Specifically, the curing rate of the PPE resin is preferably 30% or more, more preferably 50% or more, more preferably 80% or more, particularly preferably 85% or more, and particularly preferably 90% or more. .. The curing rate of the PPE resin can be 100% or less, less than 100%, 99% or less, or 98% or less.

[Measurement method of curing rate]
The curing rate is determined by performing solid-state NMR measurement of a powdered sample obtained by freeze-crushing a laminated board.

[Curable composition]
The cured resin product of the present embodiment can be obtained by curing, for example, a curable composition.
The curable composition is not particularly limited as long as it contains a PPE resin, but may contain other components such as the following peroxides, cross-linking agents, thermoplastic resins, silica fillers, and the like.

｛式（４）中、Ｒ^７及びＲ^８は、各々独立に、１〜１５の炭素数を有する１価の炭化水素基であり、Ｒ^７及びＲ^８の少なくとも一方は、芳香環を有する。｝

｛式（５）中、Ｒ^９及びＲ^１１は、各々独立に、１〜１５の炭素数を有する１価の炭化水素基であり、Ｒ^１０は、１〜１５の炭素数を有する２価の炭化水素基であり、Ｒ^９、Ｒ^１０、及びＲ^１１から成る群より選択される少なくとも一つは、芳香環を有する。｝ (Peroxide)
As an example, the curable composition of the present embodiment can contain a peroxide as a curing agent for a PPE resin containing a carbon-carbon unsaturated double bond such as a methacryl group. Examples of such peroxides include aromatic ring-containing dialkyl peroxides having a structure represented by the following formula (4) or (5).

{In formula (4), R ⁷ and R ⁸ are independently monovalent hydrocarbon groups having 1 to 15 carbon atoms, and ^{at least one of R 7} and R ⁸ has an aromatic ring. }

{In formula (5), R ⁹ and R ¹¹ are independently monovalent hydrocarbon groups having 1 to 15 carbon atoms, and R ¹⁰ is a divalent hydrocarbon group having 1 to 15 carbon atoms. A hydrocarbon group, at least one selected from the group consisting of ^{R 9} , R ¹⁰ , and R ^{11 has an aromatic ring.} }

In the formula (4) or (5), examples of the monovalent hydrocarbon group having 1 to 15 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group and sec-butyl. Linear or branched alkyl groups such as group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, cyclopropyl, cyclobutyl group, cyclopentyl group, cyclohexyl. Examples thereof include a cyclic alkyl group such as a group, an aryl group such as a phenyl group, a trill group and a naphthyl group, and an aralkyl group such as a benzyl group and a benzyl ethyl group. Examples of the divalent hydrocarbon group having 1 to 15 carbon atoms include an alkylene group such as a methylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, an ethylethylene group, a pentamethylene group and a hexamethylene group. , Aylene group such as a phenylene group and a naphthylene group.

In formula (4), ^{at least one of R 7} and R ⁸ has an aromatic ring. In formula (5), at least one selected from the group consisting of ^{R 9} , R ¹⁰ , and R ^{11 has an aromatic ring.} Examples of the aromatic ring include a benzene ring and a naphthalene ring, and a benzene ring is preferable for the reason described later.

In the curable composition and the cured resin product of the present embodiment, the heat resistance of the cured laminated plate tends to be improved as the amount of peroxide used is reduced. This is presumed for the following reasons, but this presumption does not limit the present invention in any way. That is, the unit structures of the aromatic ring and the polyphenylene ether in the aromatic ring-containing dialkyl peroxide are presumed to have relatively high compatibility from the similarity of the structures. As a result, the aromatic ring-containing dialkyl peroxide functions as a reaction initiator that can increase the cross-linking density of the cross-linked structure formed by the reaction between the polyphenylene ether and the cross-linking agent even if the content is small. Is presumed to be. Further, as will be described later, even if the content of the aromatic ring-containing dialkyl peroxide is small, the ability to increase the crosslink density can reduce the water absorption rate of the cured product, and further contribute to low dielectric constant and low dielectric loss tangent. preferable.

Examples of the aromatic ring-containing dialkyl peroxide which is an organic peroxide include t-butylcumyl peroxide, bis (1-tert-butylperoxy-1-methylethyl) benzene, and 2-phenyl-2-[(2-). Phenylpropan-2-yl) Peroxy] Propane can be mentioned. These organic peroxides may be used alone or in combination of two or more.

Among these, the aromatic ring-containing dialkyl peroxide is bis (1-tert-butylperoxy-1-) from the viewpoint of being more excellent in heat resistance, mechanical properties and electrical properties (low dielectric constant and low dielectric loss tangent) when cured. Methylethyl) benzene is preferred.

(Crosslinking agent)
For the curable composition and the cured resin product of the present embodiment, any cross-linking agent having an ability to cause or promote a cross-linking reaction can be used.

From the viewpoint of the cross-linking reaction, the cross-linking agent preferably has two or more carbon-carbon unsaturated double bonds in one molecule on average. The cross-linking agent may be composed of one kind of compound or two or more kinds of compounds. The "carbon-carbon unsaturated double bond" as used herein means a double bond located at the end branched from the main chain when the cross-linking agent is a polymer or an oligomer. Examples of carbon-carbon unsaturated double bonds include 1,2-vinyl bonds in polybutadiene.

Examples of the cross-linking agent include a trialkenyl isocyanurate compound such as triallyl isocyanurate (TAIC), a trialkenyl cyanurate compound such as triallyl cyanurate (TAC), and a polyfunctional methacrylate having two or more methacryl groups in the molecule. Compounds, polyfunctional acrylate compounds having two or more acrylic groups in their molecules, polyfunctional vinyl compounds having two or more vinyl groups in their molecules such as polybutadiene, and vinylbenzyl compounds such as divinylbenzene having vinylbenzyl groups in their molecules. , 4,4'-Bismaleimide diphenylmethane and the like, which include polyfunctional maleimide compounds having two or more maleimide groups in the molecule. These cross-linking agents may be used alone or in combination of two or more. The cross-linking agent preferably contains at least one compound selected from the group consisting of triallyl cyanurate, triallyl isocyanurate, and polybutadiene. When the cross-linking agent contains at least one compound described above, the cross-linking density becomes higher during the curing reaction (cross-linking reaction), which tends to further improve the heat resistance of the cured resin product. ..

(Thermoplastic resin)
The curable composition and the cured resin of the present embodiment may contain a thermoplastic resin as long as the object of the present embodiment is not impaired. The thermoplastic resin is a hydrogenated product obtained by hydrogenating a block copolymer of a vinyl aromatic compound and an olefin-based alkene compound and a hydrogenated product thereof (a block copolymer of a vinyl aromatic compound and an olefin-based alkene compound). It is preferably one or more selected from the group consisting of block copolymers) and homopolymers of vinyl aromatic compounds. The content of the unit derived from the vinyl aromatic compound of the block copolymer or its hydrogenated product is preferably 20% by mass or more. The vinyl aromatic compound may have an aromatic ring and a vinyl group in the molecule, and examples thereof include styrene. The olefin-based alkene compound may be an alkene having a linear or branched structure in the molecule, and examples thereof include ethylene, propylene, butylene, isobutylene, butadiene, and isoprene. Among these, the thermoplastic resin is a styrene-butadiene block copolymer, a styrene-ethylene-butadiene block copolymer, a styrene-ethylene-butylene block copolymer, and styrene from the viewpoint of being more excellent in compatibility with the polyphenylene ether. -Butadiene-butylene block copolymer, styrene-isoprene block copolymer, styrene-ethylene-propylene block copolymer, styrene-isobutylene block copolymer, hydrogenated product of styrene-butadiene block copolymer, styrene-ethylene From the group consisting of a hydrogenated product of a butadiene block copolymer, a hydrogenated product of a styrene-butadiene-butylene block copolymer, a hydrogenated product of a styrene-isoprene block copolymer, and a homopolymer of styrene (polystyrene). It is preferably one or more selected, and more preferably one or more selected from the group consisting of a styrene-butadiene block copolymer, a hydrogenated additive of a styrene-butadiene block copolymer, and polystyrene. .. Further, when the content of the unit derived from the vinyl aromatic compound of the block copolymer or its hydrogenated product is 20% by mass or more, the compatibility with polyphenylene ether is further improved, and the adhesion strength with the metal foil is further improved. Tends to improve further.

The hydrogenation rate of the hydrogenated product is not particularly limited, and a part of carbon-carbon unsaturated double bonds derived from the olefin-based alkene compound may remain.

The weight average molecular weight of the thermoplastic resin is preferably 3000 to 300,000. When the weight average molecular weight is 30,000,000 or more, the laminated board of the present embodiment tends to have further excellent heat resistance. Since the weight average molecular weight is 300,000 or less, the laminated board of the present embodiment tends to have better resin fluidity at the time of heat molding. The weight average molecular weight is determined by the method described in Examples described later.

The content of the thermoplastic resin is preferably 2 to 20 parts by mass with respect to 100 parts by mass in total of the polystyrene ether and the cross-linking agent. When the content is 2 parts by mass or more, the laminated board of the present embodiment tends to be more excellent in low dielectric constant, low dielectric loss tangent property and adhesion to the metal foil. When the content is 20 parts by mass or less, the laminated board of the present embodiment tends to have more excellent resin fluidity at the time of heat molding, and therefore tends to have excellent uniformity.

(Flame retardants)
The curable composition and the cured resin product of the present embodiment may contain a flame retardant as long as the object of the present embodiment is not impaired. The flame retardant is not particularly limited as long as it is incompatible with PPE or a cross-linking agent even after curing from the viewpoint of improving heat resistance. Examples of the flame retardant include inorganic flame retardants such as antimony trioxide, aluminum hydroxide, magnesium hydroxide and zinc borate, hexabromobenzene, decabromodiphenylethane, 4,4-dibromobiphenyl, ethylenebistetrabromophthalimide and the like. Examples include phosphorus-based flame retardants such as aromatic bromine compounds, resorcinol bis-diphenyl phosphate, and resorcinol bis-dixylenyl phosphate. These flame retardants may be used alone or in combination of two or more. Among these, the flame retardant is preferably decabromodiphenylethane from the viewpoint of further excellent low dielectric constant and low dielectric loss tangent property of the laminated board.

The content of the flame retardant is not particularly limited, but from the viewpoint of maintaining the flame retardancy of UL standard 94V-0 level, it is preferably 5 parts by mass or more with respect to a total of 100 parts by mass of the polyphenylene ether resin and the cross-linking agent. It is more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more. Further, from the viewpoint that the dielectric constant and the dielectric loss tangent of the obtained cured product can be kept low, the content is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and further preferably 40 parts by mass or less.

(Silica filler)
The curable composition and the cured resin product of the present embodiment may contain a silica filler. Examples of the silica filler include natural silica, fused silica, synthetic silica, amorphous silica, Aerosil, and hollow silica. The content of the silica filler may be about 10 to 100 parts by mass with respect to 100 parts by mass in total of the polyphenylene ether and the cross-linking agent. Further, the surface of the silica filler may be surface-treated with a silane coupling agent or the like.

(Other ingredients)
The curable composition and the cured resin product of the present embodiment may contain a heat stabilizer, an antioxidant, a UV absorber, a surfactant, a lubricant, other additives and the like as other components.

[Manufacturing method of cured resin product]
As an example of the present embodiment, the cured resin product of the present embodiment is obtained by impregnating a base material with a varnish composition obtained by dissolving the above-mentioned curable composition in an organic solvent, and then using a hot air dryer or the like to impregnate the solvent component. Can be produced by curing the prepreg obtained by drying and removing the prepreg. Curing of the curable composition described above is preferably carried out under conditions of a temperature range of 140 ° C. to 170 ° C. and a hold time of 1 minute to 30 minutes.

As the base material, various glass cloths such as roving cloth, cloth, chopped mat, and surface mat; asbestos cloth, metal fiber cloth, and other synthetic or natural inorganic fiber cloth; all aromatic polyamide fibers, all aromatic polyesters. Woven or non-woven fabrics obtained from liquid crystal fibers such as fibers and polybenzoxazole fibers; natural fiber cloths such as cotton cloth, linen cloth and felt; carbon fiber cloth, kraft paper, cotton paper, cloth obtained from paper-glass mixed fiber yarn, etc. Natural cellulose-based base material; polytetrafluoroethylene porous film and the like can be mentioned. These base materials may be used alone or in combination of two or more.

The base material is preferably glass cloth. The dielectric constant of the glass cloth is preferably 5.1 or less, and more preferably 4.9 or less. Since the base material is glass cloth, the heat resistance of the laminated board can be further improved, and the coefficient of thermal expansion tends to be further reduced. When the dielectric constant of the glass cloth is 5.1 or less, the increase in the dielectric constant of the laminated plate tends to be further suppressed as compared with the E glass cloth or the like described later.

The dielectric constant of the glass cloth is a value at 10 GHz measured by the cavity resonance method described later using a sample processed into a lump instead of the cloth.

The prepreg preferably contains 5.5 to 8.5 parts by mass of boron with respect to 100 parts by mass of the glass cloth. As a result, the prepreg can further reduce the coefficient of thermal expansion. Further, when the boron content is 5.5 mass or more, the dielectric constant and the dielectric loss tangent can be further reduced, and the drilling workability tends to be further improved. When the boron content is 8.5 parts by mass or less, the heat resistance tends to be further improved, and the fluctuation range of the dielectric constant and the dielectric loss tangent due to environmental changes such as humidity tends to be further reduced. .. The cause is considered to be derived from the manufacturing process of the glass cloth, but this speculation does not limit the present invention in any way.

As a method for measuring the boron content of the glass cloth, the method described in Examples described later is used.

[Metal-clad laminate]
The cured resin product of the present embodiment is suitably used as a material for an electronic substrate as a metal-clad laminate in which a metal foil is adhered to both sides of the prepreg and a metal foil, which are laminated and cured at the manufacturing stage. Can be done. Examples of the metal foil include aluminum foil and copper foil, and among these, copper foil is preferable because it has low electrical resistance. As a method for producing a metal-clad laminate, for example, a composite composed of a curable composition and a base material (for example, the above-mentioned prepreg) is formed, and after laminating this with a metal foil, the curable composition is formed. A method of obtaining a metal-clad laminate in which a cured product laminate and a metal foil are laminated can be mentioned. The composite to be combined with the metal foil may be one or more, and the metal foil is laminated on one side or both sides of the composite depending on the application and processed into a laminated plate. One of the particularly preferable uses of the metal-clad laminate is a printed wiring board. In the printed wiring board, it is preferable that at least a part of the metal foil is removed from the metal-clad laminate.

[Printed circuit board]
In the printed wiring board of the present embodiment, it is preferable that a part of the metal foil is removed from the metal-clad laminate. The printed wiring board of the present embodiment can be typically formed by a method of pressure heating molding using the prepreg of the present embodiment described above. Examples of the base material include the same materials as those described above for the prepreg. The printed wiring board of the present embodiment has excellent heat resistance and electrical characteristics (low dielectric constant and low dielectric loss tangent) by being composed of the cured resin product of the present embodiment, and further, electricity due to environmental changes. It is possible to suppress fluctuations in characteristics, and it also has excellent insulation reliability and mechanical properties.

Hereinafter, the present embodiment will be specifically described with reference to Examples, but the present embodiment is not limited to the following Examples.

The physical characteristics described in the following Examples and Comparative Examples were evaluated by the following measurement methods.

(1) Number average molecular weight of PPE resin, weight average molecular weight of thermoplastic resin Using GPC analysis, the number average molecular weight of PPE resin and weight average molecular weight of thermoplastic resin are obtained by comparison with the elution time of standard polystyrene with known molecular weight. rice field. Specifically, after preparing a measurement sample having a sample concentration of 0.2 w / vol% (solvent: chloroform), HLC-8220 GPC (manufactured by Showa Denko KK) was used as the measuring device, and the column: Shodex GPC KF-405L HQ. The molecular weight was measured under the conditions of × 3 (manufactured by Showa Denko KK), eluent: chloroform, injection amount: 20 μL, flow rate: 0.3 mL / min, column temperature: 40 ° C., detector: RI.

(2) Average number of terminal functional groups of PPE resin The average number of terminal functional groups per molecule of PPE resin was determined by the following method. That is, a sample obtained by adding a tetramethylammonium hydroxide solution to a methylene chloride solution of PPE in accordance with the method described in "Polymer Papers, vol.51, No. 7 (1994), p. 480". The change in absorbance at a wavelength of 318 nm was measured with an ultraviolet-visible absorptiometer. From this measured value, the number of phenolic hydroxyl groups before and after terminal denaturation of PPE was determined. Further, the number of molecules of PPE (number average number of molecules) was determined by using the number average molecular weight of PPE obtained by the method (1) above and the mass of PPE.
From these values, the average number of phenolic hydroxyl groups per PPE molecule before and after denaturation was determined according to the following formula (VI).
Average number of phenolic hydroxyl groups per molecule = number of phenolic hydroxyl groups / number average number of molecules (VI)
The average number of terminal functional groups after denaturation was determined according to the following formula (VII).
Average number of terminal functional groups per molecule = average number of phenolic hydroxyl groups before denaturation-average number of phenolic hydroxyl groups after denaturation (VII)

(3) Dielectric constant and dielectric loss tangent of the laminated plate and glass sample The dielectric constant and dielectric loss tangent of the laminated plate and glass sample at 10 GHz were measured by the cavity resonance method. As a measuring device, a network analyzer (N5230A, manufactured by Agent Technologies) and a cavity resonator (Cavity Resonator CP series) manufactured by Kanto Electronics Applied Development Co., Ltd. were used. A laminated board or a glass sample having a thickness of about 0.5 mm was cut into a size of about 2 mm in width and 50 mm in length so that the warp threads of the glass cloth were on the long side of the laminated board. Next, the sample was placed in an oven at 105 ° C. ± 2 ° C., dried for 2 hours, and then allowed to stand in an environment with a temperature of 23 ° C. and a relative humidity of 50 ± 5% for 96 ± 5 hours. Then, the dielectric constant and the dielectric loss tangent of the sample were measured by using the above measuring device in an environment of a temperature of 23 ° C. and a relative humidity of 50 ± 5%.

(4) Glass transition temperature (Tg) of cured resin
The dynamic viscoelasticity of the cured resin contained in the laminated plate was measured, and the temperature at which tan δ was maximized was determined as the glass transition temperature (Tg). A dynamic viscoelastic device (EXSTAR DMS6100, manufactured by Hitachi High-Tech Science Corporation) was used as the measuring device. A laminated plate having a thickness of about 0.6 mm was cut into a test piece having a length of about 40 mm and a width of about 5 mm so that the warp of the glass cloth described later had a long side. The dynamic viscoelasticity of the test piece was measured from room temperature to 300 ° C. under the bending mode and the condition of frequency: 1 Hz, and the peak of tan δ was read as Tg.

(5) Uniformity parameter (T value) of cured resin product
The dynamic viscoelasticity of the cured resin contained in the laminated plate was measured, and the temperature at which tan δ was maximized was determined as the glass transition temperature (Tg). A dynamic viscoelastic device (EXSTAR DMS6100, manufactured by Hitachi High-Tech Science Corporation) was used as the measuring device. A laminated plate having a thickness of about 0.6 mm was cut into a test piece having a length of about 40 mm and a width of about 5 mm so that the warp of the glass cloth described later had a long side. The dynamic viscoelasticity of the test piece was measured from room temperature to 300 ° C. under the bending mode and the condition of frequency: 1 Hz, and the peak of tan δ was read as Tg.
The uniformity parameter (T value) was defined by the following formula (I) from the ratio of the tan δ value at Tg (° C.) and the tan δ value at (Tg + 30) ° C.
T value = tanδ _{(Tg + 30)} / tanδ _(Tg) (I)

(6) Curing rate of cured resin product Each laminated board obtained in Examples and Comparative Examples was cooled with liquid nitrogen for 20 minutes using a Cryogenic Sample Crusher (manufactured by Nippon Analytical Industry Co., Ltd.), and then 60 at 50 Hz. The sample was freeze-crushed by vibrating while cooling for 1 minute to obtain a powdery sample. The sample was placed in a 4 mmφ sample tube, set in a solid-state NMR apparatus Biospin Avance 500WB (manufactured by Bruker), and rotated at a high speed of 12,000 Hz at a magic angle angle. As a measurement method, the CP / MAS method was used, and solid ¹³ C-NMR measurement was performed with a waiting time of 5 seconds and an integration number of 2024 times.

The peak (peak A) observed at 160 to 170 ppm is defined as the carbonyl carbon of the methacrylic group before addition, and the peak (peak B) observed at 170 to 180 ppm is defined as the carbonyl carbon of the methacrylic group after addition, and is calculated by the following formula (VIII). The value obtained was taken as the curing rate.
(Area of peak B) / {(area of peak A) + (area of peak B)} × 100 [%] (VIII)

(7) Hard segment ratio of cured resin [H ratio]
Each laminated plate obtained in Examples and Comparative Examples was put into a sample tube and introduced into a measuring device, measured by a pulse NMR solid echo method under the conditions shown below, and the obtained free induction decay curve was obtained by the following method. The three components were approximated and the lowest motility component (A), the intermediate motility component (B), the most motility component (C), and the composition ratio were calculated.
Measuring device: Mizuspec mp20 (manufactured by Bruker)
Observation nucleus: ¹ H (frequency 20 MHz)
Measurement: Spin-spin relaxation time Measurement method: Solid echo method Measurement temperature: 30 ° C (Measurement was started 5 minutes after reaching the measurement temperature.)
Waiting time: 1 sec.

Analytical method: Fitting was performed by Igor (manufactured by WaveMetrics) using the following formula (IX), and the three components were approximated.
M (t) = Ia × exp (− (1/2) × (t / Ta) 2) + Ib × exp (−t / Tb) + Ic × exp (−t / Tc) (IX)
{In the formula, Ia: Signal strength of component A Ta: Relaxation time of component A Ib: Signal strength of component B Tb: Relaxation time of component B Ic: Signal strength of component C Tc: Relaxation time of component C t: Observation time }

From the signal strength of each component, the composition fraction (%) of each component can be calculated by the following calculation.
Composition fraction of component A (%) Ca = Ia / (Ia + Ib + Ic) x 100
Composition fraction of component B (%) Cb = Ib / (Ia + Ib + Ic) x 100
Composition fraction of C component (%) Cc = Ic / (Ia + Ib + Ic) x 100
The composition fraction of the A component obtained by the above formula was defined as the hard segment ratio (H ratio), and the composition fraction of the C component was defined as the soft segment ratio.

(8) Drill workability test Using a drill with a diameter of 0.3 mm (NHU L020W manufactured by Union), a copper-clad laminate under the conditions of rotation speed: 150,000 rpm, feed rate: 3 m / min, and number of layers: 1 sheet. An evaluation substrate was prepared by drilling 1,000 hits, and the roughness of the inner wall of the drill hole and the plating penetration property were evaluated. The inner wall roughness was evaluated by electroless copper plating (plating thickness: 20 μm) and the maximum value of the unevenness of the through-hole cross section. When the maximum value of the unevenness of the through-hole cross section was less than 10 μm, it was evaluated as ◯, when it was 10 μm or more and less than 15 μm, it was evaluated as Δ, and when it was 15 μm or more, it was evaluated as ×.
The plating penetration property is evaluated by measuring the maximum value of the plating penetration length, and when the maximum value of the plating penetration length is less than 90 μm, it is 〇, when it is 90 μm or more and less than 100 μm, it is Δ, and when it is 100 μm or more. The case was evaluated as x.

(9) Hot oil test for thermal shock (oil dip test)
The copper-clad laminate test piece, which has been drilled and electroless copper-plated, is immersed in oil at 260 ° C for 5 seconds and in oil at 20 ° C for 20 seconds alternately for 100 cycles, and after the test. The distortion of the inner wall, the dimensional change, and the cross-sectional observation of the through-hole plating were performed.

The unevenness of the inner wall was evaluated as ◯ when no distortion was observed on the inner wall of the through hole after the test, and as × when distortion was observed.

Regarding the evaluation of dimensional change, 〇 when no dimensional change was observed after the test, × when dimensional change such as swelling of the laminated board was observed after the test, and when a swelling of slightly less than 1 μm was observed at the maximum. Was evaluated as Δ.

Regarding the evaluation of plating cracks, in the cross-sectional observation of the through hole, the case where neither the corner crack nor the inner wall crack occurred was evaluated as ◯, and the case where any of them occurred was evaluated as ×.

The components used in the following examples and comparative examples are as follows.

"PPE"
-Terminal methacrylic acid modified PPE "Product name SA9000"
(Manufactured by Sabic Innovative Plastics, Mn: 2760, Mw / Mn: 1.44, number of terminal functional groups: 2.0)

"Crosslinking agent"
・ TAIC (manufactured by Nihon Kasei Co., Ltd., molecular weight: 249.7, number of unsaturated double bonds: 3)

"Organic peroxide"
-Α, α'-di (tert-butylperoxy) diisopropylbenzene "Product name PerbutylP" (manufactured by NOF CORPORATION)

"Base material"
・ L glass cloth (manufactured by Asahi Schebel, style: 2116, boron: 7.3 parts by mass, permittivity: 4.9)

The curing conditions applied in Examples and Comparative Examples are as follows.

"Curing condition 1"(PPE> 80%, curing at 200 ° C)
While constantly applying a pressure of 40 kg / cm ^{2 to} the test piece, heat it from room temperature to 50 ° C. at a heating rate of 2 ° C./min in a vacuum state and hold it for 1 minute, and then from 50 ° C. to a heating rate of 2 ° C./min. It was heated to 160 ° C. and held for 3 minutes, then heated again at a heating rate of 2 ° C./min, and after reaching 200 ° C., the temperature was maintained at 200 ° C. for 60 minutes.

"Curing condition 2"(PPE> 80%, cured at 180 ° C)
While constantly applying a pressure of 40 kg / cm ^{2 to} the test piece, heat it from room temperature to 50 ° C. at a heating rate of 2 ° C./min in a vacuum state and hold it for 1 minute, and then from 50 ° C. to a heating rate of 2 ° C./min. It was heated to 160 ° C. and held for 3 minutes, then heated again at a heating rate of 2 ° C./min, reached 180 ° C., and then maintained at 180 ° C. for 60 minutes.

"Curing condition 3"
With a press heated to 200 ° C., the test piece was maintained in a vacuum state for 4 hours while constantly applying a pressure of ^{40 kg / cm 2.}

"Curing condition 4"
While applying a pressure of 10 kg / cm ^{2 to} the test piece, heat from room temperature to 130 ° C. at a heating rate of 3 ° C./min in a vacuum state, and then apply a pressure of ^{40 kg / cm 2 to the test piece.} , The temperature was raised to 200 ° C. at a heating rate of 3 ° C./min. After reaching 200 ° C., the temperature was maintained at 200 ° C. for 60 minutes while applying a pressure of 40 kg / cm ^2.

"Curing condition 5" (PPE 80% or less, 200 ° C. curing)
Without applying pressure to the test piece, heat from room temperature to 50 ° C. at a temperature rise rate of 2 ° C./min for 1 minute, and then heat from 50 ° C. to 160 ° C. at a temperature rise rate of 2 ° C./min. , while applying a pressure of 40 kg / cm ² on the test piece at a stage has been reached 160 ° C., 160 ° C. the temperature was kept 3 minute hold, while applying a subsequent pressure of 40 kg / cm ² on the test piece, the temperature again After heating at a temperature rate of 2 ° C./min and reaching 200 ° C., the test piece was maintained at a temperature of 200 ° C. for 60 minutes while applying a pressure of ^{40 kg / cm 2.}

"Curing condition 6" (PPE 80% or less, 180 ° C curing)
Without applying pressure to the test piece, heat from room temperature to 50 ° C. at a temperature rise rate of 2 ° C./min for 1 minute, and then heat from 50 ° C. to 160 ° C. at a temperature rise rate of 2 ° C./min. , while applying a pressure of 40 kg / cm ² on the test piece at a stage has been reached 160 ° C., 160 ° C. the temperature was kept 3 minute hold, while applying a subsequent pressure of 40 kg / cm ² on the test piece, the temperature again After heating at a temperature rate of 2 ° C./min and reaching 180 ° C., the temperature was maintained at 180 ° C. for 60 minutes while applying a pressure of ^{40 kg / cm 2 to the test piece.}

"Curing condition 7"(PPE> 80%, 1 ° C / min, 200 ° C curing)
While constantly applying a pressure of 40 kg / cm ^{2 to} the test piece, heat it from room temperature to 200 ° C. at a heating rate of 1 ° C./min in a vacuum state, and after reaching 200 ° C., keep the temperature at 200 ° C. for 60 minutes. Maintained.

"Curing condition 8"
With a press heated to 180 ° C., the test piece was maintained in a vacuum state for 4 hours while constantly applying a pressure of ^{40 kg / cm 2.}

｛式中、ｌ、ｍ、及びｎは、下記数平均分子量を満たすように任意に選択される数である｝
で表されるような構造を有するＰＰＥ（以下、ＰＰＥ１という）であると確認できた。ＧＰＣ測定の結果、得られたＰＰＥ１のポリスチレン換算での分子量はＭｎ＝１，５００であった。また、ＰＰＥ１の２０％メチルエチルケトン溶媒中での溶液粘度は１２５ｃＰｏｉｓｅであった。 <Synthesis Example 1: Synthesis of PPE1>
A three-way cock was attached to a 500 ml three-necked flask, and a Dimroth and an isobaric dropping funnel were further installed. After replacing the inside of the flask with nitrogen, 100 g of the raw material PPE S202A, 200 g of toluene, and 12.8 g of 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane as a polyfunctional phenol were added. .. A thermometer was installed in the flask, and the flask was heated to 90 ° C. in an oil bath while stirring with a magnetic stirrer to dissolve the raw material PPE. As an initiator, 37.5 g of a 40% metaxylene solution (Nippon Oil Co., Ltd .: Niper BMT) of a mixture of benzoyl peroxide, benzoyl m-methylbenzoyl peroxide, and m-toluyl peroxide was diluted to 87.5 g of toluene and added dropwise at isobaric pressure. I put it in the funnel. After the temperature in the flask was lowered to 80 ° C., the initiator solution was started dropping into the flask to start the reaction. The initiator was added dropwise over 2 hours, and after the addition, the temperature was raised to 90 ° C. again, and stirring was continued for 4 hours. After the reaction, the polymer solution was added dropwise to methanol, reprecipitated, and then filtered off from the solution to recover the polymer. Then, this was dried under vacuum at 100 ° C. for 3 hours. ¹ It was confirmed by 1 H-NMR that the small molecule phenol was incorporated into the polymer and the peak of the hydroxyl group disappeared. The ^{polymer obtained from this 1 1} H-NMR measurement result has the following formula:

{In the formula, l, m, and n are numbers arbitrarily selected to satisfy the following number average molecular weights}
It was confirmed that the PPE has a structure as represented by (hereinafter referred to as PPE1). As a result of GPC measurement, the molecular weight of the obtained PPE1 in terms of polystyrene was Mn = 1,500. The solution viscosity of PPE1 in a 20% methyl ethyl ketone solvent was 125 cPoise.

<Synthesis Example 2: Synthesis of modified PPE1>
80 g of toluene and 26 g of PPE1 synthesized above were mixed and heated to about 85 ° C. 0.55 g of dimethylaminopyridine was added to the heated mixture. When all the solids seemed to be dissolved, 4.9 g of methacrylic anhydride was gradually added to the lysate. The resulting solution was maintained at 85 ° C. for 3 hours with continuous mixing. The solution was then cooled to room temperature to give a toluene solution of methacrylate-modified PPE.

｛式中、ｌ、ｍ、及びｎは、下記数平均分子量を満たすように任意に選択される数である｝
で表されるような構造を有する変性ＰＰＥ（以下、変性ＰＰＥ１という）であると確認できた。 A part of the solution was collected, dried, and then ¹ H-NMR measurement was carried out. Since the peak derived from the hydroxyl group of PPE had disappeared, it was judged that the reaction was proceeding, and the purification operation was started. 120 g of the toluene solution of the methacrylate-modified PPE was added dropwise to 360 g of methanol vigorously stirred with a magnetic stirrer in a 1 L beaker over 30 minutes. The obtained precipitate was filtered under reduced pressure with a membrane filter and then dried to obtain 38 g of a polymer. ^{The 1} H-NMR measurement result of the dried polymer is shown in FIG. It was confirmed that the peak derived from the hydroxyl group of PPE around 4.5 ppm disappeared and the peak derived from the olefin of the methacrylic group was expressed around 5.75 ppm. In addition, since the peaks derived from dimethylaminopyridine, methacrylic anhydride, and methacrylic acid have almost disappeared by GC measurement, it is judged that the peaks derived from the methacrylic group of NMR are those of the methacrylic group bonded to the PPE terminal. bottom. From this result, the obtained polymer has the following formula:

{In the formula, l, m, and n are numbers arbitrarily selected to satisfy the following number average molecular weights}
It was confirmed that it was a modified PPE having a structure as represented by (hereinafter referred to as modified PPE1).

Moreover, as a result of GPC measurement, the molecular weight of the obtained modified PPE1 in terms of polystyrene was Mn = 1,600. Further, the average number of terminal functional groups of the modified PPE1 was calculated to be 2.5 or more according to the above formula (VII). Further, the solution viscosity of the modified PPE1 in a 20% methyl ethyl ketone solvent was 131 cPoise.

<Synthesis Example 3: PPE-R>
Pre-arranged 0.1590 g in a 1.5 liter jacketed reactor with a spudger for introducing oxygen-containing gas at the bottom of the reactor, stirring turbine blades and baffles, and a reflux condenser on the vent gas line above the reactor. A mixture of cuprous oxide and 2.2854 g of 47% hydrogen bromide, 0.4891 g of N, N'-di-t-butylethylenediamine, 7.1809 g of dimethyl-n-butylamine, and 3.3629 g of di. -N-Butylamine, 666.52 g of toluene, 265.6 g of 2,6-dimethylphenol and 54.40 g of 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane were added. Then, with vigorous stirring, air was started to be introduced into the reactor at a rate of 2.19 L / min from the spudger, and at the same time, the polymerization temperature was adjusted by passing a heat medium through the jacket so as to maintain 40 ° C. 160 minutes after the start of introducing air, the aeration of air was stopped, and 1.0053 g of ethylenediamine tetraacetate tetrasodium salt tetrahydrate (reagent manufactured by Dojin Chemical Laboratory) was added to this polymerization mixture as a 100 g aqueous solution. It was warmed to 70 ° C. After heat-retaining at 70 ° C. for 2 hours to extract the catalyst and remove diphenoquinone by-produced, the mixed solution was transferred to a centrifuge manufactured by Sharpless Co., Ltd. to obtain an unmodified polyphenylene ether composition solution (organic phase) and a catalyst metal. Was separated into the transferred aqueous phase. The obtained unmodified polyphenylene ether composition solution was transferred to a concentrated tank with a jacket, and toluene was distilled off until the solid content in the unmodified polyphenylene ether composition solution became 55% by mass for concentration. Then, toluene was further distilled off using an oil bath set at 230 ° C. and a rotary evaporator, and the solid content was dried to obtain unmodified polyphenylene ether (PPE-R).

<Synthesis Example 4: Synthesis of Modified PPE-S>
A stir bar was placed in a 300 ml three-necked flask, a Dimroth condenser with a three-way cock was installed in the main tube, and a rubber stopper with a thermometer was attached to one side tube. 20 g of PPE-R obtained in Synthesis Example 3 was charged from the other side tube, and a rubber stopper was attached. After the inside of the flask was replaced with nitrogen, it was dissolved in 140 g of toluene using a syringe while stirring the inside with a magnetic stirrer, and then 7.86 g of triethylamine was added. Then, 4.06 g of methacryloyl chloride was collected in a syringe and dropped into the system from a rubber stopper. After the completion of the dropping, stirring was continued at room temperature for 3 hours, the flask was heated in an oil bath, and the reaction was continued in a reflux state. Heating was stopped when 2 hours had passed from the start of reflux, and after returning to room temperature, 1.00 g of methanol was added to stop the reaction. Next, the reaction solution was concentrated to a solid content concentration of 20% by weight, and then washed with water using ion-exchanged water having the same weight as the concentrated solution. Then, the water tank was removed, and the organic layer was added dropwise to methanol (7 times the weight of the organic layer) with stirring. The precipitate was then filtered and the filtrate was vacuum dried at 110 ° C. for 1 hour to give PPE-S. The number average molecular weight of the obtained PPE-S was 2400, and Mw / Mn was 1.38.

<Example 1>
99 parts by mass of PPE-S was added to 72 parts by mass of toluene and stirred until PPE-S was dissolved, then 1 part by mass of perbutyl P was added and sufficiently stirred so that the solid content ratio became 58%. If necessary, toluene was added to the mixture to obtain a uniformly dissolved varnish. After impregnating this varnish with L glass cloth (manufactured by Asahi Schebel, style: 2116), excess varnish is scraped off by passing it through a 0.3 mm slit, and dried in a drying oven at 105 ° C. for a predetermined time. , Toluene was removed to obtain a prepreg. The solid content of the resin composition in the prepreg was calculated by cutting out the prepreg to a predetermined size and comparing the weight of the glass cloth with the weight of the glass cloth, which was 58% by mass. Six pieces of this prepreg are stacked, and copper foil (manufactured by Furukawa Electric Co., Ltd., thickness 12 μm, F2-WS) is superposed on both sides of the superposed prepreg, and a vacuum press is performed to laminate the prepreg. I got a board. This vacuum pressing step was performed under curing condition 1. Next, a laminated plate was obtained by removing the copper foil from the copper-clad laminate by etching. Table 1 shows the evaluation results of the copper-clad laminate and the laminate.
FIG. 1 shows a cross-sectional observation photograph of the through hole before the hot oil test of Example 1.
FIG. 2 shows a cross-sectional observation photograph of the through hole after the hot oil test of Example 1.
Example 1 had no problem with inner wall distortion, dimensional change, and through-hole plating.

<Example 2-7>, <Comparative Example 1-9>
A varnish having a solid content of 58% was prepared with the component ratios shown in Tables 1 and 2 and toluene, and cured under the curing conditions shown in Tables 1 and 2, respectively, to obtain a copper-clad laminate, which was the same as in Example 1. Evaluated.

FIG. 3 shows a cross-sectional observation photograph of the through hole before the hot oil test of Comparative Example 1.
FIG. 4 shows a cross-sectional observation photograph of the through hole after the hot oil test of Comparative Example 1.
In FIG. 4, distortion was observed on the inner wall of the through hole, a dimensional change was observed in which the laminated plate swelled in the thickness direction, and corner cracks were observed in the through hole plating.
FIG. 5 shows the TMA measurement results of the laminated boards of Example 1 and Comparative Example 1. No significant dimensional change was confirmed in the laminated board of Example 1 other than the change in expansion coefficient due to Tg, but the laminated board of Comparative Example 1 had large and irregular dimensions in a region having a high elastic modulus near Tg. Changes were observed.

From the results of Tables 1 and 2, it can be seen that the cured product and the laminated board according to the present embodiment have excellent workability, heat impact resistance, dielectric constant, and dielectric loss tangent.

The cured resin product of the present invention is suitable as an insulating material for an electronic circuit board of an electronic device that utilizes a high frequency band, for example.

Claims (10)

A cured resin product having a crosslinked structure in which a polyphenylene ether resin containing a curable functional group is crosslinked.
The hard segment ratio (H ratio) measured by the solid echo method of pulse NMR is more than 10% and less than 60.0%, and in the dynamic viscoelasticity measurement, the tan δ value at the glass transition temperature (Tg) and (Tg + 30). ) From the ratio of the tan δ value at ° C, the following formula (I):
T value = tanδ _{(Tg + 30)} / tanδ _(Tg) (I)
A cured resin product having a uniformity parameter (T value) defined by 0.10 to 0.64. The cured resin product according to claim 1, wherein the polyphenylene ether resin contains an acrylic group as the curable functional group. The cured resin product according to claim 2, wherein the polyphenylene ether resin has a curing rate of 30% or more. The cured resin product according to any one of claims 1 to 3, wherein the polyphenylene ether resin has a branched structure. The cured resin product according to any one of claims 1 to 4, wherein the polyphenylene ether resin has a number average molecular weight of 500 or more and 15,000 or less. The cured resin product according to any one of claims 1 to 5, wherein the polyphenylene ether resin has an average of 2.5 to 5.0 curable functional groups per molecule. Claims 1 to 6 include a step of curing a curable composition containing a polyphenylene ether resin containing a curable functional group in a temperature range of 140 ° C. to 170 ° C. with a hold time of 1 minute to 30 minutes. The method for producing a cured resin product according to any one of the above items. A metal-clad laminate containing a metal foil and a cured resin product according to any one of claims 1 to 6. The metal-clad laminate according to claim 8, wherein the metal foil is a copper foil. A printed wiring board containing the cured resin product according to any one of claims 1 to 6.

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