JP2007002064A - Molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding usable as a material excellent in dielectric property, exerting stable electrical performances under several use conditions and having excellent mechanical strength. <P>SOLUTION: The molding comprises a resin containing a phyllosilicate, which resin is obtained by polymerizing benzoxazine represented by formula (1), wherein, R is a ≥2C divalent substituent; and H in a benzene ring may be substituted with an alkyl or alkoxy. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a molded article comprising a resin obtained by polymerizing a benzoxazine having a specific structure, containing a layered silicate. The molded product of the present invention has a low dielectric constant and dielectric loss tangent, is excellent in heat resistance, has a reduced fiber expansion coefficient, and is suitable as a molded product for an insulating substrate.

  In recent years, electronic devices have been rapidly improved in performance, functionality, and miniaturization, and electronic components used in electronic devices are also strongly required to be smaller and lighter. Therefore, further improvements in heat resistance, mechanical strength, electrical characteristics, and the like are also strongly demanded for materials constituting electronic parts.

  A multilayer printed circuit board used in an electronic device has a plurality of insulating layers and a circuit pattern arranged between these insulating layers. Conventionally, as this type of insulating layer, for example, a thermosetting resin prepreg obtained by impregnating a glass cloth with a thermosetting resin, a resin sheet made of a thermosetting resin or a photocurable resin, or the like is used. It is used.

  Also in the multilayer printed board, it is desired that the insulating layer be made extremely thin in order to achieve high density and thinning. Therefore, as a material constituting the insulating layer, an insulating layer using a thin glass cloth and an insulating layer made of a resin containing an inorganic filler are required. The reason for using glass cloth and inorganic fillers is to ensure mechanical properties such as mechanical strength even in extremely thin layers, or to change the dimensions before and after the thermal history even when a thermal history is given, that is, thermal expansion This is to reduce the rate.

  As a resin containing an inorganic filler that exhibits the above functions, there is a method using a layered silicate compound (flaky inorganic material) in addition to a general method using silica (Patent Document 1, Patent Document). 2). Layered silicate compounds are montmorillonite, mica, hectorite, etc. (or their surface modifications) usually found in clay, and one unit (one sheet) of layered silicate is several nm thick, length and width are It has a size of about several tens to several hundreds of nanometers. By decomposing this layered silicate compound into units and dispersing it in the resin, the mechanical properties, heat resistance, and thermal expansion coefficient can be reduced with a very small addition amount (for example, 10 parts by weight or less based on the resin). Such effects can be expected.

  On the other hand, in recent years, the performance required of a substrate for an electronic circuit with high integration and high frequency is an electronic function, specifically, a dielectric constant and a dielectric loss tangent. The dielectric constant directly affects the signal transmission delay, and the lower the dielectric constant, the smaller the signal delay. On the other hand, the dielectric loss tangent relates to signal transmission loss. The smaller the dielectric loss tangent, the smaller the loss and the better.

  Conventionally used epoxy resins and phenol resins have a dielectric constant of 3 to 4 and a dielectric loss tangent of about 0.01 to 0.03, which is not necessarily high, but it has performance for recent electronic circuits. It is becoming scarce. Moreover, a fluororesin is mentioned as resin excellent in a dielectric constant and a dielectric loss tangent. However, the fluororesin has extremely poor adhesion to metals and the like, and is not a practical circuit board. Polyolefins such as polystyrene and polyethylene also have a low dielectric constant and a low dielectric loss tangent, but have poor heat resistance and soften and deform at soldering process temperatures (eg, 260 ° C.). Cannot be used. On the other hand, a liquid crystal polymer having a low dielectric constant has been developed, but it has not yet been put into practical use in terms of processability and cost.

  Under such circumstances, it is known that benzoxazine resin has a low dielectric constant and a low dielectric loss tangent. However, since benzoxazine resins are generally fragile, they are often used in combination with other thermosetting resins (for example, epoxy resins and phenol resins), and as a result, the merits of benzoxazine resins are not fully utilized. It was a fact.

On the other hand, Patent Document 3 discloses blending clay with a cured product of benzoxazine. However, the structure of benzoxazine constituting the cured body is not specified, and there is no description that allows flexibility and permittivity control.
JP 2002-220433 A JP 2003-26939 A US Pat. No. 6,323,270

  In view of the above-mentioned circumstances, the present inventors have conducted extensive research on various resins and composite materials, and as a result, molded products obtained by processing a resin in which a layered silicate compound is dispersed in a polymer of benzoxazine having a specific structure. However, it was found that the electrical performance (dielectric constant, dielectric loss tangent) and mechanical strength were extremely excellent, and the present invention was completed.

  The object of the present invention is to provide excellent dielectric properties in view of physical properties required for materials constituting current electronic components, and to exhibit stable electrical performance under each process condition and various use conditions. An object of the present invention is to provide an electronic component material having excellent mechanical strength. In particular, an object is to provide a molded body that can be used as an excellent material for an insulating substrate.

式中、Ｒは炭素原子数２以上の２価の置換基であり、べンゼン環の水素はアルキル基又はアルコキシ基で置換されていてもよい。 That is, the present invention provides a molded article comprising a resin containing a layered silicate, wherein the resin is a resin obtained by polymerizing a benzoxazine represented by the following formula (1): It is to provide.

In the formula, R is a divalent substituent having 2 or more carbon atoms, and hydrogen in the benzene ring may be substituted with an alkyl group or an alkoxy group.

  Further, the present invention provides the molded article, wherein R in the formula (1) is a linear alkylene group having 2 or more carbon atoms or a branched alkylene group in which hydrogen is alkyl-substituted. Is to provide.

  Furthermore, the present invention provides the above molded product, wherein R in the formula (1) is an alkylene group or an arylene group containing a cyclic structure.

ｎは２以上３０以下の整数を表す。 Moreover, this invention provides said molded object characterized by R in said Formula (1) being represented by following formula (2).

n represents an integer of 2 or more and 30 or less.

  Further, the present invention provides the molded article, wherein the layered silicate is one or more layered silicates selected from the group consisting of montmorillonite, hectorite, swellable mica and vermiculite. It is to provide.

  In addition, the present invention provides the above-mentioned molded product, wherein the layered silicate is a powder having an average particle diameter of 1 μm or less.

  Furthermore, the present invention provides the above-mentioned molded product, wherein the layered silicate is a single layer or multilayer powder having a thickness of 0.001 to 1 μm.

  In the present invention, the layered silicate is a single layer or a multilayer having an average particle diameter of 0.05 μm to 0.5 μm, a thickness of 0.01 to 0.5 μm, and an aspect ratio of 50 to 200. The molded article is characterized by being a powder.

  Furthermore, the present invention provides the one or more cationic compounds wherein the layered silicate is selected from the group consisting of alkyl ammonium salts having 6 or more carbon atoms, aromatic quaternary ammonium salts and heterocyclic quaternary ammonium salts. The molded article is characterized by being treated with a surfactant.

Ｒ₁、Ｒ₂、Ｒ₃、Ｒ₄は炭素原子数１以上３０以下のアルキル基であり、かつ、Ｒ₁、Ｒ₂、Ｒ₃、Ｒ₄の少なくとも一つは炭素原子数２以上の直鎖状アルキル基である。 Moreover, this invention provides said molded object characterized by the said layered silicate being chemically processed by the alkylammonium represented by following formula (3).

R ₁ , R ₂ , R ₃ and R ₄ are alkyl groups having 1 to 30 carbon atoms, and at least one of R ₁ , R ₂ , R ₃ and R ₄ is a straight chain having 2 or more carbon atoms. It is a chain alkyl group.

  Furthermore, the present invention provides the above-mentioned molded product, wherein 0.2 to 100 parts by weight of the layered silicate is contained with respect to 100 parts by weight of a resin obtained by ring-opening polymerization of the benzoxazine. It is to provide.

式中、Ｒは炭素原子数２以上の２価の置換基であり、べンゼン環の水素はアルキル基又はアルコキシ基で置換されていてもよい。 The present invention also includes (A) a step of mixing and dispersing a layered silicate powder in a benzoxazine powder represented by the following formula (1), or (B) a powder of the benzoxazine. Is dissolved in a solvent and the layered silicate is mixed and dispersed therein, or (C) the benzoxazine is heated and melted and the layered silicate is mixed and dispersed therein, or (D) the benzoxazine is dispersed. A composite resin composition obtained by mixing and dispersing a layered silicate in a partially cured benzoxazine resin or benzoxazine oligomer is cured by heating at 100 to 300 ° C. A manufacturing method is provided.

In the formula, R is a divalent substituent having 2 or more carbon atoms, and hydrogen in the benzene ring may be substituted with an alkyl group or an alkoxy group.

  Furthermore, the present invention provides a method for producing the above-mentioned molded article, wherein the composite resin composition is heated by heating stepwise in a temperature range of 100 to 300 ° C. when the composite resin composition is heated. .

  The molded article of the present invention is excellent in mechanical strength and excellent in electrical performance (dielectric constant, dielectric loss tangent), heat resistance, and low thermal linear expansion coefficient. Thereby, the electronic circuit board material corresponding to a high frequency can be provided. In particular, by using the molded article of the present invention, it is possible to provide a substrate material used for information equipment such as a high-performance (high calculation speed) computer.

  The present invention is described in detail below using preferred examples. The present invention is not limited to the following preferred examples.

1. Benzoxazine resin used in the present invention The resin used in the molded product of the present invention is a thermosetting resin obtained by heating and ring-opening polymerization of a specific structure of benzoxazine (or an oligomer thereof), and has a strong structure by so-called three-dimensional crosslinking. It is a hardening body which has. For this reason, even if the cured resin constituting the molded body is exposed to a high temperature such as immersion in a solder bath, deformation and thermal decomposition hardly occur and the resin has excellent heat resistance. Furthermore, since it is a thermosetting resin, it is excellent in water resistance and chemical resistance. Therefore, the molded body (referred to as a composite molded body) of the present invention made of a composite material containing a layered silicate in such a thermosetting resin can be used particularly suitably as an electronic circuit board material. It is.

  Since the benzoxazine used in the present invention can be produced by a non-catalytic reaction of a phenolic compound, an amine compound, and formaldehyde, there is very little possibility that a metal or halogen remains in the resin. Resins that require a curing reaction using metal catalysts, acids, bases, etc., or resins that may contain halogens in their raw materials (for example, epoxy resins are often synthesized from epichlorohydrin, so chlorine In many cases, it contains less metal and halogen. Since halogen or metal causes metal corrosion or a signal short circuit, the benzoxazine resin can be particularly preferably used as an electronic circuit board material from this viewpoint.

  Further, in the polymerization of benzoxazine, ring opening / condensation reaction takes place and the polymer is cured, but at this time, there is no component that volatilizes. Therefore, unreacted benzoxazine and oligomers exist in the benzoxazine resin, and it is exposed to heat in the subsequent manufacturing process and use state, and there is no generation of gas even if the unreacted part is further cured. There is an advantage that the wiring material formed on the surface and the mounted device are not affected.

The benzoxazine resin constituting the molded article of the present invention is considered to have a low dielectric constant and dielectric loss tangent because the phenolic OH and tertiary amine generated after curing are fixed in a ring form by hydrogen bonding (formula (Refer to (4)). Furthermore, since the water absorption is very low, there is no change during cleaning and other processes, and there is no water absorption due to changes in humidity during use, so it is possible to produce molded articles with excellent stability such as dielectric constant, dielectric loss tangent and dimensions. It is.

式中、Ｒは炭素数２以上の２価の置換基であり、べンゼン環の水素はアルキル基又はアルコキシ基で置換されていてもよい。 As the benzoxazine resin used in the present invention, a resin obtained by curing a benzoxazine represented by the following formula (1) by ring-opening polymerization is used.

In the formula, R is a divalent substituent having 2 or more carbon atoms, and hydrogen in the benzene ring may be substituted with an alkyl group or an alkoxy group.

  The benzoxazine of the formula (1) undergoes ring-opening polymerization by heating to become a cured product crosslinked with the substituent R. The substituent R functions as a spacer. This spacer makes it possible to control the density and flexibility of the entire resin. Here, when R is a long-chain substituent, the average distance of the benzene ring portion to be cross-linked becomes long, and as a result, a cured product having a low density can be formed. Thus, there is a great advantage that the density can be controlled and therefore the dielectric constant can be controlled.

式中、Ｒ₁は２価の置換基であり、Ｒ₂は１価の置換基である。 As a structure similar to the benzoxazine represented by the formula (1), a method for producing a benzoxazine resin from the benzoxazine represented by the formula (5) is known. For example, benzoxazine in which R ₁ is methylene and R ₂ is phenyl is commercially available from Shikoku Kasei Kogyo Co., Ltd. under the trade name “benzoxazine Fa”.

In the formula, R ₁ is a divalent substituent, and R ₂ is a monovalent substituent.

In the case of the benzoxazine of the formula (5), a benzoxazine resin in which the substituent R ₁ serves as a spacer can be generated by polymerization and curing with heat. Then, the compound phenol used as the starting material was bonded by R _1, R ₁ is methylene, 2,2-propylene, sulfone, sulfide, those ketone are commercially available. However, a compound with a long R ₁ chain requires new synthesis, making it difficult and expensive to produce in large quantities. Therefore, the types of R ₁ are limited, and it is extremely difficult to control the density and flexibility of the molded body with R ₁ .

  On the other hand, in the case of the benzoxazine structure represented by the formula (1), the substituent R is a diamine containing the substituent R as a raw material. In the case of a diamine, a wide variety of diamines are commercially available, including various alkylenes and cyclic structures. Therefore, the benzoxazine resin using the benzoxazine represented by the formula (1) as a raw material is much more advantageous than the benzoxazine structure represented by the formula (5) in terms of permittivity control and flexibility control. A molded body can be manufactured.

  The substituent R of benzoxazine represented by the formula (1) is a divalent substituent having 2 or more carbon atoms. There is no upper limit on the number of carbon atoms, and the greater the number, the lower the density. As a result, the dielectric constant can be lowered and the flexibility is improved. However, if it is too much, the crosslinking density as a whole is lowered and the heat resistance and strength are lowered. Therefore, the carbon number is preferably 30 or less, and more preferably 15 or less. On the other hand, when the number of carbon atoms is less than 2, the dielectric constant is not sufficiently lowered and the flexibility is insufficient, so that it may not be suitable for an electronic circuit board or the like.

ｎは２以上３０以下の整数を表す In addition, the substituent R is not specified as long as it is a divalent substituent having 2 or more carbon atoms, but a linear alkylene group or a branched alkylene group in which hydrogen is alkyl-substituted is particularly preferable. Alkylene groups are low in polarity and do not increase the dielectric constant. Further, the water absorption is reduced due to the water repellency of the alkylene groups, and water absorption due to environmental changes and processes is reduced. Is suitable. Particularly in the alkylene group, a linear alkyl group represented by the following formula (2) can be used more preferably.

n represents an integer of 2 to 30

  Since a linear alkylene group has moderate flexibility, it can impart flexibility to the resin. Specific examples of the linear alkylene group include 1,2-ethylene, 1,3-propylene, 1,4-butene, 1,6-hexylene, 1,8-octylene, 1,10-decylene, 1,12. Although -dodecylene etc. are mentioned, it is not limited to these, If it is a C2-C30 thing, it can use preferably. In the case of straight chain alkylene, if the number of carbon atoms is less than 2, flexibility is not sufficiently imparted. On the other hand, those having more than 30 carbon atoms are reduced in cross-linking density and heat resistance, so that carbon atoms A number of 2 to 30 can be preferably used. Straight chain alkylenes may be used alone or in combination with alkylenes containing other structures.

  A branched alkylene group in which a hydrogen atom of a linear alkylene group is substituted with an alkyl group can also be preferably used. Examples of the branched alkylene include 1,2-propylene, 2-methyl-1,5-pentyl and the like, but are not limited thereto, and those having 2 to 30 carbon atoms are preferably used. I can do it. Although branched alkylene is inferior to linear alkylene in flexibility, it may form intermolecular vacancies and lower the dielectric constant of the material. Branched alkylenes may be used alone or in combination with alkylenes containing other structures.

  Furthermore, it is also preferable to use an alkylene group containing a cyclic structure. Examples of the alkylene group containing a cyclic structure include 1,4-cyclohexylene, dicyclopentadienylene, adamantylene, and the like. However, the alkylene group is not limited thereto, and those having 2 to 30 carbon atoms are preferable. An alkylene group containing a cyclic structure may be more rigid than linear alkylene or branched alkylene, thereby forming intermolecular vacancies, further reducing the dielectric constant of the material, and even the dielectric loss tangent. There is. An alkylene group containing a cyclic structure may be used alone or in combination with an alkylene group containing another structure.

  It is also preferable to use an arylene group. Examples of the arylene group include 1,4-phenylene, 4,4′-biphenylene, 4,4′-biphenyl ether, 4,4′-biphenyl ketone, 4,4′-biphenyl sulfone, and the like. And those having 2 to 30 carbon atoms are preferred. The arylene group becomes rigid like the alkylene group containing a cyclic structure, and therefore, an intermolecular void is formed, which may further lower the dielectric constant of the material. It also has the effect of improving heat resistance. Arylene groups may be used alone or in combination with arylene groups containing other structures.

  A benzoxazine compound in which these nitrogen atoms are bonded by an alkylene group or an arylene group can be obtained by reacting the corresponding diamine compound, phenols and formaldehyde. As the synthesis method, a known method can be used. For example, it is described in the method shown in US Pat. No. 5,543,516 and the literature shown in the same publication. Corresponding diamine compounds are, for example, ethylenediamine for 1,2-ethylene structures, 1,3-diaminopropane for 1,3-propylene structures, 1,1 for 1,4-butene structures. For 4-diaminobutane and 1,6-hexylene structures, 1,6-diaminohexane and the like are shown, and synthesis is possible if the corresponding diamine is available for any structure.

2. Layered silicate used in the present invention The molded body of the present invention forms a composite material in which a layered silicate is contained in the resin component containing the benzoxazine polymer and dispersed.
In the present invention, the layered silicate is, for example, a smectite clay mineral such as montmorillonite, hectorite, saponite, beidellite, stevensite, nontronite, swelling mica (swelling mica), vermiculite, halloysite, etc. Means flat silicate. By adding such a layered silicate, it is possible to reduce the coefficient of thermal expansion at the time of temperature change. As mentioned above, when the coefficient of thermal expansion is significantly different from that of the metal used for the signal line, stress concentrates on the interface between the resin and the metal when the temperature changes during use or manufacturing, causing peeling or signal lines. Rupture can occur.

  It is well known to add an inorganic material in order to reduce the thermal expansion coefficient of the resin. Usually, inorganic particles such as silica and alumina are used as this inorganic material, but when these particulate materials are used, unless a large amount is added, for example, thermal expansion of copper used for signal wiring It is difficult to approach the coefficient (about 20 ppm). As described above, when a large amount of inorganic filler is added, the resin itself may become brittle and hard, or the adhesion between the resin and the signal wiring metal may deteriorate.

  However, when layered silicate is used, compared to the case where a particulate inorganic additive is introduced, since it differs depending on the type of resin, layered silicate, etc., it cannot be generally stated, but addition of 1/2 to 1/10 The amount is sufficient. Therefore, the molded article of the present invention can be used particularly suitably for electronic circuit board materials and the like without causing embrittlement of resin and lowering of adhesion.

  In addition, in connection with the present invention, as described above, in US Pat. No. 6,323,270, an invention using a layered silicate (described as clay in the patent) is disclosed for a cured product of benzoxazine. Has been. However, in US Pat. No. 6,323,270, the structure of the benzoxazine structure is not specified. In contrast, in the present invention, the use of a benzoxazine resin made from a benzoxazine having a structure specified by the formula (1) as a raw material makes it possible to impart flexibility and control the dielectric constant. There is a special feature.

  And the layered silicate added to the benzoxazine resin using benzoxazine having a specific structure as a raw material means a layered silicate compound having an exchangeable metal cation between crystal layers. This layered silicate may be a natural product or a synthetic product. The layered silicate is a layer in which the silicate layer (single layer), which is a basic structure, is laminated in a substantially parallel manner (multiple layers). When this powder is dispersed in a resin, the number of layers is less than the original number of layers. It is cleaved into a number (delamination) and dispersed in the resin constituting the molded body. Alternatively, powder that has been cleaved in advance to the number of layers that is less than or equal to the original number of layers can be dispersed in the resin that constitutes the molded body.

  The layered silicate used in the present invention is not particularly limited. For example, smectite clay minerals such as montmorillonite, hectorite, saponite, beidellite, stevensite, nontronite, and swelling mica (swelling) Sexual mica), vermiculite, halloysite and the like. Among them, at least one layered silicate selected from the group consisting of montmorillonite, hectorite, swellable mica and vermiculite is preferable because it has good dispersibility and can improve strength and dimensional stability at high temperatures. In particular, hectorite is more preferably used. These layered silicates may be used alone or in combination of two or more.

  The layered silicate is not particularly limited, but it is preferable to disperse a powder having an average particle diameter of 2 μm or less in the resin, more preferably 1 μm or less, and further preferably 0.5 μm or less. When the average particle diameter of the layered silicate is 2 μm or less, the transparency of the molded body is improved, and alignment with the lower substrate or the like can be facilitated during operation. In addition, when the average particle diameter of the layered silicate is 1 μm or less, the residue of the molded body hardly remains during laser processing, and laser workability is improved. Furthermore, when the average particle diameter of the layered silicate is 0.5 μm or less, the molded body can be used as an optical material or a material for an optical waveguide.

  The layered silicate powder (crystal shape) dispersed in the resin is not particularly limited, but the average particle diameter is 0.01 μm or more, and the thickness of the single-layer or multilayer powder is 0.001. It is preferable that the powder is ˜1 μm and the aspect ratio is 20 to 500. More preferably, the average particle diameter is 0.05 μm or more, the thickness is 0.01 to 0.5 μm, and the aspect ratio is 50 to 200.

The average particle diameter (average length) of the layered silicate is an average value of 50 particles obtained by taking the average value of the major axis and the minor axis on the surface of the layer observed from an electron micrograph as the particle diameter.
The thickness is a thickness of a layer constituting the powder (a single layer powder or a multilayer powder), and is a thickness observed from an electron micrograph.

  The exchangeable metal cation existing between the crystal layers of the layered silicate used in the present invention is a metal ion such as sodium ion or calcium ion existing on the surface of the lamellar crystal of the layered silicate. Since these metal ions have cation exchange properties with other cationic substances, various substances having a cationic property can be inserted (intercalated) or captured between the crystal layers of the layered silicate.

  The cation exchange capacity of the layered silicate is not particularly limited, but is preferably 50 to 200 meq / 100 g. When the cation exchange capacity of the layered silicate is less than 50 meq / 100 g, the amount of the cationic substance inserted or trapped between the crystal layers of the layered silicate due to cation exchange is reduced, so that the crystal layer is sufficiently hydrophobic. (Non-polarization) may not be possible. Conversely, if the cation exchange capacity of the layered silicate exceeds 200 meq / 100 g, the bonding force between the crystal layers of the layered silicate becomes too strong, and the crystal flakes may be difficult to peel off.

When the layered silicate is subjected to a chemical treatment, the dispersibility in the benzoxazine resin is improved. Hereinafter, the layered silicate whose dispersibility is improved by applying chemical treatment is referred to as “organic modified layered silicate”.
Although this chemical treatment is not particularly limited, it can be performed by, for example, the following chemical modification (1) method to chemical modification (6) method. These chemical modification methods may be used alone or in combination of two or more.

  The chemical modification (1) method is also referred to as a cation exchange method using a cationic surfactant. Specifically, the method is a method in which the cation exchange between the crystal layers of the layered silicate is performed with a cationic surfactant in advance to make it hydrophobic. is there. By previously hydrophobizing the crystal layer of the layered silicate, the affinity between the layered silicate and the component of the benzoxazine resin (including its oligomer) is increased, and it can be more uniformly finely dispersed.

  Although it does not specifically limit as said cationic surfactant, For example, a quaternary ammonium salt, a quaternary phosphonium salt, etc. are mentioned. Among them, since the crystal layer of the layered silicate can be sufficiently hydrophobized, at least one selected from the group consisting of alkyl ammonium salts having 6 or more carbon atoms, aromatic quaternary ammonium salts, and heterocyclic quaternary ammonium salts. The ammonium salt is preferably used. These cationic surfactants may be used alone or in combination of two or more.

  Although it does not specifically limit as said quaternary ammonium salt, For example, a trimethyl alkyl ammonium salt, a triethyl alkyl ammonium salt, a tributyl alkyl ammonium salt, a dimethyl dialkyl ammonium salt, a dibutyl dialkyl ammonium salt, a methyl benzyl dialkyl ammonium salt, Alkylammonium salts such as dibenzyldialkylammonium salt, trialkylmethylammonium salt, trialkylethylammonium salt, trialkylbutylammonium salt, benzylmethyl {2- [2- (p-1,1,3,3-tetramethyl) A quaternary ammonium salt (aromatic quaternary ammonium salt) having an aromatic ring such as butylphenoxy) ethoxy] ethyl} ammonium chloride, trimethylphenylammonium A quaternary ammonium salt derived from an aromatic amine (aromatic quaternary ammonium salt), an alkylpyridinium salt, an imidazolium salt and the like, a quaternary ammonium salt having a heterocyclic ring (heterocyclic quaternary ammonium salt), and 2 polyethylene glycol chains. Dialkyl quaternary ammonium salts having two polypropylene glycol chains, trialkyl quaternary ammonium salts having one polyethylene glycol chain, trialkyl quaternary ammonium salts having one polypropylene glycol chain, etc. Can be mentioned. Among them, lauryl trimethyl ammonium salt, stearyl trimethyl ammonium salt, trioctyl methyl ammonium salt, distearyl dimethyl ammonium salt, di-cured tallow dimethyl ammonium salt, distearyl dibenzyl ammonium salt, N-polyoxyethylene-N-lauryl-N , N-dimethylammonium salt and the like are preferably used. These quaternary ammonium salts may be used alone or in combination of two or more.

  The quaternary phosphonium salt is not particularly limited, and examples thereof include dodecyltriphenylphosphonium salt, methyltriphenylphosphonium salt, lauryltrimethylphosphonium salt, stearyltrimethylphosphonium salt, trioctylmethylphosphonium salt, distearyldimethyl. Examples thereof include phosphonium salts and distearyl dibenzylphosphonium salts. These quaternary phosphonium salts may be used alone or in combination of two or more.

  The chemical modification (2) method is a chemical affinity with a functional group or a hydroxyl group capable of chemically bonding a hydroxyl group present on the crystal surface of the organically modified layered silicate subjected to the chemical treatment by the chemical modification (1) method. This is a method of chemically treating with a compound having one or more functional groups having high properties at the molecular terminals.

  In the chemical modification (3) method, a hydroxyl group present on the crystal surface of the organically modified layered silicate subjected to the chemical treatment by the chemical modification (1) method is chemically bonded to a functional group or a hydroxyl group capable of chemically bonding to the hydroxyl group. This is a method of chemical treatment with a compound having one or more functional groups with high affinity at one end of the molecule and one or more reactive functional groups at the other end of the molecule.

  The functional group capable of chemically bonding to the hydroxyl group or the functional group having a large chemical affinity with the hydroxyl group is not particularly limited, and examples thereof include an alkoxyl group, an epoxy group (glycidyl group), and a carboxyl group (dibasic). Acid anhydrides), hydroxyl groups, isocyanate groups, aldehyde groups, amino groups, and the like.

  The compound having a functional group capable of chemically bonding to the hydroxyl group or the compound having a functional group having a large chemical affinity with the hydroxyl group is not particularly limited. Examples thereof include compounds, titanate compounds, epoxy compounds, carboxylic acids, sulfonic acids, alcohols, etc. Among them, silane compounds are preferably used. These compounds may be used independently and 2 or more types may be used together.

  Although it does not specifically limit as a silane compound used by the said chemical modification (2) method, For example, a methyltriethoxysilane, a dimethyldimethoxysilane, a trimethylmethoxysilane, a hexyltrimethoxysilane, a hexyltriethoxysilane, an octadecyl Examples include trimethoxysilane and octadecyltriethoxysilane. The silane compounds used in these chemical modification (2) methods may be used alone or in combination of two or more.

  In addition, the silane compound used in the chemical modification (3) method is not particularly limited, and examples thereof include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, and γ-amino. Propyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyldimethylmethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethylethoxysilane, N-β- (Aminoethyl) γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropyltriethoxysilane, N-β- (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-methacryloxypropylmethyl Dimethoxysilane, Examples include γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropyltriethoxysilane. These silane compounds used in the chemical modification (3) method may be used alone or in combination of two or more.

The chemical modification (4) method is a method in which the crystal surface of the organically modified layered silicate chemically treated by the chemical modification (1) method is chemically treated with a compound having an anionic surface activity.
The compound having anionic surface activity is not particularly limited as long as it can chemically treat the layered silicate by ionic interaction. Examples of the compound having an anionic surface activity include sodium laurate, sodium stearate, sodium oleate, higher alcohol sulfate, secondary higher alcohol sulfate, unsaturated alcohol sulfate, and the like. . These compounds having anionic surface activity may be used alone or in combination of two or more.

  The chemical modification (5) method is a method in which a chemical treatment is performed with a compound having one or more reactive functional groups other than the anion site in the molecular chain among the compounds having anionic surface activity.

  The chemical modification (6) method includes an organically modified layered silicate that has been chemically treated by any one of the chemical modification (1) method to the chemical modification (5) method, and further, for example, maleic anhydride-modified polyphenylene ether resin. It is the method of chemically processing with resin which has a functional group which can react with layered silicate like.

  In the molded product of the present invention, among the organically modified layered silicates that have been subjected to the above chemical treatment, the affinity to the benzoxazine resin component is good, and the effect of improving the physical properties of the molded product is high. A hectorite subjected to chemical treatment is particularly preferably used.

3. Mixing ratio and mixing method of benzoxazine resin and layered silicate The molded article of the present invention is that the layered silicate is contained in the range of 0.2 to 100 parts by weight with respect to 100 parts by weight of the benzoxazine resin. Features. 100 parts by weight of the benzoxazine resin includes unreacted benzoxazine and oligomers. The preferred amount of layered silicate is in the range of 0.5 to 80 parts by weight, more preferably in the range of 1 to 50 parts by weight.
If the blended amount of the layered silicate is less than 0.2 parts by weight with respect to 100 parts by weight of the benzoxazine resin component, the effect of improving high-temperature properties cannot be sufficiently obtained. On the contrary, when the compounding amount of the layered silicate exceeds 100 parts by weight with respect to 100 parts by weight of the benzoxazine resin, the density of the composite molded body becomes too high, the mechanical properties are lowered, and the practicality is impaired.
By making the amount of layered silicate to be in the range of 1 to 50 parts by weight with respect to 100 parts by weight of the benzoxazine resin component, the molded article has particularly excellent dimensional stability without impairing mechanical properties and process suitability. , A molded product exhibiting heat resistance, dielectric properties and the like can be obtained.

  Generally, when a large amount of inorganic filler is blended in the thermosetting resin composition, it is difficult to sufficiently reduce the linear expansion coefficient at a temperature higher than the glass transition temperature of the cured product, and it is also difficult to reduce the thickness. Furthermore, transparency is also impaired. Therefore, inconvenience occurs in processes such as alignment of insulating layers during laser processing. However, the layered silicate in the molded body of the present invention is small in size and has very high dispersibility, so that the above-described problems hardly occur even when blended in a large amount.

  In the thermosetting resin composition used in the present invention, when the benzoxazine resin and the layered silicate are combined, the area of the interface is very large and the interaction is strong. Therefore, compared with other inorganic fillers, if the blending amount is the same, the effect of improving physical properties is significantly increased. That is, compared with other inorganic fillers, it is possible to produce a molded body in which the amount of layered silicate is reduced without impairing mechanical properties.

  In the method for producing a molded article of the present invention, the mixing method of each component is (A) a method of mixing and dispersing a benzoxazine powder before curing and a layered silicate as powder, and (B) a benzoxazine before curing. Method of dissolving powder in solvent and mixing / dispersing layered silicate, (C) Method of mixing and dispersing layered silicate by heating and melting benzoxazine before curing, (D) Partially cured benzoxazine and / or Alternatively, a method of mixing and dispersing layered silicate in the oligomer can be used. Either method can provide a suitable molded product.

  The mixing / dispersing method is not particularly limited. For example, a conventionally known disperser or kneader such as a dispenser, a homogenizer, a planetary stirrer, a ball mill, an extruder, a two-roller, or a Banbury mixer may be used at room temperature. Alternatively, each component may be kneaded uniformly while applying a shearing force under heating.

  The obtained mixture can be completely cured by heating to form a molded body. The heating temperature varies depending on the benzoxazine compound to be used, but generally 100 to 300 ° C is preferable, preferably 120 to 250 ° C, more preferably 160 to 220 ° C, and the heating time is also a molded article to be processed. Since it differs depending on the type of the material, it cannot be generally stated, but it is usually in the range of 10 minutes to 10 hours. Further, when heating, the temperature may be increased stepwise, for example, 140 ° C., 160 ° C., and 180 ° C.

  In order to form into a desired shape during heating, a mold may be used, or a film or sheet may be sandwiched between press plates. A known method can be used as the molding method.

  In addition, the molded body of the present invention may contain, for example, a filler other than the layered silicate, a softener (plasticizer), a nucleating agent, an antioxidant (anti-aging agent), a heat stabilizer, a light as necessary. One kind or two or more kinds of various additives such as a stabilizer, an ultraviolet absorber, a lubricant, a flame retardant, an antistatic agent, an antifogging agent, a colorant, and an organic solvent may be contained.

  Although it does not specifically limit as a use of the molded object of this invention, For example, a resin sheet, a prepreg, various circuit boards, optical waveguide material, etc. which are obtained by shape | molding (film formation) into a film shape and processing it, etc. Is mentioned.

  Hereinafter, the molded product of the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to these examples.

[Evaluation method]
The molded product was evaluated for the following characteristics.
(1) Dielectric properties (dielectric constant and dielectric loss tangent)
The composite molded body was molded into a sheet having a thickness of 500 μm, and the obtained sheet-shaped molded body was cut into 15 mm × 15 mm. This was supplied to a dielectric constant measuring apparatus (manufactured by HEWLETT PAKARD, product number “HP4291B”) and measured at 23 ° C., and the dielectric constant and dielectric loss tangent at 100 MHz and 1 GHz were read.
(2) Mechanical strength (tensile strength and elongation)
The composite molded body was formed into a sheet having a thickness of 50 μm, and this was cut into 80 mm × 10 mm to obtain a test specimen for measurement. Based on JIS-K7171, it measured with the tensile tester (Orientec company make, brand name: "Tensilon").
(3) Heat resistance (glass transition temperature)
The composite molded body was formed into a sheet having a thickness of 50 μm, and this was cut into 50 mm × 5 mm to obtain a test specimen for measurement. The obtained test piece was supplied to a viscoelastic rheometer (trade name “RMS-800” manufactured by Rheometrics), and viscoelasticity measurement was performed at a frequency of 10 Hz, a strain of 0.05%, and a heating rate of 10 ° C./min. The glass transition temperature was measured as the peak temperature of tan δ.
(4) Coefficient of thermal expansion The composite molded body was formed into a sheet having a thickness of 50 μm, and this was cut into 50 mm × 5 mm to obtain a test specimen for measurement. The obtained test piece was supplied to a TMA apparatus (trade name “TMA / SS120C” manufactured by Seiko Denshi Co., Ltd.) and measured at a temperature rising rate of 5 ° C./min in the range of 23 ° C. to 150 ° C. to obtain an average linear expansion. The rate was measured.

"Synthesis of benzoxazine of general formula (1)"
(1) A reactor having a reflux condenser was charged with 1 l of chloroform, mixed with 1 mol of 1,6-diaminohexane, 2 mol of phenol and 4 mol of paraformaldehyde, and stirred at the reflux temperature of chloroform for 5 hours. Reaction was performed. After completion of the reaction, the reaction solution was washed twice with 0.5N aqueous sodium hydroxide solution and then twice with water. After the solution was dried over anhydrous sodium sulfate, chloroform was distilled off under reduced pressure to obtain a benzoxazine compound (hereinafter referred to as “benzoxazine compound (C6)”) in which R is a hexylene group.

(2) Into a reactor having a reflux condenser, 1 l of chloroform was added, and 1 mol of 4,4′-diaminodiphenyl ether, 2 mol of phenol and 4 mol of paraformaldehyde were mixed and stirred at the reflux temperature of chloroform. Time reaction was performed. After completion of the reaction, the reaction solution was washed twice with 0.5N aqueous sodium hydroxide solution and then twice with water. After the solution was dried over anhydrous sodium sulfate, chloroform was distilled off under reduced pressure to obtain a benzoxazine compound (hereinafter referred to as “benzoxazine compound (DPE)”) in which R is a diphenyl ether group.

"Layered silicate"
Synthetic smectite (manufactured by Co-op Chemical Co., Ltd., trade name: “STN”) was used.

[Example 1]
Supply 2 parts by weight of synthetic smectite (= layered silicate; trade name: “STN”) and 38 parts by weight of DMF to a homogenizer (trade name: “T.K. HOMODISPER”). The mixture was stirred at 3,000 rpm for 2 hours. To this was added 100 parts by weight of a benzoxazine compound (C6), and the mixture was stirred at 2,000 rpm for 3 hours while heating to 80 ° C. to obtain a thermosetting resin composition.
The obtained thermosetting resin composition was coated on a release PET with a thickness of 100 μm, defoamed and dried at 100 ° C. for 1 hour, then at 140 ° C. for 1 hour, at 160 ° C. for 1 hour, and finally Heating was performed at 180 ° C. for 1 hour to obtain a sheet-like molded body having a thickness of 50 μm.

[Example 2]
A thermosetting resin composition was obtained in the same manner as in Example 1 except that 5 parts by weight of synthetic smectite (= layered silicate; manufactured by Coop Chemical Co., Ltd., trade name: “STN”) was used. Coating, drying and curing were performed in the same manner as described above to obtain a sheet-like molded body having a thickness of 50 μm.

[Comparative Example 1]
<Creation of molded product by coating>
38 parts by weight of DMF was added to 100 parts by weight of the benzoxazine compound (C6), and the mixture was supplied to a homogenizer (manufactured by Tokushu Kika Kogyo Co., Ltd., trade name: “TK HOMODISPER”) and heated to 80 ° C. while being heated to 2,000. The mixture was stirred for 3 hours by rotation to obtain a thermosetting resin composition containing no layered silicate.
This was applied in the same manner as in Example 1, but the viscosity decreased during the curing process, and a uniform sheet-like molded product could not be obtained. Therefore, the molded body of Comparative Example 1 was produced by the following pressing method.

<Creation of molded body by press method>
3 g of benzoxazine compound (C6) is supplied to a 150 mm x 150 mm x 50 µm Teflon (registered trademark) mold, melted and degassed in an oven at 120 ° C for 1 hour, and then sandwiched in a stainless steel press plate. Were heated at 140 ° C. for 1 hour, 160 ° C. for 1 hour, and finally at 180 ° C. for 1 hour to obtain a sheet-like molded body having a thickness of 50 μm.

[Comparative Example 2]
A thermosetting resin composition was obtained in the same manner as in Example 1 except that 120 parts by weight of synthetic smectite (= layered silicate; manufactured by Coop Chemical Co., Ltd., trade name: “STN”) was used. Using this, an attempt was made to form a sheet by coating in the same manner as in Example 1. However, the molded sheet was hard and brittle, and did not reach a state for evaluation of various physical properties.

[Example 3]
Supply 2 parts by weight of synthetic smectite (= layered silicate; trade name: “STN”) and 38 parts by weight of DMF to a homogenizer (trade name: “T.K. HOMODISPER”). The mixture was stirred at 3,000 rpm for 2 hours. To this was added 100 parts by weight of a benzoxazine compound (DPE), and the mixture was stirred at 2,000 rpm for 3 hours while heating to 80 ° C. to obtain a thermosetting resin composition.
The obtained thermosetting resin composition was coated on a release PET with a thickness of 100 μm, defoamed and dried at 120 ° C. for 1 hour, then at 140 ° C. for 1 hour, at 160 ° C. for 1 hour, and finally Heating was performed at 180 ° C. for 1 hour to obtain a sheet-like molded body having a thickness of 50 μm.

[Example 4]
A thermosetting resin composition was obtained in the same manner as in Example 3 except that 5 parts by weight of synthetic smectite (= layered silicate; manufactured by Co-op Chemical Co., Ltd., trade name: “STN”) was used. Coating, drying and curing were performed in the same manner as described above to obtain a sheet-like molded body having a thickness of 50 μm.

[Comparative Example 3]
<Sample preparation by coating>
38 parts by weight of DMF was added to 100 parts by weight of a benzoxazine compound (DPE), and the mixture was supplied to a homogenizer (manufactured by Tokushu Kika Kogyo Co., Ltd., trade name: “TK HOMODPERPER”) and heated to 80 ° C. while being heated to 2,000. The mixture was stirred for 3 hours by rotation to obtain a thermosetting resin composition containing no layered silicate.
This was coated in the same manner as in Example 3, but the viscosity decreased during the curing process, and a uniform sheet-like molded product could not be obtained. Therefore, the molded body of Comparative Example 3 was produced by the following pressing method.

<Creation of molded body by press method>
3 g of benzoxazine compound (DPE) is supplied to a 150 mm x 150 mm x 50 µm Teflon (registered trademark) mold, melted and degassed in an oven at 120 ° C for 1 hour, and then sandwiched between stainless steel press plates and heated press Were heated at 140 ° C. for 1 hour, 160 ° C. for 1 hour, and finally at 180 ° C. for 1 hour to obtain a sheet-like molded body having a thickness of 50 μm.

  The dielectric constant, dielectric loss tangent, tensile strength (elongation), glass transition temperature, and thermal linear expansion coefficient were measured using the sheet-like molded bodies obtained in Example 1, Example 2, and Comparative Example 1. The obtained results are shown in “Table 1”.

Using the sheet-like molded bodies obtained in Example 3, Example 4, and Comparative Example 2, the dielectric constant, dielectric loss tangent, tensile strength (elongation), glass transition temperature, and thermal expansion coefficient were measured. The obtained results are shown in “Table 2”.

As is clear from the results shown in the above “Table 1” and “Table 2”, the molded article of the present invention comprising a composite resin in which a layered silicate compound is dispersed using a benzoxazine compound having a specific structure is electrically Excellent balance of performance (dielectric constant, dielectric loss tangent), heat resistance, mechanical strength, and low thermal expansion coefficient. Moreover, the suitability for coating on the sheet was greatly improved by mixing a specific layered silicate (for example, comparison between Example 1 and Comparative Example 1).
From the above, it can be seen that the molded article of the present invention is particularly useful as an insulating substrate material for electronic circuits.

The molded article of the present invention is excellent in mechanical strength and excellent in electrical performance (dielectric constant, dielectric loss tangent), heat resistance, and low thermal linear expansion coefficient, and is preferably used as an electronic circuit board material corresponding to high frequencies. Is done. With the molded article of the present invention, it is possible to provide a substrate material used for information equipment such as a computer having a high calculation speed.

Claims (13)

A molded article comprising a resin containing a layered silicate, wherein the resin is a resin obtained by polymerizing a benzoxazine represented by the following formula (1).

In the formula, R is a divalent substituent having 2 or more carbon atoms, and hydrogen in the benzene ring may be substituted with an alkyl group or an alkoxy group.   The molded article according to claim 1, wherein R in the formula (1) is a linear alkylene group having 2 or more carbon atoms or a branched alkylene group in which hydrogen is alkyl-substituted.   The molded body according to claim 1, wherein R in the formula (1) is an alkylene group or an arylene group containing a cyclic structure. R in said Formula (1) is represented by following formula (2), The molded object of Claim 1 characterized by the above-mentioned.

n represents an integer of 2 or more and 30 or less.   5. The layered silicate is one or more layered silicates selected from the group consisting of montmorillonite, hectorite, swellable mica, and vermiculite. Molded body.   The said layered silicate is powder with an average particle diameter of 1 micrometer or less, The molded object of any one of Claims 1-5 characterized by the above-mentioned.   The molded article according to any one of claims 1 to 6, wherein the layered silicate is a single-layer or multilayer powder having a thickness of 0.001 to 1 µm.   The layered silicate is a single layer or multilayer having an average particle diameter of 0.05 μm to 0.5 μm, a thickness of 0.01 to 0.5 μm, and an aspect ratio of 50 to 200. The molded body according to any one of claims 1 to 7.   The layered silicate is treated with one or more cationic surfactants selected from the group consisting of alkyl ammonium salts having 6 or more carbon atoms, aromatic quaternary ammonium salts and heterocyclic quaternary ammonium salts. The molded product according to claim 1, wherein the molded product is a molded product. The molded article according to any one of claims 1 to 8, wherein the layered silicate is chemically treated with an alkylammonium represented by the following formula (3).

R ₁ , R ₂ , R ₃ and R ₄ are alkyl groups having 1 to 30 carbon atoms, and at least one of R ₁ , R ₂ , R ₃ and R ₄ is a straight chain having 2 or more carbon atoms. It is a chain alkyl group.   11. The layered silicate is contained in an amount of 0.2 to 100 parts by weight with respect to 100 parts by weight of a resin obtained by ring-opening polymerization of the benzoxazine. Molded body. (A) A step of mixing and dispersing a layered silicate powder in a benzoxazine powder represented by the following formula (1), or (B) dissolving the benzoxazine powder in a solvent. Or (C) a step of mixing and dispersing the layered silicate by heating and melting the benzoxazine, or (D) a benzoxazine obtained by partially curing the benzoxazine. The composite resin composition obtained by mixing and dispersing a layered silicate in a resin or a benzoxazine oligomer is cured by heating to 100 to 300 ° C. A method for producing a molded article.

In the formula, R is a divalent substituent having 2 or more carbon atoms, and hydrogen in the benzene ring may be substituted with an alkyl group or an alkoxy group. 13. The method for producing a molded body according to claim 12, wherein the composite resin composition is heated by increasing the temperature stepwise in a temperature range of 100 to 300 ° C. when heating the composite resin composition.