JP2006001967A - Flame-retardant resin composition and prepreg, metal-clad laminate and printed wiring board using the same composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame-retardant resin composition having resin compounding retaining proper curability while ensuring sufficient flame retardance in a flame retarding technique using a nonhalogen flame retardant and affording mechanically, electrically and chemically proper characteristics even in products using the resin and to provide prepreg, a metal-clad laminate and a printed wiring board using the composition. <P>SOLUTION: The flame-retardant resin composition is composed of an epoxy resin containing an organophosphorus compound represented by formula (1) (wherein, R1 to R12 denote each a hydrogen atom or a 1-20C organic group without containing a halogen element and without having reactivity) or a urea resin or a melamine resin or a phenol resin. The prepreg, metal-clad laminate and printed wiring board are obtained by using the composition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laminate for electrical insulation, a prepreg, a printed wiring board, and a resin composition.

  In recent years, electrical insulation laminates (in the present invention, laminates include laminates with one or both sides covered with metal foil, that is, metal-clad laminates), prepregs, and printed wiring boards have become increasingly environmentally friendly. It is required that hazardous substances are not discharged into the environment during disposal or incineration. For this reason, an increasing number of products are characterized by not containing halogenated flame retardants in order to avoid the occurrence of dioxin problems during combustion. At present, inorganic materials, phosphorus compounds, nitrogen compounds, etc. are widely used as alternative flame retardants for halogen flame retardants.

  Industrially, flame retardancy is often secured by combining these alternative flame retardants. Various proposals have been submitted by various companies regarding the formulation of the flame retardant. This is because many of the conventional halogen flame retardant methods have been established using a brominated flame retardant represented by tetrabromobisphenol A, but non-halogen flame retardant systems This is because it is in the process of development and various flame-retarding methods are being proposed.

Japanese Patent Laid-Open No. 2-69567

  At present, the flame retardant methods mainly include a method of adding a flame retardant into the resin and a method of reacting it into the resin skeleton. Both methods have their respective characteristics, but the conventional halogen flame retardant method used many systems that incorporate a flame retardant into the resin skeleton, and the incorporation of the flame retardant into the skeleton in terms of mechanical strength, etc. For reasons such as being presumed to be excellent, flame retardants that have reactivity even in non-halogen systems tend to attract attention. In fact, products that employ a technique for imparting flame retardancy to the resin skeleton itself have been put into practical use. However, unfortunately, sufficient characteristics have not been achieved. This is because the reactive flame retardant is one of the features that it is incorporated into the resin skeleton by reacting itself, but the reactive flame retardant currently used actually contains itself. Since the proportion of flame retardant components is relatively small, if an amount that can achieve sufficient flame retardancy is added to the resin, the reactivity of the flame retardant dominates the overall reaction system, and the reaction system and This is because the properties of the resulting cured resin are greatly affected, and the reactivity itself limits the improvement of product properties.

  A typical reactive flame retardant is shown in Formula 5. A compound having the structure shown in Formula 5 and a flame retardant having a structure similar to this in the skeleton and having a relatively high flame retardancy, as described above, can acquire practical product characteristics. It has already been adopted as a flame retardant. However, if this material is used in an amount sufficient to obtain sufficient flame retardancy, the degree of freedom in designing the resin composition and product will be limited because of its significant influence on the curing characteristics due to its reactivity. There is also.

（但し，Ｒ１〜１２は水素原子もしくは，ハロゲン元素を含まず，かつ反応性を有さないＣ_１〜Ｃ_２０の炭素を有する有機基を示す）
<２>上記有機リン化合物が下記式（２）で示される化合物である<１>記載の難燃性樹脂組成物。

<３> 上記<１>または<２>に記載の難燃性樹脂組成物に下記式（３）に示す有機リン化合物を添加した難燃性樹脂組成物。

（但し，Ｒ１４〜１８は水素原子もしくは，ハロゲン元素を含まないＣ_１〜Ｃ_２０の炭素を有する有機基を示す）
<４> <３>の上記式（３）で示した有機リン化合物が下記式（４）で示される縮合型燐酸エステルである難燃性樹脂組成物。

<５> <１>〜<４>記載の難燃性樹脂組成物にフィラーを添加した難燃性樹脂組成物。
<６> <１>〜<５>記載の難燃性樹脂組成物を用いて作られるプリプレグ。
<７> <６>記載のプリプレグを用いて作られる金属張積層板。
<８> <６>記載のプリプレグ，<７>記載の金属張り積層板を任意に組合せて作られるプリント配線板。 The present inventors prepared a resin composition having sufficient physical and chemical properties, not containing a halogen-based flame retardant, having no reactivity, and having sufficient flame retardancy. As a result of various examinations on the method to do this, the following inventions have been found.
That is, the present invention relates to the following invention.
<1> A flame retardant resin composition comprising an epoxy resin, an urea resin, a melamine resin, or a phenol resin containing an organic phosphorus compound represented by the following formula (1).

(However, R1～12 is or a hydrogen atom, an organic group having a carbon of _C 1 _{-C 20} where not, and no reactivity contain a halogen element)
<2> The flame retardant resin composition according to <1>, wherein the organic phosphorus compound is a compound represented by the following formula (2).

<3> A flame retardant resin composition obtained by adding an organophosphorus compound represented by the following formula (3) to the flame retardant resin composition according to the above <1> or <2>.

(However, R14～18 is or a hydrogen atom, an organic group having a carbon of _C 1 _{-C 20} containing no halogen element)
<4> A flame retardant resin composition in which the organophosphorus compound represented by the above formula (3) of <3> is a condensed phosphate ester represented by the following formula (4).

<5> A flame retardant resin composition obtained by adding a filler to the flame retardant resin composition according to <1> to <4>.
<6> A prepreg produced using the flame retardant resin composition according to <1> to <5>.
<7> A metal-clad laminate produced using the prepreg according to <6>.
<8> A printed wiring board produced by arbitrarily combining the prepreg according to <6> and the metal-clad laminate according to <7>.

  According to the present invention, in a flame retarding method using a non-halogen flame retardant, a resin blend capable of maintaining appropriate curability while ensuring sufficient flame retardancy is established, and products using these resins are also mechanically , Electrical and chemical properties can be obtained.

  In the present invention, it is essential to use a compound represented by the above formula (1), for example, a compound of the formula (2). The compounds represented by the formulas (1) and (2) have a structure similar to that of the above formula (5), but are not reactive, which is largely different from the compound of the formula (5). In the present invention, as shown in the formulas (1) and (2), the curing characteristics are influenced by having a structure that is almost equivalent to the formula (5) but has no reactivity. Therefore, it is considered that the same flame retarding effect and good product characteristics as the formula (5) already put into practical use could be obtained.

  In the present invention, the amount of the compound of formula (1) or formula (2) is preferably added in the range of phosphorus content of 0.5 to 7 when the resin composition is 100, More preferably, it is 0.5-6, More preferably, when adding in the range of 0.8-5, a favorable characteristic is provided. When other phosphorus-based flame retardants are used in combination, the compound of formula (2) or formula (1) is not zero and the phosphorus content of each compound is in the above range, it shows good characteristics .

  The present invention is a resin composition obtained by blending a compound having a structure given by formula (1), typically a compound of formula (2), and at the same time obtaining a high flame retarding effect, Good characteristics are obtained as a resin composition, laminate, prepreg and printed wiring board.

  The present invention is characterized by using a compound having a structure represented by the above formula (1) or (2), but does not limit the use of other flame retardants. For example, an organophosphorus compound having a structure represented by the above formula (3) can be used, and R14 to R18 represent any organic group not containing a halogen element. This is a so-called condensed phosphate ester in which a plurality of phosphoryl groups are bonded via R14. Specific examples thereof include 1,3-bis (diphenylphosphoryl) benzene [resorcinol bis (diphenyl phosphate) and a common name. The same shall apply hereinafter), resorcinol bis (dixylenyl phosphate), bisphenol A bis (diphenyl phosphate), bisphenol A bis (dixylenyl phosphate), etc. Is more preferable in terms of solvent solubility and cost.

  The compound of the formula (3) or the formula (4) can be blended with the compound of the formula (1) or the formula (2) at an arbitrary ratio as long as the ratio of the formula (1) or the formula (2) is not zero. The total amount of phosphorus contained in the compound of formula (3) or formula (4) is preferably added within a range not exceeding the total amount of phosphorus contained in formula (1) or formula (2).

  Further, a compound having a structure represented by the formula (5) and a derivative thereof, or a compound having the structure in the skeleton can also be used. The compound represented by formula (6) is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide or a derivative thereof such as 10- (2,5-dihydroxyphenyl) -9,10-dihydro. -9-oxa-10-phosphaphenanthrene-10-oxide (formula (5)) and 10- (2,5-dihydroxy-6-methylphenyl) -9,10-dihydro-9-oxa-10-phospha Phenanthrene-10-oxide, 10- (1,4-dihydroxy-2-naphthyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, these compounds used in the present invention it can.

（但し，Ｒ１３は水素原子もしくは，ハロゲン元素を含まないＣ_１〜Ｃ_２６の炭素を有する有機基を示す）

(However, R13 is or a hydrogen atom, an organic group having a carbon of _C 1 _{-C 26} containing no halogen element)

  However, the compound represented by the formula (5) has reactivity as described above. For this reason, it is preferable to use together the compound shown in Formula (5) which has reactivity, or the compound shown in Formula (6) in the range which does not have big influence on the sclerosis | hardenability of resin. The addition range is not particularly specified, but it is preferable to add the total amount of phosphorus contained in the compound of formula (1) or formula (2) within a range not exceeding. Further, the addition amount of the compound represented by the formula (5) is not particularly limited, but it is preferable to add it within a range in which the hydroxyl equivalent ratio does not exceed the equivalent ratio of the hydroxyl group of the curing agent.

  In addition, the compound represented by the formula (5) or the formula (6) is reacted in advance with a compound having a dihydrobenzoxazine ring, an epoxy resin, phenolic curing, etc. May be used after deleting or reducing.

  Here, the thermosetting resin used includes an epoxy resin, a urea resin, a melamine resin, and a phenol resin, and these can be used alone or in combination, and among them, the case of using an epoxy resin is most preferable. The epoxy resin here is bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, naphthalenediol type epoxy resin, phenol novolac type epoxy resin, cresol novolak type epoxy resin, bisphenol. A novolak-type epoxy resins, cycloaliphatic epoxy resins, glycidyl ester resins, glycidyl amine resins, heterocyclic epoxy resins (triglycidyl isocyanurate, diglycidyl hydantoin, etc.), and modified epoxies modified with various reactive monomers Resins and the like can be used, and two or more of these epoxy resins can be used in appropriate combination. In particular, it is desirable to use phenol novolac type epoxy resin, cresol novolac type epoxy resin or bisphenol A novolac type epoxy resin, because high heat resistance and reliability applicable to electrical and electronic materials are required. Although not particularly specified, the range of 1 to 50% by weight in the total resin composition is preferable in order to obtain a sufficient cured product.

In addition, a curing agent can be added for the purpose of improving workability and accelerating the curing of the added epoxy. Curing agents include phenolic, amine-based, cyanate-based, acid anhydride-based, and compounds having a dihydrobenzoxazine ring. As long as the addition amount is in a range that does not significantly inhibit the curing reaction of the resin composition, an arbitrary amount can be added, and it is particularly preferable to use in the range of 0 to 50% by weight of the resin composition. Specific examples include phenolic novolaks, cresol novolacs, bisphenol A, bisphenol F, bisphenol S, curing agents having a phenolic hydroxyl group such as melamine-modified novolac phenol resins, amine-based curing agents such as dicyandiamide, and the like. A cyanate curing agent, an acid anhydride, or a compound having a dihydrobenzoxazine ring can be used. The compound having a dihydrobenzoxazine ring here is easily synthesized by heating and reacting phenols, amines and aldehydes in an appropriate solvent such as methyl ethyl ketone (MEK), and removing the solvent and water. it can. For example, 1 mole of phenol and 1 mole of aniline and 2 moles of formaldehyde are added to 1 mole of phenol to be refluxed and cooled at any reaction rate. Thereafter, the resin can be obtained by removing the solvent, moisture, and possibly unreacted substances. Phenols can be phenol, cresol, bisphenol A, bisphenol F, bisphenol S, etc., amines can be aniline, diaminobenzene, etc., and aldehydes can be formaldehyde, paraform, etc. it can. Of course, these curing agents do not need to be used alone, and may be used in combination.
Further, the epoxy resin and the curing agent used in the present invention can be used after appropriately reacting in advance.

  In addition to the above, the resin composition of the present invention can also contain a filler for the purpose of reducing combustible components. Metal oxides such as silica, talc, mica, calcium silicate, potassium silicate, calcined clay, titanium oxide, barium sulfate, aluminum oxide, magnesium carbonate, calcium carbonate, barium carbonate, molybdenum oxide, zinc oxide, magnesium silicate, etc. In addition, a compound such as an oxide composed of a plurality of elements such as molybdenum, zinc, calcium, phosphorus, aluminum, and potassium may be used. Moreover, the compound which consists of a some combination of the oxide which consists of molybdenum, silicon, magnesium, and zinc may be sufficient.

  In addition to these, an inorganic filler can be added to the resin composition of the present invention for the purpose of increasing rigidity and reducing thermal expansion. In addition, pigments, adhesion assistants, antioxidants, curing accelerators can be added. In addition, there are no particular limitations as long as a known material can be used, and a non-halogen compound does not deteriorate the characteristics of the laminated board and the printed wiring board.

  The type and amount of the organic solvent are particularly limited as long as the epoxy resin and the curing agent constituting the resin composition are uniformly dissolved or dispersed and have appropriate viscosity and volatility to produce a prepreg. Although not intended, a resin composition that satisfies these requirements and contains a solvent such as methyl ethyl ketone, 2-methoxyethanol, 2-methoxypropanol, 1-methoxy-2-propanol from the viewpoints of price, handleability, and safety It is preferable to use about 5 to 40% by weight of the total weight.

  In addition, the resin composition of the present invention can produce a prepreg by impregnating and drying a non-woven fabric made of glass or aramid resin, or a substrate such as glass cloth. Furthermore, a laminated sheet can be manufactured by stacking a metal foil on the prepreg and stacking and integrating by heating and pressing.

  It is also possible to manufacture printed wiring boards by etching away unnecessary portions of the metal foil of this laminated board. If necessary, these printed wiring boards and prepreg, copper foil with resin, or adhesive film A multilayered printed wiring board can be manufactured by appropriately laminating copper foils alone or in combination, and heating and pressing them. In the manufacture of these prepregs, laminates, resin-coated copper foils, adhesive films, and printed wiring boards, the usual coating, lamination, and circuit processing processes in the industry can be applied. A laminated board and printed wiring board that are flame retardant and highly reliable and do not contain a halogen flame retardant can be obtained.

  Hereinafter, the present invention will be described more specifically with reference to examples of the present invention and comparative examples thereof, but the present invention is not limited to these examples.

In the examples and comparative examples, the following were used as epoxy resins, curing agents, organophosphorus compounds and other special materials. For other organic solvents, additives, general-purpose inorganic fillers, glass cloths and copper foils that make up laminates and prepregs, the raw materials generally used in the chemical and electronics industries are used except for those specifically mentioned. Using.
Epoxy resin: Cresol novolac type epoxy resin manufactured by Dainippon Ink and Chemicals, Inc.
Product name N-673 (epoxy equivalent 210)
Phenol-based curing agent A: Phenol novolac resin trade name Phenolite TD-2160 manufactured by Dainippon Ink & Chemicals, Inc.
Dihydrobenzoxazine compound (curing agent B)
A mixture of bisphenol A, aniline, and formalin in methyl ethyl ketone (MEK) at a molar ratio of 1/2/4, refluxed for 4 hours, distilled off the water and MEK, and the remaining resin was taken out and ground. Phosphorus Compound A: Compound having the structure of Formula 2 Trade name: SANKO-BCA
Manufacturer: Sanko Co., Ltd. Organophosphorus Compound B: 10- (2,5-dihydroxyphenyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide Product name HCA-HQ
Manufacturer: Sanko Co., Ltd. Organophosphorus Compound C: Condensed Phosphate Ester Product Name PX-200
Manufacturer: Daihachi Chemical Co., Ltd. Inorganic flame retardant: Aluminum hydroxide manufactured by Sumitomo Chemical Brand name CL-310

  The characteristics of the laminated board and the printed wiring board are evaluated by the combustion time according to the UL-94 vertical method for the flame retardancy. When the combustion time was less than 1 second and the maximum combustion time was 30 seconds or less, V-1 was classified as HB. Other laminate characteristics (copper foil peel strength, hygroscopic solder heat resistance, chemical resistance) were evaluated based on JIS C6481. Evaluation of heat resistance of moisture-absorbing solder is as follows: ○: No change, △: Mesling or eye lift occurrence, ×: Blister occurrence, varnish curability is determined by dropping 0.5 cc of varnish on a 160 ° C hot plate. The time until gelation with stirring with a 1 mm diameter rod (gelation time) was evaluated.

Examples 1-6
A resin composition for laminates was prepared according to the formulation shown in Table 1. This resin composition was impregnated into glass cloth (thickness 0.2 mm) and dried at 160 to 175 ° C. for 4 minutes to obtain a prepreg. Similarly, glass paper (thickness after molding 80 μm) was impregnated with resin and dried at 160 to 175 ° C. for 2 minutes to obtain an adhesive sheet.
Four prepregs were stacked, 18 μm copper foil was stacked on both sides, and heated and pressed at 185 ° C. and a pressure of 4 MPa for 80 minutes to prepare a double-sided copper clad laminate having a thickness of 0.8 mm. The properties of the laminate are shown in Table 1.
Circuit formation (test pattern) was performed on the surface of the double-sided copper-clad laminate produced in Examples 1 to 6 by the subtractive method. Further, the surface of the two produced double-sided copper-clad laminates with circuits was oxidized and roughened to improve adhesion, and the two prepregs produced in Examples 1 to 6 were sandwiched and overlapped. Two sheets and 18 μm copper foil were laminated and pressed to produce a 6-layer printed wiring board with an inner layer circuit. Outer layer circuit processing, through-hole formation, resist ink printing, and component mounting were performed on these printed wiring boards by conventional methods, and it was confirmed that they could be manufactured without problems in the normal printed wiring board manufacturing process.

Comparative Examples 1-3
Resin compositions were prepared in the same manner as in Examples 1 to 3, using the formulations shown in Table 1 and the methods shown in Examples. Using this resin composition, a prepreg was produced in the same manner as in the example, and a copper-clad laminate was produced. However, in Comparative Example 1, since no phosphorus flame retardant was added, sufficient flame retardancy was not obtained. Therefore, other evaluations were stopped. In Comparative Example 2, a phosphorus-based flame retardant was added, but since the flame retardant used was a reactive phosphorus-based flame retardant, good moldability was not obtained due to a significant influence on the curing system. In Comparative Example 3, since the phosphorus-based flame retardant essential in this patent was not used and only the condensed phosphoric acid ester was added, the flame retardancy was ensured, but other characteristics were greatly deteriorated.

  As shown in Table 1, in the illustrated examples, the necessary amount of phosphorus flame retardant is included and the composition of the resin composition is appropriate, so that there is no problem in productivity and moldability and a sufficient flame retardancy is maintained. A plate was obtained. In Example 1, by using the flame retardant essential in the present invention, sufficient flame retardancy was ensured and good product characteristics could be sold. In Example 2, a reactive phosphorus-based flame retardant was used in combination, but because the ratio was appropriate, good characteristics could be obtained without greatly affecting the curing system. Furthermore, sufficient characteristics could also be obtained in Example 3 in which a condensed phosphate ester was also used. Further, in Example 4 in which the phosphorus-based flame retardant A and the condensation type were used in combination, since both of the non-reactive flame retardants were used, good cured product characteristics could be obtained without affecting the curing system. Finally, in Example 6 to which aluminum oxide was added, the flame retardancy was further improved, the reliability of the base material was further improved, and more balanced characteristics could be obtained.

On the other hand, in Comparative Example 1, flame retardance could not be ensured because no phosphorus flame retardant was added. In Comparative Example 2, a phosphorus-based flame retardant was added. However, since the reactive compound was excessive, the curing characteristics fluctuated significantly and the moldability was greatly affected. Furthermore, although it is a non-reactive type phosphorus flame retardant, the characteristic was greatly deteriorated because the flame retardant essential in the present invention was not added.
Therefore, the superiority of the present invention is clear in terms of the blending ratio and blending amount of an appropriate flame retardant capable of maintaining adequate curability while ensuring sufficient flame retardancy.

Claims (8)

A flame retardant resin composition comprising an epoxy resin, an urea resin, a melamine resin, or a phenol resin containing an organic phosphorus compound represented by the following formula (1).

(However, R1～12 is or a hydrogen atom, an organic group having a carbon of _C 1 _{-C 20} where not, and no reactivity contain a halogen element) The flame retardant resin composition according to claim 1, wherein the organophosphorus compound is a compound represented by the following formula (2).

The flame retardant resin composition which added the organophosphorus compound shown to following formula (3) to the flame retardant resin composition of Claim 1 or 2.

(However, R14～18 is or a hydrogen atom, an organic group having a carbon of _C 1 _{-C 20} containing no halogen element) A flame retardant resin composition in which the organophosphorus compound represented by the formula (3) in claim 3 is a condensed phosphate ester represented by the following formula (4).

The flame-retardant resin composition which added the filler to the flame-retardant resin composition of Claims 1-4. A prepreg made using the flame retardant resin composition according to claim 1. A metal-clad laminate produced using the prepreg according to claim 6. A printed wiring board produced by arbitrarily combining the prepreg according to claim 6 and the metal-clad laminate according to claim 7.