JPH10204255A - Thermosetting resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition, consisting essentially of a thermosetting resin having dihydrobenzoxazine rings and an epoxy resin having isocyanaurete rings, having a high glass transition temperature and a low water absorption percentage and excellent in flame retardance. SOLUTION: This composition consists essentially of (A) a thermosetting resin having dihydrobenzoxazine rings and (B) an epoxy resin having isocyanurate rings. A thermosetting resin having units represented by formulae I and II (R is methyl, phenyl, etc.) at (1/0.67) to (1/9) molar ratio of the units represented by formulae I/II and further >=1 respective numbers of the units represented by formulae I and II and 2-10 total number of the units represented by formulae I and II is preferred as the component A. For example, an epoxy resin prepared by substituting isocyanuric acid with glycidyl is cited as the component B. Furthermore, the component B is preferably compounded in an amount of 3-40 pts.wt. based on 100 pts.wt. total amount of the components A and B. A compound, etc., capable of promoting the ring opening of the dihydrobenzoxazine rings are preferably compounded in the objective composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition having a dihydrobenzoxazine ring which is suitably used as a raw material for producing prepregs, metal-clad laminates, sealing materials, wiring boards, etc., and cured products thereof. And a composite molding material containing the thermosetting resin, and a laminate and a wiring board using the same.

[0002]

2. Description of the Related Art Conventionally, phenol resins, epoxy resins, polyimide resins and the like have been used as thermosetting resin materials for electric and electronic devices typified by resins for copper-clad laminates. There has been an urgent need to develop a resin composition that is inexpensive, has a high glass transition temperature, and has a low water absorption rate, with further demands for higher density and higher reliability of parts.

[0003] The phenolic resins used so far do not satisfy both the glass transition temperature and the water absorption rate, and the epoxy resins exhibiting a high glass transition temperature have a high water absorption rate and are not sufficiently solder-resistant after water absorption. When a polyimide resin is used, it has a high glass transition temperature and a relatively low water absorption, but is not widely used because it is expensive.

[0004] In addition, a heat treatment having a dihydrobenzoxazine ring described in JP-A-49-47378, JP-A-61-78824, JP-A-2-69567 and JP-A-4-227922. The curable resin is
It is known that a cured product having a low water absorption rate and excellent in heat resistance and mechanical strength is provided, but a modification method for increasing the glass transition temperature is not yet known.

However, to achieve higher glass transition temperature and lower water absorption with the increase in density and reliability of electric and electronic parts, it is necessary to improve the reliability at the time of moisture absorption and to improve the wiring after mounting the parts. This is essential for suppressing deformation of the substrate due to heat.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin composition of a thermosetting resin having a dihydrobenzoxazine ring having a high glass transition temperature, a low water absorption, and excellent flame retardancy. And

The present invention also relates to a cured product of the thermosetting resin composition, a composite molding material containing the thermosetting resin composition, and a laminate and a wiring board using the same.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, by blending an epoxy resin having an isocyanuric ring with a thermosetting resin having a dihydrobenzoxazine ring. While maintaining a low water absorption of a thermosetting resin having a dihydrobenzoxazine ring, it is possible to impart properties such as a high glass transition temperature of an epoxy resin having an isocyanuric ring and excellent flame retardancy. When a halogenated flame retardant is used to improve the content, it has been found that the amount thereof can be reduced, and that the present invention has an environmental advantage, and based on these findings, the present invention has been completed.

That is, the present invention provides a thermosetting resin composition comprising, as essential components, at least one thermosetting resin having a dihydrobenzoxazine ring and an epoxy resin having an isocyanuric ring. It is.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The thermosetting resin having a dihydrobenzoxazine ring used in the thermosetting resin composition of the present invention has a dihydrobenzoxazine ring, and is obtained by a ring-opening polymerization reaction of the dihydrobenzoxazine ring. There is no particular limitation as long as it is a resin that cures. In particular,
For example, as shown in the following reaction formula, it can be synthesized from a compound having a phenolic hydroxyl group, a primary amine and formaldehyde.

[0011]

Embedded image (R in the formula is a methyl group, a cyclohexyl group, a phenyl group, or a phenyl group substituted with at least one alkyl group or alkoxyl group having 1 to 3 carbon atoms.) This resin is described in US Pat. No. 5,152,939. As shown in (1), a ring-opening polymerization reaction is caused by heating to form a phenolic hydroxyl group without generating volatile components, and to form a crosslinked structure having excellent properties. Further, as a feature of this resin, as shown in JP-A-7-188364, since the resin is crosslinked and cured by a ring opening reaction, voids hardly remain in the cured product, the cured product has a low water absorption,
It has relatively high glass transition temperature, high strength, and excellent flame retardancy.

The resin is prepared by adding a mixture of a compound having a phenolic hydroxyl group and a primary amine to formaldehyde such as formalin at 70 to 110 ° C., preferably at 70 to 110 ° C., as shown in the above reaction formula. 90-100 ° C
For 20 to 120 minutes, and then dried under reduced pressure at a temperature of 120 ° C. or lower.

Examples of the compound having a phenolic hydroxyl group include phenol novolak resins, resole resins, phenol-modified xylene resins (xylylene-modified phenol resins), alkylphenol resins, melamine phenol resins, phenol resins such as polybutadiene-modified phenol resins, and bis (2- (Hydroxyphenyl) methane, bis (4-hydroxyphenyl) methane, 4,4'-dihydroxydiphenylsulfone, 1,1-bis (4-hydroxyphenyl) ethane, p, p'-isopropylidenebiphenol (bisphenol A), tetra Bisphenol compounds such as fluorobisphenol A and 2,2-bis [4- (4'-hydroxyphenoxy) phenyl] propane; biphenol compounds such as 4,4'-biphenol; Rokishifeniru) methane, 1,
Examples include trisphenol compounds such as 1,1-tris (4-hydroxyphenyl) ethane, and tetraphenol compounds. These are not particularly limited, but those in which the ortho position of the hydroxyl group serving as a crosslinking point is unsubstituted are desirable from the viewpoint of curing properties.

Specific examples of the primary amine include methylamine, cyclohexylamine, substituted anilines such as aniline, toluidine and anisidine. When it is an aliphatic amine, the obtained thermosetting resin cures quickly but has poor heat resistance. If it is an aromatic amine like aniline,
The cured product obtained by curing the obtained thermosetting resin has good heat resistance, but cures slowly.

Among the thermosetting resins having a dihydrobenzoxazine ring, preferably, the structural unit (A) represented by the following formula (A) and the structural unit represented by the following formula (B) in one molecule (B), wherein each structural unit is bonded directly or via an organic group, the molar ratio of (A) / (B) is 1 / 0.25 to 1/9, and 1 molecule When the number of structural units (A) is m and the number of structural units (B) is n,
A thermosetting resin having m ≧ 1, n ≧ 1 and 10 ≧ m + n ≧ 2 is used.

[0016]

Embedded image (Wherein R is a methyl group, a cyclohexyl group, a phenyl group or a phenyl group substituted with at least one alkyl group or alkoxyl group having 1 to 3 carbon atoms,
Hydrogen in the aromatic ring of (A) and (B), except for one of the ortho positions of the hydroxyl group of (A), may be substituted with an alkyl group or alkoxyl group having 1 to 3 carbon atoms or a halogen atom. M and n are within the above ranges, and the structural units (A) and (B)
If the space is previously bound by a stable bond via a group having an appropriate chain length, the properties of the cured product will be good.

The structural unit (A) and the structural unit (B) are bonded directly or via an organic group. Examples of the organic group include an alkylene group and a divalent aromatic group. Examples of the alkylene group include an alkylene group having 5 or more carbon atoms,-
And an alkylidene group represented by CR'H- (wherein R 'is a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a phenyl group or a substituted phenyl group). Examples of the substituent of the substituted phenyl group include a methyl group, a methoxy group, and a carboxyl group. Further, examples of the divalent aromatic group include a phenylene group, a xylylene group, and a tolylene group. Two or more of the above organic groups may be inserted between each structural unit.

The thermosetting resin used in the present invention comprises:
The molar ratio of (A) / (B) is preferably 1 / 0.25 to
1/9, more preferably 1 / 0.67 to 1/9.
Outside this range, curability, mechanical strength, and heat resistance may decrease.

The epoxy resin having an isocyanuric ring used in the present invention is not particularly limited as long as it has two or more epoxy groups and an isocyanuric ring in the molecule. For example, an epoxy resin in which hydrogen of isocyanuric acid is substituted with a glycidyl group may be used.

The mixing ratio of the thermosetting resin having a dihydrobenzoxazine ring to the epoxy resin having an isocyanuric ring is such that the total amount of the thermosetting resin having a dihydrobenzoxazine ring and the epoxy resin having an isocyanuric ring is 1
It is preferable to add 3 to 40 parts by weight of the epoxy resin to 00 parts by weight. If the amount is less than 3 parts by weight, the effect of improving the glass transition temperature is small, and if it exceeds 40 parts by weight, the crosslink density of the cured product decreases, so that the improvement in the glass transition temperature cannot be expected.

The thermosetting resin composition of the present invention has a compound capable of accelerating the ring-opening reaction of the dihydrobenzoxazine ring and a compound capable of accelerating the reaction between the epoxy group and the hydroxyl group generated by opening the dihydrobenzoxazine ring. A conventionally known catalyst for an epoxy resin can be blended.

Examples of the compound capable of promoting ring opening of the dihydrobenzoxazine ring include a compound having a phenolic hydroxyl group and a primary amine. Examples of the compound having a phenolic hydroxyl group include modified phenol resins such as a phenol novolak resin, a resole resin, a xylene-modified phenol resin, and a xylylene-modified phenol resin.

The compounding ratio of the thermosetting resin having a dihydrobenzoxazine ring and the compound capable of promoting the ring opening reaction of the dihydrobenzoxazine ring is determined by the total amount of the thermosetting resin having a dihydrobenzoxazine ring and the compound. It is preferable to mix 3 to 50 parts by weight of a compound capable of promoting the ring-opening reaction of the dihydrobenzoxazine ring with 100 parts by weight. If the amount is less than 3 parts by weight, the ring-opening reaction is not remarkably accelerated. If the amount exceeds 50 parts by weight, the glass transition temperature decreases due to the decrease in crosslink density, and the water absorption, which is a feature of the thermosetting resin having a dihydrobenzoxazine ring. Characteristics will be impaired.

A cured product of a thermosetting resin having a dihydrobenzoxazine ring has a characteristic that it has a lower water absorption than a cured product of a conventional thermosetting resin such as an epoxy resin or a phenol resin. This phenomenon is considered to be because the phenolic hydroxyl group is fixed by the interaction with the nitrogen atom. For this reason, the molar ratio (phenolic hydroxyl group / nitrogen atom) of the phenolic hydroxyl group in the cured product to the nitrogen atom derived from the dihydrobenzoxazine ring of the thermosetting resin, and the OH / N ratio are 1.5 or less, preferably 0 or less. .3 ~
It is desirably 1.5.

Examples of catalysts for epoxy resins include amine compounds such as benzylmethylamine, imidazole and its derivatives, phosphorus compounds, boron trifluoride amine complex and dicyandiamide. These can be used in combination of two or more.

The mixing ratio of the epoxy resin catalyst is preferably 0.5 to 5 parts by weight based on 100 parts by weight of the epoxy resin.

A compound capable of accelerating the ring opening reaction of the dihydrobenzoxazine ring and an epoxy resin catalyst can be used in combination.

Further, the thermosetting resin composition of the present invention includes:
If necessary, an epoxy resin or a halogenated epoxy resin can be blended. As epoxy resin,
Examples include bisphenol-based epoxy resins, polyphenol-based epoxy resins, polyglycol-type epoxy resins, alicyclic epoxy resins, and the like. Examples of halogenated epoxy resins include halogenated bisphenol A such as tetrabromobisphenol A or tetrabromobisphenol F.
And glycidyl ethers of halogenated bisphenol F, and brominated novolak type epoxy resins.
These can be used in combination of two or more.

Further, the thermosetting resin composition of the present invention may be blended with ordinary reinforcing materials such as inorganic fillers, organic fillers, and fiber reinforcing materials. These may be used alone or as a mixture of two or more.

Examples of the organic filler include cotton floc, α-cellulose, pulp, wood flour and the like. As the inorganic filler, zircon powder, quartz glass powder, talc powder,
Examples include calcium carbonate powder, magnesium hydroxide powder, magnesia powder, calcium silicate powder, silica powder, zeolite, clay, and mica. Examples of the fiber reinforcing material include staple fiber, thread, cotton cloth, glass cloth, glass nonwoven fabric, glass fiber, carbon fiber, quartz fiber, organic fiber nonwoven fabric, and paper. The mixing ratio of these reinforcing agents is based on 100 parts by weight of the thermosetting resin.
Preferably it is 10 to 300 parts by weight.

Further, a releasing agent, a coloring agent, and the like can be added to the above composition, if necessary.

A composite molding material containing an inorganic filler and a fiber reinforcing material as essential components has excellent flame retardancy.

A laminate obtained by laminating a composite molding material comprising the thermosetting resin composition, wherein the fiber reinforcing material is a glass cloth, a glass nonwoven fabric, an organic fiber cloth, an organic fiber nonwoven fabric, or paper; A wiring board in which a wiring pattern is provided inside or on a surface of a substrate containing a cured material of a thermosetting resin composition as a matrix and containing an inorganic filler and a fiber reinforcing material is also excellent in flame retardancy.

With respect to the mixing of the thermosetting resin composition having a dihydrobenzoxazine ring, there is no particular limitation on the method, order and the like.

The method of impregnating the base material with these resin compositions is also not particularly limited, but usually, these resin compositions are made into a solution by using an organic solvent, and then applied to the base material and dried. The prepregs obtained in this manner are overlapped, copper foil is overlapped on both sides of the prepregs, and pressed to produce a copper-clad laminate.

The copper-clad laminate thus manufactured is
It exhibits a high glass transition temperature and a low water absorption rate, and can greatly improve the reliability at the time of water absorption and at high temperatures. Also, since the coefficient of thermal expansion is small, the warpage of the board when mounting components is extremely small, and it is suitable for mounting of BGA or the like.

The thermosetting resin composition of the present invention is kneaded by a heating roll or the like, and thereafter, at 180 to 220 ° C. and a molding pressure of 2
Cured by compression molding or transfer molding at 0 to 70 kgf / cm ² for 3 to 10 minutes to obtain a cured product having good mechanical properties and low hygroscopicity utilizing the properties of the thermosetting resin having a dihydrobenzoxazine ring. be able to.

The cured product is further heated at 180 to 220 ° C.
By post-curing for 5 to 120 minutes, a cured product having better properties can be obtained. In addition, the thermosetting resin composition of the present invention does not generate volatile by-products at the time of curing, and therefore does not have an odor or the like and does not cause deterioration of the working environment.

[0039]

EXAMPLES 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.

A thermosetting resin having four types of dihydrobenzoxazine rings was synthesized by the following method. [Resin A] (1) Synthesis of phenol novolak resin 1.9 kg of phenol, formalin (37% aqueous solution)
1.0 kg and 4 g of oxalic acid were charged into a 5-liter flask and reacted at a reflux temperature for 6 hours. Continue with 6 inside
The pressure was reduced to 666.1 Pa or less to remove unreacted phenol and water. The obtained resin had a softening point of 84 ° C. (ring and ball method) and a 3 to polynuclear / binuclear ratio of 82/18 (peak area ratio by gel permeation chromatography).

(2) Introduction of dihydrobenzoxazine ring 1.70 phenol novolak resin synthesized as described above
kg (corresponding to 16 mol of hydroxyl groups) to 0.1 kg of aniline.
The mixture was mixed with 93 kg (corresponding to 10 mol) and stirred at 80 ° C. for 5 hours to prepare a uniform mixed solution. 1.62 kg of formalin was charged into a 5 liter flask and heated to 90 ° C., and a phenol novolak resin / aniline mixed solution was gradually added thereto over 30 minutes. 30 after completion of addition
For 2 minutes at reflux temperature, then at 100 ° C. for 2 hours 66
Condensed water was removed by reducing the pressure to 66.1 Pa or less to obtain a thermosetting resin in which 71% of the reactive hydroxyl groups had been converted to dihydrobenzoxazine.

1.70 kg (corresponding to 16 mol of hydroxyl groups) of the phenol novolak resin synthesized in the above (1) were reacted in the same manner as 1.4 kg (corresponding to 16 mol) of aniline and 2.59 kg of formalin (37% aqueous solution).
A thermosetting resin having a dihydrobenzoxazine ring introduced into all of the reactive hydroxyl groups was synthesized. Excess aniline and formalin were removed during drying, and the yield of this thermosetting resin was 3.34 kg. This indicates that 14 mol of the hydroxyl groups of the phenol novolak resin had reacted and converted to dihydrobenzoxazine.

From this, the thermosetting resin obtained earlier is:
10mol out of 14mol of hydroxyl group which can react
It is presumed that 1 (= 71%) is dihydrobenzoxazinated. [Resin B] (1) Synthesis of phenol novolak resin 1.90 kg of phenol, formalin (37% aqueous solution)
1.15 kg and 4 g of oxalic acid were charged into a 5-liter flask, and a phenol novolak resin was synthesized in the same manner as in Example 1. The obtained resin has a softening point of 89 ° C (ring and ball method),
The ratio was 3 to polynuclear / binuclear 89/11 (peak area ratio by gel permeation chromatography).

(2) Introduction of Dihydrobenzoxazine Ring A dihydrobenzoxazine ring was introduced in the same manner as in Example 1. The resulting thermosetting resin had a dihydrobenzoxazine ring introduced into 75% of the reactive hydroxyl groups of the phenol novolak resin. [Resin C] In (2) of the synthesis of [Resin A], instead of the phenol novolak resin, a xylylene-modified phenol resin (Mirex XL-2 manufactured by Mitsui Toatsu Chemicals, Inc.)
1.70 kg (25-3 L) (10 mol of hydroxyl groups)
Equivalent), 0.52 kg (5.6 mol) of aniline and 0.91 kg of formalin were obtained in the same manner to obtain a thermosetting resin having a dihydrobenzoxazine ring introduced.

With respect to the xylylene-modified phenol resin,
The amount of hydroxyl groups that can react was calculated as follows.

Xylylene-modified phenolic resin 1.70k
g (corresponding to 10 mol of hydroxyl groups), aniline 0.9
2.62 kg of a thermosetting resin having a dihydrobenzoxazine ring introduced therein was obtained by mixing 3 kg (corresponding to 10 mol) and 1.62 kg of formalin. Excess aniline and formalin were removed during drying. From this yield, the amount of hydroxyl groups that can react is determined to be 7.9 mol. From this, it is estimated that in the obtained thermosetting resin, 5.6 mol (= 71%) of 7.9 mol of the reactive hydroxyl group was converted to dihydrobenzoxazine. [Resin D] In (2) of the synthesis of [Resin A], instead of aniline, 0.70 kg of aniline and 0.2 parts of toluidine were used.
A thermosetting resin having a dihydrobenzoxazine ring introduced therein was obtained in the same manner except that 7 kg of the mixture was used. The resulting thermosetting resin had a dihydrobenzoxazine ring introduced into 71% of the reactive hydroxyl groups of the phenol novolak resin.

Examples 1 to 5 and Comparative Examples 1 to 5 Cured products obtained by curing a resin composition having the composition shown in Table 1 (numbers indicate parts by weight) at 180 ° C. for 30 minutes were evaluated.

[0048]

[Table 1] HP-850N: Hitachi Chemical Co., Ltd., phenol novolak resin TEPIC: Nissan Chemical Industries, Ltd., isocyanuric ring-containing epoxy resin, epoxy equivalent 100

[0049]

[Table 2] Glass transition temperature was measured using a differential scanning calorimeter. The water absorption was measured after the PCT was treated for 10 hours.

Examples 6 to 10 and Comparative Examples 6 to 10 A brominated epoxy resin (YDB-4 manufactured by Toto Kasei KK) was added to the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 5 shown in Table 1.
00T) 20 parts by weight, and methyl ethyl ketone was used as a solvent to prepare a varnish of a 65% by weight solution. This varnish was applied to a glass cloth. Coating conditions are coating temperature,
The time was set under the following conditions: 140 ° C. for 1.5 minutes, 17 minutes
The test was performed at 0 ° C for 2 minutes, at 175 ° C for 2 minutes, and at 150 ° C for 1 minute. Copper foil was placed on both sides of the obtained eight coated cloths,
At 0 kg / cm ² , the temperature was raised from room temperature to 185 ° C. over 30 minutes, and heat and pressure were laminated at 185 ° C. for 30 minutes to obtain a copper-clad laminate.

The obtained copper-clad laminate was subjected to a water absorption treatment by a pressure cooker test (PCT) method for 10 hours, and then immersed in a solder bath to measure the time required for blistering to evaluate the moisture and heat resistance. . Also. Glass transition temperature was measured by TMA. The value of water absorption was measured after the PCT treatment for 3 hours. Table 3 shows the measurement results.

[0052]

[Table 3] The halogenated epoxy resin (YDB-400T manufactured by Toto Kasei Co., Ltd.) was mixed with the resin compositions of Example 1 and Comparative Example 1 while changing the number of parts, and halogenation necessary for achieving V-0 in the UL combustion test was obtained. The amount of epoxy resin was measured.

As a result, at least 14 parts by weight was required in Comparative Example 1, but in the resin composition of Example 1 using an epoxy resin having an isocyanuric ring, the addition of at least 10 parts by weight required the flame retardancy in the UL test. Properties V-0 could be achieved.

[0054]

The thermosetting resin composition, composite molding material, laminate and wiring board containing the thermosetting resin having a dihydrobenzoxazine ring of the present invention have a high glass transition temperature and excellent flame retardancy. In addition, it has good mechanical properties and low hygroscopicity, and can ensure high reliability when used for electric and electronic applications.

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI C08L 61/06 C08L 61/06 63/00 63/00 B H05K 1/03 610 H05K 1/03 610L 610K (72) Inventor Yoshinori Sato Ibaraki Prefecture 1,500 Ogawa, Odate, Shimodate City Hitachi Chemical Industry Co., Ltd., Shimodate Plant (72) Inventor: Shinichi Kamoshida 1500, Oji Ogawa, Shimodate City, Ibaraki Prefecture, Japan: Shimodate Plant, Hitachi Chemical Industry Co., Ltd. 1500 Shimodate Plant, Hitachi Chemical Co., Ltd. (72) Inventor Shunichi Numata 1500 Oji Ogawa, Shimodate City, Ibaraki Prefecture Shimodate Plant, Hitachi Chemical Co., Ltd.

Claims (7)

[Claims] 1. A thermosetting resin composition comprising, as essential components, at least one thermosetting resin having a dihydrobenzoxazine ring and an epoxy resin having an isocyanuric ring. 2. A thermosetting resin having at least one dihydrobenzoxazine ring, an epoxy resin having an isocyanuric ring, and a compound having a phenolic hydroxyl group capable of accelerating the ring opening reaction of the dihydrobenzoxazine ring. The thermosetting resin composition according to claim 1. 3. A cured product obtained by curing the thermosetting resin composition according to claim 1. 4. The molar ratio (phenolic hydroxyl group / nitrogen atom) of the phenolic hydroxyl group in the cured product to the nitrogen atom derived from the dihydrobenzoxazine ring of the thermosetting resin is 1.5.
The cured product according to claim 3, which is: 5. A composite molding material comprising the thermosetting resin composition according to claim 1 or 2, an inorganic filler and a fiber reinforcing material as essential components. 6. A laminate obtained by laminating and heating the composite molding material according to claim 5, wherein the fiber reinforcing material is glass cloth, glass nonwoven fabric, organic fiber cloth, organic fiber nonwoven fabric or paper. 7. A wiring substrate comprising a cured product of the thermosetting resin composition according to claim 1 or 2 as a matrix, and a wiring pattern provided inside or on a surface of the substrate containing an inorganic filler and a fiber reinforcing material.