JPS6045060B2 - Method for manufacturing flame-retardant metal-clad laminates - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a flame-retardant metal-clad laminate, and more specifically, a method for manufacturing a flame-retardant metal-clad laminate, and more specifically, a method for manufacturing a flame-retardant metal-clad laminate, and more specifically, a method for manufacturing a flame-retardant metal-clad laminate. The present invention relates to a method for manufacturing a flame-retardant metal-clad laminate having excellent solder heat resistance, which is obtained by stacking and integrally molding.

Conventionally, in the production of unsaturated polyester resin metal-clad laminates, it has been necessary to use prepregs that are not sticky at room temperature in terms of storage and workability.

Therefore, unsaturated polyester resins that are solid at room temperature, consisting of an amorphous unsaturated polyester that is solid at room temperature, and copolymerizable monomers and/or copolymerizable prepolymers that are solid at room temperature, are usually used in acetone, toluene, etc. A polymerization catalyst is dissolved in a solvent of Methods have been used to produce prepregs that are not tacky at room temperature by impregnating a fibrous substrate with the material and then allowing the solvent to evaporate under heat. In this case, expensive copolymerizable monomers or prepolymers that are solid at room temperature must be used, and solvents such as acetone and toluene are used during production, which not only complicates the process but also It was also unfavorable from an environmental standpoint.

The present inventors created an unsaturated polyester resin instead of such a prepreg by dissolving an unsaturated polyester mainly consisting of crystalline unsaturated polyester in a common liquid copolymerizable monomer such as styrene under heating. It has already been proposed to use prepregs that are non-tacky at room temperature using unsaturated polyester resins that are solid at room temperature and obtained by the method.

This metal-clad laminate obtained from prepreg and metal foil, which is not sticky at room temperature, has not only excellent adhesive properties but also excellent electrical properties, but it cannot be said to have sufficient heat resistance. . On the other hand, when looking at metal-clad laminates in general, especially copper-clad laminates, there is a strong demand for improved performance and safety, especially flame retardancy, and various standards require strict flame retardancy. requested.

Various efforts have been made to impart flame retardancy to copper-clad laminates using phenolic resins, epoxy resins, or the conventional unsaturated polyester resins mentioned above. As a result, a decrease in electrical properties, a decrease in adhesion of the copper foil, and a decrease in solder heat resistance, especially after boiling water treatment, are unavoidable. The present inventors have achieved excellent flame retardancy in manufacturing metal-clad laminates using the unsaturated polyester resin that is solid at room temperature, as well as excellent electrical properties, adhesion to metal foil, and As a result of extensive research in order to exhibit solder heat resistance after boiling water treatment, we decided to use a copolymerizable monomer mainly consisting of halogen-containing (meth)acrylic acid ester as the copolymerizable monomer of the unsaturated polyester resin. The present invention was achieved by discovering that the intended purpose could be achieved by the following methods.

That is, the present invention provides a method of producing a polyester at room temperature consisting of 40 to 8 parts of an unsaturated polyester mainly consisting of a crystalline unsaturated polyester and 60 to 2 parts of a copolymerizable monomer mainly consisting of a halogen-containing (meth)acrylic acid ester. A prepreg that is obtained by impregnating a fibrous base material with a solid unsaturated polyester resin while heating, which has no stickiness at room temperature, is layered with metal foil, and then heated and pressed to form an integral piece. This is a method for manufacturing a combustible metal-clad laminate.

The metal-clad laminate obtained in the present invention not only has excellent flame retardancy, but also excellent hanging heat resistance after boiling water treatment, and has good adhesion and electrical properties for metal foil. Are better. Furthermore, according to the method of the present invention, there is no need to use solvents such as acetone and toluene, which have been conventionally used in the production of prepregs that are not sticky at room temperature.

Therefore, it is not only possible to produce a prepreg that does not have tackiness at room temperature through a simplified process, but also to produce a prepreg that is very advantageous in terms of the environment of the production process. The crystalline unsaturated polyester used in the present invention is an unsaturated polyester produced using as raw materials a dicarboxylic acid or a functional derivative thereof having a symmetrical molecular structure and a diol also having a symmetrical molecular structure.

Specific examples include terephthalic acid, 1,4-naphthalic acid, 1,5-naphthalic acid, 2,
Symmetrical aromatic dicarboxylic acids and their functional derivatives such as 6-naphthalic acid, their lower alkyl esters or chlorides; symmetrical unsaturated aliphatic dicarboxylic acids such as fumaric acid, maleic acid, their lower alkyl esters, anhydrides or chlorides; Acids and their functional derivatives, diol raw materials include ethylene glycol, 1,3-propanediol, 1,4-butafundiol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl Glycol, 2-butene-1,
4-diol, 1,4-cyclohexanediol, 1,
4-cyclohexanedimethanol, 1,4-bis(2-
hydroxyethoxy)cyclohexane, 1,4-bis(
2-hydroxypropoxy)cyclohexane, 1,4-
Examples include symmetric diols such as bis(2-hydroxyethoxy)benzene, 1,4-bis(2-hydroxypropoxy)benzene, and p-xylylene glycol. As long as it does not significantly impair the crystallinity of the unsaturated polyester, it can be used in the production of amorphous unsaturated polyester to give ordinary liquid unsaturated polyester resin, along with the above-mentioned raw materials having molecular structure symmetry. A small amount of raw materials can be used together. Such raw materials include dicarboxylic acids and their functional derivatives, such as orthophthalic acid, isophthalic acid, tetrachloro- and tetrabromo-orthophthalic acid, succinic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, and 1,2-propane. Diol, diethylene glycol, dipropylene glycol, 1,3
-butanediol, 2,2,4-trimethyl-1,3-
Diol raw materials such as ethylene oxide and propylene oxide adducts of pentanediol, bisphenols, hydrogenated bisphenols and halogenated bisphenols can be mentioned. The general amount of these raw materials used in combination is 20 mol % or less of the total dicarboxylic acid component for the dicarboxylic acid component, and 40 mol % or less of the total diol component for the diol component. Two or more types of crystalline unsaturated polyesters can be used in combination. A normal amorphous unsaturated polyester can also be used in combination with the crystalline unsaturated polyester within a range that does not impair the solidity of the unsaturated polyester resin at room temperature.

The proportion in which they are used together varies depending on the degree of crystallinity of the crystalline unsaturated polyester, the type and amount of the copolymerizable monomer, etc., but it is necessary to maintain the solidity of the unsaturated polyester resin at room temperature. , it is desirable that the amount is 5% or less based on the total unsaturated polyester.

In this case, two or more types of amorphous unsaturated polyesters can be used together. Next, as the halogen-containing (meth)acrylic acid ester used in the present invention, 2,2-dichloroethanol, 2,2,2-trichloroethanol, 1,2-dibromoethanol, 2,3-dibromo1
-propanol, 1,1,1-terichloro-2-propanol, 1,1,1-tribromo-2-propanol,
2,2,3-trichloro-1-butanol, 2,2,3
-(meth)acrylic acid ester of halogen-containing lower alcohol such as tribromo-1-butanol, 2,2-bis(chloromethyl)-1,3-propanediol, 2,
(Meth)acrylic acid esters of halogen-containing lower glycols such as 2-bis(bromomethyl)-1,3-propanediol, halogen-containing compounds such as trichlorophenol, tribromophenol, pentachlorophenol, tetrachlorobisphenol, and tetrabromobisphenol A. Typical examples include (meth)acrylic esters and di(meth)acrylic esters of phenol and dihydric phenol.

Particularly preferred among these halogen-containing (meth)acrylic esters are 2,3-dibromo-1-propanol, 2,2-bis(bromomethyl)-1,3-propanediol, tribromophenol, and tetrabromobisphenol A. (meth)acrylic acid ester or di(meth)acrylic acid ester. Among these halogen-containing (meth)acrylic esters, chlorine-containing (
Bromine-containing (meth)acrylic esters are more effective in imparting flame retardancy than meth)acrylic esters, and halogen-containing (meth)acrylic esters with higher halogen content are more effective in imparting flame retardancy. . General copolymerizable monomers can be used in combination as long as they do not inhibit the imparting of flame retardancy to the metal-clad laminate. Such copolymerizable monomers include styrene, monochlorostyrene, t
- Styrenic monomers such as butylstyrene, α-methylstyrene, vinyltoluene, divinylbenzene, allylic monomers such as diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl fumarate, diallyl adipate, methyl or ethyl acrylate, and methacrylic acid Acrylic acid ester monomers that do not contain halogens such as methyl or ethyl,
Examples include vinyl acetate, dibutyl fumarate, and diallyl phthalate prepolymers. Halogen-containing organic compounds and phosphorus compounds, which are commonly used as additive flame retardants, not only significantly reduce the solder heat resistance of metal-clad laminates after boiling water treatment, but also affect the electrical properties and adhesion of metal foils. It cannot be used because it degrades it.

Such halogen-containing organic compounds include halogen-containing carboxylic acids such as tetrachlorophthalic anhydride, tetrachlorophthalic anhydride, tetrabromo phthalic anhydride, chlorendic anhydride, 2,3-dichloropropanol, 2,3-dibromo Halogen-containing alcohols such as 1-propanol, 1,1,2,2-tetrabromoethane, 1,2,3-tribromopropane, 1,2-dibromo-2,3-dichloropropane, 1,2,304-tetra Halogen-containing aliphatic hydrocarbons such as bromobutane,
Halogen-containing aromatic hydrocarbons such as tetrabromobenzene, hexachlorobenzene, hexabromobenzene, and pentabromotoluene, halogen-containing alicyclic hydrocarbons such as perchloropentacyclodecane and hexabromocyclododecane, 2,4, 6-trichlorophenol,
2,4,6-tribromophenol, pentachlorophenol, tetrachlorobisphenol A,) halogen-containing phenols such as tetrabromobisphenol A,
There are chlorinated paraffins, chlorinated polyethylenes, chlorinated polypropylenes, chlorinated polyphenyl, brominated polyphenyl, polyvinyl chloride, etc. Phosphorus compounds include triethyl phosphate, triphenyl phosphate, and tricresyl phosphate. , tris(monochloropropyl) phosphate, tris(dichloropropyl) phosphate, tris(dipromopropyl) phosphate, etc. A hygroscopic and non-water-soluble inorganic retardant can be used in combination with the halogen-containing (meth)acrylic ester.

Examples of such inorganic retardants include antimony trioxide, borax, zinc borate, and aluminum hydroxide. The amount of the copolymerizable monomer mainly consisting of halogen-containing (meth)acrylic acid ester is 20 to 6 weight percent of the unsaturated polyester resin.

If the blending amount exceeds 6%, the solidity of the unsaturated polyester resin at room temperature will not be sufficient, and at the same time,
It has drawbacks such as not losing flow resistance during molding and poor moldability. Furthermore, if the amount is less than 2% by weight, not only the flame retardance is insufficient, but also the physical properties of the metal-clad laminate are poor. When the halogen is bromine, the amount of the halogen-containing (meth)acrylic acid ester is preferably 15% by weight or more based on the unsaturated polyester resin, and when the halogen is chlorine, it is preferably 24% by weight or more based on the unsaturated polyester resin.

When the above-mentioned inorganic flame retardants are used together, the amount thereof can be reduced. The crystalline unsaturated polyester can be mixed with the copolymerizable monomer to form an unsaturated polyester resin that is solid at room temperature. This mixing can be carried out by a screw type or stirring blade type method such as a Panbury mixer, a pump blender, a kneader, or a high-speed mixer. The mixing is generally performed under heating. The unsaturated polyester resin used in the present invention, which is solid at room temperature, contains a polymerization catalyst, but the amount thereof is generally 0 parts per 10 parts of the unsaturated polyester resin.
．． It is contained in an amount of 3 to 3 parts by weight.

The polymerization catalyst may be a medium- or high-temperature curing catalyst used for normal liquid unsaturated polyester resins, but since the unsaturated polyester resins used in the present invention are solid at room temperature, unsaturated polyester resins Alternatively, when producing a composition containing fillers, pigments, inorganic flame retardants, thickeners, mold release agents, etc., it is necessary to knead them under heat in order to achieve sufficient mixing.
Therefore, it is necessary to select a polymerization catalyst that will not decompose under crosstalk conditions. Specific examples of such polymerization catalysts include methyl ethyl ketone peroxide, cyclohexanone peroxide, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydro Peroxide, P-menthane hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α,α2-bis(t-butylperoxy)
1 p-diisopropylbenzene, 2,5-dimethyl-2
, 5-di(benzoylperoxy)hexane, 2,5-
Dimethyl-2,5-di(t-butylperoxy)hexyne-3, decanoyl peroxide, lauroyl peroxide, stearoyl peroxide, benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, t-butylperoxy Laurate, t-butyl peroxybenzoate, di-t-butyl peroxyphthalate, t-butyl peroxymaleic acid, 1,
Examples include 1,3,3-tetramethylbutylperoxy-2-ethylhexanoate. If necessary, the unsaturated polyester resin or its composition that is solid at room temperature used in the present invention contains a polymerization inhibitor in order to prevent gelation during production or adjust the gelation time, but the content is not limited. Saturated polyester resin 1 (
4) It is generally contained in an amount of 0.5 parts by weight or less.

As the polymerization inhibitor, those used for controlling the gelation time of ordinary unsaturated polyester resins may be used, and there are no particular limitations on the polymerization inhibitor. The unsaturated polyester resin that is solid at room temperature used in the present invention may optionally contain fillers such as calcium carbonate, talc, clay, silica, calcium silicate, barium sulfate, magnesium carbonate, diatomaceous earth, glass powder, and silica sand. One or more compounding agents such as thickeners such as magnesium oxide, magnesium hydroxide, calcium oxide, and calcium hydroxide, and mold release agents such as zinc stearate and calcium stearate may be blended.

The fibrous base materials used in the present invention include glass fiber base materials such as roping cloth, glass cloth, tipped strand mat, filament mat, swirl mat, surf ace mat, glass vapor, asbestos cloth, asbestos There are asbestos fibrous substrates such as mats and asbestos paper. The metal foil used in the present invention is copper, aluminum, nickel, gold, silver, etc.
A thickness of 10 to 100 μm is preferable.

Any material generally used for metal-clad laminates, such as unsaturated polyester resin, phenol resin, or epoxy resin, may be used. In the production method of the present invention, first, the crystalline unsaturated polyester resin is impregnated into the fibrous base material while maintaining fluidity under heating, and the resin is allowed to cool to room temperature so that it does not become sticky at room temperature. Manufacture prepreg.

The blending amount of the fibrous base material varies depending on the method of forming the metal-clad laminate or the purpose of use, but it is generally 10 to 10% of the prepreg.
6% saliva volume. The prepreg thus obtained has no tackiness at room temperature. In this case, the prepreg may be covered with a film of polyester, polypropylene, polyethylene, polybutadiene, polyvinylidene chloride, polyvinyl chloride, or the like. The manufacturing method of the present invention manufactures a metal-clad laminate by overlaying a metal foil on the prepreg and integrally molding the prepreg with heat and pressure.

In general, metal foil is layered on the top, bottom, or both sides of the prepreg and integrally molded under heat and pressure. in this case,
A single sheet of prepreg may be used, or two or more sheets may be laminated. Regarding the forming conditions for metal-clad laminates,
Although it varies depending on the composition of the crystalline unsaturated polyester resin used, the type and amount of the polymerization catalyst, the composition of the prepreg, etc., generally the molding temperature is 70 to 200'C and the molding pressure is 10
~200kg/c! L. The molding time is from several minutes to several hours, and the molding is performed using a molding machine such as a multistage press or a general molding press. The production method of the present invention can be directly applied to the production of various laminate molded products such as laminate plates, laminate tubes, laminate cylinders, laminate rods, and molded laminate products without using metal foil.

The flame-retardant metal-clad laminate obtained by the manufacturing method of the present invention not only exhibits excellent flame retardancy, but also has excellent solder heat resistance especially after boiling water treatment, as well as electrical properties and adhesion with metal foil. It is also excellent. In addition, compared to conventional manufacturing methods, this copper-clad laminate does not require the use of solvents in the prepreg manufacturing stage, so it is not only extremely advantageous in terms of raw material costs and manufacturing costs, but also in terms of the working environment. is also highly preferred. The copper-clad laminate manufactured by the manufacturing method of the present invention is used in the field of printed wiring boards after being subjected to various secondary processes.

The present invention will be explained in more detail below using examples.

In the examples, "part" means part by weight, and "%" means weight %. Tests on the copper-clad laminates shown in Examples were conducted in accordance with JISO6481. The solder heat resistance was tested at 260'C, and the presence or absence of the copper foil surface was visually determined after a time period of 5 seconds had elapsed. In addition, a copper-clad laminate test piece was boiled in boiling distilled water for 2 hours, and after wiping off the moisture on the surface, the solder heat resistance was measured to determine the solder heat resistance after the boiling water treatment. Arc resistance is ASTM D-495, tracking resistance is IECPUb. Measured according to ll2. Difficulty is U
It was measured according to the method of L94, and it was determined whether it passed or failed as V-0. Reference Example Production of unsaturated polyester resin In a stainless steel autoclave equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a partial condenser equipped with a thermometer, 1.00 (molar ratio) of terephthalic acid and 2.10 (mole) of ethylene glycol were added. ratio) and 0.01 mol% potassium titanyl oxalate to terephthalic acid.
．． 03 mol% triethylamine was added and the gauge pressure was 3.
0kg/c! After reacting for 3 hours at a reaction temperature of 220 to 230° C. under pressure of t, the pressure was returned to normal pressure.

Next, 1.00 (molar ratio) of fumaric acid was added and the mixture was heated at normal pressure.
The reaction was carried out at a reaction temperature of 205 to 210°C under a nitrogen stream to obtain an unsaturated polyester (4) with an acid value of 10.
Similarly, unsaturated polyesters (B) to (D) were produced using the raw materials shown in Table 1.

(4) to (C) are crystalline unsaturated polyesters,
(D) is an amorphous unsaturated polyester. In the table, the symbols indicate the following.

FA: Fumaric acid MA: Maleic anhydride TPA: Terephthal EG: Ethylene glycol BG: 1,4-butanediol HG: 1,6-hexanediol PG: 1,2-propanediol Example 1 Crystalline unsaturated polyester (A ) 6(2) with 35 parts of 2,8-cypromopropyl acrylate and 5f of styrene! i
! The mixture was dissolved under heating to obtain an unsaturated polyester resin, and 0.04 parts of hydroquinone and 1 part of t-butyl peroxybenzoate were added under heating, mixed well, and then allowed to cool to room temperature to form a solid. An unsaturated polyester resin was obtained.

This unsaturated polyester resin was heated with a glass cloth of 50 cm width [EHlOOlN] while maintaining its fluidity.
, Nippon Glass Fiber Products] and then allowed to cool to room temperature to obtain a non-stick prepreg.

The glass content of this prepreg was about 50%. 1. The obtained prepreg was cut into 50CfrL x 50cm pieces and one piece was laminated. A polyethylene terephthalate (PET) film was laid on a pressing board heated to 140°C, a laminated prepreg was placed on top of it, and a copper foil was placed on top of it.
CF-T3, Fukuda Metal Foil Powder Industrial Products], and then P
After placing the ET film, 1. under contact pressure. Heat it for a while,
Subsequently, the two powders were heated at 140° C. under a pressure of 100 kg/(71° C.) to obtain a copper-clad laminate.

Similarly, copper-clad laminates were obtained from combinations of crystalline unsaturated polyesters shown in Table 2 and copolymerizable monomers containing halogen-containing (meth)acrylic acid esters as main components. The physical properties of the obtained copper-clad laminate are shown in Table 2. Comparative Example 1 55 parts of crystalline unsaturated polyester (B) and 20 parts of styrene
0.0% of hydroquinone was dissolved under heating to obtain an unsaturated polyester resin, and 0.0% of hydroquinone was further dissolved under heating. After adding and thoroughly mixing the mixture, 1 part of t-butyl peroxybenzoate and 25 parts of hexabromobiphenyl were allowed to cool to room temperature to obtain a solid unsaturated polyester resin composition.

A copper-clad laminate was obtained using this unsaturated polyester resin composition in the same manner as in Example 1.

Further, various halogen-containing flame retardants shown in Table 3 were blended to obtain copper-clad laminates. Table 3 shows the solder heat resistance and difficulty of the obtained copper-clad laminate.

Example 2 The ω portion of crystalline unsaturated polyester (C) was dissolved in a mixture of 25 parts of 2,2-vinis(bromomethyl)-1,3-propanediol ditacrylate and 15 parts of styrene under heating to obtain an unsaturated polyester. A saturated polyester resin was obtained, and 0.04 part of hydroquinone and 1 part of dicumyl peroxide were added to the mixture under heating, mixed well, and then allowed to cool to room temperature to obtain a solid unsaturated polyester resin.

25 parts of aluminum hydroxide and 5 parts of antimony trioxide were added to 100 parts of this unsaturated polyester resin, and mixed thoroughly using a high-speed mixer while heating to obtain an unsaturated polyester resin composition that was solid at room temperature. .

This unsaturated polyester resin composition was made into a 50cm wide tip strand while maintaining its fluidity under heating.
After impregnating a mat (EM3OO-G-1, manufactured by Nippon Glass Fiber Products), the mixture was allowed to cool to room temperature to obtain a non-tacky prepreg.

The glass content of this prepreg was about 40%. The obtained prepreg was cut into pieces of 50 CTn x 50 cm, three of them were laminated, and a copper foil (described above) was layered on top of the 50 CTn x 50 cm pieces.
Using a 50cm mold under a pressure of 100k9/d, 13
A copper clad laminate was obtained by heating at 0° C. for 3 days.

Similarly, a copper-clad laminate was obtained from a combination of a crystalline unsaturated polyester (C), a copolymerizable monomer mainly composed of a halogen-containing (meth)acrylic acid ester, and an inorganic flame retardant.

Table 4 shows the physical properties of the copper-clad laminate obtained. Comparative Example 2 A base of crystalline unsaturated polyester (C) is dissolved in 20 parts of styrene under heating to obtain an unsaturated polyester resin, and 0.0 parts of hydroquinone is further added under heating. The mixture was added with 1 part of dicumyl peroxide and 2 parts of hexabromobenzene and mixed well, and then allowed to cool to room temperature to obtain a solid unsaturated polyester resin composition.

A prepreg was obtained in the same manner as in Example 2 using this unsaturated polyester resin composition. Next, a copper-clad laminate was obtained by the same procedure as in Example 2.

Copper-clad laminates were also obtained from combinations of various halogen-containing flame retardants and inorganic flame retardants shown in Table 5. The solder heat resistance and difficulty of the obtained copper-clad laminate are shown in Table 5.

Claims (1)

[Claims] 1 An unsaturated polyester solid at room temperature consisting of 40 to 80 parts by weight of an unsaturated polyester mainly consisting of crystalline unsaturated polyester and 60 to 20 parts by weight of a copolymerizable monomer mainly consisting of a halogen-containing (meth)acrylate ester. A flame-retardant metal-clad laminate characterized in that a prepreg, which is not sticky at room temperature and is obtained by impregnating a fibrous base material with a resin under heating, is overlaid with metal foil and integrally molded by heating and pressing. Production method.