JPS642136B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention particularly relates to a cellulose-based halogen-containing unsaturated polyester resin flame-retardant electrical laminate having excellent punching workability and moisture resistance. The electrical laminate used in the present invention refers to a laminate or a metal foil-covered laminate used as a substrate for various electronic components, for example, and its shape is a plate-like material with a thickness of approximately 0.5 to 5 mm. say. The above laminate is manufactured by impregnating a cellulose base material with an unsaturated polyester resin, then laminating and curing the impregnated cellulose base material. For example, the present inventors have already proposed a method for continuously manufacturing electrical laminates using unsaturated polyester resin, which is liquid at room temperature, in Japanese Patent Application Laid-Open No. 53-77668, Japanese Patent Application No. 125541-1983, etc. There is. In addition, as an example of manufacturing a laminate by heat and pressure molding using an unsaturated polyester resin that is solid at room temperature, there is
There are many proposals such as JP-A-51-111885 and JP-A-52-92288, but these have not yet reached the stage of practical application. The cellulose-based unsaturated polyester resin laminate obtained by the method described above has extremely good electrical insulation properties, soldering heat resistance, mechanical strength, etc. under normal conditions, but moisture absorption deteriorates the properties of these laminates. It had the disadvantage that the drop was large.
Although the unsaturated polyester resin itself has excellent electrical insulation, heat resistance, and moisture resistance, it has poor adhesion to the cellulose that makes up the base material, and the interface between the resin and cellulose fibers peels due to moisture absorption. This is thought to be due to the fact that the amount of moisture absorbed increases accordingly, leading to a decrease in various performances. The present inventors have produced an unsaturated polyester resin laminate using cellulose as a base material, which has been pre-impregnated with a compound having a methylol group. It was discovered that it was possible to provide a laminate board and also eliminate the various drawbacks of the conventional unsaturated polyester resin laminates mentioned above, and patent application No. 54-53239 was filed.
and proposed No. 54-121180. Furthermore, in recent years, electrical laminates with excellent flame retardancy have been eagerly desired, as strict flame retardance requirements such as the US UL standards are now being required for this type of electrical laminates. . As a result of intensive research to solve the above problems, the present inventors have found that a cellulose base material pre-impregnated with a compound having a methylol group is impregnated with a halogen-containing unsaturated polyester resin and then molded. We discovered that it is possible to obtain electrical laminates that are flame retardant, heat resistant, and punchable.
We were able to solve the above issues all at once. The present invention will be explained in detail below. First, the halogen-containing unsaturated polyester resin used in the present invention will be explained. In general, unsaturated polyesters have a structural formula of unsaturated polyester chains, such as Polyols such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, and 1,5-pentanediol are used as raw materials; saturated polybasic acids include phthalic anhydride, isophthalic acid, terephthalic acid, and adipic acid. , sebacic acid, azelaic acid; unsaturated polybasic acids such as maleic anhydride and fumaric acid are common, and the unsaturated polyester resin is a mixture of an unsaturated polyester and a crosslinking monomer. Styrene is commonly used as a crosslinking monomer, but other examples include α-methylstyrene, vinyltoluene, chlorostyrene, divinylbenzene, alkyl acrylates having 1 to 10 carbon atoms, alkyl methacrylates having 1 to 10 carbon atoms, and phthalic acid. Monomers such as diallyl and triallyl cyanurate can also be used. Also, styrene and a mixture thereof may be used. The amount of these crosslinking monomers used is
20-50% by weight of unsaturated polyester resin. The halogen-containing unsaturated polyester resin of the present invention is completely different from general unsaturated polyester resins, and contains a halogen in the unsaturated polyester molecular structure, such as halogenated glycol as a polyol component and halogenated acid as an acid component. In addition to those using , it also includes reactive resins in which halogen is introduced after unsaturated polyester is synthesized by a conventional method, such as halogenated polyester manufactured by Japanese Patent Publication No. 46-8993.
Examples of the halogenated glycol include 2,2-dibromoneopentyl glycol, and examples of the halogenated acid include tetrabromophthalic acid, tetrachlorophthalic acid, chlorendoic acid, and acid anhydrides thereof. The halogen-containing unsaturated polyester resin is a mixture of the above-mentioned halogen-containing unsaturated polyester and a crosslinking monomer. As the crosslinking monomer, the same ones as those for general unsaturated polyester resins can be used. Of course, it is possible to incorporate rubber, plasticizers, fillers, and other additives, but the amount of flammable materials must be limited to a level that does not significantly reduce the flame retardance of the laminate. Examples of these include maleated polybutadiene and/or copolymers thereof as rubbers, commercially available ester plasticizers from adipic acid or phthalic acid and glycols as plasticizers, epoxidized soybean oil, etc. Examples of inorganic substances include calcium carbonate, silicic anhydride, and titanium oxide, which are used as fillers in polyester resins. Furthermore, in the present invention, it is desirable to add an additive type flame retardant as an additive. Commercially available additive flame retardants, i.e., non-halogen phosphate esters and halogen-containing phosphate esters, such as trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, octyl diphenyl phosphate, and tris(chloroethyl) phosphate. , tris(dichloropropyl) phosphate,
Tris (chloropropyl) phosphate, bis (2,3-dibromopropyl) 2,3-dichloropropyl phosphate, tris (2,3-dibromopropyl) phosphate, bis (chloropropyl) monooctyl phosphate, these and halogen containing Mixtures with additives, such as halogen-containing complex phosphoric esters, can be used. Furthermore, inorganic flame retardants such as antimony oxide, zirconium compounds, and aluminum hydroxide are also preferred. On the other hand, when curing, general-purpose organic peroxide,
A curing accelerator can be used if necessary.
That is, rather than using peroxydicarbonates, ketone peroxides, hydroperoxides, or diacyl peroxides as the peroxide used as the catalyst for curing the unsaturated polyester resin of the present invention, peroxyketals are preferred. Use of one or more peroxides selected from , dialkyl peroxides, and peroxy esters provides particularly favorable results in terms of solder heat resistance, electrical insulation properties, and adhesive properties. More preferred catalysts, which are preferably blended in an amount of about 0.5 to 2.0 parts based on the resin liquid, include peroxyketals such as 1-1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1-1-bis(t-butylperoxy)cyclohexane, n-butyl-4,4-bis(t-
butyl peroxy) valerate; examples of dialkyl peroxides include di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t
-butylperoxy)hexyne-3; Examples of peroxy esters include t-butylperoxyacetate, t-butylperoxy 2-ethylhexanoate, t-butylperoxylaurate, t-butylperoxybenzoate, etc. It is. As is clear from the above, the present invention includes commercially available chlorendicacid-based unsaturated polyester resins,
For example, HETRON manufactured by Futsuker, Polylite NA-281 manufactured by Dainippon Ink, reactive flame-retardant polyester resin in which bromine is introduced into the unsaturated bonds of unsaturated polyester, FMS-583 manufactured by Nippon U-Pica, etc.
FPM-531, FPM-231, etc. are also suitable. The preferred halogen content of the halogen-containing unsaturated polyester resin of the present invention varies depending on the flame retardant standards for electrical laminates, additives used together, etc., and is difficult to limit, but for example, the halogen-containing unsaturated polyester resin UL-94 V0 or
In order to achieve V1 class, it is necessary to contain approximately 20% by weight of chlorine and 15 to 18% by weight of bromine in the resin. Next, the compound having a methylol group for pre-treating the base material will be explained. There are various compounds having a methylol group that can be used as a substrate treatment agent in the present invention. Resins obtained by addition condensation include melamine resins, urea resins, and modified resins thereof, and also include those in which part or all of the methylol group is etherified with a lower alcohol such as methanol or butanol. Specifically, the general formula (However, R ₁ = H, CH ₃ , R ₂ = H, C ₁ to ₄ alkyl group) Among them, N-methylolacrylamide, N-methoxymethylolacrylamide, N-butoxy Preferable examples include methylol acrylamide, N-methylol methacrylamide, N-methoxymethylol methacrylamide, and N-butoxymethylol methacrylamide. One or two of these
A mixture of two or more types or a co-condensate of two or more types may be used. Further, as other specific examples, methylolmelamine and/or methylolguanamine are preferable, and these are initial condensates of formaldehyde and guanamines such as melamine or formoguanamine, acetoguanamine, propioguanamine, benzoguanamine, and adiposiguanamine, or their initial condensates. These include those in which part or all of the methylol group is etherified with a lower alcohol such as methylol or butanol. Furthermore, with these as main components, thermoplastic resins, various vegetable oils, modified products thereof, etc. may be mixed as appropriate for the purpose of improving mechanical properties, for example. Furthermore, better results can be obtained by mixing or condensing the following higher aliphatic derivatives in addition to the above-mentioned compounds having a methylol group such as methylolmelamine and/or methylolguanamine. Higher aliphatic derivatives include saturated fatty acids such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid; oleic acid, erucic acid,
From unsaturated fatty acids such as linoleic acid, eleostearic acid, and linolenic acid, and esters of the above fatty acids with polyhydric alcohols such as ethylene glycol, polyethylene glycol, propylene glycol, glycerin, pentaerythritol, and sorbitol, and the above fatty acids. aliphatic amides which are derivatives of and saturated or unsaturated higher alcohols such as caprylic alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, oleyl alcohol, linoleyl alcohol, and ethers of higher alcohols and polyhydric alcohols; Examples include fatty acid amines that are derivatives of higher alcohols. Oxyfatty acids such as ricinoleic acid and derivatives thereof can also be used in combination for the purpose of improving punching processability. In short, punching is achieved by having in the molecule both a group that can condense with the methylol group of the amino resin, such as a hydroxyl group, a carboxyl group, an amino group, an amide group, and a long-chain alkyl group that acts to weaken the cohesive force of the amino resin. These conditions are more preferable as a processability modifier. The number of higher aliphatic derivatives that meet these conditions is extremely large, but according to the results of studies conducted by the present inventors, when the number of carbon atoms is 8 or more, they can be used as punching processability modifiers. The effect of oleic acid and oleyl alcohol, which have 18 carbon atoms and one unsaturated group, and their derivatives such as oleic acid monoglyceride,
Oleic acid diglyceride, oleic acid amide,
It has also become clear that when oleylamine is used, the performance of the resulting laminate is well balanced and is a preferred embodiment of the present invention. The optimum amount of such a modifier to be used varies depending on the halogenated unsaturated polyester resin composition used in the laminate, but it is usually 3 to 40 parts per 100 parts of the compound having a methylol group. within the scope of the department. Regarding the method of using the processing agent, it is possible to use a compound having a methylol group or a mixture of the compound and the modifier in the form of a solution or suspension;
Alternatively, both may be used by condensing them in advance, or any method may be used. The methylol group-containing compounds of the present invention generally have a suitable affinity for both cellulose fibers and unsaturated polyester resins, making them useful for forming excellent composites, which in turn provide excellent electrical applications. Form a laminate. A pre-impregnated base material can be obtained, for example, by preparing a solution of the above-mentioned methylol group-containing compound in water or alcohol as a solvent, immersing the base material in the solution, and drying the base material. The final amount of the methylol group-containing compound treatment agent applied to the substrate is usually 5 to 30%, preferably 10 to 20%, based on the weight of the substrate. Using the treated substrate improves the bending strength. The whitening phenomenon during punching is improved. Particularly when exposed to a humid environment, the deterioration of solder heat resistance, metal foil adhesive strength, and electrical insulation properties is slight. The cellulose base material used in the present invention refers to a paper base material mainly composed of cellulose fibers such as kraft paper and linter paper, or a cellulose base material such as cotton or rayon. Paper substrates give more favorable results in the present invention. The method for producing a flame-retardant electrical laminate of the present invention includes, but is not limited to, impregnating the treated base material with the halogen-containing unsaturated polyester resin liquid, laminating the resin-impregnated base materials, and curing. Electrical laminates can be manufactured by this process. At this time, the halogen-containing unsaturated polyester resin is preferably liquid at room temperature, and its viscosity is 0.1 to 15 poise, more preferably 0.5 to 10 poise at room temperature. Furthermore, there is no restriction on the molding pressure when laminating and curing the base materials impregnated with halogen-containing unsaturated polyester resin, but as already proposed by the present inventors in Japanese Patent Application No. 125541/1983, A laminate with excellent performance can be obtained by curing under pressure-free conditions, which is a preferred embodiment of the present invention. Next, a second invention, a flame-retardant metal foil-clad electrical laminate made by adhering metal foil to a flame-retardant laminate, will be described. An adhesive layer with a thickness of 5 to 100 μm, preferably 25 to 80 μm is present between the metal foil and the laminate consisting of the pre-impregnated cellulose base material and halogen-containing unsaturated polyester resin as described above. As a result, a metal foil-clad electrical laminate having excellent flame retardancy, moisture resistance, and punching workability can be obtained. The use of flammable adhesives will not adversely affect the flame retardancy of the laminate within the thickness range of the adhesive of the present invention, ie 5 to 100 microns, preferably 25 to 80 microns. If it is less than 5μ, it will not be able to exhibit its performance as an adhesive, and if it exceeds 100μ, it will significantly reduce the flame retardance of the laminate, which is not preferable. In general, flame-retardant adhesives on the market generally have poor adhesive performance and are expensive, so the thickness of the laminate should be approximately 1 mm or more, preferably 1.2 mm or more.
When using a flame-retardant laminate with a relatively large thickness of mm or more, even if a flammable adhesive is used, the thickness of the adhesive layer is 5 to 100μ, preferably 25 to 80μ. The flame retardant effect of the invention can be expected. Furthermore, according to the method of the present invention, the deterioration of the electrical properties of the metal foil surface due to the flame retardant, which is said to be the case with phenol laminates, is caused by the combustible adhesive present between the laminate and the metal foil. It is possible to obtain a laminate with good electrical properties protected by the layers. A flammable adhesive is an adhesive that is not self-extinguishing and is an epoxy resin adhesive, that is, an adhesive consisting of a bisphenol A type epoxy resin and an amine hardener or an acid anhydride hardener; polyvinyl butyral phenol. Resins, rubbers such as nitrile rubber and phenolic resins, and phenolic resin adhesives can be used, but epoxy resins, polyamide resins such as polyamide amine resins, terminal amino group polybutadiene nitrile rubber, amine curing agents, or their curing agents can be used. Mixtures of agents are preferred as the adhesive of the present invention because the physical properties of the adhesive can be easily changed to desired ones by combining them. As the metal foil used in the present invention, copper foil, particularly electrolytic copper foil, is preferably used from the viewpoints of corrosion resistance, etching properties, adhesion properties, etc. Others include electrolytic iron foil,
Aluminum foil etc. are also illustrated. Regarding the manufacture of the flame retardant metal foil-clad electrical laminate of the present invention, the present inventors have already proposed in Japanese Patent Application No. 1983-83239, for example, when manufacturing a metal foil-clad laminate, metal foil is Another method is to apply an adhesive to the metal foil before laminating, then laminate the heat-treated adhesive-coated metal foil with a cellulose substrate impregnated with an unsaturated polyester resin, and then cure it under virtually no pressure. This is one of the preferred embodiments of the present invention. The flame-retardant electrical laminate produced by the above method has excellent flame retardancy, punching workability, and moisture resistance, and can be used as an electrical laminate for various purposes such as printed circuit boards. can. Next, the present invention will be explained in more detail with reference to Examples. Example 1 A kraft paper having a thickness of 285 μm was immersed in an 8% methanol solution of N-methylol acrylamide, taken out, and then heated and dried at 120° C. for 20 minutes to obtain an impregnated substrate. At this time, the amount of N-methylol acrylamide attached to the paper was 11.2%. This treated paper is coated with chlorendo acid-based unsaturated polyester resin Polylite NA281 (manufactured by Dainippon Ink).
Impregnate 100 parts by weight with a solution containing 1 part by weight of the curing catalyst Perhexa 3M (manufactured by NOF), stack 5 sheets of this impregnated paper and 2 sheets of polyester film on both sides, and heat at 100℃ for 45 minutes. After curing, a laminate with a thickness of 1.55 mm was obtained. The performance is shown in Table 1. Example 2 Five sheets of commercially available kraft paper (MKP-150 manufactured by Tomegawa Paper Industries) were soaked in the same treatment solution as in Example 1 and then dried. 100 parts by weight of the unsaturated polyester resin Yupica FPM-231 (made by Upica Japan) is impregnated with a resin liquid containing 1 part by weight of Perhexa 3M (made by NOF Corporation) as a curing catalyst, and the resin is superimposed using two pairs of rolls. At the same time, a commercially available electrolytic copper foil (CF-T5 manufactured by Fukuda Metals) is coated with a commercially available epoxy resin (Epicoat manufactured by Ciel Chemical Co., Ltd.), which is continuously unwound.
828), a commercially available polyamide resin (Persamide 125 manufactured by Henkel Japan), and a commercially available terminal amino group polybutadiene nitrile rubber (manufactured by BF Gutdoritsu,
ATBN) were thoroughly mixed by hand in a ratio of 7:2:1 and applied to a thickness of 80μm using a blade coater, and then passed through a tunnel furnace for adhesive heat treatment at 100℃ for 5 minutes. At the same time, the two sides are laminated, and the thickness is increased on the opposite side.
While laminating a 50 μm polyester film, the material was continuously transferred to a tunnel-shaped hot air oven at a temperature of 110° C., taking 30 minutes to pass through. After cutting,
After further heat treatment at 160℃ x 10 minutes, the thickness was reduced to approx.
A single-sided copper-clad laminate with a thickness of 1.6 mm was obtained. The performance is shown in Table 1.

[Table] The test method is as follows. 1 Punching workability: Continuous pins with a pitch of 1mmφ2.54mm
Uses molds including 23 pieces. 2 Water absorption rate: JIS-C6481 3 Soldering heat resistance: Same as above 4 Adhesive strength: Same as above 5 Flame resistance: UL-94 Example 3 Oleic acid monoglyceride (Riken vitamin oil,
Pour 50 parts by weight of water in which 6 parts by weight of methylolmelamine (Nippon Carbide Kogyo, Nikaresin S-305) was dissolved into 50 parts by weight of methanol in which 1.5 parts by weight of Rikemar OL-100) was dissolved, with strong stirring.
A suspension treatment solution was prepared. After immersing 285 μm thick kraft paper in this treatment solution and taking it out,
A treated paper base material was obtained by heating and drying at 120°C for 20 minutes. At this time, the amount of treatment agent attached to the paper was 13.8%. This treated paper is coated with chlorendo acid-based unsaturated polyester resin Polylide NA281 (manufactured by Dainippon Ink).
100 parts by weight was impregnated with a liquid containing 1 part by weight of the curing catalyst Perhexa 3M (manufactured by NOF Corporation), and 5 sheets of this impregnated liquid and 2 sheets of polyester film were laminated on both sides and heated at 100℃ for 45 minutes. harden for a minute,
A laminate with a thickness of 1.55 mm was obtained. The performance is shown second. Example 4 Commercially available kraft paper (MKP-150 manufactured by Tomegawa Paper Industries) was soaked in the same treatment solution as in Example 3 and then dried. Five sheets of commercially available kraft paper (MKP-150 manufactured by Tomegawa Paper Industries) were continuously conveyed and treated with commercially available flame retardant paper. 100 parts by weight of unsaturated polyester resin UPICA FPM-231 (manufactured by UPICA, Japan) is impregnated with a resin solution in which 1 part by weight of Perhexa 3M (manufactured by NOF Corporation) is added as a curing catalyst, and the resin is overlapped using two pairs of rolls. A commercially available epoxy resin (Epicoat 828, manufactured by Ciel Chemical Co., Ltd.) was applied to a commercially available electrolytic copper foil (CF-T5, manufactured by Fukuda Metals) that was continuously unwound.
and a commercially available polyamide resin (Versamide 125 manufactured by Henkel Japan) and a commercially available terminal amino group polybutadiene nitrile rubber (manufactured by BF Gutdrich, ATBN).
were thoroughly mixed by hand in a ratio of 7:2:1 and applied to a thickness of 80 μm using a blade coater, and then passed through a tunnel furnace for adhesive heat treatment at 100°C for 5 minutes. The objects were laminated at the same time, and a polyester film with a thickness of 50 μm was laminated on the opposite side.
Continuously transferred to a tunnel-shaped hot stove at 110℃,
It took 30 minutes to pass. After cutting, it was further heat treated at 160°C for 10 minutes to obtain a single-sided copper-clad laminate with a thickness of approximately 1.6 mm. The performance is shown in Table 2.

【table】

[Table] Note: The test method is the same as in Example 1.

Claims (1)

[Scope of Claims] 1. A flame-retardant electrical laminate obtained by impregnating a cellulose base material pre-impregnated with a compound having a methylol group with a halogen-containing unsaturated polyester resin and curing the impregnated cellulose base material. 2. The laminate according to claim 1, wherein the base material is pre-impregnated with a treatment agent whose main component is a compound having a methylol group. 3. The laminate according to claim 2, wherein the treatment agent is a mixture or condensate of methylolmelamine and/or methylolguanamine and a higher aliphatic derivative having at least one group capable of condensing with a methylol group in the molecule. Board. 4. The laminate according to claim 1, wherein an additive flame retardant is added to the resin. 5 A flame retardant product made by providing an adhesive layer with a thickness of 5 to 100μ between a flame retardant laminate obtained by impregnating a cellulose base material with a halogen-containing unsaturated polyester resin and curing it, and a metal foil. Metal foil laminate. 6. The laminate according to claim 5, wherein the adhesive layer has a thickness of 25 to 80μ. 7. The laminate according to claim 5 or 6, wherein the adhesive layer is flammable. 8. The laminate according to any one of claims 5 to 7, wherein the adhesive mainly comprises an epoxy resin and a polyamide amine curing agent. 9. The laminate according to any one of claims 5 to 8, wherein the laminate has a thickness of about 1 mm or more.