JPS6345415B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a so-called cold punching (low-temperature punching) type cellulose-based halogen-containing unsaturated polyester resin flame-retardant electrical laminate that has excellent moisture resistance and improved punching processability. The electrical laminate used in the present invention refers to a laminate or a metal foil-covered laminate that is used as a substrate for various electronic components, and its shape is, for example, a plate with a thickness of about 0.5 to 5 mm. means. 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 that is liquid at room temperature in Japanese Patent Applications No. 53-77668 and No. 53-125541, 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, Japanese Patent Publication No. 48-29625,
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. There was a tendency for the decline to be 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. In view of this current situation, the present inventors have already conducted intensive research and found that by producing an unsaturated polyester resin laminate as a base material pre-impregnated with a compound having a methylol group, it has been found that It was discovered that it was possible to provide an electrical laminate with excellent properties, and also to eliminate the various drawbacks of the conventional unsaturated polyester resin laminate described above, and proposed the invention in Japanese Patent Application No. 53239/1983. Furthermore, in practical use, these electrical laminates and copper-clad laminates are usually punched out.
Shaping and drilling are often performed, and therefore excellent punching properties are required. Especially in recent years, with the miniaturization of electronic components and higher density of circuits,
Currently, more advanced processing characteristics are desired. Conventionally, unsaturated polyester/base laminates are made by impregnating crystalline polyester or polyester that is solid at room temperature with a crosslinking agent using a solvent, drying it to form a prepreg, and then heat-pressing it to create a laminate. I've been exposed to it. However, although the laminates made by these methods have a high glass transition temperature and excellent heat resistance, they have poor punching processability, especially at temperatures typically between 50 and 80°C.
There were problems with workability during low-temperature punching, which is carried out in some areas. 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 found that a mixture of (a) a halogen-containing unsaturated polyester resin and (b) an unsaturated polyester resin for hardness adjustment was used as a base material impregnating resin. The above problems can be solved at once by using a mixed resin whose glass transition temperature after curing is 20 to 80°C, and by using a base material that has been previously treated with a compound having a methylol group. I was able to solve the problem. The present invention will be explained in detail below. First, the halogen-containing unsaturated polyester resin and the hardness-adjusting unsaturated polyester resin used in the present invention will be explained. In general, unsaturated polyesters are those whose structural formula of the unsaturated polyester chain is e.g. The raw materials include polyols such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, and 1,5-bentanediol, and saturated polybasic acids such as phthalic anhydride, isophthalic acid, terephthalic acid, and adipic acid. , sebacic acid, azelaic acid, and 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 acrylate having 1 to 10 carbon atoms, 1 carbon number
Monomers such as ~10 alkyl methacrylates, diallyl phthalates, triallyl cyanurates, etc. can also be used. Also, styrene and a mixture thereof may be used. The amount of these crosslinking monomers used is 20 to 50% by weight of the 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, and contains halogenated glycol as a polyol component and halogenated acid as an acid component. In addition to those in which unsaturated polyesters are synthesized using conventional methods, halogenated polyesters are also included, such as reactive resins in which halogen is introduced after synthesis of unsaturated polyesters using conventional methods, such as halogenated polyesters manufactured by Japanese Patent Publication No. 46-8993. Examples of the halogenated glycol include 2,2-dibromo-neopentyl glycol, and examples of the halogenated acid include tetrabromophthalic acid, tetrachlorophthalic acid, chlorendo 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. Therefore, commercially available chlorendo acid-based unsaturated polyester resins, such as those manufactured by Futsuker Co., Ltd.
HETRON, Dainippon Ink Polylite NA−281
and reactive flame-retardant polyester resins in which bromine is introduced into the unsaturated bonds in unsaturated polyester, such as FMS-583, FPM-531, and FPM-231 manufactured by Nippon U-Pica Co., Ltd.
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 The V0 range of UL-94 alone is
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. However, although halogen-containing unsaturated polyester resins have high flame retardancy, they generally have a relatively high glass transition temperature (hereinafter referred to as Tg) and have poor punching processability, especially in low-temperature punching, which is usually performed at about 50 to 80°C. They tend to have poor sex. The present inventors have already found that in the case of ordinary unsaturated polyester resins, there is a close relationship between the Tg of the cured resin composition and the optimal punching temperature of a laminate made of such a resin composition. There is a relationship between the Tg of the cured resin composition and the Tg + 20°C,
Particularly preferably, a temperature range of about Tg + 10°C is suitable, that is, the Tg of the cured product of the unsaturated polyester resin composition is 20 to 80°C, preferably 30 to 70°C.
It was discovered that excellent low-temperature punching workability could be obtained by making a laminate using the unsaturated polyester resin composition of 1989-45871. As a result of examining the punching processability of halogen-containing flame-retardant polyester resin, the present inventors found that
We have discovered that excellent low-temperature punching workability can be obtained by using a mixture of a halogen-containing flame-retardant polyester resin and a hardness-adjusting unsaturated polyester resin, leading to the present invention. That is, a mixed composition of a halogen-containing flame-retardant unsaturated polyester resin and a hardness-adjusting unsaturated polyester resin is used such that the cured product has a Tg of 20 to 80°C, preferably 30 to 70°C. Excellent low-temperature punching workability is obtained when making laminates using this method. Tg is the temperature at which a polymer substance changes from a glass-like hard state to a rubber-like state when heated.
This temperature is unique to polymeric substances with sufficiently large molecular weights. This Tg is measured by dilatometry, calorimetry, mechanical dispersion, etc. The punching workability in the present invention is 1mmφ2.54
By a mold containing 23 continuous pins with mm pitch
In accordance with ASTM-D617-44 scoring criteria, a material is considered to have good punching workability if it is evaluated in the excellent to fair range for all evaluation items of end face, surface, and hole. The present invention is characterized in that the cured composition of the halogen-containing flame-retardant unsaturated polyester resin and the hardness-adjusting unsaturated polyester resin preferably has a Tg of 20 to 80°C.
Use a composition of a halogen-containing unsaturated polyester resin and a hardness-adjusting unsaturated polyester resin that exhibits a temperature of 30 to 70°C, and if a composition outside this range is used, it is desirable to perform low-temperature punching. I can't get sex. In other words, if a material with a Tg exceeding 80°C is used, low-temperature punching may result in undesirable chipping or insect bite on the end face, cracks or clear protuberances on the end face or around the hole, severe chipping on the hole wall, and the periphery of the hole. Significant bulging or tapering of the pores occurs, and when the temperature drops below 20°C, the bulging or tapering around the pores becomes significant. In the latter case, although it is possible to perform a good punching process by cooling the test piece depending on the case, it is not practical. When an unsaturated polyester resin composition having a Tg in the range of 30 to 70°C is used, a product with particularly excellent low-temperature punching processability can be obtained. The punching temperature for low-temperature punching type products is usually about 50 to 80°C in related industries, but the present invention provides various products with a processing temperature range of about 30 to 80°C. It is. General unsaturated polyester resins are cured depending on the raw materials used, for example, the type of glycols, the copolymerization ratio of these with saturated dibasic acids or unsaturated dibasic acids, and the type and blending ratio of crosslinking monomers. Various properties change, but in halogen-containing unsaturated polyester resins, the Tg of the cured resin inevitably tends to be high due to the use of halogenated polyol components or halogenated acid components as described above. It may be difficult to obtain a laminate with good low-temperature punching workability as it is. The present invention solves this drawback of the halogen-containing unsaturated polyester resin by blending it with an unsaturated polyester resin for hardness adjustment, so that the Tg of the cured resin composition can be adjusted to 20 to 80°C, preferably 30 to 70°C. The characteristic feature is that the problem was resolved by adjusting the temperature to ℃. The unsaturated polyester resin for hardness adjustment in the present invention is an unsaturated polyester resin containing a polyol component or an acid component of an unsaturated polyester that becomes a soft segment, and is not particularly limited. Commercially available soft and ultra-soft resins, such as Takeda Pharmaceutical's Polymer 6320F, Showa Kobunshi's Rigoratsu
70F, Tg of Mitsui Toatsu Esther F2240 etc. is usually 0
~50℃ can be used. Regarding the blending amount of the unsaturated polyester resin for hardness adjustment, the halogen-containing polyester resin to be used, that is, the type and amount of halogen, and the Tg, and the Tg of the unsaturated polyester resin for hardness adjustment to be used,
Although it varies depending on the level of flame retardancy to be obtained and the level of low-temperature punching workability, generally the hardness-adjusting polyester resin is in the range of 1 to 50%, preferably 10 to 35%. It is also possible to blend rubber, plasticizers, fillers, and other additives, but it is necessary to make sure that the cured resin composition obtained by blending these and curing falls within the Tg range specified in the present invention. It needs to be prepared. Rubbers include maleated polybutadiene and/or copolymers thereof, plasticizers include commercially available ester plasticizers made from adipic acid or phthalic acid and glycol, and epoxidized soybean oil; inorganic substances include: Examples include calcium carbonate, silicic anhydride, and titanium oxide, which are used as fillers in polyester resin. 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, 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, mixtures of these with halogen-containing additives, such as halogen-containing complex phosphate esters etc. can be given. 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.
Rather than using peroxydicarbonates, ketone peroxides, hydroperoxides, or diacyl peroxides as the peroxide used as a catalyst for curing the unsaturated polyester resin of the present invention, peroxyketals, dialkyl Use of one or more peroxides selected from peroxides and peroxyesters provides particularly favorable results in terms of solder heat resistance, electrical insulation properties, and adhesive properties. A good blending amount is about 0.5 to 2.0 parts based on the resin liquid. More preferred catalysts 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-butylperoxy)valate, dialkyl peroxides such as di-t-butylperoxide, 2,5 -dimethyl-2,5-di(t-butylperoxy)hexyne-3, peroxy esters such as t-butyl peroxy acetate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxy laurate, t-butyl peroxybenzoate, etc. Next, the compound having a methylol group for pre-treating the base material will be explained. There are various compounds having a methylol group as a substrate treatment agent used in the present invention, such as phenol-formaldehyde resin obtained by using phenols and formalinic acid or an alkali as a catalyst, formalin added to an amino group or an amide group. Resins obtained by 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 _1-4 alkyl group) Amidomethylol compound represented by: Preferred are acrylamide, N-methylolmethacrylamide, N-methoxymethylolmethacrylamide, N-butoxymethylolmethacrylamide, and the like. 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 methanol or butanol. Furthermore, with these as main components, thermoplastic resins, various vegetable oils, modified products thereof, etc. may be appropriately mixed, for example, for the purpose of improving mechanical properties. 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 aliphatic 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. oleic acid, oleyl alcohol, and their derivatives such as oleic acid monoglyceride, which have 18 carbon atoms and one unsaturated group,
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 mixed resin composition used in the laminate, but it is usually within the range of 3 to 40 parts per 100 parts of the compound having a methylol group. It is in. Regarding the method of using the processing agent, either a compound having a methylol group or the compound and the above-mentioned modifier are mixed in the form of a solution or suspension, or the two are used by condensing them in advance. It may also depend on 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 makes them excellent for 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 about 5 to 30%, preferably about 10 to 20%, based on the weight of the substrate. By using a base material that has been subjected to such a pre-impregnation treatment, the bending strength is improved. 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 the flame-retardant electrical laminate of the present invention is not particularly limited, but a base material pre-impregnated with the above-mentioned compound having a methylol group is mixed with a halogen-containing unsaturated polyester resin and an unsaturated polyester resin for adjusting hardness. It can be easily manufactured by impregnating a mixture with a resin-impregnated base material, laminating the resin-impregnated base materials, and curing the resin-impregnated base materials. At this time, the mixture of the halogen-containing unsaturated polyester resin and the unsaturated polyester resin for hardness adjustment 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 base materials impregnated with a mixture of a halogen-containing unsaturated polyester resin and a hardness-adjusting unsaturated polyester resin, but the present inventors have already specified As proposed in Japanese Patent No. 53-125541, laminates with excellent performance can be obtained by curing under substantially no pressure, which is one of the preferred embodiments of the present invention. Next, a second invention, a flame-retardant metal foil-covered electrical laminate in which metal foil is adhered to a laminate, will be described. A layer of 5 to 100μ, preferably 25 to 100μ, is between the metal foil and the laminate consisting of the pre-impregnated cellulose base material and the mixture of halogen-containing unsaturated polyester resin and hardness-adjusting unsaturated polyester resin. The presence of the adhesive layer with a thickness of 80 μm makes it possible to obtain a metal foil-clad electrical laminate having flame retardancy, moisture resistance, and low-temperature punching processability. The thickness of the adhesive layer is within the above range, that is, 5 to 100μ,
If the thickness is preferably 25 to 80 μm, the use of a flammable adhesive will not adversely affect the flame retardancy of the laminate. 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 reduce the flame retardancy of the laminate, which is not preferable.
In general, flame-retardant adhesives on the market generally have poor adhesive properties and are expensive, so the thickness of the laminate is 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, it is sufficient if 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 present invention, the reduction in the electrical properties of the metal foil bonding surface due to the flame retardant, which is said to be the case with phenol laminates, is caused by the combustible adhesive layer existing between the laminate and the metal foil. It is possible to obtain a laminate with good electrical properties. 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 curing agent or an acid anhydride curing agent; polyvinyl butyral phenolic resin, Rubber and phenolic resin adhesives such as nitrile rubber and phenolic resin can be used, but epoxy resins and polyamide resins such as polyamide amine resins, terminal amino group polybutadiene nitrile rubber, amine curing agents, or these curing agents can be used. Mixtures and the like 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 production of the flame-retardant metal foil-clad electrical laminate of the present invention, the present inventors have already proposed in Japanese Patent Application No. 54-83239, for example, when manufacturing a metal foil-clad laminate, metal foil is used. A method is applied in which an adhesive is applied to the metal foil before lamination, the heat-treated metal foil with the adhesive is laminated with a cellulose base material impregnated with an unsaturated polyester resin, and the adhesive is cured under virtually no pressure. This is one of the preferred embodiments of the present invention. The electrical laminate manufactured by the above method is
It is flame retardant, has excellent punching workability and moisture resistance, and can be used for various purposes such as electrical laminates and printed circuit boards. Next, the present invention will be explained in more detail with reference to Examples. Example 1 A kraft paper with a thickness of 285 μm was immersed in an 8% methanol solution of N-methylolacrylamide, 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-methylolacrylamide adhered to the paper was 11.2%. This treated paper was impregnated with a resin liquid having the following composition. U-Pica FPM-231 80 parts by weight (Flame-retardant unsaturated polyester resin manufactured by Nippon U-Pica) Polymer 6320F 20 〃 (Unsaturated polyester resin manufactured by Takeda Pharmaceutical) Perhexa 3M (NOF curing catalyst) 1 〃 5 sheets of this impregnated paper and 2 polyester films The sheets were laminated on both sides and cured at 100°C for 45 minutes to obtain a laminate with a thickness of 1.55 mm. The performance is shown in Table 1. Comparative Example 1 A laminate was obtained in the same manner as in Example 1 except that the composition of the resin liquid was changed as follows. Polylite NA281 100 parts by weight (flame-retardant unsaturated polyester resin manufactured by Dainippon Ink) Perhexa 3M 1

[Table] The test method is as follows. (1) Punching workability: Using a mold containing 23 continuous pins with a pitch of 1mmφ2.54mm. (2) Water absorption rate: JIS-C6481 (3) Soldering heat resistance: Same as above (4) Flame resistance: UL-94 (5) Tg of cured resin: TMS method Examples 2 to 4 Treatment liquid similar to Example 1 was soaked in commercially available kraft paper (MKP-150 manufactured by Tomegawa Paper Industries) and then dried. Five sheets were continuously conveyed, impregnated with a resin liquid having the composition shown in Table 2, and then passed through two pairs of rolls. Commercially available electrolytic copper foil (Fukuda Metals CF-
T5) were mixed with a commercially available epoxy resin (Epicoat 828 manufactured by Schiel Kagaku), a commercially available polyamide resin (Persamide 125 manufactured by Henkel Japan), and a commercially available terminal amino group polybutadiene nitrile rubber (manufactured by BF Gutdrich, ATBN) in a ratio of 7:2:1. The mixture was thoroughly mixed by hand using a blade coater and applied to a thickness of 80 μm, then passed through a tunnel furnace for adhesive heat treatment at 100°C for 5 minutes, then laminated at the same time. While a polyester film with a thickness of 50 μm was laminated on the opposite side, the material was continuously transferred to a tunnel-shaped hot air oven at a temperature of 110° C., and it took 30 minutes to pass through it. 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 about 1.6 mm. The performance is shown in Table 3.

【table】

[Table] The test method is the same as in Example 1. However, adhesive strength: JIS-C6481 Insulation resistance: Comb-shaped electrode Punching temperature: 60-80℃ Example 5 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. This treatment liquid has a thickness
After soaking and taking out 285 μm kraft paper, 120
The treated paper base material was obtained by heating and drying at ℃ for 20 minutes. At this time, the amount of treatment agent attached to the paper was 13.8%. This treated paper was impregnated with a resin liquid having the following composition. U-Pica FLP-425 75 parts by weight Polymer 6320F 25 〃 Perhexa 3M 1 〃 5 sheets of this impregnated paper and 2 sheets of polyester film were laminated on both sides and cured at 100℃ for 45 minutes to form a laminate with a thickness of 1.55 mm. I got it. The performance is shown in Table 1. Comparative Example 2 A resin liquid having the following composition was impregnated. U-Pica FLP-425 100 parts by weight Perhexa 3M 1 A laminate was obtained in the same manner as in Example 5 except for the following.
The performance is shown in Table 4.

【table】

[Table] Examples 6 to 14 Commercially available kraft paper (MKP-150 manufactured by Tomegawa Paper Industries) was soaked in the same treatment solution as in Example 5, and then dried. Five sheets of paper were soaked and dried while being continuously conveyed. A single-sided copper-clad laminate with a thickness of about 1.6 mm was obtained by impregnating it with a resin liquid having the composition shown in Table 5 and in the same manner as in Examples 2 to 4. The performance is shown in Table 6.

【table】

【table】 The test method is the same as in Example 2. however, Dielectric constant: JIS-C6481 (measured at 1MHz) Dissipation tangent: Same as above

Claims (1)

[Scope of Claims] 1 A mixture of (a) a halogen-containing unsaturated polyester resin and (b) an unsaturated polyester resin for hardness adjustment on a cellulose base material, the glass transition temperature of which after curing is A flame-retardant electrical laminate impregnated with a mixed resin at 20 to 80°C and cured. 2. The laminate according to claim 1, wherein the base material is pre-impregnated with a compound having a methylol group. 3. 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. 4. The laminate according to claim 3, 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. 5. The laminate according to claim 1, wherein the content of the unsaturated polyester resin for hardness adjustment in the mixed resin is 1 to 50%. 6. The laminate according to claim 5, wherein the content of the unsaturated polyester resin for hardness adjustment in the mixed resin is 10 to 35%. 7. The laminate according to claim 1, wherein an additive flame retardant is added to the mixed resin. 8. (a) on a base material mainly composed of cellulose fibers.
A mixture of a halogen-containing unsaturated polyester resin and (b) an unsaturated polyester resin for hardness adjustment, which is obtained by impregnating and curing the mixed resin, which has a glass transition temperature of 20 to 80°C after curing. A flame-retardant electrical laminate comprising an adhesive layer with a thickness of 5 to 100 microns between the laminate and metal foil. 9. The laminate according to claim 8, wherein the adhesive layer has a thickness of 25 to 80 μm. 10. The laminate according to claim 8 or 9, wherein the adhesive layer is flammable. 11 Claims 8 to 11 in which the adhesive mainly consists of an epoxy resin and a polyamide amine curing agent
The laminate according to any one of item 10. 12. The laminate according to any one of claims 8 to 11, wherein the laminate has a thickness of about 1 mm or more.